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1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2019 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
46 /* The type of functions taking a tree, and some additional data, and
47 returning an int. */
50 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
51 instantiations have been deferred, either because their definitions
52 were not yet available, or because we were putting off doing the work. */
54 {
57 };
72 /* Live only within one (recursive) call to tsubst_expr. We use
73 this to pass the statement expression node from the STMT_EXPR
74 to the EXPR_STMT that is its result. */
77 // -------------------------------------------------------------------------- //
78 // Local Specialization Stack
79 //
80 // Implementation of the RAII helper for creating new local
81 // specializations.
84 {
87 else
89 }
92 {
95 }
97 /* True if we've recursed into fn_type_unification too many times. */
101 {
102 tree tmpl;
103 tree args;
104 tree spec;
105 };
108 {
111 };
117 /* Contains canonical template parameter types. The vector is indexed by
118 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
119 TREE_LIST, whose TREE_VALUEs contain the canonical template
120 parameters of various types and levels. */
123 #define UNIFY_ALLOW_NONE 0
124 #define UNIFY_ALLOW_MORE_CV_QUAL 1
125 #define UNIFY_ALLOW_LESS_CV_QUAL 2
126 #define UNIFY_ALLOW_DERIVED 4
127 #define UNIFY_ALLOW_INTEGER 8
128 #define UNIFY_ALLOW_OUTER_LEVEL 16
129 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
130 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
133 tbr_incomplete_type,
134 tbr_ambiguous_baseclass,
135 tbr_success
136 };
161 tree);
218 location_t);
230 /* Make the current scope suitable for access checking when we are
231 processing T. T can be FUNCTION_DECL for instantiated function
232 template, VAR_DECL for static member variable, or TYPE_DECL for
233 alias template (needed by instantiate_decl). */
235 static void
237 {
245 else
249 {
250 saved_access_scope = tree_cons
253 }
254 }
256 /* Restore the scope set up by push_access_scope. T is the node we
257 are processing. */
259 static void
261 {
263 {
266 }
270 else
272 }
274 /* Do any processing required when DECL (a member template
275 declaration) is finished. Returns the TEMPLATE_DECL corresponding
276 to DECL, unless it is a specialization, in which case the DECL
277 itself is returned. */
279 tree
281 {
288 {
289 tree type;
297 {
301 }
303 }
307 {
309 {
312 }
313 else
315 }
316 else
320 }
322 /* Create a template info node. */
324 tree
326 {
331 }
333 /* Return the template info node corresponding to T, whatever T is. */
335 tree
337 {
359 }
361 /* Returns the template nesting level of the indicated class TYPE.
363 For example, in:
364 template <class T>
365 struct A
366 {
367 template <class U>
368 struct B {};
369 };
371 A<T>::B<U> has depth two, while A<T> has depth one.
372 Both A<T>::B<int> and A<int>::B<U> have depth one, if
373 they are instantiations, not specializations.
375 This function is guaranteed to return 0 if passed NULL_TREE so
376 that, for example, `template_class_depth (current_class_type)' is
377 always safe. */
379 int
381 {
385 {
396 else
398 }
401 }
403 /* Return TRUE if NODE instantiates a template that has arguments of
404 its own, be it directly a primary template or indirectly through a
405 partial specializations. */
406 static bool
408 {
420 /* So now we know we have a specialization, but it could be a full
421 or a partial specialization. To tell which, compare the depth of
422 its template arguments with those of its context. */
431 }
433 /* Subroutine of maybe_begin_member_template_processing.
434 Returns true if processing DECL needs us to push template parms. */
436 static bool
438 {
444 }
446 /* Subroutine of maybe_begin_member_template_processing.
447 Push the template parms in PARMS, starting from LEVELS steps into the
448 chain, and ending at the beginning, since template parms are listed
449 innermost first. */
451 static void
453 {
461 current_template_parms
467 NULL);
469 {
478 {
485 /* Push the CONST_DECL. */
491 }
492 }
493 }
495 /* Restore the template parameter context for a member template, a
496 friend template defined in a class definition, or a non-template
497 member of template class. */
499 void
501 {
502 tree parms;
507 {
510 /* Disregard full specializations (c++/60999). */
513 }
516 {
521 {
524 }
527 }
529 /* Remember how many levels of template parameters we pushed so that
530 we can pop them later. */
532 }
534 /* Undo the effects of maybe_begin_member_template_processing. */
536 void
538 {
547 {
551 }
552 }
554 /* Return a new template argument vector which contains all of ARGS,
555 but has as its innermost set of arguments the EXTRA_ARGS. */
557 static tree
559 {
560 tree new_args;
578 }
580 /* Like add_to_template_args, but only the outermost ARGS are added to
581 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
582 (EXTRA_ARGS) levels are added. This function is used to combine
583 the template arguments from a partial instantiation with the
584 template arguments used to attain the full instantiation from the
585 partial instantiation. */
587 static tree
589 {
590 tree new_args;
592 /* If there are more levels of EXTRA_ARGS than there are ARGS,
593 something very fishy is going on. */
596 /* If *all* the new arguments will be the EXTRA_ARGS, just return
597 them. */
601 /* For the moment, we make ARGS look like it contains fewer levels. */
606 /* Now, we restore ARGS to its full dimensions. */
610 }
612 /* Return the N levels of innermost template arguments from the ARGS. */
614 tree
616 {
617 tree new_args;
623 /* If N is 1, just return the innermost set of template arguments. */
627 /* If we're not removing anything, just return the arguments we were
628 given. */
634 /* Make a new set of arguments, not containing the outer arguments. */
641 }
643 /* The inverse of get_innermost_template_args: Return all but the innermost
644 EXTRA_LEVELS levels of template arguments from the ARGS. */
646 static tree
648 {
649 tree new_args;
655 /* If N is 1, just return the outermost set of template arguments. */
659 /* If we're not removing anything, just return the arguments we were
660 given. */
665 /* Make a new set of arguments, not containing the inner arguments. */
672 }
674 /* We've got a template header coming up; push to a new level for storing
675 the parms. */
677 void
679 {
680 /* We use a non-tag-transparent scope here, which causes pushtag to
681 put tags in this scope, rather than in the enclosing class or
682 namespace scope. This is the right thing, since we want
683 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
684 global template class, push_template_decl handles putting the
685 TEMPLATE_DECL into top-level scope. For a nested template class,
686 e.g.:
688 template <class T> struct S1 {
689 template <class T> struct S2 {};
690 };
692 pushtag contains special code to insert the TEMPLATE_DECL for S2
693 at the right scope. */
699 /* Add a dummy parameter level while we process the parameter list. */
700 current_template_parms
703 current_template_parms);
704 }
706 /* This routine is called when a specialization is declared. If it is
707 invalid to declare a specialization here, an error is reported and
708 false is returned, otherwise this routine will return true. */
710 static bool
712 {
715 /* [temp.expl.spec]
717 An explicit specialization shall be declared in the namespace of
718 which the template is a member, or, for member templates, in the
719 namespace of which the enclosing class or enclosing class
720 template is a member. An explicit specialization of a member
721 function, member class or static data member of a class template
722 shall be declared in the namespace of which the class template
723 is a member. */
725 {
728 }
730 /* [temp.expl.spec]
732 In an explicit specialization declaration for a member of a class
733 template or a member template that appears in namespace scope,
734 the member template and some of its enclosing class templates may
735 remain unspecialized, except that the declaration shall not
736 explicitly specialize a class member template if its enclosing
737 class templates are not explicitly specialized as well. */
739 {
742 }
745 }
747 /* We've just seen template <>. */
749 bool
751 {
755 }
757 /* Called at then end of processing a declaration preceded by
758 template<>. */
760 void
762 {
765 }
767 /* Any template <>'s that we have seen thus far are not referring to a
768 function specialization. */
770 void
772 {
775 }
777 /* We've just seen a template header. If SPECIALIZATION is nonzero,
778 it was of the form template <>. */
780 static void
782 {
784 template_header_count++;
785 }
787 /* We're beginning an explicit instantiation. */
789 void
791 {
794 }
797 void
799 {
802 }
804 /* An explicit specialization or partial specialization of TMPL is being
805 declared. Check that the namespace in which the specialization is
806 occurring is permissible. Returns false iff it is invalid to
807 specialize TMPL in the current namespace. */
809 static bool
811 {
814 /* [tmpl.expl.spec]
816 An explicit specialization shall be declared in a namespace enclosing the
817 specialized template. An explicit specialization whose declarator-id is
818 not qualified shall be declared in the nearest enclosing namespace of the
819 template, or, if the namespace is inline (7.3.1), any namespace from its
820 enclosing namespace set. */
823 {
826 }
829 /* Same or enclosing namespace. */
831 else
832 {
833 auto_diagnostic_group d;
839 }
840 }
842 /* SPEC is an explicit instantiation. Check that it is valid to
843 perform this explicit instantiation in the current namespace. */
845 static void
847 {
848 tree ns;
850 /* DR 275: An explicit instantiation shall appear in an enclosing
851 namespace of its template. */
857 }
859 // Returns the type of a template specialization only if that
860 // specialization needs to be defined. Otherwise (e.g., if the type has
861 // already been defined), the function returns NULL_TREE.
862 static tree
864 {
865 // An implicit instantiation of an incomplete type implies
866 // the definition of a new class template.
867 //
868 // template<typename T>
869 // struct S;
870 //
871 // template<typename T>
872 // struct S<T*>;
873 //
874 // Here, S<T*> is an implicit instantiation of S whose type
875 // is incomplete.
879 // It can also be the case that TYPE is a completed specialization.
880 // Continuing the previous example, suppose we also declare:
881 //
882 // template<typename T>
883 // requires Integral<T>
884 // struct S<T*>;
885 //
886 // Here, S<T*> refers to the specialization S<T*> defined
887 // above. However, we need to differentiate definitions because
888 // we intend to define a new partial specialization. In this case,
889 // we rely on the fact that the constraints are different for
890 // this declaration than that above.
891 //
892 // Note that we also get here for injected class names and
893 // late-parsed template definitions. We must ensure that we
894 // do not create new type declarations for those cases.
896 {
900 // If there are no template parameters, this cannot be a new
901 // partial template specializtion?
905 // The injected-class-name is not a new partial specialization.
909 // If the constraints are not the same as those of the primary
910 // then, we can probably create a new specialization.
914 {
918 }
920 // Also, if there's a pre-existing specialization with matching
921 // constraints, then this also isn't new.
924 {
932 }
934 // Create a new type node (and corresponding type decl)
935 // for the newly declared specialization.
940 /* We only need a separate type node for storing the definition of this
941 partial specialization; uses of S<T*> are unconstrained, so all are
942 equivalent. So keep TYPE_CANONICAL the same. */
945 // Build the corresponding type decl.
951 }
954 }
956 /* The TYPE is being declared. If it is a template type, that means it
957 is a partial specialization. Do appropriate error-checking. */
959 tree
961 {
962 tree context;
967 /* A lambda that appears in specialization context is not itself a
968 specialization. */
973 {
977 }
982 {
988 else
991 }
993 {
994 /* This is for ordinary explicit specialization and partial
995 specialization of a template class such as:
997 template <> class C<int>;
999 or:
1001 template <class T> class C<T*>;
1003 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
1006 {
1013 {
1018 }
1019 }
1025 /* Trying to define a specialization either without a template<> header
1026 or in an inappropriate place. We've already given an error, so just
1027 bail now so we don't actually define the specialization. */
1029 }
1035 {
1036 /* This is for an explicit specialization of member class
1037 template according to [temp.expl.spec/18]:
1039 template <> template <class U> class C<int>::D;
1041 The context `C<int>' must be an implicit instantiation.
1042 Otherwise this is just a member class template declared
1043 earlier like:
1045 template <> class C<int> { template <class U> class D; };
1046 template <> template <class U> class C<int>::D;
1048 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1049 while in the second case, `C<int>::D' is a primary template
1050 and `C<T>::D' may not exist. */
1054 {
1055 tree t;
1060 {
1063 type))
1066 }
1068 /* Check for invalid specialization after instantiation:
1070 template <> template <> class C<int>::D<int>;
1071 template <> template <class U> class C<int>::D; */
1075 {
1079 {
1080 /* We already have a full specialization of this partial
1081 instantiation, or a full specialization has been
1082 looked up but not instantiated. Reassign it to the
1083 new member specialization template. */
1084 spec_entry elt;
1097 spec_entry **slot
1102 }
1103 else
1104 /* But if we've had an implicit instantiation, that's a
1105 problem ([temp.expl.spec]/6). */
1108 }
1110 /* Mark TYPE as a specialization. And as a result, we only
1111 have one level of template argument for the innermost
1112 class template. */
1117 }
1118 }
1120 {
1121 /* Someday C++0x may allow for enum template specialization. */
1126 else
1127 {
1130 }
1131 }
1134 }
1136 /* Returns nonzero if we can optimize the retrieval of specializations
1137 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1138 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1142 {
1145 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1146 parameter. */
1148 /* The optimized lookup depends on the fact that the
1149 template arguments for the member function template apply
1150 purely to the containing class, which is not true if the
1151 containing class is an explicit or partial
1152 specialization. */
1156 /* It is possible to have a template that is not a member
1157 template and is not a member of a template class:
1159 template <typename T>
1160 struct S { friend A::f(); };
1162 Here, the friend function is a template, but the context does
1163 not have template information. The optimized lookup relies
1164 on having ARGS be the template arguments for both the class
1165 and the function template. */
1167 }
1169 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1170 gone through coerce_template_parms by now. */
1172 static void
1174 {
1176 {
1185 /* Allow typedefs on the type of a non-type argument, since a
1187 else
1189 }
1190 }
1192 static void
1194 {
1199 }
1201 /* Retrieve the specialization (in the sense of [temp.spec] - a
1202 specialization is either an instantiation or an explicit
1203 specialization) of TMPL for the given template ARGS. If there is
1204 no such specialization, return NULL_TREE. The ARGS are a vector of
1205 arguments, or a vector of vectors of arguments, in the case of
1206 templates with more than one level of parameters.
1208 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1209 then we search for a partial specialization matching ARGS. This
1210 parameter is ignored if TMPL is not a class template.
1212 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1213 result is a NONTYPE_ARGUMENT_PACK. */
1215 static tree
1217 {
1227 /* There should be as many levels of arguments as there are
1228 levels of parameters. */
1237 /* Lambda functions in templates aren't instantiated normally, but through
1238 tsubst_lambda_expr. */
1243 {
1244 /* The template arguments actually apply to the containing
1245 class. Find the class specialization with those
1246 arguments. */
1248 tree class_specialization
1253 /* Find the instance of TMPL. */
1256 {
1259 /* using-declarations can add base methods to the method vec,
1260 and we don't want those here. */
1263 }
1265 }
1266 else
1267 {
1269 spec_entry elt;
1278 else
1286 }
1289 }
1291 /* Like retrieve_specialization, but for local declarations. */
1293 tree
1295 {
1301 }
1303 /* Returns nonzero iff DECL is a specialization of TMPL. */
1305 int
1307 {
1308 tree t;
1311 {
1317 }
1318 else
1319 {
1328 }
1331 }
1333 /* Returns nonzero iff DECL is a specialization of friend declaration
1334 FRIEND_DECL according to [temp.friend]. */
1336 bool
1338 {
1345 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1346 of a template class, we want to check if DECL is a specialization
1347 if this. */
1351 {
1352 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1355 }
1360 /* There is nothing to do if this is not a template friend. */
1367 /* [temp.friend/6]
1368 A member of a class template may be declared to be a friend of a
1369 non-template class. In this case, the corresponding member of
1370 every specialization of the class template is a friend of the
1371 class granting friendship.
1373 For example, given a template friend declaration
1375 template <class T> friend void A<T>::f();
1377 the member function below is considered a friend
1379 template <> struct A<int> {
1380 void f();
1381 };
1383 For this type of template friend, TEMPLATE_DEPTH below will be
1384 nonzero. To determine if DECL is a friend of FRIEND, we first
1385 check if the enclosing class is a specialization of another. */
1392 {
1393 /* Next, we check the members themselves. In order to handle
1394 a few tricky cases, such as when FRIEND_DECL's are
1396 template <class T> friend void A<T>::g(T t);
1397 template <class T> template <T t> friend void A<T>::h();
1399 and DECL's are
1401 void A<int>::g(int);
1402 template <int> void A<int>::h();
1404 we need to figure out ARGS, the template arguments from
1405 the context of DECL. This is required for template substitution
1406 of `T' in the function parameter of `g' and template parameter
1407 of `h' in the above examples. Here ARGS corresponds to `int'. */
1414 {
1416 {
1419 else
1421 current_depth++;
1422 }
1424 }
1427 {
1429 tree friend_type;
1430 tree decl_type;
1431 tree friend_args_type;
1432 tree decl_args_type;
1434 /* Make sure that both DECL and FRIEND_DECL are templates or
1435 non-templates. */
1441 {
1442 /* If both are templates, check template parameter list. */
1443 tree friend_parms
1448 friend_parms))
1452 }
1453 else
1461 /* Check if return types match. */
1465 /* Check if function parameter types match, ignoring the
1466 `this' parameter. */
1475 }
1476 else
1477 {
1478 /* DECL is a TYPE_DECL */
1482 /* Make sure that both DECL and FRIEND_DECL are templates or
1483 non-templates. */
1484 is_template
1491 {
1492 tree friend_parms;
1493 /* If both are templates, check the name of the two
1494 TEMPLATE_DECL's first because is_friend didn't. */
1499 /* Now check template parameter list. */
1500 friend_parms
1503 return comp_template_parms
1505 friend_parms);
1506 }
1507 else
1510 }
1511 }
1513 }
1515 /* Register the specialization SPEC as a specialization of TMPL with
1516 the indicated ARGS. IS_FRIEND indicates whether the specialization
1517 is actually just a friend declaration. ATTRLIST is the list of
1518 attributes that the specialization is declared with or NULL when
1519 it isn't. Returns SPEC, or an equivalent prior declaration, if
1520 available.
1522 We also store instantiations of field packs in the hash table, even
1523 though they are not themselves templates, to make lookup easier. */
1525 static tree
1527 hashval_t hash)
1528 {
1529 tree fn;
1531 spec_entry elt;
1539 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1540 register it; we want the corresponding TEMPLATE_DECL instead.
1541 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1542 the more obvious `uses_template_parms (spec)' to avoid problems
1543 with default function arguments. In particular, given
1544 something like this:
1546 template <class T> void f(T t1, T t = T())
1548 the default argument expression is not substituted for in an
1549 instantiation unless and until it is actually needed. */
1553 /* We don't put these specializations in the hash table, but we might
1554 want to give an error about a mismatch. */
1556 else
1557 {
1565 slot =
1569 else
1571 }
1573 /* We can sometimes try to re-register a specialization that we've
1574 already got. In particular, regenerate_decl_from_template calls
1575 duplicate_decls which will update the specialization list. But,
1576 we'll still get called again here anyhow. It's more convenient
1577 to simply allow this than to try to prevent it. */
1581 {
1583 {
1586 {
1588 fn);
1590 }
1591 else
1592 {
1593 tree clone;
1594 /* This situation should occur only if the first
1595 specialization is an implicit instantiation, the
1596 second is an explicit specialization, and the
1597 implicit instantiation has not yet been used. That
1598 situation can occur if we have implicitly
1599 instantiated a member function and then specialized
1600 it later.
1602 We can also wind up here if a friend declaration that
1603 looked like an instantiation turns out to be a
1604 specialization:
1606 template <class T> void foo(T);
1607 class S { friend void foo<>(int) };
1608 template <> void foo(int);
1610 We transform the existing DECL in place so that any
1611 pointers to it become pointers to the updated
1612 declaration.
1614 If there was a definition for the template, but not
1615 for the specialization, we want this to look as if
1616 there were no definition, and vice versa. */
1619 /* The call to duplicate_decls will have applied
1620 [temp.expl.spec]:
1622 An explicit specialization of a function template
1623 is inline only if it is explicitly declared to be,
1624 and independently of whether its function template
1625 is.
1627 to the primary function; now copy the inline bits to
1628 the various clones. */
1630 {
1637 }
1641 }
1642 }
1644 {
1647 /* We've already complained in duplicate_decls. */
1651 /* Dup decl failed, but this is a new definition. Set the
1652 line number so any errors match this new
1653 definition. */
1657 }
1658 }
1662 /* A specialization must be declared in the same namespace as the
1663 template it is specializing. */
1669 {
1678 /* If TMPL is a forward declaration of a template function, keep a list
1679 of all specializations in case we need to reassign them to a friend
1680 template later in tsubst_friend_function.
1682 Also keep a list of all variable template instantiations so that
1683 process_partial_specialization can check whether a later partial
1684 specialization would have used it. */
1687 }
1690 }
1692 /* Returns true iff two spec_entry nodes are equivalent. */
1696 bool
1698 {
1705 /* tmpl could be a FIELD_DECL for a capture pack. */
1709 {
1710 /* Partial specializations of a variable template can be distinguished by
1711 constraints. */
1715 }
1719 }
1721 /* Returns a hash for a template TMPL and template arguments ARGS. */
1723 static hashval_t
1725 {
1728 }
1730 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1731 ignoring SPEC. */
1733 hashval_t
1735 {
1737 }
1739 /* Recursively calculate a hash value for a template argument ARG, for use
1740 in the hash tables of template specializations. */
1742 hashval_t
1744 {
1764 {
1772 {
1777 }
1799 {
1803 {
1806 }
1808 }
1812 {
1815 }
1826 val = iterative_hash_template_arg
1838 val);
1840 val);
1849 /* [temp.over.link] Two lambda-expressions are never considered
1850 equivalent.
1852 So just hash the closure type. */
1863 /* Now hash operands as usual. */
1867 {
1870 {
1874 }
1876 call_expr_arg_iterator ai;
1881 }
1885 }
1888 {
1891 {
1892 // We want an alias specialization that survived strip_typedefs
1893 // to hash differently from its TYPE_CANONICAL, to avoid hash
1894 // collisions that compare as different in template_args_equal.
1895 // These could be dependent specializations that strip_typedefs
1896 // left alone, or untouched specializations because
1897 // coerce_template_parms returns the unconverted template
1898 // arguments if it sees incomplete argument packs.
1901 }
1904 val);
1907 /* Otherwise just compare the types during lookup. */
1916 {
1921 }
1922 }
1925 }
1927 /* Unregister the specialization SPEC as a specialization of TMPL.
1928 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1929 if the SPEC was listed as a specialization of TMPL.
1931 Note that SPEC has been ggc_freed, so we can't look inside it. */
1933 bool
1935 {
1937 spec_entry elt;
1945 {
1950 }
1953 }
1955 /* Like register_specialization, but for local declarations. We are
1956 registering SPEC, an instantiation of TMPL. */
1958 void
1960 {
1963 }
1965 /* TYPE is a class type. Returns true if TYPE is an explicitly
1966 specialized class. */
1968 bool
1970 {
1974 }
1976 /* Print the list of functions at FNS, going through all the overloads
1977 for each element of the list. Alternatively, FNS cannot be a
1978 TREE_LIST, in which case it will be printed together with all the
1979 overloads.
1981 MORE and *STR should respectively be FALSE and NULL when the function
1982 is called from the outside. They are used internally on recursive
1983 calls. print_candidates manages the two parameters and leaves NULL
1984 in *STR when it ends. */
1986 static void
1988 {
1992 else
1994 {
2000 {
2003 else
2006 }
2008 }
2009 }
2011 /* Print the list of candidate FNS in an error message. FNS can also
2012 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
2014 void
2016 {
2020 }
2022 /* Get a (possibly) constrained template declaration for the
2023 purpose of ordering candidates. */
2024 static tree
2026 {
2032 }
2034 /* Among candidates having the same signature, return the
2035 most constrained or NULL_TREE if there is no best candidate.
2036 If the signatures of candidates vary (e.g., template
2037 specialization vs. member function), then there can be no
2038 most constrained.
2040 Note that we don't compare constraints on the functions
2041 themselves, but rather those of their templates. */
2042 static tree
2044 {
2045 // Try to find the best candidate in a first pass.
2048 {
2055 }
2057 // Verify that the champ is better than previous candidates.
2062 }
2065 }
2068 /* Returns the template (one of the functions given by TEMPLATE_ID)
2069 which can be specialized to match the indicated DECL with the
2070 explicit template args given in TEMPLATE_ID. The DECL may be
2071 NULL_TREE if none is available. In that case, the functions in
2072 TEMPLATE_ID are non-members.
2074 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2075 specialization of a member template.
2077 The TEMPLATE_COUNT is the number of references to qualifying
2078 template classes that appeared in the name of the function. See
2079 check_explicit_specialization for a more accurate description.
2081 TSK indicates what kind of template declaration (if any) is being
2082 declared. TSK_TEMPLATE indicates that the declaration given by
2083 DECL, though a FUNCTION_DECL, has template parameters, and is
2084 therefore a template function.
2086 The template args (those explicitly specified and those deduced)
2087 are output in a newly created vector *TARGS_OUT.
2089 If it is impossible to determine the result, an error message is
2090 issued. The error_mark_node is returned to indicate failure. */
2092 static tree
2094 tree decl,
2098 tmpl_spec_kind tsk)
2099 {
2100 tree fns;
2101 tree targs;
2102 tree explicit_targs;
2105 /* A TREE_LIST of templates of which DECL may be a specialization.
2106 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2107 corresponding TREE_PURPOSE is the set of template arguments that,
2108 when used to instantiate the template, would produce a function
2109 with the signature of DECL. */
2119 /* We shouldn't be specializing a member template of an
2120 unspecialized class template; we already gave an error in
2121 check_specialization_scope, now avoid crashing. */
2125 {
2128 }
2136 /* Check for baselinks. */
2141 {
2144 }
2146 {
2149 }
2151 /* Count the number of template headers specified for this
2152 specialization. */
2162 {
2165 tf_warning_or_error,
2169 }
2171 {
2175 {
2176 tree decl_arg_types;
2177 tree fn_arg_types;
2178 tree insttype;
2180 /* In case of explicit specialization, we need to check if
2181 the number of template headers appearing in the specialization
2182 is correct. This is usually done in check_explicit_specialization,
2183 but the check done there cannot be exhaustive when specializing
2184 member functions. Consider the following code:
2186 template <> void A<int>::f(int);
2187 template <> template <> void A<int>::f(int);
2189 Assuming that A<int> is not itself an explicit specialization
2190 already, the first line specializes "f" which is a non-template
2191 member function, whilst the second line specializes "f" which
2192 is a template member function. So both lines are syntactically
2193 correct, and check_explicit_specialization does not reject
2194 them.
2196 Here, we can do better, as we are matching the specialization
2197 against the declarations. We count the number of template
2198 headers, and we check if they match TEMPLATE_COUNT + 1
2199 (TEMPLATE_COUNT is the number of qualifying template classes,
2200 plus there must be another header for the member template
2201 itself).
2203 Notice that if header_count is zero, this is not a
2204 specialization but rather a template instantiation, so there
2205 is no check we can perform here. */
2209 /* Check that the number of template arguments at the
2210 innermost level for DECL is the same as for FN. */
2218 /* DECL might be a specialization of FN. */
2222 /* For a non-static member function, we need to make sure
2223 that the const qualification is the same. Since
2224 get_bindings does not try to merge the "this" parameter,
2225 we must do the comparison explicitly. */
2227 {
2232 /* And the ref-qualification. */
2236 }
2238 /* Skip the "this" parameter and, for constructors of
2239 classes with virtual bases, the VTT parameter. A
2240 full specialization of a constructor will have a VTT
2241 parameter, but a template never will. */
2242 decl_arg_types
2244 fn_arg_types
2247 /* Function templates cannot be specializations; there are
2248 no partial specializations of functions. Therefore, if
2249 the type of DECL does not match FN, there is no
2250 match.
2252 Note that it should never be the case that we have both
2253 candidates added here, and for regular member functions
2254 below. */
2256 {
2260 }
2262 /* See whether this function might be a specialization of this
2263 template. Suppress access control because we might be trying
2264 to make this specialization a friend, and we have already done
2265 access control for the declaration of the specialization. */
2271 /* We cannot deduce template arguments that when used to
2272 specialize TMPL will produce DECL. */
2276 /* We deduced something involving 'auto', which isn't a valid
2277 template argument. */
2280 /* Remove, from the set of candidates, all those functions
2281 whose constraints are not satisfied. */
2285 // Then, try to form the new function type.
2289 fn_arg_types
2294 /* Save this template, and the arguments deduced. */
2296 }
2298 /* FN is an ordinary member function, and we need a
2299 specialization of a member template. */
2300 ;
2302 /* We can get IDENTIFIER_NODEs here in certain erroneous
2303 cases. */
2304 ;
2306 /* This is just an ordinary non-member function. Nothing can
2307 be a specialization of that. */
2308 ;
2310 /* Cannot specialize functions that are created implicitly. */
2311 ;
2312 else
2313 {
2314 tree decl_arg_types;
2316 /* This is an ordinary member function. However, since
2317 we're here, we can assume its enclosing class is a
2318 template class. For example,
2320 template <typename T> struct S { void f(); };
2321 template <> void S<int>::f() {}
2323 Here, S<int>::f is a non-template, but S<int> is a
2324 template class. If FN has the same type as DECL, we
2325 might be in business. */
2328 /* Its enclosing class is an explicit specialization
2329 of a template class. This is not a candidate. */
2334 /* The return types differ. */
2337 /* Adjust the type of DECL in case FN is a static member. */
2344 decl_arg_types))
2352 // If the deduced arguments do not satisfy the constraints,
2353 // this is not a candidate.
2357 // Add the candidate.
2359 }
2360 }
2363 {
2364 /* We have:
2366 [temp.expl.spec]
2368 It is possible for a specialization with a given function
2369 signature to be instantiated from more than one function
2370 template. In such cases, explicit specification of the
2371 template arguments must be used to uniquely identify the
2372 function template specialization being specialized.
2374 Note that here, there's no suggestion that we're supposed to
2375 determine which of the candidate templates is most
2376 specialized. However, we, also have:
2378 [temp.func.order]
2380 Partial ordering of overloaded function template
2381 declarations is used in the following contexts to select
2382 the function template to which a function template
2383 specialization refers:
2385 -- when an explicit specialization refers to a function
2386 template.
2388 So, we do use the partial ordering rules, at least for now.
2389 This extension can only serve to make invalid programs valid,
2390 so it's safe. And, there is strong anecdotal evidence that
2391 the committee intended the partial ordering rules to apply;
2392 the EDG front end has that behavior, and John Spicer claims
2393 that the committee simply forgot to delete the wording in
2394 [temp.expl.spec]. */
2397 {
2400 }
2401 }
2403 // Concepts allows multiple declarations of member functions
2404 // with the same signature. Like above, we need to rely on
2405 // on the partial ordering of those candidates to determine which
2406 // is the best.
2408 {
2410 {
2413 }
2414 }
2417 {
2424 else
2427 }
2431 {
2437 }
2439 /* We have one, and exactly one, match. */
2441 {
2445 // Propagate the candidate's constraints to the declaration.
2448 /* DECL is a re-declaration or partial instantiation of a template
2449 function. */
2452 /* It was a specialization of an ordinary member function in a
2453 template class. */
2455 }
2457 /* It was a specialization of a template. */
2460 {
2465 }
2466 else
2469 }
2471 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2472 but with the default argument values filled in from those in the
2473 TMPL_TYPES. */
2475 static tree
2477 tree tmpl_types)
2478 {
2479 tree new_spec_types;
2487 /* Substitute into the rest of the list. */
2488 new_spec_types =
2492 /* Add the default argument for this parameter. */
2495 new_spec_types);
2496 }
2498 /* DECL is an explicit specialization. Replicate default arguments
2499 from the template it specializes. (That way, code like:
2501 template <class T> void f(T = 3);
2502 template <> void f(double);
2503 void g () { f (); }
2505 works, as required.) An alternative approach would be to look up
2506 the correct default arguments at the call-site, but this approach
2507 is consistent with how implicit instantiations are handled. */
2509 static void
2511 {
2512 tree tmpl;
2513 tree spec_types;
2514 tree tmpl_types;
2515 tree new_spec_types;
2516 tree old_type;
2517 tree new_type;
2518 tree t;
2523 /* See if there's anything we need to do. */
2536 {
2537 /* Remove the this pointer, but remember the object's type for
2538 CV quals. */
2544 {
2545 /* DECL may contain more parameters than TMPL due to the extra
2546 in-charge parameter in constructors and destructors. */
2549 }
2551 {
2554 }
2555 }
2557 /* Compute the merged default arguments. */
2558 new_spec_types =
2561 /* Compute the new FUNCTION_TYPE. */
2563 {
2567 new_spec_types);
2570 /* Put the in-charge parameter back. */
2573 new_spec_types);
2577 new_spec_types);
2578 }
2579 else
2581 new_spec_types);
2587 }
2589 /* Return the number of template headers we expect to see for a definition
2590 or specialization of CTYPE or one of its non-template members. */
2592 int
2594 {
2598 {
2599 /* You're supposed to have one `template <...>' for every
2600 template class, but you don't need one for a full
2601 specialization. For example:
2603 template <class T> struct S{};
2604 template <> struct S<int> { void f(); };
2605 void S<int>::f () {}
2607 is correct; there shouldn't be a `template <>' for the
2608 definition of `S<int>::f'. */
2610 /* If CTYPE does not have template information of any
2611 kind, then it is not a template, nor is it nested
2612 within a template. */
2620 }
2623 }
2625 /* Do a simple sanity check on the template headers that precede the
2626 variable declaration DECL. */
2628 void
2630 {
2635 {
2638 "variable templates only available with "
2641 // Namespace-scope variable templates should have a template header.
2643 }
2645 {
2646 auto_diagnostic_group d;
2648 "too many template headers for %qD "
2654 "members of an explicitly specialized class are defined "
2656 }
2657 }
2659 /* An explicit specialization whose declarator-id or class-head-name is not
2660 qualified shall be declared in the nearest enclosing namespace of the
2661 template, or, if the namespace is inline (7.3.1), any namespace from its
2662 enclosing namespace set.
2664 If the name declared in the explicit instantiation is an unqualified name,
2665 the explicit instantiation shall appear in the namespace where its template
2666 is declared or, if that namespace is inline (7.3.1), any namespace from its
2667 enclosing namespace set. */
2669 void
2671 {
2676 {
2682 /* This was allowed in C++98, so only pedwarn. */
2684 "outside its namespace must use a nested-name-"
2686 }
2687 }
2689 /* Warn for a template specialization SPEC that is missing some of a set
2690 of function or type attributes that the template TEMPL is declared with.
2691 ATTRLIST is a list of additional attributes that SPEC should be taken
2692 to ultimately be declared with. */
2694 static void
2696 {
2700 /* Avoid warning if the difference between the primary and
2701 the specialization is not in one of the attributes below. */
2705 };
2707 /* Put together a list of the black listed attributes that the primary
2708 template is declared with that the specialization is not, in case
2709 it's not apparent from the most recent declaration of the primary. */
2710 pretty_printer str;
2717 auto_diagnostic_group d;
2720 spec))
2726 }
2728 /* Check to see if the function just declared, as indicated in
2729 DECLARATOR, and in DECL, is a specialization of a function
2730 template. We may also discover that the declaration is an explicit
2731 instantiation at this point.
2733 Returns DECL, or an equivalent declaration that should be used
2734 instead if all goes well. Issues an error message if something is
2735 amiss. Returns error_mark_node if the error is not easily
2736 recoverable.
2738 FLAGS is a bitmask consisting of the following flags:
2740 2: The function has a definition.
2741 4: The function is a friend.
2743 The TEMPLATE_COUNT is the number of references to qualifying
2744 template classes that appeared in the name of the function. For
2745 example, in
2747 template <class T> struct S { void f(); };
2748 void S<int>::f();
2750 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2751 classes are not counted in the TEMPLATE_COUNT, so that in
2753 template <class T> struct S {};
2754 template <> struct S<int> { void f(); }
2755 template <> void S<int>::f();
2757 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2758 invalid; there should be no template <>.)
2760 If the function is a specialization, it is marked as such via
2761 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2762 is set up correctly, and it is added to the list of specializations
2763 for that template. */
2765 tree
2767 tree decl,
2770 tree attrlist)
2771 {
2780 tmpl_spec_kind tsk;
2783 {
2786 else
2788 }
2789 else
2793 {
2796 {
2799 }
2801 {
2803 /* This could be something like:
2805 template <class T> void f(T);
2806 class S { friend void f<>(int); } */
2808 else
2809 {
2810 /* This case handles bogus declarations like template <>
2811 template <class T> void f<int>(); */
2814 declarator);
2816 }
2817 }
2821 /* The error has already been reported in
2822 check_specialization_scope. */
2828 /* Fall through. */
2841 decl);
2844 else
2848 /* Fall through. */
2854 /* In cases like template<> constexpr bool v = true;
2855 We'll give an error in check_template_variable. */
2861 else
2867 {
2868 /* This case handles bogus declarations like template <>
2869 template <class T> void f<int>(); */
2873 declarator);
2875 {
2876 /* Partial specialization of variable template. */
2880 }
2884 else
2888 ok:;
2889 }
2892 /* This is a specialization of a member template, without
2893 specialization the containing class. Something like:
2895 template <class T> struct S {
2896 template <class U> void f (U);
2897 };
2898 template <> template <class U> void S<int>::f(U) {}
2900 That's a specialization -- but of the entire template. */
2906 }
2909 /* This doesn't apply to variable templates. */
2911 {
2915 {
2919 }
2920 }
2923 {
2928 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2930 {
2931 tree fns;
2936 else
2937 {
2938 /* If there is no class context, the explicit instantiation
2939 must be at namespace scope. */
2942 /* Find the namespace binding, using the declaration
2943 context. */
2947 /* If lookup fails, look for a friend declaration so we can
2948 give a better diagnostic. */
2954 {
2957 }
2958 }
2961 }
2967 {
2969 /* A specialization in class scope. This is invalid,
2970 but the error will already have been flagged by
2971 check_specialization_scope. */
2973 else
2974 {
2975 /* It's not valid to write an explicit instantiation in
2976 class scope, e.g.:
2978 class C { template void f(); }
2980 This case is caught by the parser. However, on
2981 something like:
2983 template class C { void f(); };
2985 (which is invalid) we can get here. The error will be
2986 issued later. */
2987 ;
2988 }
2991 }
2994 {
2995 // We'll match variable templates in start_decl.
2999 /* Find the list of functions in ctype that have the same
3000 name as the declared function. */
3004 {
3008 {
3009 /* From [temp.expl.spec]:
3011 If such an explicit specialization for the member
3012 of a class template names an implicitly-declared
3013 special member function (clause _special_), the
3014 program is ill-formed.
3016 Similar language is found in [temp.explicit]. */
3019 }
3022 }
3024 /* For a type-conversion operator, We might be looking for
3025 `operator int' which will be a specialization of
3026 `operator T'. Grab all the conversion operators, and
3027 then select from them. */
3032 {
3035 }
3036 else
3038 }
3040 /* Figure out what exactly is being specialized at this point.
3041 Note that for an explicit instantiation, even one for a
3042 member function, we cannot tell a priori whether the
3043 instantiation is for a member template, or just a member
3044 function of a template class. Even if a member template is
3045 being instantiated, the member template arguments may be
3046 elided if they can be deduced from the rest of the
3047 declaration. */
3050 member_specialization,
3051 template_count,
3052 tsk);
3055 /* We couldn't figure out what this declaration was
3056 specializing. */
3058 else
3059 {
3062 {
3063 auto_diagnostic_group d;
3065 "friend declaration %qD is not visible to "
3069 }
3077 {
3078 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
3079 is done by do_decl_instantiation later. */
3085 {
3086 /* If TMPL is not the most general template (for
3087 example, if TMPL is a friend template that is
3088 injected into namespace scope), then there will
3089 be too many levels of TARGS. Remove some of them
3090 here. */
3092 tree new_targs;
3099 }
3102 }
3104 /* If we thought that the DECL was a member function, but it
3105 turns out to be specializing a static member function,
3106 make DECL a static member function as well. */
3112 /* If this is a specialization of a member template of a
3113 template class, we want to return the TEMPLATE_DECL, not
3114 the specialization of it. */
3116 {
3121 {
3122 tree parm;
3126 /* We want to use the argument list specified in the
3127 definition, not in the original declaration. */
3132 }
3135 }
3137 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3143 /* Inherit default function arguments from the template
3144 DECL is specializing. */
3148 /* This specialization has the same protection as the
3149 template it specializes. */
3153 /* 7.1.1-1 [dcl.stc]
3155 A storage-class-specifier shall not be specified in an
3156 explicit specialization...
3158 The parser rejects these, so unless action is taken here,
3159 explicit function specializations will always appear with
3160 global linkage.
