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1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2018 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
46 /* The type of functions taking a tree, and some additional data, and
47 returning an int. */
50 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
51 instantiations have been deferred, either because their definitions
52 were not yet available, or because we were putting off doing the work. */
56 };
71 /* Live only within one (recursive) call to tsubst_expr. We use
72 this to pass the statement expression node from the STMT_EXPR
73 to the EXPR_STMT that is its result. */
76 // -------------------------------------------------------------------------- //
77 // Local Specialization Stack
78 //
79 // Implementation of the RAII helper for creating new local
80 // specializations.
83 {
86 else
88 }
91 {
94 }
96 /* True if we've recursed into fn_type_unification too many times. */
100 {
101 tree tmpl;
102 tree args;
103 tree spec;
104 };
107 {
110 };
116 /* Contains canonical template parameter types. The vector is indexed by
117 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
118 TREE_LIST, whose TREE_VALUEs contain the canonical template
119 parameters of various types and levels. */
122 #define UNIFY_ALLOW_NONE 0
123 #define UNIFY_ALLOW_MORE_CV_QUAL 1
124 #define UNIFY_ALLOW_LESS_CV_QUAL 2
125 #define UNIFY_ALLOW_DERIVED 4
126 #define UNIFY_ALLOW_INTEGER 8
127 #define UNIFY_ALLOW_OUTER_LEVEL 16
128 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
129 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
132 tbr_incomplete_type,
133 tbr_ambiguous_baseclass,
134 tbr_success
135 };
158 tree);
215 location_t);
227 /* Make the current scope suitable for access checking when we are
228 processing T. T can be FUNCTION_DECL for instantiated function
229 template, VAR_DECL for static member variable, or TYPE_DECL for
230 alias template (needed by instantiate_decl). */
232 static void
234 {
242 else
246 {
247 saved_access_scope = tree_cons
250 }
251 }
253 /* Restore the scope set up by push_access_scope. T is the node we
254 are processing. */
256 static void
258 {
260 {
263 }
267 else
269 }
271 /* Do any processing required when DECL (a member template
272 declaration) is finished. Returns the TEMPLATE_DECL corresponding
273 to DECL, unless it is a specialization, in which case the DECL
274 itself is returned. */
276 tree
278 {
285 {
286 tree type;
294 {
298 }
300 }
304 {
306 {
309 }
310 else
312 }
313 else
317 }
319 /* Create a template info node. */
321 tree
323 {
328 }
330 /* Return the template info node corresponding to T, whatever T is. */
332 tree
334 {
356 }
358 /* Returns the template nesting level of the indicated class TYPE.
360 For example, in:
361 template <class T>
362 struct A
363 {
364 template <class U>
365 struct B {};
366 };
368 A<T>::B<U> has depth two, while A<T> has depth one.
369 Both A<T>::B<int> and A<int>::B<U> have depth one, if
370 they are instantiations, not specializations.
372 This function is guaranteed to return 0 if passed NULL_TREE so
373 that, for example, `template_class_depth (current_class_type)' is
374 always safe. */
376 int
378 {
382 {
393 else
395 }
398 }
400 /* Subroutine of maybe_begin_member_template_processing.
401 Returns true if processing DECL needs us to push template parms. */
403 static bool
405 {
411 }
413 /* Subroutine of maybe_begin_member_template_processing.
414 Push the template parms in PARMS, starting from LEVELS steps into the
415 chain, and ending at the beginning, since template parms are listed
416 innermost first. */
418 static void
420 {
428 current_template_parms
434 NULL);
436 {
445 {
452 /* Push the CONST_DECL. */
458 }
459 }
460 }
462 /* Restore the template parameter context for a member template, a
463 friend template defined in a class definition, or a non-template
464 member of template class. */
466 void
468 {
469 tree parms;
474 {
477 /* Disregard full specializations (c++/60999). */
480 }
483 {
488 {
491 }
494 }
496 /* Remember how many levels of template parameters we pushed so that
497 we can pop them later. */
499 }
501 /* Undo the effects of maybe_begin_member_template_processing. */
503 void
505 {
514 {
518 }
519 }
521 /* Return a new template argument vector which contains all of ARGS,
522 but has as its innermost set of arguments the EXTRA_ARGS. */
524 static tree
526 {
527 tree new_args;
545 }
547 /* Like add_to_template_args, but only the outermost ARGS are added to
548 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
549 (EXTRA_ARGS) levels are added. This function is used to combine
550 the template arguments from a partial instantiation with the
551 template arguments used to attain the full instantiation from the
552 partial instantiation. */
554 static tree
556 {
557 tree new_args;
559 /* If there are more levels of EXTRA_ARGS than there are ARGS,
560 something very fishy is going on. */
563 /* If *all* the new arguments will be the EXTRA_ARGS, just return
564 them. */
568 /* For the moment, we make ARGS look like it contains fewer levels. */
573 /* Now, we restore ARGS to its full dimensions. */
577 }
579 /* Return the N levels of innermost template arguments from the ARGS. */
581 tree
583 {
584 tree new_args;
590 /* If N is 1, just return the innermost set of template arguments. */
594 /* If we're not removing anything, just return the arguments we were
595 given. */
601 /* Make a new set of arguments, not containing the outer arguments. */
608 }
610 /* The inverse of get_innermost_template_args: Return all but the innermost
611 EXTRA_LEVELS levels of template arguments from the ARGS. */
613 static tree
615 {
616 tree new_args;
622 /* If N is 1, just return the outermost set of template arguments. */
626 /* If we're not removing anything, just return the arguments we were
627 given. */
632 /* Make a new set of arguments, not containing the inner arguments. */
639 }
641 /* We've got a template header coming up; push to a new level for storing
642 the parms. */
644 void
646 {
647 /* We use a non-tag-transparent scope here, which causes pushtag to
648 put tags in this scope, rather than in the enclosing class or
649 namespace scope. This is the right thing, since we want
650 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
651 global template class, push_template_decl handles putting the
652 TEMPLATE_DECL into top-level scope. For a nested template class,
653 e.g.:
655 template <class T> struct S1 {
656 template <class T> struct S2 {};
657 };
659 pushtag contains special code to insert the TEMPLATE_DECL for S2
660 at the right scope. */
666 /* Add a dummy parameter level while we process the parameter list. */
667 current_template_parms
670 current_template_parms);
671 }
673 /* This routine is called when a specialization is declared. If it is
674 invalid to declare a specialization here, an error is reported and
675 false is returned, otherwise this routine will return true. */
677 static bool
679 {
682 /* [temp.expl.spec]
684 An explicit specialization shall be declared in the namespace of
685 which the template is a member, or, for member templates, in the
686 namespace of which the enclosing class or enclosing class
687 template is a member. An explicit specialization of a member
688 function, member class or static data member of a class template
689 shall be declared in the namespace of which the class template
690 is a member. */
692 {
695 }
697 /* [temp.expl.spec]
699 In an explicit specialization declaration for a member of a class
700 template or a member template that appears in namespace scope,
701 the member template and some of its enclosing class templates may
702 remain unspecialized, except that the declaration shall not
703 explicitly specialize a class member template if its enclosing
704 class templates are not explicitly specialized as well. */
706 {
709 }
712 }
714 /* We've just seen template <>. */
716 bool
718 {
722 }
724 /* Called at then end of processing a declaration preceded by
725 template<>. */
727 void
729 {
732 }
734 /* Any template <>'s that we have seen thus far are not referring to a
735 function specialization. */
737 void
739 {
742 }
744 /* We've just seen a template header. If SPECIALIZATION is nonzero,
745 it was of the form template <>. */
747 static void
749 {
751 template_header_count++;
752 }
754 /* We're beginning an explicit instantiation. */
756 void
758 {
761 }
764 void
766 {
769 }
771 /* An explicit specialization or partial specialization of TMPL is being
772 declared. Check that the namespace in which the specialization is
773 occurring is permissible. Returns false iff it is invalid to
774 specialize TMPL in the current namespace. */
776 static bool
778 {
781 /* [tmpl.expl.spec]
783 An explicit specialization shall be declared in a namespace enclosing the
784 specialized template. An explicit specialization whose declarator-id is
785 not qualified shall be declared in the nearest enclosing namespace of the
786 template, or, if the namespace is inline (7.3.1), any namespace from its
787 enclosing namespace set. */
790 {
793 }
796 /* Same or enclosing namespace. */
798 else
799 {
805 }
806 }
808 /* SPEC is an explicit instantiation. Check that it is valid to
809 perform this explicit instantiation in the current namespace. */
811 static void
813 {
814 tree ns;
816 /* DR 275: An explicit instantiation shall appear in an enclosing
817 namespace of its template. */
823 }
825 // Returns the type of a template specialization only if that
826 // specialization needs to be defined. Otherwise (e.g., if the type has
827 // already been defined), the function returns NULL_TREE.
828 static tree
830 {
831 // An implicit instantiation of an incomplete type implies
832 // the definition of a new class template.
833 //
834 // template<typename T>
835 // struct S;
836 //
837 // template<typename T>
838 // struct S<T*>;
839 //
840 // Here, S<T*> is an implicit instantiation of S whose type
841 // is incomplete.
845 // It can also be the case that TYPE is a completed specialization.
846 // Continuing the previous example, suppose we also declare:
847 //
848 // template<typename T>
849 // requires Integral<T>
850 // struct S<T*>;
851 //
852 // Here, S<T*> refers to the specialization S<T*> defined
853 // above. However, we need to differentiate definitions because
854 // we intend to define a new partial specialization. In this case,
855 // we rely on the fact that the constraints are different for
856 // this declaration than that above.
857 //
858 // Note that we also get here for injected class names and
859 // late-parsed template definitions. We must ensure that we
860 // do not create new type declarations for those cases.
862 {
866 // If there are no template parameters, this cannot be a new
867 // partial template specializtion?
871 // The injected-class-name is not a new partial specialization.
875 // If the constraints are not the same as those of the primary
876 // then, we can probably create a new specialization.
880 {
884 }
886 // Also, if there's a pre-existing specialization with matching
887 // constraints, then this also isn't new.
890 {
898 }
900 // Create a new type node (and corresponding type decl)
901 // for the newly declared specialization.
906 /* We only need a separate type node for storing the definition of this
907 partial specialization; uses of S<T*> are unconstrained, so all are
908 equivalent. So keep TYPE_CANONICAL the same. */
911 // Build the corresponding type decl.
917 }
920 }
922 /* The TYPE is being declared. If it is a template type, that means it
923 is a partial specialization. Do appropriate error-checking. */
925 tree
927 {
928 tree context;
933 /* A lambda that appears in specialization context is not itself a
934 specialization. */
939 {
943 }
948 {
954 else
957 }
959 {
960 /* This is for ordinary explicit specialization and partial
961 specialization of a template class such as:
963 template <> class C<int>;
965 or:
967 template <class T> class C<T*>;
969 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
972 {
979 {
984 }
985 }
991 /* Trying to define a specialization either without a template<> header
992 or in an inappropriate place. We've already given an error, so just
993 bail now so we don't actually define the specialization. */
995 }
1001 {
1002 /* This is for an explicit specialization of member class
1003 template according to [temp.expl.spec/18]:
1005 template <> template <class U> class C<int>::D;
1007 The context `C<int>' must be an implicit instantiation.
1008 Otherwise this is just a member class template declared
1009 earlier like:
1011 template <> class C<int> { template <class U> class D; };
1012 template <> template <class U> class C<int>::D;
1014 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1015 while in the second case, `C<int>::D' is a primary template
1016 and `C<T>::D' may not exist. */
1020 {
1021 tree t;
1026 {
1031 }
1033 /* Check for invalid specialization after instantiation:
1035 template <> template <> class C<int>::D<int>;
1036 template <> template <class U> class C<int>::D; */
1040 {
1044 {
1045 /* We already have a full specialization of this partial
1046 instantiation, or a full specialization has been
1047 looked up but not instantiated. Reassign it to the
1048 new member specialization template. */
1049 spec_entry elt;
1061 spec_entry **slot
1066 }
1067 else
1068 /* But if we've had an implicit instantiation, that's a
1069 problem ([temp.expl.spec]/6). */
1072 }
1074 /* Mark TYPE as a specialization. And as a result, we only
1075 have one level of template argument for the innermost
1076 class template. */
1081 }
1082 }
1084 {
1085 /* Someday C++0x may allow for enum template specialization. */
1090 else
1091 {
1094 }
1095 }
1098 }
1100 /* Returns nonzero if we can optimize the retrieval of specializations
1101 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1102 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1106 {
1109 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1110 parameter. */
1112 /* The optimized lookup depends on the fact that the
1113 template arguments for the member function template apply
1114 purely to the containing class, which is not true if the
1115 containing class is an explicit or partial
1116 specialization. */
1120 /* It is possible to have a template that is not a member
1121 template and is not a member of a template class:
1123 template <typename T>
1124 struct S { friend A::f(); };
1126 Here, the friend function is a template, but the context does
1127 not have template information. The optimized lookup relies
1128 on having ARGS be the template arguments for both the class
1129 and the function template. */
1131 }
1133 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1134 gone through coerce_template_parms by now. */
1136 static void
1138 {
1141 {
1144 {
1151 /* Allow typedefs on the type of a non-type argument, since a
1153 else
1155 }
1156 }
1158 }
1160 /* Retrieve the specialization (in the sense of [temp.spec] - a
1161 specialization is either an instantiation or an explicit
1162 specialization) of TMPL for the given template ARGS. If there is
1163 no such specialization, return NULL_TREE. The ARGS are a vector of
1164 arguments, or a vector of vectors of arguments, in the case of
1165 templates with more than one level of parameters.
1167 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1168 then we search for a partial specialization matching ARGS. This
1169 parameter is ignored if TMPL is not a class template.
1171 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1172 result is a NONTYPE_ARGUMENT_PACK. */
1174 static tree
1176 {
1186 /* There should be as many levels of arguments as there are
1187 levels of parameters. */
1196 /* Lambda functions in templates aren't instantiated normally, but through
1197 tsubst_lambda_expr. */
1202 {
1203 /* The template arguments actually apply to the containing
1204 class. Find the class specialization with those
1205 arguments. */
1207 tree class_specialization
1212 /* Find the instance of TMPL. */
1215 {
1218 /* using-declarations can add base methods to the method vec,
1219 and we don't want those here. */
1222 }
1224 }
1225 else
1226 {
1228 spec_entry elt;
1237 else
1245 }
1248 }
1250 /* Like retrieve_specialization, but for local declarations. */
1252 tree
1254 {
1260 }
1262 /* Returns nonzero iff DECL is a specialization of TMPL. */
1264 int
1266 {
1267 tree t;
1270 {
1276 }
1277 else
1278 {
1287 }
1290 }
1292 /* Returns nonzero iff DECL is a specialization of friend declaration
1293 FRIEND_DECL according to [temp.friend]. */
1295 bool
1297 {
1304 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1305 of a template class, we want to check if DECL is a specialization
1306 if this. */
1310 {
1311 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1314 }
1319 /* There is nothing to do if this is not a template friend. */
1326 /* [temp.friend/6]
1327 A member of a class template may be declared to be a friend of a
1328 non-template class. In this case, the corresponding member of
1329 every specialization of the class template is a friend of the
1330 class granting friendship.
1332 For example, given a template friend declaration
1334 template <class T> friend void A<T>::f();
1336 the member function below is considered a friend
1338 template <> struct A<int> {
1339 void f();
1340 };
1342 For this type of template friend, TEMPLATE_DEPTH below will be
1343 nonzero. To determine if DECL is a friend of FRIEND, we first
1344 check if the enclosing class is a specialization of another. */
1351 {
1352 /* Next, we check the members themselves. In order to handle
1353 a few tricky cases, such as when FRIEND_DECL's are
1355 template <class T> friend void A<T>::g(T t);
1356 template <class T> template <T t> friend void A<T>::h();
1358 and DECL's are
1360 void A<int>::g(int);
1361 template <int> void A<int>::h();
1363 we need to figure out ARGS, the template arguments from
1364 the context of DECL. This is required for template substitution
1365 of `T' in the function parameter of `g' and template parameter
1366 of `h' in the above examples. Here ARGS corresponds to `int'. */
1373 {
1375 {
1378 else
1380 current_depth++;
1381 }
1383 }
1386 {
1388 tree friend_type;
1389 tree decl_type;
1390 tree friend_args_type;
1391 tree decl_args_type;
1393 /* Make sure that both DECL and FRIEND_DECL are templates or
1394 non-templates. */
1400 {
1401 /* If both are templates, check template parameter list. */
1402 tree friend_parms
1407 friend_parms))
1411 }
1412 else
1420 /* Check if return types match. */
1424 /* Check if function parameter types match, ignoring the
1425 `this' parameter. */
1434 }
1435 else
1436 {
1437 /* DECL is a TYPE_DECL */
1441 /* Make sure that both DECL and FRIEND_DECL are templates or
1442 non-templates. */
1443 is_template
1450 {
1451 tree friend_parms;
1452 /* If both are templates, check the name of the two
1453 TEMPLATE_DECL's first because is_friend didn't. */
1458 /* Now check template parameter list. */
1459 friend_parms
1462 return comp_template_parms
1464 friend_parms);
1465 }
1466 else
1469 }
1470 }
1472 }
1474 /* Register the specialization SPEC as a specialization of TMPL with
1475 the indicated ARGS. IS_FRIEND indicates whether the specialization
1476 is actually just a friend declaration. Returns SPEC, or an
1477 equivalent prior declaration, if available.
1479 We also store instantiations of field packs in the hash table, even
1480 though they are not themselves templates, to make lookup easier. */
1482 static tree
1484 hashval_t hash)
1485 {
1486 tree fn;
1488 spec_entry elt;
1496 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1497 register it; we want the corresponding TEMPLATE_DECL instead.
1498 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1499 the more obvious `uses_template_parms (spec)' to avoid problems
1500 with default function arguments. In particular, given
1501 something like this:
1503 template <class T> void f(T t1, T t = T())
1505 the default argument expression is not substituted for in an
1506 instantiation unless and until it is actually needed. */
1510 /* We don't put these specializations in the hash table, but we might
1511 want to give an error about a mismatch. */
1513 else
1514 {
1522 slot =
1526 else
1528 }
1530 /* We can sometimes try to re-register a specialization that we've
1531 already got. In particular, regenerate_decl_from_template calls
1532 duplicate_decls which will update the specialization list. But,
1533 we'll still get called again here anyhow. It's more convenient
1534 to simply allow this than to try to prevent it. */
1538 {
1540 {
1543 {
1545 fn);
1547 }
1548 else
1549 {
1550 tree clone;
1551 /* This situation should occur only if the first
1552 specialization is an implicit instantiation, the
1553 second is an explicit specialization, and the
1554 implicit instantiation has not yet been used. That
1555 situation can occur if we have implicitly
1556 instantiated a member function and then specialized
1557 it later.
1559 We can also wind up here if a friend declaration that
1560 looked like an instantiation turns out to be a
1561 specialization:
1563 template <class T> void foo(T);
1564 class S { friend void foo<>(int) };
1565 template <> void foo(int);
1567 We transform the existing DECL in place so that any
1568 pointers to it become pointers to the updated
1569 declaration.
1571 If there was a definition for the template, but not
1572 for the specialization, we want this to look as if
1573 there were no definition, and vice versa. */
1576 /* The call to duplicate_decls will have applied
1577 [temp.expl.spec]:
1579 An explicit specialization of a function template
1580 is inline only if it is explicitly declared to be,
1581 and independently of whether its function template
1582 is.
1584 to the primary function; now copy the inline bits to
1585 the various clones. */
1587 {
1594 }
1598 }
1599 }
1601 {
1604 /* We've already complained in duplicate_decls. */
1608 /* Dup decl failed, but this is a new definition. Set the
1609 line number so any errors match this new
1610 definition. */
1614 }
1615 }
1619 /* A specialization must be declared in the same namespace as the
1620 template it is specializing. */
1626 {
1635 /* If TMPL is a forward declaration of a template function, keep a list
1636 of all specializations in case we need to reassign them to a friend
1637 template later in tsubst_friend_function.
1639 Also keep a list of all variable template instantiations so that
1640 process_partial_specialization can check whether a later partial
1641 specialization would have used it. */
1644 }
1647 }
1649 /* Returns true iff two spec_entry nodes are equivalent. */
1653 bool
1655 {
1662 /* tmpl could be a FIELD_DECL for a capture pack. */
1666 {
1667 /* Partial specializations of a variable template can be distinguished by
1668 constraints. */
1672 }
1676 }
1678 /* Returns a hash for a template TMPL and template arguments ARGS. */
1680 static hashval_t
1682 {
1685 }
1687 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1688 ignoring SPEC. */
1690 hashval_t
1692 {
1694 }
1696 /* Recursively calculate a hash value for a template argument ARG, for use
1697 in the hash tables of template specializations. */
1699 hashval_t
1701 {
1721 {
1729 {
1734 }
1756 {
1760 {
1763 }
1765 }
1769 {
1772 }
1783 val = iterative_hash_template_arg
1795 val);
1797 val);
1806 /* A lambda can't appear in a template arg, but don't crash on
1807 erroneous input. */
1819 /* Now hash operands as usual. */
1824 }
1827 {
1830 {
1831 // We want an alias specialization that survived strip_typedefs
1832 // to hash differently from its TYPE_CANONICAL, to avoid hash
1833 // collisions that compare as different in template_args_equal.
1834 // These could be dependent specializations that strip_typedefs
1835 // left alone, or untouched specializations because
1836 // coerce_template_parms returns the unconverted template
1837 // arguments if it sees incomplete argument packs.
1840 }
1843 val);
1846 /* Otherwise just compare the types during lookup. */
1855 {
1860 }
1861 }
1864 }
1866 /* Unregister the specialization SPEC as a specialization of TMPL.
1867 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1868 if the SPEC was listed as a specialization of TMPL.
1870 Note that SPEC has been ggc_freed, so we can't look inside it. */
1872 bool
1874 {
1876 spec_entry elt;
1884 {
1889 }
1892 }
1894 /* Like register_specialization, but for local declarations. We are
1895 registering SPEC, an instantiation of TMPL. */
1897 void
1899 {
1902 }
1904 /* TYPE is a class type. Returns true if TYPE is an explicitly
1905 specialized class. */
1907 bool
1909 {
1913 }
1915 /* Print the list of functions at FNS, going through all the overloads
1916 for each element of the list. Alternatively, FNS can not be a
1917 TREE_LIST, in which case it will be printed together with all the
1918 overloads.
1920 MORE and *STR should respectively be FALSE and NULL when the function
1921 is called from the outside. They are used internally on recursive
1922 calls. print_candidates manages the two parameters and leaves NULL
1923 in *STR when it ends. */
1925 static void
1927 {
1931 else
1933 {
1939 {
1942 else
1945 }
1947 }
1948 }
1950 /* Print the list of candidate FNS in an error message. FNS can also
1951 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1953 void
1955 {
1959 }
1961 /* Get a (possibly) constrained template declaration for the
1962 purpose of ordering candidates. */
1963 static tree
1965 {
1971 }
1973 /* Among candidates having the same signature, return the
1974 most constrained or NULL_TREE if there is no best candidate.
1975 If the signatures of candidates vary (e.g., template
1976 specialization vs. member function), then there can be no
1977 most constrained.
1979 Note that we don't compare constraints on the functions
1980 themselves, but rather those of their templates. */
1981 static tree
1983 {
1984 // Try to find the best candidate in a first pass.
1987 {
1994 }
1996 // Verify that the champ is better than previous candidates.
2001 }
2004 }
2007 /* Returns the template (one of the functions given by TEMPLATE_ID)
2008 which can be specialized to match the indicated DECL with the
2009 explicit template args given in TEMPLATE_ID. The DECL may be
2010 NULL_TREE if none is available. In that case, the functions in
2011 TEMPLATE_ID are non-members.
2013 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2014 specialization of a member template.
2016 The TEMPLATE_COUNT is the number of references to qualifying
2017 template classes that appeared in the name of the function. See
2018 check_explicit_specialization for a more accurate description.
2020 TSK indicates what kind of template declaration (if any) is being
2021 declared. TSK_TEMPLATE indicates that the declaration given by
2022 DECL, though a FUNCTION_DECL, has template parameters, and is
2023 therefore a template function.
2025 The template args (those explicitly specified and those deduced)
2026 are output in a newly created vector *TARGS_OUT.
2028 If it is impossible to determine the result, an error message is
2029 issued. The error_mark_node is returned to indicate failure. */
2031 static tree
2033 tree decl,
2037 tmpl_spec_kind tsk)
2038 {
2039 tree fns;
2040 tree targs;
2041 tree explicit_targs;
2044 /* A TREE_LIST of templates of which DECL may be a specialization.
2045 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2046 corresponding TREE_PURPOSE is the set of template arguments that,
2047 when used to instantiate the template, would produce a function
2048 with the signature of DECL. */
2058 /* We shouldn't be specializing a member template of an
2059 unspecialized class template; we already gave an error in
2060 check_specialization_scope, now avoid crashing. */
2063 {
2066 }
2074 /* Check for baselinks. */
2079 {
2082 }
2084 {
2087 }
2089 /* Count the number of template headers specified for this
2090 specialization. */
2100 {
2103 tf_warning_or_error,
2107 }
2109 {
2113 {
2114 tree decl_arg_types;
2115 tree fn_arg_types;
2116 tree insttype;
2118 /* In case of explicit specialization, we need to check if
2119 the number of template headers appearing in the specialization
2120 is correct. This is usually done in check_explicit_specialization,
2121 but the check done there cannot be exhaustive when specializing
2122 member functions. Consider the following code:
2124 template <> void A<int>::f(int);
2125 template <> template <> void A<int>::f(int);
2127 Assuming that A<int> is not itself an explicit specialization
2128 already, the first line specializes "f" which is a non-template
2129 member function, whilst the second line specializes "f" which
2130 is a template member function. So both lines are syntactically
2131 correct, and check_explicit_specialization does not reject
2132 them.
2134 Here, we can do better, as we are matching the specialization
2135 against the declarations. We count the number of template
2136 headers, and we check if they match TEMPLATE_COUNT + 1
2137 (TEMPLATE_COUNT is the number of qualifying template classes,
2138 plus there must be another header for the member template
2139 itself).
2141 Notice that if header_count is zero, this is not a
2142 specialization but rather a template instantiation, so there
2143 is no check we can perform here. */
2147 /* Check that the number of template arguments at the
2148 innermost level for DECL is the same as for FN. */
2156 /* DECL might be a specialization of FN. */
2160 /* For a non-static member function, we need to make sure
2161 that the const qualification is the same. Since
2162 get_bindings does not try to merge the "this" parameter,
2163 we must do the comparison explicitly. */
2169 /* Skip the "this" parameter and, for constructors of
2170 classes with virtual bases, the VTT parameter. A
2171 full specialization of a constructor will have a VTT
2172 parameter, but a template never will. */
2173 decl_arg_types
2175 fn_arg_types
2178 /* Function templates cannot be specializations; there are
2179 no partial specializations of functions. Therefore, if
2180 the type of DECL does not match FN, there is no
2181 match.
2183 Note that it should never be the case that we have both
2184 candidates added here, and for regular member functions
2185 below. */
2187 {
2191 }
2193 /* See whether this function might be a specialization of this
2194 template. Suppress access control because we might be trying
2195 to make this specialization a friend, and we have already done
2196 access control for the declaration of the specialization. */
2202 /* We cannot deduce template arguments that when used to
2203 specialize TMPL will produce DECL. */
2206 /* Remove, from the set of candidates, all those functions
2207 whose constraints are not satisfied. */
2211 // Then, try to form the new function type.
2215 fn_arg_types
2220 /* Save this template, and the arguments deduced. */
2222 }
2224 /* FN is an ordinary member function, and we need a
2225 specialization of a member template. */
2226 ;
2228 /* We can get IDENTIFIER_NODEs here in certain erroneous
2229 cases. */
2230 ;
2232 /* This is just an ordinary non-member function. Nothing can
2233 be a specialization of that. */
2234 ;
2236 /* Cannot specialize functions that are created implicitly. */
2237 ;
2238 else
2239 {
2240 tree decl_arg_types;
2242 /* This is an ordinary member function. However, since
2243 we're here, we can assume its enclosing class is a
2244 template class. For example,
2246 template <typename T> struct S { void f(); };
2247 template <> void S<int>::f() {}
2249 Here, S<int>::f is a non-template, but S<int> is a
2250 template class. If FN has the same type as DECL, we
2251 might be in business. */
2254 /* Its enclosing class is an explicit specialization
2255 of a template class. This is not a candidate. */
2260 /* The return types differ. */
2263 /* Adjust the type of DECL in case FN is a static member. */
2270 decl_arg_types))
2273 // If the deduced arguments do not satisfy the constraints,
2274 // this is not a candidate.
2278 // Add the candidate.
2280 }
2281 }
2284 {
2285 /* We have:
2287 [temp.expl.spec]
2289 It is possible for a specialization with a given function
2290 signature to be instantiated from more than one function
2291 template. In such cases, explicit specification of the
2292 template arguments must be used to uniquely identify the
2293 function template specialization being specialized.
2295 Note that here, there's no suggestion that we're supposed to
2296 determine which of the candidate templates is most
2297 specialized. However, we, also have:
2299 [temp.func.order]
2301 Partial ordering of overloaded function template
2302 declarations is used in the following contexts to select
2303 the function template to which a function template
2304 specialization refers:
2306 -- when an explicit specialization refers to a function
2307 template.
2309 So, we do use the partial ordering rules, at least for now.
2310 This extension can only serve to make invalid programs valid,
2311 so it's safe. And, there is strong anecdotal evidence that
2312 the committee intended the partial ordering rules to apply;
2313 the EDG front end has that behavior, and John Spicer claims
2314 that the committee simply forgot to delete the wording in
2315 [temp.expl.spec]. */
2318 {
2321 }
2322 }
2324 // Concepts allows multiple declarations of member functions
2325 // with the same signature. Like above, we need to rely on
2326 // on the partial ordering of those candidates to determine which
2327 // is the best.
2329 {
2331 {
2334 }
2335 }
2338 {
2345 else
2348 }
2352 {
2358 }
2360 /* We have one, and exactly one, match. */
2362 {
2366 // Propagate the candidate's constraints to the declaration.
2369 /* DECL is a re-declaration or partial instantiation of a template
2370 function. */
2373 /* It was a specialization of an ordinary member function in a
2374 template class. */
2376 }
2378 /* It was a specialization of a template. */
2381 {
2386 }
2387 else
2390 }
2392 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2393 but with the default argument values filled in from those in the
2394 TMPL_TYPES. */
2396 static tree
2398 tree tmpl_types)
2399 {
2400 tree new_spec_types;
2408 /* Substitute into the rest of the list. */
2409 new_spec_types =
2413 /* Add the default argument for this parameter. */
2416 new_spec_types);
2417 }
2419 /* DECL is an explicit specialization. Replicate default arguments
2420 from the template it specializes. (That way, code like:
2422 template <class T> void f(T = 3);
2423 template <> void f(double);
2424 void g () { f (); }
2426 works, as required.) An alternative approach would be to look up
2427 the correct default arguments at the call-site, but this approach
2428 is consistent with how implicit instantiations are handled. */
2430 static void
2432 {
2433 tree tmpl;
2434 tree spec_types;
2435 tree tmpl_types;
2436 tree new_spec_types;
2437 tree old_type;
2438 tree new_type;
2439 tree t;
2444 /* See if there's anything we need to do. */
2457 {
2458 /* Remove the this pointer, but remember the object's type for
2459 CV quals. */
2465 {
2466 /* DECL may contain more parameters than TMPL due to the extra
2467 in-charge parameter in constructors and destructors. */
2470 }
2472 {
2475 }
2476 }
2478 /* Compute the merged default arguments. */
2479 new_spec_types =
2482 /* Compute the new FUNCTION_TYPE. */
2484 {
2488 new_spec_types);
2491 /* Put the in-charge parameter back. */
2494 new_spec_types);
2498 new_spec_types);
2499 }
2500 else
2502 new_spec_types);
2512 }
2514 /* Return the number of template headers we expect to see for a definition
2515 or specialization of CTYPE or one of its non-template members. */
2517 int
2519 {
2523 {
2524 /* You're supposed to have one `template <...>' for every
2525 template class, but you don't need one for a full
2526 specialization. For example:
2528 template <class T> struct S{};
2529 template <> struct S<int> { void f(); };
2530 void S<int>::f () {}
2532 is correct; there shouldn't be a `template <>' for the
2533 definition of `S<int>::f'. */
2535 /* If CTYPE does not have template information of any
2536 kind, then it is not a template, nor is it nested
2537 within a template. */
2545 }
2548 }
2550 /* Do a simple sanity check on the template headers that precede the
2551 variable declaration DECL. */
2553 void
2555 {
2560 {
2563 "variable templates only available with "
2566 // Namespace-scope variable templates should have a template header.
2568 }
2570 {
2572 "too many template headers for %qD "
2578 "members of an explicitly specialized class are defined "
2580 }
2581 }
2583 /* An explicit specialization whose declarator-id or class-head-name is not
2584 qualified shall be declared in the nearest enclosing namespace of the
2585 template, or, if the namespace is inline (7.3.1), any namespace from its
2586 enclosing namespace set.
2588 If the name declared in the explicit instantiation is an unqualified name,
2589 the explicit instantiation shall appear in the namespace where its template
2590 is declared or, if that namespace is inline (7.3.1), any namespace from its
2591 enclosing namespace set. */
2593 void
2595 {
2600 {
2606 /* This was allowed in C++98, so only pedwarn. */
2608 "outside its namespace must use a nested-name-"
2610 }
2611 }
2613 /* Check to see if the function just declared, as indicated in
2614 DECLARATOR, and in DECL, is a specialization of a function
2615 template. We may also discover that the declaration is an explicit
2616 instantiation at this point.
2618 Returns DECL, or an equivalent declaration that should be used
2619 instead if all goes well. Issues an error message if something is
2620 amiss. Returns error_mark_node if the error is not easily
2621 recoverable.
2623 FLAGS is a bitmask consisting of the following flags:
2625 2: The function has a definition.
2626 4: The function is a friend.
2628 The TEMPLATE_COUNT is the number of references to qualifying
2629 template classes that appeared in the name of the function. For
2630 example, in
2632 template <class T> struct S { void f(); };
2633 void S<int>::f();
2635 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2636 classes are not counted in the TEMPLATE_COUNT, so that in
2638 template <class T> struct S {};
2639 template <> struct S<int> { void f(); }
2640 template <> void S<int>::f();
2642 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2643 invalid; there should be no template <>.)
2645 If the function is a specialization, it is marked as such via
2646 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2647 is set up correctly, and it is added to the list of specializations
2648 for that template. */
2650 tree
2652 tree decl,
2655 {
2664 tmpl_spec_kind tsk;
2667 {
2670 else
2672 }
2673 else
2677 {
2680 {
2683 }
2685 {
2687 /* This could be something like:
2689 template <class T> void f(T);
2690 class S { friend void f<>(int); } */
2692 else
2693 {
2694 /* This case handles bogus declarations like template <>
2695 template <class T> void f<int>(); */
2698 declarator);
2700 }
2701 }
2705 /* The error has already been reported in
2706 check_specialization_scope. */
2712 /* Fall through. */
2725 decl);
2728 else
2732 /* Fall through. */
2738 /* In cases like template<> constexpr bool v = true;
2739 We'll give an error in check_template_variable. */
2745 else
2751 {
2752 /* This case handles bogus declarations like template <>
2753 template <class T> void f<int>(); */
2757 declarator);
2759 {
2760 /* Partial specialization of variable template. */
2764 }
2768 else
2772 ok:;
2773 }
2776 /* This is a specialization of a member template, without
2777 specialization the containing class. Something like:
2779 template <class T> struct S {
2780 template <class U> void f (U);
2781 };
2782 template <> template <class U> void S<int>::f(U) {}
2784 That's a specialization -- but of the entire template. */
2790 }
2793 /* This doesn't apply to variable templates. */
2796 {
2800 {
2804 }
2805 }
2808 {
2813 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2815 {
2816 tree fns;
2821 else
2822 {
2823 /* If there is no class context, the explicit instantiation
2824 must be at namespace scope. */
2827 /* Find the namespace binding, using the declaration
2828 context. */
2832 /* If lookup fails, look for a friend declaration so we can
2833 give a better diagnostic. */
2839 {
2842 }
2843 }
2846 }
2852 {
2854 /* A specialization in class scope. This is invalid,
2855 but the error will already have been flagged by
2856 check_specialization_scope. */
2858 else
2859 {
2860 /* It's not valid to write an explicit instantiation in
2861 class scope, e.g.:
2863 class C { template void f(); }
2865 This case is caught by the parser. However, on
2866 something like:
2868 template class C { void f(); };
2870 (which is invalid) we can get here. The error will be
2871 issued later. */
2872 ;
2873 }
2876 }
2879 {
2880 // We'll match variable templates in start_decl.
2884 /* Find the list of functions in ctype that have the same
2885 name as the declared function. */
2889 {
2893 {
2894 /* From [temp.expl.spec]:
2896 If such an explicit specialization for the member
2897 of a class template names an implicitly-declared
2898 special member function (clause _special_), the
2899 program is ill-formed.
2901 Similar language is found in [temp.explicit]. */
2904 }
2907 }
2909 /* For a type-conversion operator, We might be looking for
2910 `operator int' which will be a specialization of
2911 `operator T'. Grab all the conversion operators, and
2912 then select from them. */
2917 {
2920 }
2921 else
2923 }
2925 /* Figure out what exactly is being specialized at this point.
