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1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2017 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
44 /* The type of functions taking a tree, and some additional data, and
45 returning an int. */
48 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
49 instantiations have been deferred, either because their definitions
50 were not yet available, or because we were putting off doing the work. */
54 };
69 /* Live only within one (recursive) call to tsubst_expr. We use
70 this to pass the statement expression node from the STMT_EXPR
71 to the EXPR_STMT that is its result. */
74 // -------------------------------------------------------------------------- //
75 // Local Specialization Stack
76 //
77 // Implementation of the RAII helper for creating new local
78 // specializations.
81 {
83 }
86 {
89 }
91 /* True if we've recursed into fn_type_unification too many times. */
95 {
96 tree tmpl;
97 tree args;
98 tree spec;
99 };
102 {
105 };
111 /* Contains canonical template parameter types. The vector is indexed by
112 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
113 TREE_LIST, whose TREE_VALUEs contain the canonical template
114 parameters of various types and levels. */
117 #define UNIFY_ALLOW_NONE 0
118 #define UNIFY_ALLOW_MORE_CV_QUAL 1
119 #define UNIFY_ALLOW_LESS_CV_QUAL 2
120 #define UNIFY_ALLOW_DERIVED 4
121 #define UNIFY_ALLOW_INTEGER 8
122 #define UNIFY_ALLOW_OUTER_LEVEL 16
123 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
124 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
127 tbr_incomplete_type,
128 tbr_ambiguous_baseclass,
129 tbr_success
130 };
153 tree);
210 location_t);
219 /* Make the current scope suitable for access checking when we are
220 processing T. T can be FUNCTION_DECL for instantiated function
221 template, VAR_DECL for static member variable, or TYPE_DECL for
222 alias template (needed by instantiate_decl). */
224 static void
226 {
234 else
238 {
239 saved_access_scope = tree_cons
242 }
243 }
245 /* Restore the scope set up by push_access_scope. T is the node we
246 are processing. */
248 static void
250 {
252 {
255 }
259 else
261 }
263 /* Do any processing required when DECL (a member template
264 declaration) is finished. Returns the TEMPLATE_DECL corresponding
265 to DECL, unless it is a specialization, in which case the DECL
266 itself is returned. */
268 tree
270 {
277 {
278 tree type;
286 {
290 }
292 }
296 {
298 {
301 }
302 else
304 }
305 else
309 }
311 /* Create a template info node. */
313 tree
315 {
320 }
322 /* Return the template info node corresponding to T, whatever T is. */
324 tree
326 {
348 }
350 /* Returns the template nesting level of the indicated class TYPE.
352 For example, in:
353 template <class T>
354 struct A
355 {
356 template <class U>
357 struct B {};
358 };
360 A<T>::B<U> has depth two, while A<T> has depth one.
361 Both A<T>::B<int> and A<int>::B<U> have depth one, if
362 they are instantiations, not specializations.
364 This function is guaranteed to return 0 if passed NULL_TREE so
365 that, for example, `template_class_depth (current_class_type)' is
366 always safe. */
368 int
370 {
374 {
385 else
387 }
390 }
392 /* Subroutine of maybe_begin_member_template_processing.
393 Returns true if processing DECL needs us to push template parms. */
395 static bool
397 {
403 }
405 /* Subroutine of maybe_begin_member_template_processing.
406 Push the template parms in PARMS, starting from LEVELS steps into the
407 chain, and ending at the beginning, since template parms are listed
408 innermost first. */
410 static void
412 {
420 current_template_parms
426 NULL);
428 {
437 {
444 /* Push the CONST_DECL. */
450 }
451 }
452 }
454 /* Restore the template parameter context for a member template, a
455 friend template defined in a class definition, or a non-template
456 member of template class. */
458 void
460 {
461 tree parms;
466 {
469 /* Disregard full specializations (c++/60999). */
472 }
475 {
480 {
483 }
486 }
488 /* Remember how many levels of template parameters we pushed so that
489 we can pop them later. */
491 }
493 /* Undo the effects of maybe_begin_member_template_processing. */
495 void
497 {
506 {
510 }
511 }
513 /* Return a new template argument vector which contains all of ARGS,
514 but has as its innermost set of arguments the EXTRA_ARGS. */
516 static tree
518 {
519 tree new_args;
537 }
539 /* Like add_to_template_args, but only the outermost ARGS are added to
540 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
541 (EXTRA_ARGS) levels are added. This function is used to combine
542 the template arguments from a partial instantiation with the
543 template arguments used to attain the full instantiation from the
544 partial instantiation. */
546 static tree
548 {
549 tree new_args;
551 /* If there are more levels of EXTRA_ARGS than there are ARGS,
552 something very fishy is going on. */
555 /* If *all* the new arguments will be the EXTRA_ARGS, just return
556 them. */
560 /* For the moment, we make ARGS look like it contains fewer levels. */
565 /* Now, we restore ARGS to its full dimensions. */
569 }
571 /* Return the N levels of innermost template arguments from the ARGS. */
573 tree
575 {
576 tree new_args;
582 /* If N is 1, just return the innermost set of template arguments. */
586 /* If we're not removing anything, just return the arguments we were
587 given. */
593 /* Make a new set of arguments, not containing the outer arguments. */
600 }
602 /* The inverse of get_innermost_template_args: Return all but the innermost
603 EXTRA_LEVELS levels of template arguments from the ARGS. */
605 static tree
607 {
608 tree new_args;
614 /* If N is 1, just return the outermost set of template arguments. */
618 /* If we're not removing anything, just return the arguments we were
619 given. */
624 /* Make a new set of arguments, not containing the inner arguments. */
631 }
633 /* We've got a template header coming up; push to a new level for storing
634 the parms. */
636 void
638 {
639 /* We use a non-tag-transparent scope here, which causes pushtag to
640 put tags in this scope, rather than in the enclosing class or
641 namespace scope. This is the right thing, since we want
642 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
643 global template class, push_template_decl handles putting the
644 TEMPLATE_DECL into top-level scope. For a nested template class,
645 e.g.:
647 template <class T> struct S1 {
648 template <class T> struct S2 {};
649 };
651 pushtag contains special code to call pushdecl_with_scope on the
652 TEMPLATE_DECL for S2. */
658 /* Add a dummy parameter level while we process the parameter list. */
659 current_template_parms
662 current_template_parms);
663 }
665 /* This routine is called when a specialization is declared. If it is
666 invalid to declare a specialization here, an error is reported and
667 false is returned, otherwise this routine will return true. */
669 static bool
671 {
674 /* [temp.expl.spec]
676 An explicit specialization shall be declared in the namespace of
677 which the template is a member, or, for member templates, in the
678 namespace of which the enclosing class or enclosing class
679 template is a member. An explicit specialization of a member
680 function, member class or static data member of a class template
681 shall be declared in the namespace of which the class template
682 is a member. */
684 {
687 }
689 /* [temp.expl.spec]
691 In an explicit specialization declaration for a member of a class
692 template or a member template that appears in namespace scope,
693 the member template and some of its enclosing class templates may
694 remain unspecialized, except that the declaration shall not
695 explicitly specialize a class member template if its enclosing
696 class templates are not explicitly specialized as well. */
698 {
701 }
704 }
706 /* We've just seen template <>. */
708 bool
710 {
714 }
716 /* Called at then end of processing a declaration preceded by
717 template<>. */
719 void
721 {
724 }
726 /* Any template <>'s that we have seen thus far are not referring to a
727 function specialization. */
729 void
731 {
734 }
736 /* We've just seen a template header. If SPECIALIZATION is nonzero,
737 it was of the form template <>. */
739 static void
741 {
743 template_header_count++;
744 }
746 /* We're beginning an explicit instantiation. */
748 void
750 {
753 }
756 void
758 {
761 }
763 /* An explicit specialization or partial specialization of TMPL is being
764 declared. Check that the namespace in which the specialization is
765 occurring is permissible. Returns false iff it is invalid to
766 specialize TMPL in the current namespace. */
768 static bool
770 {
773 /* [tmpl.expl.spec]
775 An explicit specialization shall be declared in a namespace enclosing the
776 specialized template. An explicit specialization whose declarator-id is
777 not qualified shall be declared in the nearest enclosing namespace of the
778 template, or, if the namespace is inline (7.3.1), any namespace from its
779 enclosing namespace set. */
782 {
785 }
788 /* Same or enclosing namespace. */
790 else
791 {
797 }
798 }
800 /* SPEC is an explicit instantiation. Check that it is valid to
801 perform this explicit instantiation in the current namespace. */
803 static void
805 {
806 tree ns;
808 /* DR 275: An explicit instantiation shall appear in an enclosing
809 namespace of its template. */
815 }
817 // Returns the type of a template specialization only if that
818 // specialization needs to be defined. Otherwise (e.g., if the type has
819 // already been defined), the function returns NULL_TREE.
820 static tree
822 {
823 // An implicit instantiation of an incomplete type implies
824 // the definition of a new class template.
825 //
826 // template<typename T>
827 // struct S;
828 //
829 // template<typename T>
830 // struct S<T*>;
831 //
832 // Here, S<T*> is an implicit instantiation of S whose type
833 // is incomplete.
837 // It can also be the case that TYPE is a completed specialization.
838 // Continuing the previous example, suppose we also declare:
839 //
840 // template<typename T>
841 // requires Integral<T>
842 // struct S<T*>;
843 //
844 // Here, S<T*> refers to the specialization S<T*> defined
845 // above. However, we need to differentiate definitions because
846 // we intend to define a new partial specialization. In this case,
847 // we rely on the fact that the constraints are different for
848 // this declaration than that above.
849 //
850 // Note that we also get here for injected class names and
851 // late-parsed template definitions. We must ensure that we
852 // do not create new type declarations for those cases.
854 {
858 // If there are no template parameters, this cannot be a new
859 // partial template specializtion?
863 // The injected-class-name is not a new partial specialization.
867 // If the constraints are not the same as those of the primary
868 // then, we can probably create a new specialization.
872 {
876 }
878 // Also, if there's a pre-existing specialization with matching
879 // constraints, then this also isn't new.
882 {
890 }
892 // Create a new type node (and corresponding type decl)
893 // for the newly declared specialization.
898 /* We only need a separate type node for storing the definition of this
899 partial specialization; uses of S<T*> are unconstrained, so all are
900 equivalent. So keep TYPE_CANONICAL the same. */
903 // Build the corresponding type decl.
909 }
912 }
914 /* The TYPE is being declared. If it is a template type, that means it
915 is a partial specialization. Do appropriate error-checking. */
917 tree
919 {
920 tree context;
925 /* A lambda that appears in specialization context is not itself a
926 specialization. */
931 {
935 }
940 {
946 else
949 }
951 {
952 /* This is for ordinary explicit specialization and partial
953 specialization of a template class such as:
955 template <> class C<int>;
957 or:
959 template <class T> class C<T*>;
961 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
964 {
971 {
976 }
977 }
983 /* Trying to define a specialization either without a template<> header
984 or in an inappropriate place. We've already given an error, so just
985 bail now so we don't actually define the specialization. */
987 }
993 {
994 /* This is for an explicit specialization of member class
995 template according to [temp.expl.spec/18]:
997 template <> template <class U> class C<int>::D;
999 The context `C<int>' must be an implicit instantiation.
1000 Otherwise this is just a member class template declared
1001 earlier like:
1003 template <> class C<int> { template <class U> class D; };
1004 template <> template <class U> class C<int>::D;
1006 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1007 while in the second case, `C<int>::D' is a primary template
1008 and `C<T>::D' may not exist. */
1012 {
1013 tree t;
1018 {
1023 }
1025 /* Check for invalid specialization after instantiation:
1027 template <> template <> class C<int>::D<int>;
1028 template <> template <class U> class C<int>::D; */
1032 {
1036 {
1037 /* We already have a full specialization of this partial
1038 instantiation, or a full specialization has been
1039 looked up but not instantiated. Reassign it to the
1040 new member specialization template. */
1041 spec_entry elt;
1053 spec_entry **slot
1058 }
1059 else
1060 /* But if we've had an implicit instantiation, that's a
1061 problem ([temp.expl.spec]/6). */
1064 }
1066 /* Mark TYPE as a specialization. And as a result, we only
1067 have one level of template argument for the innermost
1068 class template. */
1073 }
1074 }
1076 {
1077 /* Someday C++0x may allow for enum template specialization. */
1082 else
1083 {
1086 }
1087 }
1090 }
1092 /* Returns nonzero if we can optimize the retrieval of specializations
1093 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1094 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1098 {
1101 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1102 parameter. */
1104 /* The optimized lookup depends on the fact that the
1105 template arguments for the member function template apply
1106 purely to the containing class, which is not true if the
1107 containing class is an explicit or partial
1108 specialization. */
1112 /* It is possible to have a template that is not a member
1113 template and is not a member of a template class:
1115 template <typename T>
1116 struct S { friend A::f(); };
1118 Here, the friend function is a template, but the context does
1119 not have template information. The optimized lookup relies
1120 on having ARGS be the template arguments for both the class
1121 and the function template. */
1123 }
1125 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1126 gone through coerce_template_parms by now. */
1128 static void
1130 {
1133 {
1136 {
1143 /* Allow typedefs on the type of a non-type argument, since a
1145 else
1147 }
1148 }
1150 }
1152 /* Retrieve the specialization (in the sense of [temp.spec] - a
1153 specialization is either an instantiation or an explicit
1154 specialization) of TMPL for the given template ARGS. If there is
1155 no such specialization, return NULL_TREE. The ARGS are a vector of
1156 arguments, or a vector of vectors of arguments, in the case of
1157 templates with more than one level of parameters.
1159 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1160 then we search for a partial specialization matching ARGS. This
1161 parameter is ignored if TMPL is not a class template.
1163 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1164 result is a NONTYPE_ARGUMENT_PACK. */
1166 static tree
1168 {
1178 /* There should be as many levels of arguments as there are
1179 levels of parameters. */
1189 {
1190 /* The template arguments actually apply to the containing
1191 class. Find the class specialization with those
1192 arguments. */
1194 tree class_specialization
1198 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1199 for the specialization. */
1203 /* Iterate through the methods with the indicated name, looking
1204 for the one that has an instance of TMPL. */
1207 {
1210 /* using-declarations can add base methods to the method vec,
1211 and we don't want those here. */
1214 }
1216 }
1217 else
1218 {
1220 spec_entry elt;
1229 else
1237 }
1240 }
1242 /* Like retrieve_specialization, but for local declarations. */
1244 tree
1246 {
1252 }
1254 /* Returns nonzero iff DECL is a specialization of TMPL. */
1256 int
1258 {
1259 tree t;
1262 {
1268 }
1269 else
1270 {
1279 }
1282 }
1284 /* Returns nonzero iff DECL is a specialization of friend declaration
1285 FRIEND_DECL according to [temp.friend]. */
1287 bool
1289 {
1296 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1297 of a template class, we want to check if DECL is a specialization
1298 if this. */
1302 {
1303 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1306 }
1311 /* There is nothing to do if this is not a template friend. */
1318 /* [temp.friend/6]
1319 A member of a class template may be declared to be a friend of a
1320 non-template class. In this case, the corresponding member of
1321 every specialization of the class template is a friend of the
1322 class granting friendship.