3162 The action recommended by the C++ CWG in response to C++
3163 defect report 605 is to make the storage class and linkage
3164 of the explicit specialization match the templated function:
3166 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3167 */
3169 {
3173 /* A concept cannot be specialized. */
3175 {
3177 gen_tmpl);
3179 }
3181 /* This specialization has the same linkage and visibility as
3182 the function template it specializes. */
3185 {
3188 }
3191 {
3194 }
3195 }
3197 /* If DECL is a friend declaration, declared using an
3198 unqualified name, the namespace associated with DECL may
3199 have been set incorrectly. For example, in:
3201 template <typename T> void f(T);
3202 namespace N {
3203 struct S { friend void f<int>(int); }
3204 }
3206 we will have set the DECL_CONTEXT for the friend
3207 declaration to N, rather than to the global namespace. */
3212 /* This is not really a declaration of a specialization.
3213 It's just the name of an instantiation. But, it's not
3214 a request for an instantiation, either. */
3217 /* A specialization is not necessarily COMDAT. */
3223 /* If this is a full specialization, register it so that we can find
3224 it again. Partial specializations will be registered in
3225 process_partial_specialization. */
3227 {
3232 }
3235 /* A 'structor should already have clones. */
3241 }
3242 }
3245 }
3247 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3248 parameters. These are represented in the same format used for
3249 DECL_TEMPLATE_PARMS. */
3251 int
3253 {
3254 const_tree p1;
3255 const_tree p2;
3263 {
3275 {
3279 /* If either of the template parameters are invalid, assume
3280 they match for the sake of error recovery. */
3293 }
3294 }
3297 /* One set of parameters has more parameters lists than the
3298 other. */
3302 }
3304 /* Determine whether PARM is a parameter pack. */
3306 bool
3308 {
3309 /* Determine if we have a non-type template parameter pack. */
3316 /* If this is a list of template parameters, we could get a
3317 TYPE_DECL or a TEMPLATE_DECL. */
3321 /* Otherwise it must be a type template parameter. */
3325 }
3327 /* Determine if T is a function parameter pack. */
3329 bool
3331 {
3335 }
3337 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3338 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3340 tree
3342 {
3349 }
3351 /* Return true iff the function parameter PARAM_DECL was expanded
3352 from the function parameter pack PACK. */
3354 bool
3356 {
3361 /* The parameter pack and its pack arguments have the same
3362 DECL_PARM_INDEX. */
3364 }
3366 /* Determine whether ARGS describes a variadic template args list,
3367 i.e., one that is terminated by a template argument pack. */
3369 static bool
3371 {
3373 tree last_parm;
3387 }
3389 /* Generate a new name for the parameter pack name NAME (an
3390 IDENTIFIER_NODE) that incorporates its */
3392 static tree
3394 {
3395 /* Munge the name to include the parameter index. */
3396 #define NUMBUF_LEN 128
3410 }
3412 /* Return true if T is a primary function, class or alias template
3413 specialization, not including the template pattern. */
3415 bool
3417 {
3433 }
3435 /* Return true if PARM is a template template parameter. */
3437 bool
3439 {
3441 }
3443 /* Return true iff PARM is a DECL representing a type template
3444 parameter. */
3446 bool
3448 {
3453 }
3455 /* Return the template parameters of T if T is a
3456 primary template instantiation, NULL otherwise. */
3458 tree
3460 {
3465 parms = INNERMOST_TEMPLATE_PARMS
3469 }
3471 /* Return the template parameters of the LEVELth level from the full list
3472 of template parameters PARMS. */
3474 tree
3476 {
3477 tree p;
3488 }
3490 /* Returns the template arguments of T if T is a template instantiation,
3491 NULL otherwise. */
3493 tree
3495 {
3503 }
3505 /* Return the argument pack elements of T if T is a template argument pack,
3506 NULL otherwise. */
3508 tree
3510 {
3516 }
3518 /* In an ARGUMENT_PACK_SELECT, the actual underlying argument that the
3519 ARGUMENT_PACK_SELECT represents. */
3521 static tree
3523 {
3527 /* If the selected argument is an expansion E, that most likely means we were
3528 called from gen_elem_of_pack_expansion_instantiation during the
3529 substituting of an argument pack (of which the Ith element is a pack
3530 expansion, where I is ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
3531 In this case, the Ith element resulting from this substituting is going to
3532 be a pack expansion, which pattern is the pattern of E. Let's return the
3533 pattern of E, and gen_elem_of_pack_expansion_instantiation will build the
3534 resulting pack expansion from it. */
3536 {
3537 /* Make sure we aren't throwing away arg info. */
3540 }
3543 }
3546 /* True iff FN is a function representing a built-in variadic parameter
3547 pack. */
3549 bool
3551 {
3561 }
3563 /* True iff CALL is a call to a function representing a built-in variadic
3564 parameter pack. */
3566 static bool
3568 {
3572 }
3574 /* Return a TREE_VEC for the expansion of __integer_pack(HI). */
3576 static tree
3578 tree in_decl)
3579 {
3585 {
3587 {
3590 }
3595 }
3596 else
3597 {
3601 /* Calculate the largest value of len that won't make the size of the vec
3602 overflow an int. The compiler will exceed resource limits long before
3603 this, but it seems a decent place to diagnose. */
3607 {
3611 max);
3613 }
3621 }
3622 }
3624 /* Return a TREE_VEC for the expansion of built-in template parameter pack
3625 CALL. */
3627 static tree
3629 tree in_decl)
3630 {
3640 }
3642 /* Structure used to track the progress of find_parameter_packs_r. */
3643 struct find_parameter_pack_data
3644 {
3645 /* TREE_LIST that will contain all of the parameter packs found by
3646 the traversal. */
3649 /* Set of AST nodes that have been visited by the traversal. */
3652 /* True iff we're making a type pack expansion. */
3654 };
3656 /* Identifies all of the argument packs that occur in a template
3657 argument and appends them to the TREE_LIST inside DATA, which is a
3658 find_parameter_pack_data structure. This is a subroutine of
3659 make_pack_expansion and uses_parameter_packs. */
3660 static tree
3662 {
3668 /* Handle type aliases/typedefs. */
3670 {
3677 }
3679 /* Identify whether this is a parameter pack or not. */
3681 {
3689 /* FALLTHRU */
3691 /* If the placeholder appears in the decl-specifier-seq of a function
3692 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3693 is a pack expansion, the invented template parameter is a template
3694 parameter pack. */
3704 {
3705 /* We don't want to walk into the type of a PARM_DECL,
3706 because we don't want to see the type parameter pack. */
3709 }
3714 {
3715 /* We don't want to walk into the type of a variadic capture proxy,
3716 because we don't want to see the type parameter pack. */
3719 }
3721 {
3723 find_parameter_packs_r,
3726 }
3738 /* Not a parameter pack. */
3740 }
3743 {
3744 /* Add this parameter pack to the list. */
3746 }
3752 /* This switch statement will return immediately if we don't find a
3753 parameter pack. */
3755 {
3760 /* Check the template itself. */
3763 /* Check the template arguments. */
3777 /* Ignore the declaration of a capture proxy for a parameter pack. */
3785 /* Fall through. */
3830 {
3831 /* Look at explicit captures. */
3836 /* Since we defer implicit capture, look in the parms and body. */
3844 }
3847 {
3848 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3849 type_pack_expansion_p to false so that any placeholders
3850 within the expression don't get marked as parameter packs. */
3858 }
3867 /* Don't walk into IF_STMT_EXTRA_ARGS. */
3873 }
3876 }
3878 /* Determines if the expression or type T uses any parameter packs. */
3879 bool
3881 {
3890 }
3892 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3893 representation a base-class initializer into a parameter pack
3894 expansion. If all goes well, the resulting node will be an
3895 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3896 respectively. */
3897 tree
3899 {
3900 tree result;
3909 {
3910 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3911 class initializer. In this case, the TREE_PURPOSE will be a
3912 _TYPE node (representing the base class expansion we're
3913 initializing) and the TREE_VALUE will be a TREE_LIST
3914 containing the initialization arguments.
3916 The resulting expansion looks somewhat different from most
3917 expansions. Rather than returning just one _EXPANSION, we
3918 return a TREE_LIST whose TREE_PURPOSE is a
3919 TYPE_PACK_EXPANSION containing the bases that will be
3920 initialized. The TREE_VALUE will be identical to the
3921 original TREE_VALUE, which is a list of arguments that will
3922 be passed to each base. We do not introduce any new pack
3923 expansion nodes into the TREE_VALUE (although it is possible
3924 that some already exist), because the TREE_PURPOSE and
3925 TREE_VALUE all need to be expanded together with the same
3926 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3927 resulting TREE_PURPOSE will mention the parameter packs in
3928 both the bases and the arguments to the bases. */
3929 tree purpose;
3930 tree value;
3933 /* Determine which parameter packs will be used by the base
3934 class expansion. */
3943 {
3946 arg);
3949 }
3952 {
3953 /* Collect the sets of parameter packs used in each of the
3954 initialization arguments. */
3956 {
3957 /* Determine which parameter packs will be expanded in this
3958 argument. */
3961 }
3962 }
3966 /* Create the pack expansion type for the base type. */
3972 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3973 they will rarely be compared to anything. */
3977 }
3982 /* Build the PACK_EXPANSION_* node. */
3983 result = for_types
3988 {
3989 /* Propagate type and const-expression information. */
3992 /* Mark this read now, since the expansion might be length 0. */
3994 }
3995 else
3996 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3997 they will rarely be compared to anything. */
4000 /* Determine which parameter packs will be expanded. */
4007 /* Make sure we found some parameter packs. */
4009 {
4011 {
4014 else
4016 }
4018 }
4024 }
4026 /* Checks T for any "bare" parameter packs, which have not yet been
4027 expanded, and issues an error if any are found. This operation can
4028 only be done on full expressions or types (e.g., an expression
4029 statement, "if" condition, etc.), because we could have expressions like:
4031 foo(f(g(h(args)))...)
4033 where "args" is a parameter pack. check_for_bare_parameter_packs
4034 should not be called for the subexpressions args, h(args),
4035 g(h(args)), or f(g(h(args))), because we would produce erroneous
4036 error messages.
4038 Returns TRUE and emits an error if there were bare parameter packs,
4039 returns FALSE otherwise. */
4040 bool
4042 {
4049 /* A lambda might use a parameter pack from the containing context. */
4064 {
4069 {
4080 else
4085 else
4089 }
4092 }
4095 }
4097 /* Expand any parameter packs that occur in the template arguments in
4098 ARGS. */
4099 tree
4101 {
4110 /* First, determine if we need to expand anything, and the number of
4111 slots we'll need. */
4113 {
4118 {
4122 else
4124 }
4125 else
4126 {
4128 num_result_args++;
4129 }
4130 }
4132 /* If no expansion is necessary, we're done. */
4136 /* Expand arguments. */
4139 non_default_args_count =
4142 {
4145 {
4152 }
4153 else
4154 {
4157 }
4158 }
4162 }
4164 /* Checks if DECL shadows a template parameter.
4166 [temp.local]: A template-parameter shall not be redeclared within its
4167 scope (including nested scopes).
4169 Emits an error and returns TRUE if the DECL shadows a parameter,
4170 returns FALSE otherwise. */
4172 bool
4174 {
4175 tree olddecl;
4177 /* If we're not in a template, we can't possibly shadow a template
4178 parameter. */
4182 /* Figure out what we're shadowing. */
4186 /* If there's no previous binding for this name, we're not shadowing
4187 anything, let alone a template parameter. */
4191 /* If we're not shadowing a template parameter, we're done. Note
4192 that OLDDECL might be an OVERLOAD (or perhaps even an
4193 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4194 node. */
4198 /* We check for decl != olddecl to avoid bogus errors for using a
4199 name inside a class. We check TPFI to avoid duplicate errors for
4200 inline member templates. */
4206 /* Don't complain about the injected class name, as we've already
4207 complained about the class itself. */
4214 else
4219 }
4221 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4222 ORIG_LEVEL, DECL, and TYPE. */
4224 static tree
4228 tree decl,
4229 tree type)
4230 {
4241 }
4243 /* Find the canonical type parameter for the given template type
4244 parameter. Returns the canonical type parameter, which may be TYPE
4245 if no such parameter existed. */
4247 static tree
4249 {
4250 tree list;
4264 else
4265 {
4269 }
4270 }
4272 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4273 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4274 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4275 new one is created. */
4277 static tree
4279 tsubst_flags_t complain)
4280 {
4285 {
4304 /* Template template parameters need this. */
4306 {
4313 }
4314 }
4317 }
4319 /* Process information from new template parameter PARM and append it
4320 to the LIST being built. This new parameter is a non-type
4321 parameter iff IS_NON_TYPE is true. This new parameter is a
4322 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4323 is in PARM_LOC. */
4325 tree
4328 {
4337 {
4341 {
4345 else
4347 }
4350 }
4353 {
4359 {
4360 /* [temp.param]
4362 The top-level cv-qualifiers on the template-parameter are
4363 ignored when determining its type. */
4368 && !is_parameter_pack
4369 /* If we're in a nested template parameter list, the template
4370 template parameter could be a parameter pack. */
4372 {
4373 /* This template parameter is not a parameter pack, but it
4374 should be. Complain about "bare" parameter packs. */
4377 /* Recover by calling this a parameter pack. */
4379 }
4380 }
4382 /* A template parameter is not modifiable. */
4391 processing_template_decl,
4396 }
4397 else
4398 {
4399 tree t;
4403 {
4405 /* This is for distinguishing between real templates and template
4406 template parameters */
4410 }
4411 else
4412 {
4414 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4417 }
4424 processing_template_decl,
4428 }
4432 /* Build requirements for the type/template parameter.
4433 This must be done after SET_DECL_TEMPLATE_PARM_P or
4434 process_template_parm could fail. */
4441 /* Build the parameter node linking the parameter declaration,
4442 its default argument (if any), and its constraints (if any). */
4447 }
4449 /* The end of a template parameter list has been reached. Process the
4450 tree list into a parameter vector, converting each parameter into a more
4451 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4452 as PARM_DECLs. */
4454 tree
4456 {
4461 /* Pop the dummy parameter level and add the real one. */
4464 current_template_parms
4469 {
4473 }
4478 }
4480 // Explicitly indicate the end of the template parameter list. We assume
4481 // that the current template parameters have been constructed and/or
4482 // managed explicitly, as when creating new template template parameters
4483 // from a shorthand constraint.
4484 void
4486 {
4488 }
4490 /* end_template_decl is called after a template declaration is seen. */
4492 void
4494 {
4500 /* This matches the pushlevel in begin_template_parm_list. */
4505 }
4507 /* Takes a TREE_LIST representing a template parameter and convert it
4508 into an argument suitable to be passed to the type substitution
4509 functions. Note that If the TREE_LIST contains an error_mark
4510 node, the returned argument is error_mark_node. */
4512 tree
4514 {
4527 {
4531 {
4532 /* Turn this argument into a TYPE_ARGUMENT_PACK
4533 with a single element, which expands T. */
4542 }
4543 }
4544 else
4545 {
4549 {
4550 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4551 with a single element, which expands T. */
4561 }
4562 else
4564 }
4566 }
4568 /* Given a single level of template parameters (a TREE_VEC), return it
4569 as a set of template arguments. */
4571 static tree
4573 {
4583 }
4585 /* Given a set of template parameters, return them as a set of template
4586 arguments. The template parameters are represented as a TREE_VEC, in
4587 the form documented in cp-tree.h for template arguments. */
4589 static tree
4591 {
4592 tree header;
4597 /* If there is only one level of template parameters, we do not
4598 create a TREE_VEC of TREE_VECs. Instead, we return a single
4599 TREE_VEC containing the arguments. */
4604 {
4609 else
4611 }
4614 }
4616 /* Within the declaration of a template, return the currently active
4617 template parameters as an argument TREE_VEC. */
4619 static tree
4621 {
4623 }
4625 /* Update the declared TYPE by doing any lookups which were thought to be
4626 dependent, but are not now that we know the SCOPE of the declarator. */
4628 tree
4630 {
4641 /* Don't bother building up the args in this case. */
4643 {
4644 /* tsubst in the args corresponding to the template parameters,
4645 including auto if present. Most things will be unchanged, but
4646 make_typename_type and tsubst_qualified_id will resolve
4647 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4650 tree pushed;
4652 {
4656 }
4661 }
4667 {
4670 else
4672 }
4674 }
4676 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4677 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4678 the new template is a member template. */
4680 static tree
4682 {
4691 }
4693 struct template_parm_data
4694 {
4695 /* The level of the template parameters we are currently
4696 processing. */
4699 /* The index of the specialization argument we are currently
4700 processing. */
4703 /* An array whose size is the number of template parameters. The
4704 elements are nonzero if the parameter has been used in any one
4705 of the arguments processed so far. */
4708 /* An array whose size is the number of template arguments. The
4709 elements are nonzero if the argument makes use of template
4710 parameters of this level. */
4712 };
4714 /* Subroutine of push_template_decl used to see if each template
4715 parameter in a partial specialization is used in the explicit
4716 argument list. If T is of the LEVEL given in DATA (which is
4717 treated as a template_parm_data*), then DATA->PARMS is marked
4718 appropriately. */
4720 static int
4722 {
4730 {
4733 }
4735 /* In C++17 the type of a non-type argument is a deduced context. */
4740 data,
4741 NULL,
4744 /* Return zero so that for_each_template_parm will continue the
4745 traversal of the tree; we want to mark *every* template parm. */
4747 }
4749 /* Process the partial specialization DECL. */
4751 static tree
4753 {
4760 tree inner_parms;
4761 tree inst;
4771 /* A concept cannot be specialized. */
4773 {
4776 }
4781 /* We check that each of the template parameters given in the
4782 partial specialization is used in the argument list to the
4783 specialization. For example:
4785 template <class T> struct S;
4786 template <class T> struct S<T*>;
4788 The second declaration is OK because `T*' uses the template
4789 parameter T, whereas
4791 template <class T> struct S<int>;
4793 is no good. Even trickier is:
4795 template <class T>
4796 struct S1
4797 {
4798 template <class U>
4799 struct S2;
4800 template <class U>
4801 struct S2<T>;
4802 };
4804 The S2<T> declaration is actually invalid; it is a
4805 full-specialization. Of course,
4807 template <class U>
4808 struct S2<T (*)(U)>;
4810 or some such would have been OK. */
4818 {
4823 NULL,
4825 }
4828 {
4829 /* One of the template parms was not used in a deduced context in the
4830 specialization. */
4832 {
4836 }
4840 }
4845 /* [temp.class.spec]
4847 The argument list of the specialization shall not be identical to
4848 the implicit argument list of the primary template. */
4849 tree main_args
4852 && (!flag_concepts
4855 {
4858 "any template arguments; to define the primary template, "
4860 else
4862 "template arguments and is not more constrained than "
4863 "the primary template; to define the primary template, "
4866 }
4868 /* A partial specialization that replaces multiple parameters of the
4869 primary template with a pack expansion is less specialized for those
4870 parameters. */
4872 {
4874 "primary template because it replaces multiple parameters "
4877 /* Avoid crash in process_partial_specialization. */
4879 }
4881 /* If we aren't in a dependent class, we can actually try deduction. */
4883 /* FIXME we should be able to handle a partial specialization of a
4884 partial instantiation, but currently we can't (c++/41727). */
4887 {
4888 auto_diagnostic_group d;
4892 maintmpl);
4893 }
4895 /* [temp.class.spec]
4897 A partially specialized non-type argument expression shall not
4898 involve template parameters of the partial specialization except
4899 when the argument expression is a simple identifier.
4901 The type of a template parameter corresponding to a specialized
4902 non-type argument shall not be dependent on a parameter of the
4903 specialization.
4905 Also, we verify that pack expansions only occur at the
4906 end of the argument list. */
4910 {
4917 {
4918 /* Extract the arguments from the argument pack. We'll be
4919 iterating over these in the following loop. */
4922 }
4925 {
4927 /* Get the Jth argument in the parameter pack. */
4931 {
4932 /* Pack expansions must come at the end of the
4933 argument list. */
4936 {
4940 else
4943 }
4944 }
4947 /* We only care about the pattern. */
4953 /* This next two lines are the `argument expression is not just a
4954 simple identifier' condition and also the `specialized
4955 non-type argument' bit. */
4959 {
4963 arg);
4964 else
4965 {
4966 /* Look at the corresponding template parameter,
4967 marking which template parameters its type depends
4968 upon. */
4972 {
4973 /* We haven't yet initialized TPD2. Do so now. */
4975 /* The number of parameters here is the number in the
4976 main template, which, as checked in the assertion
4977 above, is NARGS. */
4981 }
4983 /* Mark the template parameters. But this time, we're
4984 looking for the template parameters of the main
4985 template, not in the specialization. */
4992 NULL,
4996 {
4997 /* The type depended on some template parameters.
4998 If they are fully specialized in the
4999 specialization, that's OK. */
5008 "type %qT of template argument %qE depends "
5010 "type %qT of template argument %qE depends "
5012 type,
5013 arg);
5014 }
5015 }
5016 }
5017 }
5018 }
5020 /* We should only get here once. */
5024 // Build the template decl.
5033 /* Give template template parms a DECL_CONTEXT of the template
5034 for which they are a parameter. */
5036 {
5040 }
5043 /* We didn't register this in check_explicit_specialization so we could
5044 wait until the constraints were set. */
5046 else
5056 {
5062 {
5070 "declaration of %qD ambiguates earlier template "
5074 "partial specialization of %qD after instantiation "
5076 }
5077 }
5080 }
5082 /* PARM is a template parameter of some form; return the corresponding
5083 TEMPLATE_PARM_INDEX. */
5085 static tree
5087 {
5100 }
5102 /* Subroutine of fixed_parameter_pack_p below. Look for any template
5103 parameter packs used by the template parameter PARM. */
5105 static void
5107 {
5108 /* A type parm can't refer to another parm. */
5112 {
5116 }
5122 {
5126 else
5128 }
5129 }
5131 /* PARM is a template parameter pack. Return any parameter packs used in
5132 its type or the type of any of its template parameters. If there are
5133 any such packs, it will be instantiated into a fixed template parameter
5134 list by partial instantiation rather than be fully deduced. */
5136 tree
5138 {
5139 /* This can only be true in a member template. */
5142 /* This can only be true for a parameter pack. */
5145 /* A type parm can't refer to another parm. */
5159 }
5161 /* Check that a template declaration's use of default arguments and
5162 parameter packs is not invalid. Here, PARMS are the template
5163 parameters. IS_PRIMARY is true if DECL is the thing declared by
5164 a primary template. IS_PARTIAL is true if DECL is a partial
5165 specialization.
5167 IS_FRIEND_DECL is nonzero if DECL is either a non-defining friend
5168 function template declaration or a friend class template
5169 declaration. In the function case, 1 indicates a declaration, 2
5170 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
5171 emitted for extraneous default arguments.
5173 Returns TRUE if there were no errors found, FALSE otherwise. */
5175 bool
5178 {
5181 tree parm_level;
5184 /* [temp.param]
5186 A default template-argument shall not be specified in a
5187 function template declaration or a function template definition, nor
5188 in the template-parameter-list of the definition of a member of a
5189 class template. */
5193 /* You can't have a function template declaration in a local
5194 scope, nor you can you define a member of a class template in a
5195 local scope. */
5203 /* A lambda doesn't have an explicit declaration; don't complain
5204 about the parms of the enclosing class. */
5211 /* If this is either a friend defined in the scope of the class
5212 or a member function. */
5218 /* And, if it was a member function, it really was defined in
5219 the scope of the class. */
5222 /* We already checked these parameters when the template was
5223 declared, so there's no need to do it again now. This function
5224 was defined in class scope, but we're processing its body now
5225 that the class is complete. */
5228 /* Core issue 226 (C++0x only): the following only applies to class
5229 templates. */
5232 {
5233 /* [temp.param]
5235 If a template-parameter has a default template-argument, all
5236 subsequent template-parameters shall have a default
5237 template-argument supplied. */
5239 {
5246 {
5256 {
5258 /* For better subsequent error-recovery, we indicate that
5259 there should have been a default argument. */
5262 }
5264 && !is_friend_decl
5265 /* Don't complain about an enclosing partial
5266 specialization. */
5271 /* A fixed parameter pack will be partially
5272 instantiated into a fixed length list. */
5274 {
5275 /* A primary class template can only have one
5276 parameter pack, at the end of the template
5277 parameter list. */
5285 }
5286 }
5287 }
5288 }
5291 || is_partial
5292 || !is_primary
5294 /* For an ordinary class template, default template arguments are
5295 allowed at the innermost level, e.g.:
5296 template <class T = int>
5297 struct S {};
5298 but, in a partial specialization, they're not allowed even
5299 there, as we have in [temp.class.spec]:
5301 The template parameter list of a specialization shall not
5302 contain default template argument values.
5304 So, for a partial specialization, or for a function template
5305 (in C++98/C++03), we look at all of them. */
5306 ;
5307 else
5308 /* But, for a primary class template that is not a partial
5309 specialization we look at all template parameters except the
5310 innermost ones. */
5313 /* Figure out what error message to issue. */
5328 else
5329 /* Per [temp.param]/9, "A default template-argument shall not be
5330 specified in the template-parameter-lists of the definition of
5331 a member of a class template that appears outside of the member's
5332 class.", thus if we aren't handling a member of a class template
5333 there is no need to examine the parameters. */
5337 /* If we're inside a class definition, there's no need to
5338 examine the parameters to the class itself. On the one
5339 hand, they will be checked when the class is defined, and,
5340 on the other, default arguments are valid in things like:
5341 template <class T = double>
5342 struct S { template <class U> void f(U); };
5343 Here the default argument for `S' has no bearing on the
5344 declaration of `f'. */
5346 else
5347 /* Check everything. */
5353 {
5360 {
5365 {
5367 {
5374 }
5376 /* Clear out the default argument so that we are not
5377 confused later. */
5379 }
5380 }
5382 /* At this point, if we're still interested in issuing messages,
5383 they must apply to classes surrounding the object declared. */
5387 }
5390 }
5392 /* Worker for push_template_decl_real, called via
5393 for_each_template_parm. DATA is really an int, indicating the
5394 level of the parameters we are interested in. If T is a template
5395 parameter of that level, return nonzero. */
5397 static int
5399 {
5405 else
5408 }
5410 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5411 DATA is really an int, indicating the innermost outer level of parameters.
5412 If T is a template parameter of that level or further out, return
5413 nonzero. */
5415 static int
5417 {
5423 else
5426 }
5428 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5429 parameters given by current_template_args, or reuses a
5430 previously existing one, if appropriate. Returns the DECL, or an
5431 equivalent one, if it is replaced via a call to duplicate_decls.
5433 If IS_FRIEND is true, DECL is a friend declaration. */
5435 tree
5437 {
5438 tree tmpl;
5439 tree args;
5440 tree info;
5441 tree ctx;
5445 /* True if the template is a member template, in the sense of
5446 [temp.mem]. */
5452 /* See if this is a partial specialization. */
5465 /* For a friend, we want the context of the friend, not
5466 the type of which it is a friend. */
5470 /* In the case of a virtual function, we want the class in which
5471 it is defined. */
5473 else
5474 /* Otherwise, if we're currently defining some class, the DECL
5475 is assumed to be a member of the class. */
5484 /* See if this is a primary template. */
5487 /* A friend template that specifies a class context, i.e.
5488 template <typename T> friend void A<T>::f();
5489 is not primary. */
5494 else
5498 {
5505 {
5508 }
5510 {
5512 {
5515 }
5517 {
5518 /* [temp.mem]
5520 A destructor shall not be a member template. */
5523 }
5530 {
5531 /* [basic.stc.dynamic.allocation]
5533 An allocation function can be a function
5534 template. ... Template allocation functions shall
5535 have two or more parameters. */
5538 }
5539 }
5542 {
5543 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5546 {
5552 }
5553 }
5556 /* alias-declaration */
5560 else
5561 {
5564 }
5565 }
5567 /* Check to see that the rules regarding the use of default
5568 arguments are not being violated. We check args for a friend
5569 functions when we know whether it's a definition, introducing
5570 declaration or re-declaration. */
5575 /* Ensure that there are no parameter packs in the type of this
5576 declaration that have not been expanded. */
5578 {
5579 /* Check each of the arguments individually to see if there are
5580 any bare parameter packs. */
5586 {
5589 {
5590 /* This is a PARM_DECL that contains unexpanded parameter
5591 packs. We have already complained about this in the
5592 check_for_bare_parameter_packs call, so just replace
5593 these types with ERROR_MARK_NODE. */
5596 }
5600 }
5602 /* Check for bare parameter packs in the return type and the
5603 exception specifiers. */
5605 /* Errors were already issued, set return type to int
5606 as the frontend doesn't expect error_mark_node as
5607 the return type. */
5611 }
5616 {
5619 }
5632 {
5637 /* If DECL is a TYPE_DECL for a class-template, then there won't
5638 be DECL_LANG_SPECIFIC. The information equivalent to
5639 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5643 {
5644 /* Since a template declaration already existed for this
5645 class-type, we must be redeclaring it here. Make sure
5646 that the redeclaration is valid. */
5648 current_template_parms,
5650 /* We don't need to create a new TEMPLATE_DECL; just use the
5651 one we already had. */
5653 }
5654 else
5655 {
5657 member_template_p);
5662 {
5663 /* A specialization of a member template of a template
5664 class. */
5668 }
5669 }
5670 }
5671 else
5672 {
5678 {
5681 }
5689 {
5690 tree new_tmpl;
5692 /* The declaration is a specialization of a member
5693 template, declared outside the class. Therefore, the
5694 innermost template arguments will be NULL, so we
5695 replace them with the arguments determined by the
5696 earlier call to check_explicit_specialization. */
5699 new_tmpl
5701 member_template_p);
5711 args,
5714 }
5716 /* Make sure the template headers we got make sense. */
5721 {
5726 }
5727 else
5729 {
5734 {
5738 else
5742 /* Avoid crash in import_export_decl. */
5745 }
5750 /* Can happen in erroneous input. */
5752 else
5754 }
5756 /* Check that the parms are used in the appropriate qualifying scopes
5757 in the declarator. */
5761 {
5767 /* Avoid crash in import_export_decl. */
5770 }
5771 }
5776 /* Push template declarations for global functions and types. Note
5777 that we do not try to push a global template friend declared in a
5778 template class; such a thing may well depend on the template
5779 parameters of the class. */
5782 {
5787 /* Hide template friend classes that haven't been declared yet. */
5789 {
5792 }
5793 }
5796 {
5801 /* Give template template parms a DECL_CONTEXT of the template
5802 for which they are a parameter. */
5805 {
5809 }
5815 }
5817 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5818 back to its most general template. If TMPL is a specialization,
5819 ARGS may only have the innermost set of arguments. Add the missing
5820 argument levels if necessary. */
5828 else
5829 {
5834 }
5837 && !is_friend
5840 /* Set DECL_COMDAT on template instantiations; if we force
5841 them to be emitted by explicit instantiation or -frepo,
5842 mark_needed will tell cgraph to do the right thing. */
5846 }
5848 tree
5850 {
5852 }
5854 /* FN is an inheriting constructor that inherits from the constructor
5855 template INHERITED; turn FN into a constructor template with a matching
5856 template header. */
5858 tree
5860 {
5861 tree inner_parms
5864 tree parms
5875 }
5877 /* Called when a class template TYPE is redeclared with the indicated
5878 template PARMS, e.g.:
5880 template <class T> struct S;
5881 template <class T> struct S {}; */
5883 bool
5885 {
5886 tree tmpl;
5887 tree tmpl_parms;
5891 {
5894 }
5898 /* The type is nested in some template class. Nothing to worry
5899 about here; there are no new template parameters for the nested
5900 type. */
5904 {
5906 tmpl);
5908 }
5914 {
5924 }
5927 {
5928 tree tmpl_parm;
5929 tree parm;
5930 tree tmpl_default;
5931 tree parm_default;
5945 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5946 TEMPLATE_DECL. */
5956 {
5960 }
5963 {
5964 /* We have in [temp.param]:
5966 A template-parameter may not be given default arguments
5967 by two different declarations in the same scope. */
5972 }
5975 /* Update the previous template parameters (which are the ones
5976 that will really count) with the new default value. */
5979 /* Update the new parameters, too; they'll be used as the
5980 parameters for any members. */
5983 /* Give each template template parm in this redeclaration a
5984 DECL_CONTEXT of the template for which they are a parameter. */
5986 {
5989 }
5993 }
5995 // Cannot redeclare a class template with a different set of constraints.
5997 {
6002 }
6005 }
6007 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
6008 to be used when the caller has already checked
6009 (processing_template_decl
6010 && !instantiation_dependent_expression_p (expr)
6011 && potential_constant_expression (expr))
6012 and cleared processing_template_decl. */
6014 tree
6016 {
6019 complain,
6023 }
6025 /* Simplify EXPR if it is a non-dependent expression. Returns the
6026 (possibly simplified) expression. */
6028 tree
6030 {
6034 /* If we're in a template, but EXPR isn't value dependent, simplify
6035 it. We're supposed to treat:
6037 template <typename T> void f(T[1 + 1]);
6038 template <typename T> void f(T[2]);
6040 as two declarations of the same function, for example. */
6043 {
6044 processing_template_decl_sentinel s;
6046 }
6048 }
6050 tree
6052 {
6054 }
6056 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
6057 an uninstantiated expression. */
6059 tree
6061 {
6065 {
6068 else
6069 {
6070 processing_template_decl_sentinel s;
6072 }
6073 }
6075 }
6077 /* True iff T is a specialization of a variable template. */
6079 bool
6081 {
6086 }
6088 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
6089 template declaration, or a TYPE_DECL for an alias declaration. */
6091 bool
6093 {
6101 }
6103 /* Return TRUE iff T is a specialization of an alias template. */
6105 bool
6107 {
6108 /* It's an alias template specialization if it's an alias and its
6109 TYPE_NAME is a specialization of a primary template. */
6115 }
6117 /* An alias template is complex from a SFINAE perspective if a template-id
6118 using that alias can be ill-formed when the expansion is not, as with
6119 the void_t template. We determine this by checking whether the
6120 expansion for the alias template uses all its template parameters. */
6122 struct uses_all_template_parms_data
6123 {
6126 };
6128 static int
6130 {
6138 }
6140 static bool
6142 {
6157 }
6159 /* Return TRUE iff T is a specialization of a complex alias template with
6160 dependent template-arguments. */
6162 bool
6164 {
6177 }
6179 /* Return the number of innermost template parameters in TMPL. */
6181 static int
6183 {
6186 }
6188 /* Return either TMPL or another template that it is equivalent to under DR
6189 1286: An alias that just changes the name of a template is equivalent to
6190 the other template. */
6192 static tree
6194 {
6197 {
6198 /* Determine if the alias is equivalent to an underlying template. */
6210 tree alias_args = INNERMOST_TEMPLATE_ARGS
6215 /* Alias is equivalent. Strip it and repeat. */
6217 }
6220 }
6222 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6223 must be a reference-to-function or a pointer-to-function type, as specified
6224 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6225 and check that the resulting function has external linkage. */
6227 static tree
6229 tsubst_flags_t complain)
6230 {
6233 linkage_kind linkage;
6248 /* [temp.arg.nontype]/1
6250 A template-argument for a non-type, non-template template-parameter
6251 shall be one of:
6252 [...]
6253 -- the address of an object or function with external [C++11: or
6254 internal] linkage. */
6258 {
6260 {
6266 else
6269 }
6271 }
6275 {
6277 {
6282 else
6286 }
6288 }
6290 accept:
6292 {
6295 else
6297 }
6302 }
6304 /* Subroutine of convert_nontype_argument.
6305 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6306 Emit an error otherwise. */
6308 static bool
6310 tsubst_flags_t complain)
6311 {
6328 {
6333 else
6335 }
6337 }
6339 /* Returns TRUE iff the address of OP is value-dependent.
6341 14.6.2.4 [temp.dep.temp]:
6342 A non-integral non-type template-argument is dependent if its type is
6343 dependent or it has either of the following forms
6344 qualified-id
6345 & qualified-id
6346 and contains a nested-name-specifier which specifies a class-name that
6347 names a dependent type.
6349 We generalize this to just say that the address of a member of a
6350 dependent class is value-dependent; the above doesn't cover the
6351 address of a static data member named with an unqualified-id. */
6353 static bool
6355 {
6356 /* We could use get_inner_reference here, but there's no need;
6357 this is only relevant for template non-type arguments, which
6358 can only be expressed as &id-expression. */
6360 {
6364 }
6367 }
6369 /* The next set of functions are used for providing helpful explanatory
6370 diagnostics for failed overload resolution. Their messages should be
6371 indented by two spaces for consistency with the messages in
6372 call.c */
6374 static int
6376 {
6378 }
6380 /* Other failure functions should call this one, to provide a single function
6381 for setting a breakpoint on. */
6383 static int
6385 {
6387 }
6389 static int
6391 {
6396 }
6398 static int
6400 {
6406 }
6408 static int
6410 {
6414 }
6416 static int
6418 {
6421 " template parameter %qD is not a parameter pack, but "
6425 }
6427 static int
6429 {
6432 " template argument %qE does not match "
6436 }
6438 static int
6440 {
6444 }
6446 static int
6448 {
6454 }
6456 static int
6458 {
6460 {
6465 else
6467 " deduced conflicting values for non-type parameter "
6469 }
6471 }
6473 static int
6475 {
6478 " variable-sized array type %qT is not "
6480 arg);
6482 }
6484 static int
6486 {
6490 arg);
6492 }
6494 static int
6496 {
6498 {
6504 else
6509 }
6511 }
6513 static int
6515 {
6517 }
6519 static int
6522 {
6524 }
6526 static int
6529 {
6535 }
6537 static int
6540 {
6543 {
6551 }
6553 }
6555 static int
6557 {
6560 " template parameters of a template template argument are "
6563 }
6565 static int
6567 {
6573 }
6575 static int
6577 {
6582 }
6584 /* True if T is a C++20 template parameter object to store the argument for a
6585 template parameter of class type. */
6587 bool
6589 {
6592 }
6594 /* Subroutine of convert_nontype_argument, to check whether EXPR, as an
6595 argument for TYPE, points to an unsuitable object. */
6597 static bool
6599 {
6601 {
6602 CASE_CONVERT:
6604 complain);
6608 complain);
6611 {
6616 }
6620 {
6624 {
6629 }
6631 {
6637 }
6640 {
6645 }
6646 /* C++17: For a non-type template-parameter of reference or pointer
6647 type, the value of the constant expression shall not refer to (or
6648 for a pointer type, shall not be the address of):
6649 * a subobject (4.5),
6650 * a temporary object (15.2),
6651 * a string literal (5.13.5),
6652 * the result of a typeid expression (8.2.8), or
6653 * a predefined __func__ variable (11.4.1). */
6655 {
6658 decl);
6660 }
6664 {
6669 }
6671 {
6675 decl);
6677 }
6678 }
6686 else
6687 {
6689 {
6692 "because %qD is a variable, not the address of "
6695 }
6696 else
6697 {
6703 }
6704 }
6705 }
6708 }
6710 /* Return a VAR_DECL for the C++20 template parameter object corresponding to
6711 template argument EXPR. */
6713 static tree
6715 {
6720 {
6725 }
6745 }
6747 /* Attempt to convert the non-type template parameter EXPR to the
6748 indicated TYPE. If the conversion is successful, return the
6749 converted value. If the conversion is unsuccessful, return
6750 NULL_TREE if we issued an error message, or error_mark_node if we
6751 did not. We issue error messages for out-and-out bad template
6752 parameters, but not simply because the conversion failed, since we
6753 might be just trying to do argument deduction. Both TYPE and EXPR
6754 must be non-dependent.
6756 The conversion follows the special rules described in
6757 [temp.arg.nontype], and it is much more strict than an implicit
6758 conversion.
6760 This function is called twice for each template argument (see
6761 lookup_template_class for a more accurate description of this
6762 problem). This means that we need to handle expressions which
6763 are not valid in a C++ source, but can be created from the
6764 first call (for instance, casts to perform conversions). These
6765 hacks can go away after we fix the double coercion problem. */
6767 static tree
6769 {
6770 tree expr_type;
6773 /* Detect immediately string literals as invalid non-type argument.
