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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 }
3592 {
3593 /* We don't want to walk into the type of a variadic capture proxy,
3594 because we don't want to see the type parameter pack. */
3597 }
3599 {
3601 find_parameter_packs_r,
3604 }
3616 /* Not a parameter pack. */
3618 }
3621 {
3622 /* Add this parameter pack to the list. */
3624 }
3630 /* This switch statement will return immediately if we don't find a
3631 parameter pack. */
3633 {
3638 /* Check the template itself. */
3641 /* Check the template arguments. */
3655 /* Ignore the declaration of a capture proxy for a parameter pack. */
3663 /* Fall through. */
3708 {
3709 /* Look at explicit captures. */
3714 /* Since we defer implicit capture, look in the body as well. */
3720 }
3723 {
3724 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3725 type_pack_expansion_p to false so that any placeholders
3726 within the expression don't get marked as parameter packs. */
3734 }
3738 }
3741 }
3743 /* Determines if the expression or type T uses any parameter packs. */
3744 bool
3746 {
3755 }
3757 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3758 representation a base-class initializer into a parameter pack
3759 expansion. If all goes well, the resulting node will be an
3760 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3761 respectively. */
3762 tree
3764 {
3765 tree result;
3774 {
3775 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3776 class initializer. In this case, the TREE_PURPOSE will be a
3777 _TYPE node (representing the base class expansion we're
3778 initializing) and the TREE_VALUE will be a TREE_LIST
3779 containing the initialization arguments.
3781 The resulting expansion looks somewhat different from most
3782 expansions. Rather than returning just one _EXPANSION, we
3783 return a TREE_LIST whose TREE_PURPOSE is a
3784 TYPE_PACK_EXPANSION containing the bases that will be
3785 initialized. The TREE_VALUE will be identical to the
3786 original TREE_VALUE, which is a list of arguments that will
3787 be passed to each base. We do not introduce any new pack
3788 expansion nodes into the TREE_VALUE (although it is possible
3789 that some already exist), because the TREE_PURPOSE and
3790 TREE_VALUE all need to be expanded together with the same
3791 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3792 resulting TREE_PURPOSE will mention the parameter packs in
3793 both the bases and the arguments to the bases. */
3794 tree purpose;
3795 tree value;
3798 /* Determine which parameter packs will be used by the base
3799 class expansion. */
3808 {
3811 arg);
3814 }
3817 {
3818 /* Collect the sets of parameter packs used in each of the
3819 initialization arguments. */
3821 {
3822 /* Determine which parameter packs will be expanded in this
3823 argument. */
3826 }
3827 }
3831 /* Create the pack expansion type for the base type. */
3837 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3838 they will rarely be compared to anything. */
3842 }
3847 /* Build the PACK_EXPANSION_* node. */
3848 result = for_types
3853 {
3854 /* Propagate type and const-expression information. */
3857 /* Mark this read now, since the expansion might be length 0. */
3859 }
3860 else
3861 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3862 they will rarely be compared to anything. */
3865 /* Determine which parameter packs will be expanded. */
3872 /* Make sure we found some parameter packs. */
3874 {
3876 {
3879 else
3881 }
3883 }
3889 }
3891 /* Checks T for any "bare" parameter packs, which have not yet been
3892 expanded, and issues an error if any are found. This operation can
3893 only be done on full expressions or types (e.g., an expression
3894 statement, "if" condition, etc.), because we could have expressions like:
3896 foo(f(g(h(args)))...)
3898 where "args" is a parameter pack. check_for_bare_parameter_packs
3899 should not be called for the subexpressions args, h(args),
3900 g(h(args)), or f(g(h(args))), because we would produce erroneous
3901 error messages.
3903 Returns TRUE and emits an error if there were bare parameter packs,
3904 returns FALSE otherwise. */
3905 bool
3907 {
3914 /* A lambda might use a parameter pack from the containing context. */
3928 {
3932 {
3943 else
3948 else
3952 }
3955 }
3958 }
3960 /* Expand any parameter packs that occur in the template arguments in
3961 ARGS. */
3962 tree
3964 {
3973 /* First, determine if we need to expand anything, and the number of
3974 slots we'll need. */
3976 {
3981 {
3985 else
3987 }
3988 else
3989 {
3991 num_result_args++;
3992 }
3993 }
3995 /* If no expansion is necessary, we're done. */
3999 /* Expand arguments. */
4002 non_default_args_count =
4005 {
4008 {
4015 }
4016 else
4017 {
4020 }
4021 }
4025 }
4027 /* Checks if DECL shadows a template parameter.
4029 [temp.local]: A template-parameter shall not be redeclared within its
4030 scope (including nested scopes).
4032 Emits an error and returns TRUE if the DECL shadows a parameter,
4033 returns FALSE otherwise. */
4035 bool
4037 {
4038 tree olddecl;
4040 /* If we're not in a template, we can't possibly shadow a template
4041 parameter. */
4045 /* Figure out what we're shadowing. */
4049 /* If there's no previous binding for this name, we're not shadowing
4050 anything, let alone a template parameter. */
4054 /* If we're not shadowing a template parameter, we're done. Note
4055 that OLDDECL might be an OVERLOAD (or perhaps even an
4056 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4057 node. */
4061 /* We check for decl != olddecl to avoid bogus errors for using a
4062 name inside a class. We check TPFI to avoid duplicate errors for
4063 inline member templates. */
4069 /* Don't complain about the injected class name, as we've already
4070 complained about the class itself. */
4077 else
4082 }
4084 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4085 ORIG_LEVEL, DECL, and TYPE. */
4087 static tree
4091 tree decl,
4092 tree type)
4093 {
4104 }
4106 /* Find the canonical type parameter for the given template type
4107 parameter. Returns the canonical type parameter, which may be TYPE
4108 if no such parameter existed. */
4110 static tree
4112 {
4113 tree list;
4127 else
4128 {
4132 }
4133 }
4135 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4136 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4137 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4138 new one is created. */
4140 static tree
4142 tsubst_flags_t complain)
4143 {
4148 {
4167 /* Template template parameters need this. */
4169 {
4176 }
4177 }
4180 }
4182 /* Process information from new template parameter PARM and append it
4183 to the LIST being built. This new parameter is a non-type
4184 parameter iff IS_NON_TYPE is true. This new parameter is a
4185 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4186 is in PARM_LOC. */
4188 tree
4191 {
4200 {
4204 {
4208 else
4210 }
4213 }
4216 {
4222 {
4223 /* [temp.param]
4225 The top-level cv-qualifiers on the template-parameter are
4226 ignored when determining its type. */
4231 && !is_parameter_pack
4232 /* If we're in a nested template parameter list, the template
4233 template parameter could be a parameter pack. */
4235 {
4236 /* This template parameter is not a parameter pack, but it
4237 should be. Complain about "bare" parameter packs. */
4240 /* Recover by calling this a parameter pack. */
4242 }
4243 }
4245 /* A template parameter is not modifiable. */
4254 processing_template_decl,
4259 }
4260 else
4261 {
4262 tree t;
4266 {
4268 /* This is for distinguishing between real templates and template
4269 template parameters */
4273 }
4274 else
4275 {
4277 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4280 }
4287 processing_template_decl,
4291 }
4295 /* Build requirements for the type/template parameter.
4296 This must be done after SET_DECL_TEMPLATE_PARM_P or
4297 process_template_parm could fail. */
4302 /* Build the parameter node linking the parameter declaration,
4303 its default argument (if any), and its constraints (if any). */
4308 }
4310 /* The end of a template parameter list has been reached. Process the
4311 tree list into a parameter vector, converting each parameter into a more
4312 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4313 as PARM_DECLs. */
4315 tree
4317 {
4322 /* Pop the dummy parameter level and add the real one. */
4325 current_template_parms
4330 {
4334 }
4339 }
4341 // Explicitly indicate the end of the template parameter list. We assume
4342 // that the current template parameters have been constructed and/or
4343 // managed explicitly, as when creating new template template parameters
4344 // from a shorthand constraint.
4345 void
4347 {
4349 }
4351 /* end_template_decl is called after a template declaration is seen. */
4353 void
4355 {
4361 /* This matches the pushlevel in begin_template_parm_list. */
4366 }
4368 /* Takes a TREE_LIST representing a template parameter and convert it
4369 into an argument suitable to be passed to the type substitution
4370 functions. Note that If the TREE_LIST contains an error_mark
4371 node, the returned argument is error_mark_node. */
4373 tree
4375 {
4388 {
4392 {
4393 /* Turn this argument into a TYPE_ARGUMENT_PACK
4394 with a single element, which expands T. */
4403 }
4404 }
4405 else
4406 {
4410 {
4411 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4412 with a single element, which expands T. */
4422 }
4423 else
4425 }
4427 }
4429 /* Given a single level of template parameters (a TREE_VEC), return it
4430 as a set of template arguments. */
4432 static tree
4434 {
4444 }
4446 /* Given a set of template parameters, return them as a set of template
4447 arguments. The template parameters are represented as a TREE_VEC, in
4448 the form documented in cp-tree.h for template arguments. */
4450 static tree
4452 {
4453 tree header;
4458 /* If there is only one level of template parameters, we do not
4459 create a TREE_VEC of TREE_VECs. Instead, we return a single
4460 TREE_VEC containing the arguments. */
4465 {
4470 else
4472 }
4475 }
4477 /* Within the declaration of a template, return the currently active
4478 template parameters as an argument TREE_VEC. */
4480 static tree
4482 {
4484 }
4486 /* Update the declared TYPE by doing any lookups which were thought to be
4487 dependent, but are not now that we know the SCOPE of the declarator. */
4489 tree
4491 {
4502 /* Don't bother building up the args in this case. */
4504 {
4505 /* tsubst in the args corresponding to the template parameters,
4506 including auto if present. Most things will be unchanged, but
4507 make_typename_type and tsubst_qualified_id will resolve
4508 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4511 tree pushed;
4513 {
4517 }
4522 }
4528 {
4531 else
4533 }
4535 }
4537 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4538 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4539 the new template is a member template. */
4541 tree
4543 {
4551 }
4553 struct template_parm_data
4554 {
4555 /* The level of the template parameters we are currently
4556 processing. */
4559 /* The index of the specialization argument we are currently
4560 processing. */
4563 /* An array whose size is the number of template parameters. The
4564 elements are nonzero if the parameter has been used in any one
4565 of the arguments processed so far. */
4568 /* An array whose size is the number of template arguments. The
4569 elements are nonzero if the argument makes use of template
4570 parameters of this level. */
4572 };
4574 /* Subroutine of push_template_decl used to see if each template
4575 parameter in a partial specialization is used in the explicit
4576 argument list. If T is of the LEVEL given in DATA (which is
4577 treated as a template_parm_data*), then DATA->PARMS is marked
4578 appropriately. */
4580 static int
4582 {
4590 {
4593 }
4595 /* In C++17 the type of a non-type argument is a deduced context. */
4600 data,
4601 NULL,
4604 /* Return zero so that for_each_template_parm will continue the
4605 traversal of the tree; we want to mark *every* template parm. */
4607 }
4609 /* Process the partial specialization DECL. */
4611 static tree
4613 {
4620 tree inner_parms;
4621 tree inst;
4631 /* A concept cannot be specialized. */
4633 {
4636 }
4641 /* We check that each of the template parameters given in the
4642 partial specialization is used in the argument list to the
4643 specialization. For example:
4645 template <class T> struct S;
4646 template <class T> struct S<T*>;
4648 The second declaration is OK because `T*' uses the template
4649 parameter T, whereas
4651 template <class T> struct S<int>;
4653 is no good. Even trickier is:
4655 template <class T>
4656 struct S1
4657 {
4658 template <class U>
4659 struct S2;
4660 template <class U>
4661 struct S2<T>;
4662 };
4664 The S2<T> declaration is actually invalid; it is a
4665 full-specialization. Of course,
4667 template <class U>
4668 struct S2<T (*)(U)>;
4670 or some such would have been OK. */
4678 {
4683 NULL,
4685 }
4688 {
4689 /* One of the template parms was not used in a deduced context in the
4690 specialization. */
4692 {
4696 }
4700 }
4705 /* [temp.class.spec]
4707 The argument list of the specialization shall not be identical to
4708 the implicit argument list of the primary template. */
4709 tree main_args
4712 && (!flag_concepts
4715 {
4719 else
4723 }
4725 /* A partial specialization that replaces multiple parameters of the
4726 primary template with a pack expansion is less specialized for those
4727 parameters. */
4729 {
4731 "primary template because it replaces multiple parameters "
4734 /* Avoid crash in process_partial_specialization. */
4736 }
4738 /* If we aren't in a dependent class, we can actually try deduction. */
4740 /* FIXME we should be able to handle a partial specialization of a
4741 partial instantiation, but currently we can't (c++/41727). */
4744 {
4748 maintmpl);
4749 }
4751 /* [temp.class.spec]
4753 A partially specialized non-type argument expression shall not
4754 involve template parameters of the partial specialization except
4755 when the argument expression is a simple identifier.
4757 The type of a template parameter corresponding to a specialized
4758 non-type argument shall not be dependent on a parameter of the
4759 specialization.
4761 Also, we verify that pack expansions only occur at the
4762 end of the argument list. */
4766 {
4773 {
4774 /* Extract the arguments from the argument pack. We'll be
4775 iterating over these in the following loop. */
4778 }
4781 {
4783 /* Get the Jth argument in the parameter pack. */
4787 {
4788 /* Pack expansions must come at the end of the
4789 argument list. */
4792 {
4796 else
4799 }
4800 }
4803 /* We only care about the pattern. */
4809 /* This next two lines are the `argument expression is not just a
4810 simple identifier' condition and also the `specialized
4811 non-type argument' bit. */
4815 {
4819 arg);
4820 else
4821 {
4822 /* Look at the corresponding template parameter,
4823 marking which template parameters its type depends
4824 upon. */
4828 {
4829 /* We haven't yet initialized TPD2. Do so now. */
4831 /* The number of parameters here is the number in the
4832 main template, which, as checked in the assertion
4833 above, is NARGS. */
4837 }
4839 /* Mark the template parameters. But this time, we're
4840 looking for the template parameters of the main
4841 template, not in the specialization. */
4848 NULL,
4852 {
4853 /* The type depended on some template parameters.
4854 If they are fully specialized in the
4855 specialization, that's OK. */
4864 "type %qT of template argument %qE depends "
4866 "type %qT of template argument %qE depends "
4868 type,
4869 arg);
4870 }
4871 }
4872 }
4873 }
4874 }
4876 /* We should only get here once. */
4880 // Build the template decl.
4889 /* Give template template parms a DECL_CONTEXT of the template
4890 for which they are a parameter. */
4892 {
4896 }
4899 /* We didn't register this in check_explicit_specialization so we could
4900 wait until the constraints were set. */
4902 else
4912 {
4918 {
4926 "declaration of %qD ambiguates earlier template "
4930 "partial specialization of %qD after instantiation "
4932 }
4933 }
4936 }
4938 /* PARM is a template parameter of some form; return the corresponding
4939 TEMPLATE_PARM_INDEX. */
4941 static tree
4943 {
4956 }
4958 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4959 parameter packs used by the template parameter PARM. */
4961 static void
4963 {
4964 /* A type parm can't refer to another parm. */
4968 {
4972 }
4979 }
4981 /* PARM is a template parameter pack. Return any parameter packs used in
4982 its type or the type of any of its template parameters. If there are
4983 any such packs, it will be instantiated into a fixed template parameter
4984 list by partial instantiation rather than be fully deduced. */
4986 tree
4988 {
4989 /* This can only be true in a member template. */
4992 /* This can only be true for a parameter pack. */
4995 /* A type parm can't refer to another parm. */
5009 }
5011 /* Check that a template declaration's use of default arguments and
5012 parameter packs is not invalid. Here, PARMS are the template
5013 parameters. IS_PRIMARY is true if DECL is the thing declared by
5014 a primary template. IS_PARTIAL is true if DECL is a partial
5015 specialization.
5017 IS_FRIEND_DECL is nonzero if DECL is either a non-defining friend
5018 function template declaration or a friend class template
5019 declaration. In the function case, 1 indicates a declaration, 2
5020 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
5021 emitted for extraneous default arguments.
5023 Returns TRUE if there were no errors found, FALSE otherwise. */
5025 bool
5028 {
5031 tree parm_level;
5034 /* [temp.param]
5036 A default template-argument shall not be specified in a
5037 function template declaration or a function template definition, nor
5038 in the template-parameter-list of the definition of a member of a
5039 class template. */
5043 /* You can't have a function template declaration in a local
5044 scope, nor you can you define a member of a class template in a
5045 local scope. */
5053 /* A lambda doesn't have an explicit declaration; don't complain
5054 about the parms of the enclosing class. */
5061 /* If this is either a friend defined in the scope of the class
5062 or a member function. */
5068 /* And, if it was a member function, it really was defined in
5069 the scope of the class. */
5072 /* We already checked these parameters when the template was
5073 declared, so there's no need to do it again now. This function
5074 was defined in class scope, but we're processing its body now
5075 that the class is complete. */
5078 /* Core issue 226 (C++0x only): the following only applies to class
5079 templates. */
5082 {
5083 /* [temp.param]
5085 If a template-parameter has a default template-argument, all
5086 subsequent template-parameters shall have a default
5087 template-argument supplied. */
5089 {
5096 {
5106 {
5108 /* For better subsequent error-recovery, we indicate that
5109 there should have been a default argument. */
5112 }
5114 && !is_friend_decl
5115 /* Don't complain about an enclosing partial
5116 specialization. */
5121 /* A fixed parameter pack will be partially
5122 instantiated into a fixed length list. */
5124 {
5125 /* A primary class template can only have one
5126 parameter pack, at the end of the template
5127 parameter list. */
5135 }
5136 }
5137 }
5138 }
5141 || is_partial
5142 || !is_primary
5144 /* For an ordinary class template, default template arguments are
5145 allowed at the innermost level, e.g.:
5146 template <class T = int>
5147 struct S {};
5148 but, in a partial specialization, they're not allowed even
5149 there, as we have in [temp.class.spec]:
5151 The template parameter list of a specialization shall not
5152 contain default template argument values.
5154 So, for a partial specialization, or for a function template
5155 (in C++98/C++03), we look at all of them. */
5156 ;
5157 else
5158 /* But, for a primary class template that is not a partial
5159 specialization we look at all template parameters except the
5160 innermost ones. */
5163 /* Figure out what error message to issue. */
5178 else
5179 /* Per [temp.param]/9, "A default template-argument shall not be
5180 specified in the template-parameter-lists of the definition of
5181 a member of a class template that appears outside of the member's
5182 class.", thus if we aren't handling a member of a class template
5183 there is no need to examine the parameters. */
5187 /* If we're inside a class definition, there's no need to
5188 examine the parameters to the class itself. On the one
5189 hand, they will be checked when the class is defined, and,
5190 on the other, default arguments are valid in things like:
5191 template <class T = double>
5192 struct S { template <class U> void f(U); };
5193 Here the default argument for `S' has no bearing on the
5194 declaration of `f'. */
5196 else
5197 /* Check everything. */
5203 {
5210 {
5215 {
5217 {
5224 }
5226 /* Clear out the default argument so that we are not
5227 confused later. */
5229 }
5230 }
5232 /* At this point, if we're still interested in issuing messages,
5233 they must apply to classes surrounding the object declared. */
5237 }
5240 }
5242 /* Worker for push_template_decl_real, called via
5243 for_each_template_parm. DATA is really an int, indicating the
5244 level of the parameters we are interested in. If T is a template
5245 parameter of that level, return nonzero. */
5247 static int
5249 {
5255 else
5258 }
5260 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5261 DATA is really an int, indicating the innermost outer level of parameters.
5262 If T is a template parameter of that level or further out, return
5263 nonzero. */
5265 static int
5267 {
5273 else
5276 }
5278 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5279 parameters given by current_template_args, or reuses a
5280 previously existing one, if appropriate. Returns the DECL, or an
5281 equivalent one, if it is replaced via a call to duplicate_decls.
5283 If IS_FRIEND is true, DECL is a friend declaration. */
5285 tree
5287 {
5288 tree tmpl;
5289 tree args;
5290 tree info;
5291 tree ctx;
5295 /* True if the template is a member template, in the sense of
5296 [temp.mem]. */
5302 /* See if this is a partial specialization. */
5315 /* For a friend, we want the context of the friend, not
5316 the type of which it is a friend. */
5320 /* In the case of a virtual function, we want the class in which
5321 it is defined. */
5323 else
5324 /* Otherwise, if we're currently defining some class, the DECL
5325 is assumed to be a member of the class. */
5334 /* See if this is a primary template. */
5337 /* A friend template that specifies a class context, i.e.
5338 template <typename T> friend void A<T>::f();
5339 is not primary. */
5344 else
5348 {
5355 {
5358 }
5360 {
5362 {
5365 }
5367 {
5368 /* [temp.mem]
5370 A destructor shall not be a member template. */
5373 }
5380 {
5381 /* [basic.stc.dynamic.allocation]
5383 An allocation function can be a function
5384 template. ... Template allocation functions shall
5385 have two or more parameters. */
5388 }
5389 }
5392 {
5393 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5396 {
5402 }
5403 }
5406 /* alias-declaration */
5410 else
5411 {
5414 }
5415 }
5417 /* Check to see that the rules regarding the use of default
5418 arguments are not being violated. We check args for a friend
5419 functions when we know whether it's a definition, introducing
5420 declaration or re-declaration. */
5425 /* Ensure that there are no parameter packs in the type of this
5426 declaration that have not been expanded. */
5428 {
5429 /* Check each of the arguments individually to see if there are
5430 any bare parameter packs. */
5436 {
5439 {
5440 /* This is a PARM_DECL that contains unexpanded parameter
5441 packs. We have already complained about this in the
5442 check_for_bare_parameter_packs call, so just replace
5443 these types with ERROR_MARK_NODE. */
5446 }
5450 }
5452 /* Check for bare parameter packs in the return type and the
5453 exception specifiers. */
5455 /* Errors were already issued, set return type to int
5456 as the frontend doesn't expect error_mark_node as
5457 the return type. */
5461 }
5466 {
5469 }
5482 {
5487 /* If DECL is a TYPE_DECL for a class-template, then there won't
5488 be DECL_LANG_SPECIFIC. The information equivalent to
5489 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5493 {
5494 /* Since a template declaration already existed for this
5495 class-type, we must be redeclaring it here. Make sure
5496 that the redeclaration is valid. */
5498 current_template_parms,
5500 /* We don't need to create a new TEMPLATE_DECL; just use the
5501 one we already had. */
5503 }
5504 else
5505 {
5507 member_template_p);
5512 {
5513 /* A specialization of a member template of a template
5514 class. */
5518 }
5519 }
5520 }
5521 else
5522 {
5528 {
5531 }
5539 {
5540 tree new_tmpl;
5542 /* The declaration is a specialization of a member
5543 template, declared outside the class. Therefore, the
5544 innermost template arguments will be NULL, so we
5545 replace them with the arguments determined by the
5546 earlier call to check_explicit_specialization. */
5549 new_tmpl
5551 member_template_p);
5561 args,
5564 }
5566 /* Make sure the template headers we got make sense. */
5571 {
5576 }
5577 else
5579 {
5584 {
5588 else
5592 /* Avoid crash in import_export_decl. */
5595 }
5600 /* Can happen in erroneous input. */
5602 else
5604 }
5606 /* Check that the parms are used in the appropriate qualifying scopes
5607 in the declarator. */
5611 {
5617 /* Avoid crash in import_export_decl. */
5620 }
5621 }
5626 /* Push template declarations for global functions and types. Note
5627 that we do not try to push a global template friend declared in a
5628 template class; such a thing may well depend on the template
5629 parameters of the class. */
5632 {
5637 /* Hide template friend classes that haven't been declared yet. */
5639 {
5642 }
5643 }
5646 {
5651 /* Give template template parms a DECL_CONTEXT of the template
5652 for which they are a parameter. */
5655 {
5659 }
5665 }
5667 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5668 back to its most general template. If TMPL is a specialization,
5669 ARGS may only have the innermost set of arguments. Add the missing
5670 argument levels if necessary. */
5678 else
5679 {
5684 }
5687 && !is_friend
5690 /* Set DECL_COMDAT on template instantiations; if we force
5691 them to be emitted by explicit instantiation or -frepo,
5692 mark_needed will tell cgraph to do the right thing. */
5696 }
5698 tree
5700 {
5702 }
5704 /* FN is an inheriting constructor that inherits from the constructor
5705 template INHERITED; turn FN into a constructor template with a matching
5706 template header. */
5708 tree
5710 {
5711 tree inner_parms
5714 tree parms
5725 }
5727 /* Called when a class template TYPE is redeclared with the indicated
5728 template PARMS, e.g.:
5730 template <class T> struct S;
5731 template <class T> struct S {}; */
5733 bool
5735 {
5736 tree tmpl;
5737 tree tmpl_parms;
5741 {
5744 }
5748 /* The type is nested in some template class. Nothing to worry
5749 about here; there are no new template parameters for the nested
5750 type. */
5754 {
5756 tmpl);
5758 }
5764 {
5774 }
5777 {
5778 tree tmpl_parm;
5779 tree parm;
5780 tree tmpl_default;
5781 tree parm_default;
5795 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5796 TEMPLATE_DECL. */
5806 {
5810 }
5813 {
5814 /* We have in [temp.param]:
5816 A template-parameter may not be given default arguments
5817 by two different declarations in the same scope. */
5822 }
5825 /* Update the previous template parameters (which are the ones
5826 that will really count) with the new default value. */
5829 /* Update the new parameters, too; they'll be used as the
5830 parameters for any members. */
5833 /* Give each template template parm in this redeclaration a
5834 DECL_CONTEXT of the template for which they are a parameter. */
5836 {
5839 }
5843 }
5845 // Cannot redeclare a class template with a different set of constraints.
5847 {
5852 }
5855 }
5857 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5858 to be used when the caller has already checked
5859 (processing_template_decl
5860 && !instantiation_dependent_expression_p (expr)
5861 && potential_constant_expression (expr))
5862 and cleared processing_template_decl. */
5864 tree
5866 {
5869 complain,
5873 }
5875 /* Simplify EXPR if it is a non-dependent expression. Returns the
5876 (possibly simplified) expression. */
5878 tree
5880 {
5884 /* If we're in a template, but EXPR isn't value dependent, simplify
5885 it. We're supposed to treat:
5887 template <typename T> void f(T[1 + 1]);
5888 template <typename T> void f(T[2]);
5890 as two declarations of the same function, for example. */
5893 {
5894 processing_template_decl_sentinel s;
5896 }
5898 }
5900 tree
5902 {
5904 }
5906 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5907 an uninstantiated expression. */
5909 tree
5911 {
5915 {
5918 else
5919 {
5920 processing_template_decl_sentinel s;
5922 }
5923 }
5925 }
5927 /* True iff T is a specialization of a variable template. */
5929 bool
5931 {
5936 }
5938 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5939 template declaration, or a TYPE_DECL for an alias declaration. */
5941 bool
5943 {
5951 }
5953 /* Return TRUE iff T is a specialization of an alias template. */
5955 bool
5957 {
5958 /* It's an alias template specialization if it's an alias and its
5959 TYPE_NAME is a specialization of a primary template. */
5965 }
5967 /* An alias template is complex from a SFINAE perspective if a template-id
5968 using that alias can be ill-formed when the expansion is not, as with
5969 the void_t template. We determine this by checking whether the
5970 expansion for the alias template uses all its template parameters. */
5972 struct uses_all_template_parms_data
5973 {
5976 };
5978 static int
5980 {
5988 }
5990 static bool
5992 {
6007 }
6009 /* Return TRUE iff T is a specialization of a complex alias template with
6010 dependent template-arguments. */
6012 bool
6014 {
6027 }
6029 /* Return the number of innermost template parameters in TMPL. */
6031 static int
6033 {
6036 }
6038 /* Return either TMPL or another template that it is equivalent to under DR
6039 1286: An alias that just changes the name of a template is equivalent to
6040 the other template. */
6042 static tree
6044 {
6047 {
6048 /* Determine if the alias is equivalent to an underlying template. */
6060 tree alias_args = INNERMOST_TEMPLATE_ARGS
6065 /* Alias is equivalent. Strip it and repeat. */
6067 }
6070 }
6072 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6073 must be a reference-to-function or a pointer-to-function type, as specified
6074 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6075 and check that the resulting function has external linkage. */
6077 static tree
6079 tsubst_flags_t complain)
6080 {
6083 linkage_kind linkage;
6098 /* [temp.arg.nontype]/1
6100 A template-argument for a non-type, non-template template-parameter
6101 shall be one of:
6102 [...]
6103 -- the address of an object or function with external [C++11: or
6104 internal] linkage. */
6107 {
6109 {
6115 else
6118 }
6120 }
6124 {
6126 {
6131 else
6135 }
6137 }
6139 accept:
6146 }
6148 /* Subroutine of convert_nontype_argument.
6149 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6150 Emit an error otherwise. */
6152 static bool
6154 tsubst_flags_t complain)
6155 {
6172 {
6177 else
6179 }
6181 }
6183 /* Returns TRUE iff the address of OP is value-dependent.
6185 14.6.2.4 [temp.dep.temp]:
6186 A non-integral non-type template-argument is dependent if its type is
6187 dependent or it has either of the following forms
6188 qualified-id
6189 & qualified-id
6190 and contains a nested-name-specifier which specifies a class-name that
6191 names a dependent type.
6193 We generalize this to just say that the address of a member of a
6194 dependent class is value-dependent; the above doesn't cover the
6195 address of a static data member named with an unqualified-id. */
6197 static bool
6199 {
6200 /* We could use get_inner_reference here, but there's no need;
6201 this is only relevant for template non-type arguments, which
6202 can only be expressed as &id-expression. */
6204 {
6208 }
6211 }
6213 /* The next set of functions are used for providing helpful explanatory
6214 diagnostics for failed overload resolution. Their messages should be
6215 indented by two spaces for consistency with the messages in
6216 call.c */
6218 static int
6220 {
6222 }
6224 /* Other failure functions should call this one, to provide a single function
6225 for setting a breakpoint on. */
6227 static int
6229 {
6231 }
6233 static int
6235 {
6240 }
6242 static int
6244 {
6250 }
6252 static int
6254 {
6258 }
6260 static int
6262 {
6265 " template parameter %qD is not a parameter pack, but "
6269 }
6271 static int
6273 {
6276 " template argument %qE does not match "
6280 }
6282 static int
6284 {
6288 }
6290 static int
6292 {
6298 }
6300 static int
6302 {
6304 {
6309 else
6311 " deduced conflicting values for non-type parameter "
6313 }
6315 }
6317 static int
6319 {
6322 " variable-sized array type %qT is not "
6324 arg);
6326 }
6328 static int
6330 {
6334 arg);
6336 }
6338 static int
6340 {
6342 {
6348 else
6353 }
6355 }
6357 static int
6359 {
6361 }
6363 static int
6366 {
6368 }
6370 static int
6373 {
6379 }
6381 static int
6384 {
6387 {
6395 }
6397 }
6399 static int
6401 {
6404 " template parameters of a template template argument are "
6407 }
6409 static int
6411 {
6417 }
6419 static int
6421 {
6426 }
6428 /* Attempt to convert the non-type template parameter EXPR to the
6429 indicated TYPE. If the conversion is successful, return the
6430 converted value. If the conversion is unsuccessful, return
6431 NULL_TREE if we issued an error message, or error_mark_node if we
6432 did not. We issue error messages for out-and-out bad template
6433 parameters, but not simply because the conversion failed, since we
6434 might be just trying to do argument deduction. Both TYPE and EXPR
6435 must be non-dependent.
6437 The conversion follows the special rules described in
6438 [temp.arg.nontype], and it is much more strict than an implicit
6439 conversion.
6441 This function is called twice for each template argument (see
6442 lookup_template_class for a more accurate description of this
6443 problem). This means that we need to handle expressions which
6444 are not valid in a C++ source, but can be created from the
6445 first call (for instance, casts to perform conversions). These
6446 hacks can go away after we fix the double coercion problem. */
6448 static tree
6450 {
6451 tree expr_type;
6455 /* Detect immediately string literals as invalid non-type argument.