1324 For example, given a template friend declaration
1326 template <class T> friend void A<T>::f();
1328 the member function below is considered a friend
1330 template <> struct A<int> {
1331 void f();
1332 };
1334 For this type of template friend, TEMPLATE_DEPTH below will be
1335 nonzero. To determine if DECL is a friend of FRIEND, we first
1336 check if the enclosing class is a specialization of another. */
1343 {
1344 /* Next, we check the members themselves. In order to handle
1345 a few tricky cases, such as when FRIEND_DECL's are
1347 template <class T> friend void A<T>::g(T t);
1348 template <class T> template <T t> friend void A<T>::h();
1350 and DECL's are
1352 void A<int>::g(int);
1353 template <int> void A<int>::h();
1355 we need to figure out ARGS, the template arguments from
1356 the context of DECL. This is required for template substitution
1357 of `T' in the function parameter of `g' and template parameter
1358 of `h' in the above examples. Here ARGS corresponds to `int'. */
1365 {
1367 {
1370 else
1372 current_depth++;
1373 }
1375 }
1378 {
1380 tree friend_type;
1381 tree decl_type;
1382 tree friend_args_type;
1383 tree decl_args_type;
1385 /* Make sure that both DECL and FRIEND_DECL are templates or
1386 non-templates. */
1392 {
1393 /* If both are templates, check template parameter list. */
1394 tree friend_parms
1399 friend_parms))
1403 }
1404 else
1412 /* Check if return types match. */
1416 /* Check if function parameter types match, ignoring the
1417 `this' parameter. */
1426 }
1427 else
1428 {
1429 /* DECL is a TYPE_DECL */
1433 /* Make sure that both DECL and FRIEND_DECL are templates or
1434 non-templates. */
1435 is_template
1442 {
1443 tree friend_parms;
1444 /* If both are templates, check the name of the two
1445 TEMPLATE_DECL's first because is_friend didn't. */
1450 /* Now check template parameter list. */
1451 friend_parms
1454 return comp_template_parms
1456 friend_parms);
1457 }
1458 else
1461 }
1462 }
1464 }
1466 /* Register the specialization SPEC as a specialization of TMPL with
1467 the indicated ARGS. IS_FRIEND indicates whether the specialization
1468 is actually just a friend declaration. Returns SPEC, or an
1469 equivalent prior declaration, if available.
1471 We also store instantiations of field packs in the hash table, even
1472 though they are not themselves templates, to make lookup easier. */
1474 static tree
1476 hashval_t hash)
1477 {
1478 tree fn;
1480 spec_entry elt;
1488 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1489 register it; we want the corresponding TEMPLATE_DECL instead.
1490 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1491 the more obvious `uses_template_parms (spec)' to avoid problems
1492 with default function arguments. In particular, given
1493 something like this:
1495 template <class T> void f(T t1, T t = T())
1497 the default argument expression is not substituted for in an
1498 instantiation unless and until it is actually needed. */
1502 /* We don't put these specializations in the hash table, but we might
1503 want to give an error about a mismatch. */
1505 else
1506 {
1514 slot =
1518 else
1520 }
1522 /* We can sometimes try to re-register a specialization that we've
1523 already got. In particular, regenerate_decl_from_template calls
1524 duplicate_decls which will update the specialization list. But,
1525 we'll still get called again here anyhow. It's more convenient
1526 to simply allow this than to try to prevent it. */
1530 {
1532 {
1535 {
1537 fn);
1539 }
1540 else
1541 {
1542 tree clone;
1543 /* This situation should occur only if the first
1544 specialization is an implicit instantiation, the
1545 second is an explicit specialization, and the
1546 implicit instantiation has not yet been used. That
1547 situation can occur if we have implicitly
1548 instantiated a member function and then specialized
1549 it later.
1551 We can also wind up here if a friend declaration that
1552 looked like an instantiation turns out to be a
1553 specialization:
1555 template <class T> void foo(T);
1556 class S { friend void foo<>(int) };
1557 template <> void foo(int);
1559 We transform the existing DECL in place so that any
1560 pointers to it become pointers to the updated
1561 declaration.
1563 If there was a definition for the template, but not
1564 for the specialization, we want this to look as if
1565 there were no definition, and vice versa. */
1568 /* The call to duplicate_decls will have applied
1569 [temp.expl.spec]:
1571 An explicit specialization of a function template
1572 is inline only if it is explicitly declared to be,
1573 and independently of whether its function template
1574 is.
1576 to the primary function; now copy the inline bits to
1577 the various clones. */
1579 {
1586 }
1590 }
1591 }
1593 {
1596 /* We've already complained in duplicate_decls. */
1600 /* Dup decl failed, but this is a new definition. Set the
1601 line number so any errors match this new
1602 definition. */
1606 }
1607 }
1611 /* A specialization must be declared in the same namespace as the
1612 template it is specializing. */
1618 {
1627 /* If TMPL is a forward declaration of a template function, keep a list
1628 of all specializations in case we need to reassign them to a friend
1629 template later in tsubst_friend_function.
1631 Also keep a list of all variable template instantiations so that
1632 process_partial_specialization can check whether a later partial
1633 specialization would have used it. */
1636 }
1639 }
1641 /* Returns true iff two spec_entry nodes are equivalent. */
1645 bool
1647 {
1654 /* tmpl could be a FIELD_DECL for a capture pack. */
1658 {
1659 /* Partial specializations of a variable template can be distinguished by
1660 constraints. */
1664 }
1668 }
1670 /* Returns a hash for a template TMPL and template arguments ARGS. */
1672 static hashval_t
1674 {
1677 }
1679 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1680 ignoring SPEC. */
1682 hashval_t
1684 {
1686 }
1688 /* Recursively calculate a hash value for a template argument ARG, for use
1689 in the hash tables of template specializations. */
1691 hashval_t
1693 {
1713 {
1721 {
1726 }
1748 {
1752 {
1755 }
1757 }
1761 {
1764 }
1775 val = iterative_hash_template_arg
1787 val);
1789 val);
1798 /* A lambda can't appear in a template arg, but don't crash on
1799 erroneous input. */
1811 /* Now hash operands as usual. */
1816 }
1819 {
1822 {
1823 // We want an alias specialization that survived strip_typedefs
1824 // to hash differently from its TYPE_CANONICAL, to avoid hash
1825 // collisions that compare as different in template_args_equal.
1826 // These could be dependent specializations that strip_typedefs
1827 // left alone, or untouched specializations because
1828 // coerce_template_parms returns the unconverted template
1829 // arguments if it sees incomplete argument packs.
1832 }
1835 val);
1838 /* Otherwise just compare the types during lookup. */
1847 {
1852 }
1853 }
1856 }
1858 /* Unregister the specialization SPEC as a specialization of TMPL.
1859 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1860 if the SPEC was listed as a specialization of TMPL.
1862 Note that SPEC has been ggc_freed, so we can't look inside it. */
1864 bool
1866 {
1868 spec_entry elt;
1876 {
1881 }
1884 }
1886 /* Like register_specialization, but for local declarations. We are
1887 registering SPEC, an instantiation of TMPL. */
1889 void
1891 {
1893 }
1895 /* TYPE is a class type. Returns true if TYPE is an explicitly
1896 specialized class. */
1898 bool
1900 {
1904 }
1906 /* Print the list of functions at FNS, going through all the overloads
1907 for each element of the list. Alternatively, FNS can not be a
1908 TREE_LIST, in which case it will be printed together with all the
1909 overloads.
1911 MORE and *STR should respectively be FALSE and NULL when the function
1912 is called from the outside. They are used internally on recursive
1913 calls. print_candidates manages the two parameters and leaves NULL
1914 in *STR when it ends. */
1916 static void
1918 {
1922 else
1924 {
1930 {
1933 else
1936 }
1938 }
1939 }
1941 /* Print the list of candidate FNS in an error message. FNS can also
1942 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1944 void
1946 {
1950 }
1952 /* Get a (possibly) constrained template declaration for the
1953 purpose of ordering candidates. */
1954 static tree
1956 {
1962 }
1964 /* Among candidates having the same signature, return the
1965 most constrained or NULL_TREE if there is no best candidate.
1966 If the signatures of candidates vary (e.g., template
1967 specialization vs. member function), then there can be no
1968 most constrained.
1970 Note that we don't compare constraints on the functions
1971 themselves, but rather those of their templates. */
1972 static tree
1974 {
1975 // Try to find the best candidate in a first pass.
1978 {
1985 }
1987 // Verify that the champ is better than previous candidates.
1992 }
1995 }
1998 /* Returns the template (one of the functions given by TEMPLATE_ID)
1999 which can be specialized to match the indicated DECL with the
2000 explicit template args given in TEMPLATE_ID. The DECL may be
2001 NULL_TREE if none is available. In that case, the functions in
2002 TEMPLATE_ID are non-members.
2004 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2005 specialization of a member template.
2007 The TEMPLATE_COUNT is the number of references to qualifying
2008 template classes that appeared in the name of the function. See
2009 check_explicit_specialization for a more accurate description.
2011 TSK indicates what kind of template declaration (if any) is being
2012 declared. TSK_TEMPLATE indicates that the declaration given by
2013 DECL, though a FUNCTION_DECL, has template parameters, and is
2014 therefore a template function.
2016 The template args (those explicitly specified and those deduced)
2017 are output in a newly created vector *TARGS_OUT.
2019 If it is impossible to determine the result, an error message is
2020 issued. The error_mark_node is returned to indicate failure. */
2022 static tree
2024 tree decl,
2028 tmpl_spec_kind tsk)
2029 {
2030 tree fns;
2031 tree targs;
2032 tree explicit_targs;
2035 /* A TREE_LIST of templates of which DECL may be a specialization.
2036 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2037 corresponding TREE_PURPOSE is the set of template arguments that,
2038 when used to instantiate the template, would produce a function
2039 with the signature of DECL. */
2049 /* We shouldn't be specializing a member template of an
2050 unspecialized class template; we already gave an error in
2051 check_specialization_scope, now avoid crashing. */
2054 {
2057 }
2065 /* Check for baselinks. */
2070 {
2073 }
2075 {
2078 }
2080 /* Count the number of template headers specified for this
2081 specialization. */
2091 {
2094 tf_warning_or_error,
2098 }
2100 {
2104 {
2105 tree decl_arg_types;
2106 tree fn_arg_types;
2107 tree insttype;
2109 /* In case of explicit specialization, we need to check if
2110 the number of template headers appearing in the specialization
2111 is correct. This is usually done in check_explicit_specialization,
2112 but the check done there cannot be exhaustive when specializing
2113 member functions. Consider the following code:
2115 template <> void A<int>::f(int);
2116 template <> template <> void A<int>::f(int);
2118 Assuming that A<int> is not itself an explicit specialization
2119 already, the first line specializes "f" which is a non-template
2120 member function, whilst the second line specializes "f" which
2121 is a template member function. So both lines are syntactically
2122 correct, and check_explicit_specialization does not reject
2123 them.
2125 Here, we can do better, as we are matching the specialization
2126 against the declarations. We count the number of template
2127 headers, and we check if they match TEMPLATE_COUNT + 1
2128 (TEMPLATE_COUNT is the number of qualifying template classes,
2129 plus there must be another header for the member template
2130 itself).
2132 Notice that if header_count is zero, this is not a
2133 specialization but rather a template instantiation, so there
2134 is no check we can perform here. */
2138 /* Check that the number of template arguments at the
2139 innermost level for DECL is the same as for FN. */
2147 /* DECL might be a specialization of FN. */
2151 /* For a non-static member function, we need to make sure
2152 that the const qualification is the same. Since
2153 get_bindings does not try to merge the "this" parameter,
2154 we must do the comparison explicitly. */
2160 /* Skip the "this" parameter and, for constructors of
2161 classes with virtual bases, the VTT parameter. A
2162 full specialization of a constructor will have a VTT
2163 parameter, but a template never will. */
2164 decl_arg_types
2166 fn_arg_types
2169 /* Function templates cannot be specializations; there are
2170 no partial specializations of functions. Therefore, if
2171 the type of DECL does not match FN, there is no
2172 match.
2174 Note that it should never be the case that we have both
2175 candidates added here, and for regular member functions
2176 below. */
2178 {
2182 }
2184 /* See whether this function might be a specialization of this
2185 template. Suppress access control because we might be trying
2186 to make this specialization a friend, and we have already done
2187 access control for the declaration of the specialization. */
2193 /* We cannot deduce template arguments that when used to
2194 specialize TMPL will produce DECL. */
2197 /* Remove, from the set of candidates, all those functions
2198 whose constraints are not satisfied. */
2202 // Then, try to form the new function type.
2206 fn_arg_types
2211 /* Save this template, and the arguments deduced. */
2213 }
2215 /* FN is an ordinary member function, and we need a
2216 specialization of a member template. */
2217 ;
2219 /* We can get IDENTIFIER_NODEs here in certain erroneous
2220 cases. */
2221 ;
2223 /* This is just an ordinary non-member function. Nothing can
2224 be a specialization of that. */
2225 ;
2227 /* Cannot specialize functions that are created implicitly. */
2228 ;
2229 else
2230 {
2231 tree decl_arg_types;
2233 /* This is an ordinary member function. However, since
2234 we're here, we can assume its enclosing class is a
2235 template class. For example,
2237 template <typename T> struct S { void f(); };
2238 template <> void S<int>::f() {}
2240 Here, S<int>::f is a non-template, but S<int> is a
2241 template class. If FN has the same type as DECL, we
2242 might be in business. */
2245 /* Its enclosing class is an explicit specialization
2246 of a template class. This is not a candidate. */
2251 /* The return types differ. */
2254 /* Adjust the type of DECL in case FN is a static member. */
2261 decl_arg_types))
2264 // If the deduced arguments do not satisfy the constraints,
2265 // this is not a candidate.
2269 // Add the candidate.
2271 }
2272 }
2275 {
2276 /* We have:
2278 [temp.expl.spec]
2280 It is possible for a specialization with a given function
2281 signature to be instantiated from more than one function
2282 template. In such cases, explicit specification of the
2283 template arguments must be used to uniquely identify the
2284 function template specialization being specialized.
2286 Note that here, there's no suggestion that we're supposed to
2287 determine which of the candidate templates is most
2288 specialized. However, we, also have:
2290 [temp.func.order]
2292 Partial ordering of overloaded function template
2293 declarations is used in the following contexts to select
2294 the function template to which a function template
2295 specialization refers:
2297 -- when an explicit specialization refers to a function
2298 template.
2300 So, we do use the partial ordering rules, at least for now.
2301 This extension can only serve to make invalid programs valid,
2302 so it's safe. And, there is strong anecdotal evidence that
2303 the committee intended the partial ordering rules to apply;
2304 the EDG front end has that behavior, and John Spicer claims
2305 that the committee simply forgot to delete the wording in
2306 [temp.expl.spec]. */
2309 {
2312 }
2313 }
2315 // Concepts allows multiple declarations of member functions
2316 // with the same signature. Like above, we need to rely on
2317 // on the partial ordering of those candidates to determine which
2318 // is the best.