6774 This special-case is not needed for correctness (we would easily
6775 catch this later), but only to provide better diagnostic for this
6776 common user mistake. As suggested by DR 100, we do not mention
6777 linkage issues in the diagnostic as this is not the point. */
6779 {
6785 }
6787 /* Add the ADDR_EXPR now for the benefit of
6788 value_dependent_expression_p. */
6791 {
6795 }
6797 /* If we are in a template, EXPR may be non-dependent, but still
6798 have a syntactic, rather than semantic, form. For example, EXPR
6799 might be a SCOPE_REF, rather than the VAR_DECL to which the
6800 SCOPE_REF refers. Preserving the qualifying scope is necessary
6801 so that access checking can be performed when the template is
6802 instantiated -- but here we need the resolved form so that we can
6803 convert the argument. */
6815 /* If the argument is non-dependent, perform any conversions in
6816 non-dependent context as well. */
6824 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6825 to a non-type argument of "nullptr". */
6829 /* In C++11, integral or enumeration non-type template arguments can be
6830 arbitrary constant expressions. Pointer and pointer to
6831 member arguments can be general constant expressions that evaluate
6832 to a null value, but otherwise still need to be of a specific form. */
6834 {
6836 /* A PTRMEM_CST is already constant, and a valid template
6837 argument for a parameter of pointer to member type, we just want
6838 to leave it in that form rather than lower it to a
6842 {
6843 /* Calling build_converted_constant_expr might create a call to
6844 a conversion function with a value-dependent argument, which
6845 could invoke taking the address of a temporary representing
6846 the result of the conversion. */
6851 {
6855 }
6856 /* C++17: A template-argument for a non-type template-parameter shall
6857 be a converted constant expression (8.20) of the type of the
6858 template-parameter. */
6861 /* Make sure we return NULL_TREE only if we have really issued
6862 an error, as described above. */
6867 }
6869 {
6875 }
6876 }
6880 else
6883 /* HACK: Due to double coercion, we can get a
6884 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6885 which is the tree that we built on the first call (see
6886 below when coercing to reference to object or to reference to
6887 function). We just strip everything and get to the arg.
6888 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6889 for examples. */
6891 {
6897 {
6898 /* ??? Maybe we could use convert_from_reference here, but we
6899 would need to relax its constraints because the NOP_EXPR
6900 could actually change the type to something more cv-qualified,
6901 and this is not folded by convert_from_reference. */
6906 && (same_type_ignoring_top_level_qualifiers_p
6909 {
6912 }
6913 }
6914 }
6916 /* [temp.arg.nontype]/5, bullet 1
6918 For a non-type template-parameter of integral or enumeration type,
6919 integral promotions (_conv.prom_) and integral conversions
6920 (_conv.integral_) are applied. */
6922 {
6924 {
6929 }
6934 /* Notice that there are constant expressions like '4 % 0' which
6935 do not fold into integer constants. */
6938 {
6940 {
6944 else
6950 /* else cxx_constant_value complained but gave us
6951 a real constant, so go ahead. */
6953 {
6954 /* Some assemble time constant expressions like
6955 (intptr_t)&&lab1 - (intptr_t)&&lab2 or
6956 4 + (intptr_t)&&var satisfy reduced_constant_expression_p
6957 as we can emit them into .rodata initializers of
6958 variables, yet they can't fold into an INTEGER_CST at
6959 compile time. Refuse them here. */
6964 }
6965 }
6966 else
6968 }
6970 /* Avoid typedef problems. */
6973 }
6974 /* [temp.arg.nontype]/5, bullet 2
6976 For a non-type template-parameter of type pointer to object,
6977 qualification conversions (_conv.qual_) and the array-to-pointer
6978 conversion (_conv.array_) are applied. */
6980 {
6983 /* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
6984 decay_conversion or an explicit cast. If it's a problematic cast,
6985 we'll complain about it below. */
6987 {
6992 {
6995 }
6996 }
6998 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
7000 A template-argument for a non-type, non-template template-parameter
7001 shall be one of: [...]
7003 -- the name of a non-type template-parameter;
7004 -- the address of an object or function with external linkage, [...]
7005 expressed as "& id-expression" where the & is optional if the name
7006 refers to a function or array, or if the corresponding
7007 template-parameter is a reference.
7009 Here, we do not care about functions, as they are invalid anyway
7010 for a parameter of type pointer-to-object. */
7013 /* Non-type template parameters are OK. */
7014 ;
7019 /* Other values, like integer constants, might be valid
7020 non-type arguments of some other type. */
7030 }
7031 /* [temp.arg.nontype]/5, bullet 3
7033 For a non-type template-parameter of type reference to object, no
7034 conversions apply. The type referred to by the reference may be more
7035 cv-qualified than the (otherwise identical) type of the
7036 template-argument. The template-parameter is bound directly to the
7037 template-argument, which must be an lvalue. */
7039 {
7041 expr_type))
7045 {
7050 }
7053 {
7058 }
7060 /* [temp.arg.nontype]/1
7062 A template-argument for a non-type, non-template template-parameter
7063 shall be one of: [...]
7065 -- the address of an object or function with external linkage. */
7068 {
7071 {
7074 "because a reference variable does not have a constant "
7077 }
7078 }
7082 /* OK, dependent reference. We don't want to ask whether a DECL is
7084 else
7085 {
7090 }
7094 }
7095 /* [temp.arg.nontype]/5, bullet 4
7097 For a non-type template-parameter of type pointer to function, only
7098 the function-to-pointer conversion (_conv.func_) is applied. If the
7099 template-argument represents a set of overloaded functions (or a
7100 pointer to such), the matching function is selected from the set
7101 (_over.over_). */
7103 {
7104 /* If the argument is a template-id, we might not have enough
7105 context information to decay the pointer. */
7107 {
7111 }
7114 /* Null pointer values are OK in C++11. */
7120 }
7121 /* [temp.arg.nontype]/5, bullet 5
7123 For a non-type template-parameter of type reference to function, no
7124 conversions apply. If the template-argument represents a set of
7125 overloaded functions, the matching function is selected from the set
7126 (_over.over_). */
7128 {
7130 {
7132 {
7137 }
7139 }
7144 }
7145 /* [temp.arg.nontype]/5, bullet 6
7147 For a non-type template-parameter of type pointer to member function,
7148 no conversions apply. If the template-argument represents a set of
7149 overloaded member functions, the matching member function is selected
7150 from the set (_over.over_). */
7152 {
7157 /* [temp.arg.nontype] bullet 1 says the pointer to member
7158 expression must be a pointer-to-member constant. */
7163 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
7164 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
7167 }
7168 /* [temp.arg.nontype]/5, bullet 7
7170 For a non-type template-parameter of type pointer to data member,
7171 qualification conversions (_conv.qual_) are applied. */
7173 {
7174 /* [temp.arg.nontype] bullet 1 says the pointer to member
7175 expression must be a pointer-to-member constant. */
7183 }
7185 {
7187 {
7192 }
7194 }
7196 {
7197 /* Replace the argument with a reference to the corresponding template
7198 parameter object. */
7203 }
7204 /* A template non-type parameter must be one of the above. */
7205 else
7208 /* Sanity check: did we actually convert the argument to the
7209 right type? */
7213 }
7215 /* Subroutine of coerce_template_template_parms, which returns 1 if
7216 PARM_PARM and ARG_PARM match using the rule for the template
7217 parameters of template template parameters. Both PARM and ARG are
7218 template parameters; the rest of the arguments are the same as for
7219 coerce_template_template_parms.
7220 */
7221 static int
7223 tree arg,
7224 tsubst_flags_t complain,
7225 tree in_decl,
7226 tree outer_args)
7227 {
7236 {
7238 /* We encounter instantiations of templates like
7239 template <template <template <class> class> class TT>
7240 class C; */
7241 {
7248 }
7249 /* Fall through. */
7254 /* Argument is a parameter pack but parameter is not. */
7259 /* The tsubst call is used to handle cases such as
7261 template <int> class C {};
7262 template <class T, template <T> class TT> class D {};
7263 D<int, C> d;
7265 i.e. the parameter list of TT depends on earlier parameters. */
7267 {
7272 }
7276 /* Argument is a parameter pack but parameter is not. */
7283 }
7286 }
7288 /* Coerce template argument list ARGLIST for use with template
7289 template-parameter TEMPL. */
7291 static tree
7293 tsubst_flags_t complain)
7294 {
7295 /* Consider an example where a template template parameter declared as
7297 template <class T, class U = std::allocator<T> > class TT
7299 The template parameter level of T and U are one level larger than
7300 of TT. To proper process the default argument of U, say when an
7301 instantiation `TT<int>' is seen, we need to build the full
7302 arguments containing {int} as the innermost level. Outer levels,
7303 available when not appearing as default template argument, can be
7304 obtained from the arguments of the enclosing template.
7306 Suppose that TT is later substituted with std::vector. The above
7307 instantiation is `TT<int, std::allocator<T> >' with TT at
7308 level 1, and T at level 2, while the template arguments at level 1
7309 becomes {std::vector} and the inner level 2 is {int}. */
7313 {
7315 /* We want arguments for the partial specialization, not arguments for
7316 the primary template. */
7318 else
7320 }
7322 {
7323 /* This is an argument of the current template, so we haven't set
7324 DECL_CONTEXT yet. */
7325 tree relevant_template_parms;
7327 /* Parameter levels that are greater than the level of the given
7328 template template parm are irrelevant. */
7335 }
7342 complain,
7345 }
7347 /* A cache of template template parameters with match-all default
7348 arguments. */
7350 static void
7352 {
7356 }
7357 static tree
7359 {
7364 }
7366 /* T is a bound template template-parameter. Copy its arguments into default
7367 arguments of the template template-parameter's template parameters. */
7369 static tree
7371 {
7394 {
7397 {
7400 }
7401 }
7405 }
7407 /* ARG is a bound potential template template-argument, and PARGS is a list
7408 of arguments for the corresponding template template-parameter. Adjust
7409 PARGS as appropriate for application to ARG's template, and if ARG is a
7410 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7411 arguments to the template template parameter. */
7413 static tree
7415 {
7419 {
7420 /* When comparing two template template-parameters in partial ordering,
7421 rewrite the one currently being used as an argument to have default
7422 arguments for all parameters. */
7428 }
7429 else
7430 {
7431 tree aparms
7436 }
7439 }
7441 /* Subroutine of unify for the case when PARM is a
7442 BOUND_TEMPLATE_TEMPLATE_PARM. */
7444 static int
7447 {
7451 /* The template template parm might be variadic and the argument
7452 not, so flatten both argument lists. */
7457 {
7458 /* In keeping with P0522R0, adjust P's template arguments
7459 to apply to A's template; then flatten it again. */
7468 /* If the P0522 adjustment eliminated a pack expansion, deduce
7469 empty packs. */
7475 }
7476 else
7477 {
7478 /* Deduce arguments T, i from TT<T> or TT<i>.
7479 We check each element of PARMVEC and ARGVEC individually
7480 rather than the whole TREE_VEC since they can have
7481 different number of elements, which is allowed under N2555. */
7485 /* Check if the parameters end in a pack, making them
7486 variadic. */
7493 /* If the template argument list of P contains a pack
7494 expansion that is not the last template argument, the
7495 entire template argument list is a non-deduced
7496 context. */
7514 DEDUCE_EXACT,
7517 }
7520 }
7522 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7523 template template parameters. Both PARM_PARMS and ARG_PARMS are
7524 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7525 or PARM_DECL.
7527 Consider the example:
7528 template <class T> class A;
7529 template<template <class U> class TT> class B;
7531 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7532 the parameters to A, and OUTER_ARGS contains A. */
7534 static int
7536 tree arg_parms,
7537 tsubst_flags_t complain,
7538 tree in_decl,
7539 tree outer_args)
7540 {
7552 {
7553 /* P0522R0: A template template-parameter P is at least as specialized as
7554 a template template-argument A if, given the following rewrite to two
7555 function templates, the function template corresponding to P is at
7556 least as specialized as the function template corresponding to A
7557 according to the partial ordering rules for function templates
7558 ([temp.func.order]). Given an invented class template X with the
7559 template parameter list of A (including default arguments):
7561 * Each of the two function templates has the same template parameters,
7562 respectively, as P or A.
7564 * Each function template has a single function parameter whose type is
7565 a specialization of X with template arguments corresponding to the
7566 template parameters from the respective function template where, for
7567 each template parameter PP in the template parameter list of the
7568 function template, a corresponding template argument AA is formed. If
7569 PP declares a parameter pack, then AA is the pack expansion
7570 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7572 If the rewrite produces an invalid type, then P is not at least as
7573 specialized as A. */
7575 /* So coerce P's args to apply to A's parms, and then deduce between A's
7576 args and the converted args. If that succeeds, A is at least as
7577 specialized as P, so they match.*/
7585 {
7591 }
7592 }
7594 /* Determine whether we have a parameter pack at the end of the
7595 template template parameter's template parameter list. */
7597 {
7604 {
7618 }
7619 }
7625 /* Check all of the template parameters except the parameter pack at
7626 the end (if any). */
7628 {
7637 outer_args))
7640 }
7643 {
7644 /* Check each of the template parameters in the template
7645 argument against the template parameter pack at the end of
7646 the template template parameter. */
7653 {
7660 outer_args))
7662 }
7663 }
7666 }
7668 /* Verifies that the deduced template arguments (in TARGS) for the
7669 template template parameters (in TPARMS) represent valid bindings,
7670 by comparing the template parameter list of each template argument
7671 to the template parameter list of its corresponding template
7672 template parameter, in accordance with DR150. This
7673 routine can only be called after all template arguments have been
7674 deduced. It will return TRUE if all of the template template
7675 parameter bindings are okay, FALSE otherwise. */
7676 bool
7678 {
7682 /* We're dealing with template parms in this process. */
7688 {
7693 {
7698 {
7699 /* Look inside the argument pack. */
7702 }
7705 {
7709 /* Extract the next argument from the argument
7710 pack. */
7714 /* Look at the pattern of the pack expansion. */
7717 /* Extract the template parameters from the template
7718 argument. */
7724 /* Verify that we can coerce the template template
7725 parameters from the template argument to the template
7726 parameter. This requires an exact match. */
7728 && !coerce_template_template_parms
7730 targ_parms,
7731 tf_none,
7732 tparm,
7733 targs))
7734 {
7737 }
7738 }
7739 }
7740 }
7742 out:
7746 }
7748 /* Since type attributes aren't mangled, we need to strip them from
7749 template type arguments. */
7751 static tree
7753 {
7763 }
7765 /* And from inside dependent non-type arguments like sizeof(Type). */
7767 static tree
7769 {
7779 }
7781 // A template declaration can be substituted for a constrained
7782 // template template parameter only when the argument is more
7783 // constrained than the parameter.
7784 static bool
7786 {
7789 /* For now, allow constrained template template arguments
7790 and unconstrained template template parameters. */
7796 // If the template parameter is constrained, we need to rewrite its
7797 // constraints in terms of the ARG's template parameters. This ensures
7798 // that all of the template parameter types will have the same depth.
7799 //
7800 // Note that this is only valid when coerce_template_template_parm is
7801 // true for the innermost template parameters of PARM and ARG. In other
7802 // words, because coercion is successful, this conversion will be valid.
7804 {
7811 }
7814 }
7816 // Convert a placeholder argument into a binding to the original
7817 // parameter. The original parameter is saved as the TREE_TYPE of
7818 // ARG.
7821 {
7824 }
7826 /* We can't fully resolve ARG given as a non-type template argument to TYPE,
7827 because one of them is dependent. But we need to represent the
7828 conversion for the benefit of cp_tree_equal. */
7830 static tree
7832 {
7833 /* Auto parms get no conversion. */
7836 /* We don't need or want to add this conversion now if we're going to use the
7837 argument for deduction. */
7849 }
7851 /* Convert the indicated template ARG as necessary to match the
7852 indicated template PARM. Returns the converted ARG, or
7853 error_mark_node if the conversion was unsuccessful. Error and
7854 warning messages are issued under control of COMPLAIN. This
7855 conversion is for the Ith parameter in the parameter list. ARGS is
7856 the full set of template arguments deduced so far. */
7858 static tree
7860 tree arg,
7861 tree args,
7862 tsubst_flags_t complain,
7864 tree in_decl)
7865 {
7866 tree orig_arg;
7867 tree val;
7873 /* Trivially convert placeholders. */
7882 {
7883 /* The template argument was the name of some
7884 member function. That's usually
7885 invalid, but static members are OK. In any
7886 case, grab the underlying fields/functions
7887 and issue an error later if required. */
7890 }
7898 /* When determining whether an argument pack expansion is a template,
7899 look at the pattern. */
7903 /* Deal with an injected-class-name used as a template template arg. */
7905 {
7908 {
7918 }
7919 }
7921 is_tmpl_type =
7937 {
7939 {
7943 }
7946 "to refer to a type member of a template parameter, "
7951 typename_type,
7952 complain);
7955 }
7957 {
7959 {
7961 {
7966 {
7967 /* The template argument is a type, but we're expecting
7968 an expression. */
7973 /* [temp.arg]/2: "In a template-argument, an ambiguity
7974 between a type-id and an expression is resolved to a
7975 type-id, regardless of the form of the corresponding
7976 template-parameter." So give the user a clue. */
7979 "for non-type template parameter is treated as "
7981 }
7985 else
7988 }
7989 }
7991 }
7993 {
7995 {
8002 else
8005 }
8007 }
8010 /* We already did the appropriate conversion when packing args. */
8013 {
8015 {
8017 /* The number of argument required is not known yet.
8018 Just accept it for now. */
8020 else
8021 {
8023 tree argparm;
8025 /* Strip alias templates that are equivalent to another
8026 template. */
8032 args))
8033 {
8036 /* TEMPLATE_TEMPLATE_PARM node is preferred over
8037 TEMPLATE_DECL. */
8039 {
8044 }
8045 }
8046 else
8047 {
8049 {
8056 }
8059 }
8061 // Check that the constraints are compatible before allowing the
8062 // substitution.
8065 {
8067 {
8073 }
8075 }
8076 }
8077 }
8078 else
8080 /* We only form one instance of each template specialization.
8081 Therefore, if we use a non-canonical variant (i.e., a
8082 typedef), any future messages referring to the type will use
8083 the typedef, which is confusing if those future uses do not
8084 themselves also use the typedef. */
8087 }
8088 else
8089 {
8094 /* We don't have enough levels of args to do any substitution. This
8097 {
8101 }
8102 else
8113 /* We used to call digest_init here. However, digest_init
8114 will report errors, which we don't want when complain
8115 is zero. More importantly, digest_init will try too
8116 hard to convert things: for example, `0' should not be
8117 converted to pointer type at this point according to
8118 the standard. Accepting this is not merely an
8119 extension, since deciding whether or not these
8120 conversions can occur is part of determining which
8121 function template to call, or whether a given explicit
8122 argument specification is valid. */
8124 else
8125 {
8128 }
8138 {
8139 /* Reject template arguments that are references to built-in
8140 functions with no library fallbacks. */
8149 }
8152 {
8153 /* Strip typedefs from the SCOPE_REF. */
8156 complain);
8159 }
8160 }
8163 }
8165 /* Coerces the remaining template arguments in INNER_ARGS (from
8166 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
8167 Returns the coerced argument pack. PARM_IDX is the position of this
8168 parameter in the template parameter list. ARGS is the original
8169 template argument list. */
8170 static tree
8173 tree args,
8174 tree inner_args,
8176 tree new_args,
8178 tree in_decl,
8179 tsubst_flags_t complain)
8180 {
8183 tree packed_args;
8184 tree argument_pack;
8191 {
8192 /* When the template parameter is a non-type template parameter pack
8193 or template template parameter pack whose type or template
8194 parameters use parameter packs, we know exactly how many arguments
8195 we are looking for. Build a vector of the instantiated decls for
8196 these template parameters in PACKED_PARMS. */
8197 /* We can't use make_pack_expansion here because it would interpret a
8198 _DECL as a use rather than a declaration. */
8212 /* If we're doing a partial instantiation of a member template,
8213 verify that all of the types used for the non-type
8214 template parameter pack are, in fact, valid for non-type
8215 template parameters. */
8218 {
8221 {
8226 }
8227 /* We don't know how many args we have yet, just
8228 use the unconverted ones for now. */
8230 }
8233 }
8234 /* Check if we have a placeholder pack, which indicates we're
8235 in the context of a introduction list. In that case we want
8236 to match this pack to the single placeholder. */
8240 {
8243 }
8244 else
8247 /* Convert the remaining arguments, which will be a part of the
8248 parameter pack "parm". */
8251 {
8257 {
8258 /* Once we've packed as many args as we have types, stop. */
8262 /* We don't know how many args we have yet, just
8263 use the unconverted ones for now. */
8265 else
8267 }
8270 {
8273 }
8274 else
8277 in_decl);
8281 }
8285 {
8290 }
8295 else
8296 {
8299 }
8306 }
8308 /* Returns the number of pack expansions in the template argument vector
8309 ARGS. */
8311 static int
8313 {
8318 {
8322 }
8324 }
8326 /* Convert all template arguments to their appropriate types, and
8327 return a vector containing the innermost resulting template
8328 arguments. If any error occurs, return error_mark_node. Error and
8329 warning messages are issued under control of COMPLAIN.
8331 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
8332 for arguments not specified in ARGS. Otherwise, if
8333 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
8334 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
8335 USE_DEFAULT_ARGS is false, then all arguments must be specified in
8336 ARGS. */
8338 static tree
8340 tree args,
8341 tree in_decl,
8342 tsubst_flags_t complain,
8345 {
8347 tree orig_inner_args;
8348 tree inner_args;
8349 tree new_args;
8350 tree new_inner_args;
8352 /* When used as a boolean value, indicates whether this is a
8353 variadic template parameter list. Since it's an int, we can also
8354 subtract it from nparms to get the number of non-variadic
8355 parameters. */
8360 /* Adjustment to nparms for fixed parameter packs. */
8365 /* Likewise for parameters with default arguments. */
8373 /* Determine if there are any parameter packs or default arguments. */
8375 {
8383 }
8386 /* If there are no parameters that follow a parameter pack, we need to
8387 expand any argument packs so that we can deduce a parameter pack from
8388 some non-packed args followed by an argument pack, as in variadic85.C.
8389 If there are such parameters, we need to leave argument packs intact
8390 so the arguments are assigned properly. This can happen when dealing
8391 with a nested class inside a partial specialization of a class
8392 template, as in variadic92.C, or when deducing a template parameter pack
8393 from a sub-declarator, as in variadic114.C. */
8397 /* Count any pack expansion args. */
8403 && require_all_args
8404 && !variadic_args_p
8405 && (!use_default_args
8408 {
8409 bad_nargs:
8411 {
8413 {
8417 }
8418 else
8425 }
8428 }
8429 /* We can't pass a pack expansion to a non-pack parameter of an alias
8430 template (DR 1430). */
8434 && variadic_args_p
8436 {
8438 {
8440 {
8446 {
8449 "pack expansion argument for non-pack parameter "
8451 else
8453 "pack expansion argument for non-pack parameter "
8457 }
8458 }
8460 found:;
8461 }
8463 }
8465 /* We need to evaluate the template arguments, even though this
8466 template-id may be nested within a "sizeof". */
8467 cp_evaluated ev;
8473 {
8474 tree arg;
8475 tree parm;
8477 /* Get the Ith template parameter. */
8481 {
8484 }
8486 /* Calculate the next argument. */
8489 else
8495 {
8496 /* Some arguments will be placed in the
8497 template parameter pack PARM. */
8504 {
8505 /* We don't know how many args we have yet, just use the
8506 unconverted (and still packed) ones for now. */
8510 }
8514 /* Store this argument. */
8516 {
8517 lost++;
8518 /* We are done with all of the arguments. */
8521 }
8522 else
8523 {
8527 {
8530 }
8531 }
8534 }
8536 {
8538 {
8539 /* "If every valid specialization of a variadic template
8540 requires an empty template parameter pack, the template is
8541 ill-formed, no diagnostic required." So check that the
8542 pattern works with this parameter. */
8547 in_decl);
8549 {
8554 }
8556 /* Recover from missing typename. */
8560 /* We don't know how many args we have yet, just
8561 use the unconverted ones for now. */
8565 }
8566 }
8568 {
8569 /* There must be a default arg in this case. */
8572 /* The position of the first default template argument,
8573 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8574 Record that. */
8578 }
8579 else
8583 {
8586 }
8588 {
8589 /* This can occur if there was an error in the template
8590 parameter list itself (which we would already have
8591 reported) that we are trying to recover from, e.g., a class
8592 template with a parameter list such as
8593 template<typename..., typename> (cpp0x/variadic150.C). */
8596 /* This can also happen with a fixed parameter pack (71834). */
8599 }
8600 else
8606 lost++;
8608 }
8611 {
8612 /* If we had fixed parameter packs, we didn't know how many arguments we
8613 actually needed earlier; now we do. */
8617 }
8620 {
8621 /* We had some pack expansion arguments that will only work if the packs
8622 are empty, but wait until instantiation time to complain.
8623 See variadic-ttp3.C. */
8633 }
8636 {
8639 }
8646 }
8648 /* Convert all template arguments to their appropriate types, and
8649 return a vector containing the innermost resulting template
8650 arguments. If any error occurs, return error_mark_node. Error and
8651 warning messages are not issued.
8653 Note that no function argument deduction is performed, and default
8654 arguments are used to fill in unspecified arguments. */
8655 tree
8657 {
8659 }
8661 /* Convert all template arguments to their appropriate type, and
8662 instantiate default arguments as needed. This returns a vector
8663 containing the innermost resulting template arguments, or
8664 error_mark_node if unsuccessful. */
8665 tree
8667 tsubst_flags_t complain)
8668 {
8670 }
8672 /* Like coerce_template_parms. If PARMS represents all template
8673 parameters levels, this function returns a vector of vectors
8674 representing all the resulting argument levels. Note that in this
8675 case, only the innermost arguments are coerced because the
8676 outermost ones are supposed to have been coerced already.
8678 Otherwise, if PARMS represents only (the innermost) vector of
8679 parameters, this function returns a vector containing just the
8680 innermost resulting arguments. */
8682 static tree
8684 tree args,
8685 tree in_decl,
8686 tsubst_flags_t complain,
8689 {
8692 tree coerced_args;
8695 {
8697 tree level;
8703 {
8704 tree l;
8708 require_all_args,
8709 use_default_args);
8710 else
8717 }
8718 }
8719 else
8722 require_all_args,
8723 use_default_args);
8725 }
8727 /* Returns 1 if template args OT and NT are equivalent. */
8729 int
8731 {
8740 /* For member templates */
8749 {
8766 }
8770 {
8773 /* Don't treat an alias template specialization with dependent
8774 arguments as equivalent to its underlying type when used as a
8775 template argument; we need them to be distinct so that we
8776 substitute into the specialization arguments at instantiation
8777 time. And aliases can't be equivalent without being ==, so
8778 we don't need to look any deeper.
8780 During partial ordering, however, we need to treat them normally so
8781 that we can order uses of the same alias with different
8782 cv-qualification (79960). */
8786 else
8788 }
8791 else
8792 {
8793 /* Try to treat a template non-type argument that has been converted
8794 to the parameter type as equivalent to one that hasn't yet. */
8807 }
8808 }
8810 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8811 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8812 NEWARG_PTR with the offending arguments if they are non-NULL. */
8814 int
8818 {
8831 {
8836 {
8842 }
8843 }
8845 }
8849 {
8851 }
8853 /* Implement a freelist interface for objects of type T.
8855 Head is a separate object, rather than a regular member, so that we
8856 can define it as a GTY deletable pointer, which is highly
8857 desirable. A data member could be declared that way, but then the
8858 containing object would implicitly get GTY((user)), which would
8859 prevent us from instantiating freelists as global objects.
8860 Although this way we can create freelist global objects, they're
8861 such thin wrappers that instantiating temporaries at every use
8862 loses nothing and saves permanent storage for the freelist object.
8864 Member functions next, anew, poison and reinit have default
8865 implementations that work for most of the types we're interested
8866 in, but if they don't work for some type, they should be explicitly
8867 specialized. See the comments before them for requirements, and
8868 the example specializations for the tree_list_freelist. */
8870 class freelist
8871 {
8872 /* Return the next object in a chain. We could just do type
8873 punning, but if we access the object with its underlying type, we
8874 avoid strict-aliasing trouble. This needs only work between
8875 poison and reinit. */
8878 /* Return a newly allocated, uninitialized or minimally-initialized
8879 object of type T. Any initialization performed by anew should
8880 either remain across the life of the object and the execution of
8881 poison, or be redone by reinit. */
8884 /* Optionally scribble all over the bits holding the object, so that
8885 they become (mostly?) uninitialized memory. This is called while
8886 preparing to make the object part of the free list. */
8891 #ifdef ENABLE_GC_CHECKING
8892 /* Poison the data, to indicate the data is garbage. */
8895 #endif
8896 /* Let valgrind know the object is free. */
8899 /* Let valgrind know the next portion of the object is available,
8900 but uninitialized. */
8902 }
8904 /* Bring an object that underwent at least one lifecycle after anew
8905 and before the most recent free and poison, back to a usable
8906 state, reinitializing whatever is needed for it to be
8907 functionally equivalent to an object just allocated and returned
8908 by anew. This may poison or clear the next field, used by
8909 freelist housekeeping after poison was called. */
8913 #ifdef ENABLE_GC_CHECKING
8915 #endif
8916 /* Let valgrind know the entire object is available, but
8917 uninitialized. */
8919 }
8921 /* Reference a GTY-deletable pointer that points to the first object
8922 in the free list proper. */
8925 /* Construct a freelist object chaining objects off of HEAD. */
8928 /* Add OBJ to the free object list. The former head becomes OBJ's
8929 successor. */
8931 {
8935 }
8937 /* Take an object from the free list, if one is available, or
8938 allocate a new one. Objects taken from the free list should be
8939 regarded as filled with garbage, except for bits that are
8940 configured to be preserved across free and alloc. */
8942 {
8944 {
8949 }
8950 else
8952 }
8953 };
8955 /* Explicitly specialize the interfaces for freelist<tree_node>: we
8956 want to allocate a TREE_LIST using the usual interface, and ensure
8957 TREE_CHAIN remains functional. Alas, we have to duplicate a bit of
8958 build_tree_list logic in reinit, so this could go out of sync. */
8962 {
8964 }
8966 inline tree
8968 {
8970 }
8974 {
8980 #ifdef ENABLE_GC_CHECKING
8983 /* Poison the data, to indicate the data is garbage. */
8986 #endif
8987 /* Let valgrind know the object is free. */
8989 /* But we still want to use the TREE_CODE and TREE_CHAIN parts. */
8993 #ifdef ENABLE_GC_CHECKING
8995 /* Keep TREE_CHAIN functional. */
8997 #else
8999 #endif
9000 }
9004 {
9007 #ifdef ENABLE_GC_CHECKING
9011 #endif
9013 /* Let valgrind know the entire object is available, but
9014 uninitialized. */
9017 #ifdef ENABLE_GC_CHECKING
9019 #else
9021 #endif
9022 }
9024 /* Point to the first object in the TREE_LIST freelist. */
9026 /* Return the/an actual TREE_LIST freelist. */
9029 {
9031 }
9033 /* Point to the first object in the tinst_level freelist. */
9035 /* Return the/an actual tinst_level freelist. */
9038 {
9040 }
9042 /* Point to the first object in the pending_template freelist. */
9044 /* Return the/an actual pending_template freelist. */
9047 {
9049 }
9051 /* Build the TREE_LIST object out of a split list, store it
9052 permanently, and return it. */
9053 tree
9055 {
9064 }
9068 /* Increment OBJ's refcount unless it is already infinite. */
9071 {
9075 }
9077 /* Release storage for OBJ and node, if it's a TREE_LIST. */
9078 void
9080 {
9084 }
9086 /* Decrement OBJ's refcount if not infinite. If it reaches zero, release
9087 OBJ's DECL and OBJ, and start over with the tinst_level object that
9088 used to be referenced by OBJ's NEXT. */
9089 static void
9091 {
9095 {
9099 }
9100 }
9102 /* Modify PTR so that it points to OBJ, adjusting the refcounts of OBJ
9103 and of the former PTR. Omitting the second argument is equivalent
9104 to passing (T*)NULL; this is allowed because passing the
9105 zero-valued integral constant NULL confuses type deduction and/or
9106 overload resolution. */
9108 static void
9110 {
9114 }
9116 static void
9118 {
9128 /* We are called both from instantiate_decl, where we've already had a
9129 tinst_level pushed, and instantiate_template, where we haven't.
9130 Compensate. */
9132 level = !current_tinst_level
9144 else
9153 }
9156 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
9157 ARGLIST. Valid choices for FNS are given in the cp-tree.def
9158 documentation for TEMPLATE_ID_EXPR. */
9160 tree
9162 {
9169 {
9172 }
9175 {
9177 unknown_type_node,
9179 arglist);
9181 }
9184 }
9186 /* Within the scope of a template class S<T>, the name S gets bound
9187 (in build_self_reference) to a TYPE_DECL for the class, not a
9188 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
9189 or one of its enclosing classes, and that type is a template,
9190 return the associated TEMPLATE_DECL. Otherwise, the original
9191 DECL is returned.
9193 Also handle the case when DECL is a TREE_LIST of ambiguous
9194 injected-class-names from different bases. */
9196 tree
9198 {
9202 /* DR 176: A lookup that finds an injected-class-name (10.2
9203 [class.member.lookup]) can result in an ambiguity in certain cases
9204 (for example, if it is found in more than one base class). If all of
9205 the injected-class-names that are found refer to specializations of
9206 the same class template, and if the name is followed by a
9207 template-argument-list, the reference refers to the class template
9208 itself and not a specialization thereof, and is not ambiguous. */
9210 {
9213 {
9219 }
9222 else
9224 }
9230 }
9232 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
9233 parameters, find the desired type.
9235 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
9237 IN_DECL, if non-NULL, is the template declaration we are trying to
9238 instantiate.
9240 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
9241 the class we are looking up.
9243 Issue error and warning messages under control of COMPLAIN.
9245 If the template class is really a local class in a template
9246 function, then the FUNCTION_CONTEXT is the function in which it is
9247 being instantiated.
9249 ??? Note that this function is currently called *twice* for each
9250 template-id: the first time from the parser, while creating the
9251 incomplete type (finish_template_type), and the second type during the
9252 real instantiation (instantiate_template_class). This is surely something
9253 that we want to avoid. It also causes some problems with argument
9254 coercion (see convert_nontype_argument for more information on this). */
9256 static tree
9259 {
9261 tree t;
9264 spec_entry elt;
9265 hashval_t hash;
9268 {
9272 else
9273 {
9280 }
9283 }
9285 {
9288 /* If we are declaring a constructor, say A<T>::A<T>, we will get
9289 an implicit typename for the second A. Deal with it. */
9294 {
9297 }
9298 }
9301 {
9304 }
9306 {
9310 }
9312 {
9315 }
9317 /* Issue an error message if we didn't find a template. */
9319 {
9323 }
9326 /* Make sure it's a user visible template, if it was named by
9327 the user. */
9330 {
9332 {
9336 }
9338 }
9342 /* An alias that just changes the name of a template is equivalent to the
9343 other template, so if any of the arguments are pack expansions, strip
9344 the alias to avoid problems with a pack expansion passed to a non-pack
9345 alias template parameter (DR 1430). */
9350 {
9351 tree parm;
9360 }
9361 else
9362 {
9364 tree gen_tmpl;
9365 tree type_decl;
9373 /* An error occurred while building the template TEMPL, and a
9374 diagnostic has most certainly been emitted for that
9375 already. Let's propagate that error. */
9384 {
9385 /* We've been given an incomplete set of template arguments.
9386 For example, given:
9388 template <class T> struct S1 {
9389 template <class U> struct S2 {};
9390 template <class U> struct S2<U*> {};
9391 };
9393 we will be called with an ARGLIST of `U*', but the
9394 TEMPLATE will be `template <class T> template
9395 <class U> struct S1<T>::S2'. We must fill in the missing
9396 arguments. */
9400 }
9402 /* Now we should have enough arguments. */
9405 /* From here on, we're only interested in the most general
9406 template. */
9408 /* Calculate the BOUND_ARGS. These will be the args that are
9409 actually tsubst'd into the definition to create the
9410 instantiation. */
9412 complain,
9417 /* We were unable to bind the arguments. */
9420 /* In the scope of a template class, explicit references to the
9421 template class refer to the type of the template, not any
9422 instantiation of it. For example, in:
9424 template <class T> class C { void f(C<T>); }
9426 the `C<T>' is just the same as `C'. Outside of the
9427 class, however, such a reference is an instantiation. */
9431 {
9436 }
9438 /* If we already have this specialization, return it. */
9448 /* If the the template's constraints are not satisfied,
9449 then we cannot form a valid type.
9451 Note that the check is deferred until after the hash
9452 lookup. This prevents redundant checks on previously
9453 instantiated specializations. */
9455 {
9457 {
9458 auto_diagnostic_group d;
9461 }
9463 }
9467 /* If the deduced arguments are invalid, then the binding
9468 failed. */
9472 complain))
9479 {
9484 }
9488 {
9491 }
9492 else
9501 /* Create the type. */
9503 {
9504 /* The user referred to a specialization of an alias
9505 template represented by GEN_TMPL.
9507 [temp.alias]/2 says:
9509 When a template-id refers to the specialization of an
9510 alias template, it is equivalent to the associated
9511 type obtained by substitution of its
9512 template-arguments for the template-parameters in the
9513 type-id of the alias template. */
9516 /* Note that the call above (by indirectly calling
9517 register_specialization in tsubst_decl) registers the
9518 TYPE_DECL representing the specialization of the alias
9519 template. So next time someone substitutes ARGLIST for
9520 the template parms into the alias template (GEN_TMPL),
9521 she'll get that TYPE_DECL back. */
9525 }
9527 {
9529 {
9540 }
9541 else
9542 {
9543 /* We don't want to call start_enum for this type, since
9544 the values for the enumeration constants may involve
9545 template parameters. And, no one should be interested
9546 in the enumeration constants for such a type. */
9549 }
9553 }
9555 {
9556 /* Lambda closures are regenerated in tsubst_lambda_expr, not
9557 instantiated here. */
9565 /* A local class. Make sure the decl gets registered properly. */
9572 /* This instantiation is another name for the primary
9573 template type. Set the TYPE_CANONICAL field
9574 appropriately. */
9577 /* Some of the template arguments require structural
9578 equality testing, so this template class requires
9579 structural equality testing. */
9581 }
9582 else
9585 /* If we called start_enum or pushtag above, this information
9586 will already be set up. */
9588 {
9595 }
9596 else
9600 {
9606 {
9609 }
9610 }
9614 {
9618 {
9619 tree attributes
9627 }
9628 }
9630 /* Let's consider the explicit specialization of a member
9631 of a class template specialization that is implicitly instantiated,
9632 e.g.:
9633 template<class T>
9634 struct S
9635 {
9636 template<class U> struct M {}; //#0
9637 };
9639 template<>
9640 template<>
9641 struct S<int>::M<char> //#1
9642 {
9643 int i;
9644 };
9645 [temp.expl.spec]/4 says this is valid.
9647 In this case, when we write:
9648 S<int>::M<char> m;
9650 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
9651 the one of #0.
9653 When we encounter #1, we want to store the partial instantiation
9654 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
9656 For all cases other than this "explicit specialization of member of a
9657 class template", we just want to store the most general template into
9658 the CLASSTYPE_TI_TEMPLATE of M.
9660 This case of "explicit specialization of member of a class template"
9661 only happens when:
9662 1/ the enclosing class is an instantiation of, and therefore not
9663 the same as, the context of the most general template, and
9664 2/ we aren't looking at the partial instantiation itself, i.e.
9665 the innermost arguments are not the same as the innermost parms of
9666 the most general template.
9668 So it's only when 1/ and 2/ happens that we want to use the partial
9669 instantiation of the member template in lieu of its most general
9670 template. */
9674 /* the enclosing class must be an instantiation... */
9677 {
9681 tree partial_inst_args =
9688 use_partial_inst_tmpl =
9689 /*...and we must not be looking at the partial instantiation
9690 itself. */
9692 partial_inst_args);
9693 }
9696 /* This case is easy; there are no member templates involved. */
9698 else
9699 {
9700 /* This is a full instantiation of a member template. Find
9701 the partial instantiation of which this is an instance. */
9703 /* Temporarily reduce by one the number of levels in the ARGLIST
9704 so as to avoid comparing the last set of arguments. */
9708 /* FOUND is either a proper class type, or an alias
9709 template specialization. In the later case, it's a
9710 TYPE_DECL, resulting from the substituting of arguments
9711 for parameters in the TYPE_DECL of the alias template
9712 done earlier. So be careful while getting the template
9713 of FOUND. */
9715 ? found
9722 {
9723 /* If this partial instantiation is specialized, we want to
9724 use it for hash table lookup. */
9728 }
9729 }
9731 // Build template info for the new specialization.
9741 /* Note this use of the partial instantiation so we can check it
9742 later in maybe_process_partial_specialization. */
9749 /* Now that the type has been registered on the instantiations
9750 list, we set up the enumerators. Because the enumeration
9751 constants may involve the enumeration type itself, we make
9752 sure to register the type first, and then create the
9753 constants. That way, doing tsubst_expr for the enumeration
9754 constants won't result in recursive calls here; we'll find
9755 the instantiation and exit above. */
9759 /* If the type makes use of template parameters, the
9760 code that generates debugging information will crash. */
9763 /* Possibly limit visibility based on template args. */
9770 }
9771 }
9773 /* Wrapper for lookup_template_class_1. */
9775 tree
9778 {
9779 tree ret;
9785 }
9787 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9789 tree
9791 {
9792 /* The type of the expression is NULL_TREE since the template-id could refer
9793 to an explicit or partial specialization. */
9796 /* Except that concepts are always bool. */
9799 }
9801 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9803 tree
9805 {
9809 /* We never want to return a VAR_DECL for a variable concept, since they
9810 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9825 {
9827 {
9828 auto_diagnostic_group d;
9831 }
9833 }
9835 /* If a template-id refers to a specialization of a variable
9836 concept, then the expression is true if and only if the
9837 concept's constraints are satisfied by the given template
9838 arguments.
