| blob | d5ab93985a3f0192c4749227c33b2f0adc48410a |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2017 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
45 /* The type of functions taking a tree, and some additional data, and
46 returning an int. */
49 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
50 instantiations have been deferred, either because their definitions
51 were not yet available, or because we were putting off doing the work. */
55 };
70 /* Live only within one (recursive) call to tsubst_expr. We use
71 this to pass the statement expression node from the STMT_EXPR
72 to the EXPR_STMT that is its result. */
75 // -------------------------------------------------------------------------- //
76 // Local Specialization Stack
77 //
78 // Implementation of the RAII helper for creating new local
79 // specializations.
82 {
85 else
87 }
90 {
93 }
95 /* True if we've recursed into fn_type_unification too many times. */
99 {
100 tree tmpl;
101 tree args;
102 tree spec;
103 };
106 {
109 };
115 /* Contains canonical template parameter types. The vector is indexed by
116 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
117 TREE_LIST, whose TREE_VALUEs contain the canonical template
118 parameters of various types and levels. */
121 #define UNIFY_ALLOW_NONE 0
122 #define UNIFY_ALLOW_MORE_CV_QUAL 1
123 #define UNIFY_ALLOW_LESS_CV_QUAL 2
124 #define UNIFY_ALLOW_DERIVED 4
125 #define UNIFY_ALLOW_INTEGER 8
126 #define UNIFY_ALLOW_OUTER_LEVEL 16
127 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
128 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
131 tbr_incomplete_type,
132 tbr_ambiguous_baseclass,
133 tbr_success
134 };
157 tree);
214 location_t);
225 /* Make the current scope suitable for access checking when we are
226 processing T. T can be FUNCTION_DECL for instantiated function
227 template, VAR_DECL for static member variable, or TYPE_DECL for
228 alias template (needed by instantiate_decl). */
230 static void
232 {
240 else
244 {
245 saved_access_scope = tree_cons
248 }
249 }
251 /* Restore the scope set up by push_access_scope. T is the node we
252 are processing. */
254 static void
256 {
258 {
261 }
265 else
267 }
269 /* Do any processing required when DECL (a member template
270 declaration) is finished. Returns the TEMPLATE_DECL corresponding
271 to DECL, unless it is a specialization, in which case the DECL
272 itself is returned. */
274 tree
276 {
283 {
284 tree type;
292 {
296 }
298 }
302 {
304 {
307 }
308 else
310 }
311 else
315 }
317 /* Create a template info node. */
319 tree
321 {
326 }
328 /* Return the template info node corresponding to T, whatever T is. */
330 tree
332 {
354 }
356 /* Returns the template nesting level of the indicated class TYPE.
358 For example, in:
359 template <class T>
360 struct A
361 {
362 template <class U>
363 struct B {};
364 };
366 A<T>::B<U> has depth two, while A<T> has depth one.
367 Both A<T>::B<int> and A<int>::B<U> have depth one, if
368 they are instantiations, not specializations.
370 This function is guaranteed to return 0 if passed NULL_TREE so
371 that, for example, `template_class_depth (current_class_type)' is
372 always safe. */
374 int
376 {
380 {
391 else
393 }
396 }
398 /* Subroutine of maybe_begin_member_template_processing.
399 Returns true if processing DECL needs us to push template parms. */
401 static bool
403 {
409 }
411 /* Subroutine of maybe_begin_member_template_processing.
412 Push the template parms in PARMS, starting from LEVELS steps into the
413 chain, and ending at the beginning, since template parms are listed
414 innermost first. */
416 static void
418 {
426 current_template_parms
432 NULL);
434 {
443 {
450 /* Push the CONST_DECL. */
456 }
457 }
458 }
460 /* Restore the template parameter context for a member template, a
461 friend template defined in a class definition, or a non-template
462 member of template class. */
464 void
466 {
467 tree parms;
472 {
475 /* Disregard full specializations (c++/60999). */
478 }
481 {
486 {
489 }
492 }
494 /* Remember how many levels of template parameters we pushed so that
495 we can pop them later. */
497 }
499 /* Undo the effects of maybe_begin_member_template_processing. */
501 void
503 {
512 {
516 }
517 }
519 /* Return a new template argument vector which contains all of ARGS,
520 but has as its innermost set of arguments the EXTRA_ARGS. */
522 static tree
524 {
525 tree new_args;
543 }
545 /* Like add_to_template_args, but only the outermost ARGS are added to
546 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
547 (EXTRA_ARGS) levels are added. This function is used to combine
548 the template arguments from a partial instantiation with the
549 template arguments used to attain the full instantiation from the
550 partial instantiation. */
552 static tree
554 {
555 tree new_args;
557 /* If there are more levels of EXTRA_ARGS than there are ARGS,
558 something very fishy is going on. */
561 /* If *all* the new arguments will be the EXTRA_ARGS, just return
562 them. */
566 /* For the moment, we make ARGS look like it contains fewer levels. */
571 /* Now, we restore ARGS to its full dimensions. */
575 }
577 /* Return the N levels of innermost template arguments from the ARGS. */
579 tree
581 {
582 tree new_args;
588 /* If N is 1, just return the innermost set of template arguments. */
592 /* If we're not removing anything, just return the arguments we were
593 given. */
599 /* Make a new set of arguments, not containing the outer arguments. */
606 }
608 /* The inverse of get_innermost_template_args: Return all but the innermost
609 EXTRA_LEVELS levels of template arguments from the ARGS. */
611 static tree
613 {
614 tree new_args;
620 /* If N is 1, just return the outermost set of template arguments. */
624 /* If we're not removing anything, just return the arguments we were
625 given. */
630 /* Make a new set of arguments, not containing the inner arguments. */
637 }
639 /* We've got a template header coming up; push to a new level for storing
640 the parms. */
642 void
644 {
645 /* We use a non-tag-transparent scope here, which causes pushtag to
646 put tags in this scope, rather than in the enclosing class or
647 namespace scope. This is the right thing, since we want
648 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
649 global template class, push_template_decl handles putting the
650 TEMPLATE_DECL into top-level scope. For a nested template class,
651 e.g.:
653 template <class T> struct S1 {
654 template <class T> struct S2 {};
655 };
657 pushtag contains special code to insert the TEMPLATE_DECL for S2
658 at the right scope. */
664 /* Add a dummy parameter level while we process the parameter list. */
665 current_template_parms
668 current_template_parms);
669 }
671 /* This routine is called when a specialization is declared. If it is
672 invalid to declare a specialization here, an error is reported and
673 false is returned, otherwise this routine will return true. */
675 static bool
677 {
680 /* [temp.expl.spec]
682 An explicit specialization shall be declared in the namespace of
683 which the template is a member, or, for member templates, in the
684 namespace of which the enclosing class or enclosing class
685 template is a member. An explicit specialization of a member
686 function, member class or static data member of a class template
687 shall be declared in the namespace of which the class template
688 is a member. */
690 {
693 }
695 /* [temp.expl.spec]
697 In an explicit specialization declaration for a member of a class
698 template or a member template that appears in namespace scope,
699 the member template and some of its enclosing class templates may
700 remain unspecialized, except that the declaration shall not
701 explicitly specialize a class member template if its enclosing
702 class templates are not explicitly specialized as well. */
704 {
707 }
710 }
712 /* We've just seen template <>. */
714 bool
716 {
720 }
722 /* Called at then end of processing a declaration preceded by
723 template<>. */
725 void
727 {
730 }
732 /* Any template <>'s that we have seen thus far are not referring to a
733 function specialization. */
735 void
737 {
740 }
742 /* We've just seen a template header. If SPECIALIZATION is nonzero,
743 it was of the form template <>. */
745 static void
747 {
749 template_header_count++;
750 }
752 /* We're beginning an explicit instantiation. */
754 void
756 {
759 }
762 void
764 {
767 }
769 /* An explicit specialization or partial specialization of TMPL is being
770 declared. Check that the namespace in which the specialization is
771 occurring is permissible. Returns false iff it is invalid to
772 specialize TMPL in the current namespace. */
774 static bool
776 {
779 /* [tmpl.expl.spec]
781 An explicit specialization shall be declared in a namespace enclosing the
782 specialized template. An explicit specialization whose declarator-id is
783 not qualified shall be declared in the nearest enclosing namespace of the
784 template, or, if the namespace is inline (7.3.1), any namespace from its
785 enclosing namespace set. */
788 {
791 }
794 /* Same or enclosing namespace. */
796 else
797 {
803 }
804 }
806 /* SPEC is an explicit instantiation. Check that it is valid to
807 perform this explicit instantiation in the current namespace. */
809 static void
811 {
812 tree ns;
814 /* DR 275: An explicit instantiation shall appear in an enclosing
815 namespace of its template. */
821 }
823 // Returns the type of a template specialization only if that
824 // specialization needs to be defined. Otherwise (e.g., if the type has
825 // already been defined), the function returns NULL_TREE.
826 static tree
828 {
829 // An implicit instantiation of an incomplete type implies
830 // the definition of a new class template.
831 //
832 // template<typename T>
833 // struct S;
834 //
835 // template<typename T>
836 // struct S<T*>;
837 //
838 // Here, S<T*> is an implicit instantiation of S whose type
839 // is incomplete.
843 // It can also be the case that TYPE is a completed specialization.
844 // Continuing the previous example, suppose we also declare:
845 //
846 // template<typename T>
847 // requires Integral<T>
848 // struct S<T*>;
849 //
850 // Here, S<T*> refers to the specialization S<T*> defined
851 // above. However, we need to differentiate definitions because
852 // we intend to define a new partial specialization. In this case,
853 // we rely on the fact that the constraints are different for
854 // this declaration than that above.
855 //
856 // Note that we also get here for injected class names and
857 // late-parsed template definitions. We must ensure that we
858 // do not create new type declarations for those cases.
860 {
864 // If there are no template parameters, this cannot be a new
865 // partial template specializtion?
869 // The injected-class-name is not a new partial specialization.
873 // If the constraints are not the same as those of the primary
874 // then, we can probably create a new specialization.
878 {
882 }
884 // Also, if there's a pre-existing specialization with matching
885 // constraints, then this also isn't new.
888 {
896 }
898 // Create a new type node (and corresponding type decl)
899 // for the newly declared specialization.
904 /* We only need a separate type node for storing the definition of this
905 partial specialization; uses of S<T*> are unconstrained, so all are
906 equivalent. So keep TYPE_CANONICAL the same. */
909 // Build the corresponding type decl.
915 }
918 }
920 /* The TYPE is being declared. If it is a template type, that means it
921 is a partial specialization. Do appropriate error-checking. */
923 tree
925 {
926 tree context;
931 /* A lambda that appears in specialization context is not itself a
932 specialization. */
937 {
941 }
946 {
952 else
955 }
957 {
958 /* This is for ordinary explicit specialization and partial
959 specialization of a template class such as:
961 template <> class C<int>;
963 or:
965 template <class T> class C<T*>;
967 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
970 {
977 {
982 }
983 }
989 /* Trying to define a specialization either without a template<> header
990 or in an inappropriate place. We've already given an error, so just
991 bail now so we don't actually define the specialization. */
993 }
999 {
1000 /* This is for an explicit specialization of member class
1001 template according to [temp.expl.spec/18]:
1003 template <> template <class U> class C<int>::D;
1005 The context `C<int>' must be an implicit instantiation.
1006 Otherwise this is just a member class template declared
1007 earlier like:
1009 template <> class C<int> { template <class U> class D; };
1010 template <> template <class U> class C<int>::D;
1012 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1013 while in the second case, `C<int>::D' is a primary template
1014 and `C<T>::D' may not exist. */
1018 {
1019 tree t;
1024 {
1029 }
1031 /* Check for invalid specialization after instantiation:
1033 template <> template <> class C<int>::D<int>;
1034 template <> template <class U> class C<int>::D; */
1038 {
1042 {
1043 /* We already have a full specialization of this partial
1044 instantiation, or a full specialization has been
1045 looked up but not instantiated. Reassign it to the
1046 new member specialization template. */
1047 spec_entry elt;
1059 spec_entry **slot
1064 }
1065 else
1066 /* But if we've had an implicit instantiation, that's a
1067 problem ([temp.expl.spec]/6). */
1070 }
1072 /* Mark TYPE as a specialization. And as a result, we only
1073 have one level of template argument for the innermost
1074 class template. */
1079 }
1080 }
1082 {
1083 /* Someday C++0x may allow for enum template specialization. */
1088 else
1089 {
1092 }
1093 }
1096 }
1098 /* Returns nonzero if we can optimize the retrieval of specializations
1099 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1100 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1104 {
1107 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1108 parameter. */
1110 /* The optimized lookup depends on the fact that the
1111 template arguments for the member function template apply
1112 purely to the containing class, which is not true if the
1113 containing class is an explicit or partial
1114 specialization. */
1118 /* It is possible to have a template that is not a member
1119 template and is not a member of a template class:
1121 template <typename T>
1122 struct S { friend A::f(); };
1124 Here, the friend function is a template, but the context does
1125 not have template information. The optimized lookup relies
1126 on having ARGS be the template arguments for both the class
1127 and the function template. */
1129 }
1131 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1132 gone through coerce_template_parms by now. */
1134 static void
1136 {
1139 {
1142 {
1149 /* Allow typedefs on the type of a non-type argument, since a
1151 else
1153 }
1154 }
1156 }
1158 /* Retrieve the specialization (in the sense of [temp.spec] - a
1159 specialization is either an instantiation or an explicit
1160 specialization) of TMPL for the given template ARGS. If there is
1161 no such specialization, return NULL_TREE. The ARGS are a vector of
1162 arguments, or a vector of vectors of arguments, in the case of
1163 templates with more than one level of parameters.
1165 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1166 then we search for a partial specialization matching ARGS. This
1167 parameter is ignored if TMPL is not a class template.
1169 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1170 result is a NONTYPE_ARGUMENT_PACK. */
1172 static tree
1174 {
1184 /* There should be as many levels of arguments as there are
1185 levels of parameters. */
1194 /* Lambda functions in templates aren't instantiated normally, but through
1195 tsubst_lambda_expr. */
1197 {
1202 /* But generic lambda functions are instantiated normally, once their
1203 containing context is fully instantiated. */
1205 }
1208 {
1209 /* The template arguments actually apply to the containing
1210 class. Find the class specialization with those
1211 arguments. */
1213 tree class_specialization
1218 /* Find the instance of TMPL. */
1221 {
1224 /* using-declarations can add base methods to the method vec,
1225 and we don't want those here. */
1228 }
1230 }
1231 else
1232 {
1234 spec_entry elt;
1243 else
1251 }
1254 }
1256 /* Like retrieve_specialization, but for local declarations. */
1258 tree
1260 {
1266 }
1268 /* Returns nonzero iff DECL is a specialization of TMPL. */
1270 int
1272 {
1273 tree t;
1276 {
1282 }
1283 else
1284 {
1293 }
1296 }
1298 /* Returns nonzero iff DECL is a specialization of friend declaration
1299 FRIEND_DECL according to [temp.friend]. */
1301 bool
1303 {
1310 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1311 of a template class, we want to check if DECL is a specialization
1312 if this. */
1316 {
1317 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1320 }
1325 /* There is nothing to do if this is not a template friend. */
1332 /* [temp.friend/6]
1333 A member of a class template may be declared to be a friend of a
1334 non-template class. In this case, the corresponding member of
1335 every specialization of the class template is a friend of the
1336 class granting friendship.
1338 For example, given a template friend declaration
1340 template <class T> friend void A<T>::f();
1342 the member function below is considered a friend
1344 template <> struct A<int> {
1345 void f();
1346 };
1348 For this type of template friend, TEMPLATE_DEPTH below will be
1349 nonzero. To determine if DECL is a friend of FRIEND, we first
1350 check if the enclosing class is a specialization of another. */
1357 {
1358 /* Next, we check the members themselves. In order to handle
1359 a few tricky cases, such as when FRIEND_DECL's are
1361 template <class T> friend void A<T>::g(T t);
1362 template <class T> template <T t> friend void A<T>::h();
1364 and DECL's are
1366 void A<int>::g(int);
1367 template <int> void A<int>::h();
1369 we need to figure out ARGS, the template arguments from
1370 the context of DECL. This is required for template substitution
1371 of `T' in the function parameter of `g' and template parameter
1372 of `h' in the above examples. Here ARGS corresponds to `int'. */
1379 {
1381 {
1384 else
1386 current_depth++;
1387 }
1389 }
1392 {
1394 tree friend_type;
1395 tree decl_type;
1396 tree friend_args_type;
1397 tree decl_args_type;
1399 /* Make sure that both DECL and FRIEND_DECL are templates or
1400 non-templates. */
1406 {
1407 /* If both are templates, check template parameter list. */
1408 tree friend_parms
1413 friend_parms))
1417 }
1418 else
1426 /* Check if return types match. */
1430 /* Check if function parameter types match, ignoring the
1431 `this' parameter. */
1440 }
1441 else
1442 {
1443 /* DECL is a TYPE_DECL */
1447 /* Make sure that both DECL and FRIEND_DECL are templates or
1448 non-templates. */
1449 is_template
1456 {
1457 tree friend_parms;
1458 /* If both are templates, check the name of the two
1459 TEMPLATE_DECL's first because is_friend didn't. */
1464 /* Now check template parameter list. */
1465 friend_parms
1468 return comp_template_parms
1470 friend_parms);
1471 }
1472 else
1475 }
1476 }
1478 }
1480 /* Register the specialization SPEC as a specialization of TMPL with
1481 the indicated ARGS. IS_FRIEND indicates whether the specialization
1482 is actually just a friend declaration. Returns SPEC, or an
1483 equivalent prior declaration, if available.
1485 We also store instantiations of field packs in the hash table, even
1486 though they are not themselves templates, to make lookup easier. */
1488 static tree
1490 hashval_t hash)
1491 {
1492 tree fn;
1494 spec_entry elt;
1502 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1503 register it; we want the corresponding TEMPLATE_DECL instead.
1504 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1505 the more obvious `uses_template_parms (spec)' to avoid problems
1506 with default function arguments. In particular, given
1507 something like this:
1509 template <class T> void f(T t1, T t = T())
1511 the default argument expression is not substituted for in an
1512 instantiation unless and until it is actually needed. */
1516 /* We don't put these specializations in the hash table, but we might
1517 want to give an error about a mismatch. */
1519 else
1520 {
1528 slot =
1532 else
1534 }
1536 /* We can sometimes try to re-register a specialization that we've
1537 already got. In particular, regenerate_decl_from_template calls
1538 duplicate_decls which will update the specialization list. But,
1539 we'll still get called again here anyhow. It's more convenient
1540 to simply allow this than to try to prevent it. */
1544 {
1546 {
1549 {
1551 fn);
1553 }
1554 else
1555 {
1556 tree clone;
1557 /* This situation should occur only if the first
1558 specialization is an implicit instantiation, the
1559 second is an explicit specialization, and the
1560 implicit instantiation has not yet been used. That
1561 situation can occur if we have implicitly
1562 instantiated a member function and then specialized
1563 it later.
1565 We can also wind up here if a friend declaration that
1566 looked like an instantiation turns out to be a
1567 specialization:
1569 template <class T> void foo(T);
1570 class S { friend void foo<>(int) };
1571 template <> void foo(int);
1573 We transform the existing DECL in place so that any
1574 pointers to it become pointers to the updated
1575 declaration.
1577 If there was a definition for the template, but not
1578 for the specialization, we want this to look as if
1579 there were no definition, and vice versa. */
1582 /* The call to duplicate_decls will have applied
1583 [temp.expl.spec]:
1585 An explicit specialization of a function template
1586 is inline only if it is explicitly declared to be,
1587 and independently of whether its function template
1588 is.
1590 to the primary function; now copy the inline bits to
1591 the various clones. */
1593 {
1600 }
1604 }
1605 }
1607 {
1610 /* We've already complained in duplicate_decls. */
1614 /* Dup decl failed, but this is a new definition. Set the
1615 line number so any errors match this new
1616 definition. */
1620 }
1621 }
1625 /* A specialization must be declared in the same namespace as the
1626 template it is specializing. */
1632 {
1641 /* If TMPL is a forward declaration of a template function, keep a list
1642 of all specializations in case we need to reassign them to a friend
1643 template later in tsubst_friend_function.
1645 Also keep a list of all variable template instantiations so that
1646 process_partial_specialization can check whether a later partial
1647 specialization would have used it. */
1650 }
1653 }
1655 /* Returns true iff two spec_entry nodes are equivalent. */
1659 bool
1661 {
1668 /* tmpl could be a FIELD_DECL for a capture pack. */
1672 {
1673 /* Partial specializations of a variable template can be distinguished by
1674 constraints. */
1678 }
1682 }
1684 /* Returns a hash for a template TMPL and template arguments ARGS. */
1686 static hashval_t
1688 {
1691 }
1693 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1694 ignoring SPEC. */
1696 hashval_t
1698 {
1700 }
1702 /* Recursively calculate a hash value for a template argument ARG, for use
1703 in the hash tables of template specializations. */
1705 hashval_t
1707 {
1727 {
1735 {
1740 }
1762 {
1766 {
1769 }
1771 }
1775 {
1778 }
1789 val = iterative_hash_template_arg
1801 val);
1803 val);
1812 /* A lambda can't appear in a template arg, but don't crash on
1813 erroneous input. */
1825 /* Now hash operands as usual. */
1830 }
1833 {
1836 {
1837 // We want an alias specialization that survived strip_typedefs
1838 // to hash differently from its TYPE_CANONICAL, to avoid hash
1839 // collisions that compare as different in template_args_equal.
1840 // These could be dependent specializations that strip_typedefs
1841 // left alone, or untouched specializations because
1842 // coerce_template_parms returns the unconverted template
1843 // arguments if it sees incomplete argument packs.
1846 }
1849 val);
1852 /* Otherwise just compare the types during lookup. */
1861 {
1866 }
1867 }
1870 }
1872 /* Unregister the specialization SPEC as a specialization of TMPL.
1873 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1874 if the SPEC was listed as a specialization of TMPL.
1876 Note that SPEC has been ggc_freed, so we can't look inside it. */
1878 bool
1880 {
1882 spec_entry elt;
1890 {
1895 }
1898 }
1900 /* Like register_specialization, but for local declarations. We are
1901 registering SPEC, an instantiation of TMPL. */
1903 void
1905 {
1907 }
1909 /* TYPE is a class type. Returns true if TYPE is an explicitly
1910 specialized class. */
1912 bool
1914 {
1918 }
1920 /* Print the list of functions at FNS, going through all the overloads
1921 for each element of the list. Alternatively, FNS can not be a
1922 TREE_LIST, in which case it will be printed together with all the
1923 overloads.
1925 MORE and *STR should respectively be FALSE and NULL when the function
1926 is called from the outside. They are used internally on recursive
1927 calls. print_candidates manages the two parameters and leaves NULL
1928 in *STR when it ends. */
1930 static void
1932 {
1936 else
1938 {
1944 {
1947 else
1950 }
1952 }
1953 }
1955 /* Print the list of candidate FNS in an error message. FNS can also
1956 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1958 void
1960 {
1964 }
1966 /* Get a (possibly) constrained template declaration for the
1967 purpose of ordering candidates. */
1968 static tree
1970 {
1976 }
1978 /* Among candidates having the same signature, return the
1979 most constrained or NULL_TREE if there is no best candidate.
1980 If the signatures of candidates vary (e.g., template
1981 specialization vs. member function), then there can be no
1982 most constrained.
1984 Note that we don't compare constraints on the functions
1985 themselves, but rather those of their templates. */
1986 static tree
1988 {
1989 // Try to find the best candidate in a first pass.
1992 {
1999 }
2001 // Verify that the champ is better than previous candidates.
2006 }
2009 }
2012 /* Returns the template (one of the functions given by TEMPLATE_ID)
2013 which can be specialized to match the indicated DECL with the
2014 explicit template args given in TEMPLATE_ID. The DECL may be
2015 NULL_TREE if none is available. In that case, the functions in
2016 TEMPLATE_ID are non-members.
2018 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2019 specialization of a member template.
2021 The TEMPLATE_COUNT is the number of references to qualifying
2022 template classes that appeared in the name of the function. See
2023 check_explicit_specialization for a more accurate description.
2025 TSK indicates what kind of template declaration (if any) is being
2026 declared. TSK_TEMPLATE indicates that the declaration given by
2027 DECL, though a FUNCTION_DECL, has template parameters, and is
2028 therefore a template function.
2030 The template args (those explicitly specified and those deduced)
2031 are output in a newly created vector *TARGS_OUT.
2033 If it is impossible to determine the result, an error message is
2034 issued. The error_mark_node is returned to indicate failure. */
2036 static tree
2038 tree decl,
2042 tmpl_spec_kind tsk)
2043 {
2044 tree fns;
2045 tree targs;
2046 tree explicit_targs;
2049 /* A TREE_LIST of templates of which DECL may be a specialization.
2050 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2051 corresponding TREE_PURPOSE is the set of template arguments that,
2052 when used to instantiate the template, would produce a function
2053 with the signature of DECL. */
2063 /* We shouldn't be specializing a member template of an
2064 unspecialized class template; we already gave an error in
2065 check_specialization_scope, now avoid crashing. */
2068 {
2071 }
2079 /* Check for baselinks. */
2084 {
2087 }
2089 {
2092 }
2094 /* Count the number of template headers specified for this
2095 specialization. */
2105 {
2108 tf_warning_or_error,
2112 }
2114 {
2118 {
2119 tree decl_arg_types;
2120 tree fn_arg_types;
2121 tree insttype;
2123 /* In case of explicit specialization, we need to check if
2124 the number of template headers appearing in the specialization
2125 is correct. This is usually done in check_explicit_specialization,
2126 but the check done there cannot be exhaustive when specializing
2127 member functions. Consider the following code:
2129 template <> void A<int>::f(int);
2130 template <> template <> void A<int>::f(int);
2132 Assuming that A<int> is not itself an explicit specialization
2133 already, the first line specializes "f" which is a non-template
2134 member function, whilst the second line specializes "f" which
2135 is a template member function. So both lines are syntactically
2136 correct, and check_explicit_specialization does not reject
2137 them.
2139 Here, we can do better, as we are matching the specialization
2140 against the declarations. We count the number of template
2141 headers, and we check if they match TEMPLATE_COUNT + 1
2142 (TEMPLATE_COUNT is the number of qualifying template classes,
2143 plus there must be another header for the member template
2144 itself).
2146 Notice that if header_count is zero, this is not a
2147 specialization but rather a template instantiation, so there
2148 is no check we can perform here. */
2152 /* Check that the number of template arguments at the
2153 innermost level for DECL is the same as for FN. */
2161 /* DECL might be a specialization of FN. */
2165 /* For a non-static member function, we need to make sure
2166 that the const qualification is the same. Since
2167 get_bindings does not try to merge the "this" parameter,
2168 we must do the comparison explicitly. */
2174 /* Skip the "this" parameter and, for constructors of
2175 classes with virtual bases, the VTT parameter. A
2176 full specialization of a constructor will have a VTT
2177 parameter, but a template never will. */
2178 decl_arg_types
2180 fn_arg_types
2183 /* Function templates cannot be specializations; there are
2184 no partial specializations of functions. Therefore, if
2185 the type of DECL does not match FN, there is no
2186 match.
2188 Note that it should never be the case that we have both
2189 candidates added here, and for regular member functions
2190 below. */
2192 {
2196 }
2198 /* See whether this function might be a specialization of this
2199 template. Suppress access control because we might be trying
2200 to make this specialization a friend, and we have already done
2201 access control for the declaration of the specialization. */
2207 /* We cannot deduce template arguments that when used to
2208 specialize TMPL will produce DECL. */
2211 /* Remove, from the set of candidates, all those functions
2212 whose constraints are not satisfied. */
2216 // Then, try to form the new function type.
2220 fn_arg_types
2225 /* Save this template, and the arguments deduced. */
2227 }
2229 /* FN is an ordinary member function, and we need a
2230 specialization of a member template. */
2231 ;
2233 /* We can get IDENTIFIER_NODEs here in certain erroneous
2234 cases. */
2235 ;
2237 /* This is just an ordinary non-member function. Nothing can
2238 be a specialization of that. */
2239 ;
2241 /* Cannot specialize functions that are created implicitly. */
2242 ;
2243 else
2244 {
2245 tree decl_arg_types;
2247 /* This is an ordinary member function. However, since
2248 we're here, we can assume its enclosing class is a
2249 template class. For example,
2251 template <typename T> struct S { void f(); };
2252 template <> void S<int>::f() {}
2254 Here, S<int>::f is a non-template, but S<int> is a
2255 template class. If FN has the same type as DECL, we
2256 might be in business. */
2259 /* Its enclosing class is an explicit specialization
2260 of a template class. This is not a candidate. */
2265 /* The return types differ. */
2268 /* Adjust the type of DECL in case FN is a static member. */
2275 decl_arg_types))
2278 // If the deduced arguments do not satisfy the constraints,
2279 // this is not a candidate.
2283 // Add the candidate.
2285 }
2286 }
2289 {
2290 /* We have:
2292 [temp.expl.spec]
2294 It is possible for a specialization with a given function
2295 signature to be instantiated from more than one function
2296 template. In such cases, explicit specification of the
2297 template arguments must be used to uniquely identify the
2298 function template specialization being specialized.
2300 Note that here, there's no suggestion that we're supposed to
2301 determine which of the candidate templates is most
2302 specialized. However, we, also have:
2304 [temp.func.order]
2306 Partial ordering of overloaded function template
2307 declarations is used in the following contexts to select
2308 the function template to which a function template
2309 specialization refers:
2311 -- when an explicit specialization refers to a function
2312 template.
2314 So, we do use the partial ordering rules, at least for now.
2315 This extension can only serve to make invalid programs valid,
2316 so it's safe. And, there is strong anecdotal evidence that
2317 the committee intended the partial ordering rules to apply;
2318 the EDG front end has that behavior, and John Spicer claims
2319 that the committee simply forgot to delete the wording in
2320 [temp.expl.spec]. */
2323 {
2326 }
2327 }
2329 // Concepts allows multiple declarations of member functions
2330 // with the same signature. Like above, we need to rely on
2331 // on the partial ordering of those candidates to determine which
2332 // is the best.
2334 {
2336 {
2339 }
2340 }
2343 {
2350 else
2353 }
2357 {
2363 }
2365 /* We have one, and exactly one, match. */
2367 {
2371 // Propagate the candidate's constraints to the declaration.
2374 /* DECL is a re-declaration or partial instantiation of a template
2375 function. */
2378 /* It was a specialization of an ordinary member function in a
2379 template class. */
2381 }
2383 /* It was a specialization of a template. */
2386 {
2391 }
2392 else
2395 }
2397 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2398 but with the default argument values filled in from those in the
2399 TMPL_TYPES. */
2401 static tree
2403 tree tmpl_types)
2404 {
2405 tree new_spec_types;
2413 /* Substitute into the rest of the list. */
2414 new_spec_types =
2418 /* Add the default argument for this parameter. */
2421 new_spec_types);
2422 }
2424 /* DECL is an explicit specialization. Replicate default arguments
2425 from the template it specializes. (That way, code like:
2427 template <class T> void f(T = 3);
2428 template <> void f(double);
2429 void g () { f (); }
2431 works, as required.) An alternative approach would be to look up
2432 the correct default arguments at the call-site, but this approach
2433 is consistent with how implicit instantiations are handled. */
2435 static void
2437 {
2438 tree tmpl;
2439 tree spec_types;
2440 tree tmpl_types;
2441 tree new_spec_types;
2442 tree old_type;
2443 tree new_type;
2444 tree t;
2449 /* See if there's anything we need to do. */
2462 {
2463 /* Remove the this pointer, but remember the object's type for
2464 CV quals. */
2470 {
2471 /* DECL may contain more parameters than TMPL due to the extra
2472 in-charge parameter in constructors and destructors. */
2475 }
2477 {
2480 }
2481 }
2483 /* Compute the merged default arguments. */
2484 new_spec_types =
2487 /* Compute the new FUNCTION_TYPE. */
2489 {
2493 new_spec_types);
2496 /* Put the in-charge parameter back. */
2499 new_spec_types);
2503 new_spec_types);
2504 }
2505 else
2507 new_spec_types);
2517 }
2519 /* Return the number of template headers we expect to see for a definition
2520 or specialization of CTYPE or one of its non-template members. */
2522 int
2524 {
2528 {
2529 /* You're supposed to have one `template <...>' for every
2530 template class, but you don't need one for a full
2531 specialization. For example:
2533 template <class T> struct S{};
2534 template <> struct S<int> { void f(); };
2535 void S<int>::f () {}
2537 is correct; there shouldn't be a `template <>' for the
2538 definition of `S<int>::f'. */
2540 /* If CTYPE does not have template information of any
2541 kind, then it is not a template, nor is it nested
2542 within a template. */
2550 }
2553 }
2555 /* Do a simple sanity check on the template headers that precede the
2556 variable declaration DECL. */
2558 void
2560 {
2565 {
2568 "variable templates only available with "
2571 // Namespace-scope variable templates should have a template header.
2573 }
2575 {
2577 "too many template headers for %qD "
2583 "members of an explicitly specialized class are defined "
2585 }
2586 }
2588 /* An explicit specialization whose declarator-id or class-head-name is not
2589 qualified shall be declared in the nearest enclosing namespace of the
2590 template, or, if the namespace is inline (7.3.1), any namespace from its
2591 enclosing namespace set.
2593 If the name declared in the explicit instantiation is an unqualified name,
2594 the explicit instantiation shall appear in the namespace where its template
2595 is declared or, if that namespace is inline (7.3.1), any namespace from its
2596 enclosing namespace set. */
2598 void
2600 {
2605 {
2611 /* This was allowed in C++98, so only pedwarn. */
2613 "outside its namespace must use a nested-name-"
2615 }
2616 }
2618 /* Check to see if the function just declared, as indicated in
2619 DECLARATOR, and in DECL, is a specialization of a function
2620 template. We may also discover that the declaration is an explicit
2621 instantiation at this point.
2623 Returns DECL, or an equivalent declaration that should be used
2624 instead if all goes well. Issues an error message if something is
2625 amiss. Returns error_mark_node if the error is not easily
2626 recoverable.
2628 FLAGS is a bitmask consisting of the following flags:
2630 2: The function has a definition.
2631 4: The function is a friend.
2633 The TEMPLATE_COUNT is the number of references to qualifying
2634 template classes that appeared in the name of the function. For
2635 example, in
2637 template <class T> struct S { void f(); };
2638 void S<int>::f();
2640 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2641 classes are not counted in the TEMPLATE_COUNT, so that in
2643 template <class T> struct S {};
2644 template <> struct S<int> { void f(); }
2645 template <> void S<int>::f();
2647 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2648 invalid; there should be no template <>.)
2650 If the function is a specialization, it is marked as such via
2651 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2652 is set up correctly, and it is added to the list of specializations
2653 for that template. */
2655 tree
2657 tree decl,
2660 {
2669 tmpl_spec_kind tsk;
2672 {
2675 else
2677 }
2678 else
2682 {
2685 {
2688 }
2690 {
2692 /* This could be something like:
2694 template <class T> void f(T);
2695 class S { friend void f<>(int); } */
2697 else
2698 {
2699 /* This case handles bogus declarations like template <>
2700 template <class T> void f<int>(); */
2703 declarator);
2705 }
2706 }
2710 /* The error has already been reported in
2711 check_specialization_scope. */
2717 /* Fall through. */
2730 decl);
2733 else
2737 /* Fall through. */
2743 /* In cases like template<> constexpr bool v = true;
2744 We'll give an error in check_template_variable. */
2750 else
2756 {
2757 /* This case handles bogus declarations like template <>
2758 template <class T> void f<int>(); */
2762 declarator);
2764 {
2765 /* Partial specialization of variable template. */
2769 }
2773 else
2777 ok:;
2778 }
2781 /* This is a specialization of a member template, without
2782 specialization the containing class. Something like:
2784 template <class T> struct S {
2785 template <class U> void f (U);
2786 };
2787 template <> template <class U> void S<int>::f(U) {}
2789 That's a specialization -- but of the entire template. */
2795 }
2798 /* This doesn't apply to variable templates. */
2801 {
2805 {
2809 }
2810 }
2813 {
2818 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2820 {
2821 tree fns;
2826 else
2827 {
2828 /* If there is no class context, the explicit instantiation
2829 must be at namespace scope. */
2832 /* Find the namespace binding, using the declaration
2833 context. */
2837 /* If lookup fails, look for a friend declaration so we can
2838 give a better diagnostic. */
2844 {
2847 }
2848 }
2851 }
2857 {
2859 /* A specialization in class scope. This is invalid,
2860 but the error will already have been flagged by
2861 check_specialization_scope. */
2863 else
2864 {
2865 /* It's not valid to write an explicit instantiation in
2866 class scope, e.g.:
2868 class C { template void f(); }
2870 This case is caught by the parser. However, on
2871 something like:
2873 template class C { void f(); };
2875 (which is invalid) we can get here. The error will be
2876 issued later. */
2877 ;
2878 }
2881 }
2884 {
2885 // We'll match variable templates in start_decl.
2889 /* Find the list of functions in ctype that have the same
2890 name as the declared function. */
2894 {
2898 {
2899 /* From [temp.expl.spec]:
2901 If such an explicit specialization for the member
2902 of a class template names an implicitly-declared
2903 special member function (clause _special_), the
2904 program is ill-formed.
2906 Similar language is found in [temp.explicit]. */
2909 }
2912 }
2914 /* For a type-conversion operator, We might be looking for
2915 `operator int' which will be a specialization of
2916 `operator T'. Grab all the conversion operators, and
2917 then select from them. */
2923 {
2926 }
2927 else
2929 }
2931 /* Figure out what exactly is being specialized at this point.