2320 {
2322 {
2325 }
2326 }
2329 {
2336 else
2339 }
2343 {
2349 }
2351 /* We have one, and exactly one, match. */
2353 {
2357 // Propagate the candidate's constraints to the declaration.
2360 /* DECL is a re-declaration or partial instantiation of a template
2361 function. */
2364 /* It was a specialization of an ordinary member function in a
2365 template class. */
2367 }
2369 /* It was a specialization of a template. */
2372 {
2377 }
2378 else
2381 }
2383 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2384 but with the default argument values filled in from those in the
2385 TMPL_TYPES. */
2387 static tree
2389 tree tmpl_types)
2390 {
2391 tree new_spec_types;
2399 /* Substitute into the rest of the list. */
2400 new_spec_types =
2404 /* Add the default argument for this parameter. */
2407 new_spec_types);
2408 }
2410 /* DECL is an explicit specialization. Replicate default arguments
2411 from the template it specializes. (That way, code like:
2413 template <class T> void f(T = 3);
2414 template <> void f(double);
2415 void g () { f (); }
2417 works, as required.) An alternative approach would be to look up
2418 the correct default arguments at the call-site, but this approach
2419 is consistent with how implicit instantiations are handled. */
2421 static void
2423 {
2424 tree tmpl;
2425 tree spec_types;
2426 tree tmpl_types;
2427 tree new_spec_types;
2428 tree old_type;
2429 tree new_type;
2430 tree t;
2435 /* See if there's anything we need to do. */
2448 {
2449 /* Remove the this pointer, but remember the object's type for
2450 CV quals. */
2456 {
2457 /* DECL may contain more parameters than TMPL due to the extra
2458 in-charge parameter in constructors and destructors. */
2461 }
2463 {
2466 }
2467 }
2469 /* Compute the merged default arguments. */
2470 new_spec_types =
2473 /* Compute the new FUNCTION_TYPE. */
2475 {
2479 new_spec_types);
2482 /* Put the in-charge parameter back. */
2485 new_spec_types);
2489 new_spec_types);
2490 }
2491 else
2493 new_spec_types);
2503 }
2505 /* Return the number of template headers we expect to see for a definition
2506 or specialization of CTYPE or one of its non-template members. */
2508 int
2510 {
2514 {
2515 /* You're supposed to have one `template <...>' for every
2516 template class, but you don't need one for a full
2517 specialization. For example:
2519 template <class T> struct S{};
2520 template <> struct S<int> { void f(); };
2521 void S<int>::f () {}
2523 is correct; there shouldn't be a `template <>' for the
2524 definition of `S<int>::f'. */
2526 /* If CTYPE does not have template information of any
2527 kind, then it is not a template, nor is it nested
2528 within a template. */
2536 }
2539 }
2541 /* Do a simple sanity check on the template headers that precede the
2542 variable declaration DECL. */
2544 void
2546 {
2551 {
2554 "variable templates only available with "
2557 // Namespace-scope variable templates should have a template header.
2559 }
2561 {
2563 "too many template headers for %qD "
2569 "members of an explicitly specialized class are defined "
2571 }
2572 }
2574 /* An explicit specialization whose declarator-id or class-head-name is not
2575 qualified shall be declared in the nearest enclosing namespace of the
2576 template, or, if the namespace is inline (7.3.1), any namespace from its
2577 enclosing namespace set.
2579 If the name declared in the explicit instantiation is an unqualified name,
2580 the explicit instantiation shall appear in the namespace where its template
2581 is declared or, if that namespace is inline (7.3.1), any namespace from its
2582 enclosing namespace set. */
2584 void
2586 {
2591 {
2597 /* This was allowed in C++98, so only pedwarn. */
2599 "outside its namespace must use a nested-name-"
2601 }
2602 }
2604 /* Check to see if the function just declared, as indicated in
2605 DECLARATOR, and in DECL, is a specialization of a function
2606 template. We may also discover that the declaration is an explicit
2607 instantiation at this point.
2609 Returns DECL, or an equivalent declaration that should be used
2610 instead if all goes well. Issues an error message if something is
2611 amiss. Returns error_mark_node if the error is not easily
2612 recoverable.
2614 FLAGS is a bitmask consisting of the following flags:
2616 2: The function has a definition.
2617 4: The function is a friend.
2619 The TEMPLATE_COUNT is the number of references to qualifying
2620 template classes that appeared in the name of the function. For
2621 example, in
2623 template <class T> struct S { void f(); };
2624 void S<int>::f();
2626 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2627 classes are not counted in the TEMPLATE_COUNT, so that in
2629 template <class T> struct S {};
2630 template <> struct S<int> { void f(); }
2631 template <> void S<int>::f();
2633 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2634 invalid; there should be no template <>.)
2636 If the function is a specialization, it is marked as such via
2637 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2638 is set up correctly, and it is added to the list of specializations
2639 for that template. */
2641 tree
2643 tree decl,
2646 {
2655 tmpl_spec_kind tsk;
2658 {
2661 else
2663 }
2664 else
2668 {
2671 {
2674 }
2676 {
2678 /* This could be something like:
2680 template <class T> void f(T);
2681 class S { friend void f<>(int); } */
2683 else
2684 {
2685 /* This case handles bogus declarations like template <>
2686 template <class T> void f<int>(); */
2689 declarator);
2691 }
2692 }
2696 /* The error has already been reported in
2697 check_specialization_scope. */
2703 /* Fall through. */
2716 decl);
2719 else
2723 /* Fall through. */
2729 /* In cases like template<> constexpr bool v = true;
2730 We'll give an error in check_template_variable. */
2736 else
2742 {
2743 /* This case handles bogus declarations like template <>
2744 template <class T> void f<int>(); */
2748 declarator);
2750 {
2751 /* Partial specialization of variable template. */
2755 }
2759 else
2763 ok:;
2764 }
2767 /* This is a specialization of a member template, without
2768 specialization the containing class. Something like:
2770 template <class T> struct S {
2771 template <class U> void f (U);
2772 };
2773 template <> template <class U> void S<int>::f(U) {}
2775 That's a specialization -- but of the entire template. */
2781 }
2784 /* This doesn't apply to variable templates. */
2787 {
2791 {
2795 }
2796 }
2799 {
2804 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2806 {
2807 tree fns;
2812 else
2813 {
2814 /* If there is no class context, the explicit instantiation
2815 must be at namespace scope. */
2818 /* Find the namespace binding, using the declaration
2819 context. */
2823 /* If lookup fails, look for a friend declaration so we can
2824 give a better diagnostic. */
2830 {
2833 }
2834 }
2837 }
2843 {
2845 /* A specialization in class scope. This is invalid,
2846 but the error will already have been flagged by
2847 check_specialization_scope. */
2849 else
2850 {
2851 /* It's not valid to write an explicit instantiation in
2852 class scope, e.g.:
2854 class C { template void f(); }
2856 This case is caught by the parser. However, on
2857 something like:
2859 template class C { void f(); };
2861 (which is invalid) we can get here. The error will be
2862 issued later. */
2863 ;
2864 }
2867 }
2870 {
2871 // We'll match variable templates in start_decl.
2875 /* Find the list of functions in ctype that have the same
2876 name as the declared function. */
2882 {
2887 {
2888 /* From [temp.expl.spec]:
2890 If such an explicit specialization for the member
2891 of a class template names an implicitly-declared
2892 special member function (clause _special_), the
2893 program is ill-formed.
2895 Similar language is found in [temp.explicit]. */
2898 }
2901 }
2904 {
2908 }
2909 else
2910 {
2912 tree ovl;
2914 /* For a type-conversion operator, we cannot do a
2915 name-based lookup. We might be looking for `operator
2916 int' which will be a specialization of `operator T'.
2917 So, we find *all* the conversion operators, and then
2918 select from them. */
2926 {
2928 /* There are no more conversion functions. */
2931 /* Glue all these conversion functions together
2932 with those we already have. */
2935 }
2936 }
2939 {
2942 }
2943 else
2945 }
2947 /* Figure out what exactly is being specialized at this point.
2948 Note that for an explicit instantiation, even one for a
2949 member function, we cannot tell a priori whether the
2950 instantiation is for a member template, or just a member
2951 function of a template class. Even if a member template is
2952 being instantiated, the member template arguments may be
2953 elided if they can be deduced from the rest of the
2954 declaration. */
2957 member_specialization,
2958 template_count,
2959 tsk);
2962 /* We couldn't figure out what this declaration was
2963 specializing. */
2965 else
2966 {
2969 {
2971 "friend declaration %qD is not visible to "
2975 }
2983 {
2984 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2985 is done by do_decl_instantiation later. */
2991 {
2992 /* If TMPL is not the most general template (for
2993 example, if TMPL is a friend template that is
2994 injected into namespace scope), then there will
2995 be too many levels of TARGS. Remove some of them
2996 here. */
2998 tree new_targs;
3005 }
3008 }
3010 /* If we thought that the DECL was a member function, but it
3011 turns out to be specializing a static member function,
3012 make DECL a static member function as well. */
3018 /* If this is a specialization of a member template of a
3019 template class, we want to return the TEMPLATE_DECL, not
3020 the specialization of it. */
3022 {
3027 {
3028 tree parm;
3032 /* We want to use the argument list specified in the
3033 definition, not in the original declaration. */
3038 }
3041 }
3043 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3049 /* Inherit default function arguments from the template
3050 DECL is specializing. */
3054 /* This specialization has the same protection as the
3055 template it specializes. */
3059 /* 7.1.1-1 [dcl.stc]
3061 A storage-class-specifier shall not be specified in an
3062 explicit specialization...
3064 The parser rejects these, so unless action is taken here,
3065 explicit function specializations will always appear with
3066 global linkage.
3068 The action recommended by the C++ CWG in response to C++
3069 defect report 605 is to make the storage class and linkage
3070 of the explicit specialization match the templated function:
3072 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3073 */
3075 {
3079 /* A concept cannot be specialized. */
3081 {
3083 gen_tmpl);
3085 }
3087 /* This specialization has the same linkage and visibility as
3088 the function template it specializes. */
3091 {
3094 }
3097 {
3100 }
3101 }
3103 /* If DECL is a friend declaration, declared using an
3104 unqualified name, the namespace associated with DECL may
3105 have been set incorrectly. For example, in:
3107 template <typename T> void f(T);
3108 namespace N {
3109 struct S { friend void f<int>(int); }
3110 }
3112 we will have set the DECL_CONTEXT for the friend
3113 declaration to N, rather than to the global namespace. */
3118 /* This is not really a declaration of a specialization.
3119 It's just the name of an instantiation. But, it's not
3120 a request for an instantiation, either. */
3123 /* A specialization is not necessarily COMDAT. */
3129 /* If this is a full specialization, register it so that we can find
3130 it again. Partial specializations will be registered in
3131 process_partial_specialization. */
3136 /* A 'structor should already have clones. */
3142 }
3143 }
3146 }
3148 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3149 parameters. These are represented in the same format used for
3150 DECL_TEMPLATE_PARMS. */
3152 int
3154 {
3155 const_tree p1;
3156 const_tree p2;
3164 {
3176 {
3180 /* If either of the template parameters are invalid, assume
3181 they match for the sake of error recovery. */
3194 }
3195 }
3198 /* One set of parameters has more parameters lists than the
3199 other. */
3203 }
3205 /* Determine whether PARM is a parameter pack. */
3207 bool
3209 {
3210 /* Determine if we have a non-type template parameter pack. */
3217 /* If this is a list of template parameters, we could get a
3218 TYPE_DECL or a TEMPLATE_DECL. */
3222 /* Otherwise it must be a type template parameter. */
3226 }
3228 /* Determine if T is a function parameter pack. */
3230 bool
3232 {
3236 }
3238 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3239 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3241 tree
3243 {
3250 }
3252 /* Return true iff the function parameter PARAM_DECL was expanded
3253 from the function parameter pack PACK. */
3255 bool
3257 {
3262 /* The parameter pack and its pack arguments have the same
3263 DECL_PARM_INDEX. */
3265 }
3267 /* Determine whether ARGS describes a variadic template args list,
3268 i.e., one that is terminated by a template argument pack. */
3270 static bool
3272 {
3274 tree last_parm;
3288 }
3290 /* Generate a new name for the parameter pack name NAME (an
3291 IDENTIFIER_NODE) that incorporates its */
3293 static tree
3295 {
3296 /* Munge the name to include the parameter index. */
3297 #define NUMBUF_LEN 128
3311 }
3313 /* Return true if T is a primary function, class or alias template
3314 instantiation. */
3316 bool
3318 {
3332 }
3334 /* Return true if PARM is a template template parameter. */
3336 bool
3338 {
3340 }
3342 /* Return true iff PARM is a DECL representing a type template
3343 parameter. */
3345 bool
3347 {
3352 }
3354 /* Return the template parameters of T if T is a
3355 primary template instantiation, NULL otherwise. */
3357 tree
3359 {
3364 parms = INNERMOST_TEMPLATE_PARMS
3368 }
3370 /* Return the template parameters of the LEVELth level from the full list
3371 of template parameters PARMS. */
3373 tree
3375 {
3376 tree p;
3387 }
3389 /* Returns the template arguments of T if T is a template instantiation,
3390 NULL otherwise. */
3392 tree
3394 {
3402 }
3404 /* Return the argument pack elements of T if T is a template argument pack,
3405 NULL otherwise. */
3407 tree
3409 {
3415 }
3417 /* Structure used to track the progress of find_parameter_packs_r. */
3418 struct find_parameter_pack_data
3419 {
3420 /* TREE_LIST that will contain all of the parameter packs found by
3421 the traversal. */
3424 /* Set of AST nodes that have been visited by the traversal. */
3427 /* True iff we're making a type pack expansion. */
3429 };
3431 /* Identifies all of the argument packs that occur in a template
3432 argument and appends them to the TREE_LIST inside DATA, which is a
3433 find_parameter_pack_data structure. This is a subroutine of
3434 make_pack_expansion and uses_parameter_packs. */
3435 static tree
3437 {
3443 /* Handle type aliases/typedefs. */
3445 {
3452 }
3454 /* Identify whether this is a parameter pack or not. */
3456 {
3464 /* FALLTHRU */
3466 /* If the placeholder appears in the decl-specifier-seq of a function
3467 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3468 is a pack expansion, the invented template parameter is a template
3469 parameter pack. */
3479 {
3480 /* We don't want to walk into the type of a PARM_DECL,
3481 because we don't want to see the type parameter pack. */
3484 }
3487 /* Look through a lambda capture proxy to the field pack. */
3490 {
3496 }
3498 {
3500 find_parameter_packs_r,
3503 }
3510 /* Not a parameter pack. */
3512 }
3515 {
3516 /* Add this parameter pack to the list. */
3518 }
3524 /* This switch statement will return immediately if we don't find a
3525 parameter pack. */
3527 {
3532 /* Check the template itself. */
3535 /* Check the template arguments. */
3551 /* Fall through. */
3596 {
3597 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3598 type_pack_expansion_p to false so that any placeholders
3599 within the expression don't get marked as parameter packs. */
3607 }
3611 }
3614 }
3616 /* Determines if the expression or type T uses any parameter packs. */
3617 bool
3619 {
3628 }
3630 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3631 representation a base-class initializer into a parameter pack
3632 expansion. If all goes well, the resulting node will be an
3633 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3634 respectively. */
3635 tree
3637 {
3638 tree result;
3647 {
3648 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3649 class initializer. In this case, the TREE_PURPOSE will be a
3650 _TYPE node (representing the base class expansion we're
3651 initializing) and the TREE_VALUE will be a TREE_LIST
3652 containing the initialization arguments.