9840 NOTE: This is an extension of Concepts Lite TS that
9841 allows constraints to be used in expressions. */
9843 {
9846 }
9849 }
9851 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9852 TARGS template args, and instantiate it if it's not dependent. */
9854 tree
9856 tsubst_flags_t complain)
9857 {
9860 {
9863 }
9866 }
9868 \f
9869 struct pair_fn_data
9870 {
9871 tree_fn_t fn;
9872 tree_fn_t any_fn;
9874 /* True when we should also visit template parameters that occur in
9875 non-deduced contexts. */
9878 };
9880 /* Called from for_each_template_parm via walk_tree. */
9882 static tree
9884 {
9891 #define WALK_SUBTREE(NODE) \
9892 do \
9893 { \
9894 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9895 pfd->include_nondeduced_p, \
9896 pfd->any_fn); \
9897 if (result) goto out; \
9898 } \
9899 while (0)
9909 {
9913 /* Fall through. */
9919 else
9929 /* Since we're not going to walk subtrees, we have to do this
9930 explicitly here. */
9932 /* Fall through. */
9935 /* Check the return type. */
9938 /* Check the parameter types. Since default arguments are not
9939 instantiated until they are needed, the TYPE_ARG_TYPES may
9940 contain expressions that involve template parameters. But,
9941 no-one should be looking at them yet. And, once they're
9942 instantiated, they don't contain template parameters, so
9943 there's no point in looking at them then, either. */
9944 {
9945 tree parm;
9950 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9951 want walk_tree walking into them itself. */
9953 }
9956 {
9960 }
9979 /* Fall through. */
9991 /* Record template parameters such as `T' inside `TT<T>'. */
9993 /* Fall through. */
10005 /* A template template parameter is encountered. */
10009 /* Already substituted template template parameter */
10014 /* A template-id in a TYPENAME_TYPE might be a deduced context after
10015 partial instantiation. */
10027 /* If there's no type, then this thing must be some expression
10028 involving template parameters. */
10050 }
10052 #undef WALK_SUBTREE
10054 /* We didn't find any template parameters we liked. */
10055 out:
10057 }
10059 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
10060 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
10061 call FN with the parameter and the DATA.
10062 If FN returns nonzero, the iteration is terminated, and
10063 for_each_template_parm returns 1. Otherwise, the iteration
10064 continues. If FN never returns a nonzero value, the value
10065 returned by for_each_template_parm is 0. If FN is NULL, it is
10066 considered to be the function which always returns 1.
10068 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
10069 parameters that occur in non-deduced contexts. When false, only
10070 visits those template parameters that can be deduced. */
10072 static tree
10076 tree_fn_t any_fn)
10077 {
10079 tree result;
10081 /* Set up. */
10087 /* Walk the tree. (Conceptually, we would like to walk without
10088 duplicates, but for_each_template_parm_r recursively calls
10089 for_each_template_parm, so we would need to reorganize a fair
10090 bit to use walk_tree_without_duplicates, so we keep our own
10091 visited list.) */
10094 else
10097 for_each_template_parm_r,
10101 /* Clean up. */
10103 {
10106 }
10109 }
10111 /* Returns true if T depends on any template parameter. */
10113 int
10115 {
10145 else
10146 {
10149 }
10154 }
10156 /* Returns true iff current_function_decl is an incompletely instantiated
10157 template. Useful instead of processing_template_decl because the latter
10158 is set to 0 during instantiate_non_dependent_expr. */
10160 bool
10162 {
10171 }
10173 /* Returns true if T depends on any template parameter with level LEVEL. */
10175 bool
10177 {
10180 }
10182 /* Returns true if the signature of DECL depends on any template parameter from
10183 its enclosing class. */
10185 bool
10187 {
10197 template_parm_outer_level,
10207 }
10209 /* Returns TRUE iff INST is an instantiation we don't need to do in an
10210 ill-formed translation unit, i.e. a variable or function that isn't
10211 usable in a constant expression. */
10215 {
10220 }
10222 /* Returns TRUE iff we should refuse to instantiate DECL because it's
10223 neglectable and instantiated from within an erroneous instantiation. */
10225 static bool
10227 {
10238 }
10246 /* We're starting to instantiate D; record the template instantiation context
10247 at LOC for diagnostics and to restore it later. */
10249 static bool
10251 {
10255 {
10256 /* Tell error.c not to try to instantiate any templates. */
10259 "template instantiation depth exceeds maximum of %d"
10261 max_tinst_depth);
10263 }
10265 /* If the current instantiation caused problems, don't let it instantiate
10266 anything else. Do allow deduction substitution and decls usable in
10267 constant expressions. */
10271 /* When not -quiet, dump template instantiations other than functions, since
10272 announce_function will take care of those. */
10293 }
10295 /* We're starting substitution of TMPL<ARGS>; record the template
10296 substitution context for diagnostics and to restore it later. */
10298 static bool
10300 {
10302 }
10304 /* We're starting to instantiate D; record INPUT_LOCATION and the
10305 template instantiation context for diagnostics and to restore it
10306 later. */
10308 bool
10310 {
10312 }
10314 /* Likewise, but record LOC as the program location. */
10316 bool
10318 {
10321 }
10323 /* We're done instantiating this template; return to the instantiation
10324 context. */
10326 void
10328 {
10329 /* Restore the filename and line number stashed away when we started
10330 this instantiation. */
10334 }
10336 /* We're instantiating a deferred template; restore the template
10337 instantiation context in which the instantiation was requested, which
10338 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
10340 static tree
10342 {
10354 }
10356 /* Returns the TINST_LEVEL which gives the original instantiation
10357 context. */
10361 {
10367 }
10369 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
10370 vector of template arguments, as for tsubst.
10372 Returns an appropriate tsubst'd friend declaration. */
10374 static tree
10376 {
10377 tree new_friend;
10382 /* This was a friend declared with an explicit template
10383 argument list, e.g.:
10385 friend void f<>(T);
10387 to indicate that f was a template instantiation, not a new
10388 function declaration. Now, we have to figure out what
10389 instantiation of what template. */
10390 {
10392 tree new_args;
10393 tree tmpl;
10396 /* Friend functions are looked up in the containing namespace scope.
10397 We must enter that scope, to avoid finding member functions of the
10398 current class with same name. */
10413 tsk_none);
10415 }
10419 /* The NEW_FRIEND will look like an instantiation, to the
10420 compiler, but is not an instantiation from the point of view of
10421 the language. For example, we might have had:
10423 template <class T> struct S {
10424 template <class U> friend void f(T, U);
10425 };
10427 Then, in S<int>, template <class U> void f(int, U) is not an
10428 instantiation of anything. */
10434 {
10438 }
10440 /* The mangled name for the NEW_FRIEND is incorrect. The function
10441 is not a template instantiation and should not be mangled like
10442 one. Therefore, we forget the mangling here; we'll recompute it
10443 later if we need it. */
10445 {
10448 }
10451 {
10452 tree old_decl;
10453 tree new_friend_template_info;
10454 tree new_friend_result_template_info;
10455 tree ns;
10458 /* We must save some information from NEW_FRIEND before calling
10459 duplicate decls since that function will free NEW_FRIEND if
10460 possible. */
10462 new_friend_is_defn =
10467 {
10468 /* This declaration is a `primary' template. */
10471 new_friend_result_template_info
10473 }
10474 else
10477 /* Inside pushdecl_namespace_level, we will push into the
10478 current namespace. However, the friend function should go
10479 into the namespace of the template. */
10489 {
10490 /* This new friend declaration matched an existing
10491 declaration. For example, given:
10493 template <class T> void f(T);
10494 template <class U> class C {
10495 template <class T> friend void f(T) {}
10496 };
10498 the friend declaration actually provides the definition
10499 of `f', once C has been instantiated for some type. So,
10500 old_decl will be the out-of-class template declaration,
10501 while new_friend is the in-class definition.
10503 But, if `f' was called before this point, the
10504 instantiation of `f' will have DECL_TI_ARGS corresponding
10505 to `T' but not to `U', references to which might appear
10506 in the definition of `f'. Previously, the most general
10507 template for an instantiation of `f' was the out-of-class
10508 version; now it is the in-class version. Therefore, we
10509 run through all specialization of `f', adding to their
10510 DECL_TI_ARGS appropriately. In particular, they need a
10511 new set of outer arguments, corresponding to the
10512 arguments for this class instantiation.
10514 The same situation can arise with something like this:
10516 friend void f(int);
10517 template <class T> class C {
10518 friend void f(T) {}
10519 };
10521 when `C<int>' is instantiated. Now, `f(int)' is defined
10522 in the class. */
10525 /* On the other hand, if the in-class declaration does
10526 *not* provide a definition, then we don't want to alter
10527 existing definitions. We can just leave everything
10528 alone. */
10529 ;
10530 else
10531 {
10535 /* Overwrite whatever template info was there before, if
10536 any, with the new template information pertaining to
10537 the declaration. */
10541 {
10542 /* We should have called reregister_specialization in
10543 duplicate_decls. */
10548 /* Instantiate it if the global has already been used. */
10552 }
10553 else
10554 {
10555 tree t;
10557 /* Indicate that the old function template is a partial
10558 instantiation. */
10566 /* Reassign any specializations already in the hash table
10567 to the new more general template, and add the
10568 additional template args. */
10572 {
10574 spec_entry elt;
10586 register_specialization
10589 }
10591 }
10592 }
10594 /* The information from NEW_FRIEND has been merged into OLD_DECL
10595 by duplicate_decls. */
10597 }
10598 }
10599 else
10600 {
10604 /* In the code
10605 template <class T> class C {
10606 template <class U> friend void C1<U>::f (); // case 1
10607 friend void C2<T>::f (); // case 2
10608 };
10609 we only need to make sure CONTEXT is a complete type for
10610 case 2. To distinguish between the two cases, we note that
10611 CONTEXT of case 1 remains dependent type after tsubst while
10612 this isn't true for case 2. */
10622 {
10624 /* do_friend adds the TEMPLATE_DECL for any member friend
10625 template even if it isn't a member template, i.e.
10626 template <class T> friend A<T>::f();
10627 Look through it in that case. */
10631 /* Check to see that the declaration is really present, and,
10632 possibly obtain an improved declaration. */
10637 }
10638 }
10641 }
10643 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
10644 template arguments, as for tsubst.
10646 Returns an appropriate tsubst'd friend type or error_mark_node on
10647 failure. */
10649 static tree
10651 {
10652 tree tmpl;
10655 {
10658 }
10663 else
10664 {
10667 }
10674 {
10675 /* The friend template has already been declared. Just
10676 check to see that the declarations match, and install any new
10677 default parameters. We must tsubst the default parameters,
10678 of course. We only need the innermost template parameters
10679 because that is all that redeclare_class_template will look
10680 at. */
10683 {
10691 }
10692 }
10693 else
10694 {
10695 /* The friend template has not already been declared. In this
10696 case, the instantiation of the template class will cause the
10697 injection of this template into the namespace scope. */
10701 {
10702 /* The new TMPL is not an instantiation of anything, so we
10703 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE
10704 for the new type because that is supposed to be the
10705 corresponding template decl, i.e., TMPL. */
10712 /* It is hidden. */
10717 /* Inject this template into the enclosing namspace scope. */
10719 }
10720 }
10724 else
10728 }
10730 /* Returns zero if TYPE cannot be completed later due to circularity.
10731 Otherwise returns one. */
10733 static int
10735 {
10745 else
10747 }
10752 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10753 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10755 static tree
10758 {
10767 {
10774 clauses
10778 else
10780 }
10781 /* If the first attribute argument is an identifier, don't
10782 pass it through tsubst. Attributes like mode, format,
10783 cleanup and several target specific attributes expect it
10784 unmodified. */
10786 {
10787 tree chain
10792 }
10794 {
10795 /* An attribute pack expansion. */
10804 {
10808 }
10810 }
10811 else
10818 }
10820 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10821 unchanged or a new TREE_LIST chain. */
10823 static tree
10826 {
10831 {
10835 }
10839 {
10842 {
10845 {
10851 }
10852 }
10854 }
10857 }
10859 /* Apply any attributes which had to be deferred until instantiation
10860 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10861 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10863 static void
10866 {
10868 tree t;
10875 {
10879 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10880 to our attributes parameter. */
10882 }
10883 else
10884 {
10886 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10887 lookup_template_class_1, and should be preserved. */
10891 }
10895 {
10899 }
10903 {
10908 {
10911 {
10917 }
10918 else
10920 }
10923 }
10924 }
10926 /* Perform (or defer) access check for typedefs that were referenced
10927 from within the template TMPL code.
10928 This is a subroutine of instantiate_decl and instantiate_class_template.
10929 TMPL is the template to consider and TARGS is the list of arguments of
10930 that template. */
10932 static void
10934 {
10935 location_t saved_location;
10946 {
10958 /* Make access check error messages point to the location
10959 of the use of the typedef. */
10963 tf_warning_or_error);
10964 }
10966 }
10968 static tree
10970 {
10972 tree typedecl;
10973 tree pbinfo;
10974 tree base_list;
10976 tree fn_context;
10985 /* Figure out which template is being instantiated. */
10989 /* Mark the type as in the process of being defined. */
10992 /* We may be in the middle of deferred access check. Disable
10993 it now. */
10996 /* Determine what specialization of the original template to
10997 instantiate. */
11002 {
11003 /* This TYPE is actually an instantiation of a partial
11004 specialization. We replace the innermost set of ARGS with
11005 the arguments appropriate for substitution. For example,
11006 given:
11008 template <class T> struct S {};
11009 template <class T> struct S<T*> {};
11011 and supposing that we are instantiating S<int*>, ARGS will
11012 presently be {int*} -- but we need {int}. */
11015 }
11016 else
11017 {
11020 }
11022 /* If the template we're instantiating is incomplete, then clearly
11023 there's nothing we can do. */
11025 {
11026 /* We can try again later. */
11029 }
11031 /* If we've recursively instantiated too many templates, stop. */
11039 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
11044 else
11045 {
11048 }
11049 /* Use #pragma pack from the template context. */
11055 /* Set the input location to the most specialized template definition.
11056 This is needed if tsubsting causes an error. */
11068 {
11071 /* Adjust visibility for template arguments. */
11073 }
11079 /* We should never instantiate a nested class before its enclosing
11080 class; we need to look up the nested class by name before we can
11081 instantiate it, and that lookup should instantiate the enclosing
11082 class. */
11088 {
11089 tree pbase_binfo;
11090 tree pushed_scope;
11093 /* We must enter the scope containing the type, as that is where
11094 the accessibility of types named in dependent bases are
11095 looked up from. */
11098 /* Substitute into each of the bases to determine the actual
11099 basetypes. */
11101 {
11102 tree base;
11108 {
11109 expanded_bases =
11116 }
11119 {
11121 /* Extract the already-expanded base class. */
11123 else
11124 /* Substitute to figure out the base class. */
11126 NULL_TREE);
11134 }
11135 }
11137 /* The list is now in reverse order; correct that. */
11142 }
11143 /* Now call xref_basetypes to set up all the base-class
11144 information. */
11152 /* Now that our base classes are set up, enter the scope of the
11153 class, so that name lookups into base classes, etc. will work
11154 correctly. This is precisely analogous to what we do in
11155 begin_class_definition when defining an ordinary non-template
11156 class, except we also need to push the enclosing classes. */
11159 /* Now members are processed in the order of declaration. */
11162 {
11166 {
11168 {
11170 /* A closure type for a lambda in an NSDMI or default argument.
11171 Ignore it; it will be regenerated when needed. */
11174 /* Build new CLASSTYPE_NESTED_UTDS. */
11176 tree newtag;
11182 /* If the member is a class template, then -- even after
11183 substitution -- there may be dependent types in the
11184 template argument list for the class. We increment
11185 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
11186 that function will assume that no types are dependent
11187 when outside of a template. */
11197 {
11201 /* Unfortunately, lookup_template_class sets
11202 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
11203 instantiation (i.e., for the type of a member
11204 template class nested within a template class.)
11205 This behavior is required for
11206 maybe_process_partial_specialization to work
11207 correctly, but is not accurate in this case;
11208 the TAG is not an instantiation of anything.
11209 (The corresponding TEMPLATE_DECL is an
11210 instantiation, but the TYPE is not.) */
11213 /* Now, we call pushtag to put this NEWTAG into the scope of
11214 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
11215 pushtag calling push_template_decl. We don't have to do
11216 this for enums because it will already have been done in
11217 tsubst_enum. */
11221 }
11222 }
11224 {
11225 tree r;
11234 /* Instantiate members marked with attribute used. */
11240 }
11243 /* A closure type for a lambda in an NSDMI or default argument.
11245 else
11246 {
11247 /* Build new TYPE_FIELDS. */
11249 {
11250 tree condition;
11253 condition =
11263 }
11265 {
11266 tree r;
11270 /* The file and line for this declaration, to
11271 assist in error message reporting. Since we
11272 called push_tinst_level above, we don't need to
11273 restore these. */
11283 {
11284 /* A capture pack became multiple fields. */
11287 }
11290 {
11294 {
11295 /* In [temp.inst]:
11297 [t]he initialization (and any associated
11298 side-effects) of a static data member does
11299 not occur unless the static data member is
11300 itself used in a way that requires the
11301 definition of the static data member to
11302 exist.
11304 Therefore, we do not substitute into the
11305 initialized for the static data member here. */
11306 finish_static_data_member_decl
11312 /* Instantiate members marked with attribute used. */
11315 }
11317 {
11318 /* Determine whether R has a valid type and can be
11319 completed later. If R is invalid, then its type
11320 is replaced by error_mark_node. */
11326 {
11327 /* If R's type couldn't be completed and
11328 it isn't a flexible array member (whose
11329 type is incomplete by definition) give
11330 an error. */
11333 }
11338 {
11341 }
11342 }
11344 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
11345 such a thing will already have been added to the field
11346 list by tsubst_enum in finish_member_declaration in the
11347 CLASSTYPE_NESTED_UTDS case above. */
11351 {
11354 }
11355 }
11356 }
11357 }
11358 }
11359 else
11360 {
11363 {
11364 /* Build new CLASSTYPE_FRIEND_CLASSES. */
11370 {
11371 /* template <class T> friend class C; */
11374 }
11376 {
11377 /* template <class T> friend class C::D; */
11383 }
11386 {
11387 /* This could be either
11389 friend class T::C;
11391 when dependent_type_p is false or
11393 template <class U> friend class T::C;
11395 otherwise. */
11396 /* Bump processing_template_decl in case this is something like
11397 template <class T> friend struct A<T>::B. */
11404 }
11408 {
11409 /* friend class C;
11411 where C hasn't been declared yet. Let's lookup name
11412 from namespace scope directly, bypassing any name that
11413 come from dependent base class. */
11416 /* The call to xref_tag_from_type does injection for friend
11417 classes. */
11419 friend_type =
11423 }
11425 /* friend class C<T>; */
11428 /* Otherwise it's
11430 friend class C;
11432 where C is already declared or
11434 friend class C<int>;
11436 We don't have to do anything in these cases. */
11439 /* Trick make_friend_class into realizing that the friend
11440 we're adding is a template, not an ordinary class. It's
11441 important that we use make_friend_class since it will
11442 perform some error-checking and output cross-reference
11443 information. */
11451 }
11452 else
11453 {
11454 /* Build new DECL_FRIENDLIST. */
11455 tree r;
11457 /* The file and line for this declaration, to
11458 assist in error message reporting. Since we
11459 called push_tinst_level above, we don't need to
11460 restore these. */
11464 {
11467 }
11472 {
11475 }
11476 }
11477 }
11478 }
11481 {
11482 /* Restore these before substituting into the lambda capture
11483 initializers. */
11486 }
11488 /* Set the file and line number information to whatever is given for
11489 the class itself. This puts error messages involving generated
11490 implicit functions at a predictable point, and the same point
11491 that would be used for non-template classes. */
11498 /* We don't instantiate default arguments for member functions. 14.7.1:
11500 The implicit instantiation of a class template specialization causes
11501 the implicit instantiation of the declarations, but not of the
11502 definitions or default arguments, of the class member functions,
11503 member classes, static data members and member templates.... */
11505 /* Some typedefs referenced from within the template code need to be access
11506 checked at template instantiation time, i.e now. These types were
11507 added to the template at parsing time. Let's get those and perform
11508 the access checks then. */
11517 /* The vtable for a template class can be emitted in any translation
11518 unit in which the class is instantiated. When there is no key
11519 method, however, finish_struct_1 will already have added TYPE to
11520 the keyed_classes. */
11525 }
11527 /* Wrapper for instantiate_class_template_1. */
11529 tree
11531 {
11532 tree ret;
11537 }
11539 static tree
11541 {
11542 tree r;
11548 else
11549 {
11556 }
11558 }
11560 /* Given a function parameter pack TMPL_PARM and some function parameters
11561 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
11562 and set *SPEC_P to point at the next point in the list. */
11564 tree
11566 {
11567 /* Collect all of the extra "packed" parameters into an
11568 argument pack. */
11569 tree parmvec;
11579 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
11583 {
11588 }
11590 /* Build the argument packs. */
11595 }
11597 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
11598 NONTYPE_ARGUMENT_PACK. */
11600 static tree
11602 {
11604 }
11606 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
11607 pack expansion with no extra args, 2 if it has extra args, or 0
11608 if it is not a pack expansion. */
11610 static int
11612 {
11614 /* We're being called before this happens in tsubst_pack_expansion. */
11621 /* A decl pack is itself an expansion. */
11628 }
11631 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
11633 static tree
11635 {
11642 }
11644 /* This is a subroutine of tsubst_pack_expansion.
11646 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
11647 mechanism to store the (non complete list of) arguments of the
11648 substitution and return a non substituted pack expansion, in order
11649 to wait for when we have enough arguments to really perform the
11650 substitution. */
11652 static bool
11656 {
11657 /* If one pack has an expansion and another pack has a normal
11658 argument or if one pack has an empty argument and an another
11659 one hasn't then tsubst_pack_expansion cannot perform the
11660 substitution and need to fall back on the
11661 PACK_EXPANSION_EXTRA mechanism. */
11669 {
11672 parm_pack;
11674 {
11679 /* We can't substitute a pack expansion with extra args into
11680 our pattern. */
11684 else
11686 }
11690 }
11692 }
11694 /* [temp.variadic]/6 says that:
11696 The instantiation of a pack expansion [...]
11697 produces a list E1,E2, ..., En, where N is the number of elements
11698 in the pack expansion parameters.
11700 This subroutine of tsubst_pack_expansion produces one of these Ei.
11702 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11703 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11704 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11705 INDEX is the index 'i' of the element Ei to produce. ARGS,
11706 COMPLAIN, and IN_DECL are the same parameters as for the
11707 tsubst_pack_expansion function.
11709 The function returns the resulting Ei upon successful completion,
11710 or error_mark_node.
11712 Note that this function possibly modifies the ARGS parameter, so
11713 it's the responsibility of the caller to restore it. */
11715 static tree
11717 tree parm_packs,
11719 tree args /* This parm gets
11721 tsubst_flags_t complain,
11722 tree in_decl)
11723 {
11724 tree t;
11727 /* For each parameter pack, change the substitution of the parameter
11728 pack to the ith argument in its argument pack, then expand the
11729 pattern. */
11731 {
11736 ith_elem_is_expansion |=
11739 /* Select the Ith argument from the pack. */
11743 {
11745 {
11750 }
11751 else
11753 }
11754 else
11755 {
11760 {
11762 /* Update the corresponding argument. */
11764 }
11765 else
11766 /* Re-use the ARGUMENT_PACK_SELECT. */
11768 }
11770 }
11772 // Any local specialization bindings arising from this substitution
11773 // cannot be reused for a different INDEX.
11776 /* Substitute into the PATTERN with the (possibly altered)
11777 arguments. */
11779 /* Expanding a fixed parameter pack from
11780 coerce_template_parameter_pack. */
11785 {
11788 else
11791 }
11795 else
11798 /* If the Ith argument pack element is a pack expansion, then
11799 the Ith element resulting from the substituting is going to
11800 be a pack expansion as well. */
11805 }
11807 /* When the unexpanded parameter pack in a fold expression expands to an empty
11808 sequence, the value of the expression is as follows; the program is
11809 ill-formed if the operator is not listed in this table.
11811 && true
11812 || false
11813 , void() */
11815 tree
11817 {
11821 {
11830 }
11836 }
11838 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11839 form an expression that combines the two terms using the
11840 operator of T. */
11842 static tree
11844 {
11848 // Handle compound assignment operators.
11853 {
11861 complain);
11862 }
11863 }
11865 /* Substitute ARGS into the pack of a fold expression T. */
11869 {
11871 }
11873 /* Substitute ARGS into the pack of a fold expression T. */
11877 {
11879 }
11881 /* Expand a PACK of arguments into a grouped as left fold.
11882 Given a pack containing elements A0, A1, ..., An and an
11883 operator @, this builds the expression:
11885 ((A0 @ A1) @ A2) ... @ An
11887 Note that PACK must not be empty.
11889 The operator is defined by the original fold expression T. */
11891 static tree
11893 {
11896 {
11899 }
11901 }
11903 /* Substitute into a unary left fold expression. */
11905 static tree
11907 tree in_decl)
11908 {
11913 {
11917 }
11920 else
11922 }
11924 /* Substitute into a binary left fold expression.
11926 Do ths by building a single (non-empty) vector of argumnts and
11927 building the expression from those elements. */
11929 static tree
11931 tree in_decl)
11932 {
11941 {
11946 }
11954 }
11956 /* Expand a PACK of arguments into a grouped as right fold.
11957 Given a pack containing elementns A0, A1, ..., and an
11958 operator @, this builds the expression:
11960 A0@ ... (An-2 @ (An-1 @ An))
11962 Note that PACK must not be empty.
11964 The operator is defined by the original fold expression T. */
11966 tree
11968 {
11969 // Build the expression.
11973 {
11976 }
11978 }
11980 /* Substitute into a unary right fold expression. */
11982 static tree
11984 tree in_decl)
11985 {
11990 {
11994 }
11997 else
11999 }
12001 /* Substitute into a binary right fold expression.
12003 Do ths by building a single (non-empty) vector of arguments and
12004 building the expression from those elements. */
12006 static tree
12008 tree in_decl)
12009 {
12018 {
12023 }
12032 }
12034 /* Walk through the pattern of a pack expansion, adding everything in
12035 local_specializations to a list. */
12037 struct el_data
12038 {
12040 tree extra;
12041 tsubst_flags_t complain;
12045 };
12046 static tree
12048 {
12054 /* Remember local typedefs (85214). */
12060 {
12062 /* Don't mess with variables declared within the pattern. */
12065 {
12066 /* Maybe pull out the PARM_DECL for a partial instantiation. */
12069 {
12075 }
12077 {
12078 /* Handle lambda capture here, since we aren't doing any
12079 substitution now, and so tsubst_copy won't call
12080 process_outer_var_ref. */
12084 {
12090 {
12091 /* Make a new NONTYPE_ARGUMENT_PACK of the capture
12092 proxies. */
12094 {
12099 }
12101 }
12102 }
12103 }
12104 }
12108 }
12110 }
12111 static tree
12113 {
12117 }
12119 /* Extract any uses of local_specializations from PATTERN and add them to ARGS
12120 for use in PACK_EXPANSION_EXTRA_ARGS. */
12122 tree
12124 {
12130 }
12132 /* Apply any local specializations from PACK_EXPANSION_EXTRA_ARGS and add the
12133 normal template args to ARGS. */
12135 tree
12137 {
12139 {
12141 {
12142 /* The partial instantiation involved local declarations collected in
12143 extract_local_specs; map from the general template to our local
12144 context. */
12150 /* else inst is already a full instantiation of the pack. */
12152 }
12155 }
12157 }
12159 /* Substitute ARGS into T, which is an pack expansion
12160 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
12161 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
12162 (if only a partial substitution could be performed) or
12163 ERROR_MARK_NODE if there was an error. */
12164 tree
12166 tree in_decl)
12167 {
12168 tree pattern;
12173 tree result;
12181 /* Add in any args remembered from an earlier partial instantiation. */
12186 /* Determine the argument packs that will instantiate the parameter
12187 packs used in the expansion expression. While we're at it,
12188 compute the number of arguments to be expanded and make sure it
12189 is consistent. */
12192 {
12199 {
12205 complain);
12206 else
12210 }
12212 {
12214 {
12217 parm_pack);
12219 }
12222 }
12224 {
12225 /* We know we have correct local_specializations if this
12226 expansion is at function scope, or if we're dealing with a
12227 local parameter in a requires expression; for the latter,
12228 tsubst_requires_expr set it up appropriately. */
12231 else
12232 /* We can't rely on local_specializations for a parameter
12233 name used later in a function declaration (such as in a
12234 late-specified return type). Even if it exists, it might
12235 have the wrong value for a recursive call. */
12239 {
12240 /* This parameter pack was used in an unevaluated context. Just
12241 make a dummy decl, since it's only used for its type. */
12246 /* Partial instantiation of the parm_pack, we can't build
12247 up an argument pack yet. */
12249 else
12251 }
12253 /* This argument pack isn't fully instantiated yet. We set this
12254 flag rather than clear arg_pack because we do want to do the
12255 optimization below, and we don't want to substitute directly
12256 into the pattern (as that would expose a NONTYPE_ARGUMENT_PACK
12257 where it isn't expected). */
12259 }
12261 {
12265 }
12266 else
12267 {
12273 }
12280 /* This can only happen if we forget to expand an argument
12281 pack somewhere else. Just return an error, silently. */
12282 {
12286 }
12289 {
12293 /* Don't bother trying to do a partial substitution with
12294 incomplete packs; we'll try again after deduction. */
12302 {
12307 pattern);
12308 else
12310 pattern);
12312 }
12314 /* Keep track of the parameter packs and their corresponding
12315 argument packs. */
12318 }
12319 else
12320 {
12321 /* We can't substitute for this parameter pack. We use a flag as
12322 well as the missing_level counter because function parameter
12323 packs don't have a level. */
12326 }
12327 }
12329 /* If the expansion is just T..., return the matching argument pack, unless
12330 we need to call convert_from_reference on all the elements. This is an
12331 important optimization; see c++/68422. */
12334 {
12337 /* If the argument pack is a single pack expansion, pull it out. */
12342 /* Types need no adjustment, nor does sizeof..., and if we still have
12343 some pack expansion args we won't do anything yet. */
12348 /* Also optimize expression pack expansions if we can tell that the
12349 elements won't have reference type. */
12355 /* Otherwise use the normal path so we get convert_from_reference. */
12356 }
12358 /* We cannot expand this expansion expression, because we don't have
12359 all of the argument packs we need. */
12361 {
12362 /* We got some full packs, but we can't substitute them in until we
12363 have values for all the packs. So remember these until then. */
12369 }
12371 {
12372 /* There were no real arguments, we're just replacing a parameter
12373 pack with another version of itself. Substitute into the
12374 pattern and return a PACK_EXPANSION_*. The caller will need to
12375 deal with that. */
12379 else
12383 }
12388 {
12389 /* We're in a late-specified return type, so create our own local
12390 specializations map; the current map is either NULL or (in the
12391 case of recursive unification) might have bindings that we don't
12392 want to use or alter. */
12395 }
12397 /* For each argument in each argument pack, substitute into the
12398 pattern. */
12402 {
12404 i,
12406 in_decl);
12409 {
12412 }
12413 }
12415 /* Update ARGS to restore the substitution from parameter packs to
12416 their argument packs. */
12418 {
12425 else
12426 {
12434 /* Update the corresponding argument. */
12438 else
12440 }
12441 }
12444 {
12447 }
12449 /* If the dependent pack arguments were such that we end up with only a
12450 single pack expansion again, there's no need to keep it in a TREE_VEC. */
12456 }
12458 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
12459 TMPL. We do this using DECL_PARM_INDEX, which should work even with
12460 parameter packs; all parms generated from a function parameter pack will
12461 have the same DECL_PARM_INDEX. */
12463 tree
12465 {
12467 tree patparm;
12470 {
12476 }
12477 else
12478 {
12483 }
12486 }
12488 /* Make an argument pack out of the TREE_VEC VEC. */
12490 static tree
12492 {
12493 tree pack;
12497 else
12498 {
12501 }
12504 }
12506 /* Return an exact copy of template args T that can be modified
12507 independently. */
12509 static tree
12511 {
12519 {
12524 }
12530 }
12532 /* Substitute ARGS into the vector or list of template arguments T. */
12534 static tree
12536 {
12548 {
12550 tree new_arg;
12555 {
12556 /* Substitute into an expansion expression. */
12560 /* Add to the expanded length adjustment the number of
12561 expanded arguments. We subtract one from this
12562 measurement, because the argument pack expression
12563 itself is already counted as 1 in
12564 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
12565 the argument pack is empty. */
12567 }
12569 {
12570 /* Substitute into each of the arguments. */
12579 else
12584 }
12585 else
12594 }
12599 /* Make space for the expanded arguments coming from template
12600 argument packs. */
12602 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
12603 arguments for a member template.
12604 In that case each TREE_VEC in ORIG_T represents a level of template
12605 arguments, and ORIG_T won't carry any non defaulted argument count.
12606 It will rather be the nested TREE_VECs that will carry one.
12607 In other words, ORIG_T carries a non defaulted argument count only
12608 if it doesn't contain any nested TREE_VEC. */
12610 {
12614 }
12616 {
12620 {
12623 /* Now expand the template argument pack "in place". */
12626 }
12627 else
12628 {
12630 out++;
12631 }
12632 }
12635 }
12637 /* Substitute ARGS into one level PARMS of template parameters. */
12639 static tree
12641 {
12648 {
12656 }
12659 }
12661 /* Return the result of substituting ARGS into the template parameters
12662 given by PARMS. If there are m levels of ARGS and m + n levels of
12663 PARMS, then the result will contain n levels of PARMS. For
12664 example, if PARMS is `template <class T> template <class U>
12665 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
12666 result will be `template <int*, double, class V>'. */
12668 static tree
12670 {
12674 /* When substituting into a template, we must set
12675 PROCESSING_TEMPLATE_DECL as the template parameters may be
12676 dependent if they are based on one-another, and the dependency
12677 predicates are short-circuit outside of templates. */
12684 {
12691 }
12696 }
12698 /* Return the result of substituting ARGS into one template parameter
12699 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
12700 parameter and which TREE_PURPOSE is the default argument of the
12701 template parameter. */
12703 static tree
12705 {
12726 }
12728 /* Substitute the ARGS into the indicated aggregate (or enumeration)
12729 type T. If T is not an aggregate or enumeration type, it is
12730 handled as if by tsubst. IN_DECL is as for tsubst. If
12731 ENTERING_SCOPE is nonzero, T is the context for a template which
12732 we are presently tsubst'ing. Return the substituted value. */
12734 static tree
12736 tree args,
12737 tsubst_flags_t complain,
12738 tree in_decl,
12740 {
12745 {
12750 /* Fall through. */
12754 {
12755 tree argvec;
12756 tree context;
12757 tree r;
12759 /* In "sizeof(X<I>)" we need to evaluate "I". */
12760 cp_evaluated ev;
12762 /* First, determine the context for the type we are looking
12763 up. */
12766 {
12769 /* If context is a nested class inside a class template,
12770 it may still need to be instantiated (c++/33959). */
12772 }
12774 /* Then, figure out what arguments are appropriate for the
12775 type we are trying to find. For example, given:
12777 template <class T> struct S;
12778 template <class T, class U> void f(T, U) { S<U> su; }
12780 and supposing that we are instantiating f<int, double>,
12781 then our ARGS will be {int, double}, but, when looking up
12782 S we only want {double}. */
12787 else
12788 {
12792 }
12795 }
12796 else
12797 /* This is not a template type, so there's nothing to do. */
12802 }
12803 }
12807 /* Substitute into the default argument ARG (a default argument for
12808 FN), which has the indicated TYPE. */
12810 tree
12812 tsubst_flags_t complain)
12813 {
12816 /* This can happen in invalid code. */
12834 /* This default argument came from a template. Instantiate the
12835 default argument here, not in tsubst. In the case of
12836 something like:
12838 template <class T>
12839 struct S {
12840 static T t();
12841 void f(T = t());
12842 };
12844 we must be careful to do name lookup in the scope of S<T>,
12845 rather than in the current class. */
12851 /* The default argument expression may cause implicitly defined
12852 member functions to be synthesized, which will result in garbage
12853 collection. We must treat this situation as if we were within
12854 the body of function so as to avoid collecting live data on the
12855 stack. */
12864 /* Make sure the default argument is reasonable. */
12877 {
12881 }
12884 }
12886 /* Substitute into all the default arguments for FN. */
12888 static void
12890 {
12891 tree arg;
12892 tree tmpl_args;
12896 /* If this function is not yet instantiated, we certainly don't need
12897 its default arguments. */
12900 /* Don't do this again for clones. */
12906 arg;
12912 complain);
12913 }
12915 /* Hash table mapping a FUNCTION_DECL to its dependent explicit-specifier. */
12918 /* Store a pair to EXPLICIT_SPECIFIER_MAP. */
12920 void
12922 {
12927 }
12929 /* Lookup an element in EXPLICIT_SPECIFIER_MAP. */
12931 static tree
12933 {
12935 }
12937 /* Subroutine of tsubst_decl for the case when T is a FUNCTION_DECL. */
12939 static tree
12941 tree lambda_fntype)
12942 {
12947 /* Nobody should be tsubst'ing into non-template functions. */
12951 {
12952 /* If T is not dependent, just return it. */
12957 /* Calculate the most general template of which R is a
12958 specialization. */
12961 /* We're substituting a lambda function under tsubst_lambda_expr but not
12962 directly from it; find the matching function we're already inside.
12963 But don't do this if T is a generic lambda with a single level of
12964 template parms, as in that case we're doing a normal instantiation. */
12970 /* Calculate the complete set of arguments used to
12971 specialize R. */
12973 (DECL_TEMPLATE_RESULT
12979 /* Check to see if we already have this specialization. */
12981 {
12985 }
12987 /* We can see more levels of arguments than parameters if
12988 there was a specialization of a member template, like
12989 this:
12991 template <class T> struct S { template <class U> void f(); }
12992 template <> template <class U> void S<int>::f(U);
12994 Here, we'll be substituting into the specialization,
12995 because that's where we can find the code we actually
12996 want to generate, but we'll have enough arguments for
12997 the most general template.
12999 We also deal with the peculiar case:
13001 template <class T> struct S {
13002 template <class U> friend void f();
13003 };
13004 template <class U> void f() {}
13005 template S<int>;
13006 template void f<double>();
13008 Here, the ARGS for the instantiation of will be {int,
13009 double}. But, we only need as many ARGS as there are
13010 levels of template parameters in CODE_PATTERN. We are
13011 careful not to get fooled into reducing the ARGS in
13012 situations like:
13014 template <class T> struct S { template <class U> void f(U); }
13015 template <class T> template <> void S<T>::f(int) {}
13017 which we can spot because the pattern will be a
13018 specialization in this case. */
13025 }
13026 else
13027 {
13028 /* This special case arises when we have something like this:
13030 template <class T> struct S {
13031 friend void f<int>(int, double);
13032 };
13034 Here, the DECL_TI_TEMPLATE for the friend declaration
13035 will be an IDENTIFIER_NODE. We are being called from
13036 tsubst_friend_function, and we want only to create a
13037 new decl (R) with appropriate types so that we can call
13038 determine_specialization. */
13041 }
13058 /* If we hit excessive deduction depth, the type is bogus even if
13059 it isn't error_mark_node, so don't build a decl. */
13063 /* We do NOT check for matching decls pushed separately at this
13064 point, as they may not represent instantiations of this
13065 template, and in any case are considered separate under the
13066 discrete model. */
13070 /* Clear out the mangled name and RTL for the instantiation. */
13073 /* Leave DECL_INITIAL set on deleted instantiations. */
13078 /* Handle explicit(dependent-expr). */
13080 {
13087 }
13089 /* OpenMP UDRs have the only argument a reference to the declared
13090 type. We want to diagnose if the declared type is a reference,
13091 which is invalid, but as references to references are usually
13092 quietly merged, diagnose it here. */
13094 {
13095 tree argtype
13100 "reference type %qT in "
13104 argtype);
13105 }
13108 /* Type-conversion operator. Reconstruct the name, in
13109 case it's the name of one of the template's parameters. */
13119 {
13123 }
13130 /* If this is an instantiation of a function with internal
13131 linkage, we already know what object file linkage will be
13132 assigned to the instantiation. */
13141 /* We'll re-clone as appropriate in instantiate_template. */
13144 /* If we aren't complaining now, return on error before we register
13145 the specialization so that we'll complain eventually. */
13151 /* When instantiating a constrained member, substitute
13152 into the constraints to create a new constraint. */
13155 {
13158 }
13165 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
13166 this in the special friend case mentioned above where
13167 GEN_TMPL is NULL. */
13169 {
13174 tree new_r
13177 /* We instantiated this while substituting into
13178 the type earlier (template/friend54.C). */
13181 /* We're not supposed to instantiate default arguments
13182 until they are called, for a template. But, for a
13183 declaration like:
13185 template <class T> void f ()
13186 { extern void g(int i = T()); }
13188 we should do the substitution when the template is
13189 instantiated. We handle the member function case in
13190 instantiate_class_template since the default arguments
13191 might refer to other members of the class. */
13196 }
13197 else
13200 /* Copy the list of befriending classes. */
13204 {
13208 }
13211 {
13215 /* If this is an instantiation of a member template, clone it.