2932 Note that for an explicit instantiation, even one for a
2933 member function, we cannot tell a priori whether the
2934 instantiation is for a member template, or just a member
2935 function of a template class. Even if a member template is
2936 being instantiated, the member template arguments may be
2937 elided if they can be deduced from the rest of the
2938 declaration. */
2941 member_specialization,
2942 template_count,
2943 tsk);
2946 /* We couldn't figure out what this declaration was
2947 specializing. */
2949 else
2950 {
2953 {
2955 "friend declaration %qD is not visible to "
2959 }
2967 {
2968 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2969 is done by do_decl_instantiation later. */
2975 {
2976 /* If TMPL is not the most general template (for
2977 example, if TMPL is a friend template that is
2978 injected into namespace scope), then there will
2979 be too many levels of TARGS. Remove some of them
2980 here. */
2982 tree new_targs;
2989 }
2992 }
2994 /* If we thought that the DECL was a member function, but it
2995 turns out to be specializing a static member function,
2996 make DECL a static member function as well. */
3002 /* If this is a specialization of a member template of a
3003 template class, we want to return the TEMPLATE_DECL, not
3004 the specialization of it. */
3006 {
3011 {
3012 tree parm;
3016 /* We want to use the argument list specified in the
3017 definition, not in the original declaration. */
3022 }
3025 }
3027 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3033 /* Inherit default function arguments from the template
3034 DECL is specializing. */
3038 /* This specialization has the same protection as the
3039 template it specializes. */
3043 /* 7.1.1-1 [dcl.stc]
3045 A storage-class-specifier shall not be specified in an
3046 explicit specialization...
3048 The parser rejects these, so unless action is taken here,
3049 explicit function specializations will always appear with
3050 global linkage.
3052 The action recommended by the C++ CWG in response to C++
3053 defect report 605 is to make the storage class and linkage
3054 of the explicit specialization match the templated function:
3056 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3057 */
3059 {
3063 /* A concept cannot be specialized. */
3065 {
3067 gen_tmpl);
3069 }
3071 /* This specialization has the same linkage and visibility as
3072 the function template it specializes. */
3075 {
3078 }
3081 {
3084 }
3085 }
3087 /* If DECL is a friend declaration, declared using an
3088 unqualified name, the namespace associated with DECL may
3089 have been set incorrectly. For example, in:
3091 template <typename T> void f(T);
3092 namespace N {
3093 struct S { friend void f<int>(int); }
3094 }
3096 we will have set the DECL_CONTEXT for the friend
3097 declaration to N, rather than to the global namespace. */
3102 /* This is not really a declaration of a specialization.
3103 It's just the name of an instantiation. But, it's not
3104 a request for an instantiation, either. */
3107 /* A specialization is not necessarily COMDAT. */
3113 /* If this is a full specialization, register it so that we can find
3114 it again. Partial specializations will be registered in
3115 process_partial_specialization. */
3120 /* A 'structor should already have clones. */
3126 }
3127 }
3130 }
3132 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3133 parameters. These are represented in the same format used for
3134 DECL_TEMPLATE_PARMS. */
3136 int
3138 {
3139 const_tree p1;
3140 const_tree p2;
3148 {
3160 {
3164 /* If either of the template parameters are invalid, assume
3165 they match for the sake of error recovery. */
3178 }
3179 }
3182 /* One set of parameters has more parameters lists than the
3183 other. */
3187 }
3189 /* Determine whether PARM is a parameter pack. */
3191 bool
3193 {
3194 /* Determine if we have a non-type template parameter pack. */
3201 /* If this is a list of template parameters, we could get a
3202 TYPE_DECL or a TEMPLATE_DECL. */
3206 /* Otherwise it must be a type template parameter. */
3210 }
3212 /* Determine if T is a function parameter pack. */
3214 bool
3216 {
3220 }
3222 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3223 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3225 tree
3227 {
3234 }
3236 /* Return true iff the function parameter PARAM_DECL was expanded
3237 from the function parameter pack PACK. */
3239 bool
3241 {
3246 /* The parameter pack and its pack arguments have the same
3247 DECL_PARM_INDEX. */
3249 }
3251 /* Determine whether ARGS describes a variadic template args list,
3252 i.e., one that is terminated by a template argument pack. */
3254 static bool
3256 {
3258 tree last_parm;
3272 }
3274 /* Generate a new name for the parameter pack name NAME (an
3275 IDENTIFIER_NODE) that incorporates its */
3277 static tree
3279 {
3280 /* Munge the name to include the parameter index. */
3281 #define NUMBUF_LEN 128
3295 }
3297 /* Return true if T is a primary function, class or alias template
3298 instantiation. */
3300 bool
3302 {
3316 }
3318 /* Return true if PARM is a template template parameter. */
3320 bool
3322 {
3324 }
3326 /* Return true iff PARM is a DECL representing a type template
3327 parameter. */
3329 bool
3331 {
3336 }
3338 /* Return the template parameters of T if T is a
3339 primary template instantiation, NULL otherwise. */
3341 tree
3343 {
3348 parms = INNERMOST_TEMPLATE_PARMS
3352 }
3354 /* Return the template parameters of the LEVELth level from the full list
3355 of template parameters PARMS. */
3357 tree
3359 {
3360 tree p;
3371 }
3373 /* Returns the template arguments of T if T is a template instantiation,
3374 NULL otherwise. */
3376 tree
3378 {
3386 }
3388 /* Return the argument pack elements of T if T is a template argument pack,
3389 NULL otherwise. */
3391 tree
3393 {
3399 }
3401 /* True iff FN is a function representing a built-in variadic parameter
3402 pack. */
3404 bool
3406 {
3416 }
3418 /* True iff CALL is a call to a function representing a built-in variadic
3419 parameter pack. */
3421 static bool
3423 {
3427 }
3429 /* Return a TREE_VEC for the expansion of __integer_pack(HI). */
3431 static tree
3433 tree in_decl)
3434 {
3440 {
3442 {
3445 }
3450 }
3451 else
3452 {
3456 /* Calculate the largest value of len that won't make the size of the vec
3457 overflow an int. The compiler will exceed resource limits long before
3458 this, but it seems a decent place to diagnose. */
3462 {
3467 }
3475 }
3476 }
3478 /* Return a TREE_VEC for the expansion of built-in template parameter pack
3479 CALL. */
3481 static tree
3483 tree in_decl)
3484 {
3494 }
3496 /* Structure used to track the progress of find_parameter_packs_r. */
3497 struct find_parameter_pack_data
3498 {
3499 /* TREE_LIST that will contain all of the parameter packs found by
3500 the traversal. */
3503 /* Set of AST nodes that have been visited by the traversal. */
3506 /* True iff we're making a type pack expansion. */
3508 };
3510 /* Identifies all of the argument packs that occur in a template
3511 argument and appends them to the TREE_LIST inside DATA, which is a
3512 find_parameter_pack_data structure. This is a subroutine of
3513 make_pack_expansion and uses_parameter_packs. */
3514 static tree
3516 {
3522 /* Handle type aliases/typedefs. */
3524 {
3531 }
3533 /* Identify whether this is a parameter pack or not. */
3535 {
3543 /* FALLTHRU */
3545 /* If the placeholder appears in the decl-specifier-seq of a function
3546 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3547 is a pack expansion, the invented template parameter is a template
3548 parameter pack. */
3558 {
3559 /* We don't want to walk into the type of a PARM_DECL,
3560 because we don't want to see the type parameter pack. */
3563 }
3566 /* Look through a lambda capture proxy to the field pack. */
3569 {
3575 }
3577 {
3579 find_parameter_packs_r,
3582 }
3594 /* Not a parameter pack. */
3596 }
3599 {
3600 /* Add this parameter pack to the list. */
3602 }
3608 /* This switch statement will return immediately if we don't find a
3609 parameter pack. */
3611 {
3616 /* Check the template itself. */
3619 /* Check the template arguments. */
3633 /* Ignore the declaration of a capture proxy for a parameter pack. */
3641 /* Fall through. */
3686 {
3692 }
3695 {
3696 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3697 type_pack_expansion_p to false so that any placeholders
3698 within the expression don't get marked as parameter packs. */
3706 }
3710 }
3713 }
3715 /* Determines if the expression or type T uses any parameter packs. */
3716 bool
3718 {
3727 }
3729 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3730 representation a base-class initializer into a parameter pack
3731 expansion. If all goes well, the resulting node will be an
3732 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3733 respectively. */
3734 tree
3736 {
3737 tree result;
3746 {
3747 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3748 class initializer. In this case, the TREE_PURPOSE will be a
3749 _TYPE node (representing the base class expansion we're
3750 initializing) and the TREE_VALUE will be a TREE_LIST
3751 containing the initialization arguments.
3753 The resulting expansion looks somewhat different from most
3754 expansions. Rather than returning just one _EXPANSION, we
3755 return a TREE_LIST whose TREE_PURPOSE is a
3756 TYPE_PACK_EXPANSION containing the bases that will be
3757 initialized. The TREE_VALUE will be identical to the
3758 original TREE_VALUE, which is a list of arguments that will
3759 be passed to each base. We do not introduce any new pack
3760 expansion nodes into the TREE_VALUE (although it is possible
3761 that some already exist), because the TREE_PURPOSE and
3762 TREE_VALUE all need to be expanded together with the same
3763 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3764 resulting TREE_PURPOSE will mention the parameter packs in
3765 both the bases and the arguments to the bases. */
3766 tree purpose;
3767 tree value;
3770 /* Determine which parameter packs will be used by the base
3771 class expansion. */
3780 {
3784 }
3787 {
3788 /* Collect the sets of parameter packs used in each of the
3789 initialization arguments. */
3791 {
3792 /* Determine which parameter packs will be expanded in this
3793 argument. */
3796 }
3797 }
3801 /* Create the pack expansion type for the base type. */
3807 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3808 they will rarely be compared to anything. */
3812 }
3817 /* Build the PACK_EXPANSION_* node. */
3818 result = for_types
3823 {
3824 /* Propagate type and const-expression information. */
3827 /* Mark this read now, since the expansion might be length 0. */
3829 }
3830 else
3831 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3832 they will rarely be compared to anything. */
3835 /* Determine which parameter packs will be expanded. */
3842 /* Make sure we found some parameter packs. */
3844 {
3847 else
3850 }
3856 }
3858 /* Checks T for any "bare" parameter packs, which have not yet been
3859 expanded, and issues an error if any are found. This operation can
3860 only be done on full expressions or types (e.g., an expression
3861 statement, "if" condition, etc.), because we could have expressions like:
3863 foo(f(g(h(args)))...)
3865 where "args" is a parameter pack. check_for_bare_parameter_packs
3866 should not be called for the subexpressions args, h(args),
3867 g(h(args)), or f(g(h(args))), because we would produce erroneous
3868 error messages.
3870 Returns TRUE and emits an error if there were bare parameter packs,
3871 returns FALSE otherwise. */
3872 bool
3874 {
3881 /* A lambda might use a parameter pack from the containing context. */
3895 {
3899 {
3910 else
3915 else
3919 }
3922 }
3925 }
3927 /* Expand any parameter packs that occur in the template arguments in
3928 ARGS. */
3929 tree
3931 {
3940 /* First, determine if we need to expand anything, and the number of
3941 slots we'll need. */
3943 {
3948 {
3952 else
3954 }
3955 else
3956 {
3958 num_result_args++;
3959 }
3960 }
3962 /* If no expansion is necessary, we're done. */
3966 /* Expand arguments. */
3969 non_default_args_count =
3972 {
3975 {
3982 }
3983 else
3984 {
3987 }
3988 }
3992 }
3994 /* Checks if DECL shadows a template parameter.
3996 [temp.local]: A template-parameter shall not be redeclared within its
3997 scope (including nested scopes).
3999 Emits an error and returns TRUE if the DECL shadows a parameter,
4000 returns FALSE otherwise. */
4002 bool
4004 {
4005 tree olddecl;
4007 /* If we're not in a template, we can't possibly shadow a template
4008 parameter. */
4012 /* Figure out what we're shadowing. */
4016 /* If there's no previous binding for this name, we're not shadowing
4017 anything, let alone a template parameter. */
4021 /* If we're not shadowing a template parameter, we're done. Note
4022 that OLDDECL might be an OVERLOAD (or perhaps even an
4023 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4024 node. */
4028 /* We check for decl != olddecl to avoid bogus errors for using a
4029 name inside a class. We check TPFI to avoid duplicate errors for
4030 inline member templates. */
4036 /* Don't complain about the injected class name, as we've already
4037 complained about the class itself. */
4044 else
4049 }
4051 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4052 ORIG_LEVEL, DECL, and TYPE. */
4054 static tree
4058 tree decl,
4059 tree type)
4060 {
4071 }
4073 /* Find the canonical type parameter for the given template type
4074 parameter. Returns the canonical type parameter, which may be TYPE
4075 if no such parameter existed. */
4077 static tree
4079 {
4080 tree list;
4094 else
4095 {
4099 }
4100 }
4102 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4103 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4104 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4105 new one is created. */
4107 static tree
4109 tsubst_flags_t complain)
4110 {
4115 {
4134 /* Template template parameters need this. */
4136 {
4143 }
4144 }
4147 }
4149 /* Process information from new template parameter PARM and append it
4150 to the LIST being built. This new parameter is a non-type
4151 parameter iff IS_NON_TYPE is true. This new parameter is a
4152 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4153 is in PARM_LOC. */
4155 tree
4158 {
4167 {
4171 {
4175 else
4177 }
4180 }
4183 {
4189 {
4190 /* [temp.param]
4192 The top-level cv-qualifiers on the template-parameter are
4193 ignored when determining its type. */
4198 && !is_parameter_pack
4199 /* If we're in a nested template parameter list, the template
4200 template parameter could be a parameter pack. */
4202 {
4203 /* This template parameter is not a parameter pack, but it
4204 should be. Complain about "bare" parameter packs. */
4207 /* Recover by calling this a parameter pack. */
4209 }
4210 }
4212 /* A template parameter is not modifiable. */
4221 processing_template_decl,
4226 }
4227 else
4228 {
4229 tree t;
4233 {
4235 /* This is for distinguishing between real templates and template
4236 template parameters */
4240 }
4241 else
4242 {
4244 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4247 }
4254 processing_template_decl,
4258 }
4262 /* Build requirements for the type/template parameter.
4263 This must be done after SET_DECL_TEMPLATE_PARM_P or
4264 process_template_parm could fail. */
4269 /* Build the parameter node linking the parameter declaration,
4270 its default argument (if any), and its constraints (if any). */
4275 }
4277 /* The end of a template parameter list has been reached. Process the
4278 tree list into a parameter vector, converting each parameter into a more
4279 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4280 as PARM_DECLs. */
4282 tree
4284 {
4289 /* Pop the dummy parameter level and add the real one. */
4292 current_template_parms
4297 {
4301 }
4306 }
4308 // Explicitly indicate the end of the template parameter list. We assume
4309 // that the current template parameters have been constructed and/or
4310 // managed explicitly, as when creating new template template parameters
4311 // from a shorthand constraint.
4312 void
4314 {
4316 }
4318 /* end_template_decl is called after a template declaration is seen. */
4320 void
4322 {
4328 /* This matches the pushlevel in begin_template_parm_list. */
4333 }
4335 /* Takes a TREE_LIST representing a template parameter and convert it
4336 into an argument suitable to be passed to the type substitution
4337 functions. Note that If the TREE_LIST contains an error_mark
4338 node, the returned argument is error_mark_node. */
4340 tree
4342 {
4355 {
4359 {
4360 /* Turn this argument into a TYPE_ARGUMENT_PACK
4361 with a single element, which expands T. */
4370 }
4371 }
4372 else
4373 {
4377 {
4378 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4379 with a single element, which expands T. */
4389 }
4390 else
4392 }
4394 }
4396 /* Given a single level of template parameters (a TREE_VEC), return it
4397 as a set of template arguments. */
4399 static tree
4401 {
4411 }
4413 /* Given a set of template parameters, return them as a set of template
4414 arguments. The template parameters are represented as a TREE_VEC, in
4415 the form documented in cp-tree.h for template arguments. */
4417 static tree
4419 {
4420 tree header;
4425 /* If there is only one level of template parameters, we do not
4426 create a TREE_VEC of TREE_VECs. Instead, we return a single
4427 TREE_VEC containing the arguments. */
4432 {
4437 else
4439 }
4442 }
4444 /* Within the declaration of a template, return the currently active
4445 template parameters as an argument TREE_VEC. */
4447 static tree
4449 {
4451 }
4453 /* Update the declared TYPE by doing any lookups which were thought to be
4454 dependent, but are not now that we know the SCOPE of the declarator. */
4456 tree
4458 {
4469 /* Don't bother building up the args in this case. */
4471 {
4472 /* tsubst in the args corresponding to the template parameters,
4473 including auto if present. Most things will be unchanged, but
4474 make_typename_type and tsubst_qualified_id will resolve
4475 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4478 tree pushed;
4480 {
4484 }
4489 }
4495 {
4498 else
4500 }
4502 }
4504 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4505 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4506 the new template is a member template. */
4508 tree
4510 {
4518 }
4520 struct template_parm_data
4521 {
4522 /* The level of the template parameters we are currently
4523 processing. */
4526 /* The index of the specialization argument we are currently
4527 processing. */
4530 /* An array whose size is the number of template parameters. The
4531 elements are nonzero if the parameter has been used in any one
4532 of the arguments processed so far. */
4535 /* An array whose size is the number of template arguments. The
4536 elements are nonzero if the argument makes use of template
4537 parameters of this level. */
4539 };
4541 /* Subroutine of push_template_decl used to see if each template
4542 parameter in a partial specialization is used in the explicit
4543 argument list. If T is of the LEVEL given in DATA (which is
4544 treated as a template_parm_data*), then DATA->PARMS is marked
4545 appropriately. */
4547 static int
4549 {
4557 {
4560 }
4562 /* In C++17 the type of a non-type argument is a deduced context. */
4567 data,
4568 NULL,
4571 /* Return zero so that for_each_template_parm will continue the
4572 traversal of the tree; we want to mark *every* template parm. */
4574 }
4576 /* Process the partial specialization DECL. */
4578 static tree
4580 {
4587 tree inner_parms;
4588 tree inst;
4598 /* A concept cannot be specialized. */
4600 {
4603 }
4608 /* We check that each of the template parameters given in the
4609 partial specialization is used in the argument list to the
4610 specialization. For example:
4612 template <class T> struct S;
4613 template <class T> struct S<T*>;
4615 The second declaration is OK because `T*' uses the template
4616 parameter T, whereas
4618 template <class T> struct S<int>;
4620 is no good. Even trickier is:
4622 template <class T>
4623 struct S1
4624 {
4625 template <class U>
4626 struct S2;
4627 template <class U>
4628 struct S2<T>;
4629 };
4631 The S2<T> declaration is actually invalid; it is a
4632 full-specialization. Of course,
4634 template <class U>
4635 struct S2<T (*)(U)>;
4637 or some such would have been OK. */
4645 {
4650 NULL,
4652 }
4655 {
4656 /* One of the template parms was not used in a deduced context in the
4657 specialization. */
4659 {
4663 }
4667 }
4672 /* [temp.class.spec]
4674 The argument list of the specialization shall not be identical to
4675 the implicit argument list of the primary template. */
4676 tree main_args
4679 && (!flag_concepts
4682 {
4686 else
4690 }
4692 /* A partial specialization that replaces multiple parameters of the
4693 primary template with a pack expansion is less specialized for those
4694 parameters. */
4696 {
4698 "primary template because it replaces multiple parameters "
4701 /* Avoid crash in process_partial_specialization. */
4703 }
4705 /* If we aren't in a dependent class, we can actually try deduction. */
4707 /* FIXME we should be able to handle a partial specialization of a
4708 partial instantiation, but currently we can't (c++/41727). */
4711 {
4715 maintmpl);
4716 }
4718 /* [temp.class.spec]
4720 A partially specialized non-type argument expression shall not
4721 involve template parameters of the partial specialization except
4722 when the argument expression is a simple identifier.
4724 The type of a template parameter corresponding to a specialized
4725 non-type argument shall not be dependent on a parameter of the
4726 specialization.
4728 Also, we verify that pack expansions only occur at the
4729 end of the argument list. */
4733 {
4740 {
4741 /* Extract the arguments from the argument pack. We'll be
4742 iterating over these in the following loop. */
4745 }
4748 {
4750 /* Get the Jth argument in the parameter pack. */
4754 {
4755 /* Pack expansions must come at the end of the
4756 argument list. */
4759 {
4763 else
4766 }
4767 }
4770 /* We only care about the pattern. */
4776 /* This next two lines are the `argument expression is not just a
4777 simple identifier' condition and also the `specialized
4778 non-type argument' bit. */
4782 {
4786 arg);
4787 else
4788 {
4789 /* Look at the corresponding template parameter,
4790 marking which template parameters its type depends
4791 upon. */
4795 {
4796 /* We haven't yet initialized TPD2. Do so now. */
4798 /* The number of parameters here is the number in the
4799 main template, which, as checked in the assertion
4800 above, is NARGS. */
4804 }
4806 /* Mark the template parameters. But this time, we're
4807 looking for the template parameters of the main
4808 template, not in the specialization. */
4815 NULL,
4819 {
4820 /* The type depended on some template parameters.
4821 If they are fully specialized in the
4822 specialization, that's OK. */
4831 "type %qT of template argument %qE depends "
4833 "type %qT of template argument %qE depends "
4835 type,
4836 arg);
4837 }
4838 }
4839 }
4840 }
4841 }
4843 /* We should only get here once. */
4847 // Build the template decl.
4856 /* Give template template parms a DECL_CONTEXT of the template
4857 for which they are a parameter. */
4859 {
4863 }
4866 /* We didn't register this in check_explicit_specialization so we could
4867 wait until the constraints were set. */
4869 else
4879 {
4885 {
4893 "declaration of %qD ambiguates earlier template "
4897 "partial specialization of %qD after instantiation "
4899 }
4900 }
4903 }
4905 /* PARM is a template parameter of some form; return the corresponding
4906 TEMPLATE_PARM_INDEX. */
4908 static tree
4910 {
4923 }
4925 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4926 parameter packs used by the template parameter PARM. */
4928 static void
4930 {
4931 /* A type parm can't refer to another parm. */
4935 {
4939 }
4946 }
4948 /* PARM is a template parameter pack. Return any parameter packs used in
4949 its type or the type of any of its template parameters. If there are
4950 any such packs, it will be instantiated into a fixed template parameter
4951 list by partial instantiation rather than be fully deduced. */
4953 tree
4955 {
4956 /* This can only be true in a member template. */
4959 /* This can only be true for a parameter pack. */
4962 /* A type parm can't refer to another parm. */
4976 }
4978 /* Check that a template declaration's use of default arguments and
4979 parameter packs is not invalid. Here, PARMS are the template
4980 parameters. IS_PRIMARY is true if DECL is the thing declared by
4981 a primary template. IS_PARTIAL is true if DECL is a partial
4982 specialization.
4984 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4985 declaration (but not a definition); 1 indicates a declaration, 2
4986 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4987 emitted for extraneous default arguments.
4989 Returns TRUE if there were no errors found, FALSE otherwise. */
4991 bool
4994 {
4997 tree parm_level;
5000 /* [temp.param]
5002 A default template-argument shall not be specified in a
5003 function template declaration or a function template definition, nor
5004 in the template-parameter-list of the definition of a member of a
5005 class template. */
5009 /* You can't have a function template declaration in a local
5010 scope, nor you can you define a member of a class template in a
5011 local scope. */
5019 /* A lambda doesn't have an explicit declaration; don't complain
5020 about the parms of the enclosing class. */
5027 /* If this is either a friend defined in the scope of the class
5028 or a member function. */
5034 /* And, if it was a member function, it really was defined in
5035 the scope of the class. */
5038 /* We already checked these parameters when the template was
5039 declared, so there's no need to do it again now. This function
5040 was defined in class scope, but we're processing its body now
5041 that the class is complete. */
5044 /* Core issue 226 (C++0x only): the following only applies to class
5045 templates. */
5048 {
5049 /* [temp.param]
5051 If a template-parameter has a default template-argument, all
5052 subsequent template-parameters shall have a default
5053 template-argument supplied. */
5055 {
5062 {
5072 {
5074 /* For better subsequent error-recovery, we indicate that
5075 there should have been a default argument. */
5078 }
5080 && !is_friend_decl
5081 /* Don't complain about an enclosing partial
5082 specialization. */
5087 /* A fixed parameter pack will be partially
5088 instantiated into a fixed length list. */
5090 {
5091 /* A primary class template can only have one
5092 parameter pack, at the end of the template
5093 parameter list. */
5101 }
5102 }
5103 }
5104 }
5107 || is_partial
5108 || !is_primary
5110 /* For an ordinary class template, default template arguments are
5111 allowed at the innermost level, e.g.:
5112 template <class T = int>
5113 struct S {};
5114 but, in a partial specialization, they're not allowed even
5115 there, as we have in [temp.class.spec]:
5117 The template parameter list of a specialization shall not
5118 contain default template argument values.
5120 So, for a partial specialization, or for a function template
5121 (in C++98/C++03), we look at all of them. */
5122 ;
5123 else
5124 /* But, for a primary class template that is not a partial
5125 specialization we look at all template parameters except the
5126 innermost ones. */
5129 /* Figure out what error message to issue. */
5144 else
5145 /* Per [temp.param]/9, "A default template-argument shall not be
5146 specified in the template-parameter-lists of the definition of
5147 a member of a class template that appears outside of the member's
5148 class.", thus if we aren't handling a member of a class template
5149 there is no need to examine the parameters. */
5153 /* If we're inside a class definition, there's no need to
5154 examine the parameters to the class itself. On the one
5155 hand, they will be checked when the class is defined, and,
5156 on the other, default arguments are valid in things like:
5157 template <class T = double>
5158 struct S { template <class U> void f(U); };
5159 Here the default argument for `S' has no bearing on the
5160 declaration of `f'. */
5162 else
5163 /* Check everything. */
5169 {
5176 {
5181 {
5183 {
5190 }
5192 /* Clear out the default argument so that we are not
5193 confused later. */
5195 }
5196 }
5198 /* At this point, if we're still interested in issuing messages,
5199 they must apply to classes surrounding the object declared. */
5203 }
5206 }
5208 /* Worker for push_template_decl_real, called via
5209 for_each_template_parm. DATA is really an int, indicating the
5210 level of the parameters we are interested in. If T is a template
5211 parameter of that level, return nonzero. */
5213 static int
5215 {
5221 else
5224 }
5226 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5227 DATA is really an int, indicating the innermost outer level of parameters.
5228 If T is a template parameter of that level or further out, return
5229 nonzero. */
5231 static int
5233 {
5239 else
5242 }
5244 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5245 parameters given by current_template_args, or reuses a
5246 previously existing one, if appropriate. Returns the DECL, or an
5247 equivalent one, if it is replaced via a call to duplicate_decls.
5249 If IS_FRIEND is true, DECL is a friend declaration. */
5251 tree
5253 {
5254 tree tmpl;
5255 tree args;
5256 tree info;
5257 tree ctx;
5261 /* True if the template is a member template, in the sense of
5262 [temp.mem]. */
5268 /* See if this is a partial specialization. */
5281 /* For a friend, we want the context of the friend function, not
5282 the type of which it is a friend. */
5286 /* In the case of a virtual function, we want the class in which
5287 it is defined. */
5289 else
5290 /* Otherwise, if we're currently defining some class, the DECL
5291 is assumed to be a member of the class. */
5300 /* See if this is a primary template. */
5303 /* A friend template that specifies a class context, i.e.
5304 template <typename T> friend void A<T>::f();
5305 is not primary. */
5310 else
5314 {
5321 {
5324 }
5326 {
5328 {
5331 }
5333 {
5334 /* [temp.mem]
5336 A destructor shall not be a member template. */
5339 }
5346 {
5347 /* [basic.stc.dynamic.allocation]
5349 An allocation function can be a function
5350 template. ... Template allocation functions shall
5351 have two or more parameters. */
5354 }
5355 }
5358 {
5359 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5362 {
5368 }
5369 }
5372 /* alias-declaration */
5376 else
5377 {
5380 }
5381 }
5383 /* Check to see that the rules regarding the use of default
5384 arguments are not being violated. */
5388 /* Ensure that there are no parameter packs in the type of this
5389 declaration that have not been expanded. */
5391 {
5392 /* Check each of the arguments individually to see if there are
5393 any bare parameter packs. */
5399 {
5402 {
5403 /* This is a PARM_DECL that contains unexpanded parameter
5404 packs. We have already complained about this in the
5405 check_for_bare_parameter_packs call, so just replace
5406 these types with ERROR_MARK_NODE. */
5409 }
5413 }
5415 /* Check for bare parameter packs in the return type and the
5416 exception specifiers. */
5418 /* Errors were already issued, set return type to int
5419 as the frontend doesn't expect error_mark_node as
5420 the return type. */
5424 }
5429 {
5432 }
5445 {
5450 /* If DECL is a TYPE_DECL for a class-template, then there won't
5451 be DECL_LANG_SPECIFIC. The information equivalent to
5452 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5456 {
5457 /* Since a template declaration already existed for this
5458 class-type, we must be redeclaring it here. Make sure
5459 that the redeclaration is valid. */
5461 current_template_parms,
5463 /* We don't need to create a new TEMPLATE_DECL; just use the
5464 one we already had. */
5466 }
5467 else
5468 {
5470 member_template_p);
5475 {
5476 /* A specialization of a member template of a template
5477 class. */
5481 }
5482 }
5483 }
5484 else
5485 {
5491 {
5494 }
5502 {
5503 tree new_tmpl;
5505 /* The declaration is a specialization of a member
5506 template, declared outside the class. Therefore, the
5507 innermost template arguments will be NULL, so we
5508 replace them with the arguments determined by the
5509 earlier call to check_explicit_specialization. */
5512 new_tmpl
5514 member_template_p);
5524 args,
5527 }
5529 /* Make sure the template headers we got make sense. */
5534 {
5539 }
5540 else
5542 {
5547 {
5551 else
5555 /* Avoid crash in import_export_decl. */
5558 }
5563 /* Can happen in erroneous input. */
5565 else
5567 }
5569 /* Check that the parms are used in the appropriate qualifying scopes
5570 in the declarator. */
5574 {
5580 /* Avoid crash in import_export_decl. */
5583 }
5584 }
5589 /* Push template declarations for global functions and types. Note
5590 that we do not try to push a global template friend declared in a
5591 template class; such a thing may well depend on the template
5592 parameters of the class. */
5595 {
5600 /* Hide template friend classes that haven't been declared yet. */
5602 {
5605 }
5606 }
5609 {
5615 {
5618 /* It is a conversion operator. See if the type converted to
5619 depends on innermost template operands. */
5622 depth))
5624 }
5626 /* Give template template parms a DECL_CONTEXT of the template
5627 for which they are a parameter. */
5630 {
5634 }
5640 }
5642 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5643 back to its most general template. If TMPL is a specialization,
5644 ARGS may only have the innermost set of arguments. Add the missing
5645 argument levels if necessary. */
5653 else
5654 {
5659 }
5662 && !is_friend
5665 /* Set DECL_COMDAT on template instantiations; if we force
5666 them to be emitted by explicit instantiation or -frepo,
5667 mark_needed will tell cgraph to do the right thing. */
5671 }
5673 tree
5675 {
5677 }
5679 /* FN is an inheriting constructor that inherits from the constructor
5680 template INHERITED; turn FN into a constructor template with a matching
5681 template header. */
5683 tree
5685 {
5686 tree inner_parms
5689 tree parms
5700 }
5702 /* Called when a class template TYPE is redeclared with the indicated
5703 template PARMS, e.g.:
5705 template <class T> struct S;
5706 template <class T> struct S {}; */
5708 bool
5710 {
5711 tree tmpl;
5712 tree tmpl_parms;
5716 {
5719 }
5723 /* The type is nested in some template class. Nothing to worry
5724 about here; there are no new template parameters for the nested
5725 type. */
5729 {
5731 tmpl);
5733 }
5739 {
5749 }
5752 {
5753 tree tmpl_parm;
5754 tree parm;
5755 tree tmpl_default;
5756 tree parm_default;
5770 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5771 TEMPLATE_DECL. */
5781 {
5785 }
5788 {
5789 /* We have in [temp.param]:
5791 A template-parameter may not be given default arguments
5792 by two different declarations in the same scope. */
5797 }
5800 /* Update the previous template parameters (which are the ones
5801 that will really count) with the new default value. */
5804 /* Update the new parameters, too; they'll be used as the
5805 parameters for any members. */
5808 /* Give each template template parm in this redeclaration a
5809 DECL_CONTEXT of the template for which they are a parameter. */
5811 {
5814 }
5818 }
5820 // Cannot redeclare a class template with a different set of constraints.
5822 {
5827 }
5830 }
5832 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5833 to be used when the caller has already checked
5834 (processing_template_decl
5835 && !instantiation_dependent_expression_p (expr)
5836 && potential_constant_expression (expr))
5837 and cleared processing_template_decl. */
5839 tree
5841 {
5844 complain,
5848 }
5850 /* Simplify EXPR if it is a non-dependent expression. Returns the
5851 (possibly simplified) expression. */
5853 tree
5855 {
5859 /* If we're in a template, but EXPR isn't value dependent, simplify
5860 it. We're supposed to treat:
5862 template <typename T> void f(T[1 + 1]);
5863 template <typename T> void f(T[2]);
5865 as two declarations of the same function, for example. */
5868 {
5869 processing_template_decl_sentinel s;
5871 }
5873 }
5875 tree
5877 {
5879 }
5881 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5882 an uninstantiated expression. */
5884 tree
5886 {
5890 {
5893 else
5894 {
5895 processing_template_decl_sentinel s;
5897 }
5898 }
5900 }
5902 /* True iff T is a specialization of a variable template. */
5904 bool
5906 {
5911 }
5913 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5914 template declaration, or a TYPE_DECL for an alias declaration. */
5916 bool
5918 {
5926 }
5928 /* Return TRUE iff T is a specialization of an alias template. */
5930 bool
5932 {
5933 /* It's an alias template specialization if it's an alias and its
5934 TYPE_NAME is a specialization of a primary template. */
5940 }
5942 /* An alias template is complex from a SFINAE perspective if a template-id
5943 using that alias can be ill-formed when the expansion is not, as with
5944 the void_t template. We determine this by checking whether the
5945 expansion for the alias template uses all its template parameters. */
5947 struct uses_all_template_parms_data
5948 {
5951 };
5953 static int
5955 {
5963 }
5965 static bool
5967 {
5982 }
5984 /* Return TRUE iff T is a specialization of a complex alias template with
5985 dependent template-arguments. */
5987 bool
5989 {
6002 }
6004 /* Return the number of innermost template parameters in TMPL. */
6006 static int
6008 {
6011 }
6013 /* Return either TMPL or another template that it is equivalent to under DR
6014 1286: An alias that just changes the name of a template is equivalent to
6015 the other template. */
6017 static tree
6019 {
6022 {
6023 /* Determine if the alias is equivalent to an underlying template. */
6035 tree alias_args = INNERMOST_TEMPLATE_ARGS
6040 /* Alias is equivalent. Strip it and repeat. */
6042 }
6045 }
6047 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6048 must be a reference-to-function or a pointer-to-function type, as specified
6049 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6050 and check that the resulting function has external linkage. */
6052 static tree
6054 tsubst_flags_t complain)
6055 {
6058 linkage_kind linkage;
6073 /* [temp.arg.nontype]/1
6075 A template-argument for a non-type, non-template template-parameter
6076 shall be one of:
6077 [...]
6078 -- the address of an object or function with external [C++11: or
6079 internal] linkage. */
6082 {
6084 {
6090 else
6093 }
6095 }
6099 {
6101 {
6106 else
6110 }
6112 }
6114 accept:
6121 }
6123 /* Subroutine of convert_nontype_argument.
6124 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6125 Emit an error otherwise. */
6127 static bool
6129 tsubst_flags_t complain)
6130 {
6147 {
6152 else
6154 }
6156 }
6158 /* Returns TRUE iff the address of OP is value-dependent.
6160 14.6.2.4 [temp.dep.temp]:
6161 A non-integral non-type template-argument is dependent if its type is
6162 dependent or it has either of the following forms
6163 qualified-id
6164 & qualified-id
6165 and contains a nested-name-specifier which specifies a class-name that
6166 names a dependent type.
6168 We generalize this to just say that the address of a member of a
6169 dependent class is value-dependent; the above doesn't cover the
6170 address of a static data member named with an unqualified-id. */
6172 static bool
6174 {
6175 /* We could use get_inner_reference here, but there's no need;
6176 this is only relevant for template non-type arguments, which
6177 can only be expressed as &id-expression. */
6179 {
6183 }
6186 }
6188 /* The next set of functions are used for providing helpful explanatory
6189 diagnostics for failed overload resolution. Their messages should be
6190 indented by two spaces for consistency with the messages in
6191 call.c */
6193 static int
6195 {
6197 }
6199 /* Other failure functions should call this one, to provide a single function
6200 for setting a breakpoint on. */
6202 static int
6204 {
6206 }
6208 static int
6210 {
6215 }
6217 static int
6219 {
6225 }
6227 static int
6229 {
6233 }
6235 static int
6237 {
6240 " template parameter %qD is not a parameter pack, but "
6244 }
6246 static int
6248 {
6251 " template argument %qE does not match "
6255 }
6257 static int
6259 {
6263 }
6265 static int
6267 {
6273 }
6275 static int
6277 {
6279 {
6284 else
6286 " deduced conflicting values for non-type parameter "
6288 }
6290 }
6292 static int
6294 {
6297 " variable-sized array type %qT is not "
6299 arg);
6301 }
6303 static int
6305 {
6309 arg);
6311 }
6313 static int
6315 {
6317 {
6323 else
6328 }
6330 }
6332 static int
6334 {
6336 }
6338 static int
6341 {
6343 }
6345 static int
6348 {
6354 }
6356 static int
6359 {
6362 {
6370 }
6372 }
6374 static int
6376 {
6379 " template parameters of a template template argument are "
6382 }
6384 static int
6386 {
6392 }
6394 static int
6396 {
6401 }
6403 /* Attempt to convert the non-type template parameter EXPR to the
6404 indicated TYPE. If the conversion is successful, return the
6405 converted value. If the conversion is unsuccessful, return
6406 NULL_TREE if we issued an error message, or error_mark_node if we
6407 did not. We issue error messages for out-and-out bad template
6408 parameters, but not simply because the conversion failed, since we
6409 might be just trying to do argument deduction. Both TYPE and EXPR
6410 must be non-dependent.