3654 The resulting expansion looks somewhat different from most
3655 expansions. Rather than returning just one _EXPANSION, we
3656 return a TREE_LIST whose TREE_PURPOSE is a
3657 TYPE_PACK_EXPANSION containing the bases that will be
3658 initialized. The TREE_VALUE will be identical to the
3659 original TREE_VALUE, which is a list of arguments that will
3660 be passed to each base. We do not introduce any new pack
3661 expansion nodes into the TREE_VALUE (although it is possible
3662 that some already exist), because the TREE_PURPOSE and
3663 TREE_VALUE all need to be expanded together with the same
3664 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3665 resulting TREE_PURPOSE will mention the parameter packs in
3666 both the bases and the arguments to the bases. */
3667 tree purpose;
3668 tree value;
3671 /* Determine which parameter packs will be used by the base
3672 class expansion. */
3681 {
3685 }
3688 {
3689 /* Collect the sets of parameter packs used in each of the
3690 initialization arguments. */
3692 {
3693 /* Determine which parameter packs will be expanded in this
3694 argument. */
3697 }
3698 }
3702 /* Create the pack expansion type for the base type. */
3707 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3708 they will rarely be compared to anything. */
3712 }
3717 /* Build the PACK_EXPANSION_* node. */
3718 result = for_types
3723 {
3724 /* Propagate type and const-expression information. */
3727 /* Mark this read now, since the expansion might be length 0. */
3729 }
3730 else
3731 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3732 they will rarely be compared to anything. */
3735 /* Determine which parameter packs will be expanded. */
3742 /* Make sure we found some parameter packs. */
3744 {
3747 else
3750 }
3756 }
3758 /* Checks T for any "bare" parameter packs, which have not yet been
3759 expanded, and issues an error if any are found. This operation can
3760 only be done on full expressions or types (e.g., an expression
3761 statement, "if" condition, etc.), because we could have expressions like:
3763 foo(f(g(h(args)))...)
3765 where "args" is a parameter pack. check_for_bare_parameter_packs
3766 should not be called for the subexpressions args, h(args),
3767 g(h(args)), or f(g(h(args))), because we would produce erroneous
3768 error messages.
3770 Returns TRUE and emits an error if there were bare parameter packs,
3771 returns FALSE otherwise. */
3772 bool
3774 {
3791 {
3795 {
3804 else
3809 else
3813 }
3816 }
3819 }
3821 /* Expand any parameter packs that occur in the template arguments in
3822 ARGS. */
3823 tree
3825 {
3834 /* First, determine if we need to expand anything, and the number of
3835 slots we'll need. */
3837 {
3842 {
3846 else
3848 }
3849 else
3850 {
3852 num_result_args++;
3853 }
3854 }
3856 /* If no expansion is necessary, we're done. */
3860 /* Expand arguments. */
3863 non_default_args_count =
3866 {
3869 {
3876 }
3877 else
3878 {
3881 }
3882 }
3886 }
3888 /* Checks if DECL shadows a template parameter.
3890 [temp.local]: A template-parameter shall not be redeclared within its
3891 scope (including nested scopes).
3893 Emits an error and returns TRUE if the DECL shadows a parameter,
3894 returns FALSE otherwise. */
3896 bool
3898 {
3899 tree olddecl;
3901 /* If we're not in a template, we can't possibly shadow a template
3902 parameter. */
3906 /* Figure out what we're shadowing. */
3910 /* If there's no previous binding for this name, we're not shadowing
3911 anything, let alone a template parameter. */
3915 /* If we're not shadowing a template parameter, we're done. Note
3916 that OLDDECL might be an OVERLOAD (or perhaps even an
3917 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3918 node. */
3922 /* We check for decl != olddecl to avoid bogus errors for using a
3923 name inside a class. We check TPFI to avoid duplicate errors for
3924 inline member templates. */
3930 /* Don't complain about the injected class name, as we've already
3931 complained about the class itself. */
3938 else
3943 }
3945 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3946 ORIG_LEVEL, DECL, and TYPE. */
3948 static tree
3952 tree decl,
3953 tree type)
3954 {
3965 }
3967 /* Find the canonical type parameter for the given template type
3968 parameter. Returns the canonical type parameter, which may be TYPE
3969 if no such parameter existed. */
3971 static tree
3973 {
3974 tree list;
3988 else
3989 {
3993 }
3994 }
3996 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3997 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3998 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3999 new one is created. */
4001 static tree
4003 tsubst_flags_t complain)
4004 {
4009 {
4028 /* Template template parameters need this. */
4030 {
4037 }
4038 }
4041 }
4043 /* Process information from new template parameter PARM and append it
4044 to the LIST being built. This new parameter is a non-type
4045 parameter iff IS_NON_TYPE is true. This new parameter is a
4046 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4047 is in PARM_LOC. */
4049 tree
4052 {
4061 {
4065 {
4069 else
4071 }
4074 }
4077 {
4083 {
4084 /* [temp.param]
4086 The top-level cv-qualifiers on the template-parameter are
4087 ignored when determining its type. */
4092 && !is_parameter_pack
4093 /* If we're in a nested template parameter list, the template
4094 template parameter could be a parameter pack. */
4096 {
4097 /* This template parameter is not a parameter pack, but it
4098 should be. Complain about "bare" parameter packs. */
4101 /* Recover by calling this a parameter pack. */
4103 }
4104 }
4106 /* A template parameter is not modifiable. */
4115 processing_template_decl,
4120 }
4121 else
4122 {
4123 tree t;
4127 {
4129 /* This is for distinguishing between real templates and template
4130 template parameters */
4134 }
4135 else
4136 {
4138 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4141 }
4148 processing_template_decl,
4152 }
4156 /* Build requirements for the type/template parameter.
4157 This must be done after SET_DECL_TEMPLATE_PARM_P or
4158 process_template_parm could fail. */
4163 /* Build the parameter node linking the parameter declaration,
4164 its default argument (if any), and its constraints (if any). */
4169 }
4171 /* The end of a template parameter list has been reached. Process the
4172 tree list into a parameter vector, converting each parameter into a more
4173 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4174 as PARM_DECLs. */
4176 tree
4178 {
4183 /* Pop the dummy parameter level and add the real one. */
4186 current_template_parms
4191 {
4195 }
4200 }
4202 // Explicitly indicate the end of the template parameter list. We assume
4203 // that the current template parameters have been constructed and/or
4204 // managed explicitly, as when creating new template template parameters
4205 // from a shorthand constraint.
4206 void
4208 {
4210 }
4212 /* end_template_decl is called after a template declaration is seen. */
4214 void
4216 {
4222 /* This matches the pushlevel in begin_template_parm_list. */
4227 }
4229 /* Takes a TREE_LIST representing a template parameter and convert it
4230 into an argument suitable to be passed to the type substitution
4231 functions. Note that If the TREE_LIST contains an error_mark
4232 node, the returned argument is error_mark_node. */
4234 tree
4236 {
4249 {
4253 {
4254 /* Turn this argument into a TYPE_ARGUMENT_PACK
4255 with a single element, which expands T. */
4264 }
4265 }
4266 else
4267 {
4271 {
4272 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4273 with a single element, which expands T. */
4283 }
4284 else
4286 }
4288 }
4290 /* Given a single level of template parameters (a TREE_VEC), return it
4291 as a set of template arguments. */
4293 static tree
4295 {
4305 }
4307 /* Given a set of template parameters, return them as a set of template
4308 arguments. The template parameters are represented as a TREE_VEC, in
4309 the form documented in cp-tree.h for template arguments. */
4311 static tree
4313 {
4314 tree header;
4319 /* If there is only one level of template parameters, we do not
4320 create a TREE_VEC of TREE_VECs. Instead, we return a single
4321 TREE_VEC containing the arguments. */
4326 {
4331 else
4333 }
4336 }
4338 /* Within the declaration of a template, return the currently active
4339 template parameters as an argument TREE_VEC. */
4341 static tree
4343 {
4345 }
4347 /* Update the declared TYPE by doing any lookups which were thought to be
4348 dependent, but are not now that we know the SCOPE of the declarator. */
4350 tree
4352 {
4363 /* Don't bother building up the args in this case. */
4365 {
4366 /* tsubst in the args corresponding to the template parameters,
4367 including auto if present. Most things will be unchanged, but
4368 make_typename_type and tsubst_qualified_id will resolve
4369 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4372 tree pushed;
4374 {
4378 }
4383 }
4389 {
4392 else
4394 }
4396 }
4398 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4399 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4400 the new template is a member template. */
4402 tree
4404 {
4412 }
4414 struct template_parm_data
4415 {
4416 /* The level of the template parameters we are currently
4417 processing. */
4420 /* The index of the specialization argument we are currently
4421 processing. */
4424 /* An array whose size is the number of template parameters. The
4425 elements are nonzero if the parameter has been used in any one
4426 of the arguments processed so far. */
4429 /* An array whose size is the number of template arguments. The
4430 elements are nonzero if the argument makes use of template
4431 parameters of this level. */
4433 };
4435 /* Subroutine of push_template_decl used to see if each template
4436 parameter in a partial specialization is used in the explicit
4437 argument list. If T is of the LEVEL given in DATA (which is
4438 treated as a template_parm_data*), then DATA->PARMS is marked
4439 appropriately. */
4441 static int
4443 {
4451 {
4454 }
4456 /* In C++17 the type of a non-type argument is a deduced context. */
4461 data,
4462 NULL,
4465 /* Return zero so that for_each_template_parm will continue the
4466 traversal of the tree; we want to mark *every* template parm. */
4468 }
4470 /* Process the partial specialization DECL. */
4472 static tree
4474 {
4481 tree inner_parms;
4482 tree inst;
4492 /* A concept cannot be specialized. */
4494 {
4497 }
4502 /* We check that each of the template parameters given in the
4503 partial specialization is used in the argument list to the
4504 specialization. For example:
4506 template <class T> struct S;
4507 template <class T> struct S<T*>;
4509 The second declaration is OK because `T*' uses the template
4510 parameter T, whereas
4512 template <class T> struct S<int>;
4514 is no good. Even trickier is:
4516 template <class T>
4517 struct S1
4518 {
4519 template <class U>
4520 struct S2;
4521 template <class U>
4522 struct S2<T>;
4523 };
4525 The S2<T> declaration is actually invalid; it is a
4526 full-specialization. Of course,
4528 template <class U>
4529 struct S2<T (*)(U)>;
4531 or some such would have been OK. */
4539 {
4544 NULL,
4546 }
4549 {
4550 /* One of the template parms was not used in a deduced context in the
4551 specialization. */
4553 {
4557 }
4561 }
4566 /* [temp.class.spec]
4568 The argument list of the specialization shall not be identical to
4569 the implicit argument list of the primary template. */
4570 tree main_args
4573 && (!flag_concepts
4576 {
4580 else
4584 }
4586 /* A partial specialization that replaces multiple parameters of the
4587 primary template with a pack expansion is less specialized for those
4588 parameters. */
4590 {
4592 "primary template because it replaces multiple parameters "
4595 /* Avoid crash in process_partial_specialization. */
4597 }
4599 /* If we aren't in a dependent class, we can actually try deduction. */
4601 /* FIXME we should be able to handle a partial specialization of a
4602 partial instantiation, but currently we can't (c++/41727). */
4605 {
4609 maintmpl);
4610 }
4612 /* [temp.class.spec]
4614 A partially specialized non-type argument expression shall not
4615 involve template parameters of the partial specialization except
4616 when the argument expression is a simple identifier.
4618 The type of a template parameter corresponding to a specialized
4619 non-type argument shall not be dependent on a parameter of the
4620 specialization.
4622 Also, we verify that pack expansions only occur at the
4623 end of the argument list. */
4627 {
4634 {
4635 /* Extract the arguments from the argument pack. We'll be
4636 iterating over these in the following loop. */
4639 }
4642 {
4644 /* Get the Jth argument in the parameter pack. */
4648 {
4649 /* Pack expansions must come at the end of the
4650 argument list. */
4653 {
4657 else
4660 }
4661 }
4664 /* We only care about the pattern. */
4670 /* This next two lines are the `argument expression is not just a
4671 simple identifier' condition and also the `specialized
4672 non-type argument' bit. */
4676 {
4680 arg);
4681 else
4682 {
4683 /* Look at the corresponding template parameter,
4684 marking which template parameters its type depends
4685 upon. */
4689 {
4690 /* We haven't yet initialized TPD2. Do so now. */
4692 /* The number of parameters here is the number in the
4693 main template, which, as checked in the assertion
4694 above, is NARGS. */
4698 }
4700 /* Mark the template parameters. But this time, we're
4701 looking for the template parameters of the main
4702 template, not in the specialization. */
4709 NULL,
4713 {
4714 /* The type depended on some template parameters.
4715 If they are fully specialized in the
4716 specialization, that's OK. */
4725 "type %qT of template argument %qE depends "
4727 "type %qT of template argument %qE depends "
4729 type,
4730 arg);
4731 }
4732 }
4733 }
4734 }
4735 }
4737 /* We should only get here once. */
4741 // Build the template decl.
4750 /* Give template template parms a DECL_CONTEXT of the template
4751 for which they are a parameter. */
4753 {
4757 }
4760 /* We didn't register this in check_explicit_specialization so we could
4761 wait until the constraints were set. */
4763 else
4773 {
4779 {
4787 "declaration of %qD ambiguates earlier template "
4791 "partial specialization of %qD after instantiation "
4793 }
4794 }
4797 }
4799 /* PARM is a template parameter of some form; return the corresponding
4800 TEMPLATE_PARM_INDEX. */
4802 static tree
4804 {
4817 }
4819 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4820 parameter packs used by the template parameter PARM. */
4822 static void
4824 {
4825 /* A type parm can't refer to another parm. */
4829 {
4833 }
4840 }
4842 /* PARM is a template parameter pack. Return any parameter packs used in
4843 its type or the type of any of its template parameters. If there are
4844 any such packs, it will be instantiated into a fixed template parameter
4845 list by partial instantiation rather than be fully deduced. */
4847 tree
4849 {
4850 /* This can only be true in a member template. */
4853 /* This can only be true for a parameter pack. */
4856 /* A type parm can't refer to another parm. */
4870 }
4872 /* Check that a template declaration's use of default arguments and
4873 parameter packs is not invalid. Here, PARMS are the template
4874 parameters. IS_PRIMARY is true if DECL is the thing declared by
4875 a primary template. IS_PARTIAL is true if DECL is a partial
4876 specialization.