13216 If it isn't, that'll be handled by
13217 clone_constructors_and_destructors. */
13220 }
13226 /* Possibly limit visibility based on template args. */
13229 {
13233 }
13242 }
13244 /* Subroutine of tsubst_decl for the case when T is a TEMPLATE_DECL. */
13246 static tree
13248 tree lambda_fntype)
13249 {
13250 /* We can get here when processing a member function template,
13251 member class template, or template template parameter. */
13254 tree spec;
13255 tree tmpl_args;
13256 tree full_args;
13257 tree r;
13261 {
13262 /* Template template parameter is treated here. */
13266 /* If we get a real template back, return it. This can happen in
13267 the context of most_specialized_partial_spec. */
13270 else
13271 /* The new TEMPLATE_DECL was built in
13272 reduce_template_parm_level. */
13275 }
13278 {
13279 /* We might already have an instance of this template.
13280 The ARGS are for the surrounding class type, so the
13281 full args contain the tsubst'd args for the context,
13282 plus the innermost args from the template decl. */
13286 /* Because this is a template, the arguments will still be
13287 dependent, even after substitution. If
13288 PROCESSING_TEMPLATE_DECL is not set, the dependency
13289 predicates will short-circuit. */
13297 /* If this is a default template template argument,
13298 tsubst might not have changed anything. */
13305 {
13307 /* Type partial instantiations are stored as the type by
13308 lookup_template_class_1, not here as the template. */
13311 }
13312 }
13314 /* Make a new template decl. It will be similar to the
13315 original, but will record the current template arguments.
13316 We also create a new function declaration, which is just
13317 like the old one, but points to this new template, rather
13318 than the old one. */
13323 // Build new template info linking to the original template decl.
13325 {
13328 }
13329 else
13332 /* The template parameters for this new template are all the
13333 template parameters for the old template, except the
13334 outermost level of parameters. */
13337 complain);
13341 {
13342 tree new_type;
13350 /* For a partial specialization, we need to keep pointing to
13351 the primary template. */
13357 }
13358 else
13359 {
13360 tree new_decl;
13364 else
13374 {
13377 }
13378 else
13379 {
13382 }
13383 }
13393 /* Record this non-type partial instantiation. */
13399 }
13401 /* True if FN is the op() for a lambda in an uninstantiated template. */
13403 bool
13405 {
13410 }
13412 /* True if FN is the substitution (via tsubst_lambda_expr) of a function for
13413 which the above is true. */
13415 bool
13417 {
13423 }
13425 /* We're instantiating a variable from template function TCTX. Return the
13426 corresponding current enclosing scope. This gets complicated because lambda
13427 functions in templates are regenerated rather than instantiated, but generic
13428 lambda functions are subsequently instantiated. */
13430 static tree
13432 {
13442 {
13453 {
13457 }
13461 }
13463 }
13465 /* Substitute the ARGS into the T, which is a _DECL. Return the
13466 result of the substitution. Issue error and warning messages under
13467 control of COMPLAIN. */
13469 static tree
13471 {
13472 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13473 location_t saved_loc;
13478 /* Set the filename and linenumber to improve error-reporting. */
13483 {
13493 {
13501 {
13502 /* If there is a local specialization that isn't a
13503 parameter pack, it means that we're doing a "simple"
13504 substitution from inside tsubst_pack_expansion. Just
13505 return the local specialization (which will be a single
13506 parm). */
13513 /* Expand the TYPE_PACK_EXPANSION that provides the types for
13514 the parameters in this function parameter pack. */
13518 {
13521 /* Zero-length parameter packs are boring. Just substitute
13522 into the chain. */
13526 }
13527 else
13528 {
13529 /* All we did was update the type. Make a note of that. */
13532 }
13533 }
13535 /* Loop through all of the parameters we'll build. When T is
13536 a function parameter pack, LEN is the number of expanded
13537 types in EXPANDED_TYPES; otherwise, LEN is 1. */
13540 {
13547 /* We're on the Ith parameter of the function parameter
13548 pack. */
13549 {
13550 /* Get the Ith type. */
13553 /* Rename the parameter to include the index. */
13556 }
13558 /* We're dealing with a normal parameter. */
13566 {
13569 else
13572 }
13582 /* Keep track of the first new parameter we
13583 generate. That's what will be returned to the
13584 caller. */
13588 /* Build a proper chain of parameters when substituting
13589 into a function parameter pack. */
13592 }
13594 /* If cp_unevaluated_operand is set, we're just looking for a
13595 single dummy parameter, so don't keep going. */
13600 /* FIRST_R contains the start of the chain we've built. */
13602 }
13606 {
13613 {
13614 /* This field is a lambda capture pack. Return a TREE_VEC of
13615 the expanded fields to instantiate_class_template_1. */
13619 {
13622 }
13623 else
13624 {
13625 /* All we did was update the type. Make a note of that. */
13628 }
13629 }
13632 {
13635 {
13639 }
13649 /* For bit-fields, DECL_BIT_FIELD_REPRESENTATIVE gives the
13650 number of bits. */
13656 {
13657 /* Set up DECL_TEMPLATE_INFO so that we can get at the
13658 NSDMI in perform_member_init. Still set DECL_INITIAL
13659 so that we know there is one. */
13664 }
13665 /* We don't have to set DECL_CONTEXT here; it is set by
13666 finish_member_declaration. */
13674 }
13678 }
13682 /* We reach here only for member using decls. We also need to check
13683 uses_template_parms because DECL_DEPENDENT_P is not set for a
13684 using-declaration that designates a member of the current
13685 instantiation (c++/53549). */
13688 {
13692 {
13697 {
13701 {
13704 }
13705 else
13706 {
13709 }
13711 }
13712 }
13713 else
13714 {
13720 else
13721 {
13724 }
13725 }
13726 }
13727 else
13728 {
13731 }
13736 {
13739 tree spec;
13741 tree ctx;
13750 {
13751 /* If this is the canonical decl, we don't have to
13752 mess with instantiations, and often we can't (for
13753 typename, template type parms and such). Note that
13754 TYPE_NAME is not correct for the above test if
13755 we've copied the type for a typedef. */
13761 }
13763 /* Check to see if we already have the specialization we
13764 need. */
13767 {
13768 /* T is a static data member or namespace-scope entity.
13769 We have to substitute into namespace-scope variables
13770 (not just variable templates) because of cases like:
13772 template <class T> void f() { extern T t; }
13774 where the entity referenced is not known until
13775 instantiation time. */
13779 {
13781 complain,
13783 /* If CTX is unchanged, then T is in fact the
13784 specialization we want. That situation occurs when
13785 referencing a static data member within in its own
13786 class. We can use pointer equality, rather than
13787 same_type_p, because DECL_CONTEXT is always
13788 canonical... */
13790 /* ... unless T is a member template; in which
13791 case our caller can be willing to create a
13792 specialization of that template represented
13793 by T. */
13797 }
13800 {
13805 argvec = (coerce_innermost_template_parms
13813 }
13814 }
13815 else
13816 {
13817 /* A local variable. */
13819 /* Subsequent calls to pushdecl will fill this in. */
13821 /* Unless this is a reference to a static variable from an
13822 enclosing function, in which case we need to fill it in now. */
13824 {
13828 }
13830 }
13831 /* If we already have the specialization we need, there is
13832 nothing more to do. */
13834 {
13837 }
13839 /* Create a new node for the specialization we need. */
13841 {
13844 else
13852 {
13853 /* Mask off any template args past the variable's context so we
13854 don't replace the auto with an unrelated argument. */
13858 /* This should never happen with the new lambda instantiation
13859 model, but keep the handling just in case. */
13862 }
13864 /* Substituting the type might have recursively instantiated this
13865 same alias (c++/86171). */
13868 {
13871 }
13872 }
13875 {
13881 {
13882 /* It may seem that this case cannot occur, since:
13884 typedef void f();
13885 void g() { f x; }
13887 declares a function, not a variable. However:
13889 typedef void f();
13890 template <typename T> void g() { T t; }
13891 template void g<f>();
13893 is an attempt to declare a variable with function
13894 type. */
13896 /* R is not yet sufficiently initialized, so we
13897 just use its name. */
13900 }
13902 /* Wait until cp_finish_decl to set this again, to handle
13903 circular dependency (template/instantiate6.C). */
13908 {
13913 {
13916 }
13918 }
13922 }
13928 /* Clear out the mangled name and RTL for the instantiation. */
13932 /* The initializer must not be expanded until it is required;
13933 see [temp.inst]. */
13937 {
13943 /* Possibly limit visibility based on template args. */
13946 {
13950 }
13952 }
13955 {
13956 /* A static data member declaration is always marked
13957 external when it is declared in-class, even if an
13958 initializer is present. We mimic the non-template
13959 processing here. */
13968 }
13969 else
13970 {
13975 }
13983 /* Preserve a typedef that names a type. */
13985 {
13989 /* An alias template specialization can be dependent
13990 even if its underlying type is not. */
13992 }
13995 }
14000 }
14001 #undef RETURN
14003 out:
14004 /* Restore the file and line information. */
14008 }
14010 /* Substitute into the ARG_TYPES of a function type.
14011 If END is a TREE_CHAIN, leave it and any following types
14012 un-substituted. */
14014 static tree
14016 tree args,
14017 tree end,
14018 tsubst_flags_t complain,
14019 tree in_decl)
14020 {
14021 tree remaining_arg_types;
14025 tree default_arg;
14036 {
14037 /* For a pack expansion, perform substitution on the
14038 entire expression. Later on, we'll handle the arguments
14039 one-by-one. */
14044 /* So that we'll spin through the parameters, one by one. */
14046 else
14047 {
14048 /* We only partially substituted into the parameter
14049 pack. Our type is TYPE_PACK_EXPANSION. */
14052 }
14053 }
14066 {
14068 {
14072 }
14074 }
14075 /* DR 657. */
14079 /* Do array-to-pointer, function-to-pointer conversion, and ignore
14080 top-level qualifiers as required. */
14083 /* We do not substitute into default arguments here. The standard
14084 mandates that they be instantiated only when needed, which is
14085 done in build_over_call. */
14088 /* Except that we do substitute default arguments under tsubst_lambda_expr,
14089 since the new op() won't have any associated template arguments for us
14090 to refer to later. */
14096 {
14097 /* We've instantiated a template before its default arguments
14098 have been parsed. This can happen for a nested template
14099 class, and is not an error unless we require the default
14100 argument in a call of this function. */
14101 remaining_arg_types =
14104 remaining_arg_types);
14105 }
14106 else
14107 remaining_arg_types =
14109 }
14112 }
14114 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
14115 *not* handle the exception-specification for FNTYPE, because the
14116 initial substitution of explicitly provided template parameters
14117 during argument deduction forbids substitution into the
14118 exception-specification:
14120 [temp.deduct]
14122 All references in the function type of the function template to the
14123 corresponding template parameters are replaced by the specified tem-
14124 plate argument values. If a substitution in a template parameter or
14125 in the function type of the function template results in an invalid
14126 type, type deduction fails. [Note: The equivalent substitution in
14127 exception specifications is done only when the function is instanti-
14128 ated, at which point a program is ill-formed if the substitution
14129 results in an invalid type.] */
14131 static tree
14133 tree args,
14134 tsubst_flags_t complain,
14135 tree in_decl)
14136 {
14137 tree return_type;
14139 tree fntype;
14141 /* The TYPE_CONTEXT is not used for function/method types. */
14144 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
14145 failure. */
14149 {
14150 /* Substitute the argument types. */
14162 {
14163 /* DR 1207: 'this' is in scope in the trailing return type. */
14165 }
14167 /* Substitute the return type. */
14171 {
14174 }
14175 }
14176 else
14177 /* Substitute the return type. */
14182 /* DR 486 clarifies that creation of a function type with an
14183 invalid return type is a deduction failure. */
14186 {
14188 {
14191 else
14193 }
14195 }
14196 /* And DR 657. */
14201 {
14202 /* Substitute the argument types. */
14207 }
14209 /* Construct a new type node and return it. */
14211 {
14214 }
14215 else
14216 {
14218 /* Don't pick up extra function qualifiers from the basetype. */
14221 {
14222 /* [temp.deduct]
14224 Type deduction may fail for any of the following
14225 reasons:
14227 -- Attempting to create "pointer to member of T" when T
14228 is not a class type. */
14231 r);
14233 }
14237 }
14240 /* See comment above. */
14246 }
14248 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
14249 ARGS into that specification, and return the substituted
14250 specification. If there is no specification, return NULL_TREE. */
14252 static tree
14254 tree args,
14255 tsubst_flags_t complain,
14256 tree in_decl,
14258 {
14259 tree specs;
14260 tree new_specs;
14265 {
14266 /* A noexcept-specifier. */
14271 {
14272 /* Defer instantiation of noexcept-specifiers to avoid
14273 excessive instantiations (c++/49107). */
14276 {
14277 /* We already partially instantiated this member template,
14278 so combine the new args with the old. */
14283 }
14284 else
14285 {
14288 }
14289 }
14290 else
14291 {
14293 {
14295 args);
14297 }
14298 new_specs = tsubst_copy_and_build
14301 }
14303 }
14305 {
14308 else
14310 {
14311 tree spec;
14316 {
14317 /* Expand the pack expansion type. */
14320 in_decl);
14326 else
14327 {
14328 /* We're substituting into a member template, so
14329 we got a TYPE_PACK_EXPANSION back. Add that
14330 expansion and move on. */
14334 expanded_specs,
14335 complain);
14338 }
14339 }
14342 {
14345 else
14350 complain);
14351 }
14354 }
14355 }
14357 }
14359 /* Take the tree structure T and replace template parameters used
14360 therein with the argument vector ARGS. IN_DECL is an associated
14361 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
14362 Issue error and warning messages under control of COMPLAIN. Note
14363 that we must be relatively non-tolerant of extensions here, in
14364 order to preserve conformance; if we allow substitutions that
14365 should not be allowed, we may allow argument deductions that should
14366 not succeed, and therefore report ambiguous overload situations
14367 where there are none. In theory, we could allow the substitution,
14368 but indicate that it should have failed, and allow our caller to
14369 make sure that the right thing happens, but we don't try to do this
14370 yet.
14372 This function is used for dealing with types, decls and the like;
14373 for expressions, use tsubst_expr or tsubst_copy. */
14375 tree
14377 {
14400 else
14405 /* Reuse typedefs. We need to do this to handle dependent attributes,
14406 such as attribute aligned. */
14409 {
14413 {
14414 /* DECL represents an alias template and we want to
14415 instantiate it. */
14419 }
14423 {
14427 }
14432 else
14433 /* The typedef is from a non-template context. */
14437 {
14439 r = cp_build_qualified_type_real
14443 }
14444 else
14445 {
14446 /* We don't have an instantiation yet, so drop the typedef. */
14451 }
14452 }
14469 {
14495 {
14501 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
14502 needed. */
14508 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
14509 with TREE_SIDE_EFFECTS that indicates this is not an integral
14510 constant expression. */
14513 {
14516 }
14519 }
14525 {
14531 /* Early in template argument deduction substitution, we don't
14532 want to reduce the level of 'auto', or it will be confused
14533 with a normal template parm in subsequent deduction. */
14545 {
14548 /* See through ARGUMENT_PACK_SELECT arguments. */
14551 }
14556 {
14558 /* If ARG is an argument pack, we don't actually want to
14559 perform a substitution here, because substitutions
14560 for argument packs are only done
14561 element-by-element. We can get to this point when
14562 substituting the type of a non-type template
14563 parameter pack, when that type actually contains
14564 template parameter packs from an outer template, e.g.,
14566 template<typename... Types> struct A {
14567 template<Types... Values> struct B { };
14568 }; */
14572 {
14578 return cp_build_qualified_type_real
14580 }
14582 {
14583 /* We are processing a type constructed from a
14584 template template parameter. */
14595 /* Consider this code:
14597 template <template <class> class Template>
14598 struct Internal {
14599 template <class Arg> using Bind = Template<Arg>;
14600 };
14602 template <template <class> class Template, class Arg>
14603 using Instantiate = Template<Arg>; //#0
14605 template <template <class> class Template,
14606 class Argument>
14607 using Bind =
14608 Instantiate<Internal<Template>::template Bind,
14609 Argument>; //#1
14611 When #1 is parsed, the
14612 BOUND_TEMPLATE_TEMPLATE_PARM representing the
14613 parameter `Template' in #0 matches the
14614 UNBOUND_CLASS_TEMPLATE representing the argument
14615 `Internal<Template>::template Bind'; We then want
14616 to assemble the type `Bind<Argument>' that can't
14617 be fully created right now, because
14618 `Internal<Template>' not being complete, the Bind
14619 template cannot be looked up in that context. So
14620 we need to "store" `Bind<Argument>' for later
14621 when the context of Bind becomes complete. Let's
14622 store that in a TYPENAME_TYPE. */
14626 argvec),
14627 typename_type,
14628 complain);
14630 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
14631 are resolving nested-types in the signature of a
14632 member function templates. Otherwise ARG is a
14633 TEMPLATE_DECL and is the real template to be
14634 instantiated. */
14642 complain);
14643 return cp_build_qualified_type_real
14645 }
14648 else
14649 /* TEMPLATE_PARM_INDEX. */
14651 }
14654 /* This can happen during the attempted tsubst'ing in
14655 unify. This means that we don't yet have any information
14656 about the template parameter in question. */
14659 /* If we get here, we must have been looking at a parm for a
14660 more deeply nested template. Make a new version of this
14661 template parameter, but with a lower level. */
14663 {
14668 {
14670 r = cp_build_qualified_type_real
14674 }
14681 /* Break infinite recursion when substituting the constraints
14690 /* Cache the simple case of lowering a type parameter. */
14692 else
14693 {
14704 {
14705 /* Propagate constraints on placeholders. */
14710 {
14713 }
14714 }
14717 /* We have reduced the level of the template
14718 template parameter, but not the levels of its
14719 template parameters, so canonical_type_parameter
14720 will not be able to find the canonical template
14721 template parameter for this level. Thus, we
14722 require structural equality checking to compare
14723 TEMPLATE_TEMPLATE_PARMs. */
14727 else
14731 {
14733 /* We might need to substitute into the types of non-type
14734 template parameters. */
14746 }
14747 }
14751 /* OK, now substitute the type of the non-type parameter. We
14752 couldn't do it earlier because it might be an auto parameter,
14753 and we wouldn't need to if we had an argument. */
14762 }
14765 }
14768 {
14776 {
14780 }
14783 {
14787 }
14790 {
14794 }
14800 }
14803 /* We should never be tsubsting a binfo. */
14807 /* A vector of template arguments. */
14813 {
14817 /* [temp.deduct]
14819 Type deduction may fail for any of the following
14820 reasons:
14822 -- Attempting to create a pointer to reference type.
14823 -- Attempting to create a reference to a reference type or
14824 a reference to void.
14826 Core issue 106 says that creating a reference to a reference
14827 during instantiation is no longer a cause for failure. We
14828 only enforce this check in strict C++98 mode. */
14832 {
14835 /* We keep track of the last time we issued this error
14836 message to avoid spewing a ton of messages during a
14837 single bad template instantiation. */
14840 {
14845 else
14848 }
14851 }
14855 {
14857 {
14860 type);
14861 else
14863 type);
14864 }
14866 }
14868 {
14872 }
14874 /* In C++0x, during template argument substitution, when there is an
14875 attempt to create a reference to a reference type, reference
14876 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
14878 "If a template-argument for a template-parameter T names a type
14879 that is a reference to a type A, an attempt to create the type
14880 'lvalue reference to cv T' creates the type 'lvalue reference to
14881 A,' while an attempt to create the type type rvalue reference to
14882 cv T' creates the type T"
14883 */
14884 r = cp_build_reference_type
14887 else
14892 /* Will this ever be needed for TYPE_..._TO values? */
14896 }
14898 {
14901 {
14902 /* [temp.deduct]
14904 Type deduction may fail for any of the following
14905 reasons:
14907 -- Attempting to create "pointer to member of T" when T
14908 is not a class type. */
14912 }
14914 {
14918 }
14920 {
14924 }
14927 {
14928 /* The type of the implicit object parameter gets its
14929 cv-qualifiers from the FUNCTION_TYPE. */
14930 tree memptr;
14931 tree method_type
14936 complain);
14937 }
14938 else
14941 complain);
14942 }
14945 {
14946 tree fntype;
14947 tree specs;
14952 /* Substitute the exception specification. */
14960 }
14962 {
14967 /* As an optimization, we avoid regenerating the array type if
14968 it will obviously be the same as T. */
14972 /* These checks should match the ones in create_array_type_for_decl.
14974 [temp.deduct]
14976 The deduction may fail for any of the following reasons:
14978 -- Attempting to create an array with an element type that
14979 is void, a function type, or a reference type, or [DR337]
14980 an abstract class type. */
14986 {
14990 }
15002 {
15005 }
15008 }
15011 {
15014 {
15020 {
15025 }
15027 }
15028 else
15040 {
15044 }
15046 {
15047 /* Normally, make_typename_type does not require that the CTX
15048 have complete type in order to allow things like:
15050 template <class T> struct S { typename S<T>::X Y; };
15052 But, such constructs have already been resolved by this
15053 point, so here CTX really should have complete type, unless
15054 it's a partial instantiation. */
15057 {
15061 }
15062 }
15069 {
15072 }
15075 {
15077 {
15081 else
15083 }
15085 {
15089 else
15091 }
15092 }
15094 return cp_build_qualified_type_real
15096 }
15099 {
15111 }
15114 {
15115 tree type;
15131 complain);
15132 }
15135 {
15136 tree type;
15147 {
15149 {
15153 }
15156 }
15167 else
15168 {
15172 /* In a template ~id could be either a complement expression
15173 or an unqualified-id naming a destructor; if instantiating
15174 it produces an expression, it's not an id-expression or
15175 member access. */
15178 }
15183 }
15186 {
15190 }
15194 {
15195 tree r;
15199 else
15207 }
15222 /* We should use one of the expression tsubsts for these codes. */
15228 }
15229 }
15231 /* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
15232 expression on the left-hand side of the "." or "->" operator. We
15233 only do the lookup if we had a dependent BASELINK. Otherwise we
15234 adjust it onto the instantiated heirarchy. */
15236 static tree
15239 {
15251 {
15258 }
15265 {
15271 /* Treat as-if non-dependent below. */
15276 {
15282 }
15286 }
15287 else
15288 /* We're going to overwrite pieces below, make a duplicate. */
15291 /* If lookup found a single function, mark it as used at this point.
15292 (If lookup found multiple functions the one selected later by
15293 overload resolution will be marked as used at that point.) */
15295 {
15301 /* We might have instantiated an auto function. */
15303 }
15306 {
15307 /* Add back the template arguments, if present. */
15312 /* Update the conversion operator type. */
15314 }
15320 {
15322 qualifying_scope,
15323 object_type);
15325 /* We need to call adjust_result_of_qualified_name_lookup in case the
15326 destructor names a base class, but we unset BASELINK_QUALIFIED_P
15327 so that we still get virtual function binding. */
15329 }
15332 }
15334 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
15335 true if the qualified-id will be a postfix-expression in-and-of
15336 itself; false if more of the postfix-expression follows the
15337 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
15338 of "&". */
15340 static tree
15344 {
15345 tree expr;
15346 tree scope;
15347 tree name;
15349 tree template_args;
15354 /* Figure out what name to look up. */
15357 {
15367 }
15368 else
15369 {
15372 }
15374 /* Substitute into the qualifying scope. When there are no ARGS, we
15375 are just trying to simplify a non-dependent expression. In that
15376 case the qualifying scope may be dependent, and, in any case,
15377 substituting will not help. */
15380 {
15383 }
15384 else
15388 {
15395 }
15398 {
15400 {
15401 /* A BIT_NOT_EXPR is used to represent a destructor. */
15403 {
15407 }
15408 else
15411 }
15412 else
15416 {
15418 {
15422 }
15424 }
15425 }
15428 {
15430 scope);
15431 /* Remember that there was a reference to this entity. */
15434 }
15437 {
15443 }
15446 {
15447 /* We may be repeating a check already done during parsing, but
15448 if it was well-formed and passed then, it will pass again
15449 now, and if it didn't, we wouldn't have got here. The case
15450 we want to catch is when we couldn't tell then, and can now,
15451 namely when templ prior to substitution was an
15452 identifier. */
15458 complain);
15459 else
15461 }
15467 {
15468 expr = (adjust_result_of_qualified_name_lookup
15470 expr = (finish_qualified_id_expr
15474 }
15476 /* Expressions do not generally have reference type. */
15478 /* However, if we're about to form a pointer-to-member, we just
15479 want the referenced member referenced. */
15487 }
15489 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
15490 initializer, DECL is the substituted VAR_DECL. Other arguments are as
15491 for tsubst. */
15493 static tree
15496 {
15505 {
15507 {
15509 {
15514 }
15515 }
15517 {
15518 /* If we had an initializer but it
15519 instantiated to nothing,
15520 value-initialize the object. This will
15521 only occur when the initializer was a
15522 pack expansion where the parameter packs
15523 used in that expansion were of length
15524 zero. */
15530 }
15531 }
15534 }
15536 /* Like tsubst, but deals with expressions. This function just replaces
15537 template parms; to finish processing the resultant expression, use
15538 tsubst_copy_and_build or tsubst_expr. */
15540 static tree
15542 {
15544 tree r;
15552 {
15557 {
15558 /* We get here for a use of 'this' in an NSDMI. */
15562 /* This can happen for a parameter name used later in a function
15563 declaration (such as in a late-specified return type). Just
15564 make a dummy decl, since it's only used for its type. */
15567 /* Give it the template pattern as its context; its true context
15568 hasn't been instantiated yet and this is good enough for
15569 mangling. */
15571 }
15580 {
15581 tree enum_type;
15582 tree v;
15586 /* There is no need to substitute into namespace-scope
15587 enumerators. */
15590 /* If ARGS is NULL, then T is known to be non-dependent. */
15594 /* Unfortunately, we cannot just call lookup_name here.
15595 Consider:
15597 template <int I> int f() {
15598 enum E { a = I };
15599 struct S { void g() { E e = a; } };
15600 };
15602 When we instantiate f<7>::S::g(), say, lookup_name is not
15603 clever enough to find f<7>::a. */
15604 enum_type
15614 /* We didn't find the name. That should never happen; if
15615 name-lookup found it during preliminary parsing, we
15616 should find it again here during instantiation. */
15618 }
15623 {
15624 tree ctx;
15629 {
15632 {
15636 }
15638 }
15639 }
15649 {
15652 {
15653 /* First try name lookup to find the instantiation. */
15656 {
15658 {
15659 /* During error-recovery we may find a non-variable,
15660 even an OVERLOAD: just bail out and avoid ICEs and
15661 duplicate diagnostics (c++/62207). */
15664 }
15666 {
15667 /* Make sure the one we found is the one we want. */
15671 }
15672 }
15676 else
15677 {
15678 /* This can happen for a variable used in a
15679 late-specified return type of a local lambda, or for a
15680 local static or constant. Building a new VAR_DECL
15681 should be OK in all those cases. */
15684 /* Avoid infinite recursion (79640). */
15687 {
15688 /* We can't call cp_finish_decl, so handle the
15689 initializer by hand. */
15704 }
15711 }
15712 /* Remember this for subsequent uses. */
15715 }
15718 }
15719 else
15743 {
15744 /* Template template argument like the following example need
15745 special treatment:
15747 template <template <class> class TT> struct C {};
15748 template <class T> struct D {
15749 template <class U> struct E {};
15750 C<E> c; // #1
15751 };
15752 D<int> d; // #2
15754 We are processing the template argument `E' in #1 for
15755 the template instantiation #2. Originally, `E' is a
15756 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
15757 have to substitute this with one having context `D<int>'. */
15761 {
15762 /* When rewriting a constructor into a deduction guide, a
15763 non-dependent name can become dependent, so memtmpl<args>
15764 becomes context::template memtmpl<args>. */
15768 }
15770 }
15771 else
15772 /* Ordinary template template argument. */
15777 {
15778 /* Handle location wrappers by substituting the wrapped node
15779 first, *then* reusing the resulting type. Doing the type
15780 first ensures that we handle template parameters and
15781 parameter pack expansions. */
15783 {
15787 }
15791 {
15792 /* Wrapper to make a C++20 template parameter object const. */
15795 {
15798 }
15799 else
15800 {
15803 }
15804 }
15805 /* We shouldn't see any other uses of these in templates. */
15807 }
15817 {
15821 }
15826 {
15835 /* We only want to compute the number of arguments. */
15838 else
15845 {
15847 /* Set TREE_USED for the benefit of -Wunused. */
15851 }
15859 {
15864 else
15871 else
15874 }
15875 else
15877 }
15879 {
15887 }
15888 /* Fall through */
15904 {
15911 }
15914 {
15915 tree object;
15916 tree name;
15921 {
15925 }
15928 {
15938 }
15943 in_decl);
15944 else
15947 }
15985 {
15989 }
15992 {
15997 }
16000 {
16004 }
16007 {
16015 }
16021 {
16028 }
16031 {
16038 }
16041 {
16048 }
16051 {
16052 /* Substituted template arguments */
16061 }
16064 {
16084 }
16109 /* Fall through. */
16112 {
16115 }
16116 else
16120 /* This is handled by tsubst_copy_and_build. */
16124 {
16128 }
16131 /* We shouldn't have built any of these during initial template
16132 generation. Instead, they should be built during instantiation
16133 in response to the saved STMT_IS_FULL_EXPR_P setting. */
16137 {
16147 }
16165 {
16166 /* Instantiate any typedefs in the type. */
16171 }
16174 /* These can sometimes show up in a partial instantiation, but never
16175 involve template parms. */
16191 /* ??? There's no point in copying it for now, but maybe some
16192 day it will contain more information, such as a pointer back
16193 to the containing function, inlined copy or so. */
16197 /* We shouldn't get here, but keep going if !flag_checking. */
16201 }
16202 }
16204 /* Helper function for tsubst_omp_clauses, used for instantiation of
16205 OMP_CLAUSE_DECL of clauses. */
16207 static tree
16210 {
16214 /* Handle OpenMP iterators. */
16218 {
16219 tree ret;
16222 else
16223 {
16227 {
16242 }
16246 }
16250 }
16252 /* Handle an OpenMP array section represented as a TREE_LIST (or
16253 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
16254 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
16255 TREE_LIST. We can handle it exactly the same as an array section
16256 (purpose, value, and a chain), even though the nomenclature
16257 (low_bound, length, etc) is different. */
16259 {
16260 tree low_bound
16275 }
16278 /* Undo convert_from_reference tsubst_expr could have called. */
16284 }
16286 /* Like tsubst_copy, but specifically for OpenMP clauses. */
16288 static tree
16291 {
16297 {
16303 {
16306 {
16312 }
16313 /* FALLTHRU */
16365 {
16368 {
16375 }
16376 else
16378 }
16397 {
16400 }
16405 else
16408 in_decl,
16434 }
16437 {
16451 /* tsubst_expr on SCOPE_REF results in returning
16452 finish_non_static_data_member result. Undo that here. */
16456 {
16461 {
16465 CASE_CONVERT:
16474 /* FALLTHRU */
16478 }
16479 }
16485 {
16488 {
16491 }
16492 }
16496 }
16497 }
16501 {
16506 {
16509 }
16510 }
16512 }
16514 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
16516 static tree
16518 tree in_decl)
16519 {
16520 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
16540 {
16543 else
16544 {
16548 }
16549 }
16554 #undef RECUR
16555 }
16557 /* Used to temporarily communicate the list of #pragma omp parallel
16558 clauses to #pragma omp for instantiation if they are combined
16559 together. */
16566 /* Substitute one OMP_FOR iterator. */
16568 static bool
16573 {
16574 #define RECUR(NODE) \
16575 tsubst_expr ((NODE), args, complain, in_decl, \
16576 integral_constant_expression_p)
16588 {
16591 {
16596 {
16606 else
16608 {
16610 {
16616 }
16619 }
16620 }
16621 }
16625 }
16627 {
16628 /* We need to jump through some hoops to handle declarations in the
16629 init-statement, since we might need to handle auto deduction,
16630 but we need to keep control of initialization. */
16634 }
16635 else
16636 {
16638 {
16641 {
16645 {
16649 CASE_CONVERT:
16657 {
16660 }
16661 /* FALLTHRU */
16665 }
16666 }
16667 }
16668 else
16670 }
16674 {
16680 NULL_TREE);
16681 else
16683 }
16686 {
16693 {
16698 }
16701 }
16711 {
16713 {
16714 /* Declare the variable, but don't let that initialize it. */
16719 }
16722 {
16726 {
16731 }
16732 else
16736 }
16742 }
16745 {
16746 /* Declare and initialize the variable. */
16749 }
16751 {
16755 {
16757 {
16763 {
16766 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
16771 }
16774 {
16776 decl);
16778 }
16781 {
16783 decl);
16785 }
16786 else
16788 }
16791 }
16793 {
16798 {
16801 }
16802 }
16803 }
16806 {
16810 }
16811 else
16815 {
16826 {
16834 }
16835 else
16841 {
16847 }
16851 {
16859 }
16860 else
16866 }
16875 #undef RECUR
16876 }
16878 /* Helper function of tsubst_expr, find OMP_TEAMS inside
16879 of OMP_TARGET's body. */
16881 static tree
16883 {
16886 {
16895 }
16897 }
16899 /* Helper function for tsubst_expr. For decomposition declaration
16900 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
16901 also the corresponding decls representing the identifiers
16902 of the decomposition declaration. Return DECL if successful
16903 or error_mark_node otherwise, set *FIRST to the first decl
16904 in the list chained through DECL_CHAIN and *CNT to the number
16905 of such decls. */
16907 static tree
16911 {
16916 decl2
16921 {
16923 {
16926 }
16938 else
16939 {
16943 }
16950 {
16953 }
16954 else
16956 }
16959 }
16961 /* Return the proper local_specialization for init-capture pack DECL. */
16963 static tree
16965 {
16966 /* We handle normal pack captures by forwarding to the specialization of the
16967 captured parameter. We can't do that for pack init-captures; we need them
16968 to have their own local_specialization. We created the individual
16969 VAR_DECLs (if any) under build_capture_proxy, and we need to collect them
16970 when we process the DECL_EXPR for the pack init-capture in the template.
16971 So, how do we find them? We don't know the capture proxy pack when
16972 building the individual resulting proxies, and we don't know the
16973 individual proxies when instantiating the pack. What we have in common is
16974 the FIELD_DECL.
16976 So...when we instantiate the FIELD_DECL, we stick the result in
16977 local_specializations. Then at the DECL_EXPR we look up that result, see
16978 how many elements it has, synthesize the names, and look them up. */
16992 {
16997 }
16999 {
17004 else
17006 }
17008 }
17010 /* Like tsubst_copy for expressions, etc. but also does semantic
17011 processing. */
17013 tree
17016 {
17017 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
17018 #define RECUR(NODE) \
17019 tsubst_expr ((NODE), args, complain, in_decl, \
17020 integral_constant_expression_p)
17023 tree r;
17024 location_t loc;
17036 {
17038 {
17039 tree_stmt_iterator i;
17043 }
17058 else
17067 {
17069 tree init;
17075 {
17081 }
17084 {
17085 /* We're in tsubst_lambda_expr, we've already inserted a new
17086 capture proxy, so look it up and register it. */
17087 tree inst;
17089 {
17094 }
17096 {
17097 inst = (retrieve_local_specialization
17100 }
17101 else
17106 }
17113 /* Don't copy the old closure; we'll create a new one in
17114 tsubst_lambda_expr. */
17116 else
17117 {
17121 {
17122 /* By marking the declaration as instantiated, we avoid
17123 trying to instantiate it. Since instantiate_decl can't
17124 handle local variables, and since we've already done
17125 all that needs to be done, that's the right thing to
17126 do. */
17131 /* Anonymous aggregates are a special case. */
17134 {
17137 {
17141 }
17143 }
17149 {
17154 }
17155 else
17156 {
17172 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
17182 }
17183 }
17184 }
17187 }
17197 {
17201 }
17206 {
17207 /* Construct another range_for, if this is not a final
17208 substitution (for inside inside a generic lambda of a
17209 template). Otherwise convert to a regular for. */
17211 stmt = (processing_template_decl
17228 {
17234 }
17235 else
17236 {
17242 }
17248 }
17255 {
17259 }
17265 {
17269 }
17284 {
17285 /* We're partially instantiating a generic lambda, but the condition
17286 of the constexpr if is still dependent. Don't substitute into the
17287 branches now, just remember the template arguments. */
17295 }
17298 else
17299 {
17307 }
17313 {
17323 }
17331 else
17339 else
17360 {
17366 {
17371 }
17372 }
17376 {
17378 tree label;
17385 }
17391 /* Computed goto's must be tsubst'd into. On the other hand,
17392 non-computed gotos must not be; the identifier in question
17393 will have no binding. */
17395 else
17401 {
17417 }
17422 {
17427 }
17428 else
17429 {
17434 else
17441 else
17447 else
17449 }
17453 {
17457 {
17459 /* Prevent instantiate_decl from trying to instantiate
17460 this variable. We've already done all that needs to be
17461 done. */
17464 }
17469 }
17475 {
17476 /* Local classes are not independent templates; they are
17477 instantiated along with their containing function. And this
17478 way we don't have to deal with pushing out of one local class
17479 to instantiate a member of another local class. */
17480 /* Closures are handled by the LAMBDA_EXPR. */
17490 }
17494 {
17495 tree condition;
17498 condition =
17500 args,
17509 }
17515 in_decl);
17537 {
17544 }
17559 {
17573 in_decl);
17575 {
17582 }
17593 any_range_for
17597 integral_constant_expression_p);
17601 {
17610 }
17611 else
17616 else
17623 else
17624 {
17632 }
17635 t));
17637 }
17642 /* FALLTHRU */
17651 in_decl);
17653 {
17658 }
17659 else
17660 {
17664 }
17676 {
17679 {
17684 }
17685 else
17686 {
17690 }
17692 }
17693 else
17695 OMP_CLAUSE_DEPEND_SOURCE,
17704 in_decl);
17715 {
17718 {
17719 /* For combined target teams, ensure the num_teams and
17720 thread_limit clause expressions are evaluated on the host,
17721 before entering the target construct. */
17722 tree c;
17728 {
17737 OMP_CLAUSE_FIRSTPRIVATE);
17741 }
17742 }
17743 }
17806 {
17811 {
17814 }
17820 }
17821 else
17822 {
17829 {
17832 }
17835 {
17840 {
17843 }
17849 }
17850 else
17851 {
17855 }
17858 }
17862 {
17868 {
17872 {
17877 }
17881 }
17882 else
17883 {
17888 }
17889 }
17893 {
17897 }
17910 /* If the first operand was a statement, we're done with it. */
17914 complain));
17931 integral_constant_expression_p));
17932 }
17935 out:
17938 #undef RECUR
17939 #undef RETURN
17940 }
17942 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
17943 function. For description of the body see comment above
17944 cp_parser_omp_declare_reduction_exprs. */
17946 static void
17948 {
17954 tree_stmt_iterator tsi;
17965 {
17984 }
17986 {
18006 }
18007 }
18009 /* T is a postfix-expression that is not being used in a function
18010 call. Return the substituted version of T. */
18012 static tree
18014 tsubst_flags_t complain,
18015 tree in_decl)
18016 {
18020 else
18026 }
18028 /* T is a LAMBDA_EXPR. Generate a new LAMBDA_EXPR for the current
18029 instantiation context. Instantiating a pack expansion containing a lambda
18030 might result in multiple lambdas all based on the same lambda in the
18031 template. */
18033 tree
18035 {
18039 /* If we have already specialized this lambda expr, reuse it. See
18040 PR c++/87322. */
18058 /* A lambda in a default argument outside a class gets no
18059 LAMBDA_EXPR_EXTRA_SCOPE, as specified by the ABI. But
18060 tsubst_default_argument calls start_lambda_scope, so we need to
18061 specifically ignore it here, and use the global scope. */
18063 else
18073 {
18080 {
18081 /* Remember these for when we've pushed local_specializations. */
18084 }
18092 else
18097 {
18106 }
18107 else
18108 {
18114 }
18115 }
18121 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
18139 else
18140 {
18141 /* The body of a lambda-expression is not a subexpression of the
18142 enclosing expression. Parms are to have DECL_CHAIN tsubsted,
18143 which would be skipped if cp_unevaluated_operand. */
18144 cp_evaluated ev;
18146 /* Fix the type of 'this'. */
18152 {
18156 }
18157 else
18158 {
18162 }
18164 /* Let finish_function set this. */
18170 else
18171 /* Still increment function_depth so that we don't GC in the
18172 middle of an expression. */
18179 /* Now record them for lookup_init_capture_pack. */
18182 {
18186 }
18192 {
18193 /* We might not partially instantiate some parts of the function, so
18194 copy these flags from the original template. */
18200 }
18202 /* [temp.deduct] A lambda-expression appearing in a function type or a
18203 template parameter is not considered part of the immediate context for
18204 the purposes of template argument deduction. */
18214 else
18217 /* The capture list was built up in reverse order; fix that now. */
18224 }
18231 }
18233 /* Like tsubst but deals with expressions and performs semantic
18234 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
18236 tree
18238 tree args,
18239 tsubst_flags_t complain,
18240 tree in_decl,
18243 {
18244 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
18245 #define RECUR(NODE) \
18246 tsubst_copy_and_build (NODE, args, complain, in_decl, \
18248 integral_constant_expression_p)
18251 location_t loc;
18260 /* N3276 decltype magic only applies to calls at the top level or on the
18261 right side of a comma. */
18266 {
18269 /* Fall through. */
18271 {
18272 tree decl;
18273 cp_id_kind idk;
18278 {
18281 }
18283 /* Look up the name. */
18286 /* By convention, expressions use ERROR_MARK_NODE to indicate
18287 failure, not NULL_TREE. */
18293 integral_constant_expression_p,
18301 input_location);
18305 {
18309 }
18311 }
18314 {
18315 tree object;
18325 {
18330 }
18336 {
18339 }
18340 else
18347 else
18349 }
18352 {
18356 {
18357 /* A type conversion to reference type will be enclosed in
18358 such an indirect ref, but the substitution of the cast
18359 will have also added such an indirect ref. */
18361 }
18362 else
18370 }
18373 {
18377 }
18380 {
18384 {
18389 }
18391 /* We'll pass this to convert_nontype_argument again, we don't need
18392 to actually perform any conversion here. */
18400 flags));
18401 }
18404 {
18410 }
18417 {
18418 tree type;
18424 {
18429 }
18436 {
18454 }
18457 }
18490 else
18492 in_decl);
18527 {
18534 tree r = build_x_binary_op
18536 op0,
18538 ? ERROR_MARK
18540 op1,
18542 ? ERROR_MARK
18550 }
18553 {
18557 }
18573 /* Fall through */
18576 {
18577 tree r;
18585 {
18586 /* When there are no ARGS, we are trying to evaluate a
18587 non-dependent expression from the parser. Trying to do
18588 the substitutions may not work. */
18591 }
18592 else
18593 {
18598 else
18601 /*integral_constant_expression_p=*/
18605 }
18609 else
18613 {
18615 {
18617 {
18621 }
18622 else
18626 }
18628 }
18630 }
18633 {
18643 }
18659 {
18663 tree r = build_x_modify_expr
18666 /* TREE_NO_WARNING must be set if either the expression was
18667 parenthesized or it uses an operator such as >>= rather
18668 than plain assignment. In the former case, it was already
18669 set and must be copied. In the latter case,
18670 build_x_modify_expr sets it and it must not be reset
18671 here. */
18676 }
18681 /* Remember that there was a reference to this entity. */
18688 {
18693 tree ret;
18697 else
18698 {
18702 }
18704 /* If there was an initializer in the original tree, but it
18705 instantiated to an empty list, then we should pass a
18706 non-NULL empty vector to tell build_new that it was an
18707 empty initializer() rather than no initializer. This can
18708 only happen when the initializer is a pack expansion whose
18709 parameter packs are of length zero. */
18712 else
18713 {
18717 else
18718 {
18721 }
18722 }
18724 /* Avoid passing an enclosing decl to valid_array_size_p. */
18731 complain);
18739 }
18742 {
18748 complain));
18749 }
18752 {
18756 integral_constant_expression_p);
18758 op0,
18761 }
18764 {
18765 tree function;
18769 tree ret;
18772 /* Internal function with no arguments. */
18776 /* When we parsed the expression, we determined whether or
18777 not Koenig lookup should be performed. */
18780 {
18783 }
18785 {
18790 }
18792 {
18793 /* Do nothing; calling tsubst_copy_and_build on an identifier
18794 would incorrectly perform unqualified lookup again.