6456 This special-case is not needed for correctness (we would easily
6457 catch this later), but only to provide better diagnostic for this
6458 common user mistake. As suggested by DR 100, we do not mention
6459 linkage issues in the diagnostic as this is not the point. */
6460 /* FIXME we're making this OK. */
6462 {
6468 }
6470 /* Add the ADDR_EXPR now for the benefit of
6471 value_dependent_expression_p. */
6474 {
6478 }
6480 /* If we are in a template, EXPR may be non-dependent, but still
6481 have a syntactic, rather than semantic, form. For example, EXPR
6482 might be a SCOPE_REF, rather than the VAR_DECL to which the
6483 SCOPE_REF refers. Preserving the qualifying scope is necessary
6484 so that access checking can be performed when the template is
6485 instantiated -- but here we need the resolved form so that we can
6486 convert the argument. */
6498 /* If the argument is non-dependent, perform any conversions in
6499 non-dependent context as well. */
6507 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6508 to a non-type argument of "nullptr". */
6512 /* In C++11, integral or enumeration non-type template arguments can be
6513 arbitrary constant expressions. Pointer and pointer to
6514 member arguments can be general constant expressions that evaluate
6515 to a null value, but otherwise still need to be of a specific form. */
6517 {
6519 /* A PTRMEM_CST is already constant, and a valid template
6520 argument for a parameter of pointer to member type, we just want
6521 to leave it in that form rather than lower it to a
6525 {
6526 /* C++17: A template-argument for a non-type template-parameter shall
6527 be a converted constant expression (8.20) of the type of the
6528 template-parameter. */
6534 }
6536 {
6541 }
6542 }
6546 else
6549 /* HACK: Due to double coercion, we can get a
6550 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6551 which is the tree that we built on the first call (see
6552 below when coercing to reference to object or to reference to
6553 function). We just strip everything and get to the arg.
6554 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6555 for examples. */
6557 {
6563 {
6564 /* ??? Maybe we could use convert_from_reference here, but we
6565 would need to relax its constraints because the NOP_EXPR
6566 could actually change the type to something more cv-qualified,
6567 and this is not folded by convert_from_reference. */
6572 && (same_type_ignoring_top_level_qualifiers_p
6575 {
6578 }
6579 }
6580 }
6582 /* [temp.arg.nontype]/5, bullet 1
6584 For a non-type template-parameter of integral or enumeration type,
6585 integral promotions (_conv.prom_) and integral conversions
6586 (_conv.integral_) are applied. */
6588 {
6590 {
6595 }
6600 /* Notice that there are constant expressions like '4 % 0' which
6601 do not fold into integer constants. */
6604 {
6606 {
6610 else
6616 /* else cxx_constant_value complained but gave us
6617 a real constant, so go ahead. */
6619 {
6620 /* Some assemble time constant expressions like
6621 (intptr_t)&&lab1 - (intptr_t)&&lab2 or
6622 4 + (intptr_t)&&var satisfy reduced_constant_expression_p
6623 as we can emit them into .rodata initializers of
6624 variables, yet they can't fold into an INTEGER_CST at
6625 compile time. Refuse them here. */
6630 }
6631 }
6632 else
6634 }
6636 /* Avoid typedef problems. */
6639 }
6640 /* [temp.arg.nontype]/5, bullet 2
6642 For a non-type template-parameter of type pointer to object,
6643 qualification conversions (_conv.qual_) and the array-to-pointer
6644 conversion (_conv.array_) are applied. */
6646 {
6649 /* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
6650 decay_conversion or an explicit cast. If it's a problematic cast,
6651 we'll complain about it below. */
6653 {
6658 {
6661 }
6662 }
6664 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6666 A template-argument for a non-type, non-template template-parameter
6667 shall be one of: [...]
6669 -- the name of a non-type template-parameter;
6670 -- the address of an object or function with external linkage, [...]
6671 expressed as "& id-expression" where the & is optional if the name
6672 refers to a function or array, or if the corresponding
6673 template-parameter is a reference.
6675 Here, we do not care about functions, as they are invalid anyway
6676 for a parameter of type pointer-to-object. */
6679 /* Non-type template parameters are OK. */
6680 ;
6684 {
6686 {
6689 "because %qD is a variable, not the address of "
6692 }
6694 {
6700 }
6701 /* Other values, like integer constants, might be valid
6702 non-type arguments of some other type. */
6704 }
6705 else
6706 {
6710 {
6715 }
6717 {
6723 }
6726 {
6731 }
6732 /* C++17: For a non-type template-parameter of reference or pointer
6733 type, the value of the constant expression shall not refer to (or
6734 for a pointer type, shall not be the address of):
6735 * a subobject (4.5),
6736 * a temporary object (15.2),
6737 * a string literal (5.13.5),
6738 * the result of a typeid expression (8.2.8), or
6739 * a predefined __func__ variable (11.4.1). */
6741 {
6744 decl);
6746 }
6750 {
6755 }
6757 {
6761 decl);
6763 }
6764 }
6771 }
6772 /* [temp.arg.nontype]/5, bullet 3
6774 For a non-type template-parameter of type reference to object, no
6775 conversions apply. The type referred to by the reference may be more
6776 cv-qualified than the (otherwise identical) type of the
6777 template-argument. The template-parameter is bound directly to the
6778 template-argument, which must be an lvalue. */
6780 {
6782 expr_type))
6786 {
6791 }
6794 {
6799 }
6801 /* [temp.arg.nontype]/1
6803 A template-argument for a non-type, non-template template-parameter
6804 shall be one of: [...]
6806 -- the address of an object or function with external linkage. */
6809 {
6812 {
6815 "because a reference variable does not have a constant "
6818 }
6819 }
6823 /* OK, dependent reference. We don't want to ask whether a DECL is
6825 else
6826 {
6828 {
6834 }
6836 /* DR 1155 allows internal linkage in C++11 and up. */
6839 {
6845 }
6848 }
6852 }
6853 /* [temp.arg.nontype]/5, bullet 4
6855 For a non-type template-parameter of type pointer to function, only
6856 the function-to-pointer conversion (_conv.func_) is applied. If the
6857 template-argument represents a set of overloaded functions (or a
6858 pointer to such), the matching function is selected from the set
6859 (_over.over_). */
6861 {
6862 /* If the argument is a template-id, we might not have enough
6863 context information to decay the pointer. */
6865 {
6869 }
6872 /* Null pointer values are OK in C++11. */
6878 }
6879 /* [temp.arg.nontype]/5, bullet 5
6881 For a non-type template-parameter of type reference to function, no
6882 conversions apply. If the template-argument represents a set of
6883 overloaded functions, the matching function is selected from the set
6884 (_over.over_). */
6886 {
6888 {
6890 {
6895 }
6897 }
6902 }
6903 /* [temp.arg.nontype]/5, bullet 6
6905 For a non-type template-parameter of type pointer to member function,
6906 no conversions apply. If the template-argument represents a set of
6907 overloaded member functions, the matching member function is selected
6908 from the set (_over.over_). */
6910 {
6915 /* [temp.arg.nontype] bullet 1 says the pointer to member
6916 expression must be a pointer-to-member constant. */
6921 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6922 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6925 }
6926 /* [temp.arg.nontype]/5, bullet 7
6928 For a non-type template-parameter of type pointer to data member,
6929 qualification conversions (_conv.qual_) are applied. */
6931 {
6932 /* [temp.arg.nontype] bullet 1 says the pointer to member
6933 expression must be a pointer-to-member constant. */
6941 }
6943 {
6945 {
6950 }
6952 }
6953 /* A template non-type parameter must be one of the above. */
6954 else
6957 /* Sanity check: did we actually convert the argument to the
6958 right type? */
6962 }
6964 /* Subroutine of coerce_template_template_parms, which returns 1 if
6965 PARM_PARM and ARG_PARM match using the rule for the template
6966 parameters of template template parameters. Both PARM and ARG are
6967 template parameters; the rest of the arguments are the same as for
6968 coerce_template_template_parms.
6969 */
6970 static int
6972 tree arg,
6973 tsubst_flags_t complain,
6974 tree in_decl,
6975 tree outer_args)
6976 {
6985 {
6987 /* We encounter instantiations of templates like
6988 template <template <template <class> class> class TT>
6989 class C; */
6990 {
6997 }
6998 /* Fall through. */
7003 /* Argument is a parameter pack but parameter is not. */
7008 /* The tsubst call is used to handle cases such as
7010 template <int> class C {};
7011 template <class T, template <T> class TT> class D {};
7012 D<int, C> d;
7014 i.e. the parameter list of TT depends on earlier parameters. */
7016 {
7021 }
7025 /* Argument is a parameter pack but parameter is not. */
7032 }
7035 }
7037 /* Coerce template argument list ARGLIST for use with template
7038 template-parameter TEMPL. */
7040 static tree
7042 tsubst_flags_t complain)
7043 {
7044 /* Consider an example where a template template parameter declared as
7046 template <class T, class U = std::allocator<T> > class TT
7048 The template parameter level of T and U are one level larger than
7049 of TT. To proper process the default argument of U, say when an
7050 instantiation `TT<int>' is seen, we need to build the full
7051 arguments containing {int} as the innermost level. Outer levels,
7052 available when not appearing as default template argument, can be
7053 obtained from the arguments of the enclosing template.
7055 Suppose that TT is later substituted with std::vector. The above
7056 instantiation is `TT<int, std::allocator<T> >' with TT at
7057 level 1, and T at level 2, while the template arguments at level 1
7058 becomes {std::vector} and the inner level 2 is {int}. */
7062 {
7064 /* We want arguments for the partial specialization, not arguments for
7065 the primary template. */
7067 else
7069 }
7071 {
7072 /* This is an argument of the current template, so we haven't set
7073 DECL_CONTEXT yet. */
7074 tree relevant_template_parms;
7076 /* Parameter levels that are greater than the level of the given
7077 template template parm are irrelevant. */
7084 }
7091 complain,
7094 }
7096 /* A cache of template template parameters with match-all default
7097 arguments. */
7099 static void
7101 {
7105 }
7106 static tree
7108 {
7113 }
7115 /* T is a bound template template-parameter. Copy its arguments into default
7116 arguments of the template template-parameter's template parameters. */
7118 static tree
7120 {
7143 {
7146 {
7149 }
7150 }
7154 }
7156 /* ARG is a bound potential template template-argument, and PARGS is a list
7157 of arguments for the corresponding template template-parameter. Adjust
7158 PARGS as appropriate for application to ARG's template, and if ARG is a
7159 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7160 arguments to the template template parameter. */
7162 static tree
7164 {
7168 {
7169 /* When comparing two template template-parameters in partial ordering,
7170 rewrite the one currently being used as an argument to have default
7171 arguments for all parameters. */
7177 }
7178 else
7179 {
7180 tree aparms
7185 }
7188 }
7190 /* Subroutine of unify for the case when PARM is a
7191 BOUND_TEMPLATE_TEMPLATE_PARM. */
7193 static int
7196 {
7200 /* The template template parm might be variadic and the argument
7201 not, so flatten both argument lists. */
7206 {
7207 /* In keeping with P0522R0, adjust P's template arguments
7208 to apply to A's template; then flatten it again. */
7217 /* If the P0522 adjustment eliminated a pack expansion, deduce
7218 empty packs. */
7224 }
7225 else
7226 {
7227 /* Deduce arguments T, i from TT<T> or TT<i>.
7228 We check each element of PARMVEC and ARGVEC individually
7229 rather than the whole TREE_VEC since they can have
7230 different number of elements, which is allowed under N2555. */
7234 /* Check if the parameters end in a pack, making them
7235 variadic. */
7242 /* If the template argument list of P contains a pack
7243 expansion that is not the last template argument, the
7244 entire template argument list is a non-deduced
7245 context. */
7263 DEDUCE_EXACT,
7266 }
7269 }
7271 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7272 template template parameters. Both PARM_PARMS and ARG_PARMS are
7273 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7274 or PARM_DECL.
7276 Consider the example:
7277 template <class T> class A;
7278 template<template <class U> class TT> class B;
7280 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7281 the parameters to A, and OUTER_ARGS contains A. */
7283 static int
7285 tree arg_parms,
7286 tsubst_flags_t complain,
7287 tree in_decl,
7288 tree outer_args)
7289 {
7301 {
7302 /* P0522R0: A template template-parameter P is at least as specialized as
7303 a template template-argument A if, given the following rewrite to two
7304 function templates, the function template corresponding to P is at
7305 least as specialized as the function template corresponding to A
7306 according to the partial ordering rules for function templates
7307 ([temp.func.order]). Given an invented class template X with the
7308 template parameter list of A (including default arguments):
7310 * Each of the two function templates has the same template parameters,
7311 respectively, as P or A.
7313 * Each function template has a single function parameter whose type is
7314 a specialization of X with template arguments corresponding to the
7315 template parameters from the respective function template where, for
7316 each template parameter PP in the template parameter list of the
7317 function template, a corresponding template argument AA is formed. If
7318 PP declares a parameter pack, then AA is the pack expansion
7319 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7321 If the rewrite produces an invalid type, then P is not at least as
7322 specialized as A. */
7324 /* So coerce P's args to apply to A's parms, and then deduce between A's
7325 args and the converted args. If that succeeds, A is at least as
7326 specialized as P, so they match.*/
7333 {
7339 }
7340 }
7342 /* Determine whether we have a parameter pack at the end of the
7343 template template parameter's template parameter list. */
7345 {
7352 {
7366 }
7367 }
7373 /* Check all of the template parameters except the parameter pack at
7374 the end (if any). */
7376 {
7385 outer_args))
7388 }
7391 {
7392 /* Check each of the template parameters in the template
7393 argument against the template parameter pack at the end of
7394 the template template parameter. */
7401 {
7408 outer_args))
7410 }
7411 }
7414 }
7416 /* Verifies that the deduced template arguments (in TARGS) for the
7417 template template parameters (in TPARMS) represent valid bindings,
7418 by comparing the template parameter list of each template argument
7419 to the template parameter list of its corresponding template
7420 template parameter, in accordance with DR150. This
7421 routine can only be called after all template arguments have been
7422 deduced. It will return TRUE if all of the template template
7423 parameter bindings are okay, FALSE otherwise. */
7424 bool
7426 {
7430 /* We're dealing with template parms in this process. */
7436 {
7441 {
7446 {
7447 /* Look inside the argument pack. */
7450 }
7453 {
7457 /* Extract the next argument from the argument
7458 pack. */
7462 /* Look at the pattern of the pack expansion. */
7465 /* Extract the template parameters from the template
7466 argument. */
7472 /* Verify that we can coerce the template template
7473 parameters from the template argument to the template
7474 parameter. This requires an exact match. */
7476 && !coerce_template_template_parms
7478 targ_parms,
7479 tf_none,
7480 tparm,
7481 targs))
7482 {
7485 }
7486 }
7487 }
7488 }
7490 out:
7494 }
7496 /* Since type attributes aren't mangled, we need to strip them from
7497 template type arguments. */
7499 static tree
7501 {
7511 }
7513 /* And from inside dependent non-type arguments like sizeof(Type). */
7515 static tree
7517 {
7527 }
7529 // A template declaration can be substituted for a constrained
7530 // template template parameter only when the argument is more
7531 // constrained than the parameter.
7532 static bool
7534 {
7537 /* For now, allow constrained template template arguments
7538 and unconstrained template template parameters. */
7544 // If the template parameter is constrained, we need to rewrite its
7545 // constraints in terms of the ARG's template parameters. This ensures
7546 // that all of the template parameter types will have the same depth.
7547 //
7548 // Note that this is only valid when coerce_template_template_parm is
7549 // true for the innermost template parameters of PARM and ARG. In other
7550 // words, because coercion is successful, this conversion will be valid.
7552 {
7559 }
7562 }
7564 // Convert a placeholder argument into a binding to the original
7565 // parameter. The original parameter is saved as the TREE_TYPE of
7566 // ARG.
7569 {
7572 }
7574 /* We can't fully resolve ARG given as a non-type template argument to TYPE,
7575 because one of them is dependent. But we need to represent the
7576 conversion for the benefit of cp_tree_equal. */
7578 static tree
7580 {
7581 /* Auto parms get no conversion. */
7584 /* We don't need or want to add this conversion now if we're going to use the
7585 argument for deduction. */
7597 }
7599 /* Convert the indicated template ARG as necessary to match the
7600 indicated template PARM. Returns the converted ARG, or
7601 error_mark_node if the conversion was unsuccessful. Error and
7602 warning messages are issued under control of COMPLAIN. This
7603 conversion is for the Ith parameter in the parameter list. ARGS is
7604 the full set of template arguments deduced so far. */
7606 static tree
7608 tree arg,
7609 tree args,
7610 tsubst_flags_t complain,
7612 tree in_decl)
7613 {
7614 tree orig_arg;
7615 tree val;
7621 /* Trivially convert placeholders. */
7630 {
7631 /* The template argument was the name of some
7632 member function. That's usually
7633 invalid, but static members are OK. In any
7634 case, grab the underlying fields/functions
7635 and issue an error later if required. */
7638 }
7646 /* When determining whether an argument pack expansion is a template,
7647 look at the pattern. */
7651 /* Deal with an injected-class-name used as a template template arg. */
7653 {
7656 {
7666 }
7667 }
7669 is_tmpl_type =
7685 {
7687 {
7691 }
7694 "to refer to a type member of a template parameter, "
7699 typename_type,
7700 complain);
7703 }
7705 {
7707 {
7709 {
7721 else
7724 }
7725 }
7727 }
7729 {
7731 {
7738 else
7741 }
7743 }
7746 /* We already did the appropriate conversion when packing args. */
7749 {
7751 {
7753 /* The number of argument required is not known yet.
7754 Just accept it for now. */
7756 else
7757 {
7759 tree argparm;
7761 /* Strip alias templates that are equivalent to another
7762 template. */
7768 args))
7769 {
7772 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7773 TEMPLATE_DECL. */
7775 {
7780 }
7781 }
7782 else
7783 {
7785 {
7792 }
7795 }
7797 // Check that the constraints are compatible before allowing the
7798 // substitution.
7801 {
7803 {
7809 }
7811 }
7812 }
7813 }
7814 else
7816 /* We only form one instance of each template specialization.
7817 Therefore, if we use a non-canonical variant (i.e., a
7818 typedef), any future messages referring to the type will use
7819 the typedef, which is confusing if those future uses do not
7820 themselves also use the typedef. */
7823 }
7824 else
7825 {
7829 {
7833 }
7834 else
7842 /* We used to call digest_init here. However, digest_init
7843 will report errors, which we don't want when complain
7844 is zero. More importantly, digest_init will try too
7845 hard to convert things: for example, `0' should not be
7846 converted to pointer type at this point according to
7847 the standard. Accepting this is not merely an
7848 extension, since deciding whether or not these
7849 conversions can occur is part of determining which
7850 function template to call, or whether a given explicit
7851 argument specification is valid. */
7853 else
7854 {
7857 }
7867 {
7868 /* Reject template arguments that are references to built-in
7869 functions with no library fallbacks. */
7878 }
7881 {
7882 /* Strip typedefs from the SCOPE_REF. */
7885 complain);
7888 }
7889 }
7892 }
7894 /* Coerces the remaining template arguments in INNER_ARGS (from
7895 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7896 Returns the coerced argument pack. PARM_IDX is the position of this
7897 parameter in the template parameter list. ARGS is the original
7898 template argument list. */
7899 static tree
7902 tree args,
7903 tree inner_args,
7905 tree new_args,
7907 tree in_decl,
7908 tsubst_flags_t complain)
7909 {
7912 tree packed_args;
7913 tree argument_pack;
7920 {
7921 /* When the template parameter is a non-type template parameter pack
7922 or template template parameter pack whose type or template
7923 parameters use parameter packs, we know exactly how many arguments
7924 we are looking for. Build a vector of the instantiated decls for
7925 these template parameters in PACKED_PARMS. */
7926 /* We can't use make_pack_expansion here because it would interpret a
7927 _DECL as a use rather than a declaration. */
7941 /* If we're doing a partial instantiation of a member template,
7942 verify that all of the types used for the non-type
7943 template parameter pack are, in fact, valid for non-type
7944 template parameters. */
7947 {
7950 {
7954 }
7955 /* We don't know how many args we have yet, just
7956 use the unconverted ones for now. */
7958 }
7961 }
7962 /* Check if we have a placeholder pack, which indicates we're
7963 in the context of a introduction list. In that case we want
7964 to match this pack to the single placeholder. */
7968 {
7971 }
7972 else
7975 /* Convert the remaining arguments, which will be a part of the
7976 parameter pack "parm". */
7979 {
7985 {
7986 /* Once we've packed as many args as we have types, stop. */
7990 /* We don't know how many args we have yet, just
7991 use the unconverted ones for now. */
7993 else
7995 }
7998 {
8001 }
8002 else
8005 in_decl);
8009 }
8013 {
8018 }
8023 else
8024 {
8027 }
8034 }
8036 /* Returns the number of pack expansions in the template argument vector
8037 ARGS. */
8039 static int
8041 {
8046 {
8050 }
8052 }
8054 /* Convert all template arguments to their appropriate types, and
8055 return a vector containing the innermost resulting template
8056 arguments. If any error occurs, return error_mark_node. Error and
8057 warning messages are issued under control of COMPLAIN.
8059 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
8060 for arguments not specified in ARGS. Otherwise, if
8061 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
8062 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
8063 USE_DEFAULT_ARGS is false, then all arguments must be specified in
8064 ARGS. */
8066 static tree
8068 tree args,
8069 tree in_decl,
8070 tsubst_flags_t complain,
8073 {
8075 tree orig_inner_args;
8076 tree inner_args;
8077 tree new_args;
8078 tree new_inner_args;
8082 /* When used as a boolean value, indicates whether this is a
8083 variadic template parameter list. Since it's an int, we can also
8084 subtract it from nparms to get the number of non-variadic
8085 parameters. */
8090 /* Likewise for parameters with default arguments. */
8098 /* Determine if there are any parameter packs or default arguments. */
8100 {
8108 }
8111 /* If there are no parameters that follow a parameter pack, we need to
8112 expand any argument packs so that we can deduce a parameter pack from
8113 some non-packed args followed by an argument pack, as in variadic85.C.
8114 If there are such parameters, we need to leave argument packs intact
8115 so the arguments are assigned properly. This can happen when dealing
8116 with a nested class inside a partial specialization of a class
8117 template, as in variadic92.C, or when deducing a template parameter pack
8118 from a sub-declarator, as in variadic114.C. */
8122 /* Count any pack expansion args. */
8128 && require_all_args
8129 && !variadic_args_p
8130 && (!use_default_args
8133 {
8135 {
8137 {
8141 }
8142 else
8149 }
8152 }
8153 /* We can't pass a pack expansion to a non-pack parameter of an alias
8154 template (DR 1430). */
8158 && variadic_args_p
8160 {
8162 {
8164 {
8170 {
8173 "pack expansion argument for non-pack parameter "
8175 else
8177 "pack expansion argument for non-pack parameter "
8181 }
8182 }
8184 found:;
8185 }
8187 }
8189 /* We need to evaluate the template arguments, even though this
8190 template-id may be nested within a "sizeof". */
8199 {
8200 tree arg;
8201 tree parm;
8203 /* Get the Ith template parameter. */
8207 {
8210 }
8212 /* Calculate the next argument. */
8215 else
8220 {
8221 /* Some arguments will be placed in the
8222 template parameter pack PARM. */
8229 {
8230 /* We don't know how many args we have yet, just use the
8231 unconverted (and still packed) ones for now. */
8235 }
8239 /* Store this argument. */
8241 {
8242 lost++;
8243 /* We are done with all of the arguments. */
8245 }
8246 else
8247 {
8250 }
8253 }
8255 {
8257 {
8258 /* "If every valid specialization of a variadic template
8259 requires an empty template parameter pack, the template is
8260 ill-formed, no diagnostic required." So check that the
8261 pattern works with this parameter. */
8266 in_decl);
8268 {
8273 }
8275 /* Recover from missing typename. */
8279 /* We don't know how many args we have yet, just
8280 use the unconverted ones for now. */
8284 }
8285 }
8287 {
8288 /* There must be a default arg in this case. */
8291 /* The position of the first default template argument,
8292 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8293 Record that. */
8297 }
8298 else
8302 {
8305 }
8307 /* This only occurs if there was an error in the template
8308 parameter list itself (which we would already have
8309 reported) that we are trying to recover from, e.g., a class
8310 template with a parameter list such as
8311 template<typename..., typename>. */
8313 else
8319 lost++;
8321 }
8326 {
8328 {
8333 }
8335 }
8345 }
8347 /* Convert all template arguments to their appropriate types, and
8348 return a vector containing the innermost resulting template
8349 arguments. If any error occurs, return error_mark_node. Error and
8350 warning messages are not issued.
8352 Note that no function argument deduction is performed, and default
8353 arguments are used to fill in unspecified arguments. */
8354 tree
8356 {
8358 }
8360 /* Convert all template arguments to their appropriate type, and
8361 instantiate default arguments as needed. This returns a vector
8362 containing the innermost resulting template arguments, or
8363 error_mark_node if unsuccessful. */
8364 tree
8366 tsubst_flags_t complain)
8367 {
8369 }
8371 /* Like coerce_template_parms. If PARMS represents all template
8372 parameters levels, this function returns a vector of vectors
8373 representing all the resulting argument levels. Note that in this
8374 case, only the innermost arguments are coerced because the
8375 outermost ones are supposed to have been coerced already.
8377 Otherwise, if PARMS represents only (the innermost) vector of
8378 parameters, this function returns a vector containing just the
8379 innermost resulting arguments. */
8381 static tree
8383 tree args,
8384 tree in_decl,
8385 tsubst_flags_t complain,
8388 {
8391 tree coerced_args;
8394 {
8396 tree level;
8402 {
8403 tree l;
8407 require_all_args,
8408 use_default_args);
8409 else
8416 }
8417 }
8418 else
8421 require_all_args,
8422 use_default_args);
8424 }
8426 /* Returns 1 if template args OT and NT are equivalent. */
8428 int
8430 {
8439 /* For member templates */
8448 {
8465 }
8469 {
8472 /* Don't treat an alias template specialization with dependent
8473 arguments as equivalent to its underlying type when used as a
8474 template argument; we need them to be distinct so that we
8475 substitute into the specialization arguments at instantiation
8476 time. And aliases can't be equivalent without being ==, so
8477 we don't need to look any deeper.
8479 During partial ordering, however, we need to treat them normally so
8480 that we can order uses of the same alias with different
8481 cv-qualification (79960). */
8485 else
8487 }
8490 else
8491 {
8492 /* Try to treat a template non-type argument that has been converted
8493 to the parameter type as equivalent to one that hasn't yet. */
8506 }
8507 }
8509 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8510 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8511 NEWARG_PTR with the offending arguments if they are non-NULL. */
8513 int
8517 {
8530 {
8535 {
8541 }
8542 }
8544 }
8548 {
8550 }
8552 static void
8554 {
8564 /* We are called both from instantiate_decl, where we've already had a
8565 tinst_level pushed, and instantiate_template, where we haven't.
8566 Compensate. */
8577 else
8586 }
8589 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8590 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8591 documentation for TEMPLATE_ID_EXPR. */
8593 tree
8595 {
8596 tree type;
8604 {
8607 }
8610 {
8612 unknown_type_node,
8614 arglist);
8616 }
8623 }
8625 /* Within the scope of a template class S<T>, the name S gets bound
8626 (in build_self_reference) to a TYPE_DECL for the class, not a
8627 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8628 or one of its enclosing classes, and that type is a template,
8629 return the associated TEMPLATE_DECL. Otherwise, the original
8630 DECL is returned.
8632 Also handle the case when DECL is a TREE_LIST of ambiguous
8633 injected-class-names from different bases. */
8635 tree
8637 {
8641 /* DR 176: A lookup that finds an injected-class-name (10.2
8642 [class.member.lookup]) can result in an ambiguity in certain cases
8643 (for example, if it is found in more than one base class). If all of
8644 the injected-class-names that are found refer to specializations of
8645 the same class template, and if the name is followed by a
8646 template-argument-list, the reference refers to the class template
8647 itself and not a specialization thereof, and is not ambiguous. */
8649 {
8652 {
8658 }
8661 else
8663 }
8669 }
8671 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8672 parameters, find the desired type.
8674 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8676 IN_DECL, if non-NULL, is the template declaration we are trying to
8677 instantiate.
8679 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8680 the class we are looking up.
8682 Issue error and warning messages under control of COMPLAIN.
8684 If the template class is really a local class in a template
8685 function, then the FUNCTION_CONTEXT is the function in which it is
8686 being instantiated.
8688 ??? Note that this function is currently called *twice* for each
8689 template-id: the first time from the parser, while creating the
8690 incomplete type (finish_template_type), and the second type during the
8691 real instantiation (instantiate_template_class). This is surely something
8692 that we want to avoid. It also causes some problems with argument
8693 coercion (see convert_nontype_argument for more information on this). */
8695 static tree
8698 {
8700 tree t;
8703 spec_entry elt;
8704 hashval_t hash;
8707 {
8711 else
8712 {
8719 }
8722 }
8724 {
8727 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8728 an implicit typename for the second A. Deal with it. */
8733 {
8736 }
8737 }
8740 {
8743 }
8745 {
8749 }
8751 {
8754 }
8756 /* Issue an error message if we didn't find a template. */
8758 {
8762 }
8765 /* Make sure it's a user visible template, if it was named by
8766 the user. */
8769 {
8771 {
8775 }
8777 }
8781 /* An alias that just changes the name of a template is equivalent to the
8782 other template, so if any of the arguments are pack expansions, strip
8783 the alias to avoid problems with a pack expansion passed to a non-pack
8784 alias template parameter (DR 1430). */
8789 {
8790 tree parm;
8799 }
8800 else
8801 {
8803 tree gen_tmpl;
8804 tree type_decl;
8812 /* An error occurred while building the template TEMPL, and a
8813 diagnostic has most certainly been emitted for that
8814 already. Let's propagate that error. */
8823 {
8824 /* We've been given an incomplete set of template arguments.
8825 For example, given:
8827 template <class T> struct S1 {
8828 template <class U> struct S2 {};
8829 template <class U> struct S2<U*> {};
8830 };
8832 we will be called with an ARGLIST of `U*', but the
8833 TEMPLATE will be `template <class T> template
8834 <class U> struct S1<T>::S2'. We must fill in the missing
8835 arguments. */
8839 }
8841 /* Now we should have enough arguments. */
8844 /* From here on, we're only interested in the most general
8845 template. */
8847 /* Calculate the BOUND_ARGS. These will be the args that are
8848 actually tsubst'd into the definition to create the
8849 instantiation. */
8851 complain,
8856 /* We were unable to bind the arguments. */
8859 /* In the scope of a template class, explicit references to the
8860 template class refer to the type of the template, not any
8861 instantiation of it. For example, in:
8863 template <class T> class C { void f(C<T>); }
8865 the `C<T>' is just the same as `C'. Outside of the
8866 class, however, such a reference is an instantiation. */
8870 {
8875 }
8877 /* If we already have this specialization, return it. */
8887 /* If the the template's constraints are not satisfied,
8888 then we cannot form a valid type.
8890 Note that the check is deferred until after the hash
8891 lookup. This prevents redundant checks on previously
8892 instantiated specializations. */
8894 {
8896 {
8899 }
8901 }
8905 /* If the deduced arguments are invalid, then the binding
8906 failed. */
8910 complain))
8917 {
8922 }
8932 /* Create the type. */
8934 {
8935 /* The user referred to a specialization of an alias
8936 template represented by GEN_TMPL.
8938 [temp.alias]/2 says:
8940 When a template-id refers to the specialization of an
8941 alias template, it is equivalent to the associated
8942 type obtained by substitution of its
8943 template-arguments for the template-parameters in the
8944 type-id of the alias template. */
8947 /* Note that the call above (by indirectly calling
8948 register_specialization in tsubst_decl) registers the
8949 TYPE_DECL representing the specialization of the alias
8950 template. So next time someone substitutes ARGLIST for
8951 the template parms into the alias template (GEN_TMPL),
8952 she'll get that TYPE_DECL back. */
8956 }
8958 {
8960 {
8971 }
8972 else
8973 {
8974 /* We don't want to call start_enum for this type, since
8975 the values for the enumeration constants may involve
8976 template parameters. And, no one should be interested
8977 in the enumeration constants for such a type. */
8980 }
8984 }
8986 {
8987 /* Lambda closures are regenerated in tsubst_lambda_expr, not
8988 instantiated here. */
8996 /* A local class. Make sure the decl gets registered properly. */
9001 /* This instantiation is another name for the primary
9002 template type. Set the TYPE_CANONICAL field
9003 appropriately. */
9006 /* Some of the template arguments require structural
9007 equality testing, so this template class requires
9008 structural equality testing. */
9010 }
9011 else
9014 /* If we called start_enum or pushtag above, this information
9015 will already be set up. */
9017 {
9024 }
9025 else
9029 {
9035 {
9038 }
9039 }
9043 {
9047 {
9048 tree attributes
9056 }
9057 }
9059 /* Let's consider the explicit specialization of a member
9060 of a class template specialization that is implicitly instantiated,
9061 e.g.:
9062 template<class T>
9063 struct S
9064 {
9065 template<class U> struct M {}; //#0
9066 };
9068 template<>
9069 template<>
9070 struct S<int>::M<char> //#1
9071 {
9072 int i;
9073 };
9074 [temp.expl.spec]/4 says this is valid.