6412 The conversion follows the special rules described in
6413 [temp.arg.nontype], and it is much more strict than an implicit
6414 conversion.
6416 This function is called twice for each template argument (see
6417 lookup_template_class for a more accurate description of this
6418 problem). This means that we need to handle expressions which
6419 are not valid in a C++ source, but can be created from the
6420 first call (for instance, casts to perform conversions). These
6421 hacks can go away after we fix the double coercion problem. */
6423 static tree
6425 {
6426 tree expr_type;
6430 /* Detect immediately string literals as invalid non-type argument.
6431 This special-case is not needed for correctness (we would easily
6432 catch this later), but only to provide better diagnostic for this
6433 common user mistake. As suggested by DR 100, we do not mention
6434 linkage issues in the diagnostic as this is not the point. */
6435 /* FIXME we're making this OK. */
6437 {
6443 }
6445 /* Add the ADDR_EXPR now for the benefit of
6446 value_dependent_expression_p. */
6449 {
6453 }
6455 /* If we are in a template, EXPR may be non-dependent, but still
6456 have a syntactic, rather than semantic, form. For example, EXPR
6457 might be a SCOPE_REF, rather than the VAR_DECL to which the
6458 SCOPE_REF refers. Preserving the qualifying scope is necessary
6459 so that access checking can be performed when the template is
6460 instantiated -- but here we need the resolved form so that we can
6461 convert the argument. */
6473 /* If the argument is non-dependent, perform any conversions in
6474 non-dependent context as well. */
6482 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6483 to a non-type argument of "nullptr". */
6487 /* In C++11, integral or enumeration non-type template arguments can be
6488 arbitrary constant expressions. Pointer and pointer to
6489 member arguments can be general constant expressions that evaluate
6490 to a null value, but otherwise still need to be of a specific form. */
6492 {
6494 /* A PTRMEM_CST is already constant, and a valid template
6495 argument for a parameter of pointer to member type, we just want
6496 to leave it in that form rather than lower it to a
6500 {
6501 /* C++17: A template-argument for a non-type template-parameter shall
6502 be a converted constant expression (8.20) of the type of the
6503 template-parameter. */
6509 }
6511 {
6516 }
6517 }
6521 else
6524 /* HACK: Due to double coercion, we can get a
6525 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6526 which is the tree that we built on the first call (see
6527 below when coercing to reference to object or to reference to
6528 function). We just strip everything and get to the arg.
6529 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6530 for examples. */
6532 {
6538 {
6539 /* ??? Maybe we could use convert_from_reference here, but we
6540 would need to relax its constraints because the NOP_EXPR
6541 could actually change the type to something more cv-qualified,
6542 and this is not folded by convert_from_reference. */
6547 && (same_type_ignoring_top_level_qualifiers_p
6550 {
6553 }
6554 }
6555 }
6557 /* [temp.arg.nontype]/5, bullet 1
6559 For a non-type template-parameter of integral or enumeration type,
6560 integral promotions (_conv.prom_) and integral conversions
6561 (_conv.integral_) are applied. */
6563 {
6565 {
6570 }
6575 /* Notice that there are constant expressions like '4 % 0' which
6576 do not fold into integer constants. */
6579 {
6581 {
6585 else
6591 /* else cxx_constant_value complained but gave us
6592 a real constant, so go ahead. */
6594 }
6595 else
6597 }
6599 /* Avoid typedef problems. */
6602 }
6603 /* [temp.arg.nontype]/5, bullet 2
6605 For a non-type template-parameter of type pointer to object,
6606 qualification conversions (_conv.qual_) and the array-to-pointer
6607 conversion (_conv.array_) are applied. */
6609 {
6612 /* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
6613 decay_conversion or an explicit cast. If it's a problematic cast,
6614 we'll complain about it below. */
6616 {
6621 {
6624 }
6625 }
6627 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6629 A template-argument for a non-type, non-template template-parameter
6630 shall be one of: [...]
6632 -- the name of a non-type template-parameter;
6633 -- the address of an object or function with external linkage, [...]
6634 expressed as "& id-expression" where the & is optional if the name
6635 refers to a function or array, or if the corresponding
6636 template-parameter is a reference.
6638 Here, we do not care about functions, as they are invalid anyway
6639 for a parameter of type pointer-to-object. */
6642 /* Non-type template parameters are OK. */
6643 ;
6647 {
6649 {
6652 "because %qD is a variable, not the address of "
6655 }
6657 {
6663 }
6664 /* Other values, like integer constants, might be valid
6665 non-type arguments of some other type. */
6667 }
6668 else
6669 {
6673 {
6678 }
6680 {
6686 }
6689 {
6694 }
6695 /* C++17: For a non-type template-parameter of reference or pointer
6696 type, the value of the constant expression shall not refer to (or
6697 for a pointer type, shall not be the address of):
6698 * a subobject (4.5),
6699 * a temporary object (15.2),
6700 * a string literal (5.13.5),
6701 * the result of a typeid expression (8.2.8), or
6702 * a predefined __func__ variable (11.4.1). */
6704 {
6707 decl);
6709 }
6713 {
6718 }
6720 {
6724 decl);
6726 }
6727 }
6734 }
6735 /* [temp.arg.nontype]/5, bullet 3
6737 For a non-type template-parameter of type reference to object, no
6738 conversions apply. The type referred to by the reference may be more
6739 cv-qualified than the (otherwise identical) type of the
6740 template-argument. The template-parameter is bound directly to the
6741 template-argument, which must be an lvalue. */
6743 {
6745 expr_type))
6749 {
6754 }
6757 {
6762 }
6764 /* [temp.arg.nontype]/1
6766 A template-argument for a non-type, non-template template-parameter
6767 shall be one of: [...]
6769 -- the address of an object or function with external linkage. */
6772 {
6775 {
6778 "because a reference variable does not have a constant "
6781 }
6782 }
6786 /* OK, dependent reference. We don't want to ask whether a DECL is
6788 else
6789 {
6791 {
6797 }
6799 /* DR 1155 allows internal linkage in C++11 and up. */
6802 {
6808 }
6811 }
6815 }
6816 /* [temp.arg.nontype]/5, bullet 4
6818 For a non-type template-parameter of type pointer to function, only
6819 the function-to-pointer conversion (_conv.func_) is applied. If the
6820 template-argument represents a set of overloaded functions (or a
6821 pointer to such), the matching function is selected from the set
6822 (_over.over_). */
6824 {
6825 /* If the argument is a template-id, we might not have enough
6826 context information to decay the pointer. */
6828 {
6832 }
6835 /* Null pointer values are OK in C++11. */
6841 }
6842 /* [temp.arg.nontype]/5, bullet 5
6844 For a non-type template-parameter of type reference to function, no
6845 conversions apply. If the template-argument represents a set of
6846 overloaded functions, the matching function is selected from the set
6847 (_over.over_). */
6849 {
6851 {
6853 {
6858 }
6860 }
6865 }
6866 /* [temp.arg.nontype]/5, bullet 6
6868 For a non-type template-parameter of type pointer to member function,
6869 no conversions apply. If the template-argument represents a set of
6870 overloaded member functions, the matching member function is selected
6871 from the set (_over.over_). */
6873 {
6878 /* [temp.arg.nontype] bullet 1 says the pointer to member
6879 expression must be a pointer-to-member constant. */
6884 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6885 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6888 }
6889 /* [temp.arg.nontype]/5, bullet 7
6891 For a non-type template-parameter of type pointer to data member,
6892 qualification conversions (_conv.qual_) are applied. */
6894 {
6895 /* [temp.arg.nontype] bullet 1 says the pointer to member
6896 expression must be a pointer-to-member constant. */
6904 }
6906 {
6908 {
6913 }
6915 }
6916 /* A template non-type parameter must be one of the above. */
6917 else
6920 /* Sanity check: did we actually convert the argument to the
6921 right type? */
6925 }
6927 /* Subroutine of coerce_template_template_parms, which returns 1 if
6928 PARM_PARM and ARG_PARM match using the rule for the template
6929 parameters of template template parameters. Both PARM and ARG are
6930 template parameters; the rest of the arguments are the same as for
6931 coerce_template_template_parms.
6932 */
6933 static int
6935 tree arg,
6936 tsubst_flags_t complain,
6937 tree in_decl,
6938 tree outer_args)
6939 {
6948 {
6950 /* We encounter instantiations of templates like
6951 template <template <template <class> class> class TT>
6952 class C; */
6953 {
6960 }
6961 /* Fall through. */
6966 /* Argument is a parameter pack but parameter is not. */
6971 /* The tsubst call is used to handle cases such as
6973 template <int> class C {};
6974 template <class T, template <T> class TT> class D {};
6975 D<int, C> d;
6977 i.e. the parameter list of TT depends on earlier parameters. */
6979 {
6984 }
6988 /* Argument is a parameter pack but parameter is not. */
6995 }
6998 }
7000 /* Coerce template argument list ARGLIST for use with template
7001 template-parameter TEMPL. */
7003 static tree
7005 tsubst_flags_t complain)
7006 {
7007 /* Consider an example where a template template parameter declared as
7009 template <class T, class U = std::allocator<T> > class TT
7011 The template parameter level of T and U are one level larger than
7012 of TT. To proper process the default argument of U, say when an
7013 instantiation `TT<int>' is seen, we need to build the full
7014 arguments containing {int} as the innermost level. Outer levels,
7015 available when not appearing as default template argument, can be
7016 obtained from the arguments of the enclosing template.
7018 Suppose that TT is later substituted with std::vector. The above
7019 instantiation is `TT<int, std::allocator<T> >' with TT at
7020 level 1, and T at level 2, while the template arguments at level 1
7021 becomes {std::vector} and the inner level 2 is {int}. */
7025 {
7027 /* We want arguments for the partial specialization, not arguments for
7028 the primary template. */
7030 else
7032 }
7034 {
7035 /* This is an argument of the current template, so we haven't set
7036 DECL_CONTEXT yet. */
7037 tree relevant_template_parms;
7039 /* Parameter levels that are greater than the level of the given
7040 template template parm are irrelevant. */
7047 }
7054 complain,
7057 }
7059 /* A cache of template template parameters with match-all default
7060 arguments. */
7062 static void
7064 {
7068 }
7069 static tree
7071 {
7076 }
7078 /* T is a bound template template-parameter. Copy its arguments into default
7079 arguments of the template template-parameter's template parameters. */
7081 static tree
7083 {
7106 {
7109 {
7112 }
7113 }
7117 }
7119 /* ARG is a bound potential template template-argument, and PARGS is a list
7120 of arguments for the corresponding template template-parameter. Adjust
7121 PARGS as appropriate for application to ARG's template, and if ARG is a
7122 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7123 arguments to the template template parameter. */
7125 static tree
7127 {
7131 {
7132 /* When comparing two template template-parameters in partial ordering,
7133 rewrite the one currently being used as an argument to have default
7134 arguments for all parameters. */
7140 }
7141 else
7142 {
7143 tree aparms
7148 }
7151 }
7153 /* Subroutine of unify for the case when PARM is a
7154 BOUND_TEMPLATE_TEMPLATE_PARM. */
7156 static int
7159 {
7163 /* The template template parm might be variadic and the argument
7164 not, so flatten both argument lists. */
7169 {
7170 /* In keeping with P0522R0, adjust P's template arguments
7171 to apply to A's template; then flatten it again. */
7180 /* If the P0522 adjustment eliminated a pack expansion, deduce
7181 empty packs. */
7187 }
7188 else
7189 {
7190 /* Deduce arguments T, i from TT<T> or TT<i>.
7191 We check each element of PARMVEC and ARGVEC individually
7192 rather than the whole TREE_VEC since they can have
7193 different number of elements, which is allowed under N2555. */
7197 /* Check if the parameters end in a pack, making them
7198 variadic. */
7205 /* If the template argument list of P contains a pack
7206 expansion that is not the last template argument, the
7207 entire template argument list is a non-deduced
7208 context. */
7226 DEDUCE_EXACT,
7229 }
7232 }
7234 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7235 template template parameters. Both PARM_PARMS and ARG_PARMS are
7236 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7237 or PARM_DECL.
7239 Consider the example:
7240 template <class T> class A;
7241 template<template <class U> class TT> class B;
7243 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7244 the parameters to A, and OUTER_ARGS contains A. */
7246 static int
7248 tree arg_parms,
7249 tsubst_flags_t complain,
7250 tree in_decl,
7251 tree outer_args)
7252 {
7264 {
7265 /* P0522R0: A template template-parameter P is at least as specialized as
7266 a template template-argument A if, given the following rewrite to two
7267 function templates, the function template corresponding to P is at
7268 least as specialized as the function template corresponding to A
7269 according to the partial ordering rules for function templates
7270 ([temp.func.order]). Given an invented class template X with the
7271 template parameter list of A (including default arguments):
7273 * Each of the two function templates has the same template parameters,
7274 respectively, as P or A.
7276 * Each function template has a single function parameter whose type is
7277 a specialization of X with template arguments corresponding to the
7278 template parameters from the respective function template where, for
7279 each template parameter PP in the template parameter list of the
7280 function template, a corresponding template argument AA is formed. If
7281 PP declares a parameter pack, then AA is the pack expansion
7282 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7284 If the rewrite produces an invalid type, then P is not at least as
7285 specialized as A. */
7287 /* So coerce P's args to apply to A's parms, and then deduce between A's
7288 args and the converted args. If that succeeds, A is at least as
7289 specialized as P, so they match.*/
7296 {
7302 }
7303 }
7305 /* Determine whether we have a parameter pack at the end of the
7306 template template parameter's template parameter list. */
7308 {
7315 {
7329 }
7330 }
7336 /* Check all of the template parameters except the parameter pack at
7337 the end (if any). */
7339 {
7348 outer_args))
7351 }
7354 {
7355 /* Check each of the template parameters in the template
7356 argument against the template parameter pack at the end of
7357 the template template parameter. */
7364 {
7371 outer_args))
7373 }
7374 }
7377 }
7379 /* Verifies that the deduced template arguments (in TARGS) for the
7380 template template parameters (in TPARMS) represent valid bindings,
7381 by comparing the template parameter list of each template argument
7382 to the template parameter list of its corresponding template
7383 template parameter, in accordance with DR150. This
7384 routine can only be called after all template arguments have been
7385 deduced. It will return TRUE if all of the template template
7386 parameter bindings are okay, FALSE otherwise. */
7387 bool
7389 {
7393 /* We're dealing with template parms in this process. */
7399 {
7404 {
7409 {
7410 /* Look inside the argument pack. */
7413 }
7416 {
7420 /* Extract the next argument from the argument
7421 pack. */
7425 /* Look at the pattern of the pack expansion. */
7428 /* Extract the template parameters from the template
7429 argument. */
7435 /* Verify that we can coerce the template template
7436 parameters from the template argument to the template
7437 parameter. This requires an exact match. */
7439 && !coerce_template_template_parms
7441 targ_parms,
7442 tf_none,
7443 tparm,
7444 targs))
7445 {
7448 }
7449 }
7450 }
7451 }
7453 out:
7457 }
7459 /* Since type attributes aren't mangled, we need to strip them from
7460 template type arguments. */
7462 static tree
7464 {
7474 }
7476 /* And from inside dependent non-type arguments like sizeof(Type). */
7478 static tree
7480 {
7490 }
7492 // A template declaration can be substituted for a constrained
7493 // template template parameter only when the argument is more
7494 // constrained than the parameter.
7495 static bool
7497 {
7500 /* For now, allow constrained template template arguments
7501 and unconstrained template template parameters. */
7507 // If the template parameter is constrained, we need to rewrite its
7508 // constraints in terms of the ARG's template parameters. This ensures
7509 // that all of the template parameter types will have the same depth.
7510 //
7511 // Note that this is only valid when coerce_template_template_parm is
7512 // true for the innermost template parameters of PARM and ARG. In other
7513 // words, because coercion is successful, this conversion will be valid.
7515 {
7522 }
7525 }
7527 // Convert a placeholder argument into a binding to the original
7528 // parameter. The original parameter is saved as the TREE_TYPE of
7529 // ARG.
7532 {
7535 }
7537 /* Convert the indicated template ARG as necessary to match the
7538 indicated template PARM. Returns the converted ARG, or
7539 error_mark_node if the conversion was unsuccessful. Error and
7540 warning messages are issued under control of COMPLAIN. This
7541 conversion is for the Ith parameter in the parameter list. ARGS is
7542 the full set of template arguments deduced so far. */
7544 static tree
7546 tree arg,
7547 tree args,
7548 tsubst_flags_t complain,
7550 tree in_decl)
7551 {
7552 tree orig_arg;
7553 tree val;
7559 /* Trivially convert placeholders. */
7568 {
7569 /* The template argument was the name of some
7570 member function. That's usually
7571 invalid, but static members are OK. In any
7572 case, grab the underlying fields/functions
7573 and issue an error later if required. */
7576 }
7584 /* When determining whether an argument pack expansion is a template,
7585 look at the pattern. */
7589 /* Deal with an injected-class-name used as a template template arg. */
7591 {
7594 {
7604 }
7605 }
7607 is_tmpl_type =
7623 {
7625 {
7629 }
7632 "to refer to a type member of a template parameter, "
7637 typename_type,
7638 complain);
7641 }
7643 {
7645 {
7647 {
7659 else
7662 }
7663 }
7665 }
7667 {
7669 {
7676 else
7679 }
7681 }
7684 /* We already did the appropriate conversion when packing args. */
7687 {
7689 {
7691 /* The number of argument required is not known yet.
7692 Just accept it for now. */
7694 else
7695 {
7697 tree argparm;
7699 /* Strip alias templates that are equivalent to another
7700 template. */
7706 args))
7707 {
7710 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7711 TEMPLATE_DECL. */
7713 {
7718 }
7719 }
7720 else
7721 {
7723 {
7730 }
7733 }
7735 // Check that the constraints are compatible before allowing the
7736 // substitution.
7739 {
7741 {
7747 }
7749 }
7750 }
7751 }
7752 else
7754 /* We only form one instance of each template specialization.
7755 Therefore, if we use a non-canonical variant (i.e., a
7756 typedef), any future messages referring to the type will use
7757 the typedef, which is confusing if those future uses do not
7758 themselves also use the typedef. */
7761 }
7762 else
7763 {
7767 {
7771 }
7772 else
7780 /* We used to call digest_init here. However, digest_init
7781 will report errors, which we don't want when complain
7782 is zero. More importantly, digest_init will try too
7783 hard to convert things: for example, `0' should not be
7784 converted to pointer type at this point according to
7785 the standard. Accepting this is not merely an
7786 extension, since deciding whether or not these
7787 conversions can occur is part of determining which
7788 function template to call, or whether a given explicit
7789 argument specification is valid. */
7791 else
7801 {
7802 /* Reject template arguments that are references to built-in
7803 functions with no library fallbacks. */
7812 }
7815 {
7816 /* Strip typedefs from the SCOPE_REF. */
7819 complain);
7822 }
7823 }
7826 }
7828 /* Coerces the remaining template arguments in INNER_ARGS (from
7829 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7830 Returns the coerced argument pack. PARM_IDX is the position of this
7831 parameter in the template parameter list. ARGS is the original
7832 template argument list. */
7833 static tree
7836 tree args,
7837 tree inner_args,
7839 tree new_args,
7841 tree in_decl,
7842 tsubst_flags_t complain)
7843 {
7846 tree packed_args;
7847 tree argument_pack;
7854 {
7855 /* When the template parameter is a non-type template parameter pack
7856 or template template parameter pack whose type or template
7857 parameters use parameter packs, we know exactly how many arguments
7858 we are looking for. Build a vector of the instantiated decls for
7859 these template parameters in PACKED_PARMS. */
7860 /* We can't use make_pack_expansion here because it would interpret a
7861 _DECL as a use rather than a declaration. */
7875 /* If we're doing a partial instantiation of a member template,
7876 verify that all of the types used for the non-type
7877 template parameter pack are, in fact, valid for non-type
7878 template parameters. */
7881 {
7884 {
7888 }
7889 /* We don't know how many args we have yet, just
7890 use the unconverted ones for now. */
7892 }
7895 }
7896 /* Check if we have a placeholder pack, which indicates we're
7897 in the context of a introduction list. In that case we want
7898 to match this pack to the single placeholder. */
7902 {
7905 }
7906 else
7909 /* Convert the remaining arguments, which will be a part of the
7910 parameter pack "parm". */
7913 {
7919 {
7920 /* Once we've packed as many args as we have types, stop. */
7924 /* We don't know how many args we have yet, just
7925 use the unconverted ones for now. */
7927 else
7929 }
7932 {
7935 }
7936 else
7939 in_decl);
7943 }
7947 {
7952 }
7957 else
7958 {
7961 }
7968 }
7970 /* Returns the number of pack expansions in the template argument vector
7971 ARGS. */
7973 static int
7975 {
7980 {
7984 }
7986 }
7988 /* Convert all template arguments to their appropriate types, and
7989 return a vector containing the innermost resulting template
7990 arguments. If any error occurs, return error_mark_node. Error and
7991 warning messages are issued under control of COMPLAIN.
7993 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7994 for arguments not specified in ARGS. Otherwise, if
7995 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7996 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7997 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7998 ARGS. */
8000 static tree
8002 tree args,
8003 tree in_decl,
8004 tsubst_flags_t complain,
8007 {
8009 tree orig_inner_args;
8010 tree inner_args;
8011 tree new_args;
8012 tree new_inner_args;
8016 /* When used as a boolean value, indicates whether this is a
8017 variadic template parameter list. Since it's an int, we can also
8018 subtract it from nparms to get the number of non-variadic
8019 parameters. */
8024 /* Likewise for parameters with default arguments. */
8032 /* Determine if there are any parameter packs or default arguments. */
8034 {
8042 }
8045 /* If there are no parameters that follow a parameter pack, we need to
8046 expand any argument packs so that we can deduce a parameter pack from
8047 some non-packed args followed by an argument pack, as in variadic85.C.
8048 If there are such parameters, we need to leave argument packs intact
8049 so the arguments are assigned properly. This can happen when dealing
8050 with a nested class inside a partial specialization of a class
8051 template, as in variadic92.C, or when deducing a template parameter pack
8052 from a sub-declarator, as in variadic114.C. */
8056 /* Count any pack expansion args. */
8062 && require_all_args
8063 && !variadic_args_p
8064 && (!use_default_args
8067 {
8069 {
8071 {
8075 }
8076 else
8083 }
8086 }
8087 /* We can't pass a pack expansion to a non-pack parameter of an alias
8088 template (DR 1430). */
8092 && variadic_args_p
8094 {
8096 {
8098 {
8104 {
8107 "pack expansion argument for non-pack parameter "
8109 else
8111 "pack expansion argument for non-pack parameter "
8115 }
8116 }
8118 found:;
8119 }
8121 }
8123 /* We need to evaluate the template arguments, even though this
8124 template-id may be nested within a "sizeof". */
8133 {
8134 tree arg;
8135 tree parm;
8137 /* Get the Ith template parameter. */
8141 {
8144 }
8146 /* Calculate the next argument. */
8149 else
8154 {
8155 /* Some arguments will be placed in the
8156 template parameter pack PARM. */
8163 {
8164 /* We don't know how many args we have yet, just use the
8165 unconverted (and still packed) ones for now. */
8169 }
8173 /* Store this argument. */
8175 {
8176 lost++;
8177 /* We are done with all of the arguments. */
8179 }
8180 else
8181 {
8184 }
8187 }
8189 {
8191 {
8192 /* "If every valid specialization of a variadic template
8193 requires an empty template parameter pack, the template is
8194 ill-formed, no diagnostic required." So check that the
8195 pattern works with this parameter. */
8200 in_decl);
8202 {
8207 }
8209 /* Recover from missing typename. */
8213 /* We don't know how many args we have yet, just
8214 use the unconverted ones for now. */
8218 }
8219 }
8221 {
8222 /* There must be a default arg in this case. */
8225 /* The position of the first default template argument,
8226 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8227 Record that. */
8231 }
8232 else
8236 {
8239 }
8241 /* This only occurs if there was an error in the template
8242 parameter list itself (which we would already have
8243 reported) that we are trying to recover from, e.g., a class
8244 template with a parameter list such as
8245 template<typename..., typename>. */
8247 else
8253 lost++;
8255 }
8260 {
8262 {
8267 }
8269 }
8279 }
8281 /* Convert all template arguments to their appropriate types, and
8282 return a vector containing the innermost resulting template
8283 arguments. If any error occurs, return error_mark_node. Error and
8284 warning messages are not issued.
8286 Note that no function argument deduction is performed, and default
8287 arguments are used to fill in unspecified arguments. */
8288 tree
8290 {
8292 }
8294 /* Convert all template arguments to their appropriate type, and
8295 instantiate default arguments as needed. This returns a vector
8296 containing the innermost resulting template arguments, or
8297 error_mark_node if unsuccessful. */
8298 tree
8300 tsubst_flags_t complain)
8301 {
8303 }
8305 /* Like coerce_template_parms. If PARMS represents all template
8306 parameters levels, this function returns a vector of vectors
8307 representing all the resulting argument levels. Note that in this
8308 case, only the innermost arguments are coerced because the
8309 outermost ones are supposed to have been coerced already.
8311 Otherwise, if PARMS represents only (the innermost) vector of
8312 parameters, this function returns a vector containing just the
8313 innermost resulting arguments. */
8315 static tree
8317 tree args,
8318 tree in_decl,
8319 tsubst_flags_t complain,
8322 {
8325 tree coerced_args;
8328 {
8330 tree level;
8336 {
8337 tree l;
8341 require_all_args,
8342 use_default_args);
8343 else
8350 }
8351 }
8352 else
8355 require_all_args,
8356 use_default_args);
8358 }
8360 /* Returns 1 if template args OT and NT are equivalent. */
8362 int
8364 {
8373 /* For member templates */
8382 {
8399 }
8403 {
8406 /* Don't treat an alias template specialization with dependent
8407 arguments as equivalent to its underlying type when used as a
8408 template argument; we need them to be distinct so that we
8409 substitute into the specialization arguments at instantiation
8410 time. And aliases can't be equivalent without being ==, so
8411 we don't need to look any deeper.
8413 During partial ordering, however, we need to treat them normally so
8414 that we can order uses of the same alias with different
8415 cv-qualification (79960). */
8419 else
8421 }
8424 else
8425 {
8426 /* Try to treat a template non-type argument that has been converted
8427 to the parameter type as equivalent to one that hasn't yet. */
8440 }
8441 }
8443 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8444 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8445 NEWARG_PTR with the offending arguments if they are non-NULL. */
8447 int
8451 {
8464 {
8469 {
8475 }
8476 }
8478 }
8482 {
8484 }
8486 static void
8488 {
8498 /* We are called both from instantiate_decl, where we've already had a
8499 tinst_level pushed, and instantiate_template, where we haven't.
8500 Compensate. */
8511 else
8520 }
8523 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8524 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8525 documentation for TEMPLATE_ID_EXPR. */
8527 tree
8529 {
8530 tree type;
8538 {
8541 }
8544 {
8546 unknown_type_node,
8548 arglist);
8550 }
8557 }
8559 /* Within the scope of a template class S<T>, the name S gets bound
8560 (in build_self_reference) to a TYPE_DECL for the class, not a
8561 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8562 or one of its enclosing classes, and that type is a template,
8563 return the associated TEMPLATE_DECL. Otherwise, the original
8564 DECL is returned.
8566 Also handle the case when DECL is a TREE_LIST of ambiguous
8567 injected-class-names from different bases. */
8569 tree
8571 {
8575 /* DR 176: A lookup that finds an injected-class-name (10.2
8576 [class.member.lookup]) can result in an ambiguity in certain cases
8577 (for example, if it is found in more than one base class). If all of
8578 the injected-class-names that are found refer to specializations of
8579 the same class template, and if the name is followed by a
8580 template-argument-list, the reference refers to the class template
8581 itself and not a specialization thereof, and is not ambiguous. */
8583 {
8586 {
8592 }
8595 else
8597 }
8603 }
8605 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8606 parameters, find the desired type.
8608 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8610 IN_DECL, if non-NULL, is the template declaration we are trying to
8611 instantiate.
8613 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8614 the class we are looking up.
8616 Issue error and warning messages under control of COMPLAIN.
8618 If the template class is really a local class in a template
8619 function, then the FUNCTION_CONTEXT is the function in which it is
8620 being instantiated.
8622 ??? Note that this function is currently called *twice* for each
8623 template-id: the first time from the parser, while creating the
8624 incomplete type (finish_template_type), and the second type during the
8625 real instantiation (instantiate_template_class). This is surely something
8626 that we want to avoid. It also causes some problems with argument
8627 coercion (see convert_nontype_argument for more information on this). */
8629 static tree
8632 {
8634 tree t;
8637 spec_entry elt;
8638 hashval_t hash;
8641 {
8645 else
8646 {
8653 }
8656 }
8658 {
8661 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8662 an implicit typename for the second A. Deal with it. */
8667 {
8670 }
8671 }
8674 {
8677 }
8679 {
8683 }
8685 {
8688 }
8690 /* Issue an error message if we didn't find a template. */
8692 {
8696 }
8699 /* Make sure it's a user visible template, if it was named by
8700 the user. */
8703 {
8705 {
8709 }
8711 }
8715 /* An alias that just changes the name of a template is equivalent to the
8716 other template, so if any of the arguments are pack expansions, strip
8717 the alias to avoid problems with a pack expansion passed to a non-pack
8718 alias template parameter (DR 1430). */
8723 {
8724 tree parm;
8733 }
8734 else
8735 {
8737 tree gen_tmpl;
8738 tree type_decl;
8746 /* An error occurred while building the template TEMPL, and a
8747 diagnostic has most certainly been emitted for that
8748 already. Let's propagate that error. */
8757 {
8758 /* We've been given an incomplete set of template arguments.
8759 For example, given:
8761 template <class T> struct S1 {
8762 template <class U> struct S2 {};
8763 template <class U> struct S2<U*> {};
8764 };
8766 we will be called with an ARGLIST of `U*', but the
8767 TEMPLATE will be `template <class T> template
8768 <class U> struct S1<T>::S2'. We must fill in the missing
8769 arguments. */
8773 }
8775 /* Now we should have enough arguments. */
8778 /* From here on, we're only interested in the most general
8779 template. */
8781 /* Calculate the BOUND_ARGS. These will be the args that are
8782 actually tsubst'd into the definition to create the
8783 instantiation. */
8785 complain,
8790 /* We were unable to bind the arguments. */
8793 /* In the scope of a template class, explicit references to the
8794 template class refer to the type of the template, not any
8795 instantiation of it. For example, in:
8797 template <class T> class C { void f(C<T>); }
8799 the `C<T>' is just the same as `C'. Outside of the
8800 class, however, such a reference is an instantiation. */
8804 {
8809 }
8811 /* If we already have this specialization, return it. */
8821 /* If the the template's constraints are not satisfied,
8822 then we cannot form a valid type.
8824 Note that the check is deferred until after the hash
8825 lookup. This prevents redundant checks on previously
8826 instantiated specializations. */
8828 {
8830 {
8833 }
8835 }
8839 /* If the deduced arguments are invalid, then the binding
8840 failed. */
8844 complain))
8851 {
8856 }
8866 /* Create the type. */
8868 {
8869 /* The user referred to a specialization of an alias
8870 template represented by GEN_TMPL.
8872 [temp.alias]/2 says:
8874 When a template-id refers to the specialization of an
8875 alias template, it is equivalent to the associated
8876 type obtained by substitution of its
8877 template-arguments for the template-parameters in the
8878 type-id of the alias template. */
8881 /* Note that the call above (by indirectly calling
8882 register_specialization in tsubst_decl) registers the
8883 TYPE_DECL representing the specialization of the alias
8884 template. So next time someone substitutes ARGLIST for
8885 the template parms into the alias template (GEN_TMPL),
8886 she'll get that TYPE_DECL back. */
8890 }
8892 {
8894 {
8905 }
8906 else
8907 {
8908 /* We don't want to call start_enum for this type, since
8909 the values for the enumeration constants may involve
8910 template parameters. And, no one should be interested
8911 in the enumeration constants for such a type. */
8914 }
8918 }
8920 {
8926 /* A local class. Make sure the decl gets registered properly. */
8931 /* This instantiation is another name for the primary
8932 template type. Set the TYPE_CANONICAL field
8933 appropriately. */
8936 /* Some of the template arguments require structural
8937 equality testing, so this template class requires
8938 structural equality testing. */
8940 }
8941 else
8944 /* If we called start_enum or pushtag above, this information
8945 will already be set up. */
8947 {
8954 }
8955 else
8959 {
8965 {
8968 }
8969 }
8973 {
8977 {
8978 tree attributes
8986 }
8987 }
8989 /* Let's consider the explicit specialization of a member
8990 of a class template specialization that is implicitly instantiated,
8991 e.g.:
8992 template<class T>
8993 struct S
8994 {
8995 template<class U> struct M {}; //#0
8996 };
8998 template<>
8999 template<>
9000 struct S<int>::M<char> //#1
9001 {
9002 int i;
9003 };
9004 [temp.expl.spec]/4 says this is valid.
9006 In this case, when we write:
9007 S<int>::M<char> m;
9009 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
9010 the one of #0.
9012 When we encounter #1, we want to store the partial instantiation
9013 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
9015 For all cases other than this "explicit specialization of member of a
9016 class template", we just want to store the most general template into
9017 the CLASSTYPE_TI_TEMPLATE of M.
9019 This case of "explicit specialization of member of a class template"
9020 only happens when:
9021 1/ the enclosing class is an instantiation of, and therefore not
9022 the same as, the context of the most general template, and
9023 2/ we aren't looking at the partial instantiation itself, i.e.
9024 the innermost arguments are not the same as the innermost parms of
9025 the most general template.
9027 So it's only when 1/ and 2/ happens that we want to use the partial
9028 instantiation of the member template in lieu of its most general
9029 template. */
9033 /* the enclosing class must be an instantiation... */
9036 {
9040 tree partial_inst_args =
9047 use_partial_inst_tmpl =
9048 /*...and we must not be looking at the partial instantiation
9049 itself. */
9051 partial_inst_args);
9052 }
9055 /* This case is easy; there are no member templates involved. */
9057 else
9058 {
9059 /* This is a full instantiation of a member template. Find
9060 the partial instantiation of which this is an instance. */
9062 /* Temporarily reduce by one the number of levels in the ARGLIST
9063 so as to avoid comparing the last set of arguments. */
9067 /* FOUND is either a proper class type, or an alias
9068 template specialization. In the later case, it's a
9069 TYPE_DECL, resulting from the substituting of arguments
9070 for parameters in the TYPE_DECL of the alias template
9071 done earlier. So be careful while getting the template
9072 of FOUND. */
9074 ? found
9078 }
9080 // Build template info for the new specialization.
9089 /* Note this use of the partial instantiation so we can check it
9090 later in maybe_process_partial_specialization. */
9097 /* Now that the type has been registered on the instantiations
9098 list, we set up the enumerators. Because the enumeration
9099 constants may involve the enumeration type itself, we make
9100 sure to register the type first, and then create the
9101 constants. That way, doing tsubst_expr for the enumeration
9102 constants won't result in recursive calls here; we'll find
9103 the instantiation and exit above. */
9107 /* If the type makes use of template parameters, the
9108 code that generates debugging information will crash. */
9111 /* Possibly limit visibility based on template args. */
9118 }
9119 }
9121 /* Wrapper for lookup_template_class_1. */
9123 tree
9126 {
9127 tree ret;
9133 }
9135 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9137 tree
9139 {
9140 /* The type of the expression is NULL_TREE since the template-id could refer
9141 to an explicit or partial specialization. */
9144 /* Except that concepts are always bool. */
9147 }
9149 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9151 tree
9153 {
9157 /* We never want to return a VAR_DECL for a variable concept, since they
9158 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9173 {
9175 {
9178 }
9180 }
9182 /* If a template-id refers to a specialization of a variable
9183 concept, then the expression is true if and only if the
9184 concept's constraints are satisfied by the given template
9185 arguments.