18796 Note that we can also have an IDENTIFIER_NODE if the earlier
18797 unqualified lookup found a member function; in that case
18798 koenig_p will be false and we do want to do the lookup
18799 again to find the instantiated member function.
18801 FIXME but doing that causes c++/15272, so we need to stop
18802 using IDENTIFIER_NODE in that situation. */
18804 }
18805 else
18806 {
18808 {
18814 }
18815 else
18820 /* Avoid error about taking the address of a constructor. */
18824 in_decl,
18826 integral_constant_expression_p);
18830 }
18833 releasing_vec call_args;
18835 {
18840 else
18841 {
18842 /* Expand the pack expansion and push each entry onto
18843 CALL_ARGS. */
18846 {
18851 {
18856 }
18857 }
18858 else
18859 {
18860 /* A partial substitution. Add one entry. */
18862 }
18863 }
18864 }
18866 /* Stripped-down processing for a call in a thunk. Specifically, in
18867 the thunk template for a generic lambda. */
18869 {
18870 /* Now that we've expanded any packs, the number of call args
18871 might be different. */
18875 {
18882 }
18883 /* We aren't going to do normal overload resolution, so force the
18884 template-id to resolve. */
18887 {
18888 /* In a thunk, pass through args directly, without any
18889 conversions. */
18894 }
18896 {
18897 /* If there are no other args, just push 'this'. */
18900 else
18901 {
18902 /* Otherwise, shift the other args over to make room. */
18908 }
18909 }
18912 /* The thunk location is not interesting. */
18919 }
18921 /* We do not perform argument-dependent lookup if normal
18922 lookup finds a non-function, in accordance with the
18923 expected resolution of DR 218. */
18926 /* If lookup found a member function, the Koenig lookup is
18927 not appropriate, even if an unqualified-name was used
18928 to denote the function. */
18931 /* Only do this when substitution turns a dependent call
18932 into a non-dependent call. */
18940 {
18942 {
18943 /* For backwards compatibility and good diagnostics, try
18944 the unqualified lookup again if we aren't in SFINAE
18945 context. */
18946 tree unq = (tsubst_copy_and_build
18948 integral_constant_expression_p));
18953 {
18954 /* In a lambda fn, we have to be careful to not
18955 introduce new this captures. Legacy code can't
18956 be using lambdas anyway, so it's ok to be
18957 stricter. */
18962 "and no declarations were found by "
18963 "argument-dependent lookup at the point "
18970 else
18974 {
18985 {
18987 input_location);
18989 "declarations in dependent base %qT are "
18995 else
18999 }
19000 else
19002 "%qD declared here, later in the "
19006 }
19009 }
19010 }
19012 {
19016 }
19017 }
19019 /* Remember that there was a reference to this entity. */
19025 /* Put back tf_decltype for the actual call. */
19030 {
19034 {
19036 "wrong number of arguments to "
19039 }
19040 else
19042 input_location),
19049 {
19051 "wrong number of arguments to "
19055 }
19059 complain);
19065 /* Unsupported internal function with arguments. */
19067 }
19072 complain);
19074 {
19089 complain);
19090 else
19091 ret = (build_new_method_call
19096 complain));
19097 }
19098 else
19101 koenig_p,
19102 complain);
19105 {
19110 {
19115 }
19116 }
19119 }
19122 {
19129 {
19131 {
19136 }
19137 else
19138 {
19143 }
19145 }
19146 else
19147 {
19150 }
19155 }
19158 {
19163 input_location));
19164 }
19167 {
19175 {
19176 /* We have pack expansions, so expand those and
19177 create a new list out of it. */
19180 tree chain;
19183 /* Expand the argument expressions. */
19191 /* Build the rest of the list. */
19196 /* Determine the number of arguments. */
19198 {
19201 }
19204 else
19205 {
19206 /* Since we only performed a partial substitution into
19207 the argument pack, we only RETURN (a single list
19208 node. */
19215 }
19217 /* Convert the argument vectors into a TREE_LIST */
19220 {
19221 /* Grab the Ith values. */
19222 i--;
19225 value
19229 /* Build the list (backwards). */
19231 }
19234 }
19250 }
19253 {
19254 tree object;
19255 tree object_type;
19256 tree member;
19257 tree r;
19261 /* Remember that there was a reference to this entity. */
19272 else
19278 {
19283 }
19287 {
19289 {
19294 {
19297 }
19299 {
19304 }
19305 }
19306 }
19309 {
19310 /* Lookup the template functions now that we know what the
19311 scope is. */
19319 {
19322 args);
19323 member = (adjust_result_of_qualified_name_lookup
19325 object_type));
19326 }
19327 else
19328 {
19330 input_location);
19332 }
19333 }
19337 {
19339 {
19343 else
19346 }
19348 }
19352 complain);
19356 }
19363 {
19371 tree r;
19376 /* We do not want to process the index of aggregate
19377 initializers as they are identifier nodes which will be
19378 looked up by digest_init. */
19382 {
19385 }
19390 {
19392 /* An identifier index is looked up in the type
19393 being initialized, not the current scope. */
19398 {
19399 /* Substitute into the pack expansion. */
19401 in_decl);
19405 ;
19407 /* Just move the argument into place. */
19409 else
19410 {
19411 /* Update the length of the final CONSTRUCTOR
19412 arguments vector, and note that we will need to
19413 copy.*/
19416 }
19417 }
19418 else
19420 }
19423 {
19428 {
19430 {
19435 }
19436 else
19438 }
19439 }
19447 {
19452 }
19456 }
19459 {
19462 {
19465 }
19466 else
19467 {
19470 }
19471 }
19476 /* Fall through */
19479 {
19481 /* ??? We're doing a subset of finish_id_expression here. */
19483 /* Replace an evaluated use of the thread_local variable with
19484 a call to its wrapper. */
19490 /* If the original type was a reference, we'll be wrapped in
19491 the appropriate INDIRECT_REF. */
19494 }
19497 {
19501 }
19504 {
19505 tree object_ptr
19512 }
19519 {
19530 }
19533 {
19539 integral_constant_expression_p);
19543 /* If the resulting list of expression statement is empty,
19544 fold it further into void_node. */
19549 }
19552 {
19554 {
19555 /* We don't have a full set of template arguments yet; don't touch
19556 the lambda at all. */
19559 }
19563 }
19566 /* We can get here for a constant initializer of non-dependent type.
19567 FIXME stop folding in cp_parser_initializer_clause. */
19568 {
19570 complain);
19572 }
19576 integral_constant_expression_p));
19582 {
19587 complain));
19588 }
19594 /* No need to substitute further, a RANGE_EXPR will always be built
19595 with constant operands. */
19601 /* We need to do this here as well as in tsubst_copy so we get the
19602 other tsubst_copy_and_build semantics for a PARM_DECL operand. */
19605 /* fallthrough. */
19608 /* Handle Objective-C++ constructs, if appropriate. */
19609 {
19610 tree subst
19615 }
19617 }
19619 #undef RECUR
19620 #undef RETURN
19621 out:
19624 }
19626 /* Verify that the instantiated ARGS are valid. For type arguments,
19627 make sure that the type's linkage is ok. For non-type arguments,
19628 make sure they are constants if they are integral or enumerations.
19629 Emit an error under control of COMPLAIN, and return TRUE on error. */
19631 static bool
19633 {
19637 {
19647 }
19649 {
19650 /* [basic.link]: A name with no linkage (notably, the name
19651 of a class or enumeration declared in a local scope)
19652 shall not be used to declare an entity with linkage.
19653 This implies that names with no linkage cannot be used as
19654 template arguments
19656 DR 757 relaxes this restriction for C++0x. */
19661 {
19662 /* DR 488 makes use of a type with no linkage cause
19663 type deduction to fail. */
19665 {
19668 else
19671 }
19673 }
19674 /* In order to avoid all sorts of complications, we do not
19675 allow variably-modified types as template arguments. */
19677 {
19681 }
19682 }
19683 /* Class template and alias template arguments should be OK. */
19685 ;
19686 /* A non-type argument of integral or enumerated type must be a
19687 constant. */
19692 {
19696 }
19698 }
19700 static bool
19702 {
19707 {
19710 }
19714 }
19716 /* We're out of SFINAE context now, so generate diagnostics for the access
19717 errors we saw earlier when instantiating D from TMPL and ARGS. */
19719 static void
19721 {
19733 }
19735 /* Instantiate the indicated variable, function, or alias template TMPL with
19736 the template arguments in TARG_PTR. */
19738 static tree
19740 {
19742 tree fndecl;
19743 tree gen_tmpl;
19744 tree spec;
19752 /* If this function is a clone, handle it specially. */
19754 {
19755 tree spec;
19756 tree clone;
19758 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
19759 DECL_CLONED_FUNCTION. */
19765 /* Look for the clone. */
19769 /* We should always have found the clone by now. */
19772 }
19777 /* Check to see if we already have this specialization. */
19781 /* targ_ptr only has the innermost template args, so add the outer ones
19782 from tmpl, which could be either a partial instantiation or gen_tmpl (in
19783 the case of a non-dependent call within a template definition). */
19784 targ_ptr = (add_outermost_template_args
19786 targ_ptr));
19788 /* It would be nice to avoid hashing here and then again in tsubst_decl,
19789 but it doesn't seem to be on the hot path. */
19798 {
19800 {
19804 }
19806 }
19809 complain))
19812 /* We are building a FUNCTION_DECL, during which the access of its
19813 parameters and return types have to be checked. However this
19814 FUNCTION_DECL which is the desired context for access checking
19815 is not built yet. We solve this chicken-and-egg problem by
19816 deferring all checks until we have the FUNCTION_DECL. */
19819 /* Instantiation of the function happens in the context of the function
19820 template, not the context of the overload resolution we're doing. */
19822 /* If there are dependent arguments, e.g. because we're doing partial
19823 ordering, make sure processing_template_decl stays set. */
19827 {
19831 }
19837 {
19838 /* We need to determine if we're using a partial or explicit
19839 specialization now, because the type of the variable could be
19840 different. */
19846 {
19851 }
19852 }
19854 /* Substitute template parameters to obtain the specialization. */
19862 {
19865 }
19867 /* The DECL_TI_TEMPLATE should always be the immediate parent
19868 template, not the most general template. */
19872 /* Now we know the specialization, compute access previously
19873 deferred. Do no access control for inheriting constructors,
19874 as we already checked access for the inherited constructor. */
19877 {
19882 }
19885 /* If we've just instantiated the main entry point for a function,
19886 instantiate all the alternate entry points as well. We do this
19887 by cloning the instantiation of the main entry point, not by
19888 instantiating the template clones. */
19893 {
19895 {
19896 /* Remember to reinstantiate when we're out of SFINAE so the user
19897 can see the errors. */
19899 }
19901 }
19903 }
19905 /* Wrapper for instantiate_template_1. */
19907 tree
19909 {
19910 tree ret;
19915 }
19917 /* Instantiate the alias template TMPL with ARGS. Also push a template
19918 instantiation level, which instantiate_template doesn't do because
19919 functions and variables have sufficient context established by the
19920 callers. */
19922 static tree
19924 {
19930 args =
19940 }
19942 /* PARM is a template parameter pack for FN. Returns true iff
19943 PARM is used in a deducible way in the argument list of FN. */
19945 static bool
19947 {
19950 {
19952 tree packs;
19958 {
19959 /* The template parameter pack is used in a function parameter
19960 pack. If this is the end of the parameter list, the
19961 template parameter pack is deducible. */
19964 else
19965 /* Otherwise, not. Well, it could be deduced from
19966 a non-pack parameter, but doing so would end up with
19967 a deduction mismatch, so don't bother. */
19969 }
19970 }
19971 /* The template parameter pack isn't used in any function parameter
19972 packs, but it might be used deeper, e.g. tuple<Args...>. */
19974 }
19976 /* Subroutine of fn_type_unification: check non-dependent parms for
19977 convertibility. */
19979 static int
19983 {
19984 /* Non-constructor methods need to leave a conversion for 'this', which
19985 isn't included in nargs here. */
19991 {
19997 /* For a function parameter pack that occurs at the end of the
19998 parameter-declaration-list, the type A of each remaining
19999 argument of the call is compared with the type P of the
20000 declarator-id of the function parameter pack. */
20006 /* For a function parameter pack that does not occur at the
20007 end of the parameter-declaration-list, the type of the
20008 parameter pack is a non-deduced context. */
20012 {
20020 }
20023 }
20026 }
20028 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
20029 NARGS elements of the arguments that are being used when calling
20030 it. TARGS is a vector into which the deduced template arguments
20031 are placed.
20033 Returns either a FUNCTION_DECL for the matching specialization of FN or
20034 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
20035 true, diagnostics will be printed to explain why it failed.
20037 If FN is a conversion operator, or we are trying to produce a specific
20038 specialization, RETURN_TYPE is the return type desired.
20040 The EXPLICIT_TARGS are explicit template arguments provided via a
20041 template-id.
20043 The parameter STRICT is one of:
20045 DEDUCE_CALL:
20046 We are deducing arguments for a function call, as in
20047 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
20048 deducing arguments for a call to the result of a conversion
20049 function template, as in [over.call.object].
20051 DEDUCE_CONV:
20052 We are deducing arguments for a conversion function, as in
20053 [temp.deduct.conv].
20055 DEDUCE_EXACT:
20056 We are deducing arguments when doing an explicit instantiation
20057 as in [temp.explicit], when determining an explicit specialization
20058 as in [temp.expl.spec], or when taking the address of a function
20059 template, as in [temp.deduct.funcaddr]. */
20061 tree
20063 tree explicit_targs,
20064 tree targs,
20067 tree return_type,
20068 unification_kind_t strict,
20073 {
20074 tree parms;
20075 tree fntype;
20080 /* type_unification_real will pass back any access checks from default
20081 template argument substitution. */
20083 /* We don't have all the template args yet. */
20096 full_targs = (add_outermost_template_args
20098 targs));
20103 /* In C++0x, it's possible to have a function template whose type depends
20104 on itself recursively. This is most obvious with decltype, but can also
20105 occur with enumeration scope (c++/48969). So we need to catch infinite
20106 recursion and reject the substitution at deduction time; this function
20107 will return error_mark_node for any repeated substitution.
20109 This also catches excessive recursion such as when f<N> depends on
20110 f<N-1> across all integers, and returns error_mark_node for all the
20111 substitutions back up to the initial one.
20113 This is, of course, not reentrant. */
20122 {
20123 /* [temp.deduct]
20125 The specified template arguments must match the template
20126 parameters in kind (i.e., type, nontype, template), and there
20127 must not be more arguments than there are parameters;
20128 otherwise type deduction fails.
20130 Nontype arguments must match the types of the corresponding
20131 nontype template parameters, or must be convertible to the
20132 types of the corresponding nontype parameters as specified in
20133 _temp.arg.nontype_, otherwise type deduction fails.
20135 All references in the function type of the function template
20136 to the corresponding template parameters are replaced by the
20137 specified template argument values. If a substitution in a
20138 template parameter or in the function type of the function
20139 template results in an invalid type, type deduction fails. */
20150 explicit_targs);
20152 /* Adjust any explicit template arguments before entering the
20153 substitution context. */
20154 explicit_targs
20162 /* Substitute the explicit args into the function type. This is
20163 necessary so that, for instance, explicitly declared function
20164 arguments can match null pointed constants. If we were given
20165 an incomplete set of explicit args, we must not do semantic
20166 processing during substitution as we could create partial
20167 instantiations. */
20169 {
20174 /* Dig out the actual parm. */
20177 {
20180 }
20182 {
20185 }
20188 /* No explicit argument for this template parameter. */
20191 {
20192 /* Mark the argument pack as "incomplete". We could
20193 still deduce more arguments during unification.
20194 We remove this mark in type_unification_real. */
20199 /* We have some incomplete argument packs. */
20201 }
20202 }
20205 {
20207 {
20210 }
20213 /* Ignore any access checks; we'll see them again in
20214 instantiate_template and they might have the wrong
20215 access path at this point. */
20226 }
20228 /* Place the explicitly specified arguments in TARGS. */
20234 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
20236 }
20239 {
20245 }
20250 /* Never do unification on the 'this' parameter. */
20254 {
20255 /* We're deducing for a call to the result of a template conversion
20256 function. The parms we really want are in return_type. */
20260 }
20262 {
20264 }
20266 /* We allow incomplete unification without an error message here
20267 because the standard doesn't seem to explicitly prohibit it. Our
20268 callers must be ready to deal with unification failures in any
20269 event. */
20271 /* If we aren't explaining yet, push tinst context so we can see where
20272 any errors (e.g. from class instantiations triggered by instantiation
20273 of default template arguments) come from. If we are explaining, this
20274 context is redundant. */
20276 {
20279 }
20289 /* Now that we have bindings for all of the template arguments,
20290 ensure that the arguments deduced for the template template
20291 parameters have compatible template parameter lists. We cannot
20292 check this property before we have deduced all template
20293 arguments, because the template parameter types of a template
20294 template parameter might depend on prior template parameters
20295 deduced after the template template parameter. The following
20296 ill-formed example illustrates this issue:
20298 template<typename T, template<T> class C> void f(C<5>, T);
20300 template<int N> struct X {};
20302 void g() {
20303 f(X<5>(), 5l); // error: template argument deduction fails
20304 }
20306 The template parameter list of 'C' depends on the template type
20307 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
20308 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
20309 time that we deduce 'C'. */
20312 {
20315 }
20317 /* DR 1391: All parameters have args, now check non-dependent parms for
20318 convertibility. */
20323 deduced:
20324 /* All is well so far. Now, check:
20326 [temp.deduct]
20328 When all template arguments have been deduced, all uses of
20329 template parameters in nondeduced contexts are replaced with
20330 the corresponding deduced argument values. If the
20331 substitution results in an invalid type, as described above,
20332 type deduction fails. */
20334 {
20337 }
20339 /* Also collect access checks from the instantiation. */
20352 /* Now perform any access checks encountered during substitution. */
20359 /* If we're looking for an exact match, check that what we got
20360 is indeed an exact match. It might not be if some template
20361 parameters are used in non-deduced contexts. But don't check
20362 for an exact match if we have dependent template arguments;
20363 in that case we're doing partial ordering, and we already know
20364 that we have two candidates that will provide the actual type. */
20366 {
20370 tree sarg
20376 {
20380 }
20381 }
20383 /* After doing deduction with the inherited constructor, actually return an
20384 instantiation of the inheriting constructor. */
20390 fail:
20393 {
20395 /* Reset once we're all the way out. */
20397 }
20400 }
20402 /* Adjust types before performing type deduction, as described in
20403 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
20404 sections are symmetric. PARM is the type of a function parameter
20405 or the return type of the conversion function. ARG is the type of
20406 the argument passed to the call, or the type of the value
20407 initialized with the result of the conversion function.
20408 ARG_EXPR is the original argument expression, which may be null. */
20410 static int
20414 tree arg_expr)
20415 {
20419 {
20424 /* Swap PARM and ARG throughout the remainder of this
20425 function; the handling is precisely symmetric since PARM
20426 will initialize ARG rather than vice versa. */
20431 /* Core issue #873: Do the DR606 thing (see below) for these cases,
20432 too, but here handle it by stripping the reference from PARM
20433 rather than by adding it to ARG. */
20441 /* Nothing else to do in this case. */
20446 }
20449 {
20450 /* [temp.deduct.call]
20452 If P is not a reference type:
20454 --If A is an array type, the pointer type produced by the
20455 array-to-pointer standard conversion (_conv.array_) is
20456 used in place of A for type deduction; otherwise,
20458 --If A is a function type, the pointer type produced by
20459 the function-to-pointer standard conversion
20460 (_conv.func_) is used in place of A for type deduction;
20461 otherwise,
20463 --If A is a cv-qualified type, the top level
20464 cv-qualifiers of A's type are ignored for type
20465 deduction. */
20470 else
20472 }
20474 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
20475 reference to a cv-unqualified template parameter that does not represent a
20476 template parameter of a class template (during class template argument
20477 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
20478 an lvalue, the type "lvalue reference to A" is used in place of A for type
20479 deduction. */
20486 /* try_one_overload doesn't provide an arg_expr, but
20487 functions are always lvalues. */
20491 /* [temp.deduct.call]
20493 If P is a cv-qualified type, the top level cv-qualifiers
20494 of P's type are ignored for type deduction. If P is a
20495 reference type, the type referred to by P is used for
20496 type deduction. */
20499 {
20502 }
20504 /* DR 322. For conversion deduction, remove a reference type on parm
20505 too (which has been swapped into ARG). */
20510 }
20512 /* Subroutine of fn_type_unification. PARM is a function parameter of a
20513 template which doesn't contain any deducible template parameters; check if
20514 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
20515 unify_one_argument. */
20517 static int
20521 {
20522 tree type;
20526 else
20534 {
20537 }
20539 {
20543 /* Avoid recalculating this in add_function_candidate. */
20544 ok = (*conv_p
20546 else
20550 }
20554 else
20556 }
20560 /* Returns true iff the expression EXPR is one from which a template
20561 argument can be deduced. In other words, if it's an undecorated
20562 use of a template non-type parameter. */
20564 static bool
20566 {
20567 /* Strip implicit conversions. */
20571 }
20573 /* Returns true iff the array domain DOMAIN uses a template parameter in a
20574 deducible way; that is, if it has a max value of <PARM> - 1. */
20576 static bool
20578 {
20587 }
20589 /* Returns true iff the template arguments ARGS use a template parameter
20590 in a deducible way. */
20592 static bool
20594 {
20596 {
20601 else
20602 {
20609 else
20611 }
20614 }
20616 }
20618 /* Returns true iff TYPE contains any deducible references to template
20619 parameters, as per 14.8.2.5. */
20621 static bool
20623 {
20627 /* T
20628 cv-list T
20629 TT<T>
20630 TT<i>
20631 TT<> */
20636 /* T*
20637 T&
20638 T&& */
20642 /* T[integer-constant ]
20643 type [i] */
20648 /* T type ::*
20649 type T::*
20650 T T::*
20651 T (type ::*)()
20652 type (T::*)()
20653 type (type ::*)(T)
20654 type (T::*)(T)
20655 T (type ::*)(T)
20656 T (T::*)()
20657 T (T::*)(T) */
20660 || (uses_deducible_template_parms
20663 /* template-name <T> (where template-name refers to a class template)
20664 template-name <i> (where template-name refers to a class template) */
20671 /* type (T)
20672 T()
20673 T(T) */
20675 {
20684 }
20687 }
20689 /* Subroutine of type_unification_real and unify_pack_expansion to
20690 handle unification of a single P/A pair. Parameters are as
20691 for those functions. */
20693 static int
20697 {
20704 /* We can't deduce anything from this, but we might get all the
20705 template args from other function args. */
20708 /* Implicit conversions (Clause 4) will be performed on a function
20709 argument to convert it to the type of the corresponding function
20710 parameter if the parameter type contains no template-parameters that
20711 participate in template argument deduction. */
20714 /* For function parameters with no deducible template parameters,
20715 just return. We'll check non-dependent conversions later. */
20719 {
20721 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
20722 | UNIFY_ALLOW_MORE_CV_QUAL
20736 }
20738 /* We only do these transformations if this is the top-level
20739 parameter_type_list in a call or declaration matching; in other
20740 situations (nested function declarators, template argument lists) we
20741 won't be comparing a type to an expression, and we don't do any type
20742 adjustments. */
20744 {
20746 {
20749 {
20750 /* [temp.deduct.type] A template-argument can be
20751 deduced from a pointer to function or pointer
20752 to member function argument if the set of
20753 overloaded functions does not contain function
20754 templates and at most one of a set of
20755 overloaded functions provides a unique
20756 match. */
20760 /* If a unique match was not found, this is a
20761 non-deduced context, so we still succeed. */
20763 }
20769 }
20771 arg_strict |=
20773 }
20774 else
20779 /* For deduction from an init-list we need the actual list. */
20783 }
20785 /* for_each_template_parm callback that always returns 0. */
20787 static int
20789 {
20791 }
20793 /* for_each_template_parm any_fn callback to handle deduction of a template
20794 type argument from the type of an array bound. */
20796 static int
20798 {
20806 {
20812 }
20814 /* Keep walking. */
20816 }
20818 /* Try to deduce any not-yet-deduced template type arguments from the type of
20819 an array bound. This is handled separately from unify because 14.8.2.5 says
20820 "The type of a type parameter is only deduced from an array bound if it is
20821 not otherwise deduced." */
20823 static void
20825 {
20830 }
20832 /* Most parms like fn_type_unification.
20834 If SUBR is 1, we're being called recursively (to unify the
20835 arguments of a function or method parameter of a function
20836 template).
20838 CHECKS is a pointer to a vector of access checks encountered while
20839 substituting default template arguments. */
20841 static int
20843 tree full_targs,
20844 tree xparms,
20848 unification_kind_t strict,
20851 {
20856 tree parms;
20867 /* Reset the number of non-defaulted template arguments contained
20868 in TARGS. */
20871 again:
20879 {
20884 /* For a function parameter pack that occurs at the end of the
20885 parameter-declaration-list, the type A of each remaining
20886 argument of the call is compared with the type P of the
20887 declarator-id of the function parameter pack. */
20893 /* For a function parameter pack that does not occur at the
20894 end of the parameter-declaration-list, the type of the
20895 parameter pack is a non-deduced context. */
20902 explain_p))
20904 }
20909 {
20910 /* Unify the remaining arguments with the pack expansion type. */
20911 tree argvec;
20914 /* Allocate a TREE_VEC and copy in all of the arguments */
20919 /* Copy the parameter into parmvec. */
20925 /* Advance to the end of the list of parameters. */
20927 }
20929 /* Fail if we've reached the end of the parm list, and more args
20930 are present, and the parm list isn't variadic. */
20933 /* Fail if parms are left and they don't have default values and
20934 they aren't all deduced as empty packs (c++/57397). This is
20935 consistent with sufficient_parms_p. */
20938 {
20942 do
20943 {
20946 count++;
20948 }
20952 type_pack_p);
20953 }
20956 {
20957 tsubst_flags_t complain = (explain_p
20958 ? tf_warning_or_error
20963 {
20967 /* Clear the "incomplete" flags on all argument packs now so that
20968 substituting them into later default arguments works. */
20970 {
20973 }
20981 {
20986 }
20988 /* If this is an undeduced nontype parameter that depends on
20989 a type parameter, try another pass; its type may have been
20990 deduced from a later argument than the one from which
20991 this parameter can be deduced. */
20995 {
20998 }
21000 /* Core issue #226 (C++0x) [temp.deduct]:
21002 If a template argument has not been deduced, its
21003 default template argument, if any, is used.
21005 When we are in C++98 mode, TREE_PURPOSE will either
21006 be NULL_TREE or ERROR_MARK_NODE, so we do not need
21007 to explicitly check cxx_dialect here. */
21009 /* OK, there is a default argument. Wait until after the
21010 conversion check to do substitution. */
21013 /* If the type parameter is a parameter pack, then it will
21014 be deduced to an empty parameter pack. */
21016 {
21017 tree arg;
21020 {
21023 }
21024 else
21031 }
21034 }
21036 /* Now substitute into the default template arguments. */
21038 {
21054 {
21055 /* The type of this non-type parameter depends on undeduced
21056 parameters. Don't try to use its default argument yet,
21057 since we might deduce an argument for it on the next pass,
21058 but do check whether the arguments we already have cause
21059 substitution failure, so that that happens before we try
21060 later default arguments (78489). */
21063 NULL_TREE);
21067 else
21069 }
21070 else
21071 {
21072 /* Even if the call is happening in template context, getting
21073 here means it's non-dependent, and a default argument is
21074 considered a separate definition under [temp.decls], so we can
21075 do this substitution without processing_template_decl. This
21076 is important if the default argument contains something that
21077 might be instantiation-dependent like access (87480). */
21078 processing_template_decl_sentinel s;
21081 {
21082 /* First instatiate in template context, in case we still
21083 depend on undeduced template parameters. */
21086 NULL_TREE);
21090 /* We replaced all the tparms, substitute again out of
21091 template context. */
21093 }
21096 NULL_TREE);
21103 else
21105 }
21114 {
21116 /* The position of the first default template argument,
21117 is also the number of non-defaulted arguments in TARGS.
21118 Record that. */
21121 }
21122 }
21126 }
21132 }
21134 /* Subroutine of type_unification_real. Args are like the variables
21135 at the call site. ARG is an overloaded function (or template-id);
21136 we try deducing template args from each of the overloads, and if
21137 only one succeeds, we go with that. Modifies TARGS and returns
21138 true on success. */
21140 static bool
21142 tree targs,
21143 tree parm,
21144 tree arg,
21145 unification_kind_t strict,
21148 {
21155 {
21158 }
21159 else
21163 /* Handle `&x' where `x' is some static or non-static member
21164 function name. */
21170 /* Strip baselink information. */
21175 {
21176 /* If we got some explicit template args, we need to plug them into
21177 the affected templates before we try to unify, in case the
21178 explicit args will completely resolve the templates in question. */
21185 {
21198 {
21203 {
21206 }
21207 }
21210 }
21211 /* If no templates (or more than one) are fully resolved by the
21212 explicit arguments, this template-id is a non-deduced context; it
21213 could still be OK if we deduce all template arguments for the
21214 enclosing call through other arguments. */
21217 }
21219 /* If ARG is, for example, "(0, &f)" then its type will be unknown
21220 -- but the deduction does not succeed because the expression is
21221 not just the function on its own. */
21223 else
21225 {
21230 {
21233 }
21234 }
21236 /* [temp.deduct.type] A template-argument can be deduced from a pointer
21237 to function or pointer to member function argument if the set of
21238 overloaded functions does not contain function templates and at most
21239 one of a set of overloaded functions provides a unique match.
21241 So if we found multiple possibilities, we return success but don't
21242 deduce anything. */
21245 {
21249 {
21254 /* Don't forget explicit template arguments in a pack. */
21258 }
21259 }
21264 }
21266 /* Core DR 115: In contexts where deduction is done and fails, or in
21267 contexts where deduction is not done, if a template argument list is
21268 specified and it, along with any default template arguments, identifies
21269 a single function template specialization, then the template-id is an
21270 lvalue for the function template specialization. */
21272 tree
21274 {
21287 {
21290 }
21292 {
21295 }
21297 {
21300 }
21303 {
21307 /* If we got some explicit template args, we need to plug them into
21308 the affected templates before we try to unify, in case the
21309 explicit args will completely resolve the templates in question. */
21317 {
21330 {
21333 {
21336 }
21338 {
21341 }
21342 }
21343 }
21345 {
21353 {
21354 tree base
21357 }
21361 }
21363 /* There were no good options and at least one bad one, so let the
21364 user know what the problem is. */
21366 }
21368 }
21370 /* As above, but error out if the expression remains overloaded. */
21372 tree
21374 {
21377 {
21381 }
21383 }
21385 /* Subroutine of resolve_overloaded_unification; does deduction for a single
21386 overload. Fills TARGS with any deduced arguments, or error_mark_node if
21387 different overloads deduce different arguments for a given parm.
21388 ADDR_P is true if the expression for which deduction is being
21389 performed was of the form "& fn" rather than simply "fn".
21391 Returns 1 on success. */
21393 static int
21395 tree orig_targs,
21396 tree targs,
21397 tree parm,
21398 tree arg,
21399 unification_kind_t strict,
21403 {
21405 tree tempargs;
21411 /* [temp.deduct.type] A template-argument can be deduced from a pointer
21412 to function or pointer to member function argument if the set of
21413 overloaded functions does not contain function templates and at most
21414 one of a set of overloaded functions provides a unique match.
21416 So if this is a template, just return success. */
21428 /* We don't copy orig_targs for this because if we have already deduced
21429 some template args from previous args, unify would complain when we
21430 try to deduce a template parameter for the same argument, even though
21431 there isn't really a conflict. */
21438 /* First make sure we didn't deduce anything that conflicts with
21439 explicitly specified args. */
21441 {
21448 /* Since we're unifying against ourselves, we will fill in
21449 template args used in the function parm list with our own
21450 template parms. Discard them. */
21453 {
21454 /* Check that the argument at each index of the deduced argument pack
21455 is equivalent to the corresponding explicitly specified argument.
21456 We may have deduced more arguments than were explicitly specified,
21457 and that's OK. */
21459 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
21460 that's wrong if we deduce the same argument pack from multiple
21461 function arguments: it's only incomplete the first time. */
21474 }
21477 }
21480 {
21485 }
21488 }
21490 /* PARM is a template class (perhaps with unbound template
21491 parameters). ARG is a fully instantiated type. If ARG can be
21492 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
21493 TARGS are as for unify. */
21495 static tree
21498 {
21499 tree copy_of_targs;
21509 /* We need to make a new template argument vector for the call to
21510 unify. If we used TARGS, we'd clutter it up with the result of
21511 the attempted unification, even if this class didn't work out.
21512 We also don't want to commit ourselves to all the unifications
21513 we've already done, since unification is supposed to be done on
21514 an argument-by-argument basis. In other words, consider the
21515 following pathological case:
21517 template <int I, int J, int K>
21518 struct S {};
21520 template <int I, int J>
21521 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
21523 template <int I, int J, int K>
21524 void f(S<I, J, K>, S<I, I, I>);
21526 void g() {
21527 S<0, 0, 0> s0;
21528 S<0, 1, 2> s2;
21530 f(s0, s2);
21531 }
21533 Now, by the time we consider the unification involving `s2', we
21534 already know that we must have `f<0, 0, 0>'. But, even though
21535 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
21536 because there are two ways to unify base classes of S<0, 1, 2>
21537 with S<I, I, I>. If we kept the already deduced knowledge, we
21538 would reject the possibility I=1. */
21542 {
21546 }
21548 /* If unification failed, we're done. */
21554 }
21556 /* Given a template type PARM and a class type ARG, find the unique
21557 base type in ARG that is an instance of PARM. We do not examine
21558 ARG itself; only its base-classes. If there is not exactly one
21559 appropriate base class, return NULL_TREE. PARM may be the type of
21560 a partial specialization, as well as a plain template type. Used
21561 by unify. */
21563 static enum template_base_result
21566 {
21568 tree binfo;
21574 {
21575 /* The type could not be completed. */
21578 }
21580 /* Walk in inheritance graph order. The search order is not
21581 important, and this avoids multiple walks of virtual bases. */
21583 {
21588 {
21589 /* If there is more than one satisfactory baseclass, then:
21591 [temp.deduct.call]
21593 If they yield more than one possible deduced A, the type
21594 deduction fails.
21596 applies. */
21598 {
21601 }
21604 }
21605 }
21609 }
21611 /* Returns the level of DECL, which declares a template parameter. */
21613 static int
21615 {
21617 {
21627 }
21629 }
21631 /* Decide whether ARG can be unified with PARM, considering only the
21632 cv-qualifiers of each type, given STRICT as documented for unify.
21633 Returns nonzero iff the unification is OK on that basis. */
21635 static int
21637 {
21643 {
21644 /* Although a CVR qualifier is ignored when being applied to a
21645 substituted template parameter ([8.3.2]/1 for example), that
21646 does not allow us to unify "const T" with "int&" because both
21647 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
21648 It is ok when we're allowing additional CV qualifiers
21649 at the outer level [14.8.2.1]/3,1st bullet. */
21658 }
21669 }
21671 /* Determines the LEVEL and INDEX for the template parameter PARM. */
21672 void
21674 {
21678 {
21681 }
21682 else
21683 {
21686 }
21687 }
21689 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
21690 do { \
21691 if (unify (TP, TA, P, A, S, EP)) \
21692 return 1; \
21693 } while (0)
21695 /* Unifies the remaining arguments in PACKED_ARGS with the pack
21696 expansion at the end of PACKED_PARMS. Returns 0 if the type
21697 deduction succeeds, 1 otherwise. STRICT is the same as in
21698 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
21699 function call argument list. We'll need to adjust the arguments to make them
21700 types. SUBR tells us if this is from a recursive call to
21701 type_unification_real, or for comparing two template argument
21702 lists. */
21704 static int
21708 {
21709 tree parm
21715 /* Add in any args remembered from an earlier partial instantiation. */
21723 /* Determine the parameter packs we will be deducing from the
21724 pattern, and record their current deductions. */
21727 {
21731 /* Only template parameter packs can be deduced, not e.g. function
21732 parameter packs or __bases or __integer_pack. */
21736 /* Determine the index and level of this parameter pack. */
21741 /* Keep track of the parameter packs and their corresponding
21742 argument packs. */
21745 }
21747 /* Loop through all of the arguments that have not yet been
21748 unified and unify each with the pattern. */
21750 {
21751 tree parm;
21755 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
21756 or the element of its argument pack at the current index if
21757 this argument was explicitly specified. */
21759 {
21768 {
21771 }
21773 }
21775 /* If we had explicit template arguments, substitute them into the
21776 pattern before deduction. */
21778 {
21779 /* Some arguments might still be unspecified or dependent. */
21787 NULL_TREE);
21792 }
21793 else
21796 /* Unify the pattern with the current argument. */
21798 explain_p))
21801 /* For each parameter pack, collect the deduced value. */
21803 {
21809 }
21810 }
21812 /* Verify that the results of unification with the parameter packs
21813 produce results consistent with what we've seen before, and make
21814 the deduced argument packs available. */
21816 {
21823 /* By default keep the original deduced argument pack.