9076 In this case, when we write:
9077 S<int>::M<char> m;
9079 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
9080 the one of #0.
9082 When we encounter #1, we want to store the partial instantiation
9083 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
9085 For all cases other than this "explicit specialization of member of a
9086 class template", we just want to store the most general template into
9087 the CLASSTYPE_TI_TEMPLATE of M.
9089 This case of "explicit specialization of member of a class template"
9090 only happens when:
9091 1/ the enclosing class is an instantiation of, and therefore not
9092 the same as, the context of the most general template, and
9093 2/ we aren't looking at the partial instantiation itself, i.e.
9094 the innermost arguments are not the same as the innermost parms of
9095 the most general template.
9097 So it's only when 1/ and 2/ happens that we want to use the partial
9098 instantiation of the member template in lieu of its most general
9099 template. */
9103 /* the enclosing class must be an instantiation... */
9106 {
9110 tree partial_inst_args =
9117 use_partial_inst_tmpl =
9118 /*...and we must not be looking at the partial instantiation
9119 itself. */
9121 partial_inst_args);
9122 }
9125 /* This case is easy; there are no member templates involved. */
9127 else
9128 {
9129 /* This is a full instantiation of a member template. Find
9130 the partial instantiation of which this is an instance. */
9132 /* Temporarily reduce by one the number of levels in the ARGLIST
9133 so as to avoid comparing the last set of arguments. */
9137 /* FOUND is either a proper class type, or an alias
9138 template specialization. In the later case, it's a
9139 TYPE_DECL, resulting from the substituting of arguments
9140 for parameters in the TYPE_DECL of the alias template
9141 done earlier. So be careful while getting the template
9142 of FOUND. */
9144 ? found
9148 }
9150 // Build template info for the new specialization.
9159 /* Note this use of the partial instantiation so we can check it
9160 later in maybe_process_partial_specialization. */
9167 /* Now that the type has been registered on the instantiations
9168 list, we set up the enumerators. Because the enumeration
9169 constants may involve the enumeration type itself, we make
9170 sure to register the type first, and then create the
9171 constants. That way, doing tsubst_expr for the enumeration
9172 constants won't result in recursive calls here; we'll find
9173 the instantiation and exit above. */
9177 /* If the type makes use of template parameters, the
9178 code that generates debugging information will crash. */
9181 /* Possibly limit visibility based on template args. */
9188 }
9189 }
9191 /* Wrapper for lookup_template_class_1. */
9193 tree
9196 {
9197 tree ret;
9203 }
9205 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9207 tree
9209 {
9210 /* The type of the expression is NULL_TREE since the template-id could refer
9211 to an explicit or partial specialization. */
9214 /* Except that concepts are always bool. */
9217 }
9219 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9221 tree
9223 {
9227 /* We never want to return a VAR_DECL for a variable concept, since they
9228 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9243 {
9245 {
9248 }
9250 }
9252 /* If a template-id refers to a specialization of a variable
9253 concept, then the expression is true if and only if the
9254 concept's constraints are satisfied by the given template
9255 arguments.
9257 NOTE: This is an extension of Concepts Lite TS that
9258 allows constraints to be used in expressions. */
9260 {
9263 }
9266 }
9268 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9269 TARGS template args, and instantiate it if it's not dependent. */
9271 tree
9273 tsubst_flags_t complain)
9274 {
9277 {
9280 }
9283 }
9285 \f
9286 struct pair_fn_data
9287 {
9288 tree_fn_t fn;
9289 tree_fn_t any_fn;
9291 /* True when we should also visit template parameters that occur in
9292 non-deduced contexts. */
9295 };
9297 /* Called from for_each_template_parm via walk_tree. */
9299 static tree
9301 {
9308 #define WALK_SUBTREE(NODE) \
9309 do \
9310 { \
9311 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9312 pfd->include_nondeduced_p, \
9313 pfd->any_fn); \
9314 if (result) goto out; \
9315 } \
9316 while (0)
9326 {
9330 /* Fall through. */
9336 else
9346 /* Since we're not going to walk subtrees, we have to do this
9347 explicitly here. */
9349 /* Fall through. */
9352 /* Check the return type. */
9355 /* Check the parameter types. Since default arguments are not
9356 instantiated until they are needed, the TYPE_ARG_TYPES may
9357 contain expressions that involve template parameters. But,
9358 no-one should be looking at them yet. And, once they're
9359 instantiated, they don't contain template parameters, so
9360 there's no point in looking at them then, either. */
9361 {
9362 tree parm;
9367 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9368 want walk_tree walking into them itself. */
9370 }
9373 {
9377 }
9394 /* Fall through. */
9406 /* Record template parameters such as `T' inside `TT<T>'. */
9408 /* Fall through. */
9420 /* A template template parameter is encountered. */
9424 /* Already substituted template template parameter */
9429 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9430 partial instantiation. */
9442 /* If there's no type, then this thing must be some expression
9443 involving template parameters. */
9465 }
9467 #undef WALK_SUBTREE
9469 /* We didn't find any template parameters we liked. */
9470 out:
9472 }
9474 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9475 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9476 call FN with the parameter and the DATA.
9477 If FN returns nonzero, the iteration is terminated, and
9478 for_each_template_parm returns 1. Otherwise, the iteration
9479 continues. If FN never returns a nonzero value, the value
9480 returned by for_each_template_parm is 0. If FN is NULL, it is
9481 considered to be the function which always returns 1.
9483 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9484 parameters that occur in non-deduced contexts. When false, only
9485 visits those template parameters that can be deduced. */
9487 static tree
9491 tree_fn_t any_fn)
9492 {
9494 tree result;
9496 /* Set up. */
9502 /* Walk the tree. (Conceptually, we would like to walk without
9503 duplicates, but for_each_template_parm_r recursively calls
9504 for_each_template_parm, so we would need to reorganize a fair
9505 bit to use walk_tree_without_duplicates, so we keep our own
9506 visited list.) */
9509 else
9512 for_each_template_parm_r,
9516 /* Clean up. */
9518 {
9521 }
9524 }
9526 /* Returns true if T depends on any template parameter. */
9528 int
9530 {
9560 else
9561 {
9564 }
9569 }
9571 /* Returns true iff current_function_decl is an incompletely instantiated
9572 template. Useful instead of processing_template_decl because the latter
9573 is set to 0 during instantiate_non_dependent_expr. */
9575 bool
9577 {
9586 }
9588 /* Returns true if T depends on any template parameter with level LEVEL. */
9590 bool
9592 {
9595 }
9597 /* Returns true if the signature of DECL depends on any template parameter from
9598 its enclosing class. */
9600 bool
9602 {
9612 template_parm_outer_level,
9622 }
9624 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9625 ill-formed translation unit, i.e. a variable or function that isn't
9626 usable in a constant expression. */
9630 {
9635 }
9637 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9638 neglectable and instantiated from within an erroneous instantiation. */
9640 static bool
9642 {
9653 }
9661 /* We're starting to instantiate D; record the template instantiation context
9662 for diagnostics and to restore it later. */
9664 bool
9666 {
9668 }
9670 /* We're starting to instantiate D; record the template instantiation context
9671 at LOC for diagnostics and to restore it later. */
9673 bool
9675 {
9679 {
9680 /* Tell error.c not to try to instantiate any templates. */
9683 "template instantiation depth exceeds maximum of %d"
9685 max_tinst_depth);
9687 }
9689 /* If the current instantiation caused problems, don't let it instantiate
9690 anything else. Do allow deduction substitution and decls usable in
9691 constant expressions. */
9695 /* When not -quiet, dump template instantiations other than functions, since
9696 announce_function will take care of those. */
9715 }
9717 /* We're done instantiating this template; return to the instantiation
9718 context. */
9720 void
9722 {
9723 /* Restore the filename and line number stashed away when we started
9724 this instantiation. */
9728 }
9730 /* We're instantiating a deferred template; restore the template
9731 instantiation context in which the instantiation was requested, which
9732 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9734 static tree
9736 {
9748 }
9750 /* Returns the TINST_LEVEL which gives the original instantiation
9751 context. */
9755 {
9761 }
9763 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9764 vector of template arguments, as for tsubst.
9766 Returns an appropriate tsubst'd friend declaration. */
9768 static tree
9770 {
9771 tree new_friend;
9776 /* This was a friend declared with an explicit template
9777 argument list, e.g.:
9779 friend void f<>(T);
9781 to indicate that f was a template instantiation, not a new
9782 function declaration. Now, we have to figure out what
9783 instantiation of what template. */
9784 {
9786 tree new_args;
9787 tree tmpl;
9790 /* Friend functions are looked up in the containing namespace scope.
9791 We must enter that scope, to avoid finding member functions of the
9792 current class with same name. */
9807 tsk_none);
9809 }
9813 /* The NEW_FRIEND will look like an instantiation, to the
9814 compiler, but is not an instantiation from the point of view of
9815 the language. For example, we might have had:
9817 template <class T> struct S {
9818 template <class U> friend void f(T, U);
9819 };
9821 Then, in S<int>, template <class U> void f(int, U) is not an
9822 instantiation of anything. */
9828 {
9832 }
9834 /* The mangled name for the NEW_FRIEND is incorrect. The function
9835 is not a template instantiation and should not be mangled like
9836 one. Therefore, we forget the mangling here; we'll recompute it
9837 later if we need it. */
9839 {
9842 }
9845 {
9846 tree old_decl;
9847 tree new_friend_template_info;
9848 tree new_friend_result_template_info;
9849 tree ns;
9852 /* We must save some information from NEW_FRIEND before calling
9853 duplicate decls since that function will free NEW_FRIEND if
9854 possible. */
9856 new_friend_is_defn =
9861 {
9862 /* This declaration is a `primary' template. */
9865 new_friend_result_template_info
9867 }
9868 else
9871 /* Inside pushdecl_namespace_level, we will push into the
9872 current namespace. However, the friend function should go
9873 into the namespace of the template. */
9883 {
9884 /* This new friend declaration matched an existing
9885 declaration. For example, given:
9887 template <class T> void f(T);
9888 template <class U> class C {
9889 template <class T> friend void f(T) {}
9890 };
9892 the friend declaration actually provides the definition
9893 of `f', once C has been instantiated for some type. So,
9894 old_decl will be the out-of-class template declaration,
9895 while new_friend is the in-class definition.
9897 But, if `f' was called before this point, the
9898 instantiation of `f' will have DECL_TI_ARGS corresponding
9899 to `T' but not to `U', references to which might appear
9900 in the definition of `f'. Previously, the most general
9901 template for an instantiation of `f' was the out-of-class
9902 version; now it is the in-class version. Therefore, we
9903 run through all specialization of `f', adding to their
9904 DECL_TI_ARGS appropriately. In particular, they need a
9905 new set of outer arguments, corresponding to the
9906 arguments for this class instantiation.
9908 The same situation can arise with something like this:
9910 friend void f(int);
9911 template <class T> class C {
9912 friend void f(T) {}
9913 };
9915 when `C<int>' is instantiated. Now, `f(int)' is defined
9916 in the class. */
9919 /* On the other hand, if the in-class declaration does
9920 *not* provide a definition, then we don't want to alter
9921 existing definitions. We can just leave everything
9922 alone. */
9923 ;
9924 else
9925 {
9929 /* Overwrite whatever template info was there before, if
9930 any, with the new template information pertaining to
9931 the declaration. */
9935 {
9936 /* We should have called reregister_specialization in
9937 duplicate_decls. */
9942 /* Instantiate it if the global has already been used. */
9946 }
9947 else
9948 {
9949 tree t;
9951 /* Indicate that the old function template is a partial
9952 instantiation. */
9960 /* Reassign any specializations already in the hash table
9961 to the new more general template, and add the
9962 additional template args. */
9966 {
9968 spec_entry elt;
9980 register_specialization
9983 }
9985 }
9986 }
9988 /* The information from NEW_FRIEND has been merged into OLD_DECL
9989 by duplicate_decls. */
9991 }
9992 }
9993 else
9994 {
9998 /* In the code
9999 template <class T> class C {
10000 template <class U> friend void C1<U>::f (); // case 1
10001 friend void C2<T>::f (); // case 2
10002 };
10003 we only need to make sure CONTEXT is a complete type for
10004 case 2. To distinguish between the two cases, we note that
10005 CONTEXT of case 1 remains dependent type after tsubst while
10006 this isn't true for case 2. */
10016 {
10018 /* do_friend adds the TEMPLATE_DECL for any member friend
10019 template even if it isn't a member template, i.e.
10020 template <class T> friend A<T>::f();
10021 Look through it in that case. */
10025 /* Check to see that the declaration is really present, and,
10026 possibly obtain an improved declaration. */
10031 }
10032 }
10035 }
10037 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
10038 template arguments, as for tsubst.
10040 Returns an appropriate tsubst'd friend type or error_mark_node on
10041 failure. */
10043 static tree
10045 {
10046 tree tmpl;
10049 {
10052 }
10057 else
10065 {
10066 /* The friend template has already been declared. Just
10067 check to see that the declarations match, and install any new
10068 default parameters. We must tsubst the default parameters,
10069 of course. We only need the innermost template parameters
10070 because that is all that redeclare_class_template will look
10071 at. */
10074 {
10082 }
10083 }
10084 else
10085 {
10086 /* The friend template has not already been declared. In this
10087 case, the instantiation of the template class will cause the
10088 injection of this template into the namespace scope. */
10092 {
10093 /* The new TMPL is not an instantiation of anything, so we
10094 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE
10095 for the new type because that is supposed to be the
10096 corresponding template decl, i.e., TMPL. */
10103 /* It is hidden. */
10108 /* Inject this template into the enclosing namspace scope. */
10110 }
10111 }
10115 else
10119 }
10121 /* Returns zero if TYPE cannot be completed later due to circularity.
10122 Otherwise returns one. */
10124 static int
10126 {
10136 else
10138 }
10143 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10144 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10146 static tree
10149 {
10158 {
10165 clauses
10169 else
10171 }
10172 /* If the first attribute argument is an identifier, don't
10173 pass it through tsubst. Attributes like mode, format,
10174 cleanup and several target specific attributes expect it
10175 unmodified. */
10177 {
10178 tree chain
10183 }
10185 {
10186 /* An attribute pack expansion. */
10195 {
10199 }
10201 }
10202 else
10209 }
10211 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10212 unchanged or a new TREE_LIST chain. */
10214 static tree
10217 {
10222 {
10226 }
10230 {
10233 {
10236 {
10238 do
10243 }
10244 }
10246 }
10249 }
10251 /* Apply any attributes which had to be deferred until instantiation
10252 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10253 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10255 static void
10258 {
10260 tree t;
10267 {
10271 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10272 to our attributes parameter. */
10274 }
10275 else
10276 {
10278 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10279 lookup_template_class_1, and should be preserved. */
10283 }
10287 {
10291 }
10295 {
10300 {
10303 {
10307 do
10310 }
10311 else
10313 }
10316 }
10317 }
10319 /* Perform (or defer) access check for typedefs that were referenced
10320 from within the template TMPL code.
10321 This is a subroutine of instantiate_decl and instantiate_class_template.
10322 TMPL is the template to consider and TARGS is the list of arguments of
10323 that template. */
10325 static void
10327 {
10328 location_t saved_location;
10339 {
10351 /* Make access check error messages point to the location
10352 of the use of the typedef. */
10356 tf_warning_or_error);
10357 }
10359 }
10361 static tree
10363 {
10365 tree typedecl;
10366 tree pbinfo;
10367 tree base_list;
10369 tree fn_context;
10378 /* Figure out which template is being instantiated. */
10382 /* Mark the type as in the process of being defined. */
10385 /* Determine what specialization of the original template to
10386 instantiate. */
10391 {
10392 /* This TYPE is actually an instantiation of a partial
10393 specialization. We replace the innermost set of ARGS with
10394 the arguments appropriate for substitution. For example,
10395 given:
10397 template <class T> struct S {};
10398 template <class T> struct S<T*> {};
10400 and supposing that we are instantiating S<int*>, ARGS will
10401 presently be {int*} -- but we need {int}. */
10404 }
10405 else
10406 {
10409 }
10411 /* If the template we're instantiating is incomplete, then clearly
10412 there's nothing we can do. */
10414 {
10415 /* We can try again later. */
10418 }
10420 /* If we've recursively instantiated too many templates, stop. */
10424 /* We may be in the middle of deferred access check. Disable
10425 it now. */
10432 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10437 else
10438 {
10441 }
10442 /* Use #pragma pack from the template context. */
10448 /* Set the input location to the most specialized template definition.
10449 This is needed if tsubsting causes an error. */
10461 {
10464 /* Adjust visibility for template arguments. */
10466 }
10472 /* We should never instantiate a nested class before its enclosing
10473 class; we need to look up the nested class by name before we can
10474 instantiate it, and that lookup should instantiate the enclosing
10475 class. */
10481 {
10482 tree pbase_binfo;
10483 tree pushed_scope;
10486 /* We must enter the scope containing the type, as that is where
10487 the accessibility of types named in dependent bases are
10488 looked up from. */
10491 /* Substitute into each of the bases to determine the actual
10492 basetypes. */
10494 {
10495 tree base;
10501 {
10502 expanded_bases =
10509 }
10512 {
10514 /* Extract the already-expanded base class. */
10516 else
10517 /* Substitute to figure out the base class. */
10519 NULL_TREE);
10527 }
10528 }
10530 /* The list is now in reverse order; correct that. */
10535 }
10536 /* Now call xref_basetypes to set up all the base-class
10537 information. */
10545 /* Now that our base classes are set up, enter the scope of the
10546 class, so that name lookups into base classes, etc. will work
10547 correctly. This is precisely analogous to what we do in
10548 begin_class_definition when defining an ordinary non-template
10549 class, except we also need to push the enclosing classes. */
10552 /* Now members are processed in the order of declaration. */
10555 {
10559 {
10561 {
10563 /* A closure type for a lambda in an NSDMI or default argument.
10564 Ignore it; it will be regenerated when needed. */
10567 /* Build new CLASSTYPE_NESTED_UTDS. */
10569 tree newtag;
10575 /* If the member is a class template, then -- even after
10576 substitution -- there may be dependent types in the
10577 template argument list for the class. We increment
10578 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10579 that function will assume that no types are dependent
10580 when outside of a template. */
10590 {
10594 /* Unfortunately, lookup_template_class sets
10595 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10596 instantiation (i.e., for the type of a member
10597 template class nested within a template class.)
10598 This behavior is required for
10599 maybe_process_partial_specialization to work
10600 correctly, but is not accurate in this case;
10601 the TAG is not an instantiation of anything.
10602 (The corresponding TEMPLATE_DECL is an
10603 instantiation, but the TYPE is not.) */
10606 /* Now, we call pushtag to put this NEWTAG into the scope of
10607 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10608 pushtag calling push_template_decl. We don't have to do
10609 this for enums because it will already have been done in
10610 tsubst_enum. */
10614 }
10615 }
10617 {
10618 tree r;
10627 /* Instantiate members marked with attribute used. */
10633 }
10636 /* A closure type for a lambda in an NSDMI or default argument.
10638 else
10639 {
10640 /* Build new TYPE_FIELDS. */
10642 {
10643 tree condition;
10646 condition =
10656 }
10658 {
10659 tree r;
10663 /* The file and line for this declaration, to
10664 assist in error message reporting. Since we
10665 called push_tinst_level above, we don't need to
10666 restore these. */
10676 {
10677 /* A capture pack became multiple fields. */
10680 }
10683 {
10687 {
10688 /* In [temp.inst]:
10690 [t]he initialization (and any associated
10691 side-effects) of a static data member does
10692 not occur unless the static data member is
10693 itself used in a way that requires the
10694 definition of the static data member to
10695 exist.
10697 Therefore, we do not substitute into the
10698 initialized for the static data member here. */
10699 finish_static_data_member_decl
10705 /* Instantiate members marked with attribute used. */
10708 }
10710 {
10711 /* Determine whether R has a valid type and can be
10712 completed later. If R is invalid, then its type
10713 is replaced by error_mark_node. */
10719 {
10720 /* If R's type couldn't be completed and
10721 it isn't a flexible array member (whose
10722 type is incomplete by definition) give
10723 an error. */
10726 }
10727 }
10729 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10730 such a thing will already have been added to the field
10731 list by tsubst_enum in finish_member_declaration in the
10732 CLASSTYPE_NESTED_UTDS case above. */
10736 {
10739 }
10740 }
10741 }
10742 }
10743 }
10744 else
10745 {
10748 {
10749 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10755 {
10756 /* template <class T> friend class C; */
10759 }
10761 {
10762 /* template <class T> friend class C::D; */
10768 }
10771 {
10772 /* This could be either
10774 friend class T::C;
10776 when dependent_type_p is false or
10778 template <class U> friend class T::C;
10780 otherwise. */
10781 /* Bump processing_template_decl in case this is something like
10782 template <class T> friend struct A<T>::B. */
10789 }
10793 {
10794 /* friend class C;
10796 where C hasn't been declared yet. Let's lookup name
10797 from namespace scope directly, bypassing any name that
10798 come from dependent base class. */
10801 /* The call to xref_tag_from_type does injection for friend
10802 classes. */
10804 friend_type =
10808 }
10810 /* friend class C<T>; */
10813 /* Otherwise it's
10815 friend class C;
10817 where C is already declared or
10819 friend class C<int>;
10821 We don't have to do anything in these cases. */
10824 /* Trick make_friend_class into realizing that the friend
10825 we're adding is a template, not an ordinary class. It's
10826 important that we use make_friend_class since it will
10827 perform some error-checking and output cross-reference
10828 information. */
10836 }
10837 else
10838 {
10839 /* Build new DECL_FRIENDLIST. */
10840 tree r;
10842 /* The file and line for this declaration, to
10843 assist in error message reporting. Since we
10844 called push_tinst_level above, we don't need to
10845 restore these. */
10849 {
10852 }
10857 {
10860 }
10861 }
10862 }
10863 }
10866 {
10867 /* Restore these before substituting into the lambda capture
10868 initializers. */
10871 }
10873 /* Set the file and line number information to whatever is given for
10874 the class itself. This puts error messages involving generated
10875 implicit functions at a predictable point, and the same point
10876 that would be used for non-template classes. */
10883 /* We don't instantiate default arguments for member functions. 14.7.1:
10885 The implicit instantiation of a class template specialization causes
10886 the implicit instantiation of the declarations, but not of the
10887 definitions or default arguments, of the class member functions,
10888 member classes, static data members and member templates.... */
10890 /* Some typedefs referenced from within the template code need to be access
10891 checked at template instantiation time, i.e now. These types were
10892 added to the template at parsing time. Let's get those and perform
10893 the access checks then. */
10903 /* The vtable for a template class can be emitted in any translation
10904 unit in which the class is instantiated. When there is no key
10905 method, however, finish_struct_1 will already have added TYPE to
10906 the keyed_classes. */
10911 }
10913 /* Wrapper for instantiate_class_template_1. */
10915 tree
10917 {
10918 tree ret;
10923 }
10925 static tree
10927 {
10928 tree r;
10934 else
10935 {
10942 }
10944 }
10946 /* Given a function parameter pack TMPL_PARM and some function parameters
10947 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10948 and set *SPEC_P to point at the next point in the list. */
10950 tree
10952 {
10953 /* Collect all of the extra "packed" parameters into an
10954 argument pack. */
10955 tree parmvec;
10965 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10969 {
10974 }
10976 /* Build the argument packs. */
10981 }
10983 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10984 NONTYPE_ARGUMENT_PACK. */
10986 static tree
10988 {
10990 }
10992 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10993 pack expansion with no extra args, 2 if it has extra args, or 0
10994 if it is not a pack expansion. */
10996 static int
10998 {
11004 /* A decl pack is itself an expansion. */
11011 }
11014 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
11016 static tree
11018 {
11025 }
11027 /* This is a subroutine of tsubst_pack_expansion.
11029 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
11030 mechanism to store the (non complete list of) arguments of the
11031 substitution and return a non substituted pack expansion, in order
11032 to wait for when we have enough arguments to really perform the
11033 substitution. */
11035 static bool
11039 {
11040 /* If one pack has an expansion and another pack has a normal
11041 argument or if one pack has an empty argument and an another
11042 one hasn't then tsubst_pack_expansion cannot perform the
11043 substitution and need to fall back on the
11044 PACK_EXPANSION_EXTRA mechanism. */
11052 {
11055 parm_pack;
11057 {
11062 /* We can't substitute a pack expansion with extra args into
11063 our pattern. */
11067 else
11069 }
11073 }
11075 }
11077 /* [temp.variadic]/6 says that:
11079 The instantiation of a pack expansion [...]
11080 produces a list E1,E2, ..., En, where N is the number of elements
11081 in the pack expansion parameters.
11083 This subroutine of tsubst_pack_expansion produces one of these Ei.
11085 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11086 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11087 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11088 INDEX is the index 'i' of the element Ei to produce. ARGS,
11089 COMPLAIN, and IN_DECL are the same parameters as for the
11090 tsubst_pack_expansion function.
11092 The function returns the resulting Ei upon successful completion,
11093 or error_mark_node.
11095 Note that this function possibly modifies the ARGS parameter, so
11096 it's the responsibility of the caller to restore it. */
11098 static tree
11100 tree parm_packs,
11102 tree args /* This parm gets
11104 tsubst_flags_t complain,
11105 tree in_decl)
11106 {
11107 tree t;
11110 /* For each parameter pack, change the substitution of the parameter
11111 pack to the ith argument in its argument pack, then expand the
11112 pattern. */
11114 {
11119 ith_elem_is_expansion |=
11122 /* Select the Ith argument from the pack. */
11126 {
11128 {
11133 }
11134 else
11136 }
11137 else
11138 {
11143 {
11145 /* Update the corresponding argument. */
11147 }
11148 else
11149 /* Re-use the ARGUMENT_PACK_SELECT. */
11151 }
11153 }
11155 /* Substitute into the PATTERN with the (possibly altered)
11156 arguments. */
11158 /* Expanding a fixed parameter pack from
11159 coerce_template_parameter_pack. */
11164 {
11167 else
11170 }
11174 else
11177 /* If the Ith argument pack element is a pack expansion, then
11178 the Ith element resulting from the substituting is going to
11179 be a pack expansion as well. */
11184 }
11186 /* When the unexpanded parameter pack in a fold expression expands to an empty
11187 sequence, the value of the expression is as follows; the program is
11188 ill-formed if the operator is not listed in this table.
11190 && true
11191 || false
11192 , void() */
11194 tree
11196 {
11200 {
11209 }
11215 }
11217 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11218 form an expression that combines the two terms using the
11219 operator of T. */
11221 static tree
11223 {
11227 // Handle compound assignment operators.
11232 {
11242 complain);
11243 }
11244 }
11246 /* Substitute ARGS into the pack of a fold expression T. */
11250 {
11252 }
11254 /* Substitute ARGS into the pack of a fold expression T. */
11258 {
11260 }
11262 /* Expand a PACK of arguments into a grouped as left fold.
11263 Given a pack containing elements A0, A1, ..., An and an
11264 operator @, this builds the expression:
11266 ((A0 @ A1) @ A2) ... @ An
11268 Note that PACK must not be empty.
11270 The operator is defined by the original fold expression T. */
11272 static tree
11274 {
11277 {
11280 }
11282 }
11284 /* Substitute into a unary left fold expression. */
11286 static tree
11288 tree in_decl)
11289 {
11294 {
11298 }
11301 else
11303 }
11305 /* Substitute into a binary left fold expression.
11307 Do ths by building a single (non-empty) vector of argumnts and
11308 building the expression from those elements. */
11310 static tree
11312 tree in_decl)
11313 {
11322 {
11327 }
11335 }
11337 /* Expand a PACK of arguments into a grouped as right fold.
11338 Given a pack containing elementns A0, A1, ..., and an
11339 operator @, this builds the expression:
11341 A0@ ... (An-2 @ (An-1 @ An))
11343 Note that PACK must not be empty.
11345 The operator is defined by the original fold expression T. */
11347 tree
11349 {
11350 // Build the expression.
11354 {
11357 }
11359 }
11361 /* Substitute into a unary right fold expression. */
11363 static tree
11365 tree in_decl)
11366 {
11371 {
11375 }
11378 else
11380 }
11382 /* Substitute into a binary right fold expression.
11384 Do ths by building a single (non-empty) vector of arguments and
11385 building the expression from those elements. */
11387 static tree
11389 tree in_decl)
11390 {
11399 {
11404 }
11413 }
11415 /* Walk through the pattern of a pack expansion, adding everything in
11416 local_specializations to a list. */
11418 struct el_data
11419 {
11420 tree extra;
11421 tsubst_flags_t complain;
11422 };
11423 static tree
11425 {
11430 {
11432 {
11433 /* Maybe pull out the PARM_DECL for a partial instantiation. */
11436 {
11442 }
11444 {
11445 /* Handle lambda capture here, since we aren't doing any
11446 substitution now, and so tsubst_copy won't call
11447 process_outer_var_ref. */
11451 {
11457 {
11458 /* Make a new NONTYPE_ARGUMENT_PACK of the capture
11459 proxies. */
11461 {
11466 }
11468 }
11469 }
11470 }
11471 }
11475 }
11477 }
11478 static tree
11480 {
11484 }
11486 /* Substitute ARGS into T, which is an pack expansion
11487 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11488 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11489 (if only a partial substitution could be performed) or
11490 ERROR_MARK_NODE if there was an error. */
11491 tree
11493 tree in_decl)
11494 {
11495 tree pattern;
11500 tree result;
11508 /* Add in any args remembered from an earlier partial instantiation. */
11511 {
11513 {
11514 /* The partial instantiation involved local declarations collected in
11515 extract_local_specs; map from the general template to our local
11516 context. */
11521 /* else inst is already a full instantiation of the pack. */
11523 }
11526 }
11531 /* Determine the argument packs that will instantiate the parameter
11532 packs used in the expansion expression. While we're at it,
11533 compute the number of arguments to be expanded and make sure it
11534 is consistent. */
11537 {
11544 {
11549 else
11552 }
11554 {
11555 /* ??? Support use in other patterns. */
11559 }
11561 {
11562 /* We know we have correct local_specializations if this
11563 expansion is at function scope, or if we're dealing with a
11564 local parameter in a requires expression; for the latter,
11565 tsubst_requires_expr set it up appropriately. */
11568 else
11569 /* We can't rely on local_specializations for a parameter
11570 name used later in a function declaration (such as in a
11571 late-specified return type). Even if it exists, it might
11572 have the wrong value for a recursive call. */
11576 {
11577 /* This parameter pack was used in an unevaluated context. Just
11578 make a dummy decl, since it's only used for its type. */
11581 /* Partial instantiation of the parm_pack, we can't build
11582 up an argument pack yet. */
11584 else
11586 }
11588 /* This argument pack isn't fully instantiated yet. We set this
11589 flag rather than clear arg_pack because we do want to do the
11590 optimization below, and we don't want to substitute directly
11591 into the pattern (as that would expose a NONTYPE_ARGUMENT_PACK
11592 where it isn't expected). */
11594 }
11596 {
11600 }
11601 else
11602 {
11608 }
11615 /* This can only happen if we forget to expand an argument
11616 pack somewhere else. Just return an error, silently. */
11617 {
11621 }
11624 {
11628 /* Don't bother trying to do a partial substitution with
11629 incomplete packs; we'll try again after deduction. */
11637 {
11642 pattern);
11643 else
11645 pattern);
11647 }
11649 /* Keep track of the parameter packs and their corresponding
11650 argument packs. */
11653 }
11654 else
11655 {
11656 /* We can't substitute for this parameter pack. We use a flag as
11657 well as the missing_level counter because function parameter
11658 packs don't have a level. */
11661 }
11662 }
11664 /* If the expansion is just T..., return the matching argument pack, unless
11665 we need to call convert_from_reference on all the elements. This is an
11666 important optimization; see c++/68422. */
11669 {
11672 /* If the argument pack is a single pack expansion, pull it out. */
11677 /* Types need no adjustment, nor does sizeof..., and if we still have
11678 some pack expansion args we won't do anything yet. */
11683 /* Also optimize expression pack expansions if we can tell that the
11684 elements won't have reference type. */
11690 /* Otherwise use the normal path so we get convert_from_reference. */
11691 }
11693 /* We cannot expand this expansion expression, because we don't have
11694 all of the argument packs we need. */
11696 {
11697 /* We got some full packs, but we can't substitute them in until we
11698 have values for all the packs. So remember these until then. */
11707 }
11709 {
11710 /* There were no real arguments, we're just replacing a parameter
11711 pack with another version of itself. Substitute into the
11712 pattern and return a PACK_EXPANSION_*. The caller will need to
11713 deal with that. */
11717 else
11721 }
11726 {
11727 /* We're in a late-specified return type, so create our own local
11728 specializations map; the current map is either NULL or (in the
11729 case of recursive unification) might have bindings that we don't
11730 want to use or alter. */
11733 }
11735 /* For each argument in each argument pack, substitute into the
11736 pattern. */
11740 {
11742 i,
11744 in_decl);
11747 {
11750 }
11751 }
11753 /* Update ARGS to restore the substitution from parameter packs to
11754 their argument packs. */
11756 {
11763 else
11764 {
11772 /* Update the corresponding argument. */
11776 else
11778 }
11779 }
11782 {
11785 }
11787 /* If the dependent pack arguments were such that we end up with only a
11788 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11794 }
11796 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11797 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11798 parameter packs; all parms generated from a function parameter pack will
11799 have the same DECL_PARM_INDEX. */
11801 tree
11803 {
11805 tree patparm;
11808 {
11814 }
11815 else
11816 {
11821 }
11824 }
11826 /* Make an argument pack out of the TREE_VEC VEC. */
11828 static tree
11830 {
11831 tree pack;
11835 else
11836 {
11839 }
11842 }
11844 /* Return an exact copy of template args T that can be modified
11845 independently. */
11847 static tree
11849 {
11857 {
11862 }
11868 }
11870 /* Substitute ARGS into the vector or list of template arguments T. */
11872 static tree
11874 {
11886 {
11888 tree new_arg;
11893 {
11894 /* Substitute into an expansion expression. */
11898 /* Add to the expanded length adjustment the number of
11899 expanded arguments. We subtract one from this
11900 measurement, because the argument pack expression
11901 itself is already counted as 1 in
11902 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11903 the argument pack is empty. */
11905 }
11907 {
11908 /* Substitute into each of the arguments. */
11917 else
11922 }
11923 else
11932 }
11937 /* Make space for the expanded arguments coming from template
11938 argument packs. */
11940 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11941 arguments for a member template.