2926 Note that for an explicit instantiation, even one for a
2927 member function, we cannot tell a priori whether the
2928 instantiation is for a member template, or just a member
2929 function of a template class. Even if a member template is
2930 being instantiated, the member template arguments may be
2931 elided if they can be deduced from the rest of the
2932 declaration. */
2935 member_specialization,
2936 template_count,
2937 tsk);
2940 /* We couldn't figure out what this declaration was
2941 specializing. */
2943 else
2944 {
2947 {
2949 "friend declaration %qD is not visible to "
2953 }
2961 {
2962 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2963 is done by do_decl_instantiation later. */
2969 {
2970 /* If TMPL is not the most general template (for
2971 example, if TMPL is a friend template that is
2972 injected into namespace scope), then there will
2973 be too many levels of TARGS. Remove some of them
2974 here. */
2976 tree new_targs;
2983 }
2986 }
2988 /* If we thought that the DECL was a member function, but it
2989 turns out to be specializing a static member function,
2990 make DECL a static member function as well. */
2996 /* If this is a specialization of a member template of a
2997 template class, we want to return the TEMPLATE_DECL, not
2998 the specialization of it. */
3000 {
3005 {
3006 tree parm;
3010 /* We want to use the argument list specified in the
3011 definition, not in the original declaration. */
3016 }
3019 }
3021 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3027 /* Inherit default function arguments from the template
3028 DECL is specializing. */
3032 /* This specialization has the same protection as the
3033 template it specializes. */
3037 /* 7.1.1-1 [dcl.stc]
3039 A storage-class-specifier shall not be specified in an
3040 explicit specialization...
3042 The parser rejects these, so unless action is taken here,
3043 explicit function specializations will always appear with
3044 global linkage.
3046 The action recommended by the C++ CWG in response to C++
3047 defect report 605 is to make the storage class and linkage
3048 of the explicit specialization match the templated function:
3050 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3051 */
3053 {
3057 /* A concept cannot be specialized. */
3059 {
3061 gen_tmpl);
3063 }
3065 /* This specialization has the same linkage and visibility as
3066 the function template it specializes. */
3069 {
3072 }
3075 {
3078 }
3079 }
3081 /* If DECL is a friend declaration, declared using an
3082 unqualified name, the namespace associated with DECL may
3083 have been set incorrectly. For example, in:
3085 template <typename T> void f(T);
3086 namespace N {
3087 struct S { friend void f<int>(int); }
3088 }
3090 we will have set the DECL_CONTEXT for the friend
3091 declaration to N, rather than to the global namespace. */
3096 /* This is not really a declaration of a specialization.
3097 It's just the name of an instantiation. But, it's not
3098 a request for an instantiation, either. */
3101 /* A specialization is not necessarily COMDAT. */
3107 /* If this is a full specialization, register it so that we can find
3108 it again. Partial specializations will be registered in
3109 process_partial_specialization. */
3114 /* A 'structor should already have clones. */
3120 }
3121 }
3124 }
3126 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3127 parameters. These are represented in the same format used for
3128 DECL_TEMPLATE_PARMS. */
3130 int
3132 {
3133 const_tree p1;
3134 const_tree p2;
3142 {
3154 {
3158 /* If either of the template parameters are invalid, assume
3159 they match for the sake of error recovery. */
3172 }
3173 }
3176 /* One set of parameters has more parameters lists than the
3177 other. */
3181 }
3183 /* Determine whether PARM is a parameter pack. */
3185 bool
3187 {
3188 /* Determine if we have a non-type template parameter pack. */
3195 /* If this is a list of template parameters, we could get a
3196 TYPE_DECL or a TEMPLATE_DECL. */
3200 /* Otherwise it must be a type template parameter. */
3204 }
3206 /* Determine if T is a function parameter pack. */
3208 bool
3210 {
3214 }
3216 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3217 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3219 tree
3221 {
3228 }
3230 /* Return true iff the function parameter PARAM_DECL was expanded
3231 from the function parameter pack PACK. */
3233 bool
3235 {
3240 /* The parameter pack and its pack arguments have the same
3241 DECL_PARM_INDEX. */
3243 }
3245 /* Determine whether ARGS describes a variadic template args list,
3246 i.e., one that is terminated by a template argument pack. */
3248 static bool
3250 {
3252 tree last_parm;
3266 }
3268 /* Generate a new name for the parameter pack name NAME (an
3269 IDENTIFIER_NODE) that incorporates its */
3271 static tree
3273 {
3274 /* Munge the name to include the parameter index. */
3275 #define NUMBUF_LEN 128
3289 }
3291 /* Return true if T is a primary function, class or alias template
3292 specialization, not including the template pattern. */
3294 bool
3296 {
3312 }
3314 /* Return true if PARM is a template template parameter. */
3316 bool
3318 {
3320 }
3322 /* Return true iff PARM is a DECL representing a type template
3323 parameter. */
3325 bool
3327 {
3332 }
3334 /* Return the template parameters of T if T is a
3335 primary template instantiation, NULL otherwise. */
3337 tree
3339 {
3344 parms = INNERMOST_TEMPLATE_PARMS
3348 }
3350 /* Return the template parameters of the LEVELth level from the full list
3351 of template parameters PARMS. */
3353 tree
3355 {
3356 tree p;
3367 }
3369 /* Returns the template arguments of T if T is a template instantiation,
3370 NULL otherwise. */
3372 tree
3374 {
3382 }
3384 /* Return the argument pack elements of T if T is a template argument pack,
3385 NULL otherwise. */
3387 tree
3389 {
3395 }
3397 /* In an ARGUMENT_PACK_SELECT, the actual underlying argument that the
3398 ARGUMENT_PACK_SELECT represents. */
3400 static tree
3402 {
3406 /* If the selected argument is an expansion E, that most likely means we were
3407 called from gen_elem_of_pack_expansion_instantiation during the
3408 substituting of an argument pack (of which the Ith element is a pack
3409 expansion, where I is ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
3410 In this case, the Ith element resulting from this substituting is going to
3411 be a pack expansion, which pattern is the pattern of E. Let's return the
3412 pattern of E, and gen_elem_of_pack_expansion_instantiation will build the
3413 resulting pack expansion from it. */
3415 {
3416 /* Make sure we aren't throwing away arg info. */
3419 }
3422 }
3425 /* True iff FN is a function representing a built-in variadic parameter
3426 pack. */
3428 bool
3430 {
3440 }
3442 /* True iff CALL is a call to a function representing a built-in variadic
3443 parameter pack. */
3445 static bool
3447 {
3451 }
3453 /* Return a TREE_VEC for the expansion of __integer_pack(HI). */
3455 static tree
3457 tree in_decl)
3458 {
3464 {
3466 {
3469 }
3474 }
3475 else
3476 {
3480 /* Calculate the largest value of len that won't make the size of the vec
3481 overflow an int. The compiler will exceed resource limits long before
3482 this, but it seems a decent place to diagnose. */
3486 {
3491 }
3499 }
3500 }
3502 /* Return a TREE_VEC for the expansion of built-in template parameter pack
3503 CALL. */
3505 static tree
3507 tree in_decl)
3508 {
3518 }
3520 /* Structure used to track the progress of find_parameter_packs_r. */
3521 struct find_parameter_pack_data
3522 {
3523 /* TREE_LIST that will contain all of the parameter packs found by
3524 the traversal. */
3527 /* Set of AST nodes that have been visited by the traversal. */
3530 /* True iff we're making a type pack expansion. */
3532 };
3534 /* Identifies all of the argument packs that occur in a template
3535 argument and appends them to the TREE_LIST inside DATA, which is a
3536 find_parameter_pack_data structure. This is a subroutine of
3537 make_pack_expansion and uses_parameter_packs. */
3538 static tree
3540 {
3546 /* Handle type aliases/typedefs. */
3548 {
3555 }
3557 /* Identify whether this is a parameter pack or not. */
3559 {
3567 /* FALLTHRU */
3569 /* If the placeholder appears in the decl-specifier-seq of a function
3570 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3571 is a pack expansion, the invented template parameter is a template
3572 parameter pack. */
3582 {
3583 /* We don't want to walk into the type of a PARM_DECL,
3584 because we don't want to see the type parameter pack. */
3587 }
3590 /* Look through a lambda capture proxy to the field pack. */
3593 {
3594 /* We don't want to walk into the type of a variadic capture proxy,
3595 because we don't want to see the type parameter pack. */
3598 }
3600 {
3602 find_parameter_packs_r,
3605 }
3617 /* Not a parameter pack. */
3619 }
3622 {
3623 /* Add this parameter pack to the list. */
3625 }
3631 /* This switch statement will return immediately if we don't find a
3632 parameter pack. */
3634 {
3639 /* Check the template itself. */
3642 /* Check the template arguments. */
3656 /* Ignore the declaration of a capture proxy for a parameter pack. */
3664 /* Fall through. */
3709 {
3715 }
3718 {
3719 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3720 type_pack_expansion_p to false so that any placeholders
3721 within the expression don't get marked as parameter packs. */
3729 }
3733 }
3736 }
3738 /* Determines if the expression or type T uses any parameter packs. */
3739 bool
3741 {
3750 }
3752 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3753 representation a base-class initializer into a parameter pack
3754 expansion. If all goes well, the resulting node will be an
3755 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3756 respectively. */
3757 tree
3759 {
3760 tree result;
3769 {
3770 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3771 class initializer. In this case, the TREE_PURPOSE will be a
3772 _TYPE node (representing the base class expansion we're
3773 initializing) and the TREE_VALUE will be a TREE_LIST
3774 containing the initialization arguments.
3776 The resulting expansion looks somewhat different from most
3777 expansions. Rather than returning just one _EXPANSION, we
3778 return a TREE_LIST whose TREE_PURPOSE is a
3779 TYPE_PACK_EXPANSION containing the bases that will be
3780 initialized. The TREE_VALUE will be identical to the
3781 original TREE_VALUE, which is a list of arguments that will
3782 be passed to each base. We do not introduce any new pack
3783 expansion nodes into the TREE_VALUE (although it is possible
3784 that some already exist), because the TREE_PURPOSE and
3785 TREE_VALUE all need to be expanded together with the same
3786 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3787 resulting TREE_PURPOSE will mention the parameter packs in
3788 both the bases and the arguments to the bases. */
3789 tree purpose;
3790 tree value;
3793 /* Determine which parameter packs will be used by the base
3794 class expansion. */
3803 {
3806 arg);
3809 }
3812 {
3813 /* Collect the sets of parameter packs used in each of the
3814 initialization arguments. */
3816 {
3817 /* Determine which parameter packs will be expanded in this
3818 argument. */
3821 }
3822 }
3826 /* Create the pack expansion type for the base type. */
3832 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3833 they will rarely be compared to anything. */
3837 }
3842 /* Build the PACK_EXPANSION_* node. */
3843 result = for_types
3848 {
3849 /* Propagate type and const-expression information. */
3852 /* Mark this read now, since the expansion might be length 0. */
3854 }
3855 else
3856 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3857 they will rarely be compared to anything. */
3860 /* Determine which parameter packs will be expanded. */
3867 /* Make sure we found some parameter packs. */
3869 {
3871 {
3874 else
3876 }
3878 }
3884 }
3886 /* Checks T for any "bare" parameter packs, which have not yet been
3887 expanded, and issues an error if any are found. This operation can
3888 only be done on full expressions or types (e.g., an expression
3889 statement, "if" condition, etc.), because we could have expressions like:
3891 foo(f(g(h(args)))...)
3893 where "args" is a parameter pack. check_for_bare_parameter_packs
3894 should not be called for the subexpressions args, h(args),
3895 g(h(args)), or f(g(h(args))), because we would produce erroneous
3896 error messages.
3898 Returns TRUE and emits an error if there were bare parameter packs,
3899 returns FALSE otherwise. */
3900 bool
3902 {
3909 /* A lambda might use a parameter pack from the containing context. */
3923 {
3927 {
3938 else
3943 else
3947 }
3950 }
3953 }
3955 /* Expand any parameter packs that occur in the template arguments in
3956 ARGS. */
3957 tree
3959 {
3968 /* First, determine if we need to expand anything, and the number of
3969 slots we'll need. */
3971 {
3976 {
3980 else
3982 }
3983 else
3984 {
3986 num_result_args++;
3987 }
3988 }
3990 /* If no expansion is necessary, we're done. */
3994 /* Expand arguments. */
3997 non_default_args_count =
4000 {
4003 {
4010 }
4011 else
4012 {
4015 }
4016 }
4020 }
4022 /* Checks if DECL shadows a template parameter.
4024 [temp.local]: A template-parameter shall not be redeclared within its
4025 scope (including nested scopes).
4027 Emits an error and returns TRUE if the DECL shadows a parameter,
4028 returns FALSE otherwise. */
4030 bool
4032 {
4033 tree olddecl;
4035 /* If we're not in a template, we can't possibly shadow a template
4036 parameter. */
4040 /* Figure out what we're shadowing. */
4044 /* If there's no previous binding for this name, we're not shadowing
4045 anything, let alone a template parameter. */
4049 /* If we're not shadowing a template parameter, we're done. Note
4050 that OLDDECL might be an OVERLOAD (or perhaps even an
4051 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4052 node. */
4056 /* We check for decl != olddecl to avoid bogus errors for using a
4057 name inside a class. We check TPFI to avoid duplicate errors for
4058 inline member templates. */
4064 /* Don't complain about the injected class name, as we've already
4065 complained about the class itself. */
4072 else
4077 }
4079 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4080 ORIG_LEVEL, DECL, and TYPE. */
4082 static tree
4086 tree decl,
4087 tree type)
4088 {
4099 }
4101 /* Find the canonical type parameter for the given template type
4102 parameter. Returns the canonical type parameter, which may be TYPE
4103 if no such parameter existed. */
4105 static tree
4107 {
4108 tree list;
4122 else
4123 {
4127 }
4128 }
4130 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4131 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4132 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4133 new one is created. */
4135 static tree
4137 tsubst_flags_t complain)
4138 {
4143 {
4162 /* Template template parameters need this. */
4164 {
4171 }
4172 }
4175 }
4177 /* Process information from new template parameter PARM and append it
4178 to the LIST being built. This new parameter is a non-type
4179 parameter iff IS_NON_TYPE is true. This new parameter is a
4180 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4181 is in PARM_LOC. */
4183 tree
4186 {
4195 {
4199 {
4203 else
4205 }
4208 }
4211 {
4217 {
4218 /* [temp.param]
4220 The top-level cv-qualifiers on the template-parameter are
4221 ignored when determining its type. */
4226 && !is_parameter_pack
4227 /* If we're in a nested template parameter list, the template
4228 template parameter could be a parameter pack. */
4230 {
4231 /* This template parameter is not a parameter pack, but it
4232 should be. Complain about "bare" parameter packs. */
4235 /* Recover by calling this a parameter pack. */
4237 }
4238 }
4240 /* A template parameter is not modifiable. */
4249 processing_template_decl,
4254 }
4255 else
4256 {
4257 tree t;
4261 {
4263 /* This is for distinguishing between real templates and template
4264 template parameters */
4268 }
4269 else
4270 {
4272 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4275 }
4282 processing_template_decl,
4286 }
4290 /* Build requirements for the type/template parameter.
4291 This must be done after SET_DECL_TEMPLATE_PARM_P or
4292 process_template_parm could fail. */
4297 /* Build the parameter node linking the parameter declaration,
4298 its default argument (if any), and its constraints (if any). */
4303 }
4305 /* The end of a template parameter list has been reached. Process the
4306 tree list into a parameter vector, converting each parameter into a more
4307 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4308 as PARM_DECLs. */
4310 tree
4312 {
4317 /* Pop the dummy parameter level and add the real one. */
4320 current_template_parms
4325 {
4329 }
4334 }
4336 // Explicitly indicate the end of the template parameter list. We assume
4337 // that the current template parameters have been constructed and/or
4338 // managed explicitly, as when creating new template template parameters
4339 // from a shorthand constraint.
4340 void
4342 {
4344 }
4346 /* end_template_decl is called after a template declaration is seen. */
4348 void
4350 {
4356 /* This matches the pushlevel in begin_template_parm_list. */
4361 }
4363 /* Takes a TREE_LIST representing a template parameter and convert it
4364 into an argument suitable to be passed to the type substitution
4365 functions. Note that If the TREE_LIST contains an error_mark
4366 node, the returned argument is error_mark_node. */
4368 tree
4370 {
4383 {
4387 {
4388 /* Turn this argument into a TYPE_ARGUMENT_PACK
4389 with a single element, which expands T. */
4398 }
4399 }
4400 else
4401 {
4405 {
4406 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4407 with a single element, which expands T. */
4417 }
4418 else
4420 }
4422 }
4424 /* Given a single level of template parameters (a TREE_VEC), return it
4425 as a set of template arguments. */
4427 static tree
4429 {
4439 }
4441 /* Given a set of template parameters, return them as a set of template
4442 arguments. The template parameters are represented as a TREE_VEC, in
4443 the form documented in cp-tree.h for template arguments. */
4445 static tree
4447 {
4448 tree header;
4453 /* If there is only one level of template parameters, we do not
4454 create a TREE_VEC of TREE_VECs. Instead, we return a single
4455 TREE_VEC containing the arguments. */
4460 {
4465 else
4467 }
4470 }
4472 /* Within the declaration of a template, return the currently active
4473 template parameters as an argument TREE_VEC. */
4475 static tree
4477 {
4479 }
4481 /* Update the declared TYPE by doing any lookups which were thought to be
4482 dependent, but are not now that we know the SCOPE of the declarator. */
4484 tree
4486 {
4497 /* Don't bother building up the args in this case. */
4499 {
4500 /* tsubst in the args corresponding to the template parameters,
4501 including auto if present. Most things will be unchanged, but
4502 make_typename_type and tsubst_qualified_id will resolve
4503 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4506 tree pushed;
4508 {
4512 }
4517 }
4523 {
4526 else
4528 }
4530 }
4532 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4533 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4534 the new template is a member template. */
4536 tree
4538 {
4546 }
4548 struct template_parm_data
4549 {
4550 /* The level of the template parameters we are currently
4551 processing. */
4554 /* The index of the specialization argument we are currently
4555 processing. */
4558 /* An array whose size is the number of template parameters. The
4559 elements are nonzero if the parameter has been used in any one
4560 of the arguments processed so far. */
4563 /* An array whose size is the number of template arguments. The
4564 elements are nonzero if the argument makes use of template
4565 parameters of this level. */
4567 };
4569 /* Subroutine of push_template_decl used to see if each template
4570 parameter in a partial specialization is used in the explicit
4571 argument list. If T is of the LEVEL given in DATA (which is
4572 treated as a template_parm_data*), then DATA->PARMS is marked
4573 appropriately. */
4575 static int
4577 {
4585 {
4588 }
4590 /* In C++17 the type of a non-type argument is a deduced context. */
4595 data,
4596 NULL,
4599 /* Return zero so that for_each_template_parm will continue the
4600 traversal of the tree; we want to mark *every* template parm. */
4602 }
4604 /* Process the partial specialization DECL. */
4606 static tree
4608 {
4615 tree inner_parms;
4616 tree inst;
4626 /* A concept cannot be specialized. */
4628 {
4631 }
4636 /* We check that each of the template parameters given in the
4637 partial specialization is used in the argument list to the
4638 specialization. For example:
4640 template <class T> struct S;
4641 template <class T> struct S<T*>;
4643 The second declaration is OK because `T*' uses the template
4644 parameter T, whereas
4646 template <class T> struct S<int>;
4648 is no good. Even trickier is:
4650 template <class T>
4651 struct S1
4652 {
4653 template <class U>
4654 struct S2;
4655 template <class U>
4656 struct S2<T>;
4657 };
4659 The S2<T> declaration is actually invalid; it is a
4660 full-specialization. Of course,
4662 template <class U>
4663 struct S2<T (*)(U)>;
4665 or some such would have been OK. */
4673 {
4678 NULL,
4680 }
4683 {
4684 /* One of the template parms was not used in a deduced context in the
4685 specialization. */
4687 {
4691 }
4695 }
4700 /* [temp.class.spec]
4702 The argument list of the specialization shall not be identical to
4703 the implicit argument list of the primary template. */
4704 tree main_args
4707 && (!flag_concepts
4710 {
4714 else
4718 }
4720 /* A partial specialization that replaces multiple parameters of the
4721 primary template with a pack expansion is less specialized for those
4722 parameters. */
4724 {
4726 "primary template because it replaces multiple parameters "
4729 /* Avoid crash in process_partial_specialization. */
4731 }
4733 /* If we aren't in a dependent class, we can actually try deduction. */
4735 /* FIXME we should be able to handle a partial specialization of a
4736 partial instantiation, but currently we can't (c++/41727). */
4739 {
4743 maintmpl);
4744 }
4746 /* [temp.class.spec]
4748 A partially specialized non-type argument expression shall not
4749 involve template parameters of the partial specialization except
4750 when the argument expression is a simple identifier.
4752 The type of a template parameter corresponding to a specialized
4753 non-type argument shall not be dependent on a parameter of the
4754 specialization.
4756 Also, we verify that pack expansions only occur at the
4757 end of the argument list. */
4761 {
4768 {
4769 /* Extract the arguments from the argument pack. We'll be
4770 iterating over these in the following loop. */
4773 }
4776 {
4778 /* Get the Jth argument in the parameter pack. */
4782 {
4783 /* Pack expansions must come at the end of the
4784 argument list. */
4787 {
4791 else
4794 }
4795 }
4798 /* We only care about the pattern. */
4804 /* This next two lines are the `argument expression is not just a
4805 simple identifier' condition and also the `specialized
4806 non-type argument' bit. */
4810 {
4814 arg);
4815 else
4816 {
4817 /* Look at the corresponding template parameter,
4818 marking which template parameters its type depends
4819 upon. */
4823 {
4824 /* We haven't yet initialized TPD2. Do so now. */
4826 /* The number of parameters here is the number in the
4827 main template, which, as checked in the assertion
4828 above, is NARGS. */
4832 }
4834 /* Mark the template parameters. But this time, we're
4835 looking for the template parameters of the main
4836 template, not in the specialization. */
4843 NULL,
4847 {
4848 /* The type depended on some template parameters.
4849 If they are fully specialized in the
4850 specialization, that's OK. */
4859 "type %qT of template argument %qE depends "
4861 "type %qT of template argument %qE depends "
4863 type,
4864 arg);
4865 }
4866 }
4867 }
4868 }
4869 }
4871 /* We should only get here once. */
4875 // Build the template decl.
4884 /* Give template template parms a DECL_CONTEXT of the template
4885 for which they are a parameter. */
4887 {
4891 }
4894 /* We didn't register this in check_explicit_specialization so we could
4895 wait until the constraints were set. */
4897 else
4907 {
4913 {
4921 "declaration of %qD ambiguates earlier template "
4925 "partial specialization of %qD after instantiation "
4927 }
4928 }
4931 }
4933 /* PARM is a template parameter of some form; return the corresponding
4934 TEMPLATE_PARM_INDEX. */
4936 static tree
4938 {
4951 }
4953 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4954 parameter packs used by the template parameter PARM. */
4956 static void
4958 {
4959 /* A type parm can't refer to another parm. */
4963 {
4967 }
4974 }
4976 /* PARM is a template parameter pack. Return any parameter packs used in
4977 its type or the type of any of its template parameters. If there are
4978 any such packs, it will be instantiated into a fixed template parameter
4979 list by partial instantiation rather than be fully deduced. */
4981 tree
4983 {
4984 /* This can only be true in a member template. */
4987 /* This can only be true for a parameter pack. */
4990 /* A type parm can't refer to another parm. */
5004 }
5006 /* Check that a template declaration's use of default arguments and
5007 parameter packs is not invalid. Here, PARMS are the template
5008 parameters. IS_PRIMARY is true if DECL is the thing declared by
5009 a primary template. IS_PARTIAL is true if DECL is a partial
5010 specialization.
5012 IS_FRIEND_DECL is nonzero if DECL is either a non-defining friend
5013 function template declaration or a friend class template
5014 declaration. In the function case, 1 indicates a declaration, 2
5015 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
5016 emitted for extraneous default arguments.
5018 Returns TRUE if there were no errors found, FALSE otherwise. */
5020 bool
5023 {
5026 tree parm_level;
5029 /* [temp.param]
5031 A default template-argument shall not be specified in a
5032 function template declaration or a function template definition, nor
5033 in the template-parameter-list of the definition of a member of a
5034 class template. */
5038 /* You can't have a function template declaration in a local
5039 scope, nor you can you define a member of a class template in a
5040 local scope. */
5048 /* A lambda doesn't have an explicit declaration; don't complain
5049 about the parms of the enclosing class. */
5056 /* If this is either a friend defined in the scope of the class
5057 or a member function. */
5063 /* And, if it was a member function, it really was defined in
5064 the scope of the class. */
5067 /* We already checked these parameters when the template was
5068 declared, so there's no need to do it again now. This function
5069 was defined in class scope, but we're processing its body now
5070 that the class is complete. */
5073 /* Core issue 226 (C++0x only): the following only applies to class
5074 templates. */
5077 {
5078 /* [temp.param]
5080 If a template-parameter has a default template-argument, all
5081 subsequent template-parameters shall have a default
5082 template-argument supplied. */
5084 {
5091 {
5101 {
5103 /* For better subsequent error-recovery, we indicate that
5104 there should have been a default argument. */
5107 }
5109 && !is_friend_decl
5110 /* Don't complain about an enclosing partial
5111 specialization. */
5116 /* A fixed parameter pack will be partially
5117 instantiated into a fixed length list. */
5119 {
5120 /* A primary class template can only have one
5121 parameter pack, at the end of the template
5122 parameter list. */
5130 }
5131 }
5132 }
5133 }
5136 || is_partial
5137 || !is_primary
5139 /* For an ordinary class template, default template arguments are
5140 allowed at the innermost level, e.g.:
5141 template <class T = int>
5142 struct S {};
5143 but, in a partial specialization, they're not allowed even
5144 there, as we have in [temp.class.spec]:
5146 The template parameter list of a specialization shall not
5147 contain default template argument values.
5149 So, for a partial specialization, or for a function template
5150 (in C++98/C++03), we look at all of them. */
5151 ;
5152 else
5153 /* But, for a primary class template that is not a partial
5154 specialization we look at all template parameters except the
5155 innermost ones. */
5158 /* Figure out what error message to issue. */
5173 else
5174 /* Per [temp.param]/9, "A default template-argument shall not be
5175 specified in the template-parameter-lists of the definition of
5176 a member of a class template that appears outside of the member's
5177 class.", thus if we aren't handling a member of a class template
5178 there is no need to examine the parameters. */
5182 /* If we're inside a class definition, there's no need to
5183 examine the parameters to the class itself. On the one
5184 hand, they will be checked when the class is defined, and,
5185 on the other, default arguments are valid in things like:
5186 template <class T = double>
5187 struct S { template <class U> void f(U); };
5188 Here the default argument for `S' has no bearing on the
5189 declaration of `f'. */
5191 else
5192 /* Check everything. */
5198 {
5205 {
5210 {
5212 {
5219 }
5221 /* Clear out the default argument so that we are not
5222 confused later. */
5224 }
5225 }
5227 /* At this point, if we're still interested in issuing messages,
5228 they must apply to classes surrounding the object declared. */
5232 }
5235 }
5237 /* Worker for push_template_decl_real, called via
5238 for_each_template_parm. DATA is really an int, indicating the
5239 level of the parameters we are interested in. If T is a template
5240 parameter of that level, return nonzero. */
5242 static int
5244 {
5250 else
5253 }
5255 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5256 DATA is really an int, indicating the innermost outer level of parameters.
5257 If T is a template parameter of that level or further out, return
5258 nonzero. */
5260 static int
5262 {
5268 else
5271 }
5273 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5274 parameters given by current_template_args, or reuses a
5275 previously existing one, if appropriate. Returns the DECL, or an
5276 equivalent one, if it is replaced via a call to duplicate_decls.
5278 If IS_FRIEND is true, DECL is a friend declaration. */
5280 tree
5282 {
5283 tree tmpl;
5284 tree args;
5285 tree info;
5286 tree ctx;
5290 /* True if the template is a member template, in the sense of
5291 [temp.mem]. */
5297 /* See if this is a partial specialization. */
5310 /* For a friend, we want the context of the friend, not
5311 the type of which it is a friend. */
5315 /* In the case of a virtual function, we want the class in which
5316 it is defined. */
5318 else
5319 /* Otherwise, if we're currently defining some class, the DECL
5320 is assumed to be a member of the class. */
5329 /* See if this is a primary template. */
5332 /* A friend template that specifies a class context, i.e.
5333 template <typename T> friend void A<T>::f();
5334 is not primary. */
5339 else
5343 {
5350 {
5353 }
5355 {
5357 {
5360 }
5362 {
5363 /* [temp.mem]
5365 A destructor shall not be a member template. */
5368 }
5375 {
5376 /* [basic.stc.dynamic.allocation]
5378 An allocation function can be a function
5379 template. ... Template allocation functions shall
5380 have two or more parameters. */
5383 }
5384 }
5387 {
5388 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5391 {
5397 }
5398 }
5401 /* alias-declaration */
5405 else
5406 {
5409 }
5410 }
5412 /* Check to see that the rules regarding the use of default
5413 arguments are not being violated. We check args for a friend
5414 functions when we know whether it's a definition, introducing
5415 declaration or re-declaration. */
5420 /* Ensure that there are no parameter packs in the type of this
5421 declaration that have not been expanded. */
5423 {
5424 /* Check each of the arguments individually to see if there are
5425 any bare parameter packs. */
5431 {
5434 {
5435 /* This is a PARM_DECL that contains unexpanded parameter
5436 packs. We have already complained about this in the
5437 check_for_bare_parameter_packs call, so just replace
5438 these types with ERROR_MARK_NODE. */
5441 }
5445 }
5447 /* Check for bare parameter packs in the return type and the
5448 exception specifiers. */
5450 /* Errors were already issued, set return type to int
5451 as the frontend doesn't expect error_mark_node as
5452 the return type. */
5456 }
5461 {
5464 }
5477 {
5482 /* If DECL is a TYPE_DECL for a class-template, then there won't
5483 be DECL_LANG_SPECIFIC. The information equivalent to
5484 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5488 {
5489 /* Since a template declaration already existed for this
5490 class-type, we must be redeclaring it here. Make sure
5491 that the redeclaration is valid. */
5493 current_template_parms,
5495 /* We don't need to create a new TEMPLATE_DECL; just use the
5496 one we already had. */
5498 }
5499 else
5500 {
5502 member_template_p);
5507 {
5508 /* A specialization of a member template of a template
5509 class. */
5513 }
5514 }
5515 }
5516 else
5517 {
5523 {
5526 }
5534 {
5535 tree new_tmpl;
5537 /* The declaration is a specialization of a member
5538 template, declared outside the class. Therefore, the
5539 innermost template arguments will be NULL, so we
5540 replace them with the arguments determined by the
5541 earlier call to check_explicit_specialization. */
5544 new_tmpl
5546 member_template_p);
5556 args,
5559 }
5561 /* Make sure the template headers we got make sense. */
5566 {
5571 }
5572 else
5574 {
5579 {
5583 else
5587 /* Avoid crash in import_export_decl. */
5590 }
5595 /* Can happen in erroneous input. */
5597 else
5599 }
5601 /* Check that the parms are used in the appropriate qualifying scopes
5602 in the declarator. */
5606 {
5612 /* Avoid crash in import_export_decl. */
5615 }
5616 }
5621 /* Push template declarations for global functions and types. Note
5622 that we do not try to push a global template friend declared in a
5623 template class; such a thing may well depend on the template
5624 parameters of the class. */
5627 {
5632 /* Hide template friend classes that haven't been declared yet. */
5634 {
5637 }
5638 }
5641 {
5646 /* Give template template parms a DECL_CONTEXT of the template
5647 for which they are a parameter. */
5650 {
5654 }
5660 }
5662 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5663 back to its most general template. If TMPL is a specialization,
5664 ARGS may only have the innermost set of arguments. Add the missing
5665 argument levels if necessary. */
5673 else
5674 {
5679 }
5682 && !is_friend
5685 /* Set DECL_COMDAT on template instantiations; if we force
5686 them to be emitted by explicit instantiation or -frepo,
5687 mark_needed will tell cgraph to do the right thing. */
5691 }
5693 tree
5695 {
5697 }
5699 /* FN is an inheriting constructor that inherits from the constructor
5700 template INHERITED; turn FN into a constructor template with a matching
5701 template header. */
5703 tree
5705 {
5706 tree inner_parms
5709 tree parms
5720 }
5722 /* Called when a class template TYPE is redeclared with the indicated
5723 template PARMS, e.g.:
5725 template <class T> struct S;
5726 template <class T> struct S {}; */
5728 bool
5730 {
5731 tree tmpl;
5732 tree tmpl_parms;
5736 {
5739 }
5743 /* The type is nested in some template class. Nothing to worry
5744 about here; there are no new template parameters for the nested
5745 type. */
5749 {
5751 tmpl);
5753 }
5759 {
5769 }
5772 {
5773 tree tmpl_parm;
5774 tree parm;
5775 tree tmpl_default;
5776 tree parm_default;
5790 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5791 TEMPLATE_DECL. */
5801 {
5805 }
5808 {
5809 /* We have in [temp.param]:
5811 A template-parameter may not be given default arguments
5812 by two different declarations in the same scope. */
5817 }
5820 /* Update the previous template parameters (which are the ones
5821 that will really count) with the new default value. */
5824 /* Update the new parameters, too; they'll be used as the
5825 parameters for any members. */
5828 /* Give each template template parm in this redeclaration a
5829 DECL_CONTEXT of the template for which they are a parameter. */
5831 {
5834 }
5838 }
5840 // Cannot redeclare a class template with a different set of constraints.
5842 {
5847 }
5850 }
5852 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5853 to be used when the caller has already checked
5854 (processing_template_decl
5855 && !instantiation_dependent_expression_p (expr)
5856 && potential_constant_expression (expr))
5857 and cleared processing_template_decl. */
5859 tree
5861 {
5864 complain,
5868 }
5870 /* Simplify EXPR if it is a non-dependent expression. Returns the
5871 (possibly simplified) expression. */
5873 tree
5875 {
5879 /* If we're in a template, but EXPR isn't value dependent, simplify
5880 it. We're supposed to treat:
5882 template <typename T> void f(T[1 + 1]);
5883 template <typename T> void f(T[2]);
5885 as two declarations of the same function, for example. */
5888 {
5889 processing_template_decl_sentinel s;
5891 }
5893 }
5895 tree
5897 {
5899 }
5901 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5902 an uninstantiated expression. */
5904 tree
5906 {
5910 {
5913 else
5914 {
5915 processing_template_decl_sentinel s;
5917 }
5918 }
5920 }
5922 /* True iff T is a specialization of a variable template. */
5924 bool
5926 {
5931 }
5933 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5934 template declaration, or a TYPE_DECL for an alias declaration. */
5936 bool
5938 {
5946 }
5948 /* Return TRUE iff T is a specialization of an alias template. */
5950 bool
5952 {
5953 /* It's an alias template specialization if it's an alias and its
5954 TYPE_NAME is a specialization of a primary template. */
5960 }
5962 /* An alias template is complex from a SFINAE perspective if a template-id
5963 using that alias can be ill-formed when the expansion is not, as with
5964 the void_t template. We determine this by checking whether the
5965 expansion for the alias template uses all its template parameters. */
5967 struct uses_all_template_parms_data
5968 {
5971 };
5973 static int
5975 {
5983 }
5985 static bool
5987 {
6002 }
6004 /* Return TRUE iff T is a specialization of a complex alias template with
6005 dependent template-arguments. */
6007 bool
6009 {
6022 }
6024 /* Return the number of innermost template parameters in TMPL. */
6026 static int
6028 {
6031 }
6033 /* Return either TMPL or another template that it is equivalent to under DR
6034 1286: An alias that just changes the name of a template is equivalent to
6035 the other template. */
6037 static tree
6039 {
6042 {
6043 /* Determine if the alias is equivalent to an underlying template. */
6055 tree alias_args = INNERMOST_TEMPLATE_ARGS
6060 /* Alias is equivalent. Strip it and repeat. */
6062 }
6065 }
6067 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6068 must be a reference-to-function or a pointer-to-function type, as specified
6069 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6070 and check that the resulting function has external linkage. */
6072 static tree
6074 tsubst_flags_t complain)
6075 {
6078 linkage_kind linkage;
6093 /* [temp.arg.nontype]/1
6095 A template-argument for a non-type, non-template template-parameter
6096 shall be one of:
6097 [...]
6098 -- the address of an object or function with external [C++11: or
6099 internal] linkage. */
6102 {
6104 {
6110 else
6113 }
6115 }
6119 {
6121 {
6126 else
6130 }
6132 }
6134 accept:
6141 }
6143 /* Subroutine of convert_nontype_argument.
6144 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6145 Emit an error otherwise. */
6147 static bool
6149 tsubst_flags_t complain)
6150 {
6167 {
6172 else
6174 }
6176 }
6178 /* Returns TRUE iff the address of OP is value-dependent.
6180 14.6.2.4 [temp.dep.temp]:
6181 A non-integral non-type template-argument is dependent if its type is
6182 dependent or it has either of the following forms
6183 qualified-id
6184 & qualified-id
6185 and contains a nested-name-specifier which specifies a class-name that
6186 names a dependent type.