21824 If necessary, more specific code is going to update the
21825 resulting deduced argument later down in this function. */
21829 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
21830 actually deduce anything. */
21838 {
21839 /* If we had fewer function args than explicit template args,
21840 just use the explicits. */
21845 }
21848 {
21849 tree result;
21850 /* Build the deduced *_ARGUMENT_PACK. */
21852 {
21855 }
21856 else
21861 /* Note the deduced argument packs for this parameter
21862 pack. */
21864 }
21868 {
21869 /* We only had the explicitly-provided arguments before, but
21870 now we have a complete set of arguments. */
21876 }
21877 else
21878 {
21884 /* Inconsistent unification of this parameter pack. */
21886 bad_old_arg,
21887 bad_new_arg);
21888 }
21889 }
21892 }
21894 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
21895 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
21896 parameters and return value are as for unify. */
21898 static int
21902 {
21903 tree parm_max;
21904 tree arg_max;
21908 /* Our representation of array types uses "N - 1" as the
21909 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
21910 not an integer constant. We cannot unify arbitrarily
21911 complex expressions, so we eliminate the MINUS_EXPRs
21912 here. */
21916 {
21919 }
21923 {
21924 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
21925 trying to unify the type of a variable with the type
21926 of a template parameter. For example:
21928 template <unsigned int N>
21929 void f (char (&) [N]);
21930 int g();
21931 void h(int i) {
21932 char a[g(i)];
21933 f(a);
21934 }
21936 Here, the type of the ARG will be "int [g(i)]", and
21937 may be a SAVE_EXPR, etc. */
21941 }
21943 /* If only one of the bounds used a MINUS_EXPR, compensate
21944 by adding one to the other bound. */
21947 integer_type_node,
21948 parm_max,
21949 integer_one_node);
21952 integer_type_node,
21953 arg_max,
21954 integer_one_node);
21958 }
21960 /* Returns whether T, a P or A in unify, is a type, template or expression. */
21964 static pa_kind_t
21966 {
21975 else
21977 }
21979 /* Deduce the value of template parameters. TPARMS is the (innermost)
21980 set of template parameters to a template. TARGS is the bindings
21981 for those template parameters, as determined thus far; TARGS may
21982 include template arguments for outer levels of template parameters
21983 as well. PARM is a parameter to a template function, or a
21984 subcomponent of that parameter; ARG is the corresponding argument.
21985 This function attempts to match PARM with ARG in a manner
21986 consistent with the existing assignments in TARGS. If more values
21987 are deduced, then TARGS is updated.
21989 Returns 0 if the type deduction succeeds, 1 otherwise. The
21990 parameter STRICT is a bitwise or of the following flags:
21992 UNIFY_ALLOW_NONE:
21993 Require an exact match between PARM and ARG.
21994 UNIFY_ALLOW_MORE_CV_QUAL:
21995 Allow the deduced ARG to be more cv-qualified (by qualification
21996 conversion) than ARG.
21997 UNIFY_ALLOW_LESS_CV_QUAL:
21998 Allow the deduced ARG to be less cv-qualified than ARG.
21999 UNIFY_ALLOW_DERIVED:
22000 Allow the deduced ARG to be a template base class of ARG,
22001 or a pointer to a template base class of the type pointed to by
22002 ARG.
22003 UNIFY_ALLOW_INTEGER:
22004 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
22005 case for more information.
22006 UNIFY_ALLOW_OUTER_LEVEL:
22007 This is the outermost level of a deduction. Used to determine validity
22008 of qualification conversions. A valid qualification conversion must
22009 have const qualified pointers leading up to the inner type which
22010 requires additional CV quals, except at the outer level, where const
22011 is not required [conv.qual]. It would be normal to set this flag in
22012 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
22013 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
22014 This is the outermost level of a deduction, and PARM can be more CV
22015 qualified at this point.
22016 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
22017 This is the outermost level of a deduction, and PARM can be less CV
22018 qualified at this point. */
22020 static int
22023 {
22025 tree targ;
22026 tree tparm;
22028 tsubst_flags_t complain = (explain_p
22029 ? tf_warning_or_error
22032 /* I don't think this will do the right thing with respect to types.
22033 But the only case I've seen it in so far has been array bounds, where
22034 signedness is the only information lost, and I think that will be
22035 okay. */
22043 /* We can't deduce anything from this, but we might get all the
22044 template args from other function args. */
22050 /* If PARM uses template parameters, then we can't bail out here,
22051 even if ARG == PARM, since we won't record unifications for the
22052 template parameters. We might need them if we're trying to
22053 figure out which of two things is more specialized. */
22057 /* Handle init lists early, so the rest of the function can assume
22058 we're dealing with a type. */
22060 {
22065 /* Replace T with std::initializer_list<T> for deduction. */
22072 /* We can only deduce from an initializer list argument if the
22073 parameter is std::initializer_list or an array; otherwise this
22074 is a non-deduced context. */
22079 else
22080 {
22082 /* Deduction is defined in terms of a single type, so just punt
22083 on the (bizarre) std::initializer_list<T...>. */
22086 }
22091 /* If ELTTYPE has no deducible template parms, skip deduction from
22093 else
22095 {
22102 {
22106 /* It should only be possible to get here for a call. */
22108 elt_strict |= maybe_adjust_types_for_deduction
22111 }
22114 explain_p);
22115 }
22119 {
22120 /* Also deduce from the length of the initializer list. */
22127 }
22129 /* If the std::initializer_list<T> deduction worked, replace the
22130 deduced A with std::initializer_list<A>. */
22132 {
22137 }
22139 }
22141 /* If parm and arg aren't the same kind of thing (template, type, or
22142 expression), fail early. */
22146 /* Immediately reject some pairs that won't unify because of
22147 cv-qualification mismatches. */
22150 /* It is the elements of the array which hold the cv quals of an array
22151 type, and the elements might be template type parms. We'll check
22152 when we recurse. */
22154 /* We check the cv-qualifiers when unifying with template type
22155 parameters below. We want to allow ARG `const T' to unify with
22156 PARM `T' for example, when computing which of two templates
22157 is more specialized, for example. */
22171 {
22175 /* In a type which contains a nested-name-specifier, template
22176 argument values cannot be deduced for template parameters used
22177 within the nested-name-specifier. */
22189 /* The PARM is not one we're trying to unify. Just check
22190 to see if it matches ARG. */
22191 {
22196 else
22198 }
22205 /* Check for mixed types and values. */
22213 {
22216 {
22217 /* First try to match ARG directly. */
22219 explain_p);
22221 {
22222 /* Otherwise, look for a suitable base of ARG, as below. */
22229 }
22230 }
22231 /* ARG must be constructed from a template class or a template
22232 template parameter. */
22237 /* Deduce arguments T, i from TT<T> or TT<i>. */
22243 /* Fall through to deduce template name. */
22244 }
22248 {
22249 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
22251 /* Simple cases: Value already set, does match or doesn't. */
22256 }
22257 else
22258 {
22259 /* If PARM is `const T' and ARG is only `int', we don't have
22260 a match unless we are allowing additional qualification.
22261 If ARG is `const int' and PARM is just `T' that's OK;
22262 that binds `const int' to `T'. */
22267 /* Consider the case where ARG is `const volatile int' and
22268 PARM is `const T'. Then, T should be `volatile int'. */
22269 arg = cp_build_qualified_type_real
22274 /* Simple cases: Value already set, does match or doesn't. */
22280 /* Make sure that ARG is not a variable-sized array. (Note
22281 that were talking about variable-sized arrays (like
22282 `int[n]'), rather than arrays of unknown size (like
22283 `int[]').) We'll get very confused by such a type since
22284 the bound of the array is not constant, and therefore
22285 not mangleable. Besides, such types are not allowed in
22286 ISO C++, so we can do as we please here. We do allow
22287 them for 'auto' deduction, since that isn't ABI-exposed. */
22291 /* Strip typedefs as in convert_template_argument. */
22293 }
22295 /* If ARG is a parameter pack or an expansion, we cannot unify
22296 against it unless PARM is also a parameter pack. */
22301 /* If the argument deduction results is a METHOD_TYPE,
22302 then there is a problem.
22303 METHOD_TYPE doesn't map to any real C++ type the result of
22304 the deduction cannot be of that type. */
22318 {
22319 /* The PARM is not one we're trying to unify. Just check
22320 to see if it matches ARG. */
22326 }
22332 {
22336 /* We're deducing from an array bound, the type doesn't matter. */
22342 }
22344 /* [temp.deduct.type] If, in the declaration of a function template
22345 with a non-type template-parameter, the non-type
22346 template-parameter is used in an expression in the function
22347 parameter-list and, if the corresponding template-argument is
22348 deduced, the template-argument type shall match the type of the
22349 template-parameter exactly, except that a template-argument
22350 deduced from an array bound may be of any integral type.
22351 The non-type parameter might use already deduced type parameters. */
22354 /* We don't have enough levels of args to do any substitution. This
22356 else
22357 {
22363 {
22367 }
22368 }
22371 /* Template-parameter dependent expression. Just accept it for now.
22372 It will later be processed in convert_template_argument. */
22373 ;
22379 /* Convert the ARG to the type of PARM; the deduced non-type
22380 template argument must exactly match the types of the
22381 corresponding parameter. */
22384 {
22385 /* We haven't deduced the type of this parameter yet. */
22387 /* We deduce from array bounds in try_array_deduction. */
22389 {
22390 /* Deduce it from the non-type argument. */
22395 }
22396 else
22397 /* Try again later. */
22399 }
22400 else
22403 /* If ARG is a parameter pack or an expansion, we cannot unify
22404 against it unless PARM is also a parameter pack. */
22409 {
22412 }
22417 {
22418 /* A pointer-to-member constant can be unified only with
22419 another constant. */
22423 /* Just unify the class member. It would be useless (and possibly
22424 wrong, depending on the strict flags) to unify also
22425 PTRMEM_CST_CLASS, because we want to be sure that both parm and
22426 arg refer to the same variable, even if through different
22427 classes. For instance:
22429 struct A { int x; };
22430 struct B : A { };
22432 Unification of &A::x and &B::x must succeed. */
22435 }
22438 {
22442 /* [temp.deduct.call]
22444 A can be another pointer or pointer to member type that can
22445 be converted to the deduced A via a qualification
22446 conversion (_conv.qual_).
22448 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
22449 This will allow for additional cv-qualification of the
22450 pointed-to types if appropriate. */
22453 /* The derived-to-base conversion only persists through one
22454 level of pointers. */
22459 }
22491 /* We have already checked cv-qualification at the top of the
22492 function. */
22496 /* As far as unification is concerned, this wins. Later checks
22497 will invalidate it if necessary. */
22500 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
22501 /* Type INTEGER_CST can come from ordinary constant template args. */
22513 {
22523 /* Check for pack expansions in the parameters. */
22525 {
22527 {
22529 /* We can unify against something with a trailing
22530 parameter pack. */
22532 else
22533 /* [temp.deduct.type]/9: If the template argument list of
22534 P contains a pack expansion that is not the last
22535 template argument, the entire template argument list
22536 is a non-deduced context. */
22538 }
22539 }
22541 /* If we don't have enough arguments to satisfy the parameters
22542 (not counting the pack expression at the end), or we have
22543 too many arguments for a parameter list that doesn't end in
22544 a pack expression, we can't unify. */
22550 /* Unify all of the parameters that precede the (optional)
22551 pack expression. */
22553 {
22558 }
22561 DEDUCE_EXACT,
22564 }
22572 {
22580 }
22585 {
22589 {
22590 /* First, we try to unify the PARM and ARG directly. */
22595 {
22596 /* Fallback to the special case allowed in
22597 [temp.deduct.call]:
22599 If P is a class, and P has the form
22600 template-id, then A can be a derived class of
22601 the deduced A. Likewise, if P is a pointer to
22602 a class of the form template-id, A can be a
22603 pointer to a derived class pointed to by the
22604 deduced A. */
22610 {
22611 /* Don't give the derived diagnostic if we're
22612 already dealing with the same template. */
22613 bool same_template
22619 }
22620 }
22621 }
22625 /* Perhaps PARM is something like S<U> and ARG is S<int>.
22626 Then, we should unify `int' and `U'. */
22628 else
22629 /* There's no chance of unification succeeding. */
22634 }
22641 {
22644 tree a;
22650 /* CV qualifications for methods can never be deduced, they must
22651 match exactly. We need to check them explicitly here,
22652 because type_unification_real treats them as any other
22653 cv-qualified parameter. */
22655 && (!check_cv_quals_for_unify
22683 {
22695 }
22698 }
22701 /* Unify a pointer to member with a pointer to member function, which
22702 deduces the type of the member as a function type. */
22704 {
22705 /* Check top-level cv qualifiers */
22713 /* Determine the type of the function we are unifying against. */
22717 }
22736 /* Matched cases are handled by the ARG == PARM test above. */
22740 /* We might get a variable as a non-type template argument in parm if the
22741 corresponding parameter is type-dependent. Make any necessary
22742 adjustments based on whether arg is a reference. */
22746 {
22751 }
22752 /* Now use the normal expression code to check whether they match. */
22763 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
22764 or UNDERLYING_TYPE nodes. */
22768 /* Unification fails if we hit an error node. */
22773 {
22783 }
22784 /* FALLTHRU */
22787 /* An unresolved overload is a nondeduced context. */
22793 expr:
22794 /* We must be looking at an expression. This can happen with
22795 something like:
22797 template <int I>
22798 void foo(S<I>, S<I + 2>);
22800 or
22802 template<typename T>
22803 void foo(A<T, T{}>);
22805 This is a "non-deduced context":
22807 [deduct.type]
22809 The non-deduced contexts are:
22811 --A non-type template argument or an array bound in which
22812 a subexpression references a template parameter.
22814 In these cases, we assume deduction succeeded, but don't
22815 actually infer any unifications. */
22820 else
22822 }
22823 }
22824 #undef RECUR_AND_CHECK_FAILURE
22825 \f
22826 /* Note that DECL can be defined in this translation unit, if
22827 required. */
22829 static void
22831 {
22832 tree clone;
22836 }
22838 /* Called if RESULT is explicitly instantiated, or is a member of an
22839 explicitly instantiated class. */
22841 void
22843 {
22846 /* If this entity has already been written out, it's too late to
22847 make any modifications. */
22851 /* For anonymous namespace we don't need to do anything. */
22853 {
22856 }
22859 /* The TREE_PUBLIC flag for function declarations will have been
22860 set correctly by tsubst. */
22863 /* This might have been set by an earlier implicit instantiation. */
22868 else
22869 {
22872 /* Always make artificials weak. */
22875 /* For WIN32 we also want to put explicit instantiations in
22876 linkonce sections. */
22881 /* If the function has already been instantiated, clear DECL_EXTERNAL,
22882 since start_preparsed_function wouldn't have if we had an earlier
22883 extern explicit instantiation. */
22885 }
22887 /* If EXTERN_P, then this function will not be emitted -- unless
22888 followed by an explicit instantiation, at which point its linkage
22889 will be adjusted. If !EXTERN_P, then this function will be
22890 emitted here. In neither circumstance do we want
22891 import_export_decl to adjust the linkage. */
22893 }
22895 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
22896 important template arguments. If any are missing, we check whether
22897 they're important by using error_mark_node for substituting into any
22898 args that were used for partial ordering (the ones between ARGS and END)
22899 and seeing if it bubbles up. */
22901 static bool
22903 {
22908 {
22911 }
22913 {
22917 }
22919 }
22921 /* Given two function templates PAT1 and PAT2, return:
22923 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
22924 -1 if PAT2 is more specialized than PAT1.
22925 0 if neither is more specialized.
22927 LEN indicates the number of parameters we should consider
22928 (defaulted parameters should not be considered).
22930 The 1998 std underspecified function template partial ordering, and
22931 DR214 addresses the issue. We take pairs of arguments, one from
22932 each of the templates, and deduce them against each other. One of
22933 the templates will be more specialized if all the *other*
22934 template's arguments deduce against its arguments and at least one
22935 of its arguments *does* *not* deduce against the other template's
22936 corresponding argument. Deduction is done as for class templates.
22937 The arguments used in deduction have reference and top level cv
22938 qualifiers removed. Iff both arguments were originally reference
22939 types *and* deduction succeeds in both directions, an lvalue reference
22940 wins against an rvalue reference and otherwise the template
22941 with the more cv-qualified argument wins for that pairing (if
22942 neither is more cv-qualified, they both are equal). Unlike regular
22943 deduction, after all the arguments have been deduced in this way,
22944 we do *not* verify the deduced template argument values can be
22945 substituted into non-deduced contexts.
22947 The logic can be a bit confusing here, because we look at deduce1 and
22948 targs1 to see if pat2 is at least as specialized, and vice versa; if we
22949 can find template arguments for pat1 to make arg1 look like arg2, that
22950 means that arg2 is at least as specialized as arg1. */
22952 int
22954 {
22967 /* Remove the this parameter from non-static member functions. If
22968 one is a non-static member function and the other is not a static
22969 member function, remove the first parameter from that function
22970 also. This situation occurs for operator functions where we
22971 locate both a member function (with this pointer) and non-member
22972 operator (with explicit first operand). */
22974 {
22979 }
22981 {
22984 {
22985 len--;
22987 }
22988 }
22990 /* If only one is a conversion operator, they are unordered. */
22994 /* Consider the return type for a conversion function */
22996 {
22999 len++;
23000 }
23002 processing_template_decl++;
23008 /* Stop when an ellipsis is seen. */
23010 {
23021 {
23022 /* When both arguments are pack expansions, we need only
23023 unify the patterns themselves. */
23027 /* This is the last comparison we need to do. */
23029 }
23031 /* DR 1847: If a particular P contains no template-parameters that
23032 participate in template argument deduction, that P is not used to
23033 determine the ordering. */
23039 {
23043 }
23046 {
23050 }
23056 {
23062 /* Setup the parameter vector, which contains only ARG1. */
23065 /* Setup the argument vector, which contains the remaining
23066 arguments. */
23075 /* We cannot deduce in the other direction, because ARG1 is
23076 a pack expansion but ARG2 is not. */
23078 }
23080 {
23086 /* Setup the parameter vector, which contains only ARG1. */
23089 /* Setup the argument vector, which contains the remaining
23090 arguments. */
23099 /* We cannot deduce in the other direction, because ARG2 is
23100 a pack expansion but ARG1 is not.*/
23102 }
23104 else
23105 {
23106 /* The normal case, where neither argument is a pack
23107 expansion. */
23114 }
23116 /* If we couldn't deduce arguments for tparms1 to make arg1 match
23117 arg2, then arg2 is not as specialized as arg1. */
23123 /* "If, for a given type, deduction succeeds in both directions
23124 (i.e., the types are identical after the transformations above)
23125 and both P and A were reference types (before being replaced with
23126 the type referred to above):
23127 - if the type from the argument template was an lvalue reference and
23128 the type from the parameter template was not, the argument type is
23129 considered to be more specialized than the other; otherwise,
23130 - if the type from the argument template is more cv-qualified
23131 than the type from the parameter template (as described above),
23132 the argument type is considered to be more specialized than the other;
23133 otherwise,
23134 - neither type is more specialized than the other." */
23137 {
23139 {
23142 else
23144 }
23146 {
23151 }
23152 }
23155 /* We've failed to deduce something in either direction.
23156 These must be unordered. */
23159 next:
23163 /* We have already processed all of the arguments in our
23164 handing of the pack expansion type. */
23169 }
23171 /* "In most cases, all template parameters must have values in order for
23172 deduction to succeed, but for partial ordering purposes a template
23173 parameter may remain without a value provided it is not used in the
23174 types being used for partial ordering."
23176 Thus, if we are missing any of the targs1 we need to substitute into
23177 origs1, then pat2 is not as specialized as pat1. This can happen when
23178 there is a nondeduced context. */
23184 processing_template_decl--;
23186 /* If both deductions succeed, the partial ordering selects the more
23187 constrained template. */
23189 {
23194 }
23196 /* All things being equal, if the next argument is a pack expansion
23197 for one function but not for the other, prefer the
23198 non-variadic function. FIXME this is bogus; see c++/41958. */
23202 {
23205 }
23211 else
23213 }
23215 /* Determine which of two partial specializations of TMPL is more
23216 specialized.
23218 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
23219 to the first partial specialization. The TREE_PURPOSE is the
23220 innermost set of template parameters for the partial
23221 specialization. PAT2 is similar, but for the second template.
23223 Return 1 if the first partial specialization is more specialized;
23224 -1 if the second is more specialized; 0 if neither is more
23225 specialized.
23227 See [temp.class.order] for information about determining which of
23228 two templates is more specialized. */
23230 static int
23232 {
23233 tree targs;
23242 /* Just like what happens for functions, if we are ordering between
23243 different template specializations, we may encounter dependent
23244 types in the arguments, and we need our dependency check functions
23245 to behave correctly. */
23249 {
23252 }
23256 {
23259 }
23262 /* If both deductions succeed, the partial ordering selects the more
23263 constrained template. */
23267 /* In the case of a tie where at least one of the templates
23268 has a parameter pack at the end, the template with the most
23269 non-packed parameters wins. */
23271 && any_deductions
23274 {
23280 /* We don't count the pack expansion at the end. */
23290 }
23293 }
23295 /* Return the template arguments that will produce the function signature
23296 DECL from the function template FN, with the explicit template
23297 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
23298 also match. Return NULL_TREE if no satisfactory arguments could be
23299 found. */
23301 static tree
23303 {
23307 tree decl_arg_types;
23310 tree arg;
23314 /* Never do unification on the 'this' parameter. */
23336 }
23338 /* Return the innermost template arguments that, when applied to a partial
23339 specialization SPEC_TMPL of TMPL, yield the ARGS.
23341 For example, suppose we have:
23343 template <class T, class U> struct S {};
23344 template <class T> struct S<T*, int> {};
23346 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
23347 partial specialization and the ARGS will be {double*, int}. The resulting
23348 vector will be {double}, indicating that `T' is bound to `double'. */
23350 static tree
23352 {
23354 tree spec_args
23357 tree deduced_args;
23358 tree innermost_deduced_args;
23362 {
23366 innermost_deduced_args);
23367 }
23368 else
23372 again:
23381 {
23383 {
23389 }
23391 }
23394 {
23397 }
23399 /* Verify that nondeduced template arguments agree with the type
23400 obtained from argument deduction.
23402 For example:
23404 struct A { typedef int X; };
23405 template <class T, class U> struct C {};
23406 template <class T> struct C<T, typename T::X> {};
23408 Then with the instantiation `C<A, int>', we can deduce that
23409 `T' is `A' but unify () does not check whether `typename T::X'
23410 is `int'. */
23421 /* We only need to check the innermost arguments; the other
23422 arguments will always agree. */
23427 /* Now that we have bindings for all of the template arguments,
23428 ensure that the arguments deduced for the template template
23429 parameters have compatible template parameter lists. See the use
23430 of template_template_parm_bindings_ok_p in fn_type_unification
23431 for more information. */
23436 }
23438 // Compare two function templates T1 and T2 by deducing bindings
23439 // from one against the other. If both deductions succeed, compare
23440 // constraints to see which is more constrained.
23441 static int
23443 {
23448 {
23451 }
23454 {
23457 }
23459 // If both deductions succeed, then one may be more constrained.
23464 }
23466 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
23467 Return the TREE_LIST node with the most specialized template, if
23468 any. If there is no most specialized template, the error_mark_node
23469 is returned.
23471 Note that this function does not look at, or modify, the
23472 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
23473 returned is one of the elements of INSTANTIATIONS, callers may
23474 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
23475 and retrieve it from the value returned. */
23477 tree
23479 {
23486 {
23492 {
23493 /* Equally specialized, move to next function. If there
23494 is no next function, nothing's most specialized. */
23499 }
23500 }
23503 /* Now verify that champ is better than everything earlier in the
23504 instantiation list. */
23507 {
23510 }
23511 }
23513 processing_template_decl--;
23519 }
23521 /* If DECL is a specialization of some template, return the most
23522 general such template. Otherwise, returns NULL_TREE.
23524 For example, given:
23526 template <class T> struct S { template <class U> void f(U); };
23528 if TMPL is `template <class U> void S<int>::f(U)' this will return
23529 the full template. This function will not trace past partial
23530 specializations, however. For example, given in addition:
23532 template <class T> struct S<T*> { template <class U> void f(U); };
23534 if TMPL is `template <class U> void S<int*>::f(U)' this will return
23535 `template <class T> template <class U> S<T*>::f(U)'. */
23537 tree
23539 {
23541 {
23544 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
23545 template friend, or a FIELD_DECL for a capture pack. */
23548 }
23550 /* Look for more and more general templates. */
23552 {
23553 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
23554 (See cp-tree.h for details.) */
23563 /* Stop if we run into an explicitly specialized class template. */
23570 }
23573 }
23575 /* Return the most specialized of the template partial specializations
23576 which can produce TARGET, a specialization of some class or variable
23577 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
23578 a TEMPLATE_DECL node corresponding to the partial specialization, while
23579 the TREE_PURPOSE is the set of template arguments that must be
23580 substituted into the template pattern in order to generate TARGET.
23582 If the choice of partial specialization is ambiguous, a diagnostic
23583 is issued, and the error_mark_node is returned. If there are no
23584 partial specializations matching TARGET, then NULL_TREE is
23585 returned, indicating that the primary template should be used. */
23587 static tree
23589 {
23591 tree t;
23592 tree champ;
23599 {
23603 }
23605 {
23608 }
23610 {
23614 }
23615 else
23620 /* For determining which partial specialization to use, only the
23621 innermost args are interesting. */
23623 {
23626 }
23628 /* The caller hasn't called push_to_top_level yet, but we need
23629 get_partial_spec_bindings to be done in non-template context so that we'll
23630 fully resolve everything. */
23631 processing_template_decl_sentinel ptds;
23634 {
23635 tree spec_args;
23639 {
23640 /* Substitute in the template args from the enclosing class. */
23644 }
23651 {
23655 /* Keep the candidate only if the constraints are satisfied,
23656 or if we're not compiling with concepts. */
23659 {
23662 }
23663 }
23664 }
23674 {
23677 ;
23678 else
23679 {
23681 {
23684 {
23687 }
23688 }
23690 }
23691 }
23695 {
23698 {
23701 }
23702 }
23705 {
23712 else
23716 {
23721 }
23724 }
23727 }
23729 /* Explicitly instantiate DECL. */
23731 void
23733 {
23738 /* An error occurred, for which grokdeclarator has already issued
23739 an appropriate message. */
23742 {
23745 }
23747 {
23750 else
23753 }
23759 {
23760 /* There is an asymmetry here in the way VAR_DECLs and
23761 FUNCTION_DECLs are handled by grokdeclarator. In the case of
23762 the latter, the DECL we get back will be marked as a
23763 template instantiation, and the appropriate
23764 DECL_TEMPLATE_INFO will be set up. This does not happen for
23765 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
23766 should handle VAR_DECLs as it currently handles
23767 FUNCTION_DECLs. */
23769 {
23772 }
23775 {
23778 }
23780 {
23785 }
23786 }
23788 {
23791 }
23792 else
23795 /* Check for various error cases. Note that if the explicit
23796 instantiation is valid the RESULT will currently be marked as an
23797 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
23798 until we get here. */
23801 {
23802 /* DR 259 [temp.spec].
23804 Both an explicit instantiation and a declaration of an explicit
23805 specialization shall not appear in a program unless the explicit
23806 instantiation follows a declaration of the explicit specialization.
23808 For a given set of template parameters, if an explicit
23809 instantiation of a template appears after a declaration of an
23810 explicit specialization for that template, the explicit
23811 instantiation has no effect. */
23813 }
23815 {
23816 /* [temp.spec]
23818 No program shall explicitly instantiate any template more
23819 than once.
23821 We check DECL_NOT_REALLY_EXTERN so as not to complain when
23822 the first instantiation was `extern' and the second is not,
23823 and EXTERN_P for the opposite case. */
23826 /* If an "extern" explicit instantiation follows an ordinary
23827 explicit instantiation, the template is instantiated. */
23830 }
23832 {
23835 }
23837 {
23840 }
23843 ;
23845 {
23848 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
23851 }
23852 else
23860 }
23862 static void
23864 {
23870 {
23873 }
23874 }
23876 /* Called from do_type_instantiation through binding_table_foreach to
23877 do recursive instantiation for the type bound in ENTRY. */
23878 static void
23880 {
23887 }
23889 /* Perform an explicit instantiation of template class T. STORAGE, if
23890 non-null, is the RID for extern, inline or static. COMPLAIN is
23891 nonzero if this is called from the parser, zero if called recursively,
23892 since the standard is unclear (as detailed below). */
23894 void
23896 {
23906 {
23907 tree tmpl =
23911 else
23914 }
23919 {
23922 t);
23924 }
23927 {
23929 {
23931 {
23934 "ISO C++ 1998 forbids the use of %<extern%> on "
23936 }
23937 else
23939 "ISO C++ forbids the use of %qE"
23941 }
23949 else
23950 {
23952 storage);
23954 }
23955 }
23958 {
23959 /* DR 259 [temp.spec].
23961 Both an explicit instantiation and a declaration of an explicit
23962 specialization shall not appear in a program unless the explicit
23963 instantiation follows a declaration of the explicit specialization.
23965 For a given set of template parameters, if an explicit
23966 instantiation of a template appears after a declaration of an
23967 explicit specialization for that template, the explicit
23968 instantiation has no effect. */
23970 }
23972 {
23973 /* [temp.spec]
23975 No program shall explicitly instantiate any template more
23976 than once.
23978 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
23979 instantiation was `extern'. If EXTERN_P then the second is.
23980 These cases are OK. */
23987 /* If we've already instantiated the template, just return now. */
23990 }
23998 /* In contrast to implicit instantiation, where only the
23999 declarations, and not the definitions, of members are
24000 instantiated, we have here:
24002 [temp.explicit]
24004 The explicit instantiation of a class template specialization
24005 implies the instantiation of all of its members not
24006 previously explicitly specialized in the translation unit
24007 containing the explicit instantiation.
24009 Of course, we can't instantiate member template classes, since we
24010 don't have any arguments for them. Note that the standard is
24011 unclear on whether the instantiation of the members are
24012 *explicit* instantiations or not. However, the most natural
24013 interpretation is that it should be an explicit
24014 instantiation. */
24018 && !static_p
24021 {
24026 }
24031 }
24033 /* Given a function DECL, which is a specialization of TMPL, modify
24034 DECL to be a re-instantiation of TMPL with the same template
24035 arguments. TMPL should be the template into which tsubst'ing
24036 should occur for DECL, not the most general template.
24038 One reason for doing this is a scenario like this:
24040 template <class T>
24041 void f(const T&, int i);
24043 void g() { f(3, 7); }
24045 template <class T>
24046 void f(const T& t, const int i) { }
24048 Note that when the template is first instantiated, with
24049 instantiate_template, the resulting DECL will have no name for the
24050 first parameter, and the wrong type for the second. So, when we go
24051 to instantiate the DECL, we regenerate it. */
24053 static void
24055 {
24056 /* The arguments used to instantiate DECL, from the most general
24057 template. */
24058 tree code_pattern;
24062 /* Make sure that we can see identifiers, and compute access
24063 correctly. */
24067 {
24068 tree decl_parm;
24069 tree pattern_parm;
24070 tree specs;
24079 /* Instantiate a dynamic exception-specification. noexcept will be
24080 handled below. */
24083 {
24089 specs);
24090 }
24092 /* Merge parameter declarations. */
24095 pattern_parm
24099 {
24100 tree parm_type;
24101 tree attributes;
24106 NULL_TREE);
24112 {
24115 }
24118 }
24119 /* Merge any parameters that match with the function parameter
24120 pack. */
24122 {
24124 tree expanded_types;
24125 /* Expand the TYPE_PACK_EXPANSION that provides the types for
24126 the parameters in this function parameter pack. */
24131 {
24132 tree parm_type;
24133 tree attributes;
24136 /* Rename the parameter to include the index. */
24145 {
24148 }
24150 }
24151 }
24152 /* Merge additional specifiers from the CODE_PATTERN. */
24158 }
24160 {
24169 }
24170 else
24174 }
24176 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
24177 substituted to get DECL. */
24179 tree
24181 {
24184 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
24185 for the instantiation. This is not always the most general
24186 template. Consider, for example:
24188 template <class T>
24189 struct S { template <class U> void f();
24190 template <> void f<int>(); };
24192 and an instantiation of S<double>::f<int>. We want TD to be the
24193 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
24195 more general template. */
24197 /* We must also deal with friend templates. Given:
24199 template <class T> struct S {
24200 template <class U> friend void f() {};
24201 };
24203 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
24204 so far as the language is concerned, but that's still
24205 where we get the pattern for the instantiation from. On
24206 other hand, if the definition comes outside the class, say:
24208 template <class T> struct S {
24209 template <class U> friend void f();
24210 };
24211 template <class U> friend void f() {}
24213 we don't need to look any further. That's what the check for
24214 DECL_INITIAL is for. */
24218 {
24219 /* The present template, TD, should not be a definition. If it
24220 were a definition, we should be using it! Note that we
24221 cannot restructure the loop to just keep going until we find
24222 a template with a definition, since that might go too far if
24223 a specialization was declared, but not defined. */
24225 /* Fetch the more general template. */
24227 }
24230 }
24232 /* Returns true if we need to instantiate this template instance even if we
24233 know we aren't going to emit it. */
24235 bool
24237 {
24238 /* We always instantiate inline functions so that we can inline them. An
24239 explicit instantiation declaration prohibits implicit instantiation of
24240 non-inline functions. With high levels of optimization, we would
24241 normally inline non-inline functions -- but we're not allowed to do
24242 that for "extern template" functions. Therefore, we check
24243 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
24247 /* And we need to instantiate static data members so that
24248 their initializers are available in integral constant
24249 expressions. */
24252 }
24254 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
24255 instantiate it now, modifying TREE_TYPE (fn). Returns false on
24256 error, true otherwise. */
24258 bool
24260 {
24263 /* Don't instantiate a noexcept-specification from template context. */
24272 /* For a member friend template we can get a TEMPLATE_DECL. Let's use
24273 its FUNCTION_DECL for the rest of this function -- push_access_scope
24274 doesn't accept TEMPLATE_DECLs. */
24276 {
24279 }
24290 {
24294 {
24297 /* This might have failed because of an unparsed DMI, so
24298 let's try again later. */
24300 }
24302 {
24303 /* If hash_set::add returns true, the element was already there. */
24308 fn);
24310 }
24312 {
24319 /* If needed, set current_class_ptr for the benefit of
24320 tsubst_copy/PARM_DECL. */
24323 {
24328 }
24330 /* If this function is represented by a TEMPLATE_DECL, then
24331 the deferred noexcept-specification might still contain
24332 dependent types, even after substitution. And we need the
24333 dependency check functions to work in build_noexcept_spec. */
24337 /* Do deferred instantiation of the noexcept-specifier. */
24347 /* Build up the noexcept-specification. */
24356 }
24357 else
24364 {
24365 /* This failed with a hard error, so let's go with false. */
24368 }
24373 }
24376 {
24379 else
24381 }
24384 }
24386 /* We're starting to process the function INST, an instantiation of PATTERN;
24387 add their parameters to local_specializations. */
24389 static void
24391 {
24395 {
24399 }
24401 {
24403 {
24406 }
24407 else
24408 {
24409 /* Register the (value) argument pack as a specialization of
24410 TMPL_PARM, then move on. */
24413 }
24414 }
24416 }
24418 /* Produce the definition of D, a _DECL generated from a template. If
24419 DEFER_OK is true, then we don't have to actually do the
24420 instantiation now; we just have to do it sometime. Normally it is
24421 an error if this is an explicit instantiation but D is undefined.
24422 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
24423 instantiated class template. */
24425 tree
24427 {
24429 tree gen_args;
24430 tree args;
24431 tree td;
24432 tree code_pattern;
24433 tree spec;
24434 tree gen_tmpl;
24442 /* This function should only be used to instantiate templates for
24443 functions and static member variables. */
24446 /* A concept is never instantiated. */
24449 /* Variables are never deferred; if instantiation is required, they
24450 are instantiated right away. That allows for better code in the
24451 case that an expression refers to the value of the variable --
24452 if the variable has a constant value the referring expression can
24453 take advantage of that fact. */
24457 /* Don't instantiate cloned functions. Instead, instantiate the
24458 functions they cloned. */
24466 /* D has already been instantiated or explicitly specialized, so
24467 there's nothing for us to do here.