9187 NOTE: This is an extension of Concepts Lite TS that
9188 allows constraints to be used in expressions. */
9190 {
9193 }
9196 }
9198 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9199 TARGS template args, and instantiate it if it's not dependent. */
9201 tree
9203 tsubst_flags_t complain)
9204 {
9207 {
9210 }
9213 }
9215 \f
9216 struct pair_fn_data
9217 {
9218 tree_fn_t fn;
9219 tree_fn_t any_fn;
9221 /* True when we should also visit template parameters that occur in
9222 non-deduced contexts. */
9225 };
9227 /* Called from for_each_template_parm via walk_tree. */
9229 static tree
9231 {
9238 #define WALK_SUBTREE(NODE) \
9239 do \
9240 { \
9241 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9242 pfd->include_nondeduced_p, \
9243 pfd->any_fn); \
9244 if (result) goto out; \
9245 } \
9246 while (0)
9256 {
9260 /* Fall through. */
9266 else
9276 /* Since we're not going to walk subtrees, we have to do this
9277 explicitly here. */
9279 /* Fall through. */
9282 /* Check the return type. */
9285 /* Check the parameter types. Since default arguments are not
9286 instantiated until they are needed, the TYPE_ARG_TYPES may
9287 contain expressions that involve template parameters. But,
9288 no-one should be looking at them yet. And, once they're
9289 instantiated, they don't contain template parameters, so
9290 there's no point in looking at them then, either. */
9291 {
9292 tree parm;
9297 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9298 want walk_tree walking into them itself. */
9300 }
9303 {
9307 }
9324 /* Fall through. */
9336 /* Record template parameters such as `T' inside `TT<T>'. */
9338 /* Fall through. */
9350 /* A template template parameter is encountered. */
9354 /* Already substituted template template parameter */
9359 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9360 partial instantiation. */
9372 /* If there's no type, then this thing must be some expression
9373 involving template parameters. */
9395 }
9397 #undef WALK_SUBTREE
9399 /* We didn't find any template parameters we liked. */
9400 out:
9402 }
9404 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9405 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9406 call FN with the parameter and the DATA.
9407 If FN returns nonzero, the iteration is terminated, and
9408 for_each_template_parm returns 1. Otherwise, the iteration
9409 continues. If FN never returns a nonzero value, the value
9410 returned by for_each_template_parm is 0. If FN is NULL, it is
9411 considered to be the function which always returns 1.
9413 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9414 parameters that occur in non-deduced contexts. When false, only
9415 visits those template parameters that can be deduced. */
9417 static tree
9421 tree_fn_t any_fn)
9422 {
9424 tree result;
9426 /* Set up. */
9432 /* Walk the tree. (Conceptually, we would like to walk without
9433 duplicates, but for_each_template_parm_r recursively calls
9434 for_each_template_parm, so we would need to reorganize a fair
9435 bit to use walk_tree_without_duplicates, so we keep our own
9436 visited list.) */
9439 else
9442 for_each_template_parm_r,
9446 /* Clean up. */
9448 {
9451 }
9454 }
9456 /* Returns true if T depends on any template parameter. */
9458 int
9460 {
9490 else
9491 {
9494 }
9499 }
9501 /* Returns true iff current_function_decl is an incompletely instantiated
9502 template. Useful instead of processing_template_decl because the latter
9503 is set to 0 during instantiate_non_dependent_expr. */
9505 bool
9507 {
9516 }
9518 /* Returns true if T depends on any template parameter with level LEVEL. */
9520 bool
9522 {
9525 }
9527 /* Returns true if the signature of DECL depends on any template parameter from
9528 its enclosing class. */
9530 bool
9532 {
9542 template_parm_outer_level,
9552 }
9554 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9555 ill-formed translation unit, i.e. a variable or function that isn't
9556 usable in a constant expression. */
9560 {
9565 }
9567 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9568 neglectable and instantiated from within an erroneous instantiation. */
9570 static bool
9572 {
9583 }
9591 /* We're starting to instantiate D; record the template instantiation context
9592 for diagnostics and to restore it later. */
9594 bool
9596 {
9598 }
9600 /* We're starting to instantiate D; record the template instantiation context
9601 at LOC for diagnostics and to restore it later. */
9603 bool
9605 {
9609 {
9610 /* Tell error.c not to try to instantiate any templates. */
9613 "template instantiation depth exceeds maximum of %d"
9615 max_tinst_depth);
9617 }
9619 /* If the current instantiation caused problems, don't let it instantiate
9620 anything else. Do allow deduction substitution and decls usable in
9621 constant expressions. */
9625 /* When not -quiet, dump template instantiations other than functions, since
9626 announce_function will take care of those. */
9645 }
9647 /* We're done instantiating this template; return to the instantiation
9648 context. */
9650 void
9652 {
9653 /* Restore the filename and line number stashed away when we started
9654 this instantiation. */
9658 }
9660 /* We're instantiating a deferred template; restore the template
9661 instantiation context in which the instantiation was requested, which
9662 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9664 static tree
9666 {
9678 }
9680 /* Returns the TINST_LEVEL which gives the original instantiation
9681 context. */
9685 {
9691 }
9693 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9694 vector of template arguments, as for tsubst.
9696 Returns an appropriate tsubst'd friend declaration. */
9698 static tree
9700 {
9701 tree new_friend;
9706 /* This was a friend declared with an explicit template
9707 argument list, e.g.:
9709 friend void f<>(T);
9711 to indicate that f was a template instantiation, not a new
9712 function declaration. Now, we have to figure out what
9713 instantiation of what template. */
9714 {
9716 tree new_args;
9717 tree tmpl;
9720 /* Friend functions are looked up in the containing namespace scope.
9721 We must enter that scope, to avoid finding member functions of the
9722 current class with same name. */
9737 tsk_none);
9739 }
9743 /* The NEW_FRIEND will look like an instantiation, to the
9744 compiler, but is not an instantiation from the point of view of
9745 the language. For example, we might have had:
9747 template <class T> struct S {
9748 template <class U> friend void f(T, U);
9749 };
9751 Then, in S<int>, template <class U> void f(int, U) is not an
9752 instantiation of anything. */
9758 {
9762 }
9764 /* The mangled name for the NEW_FRIEND is incorrect. The function
9765 is not a template instantiation and should not be mangled like
9766 one. Therefore, we forget the mangling here; we'll recompute it
9767 later if we need it. */
9769 {
9772 }
9775 {
9776 tree old_decl;
9777 tree new_friend_template_info;
9778 tree new_friend_result_template_info;
9779 tree ns;
9782 /* We must save some information from NEW_FRIEND before calling
9783 duplicate decls since that function will free NEW_FRIEND if
9784 possible. */
9786 new_friend_is_defn =
9791 {
9792 /* This declaration is a `primary' template. */
9795 new_friend_result_template_info
9797 }
9798 else
9801 /* Inside pushdecl_namespace_level, we will push into the
9802 current namespace. However, the friend function should go
9803 into the namespace of the template. */
9813 {
9814 /* This new friend declaration matched an existing
9815 declaration. For example, given:
9817 template <class T> void f(T);
9818 template <class U> class C {
9819 template <class T> friend void f(T) {}
9820 };
9822 the friend declaration actually provides the definition
9823 of `f', once C has been instantiated for some type. So,
9824 old_decl will be the out-of-class template declaration,
9825 while new_friend is the in-class definition.
9827 But, if `f' was called before this point, the
9828 instantiation of `f' will have DECL_TI_ARGS corresponding
9829 to `T' but not to `U', references to which might appear
9830 in the definition of `f'. Previously, the most general
9831 template for an instantiation of `f' was the out-of-class
9832 version; now it is the in-class version. Therefore, we
9833 run through all specialization of `f', adding to their
9834 DECL_TI_ARGS appropriately. In particular, they need a
9835 new set of outer arguments, corresponding to the
9836 arguments for this class instantiation.
9838 The same situation can arise with something like this:
9840 friend void f(int);
9841 template <class T> class C {
9842 friend void f(T) {}
9843 };
9845 when `C<int>' is instantiated. Now, `f(int)' is defined
9846 in the class. */
9849 /* On the other hand, if the in-class declaration does
9850 *not* provide a definition, then we don't want to alter
9851 existing definitions. We can just leave everything
9852 alone. */
9853 ;
9854 else
9855 {
9859 /* Overwrite whatever template info was there before, if
9860 any, with the new template information pertaining to
9861 the declaration. */
9865 {
9866 /* We should have called reregister_specialization in
9867 duplicate_decls. */
9872 /* Instantiate it if the global has already been used. */
9876 }
9877 else
9878 {
9879 tree t;
9881 /* Indicate that the old function template is a partial
9882 instantiation. */
9890 /* Reassign any specializations already in the hash table
9891 to the new more general template, and add the
9892 additional template args. */
9896 {
9898 spec_entry elt;
9910 register_specialization
9913 }
9915 }
9916 }
9918 /* The information from NEW_FRIEND has been merged into OLD_DECL
9919 by duplicate_decls. */
9921 }
9922 }
9923 else
9924 {
9928 /* In the code
9929 template <class T> class C {
9930 template <class U> friend void C1<U>::f (); // case 1
9931 friend void C2<T>::f (); // case 2
9932 };
9933 we only need to make sure CONTEXT is a complete type for
9934 case 2. To distinguish between the two cases, we note that
9935 CONTEXT of case 1 remains dependent type after tsubst while
9936 this isn't true for case 2. */
9946 {
9948 /* do_friend adds the TEMPLATE_DECL for any member friend
9949 template even if it isn't a member template, i.e.
9950 template <class T> friend A<T>::f();
9951 Look through it in that case. */
9955 /* Check to see that the declaration is really present, and,
9956 possibly obtain an improved declaration. */
9961 }
9962 }
9965 }
9967 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9968 template arguments, as for tsubst.
9970 Returns an appropriate tsubst'd friend type or error_mark_node on
9971 failure. */
9973 static tree
9975 {
9976 tree friend_type;
9977 tree tmpl;
9978 tree context;
9981 {
9984 }
9989 {
9992 else
9994 }
9996 /* Look for a class template declaration. We look for hidden names
9997 because two friend declarations of the same template are the
9998 same. For example, in:
10000 struct A {
10001 template <typename> friend class F;
10002 };
10003 template <typename> struct B {
10004 template <typename> friend class F;
10005 };
10007 both F templates are the same. */
10011 /* But, if we don't find one, it might be because we're in a
10012 situation like this:
10014 template <class T>
10015 struct S {
10016 template <class U>
10017 friend struct S;
10018 };
10020 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
10021 for `S<int>', not the TEMPLATE_DECL. */
10023 {
10026 }
10029 {
10030 /* The friend template has already been declared. Just
10031 check to see that the declarations match, and install any new
10032 default parameters. We must tsubst the default parameters,
10033 of course. We only need the innermost template parameters
10034 because that is all that redeclare_class_template will look
10035 at. */
10038 {
10039 tree parms;
10040 location_t saved_input_location;
10050 }
10053 }
10054 else
10055 {
10056 /* The friend template has not already been declared. In this
10057 case, the instantiation of the template class will cause the
10058 injection of this template into the global scope. */
10063 /* The new TMPL is not an instantiation of anything, so we
10064 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
10065 the new type because that is supposed to be the corresponding
10066 template decl, i.e., TMPL. */
10073 /* Inject this template into the global scope. */
10075 }
10078 {
10081 else
10083 }
10086 }
10088 /* Returns zero if TYPE cannot be completed later due to circularity.
10089 Otherwise returns one. */
10091 static int
10093 {
10103 else
10105 }
10110 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10111 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10113 static tree
10116 {
10125 {
10132 clauses
10136 else
10138 }
10139 /* If the first attribute argument is an identifier, don't
10140 pass it through tsubst. Attributes like mode, format,
10141 cleanup and several target specific attributes expect it
10142 unmodified. */
10144 {
10145 tree chain
10150 }
10152 {
10153 /* An attribute pack expansion. */
10162 {
10166 }
10168 }
10169 else
10176 }
10178 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10179 unchanged or a new TREE_LIST chain. */
10181 static tree
10184 {
10189 {
10193 }
10197 {
10200 {
10203 {
10205 do
10210 }
10211 }
10213 }
10216 }
10218 /* Apply any attributes which had to be deferred until instantiation
10219 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10220 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10222 static void
10225 {
10227 tree t;
10234 {
10238 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10239 to our attributes parameter. */
10241 }
10242 else
10243 {
10245 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10246 lookup_template_class_1, and should be preserved. */
10250 }
10254 {
10258 }
10262 {
10267 {
10270 {
10274 do
10277 }
10278 else
10280 }
10283 }
10284 }
10286 /* Perform (or defer) access check for typedefs that were referenced
10287 from within the template TMPL code.
10288 This is a subroutine of instantiate_decl and instantiate_class_template.
10289 TMPL is the template to consider and TARGS is the list of arguments of
10290 that template. */
10292 static void
10294 {
10295 location_t saved_location;
10306 {
10318 /* Make access check error messages point to the location
10319 of the use of the typedef. */
10323 tf_warning_or_error);
10324 }
10326 }
10328 static tree
10330 {
10332 tree typedecl;
10333 tree pbinfo;
10334 tree base_list;
10336 tree fn_context;
10345 /* Figure out which template is being instantiated. */
10349 /* Determine what specialization of the original template to
10350 instantiate. */
10353 {
10356 }
10358 {
10359 /* This TYPE is actually an instantiation of a partial
10360 specialization. We replace the innermost set of ARGS with
10361 the arguments appropriate for substitution. For example,
10362 given:
10364 template <class T> struct S {};
10365 template <class T> struct S<T*> {};
10367 and supposing that we are instantiating S<int*>, ARGS will
10368 presently be {int*} -- but we need {int}. */
10371 }
10372 else
10373 {
10376 }
10378 /* If the template we're instantiating is incomplete, then clearly
10379 there's nothing we can do. */
10383 /* If we've recursively instantiated too many templates, stop. */
10387 /* Now we're really doing the instantiation. Mark the type as in
10388 the process of being defined. */
10391 /* We may be in the middle of deferred access check. Disable
10392 it now. */
10399 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10404 else
10405 {
10408 }
10409 /* Use #pragma pack from the template context. */
10415 /* Set the input location to the most specialized template definition.
10416 This is needed if tsubsting causes an error. */
10428 {
10431 /* Adjust visibility for template arguments. */
10433 }
10439 /* We should never instantiate a nested class before its enclosing
10440 class; we need to look up the nested class by name before we can
10441 instantiate it, and that lookup should instantiate the enclosing
10442 class. */
10448 {
10449 tree pbase_binfo;
10450 tree pushed_scope;
10453 /* We must enter the scope containing the type, as that is where
10454 the accessibility of types named in dependent bases are
10455 looked up from. */
10458 /* Substitute into each of the bases to determine the actual
10459 basetypes. */
10461 {
10462 tree base;
10468 {
10469 expanded_bases =
10476 }
10479 {
10481 /* Extract the already-expanded base class. */
10483 else
10484 /* Substitute to figure out the base class. */
10486 NULL_TREE);
10494 }
10495 }
10497 /* The list is now in reverse order; correct that. */
10502 }
10503 /* Now call xref_basetypes to set up all the base-class
10504 information. */
10512 /* Now that our base classes are set up, enter the scope of the
10513 class, so that name lookups into base classes, etc. will work
10514 correctly. This is precisely analogous to what we do in
10515 begin_class_definition when defining an ordinary non-template
10516 class, except we also need to push the enclosing classes. */
10519 /* Now members are processed in the order of declaration. */
10522 {
10526 {
10528 {
10529 /* Build new CLASSTYPE_NESTED_UTDS. */
10531 tree newtag;
10537 /* If the member is a class template, then -- even after
10538 substitution -- there may be dependent types in the
10539 template argument list for the class. We increment
10540 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10541 that function will assume that no types are dependent
10542 when outside of a template. */
10552 {
10556 /* Unfortunately, lookup_template_class sets
10557 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10558 instantiation (i.e., for the type of a member
10559 template class nested within a template class.)
10560 This behavior is required for
10561 maybe_process_partial_specialization to work
10562 correctly, but is not accurate in this case;
10563 the TAG is not an instantiation of anything.
10564 (The corresponding TEMPLATE_DECL is an
10565 instantiation, but the TYPE is not.) */
10568 /* Now, we call pushtag to put this NEWTAG into the scope of
10569 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10570 pushtag calling push_template_decl. We don't have to do
10571 this for enums because it will already have been done in
10572 tsubst_enum. */
10576 }
10577 }
10579 {
10580 tree r;
10589 /* Instantiate members marked with attribute used. */
10595 }
10598 /* A closure type for a lambda in a default argument for a
10599 member template. Ignore it; it will be instantiated with
10601 else
10602 {
10603 /* Build new TYPE_FIELDS. */
10605 {
10606 tree condition;
10609 condition =
10619 }
10621 {
10622 tree r;
10626 /* The file and line for this declaration, to
10627 assist in error message reporting. Since we
10628 called push_tinst_level above, we don't need to
10629 restore these. */
10639 {
10640 /* A capture pack became multiple fields. */
10643 }
10646 {
10650 {
10651 /* In [temp.inst]:
10653 [t]he initialization (and any associated
10654 side-effects) of a static data member does
10655 not occur unless the static data member is
10656 itself used in a way that requires the
10657 definition of the static data member to
10658 exist.
10660 Therefore, we do not substitute into the
10661 initialized for the static data member here. */
10662 finish_static_data_member_decl
10668 /* Instantiate members marked with attribute used. */
10671 }
10673 {
10674 /* Determine whether R has a valid type and can be
10675 completed later. If R is invalid, then its type
10676 is replaced by error_mark_node. */
10682 {
10683 /* If R's type couldn't be completed and
10684 it isn't a flexible array member (whose
10685 type is incomplete by definition) give
10686 an error. */
10689 }
10690 }
10692 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10693 such a thing will already have been added to the field
10694 list by tsubst_enum in finish_member_declaration in the
10695 CLASSTYPE_NESTED_UTDS case above. */
10699 {
10702 }
10703 }
10704 }
10705 }
10706 }
10707 else
10708 {
10711 {
10712 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10718 {
10719 /* template <class T> friend class C; */
10722 }
10724 {
10725 /* template <class T> friend class C::D; */
10731 }
10734 {
10735 /* This could be either
10737 friend class T::C;
10739 when dependent_type_p is false or
10741 template <class U> friend class T::C;
10743 otherwise. */
10744 /* Bump processing_template_decl in case this is something like
10745 template <class T> friend struct A<T>::B. */
10752 }
10756 {
10757 /* friend class C;
10759 where C hasn't been declared yet. Let's lookup name
10760 from namespace scope directly, bypassing any name that
10761 come from dependent base class. */
10764 /* The call to xref_tag_from_type does injection for friend
10765 classes. */
10767 friend_type =
10771 }
10773 /* friend class C<T>; */
10776 /* Otherwise it's
10778 friend class C;
10780 where C is already declared or
10782 friend class C<int>;
10784 We don't have to do anything in these cases. */
10787 /* Trick make_friend_class into realizing that the friend
10788 we're adding is a template, not an ordinary class. It's
10789 important that we use make_friend_class since it will
10790 perform some error-checking and output cross-reference
10791 information. */
10799 }
10800 else
10801 {
10802 /* Build new DECL_FRIENDLIST. */
10803 tree r;
10805 /* The file and line for this declaration, to
10806 assist in error message reporting. Since we
10807 called push_tinst_level above, we don't need to
10808 restore these. */
10812 {
10815 }
10820 {
10823 }
10824 }
10825 }
10826 }
10829 {
10830 /* Restore these before substituting into the lambda capture
10831 initializers. */
10834 }
10837 {
10840 {
10846 {
10847 /* Set function_depth to avoid garbage collection. */
10851 }
10853 /* We need to instantiate the capture list from the template
10854 after we've instantiated the closure members, but before we
10855 consider adding the conversion op. Also keep any captures
10856 that may have been added during instantiation of the op(). */
10858 tree tmpl_cap
10867 }
10868 else
10870 }
10872 /* Set the file and line number information to whatever is given for
10873 the class itself. This puts error messages involving generated
10874 implicit functions at a predictable point, and the same point
10875 that would be used for non-template classes. */
10882 /* We don't instantiate default arguments for member functions. 14.7.1:
10884 The implicit instantiation of a class template specialization causes
10885 the implicit instantiation of the declarations, but not of the
10886 definitions or default arguments, of the class member functions,
10887 member classes, static data members and member templates.... */
10889 /* Some typedefs referenced from within the template code need to be access
10890 checked at template instantiation time, i.e now. These types were
10891 added to the template at parsing time. Let's get those and perform
10892 the access checks then. */
10902 /* The vtable for a template class can be emitted in any translation
10903 unit in which the class is instantiated. When there is no key
10904 method, however, finish_struct_1 will already have added TYPE to
10905 the keyed_classes. */
10910 }
10912 /* Wrapper for instantiate_class_template_1. */
10914 tree
10916 {
10917 tree ret;
10922 }
10924 static tree
10926 {
10927 tree r;
10933 else
10934 {
10941 }
10943 }
10945 /* Given a function parameter pack TMPL_PARM and some function parameters
10946 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10947 and set *SPEC_P to point at the next point in the list. */
10949 tree
10951 {
10952 /* Collect all of the extra "packed" parameters into an
10953 argument pack. */
10954 tree parmvec;
10964 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10970 /* Build the argument packs. */
10975 }
10977 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10978 NONTYPE_ARGUMENT_PACK. */
10980 static tree
10982 {
10984 }
10986 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10987 pack expansion with no extra args, 2 if it has extra args, or 0
10988 if it is not a pack expansion. */
10990 static int
10992 {
10998 /* A decl pack is itself an expansion. */
11005 }
11008 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
11010 static tree
11012 {
11019 }
11021 /* This is a subroutine of tsubst_pack_expansion.
11023 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
11024 mechanism to store the (non complete list of) arguments of the
11025 substitution and return a non substituted pack expansion, in order
11026 to wait for when we have enough arguments to really perform the
11027 substitution. */
11029 static bool
11033 {
11034 /* If one pack has an expansion and another pack has a normal
11035 argument or if one pack has an empty argument and an another
11036 one hasn't then tsubst_pack_expansion cannot perform the
11037 substitution and need to fall back on the
11038 PACK_EXPANSION_EXTRA mechanism. */
11046 {
11049 parm_pack;
11051 {
11056 /* We can't substitute a pack expansion with extra args into
11057 our pattern. */
11061 else
11063 }
11067 }
11069 }
11071 /* [temp.variadic]/6 says that:
11073 The instantiation of a pack expansion [...]
11074 produces a list E1,E2, ..., En, where N is the number of elements
11075 in the pack expansion parameters.
11077 This subroutine of tsubst_pack_expansion produces one of these Ei.
11079 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11080 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11081 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11082 INDEX is the index 'i' of the element Ei to produce. ARGS,
11083 COMPLAIN, and IN_DECL are the same parameters as for the
11084 tsubst_pack_expansion function.
11086 The function returns the resulting Ei upon successful completion,
11087 or error_mark_node.
11089 Note that this function possibly modifies the ARGS parameter, so
11090 it's the responsibility of the caller to restore it. */
11092 static tree
11094 tree parm_packs,
11096 tree args /* This parm gets
11098 tsubst_flags_t complain,
11099 tree in_decl)
11100 {
11101 tree t;
11104 /* For each parameter pack, change the substitution of the parameter
11105 pack to the ith argument in its argument pack, then expand the
11106 pattern. */
11108 {
11113 ith_elem_is_expansion |=
11116 /* Select the Ith argument from the pack. */
11119 {
11121 {
11126 }
11127 else
11129 }
11130 else
11131 {
11136 {
11138 /* Update the corresponding argument. */
11140 }
11141 else
11142 /* Re-use the ARGUMENT_PACK_SELECT. */
11144 }
11146 }
11148 /* Substitute into the PATTERN with the (possibly altered)
11149 arguments. */
11151 /* Expanding a fixed parameter pack from
11152 coerce_template_parameter_pack. */
11157 {
11160 else
11163 }
11167 else
11170 /* If the Ith argument pack element is a pack expansion, then
11171 the Ith element resulting from the substituting is going to
11172 be a pack expansion as well. */
11177 }
11179 /* When the unexpanded parameter pack in a fold expression expands to an empty
11180 sequence, the value of the expression is as follows; the program is
11181 ill-formed if the operator is not listed in this table.
11183 && true
11184 || false
11185 , void() */
11187 tree
11189 {
11193 {
11202 }
11208 }
11210 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11211 form an expression that combines the two terms using the
11212 operator of T. */
11214 static tree
11216 {
11220 // Handle compound assignment operators.
11225 {
11235 complain);
11236 }
11237 }
11239 /* Substitute ARGS into the pack of a fold expression T. */
11243 {
11245 }
11247 /* Substitute ARGS into the pack of a fold expression T. */
11251 {
11253 }
11255 /* Expand a PACK of arguments into a grouped as left fold.
11256 Given a pack containing elements A0, A1, ..., An and an
11257 operator @, this builds the expression:
11259 ((A0 @ A1) @ A2) ... @ An
11261 Note that PACK must not be empty.
11263 The operator is defined by the original fold expression T. */
11265 static tree
11267 {
11270 {
11273 }
11275 }
11277 /* Substitute into a unary left fold expression. */
11279 static tree
11281 tree in_decl)
11282 {
11287 {
11291 }
11294 else
11296 }
11298 /* Substitute into a binary left fold expression.
11300 Do ths by building a single (non-empty) vector of argumnts and
11301 building the expression from those elements. */
11303 static tree
11305 tree in_decl)
11306 {
11315 {
11320 }
11328 }
11330 /* Expand a PACK of arguments into a grouped as right fold.
11331 Given a pack containing elementns A0, A1, ..., and an
11332 operator @, this builds the expression:
11334 A0@ ... (An-2 @ (An-1 @ An))
11336 Note that PACK must not be empty.
11338 The operator is defined by the original fold expression T. */
11340 tree
11342 {
11343 // Build the expression.
11347 {
11350 }
11352 }
11354 /* Substitute into a unary right fold expression. */
11356 static tree
11358 tree in_decl)
11359 {
11364 {
11368 }
11371 else
11373 }
11375 /* Substitute into a binary right fold expression.
11377 Do ths by building a single (non-empty) vector of arguments and
11378 building the expression from those elements. */
11380 static tree
11382 tree in_decl)
11383 {
11392 {
11397 }
11406 }
11409 /* Substitute ARGS into T, which is an pack expansion
11410 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11411 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11412 (if only a partial substitution could be performed) or
11413 ERROR_MARK_NODE if there was an error. */
11414 tree
11416 tree in_decl)
11417 {
11418 tree pattern;
11422 tree result;
11430 /* Add in any args remembered from an earlier partial instantiation. */
11435 /* Determine the argument packs that will instantiate the parameter
11436 packs used in the expansion expression. While we're at it,
11437 compute the number of arguments to be expanded and make sure it
11438 is consistent. */
11441 {
11448 {
11453 else
11456 }
11458 {
11459 /* ??? Support use in other patterns. */
11463 }
11465 {
11466 /* We know we have correct local_specializations if this
11467 expansion is at function scope, or if we're dealing with a
11468 local parameter in a requires expression; for the latter,
11469 tsubst_requires_expr set it up appropriately. */
11472 else
11473 /* We can't rely on local_specializations for a parameter
11474 name used later in a function declaration (such as in a
11475 late-specified return type). Even if it exists, it might
11476 have the wrong value for a recursive call. */
11480 {
11481 /* This parameter pack was used in an unevaluated context. Just
11482 make a dummy decl, since it's only used for its type. */
11485 /* Partial instantiation of the parm_pack, we can't build
11486 up an argument pack yet. */
11488 else
11490 }
11491 }
11494 else
11495 {
11501 }
11508 /* This can only happen if we forget to expand an argument
11509 pack somewhere else. Just return an error, silently. */
11510 {
11514 }
11517 {
11521 /* Don't bother trying to do a partial substitution with
11522 incomplete packs; we'll try again after deduction. */
11529 {
11534 pattern);
11535 else
11537 pattern);
11539 }
11541 /* Keep track of the parameter packs and their corresponding
11542 argument packs. */
11545 }
11546 else
11547 {
11548 /* We can't substitute for this parameter pack. We use a flag as
11549 well as the missing_level counter because function parameter
11550 packs don't have a level. */
11553 }
11554 }
11556 /* If the expansion is just T..., return the matching argument pack, unless
11557 we need to call convert_from_reference on all the elements. This is an
11558 important optimization; see c++/68422. */
11561 {
11563 /* Types need no adjustment, nor does sizeof..., and if we still have
11564 some pack expansion args we won't do anything yet. */
11569 /* Also optimize expression pack expansions if we can tell that the
11570 elements won't have reference type. */
11576 /* Otherwise use the normal path so we get convert_from_reference. */
11577 }
11579 /* We cannot expand this expansion expression, because we don't have
11580 all of the argument packs we need. */
11582 {
11583 /* We got some full packs, but we can't substitute them in until we
11584 have values for all the packs. So remember these until then. */
11589 }
11591 {
11592 /* There were no real arguments, we're just replacing a parameter
11593 pack with another version of itself. Substitute into the
11594 pattern and return a PACK_EXPANSION_*. The caller will need to
11595 deal with that. */
11599 else
11603 }
11608 {
11609 /* We're in a late-specified return type, so create our own local
11610 specializations map; the current map is either NULL or (in the
11611 case of recursive unification) might have bindings that we don't
11612 want to use or alter. */
11615 }
11617 /* For each argument in each argument pack, substitute into the
11618 pattern. */
11622 {
11624 i,
11626 in_decl);
11629 {
11632 }
11633 }
11635 /* Update ARGS to restore the substitution from parameter packs to
11636 their argument packs. */
11638 {
11644 else
11645 {
11653 /* Update the corresponding argument. */
11657 else
11659 }
11660 }
11663 {
11666 }
11668 /* If the dependent pack arguments were such that we end up with only a
11669 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11675 }
11677 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11678 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11679 parameter packs; all parms generated from a function parameter pack will
11680 have the same DECL_PARM_INDEX. */
11682 tree
11684 {
11686 tree patparm;
11689 {
11695 }
11696 else
11697 {
11702 }
11705 }
11707 /* Make an argument pack out of the TREE_VEC VEC. */
11709 static tree
11711 {
11712 tree pack;
11716 else
11717 {
11720 }
11723 }
11725 /* Return an exact copy of template args T that can be modified
11726 independently. */
11728 static tree
11730 {
11738 {
11743 }
11749 }
11751 /* Substitute ARGS into the vector or list of template arguments T. */
11753 static tree
11755 {
11767 {
11769 tree new_arg;
11774 {
11775 /* Substitute into an expansion expression. */
11779 /* Add to the expanded length adjustment the number of
11780 expanded arguments. We subtract one from this
11781 measurement, because the argument pack expression
11782 itself is already counted as 1 in
11783 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11784 the argument pack is empty. */
11786 }
11788 {
11789 /* Substitute into each of the arguments. */
11798 else
11803 }
11804 else
11813 }
11818 /* Make space for the expanded arguments coming from template
11819 argument packs. */
11821 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11822 arguments for a member template.
11823 In that case each TREE_VEC in ORIG_T represents a level of template
11824 arguments, and ORIG_T won't carry any non defaulted argument count.
11825 It will rather be the nested TREE_VECs that will carry one.
11826 In other words, ORIG_T carries a non defaulted argument count only
11827 if it doesn't contain any nested TREE_VEC. */
11829 {
11833 }
11835 {
11839 {
11842 /* Now expand the template argument pack "in place". */
11845 }
11846 else
11847 {
11849 out++;
11850 }
11851 }
11854 }
11856 /* Substitute ARGS into one level PARMS of template parameters. */
11858 static tree
11860 {
11867 {
11875 }
11878 }
11880 /* Return the result of substituting ARGS into the template parameters
11881 given by PARMS. If there are m levels of ARGS and m + n levels of
11882 PARMS, then the result will contain n levels of PARMS. For
11883 example, if PARMS is `template <class T> template <class U>
11884 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11885 result will be `template <int*, double, class V>'. */
11887 static tree
11889 {
11893 /* When substituting into a template, we must set
11894 PROCESSING_TEMPLATE_DECL as the template parameters may be
11895 dependent if they are based on one-another, and the dependency
11896 predicates are short-circuit outside of templates. */
11903 {
11910 }
11915 }
11917 /* Return the result of substituting ARGS into one template parameter
11918 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11919 parameter and which TREE_PURPOSE is the default argument of the
11920 template parameter. */
11922 static tree
11924 {
11945 }
11947 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11948 type T. If T is not an aggregate or enumeration type, it is
11949 handled as if by tsubst. IN_DECL is as for tsubst. If
11950 ENTERING_SCOPE is nonzero, T is the context for a template which
11951 we are presently tsubst'ing. Return the substituted value. */
11953 static tree
11955 tree args,
11956 tsubst_flags_t complain,
11957 tree in_decl,
11959 {
11964 {
11969 /* Fall through. */
11973 {
11974 tree argvec;
11975 tree context;
11976 tree r;
11980 /* In "sizeof(X<I>)" we need to evaluate "I". */
11986 /* First, determine the context for the type we are looking
11987 up. */
11990 {
11993 /* If context is a nested class inside a class template,
11994 it may still need to be instantiated (c++/33959). */
11996 }
11998 /* Then, figure out what arguments are appropriate for the
11999 type we are trying to find. For example, given:
12001 template <class T> struct S;
12002 template <class T, class U> void f(T, U) { S<U> su; }
12004 and supposing that we are instantiating f<int, double>,
12005 then our ARGS will be {int, double}, but, when looking up
12006 S we only want {double}. */
12011 else
12012 {
12016 }
12022 }
12023 else
12024 /* This is not a template type, so there's nothing to do. */
12029 }
12030 }
12034 /* Substitute into the default argument ARG (a default argument for
12035 FN), which has the indicated TYPE. */
12037 tree
12039 tsubst_flags_t complain)
12040 {
12045 /* This can happen in invalid code. */
12060 /* This default argument came from a template. Instantiate the
12061 default argument here, not in tsubst. In the case of
12062 something like:
12064 template <class T>
12065 struct S {
12066 static T t();
12067 void f(T = t());
12068 };
12070 we must be careful to do name lookup in the scope of S<T>,
12071 rather than in the current class. */
12073 /* The "this" pointer is not valid in a default argument. */
12075 {
12080 }
12085 /* The default argument expression may cause implicitly defined
12086 member functions to be synthesized, which will result in garbage
12087 collection. We must treat this situation as if we were within
12088 the body of function so as to avoid collecting live data on the
12089 stack. */
12099 /* Restore the "this" pointer. */
12101 {
12104 }
12111 /* Make sure the default argument is reasonable. */
12117 {
12121 }
12124 }
12126 /* Substitute into all the default arguments for FN. */
12128 static void
12130 {
12131 tree arg;
12132 tree tmpl_args;
12136 /* If this function is not yet instantiated, we certainly don't need
12137 its default arguments. */
12140 /* Don't do this again for clones. */
12146 arg;
12152 complain);
12153 }
12155 /* Subroutine of tsubst_decl for the case when T is a FUNCTION_DECL. */
12157 static tree
12159 tree lambda_fntype)
12160 {
12165 /* Nobody should be tsubst'ing into non-template functions. */
12169 {
12170 /* If T is not dependent, just return it. */
12174 /* Calculate the most general template of which R is a
12175 specialization, and the complete set of arguments used to
12176 specialize R. */
12179 (DECL_TEMPLATE_RESULT
12185 /* Check to see if we already have this specialization. */
12187 {
12191 }
12193 /* We can see more levels of arguments than parameters if
12194 there was a specialization of a member template, like
12195 this:
12197 template <class T> struct S { template <class U> void f(); }
12198 template <> template <class U> void S<int>::f(U);
12200 Here, we'll be substituting into the specialization,
12201 because that's where we can find the code we actually
12202 want to generate, but we'll have enough arguments for
12203 the most general template.
12205 We also deal with the peculiar case:
12207 template <class T> struct S {
12208 template <class U> friend void f();
12209 };
12210 template <class U> void f() {}
12211 template S<int>;
12212 template void f<double>();
12214 Here, the ARGS for the instantiation of will be {int,
12215 double}. But, we only need as many ARGS as there are
12216 levels of template parameters in CODE_PATTERN. We are
12217 careful not to get fooled into reducing the ARGS in
12218 situations like:
12220 template <class T> struct S { template <class U> void f(U); }
12221 template <class T> template <> void S<T>::f(int) {}
12223 which we can spot because the pattern will be a
12224 specialization in this case. */
12231 }
12232 else
12233 {
12234 /* This special case arises when we have something like this:
12236 template <class T> struct S {
12237 friend void f<int>(int, double);
12238 };
12240 Here, the DECL_TI_TEMPLATE for the friend declaration
12241 will be an IDENTIFIER_NODE. We are being called from
12242 tsubst_friend_function, and we want only to create a
12243 new decl (R) with appropriate types so that we can call
12244 determine_specialization. */
12247 }
12264 /* If we hit excessive deduction depth, the type is bogus even if
12265 it isn't error_mark_node, so don't build a decl. */
12269 /* We do NOT check for matching decls pushed separately at this
12270 point, as they may not represent instantiations of this
12271 template, and in any case are considered separate under the
12272 discrete model. */
12276 /* Clear out the mangled name and RTL for the instantiation. */
12279 /* Leave DECL_INITIAL set on deleted instantiations. */
12284 /* OpenMP UDRs have the only argument a reference to the declared
12285 type. We want to diagnose if the declared type is a reference,
12286 which is invalid, but as references to references are usually
12287 quietly merged, diagnose it here. */
12289 {
12290 tree argtype
12295 "reference type %qT in "
12299 argtype);
12300 }
12303 /* Type-conversion operator. Reconstruct the name, in
12304 case it's the name of one of the template's parameters. */
12314 {
12318 }
12325 /* If this is an instantiation of a function with internal
12326 linkage, we already know what object file linkage will be
12327 assigned to the instantiation. */
12336 /* We'll re-clone as appropriate in instantiate_template. */
12339 /* If we aren't complaining now, return on error before we register
12340 the specialization so that we'll complain eventually. */
12346 /* When instantiating a constrained member, substitute
12347 into the constraints to create a new constraint. */
12350 {
12353 }
12355 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12356 this in the special friend case mentioned above where
12357 GEN_TMPL is NULL. */
12359 {
12364 tree new_r
12367 /* We instantiated this while substituting into
12368 the type earlier (template/friend54.C). */
12371 /* We're not supposed to instantiate default arguments
12372 until they are called, for a template. But, for a
12373 declaration like:
12375 template <class T> void f ()
12376 { extern void g(int i = T()); }
12378 we should do the substitution when the template is
12379 instantiated. We handle the member function case in
12380 instantiate_class_template since the default arguments
12381 might refer to other members of the class. */
12386 }
12387 else
12390 /* Copy the list of befriending classes. */
12394 {
12398 }
12401 {
12405 /* If this is an instantiation of a member template, clone it.