6188 We generalize this to just say that the address of a member of a
6189 dependent class is value-dependent; the above doesn't cover the
6190 address of a static data member named with an unqualified-id. */
6192 static bool
6194 {
6195 /* We could use get_inner_reference here, but there's no need;
6196 this is only relevant for template non-type arguments, which
6197 can only be expressed as &id-expression. */
6199 {
6203 }
6206 }
6208 /* The next set of functions are used for providing helpful explanatory
6209 diagnostics for failed overload resolution. Their messages should be
6210 indented by two spaces for consistency with the messages in
6211 call.c */
6213 static int
6215 {
6217 }
6219 /* Other failure functions should call this one, to provide a single function
6220 for setting a breakpoint on. */
6222 static int
6224 {
6226 }
6228 static int
6230 {
6235 }
6237 static int
6239 {
6245 }
6247 static int
6249 {
6253 }
6255 static int
6257 {
6260 " template parameter %qD is not a parameter pack, but "
6264 }
6266 static int
6268 {
6271 " template argument %qE does not match "
6275 }
6277 static int
6279 {
6283 }
6285 static int
6287 {
6293 }
6295 static int
6297 {
6299 {
6304 else
6306 " deduced conflicting values for non-type parameter "
6308 }
6310 }
6312 static int
6314 {
6317 " variable-sized array type %qT is not "
6319 arg);
6321 }
6323 static int
6325 {
6329 arg);
6331 }
6333 static int
6335 {
6337 {
6343 else
6348 }
6350 }
6352 static int
6354 {
6356 }
6358 static int
6361 {
6363 }
6365 static int
6368 {
6374 }
6376 static int
6379 {
6382 {
6390 }
6392 }
6394 static int
6396 {
6399 " template parameters of a template template argument are "
6402 }
6404 static int
6406 {
6412 }
6414 static int
6416 {
6421 }
6423 /* Attempt to convert the non-type template parameter EXPR to the
6424 indicated TYPE. If the conversion is successful, return the
6425 converted value. If the conversion is unsuccessful, return
6426 NULL_TREE if we issued an error message, or error_mark_node if we
6427 did not. We issue error messages for out-and-out bad template
6428 parameters, but not simply because the conversion failed, since we
6429 might be just trying to do argument deduction. Both TYPE and EXPR
6430 must be non-dependent.
6432 The conversion follows the special rules described in
6433 [temp.arg.nontype], and it is much more strict than an implicit
6434 conversion.
6436 This function is called twice for each template argument (see
6437 lookup_template_class for a more accurate description of this
6438 problem). This means that we need to handle expressions which
6439 are not valid in a C++ source, but can be created from the
6440 first call (for instance, casts to perform conversions). These
6441 hacks can go away after we fix the double coercion problem. */
6443 static tree
6445 {
6446 tree expr_type;
6450 /* Detect immediately string literals as invalid non-type argument.
6451 This special-case is not needed for correctness (we would easily
6452 catch this later), but only to provide better diagnostic for this
6453 common user mistake. As suggested by DR 100, we do not mention
6454 linkage issues in the diagnostic as this is not the point. */
6455 /* FIXME we're making this OK. */
6457 {
6463 }
6465 /* Add the ADDR_EXPR now for the benefit of
6466 value_dependent_expression_p. */
6469 {
6473 }
6475 /* If we are in a template, EXPR may be non-dependent, but still
6476 have a syntactic, rather than semantic, form. For example, EXPR
6477 might be a SCOPE_REF, rather than the VAR_DECL to which the
6478 SCOPE_REF refers. Preserving the qualifying scope is necessary
6479 so that access checking can be performed when the template is
6480 instantiated -- but here we need the resolved form so that we can
6481 convert the argument. */
6493 /* If the argument is non-dependent, perform any conversions in
6494 non-dependent context as well. */
6502 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6503 to a non-type argument of "nullptr". */
6507 /* In C++11, integral or enumeration non-type template arguments can be
6508 arbitrary constant expressions. Pointer and pointer to
6509 member arguments can be general constant expressions that evaluate
6510 to a null value, but otherwise still need to be of a specific form. */
6512 {
6514 /* A PTRMEM_CST is already constant, and a valid template
6515 argument for a parameter of pointer to member type, we just want
6516 to leave it in that form rather than lower it to a
6520 {
6521 /* C++17: A template-argument for a non-type template-parameter shall
6522 be a converted constant expression (8.20) of the type of the
6523 template-parameter. */
6529 }
6531 {
6536 }
6537 }
6541 else
6544 /* HACK: Due to double coercion, we can get a
6545 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6546 which is the tree that we built on the first call (see
6547 below when coercing to reference to object or to reference to
6548 function). We just strip everything and get to the arg.
6549 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6550 for examples. */
6552 {
6558 {
6559 /* ??? Maybe we could use convert_from_reference here, but we
6560 would need to relax its constraints because the NOP_EXPR
6561 could actually change the type to something more cv-qualified,
6562 and this is not folded by convert_from_reference. */
6567 && (same_type_ignoring_top_level_qualifiers_p
6570 {
6573 }
6574 }
6575 }
6577 /* [temp.arg.nontype]/5, bullet 1
6579 For a non-type template-parameter of integral or enumeration type,
6580 integral promotions (_conv.prom_) and integral conversions
6581 (_conv.integral_) are applied. */
6583 {
6585 {
6590 }
6595 /* Notice that there are constant expressions like '4 % 0' which
6596 do not fold into integer constants. */
6599 {
6601 {
6605 else
6611 /* else cxx_constant_value complained but gave us
6612 a real constant, so go ahead. */
6614 {
6615 /* Some assemble time constant expressions like
6616 (intptr_t)&&lab1 - (intptr_t)&&lab2 or
6617 4 + (intptr_t)&&var satisfy reduced_constant_expression_p
6618 as we can emit them into .rodata initializers of
6619 variables, yet they can't fold into an INTEGER_CST at
6620 compile time. Refuse them here. */
6625 }
6626 }
6627 else
6629 }
6631 /* Avoid typedef problems. */
6634 }
6635 /* [temp.arg.nontype]/5, bullet 2
6637 For a non-type template-parameter of type pointer to object,
6638 qualification conversions (_conv.qual_) and the array-to-pointer
6639 conversion (_conv.array_) are applied. */
6641 {
6644 /* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
6645 decay_conversion or an explicit cast. If it's a problematic cast,
6646 we'll complain about it below. */
6648 {
6653 {
6656 }
6657 }
6659 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6661 A template-argument for a non-type, non-template template-parameter
6662 shall be one of: [...]
6664 -- the name of a non-type template-parameter;
6665 -- the address of an object or function with external linkage, [...]
6666 expressed as "& id-expression" where the & is optional if the name
6667 refers to a function or array, or if the corresponding
6668 template-parameter is a reference.
6670 Here, we do not care about functions, as they are invalid anyway
6671 for a parameter of type pointer-to-object. */
6674 /* Non-type template parameters are OK. */
6675 ;
6679 {
6681 {
6684 "because %qD is a variable, not the address of "
6687 }
6689 {
6695 }
6696 /* Other values, like integer constants, might be valid
6697 non-type arguments of some other type. */
6699 }
6700 else
6701 {
6705 {
6710 }
6712 {
6718 }
6721 {
6726 }
6727 /* C++17: For a non-type template-parameter of reference or pointer
6728 type, the value of the constant expression shall not refer to (or
6729 for a pointer type, shall not be the address of):
6730 * a subobject (4.5),
6731 * a temporary object (15.2),
6732 * a string literal (5.13.5),
6733 * the result of a typeid expression (8.2.8), or
6734 * a predefined __func__ variable (11.4.1). */
6736 {
6739 decl);
6741 }
6745 {
6750 }
6752 {
6756 decl);
6758 }
6759 }
6766 }
6767 /* [temp.arg.nontype]/5, bullet 3
6769 For a non-type template-parameter of type reference to object, no
6770 conversions apply. The type referred to by the reference may be more
6771 cv-qualified than the (otherwise identical) type of the
6772 template-argument. The template-parameter is bound directly to the
6773 template-argument, which must be an lvalue. */
6775 {
6777 expr_type))
6781 {
6786 }
6789 {
6794 }
6796 /* [temp.arg.nontype]/1
6798 A template-argument for a non-type, non-template template-parameter
6799 shall be one of: [...]
6801 -- the address of an object or function with external linkage. */
6804 {
6807 {
6810 "because a reference variable does not have a constant "
6813 }
6814 }
6818 /* OK, dependent reference. We don't want to ask whether a DECL is
6820 else
6821 {
6823 {
6829 }
6831 /* DR 1155 allows internal linkage in C++11 and up. */
6834 {
6840 }
6843 }
6847 }
6848 /* [temp.arg.nontype]/5, bullet 4
6850 For a non-type template-parameter of type pointer to function, only
6851 the function-to-pointer conversion (_conv.func_) is applied. If the
6852 template-argument represents a set of overloaded functions (or a
6853 pointer to such), the matching function is selected from the set
6854 (_over.over_). */
6856 {
6857 /* If the argument is a template-id, we might not have enough
6858 context information to decay the pointer. */
6860 {
6864 }
6867 /* Null pointer values are OK in C++11. */
6873 }
6874 /* [temp.arg.nontype]/5, bullet 5
6876 For a non-type template-parameter of type reference to function, no
6877 conversions apply. If the template-argument represents a set of
6878 overloaded functions, the matching function is selected from the set
6879 (_over.over_). */
6881 {
6883 {
6885 {
6890 }
6892 }
6897 }
6898 /* [temp.arg.nontype]/5, bullet 6
6900 For a non-type template-parameter of type pointer to member function,
6901 no conversions apply. If the template-argument represents a set of
6902 overloaded member functions, the matching member function is selected
6903 from the set (_over.over_). */
6905 {
6910 /* [temp.arg.nontype] bullet 1 says the pointer to member
6911 expression must be a pointer-to-member constant. */
6916 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6917 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6920 }
6921 /* [temp.arg.nontype]/5, bullet 7
6923 For a non-type template-parameter of type pointer to data member,
6924 qualification conversions (_conv.qual_) are applied. */
6926 {
6927 /* [temp.arg.nontype] bullet 1 says the pointer to member
6928 expression must be a pointer-to-member constant. */
6936 }
6938 {
6940 {
6945 }
6947 }
6948 /* A template non-type parameter must be one of the above. */
6949 else
6952 /* Sanity check: did we actually convert the argument to the
6953 right type? */
6957 }
6959 /* Subroutine of coerce_template_template_parms, which returns 1 if
6960 PARM_PARM and ARG_PARM match using the rule for the template
6961 parameters of template template parameters. Both PARM and ARG are
6962 template parameters; the rest of the arguments are the same as for
6963 coerce_template_template_parms.
6964 */
6965 static int
6967 tree arg,
6968 tsubst_flags_t complain,
6969 tree in_decl,
6970 tree outer_args)
6971 {
6980 {
6982 /* We encounter instantiations of templates like
6983 template <template <template <class> class> class TT>
6984 class C; */
6985 {
6992 }
6993 /* Fall through. */
6998 /* Argument is a parameter pack but parameter is not. */
7003 /* The tsubst call is used to handle cases such as
7005 template <int> class C {};
7006 template <class T, template <T> class TT> class D {};
7007 D<int, C> d;
7009 i.e. the parameter list of TT depends on earlier parameters. */
7011 {
7016 }
7020 /* Argument is a parameter pack but parameter is not. */
7027 }
7030 }
7032 /* Coerce template argument list ARGLIST for use with template
7033 template-parameter TEMPL. */
7035 static tree
7037 tsubst_flags_t complain)
7038 {
7039 /* Consider an example where a template template parameter declared as
7041 template <class T, class U = std::allocator<T> > class TT
7043 The template parameter level of T and U are one level larger than
7044 of TT. To proper process the default argument of U, say when an
7045 instantiation `TT<int>' is seen, we need to build the full
7046 arguments containing {int} as the innermost level. Outer levels,
7047 available when not appearing as default template argument, can be
7048 obtained from the arguments of the enclosing template.
7050 Suppose that TT is later substituted with std::vector. The above
7051 instantiation is `TT<int, std::allocator<T> >' with TT at
7052 level 1, and T at level 2, while the template arguments at level 1
7053 becomes {std::vector} and the inner level 2 is {int}. */
7057 {
7059 /* We want arguments for the partial specialization, not arguments for
7060 the primary template. */
7062 else
7064 }
7066 {
7067 /* This is an argument of the current template, so we haven't set
7068 DECL_CONTEXT yet. */
7069 tree relevant_template_parms;
7071 /* Parameter levels that are greater than the level of the given
7072 template template parm are irrelevant. */
7079 }
7086 complain,
7089 }
7091 /* A cache of template template parameters with match-all default
7092 arguments. */
7094 static void
7096 {
7100 }
7101 static tree
7103 {
7108 }
7110 /* T is a bound template template-parameter. Copy its arguments into default
7111 arguments of the template template-parameter's template parameters. */
7113 static tree
7115 {
7138 {
7141 {
7144 }
7145 }
7149 }
7151 /* ARG is a bound potential template template-argument, and PARGS is a list
7152 of arguments for the corresponding template template-parameter. Adjust
7153 PARGS as appropriate for application to ARG's template, and if ARG is a
7154 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7155 arguments to the template template parameter. */
7157 static tree
7159 {
7163 {
7164 /* When comparing two template template-parameters in partial ordering,
7165 rewrite the one currently being used as an argument to have default
7166 arguments for all parameters. */
7172 }
7173 else
7174 {
7175 tree aparms
7180 }
7183 }
7185 /* Subroutine of unify for the case when PARM is a
7186 BOUND_TEMPLATE_TEMPLATE_PARM. */
7188 static int
7191 {
7195 /* The template template parm might be variadic and the argument
7196 not, so flatten both argument lists. */
7201 {
7202 /* In keeping with P0522R0, adjust P's template arguments
7203 to apply to A's template; then flatten it again. */
7212 /* If the P0522 adjustment eliminated a pack expansion, deduce
7213 empty packs. */
7219 }
7220 else
7221 {
7222 /* Deduce arguments T, i from TT<T> or TT<i>.
7223 We check each element of PARMVEC and ARGVEC individually
7224 rather than the whole TREE_VEC since they can have
7225 different number of elements, which is allowed under N2555. */
7229 /* Check if the parameters end in a pack, making them
7230 variadic. */
7237 /* If the template argument list of P contains a pack
7238 expansion that is not the last template argument, the
7239 entire template argument list is a non-deduced
7240 context. */
7258 DEDUCE_EXACT,
7261 }
7264 }
7266 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7267 template template parameters. Both PARM_PARMS and ARG_PARMS are
7268 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7269 or PARM_DECL.
7271 Consider the example:
7272 template <class T> class A;
7273 template<template <class U> class TT> class B;
7275 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7276 the parameters to A, and OUTER_ARGS contains A. */
7278 static int
7280 tree arg_parms,
7281 tsubst_flags_t complain,
7282 tree in_decl,
7283 tree outer_args)
7284 {
7296 {
7297 /* P0522R0: A template template-parameter P is at least as specialized as
7298 a template template-argument A if, given the following rewrite to two
7299 function templates, the function template corresponding to P is at
7300 least as specialized as the function template corresponding to A
7301 according to the partial ordering rules for function templates
7302 ([temp.func.order]). Given an invented class template X with the
7303 template parameter list of A (including default arguments):
7305 * Each of the two function templates has the same template parameters,
7306 respectively, as P or A.
7308 * Each function template has a single function parameter whose type is
7309 a specialization of X with template arguments corresponding to the
7310 template parameters from the respective function template where, for
7311 each template parameter PP in the template parameter list of the
7312 function template, a corresponding template argument AA is formed. If
7313 PP declares a parameter pack, then AA is the pack expansion
7314 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7316 If the rewrite produces an invalid type, then P is not at least as
7317 specialized as A. */
7319 /* So coerce P's args to apply to A's parms, and then deduce between A's
7320 args and the converted args. If that succeeds, A is at least as
7321 specialized as P, so they match.*/
7328 {
7334 }
7335 }
7337 /* Determine whether we have a parameter pack at the end of the
7338 template template parameter's template parameter list. */
7340 {
7347 {
7361 }
7362 }
7368 /* Check all of the template parameters except the parameter pack at
7369 the end (if any). */
7371 {
7380 outer_args))
7383 }
7386 {
7387 /* Check each of the template parameters in the template
7388 argument against the template parameter pack at the end of
7389 the template template parameter. */
7396 {
7403 outer_args))
7405 }
7406 }
7409 }
7411 /* Verifies that the deduced template arguments (in TARGS) for the
7412 template template parameters (in TPARMS) represent valid bindings,
7413 by comparing the template parameter list of each template argument
7414 to the template parameter list of its corresponding template
7415 template parameter, in accordance with DR150. This
7416 routine can only be called after all template arguments have been
7417 deduced. It will return TRUE if all of the template template
7418 parameter bindings are okay, FALSE otherwise. */
7419 bool
7421 {
7425 /* We're dealing with template parms in this process. */
7431 {
7436 {
7441 {
7442 /* Look inside the argument pack. */
7445 }
7448 {
7452 /* Extract the next argument from the argument
7453 pack. */
7457 /* Look at the pattern of the pack expansion. */
7460 /* Extract the template parameters from the template
7461 argument. */
7467 /* Verify that we can coerce the template template
7468 parameters from the template argument to the template
7469 parameter. This requires an exact match. */
7471 && !coerce_template_template_parms
7473 targ_parms,
7474 tf_none,
7475 tparm,
7476 targs))
7477 {
7480 }
7481 }
7482 }
7483 }
7485 out:
7489 }
7491 /* Since type attributes aren't mangled, we need to strip them from
7492 template type arguments. */
7494 static tree
7496 {
7506 }
7508 /* And from inside dependent non-type arguments like sizeof(Type). */
7510 static tree
7512 {
7522 }
7524 // A template declaration can be substituted for a constrained
7525 // template template parameter only when the argument is more
7526 // constrained than the parameter.
7527 static bool
7529 {
7532 /* For now, allow constrained template template arguments
7533 and unconstrained template template parameters. */
7539 // If the template parameter is constrained, we need to rewrite its
7540 // constraints in terms of the ARG's template parameters. This ensures
7541 // that all of the template parameter types will have the same depth.
7542 //
7543 // Note that this is only valid when coerce_template_template_parm is
7544 // true for the innermost template parameters of PARM and ARG. In other
7545 // words, because coercion is successful, this conversion will be valid.
7547 {
7554 }
7557 }
7559 // Convert a placeholder argument into a binding to the original
7560 // parameter. The original parameter is saved as the TREE_TYPE of
7561 // ARG.
7564 {
7567 }
7569 /* We can't fully resolve ARG given as a non-type template argument to TYPE,
7570 because one of them is dependent. But we need to represent the
7571 conversion for the benefit of cp_tree_equal. */
7573 static tree
7575 {
7576 /* Auto parms get no conversion. */
7579 /* We don't need or want to add this conversion now if we're going to use the
7580 argument for deduction. */
7592 }
7594 /* Convert the indicated template ARG as necessary to match the
7595 indicated template PARM. Returns the converted ARG, or
7596 error_mark_node if the conversion was unsuccessful. Error and
7597 warning messages are issued under control of COMPLAIN. This
7598 conversion is for the Ith parameter in the parameter list. ARGS is
7599 the full set of template arguments deduced so far. */
7601 static tree
7603 tree arg,
7604 tree args,
7605 tsubst_flags_t complain,
7607 tree in_decl)
7608 {
7609 tree orig_arg;
7610 tree val;
7616 /* Trivially convert placeholders. */
7625 {
7626 /* The template argument was the name of some
7627 member function. That's usually
7628 invalid, but static members are OK. In any
7629 case, grab the underlying fields/functions
7630 and issue an error later if required. */
7633 }
7641 /* When determining whether an argument pack expansion is a template,
7642 look at the pattern. */
7646 /* Deal with an injected-class-name used as a template template arg. */
7648 {
7651 {
7661 }
7662 }
7664 is_tmpl_type =
7680 {
7682 {
7686 }
7689 "to refer to a type member of a template parameter, "
7694 typename_type,
7695 complain);
7698 }
7700 {
7702 {
7704 {
7716 else
7719 }
7720 }
7722 }
7724 {
7726 {
7733 else
7736 }
7738 }
7741 /* We already did the appropriate conversion when packing args. */
7744 {
7746 {
7748 /* The number of argument required is not known yet.
7749 Just accept it for now. */
7751 else
7752 {
7754 tree argparm;
7756 /* Strip alias templates that are equivalent to another
7757 template. */
7763 args))
7764 {
7767 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7768 TEMPLATE_DECL. */
7770 {
7775 }
7776 }
7777 else
7778 {
7780 {
7787 }
7790 }
7792 // Check that the constraints are compatible before allowing the
7793 // substitution.
7796 {
7798 {
7804 }
7806 }
7807 }
7808 }
7809 else
7811 /* We only form one instance of each template specialization.
7812 Therefore, if we use a non-canonical variant (i.e., a
7813 typedef), any future messages referring to the type will use
7814 the typedef, which is confusing if those future uses do not
7815 themselves also use the typedef. */
7818 }
7819 else
7820 {
7824 {
7828 }
7829 else
7837 /* We used to call digest_init here. However, digest_init
7838 will report errors, which we don't want when complain
7839 is zero. More importantly, digest_init will try too
7840 hard to convert things: for example, `0' should not be
7841 converted to pointer type at this point according to
7842 the standard. Accepting this is not merely an
7843 extension, since deciding whether or not these
7844 conversions can occur is part of determining which
7845 function template to call, or whether a given explicit
7846 argument specification is valid. */
7848 else
7849 {
7852 }
7862 {
7863 /* Reject template arguments that are references to built-in
7864 functions with no library fallbacks. */
7873 }
7876 {
7877 /* Strip typedefs from the SCOPE_REF. */
7880 complain);
7883 }
7884 }
7887 }
7889 /* Coerces the remaining template arguments in INNER_ARGS (from
7890 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7891 Returns the coerced argument pack. PARM_IDX is the position of this
7892 parameter in the template parameter list. ARGS is the original
7893 template argument list. */
7894 static tree
7897 tree args,
7898 tree inner_args,
7900 tree new_args,
7902 tree in_decl,
7903 tsubst_flags_t complain)
7904 {
7907 tree packed_args;
7908 tree argument_pack;
7915 {
7916 /* When the template parameter is a non-type template parameter pack
7917 or template template parameter pack whose type or template
7918 parameters use parameter packs, we know exactly how many arguments
7919 we are looking for. Build a vector of the instantiated decls for
7920 these template parameters in PACKED_PARMS. */
7921 /* We can't use make_pack_expansion here because it would interpret a
7922 _DECL as a use rather than a declaration. */
7936 /* If we're doing a partial instantiation of a member template,
7937 verify that all of the types used for the non-type
7938 template parameter pack are, in fact, valid for non-type
7939 template parameters. */
7942 {
7945 {
7949 }
7950 /* We don't know how many args we have yet, just
7951 use the unconverted ones for now. */
7953 }
7956 }
7957 /* Check if we have a placeholder pack, which indicates we're
7958 in the context of a introduction list. In that case we want
7959 to match this pack to the single placeholder. */
7963 {
7966 }
7967 else
7970 /* Convert the remaining arguments, which will be a part of the
7971 parameter pack "parm". */
7974 {
7980 {
7981 /* Once we've packed as many args as we have types, stop. */
7985 /* We don't know how many args we have yet, just
7986 use the unconverted ones for now. */
7988 else
7990 }
7993 {
7996 }
7997 else
8000 in_decl);
8004 }
8008 {
8013 }
8018 else
8019 {
8022 }
8029 }
8031 /* Returns the number of pack expansions in the template argument vector
8032 ARGS. */
8034 static int
8036 {
8041 {
8045 }
8047 }
8049 /* Convert all template arguments to their appropriate types, and
8050 return a vector containing the innermost resulting template
8051 arguments. If any error occurs, return error_mark_node. Error and
8052 warning messages are issued under control of COMPLAIN.
8054 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
8055 for arguments not specified in ARGS. Otherwise, if
8056 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
8057 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
8058 USE_DEFAULT_ARGS is false, then all arguments must be specified in
8059 ARGS. */
8061 static tree
8063 tree args,
8064 tree in_decl,
8065 tsubst_flags_t complain,
8068 {
8070 tree orig_inner_args;
8071 tree inner_args;
8072 tree new_args;
8073 tree new_inner_args;
8077 /* When used as a boolean value, indicates whether this is a
8078 variadic template parameter list. Since it's an int, we can also
8079 subtract it from nparms to get the number of non-variadic
8080 parameters. */
8085 /* Likewise for parameters with default arguments. */
8093 /* Determine if there are any parameter packs or default arguments. */
8095 {
8103 }
8106 /* If there are no parameters that follow a parameter pack, we need to
8107 expand any argument packs so that we can deduce a parameter pack from
8108 some non-packed args followed by an argument pack, as in variadic85.C.
8109 If there are such parameters, we need to leave argument packs intact
8110 so the arguments are assigned properly. This can happen when dealing
8111 with a nested class inside a partial specialization of a class
8112 template, as in variadic92.C, or when deducing a template parameter pack
8113 from a sub-declarator, as in variadic114.C. */
8117 /* Count any pack expansion args. */
8123 && require_all_args
8124 && !variadic_args_p
8125 && (!use_default_args
8128 {
8130 {
8132 {
8136 }
8137 else
8144 }
8147 }
8148 /* We can't pass a pack expansion to a non-pack parameter of an alias
8149 template (DR 1430). */
8153 && variadic_args_p
8155 {
8157 {
8159 {
8165 {
8168 "pack expansion argument for non-pack parameter "
8170 else
8172 "pack expansion argument for non-pack parameter "
8176 }
8177 }
8179 found:;
8180 }
8182 }
8184 /* We need to evaluate the template arguments, even though this
8185 template-id may be nested within a "sizeof". */
8194 {
8195 tree arg;
8196 tree parm;
8198 /* Get the Ith template parameter. */
8202 {
8205 }
8207 /* Calculate the next argument. */
8210 else
8215 {
8216 /* Some arguments will be placed in the
8217 template parameter pack PARM. */
8224 {
8225 /* We don't know how many args we have yet, just use the
8226 unconverted (and still packed) ones for now. */
8230 }
8234 /* Store this argument. */
8236 {
8237 lost++;
8238 /* We are done with all of the arguments. */
8240 }
8241 else
8242 {
8245 }
8248 }
8250 {
8252 {
8253 /* "If every valid specialization of a variadic template
8254 requires an empty template parameter pack, the template is
8255 ill-formed, no diagnostic required." So check that the
8256 pattern works with this parameter. */
8261 in_decl);
8263 {
8268 }
8270 /* Recover from missing typename. */
8274 /* We don't know how many args we have yet, just
8275 use the unconverted ones for now. */
8279 }
8280 }
8282 {
8283 /* There must be a default arg in this case. */
8286 /* The position of the first default template argument,
8287 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8288 Record that. */
8292 }
8293 else
8297 {
8300 }
8302 /* This only occurs if there was an error in the template
8303 parameter list itself (which we would already have
8304 reported) that we are trying to recover from, e.g., a class
8305 template with a parameter list such as
8306 template<typename..., typename>. */
8308 else
8314 lost++;
8316 }
8321 {
8323 {
8328 }
8330 }
8340 }
8342 /* Convert all template arguments to their appropriate types, and
8343 return a vector containing the innermost resulting template
8344 arguments. If any error occurs, return error_mark_node. Error and
8345 warning messages are not issued.
8347 Note that no function argument deduction is performed, and default
8348 arguments are used to fill in unspecified arguments. */
8349 tree
8351 {
8353 }
8355 /* Convert all template arguments to their appropriate type, and
8356 instantiate default arguments as needed. This returns a vector
8357 containing the innermost resulting template arguments, or
8358 error_mark_node if unsuccessful. */
8359 tree
8361 tsubst_flags_t complain)
8362 {
8364 }
8366 /* Like coerce_template_parms. If PARMS represents all template
8367 parameters levels, this function returns a vector of vectors
8368 representing all the resulting argument levels. Note that in this
8369 case, only the innermost arguments are coerced because the
8370 outermost ones are supposed to have been coerced already.
8372 Otherwise, if PARMS represents only (the innermost) vector of
8373 parameters, this function returns a vector containing just the
8374 innermost resulting arguments. */
8376 static tree
8378 tree args,
8379 tree in_decl,
8380 tsubst_flags_t complain,
8383 {
8386 tree coerced_args;
8389 {
8391 tree level;
8397 {
8398 tree l;
8402 require_all_args,
8403 use_default_args);
8404 else
8411 }
8412 }
8413 else
8416 require_all_args,
8417 use_default_args);
8419 }
8421 /* Returns 1 if template args OT and NT are equivalent. */
8423 int
8425 {
8434 /* For member templates */
8443 {
8460 }
8464 {
8467 /* Don't treat an alias template specialization with dependent
8468 arguments as equivalent to its underlying type when used as a
8469 template argument; we need them to be distinct so that we
8470 substitute into the specialization arguments at instantiation
8471 time. And aliases can't be equivalent without being ==, so
8472 we don't need to look any deeper.
8474 During partial ordering, however, we need to treat them normally so
8475 that we can order uses of the same alias with different
8476 cv-qualification (79960). */
8480 else
8482 }
8485 else
8486 {
8487 /* Try to treat a template non-type argument that has been converted
8488 to the parameter type as equivalent to one that hasn't yet. */
8501 }
8502 }
8504 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8505 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8506 NEWARG_PTR with the offending arguments if they are non-NULL. */
8508 int
8512 {
8525 {
8530 {
8536 }
8537 }
8539 }
8543 {
8545 }
8547 static void
8549 {
8559 /* We are called both from instantiate_decl, where we've already had a
8560 tinst_level pushed, and instantiate_template, where we haven't.
8561 Compensate. */
8572 else
8581 }
8584 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8585 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8586 documentation for TEMPLATE_ID_EXPR. */
8588 tree
8590 {
8591 tree type;
8599 {
8602 }
8605 {
8607 unknown_type_node,
8609 arglist);
8611 }
8618 }
8620 /* Within the scope of a template class S<T>, the name S gets bound
8621 (in build_self_reference) to a TYPE_DECL for the class, not a
8622 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8623 or one of its enclosing classes, and that type is a template,
8624 return the associated TEMPLATE_DECL. Otherwise, the original
8625 DECL is returned.
8627 Also handle the case when DECL is a TREE_LIST of ambiguous
8628 injected-class-names from different bases. */
8630 tree
8632 {
8636 /* DR 176: A lookup that finds an injected-class-name (10.2
8637 [class.member.lookup]) can result in an ambiguity in certain cases
8638 (for example, if it is found in more than one base class). If all of
8639 the injected-class-names that are found refer to specializations of
8640 the same class template, and if the name is followed by a
8641 template-argument-list, the reference refers to the class template
8642 itself and not a specialization thereof, and is not ambiguous. */
8644 {
8647 {
8653 }
8656 else
8658 }
8664 }
8666 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8667 parameters, find the desired type.
8669 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8671 IN_DECL, if non-NULL, is the template declaration we are trying to
8672 instantiate.
8674 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8675 the class we are looking up.
8677 Issue error and warning messages under control of COMPLAIN.
8679 If the template class is really a local class in a template
8680 function, then the FUNCTION_CONTEXT is the function in which it is
8681 being instantiated.
8683 ??? Note that this function is currently called *twice* for each
8684 template-id: the first time from the parser, while creating the
8685 incomplete type (finish_template_type), and the second type during the
8686 real instantiation (instantiate_template_class). This is surely something
8687 that we want to avoid. It also causes some problems with argument
8688 coercion (see convert_nontype_argument for more information on this). */
8690 static tree
8693 {
8695 tree t;
8698 spec_entry elt;
8699 hashval_t hash;
8702 {
8706 else
8707 {
8714 }
8717 }
8719 {
8722 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8723 an implicit typename for the second A. Deal with it. */
8728 {
8731 }
8732 }
8735 {
8738 }
8740 {
8744 }
8746 {
8749 }
8751 /* Issue an error message if we didn't find a template. */
8753 {
8757 }
8760 /* Make sure it's a user visible template, if it was named by
8761 the user. */
8764 {
8766 {
8770 }
8772 }
8776 /* An alias that just changes the name of a template is equivalent to the
8777 other template, so if any of the arguments are pack expansions, strip
8778 the alias to avoid problems with a pack expansion passed to a non-pack
8779 alias template parameter (DR 1430). */
8784 {
8785 tree parm;
8794 }
8795 else
8796 {
8798 tree gen_tmpl;
8799 tree type_decl;
8807 /* An error occurred while building the template TEMPL, and a
8808 diagnostic has most certainly been emitted for that
8809 already. Let's propagate that error. */
8818 {
8819 /* We've been given an incomplete set of template arguments.
8820 For example, given:
8822 template <class T> struct S1 {
8823 template <class U> struct S2 {};
8824 template <class U> struct S2<U*> {};
8825 };
8827 we will be called with an ARGLIST of `U*', but the
8828 TEMPLATE will be `template <class T> template
8829 <class U> struct S1<T>::S2'. We must fill in the missing
8830 arguments. */
8834 }
8836 /* Now we should have enough arguments. */
8839 /* From here on, we're only interested in the most general
8840 template. */
8842 /* Calculate the BOUND_ARGS. These will be the args that are
8843 actually tsubst'd into the definition to create the
8844 instantiation. */
8846 complain,
8851 /* We were unable to bind the arguments. */
8854 /* In the scope of a template class, explicit references to the
8855 template class refer to the type of the template, not any
8856 instantiation of it. For example, in:
8858 template <class T> class C { void f(C<T>); }
8860 the `C<T>' is just the same as `C'. Outside of the
8861 class, however, such a reference is an instantiation. */
8865 {
8870 }
8872 /* If we already have this specialization, return it. */
8882 /* If the the template's constraints are not satisfied,
8883 then we cannot form a valid type.
8885 Note that the check is deferred until after the hash
8886 lookup. This prevents redundant checks on previously
8887 instantiated specializations. */
8889 {
8891 {
8894 }
8896 }
8900 /* If the deduced arguments are invalid, then the binding
8901 failed. */
8905 complain))
8912 {
8917 }
8927 /* Create the type. */
8929 {
8930 /* The user referred to a specialization of an alias
8931 template represented by GEN_TMPL.
8933 [temp.alias]/2 says:
8935 When a template-id refers to the specialization of an
8936 alias template, it is equivalent to the associated
8937 type obtained by substitution of its
8938 template-arguments for the template-parameters in the
8939 type-id of the alias template. */
8942 /* Note that the call above (by indirectly calling
8943 register_specialization in tsubst_decl) registers the
8944 TYPE_DECL representing the specialization of the alias
8945 template. So next time someone substitutes ARGLIST for
8946 the template parms into the alias template (GEN_TMPL),
8947 she'll get that TYPE_DECL back. */
8951 }
8953 {
8955 {
8966 }
8967 else
8968 {
8969 /* We don't want to call start_enum for this type, since
8970 the values for the enumeration constants may involve
8971 template parameters. And, no one should be interested
8972 in the enumeration constants for such a type. */
8975 }
8979 }
8981 {
8982 /* Lambda closures are regenerated in tsubst_lambda_expr, not
8983 instantiated here. */
8991 /* A local class. Make sure the decl gets registered properly. */
8996 /* This instantiation is another name for the primary
8997 template type. Set the TYPE_CANONICAL field
8998 appropriately. */
9001 /* Some of the template arguments require structural
9002 equality testing, so this template class requires
9003 structural equality testing. */
9005 }
9006 else
9009 /* If we called start_enum or pushtag above, this information
9010 will already be set up. */
9012 {
9019 }
9020 else
9024 {
9030 {
9033 }
9034 }
9038 {
9042 {
9043 tree attributes
9051 }
9052 }
9054 /* Let's consider the explicit specialization of a member
9055 of a class template specialization that is implicitly instantiated,
9056 e.g.:
9057 template<class T>
9058 struct S
9059 {
9060 template<class U> struct M {}; //#0
9061 };
9063 template<>
9064 template<>
9065 struct S<int>::M<char> //#1
9066 {
9067 int i;
9068 };
9069 [temp.expl.spec]/4 says this is valid.
9071 In this case, when we write:
9072 S<int>::M<char> m;
9074 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
9075 the one of #0.
9077 When we encounter #1, we want to store the partial instantiation
9078 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
9080 For all cases other than this "explicit specialization of member of a
9081 class template", we just want to store the most general template into
9082 the CLASSTYPE_TI_TEMPLATE of M.
9084 This case of "explicit specialization of member of a class template"
9085 only happens when:
9086 1/ the enclosing class is an instantiation of, and therefore not
9087 the same as, the context of the most general template, and
9088 2/ we aren't looking at the partial instantiation itself, i.e.
9089 the innermost arguments are not the same as the innermost parms of
9090 the most general template.
9092 So it's only when 1/ and 2/ happens that we want to use the partial
9093 instantiation of the member template in lieu of its most general
9094 template. */
9098 /* the enclosing class must be an instantiation... */
9101 {
9105 tree partial_inst_args =
9112 use_partial_inst_tmpl =
9113 /*...and we must not be looking at the partial instantiation
9114 itself. */
9116 partial_inst_args);
9117 }
9120 /* This case is easy; there are no member templates involved. */
9122 else
9123 {
9124 /* This is a full instantiation of a member template. Find
9125 the partial instantiation of which this is an instance. */
9127 /* Temporarily reduce by one the number of levels in the ARGLIST
9128 so as to avoid comparing the last set of arguments. */
9132 /* FOUND is either a proper class type, or an alias
9133 template specialization. In the later case, it's a
9134 TYPE_DECL, resulting from the substituting of arguments
9135 for parameters in the TYPE_DECL of the alias template
9136 done earlier. So be careful while getting the template
9137 of FOUND. */
9139 ? found
9143 }
9145 // Build template info for the new specialization.
9154 /* Note this use of the partial instantiation so we can check it
9155 later in maybe_process_partial_specialization. */
9162 /* Now that the type has been registered on the instantiations
9163 list, we set up the enumerators. Because the enumeration
9164 constants may involve the enumeration type itself, we make
9165 sure to register the type first, and then create the
9166 constants. That way, doing tsubst_expr for the enumeration
9167 constants won't result in recursive calls here; we'll find
9168 the instantiation and exit above. */
9172 /* If the type makes use of template parameters, the
9173 code that generates debugging information will crash. */
9176 /* Possibly limit visibility based on template args. */
9183 }
9184 }
9186 /* Wrapper for lookup_template_class_1. */
9188 tree
9191 {
9192 tree ret;
9198 }
9200 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9202 tree
9204 {
9205 /* The type of the expression is NULL_TREE since the template-id could refer
9206 to an explicit or partial specialization. */
9209 /* Except that concepts are always bool. */
9212 }
9214 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9216 tree
9218 {
9222 /* We never want to return a VAR_DECL for a variable concept, since they
9223 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9238 {
9240 {
9243 }
9245 }
9247 /* If a template-id refers to a specialization of a variable
9248 concept, then the expression is true if and only if the
9249 concept's constraints are satisfied by the given template
9250 arguments.