11942 In that case each TREE_VEC in ORIG_T represents a level of template
11943 arguments, and ORIG_T won't carry any non defaulted argument count.
11944 It will rather be the nested TREE_VECs that will carry one.
11945 In other words, ORIG_T carries a non defaulted argument count only
11946 if it doesn't contain any nested TREE_VEC. */
11948 {
11952 }
11954 {
11958 {
11961 /* Now expand the template argument pack "in place". */
11964 }
11965 else
11966 {
11968 out++;
11969 }
11970 }
11973 }
11975 /* Substitute ARGS into one level PARMS of template parameters. */
11977 static tree
11979 {
11986 {
11994 }
11997 }
11999 /* Return the result of substituting ARGS into the template parameters
12000 given by PARMS. If there are m levels of ARGS and m + n levels of
12001 PARMS, then the result will contain n levels of PARMS. For
12002 example, if PARMS is `template <class T> template <class U>
12003 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
12004 result will be `template <int*, double, class V>'. */
12006 static tree
12008 {
12012 /* When substituting into a template, we must set
12013 PROCESSING_TEMPLATE_DECL as the template parameters may be
12014 dependent if they are based on one-another, and the dependency
12015 predicates are short-circuit outside of templates. */
12022 {
12029 }
12034 }
12036 /* Return the result of substituting ARGS into one template parameter
12037 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
12038 parameter and which TREE_PURPOSE is the default argument of the
12039 template parameter. */
12041 static tree
12043 {
12064 }
12066 /* Substitute the ARGS into the indicated aggregate (or enumeration)
12067 type T. If T is not an aggregate or enumeration type, it is
12068 handled as if by tsubst. IN_DECL is as for tsubst. If
12069 ENTERING_SCOPE is nonzero, T is the context for a template which
12070 we are presently tsubst'ing. Return the substituted value. */
12072 static tree
12074 tree args,
12075 tsubst_flags_t complain,
12076 tree in_decl,
12078 {
12083 {
12088 /* Fall through. */
12092 {
12093 tree argvec;
12094 tree context;
12095 tree r;
12099 /* In "sizeof(X<I>)" we need to evaluate "I". */
12105 /* First, determine the context for the type we are looking
12106 up. */
12109 {
12112 /* If context is a nested class inside a class template,
12113 it may still need to be instantiated (c++/33959). */
12115 }
12117 /* Then, figure out what arguments are appropriate for the
12118 type we are trying to find. For example, given:
12120 template <class T> struct S;
12121 template <class T, class U> void f(T, U) { S<U> su; }
12123 and supposing that we are instantiating f<int, double>,
12124 then our ARGS will be {int, double}, but, when looking up
12125 S we only want {double}. */
12130 else
12131 {
12135 }
12141 }
12142 else
12143 /* This is not a template type, so there's nothing to do. */
12148 }
12149 }
12153 /* Substitute into the default argument ARG (a default argument for
12154 FN), which has the indicated TYPE. */
12156 tree
12158 tsubst_flags_t complain)
12159 {
12164 /* This can happen in invalid code. */
12179 /* This default argument came from a template. Instantiate the
12180 default argument here, not in tsubst. In the case of
12181 something like:
12183 template <class T>
12184 struct S {
12185 static T t();
12186 void f(T = t());
12187 };
12189 we must be careful to do name lookup in the scope of S<T>,
12190 rather than in the current class. */
12192 /* The "this" pointer is not valid in a default argument. */
12194 {
12199 }
12204 /* The default argument expression may cause implicitly defined
12205 member functions to be synthesized, which will result in garbage
12206 collection. We must treat this situation as if we were within
12207 the body of function so as to avoid collecting live data on the
12208 stack. */
12218 /* Restore the "this" pointer. */
12220 {
12223 }
12230 /* Make sure the default argument is reasonable. */
12236 {
12240 }
12243 }
12245 /* Substitute into all the default arguments for FN. */
12247 static void
12249 {
12250 tree arg;
12251 tree tmpl_args;
12255 /* If this function is not yet instantiated, we certainly don't need
12256 its default arguments. */
12259 /* Don't do this again for clones. */
12265 arg;
12271 complain);
12272 }
12274 /* Subroutine of tsubst_decl for the case when T is a FUNCTION_DECL. */
12276 static tree
12278 tree lambda_fntype)
12279 {
12284 /* Nobody should be tsubst'ing into non-template functions. */
12288 {
12289 /* If T is not dependent, just return it. */
12293 /* Calculate the most general template of which R is a
12294 specialization. */
12297 /* We're substituting a lambda function under tsubst_lambda_expr but not
12298 directly from it; find the matching function we're already inside.
12299 But don't do this if T is a generic lambda with a single level of
12300 template parms, as in that case we're doing a normal instantiation. */
12306 /* Calculate the complete set of arguments used to
12307 specialize R. */
12309 (DECL_TEMPLATE_RESULT
12315 /* Check to see if we already have this specialization. */
12317 {
12321 }
12323 /* We can see more levels of arguments than parameters if
12324 there was a specialization of a member template, like
12325 this:
12327 template <class T> struct S { template <class U> void f(); }
12328 template <> template <class U> void S<int>::f(U);
12330 Here, we'll be substituting into the specialization,
12331 because that's where we can find the code we actually
12332 want to generate, but we'll have enough arguments for
12333 the most general template.
12335 We also deal with the peculiar case:
12337 template <class T> struct S {
12338 template <class U> friend void f();
12339 };
12340 template <class U> void f() {}
12341 template S<int>;
12342 template void f<double>();
12344 Here, the ARGS for the instantiation of will be {int,
12345 double}. But, we only need as many ARGS as there are
12346 levels of template parameters in CODE_PATTERN. We are
12347 careful not to get fooled into reducing the ARGS in
12348 situations like:
12350 template <class T> struct S { template <class U> void f(U); }
12351 template <class T> template <> void S<T>::f(int) {}
12353 which we can spot because the pattern will be a
12354 specialization in this case. */
12361 }
12362 else
12363 {
12364 /* This special case arises when we have something like this:
12366 template <class T> struct S {
12367 friend void f<int>(int, double);
12368 };
12370 Here, the DECL_TI_TEMPLATE for the friend declaration
12371 will be an IDENTIFIER_NODE. We are being called from
12372 tsubst_friend_function, and we want only to create a
12373 new decl (R) with appropriate types so that we can call
12374 determine_specialization. */
12377 }
12394 /* If we hit excessive deduction depth, the type is bogus even if
12395 it isn't error_mark_node, so don't build a decl. */
12399 /* We do NOT check for matching decls pushed separately at this
12400 point, as they may not represent instantiations of this
12401 template, and in any case are considered separate under the
12402 discrete model. */
12406 /* Clear out the mangled name and RTL for the instantiation. */
12409 /* Leave DECL_INITIAL set on deleted instantiations. */
12414 /* OpenMP UDRs have the only argument a reference to the declared
12415 type. We want to diagnose if the declared type is a reference,
12416 which is invalid, but as references to references are usually
12417 quietly merged, diagnose it here. */
12419 {
12420 tree argtype
12425 "reference type %qT in "
12429 argtype);
12430 }
12433 /* Type-conversion operator. Reconstruct the name, in
12434 case it's the name of one of the template's parameters. */
12444 {
12448 }
12455 /* If this is an instantiation of a function with internal
12456 linkage, we already know what object file linkage will be
12457 assigned to the instantiation. */
12466 /* We'll re-clone as appropriate in instantiate_template. */
12469 /* If we aren't complaining now, return on error before we register
12470 the specialization so that we'll complain eventually. */
12476 /* When instantiating a constrained member, substitute
12477 into the constraints to create a new constraint. */
12480 {
12483 }
12485 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12486 this in the special friend case mentioned above where
12487 GEN_TMPL is NULL. */
12489 {
12494 tree new_r
12497 /* We instantiated this while substituting into
12498 the type earlier (template/friend54.C). */
12501 /* We're not supposed to instantiate default arguments
12502 until they are called, for a template. But, for a
12503 declaration like:
12505 template <class T> void f ()
12506 { extern void g(int i = T()); }
12508 we should do the substitution when the template is
12509 instantiated. We handle the member function case in
12510 instantiate_class_template since the default arguments
12511 might refer to other members of the class. */
12516 }
12517 else
12520 /* Copy the list of befriending classes. */
12524 {
12528 }
12531 {
12535 /* If this is an instantiation of a member template, clone it.
12536 If it isn't, that'll be handled by
12537 clone_constructors_and_destructors. */
12540 }
12551 /* Possibly limit visibility based on template args. */
12554 {
12558 }
12567 }
12569 /* Subroutine of tsubst_decl for the case when T is a TEMPLATE_DECL. */
12571 static tree
12573 tree lambda_fntype)
12574 {
12575 /* We can get here when processing a member function template,
12576 member class template, or template template parameter. */
12579 tree spec;
12580 tree tmpl_args;
12581 tree full_args;
12582 tree r;
12586 {
12587 /* Template template parameter is treated here. */
12591 /* If we get a real template back, return it. This can happen in
12592 the context of most_specialized_partial_spec. */
12595 else
12596 /* The new TEMPLATE_DECL was built in
12597 reduce_template_parm_level. */
12600 }
12603 {
12604 /* We might already have an instance of this template.
12605 The ARGS are for the surrounding class type, so the
12606 full args contain the tsubst'd args for the context,
12607 plus the innermost args from the template decl. */
12611 /* Because this is a template, the arguments will still be
12612 dependent, even after substitution. If
12613 PROCESSING_TEMPLATE_DECL is not set, the dependency
12614 predicates will short-circuit. */
12622 /* If this is a default template template argument,
12623 tsubst might not have changed anything. */
12631 }
12633 /* Make a new template decl. It will be similar to the
12634 original, but will record the current template arguments.
12635 We also create a new function declaration, which is just
12636 like the old one, but points to this new template, rather
12637 than the old one. */
12642 // Build new template info linking to the original template decl.
12644 {
12647 }
12648 else
12651 /* The template parameters for this new template are all the
12652 template parameters for the old template, except the
12653 outermost level of parameters. */
12656 complain);
12660 {
12661 tree new_type;
12669 /* For a partial specialization, we need to keep pointing to
12670 the primary template. */
12676 }
12677 else
12678 {
12679 tree new_decl;
12683 else
12693 {
12696 }
12697 else
12698 {
12701 }
12702 }
12712 /* Record this non-type partial instantiation. */
12718 }
12720 /* True if FN is the op() for a lambda in an uninstantiated template. */
12722 bool
12724 {
12729 }
12731 /* We're instantiating a variable from template function TCTX. Return the
12732 corresponding current enclosing scope. This gets complicated because lambda
12733 functions in templates are regenerated rather than instantiated, but generic
12734 lambda functions are subsequently instantiated. */
12736 static tree
12738 {
12747 {
12760 }
12762 }
12764 /* Substitute the ARGS into the T, which is a _DECL. Return the
12765 result of the substitution. Issue error and warning messages under
12766 control of COMPLAIN. */
12768 static tree
12770 {
12771 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12772 location_t saved_loc;
12777 /* Set the filename and linenumber to improve error-reporting. */
12782 {
12792 {
12800 {
12801 /* If there is a local specialization that isn't a
12802 parameter pack, it means that we're doing a "simple"
12803 substitution from inside tsubst_pack_expansion. Just
12804 return the local specialization (which will be a single
12805 parm). */
12812 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12813 the parameters in this function parameter pack. */
12817 {
12820 /* Zero-length parameter packs are boring. Just substitute
12821 into the chain. */
12825 }
12826 else
12827 {
12828 /* All we did was update the type. Make a note of that. */
12831 }
12832 }
12834 /* Loop through all of the parameters we'll build. When T is
12835 a function parameter pack, LEN is the number of expanded
12836 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12839 {
12846 /* We're on the Ith parameter of the function parameter
12847 pack. */
12848 {
12849 /* Get the Ith type. */
12852 /* Rename the parameter to include the index. */
12855 }
12857 /* We're dealing with a normal parameter. */
12865 {
12868 else
12871 }
12881 /* Keep track of the first new parameter we
12882 generate. That's what will be returned to the
12883 caller. */
12887 /* Build a proper chain of parameters when substituting
12888 into a function parameter pack. */
12891 }
12893 /* If cp_unevaluated_operand is set, we're just looking for a
12894 single dummy parameter, so don't keep going. */
12899 /* FIRST_R contains the start of the chain we've built. */
12901 }
12905 {
12912 {
12913 /* This field is a lambda capture pack. Return a TREE_VEC of
12914 the expanded fields to instantiate_class_template_1. */
12918 {
12921 }
12922 else
12923 {
12924 /* All we did was update the type. Make a note of that. */
12927 }
12928 }
12931 {
12934 {
12938 }
12948 /* For bit-fields, DECL_BIT_FIELD_REPRESENTATIVE gives the
12949 number of bits. */
12955 {
12956 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12957 NSDMI in perform_member_init. Still set DECL_INITIAL
12958 so that we know there is one. */
12963 }
12964 /* We don't have to set DECL_CONTEXT here; it is set by
12965 finish_member_declaration. */
12973 }
12977 }
12981 /* We reach here only for member using decls. We also need to check
12982 uses_template_parms because DECL_DEPENDENT_P is not set for a
12983 using-declaration that designates a member of the current
12984 instantiation (c++/53549). */
12987 {
12991 {
12996 {
13000 {
13003 }
13004 else
13005 {
13008 }
13010 }
13011 }
13012 else
13013 {
13019 else
13020 {
13023 }
13024 }
13025 }
13026 else
13027 {
13030 }
13035 {
13038 tree spec;
13040 tree ctx;
13049 {
13050 /* If this is the canonical decl, we don't have to
13051 mess with instantiations, and often we can't (for
13052 typename, template type parms and such). Note that
13053 TYPE_NAME is not correct for the above test if
13054 we've copied the type for a typedef. */
13060 }
13062 /* Check to see if we already have the specialization we
13063 need. */
13066 {
13067 /* T is a static data member or namespace-scope entity.
13068 We have to substitute into namespace-scope variables
13069 (not just variable templates) because of cases like:
13071 template <class T> void f() { extern T t; }
13073 where the entity referenced is not known until
13074 instantiation time. */
13078 {
13080 complain,
13082 /* If CTX is unchanged, then T is in fact the
13083 specialization we want. That situation occurs when
13084 referencing a static data member within in its own
13085 class. We can use pointer equality, rather than
13086 same_type_p, because DECL_CONTEXT is always
13087 canonical... */
13089 /* ... unless T is a member template; in which
13090 case our caller can be willing to create a
13091 specialization of that template represented
13092 by T. */
13096 }
13099 {
13104 argvec = (coerce_innermost_template_parms
13112 }
13113 }
13114 else
13115 {
13116 /* A local variable. */
13118 /* Subsequent calls to pushdecl will fill this in. */
13120 /* Unless this is a reference to a static variable from an
13121 enclosing function, in which case we need to fill it in now. */
13123 {
13127 }
13129 }
13130 /* If we already have the specialization we need, there is
13131 nothing more to do. */
13133 {
13136 }
13138 /* Create a new node for the specialization we need. */
13141 {
13144 else
13152 {
13153 /* Mask off any template args past the variable's context so we
13154 don't replace the auto with an unrelated argument. */
13158 /* This should never happen with the new lambda instantiation
13159 model, but keep the handling just in case. */
13162 }
13164 }
13166 {
13167 /* Even if the original location is out of scope, the
13168 newly substituted one is not. */
13175 {
13176 /* It may seem that this case cannot occur, since:
13178 typedef void f();
13179 void g() { f x; }
13181 declares a function, not a variable. However:
13183 typedef void f();
13184 template <typename T> void g() { T t; }
13185 template void g<f>();
13187 is an attempt to declare a variable with function
13188 type. */
13190 /* R is not yet sufficiently initialized, so we
13191 just use its name. */
13194 }
13196 /* Wait until cp_finish_decl to set this again, to handle
13197 circular dependency (template/instantiate6.C). */
13202 {
13207 {
13210 }
13212 }
13216 }
13222 /* Clear out the mangled name and RTL for the instantiation. */
13226 /* The initializer must not be expanded until it is required;
13227 see [temp.inst]. */
13231 {
13237 /* Possibly limit visibility based on template args. */
13240 {
13244 }
13246 }
13249 {
13250 /* A static data member declaration is always marked
13251 external when it is declared in-class, even if an
13252 initializer is present. We mimic the non-template
13253 processing here. */
13261 }
13262 else
13263 {
13268 }
13276 /* Preserve a typedef that names a type. */
13278 {
13282 /* An alias template specialization can be dependent
13283 even if its underlying type is not. */
13285 }
13288 }
13293 }
13294 #undef RETURN
13296 out:
13297 /* Restore the file and line information. */
13301 }
13303 /* Substitute into the ARG_TYPES of a function type.
13304 If END is a TREE_CHAIN, leave it and any following types
13305 un-substituted. */
13307 static tree
13309 tree args,
13310 tree end,
13311 tsubst_flags_t complain,
13312 tree in_decl)
13313 {
13314 tree remaining_arg_types;
13318 tree default_arg;
13329 {
13330 /* For a pack expansion, perform substitution on the
13331 entire expression. Later on, we'll handle the arguments
13332 one-by-one. */
13337 /* So that we'll spin through the parameters, one by one. */
13339 else
13340 {
13341 /* We only partially substituted into the parameter
13342 pack. Our type is TYPE_PACK_EXPANSION. */
13345 }
13346 }
13359 {
13361 {
13365 }
13367 }
13368 /* DR 657. */
13372 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13373 top-level qualifiers as required. */
13376 /* We do not substitute into default arguments here. The standard
13377 mandates that they be instantiated only when needed, which is
13378 done in build_over_call. */
13381 /* Except that we do substitute default arguments under tsubst_lambda_expr,
13382 since the new op() won't have any associated template arguments for us
13383 to refer to later. */
13389 {
13390 /* We've instantiated a template before its default arguments
13391 have been parsed. This can happen for a nested template
13392 class, and is not an error unless we require the default
13393 argument in a call of this function. */
13394 remaining_arg_types =
13397 }
13398 else
13399 remaining_arg_types =
13401 }
13404 }
13406 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13407 *not* handle the exception-specification for FNTYPE, because the
13408 initial substitution of explicitly provided template parameters
13409 during argument deduction forbids substitution into the
13410 exception-specification:
13412 [temp.deduct]
13414 All references in the function type of the function template to the
13415 corresponding template parameters are replaced by the specified tem-
13416 plate argument values. If a substitution in a template parameter or
13417 in the function type of the function template results in an invalid
13418 type, type deduction fails. [Note: The equivalent substitution in
13419 exception specifications is done only when the function is instanti-
13420 ated, at which point a program is ill-formed if the substitution
13421 results in an invalid type.] */
13423 static tree
13425 tree args,
13426 tsubst_flags_t complain,
13427 tree in_decl)
13428 {
13429 tree return_type;
13431 tree fntype;
13433 /* The TYPE_CONTEXT is not used for function/method types. */
13436 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13437 failure. */
13441 {
13442 /* Substitute the argument types. */
13454 {
13455 /* DR 1207: 'this' is in scope in the trailing return type. */
13457 }
13459 /* Substitute the return type. */
13463 {
13466 }
13467 }
13468 else
13469 /* Substitute the return type. */
13474 /* DR 486 clarifies that creation of a function type with an
13475 invalid return type is a deduction failure. */
13478 {
13480 {
13483 else
13485 }
13487 }
13488 /* And DR 657. */
13493 {
13494 /* Substitute the argument types. */
13499 }
13501 /* Construct a new type node and return it. */
13503 {
13508 }
13509 else
13510 {
13512 /* Don't pick up extra function qualifiers from the basetype. */
13515 {
13516 /* [temp.deduct]
13518 Type deduction may fail for any of the following
13519 reasons:
13521 -- Attempting to create "pointer to member of T" when T
13522 is not a class type. */
13525 r);
13527 }
13532 }
13539 }
13541 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13542 ARGS into that specification, and return the substituted
13543 specification. If there is no specification, return NULL_TREE. */
13545 static tree
13547 tree args,
13548 tsubst_flags_t complain,
13549 tree in_decl,
13551 {
13552 tree specs;
13553 tree new_specs;
13558 {
13559 /* A noexcept-specifier. */
13564 {
13565 /* Defer instantiation of noexcept-specifiers to avoid
13566 excessive instantiations (c++/49107). */
13569 {
13570 /* We already partially instantiated this member template,
13571 so combine the new args with the old. */
13576 }
13577 else
13578 {
13581 }
13582 }
13583 else
13584 new_specs = tsubst_copy_and_build
13588 }
13590 {
13593 else
13595 {
13596 tree spec;
13601 {
13602 /* Expand the pack expansion type. */
13605 in_decl);
13611 else
13612 {
13613 /* We're substituting into a member template, so
13614 we got a TYPE_PACK_EXPANSION back. Add that
13615 expansion and move on. */
13619 expanded_specs,
13620 complain);
13623 }
13624 }
13627 {
13630 else
13635 complain);
13636 }
13639 }
13640 }
13642 }
13644 /* Take the tree structure T and replace template parameters used
13645 therein with the argument vector ARGS. IN_DECL is an associated
13646 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13647 Issue error and warning messages under control of COMPLAIN. Note
13648 that we must be relatively non-tolerant of extensions here, in
13649 order to preserve conformance; if we allow substitutions that
13650 should not be allowed, we may allow argument deductions that should
13651 not succeed, and therefore report ambiguous overload situations
13652 where there are none. In theory, we could allow the substitution,
13653 but indicate that it should have failed, and allow our caller to
13654 make sure that the right thing happens, but we don't try to do this
13655 yet.
13657 This function is used for dealing with types, decls and the like;
13658 for expressions, use tsubst_expr or tsubst_copy. */
13660 tree
13662 {
13685 else
13690 /* Reuse typedefs. We need to do this to handle dependent attributes,
13691 such as attribute aligned. */
13694 {
13698 {
13699 /* DECL represents an alias template and we want to
13700 instantiate it. */
13704 }
13708 {
13712 }
13717 else
13718 /* The typedef is from a non-template context. */
13722 {
13724 r = cp_build_qualified_type_real
13728 }
13729 else
13730 {
13731 /* We don't have an instantiation yet, so drop the typedef. */
13736 }
13737 }
13754 {
13780 {
13786 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13787 needed. */
13793 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13794 with TREE_SIDE_EFFECTS that indicates this is not an integral
13795 constant expression. */
13798 {
13801 }
13804 }
13810 {
13816 /* Early in template argument deduction substitution, we don't
13817 want to reduce the level of 'auto', or it will be confused
13818 with a normal template parm in subsequent deduction. */
13830 {
13833 /* See through ARGUMENT_PACK_SELECT arguments. */
13836 }
13841 {
13843 /* If ARG is an argument pack, we don't actually want to
13844 perform a substitution here, because substitutions
13845 for argument packs are only done
13846 element-by-element. We can get to this point when
13847 substituting the type of a non-type template
13848 parameter pack, when that type actually contains
13849 template parameter packs from an outer template, e.g.,
13851 template<typename... Types> struct A {
13852 template<Types... Values> struct B { };
13853 }; */
13857 {
13863 return cp_build_qualified_type_real
13865 }
13867 {
13868 /* We are processing a type constructed from a
13869 template template parameter. */
13880 /* Consider this code:
13882 template <template <class> class Template>
13883 struct Internal {
13884 template <class Arg> using Bind = Template<Arg>;
13885 };
13887 template <template <class> class Template, class Arg>
13888 using Instantiate = Template<Arg>; //#0
13890 template <template <class> class Template,
13891 class Argument>
13892 using Bind =
13893 Instantiate<Internal<Template>::template Bind,
13894 Argument>; //#1
13896 When #1 is parsed, the
13897 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13898 parameter `Template' in #0 matches the
13899 UNBOUND_CLASS_TEMPLATE representing the argument
13900 `Internal<Template>::template Bind'; We then want
13901 to assemble the type `Bind<Argument>' that can't
13902 be fully created right now, because
13903 `Internal<Template>' not being complete, the Bind
13904 template cannot be looked up in that context. So
13905 we need to "store" `Bind<Argument>' for later
13906 when the context of Bind becomes complete. Let's
13907 store that in a TYPENAME_TYPE. */
13911 argvec),
13912 typename_type,
13913 complain);
13915 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13916 are resolving nested-types in the signature of a
13917 member function templates. Otherwise ARG is a
13918 TEMPLATE_DECL and is the real template to be
13919 instantiated. */
13927 complain);
13928 return cp_build_qualified_type_real
13930 }
13933 else
13934 /* TEMPLATE_PARM_INDEX. */
13936 }
13939 /* This can happen during the attempted tsubst'ing in
13940 unify. This means that we don't yet have any information
13941 about the template parameter in question. */
13944 /* If we get here, we must have been looking at a parm for a
13945 more deeply nested template. Make a new version of this
13946 template parameter, but with a lower level. */
13948 {
13953 {
13955 r = cp_build_qualified_type_real
13959 }
13966 /* Break infinite recursion when substituting the constraints
13968 else
13969 {
13980 {
13981 /* Propagate constraints on placeholders. */
13986 {
13990 }
13991 }
13994 /* We have reduced the level of the template
13995 template parameter, but not the levels of its
13996 template parameters, so canonical_type_parameter
13997 will not be able to find the canonical template
13998 template parameter for this level. Thus, we
13999 require structural equality checking to compare
14000 TEMPLATE_TEMPLATE_PARMs. */
14004 else
14008 {
14010 /* We might need to substitute into the types of non-type
14011 template parameters. */
14023 }
14024 }
14028 /* OK, now substitute the type of the non-type parameter. We
14029 couldn't do it earlier because it might be an auto parameter,
14030 and we wouldn't need to if we had an argument. */
14039 }
14042 }
14045 {
14053 {
14057 }
14060 {
14064 }
14067 {
14071 }
14077 }
14080 /* We should never be tsubsting a binfo. */
14084 /* A vector of template arguments. */
14090 {
14094 /* [temp.deduct]
14096 Type deduction may fail for any of the following
14097 reasons:
14099 -- Attempting to create a pointer to reference type.
14100 -- Attempting to create a reference to a reference type or
14101 a reference to void.
14103 Core issue 106 says that creating a reference to a reference
14104 during instantiation is no longer a cause for failure. We
14105 only enforce this check in strict C++98 mode. */
14109 {
14112 /* We keep track of the last time we issued this error
14113 message to avoid spewing a ton of messages during a
14114 single bad template instantiation. */
14117 {
14122 else
14125 }
14128 }
14132 {
14134 {
14137 type);
14138 else
14140 type);
14141 }
14143 }
14145 {
14149 }
14151 /* In C++0x, during template argument substitution, when there is an
14152 attempt to create a reference to a reference type, reference
14153 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
14155 "If a template-argument for a template-parameter T names a type
14156 that is a reference to a type A, an attempt to create the type
14157 'lvalue reference to cv T' creates the type 'lvalue reference to
14158 A,' while an attempt to create the type type rvalue reference to
14159 cv T' creates the type T"
14160 */
14161 r = cp_build_reference_type
14164 else
14169 /* Will this ever be needed for TYPE_..._TO values? */
14173 }
14175 {
14178 {
14179 /* [temp.deduct]
14181 Type deduction may fail for any of the following
14182 reasons:
14184 -- Attempting to create "pointer to member of T" when T
14185 is not a class type. */
14189 }
14191 {
14195 }
14197 {
14201 }
14204 {
14205 /* The type of the implicit object parameter gets its
14206 cv-qualifiers from the FUNCTION_TYPE. */
14207 tree memptr;
14208 tree method_type
14213 complain);
14214 }
14215 else
14218 complain);
14219 }
14222 {
14223 tree fntype;
14224 tree specs;
14229 /* Substitute the exception specification. */
14237 }
14239 {
14244 /* As an optimization, we avoid regenerating the array type if
14245 it will obviously be the same as T. */
14249 /* These checks should match the ones in create_array_type_for_decl.
14251 [temp.deduct]
14253 The deduction may fail for any of the following reasons:
14255 -- Attempting to create an array with an element type that
14256 is void, a function type, or a reference type, or [DR337]
14257 an abstract class type. */
14263 {
14267 }
14275 {
14278 }
14281 }
14284 {
14296 {
14300 }
14302 {
14303 /* Normally, make_typename_type does not require that the CTX
14304 have complete type in order to allow things like:
14306 template <class T> struct S { typename S<T>::X Y; };
14308 But, such constructs have already been resolved by this
14309 point, so here CTX really should have complete type, unless
14310 it's a partial instantiation. */
14313 {
14317 }
14318 }
14325 {
14328 }
14331 {
14333 {
14337 else
14339 }
14341 {
14345 else
14347 }
14348 }
14350 return cp_build_qualified_type_real
14352 }
14355 {
14367 }
14370 {
14371 tree type;
14387 complain);
14388 }
14391 {
14392 tree type;
14403 {
14405 {
14409 }
14412 }
14423 else
14424 {
14428 /* In a template ~id could be either a complement expression
14429 or an unqualified-id naming a destructor; if instantiating
14430 it produces an expression, it's not an id-expression or
14431 member access. */
14434 }
14439 }
14442 {
14446 }
14450 {
14451 tree r;
14455 else
14463 }
14478 /* We should use one of the expression tsubsts for these codes. */
14484 }
14485 }
14487 /* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
14488 expression on the left-hand side of the "." or "->" operator. We
14489 only do the lookup if we had a dependent BASELINK. Otherwise we
14490 adjust it onto the instantiated heirarchy. */
14492 static tree
14495 {
14507 {
14514 }
14521 {
14527 /* Treat as-if non-dependent below. */
14532 {
14538 }
14542 }
14543 else
14544 /* We're going to overwrite pieces below, make a duplicate. */
14547 /* If lookup found a single function, mark it as used at this point.