12406 If it isn't, that'll be handled by
12407 clone_constructors_and_destructors. */
12410 }
12421 /* Possibly limit visibility based on template args. */
12424 {
12428 }
12437 }
12439 /* Subroutine of tsubst_decl for the case when T is a TEMPLATE_DECL. */
12441 static tree
12443 tree lambda_fntype)
12444 {
12445 /* We can get here when processing a member function template,
12446 member class template, or template template parameter. */
12449 tree spec;
12450 tree tmpl_args;
12451 tree full_args;
12452 tree r;
12456 {
12457 /* Template template parameter is treated here. */
12461 /* If we get a real template back, return it. This can happen in
12462 the context of most_specialized_partial_spec. */
12465 else
12466 /* The new TEMPLATE_DECL was built in
12467 reduce_template_parm_level. */
12470 }
12473 {
12474 /* We might already have an instance of this template.
12475 The ARGS are for the surrounding class type, so the
12476 full args contain the tsubst'd args for the context,
12477 plus the innermost args from the template decl. */
12481 /* Because this is a template, the arguments will still be
12482 dependent, even after substitution. If
12483 PROCESSING_TEMPLATE_DECL is not set, the dependency
12484 predicates will short-circuit. */
12492 /* If this is a default template template argument,
12493 tsubst might not have changed anything. */
12501 }
12503 /* Make a new template decl. It will be similar to the
12504 original, but will record the current template arguments.
12505 We also create a new function declaration, which is just
12506 like the old one, but points to this new template, rather
12507 than the old one. */
12512 // Build new template info linking to the original template decl.
12514 {
12517 }
12518 else
12521 /* The template parameters for this new template are all the
12522 template parameters for the old template, except the
12523 outermost level of parameters. */
12526 complain);
12530 {
12531 tree new_type;
12539 /* For a partial specialization, we need to keep pointing to
12540 the primary template. */
12546 }
12547 else
12548 {
12549 tree new_decl;
12553 else
12563 {
12566 }
12567 else
12568 {
12571 }
12572 }
12582 /* Record this non-type partial instantiation. */
12588 }
12590 /* True if FN is the op() for a lambda in an uninstantiated template. */
12592 bool
12594 {
12599 }
12601 /* True if FN is the op() for a lambda regenerated from a lambda in an
12602 uninstantiated template. */
12604 bool
12606 {
12609 }
12611 /* We're instantiating a variable from template function TCTX. Return the
12612 corresponding current enclosing scope. This gets complicated because lambda
12613 functions in templates are regenerated rather than instantiated, but generic
12614 lambda functions are subsequently instantiated. */
12616 static tree
12618 {
12626 {
12637 {
12641 }
12643 }
12645 }
12647 /* Substitute the ARGS into the T, which is a _DECL. Return the
12648 result of the substitution. Issue error and warning messages under
12649 control of COMPLAIN. */
12651 static tree
12653 {
12654 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12655 location_t saved_loc;
12660 /* Set the filename and linenumber to improve error-reporting. */
12665 {
12675 {
12683 {
12684 /* If there is a local specialization that isn't a
12685 parameter pack, it means that we're doing a "simple"
12686 substitution from inside tsubst_pack_expansion. Just
12687 return the local specialization (which will be a single
12688 parm). */
12695 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12696 the parameters in this function parameter pack. */
12700 {
12703 /* Zero-length parameter packs are boring. Just substitute
12704 into the chain. */
12708 }
12709 else
12710 {
12711 /* All we did was update the type. Make a note of that. */
12714 }
12715 }
12717 /* Loop through all of the parameters we'll build. When T is
12718 a function parameter pack, LEN is the number of expanded
12719 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12722 {
12729 /* We're on the Ith parameter of the function parameter
12730 pack. */
12731 {
12732 /* Get the Ith type. */
12735 /* Rename the parameter to include the index. */
12738 }
12740 /* We're dealing with a normal parameter. */
12748 {
12751 else
12754 }
12764 /* Keep track of the first new parameter we
12765 generate. That's what will be returned to the
12766 caller. */
12770 /* Build a proper chain of parameters when substituting
12771 into a function parameter pack. */
12774 }
12776 /* If cp_unevaluated_operand is set, we're just looking for a
12777 single dummy parameter, so don't keep going. */
12782 /* FIRST_R contains the start of the chain we've built. */
12784 }
12788 {
12795 {
12796 /* This field is a lambda capture pack. Return a TREE_VEC of
12797 the expanded fields to instantiate_class_template_1 and
12798 store them in the specializations hash table as a
12799 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12803 {
12806 }
12807 else
12808 {
12809 /* All we did was update the type. Make a note of that. */
12812 }
12813 }
12816 {
12819 {
12823 }
12833 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12834 non-bit-fields DECL_INITIAL is a non-static data member
12835 initializer, which gets deferred instantiation. */
12841 {
12842 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12843 NSDMI in perform_member_init. Still set DECL_INITIAL
12844 so that we know there is one. */
12849 }
12850 /* We don't have to set DECL_CONTEXT here; it is set by
12851 finish_member_declaration. */
12859 }
12862 {
12867 }
12868 }
12872 /* We reach here only for member using decls. We also need to check
12873 uses_template_parms because DECL_DEPENDENT_P is not set for a
12874 using-declaration that designates a member of the current
12875 instantiation (c++/53549). */
12878 {
12882 {
12887 {
12891 {
12894 }
12895 else
12896 {
12899 }
12901 }
12902 }
12903 else
12904 {
12910 else
12911 {
12914 }
12915 }
12916 }
12917 else
12918 {
12921 }
12926 {
12929 tree spec;
12931 tree ctx;
12940 {
12941 /* If this is the canonical decl, we don't have to
12942 mess with instantiations, and often we can't (for
12943 typename, template type parms and such). Note that
12944 TYPE_NAME is not correct for the above test if
12945 we've copied the type for a typedef. */
12951 }
12953 /* Check to see if we already have the specialization we
12954 need. */
12957 {
12958 /* T is a static data member or namespace-scope entity.
12959 We have to substitute into namespace-scope variables
12960 (not just variable templates) because of cases like:
12962 template <class T> void f() { extern T t; }
12964 where the entity referenced is not known until
12965 instantiation time. */
12969 {
12971 complain,
12973 /* If CTX is unchanged, then T is in fact the
12974 specialization we want. That situation occurs when
12975 referencing a static data member within in its own
12976 class. We can use pointer equality, rather than
12977 same_type_p, because DECL_CONTEXT is always
12978 canonical... */
12980 /* ... unless T is a member template; in which
12981 case our caller can be willing to create a
12982 specialization of that template represented
12983 by T. */
12987 }
12990 {
12995 argvec = (coerce_innermost_template_parms
13003 }
13004 }
13005 else
13006 {
13007 /* A local variable. */
13009 /* Subsequent calls to pushdecl will fill this in. */
13011 /* Unless this is a reference to a static variable from an
13012 enclosing function, in which case we need to fill it in now. */
13014 {
13018 }
13020 }
13021 /* If we already have the specialization we need, there is
13022 nothing more to do. */
13024 {
13027 }
13029 /* Create a new node for the specialization we need. */
13032 {
13035 else
13044 /* Mask off any template args past the variable's context so we
13045 don't replace the auto with an unrelated argument. */
13050 }
13052 {
13053 /* Even if the original location is out of scope, the
13054 newly substituted one is not. */
13061 {
13062 /* It may seem that this case cannot occur, since:
13064 typedef void f();
13065 void g() { f x; }
13067 declares a function, not a variable. However:
13069 typedef void f();
13070 template <typename T> void g() { T t; }
13071 template void g<f>();
13073 is an attempt to declare a variable with function
13074 type. */
13076 /* R is not yet sufficiently initialized, so we
13077 just use its name. */
13080 }
13082 /* Wait until cp_finish_decl to set this again, to handle
13083 circular dependency (template/instantiate6.C). */
13088 {
13093 {
13096 }
13098 }
13102 }
13108 /* Clear out the mangled name and RTL for the instantiation. */
13112 /* The initializer must not be expanded until it is required;
13113 see [temp.inst]. */
13117 {
13120 /* Possibly limit visibility based on template args. */
13123 {
13127 }
13129 }
13132 {
13133 /* A static data member declaration is always marked
13134 external when it is declared in-class, even if an
13135 initializer is present. We mimic the non-template
13136 processing here. */
13144 }
13145 else
13146 {
13151 }
13159 /* Preserve a typedef that names a type. */
13161 {
13165 /* An alias template specialization can be dependent
13166 even if its underlying type is not. */
13168 }
13171 }
13176 }
13177 #undef RETURN
13179 out:
13180 /* Restore the file and line information. */
13184 }
13186 /* Substitute into the ARG_TYPES of a function type.
13187 If END is a TREE_CHAIN, leave it and any following types
13188 un-substituted. */
13190 static tree
13192 tree args,
13193 tree end,
13194 tsubst_flags_t complain,
13195 tree in_decl)
13196 {
13197 tree remaining_arg_types;
13201 tree default_arg;
13212 {
13213 /* For a pack expansion, perform substitution on the
13214 entire expression. Later on, we'll handle the arguments
13215 one-by-one. */
13220 /* So that we'll spin through the parameters, one by one. */
13222 else
13223 {
13224 /* We only partially substituted into the parameter
13225 pack. Our type is TYPE_PACK_EXPANSION. */
13228 }
13229 }
13242 {
13244 {
13248 }
13250 }
13251 /* DR 657. */
13255 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13256 top-level qualifiers as required. */
13259 /* We do not substitute into default arguments here. The standard
13260 mandates that they be instantiated only when needed, which is
13261 done in build_over_call. */
13265 {
13266 /* We've instantiated a template before its default arguments
13267 have been parsed. This can happen for a nested template
13268 class, and is not an error unless we require the default
13269 argument in a call of this function. */
13270 remaining_arg_types =
13273 }
13274 else
13275 remaining_arg_types =
13277 }
13280 }
13282 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13283 *not* handle the exception-specification for FNTYPE, because the
13284 initial substitution of explicitly provided template parameters
13285 during argument deduction forbids substitution into the
13286 exception-specification:
13288 [temp.deduct]
13290 All references in the function type of the function template to the
13291 corresponding template parameters are replaced by the specified tem-
13292 plate argument values. If a substitution in a template parameter or
13293 in the function type of the function template results in an invalid
13294 type, type deduction fails. [Note: The equivalent substitution in
13295 exception specifications is done only when the function is instanti-
13296 ated, at which point a program is ill-formed if the substitution
13297 results in an invalid type.] */
13299 static tree
13301 tree args,
13302 tsubst_flags_t complain,
13303 tree in_decl)
13304 {
13305 tree return_type;
13307 tree fntype;
13309 /* The TYPE_CONTEXT is not used for function/method types. */
13312 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13313 failure. */
13317 {
13318 /* Substitute the argument types. */
13330 {
13331 /* DR 1207: 'this' is in scope in the trailing return type. */
13333 }
13335 /* Substitute the return type. */
13339 {
13342 }
13343 }
13344 else
13345 /* Substitute the return type. */
13350 /* DR 486 clarifies that creation of a function type with an
13351 invalid return type is a deduction failure. */
13354 {
13356 {
13359 else
13361 }
13363 }
13364 /* And DR 657. */
13369 {
13370 /* Substitute the argument types. */
13375 }
13377 /* Construct a new type node and return it. */
13379 {
13384 }
13385 else
13386 {
13388 /* Don't pick up extra function qualifiers from the basetype. */
13391 {
13392 /* [temp.deduct]
13394 Type deduction may fail for any of the following
13395 reasons:
13397 -- Attempting to create "pointer to member of T" when T
13398 is not a class type. */
13401 r);
13403 }
13408 }
13415 }
13417 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13418 ARGS into that specification, and return the substituted
13419 specification. If there is no specification, return NULL_TREE. */
13421 static tree
13423 tree args,
13424 tsubst_flags_t complain,
13425 tree in_decl,
13427 {
13428 tree specs;
13429 tree new_specs;
13434 {
13435 /* A noexcept-specifier. */
13440 {
13441 /* Defer instantiation of noexcept-specifiers to avoid
13442 excessive instantiations (c++/49107). */
13445 {
13446 /* We already partially instantiated this member template,
13447 so combine the new args with the old. */
13452 }
13453 else
13454 {
13457 }
13458 }
13459 else
13460 new_specs = tsubst_copy_and_build
13464 }
13466 {
13469 else
13471 {
13472 tree spec;
13477 {
13478 /* Expand the pack expansion type. */
13481 in_decl);
13487 else
13488 {
13489 /* We're substituting into a member template, so
13490 we got a TYPE_PACK_EXPANSION back. Add that
13491 expansion and move on. */
13495 expanded_specs,
13496 complain);
13499 }
13500 }
13503 {
13506 else
13511 complain);
13512 }
13515 }
13516 }
13518 }
13520 /* Take the tree structure T and replace template parameters used
13521 therein with the argument vector ARGS. IN_DECL is an associated
13522 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13523 Issue error and warning messages under control of COMPLAIN. Note
13524 that we must be relatively non-tolerant of extensions here, in
13525 order to preserve conformance; if we allow substitutions that
13526 should not be allowed, we may allow argument deductions that should
13527 not succeed, and therefore report ambiguous overload situations
13528 where there are none. In theory, we could allow the substitution,
13529 but indicate that it should have failed, and allow our caller to
13530 make sure that the right thing happens, but we don't try to do this
13531 yet.
13533 This function is used for dealing with types, decls and the like;
13534 for expressions, use tsubst_expr or tsubst_copy. */
13536 tree
13538 {
13561 else
13566 /* Reuse typedefs. We need to do this to handle dependent attributes,
13567 such as attribute aligned. */
13570 {
13574 {
13575 /* DECL represents an alias template and we want to
13576 instantiate it. */
13580 }
13584 {
13588 }
13593 else
13594 /* The typedef is from a non-template context. */
13598 {
13600 r = cp_build_qualified_type_real
13604 }
13605 else
13606 {
13607 /* We don't have an instantiation yet, so drop the typedef. */
13612 }
13613 }
13630 {
13656 {
13662 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13663 needed. */
13669 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13670 with TREE_SIDE_EFFECTS that indicates this is not an integral
13671 constant expression. */
13674 {
13677 }
13680 }
13686 {
13692 /* Early in template argument deduction substitution, we don't
13693 want to reduce the level of 'auto', or it will be confused
13694 with a normal template parm in subsequent deduction. */
13706 {
13710 {
13711 /* See through ARGUMENT_PACK_SELECT arguments. */
13713 /* If the selected argument is an expansion E, that most
13714 likely means we were called from
13715 gen_elem_of_pack_expansion_instantiation during the
13716 substituting of pack an argument pack (which Ith
13717 element is a pack expansion, where I is
13718 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13719 In this case, the Ith element resulting from this
13720 substituting is going to be a pack expansion, which
13721 pattern is the pattern of E. Let's return the
13722 pattern of E, and
13723 gen_elem_of_pack_expansion_instantiation will
13724 build the resulting pack expansion from it. */
13726 {
13727 /* Make sure we aren't throwing away arg info. */
13730 }
13731 }
13732 }
13737 {
13739 /* If ARG is an argument pack, we don't actually want to
13740 perform a substitution here, because substitutions
13741 for argument packs are only done
13742 element-by-element. We can get to this point when
13743 substituting the type of a non-type template
13744 parameter pack, when that type actually contains
13745 template parameter packs from an outer template, e.g.,
13747 template<typename... Types> struct A {
13748 template<Types... Values> struct B { };
13749 }; */
13753 {
13759 return cp_build_qualified_type_real
13761 }
13763 {
13764 /* We are processing a type constructed from a
13765 template template parameter. */
13776 /* Consider this code:
13778 template <template <class> class Template>
13779 struct Internal {
13780 template <class Arg> using Bind = Template<Arg>;
13781 };
13783 template <template <class> class Template, class Arg>
13784 using Instantiate = Template<Arg>; //#0
13786 template <template <class> class Template,
13787 class Argument>
13788 using Bind =
13789 Instantiate<Internal<Template>::template Bind,
13790 Argument>; //#1
13792 When #1 is parsed, the
13793 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13794 parameter `Template' in #0 matches the
13795 UNBOUND_CLASS_TEMPLATE representing the argument
13796 `Internal<Template>::template Bind'; We then want
13797 to assemble the type `Bind<Argument>' that can't
13798 be fully created right now, because
13799 `Internal<Template>' not being complete, the Bind
13800 template cannot be looked up in that context. So
13801 we need to "store" `Bind<Argument>' for later
13802 when the context of Bind becomes complete. Let's
13803 store that in a TYPENAME_TYPE. */
13807 argvec),
13808 typename_type,
13809 complain);
13811 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13812 are resolving nested-types in the signature of a
13813 member function templates. Otherwise ARG is a
13814 TEMPLATE_DECL and is the real template to be
13815 instantiated. */
13823 complain);
13824 return cp_build_qualified_type_real
13826 }
13829 else
13830 /* TEMPLATE_PARM_INDEX. */
13832 }
13835 /* This can happen during the attempted tsubst'ing in
13836 unify. This means that we don't yet have any information
13837 about the template parameter in question. */
13840 /* If we get here, we must have been looking at a parm for a
13841 more deeply nested template. Make a new version of this
13842 template parameter, but with a lower level. */
13844 {
13849 {
13851 r = cp_build_qualified_type_real
13855 }
13862 /* Break infinite recursion when substituting the constraints
13864 else
13865 {
13876 {
13877 /* Propagate constraints on placeholders. */
13882 {
13886 }
13887 }
13890 /* We have reduced the level of the template
13891 template parameter, but not the levels of its
13892 template parameters, so canonical_type_parameter
13893 will not be able to find the canonical template
13894 template parameter for this level. Thus, we
13895 require structural equality checking to compare
13896 TEMPLATE_TEMPLATE_PARMs. */
13900 else
13904 {
13906 /* We might need to substitute into the types of non-type
13907 template parameters. */
13919 }
13920 }
13924 /* OK, now substitute the type of the non-type parameter. We
13925 couldn't do it earlier because it might be an auto parameter,
13926 and we wouldn't need to if we had an argument. */
13935 }
13938 }
13941 {
13949 {
13953 }
13956 {
13960 }
13963 {
13967 }
13973 }
13976 /* We should never be tsubsting a binfo. */
13980 /* A vector of template arguments. */
13986 {
13990 /* [temp.deduct]
13992 Type deduction may fail for any of the following
13993 reasons:
13995 -- Attempting to create a pointer to reference type.
13996 -- Attempting to create a reference to a reference type or
13997 a reference to void.
13999 Core issue 106 says that creating a reference to a reference
14000 during instantiation is no longer a cause for failure. We
14001 only enforce this check in strict C++98 mode. */
14005 {
14008 /* We keep track of the last time we issued this error
14009 message to avoid spewing a ton of messages during a
14010 single bad template instantiation. */
14013 {
14018 else
14021 }
14024 }
14028 {
14030 {
14033 type);
14034 else
14036 type);
14037 }
14039 }
14041 {
14045 }
14047 /* In C++0x, during template argument substitution, when there is an
14048 attempt to create a reference to a reference type, reference
14049 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
14051 "If a template-argument for a template-parameter T names a type
14052 that is a reference to a type A, an attempt to create the type
14053 'lvalue reference to cv T' creates the type 'lvalue reference to
14054 A,' while an attempt to create the type type rvalue reference to
14055 cv T' creates the type T"
14056 */
14057 r = cp_build_reference_type
14060 else
14065 /* Will this ever be needed for TYPE_..._TO values? */
14069 }
14071 {
14074 {
14075 /* [temp.deduct]
14077 Type deduction may fail for any of the following
14078 reasons:
14080 -- Attempting to create "pointer to member of T" when T
14081 is not a class type. */
14085 }
14087 {
14091 }
14093 {
14097 }
14100 {
14101 /* The type of the implicit object parameter gets its
14102 cv-qualifiers from the FUNCTION_TYPE. */
14103 tree memptr;
14104 tree method_type
14109 complain);
14110 }
14111 else
14114 complain);
14115 }
14118 {
14119 tree fntype;
14120 tree specs;
14125 /* Substitute the exception specification. */
14133 }
14135 {
14140 /* As an optimization, we avoid regenerating the array type if
14141 it will obviously be the same as T. */
14145 /* These checks should match the ones in create_array_type_for_decl.
14147 [temp.deduct]
14149 The deduction may fail for any of the following reasons:
14151 -- Attempting to create an array with an element type that
14152 is void, a function type, or a reference type, or [DR337]
14153 an abstract class type. */
14159 {
14163 }
14171 {
14174 }
14177 }
14180 {
14192 {
14196 }
14198 {
14199 /* Normally, make_typename_type does not require that the CTX
14200 have complete type in order to allow things like:
14202 template <class T> struct S { typename S<T>::X Y; };
14204 But, such constructs have already been resolved by this
14205 point, so here CTX really should have complete type, unless
14206 it's a partial instantiation. */
14209 {
14213 }
14214 }
14221 {
14224 }
14227 {
14229 {
14233 else
14235 }
14237 {
14241 else
14243 }
14244 }
14246 return cp_build_qualified_type_real
14248 }
14251 {
14263 }
14266 {
14267 tree type;
14283 complain);
14284 }
14287 {
14288 tree type;
14299 {
14301 {
14305 }
14308 }
14319 else
14320 {
14324 /* In a template ~id could be either a complement expression
14325 or an unqualified-id naming a destructor; if instantiating
14326 it produces an expression, it's not an id-expression or
14327 member access. */
14330 }
14335 }
14338 {
14342 }
14346 {
14347 tree r;
14351 else
14359 }
14374 /* We should use one of the expression tsubsts for these codes. */
14380 }
14381 }
14383 /* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
14384 expression on the left-hand side of the "." or "->" operator. A
14385 baselink indicates a function from a base class. Both the
14386 BASELINK_ACCESS_BINFO and the base class referenced may indicate
14387 bases of the template class, rather than the instantiated class.
14388 In addition, lookups that were not ambiguous before may be
14389 ambiguous now. Therefore, we perform the lookup again. */
14391 static tree
14394 {
14407 {
14414 }
14422 {
14427 }
14429 /* If lookup found a single function, mark it as used at this point.
14430 (If it lookup found multiple functions the one selected later by
14431 overload resolution will be marked as used at that point.) */
14439 {
14440 /* Add back the template arguments, if present. */
14446 /* Update the conversion operator type. */
14448 }
14454 {
14456 qualifying_scope,
14457 object_type);
14459 /* We need to call adjust_result_of_qualified_name_lookup in case the
14460 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14461 so that we still get virtual function binding. */
14463 }
14466 }
14468 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14469 true if the qualified-id will be a postfix-expression in-and-of
14470 itself; false if more of the postfix-expression follows the
14471 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14472 of "&". */
14474 static tree
14478 {
14479 tree expr;
14480 tree scope;
14481 tree name;
14483 tree template_args;
14488 /* Figure out what name to look up. */
14491 {
14501 }
14502 else
14503 {
14506 }
14508 /* Substitute into the qualifying scope. When there are no ARGS, we
14509 are just trying to simplify a non-dependent expression. In that
14510 case the qualifying scope may be dependent, and, in any case,
14511 substituting will not help. */
14514 {
14517 }
14518 else
14522 {
14529 }
14532 {
14534 {
14535 /* A BIT_NOT_EXPR is used to represent a destructor. */
14537 {
14541 }
14542 else
14545 }
14546 else
14550 {
14552 {
14556 }
14558 }
14559 }
14562 {
14564 scope);
14565 /* Remember that there was a reference to this entity. */
14568 }
14571 {
14577 }
14580 {
14583 complain);
14584 else
14586 }
14592 {
14593 expr = (adjust_result_of_qualified_name_lookup
14595 expr = (finish_qualified_id_expr
14599 }
14601 /* Expressions do not generally have reference type. */
14603 /* However, if we're about to form a pointer-to-member, we just
14604 want the referenced member referenced. */
14612 }
14614 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14615 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14616 for tsubst. */
14618 static tree
14621 {
14628 {
14629 /* If we had an initializer but it
14630 instantiated to nothing,
14631 value-initialize the object. This will
14632 only occur when the initializer was a
14633 pack expansion where the parameter packs
14634 used in that expansion were of length
14635 zero. */
14637 complain);
14642 }
14645 }
14647 /* Like tsubst, but deals with expressions. This function just replaces
14648 template parms; to finish processing the resultant expression, use
14649 tsubst_copy_and_build or tsubst_expr. */
14651 static tree
14653 {
14655 tree r;
14663 {
14668 {
14669 /* We get here for a use of 'this' in an NSDMI. */
14673 /* This can happen for a parameter name used later in a function
14674 declaration (such as in a late-specified return type). Just
14675 make a dummy decl, since it's only used for its type. */
14678 /* Give it the template pattern as its context; its true context
14679 hasn't been instantiated yet and this is good enough for
14680 mangling. */
14682 }
14691 {
14692 tree enum_type;
14693 tree v;
14697 /* There is no need to substitute into namespace-scope
14698 enumerators. */
14701 /* If ARGS is NULL, then T is known to be non-dependent. */
14705 /* Unfortunately, we cannot just call lookup_name here.
14706 Consider:
14708 template <int I> int f() {
14709 enum E { a = I };
14710 struct S { void g() { E e = a; } };
14711 };
14713 When we instantiate f<7>::S::g(), say, lookup_name is not
14714 clever enough to find f<7>::a. */
14715 enum_type
14725 /* We didn't find the name. That should never happen; if
14726 name-lookup found it during preliminary parsing, we
14727 should find it again here during instantiation. */
14729 }
14734 {
14735 /* Check for a local specialization set up by
14736 tsubst_pack_expansion. */
14738 {
14742 }
14744 /* When retrieving a capture pack from a generic lambda, remove the
14745 lambda call op's own template argument list from ARGS. Only the
14746 template arguments active for the closure type should be used to
14747 retrieve the pack specialization. */
14753 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14754 tsubst_decl put in the hash table. */
14756 }
14759 {
14760 tree ctx;
14765 {
14768 {
14772 }
14774 }
14775 }
14785 {
14788 {
14789 /* First try name lookup to find the instantiation. */
14792 {
14793 /* Make sure that the one we found is the one we want. */
14797 }
14801 else
14802 {
14803 /* This can happen for a variable used in a
14804 late-specified return type of a local lambda, or for a
14805 local static or constant. Building a new VAR_DECL
14806 should be OK in all those cases. */
14809 /* Avoid infinite recursion (79640). */
14812 {
14813 /* We can't call cp_finish_decl, so handle the
14814 initializer by hand. */
14829 }
14836 }
14837 /* Remember this for subsequent uses. */
14840 }
14841 }
14842 else
14852 /* An OVERLOAD will always be a non-dependent overload set; an
14853 overload set from function scope will just be represented with an
14854 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14856 /* We must have marked any lookups as persistent. */
14872 {
14873 /* Template template argument like the following example need
14874 special treatment:
14876 template <template <class> class TT> struct C {};
14877 template <class T> struct D {
14878 template <class U> struct E {};
14879 C<E> c; // #1
14880 };
14881 D<int> d; // #2
14883 We are processing the template argument `E' in #1 for
14884 the template instantiation #2. Originally, `E' is a
14885 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14886 have to substitute this with one having context `D<int>'. */
14890 {
14891 /* When rewriting a constructor into a deduction guide, a
14892 non-dependent name can become dependent, so memtmpl<args>
14893 becomes context::template memtmpl<args>. */
14897 }
14899 }
14900 else
14901 /* Ordinary template template argument. */
14912 {
14916 }
14921 {
14930 /* We only want to compute the number of arguments. */
14933 else
14940 {
14942 /* Set TREE_USED for the benefit of -Wunused. */
14946 }
14954 {
14959 else
14965 else
14968 }
14969 else
14971 }
14973 {
14981 }
14982 /* Fall through */
14998 {
15002 }
15005 {
15006 tree object;
15007 tree name;
15012 {
15016 }
15019 {
15029 }
15034 in_decl);
15035 else
15038 }
15076 {
15080 }
15083 {
15088 }
15091 {
15095 }
15098 {
15106 }
15112 {
15119 }
15122 {
15129 }
15132 {
15139 }
15142 {
15143 /* Substituted template arguments */
15152 }
15155 {
15175 }
15200 /* Fall through. */
15203 {
15206 }
15207 else
15211 /* This is handled by tsubst_copy_and_build. */
15215 {
15219 }
15222 /* We shouldn't have built any of these during initial template
15223 generation. Instead, they should be built during instantiation
15224 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15228 {
15238 }
15256 {
15257 /* Instantiate any typedefs in the type. */
15262 }
15265 /* These can sometimes show up in a partial instantiation, but never
15266 involve template parms. */
15282 /* We shouldn't get here, but keep going if !flag_checking. */
15286 }
15287 }
15289 /* Helper function for tsubst_omp_clauses, used for instantiation of
15290 OMP_CLAUSE_DECL of clauses. */
15292 static tree
15294 tree in_decl)
15295 {
15299 /* Handle an OpenMP array section represented as a TREE_LIST (or
15300 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15301 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15302 TREE_LIST. We can handle it exactly the same as an array section
15303 (purpose, value, and a chain), even though the nomenclature
15304 (low_bound, length, etc) is different. */
15306 {
15307 tree low_bound
15313 in_decl);
15322 }
15325 /* Undo convert_from_reference tsubst_expr could have called. */
15331 }
15333 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15335 static tree
15338 {
15343 {
15349 {
15352 {
15358 }
15359 /* FALLTHRU */
15374 in_decl);
15406 {
15409 {
15416 }
15417 else
15419 }
15422 in_decl);
15428 in_decl);
15436 in_decl);
15438 {
15441 }
15446 else
15449 in_decl,
15473 }
15476 {
15486 /* tsubst_expr on SCOPE_REF results in returning
15487 finish_non_static_data_member result. Undo that here. */
15491 {
15496 {
15500 CASE_CONVERT:
15509 /* FALLTHRU */
15513 }
15514 }
15520 {
15523 {
15526 }
15527 }
15531 }
15532 }
15536 {
15541 {
15544 }
15545 }
15547 }
15549 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15551 static tree
15553 tree in_decl)
15554 {
15555 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15575 {
15578 else
15579 {
15583 }
15584 }
15589 #undef RECUR
15590 }
15592 /* Used to temporarily communicate the list of #pragma omp parallel
15593 clauses to #pragma omp for instantiation if they are combined
15594 together. */
15598 /* Substitute one OMP_FOR iterator. */
15600 static void
15605 {
15606 #define RECUR(NODE) \
15607 tsubst_expr ((NODE), args, complain, in_decl, \
15608 integral_constant_expression_p)
15615 {
15618 }
15624 {
15625 /* We need to jump through some hoops to handle declarations in the
15626 init-statement, since we might need to handle auto deduction,
15627 but we need to keep control of initialization. */
15631 }
15632 else
15633 {
15635 {
15638 {
15642 {
15646 CASE_CONVERT:
15654 {
15657 }
15658 /* FALLTHRU */
15662 }
15663 }
15664 }
15665 else
15667 }
15678 {
15680 {
15681 /* Declare the variable, but don't let that initialize it. */
15686 }
15691 {
15696 }
15697 else
15704 }
15707 {
15708 /* Declare and initialize the variable. */
15711 }
15713 {
15717 {
15719 {
15725 {
15728 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15733 }
15736 {
15738 decl);
15740 }
15743 {
15745 decl);
15747 }
15748 else
15750 }
15753 }
15755 {
15760 {
15763 }
15764 }
15765 }
15768 {
15772 }
15773 else
15777 {
15788 {
15796 }
15797 else
15803 {
15809 }
15813 {
15821 }
15822 else
15828 }
15834 #undef RECUR
15835 }
15837 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15838 of OMP_TARGET's body. */
15840 static tree
15842 {
15845 {
15854 }
15856 }
15858 /* Helper function for tsubst_expr. For decomposition declaration
15859 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15860 also the corresponding decls representing the identifiers
15861 of the decomposition declaration. Return DECL if successful
15862 or error_mark_node otherwise, set *FIRST to the first decl
15863 in the list chained through DECL_CHAIN and *CNT to the number
15864 of such decls. */
15866 static tree
15870 {
15875 decl2
15880 {
15882 {
15885 }
15902 {
15905 }
15906 else
15908 }
15911 }
15913 /* Like tsubst_copy for expressions, etc. but also does semantic
15914 processing. */
15916 tree
15919 {
15920 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15921 #define RECUR(NODE) \
15922 tsubst_expr ((NODE), args, complain, in_decl, \
15923 integral_constant_expression_p)
15926 tree r;
15927 location_t loc;
15939 {
15941 {
15942 tree_stmt_iterator i;
15946 }
15961 else
15971 {
15973 tree init;
15979 {
15989 else
15991 }
15993 {
15994 /* Don't build up decls for a variadic capture proxy, we'll
15995 instantiate the elements directly as needed. */
15997 }
16000 {
16001 /* We're in tsubst_lambda_expr, we've already inserted new capture
16002 proxies, and uses will find them with lookup_name. */
16004 }
16007 /* Don't copy the old closure; we'll create a new one in
16008 tsubst_lambda_expr. */
16010 else
16011 {
16015 {
16016 /* By marking the declaration as instantiated, we avoid
16017 trying to instantiate it. Since instantiate_decl can't
16018 handle local variables, and since we've already done
16019 all that needs to be done, that's the right thing to
16020 do. */
16025 /* Anonymous aggregates are a special case. */
16028 {
16031 {
16035 }
16037 }
16043 {
16048 }
16049 else
16050 {
16055 {
16056 /* For __PRETTY_FUNCTION__ we have to adjust the
16057 initializer. */
16061 }
16062 else
16066 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
16072 {
16074 tree first;
16080 }
16081 }
16082 }
16083 }
16086 }
16101 {
16109 {
16111 tree first;
16116 }
16117 else
16122 }
16148 else
16149 {
16156 }
16162 {
16171 }
16179 else
16187 else
16208 {
16215 }
16219 {
16221 tree label;
16228 }
16234 /* Computed goto's must be tsubst'd into. On the other hand,
16235 non-computed gotos must not be; the identifier in question
16236 will have no binding. */
16238 else
16244 {
16260 }
16265 {
16270 }
16271 else
16272 {
16277 else
16284 else
16290 else
16292 }
16296 {
16300 {
16302 /* Prevent instantiate_decl from trying to instantiate
16303 this variable. We've already done all that needs to be
16304 done. */
16307 }
16312 }
16318 {
16319 /* Local classes are not independent templates; they are
16320 instantiated along with their containing function. And this
16321 way we don't have to deal with pushing out of one local class
16322 to instantiate a member of another local class. */
16323 /* Closures are handled by the LAMBDA_EXPR. */
16333 }
16337 {
16338 tree condition;
16341 condition =
16343 args,
16352 }
16358 in_decl);
16395 {
16410 in_decl);
16412 {
16419 }
16431 integral_constant_expression_p);
16442 else
16443 {
16451 }
16455 }
16460 /* FALLTHRU */
16467 in_decl);
16484 in_decl);
16495 {
16498 {
16499 /* For combined target teams, ensure the num_teams and
16500 thread_limit clause expressions are evaluated on the host,
16501 before entering the target construct. */
16502 tree c;
16508 {
16517 OMP_CLAUSE_FIRSTPRIVATE);
16521 }
16522 }
16523 }
16583 {
16588 {
16591 }
16597 }
16598 else
16599 {
16606 {
16609 }
16612 {
16617 {
16620 }
16626 }
16627 else
16628 {
16632 }
16635 }
16639 {
16645 {
16649 {
16654 }
16658 }
16659 else
16660 {
16665 }
16666 }
16670 {
16674 }
16694 /* If the first operand was a statement, we're done with it. */
16698 complain));
16710 integral_constant_expression_p));
16711 }
16714 out:
16717 #undef RECUR
16718 #undef RETURN
16719 }
16721 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16722 function. For description of the body see comment above
16723 cp_parser_omp_declare_reduction_exprs. */
16725 static void
16727 {
16733 tree_stmt_iterator tsi;
16744 {
16763 }
16765 {
16785 }
16786 }
16788 /* T is a postfix-expression that is not being used in a function
16789 call. Return the substituted version of T. */
16791 static tree
16793 tsubst_flags_t complain,
16794 tree in_decl)
16795 {
16799 else
16805 }
16807 /* T is a LAMBDA_EXPR. Generate a new LAMBDA_EXPR for the current
16808 instantiation context. Instantiating a pack expansion containing a lambda
16809 might result in multiple lambdas all based on the same lambda in the
16810 template. */
16812 tree
16814 {
16828 else
16836 {
16848 else
16853 {
16862 }
16863 else
16864 {
16870 }
16871 }
16875 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
16893 else
16894 {
16895 /* Fix the type of 'this'. */
16901 {
16905 }
16906 else
16907 {
16911 }
16913 /* Let finish_function set this. */
16934 /* The capture list was built up in reverse order; fix that now. */
16941 }
16948 }
16950 /* Like tsubst but deals with expressions and performs semantic
16951 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16953 tree
16955 tree args,
16956 tsubst_flags_t complain,
16957 tree in_decl,
16960 {
16961 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16962 #define RECUR(NODE) \
16963 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16965 integral_constant_expression_p)
16968 location_t loc;
16977 /* N3276 decltype magic only applies to calls at the top level or on the
16978 right side of a comma. */
16983 {
16986 /* Fall through. */
16988 {
16989 tree decl;
16990 cp_id_kind idk;
16995 {
16998 }
17000 /* Look up the name. */
17003 /* By convention, expressions use ERROR_MARK_NODE to indicate
17004 failure, not NULL_TREE. */
17010 integral_constant_expression_p,
17018 input_location);
17022 {
17026 }
17028 }
17031 {
17032 tree object;
17042 {
17047 }
17053 {
17056 }
17057 else
17064 else
17066 }
17069 {
17073 {
17074 /* A type conversion to reference type will be enclosed in
17075 such an indirect ref, but the substitution of the cast
17076 will have also added such an indirect ref. */
17079 }
17080 else
17088 }
17091 {
17095 }
17098 {
17105 flags));
17106 }
17109 {
17113 }
17120 {
17121 tree type;
17127 {
17132 }
17138 {
17156 }
17159 }
17193 else
17195 in_decl);
17230 {
17237 tree r = build_x_binary_op
17239 op0,
17241 ? ERROR_MARK
17243 op1,
17245 ? ERROR_MARK
17253 }
17256 {
17260 }
17273 {
17282 }
17287 /* Fall through */
17290 {
17291 tree r;
17297 {
17298 /* When there are no ARGS, we are trying to evaluate a
17299 non-dependent expression from the parser. Trying to do
17300 the substitutions may not work. */
17303 }
17304 else
17305 {
17310 else
17313 /*integral_constant_expression_p=*/
17317 }
17321 else
17325 {
17327 {
17329 {
17333 }
17334 else
17338 }
17340 }
17342 }
17345 {
17355 }
17371 {
17375 tree r = build_x_modify_expr
17378 /* TREE_NO_WARNING must be set if either the expression was
17379 parenthesized or it uses an operator such as >>= rather
17380 than plain assignment. In the former case, it was already
17381 set and must be copied. In the latter case,
17382 build_x_modify_expr sets it and it must not be reset
17383 here. */
17388 }
17393 /* Remember that there was a reference to this entity. */
17400 {
17405 tree ret;
17409 else
17410 {
17414 }
17416 /* If there was an initializer in the original tree, but it
17417 instantiated to an empty list, then we should pass a
17418 non-NULL empty vector to tell build_new that it was an
17419 empty initializer() rather than no initializer. This can
17420 only happen when the initializer is a pack expansion whose
17421 parameter packs are of length zero. */
17424 else
17425 {
17429 else
17430 {
17433 }
17434 }
17440 complain);
17448 }
17451 {
17457 complain));
17458 }
17461 {
17465 integral_constant_expression_p);
17467 op0,
17470 }
17473 {
17474 tree function;
17479 tree ret;
17482 /* Internal function with no arguments. */
17486 /* When we parsed the expression, we determined whether or
17487 not Koenig lookup should be performed. */
17490 {
17493 }
17495 {
17500 }
17502 {
17503 /* Do nothing; calling tsubst_copy_and_build on an identifier
17504 would incorrectly perform unqualified lookup again.