9252 NOTE: This is an extension of Concepts Lite TS that
9253 allows constraints to be used in expressions. */
9255 {
9258 }
9261 }
9263 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9264 TARGS template args, and instantiate it if it's not dependent. */
9266 tree
9268 tsubst_flags_t complain)
9269 {
9272 {
9275 }
9278 }
9280 \f
9281 struct pair_fn_data
9282 {
9283 tree_fn_t fn;
9284 tree_fn_t any_fn;
9286 /* True when we should also visit template parameters that occur in
9287 non-deduced contexts. */
9290 };
9292 /* Called from for_each_template_parm via walk_tree. */
9294 static tree
9296 {
9303 #define WALK_SUBTREE(NODE) \
9304 do \
9305 { \
9306 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9307 pfd->include_nondeduced_p, \
9308 pfd->any_fn); \
9309 if (result) goto out; \
9310 } \
9311 while (0)
9321 {
9325 /* Fall through. */
9331 else
9341 /* Since we're not going to walk subtrees, we have to do this
9342 explicitly here. */
9344 /* Fall through. */
9347 /* Check the return type. */
9350 /* Check the parameter types. Since default arguments are not
9351 instantiated until they are needed, the TYPE_ARG_TYPES may
9352 contain expressions that involve template parameters. But,
9353 no-one should be looking at them yet. And, once they're
9354 instantiated, they don't contain template parameters, so
9355 there's no point in looking at them then, either. */
9356 {
9357 tree parm;
9362 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9363 want walk_tree walking into them itself. */
9365 }
9368 {
9372 }
9389 /* Fall through. */
9401 /* Record template parameters such as `T' inside `TT<T>'. */
9403 /* Fall through. */
9415 /* A template template parameter is encountered. */
9419 /* Already substituted template template parameter */
9424 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9425 partial instantiation. */
9437 /* If there's no type, then this thing must be some expression
9438 involving template parameters. */
9460 }
9462 #undef WALK_SUBTREE
9464 /* We didn't find any template parameters we liked. */
9465 out:
9467 }
9469 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9470 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9471 call FN with the parameter and the DATA.
9472 If FN returns nonzero, the iteration is terminated, and
9473 for_each_template_parm returns 1. Otherwise, the iteration
9474 continues. If FN never returns a nonzero value, the value
9475 returned by for_each_template_parm is 0. If FN is NULL, it is
9476 considered to be the function which always returns 1.
9478 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9479 parameters that occur in non-deduced contexts. When false, only
9480 visits those template parameters that can be deduced. */
9482 static tree
9486 tree_fn_t any_fn)
9487 {
9489 tree result;
9491 /* Set up. */
9497 /* Walk the tree. (Conceptually, we would like to walk without
9498 duplicates, but for_each_template_parm_r recursively calls
9499 for_each_template_parm, so we would need to reorganize a fair
9500 bit to use walk_tree_without_duplicates, so we keep our own
9501 visited list.) */
9504 else
9507 for_each_template_parm_r,
9511 /* Clean up. */
9513 {
9516 }
9519 }
9521 /* Returns true if T depends on any template parameter. */
9523 int
9525 {
9555 else
9556 {
9559 }
9564 }
9566 /* Returns true iff current_function_decl is an incompletely instantiated
9567 template. Useful instead of processing_template_decl because the latter
9568 is set to 0 during instantiate_non_dependent_expr. */
9570 bool
9572 {
9581 }
9583 /* Returns true if T depends on any template parameter with level LEVEL. */
9585 bool
9587 {
9590 }
9592 /* Returns true if the signature of DECL depends on any template parameter from
9593 its enclosing class. */
9595 bool
9597 {
9607 template_parm_outer_level,
9617 }
9619 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9620 ill-formed translation unit, i.e. a variable or function that isn't
9621 usable in a constant expression. */
9625 {
9630 }
9632 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9633 neglectable and instantiated from within an erroneous instantiation. */
9635 static bool
9637 {
9648 }
9656 /* We're starting to instantiate D; record the template instantiation context
9657 for diagnostics and to restore it later. */
9659 bool
9661 {
9663 }
9665 /* We're starting to instantiate D; record the template instantiation context
9666 at LOC for diagnostics and to restore it later. */
9668 bool
9670 {
9674 {
9675 /* Tell error.c not to try to instantiate any templates. */
9678 "template instantiation depth exceeds maximum of %d"
9680 max_tinst_depth);
9682 }
9684 /* If the current instantiation caused problems, don't let it instantiate
9685 anything else. Do allow deduction substitution and decls usable in
9686 constant expressions. */
9690 /* When not -quiet, dump template instantiations other than functions, since
9691 announce_function will take care of those. */
9710 }
9712 /* We're done instantiating this template; return to the instantiation
9713 context. */
9715 void
9717 {
9718 /* Restore the filename and line number stashed away when we started
9719 this instantiation. */
9723 }
9725 /* We're instantiating a deferred template; restore the template
9726 instantiation context in which the instantiation was requested, which
9727 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9729 static tree
9731 {
9743 }
9745 /* Returns the TINST_LEVEL which gives the original instantiation
9746 context. */
9750 {
9756 }
9758 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9759 vector of template arguments, as for tsubst.
9761 Returns an appropriate tsubst'd friend declaration. */
9763 static tree
9765 {
9766 tree new_friend;
9771 /* This was a friend declared with an explicit template
9772 argument list, e.g.:
9774 friend void f<>(T);
9776 to indicate that f was a template instantiation, not a new
9777 function declaration. Now, we have to figure out what
9778 instantiation of what template. */
9779 {
9781 tree new_args;
9782 tree tmpl;
9785 /* Friend functions are looked up in the containing namespace scope.
9786 We must enter that scope, to avoid finding member functions of the
9787 current class with same name. */
9802 tsk_none);
9804 }
9808 /* The NEW_FRIEND will look like an instantiation, to the
9809 compiler, but is not an instantiation from the point of view of
9810 the language. For example, we might have had:
9812 template <class T> struct S {
9813 template <class U> friend void f(T, U);
9814 };
9816 Then, in S<int>, template <class U> void f(int, U) is not an
9817 instantiation of anything. */
9823 {
9827 }
9829 /* The mangled name for the NEW_FRIEND is incorrect. The function
9830 is not a template instantiation and should not be mangled like
9831 one. Therefore, we forget the mangling here; we'll recompute it
9832 later if we need it. */
9834 {
9837 }
9840 {
9841 tree old_decl;
9842 tree new_friend_template_info;
9843 tree new_friend_result_template_info;
9844 tree ns;
9847 /* We must save some information from NEW_FRIEND before calling
9848 duplicate decls since that function will free NEW_FRIEND if
9849 possible. */
9851 new_friend_is_defn =
9856 {
9857 /* This declaration is a `primary' template. */
9860 new_friend_result_template_info
9862 }
9863 else
9866 /* Inside pushdecl_namespace_level, we will push into the
9867 current namespace. However, the friend function should go
9868 into the namespace of the template. */
9878 {
9879 /* This new friend declaration matched an existing
9880 declaration. For example, given:
9882 template <class T> void f(T);
9883 template <class U> class C {
9884 template <class T> friend void f(T) {}
9885 };
9887 the friend declaration actually provides the definition
9888 of `f', once C has been instantiated for some type. So,
9889 old_decl will be the out-of-class template declaration,
9890 while new_friend is the in-class definition.
9892 But, if `f' was called before this point, the
9893 instantiation of `f' will have DECL_TI_ARGS corresponding
9894 to `T' but not to `U', references to which might appear
9895 in the definition of `f'. Previously, the most general
9896 template for an instantiation of `f' was the out-of-class
9897 version; now it is the in-class version. Therefore, we
9898 run through all specialization of `f', adding to their
9899 DECL_TI_ARGS appropriately. In particular, they need a
9900 new set of outer arguments, corresponding to the
9901 arguments for this class instantiation.
9903 The same situation can arise with something like this:
9905 friend void f(int);
9906 template <class T> class C {
9907 friend void f(T) {}
9908 };
9910 when `C<int>' is instantiated. Now, `f(int)' is defined
9911 in the class. */
9914 /* On the other hand, if the in-class declaration does
9915 *not* provide a definition, then we don't want to alter
9916 existing definitions. We can just leave everything
9917 alone. */
9918 ;
9919 else
9920 {
9924 /* Overwrite whatever template info was there before, if
9925 any, with the new template information pertaining to
9926 the declaration. */
9930 {
9931 /* We should have called reregister_specialization in
9932 duplicate_decls. */
9937 /* Instantiate it if the global has already been used. */
9941 }
9942 else
9943 {
9944 tree t;
9946 /* Indicate that the old function template is a partial
9947 instantiation. */
9955 /* Reassign any specializations already in the hash table
9956 to the new more general template, and add the
9957 additional template args. */
9961 {
9963 spec_entry elt;
9975 register_specialization
9978 }
9980 }
9981 }
9983 /* The information from NEW_FRIEND has been merged into OLD_DECL
9984 by duplicate_decls. */
9986 }
9987 }
9988 else
9989 {
9993 /* In the code
9994 template <class T> class C {
9995 template <class U> friend void C1<U>::f (); // case 1
9996 friend void C2<T>::f (); // case 2
9997 };
9998 we only need to make sure CONTEXT is a complete type for
9999 case 2. To distinguish between the two cases, we note that
10000 CONTEXT of case 1 remains dependent type after tsubst while
10001 this isn't true for case 2. */
10011 {
10013 /* do_friend adds the TEMPLATE_DECL for any member friend
10014 template even if it isn't a member template, i.e.
10015 template <class T> friend A<T>::f();
10016 Look through it in that case. */
10020 /* Check to see that the declaration is really present, and,
10021 possibly obtain an improved declaration. */
10026 }
10027 }
10030 }
10032 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
10033 template arguments, as for tsubst.
10035 Returns an appropriate tsubst'd friend type or error_mark_node on
10036 failure. */
10038 static tree
10040 {
10041 tree tmpl;
10044 {
10047 }
10052 else
10060 {
10061 /* The friend template has already been declared. Just
10062 check to see that the declarations match, and install any new
10063 default parameters. We must tsubst the default parameters,
10064 of course. We only need the innermost template parameters
10065 because that is all that redeclare_class_template will look
10066 at. */
10069 {
10077 }
10078 }
10079 else
10080 {
10081 /* The friend template has not already been declared. In this
10082 case, the instantiation of the template class will cause the
10083 injection of this template into the namespace scope. */
10087 {
10088 /* The new TMPL is not an instantiation of anything, so we
10089 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE
10090 for the new type because that is supposed to be the
10091 corresponding template decl, i.e., TMPL. */
10098 /* It is hidden. */
10103 /* Inject this template into the enclosing namspace scope. */
10105 }
10106 }
10110 else
10114 }
10116 /* Returns zero if TYPE cannot be completed later due to circularity.
10117 Otherwise returns one. */
10119 static int
10121 {
10131 else
10133 }
10138 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10139 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10141 static tree
10144 {
10153 {
10160 clauses
10164 else
10166 }
10167 /* If the first attribute argument is an identifier, don't
10168 pass it through tsubst. Attributes like mode, format,
10169 cleanup and several target specific attributes expect it
10170 unmodified. */
10172 {
10173 tree chain
10178 }
10180 {
10181 /* An attribute pack expansion. */
10190 {
10194 }
10196 }
10197 else
10204 }
10206 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10207 unchanged or a new TREE_LIST chain. */
10209 static tree
10212 {
10217 {
10221 }
10225 {
10228 {
10231 {
10233 do
10238 }
10239 }
10241 }
10244 }
10246 /* Apply any attributes which had to be deferred until instantiation
10247 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10248 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10250 static void
10253 {
10255 tree t;
10262 {
10266 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10267 to our attributes parameter. */
10269 }
10270 else
10271 {
10273 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10274 lookup_template_class_1, and should be preserved. */
10278 }
10282 {
10286 }
10290 {
10295 {
10298 {
10302 do
10305 }
10306 else
10308 }
10311 }
10312 }
10314 /* Perform (or defer) access check for typedefs that were referenced
10315 from within the template TMPL code.
10316 This is a subroutine of instantiate_decl and instantiate_class_template.
10317 TMPL is the template to consider and TARGS is the list of arguments of
10318 that template. */
10320 static void
10322 {
10323 location_t saved_location;
10334 {
10346 /* Make access check error messages point to the location
10347 of the use of the typedef. */
10351 tf_warning_or_error);
10352 }
10354 }
10356 static tree
10358 {
10360 tree typedecl;
10361 tree pbinfo;
10362 tree base_list;
10364 tree fn_context;
10373 /* Figure out which template is being instantiated. */
10377 /* Mark the type as in the process of being defined. */
10380 /* Determine what specialization of the original template to
10381 instantiate. */
10386 {
10387 /* This TYPE is actually an instantiation of a partial
10388 specialization. We replace the innermost set of ARGS with
10389 the arguments appropriate for substitution. For example,
10390 given:
10392 template <class T> struct S {};
10393 template <class T> struct S<T*> {};
10395 and supposing that we are instantiating S<int*>, ARGS will
10396 presently be {int*} -- but we need {int}. */
10399 }
10400 else
10401 {
10404 }
10406 /* If the template we're instantiating is incomplete, then clearly
10407 there's nothing we can do. */
10409 {
10410 /* We can try again later. */
10413 }
10415 /* If we've recursively instantiated too many templates, stop. */
10419 /* We may be in the middle of deferred access check. Disable
10420 it now. */
10427 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10432 else
10433 {
10436 }
10437 /* Use #pragma pack from the template context. */
10443 /* Set the input location to the most specialized template definition.
10444 This is needed if tsubsting causes an error. */
10456 {
10459 /* Adjust visibility for template arguments. */
10461 }
10467 /* We should never instantiate a nested class before its enclosing
10468 class; we need to look up the nested class by name before we can
10469 instantiate it, and that lookup should instantiate the enclosing
10470 class. */
10476 {
10477 tree pbase_binfo;
10478 tree pushed_scope;
10481 /* We must enter the scope containing the type, as that is where
10482 the accessibility of types named in dependent bases are
10483 looked up from. */
10486 /* Substitute into each of the bases to determine the actual
10487 basetypes. */
10489 {
10490 tree base;
10496 {
10497 expanded_bases =
10504 }
10507 {
10509 /* Extract the already-expanded base class. */
10511 else
10512 /* Substitute to figure out the base class. */
10514 NULL_TREE);
10522 }
10523 }
10525 /* The list is now in reverse order; correct that. */
10530 }
10531 /* Now call xref_basetypes to set up all the base-class
10532 information. */
10540 /* Now that our base classes are set up, enter the scope of the
10541 class, so that name lookups into base classes, etc. will work
10542 correctly. This is precisely analogous to what we do in
10543 begin_class_definition when defining an ordinary non-template
10544 class, except we also need to push the enclosing classes. */
10547 /* Now members are processed in the order of declaration. */
10550 {
10554 {
10556 {
10558 /* A closure type for a lambda in an NSDMI or default argument.
10559 Ignore it; it will be regenerated when needed. */
10562 /* Build new CLASSTYPE_NESTED_UTDS. */
10564 tree newtag;
10570 /* If the member is a class template, then -- even after
10571 substitution -- there may be dependent types in the
10572 template argument list for the class. We increment
10573 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10574 that function will assume that no types are dependent
10575 when outside of a template. */
10585 {
10589 /* Unfortunately, lookup_template_class sets
10590 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10591 instantiation (i.e., for the type of a member
10592 template class nested within a template class.)
10593 This behavior is required for
10594 maybe_process_partial_specialization to work
10595 correctly, but is not accurate in this case;
10596 the TAG is not an instantiation of anything.
10597 (The corresponding TEMPLATE_DECL is an
10598 instantiation, but the TYPE is not.) */
10601 /* Now, we call pushtag to put this NEWTAG into the scope of
10602 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10603 pushtag calling push_template_decl. We don't have to do
10604 this for enums because it will already have been done in
10605 tsubst_enum. */
10609 }
10610 }
10612 {
10613 tree r;
10622 /* Instantiate members marked with attribute used. */
10628 }
10631 /* A closure type for a lambda in an NSDMI or default argument.
10633 else
10634 {
10635 /* Build new TYPE_FIELDS. */
10637 {
10638 tree condition;
10641 condition =
10651 }
10653 {
10654 tree r;
10658 /* The file and line for this declaration, to
10659 assist in error message reporting. Since we
10660 called push_tinst_level above, we don't need to
10661 restore these. */
10671 {
10672 /* A capture pack became multiple fields. */
10675 }
10678 {
10682 {
10683 /* In [temp.inst]:
10685 [t]he initialization (and any associated
10686 side-effects) of a static data member does
10687 not occur unless the static data member is
10688 itself used in a way that requires the
10689 definition of the static data member to
10690 exist.
10692 Therefore, we do not substitute into the
10693 initialized for the static data member here. */
10694 finish_static_data_member_decl
10700 /* Instantiate members marked with attribute used. */
10703 }
10705 {
10706 /* Determine whether R has a valid type and can be
10707 completed later. If R is invalid, then its type
10708 is replaced by error_mark_node. */
10714 {
10715 /* If R's type couldn't be completed and
10716 it isn't a flexible array member (whose
10717 type is incomplete by definition) give
10718 an error. */
10721 }
10722 }
10724 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10725 such a thing will already have been added to the field
10726 list by tsubst_enum in finish_member_declaration in the
10727 CLASSTYPE_NESTED_UTDS case above. */
10731 {
10734 }
10735 }
10736 }
10737 }
10738 }
10739 else
10740 {
10743 {
10744 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10750 {
10751 /* template <class T> friend class C; */
10754 }
10756 {
10757 /* template <class T> friend class C::D; */
10763 }
10766 {
10767 /* This could be either
10769 friend class T::C;
10771 when dependent_type_p is false or
10773 template <class U> friend class T::C;
10775 otherwise. */
10776 /* Bump processing_template_decl in case this is something like
10777 template <class T> friend struct A<T>::B. */
10784 }
10788 {
10789 /* friend class C;
10791 where C hasn't been declared yet. Let's lookup name
10792 from namespace scope directly, bypassing any name that
10793 come from dependent base class. */
10796 /* The call to xref_tag_from_type does injection for friend
10797 classes. */
10799 friend_type =
10803 }
10805 /* friend class C<T>; */
10808 /* Otherwise it's
10810 friend class C;
10812 where C is already declared or
10814 friend class C<int>;
10816 We don't have to do anything in these cases. */
10819 /* Trick make_friend_class into realizing that the friend
10820 we're adding is a template, not an ordinary class. It's
10821 important that we use make_friend_class since it will
10822 perform some error-checking and output cross-reference
10823 information. */
10831 }
10832 else
10833 {
10834 /* Build new DECL_FRIENDLIST. */
10835 tree r;
10837 /* The file and line for this declaration, to
10838 assist in error message reporting. Since we
10839 called push_tinst_level above, we don't need to
10840 restore these. */
10844 {
10847 }
10852 {
10855 }
10856 }
10857 }
10858 }
10861 {
10862 /* Restore these before substituting into the lambda capture
10863 initializers. */
10866 }
10868 /* Set the file and line number information to whatever is given for
10869 the class itself. This puts error messages involving generated
10870 implicit functions at a predictable point, and the same point
10871 that would be used for non-template classes. */
10878 /* We don't instantiate default arguments for member functions. 14.7.1:
10880 The implicit instantiation of a class template specialization causes
10881 the implicit instantiation of the declarations, but not of the
10882 definitions or default arguments, of the class member functions,
10883 member classes, static data members and member templates.... */
10885 /* Some typedefs referenced from within the template code need to be access
10886 checked at template instantiation time, i.e now. These types were
10887 added to the template at parsing time. Let's get those and perform
10888 the access checks then. */
10898 /* The vtable for a template class can be emitted in any translation
10899 unit in which the class is instantiated. When there is no key
10900 method, however, finish_struct_1 will already have added TYPE to
10901 the keyed_classes. */
10906 }
10908 /* Wrapper for instantiate_class_template_1. */
10910 tree
10912 {
10913 tree ret;
10918 }
10920 static tree
10922 {
10923 tree r;
10929 else
10930 {
10937 }
10939 }
10941 /* Given a function parameter pack TMPL_PARM and some function parameters
10942 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10943 and set *SPEC_P to point at the next point in the list. */
10945 tree
10947 {
10948 /* Collect all of the extra "packed" parameters into an
10949 argument pack. */
10950 tree parmvec;
10960 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10964 {
10969 }
10971 /* Build the argument packs. */
10976 }
10978 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10979 NONTYPE_ARGUMENT_PACK. */
10981 static tree
10983 {
10985 }
10987 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10988 pack expansion with no extra args, 2 if it has extra args, or 0
10989 if it is not a pack expansion. */
10991 static int
10993 {
10999 /* A decl pack is itself an expansion. */
11006 }
11009 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
11011 static tree
11013 {
11020 }
11022 /* This is a subroutine of tsubst_pack_expansion.
11024 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
11025 mechanism to store the (non complete list of) arguments of the
11026 substitution and return a non substituted pack expansion, in order
11027 to wait for when we have enough arguments to really perform the
11028 substitution. */
11030 static bool
11034 {
11035 /* If one pack has an expansion and another pack has a normal
11036 argument or if one pack has an empty argument and an another
11037 one hasn't then tsubst_pack_expansion cannot perform the
11038 substitution and need to fall back on the
11039 PACK_EXPANSION_EXTRA mechanism. */
11047 {
11050 parm_pack;
11052 {
11057 /* We can't substitute a pack expansion with extra args into
11058 our pattern. */
11062 else
11064 }
11068 }
11070 }
11072 /* [temp.variadic]/6 says that:
11074 The instantiation of a pack expansion [...]
11075 produces a list E1,E2, ..., En, where N is the number of elements
11076 in the pack expansion parameters.
11078 This subroutine of tsubst_pack_expansion produces one of these Ei.
11080 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11081 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11082 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11083 INDEX is the index 'i' of the element Ei to produce. ARGS,
11084 COMPLAIN, and IN_DECL are the same parameters as for the
11085 tsubst_pack_expansion function.
11087 The function returns the resulting Ei upon successful completion,
11088 or error_mark_node.
11090 Note that this function possibly modifies the ARGS parameter, so
11091 it's the responsibility of the caller to restore it. */
11093 static tree
11095 tree parm_packs,
11097 tree args /* This parm gets
11099 tsubst_flags_t complain,
11100 tree in_decl)
11101 {
11102 tree t;
11105 /* For each parameter pack, change the substitution of the parameter
11106 pack to the ith argument in its argument pack, then expand the
11107 pattern. */
11109 {
11114 ith_elem_is_expansion |=
11117 /* Select the Ith argument from the pack. */
11121 {
11123 {
11128 }
11129 else
11131 }
11132 else
11133 {
11138 {
11140 /* Update the corresponding argument. */
11142 }
11143 else
11144 /* Re-use the ARGUMENT_PACK_SELECT. */
11146 }
11148 }
11150 /* Substitute into the PATTERN with the (possibly altered)
11151 arguments. */
11153 /* Expanding a fixed parameter pack from
11154 coerce_template_parameter_pack. */
11159 {
11162 else
11165 }
11169 else
11172 /* If the Ith argument pack element is a pack expansion, then
11173 the Ith element resulting from the substituting is going to
11174 be a pack expansion as well. */
11179 }
11181 /* When the unexpanded parameter pack in a fold expression expands to an empty
11182 sequence, the value of the expression is as follows; the program is
11183 ill-formed if the operator is not listed in this table.
11185 && true
11186 || false
11187 , void() */
11189 tree
11191 {
11195 {
11204 }
11210 }
11212 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11213 form an expression that combines the two terms using the
11214 operator of T. */
11216 static tree
11218 {
11222 // Handle compound assignment operators.
11227 {
11237 complain);
11238 }
11239 }
11241 /* Substitute ARGS into the pack of a fold expression T. */
11245 {
11247 }
11249 /* Substitute ARGS into the pack of a fold expression T. */
11253 {
11255 }
11257 /* Expand a PACK of arguments into a grouped as left fold.
11258 Given a pack containing elements A0, A1, ..., An and an
11259 operator @, this builds the expression:
11261 ((A0 @ A1) @ A2) ... @ An
11263 Note that PACK must not be empty.
11265 The operator is defined by the original fold expression T. */
11267 static tree
11269 {
11272 {
11275 }
11277 }
11279 /* Substitute into a unary left fold expression. */
11281 static tree
11283 tree in_decl)
11284 {
11289 {
11293 }
11296 else
11298 }
11300 /* Substitute into a binary left fold expression.
11302 Do ths by building a single (non-empty) vector of argumnts and
11303 building the expression from those elements. */
11305 static tree
11307 tree in_decl)
11308 {
11317 {
11322 }
11330 }
11332 /* Expand a PACK of arguments into a grouped as right fold.
11333 Given a pack containing elementns A0, A1, ..., and an
11334 operator @, this builds the expression:
11336 A0@ ... (An-2 @ (An-1 @ An))
11338 Note that PACK must not be empty.
11340 The operator is defined by the original fold expression T. */
11342 tree
11344 {
11345 // Build the expression.
11349 {
11352 }
11354 }
11356 /* Substitute into a unary right fold expression. */
11358 static tree
11360 tree in_decl)
11361 {
11366 {
11370 }
11373 else
11375 }
11377 /* Substitute into a binary right fold expression.
11379 Do ths by building a single (non-empty) vector of arguments and
11380 building the expression from those elements. */
11382 static tree
11384 tree in_decl)
11385 {
11394 {
11399 }
11408 }
11410 /* Walk through the pattern of a pack expansion, adding everything in
11411 local_specializations to a list. */
11413 static tree
11415 {
11418 {
11420 {
11421 /* Pull out the actual PARM_DECL for the partial instantiation. */
11426 }
11428 }
11430 }
11431 static tree
11433 {
11437 }
11439 /* Substitute ARGS into T, which is an pack expansion
11440 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11441 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11442 (if only a partial substitution could be performed) or
11443 ERROR_MARK_NODE if there was an error. */
11444 tree
11446 tree in_decl)
11447 {
11448 tree pattern;
11453 tree result;
11461 /* Add in any args remembered from an earlier partial instantiation. */
11464 {
11466 {
11467 /* The partial instantiation involved local declarations collected in
11468 extract_local_specs; map from the general template to our local
11469 context. */
11474 }
11477 }
11482 /* Determine the argument packs that will instantiate the parameter
11483 packs used in the expansion expression. While we're at it,
11484 compute the number of arguments to be expanded and make sure it
11485 is consistent. */
11488 {
11495 {
11500 else
11503 }
11505 {
11506 /* ??? Support use in other patterns. */
11510 }
11512 {
11513 /* We know we have correct local_specializations if this
11514 expansion is at function scope, or if we're dealing with a
11515 local parameter in a requires expression; for the latter,
11516 tsubst_requires_expr set it up appropriately. */
11519 else
11520 /* We can't rely on local_specializations for a parameter
11521 name used later in a function declaration (such as in a
11522 late-specified return type). Even if it exists, it might
11523 have the wrong value for a recursive call. */
11527 {
11528 /* This parameter pack was used in an unevaluated context. Just
11529 make a dummy decl, since it's only used for its type. */
11532 /* Partial instantiation of the parm_pack, we can't build
11533 up an argument pack yet. */
11535 else
11537 }
11539 /* This argument pack isn't fully instantiated yet. We set this
11540 flag rather than clear arg_pack because we do want to do the
11541 optimization below, and we don't want to substitute directly
11542 into the pattern (as that would expose a NONTYPE_ARGUMENT_PACK
11543 where it isn't expected). */
11545 }
11547 {
11551 }
11552 else
11553 {
11559 }
11566 /* This can only happen if we forget to expand an argument
11567 pack somewhere else. Just return an error, silently. */
11568 {
11572 }
11575 {
11579 /* Don't bother trying to do a partial substitution with
11580 incomplete packs; we'll try again after deduction. */
11588 {
11593 pattern);
11594 else
11596 pattern);
11598 }
11600 /* Keep track of the parameter packs and their corresponding
11601 argument packs. */
11604 }
11605 else
11606 {
11607 /* We can't substitute for this parameter pack. We use a flag as
11608 well as the missing_level counter because function parameter
11609 packs don't have a level. */
11612 }
11613 }
11615 /* If the expansion is just T..., return the matching argument pack, unless
11616 we need to call convert_from_reference on all the elements. This is an
11617 important optimization; see c++/68422. */
11620 {
11623 /* If the argument pack is a single pack expansion, pull it out. */
11628 /* Types need no adjustment, nor does sizeof..., and if we still have
11629 some pack expansion args we won't do anything yet. */
11634 /* Also optimize expression pack expansions if we can tell that the
11635 elements won't have reference type. */
11641 /* Otherwise use the normal path so we get convert_from_reference. */
11642 }
11644 /* We cannot expand this expansion expression, because we don't have
11645 all of the argument packs we need. */
11647 {
11648 /* We got some full packs, but we can't substitute them in until we
11649 have values for all the packs. So remember these until then. */
11658 }
11660 {
11661 /* There were no real arguments, we're just replacing a parameter
11662 pack with another version of itself. Substitute into the
11663 pattern and return a PACK_EXPANSION_*. The caller will need to
11664 deal with that. */
11668 else
11672 }
11677 {
11678 /* We're in a late-specified return type, so create our own local
11679 specializations map; the current map is either NULL or (in the
11680 case of recursive unification) might have bindings that we don't
11681 want to use or alter. */
11684 }
11686 /* For each argument in each argument pack, substitute into the
11687 pattern. */
11691 {
11693 i,
11695 in_decl);
11698 {
11701 }
11702 }
11704 /* Update ARGS to restore the substitution from parameter packs to
11705 their argument packs. */
11707 {
11714 else
11715 {
11723 /* Update the corresponding argument. */
11727 else
11729 }
11730 }
11733 {
11736 }
11738 /* If the dependent pack arguments were such that we end up with only a
11739 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11745 }
11747 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11748 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11749 parameter packs; all parms generated from a function parameter pack will
11750 have the same DECL_PARM_INDEX. */
11752 tree
11754 {
11756 tree patparm;
11759 {
11765 }
11766 else
11767 {
11772 }
11775 }
11777 /* Make an argument pack out of the TREE_VEC VEC. */
11779 static tree
11781 {
11782 tree pack;
11786 else
11787 {
11790 }
11793 }
11795 /* Return an exact copy of template args T that can be modified
11796 independently. */
11798 static tree
11800 {
11808 {
11813 }
11819 }
11821 /* Substitute ARGS into the vector or list of template arguments T. */
11823 static tree
11825 {
11837 {
11839 tree new_arg;
11844 {
11845 /* Substitute into an expansion expression. */
11849 /* Add to the expanded length adjustment the number of
11850 expanded arguments. We subtract one from this
11851 measurement, because the argument pack expression
11852 itself is already counted as 1 in
11853 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11854 the argument pack is empty. */
11856 }
11858 {
11859 /* Substitute into each of the arguments. */
11868 else
11873 }
11874 else
11883 }
11888 /* Make space for the expanded arguments coming from template
11889 argument packs. */
11891 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11892 arguments for a member template.
11893 In that case each TREE_VEC in ORIG_T represents a level of template
11894 arguments, and ORIG_T won't carry any non defaulted argument count.
11895 It will rather be the nested TREE_VECs that will carry one.
11896 In other words, ORIG_T carries a non defaulted argument count only
11897 if it doesn't contain any nested TREE_VEC. */
11899 {
11903 }
11905 {
11909 {
11912 /* Now expand the template argument pack "in place". */
11915 }
11916 else
11917 {
11919 out++;
11920 }
11921 }
11924 }
11926 /* Substitute ARGS into one level PARMS of template parameters. */
11928 static tree
11930 {
11937 {
11945 }
11948 }
11950 /* Return the result of substituting ARGS into the template parameters
11951 given by PARMS. If there are m levels of ARGS and m + n levels of
11952 PARMS, then the result will contain n levels of PARMS. For
11953 example, if PARMS is `template <class T> template <class U>
11954 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11955 result will be `template <int*, double, class V>'. */
11957 static tree
11959 {
11963 /* When substituting into a template, we must set
11964 PROCESSING_TEMPLATE_DECL as the template parameters may be
11965 dependent if they are based on one-another, and the dependency
11966 predicates are short-circuit outside of templates. */
11973 {
11980 }
11985 }
11987 /* Return the result of substituting ARGS into one template parameter
11988 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11989 parameter and which TREE_PURPOSE is the default argument of the
11990 template parameter. */
11992 static tree
11994 {
12015 }
12017 /* Substitute the ARGS into the indicated aggregate (or enumeration)
12018 type T. If T is not an aggregate or enumeration type, it is
12019 handled as if by tsubst. IN_DECL is as for tsubst. If
12020 ENTERING_SCOPE is nonzero, T is the context for a template which
12021 we are presently tsubst'ing. Return the substituted value. */
12023 static tree
12025 tree args,
12026 tsubst_flags_t complain,
12027 tree in_decl,
12029 {
12034 {
12039 /* Fall through. */
12043 {
12044 tree argvec;
12045 tree context;
12046 tree r;
12050 /* In "sizeof(X<I>)" we need to evaluate "I". */
12056 /* First, determine the context for the type we are looking
12057 up. */
12060 {
12063 /* If context is a nested class inside a class template,
12064 it may still need to be instantiated (c++/33959). */
12066 }
12068 /* Then, figure out what arguments are appropriate for the
12069 type we are trying to find. For example, given:
12071 template <class T> struct S;
12072 template <class T, class U> void f(T, U) { S<U> su; }
12074 and supposing that we are instantiating f<int, double>,
12075 then our ARGS will be {int, double}, but, when looking up
12076 S we only want {double}. */
12081 else
12082 {
12086 }
12092 }
12093 else
12094 /* This is not a template type, so there's nothing to do. */
12099 }
12100 }
12104 /* Substitute into the default argument ARG (a default argument for
12105 FN), which has the indicated TYPE. */
12107 tree
12109 tsubst_flags_t complain)
12110 {
12115 /* This can happen in invalid code. */
12130 /* This default argument came from a template. Instantiate the
12131 default argument here, not in tsubst. In the case of
12132 something like:
12134 template <class T>
12135 struct S {
12136 static T t();
12137 void f(T = t());
12138 };
12140 we must be careful to do name lookup in the scope of S<T>,
12141 rather than in the current class. */
12143 /* The "this" pointer is not valid in a default argument. */
12145 {
12150 }
12155 /* The default argument expression may cause implicitly defined
12156 member functions to be synthesized, which will result in garbage
12157 collection. We must treat this situation as if we were within
12158 the body of function so as to avoid collecting live data on the
12159 stack. */
12169 /* Restore the "this" pointer. */
12171 {
12174 }
12181 /* Make sure the default argument is reasonable. */
12187 {
12191 }
12194 }
12196 /* Substitute into all the default arguments for FN. */
12198 static void
12200 {
12201 tree arg;
12202 tree tmpl_args;
12206 /* If this function is not yet instantiated, we certainly don't need
12207 its default arguments. */
12210 /* Don't do this again for clones. */
12216 arg;
12222 complain);
12223 }
12225 /* Subroutine of tsubst_decl for the case when T is a FUNCTION_DECL. */
12227 static tree
12229 tree lambda_fntype)
12230 {
12235 /* Nobody should be tsubst'ing into non-template functions. */
12239 {
12240 /* If T is not dependent, just return it. */
12244 /* Calculate the most general template of which R is a
12245 specialization. */
12248 /* We're substituting a lambda function under tsubst_lambda_expr but not
12249 directly from it; find the matching function we're already inside.
12250 But don't do this if T is a generic lambda with a single level of
12251 template parms, as in that case we're doing a normal instantiation. */
12257 /* Calculate the complete set of arguments used to
12258 specialize R. */
12260 (DECL_TEMPLATE_RESULT
12266 /* Check to see if we already have this specialization. */
12268 {
12272 }
12274 /* We can see more levels of arguments than parameters if
12275 there was a specialization of a member template, like
12276 this:
12278 template <class T> struct S { template <class U> void f(); }
12279 template <> template <class U> void S<int>::f(U);
12281 Here, we'll be substituting into the specialization,
12282 because that's where we can find the code we actually
12283 want to generate, but we'll have enough arguments for
12284 the most general template.
12286 We also deal with the peculiar case:
12288 template <class T> struct S {
12289 template <class U> friend void f();
12290 };
12291 template <class U> void f() {}
12292 template S<int>;
12293 template void f<double>();
12295 Here, the ARGS for the instantiation of will be {int,
12296 double}. But, we only need as many ARGS as there are
12297 levels of template parameters in CODE_PATTERN. We are
12298 careful not to get fooled into reducing the ARGS in
12299 situations like:
12301 template <class T> struct S { template <class U> void f(U); }
12302 template <class T> template <> void S<T>::f(int) {}
12304 which we can spot because the pattern will be a
12305 specialization in this case. */
12312 }
12313 else
12314 {
12315 /* This special case arises when we have something like this:
12317 template <class T> struct S {
12318 friend void f<int>(int, double);
12319 };
12321 Here, the DECL_TI_TEMPLATE for the friend declaration
12322 will be an IDENTIFIER_NODE. We are being called from
12323 tsubst_friend_function, and we want only to create a
12324 new decl (R) with appropriate types so that we can call
12325 determine_specialization. */
12328 }
12345 /* If we hit excessive deduction depth, the type is bogus even if
12346 it isn't error_mark_node, so don't build a decl. */
12350 /* We do NOT check for matching decls pushed separately at this
12351 point, as they may not represent instantiations of this
12352 template, and in any case are considered separate under the
12353 discrete model. */
12357 /* Clear out the mangled name and RTL for the instantiation. */
12360 /* Leave DECL_INITIAL set on deleted instantiations. */
12365 /* OpenMP UDRs have the only argument a reference to the declared
12366 type. We want to diagnose if the declared type is a reference,
12367 which is invalid, but as references to references are usually
12368 quietly merged, diagnose it here. */
12370 {
12371 tree argtype
12376 "reference type %qT in "
12380 argtype);
12381 }
12384 /* Type-conversion operator. Reconstruct the name, in
12385 case it's the name of one of the template's parameters. */
12395 {
12399 }
12406 /* If this is an instantiation of a function with internal
12407 linkage, we already know what object file linkage will be
12408 assigned to the instantiation. */
12417 /* We'll re-clone as appropriate in instantiate_template. */
12420 /* If we aren't complaining now, return on error before we register
12421 the specialization so that we'll complain eventually. */
12427 /* When instantiating a constrained member, substitute
12428 into the constraints to create a new constraint. */
12431 {
12434 }
12436 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12437 this in the special friend case mentioned above where
12438 GEN_TMPL is NULL. */
12440 {
12445 tree new_r
12448 /* We instantiated this while substituting into
12449 the type earlier (template/friend54.C). */
12452 /* We're not supposed to instantiate default arguments
12453 until they are called, for a template. But, for a
12454 declaration like:
12456 template <class T> void f ()
12457 { extern void g(int i = T()); }
12459 we should do the substitution when the template is
12460 instantiated. We handle the member function case in
12461 instantiate_class_template since the default arguments
12462 might refer to other members of the class. */
12467 }
12468 else
12471 /* Copy the list of befriending classes. */
12475 {
12479 }
12482 {
12486 /* If this is an instantiation of a member template, clone it.