14548 (If lookup found multiple functions the one selected later by
14549 overload resolution will be marked as used at that point.) */
14555 {
14556 /* Add back the template arguments, if present. */
14561 /* Update the conversion operator type. */
14563 }
14569 {
14571 qualifying_scope,
14572 object_type);
14574 /* We need to call adjust_result_of_qualified_name_lookup in case the
14575 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14576 so that we still get virtual function binding. */
14578 }
14581 }
14583 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14584 true if the qualified-id will be a postfix-expression in-and-of
14585 itself; false if more of the postfix-expression follows the
14586 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14587 of "&". */
14589 static tree
14593 {
14594 tree expr;
14595 tree scope;
14596 tree name;
14598 tree template_args;
14603 /* Figure out what name to look up. */
14606 {
14616 }
14617 else
14618 {
14621 }
14623 /* Substitute into the qualifying scope. When there are no ARGS, we
14624 are just trying to simplify a non-dependent expression. In that
14625 case the qualifying scope may be dependent, and, in any case,
14626 substituting will not help. */
14629 {
14632 }
14633 else
14637 {
14644 }
14647 {
14649 {
14650 /* A BIT_NOT_EXPR is used to represent a destructor. */
14652 {
14656 }
14657 else
14660 }
14661 else
14665 {
14667 {
14671 }
14673 }
14674 }
14677 {
14679 scope);
14680 /* Remember that there was a reference to this entity. */
14683 }
14686 {
14692 }
14695 {
14698 complain);
14699 else
14701 }
14707 {
14708 expr = (adjust_result_of_qualified_name_lookup
14710 expr = (finish_qualified_id_expr
14714 }
14716 /* Expressions do not generally have reference type. */
14718 /* However, if we're about to form a pointer-to-member, we just
14719 want the referenced member referenced. */
14727 }
14729 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14730 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14731 for tsubst. */
14733 static tree
14736 {
14743 {
14744 /* If we had an initializer but it
14745 instantiated to nothing,
14746 value-initialize the object. This will
14747 only occur when the initializer was a
14748 pack expansion where the parameter packs
14749 used in that expansion were of length
14750 zero. */
14752 complain);
14757 }
14760 }
14762 /* Like tsubst, but deals with expressions. This function just replaces
14763 template parms; to finish processing the resultant expression, use
14764 tsubst_copy_and_build or tsubst_expr. */
14766 static tree
14768 {
14770 tree r;
14778 {
14783 {
14784 /* We get here for a use of 'this' in an NSDMI. */
14788 /* This can happen for a parameter name used later in a function
14789 declaration (such as in a late-specified return type). Just
14790 make a dummy decl, since it's only used for its type. */
14793 /* Give it the template pattern as its context; its true context
14794 hasn't been instantiated yet and this is good enough for
14795 mangling. */
14797 }
14806 {
14807 tree enum_type;
14808 tree v;
14812 /* There is no need to substitute into namespace-scope
14813 enumerators. */
14816 /* If ARGS is NULL, then T is known to be non-dependent. */
14820 /* Unfortunately, we cannot just call lookup_name here.
14821 Consider:
14823 template <int I> int f() {
14824 enum E { a = I };
14825 struct S { void g() { E e = a; } };
14826 };
14828 When we instantiate f<7>::S::g(), say, lookup_name is not
14829 clever enough to find f<7>::a. */
14830 enum_type
14840 /* We didn't find the name. That should never happen; if
14841 name-lookup found it during preliminary parsing, we
14842 should find it again here during instantiation. */
14844 }
14849 {
14850 tree ctx;
14855 {
14858 {
14862 }
14864 }
14865 }
14875 {
14878 {
14879 /* First try name lookup to find the instantiation. */
14882 {
14883 /* Make sure that the one we found is the one we want. */
14887 }
14891 else
14892 {
14893 /* This can happen for a variable used in a
14894 late-specified return type of a local lambda, or for a
14895 local static or constant. Building a new VAR_DECL
14896 should be OK in all those cases. */
14899 /* Avoid infinite recursion (79640). */
14902 {
14903 /* We can't call cp_finish_decl, so handle the
14904 initializer by hand. */
14919 }
14926 }
14927 /* Remember this for subsequent uses. */
14930 }
14933 }
14934 else
14944 /* An OVERLOAD will always be a non-dependent overload set; an
14945 overload set from function scope will just be represented with an
14946 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14948 /* We must have marked any lookups as persistent. */
14964 {
14965 /* Template template argument like the following example need
14966 special treatment:
14968 template <template <class> class TT> struct C {};
14969 template <class T> struct D {
14970 template <class U> struct E {};
14971 C<E> c; // #1
14972 };
14973 D<int> d; // #2
14975 We are processing the template argument `E' in #1 for
14976 the template instantiation #2. Originally, `E' is a
14977 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14978 have to substitute this with one having context `D<int>'. */
14982 {
14983 /* When rewriting a constructor into a deduction guide, a
14984 non-dependent name can become dependent, so memtmpl<args>
14985 becomes context::template memtmpl<args>. */
14989 }
14991 }
14992 else
14993 /* Ordinary template template argument. */
14998 {
14999 /* Handle location wrappers by substituting the wrapped node
15000 first, *then* reusing the resulting type. Doing the type
15001 first ensures that we handle template parameters and
15002 parameter pack expansions. */
15006 }
15016 {
15020 }
15025 {
15034 /* We only want to compute the number of arguments. */
15037 else
15044 {
15046 /* Set TREE_USED for the benefit of -Wunused. */
15050 }
15058 {
15063 else
15069 else
15072 }
15073 else
15075 }
15077 {
15085 }
15086 /* Fall through */
15102 {
15106 }
15109 {
15110 tree object;
15111 tree name;
15116 {
15120 }
15123 {
15133 }
15138 in_decl);
15139 else
15142 }
15180 {
15184 }
15187 {
15192 }
15195 {
15199 }
15202 {
15210 }
15216 {
15223 }
15226 {
15233 }
15236 {
15243 }
15246 {
15247 /* Substituted template arguments */
15256 }
15259 {
15279 }
15304 /* Fall through. */
15307 {
15310 }
15311 else
15315 /* This is handled by tsubst_copy_and_build. */
15319 {
15323 }
15326 /* We shouldn't have built any of these during initial template
15327 generation. Instead, they should be built during instantiation
15328 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15332 {
15342 }
15360 {
15361 /* Instantiate any typedefs in the type. */
15366 }
15369 /* These can sometimes show up in a partial instantiation, but never
15370 involve template parms. */
15386 /* ??? There's no point in copying it for now, but maybe some
15387 day it will contain more information, such as a pointer back
15388 to the containing function, inlined copy or so. */
15392 /* We shouldn't get here, but keep going if !flag_checking. */
15396 }
15397 }
15399 /* Helper function for tsubst_omp_clauses, used for instantiation of
15400 OMP_CLAUSE_DECL of clauses. */
15402 static tree
15404 tree in_decl)
15405 {
15409 /* Handle an OpenMP array section represented as a TREE_LIST (or
15410 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15411 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15412 TREE_LIST. We can handle it exactly the same as an array section
15413 (purpose, value, and a chain), even though the nomenclature
15414 (low_bound, length, etc) is different. */
15416 {
15417 tree low_bound
15423 in_decl);
15432 }
15435 /* Undo convert_from_reference tsubst_expr could have called. */
15441 }
15443 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15445 static tree
15448 {
15453 {
15459 {
15462 {
15468 }
15469 /* FALLTHRU */
15484 in_decl);
15516 {
15519 {
15526 }
15527 else
15529 }
15532 in_decl);
15538 in_decl);
15546 in_decl);
15548 {
15551 }
15556 else
15559 in_decl,
15583 }
15586 {
15596 /* tsubst_expr on SCOPE_REF results in returning
15597 finish_non_static_data_member result. Undo that here. */
15601 {
15606 {
15610 CASE_CONVERT:
15619 /* FALLTHRU */
15623 }
15624 }
15630 {
15633 {
15636 }
15637 }
15641 }
15642 }
15646 {
15651 {
15654 }
15655 }
15657 }
15659 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15661 static tree
15663 tree in_decl)
15664 {
15665 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15685 {
15688 else
15689 {
15693 }
15694 }
15699 #undef RECUR
15700 }
15702 /* Used to temporarily communicate the list of #pragma omp parallel
15703 clauses to #pragma omp for instantiation if they are combined
15704 together. */
15708 /* Substitute one OMP_FOR iterator. */
15710 static void
15715 {
15716 #define RECUR(NODE) \
15717 tsubst_expr ((NODE), args, complain, in_decl, \
15718 integral_constant_expression_p)
15725 {
15728 }
15734 {
15735 /* We need to jump through some hoops to handle declarations in the
15736 init-statement, since we might need to handle auto deduction,
15737 but we need to keep control of initialization. */
15741 }
15742 else
15743 {
15745 {
15748 {
15752 {
15756 CASE_CONVERT:
15764 {
15767 }
15768 /* FALLTHRU */
15772 }
15773 }
15774 }
15775 else
15777 }
15788 {
15790 {
15791 /* Declare the variable, but don't let that initialize it. */
15796 }
15801 {
15806 }
15807 else
15814 }
15817 {
15818 /* Declare and initialize the variable. */
15821 }
15823 {
15827 {
15829 {
15835 {
15838 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15843 }
15846 {
15848 decl);
15850 }
15853 {
15855 decl);
15857 }
15858 else
15860 }
15863 }
15865 {
15870 {
15873 }
15874 }
15875 }
15878 {
15882 }
15883 else
15887 {
15898 {
15906 }
15907 else
15913 {
15919 }
15923 {
15931 }
15932 else
15938 }
15944 #undef RECUR
15945 }
15947 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15948 of OMP_TARGET's body. */
15950 static tree
15952 {
15955 {
15964 }
15966 }
15968 /* Helper function for tsubst_expr. For decomposition declaration
15969 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15970 also the corresponding decls representing the identifiers
15971 of the decomposition declaration. Return DECL if successful
15972 or error_mark_node otherwise, set *FIRST to the first decl
15973 in the list chained through DECL_CHAIN and *CNT to the number
15974 of such decls. */
15976 static tree
15980 {
15985 decl2
15990 {
15992 {
15995 }
16012 {
16015 }
16016 else
16018 }
16021 }
16023 /* Like tsubst_copy for expressions, etc. but also does semantic
16024 processing. */
16026 tree
16029 {
16030 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
16031 #define RECUR(NODE) \
16032 tsubst_expr ((NODE), args, complain, in_decl, \
16033 integral_constant_expression_p)
16036 tree r;
16037 location_t loc;
16049 {
16051 {
16052 tree_stmt_iterator i;
16056 }
16071 else
16081 {
16083 tree init;
16089 {
16099 else
16101 }
16104 {
16105 /* We're in tsubst_lambda_expr, we've already inserted a new
16106 capture proxy, so look it up and register it. */
16107 tree inst;
16109 {
16110 inst = (retrieve_local_specialization
16113 }
16114 else
16115 {
16119 }
16122 }
16125 /* Don't copy the old closure; we'll create a new one in
16126 tsubst_lambda_expr. */
16128 else
16129 {
16133 {
16134 /* By marking the declaration as instantiated, we avoid
16135 trying to instantiate it. Since instantiate_decl can't
16136 handle local variables, and since we've already done
16137 all that needs to be done, that's the right thing to
16138 do. */
16143 /* Anonymous aggregates are a special case. */
16146 {
16149 {
16153 }
16155 }
16161 {
16166 }
16167 else
16168 {
16173 {
16174 /* For __PRETTY_FUNCTION__ we have to adjust the
16175 initializer. */
16179 }
16180 else
16184 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
16189 {
16191 tree first;
16192 tree ndecl
16200 }
16201 else
16203 }
16204 }
16205 }
16208 }
16218 {
16222 }
16227 {
16228 /* Construct another range_for, if this is not a final
16229 substitution (for inside inside a generic lambda of a
16230 template). Otherwise convert to a regular for. */
16232 stmt = (processing_template_decl
16248 {
16252 }
16253 else
16254 {
16260 }
16266 }
16273 {
16277 }
16283 {
16287 }
16300 else
16301 {
16308 }
16314 {
16323 }
16331 else
16339 else
16360 {
16367 }
16371 {
16373 tree label;
16380 }
16386 /* Computed goto's must be tsubst'd into. On the other hand,
16387 non-computed gotos must not be; the identifier in question
16388 will have no binding. */
16390 else
16396 {
16412 }
16417 {
16422 }
16423 else
16424 {
16429 else
16436 else
16442 else
16444 }
16448 {
16452 {
16454 /* Prevent instantiate_decl from trying to instantiate
16455 this variable. We've already done all that needs to be
16456 done. */
16459 }
16464 }
16470 {
16471 /* Local classes are not independent templates; they are
16472 instantiated along with their containing function. And this
16473 way we don't have to deal with pushing out of one local class
16474 to instantiate a member of another local class. */
16475 /* Closures are handled by the LAMBDA_EXPR. */
16485 }
16489 {
16490 tree condition;
16493 condition =
16495 args,
16504 }
16510 in_decl);
16545 {
16558 in_decl);
16560 {
16567 }
16579 integral_constant_expression_p);
16590 else
16591 {
16599 }
16603 }
16608 /* FALLTHRU */
16615 in_decl);
16632 in_decl);
16643 {
16646 {
16647 /* For combined target teams, ensure the num_teams and
16648 thread_limit clause expressions are evaluated on the host,
16649 before entering the target construct. */
16650 tree c;
16656 {
16665 OMP_CLAUSE_FIRSTPRIVATE);
16669 }
16670 }
16671 }
16731 {
16736 {
16739 }
16745 }
16746 else
16747 {
16754 {
16757 }
16760 {
16765 {
16768 }
16774 }
16775 else
16776 {
16780 }
16783 }
16787 {
16793 {
16797 {
16802 }
16806 }
16807 else
16808 {
16813 }
16814 }
16818 {
16822 }
16835 /* If the first operand was a statement, we're done with it. */
16839 complain));
16853 integral_constant_expression_p));
16854 }
16857 out:
16860 #undef RECUR
16861 #undef RETURN
16862 }
16864 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16865 function. For description of the body see comment above
16866 cp_parser_omp_declare_reduction_exprs. */
16868 static void
16870 {
16876 tree_stmt_iterator tsi;
16887 {
16906 }
16908 {
16928 }
16929 }
16931 /* T is a postfix-expression that is not being used in a function
16932 call. Return the substituted version of T. */
16934 static tree
16936 tsubst_flags_t complain,
16937 tree in_decl)
16938 {
16942 else
16948 }
16950 /* T is a LAMBDA_EXPR. Generate a new LAMBDA_EXPR for the current
16951 instantiation context. Instantiating a pack expansion containing a lambda
16952 might result in multiple lambdas all based on the same lambda in the
16953 template. */
16955 tree
16957 {
16971 else
16979 {
16991 else
16996 {
17005 }
17006 else
17007 {
17013 }
17014 }
17018 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17036 else
17037 {
17038 /* Fix the type of 'this'. */
17044 {
17048 }
17049 else
17050 {
17054 }
17056 /* Let finish_function set this. */
17077 /* The capture list was built up in reverse order; fix that now. */
17084 }
17091 }
17093 /* Like tsubst but deals with expressions and performs semantic
17094 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
17096 tree
17098 tree args,
17099 tsubst_flags_t complain,
17100 tree in_decl,
17103 {
17104 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
17105 #define RECUR(NODE) \
17106 tsubst_copy_and_build (NODE, args, complain, in_decl, \
17108 integral_constant_expression_p)
17111 location_t loc;
17120 /* N3276 decltype magic only applies to calls at the top level or on the
17121 right side of a comma. */
17126 {
17129 /* Fall through. */
17131 {
17132 tree decl;
17133 cp_id_kind idk;
17138 {
17141 }
17143 /* Look up the name. */
17146 /* By convention, expressions use ERROR_MARK_NODE to indicate
17147 failure, not NULL_TREE. */
17153 integral_constant_expression_p,
17161 input_location);
17165 {
17169 }
17171 }
17174 {
17175 tree object;
17185 {
17190 }
17196 {
17199 }
17200 else
17207 else
17209 }
17212 {
17216 {
17217 /* A type conversion to reference type will be enclosed in
17218 such an indirect ref, but the substitution of the cast
17219 will have also added such an indirect ref. */
17221 }
17222 else
17230 }
17233 {
17237 }
17240 {
17244 {
17249 }
17251 /* We'll pass this to convert_nontype_argument again, we don't need
17252 to actually perform any conversion here. */
17258 flags));
17259 }
17262 {
17266 }
17273 {
17274 tree type;
17280 {
17285 }
17292 {
17310 }
17313 }
17347 else
17349 in_decl);
17384 {
17391 tree r = build_x_binary_op
17393 op0,
17395 ? ERROR_MARK
17397 op1,
17399 ? ERROR_MARK
17407 }
17410 {
17414 }
17430 /* Fall through */
17433 {
17434 tree r;
17440 {
17441 /* When there are no ARGS, we are trying to evaluate a
17442 non-dependent expression from the parser. Trying to do
17443 the substitutions may not work. */
17446 }
17447 else
17448 {
17453 else
17456 /*integral_constant_expression_p=*/
17460 }
17464 else
17468 {
17470 {
17472 {
17476 }
17477 else
17481 }
17483 }
17485 }
17488 {
17498 }
17514 {
17518 tree r = build_x_modify_expr
17521 /* TREE_NO_WARNING must be set if either the expression was
17522 parenthesized or it uses an operator such as >>= rather
17523 than plain assignment. In the former case, it was already
17524 set and must be copied. In the latter case,
17525 build_x_modify_expr sets it and it must not be reset
17526 here. */
17531 }
17536 /* Remember that there was a reference to this entity. */
17543 {
17548 tree ret;
17552 else
17553 {
17557 }
17559 /* If there was an initializer in the original tree, but it
17560 instantiated to an empty list, then we should pass a
17561 non-NULL empty vector to tell build_new that it was an
17562 empty initializer() rather than no initializer. This can
17563 only happen when the initializer is a pack expansion whose
17564 parameter packs are of length zero. */
17567 else
17568 {
17572 else
17573 {
17576 }
17577 }
17583 complain);
17591 }
17594 {
17600 complain));
17601 }
17604 {
17608 integral_constant_expression_p);
17610 op0,
17613 }
17616 {
17617 tree function;
17622 tree ret;
17625 /* Internal function with no arguments. */
17629 /* When we parsed the expression, we determined whether or
17630 not Koenig lookup should be performed. */
17633 {
17636 }
17638 {
17643 }
17645 {
17646 /* Do nothing; calling tsubst_copy_and_build on an identifier
17647 would incorrectly perform unqualified lookup again.
17649 Note that we can also have an IDENTIFIER_NODE if the earlier
17650 unqualified lookup found a member function; in that case
17651 koenig_p will be false and we do want to do the lookup
17652 again to find the instantiated member function.
17654 FIXME but doing that causes c++/15272, so we need to stop
17655 using IDENTIFIER_NODE in that situation. */
17657 }
17658 else
17659 {
17661 {
17667 }
17668 else
17673 /* Avoid error about taking the address of a constructor. */
17677 in_decl,
17679 integral_constant_expression_p);
17683 }
17688 {
17693 else
17694 {
17695 /* Expand the pack expansion and push each entry onto
17696 CALL_ARGS. */
17699 {
17704 {
17709 }
17710 }
17711 else
17712 {
17713 /* A partial substitution. Add one entry. */
17715 }
17716 }
17717 }
17719 /* We do not perform argument-dependent lookup if normal
17720 lookup finds a non-function, in accordance with the
17721 expected resolution of DR 218. */
17724 /* If lookup found a member function, the Koenig lookup is
17725 not appropriate, even if an unqualified-name was used
17726 to denote the function. */
17729 /* Only do this when substitution turns a dependent call
17730 into a non-dependent call. */
17738 {
17740 {
17741 /* For backwards compatibility and good diagnostics, try
17742 the unqualified lookup again if we aren't in SFINAE
17743 context. */
17744 tree unq = (tsubst_copy_and_build
17746 integral_constant_expression_p));
17748 {
17751 }
17754 {
17755 /* In a lambda fn, we have to be careful to not
17756 introduce new this captures. Legacy code can't
17757 be using lambdas anyway, so it's ok to be
17758 stricter. */
17763 "and no declarations were found by "
17764 "argument-dependent lookup at the point "
17771 else
17775 {
17786 {
17788 input_location);
17790 "declarations in dependent base %qT are "
17796 else
17800 }
17801 else
17803 "%qD declared here, later in the "
17806 {
17809 }
17810 }
17813 }
17814 }
17816 {
17821 }
17822 }
17824 /* Remember that there was a reference to this entity. */
17828 {
17831 }
17833 /* Put back tf_decltype for the actual call. */
17838 {
17842 {
17844 "wrong number of arguments to "
17847 }
17848 else
17850 input_location),
17855 /* Unsupported internal function with arguments. */
17857 }
17860 complain);
17862 {
17877 complain);
17878 else
17879 ret = (build_new_method_call
17884 complain));
17885 }
17886 else
17889 koenig_p,
17890 complain);
17895 {
17901 {
17907 {
17910 else
17912 /* The thunk location is not interesting. */
17914 }
17915 }
17916 }
17919 }
17922 {
17928 {
17930 {
17935 }
17936 else
17937 {
17942 }
17944 }
17945 else
17946 {
17949 }
17954 }
17957 {
17962 input_location));
17963 }
17966 {
17974 {
17975 /* We have pack expansions, so expand those and
17976 create a new list out of it. */
17979 tree chain;
17982 /* Expand the argument expressions. */
17990 /* Build the rest of the list. */
17995 /* Determine the number of arguments. */
17997 {
18000 }
18003 else
18004 {
18005 /* Since we only performed a partial substitution into
18006 the argument pack, we only RETURN (a single list
18007 node. */
18014 }
18016 /* Convert the argument vectors into a TREE_LIST */
18019 {
18020 /* Grab the Ith values. */
18021 i--;
18024 value
18028 /* Build the list (backwards). */
18030 }
18033 }
18049 }
18052 {
18053 tree object;
18054 tree object_type;
18055 tree member;
18056 tree r;
18060 /* Remember that there was a reference to this entity. */
18071 else
18077 {
18082 }
18086 {
18088 {
18093 {
18096 }
18098 {
18103 }
18104 }
18105 }
18108 {
18109 /* Lookup the template functions now that we know what the
18110 scope is. */
18118 {
18121 args);
18122 member = (adjust_result_of_qualified_name_lookup
18124 object_type));
18125 }
18126 else
18127 {
18129 input_location);
18131 }
18132 }
18136 {
18138 {
18142 else
18145 }
18147 }
18151 complain);
18155 }
18162 {
18170 tree r;
18175 /* We do not want to process the index of aggregate
18176 initializers as they are identifier nodes which will be
18177 looked up by digest_init. */
18183 {
18185 /* An identifier index is looked up in the type
18186 being initialized, not the current scope. */
18191 {
18192 /* Substitute into the pack expansion. */
18194 in_decl);
18198 ;
18200 /* Just move the argument into place. */
18202 else
18203 {
18204 /* Update the length of the final CONSTRUCTOR
18205 arguments vector, and note that we will need to
18206 copy.*/
18209 }
18210 }
18211 else
18213 }
18216 {
18221 {
18223 {
18228 }
18229 else
18231 }
18232 }
18238 {
18243 }
18247 }
18250 {
18253 {
18256 }
18257 else
18258 {
18261 }
18262 }
18267 /* Fall through */
18270 {
18272 /* ??? We're doing a subset of finish_id_expression here. */
18274 && !processing_template_decl
18275 && !cp_unevaluated_operand
18278 {
18280 /* Replace an evaluated use of the thread_local variable with
18281 a call to its wrapper. */
18283 }
18288 /* If the original type was a reference, we'll be wrapped in
18289 the appropriate INDIRECT_REF. */
18292 }
18295 {
18299 }
18302 {
18303 tree object_ptr
18310 }
18317 {
18328 }
18331 {
18337 integral_constant_expression_p);
18341 /* If the resulting list of expression statement is empty,
18342 fold it further into void_node. */
18347 }
18350 {
18354 }
18357 /* We can get here for a constant initializer of non-dependent type.
18358 FIXME stop folding in cp_parser_initializer_clause. */
18359 {
18361 complain);
18363 }
18367 integral_constant_expression_p));
18373 {
18378 complain));
18379 }
18386 /* We should only see these for location wrapper nodes, or within
18387 instantiate_non_dependent_expr (when args is NULL_TREE). */
18392 /* fallthrough. */
18395 /* Handle Objective-C++ constructs, if appropriate. */
18396 {
18397 tree subst
18402 }
18404 }
18406 #undef RECUR
18407 #undef RETURN
18408 out:
18411 }
18413 /* Verify that the instantiated ARGS are valid. For type arguments,
18414 make sure that the type's linkage is ok. For non-type arguments,
18415 make sure they are constants if they are integral or enumerations.
18416 Emit an error under control of COMPLAIN, and return TRUE on error. */
18418 static bool
18420 {
18424 {
18434 }
18436 {
18437 /* [basic.link]: A name with no linkage (notably, the name
18438 of a class or enumeration declared in a local scope)
18439 shall not be used to declare an entity with linkage.
18440 This implies that names with no linkage cannot be used as
18441 template arguments
18443 DR 757 relaxes this restriction for C++0x. */
18448 {
18449 /* DR 488 makes use of a type with no linkage cause
18450 type deduction to fail. */
18452 {
18455 else
18458 }
18460 }
18461 /* In order to avoid all sorts of complications, we do not
18462 allow variably-modified types as template arguments. */
18464 {
18468 }
18469 }
18470 /* Class template and alias template arguments should be OK. */
18472 ;
18473 /* A non-type argument of integral or enumerated type must be a
18474 constant. */
18479 {
18483 }
18485 }
18487 static bool
18489 {
18494 {
18497 }
18501 }
18503 /* We're out of SFINAE context now, so generate diagnostics for the access
18504 errors we saw earlier when instantiating D from TMPL and ARGS. */
18506 static void
18508 {
18520 }
18522 /* Instantiate the indicated variable, function, or alias template TMPL with
18523 the template arguments in TARG_PTR. */
18525 static tree
18527 {
18529 tree fndecl;
18530 tree gen_tmpl;
18531 tree spec;
18539 /* If this function is a clone, handle it specially. */
18541 {
18542 tree spec;
18543 tree clone;
18545 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18546 DECL_CLONED_FUNCTION. */
18552 /* Look for the clone. */
18556 /* We should always have found the clone by now. */
18559 }
18564 /* Check to see if we already have this specialization. */
18568 /* targ_ptr only has the innermost template args, so add the outer ones
18569 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18570 the case of a non-dependent call within a template definition). */
18571 targ_ptr = (add_outermost_template_args
18573 targ_ptr));
18575 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18576 but it doesn't seem to be on the hot path. */
18585 {
18587 {
18591 }
18593 }
18596 complain))
18599 /* We are building a FUNCTION_DECL, during which the access of its
18600 parameters and return types have to be checked. However this
18601 FUNCTION_DECL which is the desired context for access checking
18602 is not built yet. We solve this chicken-and-egg problem by
18603 deferring all checks until we have the FUNCTION_DECL. */
18606 /* Instantiation of the function happens in the context of the function
18607 template, not the context of the overload resolution we're doing. */
18609 /* If there are dependent arguments, e.g. because we're doing partial
18610 ordering, make sure processing_template_decl stays set. */
18614 {
18618 }
18624 {
18625 /* We need to determine if we're using a partial or explicit
18626 specialization now, because the type of the variable could be
18627 different. */
18633 {
18638 }
18639 }
18641 /* Substitute template parameters to obtain the specialization. */
18649 {
18652 }
18654 /* The DECL_TI_TEMPLATE should always be the immediate parent
18655 template, not the most general template. */
18659 /* Now we know the specialization, compute access previously
18660 deferred. Do no access control for inheriting constructors,
18661 as we already checked access for the inherited constructor. */
18664 {
18669 }
18672 /* If we've just instantiated the main entry point for a function,
18673 instantiate all the alternate entry points as well. We do this
18674 by cloning the instantiation of the main entry point, not by
18675 instantiating the template clones. */
18680 {
18682 {
18683 /* Remember to reinstantiate when we're out of SFINAE so the user
18684 can see the errors. */
18686 }
18688 }
18690 }
18692 /* Wrapper for instantiate_template_1. */
18694 tree
18696 {
18697 tree ret;
18702 }
18704 /* Instantiate the alias template TMPL with ARGS. Also push a template
18705 instantiation level, which instantiate_template doesn't do because
18706 functions and variables have sufficient context established by the
18707 callers. */
18709 static tree
18711 {
18718 {
18721 }
18723 args =
18731 /* We can't free this if a pending_template entry or last_error_tinst_level
18732 is pointing at it. */
18738 }
18740 /* PARM is a template parameter pack for FN. Returns true iff
18741 PARM is used in a deducible way in the argument list of FN. */
18743 static bool
18745 {
18748 {
18750 tree packs;
18756 {
18757 /* The template parameter pack is used in a function parameter
18758 pack. If this is the end of the parameter list, the
18759 template parameter pack is deducible. */
18762 else
18763 /* Otherwise, not. Well, it could be deduced from
18764 a non-pack parameter, but doing so would end up with
18765 a deduction mismatch, so don't bother. */
18767 }
18768 }
18769 /* The template parameter pack isn't used in any function parameter
18770 packs, but it might be used deeper, e.g. tuple<Args...>. */
18772 }
18774 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18775 NARGS elements of the arguments that are being used when calling
18776 it. TARGS is a vector into which the deduced template arguments
18777 are placed.
18779 Returns either a FUNCTION_DECL for the matching specialization of FN or
18780 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18781 true, diagnostics will be printed to explain why it failed.
18783 If FN is a conversion operator, or we are trying to produce a specific
18784 specialization, RETURN_TYPE is the return type desired.
18786 The EXPLICIT_TARGS are explicit template arguments provided via a
18787 template-id.
18789 The parameter STRICT is one of:
18791 DEDUCE_CALL:
18792 We are deducing arguments for a function call, as in
18793 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18794 deducing arguments for a call to the result of a conversion
18795 function template, as in [over.call.object].
18797 DEDUCE_CONV:
18798 We are deducing arguments for a conversion function, as in
18799 [temp.deduct.conv].
18801 DEDUCE_EXACT:
18802 We are deducing arguments when doing an explicit instantiation
18803 as in [temp.explicit], when determining an explicit specialization
18804 as in [temp.expl.spec], or when taking the address of a function
18805 template, as in [temp.deduct.funcaddr]. */
18807 tree
18809 tree explicit_targs,
18810 tree targs,
18813 tree return_type,
18814 unification_kind_t strict,
18818 {
18819 tree parms;
18820 tree fntype;
18833 tree tinst;
18839 full_targs = (add_outermost_template_args
18841 targs));
18846 /* In C++0x, it's possible to have a function template whose type depends
18847 on itself recursively. This is most obvious with decltype, but can also
18848 occur with enumeration scope (c++/48969). So we need to catch infinite
18849 recursion and reject the substitution at deduction time; this function
18850 will return error_mark_node for any repeated substitution.
18852 This also catches excessive recursion such as when f<N> depends on
18853 f<N-1> across all integers, and returns error_mark_node for all the
18854 substitutions back up to the initial one.
18856 This is, of course, not reentrant. */
18866 {
18867 /* [temp.deduct]
18869 The specified template arguments must match the template
18870 parameters in kind (i.e., type, nontype, template), and there
18871 must not be more arguments than there are parameters;
18872 otherwise type deduction fails.
18874 Nontype arguments must match the types of the corresponding
18875 nontype template parameters, or must be convertible to the
18876 types of the corresponding nontype parameters as specified in
18877 _temp.arg.nontype_, otherwise type deduction fails.