17506 Note that we can also have an IDENTIFIER_NODE if the earlier
17507 unqualified lookup found a member function; in that case
17508 koenig_p will be false and we do want to do the lookup
17509 again to find the instantiated member function.
17511 FIXME but doing that causes c++/15272, so we need to stop
17512 using IDENTIFIER_NODE in that situation. */
17514 }
17515 else
17516 {
17518 {
17524 }
17525 else
17530 /* Avoid error about taking the address of a constructor. */
17534 in_decl,
17536 integral_constant_expression_p);
17540 }
17545 {
17550 else
17551 {
17552 /* Expand the pack expansion and push each entry onto
17553 CALL_ARGS. */
17556 {
17561 {
17566 }
17567 }
17568 else
17569 {
17570 /* A partial substitution. Add one entry. */
17572 }
17573 }
17574 }
17576 /* We do not perform argument-dependent lookup if normal
17577 lookup finds a non-function, in accordance with the
17578 expected resolution of DR 218. */
17581 /* If lookup found a member function, the Koenig lookup is
17582 not appropriate, even if an unqualified-name was used
17583 to denote the function. */
17586 /* Only do this when substitution turns a dependent call
17587 into a non-dependent call. */
17595 {
17597 {
17598 /* For backwards compatibility and good diagnostics, try
17599 the unqualified lookup again if we aren't in SFINAE
17600 context. */
17601 tree unq = (tsubst_copy_and_build
17603 integral_constant_expression_p));
17605 {
17608 }
17611 {
17612 /* In a lambda fn, we have to be careful to not
17613 introduce new this captures. Legacy code can't
17614 be using lambdas anyway, so it's ok to be
17615 stricter. */
17620 "and no declarations were found by "
17621 "argument-dependent lookup at the point "
17628 else
17632 {
17643 {
17645 input_location);
17647 "declarations in dependent base %qT are "
17653 else
17657 }
17658 else
17660 "%qD declared here, later in the "
17663 {
17666 }
17667 }
17670 }
17671 }
17673 {
17678 }
17679 }
17681 /* Remember that there was a reference to this entity. */
17685 {
17688 }
17690 /* Put back tf_decltype for the actual call. */
17695 {
17699 {
17701 "wrong number of arguments to "
17704 }
17705 else
17707 input_location),
17712 /* Unsupported internal function with arguments. */
17714 }
17717 complain);
17719 {
17734 complain);
17735 else
17736 ret = (build_new_method_call
17741 complain));
17742 }
17743 else
17746 koenig_p,
17747 complain);
17752 {
17758 {
17764 {
17766 /* The thunk location is not interesting. */
17768 }
17769 }
17770 }
17773 }
17776 {
17782 {
17784 {
17789 }
17790 else
17791 {
17796 }
17798 }
17799 else
17800 {
17803 }
17807 }
17810 {
17815 input_location));
17816 }
17819 {
17827 {
17828 /* We have pack expansions, so expand those and
17829 create a new list out of it. */
17832 tree chain;
17835 /* Expand the argument expressions. */
17843 /* Build the rest of the list. */
17848 /* Determine the number of arguments. */
17850 {
17853 }
17856 else
17857 {
17858 /* Since we only performed a partial substitution into
17859 the argument pack, we only RETURN (a single list
17860 node. */
17867 }
17869 /* Convert the argument vectors into a TREE_LIST */
17872 {
17873 /* Grab the Ith values. */
17874 i--;
17877 value
17881 /* Build the list (backwards). */
17883 }
17886 }
17902 }
17905 {
17906 tree object;
17907 tree object_type;
17908 tree member;
17909 tree r;
17913 /* Remember that there was a reference to this entity. */
17924 else
17930 {
17935 }
17939 {
17941 {
17946 {
17949 }
17951 {
17956 }
17957 }
17958 }
17961 {
17962 /* Lookup the template functions now that we know what the
17963 scope is. */
17971 {
17974 args);
17975 member = (adjust_result_of_qualified_name_lookup
17977 object_type));
17978 }
17979 else
17980 {
17982 input_location);
17984 }
17985 }
17989 {
17991 {
17995 else
17998 }
18000 }
18004 complain);
18008 }
18015 {
18023 tree r;
18028 /* digest_init will do the wrong thing if we let it. */
18032 /* We do not want to process the index of aggregate
18033 initializers as they are identifier nodes which will be
18034 looked up by digest_init. */
18040 {
18042 /* An identifier index is looked up in the type
18043 being initialized, not the current scope. */
18048 {
18049 /* Substitute into the pack expansion. */
18051 in_decl);
18055 ;
18057 /* Just move the argument into place. */
18059 else
18060 {
18061 /* Update the length of the final CONSTRUCTOR
18062 arguments vector, and note that we will need to
18063 copy.*/
18066 }
18067 }
18068 else
18070 }
18073 {
18078 {
18080 {
18085 }
18086 else
18088 }
18089 }
18095 {
18100 }
18104 }
18107 {
18110 {
18113 }
18114 else
18115 {
18118 }
18119 }
18125 {
18126 /* We don't build decls for an instantiation of a
18127 variadic capture proxy, we instantiate the elements
18128 when needed. */
18131 }
18132 /* Fall through */
18135 {
18137 /* ??? We're doing a subset of finish_id_expression here. */
18139 && !processing_template_decl
18140 && !cp_unevaluated_operand
18143 {
18145 /* Replace an evaluated use of the thread_local variable with
18146 a call to its wrapper. */
18148 }
18150 {
18154 }
18157 /* If the original type was a reference, we'll be wrapped in
18158 the appropriate INDIRECT_REF. */
18161 }
18164 {
18168 }
18171 {
18172 tree object_ptr
18179 }
18186 {
18197 }
18200 {
18206 integral_constant_expression_p);
18210 /* If the resulting list of expression statement is empty,
18211 fold it further into void_node. */
18216 }
18219 {
18223 }
18226 /* We can get here for a constant initializer of non-dependent type.
18227 FIXME stop folding in cp_parser_initializer_clause. */
18228 {
18230 complain);
18232 }
18236 integral_constant_expression_p));
18242 {
18247 complain));
18248 }
18254 /* Handle Objective-C++ constructs, if appropriate. */
18255 {
18256 tree subst
18261 }
18263 }
18265 #undef RECUR
18266 #undef RETURN
18267 out:
18270 }
18272 /* Verify that the instantiated ARGS are valid. For type arguments,
18273 make sure that the type's linkage is ok. For non-type arguments,
18274 make sure they are constants if they are integral or enumerations.
18275 Emit an error under control of COMPLAIN, and return TRUE on error. */
18277 static bool
18279 {
18283 {
18293 }
18295 {
18296 /* [basic.link]: A name with no linkage (notably, the name
18297 of a class or enumeration declared in a local scope)
18298 shall not be used to declare an entity with linkage.
18299 This implies that names with no linkage cannot be used as
18300 template arguments
18302 DR 757 relaxes this restriction for C++0x. */
18307 {
18308 /* DR 488 makes use of a type with no linkage cause
18309 type deduction to fail. */
18311 {
18314 else
18317 }
18319 }
18320 /* In order to avoid all sorts of complications, we do not
18321 allow variably-modified types as template arguments. */
18323 {
18327 }
18328 }
18329 /* Class template and alias template arguments should be OK. */
18331 ;
18332 /* A non-type argument of integral or enumerated type must be a
18333 constant. */
18338 {
18342 }
18344 }
18346 static bool
18348 {
18353 {
18356 }
18360 }
18362 /* We're out of SFINAE context now, so generate diagnostics for the access
18363 errors we saw earlier when instantiating D from TMPL and ARGS. */
18365 static void
18367 {
18379 }
18381 /* Instantiate the indicated variable, function, or alias template TMPL with
18382 the template arguments in TARG_PTR. */
18384 static tree
18386 {
18388 tree fndecl;
18389 tree gen_tmpl;
18390 tree spec;
18398 /* If this function is a clone, handle it specially. */
18400 {
18401 tree spec;
18402 tree clone;
18404 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18405 DECL_CLONED_FUNCTION. */
18411 /* Look for the clone. */
18415 /* We should always have found the clone by now. */
18418 }
18423 /* Check to see if we already have this specialization. */
18427 /* targ_ptr only has the innermost template args, so add the outer ones
18428 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18429 the case of a non-dependent call within a template definition). */
18430 targ_ptr = (add_outermost_template_args
18432 targ_ptr));
18434 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18435 but it doesn't seem to be on the hot path. */
18444 {
18446 {
18450 }
18452 }
18455 complain))
18458 /* We are building a FUNCTION_DECL, during which the access of its
18459 parameters and return types have to be checked. However this
18460 FUNCTION_DECL which is the desired context for access checking
18461 is not built yet. We solve this chicken-and-egg problem by
18462 deferring all checks until we have the FUNCTION_DECL. */
18465 /* Instantiation of the function happens in the context of the function
18466 template, not the context of the overload resolution we're doing. */
18468 /* If there are dependent arguments, e.g. because we're doing partial
18469 ordering, make sure processing_template_decl stays set. */
18473 {
18477 }
18483 {
18484 /* We need to determine if we're using a partial or explicit
18485 specialization now, because the type of the variable could be
18486 different. */
18492 {
18497 }
18498 }
18500 /* Substitute template parameters to obtain the specialization. */
18508 {
18511 }
18513 /* The DECL_TI_TEMPLATE should always be the immediate parent
18514 template, not the most general template. */
18518 /* Now we know the specialization, compute access previously
18519 deferred. Do no access control for inheriting constructors,
18520 as we already checked access for the inherited constructor. */
18523 {
18528 }
18531 /* If we've just instantiated the main entry point for a function,
18532 instantiate all the alternate entry points as well. We do this
18533 by cloning the instantiation of the main entry point, not by
18534 instantiating the template clones. */
18539 {
18541 {
18542 /* Remember to reinstantiate when we're out of SFINAE so the user
18543 can see the errors. */
18545 }
18547 }
18549 }
18551 /* Wrapper for instantiate_template_1. */
18553 tree
18555 {
18556 tree ret;
18561 }
18563 /* Instantiate the alias template TMPL with ARGS. Also push a template
18564 instantiation level, which instantiate_template doesn't do because
18565 functions and variables have sufficient context established by the
18566 callers. */
18568 static tree
18570 {
18577 {
18580 }
18582 args =
18590 /* We can't free this if a pending_template entry or last_error_tinst_level
18591 is pointing at it. */
18597 }
18599 /* PARM is a template parameter pack for FN. Returns true iff
18600 PARM is used in a deducible way in the argument list of FN. */
18602 static bool
18604 {
18607 {
18609 tree packs;
18615 {
18616 /* The template parameter pack is used in a function parameter
18617 pack. If this is the end of the parameter list, the
18618 template parameter pack is deducible. */
18621 else
18622 /* Otherwise, not. Well, it could be deduced from
18623 a non-pack parameter, but doing so would end up with
18624 a deduction mismatch, so don't bother. */
18626 }
18627 }
18628 /* The template parameter pack isn't used in any function parameter
18629 packs, but it might be used deeper, e.g. tuple<Args...>. */
18631 }
18633 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18634 NARGS elements of the arguments that are being used when calling
18635 it. TARGS is a vector into which the deduced template arguments
18636 are placed.
18638 Returns either a FUNCTION_DECL for the matching specialization of FN or
18639 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18640 true, diagnostics will be printed to explain why it failed.
18642 If FN is a conversion operator, or we are trying to produce a specific
18643 specialization, RETURN_TYPE is the return type desired.
18645 The EXPLICIT_TARGS are explicit template arguments provided via a
18646 template-id.
18648 The parameter STRICT is one of:
18650 DEDUCE_CALL:
18651 We are deducing arguments for a function call, as in
18652 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18653 deducing arguments for a call to the result of a conversion
18654 function template, as in [over.call.object].
18656 DEDUCE_CONV:
18657 We are deducing arguments for a conversion function, as in
18658 [temp.deduct.conv].
18660 DEDUCE_EXACT:
18661 We are deducing arguments when doing an explicit instantiation
18662 as in [temp.explicit], when determining an explicit specialization
18663 as in [temp.expl.spec], or when taking the address of a function
18664 template, as in [temp.deduct.funcaddr]. */
18666 tree
18668 tree explicit_targs,
18669 tree targs,
18672 tree return_type,
18673 unification_kind_t strict,
18677 {
18678 tree parms;
18679 tree fntype;
18692 tree tinst;
18698 full_targs = (add_outermost_template_args
18700 targs));
18705 /* In C++0x, it's possible to have a function template whose type depends
18706 on itself recursively. This is most obvious with decltype, but can also
18707 occur with enumeration scope (c++/48969). So we need to catch infinite
18708 recursion and reject the substitution at deduction time; this function
18709 will return error_mark_node for any repeated substitution.
18711 This also catches excessive recursion such as when f<N> depends on
18712 f<N-1> across all integers, and returns error_mark_node for all the
18713 substitutions back up to the initial one.
18715 This is, of course, not reentrant. */
18725 {
18726 /* [temp.deduct]
18728 The specified template arguments must match the template
18729 parameters in kind (i.e., type, nontype, template), and there
18730 must not be more arguments than there are parameters;
18731 otherwise type deduction fails.
18733 Nontype arguments must match the types of the corresponding
18734 nontype template parameters, or must be convertible to the
18735 types of the corresponding nontype parameters as specified in
18736 _temp.arg.nontype_, otherwise type deduction fails.
18738 All references in the function type of the function template
18739 to the corresponding template parameters are replaced by the
18740 specified template argument values. If a substitution in a
18741 template parameter or in the function type of the function
18742 template results in an invalid type, type deduction fails. */
18753 explicit_targs);
18755 /* Adjust any explicit template arguments before entering the
18756 substitution context. */
18757 explicit_targs
18759 complain,
18765 /* Substitute the explicit args into the function type. This is
18766 necessary so that, for instance, explicitly declared function
18767 arguments can match null pointed constants. If we were given
18768 an incomplete set of explicit args, we must not do semantic
18769 processing during substitution as we could create partial
18770 instantiations. */
18772 {
18777 /* Dig out the actual parm. */
18780 {
18783 }
18785 {
18788 }
18791 /* No explicit argument for this template parameter. */
18795 {
18796 /* Mark the argument pack as "incomplete". We could
18797 still deduce more arguments during unification.
18798 We remove this mark in type_unification_real. */
18800 {
18804 }
18806 /* We have some incomplete argument packs. */
18808 }
18809 }
18813 {
18816 }
18819 /* Ignore any access checks; we'll see them again in
18820 instantiate_template and they might have the wrong
18821 access path at this point. */
18833 /* Place the explicitly specified arguments in TARGS. */
18837 }
18839 /* Never do unification on the 'this' parameter. */
18843 {
18844 /* We're deducing for a call to the result of a template conversion
18845 function. The parms we really want are in return_type. */
18849 }
18851 {
18860 }
18862 /* We allow incomplete unification without an error message here
18863 because the standard doesn't seem to explicitly prohibit it. Our
18864 callers must be ready to deal with unification failures in any
18865 event. */
18868 /* If we aren't explaining yet, push tinst context so we can see where
18869 any errors (e.g. from class instantiations triggered by instantiation
18870 of default template arguments) come from. If we are explaining, this
18871 context is redundant. */
18873 {
18876 }
18878 /* type_unification_real will pass back any access checks from default
18879 template argument substitution. */
18891 /* Now that we have bindings for all of the template arguments,
18892 ensure that the arguments deduced for the template template
18893 parameters have compatible template parameter lists. We cannot
18894 check this property before we have deduced all template
18895 arguments, because the template parameter types of a template
18896 template parameter might depend on prior template parameters
18897 deduced after the template template parameter. The following
18898 ill-formed example illustrates this issue:
18900 template<typename T, template<T> class C> void f(C<5>, T);
18902 template<int N> struct X {};
18904 void g() {
18905 f(X<5>(), 5l); // error: template argument deduction fails
18906 }
18908 The template parameter list of 'C' depends on the template type
18909 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18910 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18911 time that we deduce 'C'. */
18914 {
18917 }
18919 /* All is well so far. Now, check:
18921 [temp.deduct]
18923 When all template arguments have been deduced, all uses of
18924 template parameters in nondeduced contexts are replaced with
18925 the corresponding deduced argument values. If the
18926 substitution results in an invalid type, as described above,
18927 type deduction fails. */
18930 {
18933 }
18935 /* Also collect access checks from the instantiation. */
18948 /* Now perform any access checks encountered during substitution. */
18955 /* If we're looking for an exact match, check that what we got
18956 is indeed an exact match. It might not be if some template
18957 parameters are used in non-deduced contexts. But don't check
18958 for an exact match if we have dependent template arguments;
18959 in that case we're doing partial ordering, and we already know
18960 that we have two candidates that will provide the actual type. */
18962 {
18966 tree sarg
18972 {
18976 }
18977 }
18979 /* After doing deduction with the inherited constructor, actually return an
18980 instantiation of the inheriting constructor. */
18986 fail:
18989 {
18991 /* Reset once we're all the way out. */
18993 }
18995 /* We can't free this if a pending_template entry or last_error_tinst_level
18996 is pointing at it. */
19002 }
19004 /* Adjust types before performing type deduction, as described in
19005 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
19006 sections are symmetric. PARM is the type of a function parameter
19007 or the return type of the conversion function. ARG is the type of
19008 the argument passed to the call, or the type of the value
19009 initialized with the result of the conversion function.
19010 ARG_EXPR is the original argument expression, which may be null. */
19012 static int
19016 tree arg_expr)
19017 {
19021 {
19026 /* Swap PARM and ARG throughout the remainder of this
19027 function; the handling is precisely symmetric since PARM
19028 will initialize ARG rather than vice versa. */
19033 /* Core issue #873: Do the DR606 thing (see below) for these cases,
19034 too, but here handle it by stripping the reference from PARM
19035 rather than by adding it to ARG. */
19043 /* Nothing else to do in this case. */
19048 }
19051 {
19052 /* [temp.deduct.call]
19054 If P is not a reference type:
19056 --If A is an array type, the pointer type produced by the
19057 array-to-pointer standard conversion (_conv.array_) is
19058 used in place of A for type deduction; otherwise,
19060 --If A is a function type, the pointer type produced by
19061 the function-to-pointer standard conversion
19062 (_conv.func_) is used in place of A for type deduction;
19063 otherwise,
19065 --If A is a cv-qualified type, the top level
19066 cv-qualifiers of A's type are ignored for type
19067 deduction. */
19072 else
19074 }
19076 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
19077 reference to a cv-unqualified template parameter that does not represent a
19078 template parameter of a class template (during class template argument
19079 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
19080 an lvalue, the type "lvalue reference to A" is used in place of A for type
19081 deduction. */
19088 /* try_one_overload doesn't provide an arg_expr, but
19089 functions are always lvalues. */
19093 /* [temp.deduct.call]
19095 If P is a cv-qualified type, the top level cv-qualifiers
19096 of P's type are ignored for type deduction. If P is a
19097 reference type, the type referred to by P is used for
19098 type deduction. */
19101 {
19104 }
19106 /* DR 322. For conversion deduction, remove a reference type on parm
19107 too (which has been swapped into ARG). */
19112 }
19114 /* Subroutine of unify_one_argument. PARM is a function parameter of a
19115 template which does contain any deducible template parameters; check if
19116 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
19117 unify_one_argument. */
19119 static int
19122 {
19123 tree type;
19127 else
19134 {
19138 }
19140 {
19145 }
19149 else
19151 }
19155 /* Returns true iff the expression EXPR is one from which a template
19156 argument can be deduced. In other words, if it's an undecorated
19157 use of a template non-type parameter. */
19159 static bool
19161 {
19162 /* Strip implicit conversions. */
19166 }
19168 /* Returns true iff the array domain DOMAIN uses a template parameter in a
19169 deducible way; that is, if it has a max value of <PARM> - 1. */
19171 static bool
19173 {
19182 }
19184 /* Returns true iff the template arguments ARGS use a template parameter
19185 in a deducible way. */
19187 static bool
19189 {
19191 {
19196 else
19197 {
19204 else
19206 }
19209 }
19211 }
19213 /* Returns true iff TYPE contains any deducible references to template
19214 parameters, as per 14.8.2.5. */
19216 static bool
19218 {
19222 /* T
19223 cv-list T
19224 TT<T>
19225 TT<i>
19226 TT<> */
19231 /* T*
19232 T&
19233 T&& */
19237 /* T[integer-constant ]
19238 type [i] */
19243 /* T type ::*
19244 type T::*
19245 T T::*
19246 T (type ::*)()
19247 type (T::*)()
19248 type (type ::*)(T)
19249 type (T::*)(T)
19250 T (type ::*)(T)
19251 T (T::*)()
19252 T (T::*)(T) */
19255 || (uses_deducible_template_parms
19258 /* template-name <T> (where template-name refers to a class template)
19259 template-name <i> (where template-name refers to a class template) */
19266 /* type (T)
19267 T()
19268 T(T) */
19271 {
19280 }
19283 }
19285 /* Subroutine of type_unification_real and unify_pack_expansion to
19286 handle unification of a single P/A pair. Parameters are as
19287 for those functions. */
19289 static int
19293 {
19300 /* We can't deduce anything from this, but we might get all the
19301 template args from other function args. */
19304 /* Implicit conversions (Clause 4) will be performed on a function
19305 argument to convert it to the type of the corresponding function
19306 parameter if the parameter type contains no template-parameters that
19307 participate in template argument deduction. */
19310 /* For function parameters with no deducible template parameters,
19311 just return. We'll check non-dependent conversions later. */
19315 {
19317 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19318 | UNIFY_ALLOW_MORE_CV_QUAL
19332 }
19334 /* We only do these transformations if this is the top-level
19335 parameter_type_list in a call or declaration matching; in other
19336 situations (nested function declarators, template argument lists) we
19337 won't be comparing a type to an expression, and we don't do any type
19338 adjustments. */
19340 {
19342 {
19345 {
19346 /* [temp.deduct.type] A template-argument can be
19347 deduced from a pointer to function or pointer
19348 to member function argument if the set of
19349 overloaded functions does not contain function
19350 templates and at most one of a set of
19351 overloaded functions provides a unique
19352 match. */
19356 /* If a unique match was not found, this is a
19357 non-deduced context, so we still succeed. */
19359 }
19365 }
19367 arg_strict |=
19369 }
19370 else
19375 /* For deduction from an init-list we need the actual list. */
19379 }
19381 /* for_each_template_parm callback that always returns 0. */
19383 static int
19385 {
19387 }
19389 /* for_each_template_parm any_fn callback to handle deduction of a template
19390 type argument from the type of an array bound. */
19392 static int
19394 {
19402 {
19408 }
19410 /* Keep walking. */
19412 }
19414 /* Try to deduce any not-yet-deduced template type arguments from the type of
19415 an array bound. This is handled separately from unify because 14.8.2.5 says
19416 "The type of a type parameter is only deduced from an array bound if it is
19417 not otherwise deduced." */
19419 static void
19421 {
19426 }
19428 /* Most parms like fn_type_unification.
19430 If SUBR is 1, we're being called recursively (to unify the
19431 arguments of a function or method parameter of a function
19432 template).
19434 CHECKS is a pointer to a vector of access checks encountered while
19435 substituting default template arguments. */
19437 static int
19439 tree full_targs,
19440 tree xparms,
19444 unification_kind_t strict,
19448 {
19453 tree parms;
19464 /* Reset the number of non-defaulted template arguments contained
19465 in TARGS. */
19468 again:
19476 {
19481 /* For a function parameter pack that occurs at the end of the
19482 parameter-declaration-list, the type A of each remaining
19483 argument of the call is compared with the type P of the
19484 declarator-id of the function parameter pack. */
19490 /* For a function parameter pack that does not occur at the
19491 end of the parameter-declaration-list, the type of the
19492 parameter pack is a non-deduced context. */
19499 explain_p))
19501 }
19506 {
19507 /* Unify the remaining arguments with the pack expansion type. */
19508 tree argvec;
19511 /* Allocate a TREE_VEC and copy in all of the arguments */
19516 /* Copy the parameter into parmvec. */
19522 /* Advance to the end of the list of parameters. */
19524 }
19526 /* Fail if we've reached the end of the parm list, and more args
19527 are present, and the parm list isn't variadic. */
19530 /* Fail if parms are left and they don't have default values and
19531 they aren't all deduced as empty packs (c++/57397). This is
19532 consistent with sufficient_parms_p. */
19535 {
19539 do
19540 {
19543 count++;
19545 }
19549 type_pack_p);
19550 }
19553 {
19554 tsubst_flags_t complain = (explain_p
19555 ? tf_warning_or_error
19560 {
19564 /* Clear the "incomplete" flags on all argument packs now so that
19565 substituting them into later default arguments works. */
19567 {
19570 }
19578 {
19583 }
19585 /* If this is an undeduced nontype parameter that depends on
19586 a type parameter, try another pass; its type may have been
19587 deduced from a later argument than the one from which
19588 this parameter can be deduced. */
19592 {
19595 }
19597 /* Core issue #226 (C++0x) [temp.deduct]:
19599 If a template argument has not been deduced, its
19600 default template argument, if any, is used.
19602 When we are in C++98 mode, TREE_PURPOSE will either
19603 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19604 to explicitly check cxx_dialect here. */
19606 /* OK, there is a default argument. Wait until after the
19607 conversion check to do substitution. */
19610 /* If the type parameter is a parameter pack, then it will
19611 be deduced to an empty parameter pack. */
19613 {
19614 tree arg;
19617 {
19620 }
19621 else
19628 }
19631 }
19633 /* DR 1391: All parameters have args, now check non-dependent parms for
19634 convertibility. */
19638 {
19644 /* For a function parameter pack that occurs at the end of the
19645 parameter-declaration-list, the type A of each remaining
19646 argument of the call is compared with the type P of the
19647 declarator-id of the function parameter pack. */
19653 /* For a function parameter pack that does not occur at the
19654 end of the parameter-declaration-list, the type of the
19655 parameter pack is a non-deduced context. */
19664 explain_p))
19666 }
19668 /* Now substitute into the default template arguments. */
19670 {
19694 else
19702 {
19704 /* The position of the first default template argument,
19705 is also the number of non-defaulted arguments in TARGS.
19706 Record that. */
19709 }
19710 }
19714 }
19720 }
19722 /* Subroutine of type_unification_real. Args are like the variables
19723 at the call site. ARG is an overloaded function (or template-id);
19724 we try deducing template args from each of the overloads, and if
19725 only one succeeds, we go with that. Modifies TARGS and returns
19726 true on success. */
19728 static bool
19730 tree targs,
19731 tree parm,
19732 tree arg,
19733 unification_kind_t strict,
19736 {
19743 {
19746 }
19747 else
19751 /* Handle `&x' where `x' is some static or non-static member
19752 function name. */
19758 /* Strip baselink information. */
19763 {
19764 /* If we got some explicit template args, we need to plug them into
19765 the affected templates before we try to unify, in case the
19766 explicit args will completely resolve the templates in question. */
19773 {
19786 {
19791 {
19794 }
19795 }
19798 }
19799 /* If no templates (or more than one) are fully resolved by the
19800 explicit arguments, this template-id is a non-deduced context; it
19801 could still be OK if we deduce all template arguments for the
19802 enclosing call through other arguments. */
19805 }
19808 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19809 -- but the deduction does not succeed because the expression is
19810 not just the function on its own. */
19812 else
19814 {
19819 {
19822 }
19823 }
19825 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19826 to function or pointer to member function argument if the set of
19827 overloaded functions does not contain function templates and at most
19828 one of a set of overloaded functions provides a unique match.
19830 So if we found multiple possibilities, we return success but don't
19831 deduce anything. */
19834 {
19838 {
19843 /* Don't forget explicit template arguments in a pack. */
19847 }
19848 }
19853 }
19855 /* Core DR 115: In contexts where deduction is done and fails, or in
19856 contexts where deduction is not done, if a template argument list is
19857 specified and it, along with any default template arguments, identifies
19858 a single function template specialization, then the template-id is an
19859 lvalue for the function template specialization. */
19861 tree
19863 {
19876 {
19879 }
19881 {
19884 }
19886 {
19889 }
19892 {
19896 /* If we got some explicit template args, we need to plug them into
19897 the affected templates before we try to unify, in case the
19898 explicit args will completely resolve the templates in question. */
19906 {
19919 {
19922 {
19925 }
19927 {
19930 }
19931 }
19932 }
19934 {
19942 {
19943 tree base
19946 }
19950 }
19952 /* There were no good options and at least one bad one, so let the
19953 user know what the problem is. */
19955 }
19957 }
19959 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19960 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19961 different overloads deduce different arguments for a given parm.
19962 ADDR_P is true if the expression for which deduction is being
19963 performed was of the form "& fn" rather than simply "fn".
19965 Returns 1 on success. */
19967 static int
19969 tree orig_targs,
19970 tree targs,
19971 tree parm,
19972 tree arg,
19973 unification_kind_t strict,
19977 {
19979 tree tempargs;
19985 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19986 to function or pointer to member function argument if the set of
19987 overloaded functions does not contain function templates and at most
19988 one of a set of overloaded functions provides a unique match.
19990 So if this is a template, just return success. */
20002 /* We don't copy orig_targs for this because if we have already deduced
20003 some template args from previous args, unify would complain when we
20004 try to deduce a template parameter for the same argument, even though
20005 there isn't really a conflict. */
20012 /* First make sure we didn't deduce anything that conflicts with
20013 explicitly specified args. */
20015 {
20022 /* Since we're unifying against ourselves, we will fill in
20023 template args used in the function parm list with our own
20024 template parms. Discard them. */
20027 {
20028 /* Check that the argument at each index of the deduced argument pack
20029 is equivalent to the corresponding explicitly specified argument.
20030 We may have deduced more arguments than were explicitly specified,
20031 and that's OK. */
20033 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
20034 that's wrong if we deduce the same argument pack from multiple
20035 function arguments: it's only incomplete the first time. */
20048 }
20051 }
20054 {
20059 }
20062 }
20064 /* PARM is a template class (perhaps with unbound template
20065 parameters). ARG is a fully instantiated type. If ARG can be
20066 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
20067 TARGS are as for unify. */
20069 static tree
20072 {
20073 tree copy_of_targs;
20083 /* We need to make a new template argument vector for the call to
20084 unify. If we used TARGS, we'd clutter it up with the result of
20085 the attempted unification, even if this class didn't work out.
20086 We also don't want to commit ourselves to all the unifications
20087 we've already done, since unification is supposed to be done on
20088 an argument-by-argument basis. In other words, consider the
20089 following pathological case:
20091 template <int I, int J, int K>
20092 struct S {};
20094 template <int I, int J>
20095 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
20097 template <int I, int J, int K>
20098 void f(S<I, J, K>, S<I, I, I>);
20100 void g() {
20101 S<0, 0, 0> s0;
20102 S<0, 1, 2> s2;
20104 f(s0, s2);
20105 }
20107 Now, by the time we consider the unification involving `s2', we
20108 already know that we must have `f<0, 0, 0>'. But, even though
20109 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
20110 because there are two ways to unify base classes of S<0, 1, 2>
20111 with S<I, I, I>. If we kept the already deduced knowledge, we
20112 would reject the possibility I=1. */
20116 {
20120 }
20122 /* If unification failed, we're done. */
20128 }
20130 /* Given a template type PARM and a class type ARG, find the unique
20131 base type in ARG that is an instance of PARM. We do not examine
20132 ARG itself; only its base-classes. If there is not exactly one
20133 appropriate base class, return NULL_TREE. PARM may be the type of
20134 a partial specialization, as well as a plain template type. Used
20135 by unify. */
20137 static enum template_base_result
20140 {
20142 tree binfo;
20148 {
20149 /* The type could not be completed. */
20152 }
20154 /* Walk in inheritance graph order. The search order is not
20155 important, and this avoids multiple walks of virtual bases. */
20157 {
20162 {
20163 /* If there is more than one satisfactory baseclass, then:
20165 [temp.deduct.call]
20167 If they yield more than one possible deduced A, the type
20168 deduction fails.
20170 applies. */
20172 {
20175 }
20178 }
20179 }
20183 }
20185 /* Returns the level of DECL, which declares a template parameter. */
20187 static int
20189 {
20191 {
20201 }
20203 }
20205 /* Decide whether ARG can be unified with PARM, considering only the
20206 cv-qualifiers of each type, given STRICT as documented for unify.
20207 Returns nonzero iff the unification is OK on that basis. */
20209 static int
20211 {
20217 {
20218 /* Although a CVR qualifier is ignored when being applied to a
20219 substituted template parameter ([8.3.2]/1 for example), that
20220 does not allow us to unify "const T" with "int&" because both
20221 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
20222 It is ok when we're allowing additional CV qualifiers
20223 at the outer level [14.8.2.1]/3,1st bullet. */
20233 }
20244 }
20246 /* Determines the LEVEL and INDEX for the template parameter PARM. */
20247 void
20249 {
20253 {
20256 }
20257 else
20258 {
20261 }
20262 }
20264 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
20265 do { \
20266 if (unify (TP, TA, P, A, S, EP)) \
20267 return 1; \
20268 } while (0)
20270 /* Unifies the remaining arguments in PACKED_ARGS with the pack
20271 expansion at the end of PACKED_PARMS. Returns 0 if the type
20272 deduction succeeds, 1 otherwise. STRICT is the same as in
20273 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
20274 function call argument list. We'll need to adjust the arguments to make them
20275 types. SUBR tells us if this is from a recursive call to
20276 type_unification_real, or for comparing two template argument
20277 lists. */
20279 static int
20283 {
20284 tree parm
20290 /* Add in any args remembered from an earlier partial instantiation. */
20297 /* Determine the parameter packs we will be deducing from the
20298 pattern, and record their current deductions. */
20301 {
20305 /* Determine the index and level of this parameter pack. */
20308 /* Keep track of the parameter packs and their corresponding
20309 argument packs. */
20312 }
20314 /* Loop through all of the arguments that have not yet been
20315 unified and unify each with the pattern. */
20317 {
20318 tree parm;
20322 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20323 or the element of its argument pack at the current index if
20324 this argument was explicitly specified. */
20326 {
20335 {
20338 }
20340 }
20342 /* If we had explicit template arguments, substitute them into the
20343 pattern before deduction. */
20345 {
20346 /* Some arguments might still be unspecified or dependent. */
20354 NULL_TREE);
20359 }
20360 else
20363 /* Unify the pattern with the current argument. */
20365 explain_p))
20368 /* For each parameter pack, collect the deduced value. */
20370 {
20376 }
20377 }
20379 /* Verify that the results of unification with the parameter packs
20380 produce results consistent with what we've seen before, and make
20381 the deduced argument packs available. */
20383 {
20390 /* By default keep the original deduced argument pack.