12487 If it isn't, that'll be handled by
12488 clone_constructors_and_destructors. */
12491 }
12502 /* Possibly limit visibility based on template args. */
12505 {
12509 }
12518 }
12520 /* Subroutine of tsubst_decl for the case when T is a TEMPLATE_DECL. */
12522 static tree
12524 tree lambda_fntype)
12525 {
12526 /* We can get here when processing a member function template,
12527 member class template, or template template parameter. */
12530 tree spec;
12531 tree tmpl_args;
12532 tree full_args;
12533 tree r;
12537 {
12538 /* Template template parameter is treated here. */
12542 /* If we get a real template back, return it. This can happen in
12543 the context of most_specialized_partial_spec. */
12546 else
12547 /* The new TEMPLATE_DECL was built in
12548 reduce_template_parm_level. */
12551 }
12554 {
12555 /* We might already have an instance of this template.
12556 The ARGS are for the surrounding class type, so the
12557 full args contain the tsubst'd args for the context,
12558 plus the innermost args from the template decl. */
12562 /* Because this is a template, the arguments will still be
12563 dependent, even after substitution. If
12564 PROCESSING_TEMPLATE_DECL is not set, the dependency
12565 predicates will short-circuit. */
12573 /* If this is a default template template argument,
12574 tsubst might not have changed anything. */
12582 }
12584 /* Make a new template decl. It will be similar to the
12585 original, but will record the current template arguments.
12586 We also create a new function declaration, which is just
12587 like the old one, but points to this new template, rather
12588 than the old one. */
12593 // Build new template info linking to the original template decl.
12595 {
12598 }
12599 else
12602 /* The template parameters for this new template are all the
12603 template parameters for the old template, except the
12604 outermost level of parameters. */
12607 complain);
12611 {
12612 tree new_type;
12620 /* For a partial specialization, we need to keep pointing to
12621 the primary template. */
12627 }
12628 else
12629 {
12630 tree new_decl;
12634 else
12644 {
12647 }
12648 else
12649 {
12652 }
12653 }
12663 /* Record this non-type partial instantiation. */
12669 }
12671 /* True if FN is the op() for a lambda in an uninstantiated template. */
12673 bool
12675 {
12680 }
12682 /* We're instantiating a variable from template function TCTX. Return the
12683 corresponding current enclosing scope. This gets complicated because lambda
12684 functions in templates are regenerated rather than instantiated, but generic
12685 lambda functions are subsequently instantiated. */
12687 static tree
12689 {
12698 {
12711 }
12713 }
12715 /* Substitute the ARGS into the T, which is a _DECL. Return the
12716 result of the substitution. Issue error and warning messages under
12717 control of COMPLAIN. */
12719 static tree
12721 {
12722 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12723 location_t saved_loc;
12728 /* Set the filename and linenumber to improve error-reporting. */
12733 {
12743 {
12751 {
12752 /* If there is a local specialization that isn't a
12753 parameter pack, it means that we're doing a "simple"
12754 substitution from inside tsubst_pack_expansion. Just
12755 return the local specialization (which will be a single
12756 parm). */
12763 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12764 the parameters in this function parameter pack. */
12768 {
12771 /* Zero-length parameter packs are boring. Just substitute
12772 into the chain. */
12776 }
12777 else
12778 {
12779 /* All we did was update the type. Make a note of that. */
12782 }
12783 }
12785 /* Loop through all of the parameters we'll build. When T is
12786 a function parameter pack, LEN is the number of expanded
12787 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12790 {
12797 /* We're on the Ith parameter of the function parameter
12798 pack. */
12799 {
12800 /* Get the Ith type. */
12803 /* Rename the parameter to include the index. */
12806 }
12808 /* We're dealing with a normal parameter. */
12816 {
12819 else
12822 }
12832 /* Keep track of the first new parameter we
12833 generate. That's what will be returned to the
12834 caller. */
12838 /* Build a proper chain of parameters when substituting
12839 into a function parameter pack. */
12842 }
12844 /* If cp_unevaluated_operand is set, we're just looking for a
12845 single dummy parameter, so don't keep going. */
12850 /* FIRST_R contains the start of the chain we've built. */
12852 }
12856 {
12863 {
12864 /* This field is a lambda capture pack. Return a TREE_VEC of
12865 the expanded fields to instantiate_class_template_1. */
12869 {
12872 }
12873 else
12874 {
12875 /* All we did was update the type. Make a note of that. */
12878 }
12879 }
12882 {
12885 {
12889 }
12899 /* For bit-fields, DECL_BIT_FIELD_REPRESENTATIVE gives the
12900 number of bits. */
12906 {
12907 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12908 NSDMI in perform_member_init. Still set DECL_INITIAL
12909 so that we know there is one. */
12914 }
12915 /* We don't have to set DECL_CONTEXT here; it is set by
12916 finish_member_declaration. */
12924 }
12928 }
12932 /* We reach here only for member using decls. We also need to check
12933 uses_template_parms because DECL_DEPENDENT_P is not set for a
12934 using-declaration that designates a member of the current
12935 instantiation (c++/53549). */
12938 {
12942 {
12947 {
12951 {
12954 }
12955 else
12956 {
12959 }
12961 }
12962 }
12963 else
12964 {
12970 else
12971 {
12974 }
12975 }
12976 }
12977 else
12978 {
12981 }
12986 {
12989 tree spec;
12991 tree ctx;
13000 {
13001 /* If this is the canonical decl, we don't have to
13002 mess with instantiations, and often we can't (for
13003 typename, template type parms and such). Note that
13004 TYPE_NAME is not correct for the above test if
13005 we've copied the type for a typedef. */
13011 }
13013 /* Check to see if we already have the specialization we
13014 need. */
13017 {
13018 /* T is a static data member or namespace-scope entity.
13019 We have to substitute into namespace-scope variables
13020 (not just variable templates) because of cases like:
13022 template <class T> void f() { extern T t; }
13024 where the entity referenced is not known until
13025 instantiation time. */
13029 {
13031 complain,
13033 /* If CTX is unchanged, then T is in fact the
13034 specialization we want. That situation occurs when
13035 referencing a static data member within in its own
13036 class. We can use pointer equality, rather than
13037 same_type_p, because DECL_CONTEXT is always
13038 canonical... */
13040 /* ... unless T is a member template; in which
13041 case our caller can be willing to create a
13042 specialization of that template represented
13043 by T. */
13047 }
13050 {
13055 argvec = (coerce_innermost_template_parms
13063 }
13064 }
13065 else
13066 {
13067 /* A local variable. */
13069 /* Subsequent calls to pushdecl will fill this in. */
13071 /* Unless this is a reference to a static variable from an
13072 enclosing function, in which case we need to fill it in now. */
13074 {
13078 }
13080 }
13081 /* If we already have the specialization we need, there is
13082 nothing more to do. */
13084 {
13087 }
13089 /* Create a new node for the specialization we need. */
13092 {
13095 else
13103 {
13104 /* Mask off any template args past the variable's context so we
13105 don't replace the auto with an unrelated argument. */
13109 /* This should never happen with the new lambda instantiation
13110 model, but keep the handling just in case. */
13113 }
13115 }
13117 {
13118 /* Even if the original location is out of scope, the
13119 newly substituted one is not. */
13126 {
13127 /* It may seem that this case cannot occur, since:
13129 typedef void f();
13130 void g() { f x; }
13132 declares a function, not a variable. However:
13134 typedef void f();
13135 template <typename T> void g() { T t; }
13136 template void g<f>();
13138 is an attempt to declare a variable with function
13139 type. */
13141 /* R is not yet sufficiently initialized, so we
13142 just use its name. */
13145 }
13147 /* Wait until cp_finish_decl to set this again, to handle
13148 circular dependency (template/instantiate6.C). */
13153 {
13158 {
13161 }
13163 }
13167 }
13173 /* Clear out the mangled name and RTL for the instantiation. */
13177 /* The initializer must not be expanded until it is required;
13178 see [temp.inst]. */
13182 {
13188 /* Possibly limit visibility based on template args. */
13191 {
13195 }
13197 }
13200 {
13201 /* A static data member declaration is always marked
13202 external when it is declared in-class, even if an
13203 initializer is present. We mimic the non-template
13204 processing here. */
13212 }
13213 else
13214 {
13219 }
13227 /* Preserve a typedef that names a type. */
13229 {
13233 /* An alias template specialization can be dependent
13234 even if its underlying type is not. */
13236 }
13239 }
13244 }
13245 #undef RETURN
13247 out:
13248 /* Restore the file and line information. */
13252 }
13254 /* Substitute into the ARG_TYPES of a function type.
13255 If END is a TREE_CHAIN, leave it and any following types
13256 un-substituted. */
13258 static tree
13260 tree args,
13261 tree end,
13262 tsubst_flags_t complain,
13263 tree in_decl)
13264 {
13265 tree remaining_arg_types;
13269 tree default_arg;
13280 {
13281 /* For a pack expansion, perform substitution on the
13282 entire expression. Later on, we'll handle the arguments
13283 one-by-one. */
13288 /* So that we'll spin through the parameters, one by one. */
13290 else
13291 {
13292 /* We only partially substituted into the parameter
13293 pack. Our type is TYPE_PACK_EXPANSION. */
13296 }
13297 }
13310 {
13312 {
13316 }
13318 }
13319 /* DR 657. */
13323 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13324 top-level qualifiers as required. */
13327 /* We do not substitute into default arguments here. The standard
13328 mandates that they be instantiated only when needed, which is
13329 done in build_over_call. */
13332 /* Except that we do substitute default arguments under tsubst_lambda_expr,
13333 since the new op() won't have any associated template arguments for us
13334 to refer to later. */
13340 {
13341 /* We've instantiated a template before its default arguments
13342 have been parsed. This can happen for a nested template
13343 class, and is not an error unless we require the default
13344 argument in a call of this function. */
13345 remaining_arg_types =
13348 }
13349 else
13350 remaining_arg_types =
13352 }
13355 }
13357 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13358 *not* handle the exception-specification for FNTYPE, because the
13359 initial substitution of explicitly provided template parameters
13360 during argument deduction forbids substitution into the
13361 exception-specification:
13363 [temp.deduct]
13365 All references in the function type of the function template to the
13366 corresponding template parameters are replaced by the specified tem-
13367 plate argument values. If a substitution in a template parameter or
13368 in the function type of the function template results in an invalid
13369 type, type deduction fails. [Note: The equivalent substitution in
13370 exception specifications is done only when the function is instanti-
13371 ated, at which point a program is ill-formed if the substitution
13372 results in an invalid type.] */
13374 static tree
13376 tree args,
13377 tsubst_flags_t complain,
13378 tree in_decl)
13379 {
13380 tree return_type;
13382 tree fntype;
13384 /* The TYPE_CONTEXT is not used for function/method types. */
13387 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13388 failure. */
13392 {
13393 /* Substitute the argument types. */
13405 {
13406 /* DR 1207: 'this' is in scope in the trailing return type. */
13408 }
13410 /* Substitute the return type. */
13414 {
13417 }
13418 }
13419 else
13420 /* Substitute the return type. */
13425 /* DR 486 clarifies that creation of a function type with an
13426 invalid return type is a deduction failure. */
13429 {
13431 {
13434 else
13436 }
13438 }
13439 /* And DR 657. */
13444 {
13445 /* Substitute the argument types. */
13450 }
13452 /* Construct a new type node and return it. */
13454 {
13459 }
13460 else
13461 {
13463 /* Don't pick up extra function qualifiers from the basetype. */
13466 {
13467 /* [temp.deduct]
13469 Type deduction may fail for any of the following
13470 reasons:
13472 -- Attempting to create "pointer to member of T" when T
13473 is not a class type. */
13476 r);
13478 }
13483 }
13490 }
13492 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13493 ARGS into that specification, and return the substituted
13494 specification. If there is no specification, return NULL_TREE. */
13496 static tree
13498 tree args,
13499 tsubst_flags_t complain,
13500 tree in_decl,
13502 {
13503 tree specs;
13504 tree new_specs;
13509 {
13510 /* A noexcept-specifier. */
13515 {
13516 /* Defer instantiation of noexcept-specifiers to avoid
13517 excessive instantiations (c++/49107). */
13520 {
13521 /* We already partially instantiated this member template,
13522 so combine the new args with the old. */
13527 }
13528 else
13529 {
13532 }
13533 }
13534 else
13535 new_specs = tsubst_copy_and_build
13539 }
13541 {
13544 else
13546 {
13547 tree spec;
13552 {
13553 /* Expand the pack expansion type. */
13556 in_decl);
13562 else
13563 {
13564 /* We're substituting into a member template, so
13565 we got a TYPE_PACK_EXPANSION back. Add that
13566 expansion and move on. */
13570 expanded_specs,
13571 complain);
13574 }
13575 }
13578 {
13581 else
13586 complain);
13587 }
13590 }
13591 }
13593 }
13595 /* Take the tree structure T and replace template parameters used
13596 therein with the argument vector ARGS. IN_DECL is an associated
13597 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13598 Issue error and warning messages under control of COMPLAIN. Note
13599 that we must be relatively non-tolerant of extensions here, in
13600 order to preserve conformance; if we allow substitutions that
13601 should not be allowed, we may allow argument deductions that should
13602 not succeed, and therefore report ambiguous overload situations
13603 where there are none. In theory, we could allow the substitution,
13604 but indicate that it should have failed, and allow our caller to
13605 make sure that the right thing happens, but we don't try to do this
13606 yet.
13608 This function is used for dealing with types, decls and the like;
13609 for expressions, use tsubst_expr or tsubst_copy. */
13611 tree
13613 {
13636 else
13641 /* Reuse typedefs. We need to do this to handle dependent attributes,
13642 such as attribute aligned. */
13645 {
13649 {
13650 /* DECL represents an alias template and we want to
13651 instantiate it. */
13655 }
13659 {
13663 }
13668 else
13669 /* The typedef is from a non-template context. */
13673 {
13675 r = cp_build_qualified_type_real
13679 }
13680 else
13681 {
13682 /* We don't have an instantiation yet, so drop the typedef. */
13687 }
13688 }
13705 {
13731 {
13737 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13738 needed. */
13744 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13745 with TREE_SIDE_EFFECTS that indicates this is not an integral
13746 constant expression. */
13749 {
13752 }
13755 }
13761 {
13767 /* Early in template argument deduction substitution, we don't
13768 want to reduce the level of 'auto', or it will be confused
13769 with a normal template parm in subsequent deduction. */
13781 {
13784 /* See through ARGUMENT_PACK_SELECT arguments. */
13787 }
13792 {
13794 /* If ARG is an argument pack, we don't actually want to
13795 perform a substitution here, because substitutions
13796 for argument packs are only done
13797 element-by-element. We can get to this point when
13798 substituting the type of a non-type template
13799 parameter pack, when that type actually contains
13800 template parameter packs from an outer template, e.g.,
13802 template<typename... Types> struct A {
13803 template<Types... Values> struct B { };
13804 }; */
13808 {
13814 return cp_build_qualified_type_real
13816 }
13818 {
13819 /* We are processing a type constructed from a
13820 template template parameter. */
13831 /* Consider this code:
13833 template <template <class> class Template>
13834 struct Internal {
13835 template <class Arg> using Bind = Template<Arg>;
13836 };
13838 template <template <class> class Template, class Arg>
13839 using Instantiate = Template<Arg>; //#0
13841 template <template <class> class Template,
13842 class Argument>
13843 using Bind =
13844 Instantiate<Internal<Template>::template Bind,
13845 Argument>; //#1
13847 When #1 is parsed, the
13848 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13849 parameter `Template' in #0 matches the
13850 UNBOUND_CLASS_TEMPLATE representing the argument
13851 `Internal<Template>::template Bind'; We then want
13852 to assemble the type `Bind<Argument>' that can't
13853 be fully created right now, because
13854 `Internal<Template>' not being complete, the Bind
13855 template cannot be looked up in that context. So
13856 we need to "store" `Bind<Argument>' for later
13857 when the context of Bind becomes complete. Let's
13858 store that in a TYPENAME_TYPE. */
13862 argvec),
13863 typename_type,
13864 complain);
13866 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13867 are resolving nested-types in the signature of a
13868 member function templates. Otherwise ARG is a
13869 TEMPLATE_DECL and is the real template to be
13870 instantiated. */
13878 complain);
13879 return cp_build_qualified_type_real
13881 }
13884 else
13885 /* TEMPLATE_PARM_INDEX. */
13887 }
13890 /* This can happen during the attempted tsubst'ing in
13891 unify. This means that we don't yet have any information
13892 about the template parameter in question. */
13895 /* If we get here, we must have been looking at a parm for a
13896 more deeply nested template. Make a new version of this
13897 template parameter, but with a lower level. */
13899 {
13904 {
13906 r = cp_build_qualified_type_real
13910 }
13917 /* Break infinite recursion when substituting the constraints
13919 else
13920 {
13931 {
13932 /* Propagate constraints on placeholders. */
13937 {
13941 }
13942 }
13945 /* We have reduced the level of the template
13946 template parameter, but not the levels of its
13947 template parameters, so canonical_type_parameter
13948 will not be able to find the canonical template
13949 template parameter for this level. Thus, we
13950 require structural equality checking to compare
13951 TEMPLATE_TEMPLATE_PARMs. */
13955 else
13959 {
13961 /* We might need to substitute into the types of non-type
13962 template parameters. */
13974 }
13975 }
13979 /* OK, now substitute the type of the non-type parameter. We
13980 couldn't do it earlier because it might be an auto parameter,
13981 and we wouldn't need to if we had an argument. */
13990 }
13993 }
13996 {
14004 {
14008 }
14011 {
14015 }
14018 {
14022 }
14028 }
14031 /* We should never be tsubsting a binfo. */
14035 /* A vector of template arguments. */
14041 {
14045 /* [temp.deduct]
14047 Type deduction may fail for any of the following
14048 reasons:
14050 -- Attempting to create a pointer to reference type.
14051 -- Attempting to create a reference to a reference type or
14052 a reference to void.
14054 Core issue 106 says that creating a reference to a reference
14055 during instantiation is no longer a cause for failure. We
14056 only enforce this check in strict C++98 mode. */
14060 {
14063 /* We keep track of the last time we issued this error
14064 message to avoid spewing a ton of messages during a
14065 single bad template instantiation. */
14068 {
14073 else
14076 }
14079 }
14083 {
14085 {
14088 type);
14089 else
14091 type);
14092 }
14094 }
14096 {
14100 }
14102 /* In C++0x, during template argument substitution, when there is an
14103 attempt to create a reference to a reference type, reference
14104 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
14106 "If a template-argument for a template-parameter T names a type
14107 that is a reference to a type A, an attempt to create the type
14108 'lvalue reference to cv T' creates the type 'lvalue reference to
14109 A,' while an attempt to create the type type rvalue reference to
14110 cv T' creates the type T"
14111 */
14112 r = cp_build_reference_type
14115 else
14120 /* Will this ever be needed for TYPE_..._TO values? */
14124 }
14126 {
14129 {
14130 /* [temp.deduct]
14132 Type deduction may fail for any of the following
14133 reasons:
14135 -- Attempting to create "pointer to member of T" when T
14136 is not a class type. */
14140 }
14142 {
14146 }
14148 {
14152 }
14155 {
14156 /* The type of the implicit object parameter gets its
14157 cv-qualifiers from the FUNCTION_TYPE. */
14158 tree memptr;
14159 tree method_type
14164 complain);
14165 }
14166 else
14169 complain);
14170 }
14173 {
14174 tree fntype;
14175 tree specs;
14180 /* Substitute the exception specification. */
14188 }
14190 {
14195 /* As an optimization, we avoid regenerating the array type if
14196 it will obviously be the same as T. */
14200 /* These checks should match the ones in create_array_type_for_decl.
14202 [temp.deduct]
14204 The deduction may fail for any of the following reasons:
14206 -- Attempting to create an array with an element type that
14207 is void, a function type, or a reference type, or [DR337]
14208 an abstract class type. */
14214 {
14218 }
14226 {
14229 }
14232 }
14235 {
14247 {
14251 }
14253 {
14254 /* Normally, make_typename_type does not require that the CTX
14255 have complete type in order to allow things like:
14257 template <class T> struct S { typename S<T>::X Y; };
14259 But, such constructs have already been resolved by this
14260 point, so here CTX really should have complete type, unless
14261 it's a partial instantiation. */
14264 {
14268 }
14269 }
14276 {
14279 }
14282 {
14284 {
14288 else
14290 }
14292 {
14296 else
14298 }
14299 }
14301 return cp_build_qualified_type_real
14303 }
14306 {
14318 }
14321 {
14322 tree type;
14338 complain);
14339 }
14342 {
14343 tree type;
14354 {
14356 {
14360 }
14363 }
14374 else
14375 {
14379 /* In a template ~id could be either a complement expression
14380 or an unqualified-id naming a destructor; if instantiating
14381 it produces an expression, it's not an id-expression or
14382 member access. */
14385 }
14390 }
14393 {
14397 }
14401 {
14402 tree r;
14406 else
14414 }
14429 /* We should use one of the expression tsubsts for these codes. */
14435 }
14436 }
14438 /* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
14439 expression on the left-hand side of the "." or "->" operator. We
14440 only do the lookup if we had a dependent BASELINK. Otherwise we
14441 adjust it onto the instantiated heirarchy. */
14443 static tree
14446 {
14458 {
14465 }
14472 {
14478 /* Treat as-if non-dependent below. */
14483 {
14489 }
14493 }
14494 else
14495 /* We're going to overwrite pieces below, make a duplicate. */
14498 /* If lookup found a single function, mark it as used at this point.
14499 (If lookup found multiple functions the one selected later by
14500 overload resolution will be marked as used at that point.) */
14506 {
14507 /* Add back the template arguments, if present. */
14512 /* Update the conversion operator type. */
14514 }
14520 {
14522 qualifying_scope,
14523 object_type);
14525 /* We need to call adjust_result_of_qualified_name_lookup in case the
14526 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14527 so that we still get virtual function binding. */
14529 }
14532 }
14534 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14535 true if the qualified-id will be a postfix-expression in-and-of
14536 itself; false if more of the postfix-expression follows the
14537 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14538 of "&". */
14540 static tree
14544 {
14545 tree expr;
14546 tree scope;
14547 tree name;
14549 tree template_args;
14554 /* Figure out what name to look up. */
14557 {
14567 }
14568 else
14569 {
14572 }
14574 /* Substitute into the qualifying scope. When there are no ARGS, we
14575 are just trying to simplify a non-dependent expression. In that
14576 case the qualifying scope may be dependent, and, in any case,
14577 substituting will not help. */
14580 {
14583 }
14584 else
14588 {
14595 }
14598 {
14600 {
14601 /* A BIT_NOT_EXPR is used to represent a destructor. */
14603 {
14607 }
14608 else
14611 }
14612 else
14616 {
14618 {
14622 }
14624 }
14625 }
14628 {
14630 scope);
14631 /* Remember that there was a reference to this entity. */
14634 }
14637 {
14643 }
14646 {
14649 complain);
14650 else
14652 }
14658 {
14659 expr = (adjust_result_of_qualified_name_lookup
14661 expr = (finish_qualified_id_expr
14665 }
14667 /* Expressions do not generally have reference type. */
14669 /* However, if we're about to form a pointer-to-member, we just
14670 want the referenced member referenced. */
14678 }
14680 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14681 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14682 for tsubst. */
14684 static tree
14687 {
14694 {
14695 /* If we had an initializer but it
14696 instantiated to nothing,
14697 value-initialize the object. This will
14698 only occur when the initializer was a
14699 pack expansion where the parameter packs
14700 used in that expansion were of length
14701 zero. */
14703 complain);
14708 }
14711 }
14713 /* Like tsubst, but deals with expressions. This function just replaces
14714 template parms; to finish processing the resultant expression, use
14715 tsubst_copy_and_build or tsubst_expr. */
14717 static tree
14719 {
14721 tree r;
14729 {
14734 {
14735 /* We get here for a use of 'this' in an NSDMI. */
14739 /* This can happen for a parameter name used later in a function
14740 declaration (such as in a late-specified return type). Just
14741 make a dummy decl, since it's only used for its type. */
14744 /* Give it the template pattern as its context; its true context
14745 hasn't been instantiated yet and this is good enough for
14746 mangling. */
14748 }
14757 {
14758 tree enum_type;
14759 tree v;
14763 /* There is no need to substitute into namespace-scope
14764 enumerators. */
14767 /* If ARGS is NULL, then T is known to be non-dependent. */
14771 /* Unfortunately, we cannot just call lookup_name here.
14772 Consider:
14774 template <int I> int f() {
14775 enum E { a = I };
14776 struct S { void g() { E e = a; } };
14777 };
14779 When we instantiate f<7>::S::g(), say, lookup_name is not
14780 clever enough to find f<7>::a. */
14781 enum_type
14791 /* We didn't find the name. That should never happen; if
14792 name-lookup found it during preliminary parsing, we
14793 should find it again here during instantiation. */
14795 }
14800 {
14801 tree ctx;
14806 {
14809 {
14813 }
14815 }
14816 }
14826 {
14829 {
14830 /* First try name lookup to find the instantiation. */
14833 {
14834 /* Make sure that the one we found is the one we want. */
14838 }
14842 else
14843 {
14844 /* This can happen for a variable used in a
14845 late-specified return type of a local lambda, or for a
14846 local static or constant. Building a new VAR_DECL
14847 should be OK in all those cases. */
14850 /* Avoid infinite recursion (79640). */
14853 {
14854 /* We can't call cp_finish_decl, so handle the
14855 initializer by hand. */
14870 }
14877 }
14878 /* Remember this for subsequent uses. */
14881 }
14884 }
14885 else
14895 /* An OVERLOAD will always be a non-dependent overload set; an
14896 overload set from function scope will just be represented with an
14897 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14899 /* We must have marked any lookups as persistent. */
14915 {
14916 /* Template template argument like the following example need
14917 special treatment:
14919 template <template <class> class TT> struct C {};
14920 template <class T> struct D {
14921 template <class U> struct E {};
14922 C<E> c; // #1
14923 };
14924 D<int> d; // #2
14926 We are processing the template argument `E' in #1 for
14927 the template instantiation #2. Originally, `E' is a
14928 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14929 have to substitute this with one having context `D<int>'. */
14933 {
14934 /* When rewriting a constructor into a deduction guide, a
14935 non-dependent name can become dependent, so memtmpl<args>
14936 becomes context::template memtmpl<args>. */
14940 }
14942 }
14943 else
14944 /* Ordinary template template argument. */
14949 {
14950 /* Handle location wrappers by substituting the wrapped node
14951 first, *then* reusing the resulting type. Doing the type
14952 first ensures that we handle template parameters and
14953 parameter pack expansions. */
14957 }
14967 {
14971 }
14976 {
14985 /* We only want to compute the number of arguments. */
14988 else
14995 {
14997 /* Set TREE_USED for the benefit of -Wunused. */
15001 }
15009 {
15014 else
15020 else
15023 }
15024 else
15026 }
15028 {
15036 }
15037 /* Fall through */
15053 {
15057 }
15060 {
15061 tree object;
15062 tree name;
15067 {
15071 }
15074 {
15084 }
15089 in_decl);
15090 else
15093 }
15131 {
15135 }
15138 {
15143 }
15146 {
15150 }
15153 {
15161 }
15167 {
15174 }
15177 {
15184 }
15187 {
15194 }
15197 {
15198 /* Substituted template arguments */
15207 }
15210 {
15230 }
15255 /* Fall through. */
15258 {
15261 }
15262 else
15266 /* This is handled by tsubst_copy_and_build. */
15270 {
15274 }
15277 /* We shouldn't have built any of these during initial template
15278 generation. Instead, they should be built during instantiation
15279 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15283 {
15293 }
15311 {
15312 /* Instantiate any typedefs in the type. */
15317 }
15320 /* These can sometimes show up in a partial instantiation, but never
15321 involve template parms. */
15337 /* ??? There's no point in copying it for now, but maybe some
15338 day it will contain more information, such as a pointer back
15339 to the containing function, inlined copy or so. */
15343 /* We shouldn't get here, but keep going if !flag_checking. */
15347 }
15348 }
15350 /* Helper function for tsubst_omp_clauses, used for instantiation of
15351 OMP_CLAUSE_DECL of clauses. */
15353 static tree
15355 tree in_decl)
15356 {
15360 /* Handle an OpenMP array section represented as a TREE_LIST (or
15361 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15362 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15363 TREE_LIST. We can handle it exactly the same as an array section
15364 (purpose, value, and a chain), even though the nomenclature
15365 (low_bound, length, etc) is different. */
15367 {
15368 tree low_bound
15374 in_decl);
15383 }
15386 /* Undo convert_from_reference tsubst_expr could have called. */
15392 }
15394 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15396 static tree
15399 {
15404 {
15410 {
15413 {
15419 }
15420 /* FALLTHRU */
15435 in_decl);
15467 {
15470 {
15477 }
15478 else
15480 }
15483 in_decl);
15489 in_decl);
15497 in_decl);
15499 {
15502 }
15507 else
15510 in_decl,
15534 }
15537 {
15547 /* tsubst_expr on SCOPE_REF results in returning
15548 finish_non_static_data_member result. Undo that here. */
15552 {
15557 {
15561 CASE_CONVERT:
15570 /* FALLTHRU */
15574 }
15575 }
15581 {
15584 {
15587 }
15588 }
15592 }
15593 }
15597 {
15602 {
15605 }
15606 }
15608 }
15610 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15612 static tree
15614 tree in_decl)
15615 {
15616 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15636 {
15639 else
15640 {
15644 }
15645 }
15650 #undef RECUR
15651 }
15653 /* Used to temporarily communicate the list of #pragma omp parallel
15654 clauses to #pragma omp for instantiation if they are combined
15655 together. */
15659 /* Substitute one OMP_FOR iterator. */
15661 static void
15666 {
15667 #define RECUR(NODE) \
15668 tsubst_expr ((NODE), args, complain, in_decl, \
15669 integral_constant_expression_p)
15676 {
15679 }
15685 {
15686 /* We need to jump through some hoops to handle declarations in the
15687 init-statement, since we might need to handle auto deduction,
15688 but we need to keep control of initialization. */
15692 }
15693 else
15694 {
15696 {
15699 {
15703 {
15707 CASE_CONVERT:
15715 {
15718 }
15719 /* FALLTHRU */
15723 }
15724 }
15725 }
15726 else
15728 }
15739 {
15741 {
15742 /* Declare the variable, but don't let that initialize it. */
15747 }
15752 {
15757 }
15758 else
15765 }
15768 {
15769 /* Declare and initialize the variable. */
15772 }
15774 {
15778 {
15780 {
15786 {
15789 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15794 }
15797 {
15799 decl);
15801 }
15804 {
15806 decl);
15808 }
15809 else
15811 }
15814 }
15816 {
15821 {
15824 }
15825 }
15826 }
15829 {
15833 }
15834 else
15838 {
15849 {
15857 }
15858 else
15864 {
15870 }
15874 {
15882 }
15883 else
15889 }
15895 #undef RECUR
15896 }
15898 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15899 of OMP_TARGET's body. */
15901 static tree
15903 {
15906 {
15915 }
15917 }
15919 /* Helper function for tsubst_expr. For decomposition declaration
15920 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15921 also the corresponding decls representing the identifiers
15922 of the decomposition declaration. Return DECL if successful
15923 or error_mark_node otherwise, set *FIRST to the first decl
15924 in the list chained through DECL_CHAIN and *CNT to the number
15925 of such decls. */
15927 static tree
15931 {
15936 decl2
15941 {
15943 {
15946 }
15963 {
15966 }
15967 else
15969 }
15972 }
15974 /* Like tsubst_copy for expressions, etc. but also does semantic
15975 processing. */
15977 tree
15980 {
15981 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15982 #define RECUR(NODE) \
15983 tsubst_expr ((NODE), args, complain, in_decl, \
15984 integral_constant_expression_p)
15987 tree r;
15988 location_t loc;
16000 {
16002 {
16003 tree_stmt_iterator i;
16007 }
16022 else
16032 {
16034 tree init;
16040 {
16050 else
16052 }
16055 {
16056 /* We're in tsubst_lambda_expr, we've already inserted a new
16057 capture proxy, so look it up and register it. */
16058 tree inst;
16060 {
16061 inst = (retrieve_local_specialization
16064 }
16065 else
16066 {
16070 }
16073 }
16076 /* Don't copy the old closure; we'll create a new one in
16077 tsubst_lambda_expr. */
16079 else
16080 {
16084 {
16085 /* By marking the declaration as instantiated, we avoid
16086 trying to instantiate it. Since instantiate_decl can't
16087 handle local variables, and since we've already done
16088 all that needs to be done, that's the right thing to
16089 do. */
16094 /* Anonymous aggregates are a special case. */
16097 {
16100 {
16104 }
16106 }
16112 {
16117 }
16118 else
16119 {
16124 {
16125 /* For __PRETTY_FUNCTION__ we have to adjust the
16126 initializer. */
16130 }
16131 else
16135 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
16140 {
16142 tree first;
16143 tree ndecl
16151 }
16152 else
16154 }
16155 }
16156 }
16159 }
16169 {
16173 }
16178 {
16179 /* Construct another range_for, if this is not a final
16180 substitution (for inside inside a generic lambda of a
16181 template). Otherwise convert to a regular for. */
16183 stmt = (processing_template_decl
16199 {
16203 }
16204 else
16205 {
16211 }
16217 }
16224 {
16228 }
16234 {
16238 }
16251 else
16252 {
16259 }
16265 {
16274 }
16282 else
16290 else
16311 {
16318 }
16322 {
16324 tree label;
16331 }
16337 /* Computed goto's must be tsubst'd into. On the other hand,
16338 non-computed gotos must not be; the identifier in question
16339 will have no binding. */
16341 else
16347 {
16363 }
16368 {
16373 }
16374 else
16375 {
16380 else
16387 else
16393 else
16395 }
16399 {
16403 {
16405 /* Prevent instantiate_decl from trying to instantiate
16406 this variable. We've already done all that needs to be
16407 done. */
16410 }
16415 }
16421 {
16422 /* Local classes are not independent templates; they are
16423 instantiated along with their containing function. And this
16424 way we don't have to deal with pushing out of one local class
16425 to instantiate a member of another local class. */
16426 /* Closures are handled by the LAMBDA_EXPR. */
16436 }
16440 {
16441 tree condition;
16444 condition =
16446 args,
16455 }
16461 in_decl);
16496 {
16509 in_decl);
16511 {
16518 }
16530 integral_constant_expression_p);
16541 else
16542 {
16550 }
16554 }
16559 /* FALLTHRU */
16566 in_decl);
16583 in_decl);
16594 {
16597 {
16598 /* For combined target teams, ensure the num_teams and
16599 thread_limit clause expressions are evaluated on the host,
16600 before entering the target construct. */
16601 tree c;
16607 {
16616 OMP_CLAUSE_FIRSTPRIVATE);
16620 }
16621 }
16622 }
16682 {
16687 {
16690 }
16696 }
16697 else
16698 {
16705 {
16708 }
16711 {
16716 {
16719 }
16725 }
16726 else
16727 {
16731 }
16734 }
16738 {
16744 {
16748 {
16753 }
16757 }
16758 else
16759 {
16764 }
16765 }
16769 {
16773 }
16786 /* If the first operand was a statement, we're done with it. */
16790 complain));
16804 integral_constant_expression_p));
16805 }
16808 out:
16811 #undef RECUR
16812 #undef RETURN
16813 }
16815 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16816 function. For description of the body see comment above
16817 cp_parser_omp_declare_reduction_exprs. */
16819 static void
16821 {
16827 tree_stmt_iterator tsi;
16838 {
16857 }
16859 {
16879 }
16880 }
16882 /* T is a postfix-expression that is not being used in a function
16883 call. Return the substituted version of T. */
16885 static tree
16887 tsubst_flags_t complain,
16888 tree in_decl)
16889 {
16893 else
16899 }
16901 /* T is a LAMBDA_EXPR. Generate a new LAMBDA_EXPR for the current
16902 instantiation context. Instantiating a pack expansion containing a lambda
16903 might result in multiple lambdas all based on the same lambda in the
16904 template. */
16906 tree
16908 {
16922 else
16930 {
16942 else
16947 {
16956 }
16957 else
16958 {
16964 }
16965 }
16969 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
16987 else
16988 {
16989 /* Fix the type of 'this'. */
16995 {
16999 }
17000 else
17001 {
17005 }
17007 /* Let finish_function set this. */
17028 /* The capture list was built up in reverse order; fix that now. */
17035 }
17042 }
17044 /* Like tsubst but deals with expressions and performs semantic
17045 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
17047 tree
17049 tree args,
17050 tsubst_flags_t complain,
17051 tree in_decl,
17054 {
17055 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
17056 #define RECUR(NODE) \
17057 tsubst_copy_and_build (NODE, args, complain, in_decl, \
17059 integral_constant_expression_p)
17062 location_t loc;
17071 /* N3276 decltype magic only applies to calls at the top level or on the
17072 right side of a comma. */
17077 {
17080 /* Fall through. */
17082 {
17083 tree decl;
17084 cp_id_kind idk;
17089 {
17092 }
17094 /* Look up the name. */
17097 /* By convention, expressions use ERROR_MARK_NODE to indicate
17098 failure, not NULL_TREE. */
17104 integral_constant_expression_p,
17112 input_location);
17116 {
17120 }
17122 }
17125 {
17126 tree object;
17136 {
17141 }
17147 {
17150 }
17151 else
17158 else
17160 }
17163 {
17167 {
17168 /* A type conversion to reference type will be enclosed in
17169 such an indirect ref, but the substitution of the cast
17170 will have also added such an indirect ref. */
17172 }
17173 else
17181 }
17184 {
17188 }
17191 {
17195 {
17200 }
17202 /* We'll pass this to convert_nontype_argument again, we don't need
17203 to actually perform any conversion here. */
17209 flags));
17210 }
17213 {
17217 }
17224 {
17225 tree type;
17231 {
17236 }
17243 {
17261 }
17264 }
17298 else
17300 in_decl);
17335 {
17342 tree r = build_x_binary_op
17344 op0,
17346 ? ERROR_MARK
17348 op1,
17350 ? ERROR_MARK
17358 }
17361 {
17365 }
17381 /* Fall through */
17384 {
17385 tree r;
17391 {
17392 /* When there are no ARGS, we are trying to evaluate a
17393 non-dependent expression from the parser. Trying to do
17394 the substitutions may not work. */
17397 }
17398 else
17399 {
17404 else
17407 /*integral_constant_expression_p=*/
17411 }
17415 else
17419 {
17421 {
17423 {
17427 }
17428 else
17432 }
17434 }
17436 }
17439 {
17449 }
17465 {
17469 tree r = build_x_modify_expr
17472 /* TREE_NO_WARNING must be set if either the expression was
17473 parenthesized or it uses an operator such as >>= rather
17474 than plain assignment. In the former case, it was already
17475 set and must be copied. In the latter case,
17476 build_x_modify_expr sets it and it must not be reset
17477 here. */
17482 }
17487 /* Remember that there was a reference to this entity. */
17494 {
17499 tree ret;
17503 else
17504 {
17508 }
17510 /* If there was an initializer in the original tree, but it
17511 instantiated to an empty list, then we should pass a
17512 non-NULL empty vector to tell build_new that it was an
17513 empty initializer() rather than no initializer. This can
17514 only happen when the initializer is a pack expansion whose
17515 parameter packs are of length zero. */
17518 else
17519 {
17523 else
17524 {
17527 }
17528 }
17534 complain);
17542 }
17545 {
17551 complain));
17552 }
17555 {
17559 integral_constant_expression_p);
17561 op0,
17564 }
17567 {
17568 tree function;
17573 tree ret;
17576 /* Internal function with no arguments. */
17580 /* When we parsed the expression, we determined whether or
17581 not Koenig lookup should be performed. */
17584 {
17587 }
17589 {
17594 }
17596 {
17597 /* Do nothing; calling tsubst_copy_and_build on an identifier
17598 would incorrectly perform unqualified lookup again.