4878 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4879 declaration (but not a definition); 1 indicates a declaration, 2
4880 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4881 emitted for extraneous default arguments.
4883 Returns TRUE if there were no errors found, FALSE otherwise. */
4885 bool
4888 {
4891 tree parm_level;
4894 /* [temp.param]
4896 A default template-argument shall not be specified in a
4897 function template declaration or a function template definition, nor
4898 in the template-parameter-list of the definition of a member of a
4899 class template. */
4903 /* You can't have a function template declaration in a local
4904 scope, nor you can you define a member of a class template in a
4905 local scope. */
4913 /* A lambda doesn't have an explicit declaration; don't complain
4914 about the parms of the enclosing class. */
4921 /* If this is either a friend defined in the scope of the class
4922 or a member function. */
4928 /* And, if it was a member function, it really was defined in
4929 the scope of the class. */
4932 /* We already checked these parameters when the template was
4933 declared, so there's no need to do it again now. This function
4934 was defined in class scope, but we're processing its body now
4935 that the class is complete. */
4938 /* Core issue 226 (C++0x only): the following only applies to class
4939 templates. */
4942 {
4943 /* [temp.param]
4945 If a template-parameter has a default template-argument, all
4946 subsequent template-parameters shall have a default
4947 template-argument supplied. */
4949 {
4956 {
4966 {
4968 /* For better subsequent error-recovery, we indicate that
4969 there should have been a default argument. */
4972 }
4974 && !is_friend_decl
4975 /* Don't complain about an enclosing partial
4976 specialization. */
4981 /* A fixed parameter pack will be partially
4982 instantiated into a fixed length list. */
4984 {
4985 /* A primary class template can only have one
4986 parameter pack, at the end of the template
4987 parameter list. */
4995 }
4996 }
4997 }
4998 }
5001 || is_partial
5002 || !is_primary
5004 /* For an ordinary class template, default template arguments are
5005 allowed at the innermost level, e.g.:
5006 template <class T = int>
5007 struct S {};
5008 but, in a partial specialization, they're not allowed even
5009 there, as we have in [temp.class.spec]:
5011 The template parameter list of a specialization shall not
5012 contain default template argument values.
5014 So, for a partial specialization, or for a function template
5015 (in C++98/C++03), we look at all of them. */
5016 ;
5017 else
5018 /* But, for a primary class template that is not a partial
5019 specialization we look at all template parameters except the
5020 innermost ones. */
5023 /* Figure out what error message to issue. */
5038 else
5039 /* Per [temp.param]/9, "A default template-argument shall not be
5040 specified in the template-parameter-lists of the definition of
5041 a member of a class template that appears outside of the member's
5042 class.", thus if we aren't handling a member of a class template
5043 there is no need to examine the parameters. */
5047 /* If we're inside a class definition, there's no need to
5048 examine the parameters to the class itself. On the one
5049 hand, they will be checked when the class is defined, and,
5050 on the other, default arguments are valid in things like:
5051 template <class T = double>
5052 struct S { template <class U> void f(U); };
5053 Here the default argument for `S' has no bearing on the
5054 declaration of `f'. */
5056 else
5057 /* Check everything. */
5063 {
5070 {
5075 {
5077 {
5084 }
5086 /* Clear out the default argument so that we are not
5087 confused later. */
5089 }
5090 }
5092 /* At this point, if we're still interested in issuing messages,
5093 they must apply to classes surrounding the object declared. */
5097 }
5100 }
5102 /* Worker for push_template_decl_real, called via
5103 for_each_template_parm. DATA is really an int, indicating the
5104 level of the parameters we are interested in. If T is a template
5105 parameter of that level, return nonzero. */
5107 static int
5109 {
5115 else
5118 }
5120 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5121 DATA is really an int, indicating the innermost outer level of parameters.
5122 If T is a template parameter of that level or further out, return
5123 nonzero. */
5125 static int
5127 {
5133 else
5136 }
5138 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5139 parameters given by current_template_args, or reuses a
5140 previously existing one, if appropriate. Returns the DECL, or an
5141 equivalent one, if it is replaced via a call to duplicate_decls.
5143 If IS_FRIEND is true, DECL is a friend declaration. */
5145 tree
5147 {
5148 tree tmpl;
5149 tree args;
5150 tree info;
5151 tree ctx;
5155 /* True if the template is a member template, in the sense of
5156 [temp.mem]. */
5162 /* See if this is a partial specialization. */
5175 /* For a friend, we want the context of the friend function, not
5176 the type of which it is a friend. */
5180 /* In the case of a virtual function, we want the class in which
5181 it is defined. */
5183 else
5184 /* Otherwise, if we're currently defining some class, the DECL
5185 is assumed to be a member of the class. */
5194 /* See if this is a primary template. */
5197 /* A friend template that specifies a class context, i.e.
5198 template <typename T> friend void A<T>::f();
5199 is not primary. */
5204 else
5208 {
5215 {
5218 }
5220 {
5222 {
5225 }
5227 {
5228 /* [temp.mem]
5230 A destructor shall not be a member template. */
5233 }
5240 {
5241 /* [basic.stc.dynamic.allocation]
5243 An allocation function can be a function
5244 template. ... Template allocation functions shall
5245 have two or more parameters. */
5248 }
5249 }
5252 {
5253 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5256 {
5262 }
5263 }
5266 /* alias-declaration */
5270 else
5271 {
5274 }
5275 }
5277 /* Check to see that the rules regarding the use of default
5278 arguments are not being violated. */
5282 /* Ensure that there are no parameter packs in the type of this
5283 declaration that have not been expanded. */
5285 {
5286 /* Check each of the arguments individually to see if there are
5287 any bare parameter packs. */
5293 {
5296 {
5297 /* This is a PARM_DECL that contains unexpanded parameter
5298 packs. We have already complained about this in the
5299 check_for_bare_parameter_packs call, so just replace
5300 these types with ERROR_MARK_NODE. */
5303 }
5307 }
5309 /* Check for bare parameter packs in the return type and the
5310 exception specifiers. */
5312 /* Errors were already issued, set return type to int
5313 as the frontend doesn't expect error_mark_node as
5314 the return type. */
5318 }
5323 {
5326 }
5339 {
5344 /* If DECL is a TYPE_DECL for a class-template, then there won't
5345 be DECL_LANG_SPECIFIC. The information equivalent to
5346 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5350 {
5351 /* Since a template declaration already existed for this
5352 class-type, we must be redeclaring it here. Make sure
5353 that the redeclaration is valid. */
5355 current_template_parms,
5357 /* We don't need to create a new TEMPLATE_DECL; just use the
5358 one we already had. */
5360 }
5361 else
5362 {
5364 member_template_p);
5369 {
5370 /* A specialization of a member template of a template
5371 class. */
5375 }
5376 }
5377 }
5378 else
5379 {
5385 {
5388 }
5396 {
5397 tree new_tmpl;
5399 /* The declaration is a specialization of a member
5400 template, declared outside the class. Therefore, the
5401 innermost template arguments will be NULL, so we
5402 replace them with the arguments determined by the
5403 earlier call to check_explicit_specialization. */
5406 new_tmpl
5408 member_template_p);
5418 args,
5421 }
5423 /* Make sure the template headers we got make sense. */
5428 {
5433 }
5434 else
5436 {
5441 {
5445 else
5449 /* Avoid crash in import_export_decl. */
5452 }
5457 /* Can happen in erroneous input. */
5459 else
5461 }
5463 /* Check that the parms are used in the appropriate qualifying scopes
5464 in the declarator. */
5468 {
5474 /* Avoid crash in import_export_decl. */
5477 }
5478 }
5483 /* Push template declarations for global functions and types. Note
5484 that we do not try to push a global template friend declared in a
5485 template class; such a thing may well depend on the template
5486 parameters of the class. */
5489 {
5494 /* Hide template friend classes that haven't been declared yet. */
5496 {
5499 }
5500 }
5503 {
5509 {
5512 /* It is a conversion operator. See if the type converted to
5513 depends on innermost template operands. */
5516 depth))
5518 }
5520 /* Give template template parms a DECL_CONTEXT of the template
5521 for which they are a parameter. */
5524 {
5528 }
5534 }
5536 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5537 back to its most general template. If TMPL is a specialization,
5538 ARGS may only have the innermost set of arguments. Add the missing
5539 argument levels if necessary. */
5547 else
5548 {
5553 }
5556 && !is_friend
5559 /* Set DECL_COMDAT on template instantiations; if we force
5560 them to be emitted by explicit instantiation or -frepo,
5561 mark_needed will tell cgraph to do the right thing. */
5565 }
5567 tree
5569 {
5571 }
5573 /* FN is an inheriting constructor that inherits from the constructor
5574 template INHERITED; turn FN into a constructor template with a matching
5575 template header. */
5577 tree
5579 {
5580 tree inner_parms
5583 tree parms
5594 }
5596 /* Called when a class template TYPE is redeclared with the indicated
5597 template PARMS, e.g.:
5599 template <class T> struct S;
5600 template <class T> struct S {}; */
5602 bool
5604 {
5605 tree tmpl;
5606 tree tmpl_parms;
5610 {
5613 }
5617 /* The type is nested in some template class. Nothing to worry
5618 about here; there are no new template parameters for the nested
5619 type. */
5623 {
5625 tmpl);
5627 }
5633 {
5643 }
5646 {
5647 tree tmpl_parm;
5648 tree parm;
5649 tree tmpl_default;
5650 tree parm_default;
5664 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5665 TEMPLATE_DECL. */
5675 {
5679 }
5682 {
5683 /* We have in [temp.param]:
5685 A template-parameter may not be given default arguments
5686 by two different declarations in the same scope. */
5691 }
5694 /* Update the previous template parameters (which are the ones
5695 that will really count) with the new default value. */
5698 /* Update the new parameters, too; they'll be used as the
5699 parameters for any members. */
5702 /* Give each template template parm in this redeclaration a
5703 DECL_CONTEXT of the template for which they are a parameter. */
5705 {
5708 }
5712 }
5714 // Cannot redeclare a class template with a different set of constraints.
5716 {
5721 }
5724 }
5726 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5727 to be used when the caller has already checked
5728 (processing_template_decl
5729 && !instantiation_dependent_expression_p (expr)
5730 && potential_constant_expression (expr))
5731 and cleared processing_template_decl. */
5733 tree
5735 {
5738 complain,
5742 }
5744 /* Simplify EXPR if it is a non-dependent expression. Returns the
5745 (possibly simplified) expression. */
5747 tree
5749 {
5753 /* If we're in a template, but EXPR isn't value dependent, simplify
5754 it. We're supposed to treat:
5756 template <typename T> void f(T[1 + 1]);
5757 template <typename T> void f(T[2]);
5759 as two declarations of the same function, for example. */
5762 {
5763 processing_template_decl_sentinel s;
5765 }
5767 }
5769 tree
5771 {
5773 }
5775 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5776 an uninstantiated expression. */
5778 tree
5780 {
5784 {
5787 else
5788 {
5789 processing_template_decl_sentinel s;
5791 }
5792 }
5794 }
5796 /* True iff T is a specialization of a variable template. */
5798 bool
5800 {
5805 }
5807 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5808 template declaration, or a TYPE_DECL for an alias declaration. */
5810 bool
5812 {
5820 }
5822 /* Return TRUE iff T is a specialization of an alias template. */
5824 bool
5826 {
5827 /* It's an alias template specialization if it's an alias and its
5828 TYPE_NAME is a specialization of a primary template. */
5834 }
5836 /* An alias template is complex from a SFINAE perspective if a template-id
5837 using that alias can be ill-formed when the expansion is not, as with
5838 the void_t template. We determine this by checking whether the
5839 expansion for the alias template uses all its template parameters. */
5841 struct uses_all_template_parms_data
5842 {
5845 };
5847 static int
5849 {
5857 }
5859 static bool
5861 {
5876 }
5878 /* Return TRUE iff T is a specialization of a complex alias template with
5879 dependent template-arguments. */
5881 bool
5883 {
5896 }
5898 /* Return the number of innermost template parameters in TMPL. */
5900 static int
5902 {
5905 }
5907 /* Return either TMPL or another template that it is equivalent to under DR
5908 1286: An alias that just changes the name of a template is equivalent to
5909 the other template. */
5911 static tree
5913 {
5916 {
5917 /* Determine if the alias is equivalent to an underlying template. */
5929 tree alias_args = INNERMOST_TEMPLATE_ARGS
5934 /* Alias is equivalent. Strip it and repeat. */
5936 }
5939 }
5941 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5942 must be a reference-to-function or a pointer-to-function type, as specified
5943 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5944 and check that the resulting function has external linkage. */
5946 static tree
5948 tsubst_flags_t complain)
5949 {
5952 linkage_kind linkage;
5967 /* [temp.arg.nontype]/1
5969 A template-argument for a non-type, non-template template-parameter
5970 shall be one of:
5971 [...]
5972 -- the address of an object or function with external [C++11: or
5973 internal] linkage. */
5976 {
5978 {
5984 else
5987 }
5989 }
5993 {
5995 {
6000 else
6004 }
6006 }
6008 accept:
6015 }
6017 /* Subroutine of convert_nontype_argument.
6018 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6019 Emit an error otherwise. */
6021 static bool
6023 tsubst_flags_t complain)
6024 {
6035 {
6039 }
6041 }
6043 /* Returns TRUE iff the address of OP is value-dependent.
6045 14.6.2.4 [temp.dep.temp]:
6046 A non-integral non-type template-argument is dependent if its type is
6047 dependent or it has either of the following forms
6048 qualified-id
6049 & qualified-id
6050 and contains a nested-name-specifier which specifies a class-name that
6051 names a dependent type.
6053 We generalize this to just say that the address of a member of a
6054 dependent class is value-dependent; the above doesn't cover the
6055 address of a static data member named with an unqualified-id. */
6057 static bool
6059 {
6060 /* We could use get_inner_reference here, but there's no need;
6061 this is only relevant for template non-type arguments, which
6062 can only be expressed as &id-expression. */
6064 {
6068 }
6071 }
6073 /* The next set of functions are used for providing helpful explanatory
6074 diagnostics for failed overload resolution. Their messages should be
6075 indented by two spaces for consistency with the messages in
6076 call.c */
6078 static int
6080 {
6082 }
6084 /* Other failure functions should call this one, to provide a single function
6085 for setting a breakpoint on. */
6087 static int
6089 {
6091 }
6093 static int
6095 {
6100 }
6102 static int
6104 {
6110 }
6112 static int
6114 {
6118 }
6120 static int
6122 {
6125 " template parameter %qD is not a parameter pack, but "
6129 }
6131 static int
6133 {
6136 " template argument %qE does not match "
6140 }
6142 static int
6144 {
6148 }
6150 static int
6152 {
6158 }
6160 static int
6162 {
6164 {
6169 else
6171 " deduced conflicting values for non-type parameter "
6173 }
6175 }
6177 static int
6179 {
6182 " variable-sized array type %qT is not "
6184 arg);
6186 }
6188 static int
6190 {
6194 arg);
6196 }
6198 static int
6200 {
6202 {
6208 else
6213 }
6215 }
6217 static int
6219 {
6221 }
6223 static int
6226 {
6228 }
6230 static int
6233 {
6239 }
6241 static int
6244 {
6247 {
6255 }
6257 }
6259 static int
6261 {
6264 " template parameters of a template template argument are "
6267 }
6269 static int
6271 {
6277 }
6279 static int
6281 {
6286 }
6288 static int
6290 {
6294 arg);
6296 }
6298 /* Attempt to convert the non-type template parameter EXPR to the
6299 indicated TYPE. If the conversion is successful, return the
6300 converted value. If the conversion is unsuccessful, return
6301 NULL_TREE if we issued an error message, or error_mark_node if we
6302 did not. We issue error messages for out-and-out bad template
6303 parameters, but not simply because the conversion failed, since we
6304 might be just trying to do argument deduction. Both TYPE and EXPR
6305 must be non-dependent.