20391 If necessary, more specific code is going to update the
20392 resulting deduced argument later down in this function. */
20396 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20397 actually deduce anything. */
20405 {
20406 /* If we had fewer function args than explicit template args,
20407 just use the explicits. */
20412 }
20415 {
20416 tree result;
20417 /* Build the deduced *_ARGUMENT_PACK. */
20419 {
20422 }
20423 else
20428 /* Note the deduced argument packs for this parameter
20429 pack. */
20431 }
20435 {
20436 /* We only had the explicitly-provided arguments before, but
20437 now we have a complete set of arguments. */
20443 }
20444 else
20445 {
20451 /* Inconsistent unification of this parameter pack. */
20453 bad_old_arg,
20454 bad_new_arg);
20455 }
20456 }
20459 }
20461 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20462 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20463 parameters and return value are as for unify. */
20465 static int
20469 {
20470 tree parm_max;
20471 tree arg_max;
20475 /* Our representation of array types uses "N - 1" as the
20476 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20477 not an integer constant. We cannot unify arbitrarily
20478 complex expressions, so we eliminate the MINUS_EXPRs
20479 here. */
20483 {
20486 }
20490 {
20491 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20492 trying to unify the type of a variable with the type
20493 of a template parameter. For example:
20495 template <unsigned int N>
20496 void f (char (&) [N]);
20497 int g();
20498 void h(int i) {
20499 char a[g(i)];
20500 f(a);
20501 }
20503 Here, the type of the ARG will be "int [g(i)]", and
20504 may be a SAVE_EXPR, etc. */
20508 }
20510 /* If only one of the bounds used a MINUS_EXPR, compensate
20511 by adding one to the other bound. */
20514 integer_type_node,
20515 parm_max,
20516 integer_one_node);
20519 integer_type_node,
20520 arg_max,
20521 integer_one_node);
20525 }
20527 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20531 static pa_kind_t
20533 {
20542 else
20544 }
20546 /* Deduce the value of template parameters. TPARMS is the (innermost)
20547 set of template parameters to a template. TARGS is the bindings
20548 for those template parameters, as determined thus far; TARGS may
20549 include template arguments for outer levels of template parameters
20550 as well. PARM is a parameter to a template function, or a
20551 subcomponent of that parameter; ARG is the corresponding argument.
20552 This function attempts to match PARM with ARG in a manner
20553 consistent with the existing assignments in TARGS. If more values
20554 are deduced, then TARGS is updated.
20556 Returns 0 if the type deduction succeeds, 1 otherwise. The
20557 parameter STRICT is a bitwise or of the following flags:
20559 UNIFY_ALLOW_NONE:
20560 Require an exact match between PARM and ARG.
20561 UNIFY_ALLOW_MORE_CV_QUAL:
20562 Allow the deduced ARG to be more cv-qualified (by qualification
20563 conversion) than ARG.
20564 UNIFY_ALLOW_LESS_CV_QUAL:
20565 Allow the deduced ARG to be less cv-qualified than ARG.
20566 UNIFY_ALLOW_DERIVED:
20567 Allow the deduced ARG to be a template base class of ARG,
20568 or a pointer to a template base class of the type pointed to by
20569 ARG.
20570 UNIFY_ALLOW_INTEGER:
20571 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20572 case for more information.
20573 UNIFY_ALLOW_OUTER_LEVEL:
20574 This is the outermost level of a deduction. Used to determine validity
20575 of qualification conversions. A valid qualification conversion must
20576 have const qualified pointers leading up to the inner type which
20577 requires additional CV quals, except at the outer level, where const
20578 is not required [conv.qual]. It would be normal to set this flag in
20579 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20580 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20581 This is the outermost level of a deduction, and PARM can be more CV
20582 qualified at this point.
20583 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20584 This is the outermost level of a deduction, and PARM can be less CV
20585 qualified at this point. */
20587 static int
20590 {
20592 tree targ;
20593 tree tparm;
20595 tsubst_flags_t complain = (explain_p
20596 ? tf_warning_or_error
20599 /* I don't think this will do the right thing with respect to types.
20600 But the only case I've seen it in so far has been array bounds, where
20601 signedness is the only information lost, and I think that will be
20602 okay. */
20610 /* We can't deduce anything from this, but we might get all the
20611 template args from other function args. */
20617 /* If PARM uses template parameters, then we can't bail out here,
20618 even if ARG == PARM, since we won't record unifications for the
20619 template parameters. We might need them if we're trying to
20620 figure out which of two things is more specialized. */
20624 /* Handle init lists early, so the rest of the function can assume
20625 we're dealing with a type. */
20627 {
20632 /* Replace T with std::initializer_list<T> for deduction. */
20639 /* We can only deduce from an initializer list argument if the
20640 parameter is std::initializer_list or an array; otherwise this
20641 is a non-deduced context. */
20646 else
20647 {
20649 /* Deduction is defined in terms of a single type, so just punt
20650 on the (bizarre) std::initializer_list<T...>. */
20653 }
20656 {
20663 {
20667 /* It should only be possible to get here for a call. */
20669 elt_strict |= maybe_adjust_types_for_deduction
20672 }
20675 explain_p);
20676 }
20680 {
20681 /* Also deduce from the length of the initializer list. */
20688 }
20690 /* If the std::initializer_list<T> deduction worked, replace the
20691 deduced A with std::initializer_list<A>. */
20693 {
20698 }
20700 }
20702 /* If parm and arg aren't the same kind of thing (template, type, or
20703 expression), fail early. */
20707 /* Immediately reject some pairs that won't unify because of
20708 cv-qualification mismatches. */
20711 /* It is the elements of the array which hold the cv quals of an array
20712 type, and the elements might be template type parms. We'll check
20713 when we recurse. */
20715 /* We check the cv-qualifiers when unifying with template type
20716 parameters below. We want to allow ARG `const T' to unify with
20717 PARM `T' for example, when computing which of two templates
20718 is more specialized, for example. */
20732 {
20736 /* In a type which contains a nested-name-specifier, template
20737 argument values cannot be deduced for template parameters used
20738 within the nested-name-specifier. */
20750 /* The PARM is not one we're trying to unify. Just check
20751 to see if it matches ARG. */
20752 {
20757 else
20759 }
20766 /* Check for mixed types and values. */
20774 {
20777 {
20778 /* First try to match ARG directly. */
20780 explain_p);
20782 {
20783 /* Otherwise, look for a suitable base of ARG, as below. */
20790 }
20791 }
20792 /* ARG must be constructed from a template class or a template
20793 template parameter. */
20798 /* Deduce arguments T, i from TT<T> or TT<i>. */
20804 /* Fall through to deduce template name. */
20805 }
20809 {
20810 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20812 /* Simple cases: Value already set, does match or doesn't. */
20817 }
20818 else
20819 {
20820 /* If PARM is `const T' and ARG is only `int', we don't have
20821 a match unless we are allowing additional qualification.
20822 If ARG is `const int' and PARM is just `T' that's OK;
20823 that binds `const int' to `T'. */
20828 /* Consider the case where ARG is `const volatile int' and
20829 PARM is `const T'. Then, T should be `volatile int'. */
20830 arg = cp_build_qualified_type_real
20835 /* Simple cases: Value already set, does match or doesn't. */
20841 /* Make sure that ARG is not a variable-sized array. (Note
20842 that were talking about variable-sized arrays (like
20843 `int[n]'), rather than arrays of unknown size (like
20844 `int[]').) We'll get very confused by such a type since
20845 the bound of the array is not constant, and therefore
20846 not mangleable. Besides, such types are not allowed in
20847 ISO C++, so we can do as we please here. We do allow
20848 them for 'auto' deduction, since that isn't ABI-exposed. */
20852 /* Strip typedefs as in convert_template_argument. */
20854 }
20856 /* If ARG is a parameter pack or an expansion, we cannot unify
20857 against it unless PARM is also a parameter pack. */
20862 /* If the argument deduction results is a METHOD_TYPE,
20863 then there is a problem.
20864 METHOD_TYPE doesn't map to any real C++ type the result of
20865 the deduction can not be of that type. */
20879 {
20880 /* The PARM is not one we're trying to unify. Just check
20881 to see if it matches ARG. */
20887 }
20893 {
20898 }
20900 /* [temp.deduct.type] If, in the declaration of a function template
20901 with a non-type template-parameter, the non-type
20902 template-parameter is used in an expression in the function
20903 parameter-list and, if the corresponding template-argument is
20904 deduced, the template-argument type shall match the type of the
20905 template-parameter exactly, except that a template-argument
20906 deduced from an array bound may be of any integral type.
20907 The non-type parameter might use already deduced type parameters. */
20910 {
20914 }
20917 /* Template-parameter dependent expression. Just accept it for now.
20918 It will later be processed in convert_template_argument. */
20919 ;
20925 /* Convert the ARG to the type of PARM; the deduced non-type
20926 template argument must exactly match the types of the
20927 corresponding parameter. */
20930 {
20931 /* We haven't deduced the type of this parameter yet. */
20933 /* We deduce from array bounds in try_array_deduction. */
20935 {
20936 /* Deduce it from the non-type argument. */
20941 }
20942 else
20943 /* Try again later. */
20945 }
20946 else
20949 /* If ARG is a parameter pack or an expansion, we cannot unify
20950 against it unless PARM is also a parameter pack. */
20955 {
20958 }
20963 {
20964 /* A pointer-to-member constant can be unified only with
20965 another constant. */
20969 /* Just unify the class member. It would be useless (and possibly
20970 wrong, depending on the strict flags) to unify also
20971 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20972 arg refer to the same variable, even if through different
20973 classes. For instance:
20975 struct A { int x; };
20976 struct B : A { };
20978 Unification of &A::x and &B::x must succeed. */
20981 }
20984 {
20988 /* [temp.deduct.call]
20990 A can be another pointer or pointer to member type that can
20991 be converted to the deduced A via a qualification
20992 conversion (_conv.qual_).
20994 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
20995 This will allow for additional cv-qualification of the
20996 pointed-to types if appropriate. */
20999 /* The derived-to-base conversion only persists through one
21000 level of pointers. */
21005 }
21037 /* We have already checked cv-qualification at the top of the
21038 function. */
21042 /* As far as unification is concerned, this wins. Later checks
21043 will invalidate it if necessary. */
21046 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
21047 /* Type INTEGER_CST can come from ordinary constant template args. */
21059 {
21069 /* Check for pack expansions in the parameters. */
21071 {
21073 {
21075 /* We can unify against something with a trailing
21076 parameter pack. */
21078 else
21079 /* [temp.deduct.type]/9: If the template argument list of
21080 P contains a pack expansion that is not the last
21081 template argument, the entire template argument list
21082 is a non-deduced context. */
21084 }
21085 }
21087 /* If we don't have enough arguments to satisfy the parameters
21088 (not counting the pack expression at the end), or we have
21089 too many arguments for a parameter list that doesn't end in
21090 a pack expression, we can't unify. */
21096 /* Unify all of the parameters that precede the (optional)
21097 pack expression. */
21099 {
21104 }
21107 DEDUCE_EXACT,
21110 }
21118 {
21126 }
21131 {
21135 {
21136 /* First, we try to unify the PARM and ARG directly. */
21141 {
21142 /* Fallback to the special case allowed in
21143 [temp.deduct.call]:
21145 If P is a class, and P has the form
21146 template-id, then A can be a derived class of
21147 the deduced A. Likewise, if P is a pointer to
21148 a class of the form template-id, A can be a
21149 pointer to a derived class pointed to by the
21150 deduced A. */
21156 {
21157 /* Don't give the derived diagnostic if we're
21158 already dealing with the same template. */
21159 bool same_template
21165 }
21166 }
21167 }
21171 /* Perhaps PARM is something like S<U> and ARG is S<int>.
21172 Then, we should unify `int' and `U'. */
21174 else
21175 /* There's no chance of unification succeeding. */
21180 }
21187 {
21190 tree a;
21196 /* CV qualifications for methods can never be deduced, they must
21197 match exactly. We need to check them explicitly here,
21198 because type_unification_real treats them as any other
21199 cv-qualified parameter. */
21201 && (!check_cv_quals_for_unify
21229 {
21241 }
21244 }
21247 /* Unify a pointer to member with a pointer to member function, which
21248 deduces the type of the member as a function type. */
21250 {
21251 /* Check top-level cv qualifiers */
21259 /* Determine the type of the function we are unifying against. */
21263 }
21282 /* Matched cases are handled by the ARG == PARM test above. */
21286 /* We might get a variable as a non-type template argument in parm if the
21287 corresponding parameter is type-dependent. Make any necessary
21288 adjustments based on whether arg is a reference. */
21292 {
21297 }
21298 /* Now use the normal expression code to check whether they match. */
21309 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21310 or UNDERLYING_TYPE nodes. */
21314 /* Unification fails if we hit an error node. */
21319 {
21329 }
21330 /* FALLTHRU */
21333 /* An unresolved overload is a nondeduced context. */
21337 expr:
21338 /* We must be looking at an expression. This can happen with
21339 something like:
21341 template <int I>
21342 void foo(S<I>, S<I + 2>);
21344 This is a "nondeduced context":
21346 [deduct.type]
21348 The nondeduced contexts are:
21350 --A type that is a template-id in which one or more of
21351 the template-arguments is an expression that references
21352 a template-parameter.
21354 In these cases, we assume deduction succeeded, but don't
21355 actually infer any unifications. */
21360 else
21362 }
21363 }
21364 #undef RECUR_AND_CHECK_FAILURE
21365 \f
21366 /* Note that DECL can be defined in this translation unit, if
21367 required. */
21369 static void
21371 {
21372 tree clone;
21376 }
21378 /* Called if RESULT is explicitly instantiated, or is a member of an
21379 explicitly instantiated class. */
21381 void
21383 {
21386 /* If this entity has already been written out, it's too late to
21387 make any modifications. */
21391 /* For anonymous namespace we don't need to do anything. */
21393 {
21396 }
21399 /* The TREE_PUBLIC flag for function declarations will have been
21400 set correctly by tsubst. */
21403 /* This might have been set by an earlier implicit instantiation. */
21408 else
21409 {
21412 /* Always make artificials weak. */
21415 /* For WIN32 we also want to put explicit instantiations in
21416 linkonce sections. */
21419 }
21421 /* If EXTERN_P, then this function will not be emitted -- unless
21422 followed by an explicit instantiation, at which point its linkage
21423 will be adjusted. If !EXTERN_P, then this function will be
21424 emitted here. In neither circumstance do we want
21425 import_export_decl to adjust the linkage. */
21427 }
21429 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21430 important template arguments. If any are missing, we check whether
21431 they're important by using error_mark_node for substituting into any
21432 args that were used for partial ordering (the ones between ARGS and END)
21433 and seeing if it bubbles up. */
21435 static bool
21437 {
21442 {
21445 }
21447 {
21451 }
21453 }
21455 /* Given two function templates PAT1 and PAT2, return:
21457 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21458 -1 if PAT2 is more specialized than PAT1.
21459 0 if neither is more specialized.
21461 LEN indicates the number of parameters we should consider
21462 (defaulted parameters should not be considered).
21464 The 1998 std underspecified function template partial ordering, and
21465 DR214 addresses the issue. We take pairs of arguments, one from
21466 each of the templates, and deduce them against each other. One of
21467 the templates will be more specialized if all the *other*
21468 template's arguments deduce against its arguments and at least one
21469 of its arguments *does* *not* deduce against the other template's
21470 corresponding argument. Deduction is done as for class templates.
21471 The arguments used in deduction have reference and top level cv
21472 qualifiers removed. Iff both arguments were originally reference
21473 types *and* deduction succeeds in both directions, an lvalue reference
21474 wins against an rvalue reference and otherwise the template
21475 with the more cv-qualified argument wins for that pairing (if
21476 neither is more cv-qualified, they both are equal). Unlike regular
21477 deduction, after all the arguments have been deduced in this way,
21478 we do *not* verify the deduced template argument values can be
21479 substituted into non-deduced contexts.
21481 The logic can be a bit confusing here, because we look at deduce1 and
21482 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21483 can find template arguments for pat1 to make arg1 look like arg2, that
21484 means that arg2 is at least as specialized as arg1. */
21486 int
21488 {
21501 /* Remove the this parameter from non-static member functions. If
21502 one is a non-static member function and the other is not a static
21503 member function, remove the first parameter from that function
21504 also. This situation occurs for operator functions where we
21505 locate both a member function (with this pointer) and non-member
21506 operator (with explicit first operand). */
21508 {
21513 }
21515 {
21518 {
21519 len--;
21521 }
21522 }
21524 /* If only one is a conversion operator, they are unordered. */
21528 /* Consider the return type for a conversion function */
21530 {
21533 len++;
21534 }
21536 processing_template_decl++;
21542 /* Stop when an ellipsis is seen. */
21544 {
21555 {
21556 /* When both arguments are pack expansions, we need only
21557 unify the patterns themselves. */
21561 /* This is the last comparison we need to do. */
21563 }
21565 /* DR 1847: If a particular P contains no template-parameters that
21566 participate in template argument deduction, that P is not used to
21567 determine the ordering. */
21573 {
21577 }
21580 {
21584 }
21590 {
21596 /* Setup the parameter vector, which contains only ARG1. */
21599 /* Setup the argument vector, which contains the remaining
21600 arguments. */
21609 /* We cannot deduce in the other direction, because ARG1 is
21610 a pack expansion but ARG2 is not. */
21612 }
21614 {
21620 /* Setup the parameter vector, which contains only ARG1. */
21623 /* Setup the argument vector, which contains the remaining
21624 arguments. */
21633 /* We cannot deduce in the other direction, because ARG2 is
21634 a pack expansion but ARG1 is not.*/
21636 }
21638 else
21639 {
21640 /* The normal case, where neither argument is a pack
21641 expansion. */
21648 }
21650 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21651 arg2, then arg2 is not as specialized as arg1. */
21657 /* "If, for a given type, deduction succeeds in both directions
21658 (i.e., the types are identical after the transformations above)
21659 and both P and A were reference types (before being replaced with
21660 the type referred to above):
21661 - if the type from the argument template was an lvalue reference and
21662 the type from the parameter template was not, the argument type is
21663 considered to be more specialized than the other; otherwise,
21664 - if the type from the argument template is more cv-qualified
21665 than the type from the parameter template (as described above),
21666 the argument type is considered to be more specialized than the other;
21667 otherwise,
21668 - neither type is more specialized than the other." */
21671 {
21673 {
21676 else
21678 }
21680 {
21685 }
21686 }
21689 /* We've failed to deduce something in either direction.
21690 These must be unordered. */
21693 next:
21697 /* We have already processed all of the arguments in our
21698 handing of the pack expansion type. */
21703 }
21705 /* "In most cases, all template parameters must have values in order for
21706 deduction to succeed, but for partial ordering purposes a template
21707 parameter may remain without a value provided it is not used in the
21708 types being used for partial ordering."
21710 Thus, if we are missing any of the targs1 we need to substitute into
21711 origs1, then pat2 is not as specialized as pat1. This can happen when
21712 there is a nondeduced context. */
21718 processing_template_decl--;
21720 /* If both deductions succeed, the partial ordering selects the more
21721 constrained template. */
21723 {
21728 }
21730 /* All things being equal, if the next argument is a pack expansion
21731 for one function but not for the other, prefer the
21732 non-variadic function. FIXME this is bogus; see c++/41958. */
21736 {
21739 }
21745 else
21747 }
21749 /* Determine which of two partial specializations of TMPL is more
21750 specialized.
21752 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21753 to the first partial specialization. The TREE_PURPOSE is the
21754 innermost set of template parameters for the partial
21755 specialization. PAT2 is similar, but for the second template.
21757 Return 1 if the first partial specialization is more specialized;
21758 -1 if the second is more specialized; 0 if neither is more
21759 specialized.
21761 See [temp.class.order] for information about determining which of
21762 two templates is more specialized. */
21764 static int
21766 {
21767 tree targs;
21776 /* Just like what happens for functions, if we are ordering between
21777 different template specializations, we may encounter dependent
21778 types in the arguments, and we need our dependency check functions
21779 to behave correctly. */
21783 {
21786 }
21790 {
21793 }
21796 /* If both deductions succeed, the partial ordering selects the more
21797 constrained template. */
21801 /* In the case of a tie where at least one of the templates
21802 has a parameter pack at the end, the template with the most
21803 non-packed parameters wins. */
21805 && any_deductions
21808 {
21814 /* We don't count the pack expansion at the end. */
21824 }
21827 }
21829 /* Return the template arguments that will produce the function signature
21830 DECL from the function template FN, with the explicit template
21831 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21832 also match. Return NULL_TREE if no satisfactory arguments could be
21833 found. */
21835 static tree
21837 {
21841 tree decl_arg_types;
21844 tree arg;
21848 /* Never do unification on the 'this' parameter. */
21869 }
21871 /* Return the innermost template arguments that, when applied to a partial
21872 specialization SPEC_TMPL of TMPL, yield the ARGS.
21874 For example, suppose we have:
21876 template <class T, class U> struct S {};
21877 template <class T> struct S<T*, int> {};
21879 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21880 partial specialization and the ARGS will be {double*, int}. The resulting
21881 vector will be {double}, indicating that `T' is bound to `double'. */
21883 static tree
21885 {
21887 tree spec_args
21890 tree deduced_args;
21891 tree innermost_deduced_args;
21895 {
21899 innermost_deduced_args);
21900 }
21901 else
21905 again:
21914 {
21916 {
21922 }
21924 }
21928 {
21931 }
21933 /* Verify that nondeduced template arguments agree with the type
21934 obtained from argument deduction.
21936 For example:
21938 struct A { typedef int X; };
21939 template <class T, class U> struct C {};
21940 template <class T> struct C<T, typename T::X> {};
21942 Then with the instantiation `C<A, int>', we can deduce that
21943 `T' is `A' but unify () does not check whether `typename T::X'
21944 is `int'. */
21955 /* We only need to check the innermost arguments; the other
21956 arguments will always agree. */
21961 /* Now that we have bindings for all of the template arguments,
21962 ensure that the arguments deduced for the template template
21963 parameters have compatible template parameter lists. See the use
21964 of template_template_parm_bindings_ok_p in fn_type_unification
21965 for more information. */
21970 }
21972 // Compare two function templates T1 and T2 by deducing bindings
21973 // from one against the other. If both deductions succeed, compare
21974 // constraints to see which is more constrained.
21975 static int
21977 {
21982 {
21985 }
21988 {
21991 }
21993 // If both deductions succeed, then one may be more constrained.
21998 }
22000 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
22001 Return the TREE_LIST node with the most specialized template, if
22002 any. If there is no most specialized template, the error_mark_node
22003 is returned.
22005 Note that this function does not look at, or modify, the
22006 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
22007 returned is one of the elements of INSTANTIATIONS, callers may
22008 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
22009 and retrieve it from the value returned. */
22011 tree
22013 {
22020 {
22026 {
22027 /* Equally specialized, move to next function. If there
22028 is no next function, nothing's most specialized. */
22033 }
22034 }
22037 /* Now verify that champ is better than everything earlier in the
22038 instantiation list. */
22041 {
22044 }
22045 }
22047 processing_template_decl--;
22053 }
22055 /* If DECL is a specialization of some template, return the most
22056 general such template. Otherwise, returns NULL_TREE.
22058 For example, given:
22060 template <class T> struct S { template <class U> void f(U); };
22062 if TMPL is `template <class U> void S<int>::f(U)' this will return
22063 the full template. This function will not trace past partial
22064 specializations, however. For example, given in addition:
22066 template <class T> struct S<T*> { template <class U> void f(U); };
22068 if TMPL is `template <class U> void S<int*>::f(U)' this will return
22069 `template <class T> template <class U> S<T*>::f(U)'. */
22071 tree
22073 {
22075 {
22078 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
22079 template friend, or a FIELD_DECL for a capture pack. */
22082 }
22084 /* Look for more and more general templates. */
22086 {
22087 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
22088 (See cp-tree.h for details.) */
22097 /* Stop if we run into an explicitly specialized class template. */
22104 }
22107 }
22109 /* Return the most specialized of the template partial specializations
22110 which can produce TARGET, a specialization of some class or variable
22111 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
22112 a TEMPLATE_DECL node corresponding to the partial specialization, while
22113 the TREE_PURPOSE is the set of template arguments that must be
22114 substituted into the template pattern in order to generate TARGET.
22116 If the choice of partial specialization is ambiguous, a diagnostic
22117 is issued, and the error_mark_node is returned. If there are no
22118 partial specializations matching TARGET, then NULL_TREE is
22119 returned, indicating that the primary template should be used. */
22121 static tree
22123 {
22125 tree t;
22126 tree champ;
22133 {
22137 }
22139 {
22142 }
22144 {
22148 }
22149 else
22154 /* For determining which partial specialization to use, only the
22155 innermost args are interesting. */
22157 {
22160 }
22163 {
22164 tree spec_args;
22168 {
22169 /* Substitute in the template args from the enclosing class. */
22173 }
22180 {
22184 /* Keep the candidate only if the constraints are satisfied,
22185 or if we're not compiling with concepts. */
22188 {
22191 }
22192 }
22193 }
22203 {
22206 ;
22207 else
22208 {
22210 {
22213 {
22216 }
22217 }
22219 }
22220 }
22224 {
22227 {
22230 }
22231 }
22234 {
22241 else
22245 {
22250 }
22253 }
22256 }
22258 /* Explicitly instantiate DECL. */
22260 void
22262 {
22267 /* An error occurred, for which grokdeclarator has already issued
22268 an appropriate message. */
22271 {
22274 }
22280 {
22281 /* There is an asymmetry here in the way VAR_DECLs and
22282 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22283 the latter, the DECL we get back will be marked as a
22284 template instantiation, and the appropriate
22285 DECL_TEMPLATE_INFO will be set up. This does not happen for
22286 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22287 should handle VAR_DECLs as it currently handles
22288 FUNCTION_DECLs. */
22290 {
22293 }
22296 {
22299 }
22301 {
22306 }
22307 }
22309 {
22312 }
22313 else
22316 /* Check for various error cases. Note that if the explicit
22317 instantiation is valid the RESULT will currently be marked as an
22318 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22319 until we get here. */
22322 {
22323 /* DR 259 [temp.spec].
22325 Both an explicit instantiation and a declaration of an explicit
22326 specialization shall not appear in a program unless the explicit
22327 instantiation follows a declaration of the explicit specialization.
22329 For a given set of template parameters, if an explicit
22330 instantiation of a template appears after a declaration of an
22331 explicit specialization for that template, the explicit
22332 instantiation has no effect. */
22334 }
22336 {
22337 /* [temp.spec]
22339 No program shall explicitly instantiate any template more
22340 than once.
22342 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22343 the first instantiation was `extern' and the second is not,
22344 and EXTERN_P for the opposite case. */
22347 /* If an "extern" explicit instantiation follows an ordinary
22348 explicit instantiation, the template is instantiated. */
22351 }
22353 {
22356 }
22358 {
22361 }
22364 ;
22366 {
22369 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22372 }
22373 else
22381 }
22383 static void
22385 {
22391 {
22394 }
22395 }
22397 /* Called from do_type_instantiation through binding_table_foreach to
22398 do recursive instantiation for the type bound in ENTRY. */
22399 static void
22401 {
22407 }
22409 /* Perform an explicit instantiation of template class T. STORAGE, if
22410 non-null, is the RID for extern, inline or static. COMPLAIN is
22411 nonzero if this is called from the parser, zero if called recursively,
22412 since the standard is unclear (as detailed below). */
22414 void
22416 {
22426 {
22427 tree tmpl =
22431 else
22434 }
22439 {
22442 t);
22444 }
22447 {
22449 {
22451 {
22454 "ISO C++ 1998 forbids the use of %<extern%> on "
22456 }
22457 else
22459 "ISO C++ forbids the use of %qE"
22461 }
22469 else
22470 {
22472 storage);
22474 }
22475 }
22478 {
22479 /* DR 259 [temp.spec].
22481 Both an explicit instantiation and a declaration of an explicit
22482 specialization shall not appear in a program unless the explicit
22483 instantiation follows a declaration of the explicit specialization.
22485 For a given set of template parameters, if an explicit
22486 instantiation of a template appears after a declaration of an
22487 explicit specialization for that template, the explicit
22488 instantiation has no effect. */
22490 }
22492 {
22493 /* [temp.spec]
22495 No program shall explicitly instantiate any template more
22496 than once.
22498 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22499 instantiation was `extern'. If EXTERN_P then the second is.
22500 These cases are OK. */
22507 /* If we've already instantiated the template, just return now. */
22510 }
22518 /* In contrast to implicit instantiation, where only the
22519 declarations, and not the definitions, of members are
22520 instantiated, we have here:
22522 [temp.explicit]
22524 The explicit instantiation of a class template specialization
22525 implies the instantiation of all of its members not
22526 previously explicitly specialized in the translation unit
22527 containing the explicit instantiation.
22529 Of course, we can't instantiate member template classes, since we
22530 don't have any arguments for them. Note that the standard is
22531 unclear on whether the instantiation of the members are
22532 *explicit* instantiations or not. However, the most natural
22533 interpretation is that it should be an explicit
22534 instantiation. */
22538 && !static_p
22541 {
22546 }
22551 }
22553 /* Given a function DECL, which is a specialization of TMPL, modify
22554 DECL to be a re-instantiation of TMPL with the same template
22555 arguments. TMPL should be the template into which tsubst'ing
22556 should occur for DECL, not the most general template.
22558 One reason for doing this is a scenario like this:
22560 template <class T>
22561 void f(const T&, int i);
22563 void g() { f(3, 7); }
22565 template <class T>
22566 void f(const T& t, const int i) { }
22568 Note that when the template is first instantiated, with
22569 instantiate_template, the resulting DECL will have no name for the
22570 first parameter, and the wrong type for the second. So, when we go
22571 to instantiate the DECL, we regenerate it. */
22573 static void
22575 {
22576 /* The arguments used to instantiate DECL, from the most general
22577 template. */
22578 tree code_pattern;
22582 /* Make sure that we can see identifiers, and compute access
22583 correctly. */
22587 {
22588 tree decl_parm;
22589 tree pattern_parm;
22590 tree specs;
22604 specs);
22606 /* Merge parameter declarations. */
22609 pattern_parm
22613 {
22614 tree parm_type;
22615 tree attributes;
22620 NULL_TREE);
22626 {
22629 }
22632 }
22633 /* Merge any parameters that match with the function parameter
22634 pack. */
22636 {
22638 tree expanded_types;
22639 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22640 the parameters in this function parameter pack. */
22645 {
22646 tree parm_type;
22647 tree attributes;
22650 /* Rename the parameter to include the index. */
22659 {
22662 }
22664 }
22665 }
22666 /* Merge additional specifiers from the CODE_PATTERN. */
22670 }
22672 {
22682 }
22683 else
22687 }
22689 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22690 substituted to get DECL. */
22692 tree
22694 {
22697 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22698 for the instantiation. This is not always the most general
22699 template. Consider, for example:
22701 template <class T>
22702 struct S { template <class U> void f();
22703 template <> void f<int>(); };
22705 and an instantiation of S<double>::f<int>. We want TD to be the
22706 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22708 more general template. */
22710 /* We must also deal with friend templates. Given:
22712 template <class T> struct S {
22713 template <class U> friend void f() {};
22714 };
22716 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22717 so far as the language is concerned, but that's still
22718 where we get the pattern for the instantiation from. On
22719 other hand, if the definition comes outside the class, say:
22721 template <class T> struct S {
22722 template <class U> friend void f();
22723 };
22724 template <class U> friend void f() {}
22726 we don't need to look any further. That's what the check for
22727 DECL_INITIAL is for. */
22731 {
22732 /* The present template, TD, should not be a definition. If it
22733 were a definition, we should be using it! Note that we
22734 cannot restructure the loop to just keep going until we find
22735 a template with a definition, since that might go too far if
22736 a specialization was declared, but not defined. */
22738 /* Fetch the more general template. */
22740 }
22743 }
22745 /* Returns true if we need to instantiate this template instance even if we
22746 know we aren't going to emit it. */
22748 bool
22750 {
22751 /* We always instantiate inline functions so that we can inline them. An
22752 explicit instantiation declaration prohibits implicit instantiation of
22753 non-inline functions. With high levels of optimization, we would
22754 normally inline non-inline functions -- but we're not allowed to do
22755 that for "extern template" functions. Therefore, we check
22756 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22760 /* And we need to instantiate static data members so that
22761 their initializers are available in integral constant
22762 expressions. */
22765 }
22767 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22768 instantiate it now, modifying TREE_TYPE (fn). Returns false on
22769 error, true otherwise. */
22771 bool
22773 {
22776 /* Don't instantiate a noexcept-specification from template context. */
22791 {
22797 {
22798 /* If hash_set::add returns true, the element was already there. */
22803 fn);
22805 }
22807 {
22822 }
22823 else
22833 }
22836 {
22839 else
22841 }
22844 }
22846 /* We're starting to process the function INST, an instantiation of PATTERN;
22847 add their parameters to local_specializations. */
22849 static void
22851 {
22855 {
22859 }
22861 {
22863 {
22866 }
22867 else
22868 {
22869 /* Register the (value) argument pack as a specialization of
22870 TMPL_PARM, then move on. */
22873 }
22874 }
22876 }
22878 /* Produce the definition of D, a _DECL generated from a template. If
22879 DEFER_OK is true, then we don't have to actually do the
22880 instantiation now; we just have to do it sometime. Normally it is
22881 an error if this is an explicit instantiation but D is undefined.
22882 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22883 instantiated class template. */
22885 tree
22887 {
22889 tree gen_args;
22890 tree args;
22891 tree td;
22892 tree code_pattern;
22893 tree spec;
22894 tree gen_tmpl;
22902 /* This function should only be used to instantiate templates for
22903 functions and static member variables. */
22906 /* A concept is never instantiated. */
22909 /* Variables are never deferred; if instantiation is required, they
22910 are instantiated right away. That allows for better code in the
22911 case that an expression refers to the value of the variable --
22912 if the variable has a constant value the referring expression can
22913 take advantage of that fact. */
22917 /* Don't instantiate cloned functions. Instead, instantiate the
22918 functions they cloned. */
22926 /* D has already been instantiated or explicitly specialized, so
22927 there's nothing for us to do here.