17600 Note that we can also have an IDENTIFIER_NODE if the earlier
17601 unqualified lookup found a member function; in that case
17602 koenig_p will be false and we do want to do the lookup
17603 again to find the instantiated member function.
17605 FIXME but doing that causes c++/15272, so we need to stop
17606 using IDENTIFIER_NODE in that situation. */
17608 }
17609 else
17610 {
17612 {
17618 }
17619 else
17624 /* Avoid error about taking the address of a constructor. */
17628 in_decl,
17630 integral_constant_expression_p);
17634 }
17639 {
17644 else
17645 {
17646 /* Expand the pack expansion and push each entry onto
17647 CALL_ARGS. */
17650 {
17655 {
17660 }
17661 }
17662 else
17663 {
17664 /* A partial substitution. Add one entry. */
17666 }
17667 }
17668 }
17670 /* We do not perform argument-dependent lookup if normal
17671 lookup finds a non-function, in accordance with the
17672 expected resolution of DR 218. */
17675 /* If lookup found a member function, the Koenig lookup is
17676 not appropriate, even if an unqualified-name was used
17677 to denote the function. */
17680 /* Only do this when substitution turns a dependent call
17681 into a non-dependent call. */
17689 {
17691 {
17692 /* For backwards compatibility and good diagnostics, try
17693 the unqualified lookup again if we aren't in SFINAE
17694 context. */
17695 tree unq = (tsubst_copy_and_build
17697 integral_constant_expression_p));
17699 {
17702 }
17705 {
17706 /* In a lambda fn, we have to be careful to not
17707 introduce new this captures. Legacy code can't
17708 be using lambdas anyway, so it's ok to be
17709 stricter. */
17714 "and no declarations were found by "
17715 "argument-dependent lookup at the point "
17722 else
17726 {
17737 {
17739 input_location);
17741 "declarations in dependent base %qT are "
17747 else
17751 }
17752 else
17754 "%qD declared here, later in the "
17757 {
17760 }
17761 }
17764 }
17765 }
17767 {
17772 }
17773 }
17775 /* Remember that there was a reference to this entity. */
17779 {
17782 }
17784 /* Put back tf_decltype for the actual call. */
17789 {
17793 {
17795 "wrong number of arguments to "
17798 }
17799 else
17801 input_location),
17806 /* Unsupported internal function with arguments. */
17808 }
17811 complain);
17813 {
17828 complain);
17829 else
17830 ret = (build_new_method_call
17835 complain));
17836 }
17837 else
17840 koenig_p,
17841 complain);
17846 {
17852 {
17858 {
17861 else
17863 /* The thunk location is not interesting. */
17865 }
17866 }
17867 }
17870 }
17873 {
17879 {
17881 {
17886 }
17887 else
17888 {
17893 }
17895 }
17896 else
17897 {
17900 }
17905 }
17908 {
17913 input_location));
17914 }
17917 {
17925 {
17926 /* We have pack expansions, so expand those and
17927 create a new list out of it. */
17930 tree chain;
17933 /* Expand the argument expressions. */
17941 /* Build the rest of the list. */
17946 /* Determine the number of arguments. */
17948 {
17951 }
17954 else
17955 {
17956 /* Since we only performed a partial substitution into
17957 the argument pack, we only RETURN (a single list
17958 node. */
17965 }
17967 /* Convert the argument vectors into a TREE_LIST */
17970 {
17971 /* Grab the Ith values. */
17972 i--;
17975 value
17979 /* Build the list (backwards). */
17981 }
17984 }
18000 }
18003 {
18004 tree object;
18005 tree object_type;
18006 tree member;
18007 tree r;
18011 /* Remember that there was a reference to this entity. */
18022 else
18028 {
18033 }
18037 {
18039 {
18044 {
18047 }
18049 {
18054 }
18055 }
18056 }
18059 {
18060 /* Lookup the template functions now that we know what the
18061 scope is. */
18069 {
18072 args);
18073 member = (adjust_result_of_qualified_name_lookup
18075 object_type));
18076 }
18077 else
18078 {
18080 input_location);
18082 }
18083 }
18087 {
18089 {
18093 else
18096 }
18098 }
18102 complain);
18106 }
18113 {
18121 tree r;
18126 /* We do not want to process the index of aggregate
18127 initializers as they are identifier nodes which will be
18128 looked up by digest_init. */
18134 {
18136 /* An identifier index is looked up in the type
18137 being initialized, not the current scope. */
18142 {
18143 /* Substitute into the pack expansion. */
18145 in_decl);
18149 ;
18151 /* Just move the argument into place. */
18153 else
18154 {
18155 /* Update the length of the final CONSTRUCTOR
18156 arguments vector, and note that we will need to
18157 copy.*/
18160 }
18161 }
18162 else
18164 }
18167 {
18172 {
18174 {
18179 }
18180 else
18182 }
18183 }
18189 {
18194 }
18198 }
18201 {
18204 {
18207 }
18208 else
18209 {
18212 }
18213 }
18218 /* Fall through */
18221 {
18223 /* ??? We're doing a subset of finish_id_expression here. */
18225 && !processing_template_decl
18226 && !cp_unevaluated_operand
18229 {
18231 /* Replace an evaluated use of the thread_local variable with
18232 a call to its wrapper. */
18234 }
18239 /* If the original type was a reference, we'll be wrapped in
18240 the appropriate INDIRECT_REF. */
18243 }
18246 {
18250 }
18253 {
18254 tree object_ptr
18261 }
18268 {
18279 }
18282 {
18288 integral_constant_expression_p);
18292 /* If the resulting list of expression statement is empty,
18293 fold it further into void_node. */
18298 }
18301 {
18305 }
18308 /* We can get here for a constant initializer of non-dependent type.
18309 FIXME stop folding in cp_parser_initializer_clause. */
18310 {
18312 complain);
18314 }
18318 integral_constant_expression_p));
18324 {
18329 complain));
18330 }
18337 /* We should only see these for location wrapper nodes, or within
18338 instantiate_non_dependent_expr (when args is NULL_TREE). */
18343 /* fallthrough. */
18346 /* Handle Objective-C++ constructs, if appropriate. */
18347 {
18348 tree subst
18353 }
18355 }
18357 #undef RECUR
18358 #undef RETURN
18359 out:
18362 }
18364 /* Verify that the instantiated ARGS are valid. For type arguments,
18365 make sure that the type's linkage is ok. For non-type arguments,
18366 make sure they are constants if they are integral or enumerations.
18367 Emit an error under control of COMPLAIN, and return TRUE on error. */
18369 static bool
18371 {
18375 {
18385 }
18387 {
18388 /* [basic.link]: A name with no linkage (notably, the name
18389 of a class or enumeration declared in a local scope)
18390 shall not be used to declare an entity with linkage.
18391 This implies that names with no linkage cannot be used as
18392 template arguments
18394 DR 757 relaxes this restriction for C++0x. */
18399 {
18400 /* DR 488 makes use of a type with no linkage cause
18401 type deduction to fail. */
18403 {
18406 else
18409 }
18411 }
18412 /* In order to avoid all sorts of complications, we do not
18413 allow variably-modified types as template arguments. */
18415 {
18419 }
18420 }
18421 /* Class template and alias template arguments should be OK. */
18423 ;
18424 /* A non-type argument of integral or enumerated type must be a
18425 constant. */
18430 {
18434 }
18436 }
18438 static bool
18440 {
18445 {
18448 }
18452 }
18454 /* We're out of SFINAE context now, so generate diagnostics for the access
18455 errors we saw earlier when instantiating D from TMPL and ARGS. */
18457 static void
18459 {
18471 }
18473 /* Instantiate the indicated variable, function, or alias template TMPL with
18474 the template arguments in TARG_PTR. */
18476 static tree
18478 {
18480 tree fndecl;
18481 tree gen_tmpl;
18482 tree spec;
18490 /* If this function is a clone, handle it specially. */
18492 {
18493 tree spec;
18494 tree clone;
18496 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18497 DECL_CLONED_FUNCTION. */
18503 /* Look for the clone. */
18507 /* We should always have found the clone by now. */
18510 }
18515 /* Check to see if we already have this specialization. */
18519 /* targ_ptr only has the innermost template args, so add the outer ones
18520 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18521 the case of a non-dependent call within a template definition). */
18522 targ_ptr = (add_outermost_template_args
18524 targ_ptr));
18526 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18527 but it doesn't seem to be on the hot path. */
18536 {
18538 {
18542 }
18544 }
18547 complain))
18550 /* We are building a FUNCTION_DECL, during which the access of its
18551 parameters and return types have to be checked. However this
18552 FUNCTION_DECL which is the desired context for access checking
18553 is not built yet. We solve this chicken-and-egg problem by
18554 deferring all checks until we have the FUNCTION_DECL. */
18557 /* Instantiation of the function happens in the context of the function
18558 template, not the context of the overload resolution we're doing. */
18560 /* If there are dependent arguments, e.g. because we're doing partial
18561 ordering, make sure processing_template_decl stays set. */
18565 {
18569 }
18575 {
18576 /* We need to determine if we're using a partial or explicit
18577 specialization now, because the type of the variable could be
18578 different. */
18584 {
18589 }
18590 }
18592 /* Substitute template parameters to obtain the specialization. */
18600 {
18603 }
18605 /* The DECL_TI_TEMPLATE should always be the immediate parent
18606 template, not the most general template. */
18610 /* Now we know the specialization, compute access previously
18611 deferred. Do no access control for inheriting constructors,
18612 as we already checked access for the inherited constructor. */
18615 {
18620 }
18623 /* If we've just instantiated the main entry point for a function,
18624 instantiate all the alternate entry points as well. We do this
18625 by cloning the instantiation of the main entry point, not by
18626 instantiating the template clones. */
18631 {
18633 {
18634 /* Remember to reinstantiate when we're out of SFINAE so the user
18635 can see the errors. */
18637 }
18639 }
18641 }
18643 /* Wrapper for instantiate_template_1. */
18645 tree
18647 {
18648 tree ret;
18653 }
18655 /* Instantiate the alias template TMPL with ARGS. Also push a template
18656 instantiation level, which instantiate_template doesn't do because
18657 functions and variables have sufficient context established by the
18658 callers. */
18660 static tree
18662 {
18669 {
18672 }
18674 args =
18682 /* We can't free this if a pending_template entry or last_error_tinst_level
18683 is pointing at it. */
18689 }
18691 /* PARM is a template parameter pack for FN. Returns true iff
18692 PARM is used in a deducible way in the argument list of FN. */
18694 static bool
18696 {
18699 {
18701 tree packs;
18707 {
18708 /* The template parameter pack is used in a function parameter
18709 pack. If this is the end of the parameter list, the
18710 template parameter pack is deducible. */
18713 else
18714 /* Otherwise, not. Well, it could be deduced from
18715 a non-pack parameter, but doing so would end up with
18716 a deduction mismatch, so don't bother. */
18718 }
18719 }
18720 /* The template parameter pack isn't used in any function parameter
18721 packs, but it might be used deeper, e.g. tuple<Args...>. */
18723 }
18725 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18726 NARGS elements of the arguments that are being used when calling
18727 it. TARGS is a vector into which the deduced template arguments
18728 are placed.
18730 Returns either a FUNCTION_DECL for the matching specialization of FN or
18731 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18732 true, diagnostics will be printed to explain why it failed.
18734 If FN is a conversion operator, or we are trying to produce a specific
18735 specialization, RETURN_TYPE is the return type desired.
18737 The EXPLICIT_TARGS are explicit template arguments provided via a
18738 template-id.
18740 The parameter STRICT is one of:
18742 DEDUCE_CALL:
18743 We are deducing arguments for a function call, as in
18744 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18745 deducing arguments for a call to the result of a conversion
18746 function template, as in [over.call.object].
18748 DEDUCE_CONV:
18749 We are deducing arguments for a conversion function, as in
18750 [temp.deduct.conv].
18752 DEDUCE_EXACT:
18753 We are deducing arguments when doing an explicit instantiation
18754 as in [temp.explicit], when determining an explicit specialization
18755 as in [temp.expl.spec], or when taking the address of a function
18756 template, as in [temp.deduct.funcaddr]. */
18758 tree
18760 tree explicit_targs,
18761 tree targs,
18764 tree return_type,
18765 unification_kind_t strict,
18769 {
18770 tree parms;
18771 tree fntype;
18784 tree tinst;
18790 full_targs = (add_outermost_template_args
18792 targs));
18797 /* In C++0x, it's possible to have a function template whose type depends
18798 on itself recursively. This is most obvious with decltype, but can also
18799 occur with enumeration scope (c++/48969). So we need to catch infinite
18800 recursion and reject the substitution at deduction time; this function
18801 will return error_mark_node for any repeated substitution.
18803 This also catches excessive recursion such as when f<N> depends on
18804 f<N-1> across all integers, and returns error_mark_node for all the
18805 substitutions back up to the initial one.
18807 This is, of course, not reentrant. */
18817 {
18818 /* [temp.deduct]
18820 The specified template arguments must match the template
18821 parameters in kind (i.e., type, nontype, template), and there
18822 must not be more arguments than there are parameters;
18823 otherwise type deduction fails.
18825 Nontype arguments must match the types of the corresponding
18826 nontype template parameters, or must be convertible to the
18827 types of the corresponding nontype parameters as specified in
18828 _temp.arg.nontype_, otherwise type deduction fails.
18830 All references in the function type of the function template
18831 to the corresponding template parameters are replaced by the
18832 specified template argument values. If a substitution in a
18833 template parameter or in the function type of the function
18834 template results in an invalid type, type deduction fails. */
18845 explicit_targs);
18847 /* Adjust any explicit template arguments before entering the
18848 substitution context. */
18849 explicit_targs
18851 complain,
18857 /* Substitute the explicit args into the function type. This is
18858 necessary so that, for instance, explicitly declared function
18859 arguments can match null pointed constants. If we were given
18860 an incomplete set of explicit args, we must not do semantic
18861 processing during substitution as we could create partial
18862 instantiations. */
18864 {
18869 /* Dig out the actual parm. */
18872 {
18875 }
18877 {
18880 }
18883 /* No explicit argument for this template parameter. */
18887 {
18888 /* Mark the argument pack as "incomplete". We could
18889 still deduce more arguments during unification.
18890 We remove this mark in type_unification_real. */
18892 {
18896 }
18898 /* We have some incomplete argument packs. */
18900 }
18901 }
18905 {
18908 }
18911 /* Ignore any access checks; we'll see them again in
18912 instantiate_template and they might have the wrong
18913 access path at this point. */
18925 /* Place the explicitly specified arguments in TARGS. */
18929 }
18931 /* Never do unification on the 'this' parameter. */
18935 {
18936 /* We're deducing for a call to the result of a template conversion
18937 function. The parms we really want are in return_type. */
18941 }
18943 {
18952 }
18954 /* We allow incomplete unification without an error message here
18955 because the standard doesn't seem to explicitly prohibit it. Our
18956 callers must be ready to deal with unification failures in any
18957 event. */
18960 /* If we aren't explaining yet, push tinst context so we can see where
18961 any errors (e.g. from class instantiations triggered by instantiation
18962 of default template arguments) come from. If we are explaining, this
18963 context is redundant. */
18965 {
18968 }
18970 /* type_unification_real will pass back any access checks from default
18971 template argument substitution. */
18983 /* Now that we have bindings for all of the template arguments,
18984 ensure that the arguments deduced for the template template
18985 parameters have compatible template parameter lists. We cannot
18986 check this property before we have deduced all template
18987 arguments, because the template parameter types of a template
18988 template parameter might depend on prior template parameters
18989 deduced after the template template parameter. The following
18990 ill-formed example illustrates this issue:
18992 template<typename T, template<T> class C> void f(C<5>, T);
18994 template<int N> struct X {};
18996 void g() {
18997 f(X<5>(), 5l); // error: template argument deduction fails
18998 }
19000 The template parameter list of 'C' depends on the template type
19001 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
19002 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
19003 time that we deduce 'C'. */
19006 {
19009 }
19011 /* All is well so far. Now, check:
19013 [temp.deduct]
19015 When all template arguments have been deduced, all uses of
19016 template parameters in nondeduced contexts are replaced with
19017 the corresponding deduced argument values. If the
19018 substitution results in an invalid type, as described above,
19019 type deduction fails. */
19022 {
19025 }
19027 /* Also collect access checks from the instantiation. */
19040 /* Now perform any access checks encountered during substitution. */
19047 /* If we're looking for an exact match, check that what we got
19048 is indeed an exact match. It might not be if some template
19049 parameters are used in non-deduced contexts. But don't check
19050 for an exact match if we have dependent template arguments;
19051 in that case we're doing partial ordering, and we already know
19052 that we have two candidates that will provide the actual type. */
19054 {
19058 tree sarg
19064 {
19068 }
19069 }
19071 /* After doing deduction with the inherited constructor, actually return an
19072 instantiation of the inheriting constructor. */
19078 fail:
19081 {
19083 /* Reset once we're all the way out. */
19085 }
19087 /* We can't free this if a pending_template entry or last_error_tinst_level
19088 is pointing at it. */
19094 }
19096 /* Adjust types before performing type deduction, as described in
19097 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
19098 sections are symmetric. PARM is the type of a function parameter
19099 or the return type of the conversion function. ARG is the type of
19100 the argument passed to the call, or the type of the value
19101 initialized with the result of the conversion function.
19102 ARG_EXPR is the original argument expression, which may be null. */
19104 static int
19108 tree arg_expr)
19109 {
19113 {
19118 /* Swap PARM and ARG throughout the remainder of this
19119 function; the handling is precisely symmetric since PARM
19120 will initialize ARG rather than vice versa. */
19125 /* Core issue #873: Do the DR606 thing (see below) for these cases,
19126 too, but here handle it by stripping the reference from PARM
19127 rather than by adding it to ARG. */
19135 /* Nothing else to do in this case. */
19140 }
19143 {
19144 /* [temp.deduct.call]
19146 If P is not a reference type:
19148 --If A is an array type, the pointer type produced by the
19149 array-to-pointer standard conversion (_conv.array_) is
19150 used in place of A for type deduction; otherwise,
19152 --If A is a function type, the pointer type produced by
19153 the function-to-pointer standard conversion
19154 (_conv.func_) is used in place of A for type deduction;
19155 otherwise,
19157 --If A is a cv-qualified type, the top level
19158 cv-qualifiers of A's type are ignored for type
19159 deduction. */
19164 else
19166 }
19168 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
19169 reference to a cv-unqualified template parameter that does not represent a
19170 template parameter of a class template (during class template argument
19171 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
19172 an lvalue, the type "lvalue reference to A" is used in place of A for type
19173 deduction. */
19180 /* try_one_overload doesn't provide an arg_expr, but
19181 functions are always lvalues. */
19185 /* [temp.deduct.call]
19187 If P is a cv-qualified type, the top level cv-qualifiers
19188 of P's type are ignored for type deduction. If P is a
19189 reference type, the type referred to by P is used for
19190 type deduction. */
19193 {
19196 }
19198 /* DR 322. For conversion deduction, remove a reference type on parm
19199 too (which has been swapped into ARG). */
19204 }
19206 /* Subroutine of unify_one_argument. PARM is a function parameter of a
19207 template which does contain any deducible template parameters; check if
19208 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
19209 unify_one_argument. */
19211 static int
19214 {
19215 tree type;
19219 else
19226 {
19230 }
19232 {
19237 }
19241 else
19243 }
19247 /* Returns true iff the expression EXPR is one from which a template
19248 argument can be deduced. In other words, if it's an undecorated
19249 use of a template non-type parameter. */
19251 static bool
19253 {
19254 /* Strip implicit conversions. */
19258 }
19260 /* Returns true iff the array domain DOMAIN uses a template parameter in a
19261 deducible way; that is, if it has a max value of <PARM> - 1. */
19263 static bool
19265 {
19274 }
19276 /* Returns true iff the template arguments ARGS use a template parameter
19277 in a deducible way. */
19279 static bool
19281 {
19283 {
19288 else
19289 {
19296 else
19298 }
19301 }
19303 }
19305 /* Returns true iff TYPE contains any deducible references to template
19306 parameters, as per 14.8.2.5. */
19308 static bool
19310 {
19314 /* T
19315 cv-list T
19316 TT<T>
19317 TT<i>
19318 TT<> */
19323 /* T*
19324 T&
19325 T&& */
19329 /* T[integer-constant ]
19330 type [i] */
19335 /* T type ::*
19336 type T::*
19337 T T::*
19338 T (type ::*)()
19339 type (T::*)()
19340 type (type ::*)(T)
19341 type (T::*)(T)
19342 T (type ::*)(T)
19343 T (T::*)()
19344 T (T::*)(T) */
19347 || (uses_deducible_template_parms
19350 /* template-name <T> (where template-name refers to a class template)
19351 template-name <i> (where template-name refers to a class template) */
19358 /* type (T)
19359 T()
19360 T(T) */
19363 {
19372 }
19375 }
19377 /* Subroutine of type_unification_real and unify_pack_expansion to
19378 handle unification of a single P/A pair. Parameters are as
19379 for those functions. */
19381 static int
19385 {
19392 /* We can't deduce anything from this, but we might get all the
19393 template args from other function args. */
19396 /* Implicit conversions (Clause 4) will be performed on a function
19397 argument to convert it to the type of the corresponding function
19398 parameter if the parameter type contains no template-parameters that
19399 participate in template argument deduction. */
19402 /* For function parameters with no deducible template parameters,
19403 just return. We'll check non-dependent conversions later. */
19407 {
19409 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19410 | UNIFY_ALLOW_MORE_CV_QUAL
19424 }
19426 /* We only do these transformations if this is the top-level
19427 parameter_type_list in a call or declaration matching; in other
19428 situations (nested function declarators, template argument lists) we
19429 won't be comparing a type to an expression, and we don't do any type
19430 adjustments. */
19432 {
19434 {
19437 {
19438 /* [temp.deduct.type] A template-argument can be
19439 deduced from a pointer to function or pointer
19440 to member function argument if the set of
19441 overloaded functions does not contain function
19442 templates and at most one of a set of
19443 overloaded functions provides a unique
19444 match. */
19448 /* If a unique match was not found, this is a
19449 non-deduced context, so we still succeed. */
19451 }
19457 }
19459 arg_strict |=
19461 }
19462 else
19467 /* For deduction from an init-list we need the actual list. */
19471 }
19473 /* for_each_template_parm callback that always returns 0. */
19475 static int
19477 {
19479 }
19481 /* for_each_template_parm any_fn callback to handle deduction of a template
19482 type argument from the type of an array bound. */
19484 static int
19486 {
19494 {
19500 }
19502 /* Keep walking. */
19504 }
19506 /* Try to deduce any not-yet-deduced template type arguments from the type of
19507 an array bound. This is handled separately from unify because 14.8.2.5 says
19508 "The type of a type parameter is only deduced from an array bound if it is
19509 not otherwise deduced." */
19511 static void
19513 {
19518 }
19520 /* Most parms like fn_type_unification.
19522 If SUBR is 1, we're being called recursively (to unify the
19523 arguments of a function or method parameter of a function
19524 template).
19526 CHECKS is a pointer to a vector of access checks encountered while
19527 substituting default template arguments. */
19529 static int
19531 tree full_targs,
19532 tree xparms,
19536 unification_kind_t strict,
19540 {
19545 tree parms;
19556 /* Reset the number of non-defaulted template arguments contained
19557 in TARGS. */
19560 again:
19568 {
19573 /* For a function parameter pack that occurs at the end of the
19574 parameter-declaration-list, the type A of each remaining
19575 argument of the call is compared with the type P of the
19576 declarator-id of the function parameter pack. */
19582 /* For a function parameter pack that does not occur at the
19583 end of the parameter-declaration-list, the type of the
19584 parameter pack is a non-deduced context. */
19591 explain_p))
19593 }
19598 {
19599 /* Unify the remaining arguments with the pack expansion type. */
19600 tree argvec;
19603 /* Allocate a TREE_VEC and copy in all of the arguments */
19608 /* Copy the parameter into parmvec. */
19614 /* Advance to the end of the list of parameters. */
19616 }
19618 /* Fail if we've reached the end of the parm list, and more args
19619 are present, and the parm list isn't variadic. */
19622 /* Fail if parms are left and they don't have default values and
19623 they aren't all deduced as empty packs (c++/57397). This is
19624 consistent with sufficient_parms_p. */
19627 {
19631 do
19632 {
19635 count++;
19637 }
19641 type_pack_p);
19642 }
19645 {
19646 tsubst_flags_t complain = (explain_p
19647 ? tf_warning_or_error
19652 {
19656 /* Clear the "incomplete" flags on all argument packs now so that
19657 substituting them into later default arguments works. */
19659 {
19662 }
19670 {
19675 }
19677 /* If this is an undeduced nontype parameter that depends on
19678 a type parameter, try another pass; its type may have been
19679 deduced from a later argument than the one from which
19680 this parameter can be deduced. */
19684 {
19687 }
19689 /* Core issue #226 (C++0x) [temp.deduct]:
19691 If a template argument has not been deduced, its
19692 default template argument, if any, is used.
19694 When we are in C++98 mode, TREE_PURPOSE will either
19695 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19696 to explicitly check cxx_dialect here. */
19698 /* OK, there is a default argument. Wait until after the
19699 conversion check to do substitution. */
19702 /* If the type parameter is a parameter pack, then it will
19703 be deduced to an empty parameter pack. */
19705 {
19706 tree arg;
19709 {
19712 }
19713 else
19720 }
19723 }
19725 /* DR 1391: All parameters have args, now check non-dependent parms for
19726 convertibility. */
19730 {
19736 /* For a function parameter pack that occurs at the end of the
19737 parameter-declaration-list, the type A of each remaining
19738 argument of the call is compared with the type P of the
19739 declarator-id of the function parameter pack. */
19745 /* For a function parameter pack that does not occur at the
19746 end of the parameter-declaration-list, the type of the
19747 parameter pack is a non-deduced context. */
19756 explain_p))
19758 }
19760 /* Now substitute into the default template arguments. */
19762 {
19786 else
19794 {
19796 /* The position of the first default template argument,
19797 is also the number of non-defaulted arguments in TARGS.
19798 Record that. */
19801 }
19802 }
19806 }
19812 }
19814 /* Subroutine of type_unification_real. Args are like the variables
19815 at the call site. ARG is an overloaded function (or template-id);
19816 we try deducing template args from each of the overloads, and if
19817 only one succeeds, we go with that. Modifies TARGS and returns
19818 true on success. */
19820 static bool
19822 tree targs,
19823 tree parm,
19824 tree arg,
19825 unification_kind_t strict,
19828 {
19835 {
19838 }
19839 else
19843 /* Handle `&x' where `x' is some static or non-static member
19844 function name. */
19850 /* Strip baselink information. */
19855 {
19856 /* If we got some explicit template args, we need to plug them into
19857 the affected templates before we try to unify, in case the
19858 explicit args will completely resolve the templates in question. */
19865 {
19878 {
19883 {
19886 }
19887 }
19890 }
19891 /* If no templates (or more than one) are fully resolved by the
19892 explicit arguments, this template-id is a non-deduced context; it
19893 could still be OK if we deduce all template arguments for the
19894 enclosing call through other arguments. */
19897 }
19900 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19901 -- but the deduction does not succeed because the expression is
19902 not just the function on its own. */
19904 else
19906 {
19911 {
19914 }
19915 }
19917 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19918 to function or pointer to member function argument if the set of
19919 overloaded functions does not contain function templates and at most
19920 one of a set of overloaded functions provides a unique match.
19922 So if we found multiple possibilities, we return success but don't
19923 deduce anything. */
19926 {
19930 {
19935 /* Don't forget explicit template arguments in a pack. */
19939 }
19940 }
19945 }
19947 /* Core DR 115: In contexts where deduction is done and fails, or in
19948 contexts where deduction is not done, if a template argument list is
19949 specified and it, along with any default template arguments, identifies
19950 a single function template specialization, then the template-id is an
19951 lvalue for the function template specialization. */
19953 tree
19955 {
19968 {
19971 }
19973 {
19976 }
19978 {
19981 }
19984 {
19988 /* If we got some explicit template args, we need to plug them into
19989 the affected templates before we try to unify, in case the
19990 explicit args will completely resolve the templates in question. */
19998 {
20011 {
20014 {
20017 }
20019 {
20022 }
20023 }
20024 }
20026 {
20034 {
20035 tree base
20038 }
20042 }
20044 /* There were no good options and at least one bad one, so let the
20045 user know what the problem is. */
20047 }
20049 }
20051 /* Subroutine of resolve_overloaded_unification; does deduction for a single
20052 overload. Fills TARGS with any deduced arguments, or error_mark_node if
20053 different overloads deduce different arguments for a given parm.
20054 ADDR_P is true if the expression for which deduction is being
20055 performed was of the form "& fn" rather than simply "fn".
20057 Returns 1 on success. */
20059 static int
20061 tree orig_targs,
20062 tree targs,
20063 tree parm,
20064 tree arg,
20065 unification_kind_t strict,
20069 {
20071 tree tempargs;
20077 /* [temp.deduct.type] A template-argument can be deduced from a pointer
20078 to function or pointer to member function argument if the set of
20079 overloaded functions does not contain function templates and at most
20080 one of a set of overloaded functions provides a unique match.
20082 So if this is a template, just return success. */
20094 /* We don't copy orig_targs for this because if we have already deduced
20095 some template args from previous args, unify would complain when we
20096 try to deduce a template parameter for the same argument, even though
20097 there isn't really a conflict. */
20104 /* First make sure we didn't deduce anything that conflicts with
20105 explicitly specified args. */
20107 {
20114 /* Since we're unifying against ourselves, we will fill in
20115 template args used in the function parm list with our own
20116 template parms. Discard them. */
20119 {
20120 /* Check that the argument at each index of the deduced argument pack
20121 is equivalent to the corresponding explicitly specified argument.
20122 We may have deduced more arguments than were explicitly specified,
20123 and that's OK. */
20125 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
20126 that's wrong if we deduce the same argument pack from multiple
20127 function arguments: it's only incomplete the first time. */
20140 }
20143 }
20146 {
20151 }
20154 }
20156 /* PARM is a template class (perhaps with unbound template
20157 parameters). ARG is a fully instantiated type. If ARG can be
20158 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
20159 TARGS are as for unify. */
20161 static tree
20164 {
20165 tree copy_of_targs;
20175 /* We need to make a new template argument vector for the call to
20176 unify. If we used TARGS, we'd clutter it up with the result of
20177 the attempted unification, even if this class didn't work out.
20178 We also don't want to commit ourselves to all the unifications
20179 we've already done, since unification is supposed to be done on
20180 an argument-by-argument basis. In other words, consider the
20181 following pathological case:
20183 template <int I, int J, int K>
20184 struct S {};
20186 template <int I, int J>
20187 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
20189 template <int I, int J, int K>
20190 void f(S<I, J, K>, S<I, I, I>);
20192 void g() {
20193 S<0, 0, 0> s0;
20194 S<0, 1, 2> s2;
20196 f(s0, s2);
20197 }
20199 Now, by the time we consider the unification involving `s2', we
20200 already know that we must have `f<0, 0, 0>'. But, even though
20201 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
20202 because there are two ways to unify base classes of S<0, 1, 2>
20203 with S<I, I, I>. If we kept the already deduced knowledge, we
20204 would reject the possibility I=1. */
20208 {
20212 }
20214 /* If unification failed, we're done. */
20220 }
20222 /* Given a template type PARM and a class type ARG, find the unique
20223 base type in ARG that is an instance of PARM. We do not examine
20224 ARG itself; only its base-classes. If there is not exactly one
20225 appropriate base class, return NULL_TREE. PARM may be the type of
20226 a partial specialization, as well as a plain template type. Used
20227 by unify. */
20229 static enum template_base_result
20232 {
20234 tree binfo;
20240 {
20241 /* The type could not be completed. */
20244 }
20246 /* Walk in inheritance graph order. The search order is not
20247 important, and this avoids multiple walks of virtual bases. */
20249 {
20254 {
20255 /* If there is more than one satisfactory baseclass, then:
20257 [temp.deduct.call]
20259 If they yield more than one possible deduced A, the type
20260 deduction fails.
20262 applies. */
20264 {
20267 }
20270 }
20271 }
20275 }
20277 /* Returns the level of DECL, which declares a template parameter. */
20279 static int
20281 {
20283 {
20293 }
20295 }
20297 /* Decide whether ARG can be unified with PARM, considering only the
20298 cv-qualifiers of each type, given STRICT as documented for unify.
20299 Returns nonzero iff the unification is OK on that basis. */
20301 static int
20303 {
20309 {
20310 /* Although a CVR qualifier is ignored when being applied to a
20311 substituted template parameter ([8.3.2]/1 for example), that
20312 does not allow us to unify "const T" with "int&" because both
20313 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
20314 It is ok when we're allowing additional CV qualifiers
20315 at the outer level [14.8.2.1]/3,1st bullet. */
20325 }
20336 }
20338 /* Determines the LEVEL and INDEX for the template parameter PARM. */
20339 void
20341 {
20345 {
20348 }
20349 else
20350 {
20353 }
20354 }
20356 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
20357 do { \
20358 if (unify (TP, TA, P, A, S, EP)) \
20359 return 1; \
20360 } while (0)
20362 /* Unifies the remaining arguments in PACKED_ARGS with the pack
20363 expansion at the end of PACKED_PARMS. Returns 0 if the type
20364 deduction succeeds, 1 otherwise. STRICT is the same as in
20365 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
20366 function call argument list. We'll need to adjust the arguments to make them
20367 types. SUBR tells us if this is from a recursive call to
20368 type_unification_real, or for comparing two template argument
20369 lists. */
20371 static int
20375 {
20376 tree parm
20382 /* Add in any args remembered from an earlier partial instantiation. */
20390 /* Determine the parameter packs we will be deducing from the
20391 pattern, and record their current deductions. */
20394 {
20398 /* Determine the index and level of this parameter pack. */
20403 /* Keep track of the parameter packs and their corresponding
20404 argument packs. */
20407 }
20409 /* Loop through all of the arguments that have not yet been
20410 unified and unify each with the pattern. */
20412 {
20413 tree parm;
20417 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20418 or the element of its argument pack at the current index if
20419 this argument was explicitly specified. */
20421 {
20430 {
20433 }
20435 }
20437 /* If we had explicit template arguments, substitute them into the
20438 pattern before deduction. */
20440 {
20441 /* Some arguments might still be unspecified or dependent. */
20449 NULL_TREE);
20454 }
20455 else
20458 /* Unify the pattern with the current argument. */
20460 explain_p))
20463 /* For each parameter pack, collect the deduced value. */
20465 {
20471 }
20472 }
20474 /* Verify that the results of unification with the parameter packs
20475 produce results consistent with what we've seen before, and make
20476 the deduced argument packs available. */
20478 {
20485 /* By default keep the original deduced argument pack.