6307 The conversion follows the special rules described in
6308 [temp.arg.nontype], and it is much more strict than an implicit
6309 conversion.
6311 This function is called twice for each template argument (see
6312 lookup_template_class for a more accurate description of this
6313 problem). This means that we need to handle expressions which
6314 are not valid in a C++ source, but can be created from the
6315 first call (for instance, casts to perform conversions). These
6316 hacks can go away after we fix the double coercion problem. */
6318 static tree
6320 {
6321 tree expr_type;
6323 /* Detect immediately string literals as invalid non-type argument.
6324 This special-case is not needed for correctness (we would easily
6325 catch this later), but only to provide better diagnostic for this
6326 common user mistake. As suggested by DR 100, we do not mention
6327 linkage issues in the diagnostic as this is not the point. */
6328 /* FIXME we're making this OK. */
6330 {
6336 }
6338 /* Add the ADDR_EXPR now for the benefit of
6339 value_dependent_expression_p. */
6342 {
6346 }
6348 /* If we are in a template, EXPR may be non-dependent, but still
6349 have a syntactic, rather than semantic, form. For example, EXPR
6350 might be a SCOPE_REF, rather than the VAR_DECL to which the
6351 SCOPE_REF refers. Preserving the qualifying scope is necessary
6352 so that access checking can be performed when the template is
6353 instantiated -- but here we need the resolved form so that we can
6354 convert the argument. */
6367 else
6370 /* If the argument is non-dependent, perform any conversions in
6371 non-dependent context as well. */
6379 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6380 to a non-type argument of "nullptr". */
6384 /* In C++11, integral or enumeration non-type template arguments can be
6385 arbitrary constant expressions. Pointer and pointer to
6386 member arguments can be general constant expressions that evaluate
6387 to a null value, but otherwise still need to be of a specific form. */
6389 {
6391 /* A PTRMEM_CST is already constant, and a valid template
6392 argument for a parameter of pointer to member type, we just want
6393 to leave it in that form rather than lower it to a
6398 {
6402 {
6406 }
6407 }
6409 {
6414 }
6415 }
6417 /* HACK: Due to double coercion, we can get a
6418 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6419 which is the tree that we built on the first call (see
6420 below when coercing to reference to object or to reference to
6421 function). We just strip everything and get to the arg.
6422 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6423 for examples. */
6425 {
6431 {
6432 /* ??? Maybe we could use convert_from_reference here, but we
6433 would need to relax its constraints because the NOP_EXPR
6434 could actually change the type to something more cv-qualified,
6435 and this is not folded by convert_from_reference. */
6440 && (same_type_ignoring_top_level_qualifiers_p
6443 {
6446 }
6447 }
6448 }
6450 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
6451 parameter is a pointer to object, through decay and
6452 qualification conversion. Let's strip everything. */
6454 {
6459 {
6460 /* Skip the ADDR_EXPR only if it is part of the decay for
6461 an array. Otherwise, it is part of the original argument
6462 in the source code. */
6467 }
6468 }
6470 /* [temp.arg.nontype]/5, bullet 1
6472 For a non-type template-parameter of integral or enumeration type,
6473 integral promotions (_conv.prom_) and integral conversions
6474 (_conv.integral_) are applied. */
6476 {
6485 /* Notice that there are constant expressions like '4 % 0' which
6486 do not fold into integer constants. */
6489 {
6491 {
6502 /* else cxx_constant_value complained but gave us
6503 a real constant, so go ahead. */
6505 }
6506 else
6508 }
6510 /* Avoid typedef problems. */
6513 }
6514 /* [temp.arg.nontype]/5, bullet 2
6516 For a non-type template-parameter of type pointer to object,
6517 qualification conversions (_conv.qual_) and the array-to-pointer
6518 conversion (_conv.array_) are applied. */
6520 {
6521 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6523 A template-argument for a non-type, non-template template-parameter
6524 shall be one of: [...]
6526 -- the name of a non-type template-parameter;
6527 -- the address of an object or function with external linkage, [...]
6528 expressed as "& id-expression" where the & is optional if the name
6529 refers to a function or array, or if the corresponding
6530 template-parameter is a reference.
6532 Here, we do not care about functions, as they are invalid anyway
6533 for a parameter of type pointer-to-object. */
6536 /* Non-type template parameters are OK. */
6537 ;
6542 {
6544 {
6547 "because %qD is a variable, not the address of "
6550 }
6552 {
6558 }
6559 /* Other values, like integer constants, might be valid
6560 non-type arguments of some other type. */
6562 }
6563 else
6564 {
6565 tree decl;
6570 {
6575 }
6577 {
6583 }
6585 {
6590 }
6591 }
6600 }
6601 /* [temp.arg.nontype]/5, bullet 3
6603 For a non-type template-parameter of type reference to object, no
6604 conversions apply. The type referred to by the reference may be more
6605 cv-qualified than the (otherwise identical) type of the
6606 template-argument. The template-parameter is bound directly to the
6607 template-argument, which must be an lvalue. */
6609 {
6611 expr_type))
6615 {
6620 }
6623 {
6628 }
6630 /* [temp.arg.nontype]/1
6632 A template-argument for a non-type, non-template template-parameter
6633 shall be one of: [...]
6635 -- the address of an object or function with external linkage. */
6638 {
6641 {
6644 "because a reference variable does not have a constant "
6647 }
6648 }
6651 {
6653 {
6659 }
6661 /* DR 1155 allows internal linkage in C++11 and up. */
6664 {
6670 }
6673 }
6674 }
6675 /* [temp.arg.nontype]/5, bullet 4
6677 For a non-type template-parameter of type pointer to function, only
6678 the function-to-pointer conversion (_conv.func_) is applied. If the
6679 template-argument represents a set of overloaded functions (or a
6680 pointer to such), the matching function is selected from the set
6681 (_over.over_). */
6683 {
6684 /* If the argument is a template-id, we might not have enough
6685 context information to decay the pointer. */
6687 {
6691 }
6694 /* Null pointer values are OK in C++11. */
6700 }
6701 /* [temp.arg.nontype]/5, bullet 5
6703 For a non-type template-parameter of type reference to function, no
6704 conversions apply. If the template-argument represents a set of
6705 overloaded functions, the matching function is selected from the set
6706 (_over.over_). */
6708 {
6710 {
6712 {
6717 }
6719 }
6724 }
6725 /* [temp.arg.nontype]/5, bullet 6
6727 For a non-type template-parameter of type pointer to member function,
6728 no conversions apply. If the template-argument represents a set of
6729 overloaded member functions, the matching member function is selected
6730 from the set (_over.over_). */
6732 {
6737 /* [temp.arg.nontype] bullet 1 says the pointer to member
6738 expression must be a pointer-to-member constant. */
6743 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6744 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6748 /* There is no way to disable standard conversions in
6749 resolve_address_of_overloaded_function (called by
6750 instantiate_type). It is possible that the call succeeded by
6751 converting &B::I to &D::I (where B is a base of D), so we need
6752 to reject this conversion here.
6754 Actually, even if there was a way to disable standard conversions,
6755 it would still be better to reject them here so that we can
6756 provide a superior diagnostic. */
6758 {
6760 {
6764 /* If we are just one standard conversion off, explain. */
6768 }
6770 }
6771 }
6772 /* [temp.arg.nontype]/5, bullet 7
6774 For a non-type template-parameter of type pointer to data member,
6775 qualification conversions (_conv.qual_) are applied. */
6777 {
6778 /* [temp.arg.nontype] bullet 1 says the pointer to member
6779 expression must be a pointer-to-member constant. */
6787 }
6789 {
6791 {
6796 }
6798 }
6799 /* A template non-type parameter must be one of the above. */
6800 else
6803 /* Sanity check: did we actually convert the argument to the
6804 right type? */
6808 }
6810 /* Subroutine of coerce_template_template_parms, which returns 1 if
6811 PARM_PARM and ARG_PARM match using the rule for the template
6812 parameters of template template parameters. Both PARM and ARG are
6813 template parameters; the rest of the arguments are the same as for
6814 coerce_template_template_parms.
6815 */
6816 static int
6818 tree arg,
6819 tsubst_flags_t complain,
6820 tree in_decl,
6821 tree outer_args)
6822 {
6831 {
6833 /* We encounter instantiations of templates like
6834 template <template <template <class> class> class TT>
6835 class C; */
6836 {
6843 }
6844 /* Fall through. */
6849 /* Argument is a parameter pack but parameter is not. */
6854 /* The tsubst call is used to handle cases such as
6856 template <int> class C {};
6857 template <class T, template <T> class TT> class D {};
6858 D<int, C> d;
6860 i.e. the parameter list of TT depends on earlier parameters. */
6862 {
6867 }
6871 /* Argument is a parameter pack but parameter is not. */
6878 }
6881 }
6883 /* Coerce template argument list ARGLIST for use with template
6884 template-parameter TEMPL. */
6886 static tree
6888 tsubst_flags_t complain)
6889 {
6890 /* Consider an example where a template template parameter declared as
6892 template <class T, class U = std::allocator<T> > class TT
6894 The template parameter level of T and U are one level larger than
6895 of TT. To proper process the default argument of U, say when an
6896 instantiation `TT<int>' is seen, we need to build the full
6897 arguments containing {int} as the innermost level. Outer levels,
6898 available when not appearing as default template argument, can be
6899 obtained from the arguments of the enclosing template.
6901 Suppose that TT is later substituted with std::vector. The above
6902 instantiation is `TT<int, std::allocator<T> >' with TT at
6903 level 1, and T at level 2, while the template arguments at level 1
6904 becomes {std::vector} and the inner level 2 is {int}. */
6908 {
6910 /* We want arguments for the partial specialization, not arguments for
6911 the primary template. */
6913 else
6915 }
6917 {
6918 /* This is an argument of the current template, so we haven't set
6919 DECL_CONTEXT yet. */
6920 tree relevant_template_parms;
6922 /* Parameter levels that are greater than the level of the given
6923 template template parm are irrelevant. */
6930 }
6937 complain,
6940 }
6942 /* A cache of template template parameters with match-all default
6943 arguments. */
6945 static void
6947 {
6951 }
6952 static tree
6954 {
6959 }
6961 /* T is a bound template template-parameter. Copy its arguments into default
6962 arguments of the template template-parameter's template parameters. */
6964 static tree
6966 {
6989 {
6992 {
6995 }
6996 }
7000 }
7002 /* ARG is a bound potential template template-argument, and PARGS is a list
7003 of arguments for the corresponding template template-parameter. Adjust
7004 PARGS as appropriate for application to ARG's template, and if ARG is a
7005 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7006 arguments to the template template parameter. */
7008 static tree
7010 {
7014 {
7015 /* When comparing two template template-parameters in partial ordering,
7016 rewrite the one currently being used as an argument to have default
7017 arguments for all parameters. */
7023 }
7024 else
7025 {
7026 tree aparms
7031 }
7034 }
7036 /* Subroutine of unify for the case when PARM is a
7037 BOUND_TEMPLATE_TEMPLATE_PARM. */
7039 static int
7042 {
7046 /* The template template parm might be variadic and the argument
7047 not, so flatten both argument lists. */
7053 {
7054 /* In keeping with P0522R0, adjust P's template arguments
7055 to apply to A's template; then flatten it again. */
7058 }
7064 /* If the P0522 adjustment eliminated a pack expansion, deduce
7065 empty packs. */
7073 }
7075 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7076 template template parameters. Both PARM_PARMS and ARG_PARMS are
7077 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7078 or PARM_DECL.
7080 Consider the example:
7081 template <class T> class A;
7082 template<template <class U> class TT> class B;
7084 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7085 the parameters to A, and OUTER_ARGS contains A. */
7087 static int
7089 tree arg_parms,
7090 tsubst_flags_t complain,
7091 tree in_decl,
7092 tree outer_args)
7093 {
7105 {
7106 /* P0522R0: A template template-parameter P is at least as specialized as
7107 a template template-argument A if, given the following rewrite to two
7108 function templates, the function template corresponding to P is at
7109 least as specialized as the function template corresponding to A
7110 according to the partial ordering rules for function templates
7111 ([temp.func.order]). Given an invented class template X with the
7112 template parameter list of A (including default arguments):
7114 * Each of the two function templates has the same template parameters,
7115 respectively, as P or A.
7117 * Each function template has a single function parameter whose type is
7118 a specialization of X with template arguments corresponding to the
7119 template parameters from the respective function template where, for
7120 each template parameter PP in the template parameter list of the
7121 function template, a corresponding template argument AA is formed. If
7122 PP declares a parameter pack, then AA is the pack expansion
7123 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7125 If the rewrite produces an invalid type, then P is not at least as
7126 specialized as A. */
7128 /* So coerce P's args to apply to A's parms, and then deduce between A's
7129 args and the converted args. If that succeeds, A is at least as
7130 specialized as P, so they match.*/
7137 {
7143 }
7144 }
7146 /* Determine whether we have a parameter pack at the end of the
7147 template template parameter's template parameter list. */
7149 {
7156 {
7170 }
7171 }
7177 /* Check all of the template parameters except the parameter pack at
7178 the end (if any). */
7180 {
7189 outer_args))
7192 }
7195 {
7196 /* Check each of the template parameters in the template
7197 argument against the template parameter pack at the end of
7198 the template template parameter. */
7205 {
7212 outer_args))
7214 }
7215 }
7218 }
7220 /* Verifies that the deduced template arguments (in TARGS) for the
7221 template template parameters (in TPARMS) represent valid bindings,
7222 by comparing the template parameter list of each template argument
7223 to the template parameter list of its corresponding template
7224 template parameter, in accordance with DR150. This
7225 routine can only be called after all template arguments have been
7226 deduced. It will return TRUE if all of the template template
7227 parameter bindings are okay, FALSE otherwise. */
7228 bool
7230 {
7234 /* We're dealing with template parms in this process. */
7240 {
7245 {
7250 {
7251 /* Look inside the argument pack. */
7254 }
7257 {
7261 /* Extract the next argument from the argument
7262 pack. */
7266 /* Look at the pattern of the pack expansion. */
7269 /* Extract the template parameters from the template
7270 argument. */
7276 /* Verify that we can coerce the template template
7277 parameters from the template argument to the template
7278 parameter. This requires an exact match. */
7280 && !coerce_template_template_parms
7282 targ_parms,
7283 tf_none,
7284 tparm,
7285 targs))
7286 {
7289 }
7290 }
7291 }
7292 }
7294 out:
7298 }
7300 /* Since type attributes aren't mangled, we need to strip them from
7301 template type arguments. */
7303 static tree
7305 {
7315 }
7317 /* And from inside dependent non-type arguments like sizeof(Type). */
7319 static tree
7321 {
7331 }
7333 // A template declaration can be substituted for a constrained
7334 // template template parameter only when the argument is more
7335 // constrained than the parameter.