18879 All references in the function type of the function template
18880 to the corresponding template parameters are replaced by the
18881 specified template argument values. If a substitution in a
18882 template parameter or in the function type of the function
18883 template results in an invalid type, type deduction fails. */
18894 explicit_targs);
18896 /* Adjust any explicit template arguments before entering the
18897 substitution context. */
18898 explicit_targs
18900 complain,
18906 /* Substitute the explicit args into the function type. This is
18907 necessary so that, for instance, explicitly declared function
18908 arguments can match null pointed constants. If we were given
18909 an incomplete set of explicit args, we must not do semantic
18910 processing during substitution as we could create partial
18911 instantiations. */
18913 {
18918 /* Dig out the actual parm. */
18921 {
18924 }
18926 {
18929 }
18932 /* No explicit argument for this template parameter. */
18936 {
18937 /* Mark the argument pack as "incomplete". We could
18938 still deduce more arguments during unification.
18939 We remove this mark in type_unification_real. */
18941 {
18945 }
18947 /* We have some incomplete argument packs. */
18949 }
18950 }
18954 {
18957 }
18960 /* Ignore any access checks; we'll see them again in
18961 instantiate_template and they might have the wrong
18962 access path at this point. */
18974 /* Place the explicitly specified arguments in TARGS. */
18978 }
18980 /* Never do unification on the 'this' parameter. */
18984 {
18985 /* We're deducing for a call to the result of a template conversion
18986 function. The parms we really want are in return_type. */
18990 }
18992 {
19001 }
19003 /* We allow incomplete unification without an error message here
19004 because the standard doesn't seem to explicitly prohibit it. Our
19005 callers must be ready to deal with unification failures in any
19006 event. */
19009 /* If we aren't explaining yet, push tinst context so we can see where
19010 any errors (e.g. from class instantiations triggered by instantiation
19011 of default template arguments) come from. If we are explaining, this
19012 context is redundant. */
19014 {
19017 }
19019 /* type_unification_real will pass back any access checks from default
19020 template argument substitution. */
19032 /* Now that we have bindings for all of the template arguments,
19033 ensure that the arguments deduced for the template template
19034 parameters have compatible template parameter lists. We cannot
19035 check this property before we have deduced all template
19036 arguments, because the template parameter types of a template
19037 template parameter might depend on prior template parameters
19038 deduced after the template template parameter. The following
19039 ill-formed example illustrates this issue:
19041 template<typename T, template<T> class C> void f(C<5>, T);
19043 template<int N> struct X {};
19045 void g() {
19046 f(X<5>(), 5l); // error: template argument deduction fails
19047 }
19049 The template parameter list of 'C' depends on the template type
19050 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
19051 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
19052 time that we deduce 'C'. */
19055 {
19058 }
19060 /* All is well so far. Now, check:
19062 [temp.deduct]
19064 When all template arguments have been deduced, all uses of
19065 template parameters in nondeduced contexts are replaced with
19066 the corresponding deduced argument values. If the
19067 substitution results in an invalid type, as described above,
19068 type deduction fails. */
19071 {
19074 }
19076 /* Also collect access checks from the instantiation. */
19089 /* Now perform any access checks encountered during substitution. */
19096 /* If we're looking for an exact match, check that what we got
19097 is indeed an exact match. It might not be if some template
19098 parameters are used in non-deduced contexts. But don't check
19099 for an exact match if we have dependent template arguments;
19100 in that case we're doing partial ordering, and we already know
19101 that we have two candidates that will provide the actual type. */
19103 {
19107 tree sarg
19113 {
19117 }
19118 }
19120 /* After doing deduction with the inherited constructor, actually return an
19121 instantiation of the inheriting constructor. */
19127 fail:
19130 {
19132 /* Reset once we're all the way out. */
19134 }
19136 /* We can't free this if a pending_template entry or last_error_tinst_level
19137 is pointing at it. */
19143 }
19145 /* Adjust types before performing type deduction, as described in
19146 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
19147 sections are symmetric. PARM is the type of a function parameter
19148 or the return type of the conversion function. ARG is the type of
19149 the argument passed to the call, or the type of the value
19150 initialized with the result of the conversion function.
19151 ARG_EXPR is the original argument expression, which may be null. */
19153 static int
19157 tree arg_expr)
19158 {
19162 {
19167 /* Swap PARM and ARG throughout the remainder of this
19168 function; the handling is precisely symmetric since PARM
19169 will initialize ARG rather than vice versa. */
19174 /* Core issue #873: Do the DR606 thing (see below) for these cases,
19175 too, but here handle it by stripping the reference from PARM
19176 rather than by adding it to ARG. */
19184 /* Nothing else to do in this case. */
19189 }
19192 {
19193 /* [temp.deduct.call]
19195 If P is not a reference type:
19197 --If A is an array type, the pointer type produced by the
19198 array-to-pointer standard conversion (_conv.array_) is
19199 used in place of A for type deduction; otherwise,
19201 --If A is a function type, the pointer type produced by
19202 the function-to-pointer standard conversion
19203 (_conv.func_) is used in place of A for type deduction;
19204 otherwise,
19206 --If A is a cv-qualified type, the top level
19207 cv-qualifiers of A's type are ignored for type
19208 deduction. */
19213 else
19215 }
19217 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
19218 reference to a cv-unqualified template parameter that does not represent a
19219 template parameter of a class template (during class template argument
19220 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
19221 an lvalue, the type "lvalue reference to A" is used in place of A for type
19222 deduction. */
19229 /* try_one_overload doesn't provide an arg_expr, but
19230 functions are always lvalues. */
19234 /* [temp.deduct.call]
19236 If P is a cv-qualified type, the top level cv-qualifiers
19237 of P's type are ignored for type deduction. If P is a
19238 reference type, the type referred to by P is used for
19239 type deduction. */
19242 {
19245 }
19247 /* DR 322. For conversion deduction, remove a reference type on parm
19248 too (which has been swapped into ARG). */
19253 }
19255 /* Subroutine of unify_one_argument. PARM is a function parameter of a
19256 template which does contain any deducible template parameters; check if
19257 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
19258 unify_one_argument. */
19260 static int
19263 {
19264 tree type;
19268 else
19275 {
19279 }
19281 {
19286 }
19290 else
19292 }
19296 /* Returns true iff the expression EXPR is one from which a template
19297 argument can be deduced. In other words, if it's an undecorated
19298 use of a template non-type parameter. */
19300 static bool
19302 {
19303 /* Strip implicit conversions. */
19307 }
19309 /* Returns true iff the array domain DOMAIN uses a template parameter in a
19310 deducible way; that is, if it has a max value of <PARM> - 1. */
19312 static bool
19314 {
19323 }
19325 /* Returns true iff the template arguments ARGS use a template parameter
19326 in a deducible way. */
19328 static bool
19330 {
19332 {
19337 else
19338 {
19345 else
19347 }
19350 }
19352 }
19354 /* Returns true iff TYPE contains any deducible references to template
19355 parameters, as per 14.8.2.5. */
19357 static bool
19359 {
19363 /* T
19364 cv-list T
19365 TT<T>
19366 TT<i>
19367 TT<> */
19372 /* T*
19373 T&
19374 T&& */
19378 /* T[integer-constant ]
19379 type [i] */
19384 /* T type ::*
19385 type T::*
19386 T T::*
19387 T (type ::*)()
19388 type (T::*)()
19389 type (type ::*)(T)
19390 type (T::*)(T)
19391 T (type ::*)(T)
19392 T (T::*)()
19393 T (T::*)(T) */
19396 || (uses_deducible_template_parms
19399 /* template-name <T> (where template-name refers to a class template)
19400 template-name <i> (where template-name refers to a class template) */
19407 /* type (T)
19408 T()
19409 T(T) */
19412 {
19421 }
19424 }
19426 /* Subroutine of type_unification_real and unify_pack_expansion to
19427 handle unification of a single P/A pair. Parameters are as
19428 for those functions. */
19430 static int
19434 {
19441 /* We can't deduce anything from this, but we might get all the
19442 template args from other function args. */
19445 /* Implicit conversions (Clause 4) will be performed on a function
19446 argument to convert it to the type of the corresponding function
19447 parameter if the parameter type contains no template-parameters that
19448 participate in template argument deduction. */
19451 /* For function parameters with no deducible template parameters,
19452 just return. We'll check non-dependent conversions later. */
19456 {
19458 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19459 | UNIFY_ALLOW_MORE_CV_QUAL
19473 }
19475 /* We only do these transformations if this is the top-level
19476 parameter_type_list in a call or declaration matching; in other
19477 situations (nested function declarators, template argument lists) we
19478 won't be comparing a type to an expression, and we don't do any type
19479 adjustments. */
19481 {
19483 {
19486 {
19487 /* [temp.deduct.type] A template-argument can be
19488 deduced from a pointer to function or pointer
19489 to member function argument if the set of
19490 overloaded functions does not contain function
19491 templates and at most one of a set of
19492 overloaded functions provides a unique
19493 match. */
19497 /* If a unique match was not found, this is a
19498 non-deduced context, so we still succeed. */
19500 }
19506 }
19508 arg_strict |=
19510 }
19511 else
19516 /* For deduction from an init-list we need the actual list. */
19520 }
19522 /* for_each_template_parm callback that always returns 0. */
19524 static int
19526 {
19528 }
19530 /* for_each_template_parm any_fn callback to handle deduction of a template
19531 type argument from the type of an array bound. */
19533 static int
19535 {
19543 {
19549 }
19551 /* Keep walking. */
19553 }
19555 /* Try to deduce any not-yet-deduced template type arguments from the type of
19556 an array bound. This is handled separately from unify because 14.8.2.5 says
19557 "The type of a type parameter is only deduced from an array bound if it is
19558 not otherwise deduced." */
19560 static void
19562 {
19567 }
19569 /* Most parms like fn_type_unification.
19571 If SUBR is 1, we're being called recursively (to unify the
19572 arguments of a function or method parameter of a function
19573 template).
19575 CHECKS is a pointer to a vector of access checks encountered while
19576 substituting default template arguments. */
19578 static int
19580 tree full_targs,
19581 tree xparms,
19585 unification_kind_t strict,
19589 {
19594 tree parms;
19605 /* Reset the number of non-defaulted template arguments contained
19606 in TARGS. */
19609 again:
19617 {
19622 /* For a function parameter pack that occurs at the end of the
19623 parameter-declaration-list, the type A of each remaining
19624 argument of the call is compared with the type P of the
19625 declarator-id of the function parameter pack. */
19631 /* For a function parameter pack that does not occur at the
19632 end of the parameter-declaration-list, the type of the
19633 parameter pack is a non-deduced context. */
19640 explain_p))
19642 }
19647 {
19648 /* Unify the remaining arguments with the pack expansion type. */
19649 tree argvec;
19652 /* Allocate a TREE_VEC and copy in all of the arguments */
19657 /* Copy the parameter into parmvec. */
19663 /* Advance to the end of the list of parameters. */
19665 }
19667 /* Fail if we've reached the end of the parm list, and more args
19668 are present, and the parm list isn't variadic. */
19671 /* Fail if parms are left and they don't have default values and
19672 they aren't all deduced as empty packs (c++/57397). This is
19673 consistent with sufficient_parms_p. */
19676 {
19680 do
19681 {
19684 count++;
19686 }
19690 type_pack_p);
19691 }
19694 {
19695 tsubst_flags_t complain = (explain_p
19696 ? tf_warning_or_error
19701 {
19705 /* Clear the "incomplete" flags on all argument packs now so that
19706 substituting them into later default arguments works. */
19708 {
19711 }
19719 {
19724 }
19726 /* If this is an undeduced nontype parameter that depends on
19727 a type parameter, try another pass; its type may have been
19728 deduced from a later argument than the one from which
19729 this parameter can be deduced. */
19733 {
19736 }
19738 /* Core issue #226 (C++0x) [temp.deduct]:
19740 If a template argument has not been deduced, its
19741 default template argument, if any, is used.
19743 When we are in C++98 mode, TREE_PURPOSE will either
19744 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19745 to explicitly check cxx_dialect here. */
19747 /* OK, there is a default argument. Wait until after the
19748 conversion check to do substitution. */
19751 /* If the type parameter is a parameter pack, then it will
19752 be deduced to an empty parameter pack. */
19754 {
19755 tree arg;
19758 {
19761 }
19762 else
19769 }
19772 }
19774 /* DR 1391: All parameters have args, now check non-dependent parms for
19775 convertibility. */
19779 {
19785 /* For a function parameter pack that occurs at the end of the
19786 parameter-declaration-list, the type A of each remaining
19787 argument of the call is compared with the type P of the
19788 declarator-id of the function parameter pack. */
19794 /* For a function parameter pack that does not occur at the
19795 end of the parameter-declaration-list, the type of the
19796 parameter pack is a non-deduced context. */
19805 explain_p))
19807 }
19809 /* Now substitute into the default template arguments. */
19811 {
19835 else
19843 {
19845 /* The position of the first default template argument,
19846 is also the number of non-defaulted arguments in TARGS.
19847 Record that. */
19850 }
19851 }
19855 }
19861 }
19863 /* Subroutine of type_unification_real. Args are like the variables
19864 at the call site. ARG is an overloaded function (or template-id);
19865 we try deducing template args from each of the overloads, and if
19866 only one succeeds, we go with that. Modifies TARGS and returns
19867 true on success. */
19869 static bool
19871 tree targs,
19872 tree parm,
19873 tree arg,
19874 unification_kind_t strict,
19877 {
19884 {
19887 }
19888 else
19892 /* Handle `&x' where `x' is some static or non-static member
19893 function name. */
19899 /* Strip baselink information. */
19904 {
19905 /* If we got some explicit template args, we need to plug them into
19906 the affected templates before we try to unify, in case the
19907 explicit args will completely resolve the templates in question. */
19914 {
19927 {
19932 {
19935 }
19936 }
19939 }
19940 /* If no templates (or more than one) are fully resolved by the
19941 explicit arguments, this template-id is a non-deduced context; it
19942 could still be OK if we deduce all template arguments for the
19943 enclosing call through other arguments. */
19946 }
19949 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19950 -- but the deduction does not succeed because the expression is
19951 not just the function on its own. */
19953 else
19955 {
19960 {
19963 }
19964 }
19966 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19967 to function or pointer to member function argument if the set of
19968 overloaded functions does not contain function templates and at most
19969 one of a set of overloaded functions provides a unique match.
19971 So if we found multiple possibilities, we return success but don't
19972 deduce anything. */
19975 {
19979 {
19984 /* Don't forget explicit template arguments in a pack. */
19988 }
19989 }
19994 }
19996 /* Core DR 115: In contexts where deduction is done and fails, or in
19997 contexts where deduction is not done, if a template argument list is
19998 specified and it, along with any default template arguments, identifies
19999 a single function template specialization, then the template-id is an
20000 lvalue for the function template specialization. */
20002 tree
20004 {
20017 {
20020 }
20022 {
20025 }
20027 {
20030 }
20033 {
20037 /* If we got some explicit template args, we need to plug them into
20038 the affected templates before we try to unify, in case the
20039 explicit args will completely resolve the templates in question. */
20047 {
20060 {
20063 {
20066 }
20068 {
20071 }
20072 }
20073 }
20075 {
20083 {
20084 tree base
20087 }
20091 }
20093 /* There were no good options and at least one bad one, so let the
20094 user know what the problem is. */
20096 }
20098 }
20100 /* Subroutine of resolve_overloaded_unification; does deduction for a single
20101 overload. Fills TARGS with any deduced arguments, or error_mark_node if
20102 different overloads deduce different arguments for a given parm.
20103 ADDR_P is true if the expression for which deduction is being
20104 performed was of the form "& fn" rather than simply "fn".
20106 Returns 1 on success. */
20108 static int
20110 tree orig_targs,
20111 tree targs,
20112 tree parm,
20113 tree arg,
20114 unification_kind_t strict,
20118 {
20120 tree tempargs;
20126 /* [temp.deduct.type] A template-argument can be deduced from a pointer
20127 to function or pointer to member function argument if the set of
20128 overloaded functions does not contain function templates and at most
20129 one of a set of overloaded functions provides a unique match.
20131 So if this is a template, just return success. */
20143 /* We don't copy orig_targs for this because if we have already deduced
20144 some template args from previous args, unify would complain when we
20145 try to deduce a template parameter for the same argument, even though
20146 there isn't really a conflict. */
20153 /* First make sure we didn't deduce anything that conflicts with
20154 explicitly specified args. */
20156 {
20163 /* Since we're unifying against ourselves, we will fill in
20164 template args used in the function parm list with our own
20165 template parms. Discard them. */
20168 {
20169 /* Check that the argument at each index of the deduced argument pack
20170 is equivalent to the corresponding explicitly specified argument.
20171 We may have deduced more arguments than were explicitly specified,
20172 and that's OK. */
20174 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
20175 that's wrong if we deduce the same argument pack from multiple
20176 function arguments: it's only incomplete the first time. */
20189 }
20192 }
20195 {
20200 }
20203 }
20205 /* PARM is a template class (perhaps with unbound template
20206 parameters). ARG is a fully instantiated type. If ARG can be
20207 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
20208 TARGS are as for unify. */
20210 static tree
20213 {
20214 tree copy_of_targs;
20224 /* We need to make a new template argument vector for the call to
20225 unify. If we used TARGS, we'd clutter it up with the result of
20226 the attempted unification, even if this class didn't work out.
20227 We also don't want to commit ourselves to all the unifications
20228 we've already done, since unification is supposed to be done on
20229 an argument-by-argument basis. In other words, consider the
20230 following pathological case:
20232 template <int I, int J, int K>
20233 struct S {};
20235 template <int I, int J>
20236 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
20238 template <int I, int J, int K>
20239 void f(S<I, J, K>, S<I, I, I>);
20241 void g() {
20242 S<0, 0, 0> s0;
20243 S<0, 1, 2> s2;
20245 f(s0, s2);
20246 }
20248 Now, by the time we consider the unification involving `s2', we
20249 already know that we must have `f<0, 0, 0>'. But, even though
20250 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
20251 because there are two ways to unify base classes of S<0, 1, 2>
20252 with S<I, I, I>. If we kept the already deduced knowledge, we
20253 would reject the possibility I=1. */
20257 {
20261 }
20263 /* If unification failed, we're done. */
20269 }
20271 /* Given a template type PARM and a class type ARG, find the unique
20272 base type in ARG that is an instance of PARM. We do not examine
20273 ARG itself; only its base-classes. If there is not exactly one
20274 appropriate base class, return NULL_TREE. PARM may be the type of
20275 a partial specialization, as well as a plain template type. Used
20276 by unify. */
20278 static enum template_base_result
20281 {
20283 tree binfo;
20289 {
20290 /* The type could not be completed. */
20293 }
20295 /* Walk in inheritance graph order. The search order is not
20296 important, and this avoids multiple walks of virtual bases. */
20298 {
20303 {
20304 /* If there is more than one satisfactory baseclass, then:
20306 [temp.deduct.call]
20308 If they yield more than one possible deduced A, the type
20309 deduction fails.
20311 applies. */
20313 {
20316 }
20319 }
20320 }
20324 }
20326 /* Returns the level of DECL, which declares a template parameter. */
20328 static int
20330 {
20332 {
20342 }
20344 }
20346 /* Decide whether ARG can be unified with PARM, considering only the
20347 cv-qualifiers of each type, given STRICT as documented for unify.
20348 Returns nonzero iff the unification is OK on that basis. */
20350 static int
20352 {
20358 {
20359 /* Although a CVR qualifier is ignored when being applied to a
20360 substituted template parameter ([8.3.2]/1 for example), that
20361 does not allow us to unify "const T" with "int&" because both
20362 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
20363 It is ok when we're allowing additional CV qualifiers
20364 at the outer level [14.8.2.1]/3,1st bullet. */
20374 }
20385 }
20387 /* Determines the LEVEL and INDEX for the template parameter PARM. */
20388 void
20390 {
20394 {
20397 }
20398 else
20399 {
20402 }
20403 }
20405 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
20406 do { \
20407 if (unify (TP, TA, P, A, S, EP)) \
20408 return 1; \
20409 } while (0)
20411 /* Unifies the remaining arguments in PACKED_ARGS with the pack
20412 expansion at the end of PACKED_PARMS. Returns 0 if the type
20413 deduction succeeds, 1 otherwise. STRICT is the same as in
20414 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
20415 function call argument list. We'll need to adjust the arguments to make them
20416 types. SUBR tells us if this is from a recursive call to
20417 type_unification_real, or for comparing two template argument
20418 lists. */
20420 static int
20424 {
20425 tree parm
20431 /* Add in any args remembered from an earlier partial instantiation. */
20439 /* Determine the parameter packs we will be deducing from the
20440 pattern, and record their current deductions. */
20443 {
20447 /* Determine the index and level of this parameter pack. */
20452 /* Keep track of the parameter packs and their corresponding
20453 argument packs. */
20456 }
20458 /* Loop through all of the arguments that have not yet been
20459 unified and unify each with the pattern. */
20461 {
20462 tree parm;
20466 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20467 or the element of its argument pack at the current index if
20468 this argument was explicitly specified. */
20470 {
20479 {
20482 }
20484 }
20486 /* If we had explicit template arguments, substitute them into the
20487 pattern before deduction. */
20489 {
20490 /* Some arguments might still be unspecified or dependent. */
20498 NULL_TREE);
20503 }
20504 else
20507 /* Unify the pattern with the current argument. */
20509 explain_p))
20512 /* For each parameter pack, collect the deduced value. */
20514 {
20520 }
20521 }
20523 /* Verify that the results of unification with the parameter packs
20524 produce results consistent with what we've seen before, and make
20525 the deduced argument packs available. */
20527 {
20534 /* By default keep the original deduced argument pack.
20535 If necessary, more specific code is going to update the
20536 resulting deduced argument later down in this function. */
20540 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20541 actually deduce anything. */
20549 {
20550 /* If we had fewer function args than explicit template args,
20551 just use the explicits. */
20556 }
20559 {
20560 tree result;
20561 /* Build the deduced *_ARGUMENT_PACK. */
20563 {
20566 }
20567 else
20572 /* Note the deduced argument packs for this parameter
20573 pack. */
20575 }
20579 {
20580 /* We only had the explicitly-provided arguments before, but
20581 now we have a complete set of arguments. */
20587 }
20588 else
20589 {
20595 /* Inconsistent unification of this parameter pack. */
20597 bad_old_arg,
20598 bad_new_arg);
20599 }
20600 }
20603 }
20605 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20606 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20607 parameters and return value are as for unify. */
20609 static int
20613 {
20614 tree parm_max;
20615 tree arg_max;
20619 /* Our representation of array types uses "N - 1" as the
20620 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20621 not an integer constant. We cannot unify arbitrarily
20622 complex expressions, so we eliminate the MINUS_EXPRs
20623 here. */
20627 {
20630 }
20634 {
20635 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20636 trying to unify the type of a variable with the type
20637 of a template parameter. For example:
20639 template <unsigned int N>
20640 void f (char (&) [N]);
20641 int g();
20642 void h(int i) {
20643 char a[g(i)];
20644 f(a);
20645 }
20647 Here, the type of the ARG will be "int [g(i)]", and
20648 may be a SAVE_EXPR, etc. */
20652 }
20654 /* If only one of the bounds used a MINUS_EXPR, compensate
20655 by adding one to the other bound. */
20658 integer_type_node,
20659 parm_max,
20660 integer_one_node);
20663 integer_type_node,
20664 arg_max,
20665 integer_one_node);
20669 }
20671 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20675 static pa_kind_t
20677 {
20686 else
20688 }
20690 /* Deduce the value of template parameters. TPARMS is the (innermost)
20691 set of template parameters to a template. TARGS is the bindings
20692 for those template parameters, as determined thus far; TARGS may
20693 include template arguments for outer levels of template parameters
20694 as well. PARM is a parameter to a template function, or a
20695 subcomponent of that parameter; ARG is the corresponding argument.
20696 This function attempts to match PARM with ARG in a manner
20697 consistent with the existing assignments in TARGS. If more values
20698 are deduced, then TARGS is updated.
20700 Returns 0 if the type deduction succeeds, 1 otherwise. The
20701 parameter STRICT is a bitwise or of the following flags:
20703 UNIFY_ALLOW_NONE:
20704 Require an exact match between PARM and ARG.
20705 UNIFY_ALLOW_MORE_CV_QUAL:
20706 Allow the deduced ARG to be more cv-qualified (by qualification
20707 conversion) than ARG.
20708 UNIFY_ALLOW_LESS_CV_QUAL:
20709 Allow the deduced ARG to be less cv-qualified than ARG.
20710 UNIFY_ALLOW_DERIVED:
20711 Allow the deduced ARG to be a template base class of ARG,
20712 or a pointer to a template base class of the type pointed to by
20713 ARG.
20714 UNIFY_ALLOW_INTEGER:
20715 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20716 case for more information.
20717 UNIFY_ALLOW_OUTER_LEVEL:
20718 This is the outermost level of a deduction. Used to determine validity
20719 of qualification conversions. A valid qualification conversion must
20720 have const qualified pointers leading up to the inner type which
20721 requires additional CV quals, except at the outer level, where const
20722 is not required [conv.qual]. It would be normal to set this flag in
20723 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20724 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20725 This is the outermost level of a deduction, and PARM can be more CV
20726 qualified at this point.
20727 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20728 This is the outermost level of a deduction, and PARM can be less CV
20729 qualified at this point. */
20731 static int
20734 {
20736 tree targ;
20737 tree tparm;
20739 tsubst_flags_t complain = (explain_p
20740 ? tf_warning_or_error
20743 /* I don't think this will do the right thing with respect to types.
20744 But the only case I've seen it in so far has been array bounds, where
20745 signedness is the only information lost, and I think that will be
20746 okay. */
20754 /* We can't deduce anything from this, but we might get all the
20755 template args from other function args. */
20761 /* If PARM uses template parameters, then we can't bail out here,
20762 even if ARG == PARM, since we won't record unifications for the
20763 template parameters. We might need them if we're trying to
20764 figure out which of two things is more specialized. */
20768 /* Handle init lists early, so the rest of the function can assume
20769 we're dealing with a type. */
20771 {
20776 /* Replace T with std::initializer_list<T> for deduction. */
20783 /* We can only deduce from an initializer list argument if the
20784 parameter is std::initializer_list or an array; otherwise this
20785 is a non-deduced context. */
20790 else
20791 {
20793 /* Deduction is defined in terms of a single type, so just punt
20794 on the (bizarre) std::initializer_list<T...>. */
20797 }
20800 {
20807 {
20811 /* It should only be possible to get here for a call. */
20813 elt_strict |= maybe_adjust_types_for_deduction
20816 }
20819 explain_p);
20820 }
20824 {
20825 /* Also deduce from the length of the initializer list. */
20832 }
20834 /* If the std::initializer_list<T> deduction worked, replace the
20835 deduced A with std::initializer_list<A>. */
20837 {
20842 }
20844 }
20846 /* If parm and arg aren't the same kind of thing (template, type, or
20847 expression), fail early. */
20851 /* Immediately reject some pairs that won't unify because of
20852 cv-qualification mismatches. */
20855 /* It is the elements of the array which hold the cv quals of an array
20856 type, and the elements might be template type parms. We'll check
20857 when we recurse. */
20859 /* We check the cv-qualifiers when unifying with template type
20860 parameters below. We want to allow ARG `const T' to unify with
20861 PARM `T' for example, when computing which of two templates
20862 is more specialized, for example. */
20876 {
20880 /* In a type which contains a nested-name-specifier, template
20881 argument values cannot be deduced for template parameters used
20882 within the nested-name-specifier. */
20894 /* The PARM is not one we're trying to unify. Just check
20895 to see if it matches ARG. */
20896 {
20901 else
20903 }
20910 /* Check for mixed types and values. */
20918 {
20921 {
20922 /* First try to match ARG directly. */
20924 explain_p);
20926 {
20927 /* Otherwise, look for a suitable base of ARG, as below. */
20934 }
20935 }
20936 /* ARG must be constructed from a template class or a template
20937 template parameter. */
20942 /* Deduce arguments T, i from TT<T> or TT<i>. */
20948 /* Fall through to deduce template name. */
20949 }
20953 {
20954 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20956 /* Simple cases: Value already set, does match or doesn't. */
20961 }
20962 else
20963 {
20964 /* If PARM is `const T' and ARG is only `int', we don't have
20965 a match unless we are allowing additional qualification.
20966 If ARG is `const int' and PARM is just `T' that's OK;
20967 that binds `const int' to `T'. */
20972 /* Consider the case where ARG is `const volatile int' and
20973 PARM is `const T'. Then, T should be `volatile int'. */
20974 arg = cp_build_qualified_type_real
20979 /* Simple cases: Value already set, does match or doesn't. */
20985 /* Make sure that ARG is not a variable-sized array. (Note
20986 that were talking about variable-sized arrays (like
20987 `int[n]'), rather than arrays of unknown size (like
20988 `int[]').) We'll get very confused by such a type since
20989 the bound of the array is not constant, and therefore
20990 not mangleable. Besides, such types are not allowed in
20991 ISO C++, so we can do as we please here. We do allow
20992 them for 'auto' deduction, since that isn't ABI-exposed. */
20996 /* Strip typedefs as in convert_template_argument. */
20998 }
21000 /* If ARG is a parameter pack or an expansion, we cannot unify
21001 against it unless PARM is also a parameter pack. */
21006 /* If the argument deduction results is a METHOD_TYPE,
21007 then there is a problem.
21008 METHOD_TYPE doesn't map to any real C++ type the result of
21009 the deduction can not be of that type. */
21023 {
21024 /* The PARM is not one we're trying to unify. Just check
21025 to see if it matches ARG. */
21031 }
21037 {
21041 /* We're deducing from an array bound, the type doesn't matter. */
21047 }
21049 /* [temp.deduct.type] If, in the declaration of a function template
21050 with a non-type template-parameter, the non-type
21051 template-parameter is used in an expression in the function
21052 parameter-list and, if the corresponding template-argument is
21053 deduced, the template-argument type shall match the type of the
21054 template-parameter exactly, except that a template-argument
21055 deduced from an array bound may be of any integral type.
21056 The non-type parameter might use already deduced type parameters. */
21061 {
21065 }
21068 /* Template-parameter dependent expression. Just accept it for now.
21069 It will later be processed in convert_template_argument. */
21070 ;
21076 /* Convert the ARG to the type of PARM; the deduced non-type
21077 template argument must exactly match the types of the
21078 corresponding parameter. */
21081 {
21082 /* We haven't deduced the type of this parameter yet. */
21084 /* We deduce from array bounds in try_array_deduction. */
21086 {
21087 /* Deduce it from the non-type argument. */
21092 }
21093 else
21094 /* Try again later. */
21096 }
21097 else
21100 /* If ARG is a parameter pack or an expansion, we cannot unify
21101 against it unless PARM is also a parameter pack. */
21106 {
21109 }
21114 {
21115 /* A pointer-to-member constant can be unified only with
21116 another constant. */
21120 /* Just unify the class member. It would be useless (and possibly
21121 wrong, depending on the strict flags) to unify also
21122 PTRMEM_CST_CLASS, because we want to be sure that both parm and
21123 arg refer to the same variable, even if through different
21124 classes. For instance:
21126 struct A { int x; };
21127 struct B : A { };
21129 Unification of &A::x and &B::x must succeed. */
21132 }
21135 {
21139 /* [temp.deduct.call]
21141 A can be another pointer or pointer to member type that can
21142 be converted to the deduced A via a qualification
21143 conversion (_conv.qual_).
21145 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
21146 This will allow for additional cv-qualification of the
21147 pointed-to types if appropriate. */
21150 /* The derived-to-base conversion only persists through one
21151 level of pointers. */
21156 }
21188 /* We have already checked cv-qualification at the top of the
21189 function. */
21193 /* As far as unification is concerned, this wins. Later checks
21194 will invalidate it if necessary. */
21197 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
21198 /* Type INTEGER_CST can come from ordinary constant template args. */
21210 {
21220 /* Check for pack expansions in the parameters. */
21222 {
21224 {
21226 /* We can unify against something with a trailing
21227 parameter pack. */
21229 else
21230 /* [temp.deduct.type]/9: If the template argument list of
21231 P contains a pack expansion that is not the last
21232 template argument, the entire template argument list
21233 is a non-deduced context. */
21235 }
21236 }
21238 /* If we don't have enough arguments to satisfy the parameters
21239 (not counting the pack expression at the end), or we have
21240 too many arguments for a parameter list that doesn't end in
21241 a pack expression, we can't unify. */
21247 /* Unify all of the parameters that precede the (optional)
21248 pack expression. */
21250 {
21255 }
21258 DEDUCE_EXACT,
21261 }
21269 {
21277 }
21282 {
21286 {
21287 /* First, we try to unify the PARM and ARG directly. */
21292 {
21293 /* Fallback to the special case allowed in
21294 [temp.deduct.call]:
21296 If P is a class, and P has the form
21297 template-id, then A can be a derived class of
21298 the deduced A. Likewise, if P is a pointer to
21299 a class of the form template-id, A can be a
21300 pointer to a derived class pointed to by the
21301 deduced A. */
21307 {
21308 /* Don't give the derived diagnostic if we're
21309 already dealing with the same template. */
21310 bool same_template
21316 }
21317 }
21318 }
21322 /* Perhaps PARM is something like S<U> and ARG is S<int>.