20486 If necessary, more specific code is going to update the
20487 resulting deduced argument later down in this function. */
20491 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20492 actually deduce anything. */
20500 {
20501 /* If we had fewer function args than explicit template args,
20502 just use the explicits. */
20507 }
20510 {
20511 tree result;
20512 /* Build the deduced *_ARGUMENT_PACK. */
20514 {
20517 }
20518 else
20523 /* Note the deduced argument packs for this parameter
20524 pack. */
20526 }
20530 {
20531 /* We only had the explicitly-provided arguments before, but
20532 now we have a complete set of arguments. */
20538 }
20539 else
20540 {
20546 /* Inconsistent unification of this parameter pack. */
20548 bad_old_arg,
20549 bad_new_arg);
20550 }
20551 }
20554 }
20556 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20557 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20558 parameters and return value are as for unify. */
20560 static int
20564 {
20565 tree parm_max;
20566 tree arg_max;
20570 /* Our representation of array types uses "N - 1" as the
20571 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20572 not an integer constant. We cannot unify arbitrarily
20573 complex expressions, so we eliminate the MINUS_EXPRs
20574 here. */
20578 {
20581 }
20585 {
20586 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20587 trying to unify the type of a variable with the type
20588 of a template parameter. For example:
20590 template <unsigned int N>
20591 void f (char (&) [N]);
20592 int g();
20593 void h(int i) {
20594 char a[g(i)];
20595 f(a);
20596 }
20598 Here, the type of the ARG will be "int [g(i)]", and
20599 may be a SAVE_EXPR, etc. */
20603 }
20605 /* If only one of the bounds used a MINUS_EXPR, compensate
20606 by adding one to the other bound. */
20609 integer_type_node,
20610 parm_max,
20611 integer_one_node);
20614 integer_type_node,
20615 arg_max,
20616 integer_one_node);
20620 }
20622 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20626 static pa_kind_t
20628 {
20637 else
20639 }
20641 /* Deduce the value of template parameters. TPARMS is the (innermost)
20642 set of template parameters to a template. TARGS is the bindings
20643 for those template parameters, as determined thus far; TARGS may
20644 include template arguments for outer levels of template parameters
20645 as well. PARM is a parameter to a template function, or a
20646 subcomponent of that parameter; ARG is the corresponding argument.
20647 This function attempts to match PARM with ARG in a manner
20648 consistent with the existing assignments in TARGS. If more values
20649 are deduced, then TARGS is updated.
20651 Returns 0 if the type deduction succeeds, 1 otherwise. The
20652 parameter STRICT is a bitwise or of the following flags:
20654 UNIFY_ALLOW_NONE:
20655 Require an exact match between PARM and ARG.
20656 UNIFY_ALLOW_MORE_CV_QUAL:
20657 Allow the deduced ARG to be more cv-qualified (by qualification
20658 conversion) than ARG.
20659 UNIFY_ALLOW_LESS_CV_QUAL:
20660 Allow the deduced ARG to be less cv-qualified than ARG.
20661 UNIFY_ALLOW_DERIVED:
20662 Allow the deduced ARG to be a template base class of ARG,
20663 or a pointer to a template base class of the type pointed to by
20664 ARG.
20665 UNIFY_ALLOW_INTEGER:
20666 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20667 case for more information.
20668 UNIFY_ALLOW_OUTER_LEVEL:
20669 This is the outermost level of a deduction. Used to determine validity
20670 of qualification conversions. A valid qualification conversion must
20671 have const qualified pointers leading up to the inner type which
20672 requires additional CV quals, except at the outer level, where const
20673 is not required [conv.qual]. It would be normal to set this flag in
20674 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20675 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20676 This is the outermost level of a deduction, and PARM can be more CV
20677 qualified at this point.
20678 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20679 This is the outermost level of a deduction, and PARM can be less CV
20680 qualified at this point. */
20682 static int
20685 {
20687 tree targ;
20688 tree tparm;
20690 tsubst_flags_t complain = (explain_p
20691 ? tf_warning_or_error
20694 /* I don't think this will do the right thing with respect to types.
20695 But the only case I've seen it in so far has been array bounds, where
20696 signedness is the only information lost, and I think that will be
20697 okay. */
20705 /* We can't deduce anything from this, but we might get all the
20706 template args from other function args. */
20712 /* If PARM uses template parameters, then we can't bail out here,
20713 even if ARG == PARM, since we won't record unifications for the
20714 template parameters. We might need them if we're trying to
20715 figure out which of two things is more specialized. */
20719 /* Handle init lists early, so the rest of the function can assume
20720 we're dealing with a type. */
20722 {
20727 /* Replace T with std::initializer_list<T> for deduction. */
20734 /* We can only deduce from an initializer list argument if the
20735 parameter is std::initializer_list or an array; otherwise this
20736 is a non-deduced context. */
20741 else
20742 {
20744 /* Deduction is defined in terms of a single type, so just punt
20745 on the (bizarre) std::initializer_list<T...>. */
20748 }
20751 {
20758 {
20762 /* It should only be possible to get here for a call. */
20764 elt_strict |= maybe_adjust_types_for_deduction
20767 }
20770 explain_p);
20771 }
20775 {
20776 /* Also deduce from the length of the initializer list. */
20783 }
20785 /* If the std::initializer_list<T> deduction worked, replace the
20786 deduced A with std::initializer_list<A>. */
20788 {
20793 }
20795 }
20797 /* If parm and arg aren't the same kind of thing (template, type, or
20798 expression), fail early. */
20802 /* Immediately reject some pairs that won't unify because of
20803 cv-qualification mismatches. */
20806 /* It is the elements of the array which hold the cv quals of an array
20807 type, and the elements might be template type parms. We'll check
20808 when we recurse. */
20810 /* We check the cv-qualifiers when unifying with template type
20811 parameters below. We want to allow ARG `const T' to unify with
20812 PARM `T' for example, when computing which of two templates
20813 is more specialized, for example. */
20827 {
20831 /* In a type which contains a nested-name-specifier, template
20832 argument values cannot be deduced for template parameters used
20833 within the nested-name-specifier. */
20845 /* The PARM is not one we're trying to unify. Just check
20846 to see if it matches ARG. */
20847 {
20852 else
20854 }
20861 /* Check for mixed types and values. */
20869 {
20872 {
20873 /* First try to match ARG directly. */
20875 explain_p);
20877 {
20878 /* Otherwise, look for a suitable base of ARG, as below. */
20885 }
20886 }
20887 /* ARG must be constructed from a template class or a template
20888 template parameter. */
20893 /* Deduce arguments T, i from TT<T> or TT<i>. */
20899 /* Fall through to deduce template name. */
20900 }
20904 {
20905 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20907 /* Simple cases: Value already set, does match or doesn't. */
20912 }
20913 else
20914 {
20915 /* If PARM is `const T' and ARG is only `int', we don't have
20916 a match unless we are allowing additional qualification.
20917 If ARG is `const int' and PARM is just `T' that's OK;
20918 that binds `const int' to `T'. */
20923 /* Consider the case where ARG is `const volatile int' and
20924 PARM is `const T'. Then, T should be `volatile int'. */
20925 arg = cp_build_qualified_type_real
20930 /* Simple cases: Value already set, does match or doesn't. */
20936 /* Make sure that ARG is not a variable-sized array. (Note
20937 that were talking about variable-sized arrays (like
20938 `int[n]'), rather than arrays of unknown size (like
20939 `int[]').) We'll get very confused by such a type since
20940 the bound of the array is not constant, and therefore
20941 not mangleable. Besides, such types are not allowed in
20942 ISO C++, so we can do as we please here. We do allow
20943 them for 'auto' deduction, since that isn't ABI-exposed. */
20947 /* Strip typedefs as in convert_template_argument. */
20949 }
20951 /* If ARG is a parameter pack or an expansion, we cannot unify
20952 against it unless PARM is also a parameter pack. */
20957 /* If the argument deduction results is a METHOD_TYPE,
20958 then there is a problem.
20959 METHOD_TYPE doesn't map to any real C++ type the result of
20960 the deduction can not be of that type. */
20974 {
20975 /* The PARM is not one we're trying to unify. Just check
20976 to see if it matches ARG. */
20982 }
20988 {
20992 /* We're deducing from an array bound, the type doesn't matter. */
20998 }
21000 /* [temp.deduct.type] If, in the declaration of a function template
21001 with a non-type template-parameter, the non-type
21002 template-parameter is used in an expression in the function
21003 parameter-list and, if the corresponding template-argument is
21004 deduced, the template-argument type shall match the type of the
21005 template-parameter exactly, except that a template-argument
21006 deduced from an array bound may be of any integral type.
21007 The non-type parameter might use already deduced type parameters. */
21012 {
21016 }
21019 /* Template-parameter dependent expression. Just accept it for now.
21020 It will later be processed in convert_template_argument. */
21021 ;
21027 /* Convert the ARG to the type of PARM; the deduced non-type
21028 template argument must exactly match the types of the
21029 corresponding parameter. */
21032 {
21033 /* We haven't deduced the type of this parameter yet. */
21035 /* We deduce from array bounds in try_array_deduction. */
21037 {
21038 /* Deduce it from the non-type argument. */
21043 }
21044 else
21045 /* Try again later. */
21047 }
21048 else
21051 /* If ARG is a parameter pack or an expansion, we cannot unify
21052 against it unless PARM is also a parameter pack. */
21057 {
21060 }
21065 {
21066 /* A pointer-to-member constant can be unified only with
21067 another constant. */
21071 /* Just unify the class member. It would be useless (and possibly
21072 wrong, depending on the strict flags) to unify also
21073 PTRMEM_CST_CLASS, because we want to be sure that both parm and
21074 arg refer to the same variable, even if through different
21075 classes. For instance:
21077 struct A { int x; };
21078 struct B : A { };
21080 Unification of &A::x and &B::x must succeed. */
21083 }
21086 {
21090 /* [temp.deduct.call]
21092 A can be another pointer or pointer to member type that can
21093 be converted to the deduced A via a qualification
21094 conversion (_conv.qual_).
21096 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
21097 This will allow for additional cv-qualification of the
21098 pointed-to types if appropriate. */
21101 /* The derived-to-base conversion only persists through one
21102 level of pointers. */
21107 }
21139 /* We have already checked cv-qualification at the top of the
21140 function. */
21144 /* As far as unification is concerned, this wins. Later checks
21145 will invalidate it if necessary. */
21148 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
21149 /* Type INTEGER_CST can come from ordinary constant template args. */
21161 {
21171 /* Check for pack expansions in the parameters. */
21173 {
21175 {
21177 /* We can unify against something with a trailing
21178 parameter pack. */
21180 else
21181 /* [temp.deduct.type]/9: If the template argument list of
21182 P contains a pack expansion that is not the last
21183 template argument, the entire template argument list
21184 is a non-deduced context. */
21186 }
21187 }
21189 /* If we don't have enough arguments to satisfy the parameters
21190 (not counting the pack expression at the end), or we have
21191 too many arguments for a parameter list that doesn't end in
21192 a pack expression, we can't unify. */
21198 /* Unify all of the parameters that precede the (optional)
21199 pack expression. */
21201 {
21206 }
21209 DEDUCE_EXACT,
21212 }
21220 {
21228 }
21233 {
21237 {
21238 /* First, we try to unify the PARM and ARG directly. */
21243 {
21244 /* Fallback to the special case allowed in
21245 [temp.deduct.call]:
21247 If P is a class, and P has the form
21248 template-id, then A can be a derived class of
21249 the deduced A. Likewise, if P is a pointer to
21250 a class of the form template-id, A can be a
21251 pointer to a derived class pointed to by the
21252 deduced A. */
21258 {
21259 /* Don't give the derived diagnostic if we're
21260 already dealing with the same template. */
21261 bool same_template
21267 }
21268 }
21269 }
21273 /* Perhaps PARM is something like S<U> and ARG is S<int>.
21274 Then, we should unify `int' and `U'. */
21276 else
21277 /* There's no chance of unification succeeding. */
21282 }
21289 {
21292 tree a;
21298 /* CV qualifications for methods can never be deduced, they must
21299 match exactly. We need to check them explicitly here,
21300 because type_unification_real treats them as any other
21301 cv-qualified parameter. */
21303 && (!check_cv_quals_for_unify
21331 {
21343 }
21346 }
21349 /* Unify a pointer to member with a pointer to member function, which
21350 deduces the type of the member as a function type. */
21352 {
21353 /* Check top-level cv qualifiers */
21361 /* Determine the type of the function we are unifying against. */
21365 }
21384 /* Matched cases are handled by the ARG == PARM test above. */
21388 /* We might get a variable as a non-type template argument in parm if the
21389 corresponding parameter is type-dependent. Make any necessary
21390 adjustments based on whether arg is a reference. */
21394 {
21399 }
21400 /* Now use the normal expression code to check whether they match. */
21411 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21412 or UNDERLYING_TYPE nodes. */
21416 /* Unification fails if we hit an error node. */
21421 {
21431 }
21432 /* FALLTHRU */
21435 /* An unresolved overload is a nondeduced context. */
21439 expr:
21440 /* We must be looking at an expression. This can happen with
21441 something like:
21443 template <int I>
21444 void foo(S<I>, S<I + 2>);
21446 This is a "nondeduced context":
21448 [deduct.type]
21450 The nondeduced contexts are:
21452 --A type that is a template-id in which one or more of
21453 the template-arguments is an expression that references
21454 a template-parameter.
21456 In these cases, we assume deduction succeeded, but don't
21457 actually infer any unifications. */
21462 else
21464 }
21465 }
21466 #undef RECUR_AND_CHECK_FAILURE
21467 \f
21468 /* Note that DECL can be defined in this translation unit, if
21469 required. */
21471 static void
21473 {
21474 tree clone;
21478 }
21480 /* Called if RESULT is explicitly instantiated, or is a member of an
21481 explicitly instantiated class. */
21483 void
21485 {
21488 /* If this entity has already been written out, it's too late to
21489 make any modifications. */
21493 /* For anonymous namespace we don't need to do anything. */
21495 {
21498 }
21501 /* The TREE_PUBLIC flag for function declarations will have been
21502 set correctly by tsubst. */
21505 /* This might have been set by an earlier implicit instantiation. */
21510 else
21511 {
21514 /* Always make artificials weak. */
21517 /* For WIN32 we also want to put explicit instantiations in
21518 linkonce sections. */
21521 }
21523 /* If EXTERN_P, then this function will not be emitted -- unless
21524 followed by an explicit instantiation, at which point its linkage
21525 will be adjusted. If !EXTERN_P, then this function will be
21526 emitted here. In neither circumstance do we want
21527 import_export_decl to adjust the linkage. */
21529 }
21531 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21532 important template arguments. If any are missing, we check whether
21533 they're important by using error_mark_node for substituting into any
21534 args that were used for partial ordering (the ones between ARGS and END)
21535 and seeing if it bubbles up. */
21537 static bool
21539 {
21544 {
21547 }
21549 {
21553 }
21555 }
21557 /* Given two function templates PAT1 and PAT2, return:
21559 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21560 -1 if PAT2 is more specialized than PAT1.
21561 0 if neither is more specialized.
21563 LEN indicates the number of parameters we should consider
21564 (defaulted parameters should not be considered).
21566 The 1998 std underspecified function template partial ordering, and
21567 DR214 addresses the issue. We take pairs of arguments, one from
21568 each of the templates, and deduce them against each other. One of
21569 the templates will be more specialized if all the *other*
21570 template's arguments deduce against its arguments and at least one
21571 of its arguments *does* *not* deduce against the other template's
21572 corresponding argument. Deduction is done as for class templates.
21573 The arguments used in deduction have reference and top level cv
21574 qualifiers removed. Iff both arguments were originally reference
21575 types *and* deduction succeeds in both directions, an lvalue reference
21576 wins against an rvalue reference and otherwise the template
21577 with the more cv-qualified argument wins for that pairing (if
21578 neither is more cv-qualified, they both are equal). Unlike regular
21579 deduction, after all the arguments have been deduced in this way,
21580 we do *not* verify the deduced template argument values can be
21581 substituted into non-deduced contexts.
21583 The logic can be a bit confusing here, because we look at deduce1 and
21584 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21585 can find template arguments for pat1 to make arg1 look like arg2, that
21586 means that arg2 is at least as specialized as arg1. */
21588 int
21590 {
21603 /* Remove the this parameter from non-static member functions. If
21604 one is a non-static member function and the other is not a static
21605 member function, remove the first parameter from that function
21606 also. This situation occurs for operator functions where we
21607 locate both a member function (with this pointer) and non-member
21608 operator (with explicit first operand). */
21610 {
21615 }
21617 {
21620 {
21621 len--;
21623 }
21624 }
21626 /* If only one is a conversion operator, they are unordered. */
21630 /* Consider the return type for a conversion function */
21632 {
21635 len++;
21636 }
21638 processing_template_decl++;
21644 /* Stop when an ellipsis is seen. */
21646 {
21657 {
21658 /* When both arguments are pack expansions, we need only
21659 unify the patterns themselves. */
21663 /* This is the last comparison we need to do. */
21665 }
21667 /* DR 1847: If a particular P contains no template-parameters that
21668 participate in template argument deduction, that P is not used to
21669 determine the ordering. */
21675 {
21679 }
21682 {
21686 }
21692 {
21698 /* Setup the parameter vector, which contains only ARG1. */
21701 /* Setup the argument vector, which contains the remaining
21702 arguments. */
21711 /* We cannot deduce in the other direction, because ARG1 is
21712 a pack expansion but ARG2 is not. */
21714 }
21716 {
21722 /* Setup the parameter vector, which contains only ARG1. */
21725 /* Setup the argument vector, which contains the remaining
21726 arguments. */
21735 /* We cannot deduce in the other direction, because ARG2 is
21736 a pack expansion but ARG1 is not.*/
21738 }
21740 else
21741 {
21742 /* The normal case, where neither argument is a pack
21743 expansion. */
21750 }
21752 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21753 arg2, then arg2 is not as specialized as arg1. */
21759 /* "If, for a given type, deduction succeeds in both directions
21760 (i.e., the types are identical after the transformations above)
21761 and both P and A were reference types (before being replaced with
21762 the type referred to above):
21763 - if the type from the argument template was an lvalue reference and
21764 the type from the parameter template was not, the argument type is
21765 considered to be more specialized than the other; otherwise,
21766 - if the type from the argument template is more cv-qualified
21767 than the type from the parameter template (as described above),
21768 the argument type is considered to be more specialized than the other;
21769 otherwise,
21770 - neither type is more specialized than the other." */
21773 {
21775 {
21778 else
21780 }
21782 {
21787 }
21788 }
21791 /* We've failed to deduce something in either direction.
21792 These must be unordered. */
21795 next:
21799 /* We have already processed all of the arguments in our
21800 handing of the pack expansion type. */
21805 }
21807 /* "In most cases, all template parameters must have values in order for
21808 deduction to succeed, but for partial ordering purposes a template
21809 parameter may remain without a value provided it is not used in the
21810 types being used for partial ordering."
21812 Thus, if we are missing any of the targs1 we need to substitute into
21813 origs1, then pat2 is not as specialized as pat1. This can happen when
21814 there is a nondeduced context. */
21820 processing_template_decl--;
21822 /* If both deductions succeed, the partial ordering selects the more
21823 constrained template. */
21825 {
21830 }
21832 /* All things being equal, if the next argument is a pack expansion
21833 for one function but not for the other, prefer the
21834 non-variadic function. FIXME this is bogus; see c++/41958. */
21838 {
21841 }
21847 else
21849 }
21851 /* Determine which of two partial specializations of TMPL is more
21852 specialized.
21854 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21855 to the first partial specialization. The TREE_PURPOSE is the
21856 innermost set of template parameters for the partial
21857 specialization. PAT2 is similar, but for the second template.
21859 Return 1 if the first partial specialization is more specialized;
21860 -1 if the second is more specialized; 0 if neither is more
21861 specialized.
21863 See [temp.class.order] for information about determining which of
21864 two templates is more specialized. */
21866 static int
21868 {
21869 tree targs;
21878 /* Just like what happens for functions, if we are ordering between
21879 different template specializations, we may encounter dependent
21880 types in the arguments, and we need our dependency check functions
21881 to behave correctly. */
21885 {
21888 }
21892 {
21895 }
21898 /* If both deductions succeed, the partial ordering selects the more
21899 constrained template. */
21903 /* In the case of a tie where at least one of the templates
21904 has a parameter pack at the end, the template with the most
21905 non-packed parameters wins. */
21907 && any_deductions
21910 {
21916 /* We don't count the pack expansion at the end. */
21926 }
21929 }
21931 /* Return the template arguments that will produce the function signature
21932 DECL from the function template FN, with the explicit template
21933 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21934 also match. Return NULL_TREE if no satisfactory arguments could be
21935 found. */
21937 static tree
21939 {
21943 tree decl_arg_types;
21946 tree arg;
21950 /* Never do unification on the 'this' parameter. */
21971 }
21973 /* Return the innermost template arguments that, when applied to a partial
21974 specialization SPEC_TMPL of TMPL, yield the ARGS.
21976 For example, suppose we have:
21978 template <class T, class U> struct S {};
21979 template <class T> struct S<T*, int> {};
21981 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21982 partial specialization and the ARGS will be {double*, int}. The resulting
21983 vector will be {double}, indicating that `T' is bound to `double'. */
21985 static tree
21987 {
21989 tree spec_args
21992 tree deduced_args;
21993 tree innermost_deduced_args;
21997 {
22001 innermost_deduced_args);
22002 }
22003 else
22007 again:
22016 {
22018 {
22024 }
22026 }
22030 {
22033 }
22035 /* Verify that nondeduced template arguments agree with the type
22036 obtained from argument deduction.
22038 For example:
22040 struct A { typedef int X; };
22041 template <class T, class U> struct C {};
22042 template <class T> struct C<T, typename T::X> {};
22044 Then with the instantiation `C<A, int>', we can deduce that
22045 `T' is `A' but unify () does not check whether `typename T::X'
22046 is `int'. */
22057 /* We only need to check the innermost arguments; the other
22058 arguments will always agree. */
22063 /* Now that we have bindings for all of the template arguments,
22064 ensure that the arguments deduced for the template template
22065 parameters have compatible template parameter lists. See the use
22066 of template_template_parm_bindings_ok_p in fn_type_unification
22067 for more information. */
22072 }
22074 // Compare two function templates T1 and T2 by deducing bindings
22075 // from one against the other. If both deductions succeed, compare
22076 // constraints to see which is more constrained.
22077 static int
22079 {
22084 {
22087 }
22090 {
22093 }
22095 // If both deductions succeed, then one may be more constrained.
22100 }
22102 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
22103 Return the TREE_LIST node with the most specialized template, if
22104 any. If there is no most specialized template, the error_mark_node
22105 is returned.
22107 Note that this function does not look at, or modify, the
22108 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
22109 returned is one of the elements of INSTANTIATIONS, callers may
22110 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
22111 and retrieve it from the value returned. */
22113 tree
22115 {
22122 {
22128 {
22129 /* Equally specialized, move to next function. If there
22130 is no next function, nothing's most specialized. */
22135 }
22136 }
22139 /* Now verify that champ is better than everything earlier in the
22140 instantiation list. */
22143 {
22146 }
22147 }
22149 processing_template_decl--;
22155 }
22157 /* If DECL is a specialization of some template, return the most
22158 general such template. Otherwise, returns NULL_TREE.
22160 For example, given:
22162 template <class T> struct S { template <class U> void f(U); };
22164 if TMPL is `template <class U> void S<int>::f(U)' this will return
22165 the full template. This function will not trace past partial
22166 specializations, however. For example, given in addition:
22168 template <class T> struct S<T*> { template <class U> void f(U); };
22170 if TMPL is `template <class U> void S<int*>::f(U)' this will return
22171 `template <class T> template <class U> S<T*>::f(U)'. */
22173 tree
22175 {
22177 {
22180 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
22181 template friend, or a FIELD_DECL for a capture pack. */
22184 }
22186 /* Look for more and more general templates. */
22188 {
22189 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
22190 (See cp-tree.h for details.) */
22199 /* Stop if we run into an explicitly specialized class template. */
22206 }
22209 }
22211 /* Return the most specialized of the template partial specializations
22212 which can produce TARGET, a specialization of some class or variable
22213 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
22214 a TEMPLATE_DECL node corresponding to the partial specialization, while
22215 the TREE_PURPOSE is the set of template arguments that must be
22216 substituted into the template pattern in order to generate TARGET.
22218 If the choice of partial specialization is ambiguous, a diagnostic
22219 is issued, and the error_mark_node is returned. If there are no
22220 partial specializations matching TARGET, then NULL_TREE is
22221 returned, indicating that the primary template should be used. */
22223 static tree
22225 {
22227 tree t;
22228 tree champ;
22235 {
22239 }
22241 {
22244 }
22246 {
22250 }
22251 else
22256 /* For determining which partial specialization to use, only the
22257 innermost args are interesting. */
22259 {
22262 }
22265 {
22266 tree spec_args;
22270 {
22271 /* Substitute in the template args from the enclosing class. */
22275 }
22282 {
22286 /* Keep the candidate only if the constraints are satisfied,
22287 or if we're not compiling with concepts. */
22290 {
22293 }
22294 }
22295 }
22305 {
22308 ;
22309 else
22310 {
22312 {
22315 {
22318 }
22319 }
22321 }
22322 }
22326 {
22329 {
22332 }
22333 }
22336 {
22343 else
22347 {
22352 }
22355 }
22358 }
22360 /* Explicitly instantiate DECL. */
22362 void
22364 {
22369 /* An error occurred, for which grokdeclarator has already issued
22370 an appropriate message. */
22373 {
22376 }
22382 {
22383 /* There is an asymmetry here in the way VAR_DECLs and
22384 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22385 the latter, the DECL we get back will be marked as a
22386 template instantiation, and the appropriate
22387 DECL_TEMPLATE_INFO will be set up. This does not happen for
22388 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22389 should handle VAR_DECLs as it currently handles
22390 FUNCTION_DECLs. */
22392 {
22395 }
22398 {
22401 }
22403 {
22408 }
22409 }
22411 {
22414 }
22415 else
22418 /* Check for various error cases. Note that if the explicit
22419 instantiation is valid the RESULT will currently be marked as an
22420 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22421 until we get here. */
22424 {
22425 /* DR 259 [temp.spec].
22427 Both an explicit instantiation and a declaration of an explicit
22428 specialization shall not appear in a program unless the explicit
22429 instantiation follows a declaration of the explicit specialization.
22431 For a given set of template parameters, if an explicit
22432 instantiation of a template appears after a declaration of an
22433 explicit specialization for that template, the explicit
22434 instantiation has no effect. */
22436 }
22438 {
22439 /* [temp.spec]
22441 No program shall explicitly instantiate any template more
22442 than once.
22444 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22445 the first instantiation was `extern' and the second is not,
22446 and EXTERN_P for the opposite case. */
22449 /* If an "extern" explicit instantiation follows an ordinary
22450 explicit instantiation, the template is instantiated. */
22453 }
22455 {
22458 }
22460 {
22463 }
22466 ;
22468 {
22471 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22474 }
22475 else
22483 }
22485 static void
22487 {
22493 {
22496 }
22497 }
22499 /* Called from do_type_instantiation through binding_table_foreach to
22500 do recursive instantiation for the type bound in ENTRY. */
22501 static void
22503 {
22509 }
22511 /* Perform an explicit instantiation of template class T. STORAGE, if
22512 non-null, is the RID for extern, inline or static. COMPLAIN is
22513 nonzero if this is called from the parser, zero if called recursively,
22514 since the standard is unclear (as detailed below). */
22516 void
22518 {
22528 {
22529 tree tmpl =
22533 else
22536 }
22541 {
22544 t);
22546 }
22549 {
22551 {
22553 {
22556 "ISO C++ 1998 forbids the use of %<extern%> on "
22558 }
22559 else
22561 "ISO C++ forbids the use of %qE"
22563 }
22571 else
22572 {
22574 storage);
22576 }
22577 }
22580 {
22581 /* DR 259 [temp.spec].
22583 Both an explicit instantiation and a declaration of an explicit
22584 specialization shall not appear in a program unless the explicit
22585 instantiation follows a declaration of the explicit specialization.
22587 For a given set of template parameters, if an explicit
22588 instantiation of a template appears after a declaration of an
22589 explicit specialization for that template, the explicit
22590 instantiation has no effect. */
22592 }
22594 {
22595 /* [temp.spec]
22597 No program shall explicitly instantiate any template more
22598 than once.
22600 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22601 instantiation was `extern'. If EXTERN_P then the second is.
22602 These cases are OK. */
22609 /* If we've already instantiated the template, just return now. */
22612 }
22620 /* In contrast to implicit instantiation, where only the
22621 declarations, and not the definitions, of members are
22622 instantiated, we have here:
22624 [temp.explicit]
22626 The explicit instantiation of a class template specialization
22627 implies the instantiation of all of its members not
22628 previously explicitly specialized in the translation unit
22629 containing the explicit instantiation.
22631 Of course, we can't instantiate member template classes, since we
22632 don't have any arguments for them. Note that the standard is
22633 unclear on whether the instantiation of the members are
22634 *explicit* instantiations or not. However, the most natural
22635 interpretation is that it should be an explicit
22636 instantiation. */
22640 && !static_p
22643 {
22648 }
22653 }
22655 /* Given a function DECL, which is a specialization of TMPL, modify
22656 DECL to be a re-instantiation of TMPL with the same template
22657 arguments. TMPL should be the template into which tsubst'ing
22658 should occur for DECL, not the most general template.
22660 One reason for doing this is a scenario like this:
22662 template <class T>
22663 void f(const T&, int i);
22665 void g() { f(3, 7); }
22667 template <class T>
22668 void f(const T& t, const int i) { }
22670 Note that when the template is first instantiated, with
22671 instantiate_template, the resulting DECL will have no name for the
22672 first parameter, and the wrong type for the second. So, when we go
22673 to instantiate the DECL, we regenerate it. */
22675 static void
22677 {
22678 /* The arguments used to instantiate DECL, from the most general
22679 template. */
22680 tree code_pattern;
22684 /* Make sure that we can see identifiers, and compute access
22685 correctly. */
22689 {
22690 tree decl_parm;
22691 tree pattern_parm;
22692 tree specs;
22706 specs);
22708 /* Merge parameter declarations. */
22711 pattern_parm
22715 {
22716 tree parm_type;
22717 tree attributes;
22722 NULL_TREE);
22728 {
22731 }
22734 }
22735 /* Merge any parameters that match with the function parameter
22736 pack. */
22738 {
22740 tree expanded_types;
22741 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22742 the parameters in this function parameter pack. */
22747 {
22748 tree parm_type;
22749 tree attributes;
22752 /* Rename the parameter to include the index. */
22761 {
22764 }
22766 }
22767 }
22768 /* Merge additional specifiers from the CODE_PATTERN. */
22772 }
22774 {
22784 }
22785 else
22789 }
22791 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22792 substituted to get DECL. */
22794 tree
22796 {
22799 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22800 for the instantiation. This is not always the most general
22801 template. Consider, for example:
22803 template <class T>
22804 struct S { template <class U> void f();
22805 template <> void f<int>(); };
22807 and an instantiation of S<double>::f<int>. We want TD to be the
22808 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22810 more general template. */
22812 /* We must also deal with friend templates. Given:
22814 template <class T> struct S {
22815 template <class U> friend void f() {};
22816 };
22818 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22819 so far as the language is concerned, but that's still
22820 where we get the pattern for the instantiation from. On
22821 other hand, if the definition comes outside the class, say:
22823 template <class T> struct S {
22824 template <class U> friend void f();
22825 };
22826 template <class U> friend void f() {}
22828 we don't need to look any further. That's what the check for
22829 DECL_INITIAL is for. */
22833 {
22834 /* The present template, TD, should not be a definition. If it
22835 were a definition, we should be using it! Note that we
22836 cannot restructure the loop to just keep going until we find
22837 a template with a definition, since that might go too far if
22838 a specialization was declared, but not defined. */
22840 /* Fetch the more general template. */
22842 }
22845 }
22847 /* Returns true if we need to instantiate this template instance even if we
22848 know we aren't going to emit it. */
22850 bool
22852 {
22853 /* We always instantiate inline functions so that we can inline them. An
22854 explicit instantiation declaration prohibits implicit instantiation of
22855 non-inline functions. With high levels of optimization, we would
22856 normally inline non-inline functions -- but we're not allowed to do
22857 that for "extern template" functions. Therefore, we check
22858 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22862 /* And we need to instantiate static data members so that
22863 their initializers are available in integral constant
22864 expressions. */
22867 }
22869 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22870 instantiate it now, modifying TREE_TYPE (fn). Returns false on
22871 error, true otherwise. */
22873 bool
22875 {
22878 /* Don't instantiate a noexcept-specification from template context. */
22893 {
22899 {
22900 /* If hash_set::add returns true, the element was already there. */
22905 fn);
22907 }
22909 {
22924 }
22925 else
22935 }
22938 {
22941 else
22943 }
22946 }
22948 /* We're starting to process the function INST, an instantiation of PATTERN;
22949 add their parameters to local_specializations. */
22951 static void
22953 {
22957 {
22961 }
22963 {
22965 {
22968 }
22969 else
22970 {
22971 /* Register the (value) argument pack as a specialization of
22972 TMPL_PARM, then move on. */
22975 }
22976 }
22978 }
22980 /* Produce the definition of D, a _DECL generated from a template. If
22981 DEFER_OK is true, then we don't have to actually do the
22982 instantiation now; we just have to do it sometime. Normally it is
22983 an error if this is an explicit instantiation but D is undefined.
22984 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22985 instantiated class template. */
22987 tree
22989 {
22991 tree gen_args;
22992 tree args;
22993 tree td;
22994 tree code_pattern;
22995 tree spec;
22996 tree gen_tmpl;
23004 /* This function should only be used to instantiate templates for
23005 functions and static member variables. */
23008 /* A concept is never instantiated. */
23011 /* Variables are never deferred; if instantiation is required, they
23012 are instantiated right away. That allows for better code in the
23013 case that an expression refers to the value of the variable --
23014 if the variable has a constant value the referring expression can
23015 take advantage of that fact. */
23019 /* Don't instantiate cloned functions. Instead, instantiate the
23020 functions they cloned. */
23028 /* D has already been instantiated or explicitly specialized, so
23029 there's nothing for us to do here.