7336 static bool
7338 {
7341 /* For now, allow constrained template template arguments
7342 and unconstrained template template parameters. */
7348 // If the template parameter is constrained, we need to rewrite its
7349 // constraints in terms of the ARG's template parameters. This ensures
7350 // that all of the template parameter types will have the same depth.
7351 //
7352 // Note that this is only valid when coerce_template_template_parm is
7353 // true for the innermost template parameters of PARM and ARG. In other
7354 // words, because coercion is successful, this conversion will be valid.
7356 {
7363 }
7366 }
7368 // Convert a placeholder argument into a binding to the original
7369 // parameter. The original parameter is saved as the TREE_TYPE of
7370 // ARG.
7373 {
7376 }
7378 /* Convert the indicated template ARG as necessary to match the
7379 indicated template PARM. Returns the converted ARG, or
7380 error_mark_node if the conversion was unsuccessful. Error and
7381 warning messages are issued under control of COMPLAIN. This
7382 conversion is for the Ith parameter in the parameter list. ARGS is
7383 the full set of template arguments deduced so far. */
7385 static tree
7387 tree arg,
7388 tree args,
7389 tsubst_flags_t complain,
7391 tree in_decl)
7392 {
7393 tree orig_arg;
7394 tree val;
7400 /* Trivially convert placeholders. */
7409 {
7410 /* The template argument was the name of some
7411 member function. That's usually
7412 invalid, but static members are OK. In any
7413 case, grab the underlying fields/functions
7414 and issue an error later if required. */
7417 }
7425 /* When determining whether an argument pack expansion is a template,
7426 look at the pattern. */
7430 /* Deal with an injected-class-name used as a template template arg. */
7432 {
7435 {
7445 }
7446 }
7448 is_tmpl_type =
7464 {
7466 {
7470 }
7473 "to refer to a type member of a template parameter, "
7478 typename_type,
7479 complain);
7482 }
7484 {
7486 {
7488 {
7500 else
7503 }
7504 }
7506 }
7508 {
7510 {
7517 else
7520 }
7522 }
7525 /* We already did the appropriate conversion when packing args. */
7528 {
7530 {
7532 /* The number of argument required is not known yet.
7533 Just accept it for now. */
7535 else
7536 {
7538 tree argparm;
7540 /* Strip alias templates that are equivalent to another
7541 template. */
7547 args))
7548 {
7551 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7552 TEMPLATE_DECL. */
7554 {
7559 }
7560 }
7561 else
7562 {
7564 {
7571 }
7574 }
7576 // Check that the constraints are compatible before allowing the
7577 // substitution.
7580 {
7582 {
7588 }
7590 }
7591 }
7592 }
7593 else
7595 /* We only form one instance of each template specialization.
7596 Therefore, if we use a non-canonical variant (i.e., a
7597 typedef), any future messages referring to the type will use
7598 the typedef, which is confusing if those future uses do not
7599 themselves also use the typedef. */
7602 }
7603 else
7604 {
7608 {
7612 }
7613 else
7621 /* We used to call digest_init here. However, digest_init
7622 will report errors, which we don't want when complain
7623 is zero. More importantly, digest_init will try too
7624 hard to convert things: for example, `0' should not be
7625 converted to pointer type at this point according to
7626 the standard. Accepting this is not merely an
7627 extension, since deciding whether or not these
7628 conversions can occur is part of determining which
7629 function template to call, or whether a given explicit
7630 argument specification is valid. */
7632 else
7642 {
7643 /* Reject template arguments that are references to built-in
7644 functions with no library fallbacks. */
7653 }
7656 {
7657 /* Strip typedefs from the SCOPE_REF. */
7660 complain);
7663 }
7664 }
7667 }
7669 /* Coerces the remaining template arguments in INNER_ARGS (from
7670 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7671 Returns the coerced argument pack. PARM_IDX is the position of this
7672 parameter in the template parameter list. ARGS is the original
7673 template argument list. */
7674 static tree
7677 tree args,
7678 tree inner_args,
7680 tree new_args,
7682 tree in_decl,
7683 tsubst_flags_t complain)
7684 {
7687 tree packed_args;
7688 tree argument_pack;
7695 {
7696 /* When the template parameter is a non-type template parameter pack
7697 or template template parameter pack whose type or template
7698 parameters use parameter packs, we know exactly how many arguments
7699 we are looking for. Build a vector of the instantiated decls for
7700 these template parameters in PACKED_PARMS. */
7701 /* We can't use make_pack_expansion here because it would interpret a
7702 _DECL as a use rather than a declaration. */
7716 /* If we're doing a partial instantiation of a member template,
7717 verify that all of the types used for the non-type
7718 template parameter pack are, in fact, valid for non-type
7719 template parameters. */
7722 {
7725 {
7729 }
7730 /* We don't know how many args we have yet, just
7731 use the unconverted ones for now. */
7733 }
7736 }
7737 /* Check if we have a placeholder pack, which indicates we're
7738 in the context of a introduction list. In that case we want
7739 to match this pack to the single placeholder. */
7743 {
7746 }
7747 else
7750 /* Convert the remaining arguments, which will be a part of the
7751 parameter pack "parm". */
7754 {
7760 {
7761 /* Once we've packed as many args as we have types, stop. */
7765 /* We don't know how many args we have yet, just
7766 use the unconverted ones for now. */
7768 else
7770 }
7773 {
7776 }
7777 else
7780 in_decl);
7784 }
7788 {
7793 }
7798 else
7799 {
7802 }
7809 }
7811 /* Returns the number of pack expansions in the template argument vector
7812 ARGS. */
7814 static int
7816 {
7821 {
7825 }
7827 }
7829 /* Convert all template arguments to their appropriate types, and
7830 return a vector containing the innermost resulting template
7831 arguments. If any error occurs, return error_mark_node. Error and
7832 warning messages are issued under control of COMPLAIN.
7834 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7835 for arguments not specified in ARGS. Otherwise, if
7836 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7837 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7838 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7839 ARGS. */
7841 static tree
7843 tree args,
7844 tree in_decl,
7845 tsubst_flags_t complain,
7848 {
7850 tree orig_inner_args;
7851 tree inner_args;
7852 tree new_args;
7853 tree new_inner_args;
7857 /* When used as a boolean value, indicates whether this is a
7858 variadic template parameter list. Since it's an int, we can also
7859 subtract it from nparms to get the number of non-variadic
7860 parameters. */
7865 /* Likewise for parameters with default arguments. */
7873 /* Determine if there are any parameter packs or default arguments. */
7875 {
7883 }
7886 /* If there are no parameters that follow a parameter pack, we need to
7887 expand any argument packs so that we can deduce a parameter pack from
7888 some non-packed args followed by an argument pack, as in variadic85.C.
7889 If there are such parameters, we need to leave argument packs intact
7890 so the arguments are assigned properly. This can happen when dealing
7891 with a nested class inside a partial specialization of a class
7892 template, as in variadic92.C, or when deducing a template parameter pack
7893 from a sub-declarator, as in variadic114.C. */
7897 /* Count any pack expansion args. */
7903 && require_all_args
7904 && !variadic_args_p
7905 && (!use_default_args
7908 {
7910 {
7912 {
7916 }
7917 else
7924 }
7927 }
7928 /* We can't pass a pack expansion to a non-pack parameter of an alias
7929 template (DR 1430). */
7933 && variadic_args_p
7935 {
7937 {
7939 {
7945 {
7948 "pack expansion argument for non-pack parameter "
7950 else
7952 "pack expansion argument for non-pack parameter "
7956 }
7957 }
7959 found:;
7960 }
7962 }
7964 /* We need to evaluate the template arguments, even though this
7965 template-id may be nested within a "sizeof". */
7974 {
7975 tree arg;
7976 tree parm;
7978 /* Get the Ith template parameter. */
7982 {
7985 }
7987 /* Calculate the next argument. */
7990 else
7995 {
7996 /* Some arguments will be placed in the
7997 template parameter pack PARM. */
8004 {
8005 /* We don't know how many args we have yet, just use the
8006 unconverted (and still packed) ones for now. */
8010 }
8014 /* Store this argument. */
8016 {
8017 lost++;
8018 /* We are done with all of the arguments. */
8020 }
8021 else
8022 {
8025 }
8028 }
8030 {
8032 {
8033 /* "If every valid specialization of a variadic template
8034 requires an empty template parameter pack, the template is
8035 ill-formed, no diagnostic required." So check that the
8036 pattern works with this parameter. */
8041 in_decl);
8043 {
8048 }
8050 /* Recover from missing typename. */
8054 /* We don't know how many args we have yet, just
8055 use the unconverted ones for now. */
8059 }
8060 }
8062 {
8063 /* There must be a default arg in this case. */
8066 /* The position of the first default template argument,
8067 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8068 Record that. */
8072 }
8073 else
8077 {
8080 }
8082 /* This only occurs if there was an error in the template
8083 parameter list itself (which we would already have
8084 reported) that we are trying to recover from, e.g., a class
8085 template with a parameter list such as
8086 template<typename..., typename>. */
8088 else
8094 lost++;
8096 }
8101 {
8103 {
8108 }
8110 }
8120 }
8122 /* Convert all template arguments to their appropriate types, and
8123 return a vector containing the innermost resulting template
8124 arguments. If any error occurs, return error_mark_node. Error and
8125 warning messages are not issued.
8127 Note that no function argument deduction is performed, and default
8128 arguments are used to fill in unspecified arguments. */
8129 tree
8131 {
8133 }
8135 /* Convert all template arguments to their appropriate type, and
8136 instantiate default arguments as needed. This returns a vector
8137 containing the innermost resulting template arguments, or
8138 error_mark_node if unsuccessful. */
8139 tree
8141 tsubst_flags_t complain)
8142 {
8144 }
8146 /* Like coerce_template_parms. If PARMS represents all template
8147 parameters levels, this function returns a vector of vectors
8148 representing all the resulting argument levels. Note that in this
8149 case, only the innermost arguments are coerced because the
8150 outermost ones are supposed to have been coerced already.
8152 Otherwise, if PARMS represents only (the innermost) vector of
8153 parameters, this function returns a vector containing just the
8154 innermost resulting arguments. */
8156 static tree
8158 tree args,
8159 tree in_decl,
8160 tsubst_flags_t complain,
8163 {
8166 tree coerced_args;
8169 {
8171 tree level;
8177 {
8178 tree l;
8182 require_all_args,
8183 use_default_args);
8184 else
8191 }
8192 }
8193 else
8196 require_all_args,
8197 use_default_args);
8199 }
8201 /* Returns 1 if template args OT and NT are equivalent. */
8203 int
8205 {
8214 /* For member templates */
8223 {
8240 }
8244 {
8247 /* Don't treat an alias template specialization with dependent
8248 arguments as equivalent to its underlying type when used as a
8249 template argument; we need them to be distinct so that we
8250 substitute into the specialization arguments at instantiation
8251 time. And aliases can't be equivalent without being ==, so
8252 we don't need to look any deeper.
8254 During partial ordering, however, we need to treat them normally so
8255 that we can order uses of the same alias with different
8256 cv-qualification (79960). */
8260 else
8262 }
8265 else
8266 {
8267 /* Try to treat a template non-type argument that has been converted
8268 to the parameter type as equivalent to one that hasn't yet. */
8281 }
8282 }
8284 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8285 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8286 NEWARG_PTR with the offending arguments if they are non-NULL. */
8288 int
8292 {
8305 {
8310 {
8316 }
8317 }
8319 }
8323 {
8325 }
8327 static void
8329 {
8339 /* We are called both from instantiate_decl, where we've already had a
8340 tinst_level pushed, and instantiate_template, where we haven't.
8341 Compensate. */
8352 else
8361 }
8364 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8365 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8366 documentation for TEMPLATE_ID_EXPR. */
8368 tree
8370 {
8371 tree type;
8379 {
8382 }
8385 {
8387 unknown_type_node,
8389 arglist);
8391 }
8398 }
8400 /* Within the scope of a template class S<T>, the name S gets bound
8401 (in build_self_reference) to a TYPE_DECL for the class, not a
8402 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8403 or one of its enclosing classes, and that type is a template,
8404 return the associated TEMPLATE_DECL. Otherwise, the original
8405 DECL is returned.
8407 Also handle the case when DECL is a TREE_LIST of ambiguous
8408 injected-class-names from different bases. */
8410 tree
8412 {
8416 /* DR 176: A lookup that finds an injected-class-name (10.2
8417 [class.member.lookup]) can result in an ambiguity in certain cases
8418 (for example, if it is found in more than one base class). If all of
8419 the injected-class-names that are found refer to specializations of
8420 the same class template, and if the name is followed by a
8421 template-argument-list, the reference refers to the class template
8422 itself and not a specialization thereof, and is not ambiguous. */
8424 {
8427 {
8433 }
8436 else
8438 }
8444 }
8446 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8447 parameters, find the desired type.
8449 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8451 IN_DECL, if non-NULL, is the template declaration we are trying to
8452 instantiate.
8454 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8455 the class we are looking up.
8457 Issue error and warning messages under control of COMPLAIN.
8459 If the template class is really a local class in a template
8460 function, then the FUNCTION_CONTEXT is the function in which it is
8461 being instantiated.
8463 ??? Note that this function is currently called *twice* for each
8464 template-id: the first time from the parser, while creating the
8465 incomplete type (finish_template_type), and the second type during the
8466 real instantiation (instantiate_template_class). This is surely something
8467 that we want to avoid. It also causes some problems with argument
8468 coercion (see convert_nontype_argument for more information on this). */
8470 static tree
8473 {
8475 tree t;
8478 spec_entry elt;
8479 hashval_t hash;
8482 {
8486 else
8487 {
8494 }
8497 }
8499 {
8502 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8503 an implicit typename for the second A. Deal with it. */
8508 {
8511 }
8512 }
8515 {
8518 }
8520 {
8524 }
8526 {
8529 }
8531 /* Issue an error message if we didn't find a template. */
8533 {
8537 }
8540 /* Make sure it's a user visible template, if it was named by
8541 the user. */
8544 {
8546 {
8550 }
8552 }
8556 /* An alias that just changes the name of a template is equivalent to the
8557 other template, so if any of the arguments are pack expansions, strip
8558 the alias to avoid problems with a pack expansion passed to a non-pack
8559 alias template parameter (DR 1430). */
8564 {
8565 tree parm;
8574 }
8575 else
8576 {
8578 tree gen_tmpl;
8579 tree type_decl;
8587 /* An error occurred while building the template TEMPL, and a
8588 diagnostic has most certainly been emitted for that
8589 already. Let's propagate that error. */
8598 {
8599 /* We've been given an incomplete set of template arguments.