21323 Then, we should unify `int' and `U'. */
21325 else
21326 /* There's no chance of unification succeeding. */
21331 }
21338 {
21341 tree a;
21347 /* CV qualifications for methods can never be deduced, they must
21348 match exactly. We need to check them explicitly here,
21349 because type_unification_real treats them as any other
21350 cv-qualified parameter. */
21352 && (!check_cv_quals_for_unify
21380 {
21392 }
21395 }
21398 /* Unify a pointer to member with a pointer to member function, which
21399 deduces the type of the member as a function type. */
21401 {
21402 /* Check top-level cv qualifiers */
21410 /* Determine the type of the function we are unifying against. */
21414 }
21433 /* Matched cases are handled by the ARG == PARM test above. */
21437 /* We might get a variable as a non-type template argument in parm if the
21438 corresponding parameter is type-dependent. Make any necessary
21439 adjustments based on whether arg is a reference. */
21443 {
21448 }
21449 /* Now use the normal expression code to check whether they match. */
21460 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21461 or UNDERLYING_TYPE nodes. */
21465 /* Unification fails if we hit an error node. */
21470 {
21480 }
21481 /* FALLTHRU */
21484 /* An unresolved overload is a nondeduced context. */
21488 expr:
21489 /* We must be looking at an expression. This can happen with
21490 something like:
21492 template <int I>
21493 void foo(S<I>, S<I + 2>);
21495 This is a "nondeduced context":
21497 [deduct.type]
21499 The nondeduced contexts are:
21501 --A type that is a template-id in which one or more of
21502 the template-arguments is an expression that references
21503 a template-parameter.
21505 In these cases, we assume deduction succeeded, but don't
21506 actually infer any unifications. */
21511 else
21513 }
21514 }
21515 #undef RECUR_AND_CHECK_FAILURE
21516 \f
21517 /* Note that DECL can be defined in this translation unit, if
21518 required. */
21520 static void
21522 {
21523 tree clone;
21527 }
21529 /* Called if RESULT is explicitly instantiated, or is a member of an
21530 explicitly instantiated class. */
21532 void
21534 {
21537 /* If this entity has already been written out, it's too late to
21538 make any modifications. */
21542 /* For anonymous namespace we don't need to do anything. */
21544 {
21547 }
21550 /* The TREE_PUBLIC flag for function declarations will have been
21551 set correctly by tsubst. */
21554 /* This might have been set by an earlier implicit instantiation. */
21559 else
21560 {
21563 /* Always make artificials weak. */
21566 /* For WIN32 we also want to put explicit instantiations in
21567 linkonce sections. */
21570 }
21572 /* If EXTERN_P, then this function will not be emitted -- unless
21573 followed by an explicit instantiation, at which point its linkage
21574 will be adjusted. If !EXTERN_P, then this function will be
21575 emitted here. In neither circumstance do we want
21576 import_export_decl to adjust the linkage. */
21578 }
21580 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21581 important template arguments. If any are missing, we check whether
21582 they're important by using error_mark_node for substituting into any
21583 args that were used for partial ordering (the ones between ARGS and END)
21584 and seeing if it bubbles up. */
21586 static bool
21588 {
21593 {
21596 }
21598 {
21602 }
21604 }
21606 /* Given two function templates PAT1 and PAT2, return:
21608 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21609 -1 if PAT2 is more specialized than PAT1.
21610 0 if neither is more specialized.
21612 LEN indicates the number of parameters we should consider
21613 (defaulted parameters should not be considered).
21615 The 1998 std underspecified function template partial ordering, and
21616 DR214 addresses the issue. We take pairs of arguments, one from
21617 each of the templates, and deduce them against each other. One of
21618 the templates will be more specialized if all the *other*
21619 template's arguments deduce against its arguments and at least one
21620 of its arguments *does* *not* deduce against the other template's
21621 corresponding argument. Deduction is done as for class templates.
21622 The arguments used in deduction have reference and top level cv
21623 qualifiers removed. Iff both arguments were originally reference
21624 types *and* deduction succeeds in both directions, an lvalue reference
21625 wins against an rvalue reference and otherwise the template
21626 with the more cv-qualified argument wins for that pairing (if
21627 neither is more cv-qualified, they both are equal). Unlike regular
21628 deduction, after all the arguments have been deduced in this way,
21629 we do *not* verify the deduced template argument values can be
21630 substituted into non-deduced contexts.
21632 The logic can be a bit confusing here, because we look at deduce1 and
21633 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21634 can find template arguments for pat1 to make arg1 look like arg2, that
21635 means that arg2 is at least as specialized as arg1. */
21637 int
21639 {
21652 /* Remove the this parameter from non-static member functions. If
21653 one is a non-static member function and the other is not a static
21654 member function, remove the first parameter from that function
21655 also. This situation occurs for operator functions where we
21656 locate both a member function (with this pointer) and non-member
21657 operator (with explicit first operand). */
21659 {
21664 }
21666 {
21669 {
21670 len--;
21672 }
21673 }
21675 /* If only one is a conversion operator, they are unordered. */
21679 /* Consider the return type for a conversion function */
21681 {
21684 len++;
21685 }
21687 processing_template_decl++;
21693 /* Stop when an ellipsis is seen. */
21695 {
21706 {
21707 /* When both arguments are pack expansions, we need only
21708 unify the patterns themselves. */
21712 /* This is the last comparison we need to do. */
21714 }
21716 /* DR 1847: If a particular P contains no template-parameters that
21717 participate in template argument deduction, that P is not used to
21718 determine the ordering. */
21724 {
21728 }
21731 {
21735 }
21741 {
21747 /* Setup the parameter vector, which contains only ARG1. */
21750 /* Setup the argument vector, which contains the remaining
21751 arguments. */
21760 /* We cannot deduce in the other direction, because ARG1 is
21761 a pack expansion but ARG2 is not. */
21763 }
21765 {
21771 /* Setup the parameter vector, which contains only ARG1. */
21774 /* Setup the argument vector, which contains the remaining
21775 arguments. */
21784 /* We cannot deduce in the other direction, because ARG2 is
21785 a pack expansion but ARG1 is not.*/
21787 }
21789 else
21790 {
21791 /* The normal case, where neither argument is a pack
21792 expansion. */
21799 }
21801 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21802 arg2, then arg2 is not as specialized as arg1. */
21808 /* "If, for a given type, deduction succeeds in both directions
21809 (i.e., the types are identical after the transformations above)
21810 and both P and A were reference types (before being replaced with
21811 the type referred to above):
21812 - if the type from the argument template was an lvalue reference and
21813 the type from the parameter template was not, the argument type is
21814 considered to be more specialized than the other; otherwise,
21815 - if the type from the argument template is more cv-qualified
21816 than the type from the parameter template (as described above),
21817 the argument type is considered to be more specialized than the other;
21818 otherwise,
21819 - neither type is more specialized than the other." */
21822 {
21824 {
21827 else
21829 }
21831 {
21836 }
21837 }
21840 /* We've failed to deduce something in either direction.
21841 These must be unordered. */
21844 next:
21848 /* We have already processed all of the arguments in our
21849 handing of the pack expansion type. */
21854 }
21856 /* "In most cases, all template parameters must have values in order for
21857 deduction to succeed, but for partial ordering purposes a template
21858 parameter may remain without a value provided it is not used in the
21859 types being used for partial ordering."
21861 Thus, if we are missing any of the targs1 we need to substitute into
21862 origs1, then pat2 is not as specialized as pat1. This can happen when
21863 there is a nondeduced context. */
21869 processing_template_decl--;
21871 /* If both deductions succeed, the partial ordering selects the more
21872 constrained template. */
21874 {
21879 }
21881 /* All things being equal, if the next argument is a pack expansion
21882 for one function but not for the other, prefer the
21883 non-variadic function. FIXME this is bogus; see c++/41958. */
21887 {
21890 }
21896 else
21898 }
21900 /* Determine which of two partial specializations of TMPL is more
21901 specialized.
21903 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21904 to the first partial specialization. The TREE_PURPOSE is the
21905 innermost set of template parameters for the partial
21906 specialization. PAT2 is similar, but for the second template.
21908 Return 1 if the first partial specialization is more specialized;
21909 -1 if the second is more specialized; 0 if neither is more
21910 specialized.
21912 See [temp.class.order] for information about determining which of
21913 two templates is more specialized. */
21915 static int
21917 {
21918 tree targs;
21927 /* Just like what happens for functions, if we are ordering between
21928 different template specializations, we may encounter dependent
21929 types in the arguments, and we need our dependency check functions
21930 to behave correctly. */
21934 {
21937 }
21941 {
21944 }
21947 /* If both deductions succeed, the partial ordering selects the more
21948 constrained template. */
21952 /* In the case of a tie where at least one of the templates
21953 has a parameter pack at the end, the template with the most
21954 non-packed parameters wins. */
21956 && any_deductions
21959 {
21965 /* We don't count the pack expansion at the end. */
21975 }
21978 }
21980 /* Return the template arguments that will produce the function signature
21981 DECL from the function template FN, with the explicit template
21982 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21983 also match. Return NULL_TREE if no satisfactory arguments could be
21984 found. */
21986 static tree
21988 {
21992 tree decl_arg_types;
21995 tree arg;
21999 /* Never do unification on the 'this' parameter. */
22020 }
22022 /* Return the innermost template arguments that, when applied to a partial
22023 specialization SPEC_TMPL of TMPL, yield the ARGS.
22025 For example, suppose we have:
22027 template <class T, class U> struct S {};
22028 template <class T> struct S<T*, int> {};
22030 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
22031 partial specialization and the ARGS will be {double*, int}. The resulting
22032 vector will be {double}, indicating that `T' is bound to `double'. */
22034 static tree
22036 {
22038 tree spec_args
22041 tree deduced_args;
22042 tree innermost_deduced_args;
22046 {
22050 innermost_deduced_args);
22051 }
22052 else
22056 again:
22065 {
22067 {
22073 }
22075 }
22079 {
22082 }
22084 /* Verify that nondeduced template arguments agree with the type
22085 obtained from argument deduction.
22087 For example:
22089 struct A { typedef int X; };
22090 template <class T, class U> struct C {};
22091 template <class T> struct C<T, typename T::X> {};
22093 Then with the instantiation `C<A, int>', we can deduce that
22094 `T' is `A' but unify () does not check whether `typename T::X'
22095 is `int'. */
22106 /* We only need to check the innermost arguments; the other
22107 arguments will always agree. */
22112 /* Now that we have bindings for all of the template arguments,
22113 ensure that the arguments deduced for the template template
22114 parameters have compatible template parameter lists. See the use
22115 of template_template_parm_bindings_ok_p in fn_type_unification
22116 for more information. */
22121 }
22123 // Compare two function templates T1 and T2 by deducing bindings
22124 // from one against the other. If both deductions succeed, compare
22125 // constraints to see which is more constrained.
22126 static int
22128 {
22133 {
22136 }
22139 {
22142 }
22144 // If both deductions succeed, then one may be more constrained.
22149 }
22151 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
22152 Return the TREE_LIST node with the most specialized template, if
22153 any. If there is no most specialized template, the error_mark_node
22154 is returned.
22156 Note that this function does not look at, or modify, the
22157 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
22158 returned is one of the elements of INSTANTIATIONS, callers may
22159 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
22160 and retrieve it from the value returned. */
22162 tree
22164 {
22171 {
22177 {
22178 /* Equally specialized, move to next function. If there
22179 is no next function, nothing's most specialized. */
22184 }
22185 }
22188 /* Now verify that champ is better than everything earlier in the
22189 instantiation list. */
22192 {
22195 }
22196 }
22198 processing_template_decl--;
22204 }
22206 /* If DECL is a specialization of some template, return the most
22207 general such template. Otherwise, returns NULL_TREE.
22209 For example, given:
22211 template <class T> struct S { template <class U> void f(U); };
22213 if TMPL is `template <class U> void S<int>::f(U)' this will return
22214 the full template. This function will not trace past partial
22215 specializations, however. For example, given in addition:
22217 template <class T> struct S<T*> { template <class U> void f(U); };
22219 if TMPL is `template <class U> void S<int*>::f(U)' this will return
22220 `template <class T> template <class U> S<T*>::f(U)'. */
22222 tree
22224 {
22226 {
22229 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
22230 template friend, or a FIELD_DECL for a capture pack. */
22233 }
22235 /* Look for more and more general templates. */
22237 {
22238 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
22239 (See cp-tree.h for details.) */
22248 /* Stop if we run into an explicitly specialized class template. */
22255 }
22258 }
22260 /* Return the most specialized of the template partial specializations
22261 which can produce TARGET, a specialization of some class or variable
22262 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
22263 a TEMPLATE_DECL node corresponding to the partial specialization, while
22264 the TREE_PURPOSE is the set of template arguments that must be
22265 substituted into the template pattern in order to generate TARGET.
22267 If the choice of partial specialization is ambiguous, a diagnostic
22268 is issued, and the error_mark_node is returned. If there are no
22269 partial specializations matching TARGET, then NULL_TREE is
22270 returned, indicating that the primary template should be used. */
22272 static tree
22274 {
22276 tree t;
22277 tree champ;
22284 {
22288 }
22290 {
22293 }
22295 {
22299 }
22300 else
22305 /* For determining which partial specialization to use, only the
22306 innermost args are interesting. */
22308 {
22311 }
22314 {
22315 tree spec_args;
22319 {
22320 /* Substitute in the template args from the enclosing class. */
22324 }
22331 {
22335 /* Keep the candidate only if the constraints are satisfied,
22336 or if we're not compiling with concepts. */
22339 {
22342 }
22343 }
22344 }
22354 {
22357 ;
22358 else
22359 {
22361 {
22364 {
22367 }
22368 }
22370 }
22371 }
22375 {
22378 {
22381 }
22382 }
22385 {
22392 else
22396 {
22401 }
22404 }
22407 }
22409 /* Explicitly instantiate DECL. */
22411 void
22413 {
22418 /* An error occurred, for which grokdeclarator has already issued
22419 an appropriate message. */
22422 {
22425 }
22431 {
22432 /* There is an asymmetry here in the way VAR_DECLs and
22433 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22434 the latter, the DECL we get back will be marked as a
22435 template instantiation, and the appropriate
22436 DECL_TEMPLATE_INFO will be set up. This does not happen for
22437 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22438 should handle VAR_DECLs as it currently handles
22439 FUNCTION_DECLs. */
22441 {
22444 }
22447 {
22450 }
22452 {
22457 }
22458 }
22460 {
22463 }
22464 else
22467 /* Check for various error cases. Note that if the explicit
22468 instantiation is valid the RESULT will currently be marked as an
22469 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22470 until we get here. */
22473 {
22474 /* DR 259 [temp.spec].
22476 Both an explicit instantiation and a declaration of an explicit
22477 specialization shall not appear in a program unless the explicit
22478 instantiation follows a declaration of the explicit specialization.
22480 For a given set of template parameters, if an explicit
22481 instantiation of a template appears after a declaration of an
22482 explicit specialization for that template, the explicit
22483 instantiation has no effect. */
22485 }
22487 {
22488 /* [temp.spec]
22490 No program shall explicitly instantiate any template more
22491 than once.
22493 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22494 the first instantiation was `extern' and the second is not,
22495 and EXTERN_P for the opposite case. */
22498 /* If an "extern" explicit instantiation follows an ordinary
22499 explicit instantiation, the template is instantiated. */
22502 }
22504 {
22507 }
22509 {
22512 }
22515 ;
22517 {
22520 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22523 }
22524 else
22532 }
22534 static void
22536 {
22542 {
22545 }
22546 }
22548 /* Called from do_type_instantiation through binding_table_foreach to
22549 do recursive instantiation for the type bound in ENTRY. */
22550 static void
22552 {
22558 }
22560 /* Perform an explicit instantiation of template class T. STORAGE, if
22561 non-null, is the RID for extern, inline or static. COMPLAIN is
22562 nonzero if this is called from the parser, zero if called recursively,
22563 since the standard is unclear (as detailed below). */
22565 void
22567 {
22577 {
22578 tree tmpl =
22582 else
22585 }
22590 {
22593 t);
22595 }
22598 {
22600 {
22602 {
22605 "ISO C++ 1998 forbids the use of %<extern%> on "
22607 }
22608 else
22610 "ISO C++ forbids the use of %qE"
22612 }
22620 else
22621 {
22623 storage);
22625 }
22626 }
22629 {
22630 /* DR 259 [temp.spec].
22632 Both an explicit instantiation and a declaration of an explicit
22633 specialization shall not appear in a program unless the explicit
22634 instantiation follows a declaration of the explicit specialization.
22636 For a given set of template parameters, if an explicit
22637 instantiation of a template appears after a declaration of an
22638 explicit specialization for that template, the explicit
22639 instantiation has no effect. */
22641 }
22643 {
22644 /* [temp.spec]
22646 No program shall explicitly instantiate any template more
22647 than once.
22649 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22650 instantiation was `extern'. If EXTERN_P then the second is.
22651 These cases are OK. */
22658 /* If we've already instantiated the template, just return now. */
22661 }
22669 /* In contrast to implicit instantiation, where only the
22670 declarations, and not the definitions, of members are
22671 instantiated, we have here:
22673 [temp.explicit]
22675 The explicit instantiation of a class template specialization
22676 implies the instantiation of all of its members not
22677 previously explicitly specialized in the translation unit
22678 containing the explicit instantiation.
22680 Of course, we can't instantiate member template classes, since we
22681 don't have any arguments for them. Note that the standard is
22682 unclear on whether the instantiation of the members are
22683 *explicit* instantiations or not. However, the most natural
22684 interpretation is that it should be an explicit
22685 instantiation. */
22689 && !static_p
22692 {
22697 }
22702 }
22704 /* Given a function DECL, which is a specialization of TMPL, modify
22705 DECL to be a re-instantiation of TMPL with the same template
22706 arguments. TMPL should be the template into which tsubst'ing
22707 should occur for DECL, not the most general template.
22709 One reason for doing this is a scenario like this:
22711 template <class T>
22712 void f(const T&, int i);
22714 void g() { f(3, 7); }
22716 template <class T>
22717 void f(const T& t, const int i) { }
22719 Note that when the template is first instantiated, with
22720 instantiate_template, the resulting DECL will have no name for the
22721 first parameter, and the wrong type for the second. So, when we go
22722 to instantiate the DECL, we regenerate it. */
22724 static void
22726 {
22727 /* The arguments used to instantiate DECL, from the most general
22728 template. */
22729 tree code_pattern;
22733 /* Make sure that we can see identifiers, and compute access
22734 correctly. */
22738 {
22739 tree decl_parm;
22740 tree pattern_parm;
22741 tree specs;
22755 specs);
22757 /* Merge parameter declarations. */
22760 pattern_parm
22764 {
22765 tree parm_type;
22766 tree attributes;
22771 NULL_TREE);
22777 {
22780 }
22783 }
22784 /* Merge any parameters that match with the function parameter
22785 pack. */
22787 {
22789 tree expanded_types;
22790 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22791 the parameters in this function parameter pack. */
22796 {
22797 tree parm_type;
22798 tree attributes;
22801 /* Rename the parameter to include the index. */
22810 {
22813 }
22815 }
22816 }
22817 /* Merge additional specifiers from the CODE_PATTERN. */
22821 }
22823 {
22833 }
22834 else
22838 }
22840 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22841 substituted to get DECL. */
22843 tree
22845 {
22848 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22849 for the instantiation. This is not always the most general
22850 template. Consider, for example:
22852 template <class T>
22853 struct S { template <class U> void f();
22854 template <> void f<int>(); };
22856 and an instantiation of S<double>::f<int>. We want TD to be the
22857 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22859 more general template. */
22861 /* We must also deal with friend templates. Given:
22863 template <class T> struct S {
22864 template <class U> friend void f() {};
22865 };
22867 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22868 so far as the language is concerned, but that's still
22869 where we get the pattern for the instantiation from. On
22870 other hand, if the definition comes outside the class, say:
22872 template <class T> struct S {
22873 template <class U> friend void f();
22874 };
22875 template <class U> friend void f() {}
22877 we don't need to look any further. That's what the check for
22878 DECL_INITIAL is for. */
22882 {
22883 /* The present template, TD, should not be a definition. If it
22884 were a definition, we should be using it! Note that we
22885 cannot restructure the loop to just keep going until we find
22886 a template with a definition, since that might go too far if
22887 a specialization was declared, but not defined. */
22889 /* Fetch the more general template. */
22891 }
22894 }
22896 /* Returns true if we need to instantiate this template instance even if we
22897 know we aren't going to emit it. */
22899 bool
22901 {
22902 /* We always instantiate inline functions so that we can inline them. An
22903 explicit instantiation declaration prohibits implicit instantiation of
22904 non-inline functions. With high levels of optimization, we would
22905 normally inline non-inline functions -- but we're not allowed to do
22906 that for "extern template" functions. Therefore, we check
22907 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22911 /* And we need to instantiate static data members so that
22912 their initializers are available in integral constant
22913 expressions. */
22916 }
22918 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22919 instantiate it now, modifying TREE_TYPE (fn). Returns false on
22920 error, true otherwise. */
22922 bool
22924 {
22927 /* Don't instantiate a noexcept-specification from template context. */
22942 {
22948 {
22949 /* If hash_set::add returns true, the element was already there. */
22954 fn);
22956 }
22958 {
22973 }
22974 else
22984 }
22987 {
22990 else
22992 }
22995 }
22997 /* We're starting to process the function INST, an instantiation of PATTERN;
22998 add their parameters to local_specializations. */
23000 static void
23002 {
23006 {
23010 }
23012 {
23014 {
23017 }
23018 else
23019 {
23020 /* Register the (value) argument pack as a specialization of
23021 TMPL_PARM, then move on. */
23024 }
23025 }
23027 }
23029 /* Produce the definition of D, a _DECL generated from a template. If
23030 DEFER_OK is true, then we don't have to actually do the
23031 instantiation now; we just have to do it sometime. Normally it is
23032 an error if this is an explicit instantiation but D is undefined.
23033 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
23034 instantiated class template. */
23036 tree
23038 {
23040 tree gen_args;
23041 tree args;
23042 tree td;
23043 tree code_pattern;
23044 tree spec;
23045 tree gen_tmpl;
23053 /* This function should only be used to instantiate templates for
23054 functions and static member variables. */
23057 /* A concept is never instantiated. */
23060 /* Variables are never deferred; if instantiation is required, they
23061 are instantiated right away. That allows for better code in the
23062 case that an expression refers to the value of the variable --
23063 if the variable has a constant value the referring expression can
23064 take advantage of that fact. */
23068 /* Don't instantiate cloned functions. Instead, instantiate the
23069 functions they cloned. */
23077 /* D has already been instantiated or explicitly specialized, so
23078 there's nothing for us to do here.
23080 It might seem reasonable to check whether or not D is an explicit
23081 instantiation, and, if so, stop here. But when an explicit
23082 instantiation is deferred until the end of the compilation,
23083 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
23084 the instantiation. */
23087 /* Check to see whether we know that this template will be
23088 instantiated in some other file, as with "extern template"
23089 extension. */
23092 /* In general, we do not instantiate such templates. */
23100 /* We should already have the extra args. */
23103 /* And what's in the hash table should match D. */
23107 /* This needs to happen before any tsubsting. */
23113 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
23114 for the instantiation. */
23119 {
23120 /* Look up an explicit specialization, if any. */
23124 {
23127 }
23128 }
23132 /* We should never be trying to instantiate a member of a class
23133 template or partial specialization. */
23138 /* In the case of a friend template whose definition is provided
23139 outside the class, we may have too many arguments. Drop the
23140 ones we don't need. The same is true for specializations. */
23141 args = get_innermost_template_args
23145 {
23151 }
23152 else
23153 {
23158 else
23160 }
23162 /* We may be in the middle of deferred access check. Disable it now. */
23165 /* Unless an explicit instantiation directive has already determined
23166 the linkage of D, remember that a definition is available for
23167 this entity. */
23177 /* If D is a member of an explicitly instantiated class template,
23178 and no definition is available, treat it like an implicit
23179 instantiation. */
23182 {
23183 /* Leave linkage flags alone on instantiations with anonymous
23184 visibility. */
23186 {
23189 }
23191 }
23193 /* Defer all other templates, unless we have been explicitly
23194 forbidden from doing so. */
23196 template. */
23197 ! pattern_defined
23198 /* If it's OK to postpone instantiation, do so. */
23199 || defer_ok
23200 /* If this is a static data member that will be defined
23201 elsewhere, we don't want to instantiate the entire data
23202 member, but we do want to instantiate the initializer so that
23203 we can substitute that elsewhere. */
23205 /* Handle here a deleted function too, avoid generating
23206 its body (c++/61080). */
23208 {
23209 /* The definition of the static data member is now required so
23210 we must substitute the initializer. */
23214 {
23215 tree ns;
23216 tree init;
23225 args,
23228 /* If instantiating the initializer involved instantiating this
23229 again, don't call cp_finish_decl twice. */
23231 {
23232 /* Make sure the initializer is still constant, in case of
23233 circular dependency (template/instantiate6.C). */
23234 const_init
23238 LOOKUP_ONLYCONVERTING);
23239 }
23243 }
23245 /* We restore the source position here because it's used by
23246 add_pending_template. */
23252 /* [temp.explicit]
23254 The definition of a non-exported function template, a
23255 non-exported member function template, or a non-exported
23256 member function or static data member of a class template
23257 shall be present in every translation unit in which it is
23258 explicitly instantiated. */
23262 /* If we're in unevaluated context, we just wanted to get the
23263 constant value; this isn't an odr use, so don't queue
23264 a full instantiation. */
23267 /* ??? Historically, we have instantiated inline functions, even
23268 when marked as "extern template". */
23272 }
23273 /* Tell the repository that D is available in this translation unit
23274 -- and see if it is supposed to be instantiated here. */
23276 {
23277 /* In a PCH file, despite the fact that the repository hasn't
23278 requested instantiation in the PCH it is still possible that
23279 an instantiation will be required in a file that includes the
23280 PCH. */
23283 /* Instantiate inline functions so that the inliner can do its
23284 job, even though we'll not be emitting a copy of this
23285 function. */
23288 }
23291 tree fn_context;
23302 else
23303 {
23307 }
23309 /* Mark D as instantiated so that recursive calls to
23310 instantiate_decl do not try to instantiate it again. */
23313 /* Regenerate the declaration in case the template has been modified
23314 by a subsequent redeclaration. */
23317 /* We already set the file and line above. Reset them now in case
23318 they changed as a result of calling regenerate_decl_from_template. */
23322 {
23323 tree init;
23326 /* Clear out DECL_RTL; whatever was there before may not be right
23327 since we've reset the type of the declaration. */
23331 /* The initializer is placed in DECL_INITIAL by
23332 regenerate_decl_from_template so we don't need to
23333 push/pop_access_scope again here. Pull it out so that
23334 cp_finish_decl can process it. */
23339 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
23340 initializer. That function will defer actual emission until
23341 we have a chance to determine linkage. */
23344 /* Enter the scope of D so that access-checking works correctly. */
23357 }
23361 {
23362 /* Set up the list of local specializations. */
23366 /* Set up context. */
23370 else
23373 /* Some typedefs referenced from within the template code need to be
23374 access checked at template instantiation time, i.e now. These
23375 types were added to the template at parsing time. Let's get those
23376 and perform the access checks then. */
23378 args);
23380 /* Create substitution entries for the parameters. */
23383 /* Substitute into the body of the function. */
23387 else
23388 {
23393 /* Set the current input_location to the end of the function
23394 so that finish_function knows where we are. */
23395 input_location
23398 /* Remember if we saw an infinite loop in the template. */
23399 current_function_infinite_loop
23401 }
23403 /* Finish the function. */
23407 else
23408 {
23411 }
23415 }
23417 /* We're not deferring instantiation any more. */
23422 else
23428 out:
23437 }
23439 /* Run through the list of templates that we wish we could
23440 instantiate, and instantiate any we can. RETRIES is the
23441 number of times we retry pending template instantiation. */
23443 void
23445 {
23449 /* Instantiating templates may trigger vtable generation. This in turn
23450 may require further template instantiations. We place a limit here
23451 to avoid infinite loop. */
23453 {
23457 "template instantiation depth exceeds maximum of %d"
23458 " instantiating %q+D, possibly from virtual table generation"
23462 /* Pretend that we defined it. */
23465 }
23467 do
23468 {
23473 {
23478 {
23480 {
23495 }
23498 }
23499 else
23500 {
23503 {
23504 instantiation
23510 }
23514 }
23517 /* If INSTANTIATION has been instantiated, then we don't
23518 need to consider it again in the future. */
23520 else
23521 {
23524 }
23527 }
23529 }
23533 }
23535 /* Substitute ARGVEC into T, which is a list of initializers for
23536 either base class or a non-static data member. The TREE_PURPOSEs
23537 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23538 instantiate_decl. */
23540 static tree
23542 {
23546 {
23547 tree decl;
23548 tree init;
23554 {
23555 tree expr;
23556 tree arg;
23558 /* Expand the base class expansion type into separate base
23559 classes. */
23561 tf_warning_or_error,
23562 NULL_TREE);
23566 /* We'll be building separate TREE_LISTs of arguments for
23567 each base. */
23573 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23574 expand each argument in the TREE_VALUE of t. */
23581 /* VOID_TYPE_NODE is used to indicate
23582 value-initialization. */
23583 {
23586 }
23587 else
23588 {
23589 /* Substitute parameter packs into each argument in the
23590 TREE_LIST. */
23593 {
23594 tree expanded_exprs;
23596 /* Expand the argument. */
23598 expanded_exprs
23600 tf_warning_or_error,
23601 NULL_TREE);
23605 /* Prepend each of the expanded expressions to the
23606 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23608 {
23613 }
23614 }
23617 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23618 since we built them backwards. */
23620 {
23623 }
23624 }
23625 }
23628 {
23630 {
23634 }
23635 else
23636 {
23637 tree tmp;
23652 /* If we had an initializer but it instantiated to nothing,
23653 value-initialize the object. This will only occur when
23654 the initializer was a pack expansion where the parameter
23655 packs used in that expansion were of length zero. */
23658 }
23661 {
23665 }
23666 }
23667 }
23669 }
23671 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23673 static void
23675 {
23680 else
23682 }
23684 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23685 is the instantiation (which should have been created with
23686 start_enum) and ARGS are the template arguments to use. */
23688 static void
23690 {
23691 tree e;
23697 {
23698 tree value;
23699 tree decl;
23702 /* Note that in a template enum, the TREE_VALUE is the
23703 CONST_DECL, not the corresponding INTEGER_CST. */
23708 /* Give this enumeration constant the correct access. */
23711 /* Actually build the enumerator itself. Here we're assuming that
23712 enumerators can't have dependent attributes. */
23715 }
23725 }
23727 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23728 its type -- but without substituting the innermost set of template
23729 arguments. So, innermost set of template parameters will appear in
23730 the type. */
23732 tree
23734 {
23735 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23737 }
23739 /* Return truthvalue if we're processing a template different from
23740 the last one involved in diagnostics. */
23741 bool
23743 {
23745 }
23747 /* Remember current template involved in diagnostics. */
23748 void
23750 {
23752 }
23756 {
23758 }
23760 /* Return TRUE if current_function_decl is being instantiated, false
23761 otherwise. */
23763 bool
23765 {
23768 }
23770 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23771 type. Return false for ok, true for disallowed. Issue error and
23772 inform messages under control of COMPLAIN. */
23774 static bool
23776 {
23791 /* A bound template template parm could later be instantiated to have a valid
23792 nontype parm type via an alias template. */
23798 {
23801 else
23803 type);
23804 }
23806 }
23808 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23809 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23811 static bool
23813 {
23814 tree scope;
23816 /* [temp.dep.type]
23818 A type is dependent if it is:
23820 -- a template parameter. Template template parameters are types
23821 for us (since TYPE_P holds true for them) so we handle
23822 them here. */
23826 /* -- a qualified-id with a nested-name-specifier which contains a
23827 class-name that names a dependent type or whose unqualified-id
23828 names a dependent type. */
23832 /* An alias template specialization can be dependent even if the
23833 resulting type is not. */
23837 /* -- a cv-qualified type where the cv-unqualified type is
23838 dependent.