23031 It might seem reasonable to check whether or not D is an explicit
23032 instantiation, and, if so, stop here. But when an explicit
23033 instantiation is deferred until the end of the compilation,
23034 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
23035 the instantiation. */
23038 /* Check to see whether we know that this template will be
23039 instantiated in some other file, as with "extern template"
23040 extension. */
23043 /* In general, we do not instantiate such templates. */
23051 /* We should already have the extra args. */
23054 /* And what's in the hash table should match D. */
23058 /* This needs to happen before any tsubsting. */
23064 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
23065 for the instantiation. */
23070 {
23071 /* Look up an explicit specialization, if any. */
23075 {
23078 }
23079 }
23083 /* We should never be trying to instantiate a member of a class
23084 template or partial specialization. */
23089 /* In the case of a friend template whose definition is provided
23090 outside the class, we may have too many arguments. Drop the
23091 ones we don't need. The same is true for specializations. */
23092 args = get_innermost_template_args
23096 {
23102 }
23103 else
23104 {
23109 else
23111 }
23113 /* We may be in the middle of deferred access check. Disable it now. */
23116 /* Unless an explicit instantiation directive has already determined
23117 the linkage of D, remember that a definition is available for
23118 this entity. */
23128 /* If D is a member of an explicitly instantiated class template,
23129 and no definition is available, treat it like an implicit
23130 instantiation. */
23133 {
23134 /* Leave linkage flags alone on instantiations with anonymous
23135 visibility. */
23137 {
23140 }
23142 }
23144 /* Defer all other templates, unless we have been explicitly
23145 forbidden from doing so. */
23147 template. */
23148 ! pattern_defined
23149 /* If it's OK to postpone instantiation, do so. */
23150 || defer_ok
23151 /* If this is a static data member that will be defined
23152 elsewhere, we don't want to instantiate the entire data
23153 member, but we do want to instantiate the initializer so that
23154 we can substitute that elsewhere. */
23156 /* Handle here a deleted function too, avoid generating
23157 its body (c++/61080). */
23159 {
23160 /* The definition of the static data member is now required so
23161 we must substitute the initializer. */
23165 {
23166 tree ns;
23167 tree init;
23176 args,
23179 /* If instantiating the initializer involved instantiating this
23180 again, don't call cp_finish_decl twice. */
23182 {
23183 /* Make sure the initializer is still constant, in case of
23184 circular dependency (template/instantiate6.C). */
23185 const_init
23189 LOOKUP_ONLYCONVERTING);
23190 }
23194 }
23196 /* We restore the source position here because it's used by
23197 add_pending_template. */
23203 /* [temp.explicit]
23205 The definition of a non-exported function template, a
23206 non-exported member function template, or a non-exported
23207 member function or static data member of a class template
23208 shall be present in every translation unit in which it is
23209 explicitly instantiated. */
23213 /* If we're in unevaluated context, we just wanted to get the
23214 constant value; this isn't an odr use, so don't queue
23215 a full instantiation. */
23218 /* ??? Historically, we have instantiated inline functions, even
23219 when marked as "extern template". */
23223 }
23224 /* Tell the repository that D is available in this translation unit
23225 -- and see if it is supposed to be instantiated here. */
23227 {
23228 /* In a PCH file, despite the fact that the repository hasn't
23229 requested instantiation in the PCH it is still possible that
23230 an instantiation will be required in a file that includes the
23231 PCH. */
23234 /* Instantiate inline functions so that the inliner can do its
23235 job, even though we'll not be emitting a copy of this
23236 function. */
23239 }
23242 tree fn_context;
23253 else
23254 {
23258 }
23260 /* Mark D as instantiated so that recursive calls to
23261 instantiate_decl do not try to instantiate it again. */
23264 /* Regenerate the declaration in case the template has been modified
23265 by a subsequent redeclaration. */
23268 /* We already set the file and line above. Reset them now in case
23269 they changed as a result of calling regenerate_decl_from_template. */
23273 {
23274 tree init;
23277 /* Clear out DECL_RTL; whatever was there before may not be right
23278 since we've reset the type of the declaration. */
23282 /* The initializer is placed in DECL_INITIAL by
23283 regenerate_decl_from_template so we don't need to
23284 push/pop_access_scope again here. Pull it out so that
23285 cp_finish_decl can process it. */
23290 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
23291 initializer. That function will defer actual emission until
23292 we have a chance to determine linkage. */
23295 /* Enter the scope of D so that access-checking works correctly. */
23308 }
23312 {
23313 /* Set up the list of local specializations. */
23317 /* Set up context. */
23321 else
23324 /* Some typedefs referenced from within the template code need to be
23325 access checked at template instantiation time, i.e now. These
23326 types were added to the template at parsing time. Let's get those
23327 and perform the access checks then. */
23329 args);
23331 /* Create substitution entries for the parameters. */
23334 /* Substitute into the body of the function. */
23338 else
23339 {
23344 /* Set the current input_location to the end of the function
23345 so that finish_function knows where we are. */
23346 input_location
23349 /* Remember if we saw an infinite loop in the template. */
23350 current_function_infinite_loop
23352 }
23354 /* Finish the function. */
23358 else
23359 {
23362 }
23366 }
23368 /* We're not deferring instantiation any more. */
23373 else
23379 out:
23388 }
23390 /* Run through the list of templates that we wish we could
23391 instantiate, and instantiate any we can. RETRIES is the
23392 number of times we retry pending template instantiation. */
23394 void
23396 {
23400 /* Instantiating templates may trigger vtable generation. This in turn
23401 may require further template instantiations. We place a limit here
23402 to avoid infinite loop. */
23404 {
23408 "template instantiation depth exceeds maximum of %d"
23409 " instantiating %q+D, possibly from virtual table generation"
23413 /* Pretend that we defined it. */
23416 }
23418 do
23419 {
23424 {
23429 {
23431 {
23446 }
23449 }
23450 else
23451 {
23454 {
23455 instantiation
23461 }
23465 }
23468 /* If INSTANTIATION has been instantiated, then we don't
23469 need to consider it again in the future. */
23471 else
23472 {
23475 }
23478 }
23480 }
23484 }
23486 /* Substitute ARGVEC into T, which is a list of initializers for
23487 either base class or a non-static data member. The TREE_PURPOSEs
23488 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23489 instantiate_decl. */
23491 static tree
23493 {
23497 {
23498 tree decl;
23499 tree init;
23505 {
23506 tree expr;
23507 tree arg;
23509 /* Expand the base class expansion type into separate base
23510 classes. */
23512 tf_warning_or_error,
23513 NULL_TREE);
23517 /* We'll be building separate TREE_LISTs of arguments for
23518 each base. */
23524 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23525 expand each argument in the TREE_VALUE of t. */
23532 /* VOID_TYPE_NODE is used to indicate
23533 value-initialization. */
23534 {
23537 }
23538 else
23539 {
23540 /* Substitute parameter packs into each argument in the
23541 TREE_LIST. */
23544 {
23545 tree expanded_exprs;
23547 /* Expand the argument. */
23549 expanded_exprs
23551 tf_warning_or_error,
23552 NULL_TREE);
23556 /* Prepend each of the expanded expressions to the
23557 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23559 {
23564 }
23565 }
23568 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23569 since we built them backwards. */
23571 {
23574 }
23575 }
23576 }
23579 {
23581 {
23585 }
23586 else
23587 {
23588 tree tmp;
23603 /* If we had an initializer but it instantiated to nothing,
23604 value-initialize the object. This will only occur when
23605 the initializer was a pack expansion where the parameter
23606 packs used in that expansion were of length zero. */
23609 }
23612 {
23616 }
23617 }
23618 }
23620 }
23622 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23624 static void
23626 {
23631 else
23633 }
23635 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23636 is the instantiation (which should have been created with
23637 start_enum) and ARGS are the template arguments to use. */
23639 static void
23641 {
23642 tree e;
23648 {
23649 tree value;
23650 tree decl;
23653 /* Note that in a template enum, the TREE_VALUE is the
23654 CONST_DECL, not the corresponding INTEGER_CST. */
23659 /* Give this enumeration constant the correct access. */
23662 /* Actually build the enumerator itself. Here we're assuming that
23663 enumerators can't have dependent attributes. */
23666 }
23676 }
23678 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23679 its type -- but without substituting the innermost set of template
23680 arguments. So, innermost set of template parameters will appear in
23681 the type. */
23683 tree
23685 {
23686 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23688 }
23690 /* Return truthvalue if we're processing a template different from
23691 the last one involved in diagnostics. */
23692 bool
23694 {
23696 }
23698 /* Remember current template involved in diagnostics. */
23699 void
23701 {
23703 }
23707 {
23709 }
23711 /* Return TRUE if current_function_decl is being instantiated, false
23712 otherwise. */
23714 bool
23716 {
23719 }
23721 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23722 type. Return false for ok, true for disallowed. Issue error and
23723 inform messages under control of COMPLAIN. */
23725 static bool
23727 {
23742 /* A bound template template parm could later be instantiated to have a valid
23743 nontype parm type via an alias template. */
23749 {
23752 else
23754 type);
23755 }
23757 }
23759 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23760 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23762 static bool
23764 {
23765 tree scope;
23767 /* [temp.dep.type]
23769 A type is dependent if it is:
23771 -- a template parameter. Template template parameters are types
23772 for us (since TYPE_P holds true for them) so we handle
23773 them here. */
23777 /* -- a qualified-id with a nested-name-specifier which contains a
23778 class-name that names a dependent type or whose unqualified-id
23779 names a dependent type. */
23783 /* An alias template specialization can be dependent even if the
23784 resulting type is not. */
23788 /* -- a cv-qualified type where the cv-unqualified type is
23789 dependent.
23790 No code is necessary for this bullet; the code below handles
23791 cv-qualified types, and we don't want to strip aliases with
23792 TYPE_MAIN_VARIANT because of DR 1558. */
23793 /* -- a compound type constructed from any dependent type. */
23803 {
23804 tree arg_type;
23809 arg_type;
23814 /* A value-dependent noexcept-specifier makes the type dependent. */
23817 /* Treat DEFERRED_NOEXCEPT as non-dependent, since it doesn't
23818 affect overload resolution and treating it as dependent breaks
23819 things. */
23824 }
23825 /* -- an array type constructed from any dependent type or whose
23826 size is specified by a constant expression that is
23827 value-dependent.
23829 We checked for type- and value-dependence of the bounds in
23830 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23832 {
23837 }
23839 /* -- a template-id in which either the template name is a template
23840 parameter ... */
23843 /* ... or any of the template arguments is a dependent type or
23844 an expression that is type-dependent or value-dependent. */
23846 && (any_dependent_template_arguments_p
23850 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23851 dependent; if the argument of the `typeof' expression is not
23852 type-dependent, then it should already been have resolved. */
23858 /* A template argument pack is dependent if any of its packed
23859 arguments are. */
23861 {
23867 }
23869 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23870 be template parameters. */
23877 /* The standard does not specifically mention types that are local
23878 to template functions or local classes, but they should be
23879 considered dependent too. For example:
23881 template <int I> void f() {
23882 enum E { a = I };
23883 S<sizeof (E)> s;
23884 }
23886 The size of `E' cannot be known until the value of `I' has been
23887 determined. Therefore, `E' must be considered dependent. */
23891 /* Don't use type_dependent_expression_p here, as it can lead
23892 to infinite recursion trying to determine whether a lambda
23893 nested in a lambda is dependent (c++/47687). */
23897 && (any_dependent_template_arguments_p
23901 /* Other types are non-dependent. */
23903 }
23905 /* Returns TRUE if TYPE is dependent, in the sense of
23906 [temp.dep.type]. Note that a NULL type is considered dependent. */
23908 bool
23910 {
23911 /* If there are no template parameters in scope, then there can't be
23912 any dependent types. */
23914 {
23915 /* If we are not processing a template, then nobody should be
23916 providing us with a dependent type. */
23920 }
23922 /* If the type is NULL, we have not computed a type for the entity
23923 in question; in that case, the type is dependent. */
23927 /* Erroneous types can be considered non-dependent. */
23931 /* Getting here with global_type_node means we improperly called this
23932 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23935 /* If we have not already computed the appropriate value for TYPE,
23936 do so now. */
23938 {
23941 }
23944 }
23946 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23947 lookup. In other words, a dependent type that is not the current
23948 instantiation. */
23950 bool
23952 {
23955 }
23957 /* T is a SCOPE_REF. Return whether it represents a non-static member of
23958 an unknown base of 'this' (and is therefore instantiation-dependent). */
23960 static bool
23962 {
23979 }
23981 /* T is a SCOPE_REF; return whether we need to consider it
23982 instantiation-dependent so that we can check access at instantiation
23983 time even though we know which member it resolves to. */
23985 static bool
23987 {
23994 else
23996 }
23998 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23999 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
24000 expression. */
24002 /* Note that this predicate is not appropriate for general expressions;
24003 only constant expressions (that satisfy potential_constant_expression)
24004 can be tested for value dependence. */
24006 bool
24008 {
24012 /* A type-dependent expression is also value-dependent. */
24017 {
24019 /* A dependent member function of the current instantiation. */
24023 /* A dependent member function of the current instantiation. */
24030 /* A name that has not been looked up -- must be dependent. */
24034 /* A non-type template parm. */
24038 /* A non-type template parm. */
24044 /* A constant with literal type and is initialized
24045 with an expression that is value-dependent. */
24047 /* FIXME cp_finish_decl doesn't fold reference initializers. */
24051 {
24055 }
24064 /* These expressions are value-dependent if the type to which
24065 the cast occurs is dependent or the expression being casted
24066 is value-dependent. */
24067 {
24073 /* A functional cast has a list of operands. */
24076 {
24077 /* If there are no operands, it must be an expression such
24078 as "int()". This should not happen for aggregate types
24079 because it would form non-constant expressions. */
24084 }
24090 }
24095 /* FALLTHRU */
24098 /* A `sizeof' expression is value-dependent if the operand is
24099 type-dependent or is a pack expansion. */
24108 /* An 'encode' expression is value-dependent if the operand is
24109 type-dependent. */
24118 /* All instantiation-dependent expressions should also be considered
24119 value-dependent. */
24127 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
24128 is value-dependent. */
24129 {
24138 }
24141 {
24158 }
24169 {
24173 }
24176 /* Treat all requires-expressions as value-dependent so
24177 we don't try to fold them. */
24184 {
24191 {
24193 /* In a call to a constexpr member function, look through the
24194 implicit ADDR_EXPR on the object argument so that it doesn't
24195 cause the call to be considered value-dependent. We also
24196 look through it in potential_constant_expression. */
24203 }
24205 }
24211 {
24213 tree val;
24220 }
24223 /* Treat a GNU statement expression as dependent to avoid crashing
24224 under instantiate_non_dependent_expr; it can't be constant. */
24228 /* A constant expression is value-dependent if any subexpression is
24229 value-dependent. */
24231 {
24238 {
24242 {
24245 /* In some cases, some of the operands may be missing.
24246 (For example, in the case of PREDECREMENT_EXPR, the
24247 amount to increment by may be missing.) That doesn't
24248 make the expression dependent. */
24251 }
24252 }
24256 }
24258 }
24260 /* The expression is not value-dependent. */
24262 }
24264 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
24265 [temp.dep.expr]. Note that an expression with no type is
24266 considered dependent. Other parts of the compiler arrange for an
24267 expression with type-dependent subexpressions to have no type, so
24268 this function doesn't have to be fully recursive. */
24270 bool
24272 {
24281 /* An unresolved name is always dependent. */
24287 /* A fold expression is type-dependent. */
24294 /* Some expression forms are never type-dependent. */
24308 /* The types of these expressions depends only on the type to which
24309 the cast occurs. */
24318 /* The types of these expressions depends only on the type created
24319 by the expression. */
24322 {
24323 /* For NEW_EXPR tree nodes created inside a template, either
24324 the object type itself or a TREE_LIST may appear as the
24325 operand 1. */
24328 /* This is an array type. We need to check array dimensions
24329 as well. */
24331 || value_dependent_expression_p
24333 else
24335 }
24338 {
24342 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
24343 contains an identifier associated by name lookup with one or more
24344 declarations declared with a dependent type, or...a
24345 nested-name-specifier or qualified-id that names a member of an
24346 unknown specialization. */
24349 }
24359 {
24360 tree elt;
24364 {
24367 }
24369 }
24371 /* A static data member of the current instantiation with incomplete
24372 array type is type-dependent, as the definition and specializations
24373 can have different bounds. */
24380 /* An array of unknown bound depending on a variadic parameter, eg:
24382 template<typename... Args>
24383 void foo (Args... args)
24384 {
24385 int arr[] = { args... };
24386 }
24388 template<int... vals>
24389 void bar ()
24390 {
24391 int arr[] = { vals... };
24392 }
24394 If the array has no length and has an initializer, it must be that
24395 we couldn't determine its length in cp_complete_array_type because
24396 it is dependent. */
24404 /* A function or variable template-id is type-dependent if it has any
24405 dependent template arguments. */
24409 {
24410 /* Consider the innermost template arguments, since those are the ones
24411 that come from the template-id; the template arguments for the
24412 enclosing class do not make it type-dependent unless they are used in
24413 the type of the decl. */
24415 && (any_dependent_template_arguments_p
24418 }
24420 /* Otherwise, if the function decl isn't from a dependent scope, it can't be
24421 type-dependent. Checking this is important for functions with auto return
24422 type, which looks like a dependent type. */
24430 {
24434 }
24436 /* Always dependent, on the number of arguments if nothing else. */
24441 {
24446 {
24452 }
24453 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24458 {
24463 }
24466 {
24473 }
24483 }
24487 /* Dependent type attributes might not have made it from the decl to
24488 the type yet. */
24494 }
24496 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24497 type-dependent if the expression refers to a member of the current
24498 instantiation and the type of the referenced member is dependent, or the
24499 class member access expression refers to a member of an unknown
24500 specialization.
24502 This function returns true if the OBJECT in such a class member access
24503 expression is of an unknown specialization. */
24505 bool
24507 {
24508 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24509 dependent. */
24514 }
24516 /* walk_tree callback function for instantiation_dependent_expression_p,
24517 below. Returns non-zero if a dependent subexpression is found. */
24519 static tree
24522 {
24524 {
24525 /* We don't have to worry about decltype currently because decltype
24526 of an instantiation-dependent expr is a dependent type. This
24527 might change depending on the resolution of DR 1172. */
24530 }
24533 {
24534 /* Don't treat an argument list as dependent just because it has no
24535 TREE_TYPE. */
24543 /* Handle expressions with type operands. */
24548 {
24553 {
24556 else
24557 {
24560 }
24561 }
24563 }
24567 /* In a template, finish_class_member_access_expr creates a
24568 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24569 type-dependent, so that we can check access control at
24570 instantiation time (PR 42277). See also Core issue 1273. */
24577 else
24580 /* Treat statement-expressions as dependent. */
24584 /* Treat requires-expressions as dependent. */
24589 /* Treat calls to function concepts as dependent. */
24595 /* And variable concepts. */
24602 }
24606 else
24608 }
24610 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24611 sense defined by the ABI:
24613 "An expression is instantiation-dependent if it is type-dependent
24614 or value-dependent, or it has a subexpression that is type-dependent
24615 or value-dependent."
24617 Except don't actually check value-dependence for unevaluated expressions,
24618 because in sizeof(i) we don't care about the value of i. Checking
24619 type-dependence will in turn check value-dependence of array bounds/template
24620 arguments as needed. */
24622 bool
24624 {
24625 tree result;
24636 }
24638 /* As above, but also check value-dependence of the expression as a whole. */
24640 bool
24642 {
24645 }
24647 /* Like type_dependent_expression_p, but it also works while not processing
24648 a template definition, i.e. during substitution or mangling. */
24650 bool
24652 {
24658 }
24660 /* Returns TRUE if ARGS contains a type-dependent expression. */
24662 bool
24664 {
24666 tree arg;
24669 {
24672 }
24674 }
24676 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24677 expressions) contains any type-dependent expressions. */
24679 bool
24681 {
24687 }
24689 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24690 expressions) contains any value-dependent expressions. */
24692 bool
24694 {
24700 }
24702 /* Returns TRUE if the ARG (a template argument) is dependent. */
24704 bool
24706 {
24710 /* Assume a template argument that was wrongly written by the user
24711 is dependent. This is consistent with what
24712 any_dependent_template_arguments_p [that calls this function]
24713 does. */
24723 {
24726 /* A member template of a dependent class is not necessarily
24727 type-dependent, but it is a dependent template argument because it
24728 will be a member of an unknown specialization to that template. */
24731 }
24733 {
24737 {
24740 }
24743 }
24746 else
24749 }
24751 /* Returns true if ARGS (a collection of template arguments) contains
24752 any types that require structural equality testing. */
24754 bool
24756 {
24766 {
24769 {
24775 {
24776 /* Look inside the argument pack. */
24779 }
24782 {
24795 }
24796 }
24797 }
24800 }
24802 /* Returns true if ARGS (a collection of template arguments) contains
24803 any dependent arguments. */
24805 bool
24807 {
24817 {
24822 }
24825 }
24827 /* Returns TRUE if the template TMPL is type-dependent. */
24829 bool
24831 {
24833 {
24838 }
24840 /* Template template parameters are dependent. */
24844 /* So are names that have not been looked up. */
24848 }
24850 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24852 bool
24854 {
24857 }
24859 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24860 are dependent. */
24862 bool
24864 {
24871 {
24893 {
24897 }
24901 {
24905 {
24910 }
24911 }
24912 }
24915 }
24917 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24918 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24919 no such TYPE can be found. Note that this function peers inside
24920 uninstantiated templates and therefore should be used only in
24921 extremely limited situations. ONLY_CURRENT_P restricts this
24922 peering to the currently open classes hierarchy (which is required
24923 when comparing types). */
24925 tree
24927 {
24928 tree scope;
24929 tree name;
24930 tree decl;
24932 tree pushed_scope;
24933 tree result;
24938 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24939 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24940 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24941 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24942 identifier of the TYPENAME_TYPE anymore.
24943 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24944 TYPENAME_TYPE instead, we avoid messing up with a possible
24945 typedef variant case. */
24948 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24949 it first before we can figure out what NAME refers to. */
24951 {
24953 /* Given a class template A with a dependent base with nested type C,
24954 typedef typename A::C::C C will land us here, as trying to resolve
24955 the initial A::C leads to the local C typedef, which leads back to
24956 A::C::C. So we break the recursion now. */
24958 else
24960 }
24961 /* If we don't know what SCOPE refers to, then we cannot resolve the
24962 TYPENAME_TYPE. */
24965 /* If this is a typedef, we don't want to look inside (c++/11987). */
24968 /* If SCOPE isn't the template itself, it will not have a valid
24969 TYPE_FIELDS list. */
24971 /* scope is either the template itself or a compatible instantiation
24972 like X<T>, so look up the name in the original template. */
24974 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24976 /* If scope has no fields, it can't be a current instantiation. Check this
24977 before currently_open_class to avoid infinite recursion (71515). */
24980 /* If the SCOPE is not the current instantiation, there's no reason
24981 to look inside it. */
24984 /* Enter the SCOPE so that name lookup will be resolved as if we
24985 were in the class definition. In particular, SCOPE will no
24986 longer be considered a dependent type. */
24988 /* Look up the declaration. */
24990 tf_warning_or_error);
24994 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24995 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
25001 {
25005 }
25008 {
25009 /* Obtain the template and the arguments. */
25012 {
25013 /* We get here with a plain identifier because a previous tentative
25014 parse of the nested-name-specifier as part of a ptr-operator saw
25015 ::template X<A>. The use of ::template is necessary in a
25016 ptr-operator, but wrong in a declarator-id.
25018 [temp.names]: In a qualified-id of a declarator-id, the keyword
25019 template shall not appear at the top level. */
25023 }
25025 /* Instantiate the template. */
25031 }
25033 /* Leave the SCOPE. */
25037 /* If we failed to resolve it, return the original typename. */
25041 /* If lookup found a typename type, resolve that too. */
25043 {
25044 /* Ill-formed programs can cause infinite recursion here, so we
25045 must catch that. */
25049 }
25051 /* Qualify the resulting type. */
25057 }
25059 /* EXPR is an expression which is not type-dependent. Return a proxy
25060 for EXPR that can be used to compute the types of larger
25061 expressions containing EXPR. */
25063 tree
25065 {
25067 tree inner_expr;
25069 /* When checking, try to get a constant value for all non-dependent
25070 expressions in order to expose bugs in *_dependent_expression_p
25071 and constexpr. This can affect code generation, see PR70704, so
25072 only do this for -fchecking=2. */
25075 /* Don't do this during nsdmi parsing as it can lead to
25076 unexpected recursive instantiations. */
25078 /* Don't do this during concept expansion either and for
25079 the same reason. */
25085 /* Preserve OVERLOADs; the functions must be available to resolve
25086 types. */
25097 /* There is no need to return a proxy for a variable. */
25100 /* Preserve string constants; conversions from string constants to
25101 "char *" are allowed, even though normally a "const char *"
25102 cannot be used to initialize a "char *". */
25105 /* Preserve void and arithmetic constants, as an optimization -- there is no
25106 reason to create a new node. */
25111 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
25112 There is at least one place where we want to know that a
25113 particular expression is a throw-expression: when checking a ?:
25114 expression, there are special rules if the second or third
25115 argument is a throw-expression. */
25119 /* Don't wrap an initializer list, we need to be able to look inside. */
25123 /* Don't wrap a dummy object, we need to be able to test for it. */
25142 /* If the type is unknown, it can't really be non-dependent */
25145 /* Otherwise, build a NON_DEPENDENT_EXPR. */
25147 }
25149 /* ARGS is a vector of expressions as arguments to a function call.
25150 Replace the arguments with equivalent non-dependent expressions.
25151 This modifies ARGS in place. */
25153 void
25155 {
25157 tree arg;
25160 {
25164 }
25165 }
25167 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
25168 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
25169 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
25171 static tree
25173 {
25187 }
25189 tree
25191 {
25193 }
25195 tree
25197 {
25199 }
25201 /* Return a C++17 deduction placeholder for class template TMPL. */
25203 tree
25205 {
25209 }
25211 /* True iff T is a C++17 class template deduction placeholder. */
25213 bool
25215 {
25217 }
25219 /* Make a "constrained auto" type-specifier. This is an
25220 auto type with constraints that must be associated after
25221 deduction. The constraint is formed from the given
25222 CONC and its optional sequence of arguments, which are
25223 non-null if written as partial-concept-id. */
25225 tree
25227 {
25230 /* Build the constraint. */
25238 /* Our canonical type depends on the constraint. */
25241 /* Attach the constraint to the type declaration. */
25244 }
25246 /* Given type ARG, return std::initializer_list<ARG>. */
25248 static tree
25250 {
25254 {
25258 "deducing from brace-enclosed initializer list"
25262 }
25268 }
25270 /* Replace auto in TYPE with std::initializer_list<auto>. */
25272 static tree
25274 {
25281 }
25283 /* Hash traits for hashing possibly constrained 'auto'
25284 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
25287 {
25290 };
25292 /* Hash the 'auto' T. */
25294 inline hashval_t
25296 {
25298 /* Matching constrained-type-specifiers denote the same template
25299 parameter, so hash the constraint. */
25301 else
25302 /* But unconstrained autos are all separate, so just hash the pointer. */
25304 }
25306 /* Compare two 'auto's. */
25310 {
25317 /* Two unconstrained autos are distinct. */
25322 }
25324 /* for_each_template_parm callback for extract_autos: if t is a (possibly
25325 constrained) auto, add it to the vector. */
25327 static int
25329 {
25332 {
25333 /* All the autos were built with index 0; fix that up now. */
25337 /* If this is a repeated constrained-type-specifier, use the index we
25338 chose before. */
25340 else
25341 {
25342 /* Otherwise this is new, so use the current count. */
25345 }
25347 }
25349 /* Always keep walking. */
25351 }
25353 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
25354 says they can appear anywhere in the type. */
25356 static tree
25358 {
25367 {
25372 }
25375 }
25377 /* The stem for deduction guide names. */
25380 /* Return the name for a deduction guide for class template TMPL. */
25382 tree
25384 {
25395 }
25397 /* True if NAME is the name of a deduction guide. */
25399 bool
25401 {
25405 }
25407 /* True if FN is a deduction guide. */
25409 bool
25411 {
25416 }
25418 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
25420 bool
25422 {
25429 }
25431 /* True if FN is a guide generated from a constructor template. */
25433 bool
25435 {
25443 }
25445 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
25446 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
25447 template parameter types. Note that the handling of template template
25448 parameters relies on current_template_parms being set appropriately for the
25449 new template. */
25451 static tree
25454 {
25457 tree newtype;
25460 {
25467 }
25468 else
25472 tree newdecl
25477 tree newidx;
25480 {
25490 {
25495 // First create a copy (ttargs) of tsubst_args with an
25496 // additional level for the template template parameter's own
25497 // template parameters (ttparms).
25498 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25506 // Substitute ttargs into ttparms to fix references to
25507 // other template parameters.
25509 complain);
25510 // Now substitute again with args based on tparms, to reduce
25511 // the level of the ttparms.
25514 complain);
25515 // Finally, tack the adjusted parms onto tparms.
25517 current_template_parms);
25519 }
25520 }
25521 else
25522 {
25524 tree newconst
25536 }
25539 }
25541 /* Returns a C++17 class deduction guide template based on the constructor
25542 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25543 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25545 static tree
25547 {
25551 location_t loc;
25555 {
25559 {
25562 }
25563 else
25573 }
25574 else
25575 {
25578 fn_tmpl
25588 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25589 fully specialized args for the enclosing class. Strip those off, as
25590 the deduction guide won't have those template parameters. */
25593 /* Discard the 'this' parameter. */
25601 {
25604 /* For a member template constructor, we need to flatten the two
25605 template parameter lists into one, and then adjust the function
25606 signature accordingly. This gets...complicated. */
25609 /* For a member template we should have two levels of parms/args, one
25610 for the class and one for the constructor. We stripped
25611 specialized args for further enclosing classes above. */
25615 /* Template args for translating references to the two-level template
25616 parameters into references to the one-level template parameters we
25617 are creating. */
25622 /* Template parms for the constructor template. */
25625 /* Template parms for the class template. */
25629 /* Template parms for the deduction guide start as a copy of the
25630 template parms for the class. We set current_template_parms for
25631 lookup_template_class_1. */
25637 /* Now we need to rewrite the constructor parms to append them to the
25638 class parms. */
25640 {
25655 }
25657 /* Now we have a final set of template parms to substitute into the
25658 function signature. */
25667 }
25669 }
25672 {
25673 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25677 }
25681 FUNCTION_DECL,
25698 }
25700 /* Deduce template arguments for the class template placeholder PTYPE for
25701 template TMPL based on the initializer INIT, and return the resulting
25702 type. */
25704 static tree
25706 tsubst_flags_t complain)
25707 {
25709 {
25710 /* We should have handled this in the caller. */
25716 }
25727 {
25730 {
25731 /* As an exception, the first phase in 16.3.1.7 (considering the
25732 initializer list as a single argument) is omitted if the
25733 initializer list consists of a single expression of type cv U,
25734 where U is a specialization of C or a class derived from a
25735 specialization of C. */
25746 }
25749 else
25751 }
25752 else
25763 /* Prune explicit deduction guides in copy-initialization context. */
25765 {
25771 {
25772 /* Found a nonconverting guide, prune the candidates. */
25779 }
25780 }
25785 {
25788 }
25791 // FIXME cache artificial deduction guides
25793 {
25798 else
25802 }
25806 /* If this is list-initialization and the class has a list constructor, first
25807 try deducing from the list as a single argument, as [over.match.list]. */
25811 {
25815 }
25817 {
25823 {
25824 /* That didn't work, now try treating the list as a sequence of
25825 arguments. */
25828 }
25829 }
25831 /* Maybe generate an implicit deduction guide. */
25833 {
25837 /* Generate a copy guide. */
25840 /* Generate a default guide. */
25844 {
25847 }
25848 }
25851 {
25853 " of %qT, as it has no non-explicit deduction guides or "
25856 }
25858 {
25862 }
25865 {
25869 }
25872 {
25882 }
25887 }
25889 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25890 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25892 tree
25894 {
25896 tf_warning_or_error,
25897 adc_unspecified);
25898 }
25900 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25901 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25902 The CONTEXT determines the context in which auto deduction is performed
25903 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25904 OUTER_TARGS are used during template argument deduction
25905 (context == adc_unify) to properly substitute the result, and is ignored
25906 in other contexts.
25908 For partial-concept-ids, extra args may be appended to the list of deduced
25909 template arguments prior to determining constraint satisfaction. */
25911 tree
25915 {
25916 tree targs;
25923 /* Defining a subset of type-dependent expressions that we can deduce
25924 from ahead of time isn't worth the trouble. */
25927 /* Similarly, we can't deduce from another undeduced decl. */
25932 /* C++17 class template argument deduction. */
25936 /* Nothing we can do with this, even in deduction context. */
25939 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25940 with either a new invented type template parameter U or, if the
25941 initializer is a braced-init-list (8.5.4), with
25942 std::initializer_list<U>. */
25944 {
25949 else
25950 {
25952 {
25956 "for deduction to %<std::initializer_list%>, use copy-"
25958 }
25960 }
25961 }
25972 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25973 and initializer has array type, deduce cv-qualified array type. */
25975 complain);
25977 {
25986 {
25990 }
25991 }
25992 else
25993 {
25995 tree tparms;
25999 else
26000 {
26004 }
26011 {
26013 /* Try again at instantiation time. */
26017 /* If type is error_mark_node a diagnostic must have been
26018 emitted by now. Also, having a mention to '<type error>'
26019 in the diagnostic is not really useful to the user. */
26020 {
26024 else
26029 }
26031 }
26032 }
26034 /* Check any placeholder constraints against the deduced type. */
26037 {
26038 /* Use the deduced type to check the associated constraints. If we
26039 have a partial-concept-id, rebuild the argument list so that
26040 we check using the extra arguments. */
26044 {
26047 }
26048 else
26051 {
26053 {
26055 {
26073 }
26075 }
26077 }
26078 }
26084 }
26086 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
26087 result. */
26089 tree
26091 {
26093 {
26099 /* In an abbreviated function template we didn't know we were dealing
26100 with a function template when we saw the auto return type, so update
26101 it to have the correct level. */
26103 }
26105 }
26107 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
26108 'decltype(auto)' or a deduced class template. */
26110 bool
26112 {
26118 else
26120 }
26122 /* for_each_template_parm callback for type_uses_auto. */
26124 int
26126 {
26128 }
26130 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
26131 a use of `auto'. Returns NULL_TREE otherwise. */
26133 tree
26135 {
26139 {
26140 /* The Concepts TS allows multiple autos in one type-specifier; just
26141 return the first one we find, do_auto_deduction will collect all of
26142 them. */
26146 else
26148 }
26149 else
26151 }
26153 /* For a given template T, return the vector of typedefs referenced
26154 in T for which access check is needed at T instantiation time.
26155 T is either a FUNCTION_DECL or a RECORD_TYPE.
26156 Those typedefs were added to T by the function
26157 append_type_to_template_for_access_check. */
26161 {
26162 tree ti;
26173 {
26178 }
26181 }
26183 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
26184 tied to T. That list of typedefs will be access checked at
26185 T instantiation time.
26186 T is either a FUNCTION_DECL or a RECORD_TYPE.
26187 TYPE_DECL is a TYPE_DECL node representing a typedef.
26188 SCOPE is the scope through which TYPE_DECL is accessed.
26189 LOCATION is the location of the usage point of TYPE_DECL.
26191 This function is a subroutine of
26192 append_type_to_template_for_access_check. */
26194 static void
26196 tree type_decl,
26197 tree scope,
26198 location_t location)
26199 {
26200 qualified_typedef_usage_t typedef_usage;
26201 tree ti;
26208 && type_decl
26222 }
26224 /* Append TYPE_DECL to the template TEMPL.
26225 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
26226 At TEMPL instanciation time, TYPE_DECL will be checked to see
26227 if it can be accessed through SCOPE.
26228 LOCATION is the location of the usage point of TYPE_DECL.
26230 e.g. consider the following code snippet:
26232 class C
26233 {
26234 typedef int myint;
26235 };
26237 template<class U> struct S
26238 {
26239 C::myint mi; // <-- usage point of the typedef C::myint
26240 };
26242 S<char> s;
26244 At S<char> instantiation time, we need to check the access of C::myint
26245 In other words, we need to check the access of the myint typedef through
26246 the C scope. For that purpose, this function will add the myint typedef
26247 and the scope C through which its being accessed to a list of typedefs
26248 tied to the template S. That list will be walked at template instantiation
26249 time and access check performed on each typedefs it contains.
26250 Note that this particular code snippet should yield an error because
26251 myint is private to C. */
26253 void
26255 tree type_decl,
26256 tree scope,
26257 location_t location)
26258 {
26264 /* Make sure we don't append the type to the template twice. */
26271 }
26273 /* Convert the generic type parameters in PARM that match the types given in the
26274 range [START_IDX, END_IDX) from the current_template_parms into generic type
26275 packs. */
26277 tree
26279 {
26290 {
26291 /* Create a distinct parameter pack type from the current parm and add it
26292 to the replacement args to tsubst below into the generic function
26293 parameter. */
26308 }
26314 /* If there are more levels then build up the replacement with the outer
26315 template parms. */
26319 replacement);
26322 }
26324 /* Entries in the decl_constraint hash table. */
26326 {
26327 tree decl;
26328 tree ci;
26329 };
26331 /* Hashing function and equality for constraint entries. */
26333 {
26335 {
26337 }
26340 {
26342 }
26343 };
26345 /* A mapping from declarations to constraint information. Note that
26346 both templates and their underlying declarations are mapped to the
26347 same constraint information.
26349 FIXME: This is defined in pt.c because garbage collection
26350 code is not being generated for constraint.cc. */
26354 /* Returns the template constraints of declaration T. If T is not
26355 constrained, return NULL_TREE. Note that T must be non-null. */
26357 tree
26359 {
26370 else
26372 }
26374 /* Associate the given constraint information CI with the declaration
26375 T. If T is a template, then the constraints are associated with
26376 its underlying declaration. Don't build associations if CI is
26377 NULL_TREE. */
26379 void
26381 {
26393 }
26395 /* Remove the associated constraints of the declaration T. */
26397 void
26399 {
26408 }
26410 /* Memoized satisfaction results for declarations. This
26411 maps the pair (constraint_info, arguments) to the result computed
26412 by constraints_satisfied_p. */
26415 {
26416 tree ci;
26417 tree args;
26418 tree result;
26419 };
26421 /* Hashing function and equality for constraint entries. */
26424 {
26426 {
26429 }
26432 {
26434 }
26435 };
26437 /* Memoized satisfaction results for concept checks. */
26440 {
26441 tree tmpl;
26442 tree args;
26443 tree result;
26444 };
26446 /* Hashing function and equality for constraint entries. */
26449 {
26451 {
26453 }
26456 {
26461 }
26462 };
26467 /* Search for a memoized satisfaction result. Returns one of the
26468 truth value nodes if previously memoized, or NULL_TREE otherwise. */
26470 tree
26472 {
26477 else
26479 }
26481 /* Memoize the result of a satisfication test. Returns the saved result. */
26483 tree
26485 {
26492 }
26494 /* Search for a memoized satisfaction result for a concept. */
26496 tree
26498 {
26503 else
26505 }
26507 /* Memoize the result of a concept check. Returns the saved result. */
26509 tree
26511 {
26518 }
26522 /* Returns a prior concept specialization. This returns the substituted
26523 and normalized constraints defined by the concept. */
26525 tree
26527 {
26532 else
26534 }
26536 /* Save a concept expansion for later. */
26538 tree
26540 {
26547 }
26549 static hashval_t
26551 {
26560 }
26562 /* Compare the constraints of two subsumption entries. The LEFT1 and
26563 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26564 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26566 static bool
26568 {
26576 }
26578 /* Key/value pair for learning and memoizing subsumption results. This
26579 associates a pair of check constraints (including arguments) with
26580 a boolean value indicating the result. */
26583 {
26584 tree t1;
26585 tree t2;
26587 };
26589 /* Hashing function and equality for constraint entries. */
26592 {
26594 {
26596 }
26599 {
26604 }
26605 };
26609 /* Search for a previously cached subsumption result. */
26613 {
26618 else
26620 }
26622 /* Save a subsumption result. */
26624 bool
26626 {
26633 }
26635 /* Set up the hash table for constraint association. */
26637 void
26639 {
26648 }
26650 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26651 0..N-1. */
26653 void
26655 {
26658 integer_type_node,
26659 NULL_TREE),
26663 }
26665 /* Set up the hash tables for template instantiations. */
26667 void
26669 {
26675 }
26677 /* Print stats about the template hash tables for -fstats. */
26679 void
26681 {
26690 }
26692 #if CHECKING_P
26696 /* Verify that build_non_dependent_expr () works, for various expressions,
26697 and that location wrappers don't affect the results. */
26699 static void
26701 {
26704 /* Verify constants, without and with location wrappers. */
26721 }
26723 /* Verify that type_dependent_expression_p () works correctly, even
26724 in the presence of location wrapper nodes. */
26726 static void
26728 {
26733 /* If no templates are involved, nothing is type-dependent. */
26739 /* Within a template, an unresolved name is always type-dependent. */
26742 /* Ensure it copes with NULL_TREE and errors. */
26746 /* A USING_DECL in a template should be type-dependent, even if wrapped
26747 with a location wrapper (PR c++/83799). */
26756 }
26758 /* Run all of the selftests within this file. */
26760 void
26762 {
26765 }