22929 It might seem reasonable to check whether or not D is an explicit
22930 instantiation, and, if so, stop here. But when an explicit
22931 instantiation is deferred until the end of the compilation,
22932 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22933 the instantiation. */
22936 /* Check to see whether we know that this template will be
22937 instantiated in some other file, as with "extern template"
22938 extension. */
22941 /* In general, we do not instantiate such templates. */
22949 /* We should already have the extra args. */
22952 /* And what's in the hash table should match D. */
22956 /* This needs to happen before any tsubsting. */
22962 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22963 for the instantiation. */
22968 {
22969 /* Look up an explicit specialization, if any. */
22973 {
22976 }
22977 }
22981 /* We should never be trying to instantiate a member of a class
22982 template or partial specialization. */
22987 /* In the case of a friend template whose definition is provided
22988 outside the class, we may have too many arguments. Drop the
22989 ones we don't need. The same is true for specializations. */
22990 args = get_innermost_template_args
22994 {
23000 }
23001 else
23002 {
23007 else
23009 }
23011 /* We may be in the middle of deferred access check. Disable it now. */
23014 /* Unless an explicit instantiation directive has already determined
23015 the linkage of D, remember that a definition is available for
23016 this entity. */
23026 /* If D is a member of an explicitly instantiated class template,
23027 and no definition is available, treat it like an implicit
23028 instantiation. */
23031 {
23032 /* Leave linkage flags alone on instantiations with anonymous
23033 visibility. */
23035 {
23038 }
23040 }
23042 /* Defer all other templates, unless we have been explicitly
23043 forbidden from doing so. */
23045 template. */
23046 ! pattern_defined
23047 /* If it's OK to postpone instantiation, do so. */
23048 || defer_ok
23049 /* If this is a static data member that will be defined
23050 elsewhere, we don't want to instantiate the entire data
23051 member, but we do want to instantiate the initializer so that
23052 we can substitute that elsewhere. */
23054 /* Handle here a deleted function too, avoid generating
23055 its body (c++/61080). */
23057 {
23058 /* The definition of the static data member is now required so
23059 we must substitute the initializer. */
23063 {
23064 tree ns;
23065 tree init;
23074 args,
23077 /* If instantiating the initializer involved instantiating this
23078 again, don't call cp_finish_decl twice. */
23080 {
23081 /* Make sure the initializer is still constant, in case of
23082 circular dependency (template/instantiate6.C). */
23083 const_init
23087 LOOKUP_ONLYCONVERTING);
23088 }
23092 }
23094 /* We restore the source position here because it's used by
23095 add_pending_template. */
23101 /* [temp.explicit]
23103 The definition of a non-exported function template, a
23104 non-exported member function template, or a non-exported
23105 member function or static data member of a class template
23106 shall be present in every translation unit in which it is
23107 explicitly instantiated. */
23111 /* If we're in unevaluated context, we just wanted to get the
23112 constant value; this isn't an odr use, so don't queue
23113 a full instantiation. */
23116 /* ??? Historically, we have instantiated inline functions, even
23117 when marked as "extern template". */
23121 }
23122 /* Tell the repository that D is available in this translation unit
23123 -- and see if it is supposed to be instantiated here. */
23125 {
23126 /* In a PCH file, despite the fact that the repository hasn't
23127 requested instantiation in the PCH it is still possible that
23128 an instantiation will be required in a file that includes the
23129 PCH. */
23132 /* Instantiate inline functions so that the inliner can do its
23133 job, even though we'll not be emitting a copy of this
23134 function. */
23137 }
23140 tree fn_context;
23151 else
23152 {
23156 }
23158 /* Mark D as instantiated so that recursive calls to
23159 instantiate_decl do not try to instantiate it again. */
23162 /* Regenerate the declaration in case the template has been modified
23163 by a subsequent redeclaration. */
23166 /* We already set the file and line above. Reset them now in case
23167 they changed as a result of calling regenerate_decl_from_template. */
23171 {
23172 tree init;
23175 /* Clear out DECL_RTL; whatever was there before may not be right
23176 since we've reset the type of the declaration. */
23180 /* The initializer is placed in DECL_INITIAL by
23181 regenerate_decl_from_template so we don't need to
23182 push/pop_access_scope again here. Pull it out so that
23183 cp_finish_decl can process it. */
23188 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
23189 initializer. That function will defer actual emission until
23190 we have a chance to determine linkage. */
23193 /* Enter the scope of D so that access-checking works correctly. */
23206 }
23210 {
23214 /* Save away the current list, in case we are instantiating one
23215 template from within the body of another. */
23218 /* Set up the list of local specializations. */
23221 /* Set up context. */
23225 else
23228 /* Some typedefs referenced from within the template code need to be
23229 access checked at template instantiation time, i.e now. These
23230 types were added to the template at parsing time. Let's get those
23231 and perform the access checks then. */
23233 args);
23235 /* Create substitution entries for the parameters. */
23238 /* Substitute into the body of the function. */
23242 else
23243 {
23248 /* Set the current input_location to the end of the function
23249 so that finish_function knows where we are. */
23250 input_location
23253 /* Remember if we saw an infinite loop in the template. */
23254 current_function_infinite_loop
23256 }
23258 /* We don't need the local specializations any more. */
23262 /* Finish the function. */
23266 else
23267 {
23270 }
23274 }
23276 /* We're not deferring instantiation any more. */
23281 else
23287 out:
23296 }
23298 /* Run through the list of templates that we wish we could
23299 instantiate, and instantiate any we can. RETRIES is the
23300 number of times we retry pending template instantiation. */
23302 void
23304 {
23308 /* Instantiating templates may trigger vtable generation. This in turn
23309 may require further template instantiations. We place a limit here
23310 to avoid infinite loop. */
23312 {
23316 "template instantiation depth exceeds maximum of %d"
23317 " instantiating %q+D, possibly from virtual table generation"
23321 /* Pretend that we defined it. */
23324 }
23326 do
23327 {
23332 {
23337 {
23339 {
23354 }
23357 }
23358 else
23359 {
23362 {
23363 instantiation
23369 }
23373 }
23376 /* If INSTANTIATION has been instantiated, then we don't
23377 need to consider it again in the future. */
23379 else
23380 {
23383 }
23386 }
23388 }
23392 }
23394 /* Substitute ARGVEC into T, which is a list of initializers for
23395 either base class or a non-static data member. The TREE_PURPOSEs
23396 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23397 instantiate_decl. */
23399 static tree
23401 {
23405 {
23406 tree decl;
23407 tree init;
23413 {
23414 tree expr;
23415 tree arg;
23417 /* Expand the base class expansion type into separate base
23418 classes. */
23420 tf_warning_or_error,
23421 NULL_TREE);
23425 /* We'll be building separate TREE_LISTs of arguments for
23426 each base. */
23432 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23433 expand each argument in the TREE_VALUE of t. */
23440 /* VOID_TYPE_NODE is used to indicate
23441 value-initialization. */
23442 {
23445 }
23446 else
23447 {
23448 /* Substitute parameter packs into each argument in the
23449 TREE_LIST. */
23452 {
23453 tree expanded_exprs;
23455 /* Expand the argument. */
23457 expanded_exprs
23459 tf_warning_or_error,
23460 NULL_TREE);
23464 /* Prepend each of the expanded expressions to the
23465 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23467 {
23472 }
23473 }
23476 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23477 since we built them backwards. */
23479 {
23482 }
23483 }
23484 }
23487 {
23489 {
23493 }
23494 else
23495 {
23496 tree tmp;
23511 /* If we had an initializer but it instantiated to nothing,
23512 value-initialize the object. This will only occur when
23513 the initializer was a pack expansion where the parameter
23514 packs used in that expansion were of length zero. */
23517 }
23520 {
23524 }
23525 }
23526 }
23528 }
23530 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23532 static void
23534 {
23539 else
23541 }
23543 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23544 is the instantiation (which should have been created with
23545 start_enum) and ARGS are the template arguments to use. */
23547 static void
23549 {
23550 tree e;
23556 {
23557 tree value;
23558 tree decl;
23561 /* Note that in a template enum, the TREE_VALUE is the
23562 CONST_DECL, not the corresponding INTEGER_CST. */
23567 /* Give this enumeration constant the correct access. */
23570 /* Actually build the enumerator itself. Here we're assuming that
23571 enumerators can't have dependent attributes. */
23574 }
23584 }
23586 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23587 its type -- but without substituting the innermost set of template
23588 arguments. So, innermost set of template parameters will appear in
23589 the type. */
23591 tree
23593 {
23594 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23596 }
23598 /* Return truthvalue if we're processing a template different from
23599 the last one involved in diagnostics. */
23600 bool
23602 {
23604 }
23606 /* Remember current template involved in diagnostics. */
23607 void
23609 {
23611 }
23615 {
23617 }
23619 /* Return TRUE if current_function_decl is being instantiated, false
23620 otherwise. */
23622 bool
23624 {
23627 }
23629 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23630 type. Return zero for ok, nonzero for disallowed. Issue error and
23631 warning messages under control of COMPLAIN. */
23633 static int
23635 {
23650 /* A bound template template parm could later be instantiated to have a valid
23651 nontype parm type via an alias template. */
23657 {
23660 else
23662 type);
23663 }
23665 }
23667 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23668 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23670 static bool
23672 {
23673 tree scope;
23675 /* [temp.dep.type]
23677 A type is dependent if it is:
23679 -- a template parameter. Template template parameters are types
23680 for us (since TYPE_P holds true for them) so we handle
23681 them here. */
23685 /* -- a qualified-id with a nested-name-specifier which contains a
23686 class-name that names a dependent type or whose unqualified-id
23687 names a dependent type. */
23691 /* An alias template specialization can be dependent even if the
23692 resulting type is not. */
23696 /* -- a cv-qualified type where the cv-unqualified type is
23697 dependent.
23698 No code is necessary for this bullet; the code below handles
23699 cv-qualified types, and we don't want to strip aliases with
23700 TYPE_MAIN_VARIANT because of DR 1558. */
23701 /* -- a compound type constructed from any dependent type. */
23711 {
23712 tree arg_type;
23717 arg_type;
23722 {
23723 /* A value-dependent noexcept-specifier makes the type dependent. */
23728 }
23730 }
23731 /* -- an array type constructed from any dependent type or whose
23732 size is specified by a constant expression that is
23733 value-dependent.
23735 We checked for type- and value-dependence of the bounds in
23736 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23738 {
23743 }
23745 /* -- a template-id in which either the template name is a template
23746 parameter ... */
23749 /* ... or any of the template arguments is a dependent type or
23750 an expression that is type-dependent or value-dependent. */
23752 && (any_dependent_template_arguments_p
23756 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23757 dependent; if the argument of the `typeof' expression is not
23758 type-dependent, then it should already been have resolved. */
23764 /* A template argument pack is dependent if any of its packed
23765 arguments are. */
23767 {
23773 }
23775 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23776 be template parameters. */
23783 /* The standard does not specifically mention types that are local
23784 to template functions or local classes, but they should be
23785 considered dependent too. For example:
23787 template <int I> void f() {
23788 enum E { a = I };
23789 S<sizeof (E)> s;
23790 }
23792 The size of `E' cannot be known until the value of `I' has been
23793 determined. Therefore, `E' must be considered dependent. */
23797 /* Don't use type_dependent_expression_p here, as it can lead
23798 to infinite recursion trying to determine whether a lambda
23799 nested in a lambda is dependent (c++/47687). */
23803 && (any_dependent_template_arguments_p
23807 /* Other types are non-dependent. */
23809 }
23811 /* Returns TRUE if TYPE is dependent, in the sense of
23812 [temp.dep.type]. Note that a NULL type is considered dependent. */
23814 bool
23816 {
23817 /* If there are no template parameters in scope, then there can't be
23818 any dependent types. */
23820 {
23821 /* If we are not processing a template, then nobody should be
23822 providing us with a dependent type. */
23826 }
23828 /* If the type is NULL, we have not computed a type for the entity
23829 in question; in that case, the type is dependent. */
23833 /* Erroneous types can be considered non-dependent. */
23837 /* Getting here with global_type_node means we improperly called this
23838 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23841 /* If we have not already computed the appropriate value for TYPE,
23842 do so now. */
23844 {
23847 }
23850 }
23852 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23853 lookup. In other words, a dependent type that is not the current
23854 instantiation. */
23856 bool
23858 {
23861 }
23863 /* T is a SCOPE_REF; return whether we need to consider it
23864 instantiation-dependent so that we can check access at instantiation
23865 time even though we know which member it resolves to. */
23867 static bool
23869 {
23875 else
23877 }
23879 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23880 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23881 expression. */
23883 /* Note that this predicate is not appropriate for general expressions;
23884 only constant expressions (that satisfy potential_constant_expression)
23885 can be tested for value dependence. */
23887 bool
23889 {
23893 /* A name declared with a dependent type. */
23898 {
23900 /* A dependent member function of the current instantiation. */
23904 /* A dependent member function of the current instantiation. */
23911 /* A name that has not been looked up -- must be dependent. */
23915 /* A non-type template parm. */
23919 /* A non-type template parm. */
23925 /* A constant with literal type and is initialized
23926 with an expression that is value-dependent.
23928 Note that a non-dependent parenthesized initializer will have
23929 already been replaced with its constant value, so if we see
23930 a TREE_LIST it must be dependent. */
23934 /* cp_finish_decl doesn't fold reference initializers. */
23940 {
23944 }
23952 /* These expressions are value-dependent if the type to which
23953 the cast occurs is dependent or the expression being casted
23954 is value-dependent. */
23955 {
23961 /* A functional cast has a list of operands. */
23964 {
23965 /* If there are no operands, it must be an expression such
23966 as "int()". This should not happen for aggregate types
23967 because it would form non-constant expressions. */
23972 }
23978 }
23983 /* FALLTHRU */
23986 /* A `sizeof' expression is value-dependent if the operand is
23987 type-dependent or is a pack expansion. */
23996 /* An 'encode' expression is value-dependent if the operand is
23997 type-dependent. */
24006 /* All instantiation-dependent expressions should also be considered
24007 value-dependent. */
24015 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
24016 is value-dependent. */
24017 {
24026 }
24029 {
24033 }
24044 {
24048 }
24051 /* Treat all requires-expressions as value-dependent so
24052 we don't try to fold them. */
24059 {
24066 {
24068 /* In a call to a constexpr member function, look through the
24069 implicit ADDR_EXPR on the object argument so that it doesn't
24070 cause the call to be considered value-dependent. We also
24071 look through it in potential_constant_expression. */
24078 }
24080 }
24083 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
24084 type-dependent. */
24089 {
24091 tree val;
24098 }
24101 /* Treat a GNU statement expression as dependent to avoid crashing
24102 under instantiate_non_dependent_expr; it can't be constant. */
24106 /* A constant expression is value-dependent if any subexpression is
24107 value-dependent. */
24109 {
24116 {
24120 {
24123 /* In some cases, some of the operands may be missing.
24124 (For example, in the case of PREDECREMENT_EXPR, the
24125 amount to increment by may be missing.) That doesn't
24126 make the expression dependent. */
24129 }
24130 }
24134 }
24136 }
24138 /* The expression is not value-dependent. */
24140 }
24142 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
24143 [temp.dep.expr]. Note that an expression with no type is
24144 considered dependent. Other parts of the compiler arrange for an
24145 expression with type-dependent subexpressions to have no type, so
24146 this function doesn't have to be fully recursive. */
24148 bool
24150 {
24157 /* An unresolved name is always dependent. */
24163 /* A fold expression is type-dependent. */
24170 /* Some expression forms are never type-dependent. */
24184 /* The types of these expressions depends only on the type to which
24185 the cast occurs. */
24194 /* The types of these expressions depends only on the type created
24195 by the expression. */
24198 {
24199 /* For NEW_EXPR tree nodes created inside a template, either
24200 the object type itself or a TREE_LIST may appear as the
24201 operand 1. */
24204 /* This is an array type. We need to check array dimensions
24205 as well. */
24207 || value_dependent_expression_p
24209 else
24211 }
24214 {
24218 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
24219 contains an identifier associated by name lookup with one or more
24220 declarations declared with a dependent type, or...a
24221 nested-name-specifier or qualified-id that names a member of an
24222 unknown specialization. */
24225 }
24235 {
24236 tree elt;
24240 {
24243 }
24245 }
24247 /* A static data member of the current instantiation with incomplete
24248 array type is type-dependent, as the definition and specializations
24249 can have different bounds. */
24256 /* An array of unknown bound depending on a variadic parameter, eg:
24258 template<typename... Args>
24259 void foo (Args... args)
24260 {
24261 int arr[] = { args... };
24262 }
24264 template<int... vals>
24265 void bar ()
24266 {
24267 int arr[] = { vals... };
24268 }
24270 If the array has no length and has an initializer, it must be that
24271 we couldn't determine its length in cp_complete_array_type because
24272 it is dependent. */
24280 /* A function or variable template-id is type-dependent if it has any
24281 dependent template arguments. */
24285 {
24286 /* Consider the innermost template arguments, since those are the ones
24287 that come from the template-id; the template arguments for the
24288 enclosing class do not make it type-dependent unless they are used in
24289 the type of the decl. */
24291 && (any_dependent_template_arguments_p
24295 /* Otherwise, if the decl isn't from a dependent scope, it can't be
24296 type-dependent. Checking this is important for functions with auto
24297 return type, which looks like a dependent type. */
24304 {
24308 }
24309 }
24311 /* Always dependent, on the number of arguments if nothing else. */
24316 {
24321 {
24327 }
24328 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24333 {
24338 }
24341 {
24348 }
24358 }
24362 /* Dependent type attributes might not have made it from the decl to
24363 the type yet. */
24369 }
24371 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24372 type-dependent if the expression refers to a member of the current
24373 instantiation and the type of the referenced member is dependent, or the
24374 class member access expression refers to a member of an unknown
24375 specialization.
24377 This function returns true if the OBJECT in such a class member access
24378 expression is of an unknown specialization. */
24380 bool
24382 {
24383 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24384 dependent. */
24389 }
24391 /* walk_tree callback function for instantiation_dependent_expression_p,
24392 below. Returns non-zero if a dependent subexpression is found. */
24394 static tree
24397 {
24399 {
24400 /* We don't have to worry about decltype currently because decltype
24401 of an instantiation-dependent expr is a dependent type. This
24402 might change depending on the resolution of DR 1172. */
24405 }
24408 {
24409 /* Don't treat an argument list as dependent just because it has no
24410 TREE_TYPE. */
24418 /* Handle expressions with type operands. */
24423 {
24428 {
24431 else
24432 {
24435 }
24436 }
24438 }
24442 /* In a template, finish_class_member_access_expr creates a
24443 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24444 type-dependent, so that we can check access control at
24445 instantiation time (PR 42277). See also Core issue 1273. */
24452 else
24455 /* Treat statement-expressions as dependent. */
24459 /* Treat requires-expressions as dependent. */
24464 /* Treat calls to function concepts as dependent. */
24470 /* And variable concepts. */
24477 }
24481 else
24483 }
24485 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24486 sense defined by the ABI:
24488 "An expression is instantiation-dependent if it is type-dependent
24489 or value-dependent, or it has a subexpression that is type-dependent
24490 or value-dependent."
24492 Except don't actually check value-dependence for unevaluated expressions,
24493 because in sizeof(i) we don't care about the value of i. Checking
24494 type-dependence will in turn check value-dependence of array bounds/template
24495 arguments as needed. */
24497 bool
24499 {
24500 tree result;
24511 }
24513 /* As above, but also check value-dependence of the expression as a whole. */
24515 bool
24517 {
24520 }
24522 /* Like type_dependent_expression_p, but it also works while not processing
24523 a template definition, i.e. during substitution or mangling. */
24525 bool
24527 {
24533 }
24535 /* Returns TRUE if ARGS contains a type-dependent expression. */
24537 bool
24539 {
24541 tree arg;
24544 {
24547 }
24549 }
24551 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24552 expressions) contains any type-dependent expressions. */
24554 bool
24556 {
24562 }
24564 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24565 expressions) contains any value-dependent expressions. */
24567 bool
24569 {
24575 }
24577 /* Returns TRUE if the ARG (a template argument) is dependent. */
24579 bool
24581 {
24585 /* Assume a template argument that was wrongly written by the user
24586 is dependent. This is consistent with what
24587 any_dependent_template_arguments_p [that calls this function]
24588 does. */
24598 {
24601 /* A member template of a dependent class is not necessarily
24602 type-dependent, but it is a dependent template argument because it
24603 will be a member of an unknown specialization to that template. */
24606 }
24608 {
24612 {
24615 }
24618 }
24621 else
24624 }
24626 /* Returns true if ARGS (a collection of template arguments) contains
24627 any types that require structural equality testing. */
24629 bool
24631 {
24641 {
24644 {
24650 {
24651 /* Look inside the argument pack. */
24654 }
24657 {
24670 }
24671 }
24672 }
24675 }
24677 /* Returns true if ARGS (a collection of template arguments) contains
24678 any dependent arguments. */
24680 bool
24682 {
24692 {
24697 }
24700 }
24702 /* Returns TRUE if the template TMPL is type-dependent. */
24704 bool
24706 {
24708 {
24713 }
24715 /* Template template parameters are dependent. */
24719 /* So are names that have not been looked up. */
24723 }
24725 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24727 bool
24729 {
24732 }
24734 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24735 are dependent. */
24737 bool
24739 {
24746 {
24768 {
24772 }
24776 {
24780 {
24785 }
24786 }
24787 }
24790 }
24792 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24793 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24794 no such TYPE can be found. Note that this function peers inside
24795 uninstantiated templates and therefore should be used only in
24796 extremely limited situations. ONLY_CURRENT_P restricts this
24797 peering to the currently open classes hierarchy (which is required
24798 when comparing types). */
24800 tree
24802 {
24803 tree scope;
24804 tree name;
24805 tree decl;
24807 tree pushed_scope;
24808 tree result;
24813 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24814 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24815 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24816 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24817 identifier of the TYPENAME_TYPE anymore.
24818 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24819 TYPENAME_TYPE instead, we avoid messing up with a possible
24820 typedef variant case. */
24823 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24824 it first before we can figure out what NAME refers to. */
24826 {
24828 /* Given a class template A with a dependent base with nested type C,
24829 typedef typename A::C::C C will land us here, as trying to resolve
24830 the initial A::C leads to the local C typedef, which leads back to
24831 A::C::C. So we break the recursion now. */
24833 else
24835 }
24836 /* If we don't know what SCOPE refers to, then we cannot resolve the
24837 TYPENAME_TYPE. */
24840 /* If this is a typedef, we don't want to look inside (c++/11987). */
24843 /* If SCOPE isn't the template itself, it will not have a valid
24844 TYPE_FIELDS list. */
24846 /* scope is either the template itself or a compatible instantiation
24847 like X<T>, so look up the name in the original template. */
24849 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24851 /* If scope has no fields, it can't be a current instantiation. Check this
24852 before currently_open_class to avoid infinite recursion (71515). */
24855 /* If the SCOPE is not the current instantiation, there's no reason
24856 to look inside it. */
24859 /* Enter the SCOPE so that name lookup will be resolved as if we
24860 were in the class definition. In particular, SCOPE will no
24861 longer be considered a dependent type. */
24863 /* Look up the declaration. */
24865 tf_warning_or_error);
24869 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24870 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24876 {
24880 }
24883 {
24884 /* Obtain the template and the arguments. */
24887 {
24888 /* We get here with a plain identifier because a previous tentative
24889 parse of the nested-name-specifier as part of a ptr-operator saw
24890 ::template X<A>. The use of ::template is necessary in a
24891 ptr-operator, but wrong in a declarator-id.
24893 [temp.names]: In a qualified-id of a declarator-id, the keyword
24894 template shall not appear at the top level. */
24898 }
24900 /* Instantiate the template. */
24906 }
24908 /* Leave the SCOPE. */
24912 /* If we failed to resolve it, return the original typename. */
24916 /* If lookup found a typename type, resolve that too. */
24918 {
24919 /* Ill-formed programs can cause infinite recursion here, so we
24920 must catch that. */
24924 }
24926 /* Qualify the resulting type. */
24932 }
24934 /* EXPR is an expression which is not type-dependent. Return a proxy
24935 for EXPR that can be used to compute the types of larger
24936 expressions containing EXPR. */
24938 tree
24940 {
24941 tree inner_expr;
24943 /* When checking, try to get a constant value for all non-dependent
24944 expressions in order to expose bugs in *_dependent_expression_p
24945 and constexpr. This can affect code generation, see PR70704, so
24946 only do this for -fchecking=2. */
24949 /* Don't do this during nsdmi parsing as it can lead to
24950 unexpected recursive instantiations. */
24952 /* Don't do this during concept expansion either and for
24953 the same reason. */
24957 /* Preserve OVERLOADs; the functions must be available to resolve
24958 types. */
24969 /* There is no need to return a proxy for a variable. */
24972 /* Preserve string constants; conversions from string constants to
24973 "char *" are allowed, even though normally a "const char *"
24974 cannot be used to initialize a "char *". */
24977 /* Preserve void and arithmetic constants, as an optimization -- there is no
24978 reason to create a new node. */
24983 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24984 There is at least one place where we want to know that a
24985 particular expression is a throw-expression: when checking a ?:
24986 expression, there are special rules if the second or third
24987 argument is a throw-expression. */
24991 /* Don't wrap an initializer list, we need to be able to look inside. */
24995 /* Don't wrap a dummy object, we need to be able to test for it. */
25014 /* If the type is unknown, it can't really be non-dependent */
25017 /* Otherwise, build a NON_DEPENDENT_EXPR. */
25019 }
25021 /* ARGS is a vector of expressions as arguments to a function call.
25022 Replace the arguments with equivalent non-dependent expressions.
25023 This modifies ARGS in place. */
25025 void
25027 {
25029 tree arg;
25032 {
25036 }
25037 }
25039 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
25040 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
25041 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
25043 static tree
25045 {
25059 }
25061 tree
25063 {
25065 }
25067 tree
25069 {
25071 }
25073 /* Return a C++17 deduction placeholder for class template TMPL. */
25075 tree
25077 {
25081 }
25083 /* True iff T is a C++17 class template deduction placeholder. */
25085 bool
25087 {
25089 }
25091 /* Make a "constrained auto" type-specifier. This is an
25092 auto type with constraints that must be associated after
25093 deduction. The constraint is formed from the given
25094 CONC and its optional sequence of arguments, which are
25095 non-null if written as partial-concept-id. */
25097 tree
25099 {
25102 /* Build the constraint. */
25110 /* Our canonical type depends on the constraint. */
25113 /* Attach the constraint to the type declaration. */
25116 }
25118 /* Given type ARG, return std::initializer_list<ARG>. */
25120 static tree
25122 {
25126 {
25130 "deducing from brace-enclosed initializer list"
25134 }
25140 }
25142 /* Replace auto in TYPE with std::initializer_list<auto>. */
25144 static tree
25146 {
25153 }
25155 /* Hash traits for hashing possibly constrained 'auto'
25156 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
25159 {
25162 };
25164 /* Hash the 'auto' T. */
25166 inline hashval_t
25168 {
25170 /* Matching constrained-type-specifiers denote the same template
25171 parameter, so hash the constraint. */
25173 else
25174 /* But unconstrained autos are all separate, so just hash the pointer. */
25176 }
25178 /* Compare two 'auto's. */
25182 {
25189 /* Two unconstrained autos are distinct. */
25194 }
25196 /* for_each_template_parm callback for extract_autos: if t is a (possibly
25197 constrained) auto, add it to the vector. */
25199 static int
25201 {
25204 {
25205 /* All the autos were built with index 0; fix that up now. */
25209 /* If this is a repeated constrained-type-specifier, use the index we
25210 chose before. */
25212 else
25213 {
25214 /* Otherwise this is new, so use the current count. */
25217 }
25219 }
25221 /* Always keep walking. */
25223 }
25225 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
25226 says they can appear anywhere in the type. */
25228 static tree
25230 {
25239 {
25244 }
25247 }
25249 /* The stem for deduction guide names. */
25252 /* Return the name for a deduction guide for class template TMPL. */
25254 tree
25256 {
25267 }
25269 /* True if NAME is the name of a deduction guide. */
25271 bool
25273 {
25277 }
25279 /* True if FN is a deduction guide. */
25281 bool
25283 {
25288 }
25290 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
25292 bool
25294 {
25301 }
25303 /* True if FN is a guide generated from a constructor template. */
25305 bool
25307 {
25315 }
25317 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
25318 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
25319 template parameter types. Note that the handling of template template
25320 parameters relies on current_template_parms being set appropriately for the
25321 new template. */
25323 static tree
25326 {
25329 tree newtype;
25332 {
25339 }
25340 else
25344 tree newdecl
25349 tree newidx;
25352 {
25362 {
25367 // First create a copy (ttargs) of tsubst_args with an
25368 // additional level for the template template parameter's own
25369 // template parameters (ttparms).
25370 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25378 // Substitute ttargs into ttparms to fix references to
25379 // other template parameters.
25381 complain);
25382 // Now substitute again with args based on tparms, to reduce
25383 // the level of the ttparms.
25386 complain);
25387 // Finally, tack the adjusted parms onto tparms.
25389 current_template_parms);
25391 }
25392 }
25393 else
25394 {
25396 tree newconst
25408 }
25411 }
25413 /* Returns a C++17 class deduction guide template based on the constructor
25414 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25415 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25417 static tree
25419 {
25423 location_t loc;
25427 {
25431 {
25434 }
25435 else
25445 }
25446 else
25447 {
25450 fn_tmpl
25460 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25461 fully specialized args for the enclosing class. Strip those off, as
25462 the deduction guide won't have those template parameters. */
25465 /* Discard the 'this' parameter. */
25473 {
25476 /* For a member template constructor, we need to flatten the two
25477 template parameter lists into one, and then adjust the function
25478 signature accordingly. This gets...complicated. */
25481 /* For a member template we should have two levels of parms/args, one
25482 for the class and one for the constructor. We stripped
25483 specialized args for further enclosing classes above. */
25487 /* Template args for translating references to the two-level template
25488 parameters into references to the one-level template parameters we
25489 are creating. */
25494 /* Template parms for the constructor template. */
25497 /* Template parms for the class template. */
25501 /* Template parms for the deduction guide start as a copy of the
25502 template parms for the class. We set current_template_parms for
25503 lookup_template_class_1. */
25509 /* Now we need to rewrite the constructor parms to append them to the
25510 class parms. */
25512 {
25527 }
25529 /* Now we have a final set of template parms to substitute into the
25530 function signature. */
25539 }
25541 }
25544 {
25545 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25549 }
25553 FUNCTION_DECL,
25570 }
25572 /* Deduce template arguments for the class template placeholder PTYPE for
25573 template TMPL based on the initializer INIT, and return the resulting
25574 type. */
25576 static tree
25578 tsubst_flags_t complain)
25579 {
25581 {
25582 /* We should have handled this in the caller. */
25588 }
25599 {
25602 {
25603 /* As an exception, the first phase in 16.3.1.7 (considering the
25604 initializer list as a single argument) is omitted if the
25605 initializer list consists of a single expression of type cv U,
25606 where U is a specialization of C or a class derived from a
25607 specialization of C. */
25618 }
25621 else
25623 }
25624 else
25635 /* Prune explicit deduction guides in copy-initialization context. */
25637 {
25643 {
25644 /* Found a nonconverting guide, prune the candidates. */
25651 }
25652 }
25657 {
25660 }
25664 // FIXME cache artificial deduction guides
25667 {
25672 else
25676 }
25680 /* If this is list-initialization and the class has a list constructor, first
25681 try deducing from the list as a single argument, as [over.match.list]. */
25685 {
25689 }
25691 {
25697 {
25698 /* That didn't work, now try treating the list as a sequence of
25699 arguments. */
25702 }
25703 }
25705 /* Maybe generate an implicit deduction guide. */
25707 {
25711 /* Generate a copy guide. */
25714 /* Generate a default guide. */
25718 {
25721 }
25722 }
25725 {
25727 " of %qT, as it has no non-explicit deduction guides or "
25730 }
25732 {
25736 }
25739 {
25743 }
25746 {
25756 }
25761 }
25763 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25764 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25766 tree
25768 {
25770 tf_warning_or_error,
25771 adc_unspecified);
25772 }
25774 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25775 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25776 The CONTEXT determines the context in which auto deduction is performed
25777 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25778 OUTER_TARGS are used during template argument deduction
25779 (context == adc_unify) to properly substitute the result, and is ignored
25780 in other contexts.
25782 For partial-concept-ids, extra args may be appended to the list of deduced
25783 template arguments prior to determining constraint satisfaction. */
25785 tree
25789 {
25790 tree targs;
25797 /* Defining a subset of type-dependent expressions that we can deduce
25798 from ahead of time isn't worth the trouble. */
25802 /* C++17 class template argument deduction. */
25806 /* Nothing we can do with this, even in deduction context. */
25809 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25810 with either a new invented type template parameter U or, if the
25811 initializer is a braced-init-list (8.5.4), with
25812 std::initializer_list<U>. */
25814 {
25819 else
25820 {
25822 {
25826 "for deduction to %<std::initializer_list%>, use copy-"
25828 }
25830 }
25831 }
25842 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25843 and initializer has array type, deduce cv-qualified array type. */
25845 complain);
25847 {
25856 {
25860 }
25861 }
25862 else
25863 {
25865 tree tparms;
25869 else
25870 {
25874 }
25881 {
25883 /* Try again at instantiation time. */
25887 /* If type is error_mark_node a diagnostic must have been
25888 emitted by now. Also, having a mention to '<type error>'
25889 in the diagnostic is not really useful to the user. */
25890 {
25894 else
25899 }
25901 }
25902 }
25904 /* Check any placeholder constraints against the deduced type. */
25907 {
25908 /* Use the deduced type to check the associated constraints. If we
25909 have a partial-concept-id, rebuild the argument list so that
25910 we check using the extra arguments. */
25914 {
25917 }
25918 else
25921 {
25923 {
25925 {
25943 }
25945 }
25947 }
25948 }
25954 }
25956 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25957 result. */
25959 tree
25961 {
25963 {
25969 /* In an abbreviated function template we didn't know we were dealing
25970 with a function template when we saw the auto return type, so update
25971 it to have the correct level. */
25973 }
25975 }
25977 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25978 'decltype(auto)' or a deduced class template. */
25980 bool
25982 {
25988 else
25990 }
25992 /* for_each_template_parm callback for type_uses_auto. */
25994 int
25996 {
25998 }
26000 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
26001 a use of `auto'. Returns NULL_TREE otherwise. */
26003 tree
26005 {
26009 {
26010 /* The Concepts TS allows multiple autos in one type-specifier; just
26011 return the first one we find, do_auto_deduction will collect all of
26012 them. */
26016 else
26018 }
26019 else
26021 }
26023 /* For a given template T, return the vector of typedefs referenced
26024 in T for which access check is needed at T instantiation time.
26025 T is either a FUNCTION_DECL or a RECORD_TYPE.
26026 Those typedefs were added to T by the function
26027 append_type_to_template_for_access_check. */
26031 {
26032 tree ti;
26043 {
26048 }
26051 }
26053 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
26054 tied to T. That list of typedefs will be access checked at
26055 T instantiation time.
26056 T is either a FUNCTION_DECL or a RECORD_TYPE.
26057 TYPE_DECL is a TYPE_DECL node representing a typedef.
26058 SCOPE is the scope through which TYPE_DECL is accessed.
26059 LOCATION is the location of the usage point of TYPE_DECL.
26061 This function is a subroutine of
26062 append_type_to_template_for_access_check. */
26064 static void
26066 tree type_decl,
26067 tree scope,
26068 location_t location)
26069 {
26070 qualified_typedef_usage_t typedef_usage;
26071 tree ti;
26078 && type_decl
26092 }
26094 /* Append TYPE_DECL to the template TEMPL.
26095 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
26096 At TEMPL instanciation time, TYPE_DECL will be checked to see
26097 if it can be accessed through SCOPE.
26098 LOCATION is the location of the usage point of TYPE_DECL.
26100 e.g. consider the following code snippet:
26102 class C
26103 {
26104 typedef int myint;
26105 };
26107 template<class U> struct S
26108 {
26109 C::myint mi; // <-- usage point of the typedef C::myint
26110 };
26112 S<char> s;
26114 At S<char> instantiation time, we need to check the access of C::myint
26115 In other words, we need to check the access of the myint typedef through
26116 the C scope. For that purpose, this function will add the myint typedef
26117 and the scope C through which its being accessed to a list of typedefs
26118 tied to the template S. That list will be walked at template instantiation
26119 time and access check performed on each typedefs it contains.
26120 Note that this particular code snippet should yield an error because
26121 myint is private to C. */
26123 void
26125 tree type_decl,
26126 tree scope,
26127 location_t location)
26128 {
26134 /* Make sure we don't append the type to the template twice. */
26141 }
26143 /* Convert the generic type parameters in PARM that match the types given in the
26144 range [START_IDX, END_IDX) from the current_template_parms into generic type
26145 packs. */
26147 tree
26149 {
26160 {
26161 /* Create a distinct parameter pack type from the current parm and add it
26162 to the replacement args to tsubst below into the generic function
26163 parameter. */
26178 }
26184 /* If there are more levels then build up the replacement with the outer
26185 template parms. */
26189 replacement);
26192 }
26194 /* Entries in the decl_constraint hash table. */
26196 {
26197 tree decl;
26198 tree ci;
26199 };
26201 /* Hashing function and equality for constraint entries. */
26203 {
26205 {
26207 }
26210 {
26212 }
26213 };
26215 /* A mapping from declarations to constraint information. Note that
26216 both templates and their underlying declarations are mapped to the
26217 same constraint information.
26219 FIXME: This is defined in pt.c because garbage collection
26220 code is not being generated for constraint.cc. */
26224 /* Returns the template constraints of declaration T. If T is not
26225 constrained, return NULL_TREE. Note that T must be non-null. */
26227 tree
26229 {
26240 else
26242 }
26244 /* Associate the given constraint information CI with the declaration
26245 T. If T is a template, then the constraints are associated with
26246 its underlying declaration. Don't build associations if CI is
26247 NULL_TREE. */
26249 void
26251 {
26263 }
26265 /* Remove the associated constraints of the declaration T. */
26267 void
26269 {
26278 }
26280 /* Memoized satisfaction results for declarations. This
26281 maps the pair (constraint_info, arguments) to the result computed
26282 by constraints_satisfied_p. */
26285 {
26286 tree ci;
26287 tree args;
26288 tree result;
26289 };
26291 /* Hashing function and equality for constraint entries. */
26294 {
26296 {
26299 }
26302 {
26304 }
26305 };
26307 /* Memoized satisfaction results for concept checks. */
26310 {
26311 tree tmpl;
26312 tree args;
26313 tree result;
26314 };
26316 /* Hashing function and equality for constraint entries. */
26319 {
26321 {
26323 }
26326 {
26331 }
26332 };
26337 /* Search for a memoized satisfaction result. Returns one of the
26338 truth value nodes if previously memoized, or NULL_TREE otherwise. */
26340 tree
26342 {
26347 else
26349 }
26351 /* Memoize the result of a satisfication test. Returns the saved result. */
26353 tree
26355 {
26362 }
26364 /* Search for a memoized satisfaction result for a concept. */
26366 tree
26368 {
26373 else
26375 }
26377 /* Memoize the result of a concept check. Returns the saved result. */
26379 tree
26381 {
26388 }
26392 /* Returns a prior concept specialization. This returns the substituted
26393 and normalized constraints defined by the concept. */
26395 tree
26397 {
26402 else
26404 }
26406 /* Save a concept expansion for later. */
26408 tree
26410 {
26417 }
26419 static hashval_t
26421 {
26430 }
26432 /* Compare the constraints of two subsumption entries. The LEFT1 and
26433 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26434 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26436 static bool
26438 {
26446 }
26448 /* Key/value pair for learning and memoizing subsumption results. This
26449 associates a pair of check constraints (including arguments) with
26450 a boolean value indicating the result. */
26453 {
26454 tree t1;
26455 tree t2;
26457 };
26459 /* Hashing function and equality for constraint entries. */
26462 {
26464 {
26466 }
26469 {
26474 }
26475 };
26479 /* Search for a previously cached subsumption result. */
26483 {
26488 else
26490 }
26492 /* Save a subsumption result. */
26494 bool
26496 {
26503 }
26505 /* Set up the hash table for constraint association. */
26507 void
26509 {
26518 }
26520 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26521 0..N-1. */
26523 void
26525 {
26528 integer_type_node,
26529 NULL_TREE),
26533 }
26535 /* Set up the hash tables for template instantiations. */
26537 void
26539 {
26545 }
26547 /* Print stats about the template hash tables for -fstats. */
26549 void
26551 {
26560 }