23839 No code is necessary for this bullet; the code below handles
23840 cv-qualified types, and we don't want to strip aliases with
23841 TYPE_MAIN_VARIANT because of DR 1558. */
23842 /* -- a compound type constructed from any dependent type. */
23852 {
23853 tree arg_type;
23858 arg_type;
23863 /* A value-dependent noexcept-specifier makes the type dependent. */
23866 /* Treat DEFERRED_NOEXCEPT as non-dependent, since it doesn't
23867 affect overload resolution and treating it as dependent breaks
23868 things. */
23873 }
23874 /* -- an array type constructed from any dependent type or whose
23875 size is specified by a constant expression that is
23876 value-dependent.
23878 We checked for type- and value-dependence of the bounds in
23879 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23881 {
23886 }
23888 /* -- a template-id in which either the template name is a template
23889 parameter ... */
23892 /* ... or any of the template arguments is a dependent type or
23893 an expression that is type-dependent or value-dependent. */
23895 && (any_dependent_template_arguments_p
23899 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23900 dependent; if the argument of the `typeof' expression is not
23901 type-dependent, then it should already been have resolved. */
23907 /* A template argument pack is dependent if any of its packed
23908 arguments are. */
23910 {
23916 }
23918 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23919 be template parameters. */
23926 /* The standard does not specifically mention types that are local
23927 to template functions or local classes, but they should be
23928 considered dependent too. For example:
23930 template <int I> void f() {
23931 enum E { a = I };
23932 S<sizeof (E)> s;
23933 }
23935 The size of `E' cannot be known until the value of `I' has been
23936 determined. Therefore, `E' must be considered dependent. */
23940 /* Don't use type_dependent_expression_p here, as it can lead
23941 to infinite recursion trying to determine whether a lambda
23942 nested in a lambda is dependent (c++/47687). */
23946 && (any_dependent_template_arguments_p
23950 /* Other types are non-dependent. */
23952 }
23954 /* Returns TRUE if TYPE is dependent, in the sense of
23955 [temp.dep.type]. Note that a NULL type is considered dependent. */
23957 bool
23959 {
23960 /* If there are no template parameters in scope, then there can't be
23961 any dependent types. */
23963 {
23964 /* If we are not processing a template, then nobody should be
23965 providing us with a dependent type. */
23969 }
23971 /* If the type is NULL, we have not computed a type for the entity
23972 in question; in that case, the type is dependent. */
23976 /* Erroneous types can be considered non-dependent. */
23980 /* Getting here with global_type_node means we improperly called this
23981 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23984 /* If we have not already computed the appropriate value for TYPE,
23985 do so now. */
23987 {
23990 }
23993 }
23995 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23996 lookup. In other words, a dependent type that is not the current
23997 instantiation. */
23999 bool
24001 {
24004 }
24006 /* T is a SCOPE_REF. Return whether it represents a non-static member of
24007 an unknown base of 'this' (and is therefore instantiation-dependent). */
24009 static bool
24011 {
24028 }
24030 /* T is a SCOPE_REF; return whether we need to consider it
24031 instantiation-dependent so that we can check access at instantiation
24032 time even though we know which member it resolves to. */
24034 static bool
24036 {
24043 else
24045 }
24047 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
24048 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
24049 expression. */
24051 /* Note that this predicate is not appropriate for general expressions;
24052 only constant expressions (that satisfy potential_constant_expression)
24053 can be tested for value dependence. */
24055 bool
24057 {
24061 /* A type-dependent expression is also value-dependent. */
24066 {
24068 /* A dependent member function of the current instantiation. */
24072 /* A dependent member function of the current instantiation. */
24079 /* A name that has not been looked up -- must be dependent. */
24083 /* A non-type template parm. */
24087 /* A non-type template parm. */
24093 /* A constant with literal type and is initialized
24094 with an expression that is value-dependent. */
24096 /* FIXME cp_finish_decl doesn't fold reference initializers. */
24100 {
24104 }
24113 /* These expressions are value-dependent if the type to which
24114 the cast occurs is dependent or the expression being casted
24115 is value-dependent. */
24116 {
24122 /* A functional cast has a list of operands. */
24125 {
24126 /* If there are no operands, it must be an expression such
24127 as "int()". This should not happen for aggregate types
24128 because it would form non-constant expressions. */
24133 }
24139 }
24144 /* FALLTHRU */
24147 /* A `sizeof' expression is value-dependent if the operand is
24148 type-dependent or is a pack expansion. */
24157 /* An 'encode' expression is value-dependent if the operand is
24158 type-dependent. */
24167 /* All instantiation-dependent expressions should also be considered
24168 value-dependent. */
24176 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
24177 is value-dependent. */
24178 {
24187 }
24190 {
24207 }
24218 {
24222 }
24225 /* Treat all requires-expressions as value-dependent so
24226 we don't try to fold them. */
24233 {
24240 {
24242 /* In a call to a constexpr member function, look through the
24243 implicit ADDR_EXPR on the object argument so that it doesn't
24244 cause the call to be considered value-dependent. We also
24245 look through it in potential_constant_expression. */
24252 }
24254 }
24260 {
24262 tree val;
24269 }
24272 /* Treat a GNU statement expression as dependent to avoid crashing
24273 under instantiate_non_dependent_expr; it can't be constant. */
24277 /* A constant expression is value-dependent if any subexpression is
24278 value-dependent. */
24280 {
24287 {
24291 {
24294 /* In some cases, some of the operands may be missing.
24295 (For example, in the case of PREDECREMENT_EXPR, the
24296 amount to increment by may be missing.) That doesn't
24297 make the expression dependent. */
24300 }
24301 }
24305 }
24307 }
24309 /* The expression is not value-dependent. */
24311 }
24313 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
24314 [temp.dep.expr]. Note that an expression with no type is
24315 considered dependent. Other parts of the compiler arrange for an
24316 expression with type-dependent subexpressions to have no type, so
24317 this function doesn't have to be fully recursive. */
24319 bool
24321 {
24330 /* An unresolved name is always dependent. */
24336 /* A fold expression is type-dependent. */
24343 /* Some expression forms are never type-dependent. */
24357 /* The types of these expressions depends only on the type to which
24358 the cast occurs. */
24367 /* The types of these expressions depends only on the type created
24368 by the expression. */
24371 {
24372 /* For NEW_EXPR tree nodes created inside a template, either
24373 the object type itself or a TREE_LIST may appear as the
24374 operand 1. */
24377 /* This is an array type. We need to check array dimensions
24378 as well. */
24380 || value_dependent_expression_p
24382 else
24384 }
24387 {
24391 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
24392 contains an identifier associated by name lookup with one or more
24393 declarations declared with a dependent type, or...a
24394 nested-name-specifier or qualified-id that names a member of an
24395 unknown specialization. */
24398 }
24408 {
24409 tree elt;
24413 {
24416 }
24418 }
24420 /* A static data member of the current instantiation with incomplete
24421 array type is type-dependent, as the definition and specializations
24422 can have different bounds. */
24429 /* An array of unknown bound depending on a variadic parameter, eg:
24431 template<typename... Args>
24432 void foo (Args... args)
24433 {
24434 int arr[] = { args... };
24435 }
24437 template<int... vals>
24438 void bar ()
24439 {
24440 int arr[] = { vals... };
24441 }
24443 If the array has no length and has an initializer, it must be that
24444 we couldn't determine its length in cp_complete_array_type because
24445 it is dependent. */
24453 /* A function or variable template-id is type-dependent if it has any
24454 dependent template arguments. */
24458 {
24459 /* Consider the innermost template arguments, since those are the ones
24460 that come from the template-id; the template arguments for the
24461 enclosing class do not make it type-dependent unless they are used in
24462 the type of the decl. */
24464 && (any_dependent_template_arguments_p
24467 }
24469 /* Otherwise, if the function decl isn't from a dependent scope, it can't be
24470 type-dependent. Checking this is important for functions with auto return
24471 type, which looks like a dependent type. */
24479 {
24483 }
24485 /* Always dependent, on the number of arguments if nothing else. */
24490 {
24495 {
24501 }
24502 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24507 {
24512 }
24515 {
24522 }
24532 }
24536 /* Dependent type attributes might not have made it from the decl to
24537 the type yet. */
24543 }
24545 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24546 type-dependent if the expression refers to a member of the current
24547 instantiation and the type of the referenced member is dependent, or the
24548 class member access expression refers to a member of an unknown
24549 specialization.
24551 This function returns true if the OBJECT in such a class member access
24552 expression is of an unknown specialization. */
24554 bool
24556 {
24557 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24558 dependent. */
24563 }
24565 /* walk_tree callback function for instantiation_dependent_expression_p,
24566 below. Returns non-zero if a dependent subexpression is found. */
24568 static tree
24571 {
24573 {
24574 /* We don't have to worry about decltype currently because decltype
24575 of an instantiation-dependent expr is a dependent type. This
24576 might change depending on the resolution of DR 1172. */
24579 }
24582 {
24583 /* Don't treat an argument list as dependent just because it has no
24584 TREE_TYPE. */
24592 /* Handle expressions with type operands. */
24597 {
24602 {
24605 else
24606 {
24609 }
24610 }
24612 }
24616 /* In a template, finish_class_member_access_expr creates a
24617 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24618 type-dependent, so that we can check access control at
24619 instantiation time (PR 42277). See also Core issue 1273. */
24626 else
24629 /* Treat statement-expressions as dependent. */
24633 /* Treat requires-expressions as dependent. */
24638 /* Treat calls to function concepts as dependent. */
24644 /* And variable concepts. */
24651 }
24655 else
24657 }
24659 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24660 sense defined by the ABI:
24662 "An expression is instantiation-dependent if it is type-dependent
24663 or value-dependent, or it has a subexpression that is type-dependent
24664 or value-dependent."
24666 Except don't actually check value-dependence for unevaluated expressions,
24667 because in sizeof(i) we don't care about the value of i. Checking
24668 type-dependence will in turn check value-dependence of array bounds/template
24669 arguments as needed. */
24671 bool
24673 {
24674 tree result;
24685 }
24687 /* As above, but also check value-dependence of the expression as a whole. */
24689 bool
24691 {
24694 }
24696 /* Like type_dependent_expression_p, but it also works while not processing
24697 a template definition, i.e. during substitution or mangling. */
24699 bool
24701 {
24707 }
24709 /* Returns TRUE if ARGS contains a type-dependent expression. */
24711 bool
24713 {
24715 tree arg;
24718 {
24721 }
24723 }
24725 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24726 expressions) contains any type-dependent expressions. */
24728 bool
24730 {
24736 }
24738 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24739 expressions) contains any value-dependent expressions. */
24741 bool
24743 {
24749 }
24751 /* Returns TRUE if the ARG (a template argument) is dependent. */
24753 bool
24755 {
24759 /* Assume a template argument that was wrongly written by the user
24760 is dependent. This is consistent with what
24761 any_dependent_template_arguments_p [that calls this function]
24762 does. */
24772 {
24775 /* A member template of a dependent class is not necessarily
24776 type-dependent, but it is a dependent template argument because it
24777 will be a member of an unknown specialization to that template. */
24780 }
24782 {
24786 {
24789 }
24792 }
24795 else
24798 }
24800 /* Returns true if ARGS (a collection of template arguments) contains
24801 any types that require structural equality testing. */
24803 bool
24805 {
24815 {
24818 {
24824 {
24825 /* Look inside the argument pack. */
24828 }
24831 {
24844 }
24845 }
24846 }
24849 }
24851 /* Returns true if ARGS (a collection of template arguments) contains
24852 any dependent arguments. */
24854 bool
24856 {
24866 {
24871 }
24874 }
24876 /* Returns TRUE if the template TMPL is type-dependent. */
24878 bool
24880 {
24882 {
24887 }
24889 /* Template template parameters are dependent. */
24893 /* So are names that have not been looked up. */
24897 }
24899 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24901 bool
24903 {
24906 }
24908 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24909 are dependent. */
24911 bool
24913 {
24920 {
24942 {
24946 }
24950 {
24954 {
24959 }
24960 }
24961 }
24964 }
24966 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24967 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24968 no such TYPE can be found. Note that this function peers inside
24969 uninstantiated templates and therefore should be used only in
24970 extremely limited situations. ONLY_CURRENT_P restricts this
24971 peering to the currently open classes hierarchy (which is required
24972 when comparing types). */
24974 tree
24976 {
24977 tree scope;
24978 tree name;
24979 tree decl;
24981 tree pushed_scope;
24982 tree result;
24987 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24988 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24989 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24990 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24991 identifier of the TYPENAME_TYPE anymore.
24992 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24993 TYPENAME_TYPE instead, we avoid messing up with a possible
24994 typedef variant case. */
24997 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24998 it first before we can figure out what NAME refers to. */
25000 {
25002 /* Given a class template A with a dependent base with nested type C,
25003 typedef typename A::C::C C will land us here, as trying to resolve
25004 the initial A::C leads to the local C typedef, which leads back to
25005 A::C::C. So we break the recursion now. */
25007 else
25009 }
25010 /* If we don't know what SCOPE refers to, then we cannot resolve the
25011 TYPENAME_TYPE. */
25014 /* If this is a typedef, we don't want to look inside (c++/11987). */
25017 /* If SCOPE isn't the template itself, it will not have a valid
25018 TYPE_FIELDS list. */
25020 /* scope is either the template itself or a compatible instantiation
25021 like X<T>, so look up the name in the original template. */
25023 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
25025 /* If scope has no fields, it can't be a current instantiation. Check this
25026 before currently_open_class to avoid infinite recursion (71515). */
25029 /* If the SCOPE is not the current instantiation, there's no reason
25030 to look inside it. */
25033 /* Enter the SCOPE so that name lookup will be resolved as if we
25034 were in the class definition. In particular, SCOPE will no
25035 longer be considered a dependent type. */
25037 /* Look up the declaration. */
25039 tf_warning_or_error);
25043 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
25044 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
25050 {
25054 }
25057 {
25058 /* Obtain the template and the arguments. */
25061 {
25062 /* We get here with a plain identifier because a previous tentative
25063 parse of the nested-name-specifier as part of a ptr-operator saw
25064 ::template X<A>. The use of ::template is necessary in a
25065 ptr-operator, but wrong in a declarator-id.
25067 [temp.names]: In a qualified-id of a declarator-id, the keyword
25068 template shall not appear at the top level. */
25072 }
25074 /* Instantiate the template. */
25080 }
25082 /* Leave the SCOPE. */
25086 /* If we failed to resolve it, return the original typename. */
25090 /* If lookup found a typename type, resolve that too. */
25092 {
25093 /* Ill-formed programs can cause infinite recursion here, so we
25094 must catch that. */
25098 }
25100 /* Qualify the resulting type. */
25106 }
25108 /* EXPR is an expression which is not type-dependent. Return a proxy
25109 for EXPR that can be used to compute the types of larger
25110 expressions containing EXPR. */
25112 tree
25114 {
25116 tree inner_expr;
25118 /* When checking, try to get a constant value for all non-dependent
25119 expressions in order to expose bugs in *_dependent_expression_p
25120 and constexpr. This can affect code generation, see PR70704, so
25121 only do this for -fchecking=2. */
25124 /* Don't do this during nsdmi parsing as it can lead to
25125 unexpected recursive instantiations. */
25127 /* Don't do this during concept expansion either and for
25128 the same reason. */
25134 /* Preserve OVERLOADs; the functions must be available to resolve
25135 types. */
25146 /* There is no need to return a proxy for a variable. */
25149 /* Preserve string constants; conversions from string constants to
25150 "char *" are allowed, even though normally a "const char *"
25151 cannot be used to initialize a "char *". */
25154 /* Preserve void and arithmetic constants, as an optimization -- there is no
25155 reason to create a new node. */
25160 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
25161 There is at least one place where we want to know that a
25162 particular expression is a throw-expression: when checking a ?:
25163 expression, there are special rules if the second or third
25164 argument is a throw-expression. */
25168 /* Don't wrap an initializer list, we need to be able to look inside. */
25172 /* Don't wrap a dummy object, we need to be able to test for it. */
25191 /* If the type is unknown, it can't really be non-dependent */
25194 /* Otherwise, build a NON_DEPENDENT_EXPR. */
25196 }
25198 /* ARGS is a vector of expressions as arguments to a function call.
25199 Replace the arguments with equivalent non-dependent expressions.
25200 This modifies ARGS in place. */
25202 void
25204 {
25206 tree arg;
25209 {
25213 }
25214 }
25216 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
25217 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
25218 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
25220 static tree
25222 {
25236 }
25238 tree
25240 {
25242 }
25244 tree
25246 {
25248 }
25250 /* Return a C++17 deduction placeholder for class template TMPL. */
25252 tree
25254 {
25258 }
25260 /* True iff T is a C++17 class template deduction placeholder. */
25262 bool
25264 {
25266 }
25268 /* Make a "constrained auto" type-specifier. This is an
25269 auto type with constraints that must be associated after
25270 deduction. The constraint is formed from the given
25271 CONC and its optional sequence of arguments, which are
25272 non-null if written as partial-concept-id. */
25274 tree
25276 {
25279 /* Build the constraint. */
25287 /* Our canonical type depends on the constraint. */
25290 /* Attach the constraint to the type declaration. */
25293 }
25295 /* Given type ARG, return std::initializer_list<ARG>. */
25297 static tree
25299 {
25303 {
25307 "deducing from brace-enclosed initializer list"
25311 }
25317 }
25319 /* Replace auto in TYPE with std::initializer_list<auto>. */
25321 static tree
25323 {
25330 }
25332 /* Hash traits for hashing possibly constrained 'auto'
25333 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
25336 {
25339 };
25341 /* Hash the 'auto' T. */
25343 inline hashval_t
25345 {
25347 /* Matching constrained-type-specifiers denote the same template
25348 parameter, so hash the constraint. */
25350 else
25351 /* But unconstrained autos are all separate, so just hash the pointer. */
25353 }
25355 /* Compare two 'auto's. */
25359 {
25366 /* Two unconstrained autos are distinct. */
25371 }
25373 /* for_each_template_parm callback for extract_autos: if t is a (possibly
25374 constrained) auto, add it to the vector. */
25376 static int
25378 {
25381 {
25382 /* All the autos were built with index 0; fix that up now. */
25386 /* If this is a repeated constrained-type-specifier, use the index we
25387 chose before. */
25389 else
25390 {
25391 /* Otherwise this is new, so use the current count. */
25394 }
25396 }
25398 /* Always keep walking. */
25400 }
25402 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
25403 says they can appear anywhere in the type. */
25405 static tree
25407 {
25416 {
25421 }
25424 }
25426 /* The stem for deduction guide names. */
25429 /* Return the name for a deduction guide for class template TMPL. */
25431 tree
25433 {
25444 }
25446 /* True if NAME is the name of a deduction guide. */
25448 bool
25450 {
25454 }
25456 /* True if FN is a deduction guide. */
25458 bool
25460 {
25465 }
25467 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
25469 bool
25471 {
25478 }
25480 /* True if FN is a guide generated from a constructor template. */
25482 bool
25484 {
25492 }
25494 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
25495 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
25496 template parameter types. Note that the handling of template template
25497 parameters relies on current_template_parms being set appropriately for the
25498 new template. */
25500 static tree
25503 {
25506 tree newtype;
25509 {
25516 }
25517 else
25521 tree newdecl
25526 tree newidx;
25529 {
25539 {
25544 // First create a copy (ttargs) of tsubst_args with an
25545 // additional level for the template template parameter's own
25546 // template parameters (ttparms).
25547 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25555 // Substitute ttargs into ttparms to fix references to
25556 // other template parameters.
25558 complain);
25559 // Now substitute again with args based on tparms, to reduce
25560 // the level of the ttparms.
25563 complain);
25564 // Finally, tack the adjusted parms onto tparms.
25566 current_template_parms);
25568 }
25569 }
25570 else
25571 {
25573 tree newconst
25585 }
25588 }
25590 /* Returns a C++17 class deduction guide template based on the constructor
25591 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25592 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25594 static tree
25596 {
25600 location_t loc;
25604 {
25608 {
25611 }
25612 else
25622 }
25623 else
25624 {
25627 fn_tmpl
25637 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25638 fully specialized args for the enclosing class. Strip those off, as
25639 the deduction guide won't have those template parameters. */
25642 /* Discard the 'this' parameter. */
25650 {
25653 /* For a member template constructor, we need to flatten the two
25654 template parameter lists into one, and then adjust the function
25655 signature accordingly. This gets...complicated. */
25658 /* For a member template we should have two levels of parms/args, one
25659 for the class and one for the constructor. We stripped
25660 specialized args for further enclosing classes above. */
25664 /* Template args for translating references to the two-level template
25665 parameters into references to the one-level template parameters we
25666 are creating. */
25671 /* Template parms for the constructor template. */
25674 /* Template parms for the class template. */
25678 /* Template parms for the deduction guide start as a copy of the
25679 template parms for the class. We set current_template_parms for
25680 lookup_template_class_1. */
25686 /* Now we need to rewrite the constructor parms to append them to the
25687 class parms. */
25689 {
25704 }
25706 /* Now we have a final set of template parms to substitute into the
25707 function signature. */
25716 }
25718 }
25721 {
25722 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25726 }
25730 FUNCTION_DECL,
25747 }
25749 /* Deduce template arguments for the class template placeholder PTYPE for
25750 template TMPL based on the initializer INIT, and return the resulting
25751 type. */
25753 static tree
25755 tsubst_flags_t complain)
25756 {
25758 {
25759 /* We should have handled this in the caller. */
25765 }
25776 {
25779 {
25780 /* As an exception, the first phase in 16.3.1.7 (considering the
25781 initializer list as a single argument) is omitted if the
25782 initializer list consists of a single expression of type cv U,
25783 where U is a specialization of C or a class derived from a
25784 specialization of C. */
25795 }
25798 else
25800 }
25801 else
25812 /* Prune explicit deduction guides in copy-initialization context. */
25814 {
25820 {
25821 /* Found a nonconverting guide, prune the candidates. */
25828 }
25829 }
25834 {
25837 }
25840 // FIXME cache artificial deduction guides
25842 {
25847 else
25851 }
25855 /* If this is list-initialization and the class has a list constructor, first
25856 try deducing from the list as a single argument, as [over.match.list]. */
25860 {
25864 }
25866 {
25872 {
25873 /* That didn't work, now try treating the list as a sequence of
25874 arguments. */
25877 }
25878 }
25880 /* Maybe generate an implicit deduction guide. */
25882 {
25886 /* Generate a copy guide. */
25889 /* Generate a default guide. */
25893 {
25896 }
25897 }
25900 {
25902 " of %qT, as it has no non-explicit deduction guides or "
25905 }
25907 {
25911 }
25914 {
25918 }
25921 {
25931 }
25936 }
25938 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25939 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25941 tree
25943 {
25945 tf_warning_or_error,
25946 adc_unspecified);
25947 }
25949 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25950 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25951 The CONTEXT determines the context in which auto deduction is performed
25952 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25953 OUTER_TARGS are used during template argument deduction
25954 (context == adc_unify) to properly substitute the result, and is ignored
25955 in other contexts.
25957 For partial-concept-ids, extra args may be appended to the list of deduced
25958 template arguments prior to determining constraint satisfaction. */
25960 tree
25964 {
25965 tree targs;
25972 /* Defining a subset of type-dependent expressions that we can deduce
25973 from ahead of time isn't worth the trouble. */
25976 /* Similarly, we can't deduce from another undeduced decl. */
25981 /* C++17 class template argument deduction. */
25985 /* Nothing we can do with this, even in deduction context. */
25988 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25989 with either a new invented type template parameter U or, if the
25990 initializer is a braced-init-list (8.5.4), with
25991 std::initializer_list<U>. */
25993 {
25998 else
25999 {
26001 {
26005 "for deduction to %<std::initializer_list%>, use copy-"
26007 }
26009 }
26010 }
26021 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
26022 and initializer has array type, deduce cv-qualified array type. */
26024 complain);
26026 {
26035 {
26039 }
26040 }
26041 else
26042 {
26044 tree tparms;
26048 else
26049 {
26053 }
26060 {
26062 /* Try again at instantiation time. */
26066 /* If type is error_mark_node a diagnostic must have been
26067 emitted by now. Also, having a mention to '<type error>'
26068 in the diagnostic is not really useful to the user. */
26069 {
26073 else
26078 }
26080 }
26081 }
26083 /* Check any placeholder constraints against the deduced type. */
26086 {
26087 /* Use the deduced type to check the associated constraints. If we
26088 have a partial-concept-id, rebuild the argument list so that
26089 we check using the extra arguments. */
26093 {
26096 }
26097 else
26100 {
26102 {
26104 {
26122 }
26124 }
26126 }
26127 }
26133 }
26135 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
26136 result. */
26138 tree
26140 {
26142 {
26148 /* In an abbreviated function template we didn't know we were dealing
26149 with a function template when we saw the auto return type, so update
26150 it to have the correct level. */
26152 }
26154 }
26156 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
26157 'decltype(auto)' or a deduced class template. */
26159 bool
26161 {
26167 else
26169 }
26171 /* for_each_template_parm callback for type_uses_auto. */
26173 int
26175 {
26177 }
26179 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
26180 a use of `auto'. Returns NULL_TREE otherwise. */
26182 tree
26184 {
26188 {
26189 /* The Concepts TS allows multiple autos in one type-specifier; just
26190 return the first one we find, do_auto_deduction will collect all of
26191 them. */
26195 else
26197 }
26198 else
26200 }
26202 /* For a given template T, return the vector of typedefs referenced
26203 in T for which access check is needed at T instantiation time.
26204 T is either a FUNCTION_DECL or a RECORD_TYPE.
26205 Those typedefs were added to T by the function
26206 append_type_to_template_for_access_check. */
26210 {
26211 tree ti;
26222 {
26227 }
26230 }
26232 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
26233 tied to T. That list of typedefs will be access checked at
26234 T instantiation time.
26235 T is either a FUNCTION_DECL or a RECORD_TYPE.
26236 TYPE_DECL is a TYPE_DECL node representing a typedef.
26237 SCOPE is the scope through which TYPE_DECL is accessed.
26238 LOCATION is the location of the usage point of TYPE_DECL.
26240 This function is a subroutine of
26241 append_type_to_template_for_access_check. */
26243 static void
26245 tree type_decl,
26246 tree scope,
26247 location_t location)
26248 {
26249 qualified_typedef_usage_t typedef_usage;
26250 tree ti;
26257 && type_decl
26271 }
26273 /* Append TYPE_DECL to the template TEMPL.
26274 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
26275 At TEMPL instanciation time, TYPE_DECL will be checked to see
26276 if it can be accessed through SCOPE.
26277 LOCATION is the location of the usage point of TYPE_DECL.
26279 e.g. consider the following code snippet:
26281 class C
26282 {
26283 typedef int myint;
26284 };
26286 template<class U> struct S
26287 {
26288 C::myint mi; // <-- usage point of the typedef C::myint
26289 };
26291 S<char> s;
26293 At S<char> instantiation time, we need to check the access of C::myint
26294 In other words, we need to check the access of the myint typedef through
26295 the C scope. For that purpose, this function will add the myint typedef
26296 and the scope C through which its being accessed to a list of typedefs
26297 tied to the template S. That list will be walked at template instantiation
26298 time and access check performed on each typedefs it contains.
26299 Note that this particular code snippet should yield an error because
26300 myint is private to C. */
26302 void
26304 tree type_decl,
26305 tree scope,
26306 location_t location)
26307 {
26313 /* Make sure we don't append the type to the template twice. */
26320 }
26322 /* Convert the generic type parameters in PARM that match the types given in the
26323 range [START_IDX, END_IDX) from the current_template_parms into generic type
26324 packs. */
26326 tree
26328 {
26339 {
26340 /* Create a distinct parameter pack type from the current parm and add it
26341 to the replacement args to tsubst below into the generic function
26342 parameter. */
26357 }
26363 /* If there are more levels then build up the replacement with the outer
26364 template parms. */
26368 replacement);
26371 }
26373 /* Entries in the decl_constraint hash table. */
26375 {
26376 tree decl;
26377 tree ci;
26378 };
26380 /* Hashing function and equality for constraint entries. */
26382 {
26384 {
26386 }
26389 {
26391 }
26392 };
26394 /* A mapping from declarations to constraint information. Note that
26395 both templates and their underlying declarations are mapped to the
26396 same constraint information.
26398 FIXME: This is defined in pt.c because garbage collection
26399 code is not being generated for constraint.cc. */
26403 /* Returns the template constraints of declaration T. If T is not
26404 constrained, return NULL_TREE. Note that T must be non-null. */
26406 tree
26408 {
26419 else
26421 }
26423 /* Associate the given constraint information CI with the declaration
26424 T. If T is a template, then the constraints are associated with
26425 its underlying declaration. Don't build associations if CI is
26426 NULL_TREE. */
26428 void
26430 {
26442 }
26444 /* Remove the associated constraints of the declaration T. */
26446 void
26448 {
26457 }
26459 /* Memoized satisfaction results for declarations. This
26460 maps the pair (constraint_info, arguments) to the result computed
26461 by constraints_satisfied_p. */
26464 {
26465 tree ci;
26466 tree args;
26467 tree result;
26468 };
26470 /* Hashing function and equality for constraint entries. */
26473 {
26475 {
26478 }
26481 {
26483 }
26484 };
26486 /* Memoized satisfaction results for concept checks. */
26489 {
26490 tree tmpl;
26491 tree args;
26492 tree result;
26493 };
26495 /* Hashing function and equality for constraint entries. */
26498 {
26500 {
26502 }
26505 {
26510 }
26511 };
26516 /* Search for a memoized satisfaction result. Returns one of the
26517 truth value nodes if previously memoized, or NULL_TREE otherwise. */
26519 tree
26521 {
26526 else
26528 }
26530 /* Memoize the result of a satisfication test. Returns the saved result. */
26532 tree
26534 {
26541 }
26543 /* Search for a memoized satisfaction result for a concept. */
26545 tree
26547 {
26552 else
26554 }
26556 /* Memoize the result of a concept check. Returns the saved result. */
26558 tree
26560 {
26567 }
26571 /* Returns a prior concept specialization. This returns the substituted
26572 and normalized constraints defined by the concept. */
26574 tree
26576 {
26581 else
26583 }
26585 /* Save a concept expansion for later. */
26587 tree
26589 {
26596 }
26598 static hashval_t
26600 {
26609 }
26611 /* Compare the constraints of two subsumption entries. The LEFT1 and
26612 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26613 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26615 static bool
26617 {
26625 }
26627 /* Key/value pair for learning and memoizing subsumption results. This
26628 associates a pair of check constraints (including arguments) with
26629 a boolean value indicating the result. */
26632 {
26633 tree t1;
26634 tree t2;
26636 };
26638 /* Hashing function and equality for constraint entries. */
26641 {
26643 {
26645 }
26648 {
26653 }
26654 };
26658 /* Search for a previously cached subsumption result. */
26662 {
26667 else
26669 }
26671 /* Save a subsumption result. */
26673 bool
26675 {
26682 }
26684 /* Set up the hash table for constraint association. */
26686 void
26688 {
26697 }
26699 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26700 0..N-1. */
26702 void
26704 {
26707 integer_type_node,
26708 NULL_TREE),
26712 }
26714 /* Set up the hash tables for template instantiations. */
26716 void
26718 {
26724 }
26726 /* Print stats about the template hash tables for -fstats. */
26728 void
26730 {
26739 }
26741 #if CHECKING_P
26745 /* Verify that build_non_dependent_expr () works, for various expressions,
26746 and that location wrappers don't affect the results. */
26748 static void
26750 {
26753 /* Verify constants, without and with location wrappers. */
26770 }
26772 /* Verify that type_dependent_expression_p () works correctly, even
26773 in the presence of location wrapper nodes. */
26775 static void
26777 {
26782 /* If no templates are involved, nothing is type-dependent. */
26788 /* Within a template, an unresolved name is always type-dependent. */
26791 /* Ensure it copes with NULL_TREE and errors. */
26795 /* A USING_DECL in a template should be type-dependent, even if wrapped
26796 with a location wrapper (PR c++/83799). */
26805 }
26807 /* Run all of the selftests within this file. */
26809 void
26811 {
26814 }