24469 It might seem reasonable to check whether or not D is an explicit
24470 instantiation, and, if so, stop here. But when an explicit
24471 instantiation is deferred until the end of the compilation,
24472 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
24473 the instantiation. */
24476 /* Check to see whether we know that this template will be
24477 instantiated in some other file, as with "extern template"
24478 extension. */
24481 /* In general, we do not instantiate such templates. */
24489 /* We should already have the extra args. */
24492 /* And what's in the hash table should match D. */
24496 /* This needs to happen before any tsubsting. */
24502 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
24503 for the instantiation. */
24508 {
24509 /* Look up an explicit specialization, if any. */
24513 {
24516 }
24517 }
24521 /* We should never be trying to instantiate a member of a class
24522 template or partial specialization. */
24527 /* In the case of a friend template whose definition is provided
24528 outside the class, we may have too many arguments. Drop the
24529 ones we don't need. The same is true for specializations. */
24530 args = get_innermost_template_args
24534 {
24540 }
24541 else
24542 {
24546 else
24548 }
24550 /* We may be in the middle of deferred access check. Disable it now. */
24553 /* Unless an explicit instantiation directive has already determined
24554 the linkage of D, remember that a definition is available for
24555 this entity. */
24565 /* If D is a member of an explicitly instantiated class template,
24566 and no definition is available, treat it like an implicit
24567 instantiation. */
24570 {
24571 /* Leave linkage flags alone on instantiations with anonymous
24572 visibility. */
24574 {
24577 }
24579 }
24581 /* Defer all other templates, unless we have been explicitly
24582 forbidden from doing so. */
24584 template. */
24585 ! pattern_defined
24586 /* If it's OK to postpone instantiation, do so. */
24587 || defer_ok
24588 /* If this is a static data member that will be defined
24589 elsewhere, we don't want to instantiate the entire data
24590 member, but we do want to instantiate the initializer so that
24591 we can substitute that elsewhere. */
24593 /* Handle here a deleted function too, avoid generating
24594 its body (c++/61080). */
24596 {
24597 /* The definition of the static data member is now required so
24598 we must substitute the initializer. */
24602 {
24603 tree ns;
24604 tree init;
24613 args,
24616 /* If instantiating the initializer involved instantiating this
24617 again, don't call cp_finish_decl twice. */
24619 {
24620 /* Make sure the initializer is still constant, in case of
24621 circular dependency (template/instantiate6.C). */
24622 const_init
24626 LOOKUP_ONLYCONVERTING);
24627 }
24631 }
24633 /* We restore the source position here because it's used by
24634 add_pending_template. */
24640 /* [temp.explicit]
24642 The definition of a non-exported function template, a
24643 non-exported member function template, or a non-exported
24644 member function or static data member of a class template
24645 shall be present in every translation unit in which it is
24646 explicitly instantiated. */
24650 /* If we're in unevaluated context, we just wanted to get the
24651 constant value; this isn't an odr use, so don't queue
24652 a full instantiation. */
24655 /* ??? Historically, we have instantiated inline functions, even
24656 when marked as "extern template". */
24660 }
24661 /* Tell the repository that D is available in this translation unit
24662 -- and see if it is supposed to be instantiated here. */
24664 {
24665 /* In a PCH file, despite the fact that the repository hasn't
24666 requested instantiation in the PCH it is still possible that
24667 an instantiation will be required in a file that includes the
24668 PCH. */
24671 /* Instantiate inline functions so that the inliner can do its
24672 job, even though we'll not be emitting a copy of this
24673 function. */
24676 }
24679 tree fn_context;
24682 /* tsubst_lambda_expr resolved any references to enclosing functions. */
24693 else
24694 {
24699 }
24701 /* Mark D as instantiated so that recursive calls to
24702 instantiate_decl do not try to instantiate it again. */
24705 /* Regenerate the declaration in case the template has been modified
24706 by a subsequent redeclaration. */
24709 /* We already set the file and line above. Reset them now in case
24710 they changed as a result of calling regenerate_decl_from_template. */
24714 {
24715 tree init;
24718 /* Clear out DECL_RTL; whatever was there before may not be right
24719 since we've reset the type of the declaration. */
24723 /* The initializer is placed in DECL_INITIAL by
24724 regenerate_decl_from_template so we don't need to
24725 push/pop_access_scope again here. Pull it out so that
24726 cp_finish_decl can process it. */
24731 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
24732 initializer. That function will defer actual emission until
24733 we have a chance to determine linkage. */
24736 /* Enter the scope of D so that access-checking works correctly. */
24749 }
24753 {
24754 /* Set up the list of local specializations. */
24758 /* Set up context. */
24762 else
24765 /* Some typedefs referenced from within the template code need to be
24766 access checked at template instantiation time, i.e now. These
24767 types were added to the template at parsing time. Let's get those
24768 and perform the access checks then. */
24770 args);
24772 /* Create substitution entries for the parameters. */
24775 /* Substitute into the body of the function. */
24779 else
24780 {
24785 /* Set the current input_location to the end of the function
24786 so that finish_function knows where we are. */
24787 input_location
24790 /* Remember if we saw an infinite loop in the template. */
24791 current_function_infinite_loop
24793 }
24795 /* Finish the function. */
24799 else
24800 {
24803 }
24807 }
24809 /* We're not deferring instantiation any more. */
24814 else
24820 out:
24829 }
24831 /* Run through the list of templates that we wish we could
24832 instantiate, and instantiate any we can. RETRIES is the
24833 number of times we retry pending template instantiation. */
24835 void
24837 {
24841 /* Instantiating templates may trigger vtable generation. This in turn
24842 may require further template instantiations. We place a limit here
24843 to avoid infinite loop. */
24845 {
24849 "template instantiation depth exceeds maximum of %d"
24850 " instantiating %q+D, possibly from virtual table generation"
24854 /* Pretend that we defined it. */
24857 }
24859 do
24860 {
24865 {
24870 {
24872 {
24887 }
24890 }
24891 else
24892 {
24895 {
24896 instantiation
24902 }
24906 }
24909 {
24910 /* If INSTANTIATION has been instantiated, then we don't
24911 need to consider it again in the future. */
24916 }
24917 else
24918 {
24921 }
24924 }
24926 }
24930 }
24932 /* Substitute ARGVEC into T, which is a list of initializers for
24933 either base class or a non-static data member. The TREE_PURPOSEs
24934 are DECLs, and the TREE_VALUEs are the initializer values. Used by
24935 instantiate_decl. */
24937 static tree
24939 {
24944 {
24945 tree decl;
24946 tree init;
24952 {
24953 tree expr;
24954 tree arg;
24956 /* Expand the base class expansion type into separate base
24957 classes. */
24959 tf_warning_or_error,
24960 NULL_TREE);
24964 /* We'll be building separate TREE_LISTs of arguments for
24965 each base. */
24971 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
24972 expand each argument in the TREE_VALUE of t. */
24979 /* VOID_TYPE_NODE is used to indicate
24980 value-initialization. */
24981 {
24984 }
24985 else
24986 {
24987 /* Substitute parameter packs into each argument in the
24988 TREE_LIST. */
24991 {
24992 tree expanded_exprs;
24994 /* Expand the argument. */
24996 expanded_exprs
24998 tf_warning_or_error,
24999 NULL_TREE);
25003 /* Prepend each of the expanded expressions to the
25004 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
25006 {
25011 }
25012 }
25015 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
25016 since we built them backwards. */
25018 {
25021 }
25022 }
25023 }
25026 {
25028 {
25032 }
25033 else
25034 {
25035 tree tmp;
25050 /* If we had an initializer but it instantiated to nothing,
25051 value-initialize the object. This will only occur when
25052 the initializer was a pack expansion where the parameter
25053 packs used in that expansion were of length zero. */
25056 }
25060 {
25062 decl);
25064 }
25065 /* Look for a target constructor. */
25069 {
25072 {
25076 }
25078 }
25081 {
25085 }
25086 }
25087 }
25089 }
25091 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
25093 static void
25095 {
25100 else
25102 }
25104 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
25105 is the instantiation (which should have been created with
25106 start_enum) and ARGS are the template arguments to use. */
25108 static void
25110 {
25111 tree e;
25117 {
25118 tree value;
25119 tree decl;
25122 /* Note that in a template enum, the TREE_VALUE is the
25123 CONST_DECL, not the corresponding INTEGER_CST. */
25128 /* Give this enumeration constant the correct access. */
25131 /* Actually build the enumerator itself. Here we're assuming that
25132 enumerators can't have dependent attributes. */
25135 }
25145 }
25147 /* DECL is a FUNCTION_DECL that is a template specialization. Return
25148 its type -- but without substituting the innermost set of template
25149 arguments. So, innermost set of template parameters will appear in
25150 the type. */
25152 tree
25154 {
25155 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
25157 }
25159 /* Return truthvalue if we're processing a template different from
25160 the last one involved in diagnostics. */
25161 bool
25163 {
25165 }
25167 /* Remember current template involved in diagnostics. */
25168 void
25170 {
25172 }
25176 {
25178 }
25180 /* Return TRUE if current_function_decl is being instantiated, false
25181 otherwise. */
25183 bool
25185 {
25189 }
25191 /* [temp.param] Check that template non-type parm TYPE is of an allowable
25192 type. Return false for ok, true for disallowed. Issue error and
25193 inform messages under control of COMPLAIN. */
25195 static bool
25197 {
25215 /* A bound template template parm could later be instantiated to have a valid
25216 nontype parm type via an alias template. */
25221 {
25223 {
25227 }
25231 {
25236 }
25238 {
25242 }
25243 /* FIXME check op<=> and strong structural equality once spaceship is
25244 implemented. */
25246 }
25249 {
25252 else
25254 type);
25255 }
25257 }
25259 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
25260 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
25262 static bool
25264 {
25265 tree scope;
25267 /* [temp.dep.type]
25269 A type is dependent if it is:
25271 -- a template parameter. Template template parameters are types
25272 for us (since TYPE_P holds true for them) so we handle
25273 them here. */
25277 /* -- a qualified-id with a nested-name-specifier which contains a
25278 class-name that names a dependent type or whose unqualified-id
25279 names a dependent type. */
25283 /* An alias template specialization can be dependent even if the
25284 resulting type is not. */
25288 /* -- a cv-qualified type where the cv-unqualified type is
25289 dependent.
25290 No code is necessary for this bullet; the code below handles
25291 cv-qualified types, and we don't want to strip aliases with
25292 TYPE_MAIN_VARIANT because of DR 1558. */
25293 /* -- a compound type constructed from any dependent type. */
25301 {
25302 tree arg_type;
25307 arg_type;
25312 /* A value-dependent noexcept-specifier makes the type dependent. */
25315 /* Treat DEFERRED_NOEXCEPT as non-dependent, since it doesn't
25316 affect overload resolution and treating it as dependent breaks
25317 things. Same for an unparsed noexcept expression. */
25323 }
25324 /* -- an array type constructed from any dependent type or whose
25325 size is specified by a constant expression that is
25326 value-dependent.
25328 We checked for type- and value-dependence of the bounds in
25329 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
25331 {
25336 }
25338 /* -- a template-id in which either the template name is a template
25339 parameter ... */
25342 /* ... or any of the template arguments is a dependent type or
25343 an expression that is type-dependent or value-dependent. */
25345 && (any_dependent_template_arguments_p
25349 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
25350 dependent; if the argument of the `typeof' expression is not
25351 type-dependent, then it should already been have resolved. */
25357 /* A template argument pack is dependent if any of its packed
25358 arguments are. */
25360 {
25366 }
25368 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
25369 be template parameters. */
25376 /* The standard does not specifically mention types that are local
25377 to template functions or local classes, but they should be
25378 considered dependent too. For example:
25380 template <int I> void f() {
25381 enum E { a = I };
25382 S<sizeof (E)> s;
25383 }
25385 The size of `E' cannot be known until the value of `I' has been
25386 determined. Therefore, `E' must be considered dependent. */
25390 /* Don't use type_dependent_expression_p here, as it can lead
25391 to infinite recursion trying to determine whether a lambda
25392 nested in a lambda is dependent (c++/47687). */
25396 && (any_dependent_template_arguments_p
25400 /* Other types are non-dependent. */
25402 }
25404 /* Returns TRUE if TYPE is dependent, in the sense of
25405 [temp.dep.type]. Note that a NULL type is considered dependent. */
25407 bool
25409 {
25410 /* If there are no template parameters in scope, then there can't be
25411 any dependent types. */
25413 {
25414 /* If we are not processing a template, then nobody should be
25415 providing us with a dependent type. */
25419 }
25421 /* If the type is NULL, we have not computed a type for the entity
25422 in question; in that case, the type is dependent. */
25426 /* Erroneous types can be considered non-dependent. */
25430 /* Getting here with global_type_node means we improperly called this
25431 function on the TREE_TYPE of an IDENTIFIER_NODE. */
25434 /* If we have not already computed the appropriate value for TYPE,
25435 do so now. */
25437 {
25440 }
25443 }
25445 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
25446 lookup. In other words, a dependent type that is not the current
25447 instantiation. */
25449 bool
25451 {
25454 }
25456 /* T is a SCOPE_REF. Return whether it represents a non-static member of
25457 an unknown base of 'this' (and is therefore instantiation-dependent). */
25459 static bool
25461 {
25478 }
25480 /* T is a SCOPE_REF; return whether we need to consider it
25481 instantiation-dependent so that we can check access at instantiation
25482 time even though we know which member it resolves to. */
25484 static bool
25486 {
25493 else
25495 }
25497 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
25498 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
25499 expression. */
25501 /* Note that this predicate is not appropriate for general expressions;
25502 only constant expressions (that satisfy potential_constant_expression)
25503 can be tested for value dependence. */
25505 bool
25507 {
25511 /* A type-dependent expression is also value-dependent. */
25516 {
25518 /* A dependent member function of the current instantiation. */
25522 /* A dependent member function of the current instantiation. */
25529 /* A name that has not been looked up -- must be dependent. */
25533 /* A non-type template parm. */
25537 /* A non-type template parm. */
25543 /* A constant with literal type and is initialized
25544 with an expression that is value-dependent. */
25546 /* FIXME cp_finish_decl doesn't fold reference initializers. */
25550 {
25554 }
25563 /* These expressions are value-dependent if the type to which
25564 the cast occurs is dependent or the expression being casted
25565 is value-dependent. */
25566 {
25572 /* A functional cast has a list of operands. */
25575 {
25576 /* If there are no operands, it must be an expression such
25577 as "int()". This should not happen for aggregate types
25578 because it would form non-constant expressions. */
25583 }
25589 }
25594 /* FALLTHRU */
25597 /* A `sizeof' expression is value-dependent if the operand is
25598 type-dependent or is a pack expansion. */
25607 /* An 'encode' expression is value-dependent if the operand is
25608 type-dependent. */
25617 /* All instantiation-dependent expressions should also be considered
25618 value-dependent. */
25626 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
25627 is value-dependent. */
25628 {
25637 }
25640 {
25657 }
25668 {
25672 }
25675 /* Treat all requires-expressions as value-dependent so
25676 we don't try to fold them. */
25683 {
25690 {
25692 /* In a call to a constexpr member function, look through the
25693 implicit ADDR_EXPR on the object argument so that it doesn't
25694 cause the call to be considered value-dependent. We also
25695 look through it in potential_constant_expression. */
25702 }
25704 }
25710 {
25712 tree val;
25719 }
25722 /* Treat a GNU statement expression as dependent to avoid crashing
25723 under instantiate_non_dependent_expr; it can't be constant. */
25727 /* A constant expression is value-dependent if any subexpression is
25728 value-dependent. */
25730 {
25737 {
25741 {
25744 /* In some cases, some of the operands may be missing.
25745 (For example, in the case of PREDECREMENT_EXPR, the
25746 amount to increment by may be missing.) That doesn't
25747 make the expression dependent. */
25750 }
25751 }
25755 }
25757 }
25759 /* The expression is not value-dependent. */
25761 }
25763 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
25764 [temp.dep.expr]. Note that an expression with no type is
25765 considered dependent. Other parts of the compiler arrange for an
25766 expression with type-dependent subexpressions to have no type, so
25767 this function doesn't have to be fully recursive. */
25769 bool
25771 {
25780 /* An unresolved name is always dependent. */
25786 /* A lambda-expression in template context is dependent. dependent_type_p is
25787 true for a lambda in the scope of a class or function template, but that
25788 doesn't cover all template contexts, like a default template argument. */
25792 /* A fold expression is type-dependent. */
25799 /* Some expression forms are never type-dependent. */
25813 /* The types of these expressions depends only on the type to which
25814 the cast occurs. */
25823 /* The types of these expressions depends only on the type created
25824 by the expression. */
25827 {
25828 /* For NEW_EXPR tree nodes created inside a template, either
25829 the object type itself or a TREE_LIST may appear as the
25830 operand 1. */
25833 /* This is an array type. We need to check array dimensions
25834 as well. */
25836 || value_dependent_expression_p
25838 else
25840 }
25843 {
25847 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
25848 contains an identifier associated by name lookup with one or more
25849 declarations declared with a dependent type, or...a
25850 nested-name-specifier or qualified-id that names a member of an
25851 unknown specialization. */
25854 }
25864 {
25865 tree elt;
25869 {
25872 }
25874 }
25876 /* A static data member of the current instantiation with incomplete
25877 array type is type-dependent, as the definition and specializations
25878 can have different bounds. */
25885 /* An array of unknown bound depending on a variadic parameter, eg:
25887 template<typename... Args>
25888 void foo (Args... args)
25889 {
25890 int arr[] = { args... };
25891 }
25893 template<int... vals>
25894 void bar ()
25895 {
25896 int arr[] = { vals... };
25897 }
25899 If the array has no length and has an initializer, it must be that
25900 we couldn't determine its length in cp_complete_array_type because
25901 it is dependent. */
25909 /* A function or variable template-id is type-dependent if it has any
25910 dependent template arguments. */
25914 {
25915 /* Consider the innermost template arguments, since those are the ones
25916 that come from the template-id; the template arguments for the
25917 enclosing class do not make it type-dependent unless they are used in
25918 the type of the decl. */
25920 && (any_dependent_template_arguments_p
25923 }
25925 /* Otherwise, if the function decl isn't from a dependent scope, it can't be
25926 type-dependent. Checking this is important for functions with auto return
25927 type, which looks like a dependent type. */
25936 {
25940 }
25942 /* Always dependent, on the number of arguments if nothing else. */
25947 {
25952 {
25958 }
25959 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
25964 {
25969 }
25972 {
25979 }
25988 }
25990 /* The type of a non-type template parm declared with a placeholder type
25991 depends on the corresponding template argument, even though
25992 placeholders are not normally considered dependent. */
25999 /* Dependent type attributes might not have made it from the decl to
26000 the type yet. */
26006 }
26008 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
26009 type-dependent if the expression refers to a member of the current
26010 instantiation and the type of the referenced member is dependent, or the
26011 class member access expression refers to a member of an unknown
26012 specialization.
26014 This function returns true if the OBJECT in such a class member access
26015 expression is of an unknown specialization. */
26017 bool
26019 {
26020 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
26021 dependent. */
26026 }
26028 /* walk_tree callback function for instantiation_dependent_expression_p,
26029 below. Returns non-zero if a dependent subexpression is found. */
26031 static tree
26034 {
26036 {
26037 /* We don't have to worry about decltype currently because decltype
26038 of an instantiation-dependent expr is a dependent type. This
26039 might change depending on the resolution of DR 1172. */
26042 }
26045 {
26046 /* Don't treat an argument list as dependent just because it has no
26047 TREE_TYPE. */
26058 /* We'll check value-dependence separately. */
26061 /* Handle expressions with type operands. */
26066 {
26071 {
26074 else
26075 {
26078 }
26079 }
26081 }
26085 /* In a template, finish_class_member_access_expr creates a
26086 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
26087 type-dependent, so that we can check access control at
26088 instantiation time (PR 42277). See also Core issue 1273. */
26095 else
26098 /* Treat statement-expressions as dependent. */
26102 /* Treat requires-expressions as dependent. */
26107 /* Treat calls to function concepts as dependent. */
26113 /* And variable concepts. */
26125 }
26129 else
26131 }
26133 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
26134 sense defined by the ABI:
26136 "An expression is instantiation-dependent if it is type-dependent
26137 or value-dependent, or it has a subexpression that is type-dependent
26138 or value-dependent."
26140 Except don't actually check value-dependence for unevaluated expressions,
26141 because in sizeof(i) we don't care about the value of i. Checking
26142 type-dependence will in turn check value-dependence of array bounds/template
26143 arguments as needed. */
26145 bool
26147 {
26148 tree result;
26159 }
26161 /* As above, but also check value-dependence of the expression as a whole. */
26163 bool
26165 {
26168 }
26170 /* Like type_dependent_expression_p, but it also works while not processing
26171 a template definition, i.e. during substitution or mangling. */
26173 bool
26175 {
26181 }
26183 /* Returns TRUE if ARGS contains a type-dependent expression. */
26185 bool
26187 {
26189 tree arg;
26192 {
26195 }
26197 }
26199 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
26200 expressions) contains any type-dependent expressions. */
26202 bool
26204 {
26210 }
26212 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
26213 expressions) contains any value-dependent expressions. */
26215 bool
26217 {
26223 }
26225 /* Returns TRUE if the ARG (a template argument) is dependent. */
26227 bool
26229 {
26233 /* Assume a template argument that was wrongly written by the user
26234 is dependent. This is consistent with what
26235 any_dependent_template_arguments_p [that calls this function]
26236 does. */
26246 {
26249 /* A member template of a dependent class is not necessarily
26250 type-dependent, but it is a dependent template argument because it
26251 will be a member of an unknown specialization to that template. */
26254 }
26256 {
26260 {
26263 }
26266 }
26269 else
26272 }
26274 /* Returns true if ARGS (a collection of template arguments) contains
26275 any types that require structural equality testing. */
26277 bool
26279 {
26289 {
26292 {
26298 {
26299 /* Look inside the argument pack. */
26302 }
26305 {
26318 }
26319 }
26320 }
26323 }
26325 /* Returns true if ARGS (a collection of template arguments) contains
26326 any dependent arguments. */
26328 bool
26330 {
26340 {
26345 }
26348 }
26350 /* Returns true if ARGS contains any errors. */
26352 bool
26354 {
26362 {
26365 else
26367 }
26373 {
26378 }
26381 }
26383 /* Returns TRUE if the template TMPL is type-dependent. */
26385 bool
26387 {
26389 {
26394 }
26396 /* Template template parameters are dependent. */
26400 /* So are names that have not been looked up. */
26404 }
26406 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
26408 bool
26410 {
26413 }
26415 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
26416 are dependent. */
26418 bool
26420 {
26427 {
26452 {
26456 }
26460 {
26464 {
26470 /* If this loop has a class iterator with != comparison
26471 with increment other than i++/++i/i--/--i, make sure the
26472 increment is constant. */
26475 {
26478 else
26482 }
26483 }
26484 }
26485 }
26488 }
26490 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
26491 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
26492 no such TYPE can be found. Note that this function peers inside
26493 uninstantiated templates and therefore should be used only in
26494 extremely limited situations. ONLY_CURRENT_P restricts this
26495 peering to the currently open classes hierarchy (which is required
26496 when comparing types). */
26498 tree
26500 {
26501 tree scope;
26502 tree name;
26503 tree decl;
26505 tree pushed_scope;
26506 tree result;
26511 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
26514 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
26515 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
26516 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
26517 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
26518 identifier of the TYPENAME_TYPE anymore.
26519 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
26520 TYPENAME_TYPE instead, we avoid messing up with a possible
26521 typedef variant case. */
26524 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
26525 it first before we can figure out what NAME refers to. */
26527 {
26529 /* Given a class template A with a dependent base with nested type C,
26530 typedef typename A::C::C C will land us here, as trying to resolve
26531 the initial A::C leads to the local C typedef, which leads back to
26532 A::C::C. So we break the recursion now. */
26534 else
26536 }
26537 /* If we don't know what SCOPE refers to, then we cannot resolve the
26538 TYPENAME_TYPE. */
26541 /* If this is a typedef, we don't want to look inside (c++/11987). */
26544 /* If SCOPE isn't the template itself, it will not have a valid
26545 TYPE_FIELDS list. */
26547 /* scope is either the template itself or a compatible instantiation
26548 like X<T>, so look up the name in the original template. */
26550 /* If scope has no fields, it can't be a current instantiation. Check this
26551 before currently_open_class to avoid infinite recursion (71515). */
26554 /* If the SCOPE is not the current instantiation, there's no reason
26555 to look inside it. */
26558 /* Enter the SCOPE so that name lookup will be resolved as if we
26559 were in the class definition. In particular, SCOPE will no
26560 longer be considered a dependent type. */
26562 /* Look up the declaration. */
26564 tf_warning_or_error);
26568 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
26569 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
26575 {
26579 }
26582 {
26583 /* Obtain the template and the arguments. */
26586 {
26587 /* We get here with a plain identifier because a previous tentative
26588 parse of the nested-name-specifier as part of a ptr-operator saw
26589 ::template X<A>. The use of ::template is necessary in a
26590 ptr-operator, but wrong in a declarator-id.
26592 [temp.names]: In a qualified-id of a declarator-id, the keyword
26593 template shall not appear at the top level. */
26597 }
26599 /* Instantiate the template. */
26605 }
26607 /* Leave the SCOPE. */
26611 /* If we failed to resolve it, return the original typename. */
26615 /* If lookup found a typename type, resolve that too. */
26617 {
26618 /* Ill-formed programs can cause infinite recursion here, so we
26619 must catch that. */
26623 }
26625 /* Qualify the resulting type. */
26631 }
26633 /* EXPR is an expression which is not type-dependent. Return a proxy
26634 for EXPR that can be used to compute the types of larger
26635 expressions containing EXPR. */
26637 tree
26639 {
26641 tree inner_expr;
26643 /* When checking, try to get a constant value for all non-dependent
26644 expressions in order to expose bugs in *_dependent_expression_p
26645 and constexpr. This can affect code generation, see PR70704, so
26646 only do this for -fchecking=2. */
26649 /* Don't do this during nsdmi parsing as it can lead to
26650 unexpected recursive instantiations. */
26652 /* Don't do this during concept expansion either and for
26653 the same reason. */
26659 /* Preserve OVERLOADs; the functions must be available to resolve
26660 types. */
26671 /* There is no need to return a proxy for a variable or enumerator. */
26674 /* Preserve string constants; conversions from string constants to
26675 "char *" are allowed, even though normally a "const char *"
26676 cannot be used to initialize a "char *". */
26679 /* Preserve void and arithmetic constants, as an optimization -- there is no
26680 reason to create a new node. */
26685 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
26686 There is at least one place where we want to know that a
26687 particular expression is a throw-expression: when checking a ?:
26688 expression, there are special rules if the second or third
26689 argument is a throw-expression. */
26693 /* Don't wrap an initializer list, we need to be able to look inside. */
26697 /* Don't wrap a dummy object, we need to be able to test for it. */
26716 /* If the type is unknown, it can't really be non-dependent */
26719 /* Otherwise, build a NON_DEPENDENT_EXPR. */
26722 }
26724 /* ARGS is a vector of expressions as arguments to a function call.
26725 Replace the arguments with equivalent non-dependent expressions.
26726 This modifies ARGS in place. */
26728 void
26730 {
26732 tree arg;
26735 {
26739 }
26740 }
26742 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
26743 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
26744 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
26746 static tree
26748 {
26762 }
26764 tree
26766 {
26768 }
26770 tree
26772 {
26774 }
26776 /* Return a C++17 deduction placeholder for class template TMPL. */
26778 tree
26780 {
26783 /* Our canonical type depends on the placeholder. */
26786 }
26788 /* True iff T is a C++17 class template deduction placeholder. */
26790 bool
26792 {
26794 }
26796 /* Make a "constrained auto" type-specifier. This is an
26797 auto type with constraints that must be associated after
26798 deduction. The constraint is formed from the given
26799 CONC and its optional sequence of arguments, which are
26800 non-null if written as partial-concept-id. */
26802 tree
26804 {
26807 /* Build the constraint. */
26815 /* Our canonical type depends on the constraint. */
26818 /* Attach the constraint to the type declaration. */
26821 }
26823 /* Given type ARG, return std::initializer_list<ARG>. */
26825 static tree
26827 {
26831 {
26835 "deducing from brace-enclosed initializer list"
26839 }
26845 }
26847 /* Replace auto in TYPE with std::initializer_list<auto>. */
26849 static tree
26851 {
26858 }
26860 /* Hash traits for hashing possibly constrained 'auto'
26861 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
26864 {
26867 };
26869 /* Hash the 'auto' T. */
26871 inline hashval_t
26873 {
26875 /* Matching constrained-type-specifiers denote the same template
26876 parameter, so hash the constraint. */
26878 else
26879 /* But unconstrained autos are all separate, so just hash the pointer. */
26881 }
26883 /* Compare two 'auto's. */
26887 {
26894 /* Two unconstrained autos are distinct. */
26899 }
26901 /* for_each_template_parm callback for extract_autos: if t is a (possibly
26902 constrained) auto, add it to the vector. */
26904 static int
26906 {
26909 {
26910 /* All the autos were built with index 0; fix that up now. */
26914 /* If this is a repeated constrained-type-specifier, use the index we
26915 chose before. */
26917 else
26918 {
26919 /* Otherwise this is new, so use the current count. */
26922 }
26924 }
26926 /* Always keep walking. */
26928 }
26930 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
26931 says they can appear anywhere in the type. */
26933 static tree
26935 {
26944 {
26949 }
26952 }
26954 /* The stem for deduction guide names. */
26957 /* Return the name for a deduction guide for class template TMPL. */
26959 tree
26961 {
26972 }
26974 /* True if NAME is the name of a deduction guide. */
26976 bool
26978 {
26983 }
26985 /* True if FN is a deduction guide. */
26987 bool
26989 {
26994 }
26996 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
26998 bool
27000 {
27007 }
27009 /* True if FN is a guide generated from a constructor template. */
27011 bool
27013 {
27021 }
27023 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
27024 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
27025 template parameter types. Note that the handling of template template
27026 parameters relies on current_template_parms being set appropriately for the
27027 new template. */
27029 static tree
27032 {
27038 tree newtype;
27041 {
27048 }
27049 else
27050 {
27053 {
27054 // Substitute once to fix references to other template parameters.
27057 // Now substitute again to reduce the level of the auto.
27060 }
27061 else
27064 }
27066 tree newdecl
27071 tree newidx;
27074 {
27084 {
27089 // First create a copy (ttargs) of tsubst_args with an
27090 // additional level for the template template parameter's own
27091 // template parameters (ttparms).
27092 tree ttparms = (INNERMOST_TEMPLATE_PARMS
27100 // Substitute ttargs into ttparms to fix references to
27101 // other template parameters.
27104 // Now substitute again with args based on tparms, to reduce
27105 // the level of the ttparms.
27108 complain);
27109 // Finally, tack the adjusted parms onto tparms.
27111 current_template_parms);
27113 }
27114 }
27115 else
27116 {
27118 tree newconst
27130 }
27133 }
27135 /* Returns a C++17 class deduction guide template based on the constructor
27136 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
27137 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
27139 static tree
27141 {
27145 location_t loc;
27149 {
27153 {
27156 }
27157 else
27167 }
27168 else
27169 {
27173 fn_tmpl
27183 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
27184 fully specialized args for the enclosing class. Strip those off, as
27185 the deduction guide won't have those template parameters. */
27188 /* Discard the 'this' parameter. */
27196 {
27199 /* For a member template constructor, we need to flatten the two
27200 template parameter lists into one, and then adjust the function
27201 signature accordingly. This gets...complicated. */
27204 /* For a member template we should have two levels of parms/args, one
27205 for the class and one for the constructor. We stripped
27206 specialized args for further enclosing classes above. */
27210 /* Template args for translating references to the two-level template
27211 parameters into references to the one-level template parameters we
27212 are creating. */
27217 /* Template parms for the constructor template. */
27220 /* Template parms for the class template. */
27224 /* Template parms for the deduction guide start as a copy of the
27225 template parms for the class. We set current_template_parms for
27226 lookup_template_class_1. */
27232 /* Now we need to rewrite the constructor parms to append them to the
27233 class parms. */
27235 {
27252 }
27254 /* Now we have a final set of template parms to substitute into the
27255 function signature. */
27266 }
27271 }
27274 {
27275 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
27279 }
27283 FUNCTION_DECL,
27300 }
27302 /* Deduce template arguments for the class template placeholder PTYPE for
27303 template TMPL based on the initializer INIT, and return the resulting
27304 type. */
27306 static tree
27308 tsubst_flags_t complain)
27309 {
27311 {
27312 /* We should have handled this in the caller. */
27318 }
27320 /* Using the template parm as its own argument. */
27333 {
27336 {
27337 /* As an exception, the first phase in 16.3.1.7 (considering the
27338 initializer list as a single argument) is omitted if the
27339 initializer list consists of a single expression of type cv U,
27340 where U is a specialization of C or a class derived from a
27341 specialization of C. */
27344 {
27346 tree tparms = (INNERMOST_TEMPLATE_PARMS
27354 }
27355 }
27358 else
27360 }
27361 else
27372 /* Prune explicit deduction guides in copy-initialization context. */
27374 {
27380 {
27381 /* Found a nonconverting guide, prune the candidates. */
27388 }
27389 }
27394 {
27397 }
27400 // FIXME cache artificial deduction guides
27402 {
27403 /* Skip inherited constructors. */
27413 else
27417 }
27421 /* If this is list-initialization and the class has a list constructor, first
27422 try deducing from the list as a single argument, as [over.match.list]. */
27426 {
27430 }
27432 {
27438 {
27439 /* That didn't work, now try treating the list as a sequence of
27440 arguments. */
27443 }
27444 }
27446 /* Maybe generate an implicit deduction guide. */
27448 {
27452 /* Generate a copy guide. */
27455 /* Generate a default guide. */
27459 {
27464 }
27465 }
27468 {
27470 " of %qT, as it has no non-explicit deduction guides or "
27473 }
27475 {
27479 }
27482 {
27486 }
27489 {
27499 }
27502 }
27504 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
27505 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
27506 The CONTEXT determines the context in which auto deduction is performed
27507 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
27508 OUTER_TARGS are used during template argument deduction
27509 (context == adc_unify) to properly substitute the result, and is ignored
27510 in other contexts.
27512 For partial-concept-ids, extra args may be appended to the list of deduced
27513 template arguments prior to determining constraint satisfaction. */
27515 tree
27519 {
27520 tree targs;
27527 /* Defining a subset of type-dependent expressions that we can deduce
27528 from ahead of time isn't worth the trouble. */
27531 /* Similarly, we can't deduce from another undeduced decl. */
27535 /* We may be doing a partial substitution, but we still want to replace
27536 auto_node. */
27540 /* C++17 class template argument deduction. */
27544 /* Nothing we can do with this, even in deduction context. */
27547 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
27548 with either a new invented type template parameter U or, if the
27549 initializer is a braced-init-list (8.5.4), with
27550 std::initializer_list<U>. */
27552 {
27557 else
27558 {
27560 {
27564 "for deduction to %<std::initializer_list%>, use copy-"
27566 }
27568 }
27569 }
27580 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
27581 and initializer has array type, deduce cv-qualified array type. */
27583 complain);
27585 {
27595 {
27599 }
27600 }
27601 else
27602 {
27604 tree tparms;
27608 else
27609 {
27613 }
27617 DEDUCE_CALL,
27620 {
27622 /* Try again at instantiation time. */
27626 /* If type is error_mark_node a diagnostic must have been
27627 emitted by now. Also, having a mention to '<type error>'
27628 in the diagnostic is not really useful to the user. */
27629 {
27632 && (auto_node
27636 else
27639 DEDUCE_CALL,
27641 }
27643 }
27644 }
27646 /* Check any placeholder constraints against the deduced type. */
27649 {
27650 /* Use the deduced type to check the associated constraints. If we
27651 have a partial-concept-id, rebuild the argument list so that
27652 we check using the extra arguments. */
27656 {
27659 }
27660 else
27663 {
27665 {
27666 auto_diagnostic_group d;
27668 {
27686 }
27688 }
27690 }
27691 }
27697 }
27699 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
27700 result. */
27702 tree
27704 {
27706 {
27712 /* In an abbreviated function template we didn't know we were dealing
27713 with a function template when we saw the auto return type, so update
27714 it to have the correct level. */
27716 }
27718 }
27720 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
27721 'decltype(auto)' or a deduced class template. */
27723 bool
27725 {
27730 else
27732 }
27734 /* for_each_template_parm callback for type_uses_auto. */
27736 int
27738 {
27740 }
27742 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
27743 a use of `auto'. Returns NULL_TREE otherwise. */
27745 tree
27747 {
27751 {
27752 /* The Concepts TS allows multiple autos in one type-specifier; just
27753 return the first one we find, do_auto_deduction will collect all of
27754 them. */
27758 else
27760 }
27761 else
27763 }
27765 /* Report ill-formed occurrences of auto types in ARGUMENTS. If
27766 concepts are enabled, auto is acceptable in template arguments, but
27767 only when TEMPL identifies a template class. Return TRUE if any
27768 such errors were reported. */
27770 bool
27772 {
27773 /* If there were previous errors, nevermind. */
27777 /* If TMPL is an identifier, we're parsing and we can't tell yet
27778 whether TMPL is supposed to be a type, a function or a variable.
27779 We'll only be able to tell during template substitution, so we
27780 expect to be called again then. If concepts are enabled and we
27781 know we have a type, we're ok. */
27789 /* Quickly search for any occurrences of auto; usually there won't
27790 be any, and then we'll avoid allocating the vector. */
27798 {
27803 }
27806 }
27808 /* For a given template T, return the vector of typedefs referenced
27809 in T for which access check is needed at T instantiation time.
27810 T is either a FUNCTION_DECL or a RECORD_TYPE.
27811 Those typedefs were added to T by the function
27812 append_type_to_template_for_access_check. */
27816 {
27817 tree ti;
27828 {
27833 }
27836 }
27838 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
27839 tied to T. That list of typedefs will be access checked at
27840 T instantiation time.
27841 T is either a FUNCTION_DECL or a RECORD_TYPE.
27842 TYPE_DECL is a TYPE_DECL node representing a typedef.
27843 SCOPE is the scope through which TYPE_DECL is accessed.
27844 LOCATION is the location of the usage point of TYPE_DECL.
27846 This function is a subroutine of
27847 append_type_to_template_for_access_check. */
27849 static void
27851 tree type_decl,
27852 tree scope,
27853 location_t location)
27854 {
27855 qualified_typedef_usage_t typedef_usage;
27856 tree ti;
27863 && type_decl
27877 }
27879 /* Append TYPE_DECL to the template TEMPL.
27880 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
27881 At TEMPL instanciation time, TYPE_DECL will be checked to see
27882 if it can be accessed through SCOPE.
27883 LOCATION is the location of the usage point of TYPE_DECL.
27885 e.g. consider the following code snippet:
27887 class C
27888 {
27889 typedef int myint;
27890 };
27892 template<class U> struct S
27893 {
27894 C::myint mi; // <-- usage point of the typedef C::myint
27895 };
27897 S<char> s;
27899 At S<char> instantiation time, we need to check the access of C::myint
27900 In other words, we need to check the access of the myint typedef through
27901 the C scope. For that purpose, this function will add the myint typedef
27902 and the scope C through which its being accessed to a list of typedefs
27903 tied to the template S. That list will be walked at template instantiation
27904 time and access check performed on each typedefs it contains.
27905 Note that this particular code snippet should yield an error because
27906 myint is private to C. */
27908 void
27910 tree type_decl,
27911 tree scope,
27912 location_t location)
27913 {
27919 /* Make sure we don't append the type to the template twice. */
27926 }
27928 /* Convert the generic type parameters in PARM that match the types given in the
27929 range [START_IDX, END_IDX) from the current_template_parms into generic type
27930 packs. */
27932 tree
27934 {
27945 {
27946 /* Create a distinct parameter pack type from the current parm and add it
27947 to the replacement args to tsubst below into the generic function
27948 parameter. */
27963 }
27969 /* If there are more levels then build up the replacement with the outer
27970 template parms. */
27974 replacement);
27977 }
27979 /* Entries in the decl_constraint hash table. */
27981 {
27982 tree decl;
27983 tree ci;
27984 };
27986 /* Hashing function and equality for constraint entries. */
27988 {
27990 {
27992 }
27995 {
27997 }
27998 };
28000 /* A mapping from declarations to constraint information. Note that
28001 both templates and their underlying declarations are mapped to the
28002 same constraint information.
28004 FIXME: This is defined in pt.c because garbage collection
28005 code is not being generated for constraint.cc. */
28009 /* Returns the template constraints of declaration T. If T is not
28010 constrained, return NULL_TREE. Note that T must be non-null. */
28012 tree
28014 {
28025 else
28027 }
28029 /* Associate the given constraint information CI with the declaration
28030 T. If T is a template, then the constraints are associated with
28031 its underlying declaration. Don't build associations if CI is
28032 NULL_TREE. */
28034 void
28036 {
28048 }
28050 /* Remove the associated constraints of the declaration T. */
28052 void
28054 {
28063 }
28065 /* Memoized satisfaction results for declarations. This
28066 maps the pair (constraint_info, arguments) to the result computed
28067 by constraints_satisfied_p. */
28070 {
28071 tree ci;
28072 tree args;
28073 tree result;
28074 };
28076 /* Hashing function and equality for constraint entries. */
28079 {
28081 {
28084 }
28087 {
28089 }
28090 };
28092 /* Memoized satisfaction results for concept checks. */
28095 {
28096 tree tmpl;
28097 tree args;
28098 tree result;
28099 };
28101 /* Hashing function and equality for constraint entries. */
28104 {
28106 {
28108 }
28111 {
28116 }
28117 };
28122 /* Search for a memoized satisfaction result. Returns one of the
28123 truth value nodes if previously memoized, or NULL_TREE otherwise. */
28125 tree
28127 {
28132 else
28134 }
28136 /* Memoize the result of a satisfication test. Returns the saved result. */
28138 tree
28140 {
28147 }
28149 /* Search for a memoized satisfaction result for a concept. */
28151 tree
28153 {
28158 else
28160 }
28162 /* Memoize the result of a concept check. Returns the saved result. */
28164 tree
28166 {
28173 }
28177 /* Returns a prior concept specialization. This returns the substituted
28178 and normalized constraints defined by the concept. */
28180 tree
28182 {
28187 else
28189 }
28191 /* Save a concept expansion for later. */
28193 tree
28195 {
28202 }
28204 static hashval_t
28206 {
28215 }
28217 /* Compare the constraints of two subsumption entries. The LEFT1 and
28218 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
28219 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
28221 static bool
28223 {
28231 }
28233 /* Key/value pair for learning and memoizing subsumption results. This
28234 associates a pair of check constraints (including arguments) with
28235 a boolean value indicating the result. */
28238 {
28239 tree t1;
28240 tree t2;
28242 };
28244 /* Hashing function and equality for constraint entries. */
28247 {
28249 {
28251 }
28254 {
28259 }
28260 };
28264 /* Search for a previously cached subsumption result. */
28268 {
28273 else
28275 }
28277 /* Save a subsumption result. */
28279 bool
28281 {
28288 }
28290 /* Set up the hash table for constraint association. */
28292 void
28294 {
28303 }
28305 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
28306 0..N-1. */
28308 void
28310 {
28313 integer_type_node,
28314 NULL_TREE),
28320 }
28322 /* Set up the hash tables for template instantiations. */
28324 void
28326 {
28327 /* FIXME: enable sanitization (PR87847) */
28333 }
28335 /* Print stats about the template hash tables for -fstats. */
28337 void
28339 {
28348 }
28350 #if CHECKING_P
28354 /* Verify that build_non_dependent_expr () works, for various expressions,
28355 and that location wrappers don't affect the results. */
28357 static void
28359 {
28362 /* Verify constants, without and with location wrappers. */
28379 }
28381 /* Verify that type_dependent_expression_p () works correctly, even
28382 in the presence of location wrapper nodes. */
28384 static void
28386 {
28391 /* If no templates are involved, nothing is type-dependent. */
28397 /* Within a template, an unresolved name is always type-dependent. */
28400 /* Ensure it copes with NULL_TREE and errors. */
28404 /* A USING_DECL in a template should be type-dependent, even if wrapped
28405 with a location wrapper (PR c++/83799). */
28414 }
28416 /* Run all of the selftests within this file. */
28418 void
28420 {
28423 }