8600 For example, given:
8602 template <class T> struct S1 {
8603 template <class U> struct S2 {};
8604 template <class U> struct S2<U*> {};
8605 };
8607 we will be called with an ARGLIST of `U*', but the
8608 TEMPLATE will be `template <class T> template
8609 <class U> struct S1<T>::S2'. We must fill in the missing
8610 arguments. */
8614 }
8616 /* Now we should have enough arguments. */
8619 /* From here on, we're only interested in the most general
8620 template. */
8622 /* Calculate the BOUND_ARGS. These will be the args that are
8623 actually tsubst'd into the definition to create the
8624 instantiation. */
8626 complain,
8631 /* We were unable to bind the arguments. */
8634 /* In the scope of a template class, explicit references to the
8635 template class refer to the type of the template, not any
8636 instantiation of it. For example, in:
8638 template <class T> class C { void f(C<T>); }
8640 the `C<T>' is just the same as `C'. Outside of the
8641 class, however, such a reference is an instantiation. */
8645 {
8650 }
8652 /* If we already have this specialization, return it. */
8662 /* If the the template's constraints are not satisfied,
8663 then we cannot form a valid type.
8665 Note that the check is deferred until after the hash
8666 lookup. This prevents redundant checks on previously
8667 instantiated specializations. */
8669 {
8671 {
8674 }
8676 }
8680 /* If the deduced arguments are invalid, then the binding
8681 failed. */
8685 complain))
8692 {
8697 }
8707 /* Create the type. */
8709 {
8710 /* The user referred to a specialization of an alias
8711 template represented by GEN_TMPL.
8713 [temp.alias]/2 says:
8715 When a template-id refers to the specialization of an
8716 alias template, it is equivalent to the associated
8717 type obtained by substitution of its
8718 template-arguments for the template-parameters in the
8719 type-id of the alias template. */
8722 /* Note that the call above (by indirectly calling
8723 register_specialization in tsubst_decl) registers the
8724 TYPE_DECL representing the specialization of the alias
8725 template. So next time someone substitutes ARGLIST for
8726 the template parms into the alias template (GEN_TMPL),
8727 she'll get that TYPE_DECL back. */
8731 }
8733 {
8735 {
8746 }
8747 else
8748 {
8749 /* We don't want to call start_enum for this type, since
8750 the values for the enumeration constants may involve
8751 template parameters. And, no one should be interested
8752 in the enumeration constants for such a type. */
8755 }
8759 }
8761 {
8767 /* A local class. Make sure the decl gets registered properly. */
8772 /* This instantiation is another name for the primary
8773 template type. Set the TYPE_CANONICAL field
8774 appropriately. */
8777 /* Some of the template arguments require structural
8778 equality testing, so this template class requires
8779 structural equality testing. */
8781 }
8782 else
8785 /* If we called start_enum or pushtag above, this information
8786 will already be set up. */
8788 {
8795 }
8796 else
8800 {
8806 {
8809 }
8810 }
8814 {
8818 {
8819 tree attributes
8827 }
8828 }
8830 /* Let's consider the explicit specialization of a member
8831 of a class template specialization that is implicitly instantiated,
8832 e.g.:
8833 template<class T>
8834 struct S
8835 {
8836 template<class U> struct M {}; //#0
8837 };
8839 template<>
8840 template<>
8841 struct S<int>::M<char> //#1
8842 {
8843 int i;
8844 };
8845 [temp.expl.spec]/4 says this is valid.
8847 In this case, when we write:
8848 S<int>::M<char> m;
8850 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8851 the one of #0.
8853 When we encounter #1, we want to store the partial instantiation
8854 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
8856 For all cases other than this "explicit specialization of member of a
8857 class template", we just want to store the most general template into
8858 the CLASSTYPE_TI_TEMPLATE of M.
8860 This case of "explicit specialization of member of a class template"
8861 only happens when:
8862 1/ the enclosing class is an instantiation of, and therefore not
8863 the same as, the context of the most general template, and
8864 2/ we aren't looking at the partial instantiation itself, i.e.
8865 the innermost arguments are not the same as the innermost parms of
8866 the most general template.
8868 So it's only when 1/ and 2/ happens that we want to use the partial
8869 instantiation of the member template in lieu of its most general
8870 template. */
8874 /* the enclosing class must be an instantiation... */
8877 {
8881 tree partial_inst_args =
8888 use_partial_inst_tmpl =
8889 /*...and we must not be looking at the partial instantiation
8890 itself. */
8892 partial_inst_args);
8893 }
8896 /* This case is easy; there are no member templates involved. */
8898 else
8899 {
8900 /* This is a full instantiation of a member template. Find
8901 the partial instantiation of which this is an instance. */
8903 /* Temporarily reduce by one the number of levels in the ARGLIST
8904 so as to avoid comparing the last set of arguments. */
8908 /* FOUND is either a proper class type, or an alias
8909 template specialization. In the later case, it's a
8910 TYPE_DECL, resulting from the substituting of arguments
8911 for parameters in the TYPE_DECL of the alias template
8912 done earlier. So be careful while getting the template
8913 of FOUND. */
8915 ? found
8919 }
8921 // Build template info for the new specialization.
8930 /* Note this use of the partial instantiation so we can check it
8931 later in maybe_process_partial_specialization. */
8938 /* Now that the type has been registered on the instantiations
8939 list, we set up the enumerators. Because the enumeration
8940 constants may involve the enumeration type itself, we make
8941 sure to register the type first, and then create the
8942 constants. That way, doing tsubst_expr for the enumeration
8943 constants won't result in recursive calls here; we'll find
8944 the instantiation and exit above. */
8948 /* If the type makes use of template parameters, the
8949 code that generates debugging information will crash. */
8952 /* Possibly limit visibility based on template args. */
8959 }
8960 }
8962 /* Wrapper for lookup_template_class_1. */
8964 tree
8967 {
8968 tree ret;
8974 }
8976 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
8978 tree
8980 {
8981 /* The type of the expression is NULL_TREE since the template-id could refer
8982 to an explicit or partial specialization. */
8985 /* Except that concepts are always bool. */
8988 }
8990 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
8992 tree
8994 {
8998 /* We never want to return a VAR_DECL for a variable concept, since they
8999 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9014 {
9016 {
9019 }
9021 }
9023 /* If a template-id refers to a specialization of a variable
9024 concept, then the expression is true if and only if the
9025 concept's constraints are satisfied by the given template
9026 arguments.
9028 NOTE: This is an extension of Concepts Lite TS that
9029 allows constraints to be used in expressions. */
9031 {
9034 }
9037 }
9039 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9040 TARGS template args, and instantiate it if it's not dependent. */
9042 tree
9044 tsubst_flags_t complain)
9045 {
9048 {
9051 }
9054 }
9056 \f
9057 struct pair_fn_data
9058 {
9059 tree_fn_t fn;
9060 tree_fn_t any_fn;
9062 /* True when we should also visit template parameters that occur in
9063 non-deduced contexts. */
9066 };
9068 /* Called from for_each_template_parm via walk_tree. */
9070 static tree
9072 {
9079 #define WALK_SUBTREE(NODE) \
9080 do \
9081 { \
9082 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9083 pfd->include_nondeduced_p, \
9084 pfd->any_fn); \
9085 if (result) goto out; \
9086 } \
9087 while (0)
9097 {
9101 /* Fall through. */
9107 else
9117 /* Since we're not going to walk subtrees, we have to do this
9118 explicitly here. */
9120 /* Fall through. */
9123 /* Check the return type. */
9126 /* Check the parameter types. Since default arguments are not
9127 instantiated until they are needed, the TYPE_ARG_TYPES may
9128 contain expressions that involve template parameters. But,
9129 no-one should be looking at them yet. And, once they're
9130 instantiated, they don't contain template parameters, so
9131 there's no point in looking at them then, either. */
9132 {
9133 tree parm;
9138 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9139 want walk_tree walking into them itself. */
9141 }
9144 {
9148 }
9165 /* Fall through. */
9177 /* Record template parameters such as `T' inside `TT<T>'. */
9179 /* Fall through. */
9191 /* A template template parameter is encountered. */
9195 /* Already substituted template template parameter */
9200 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9201 partial instantiation. */
9213 /* If there's no type, then this thing must be some expression
9214 involving template parameters. */
9236 }
9238 #undef WALK_SUBTREE
9240 /* We didn't find any template parameters we liked. */
9241 out:
9243 }
9245 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9246 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9247 call FN with the parameter and the DATA.
9248 If FN returns nonzero, the iteration is terminated, and
9249 for_each_template_parm returns 1. Otherwise, the iteration
9250 continues. If FN never returns a nonzero value, the value
9251 returned by for_each_template_parm is 0. If FN is NULL, it is
9252 considered to be the function which always returns 1.
9254 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9255 parameters that occur in non-deduced contexts. When false, only
9256 visits those template parameters that can be deduced. */
9258 static tree
9262 tree_fn_t any_fn)
9263 {
9265 tree result;
9267 /* Set up. */
9273 /* Walk the tree. (Conceptually, we would like to walk without
9274 duplicates, but for_each_template_parm_r recursively calls
9275 for_each_template_parm, so we would need to reorganize a fair
9276 bit to use walk_tree_without_duplicates, so we keep our own
9277 visited list.) */
9280 else
9283 for_each_template_parm_r,
9287 /* Clean up. */
9289 {
9292 }
9295 }
9297 /* Returns true if T depends on any template parameter. */
9299 int
9301 {
9331 else
9332 {
9335 }
9340 }
9342 /* Returns true iff current_function_decl is an incompletely instantiated
9343 template. Useful instead of processing_template_decl because the latter
9344 is set to 0 during instantiate_non_dependent_expr. */
9346 bool
9348 {
9357 }
9359 /* Returns true if T depends on any template parameter with level LEVEL. */
9361 bool
9363 {
9366 }
9368 /* Returns true if the signature of DECL depends on any template parameter from
9369 its enclosing class. */
9371 bool
9373 {
9383 template_parm_outer_level,
9393 }
9395 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9396 ill-formed translation unit, i.e. a variable or function that isn't
9397 usable in a constant expression. */
9401 {
9405 }
9407 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9408 neglectable and instantiated from within an erroneous instantiation. */
9410 static bool
9412 {
9423 }
9431 /* We're starting to instantiate D; record the template instantiation context
9432 for diagnostics and to restore it later. */
9434 bool
9436 {
9438 }
9440 /* We're starting to instantiate D; record the template instantiation context
9441 at LOC for diagnostics and to restore it later. */
9443 bool
9445 {
9449 {
9450 /* Tell error.c not to try to instantiate any templates. */
9453 "template instantiation depth exceeds maximum of %d"
9455 max_tinst_depth);
9457 }
9459 /* If the current instantiation caused problems, don't let it instantiate
9460 anything else. Do allow deduction substitution and decls usable in
9461 constant expressions. */
9465 /* When not -quiet, dump template instantiations other than functions, since
9466 announce_function will take care of those. */
9485 }
9487 /* We're done instantiating this template; return to the instantiation
9488 context. */
9490 void
9492 {
9493 /* Restore the filename and line number stashed away when we started
9494 this instantiation. */
9498 }
9500 /* We're instantiating a deferred template; restore the template
9501 instantiation context in which the instantiation was requested, which
9502 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9504 static tree
9506 {
9518 }
9520 /* Returns the TINST_LEVEL which gives the original instantiation
9521 context. */
9525 {
9531 }
9533 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9534 vector of template arguments, as for tsubst.
9536 Returns an appropriate tsubst'd friend declaration. */
9538 static tree
9540 {
9541 tree new_friend;
9546 /* This was a friend declared with an explicit template
9547 argument list, e.g.:
9549 friend void f<>(T);
9551 to indicate that f was a template instantiation, not a new
9552 function declaration. Now, we have to figure out what
9553 instantiation of what template. */
9554 {
9556 tree new_args;
9557 tree tmpl;
9560 /* Friend functions are looked up in the containing namespace scope.
9561 We must enter that scope, to avoid finding member functions of the
9562 current class with same name. */
9577 tsk_none);
9579 }
9583 /* The NEW_FRIEND will look like an instantiation, to the
9584 compiler, but is not an instantiation from the point of view of
9585 the language. For example, we might have had:
9587 template <class T> struct S {
9588 template <class U> friend void f(T, U);
9589 };
9591 Then, in S<int>, template <class U> void f(int, U) is not an
9592 instantiation of anything. */
9598 {
9602 }
9604 /* The mangled name for the NEW_FRIEND is incorrect. The function
9605 is not a template instantiation and should not be mangled like
9606 one. Therefore, we forget the mangling here; we'll recompute it
9607 later if we need it. */
9609 {
9612 }
9615 {
9616 tree old_decl;
9617 tree new_friend_template_info;
9618 tree new_friend_result_template_info;
9619 tree ns;
9622 /* We must save some information from NEW_FRIEND before calling
9623 duplicate decls since that function will free NEW_FRIEND if
9624 possible. */
9626 new_friend_is_defn =
9631 {
9632 /* This declaration is a `primary' template. */
9635 new_friend_result_template_info
9637 }
9638 else
9641 /* Inside pushdecl_namespace_level, we will push into the
9642 current namespace. However, the friend function should go
9643 into the namespace of the template. */
9653 {
9654 /* This new friend declaration matched an existing
9655 declaration. For example, given:
9657 template <class T> void f(T);
9658 template <class U> class C {
9659 template <class T> friend void f(T) {}
9660 };
9662 the friend declaration actually provides the definition
9663 of `f', once C has been instantiated for some type. So,
9664 old_decl will be the out-of-class template declaration,
9665 while new_friend is the in-class definition.
9667 But, if `f' was called before this point, the
9668 instantiation of `f' will have DECL_TI_ARGS corresponding
9669 to `T' but not to `U', references to which might appear
9670 in the definition of `f'. Previously, the most general
9671 template for an instantiation of `f' was the out-of-class
9672 version; now it is the in-class version. Therefore, we
9673 run through all specialization of `f', adding to their
9674 DECL_TI_ARGS appropriately. In particular, they need a
9675 new set of outer arguments, corresponding to the
9676 arguments for this class instantiation.
9678 The same situation can arise with something like this:
9680 friend void f(int);
9681 template <class T> class C {
9682 friend void f(T) {}
9683 };
9685 when `C<int>' is instantiated. Now, `f(int)' is defined
9686 in the class. */
9689 /* On the other hand, if the in-class declaration does
9690 *not* provide a definition, then we don't want to alter
9691 existing definitions. We can just leave everything
9692 alone. */
9693 ;
9694 else
9695 {
9699 /* Overwrite whatever template info was there before, if
9700 any, with the new template information pertaining to
9701 the declaration. */
9705 {
9706 /* We should have called reregister_specialization in
9707 duplicate_decls. */
9712 /* Instantiate it if the global has already been used. */
9716 }
9717 else
9718 {
9719 tree t;
9721 /* Indicate that the old function template is a partial
9722 instantiation. */
9730 /* Reassign any specializations already in the hash table
9731 to the new more general template, and add the
9732 additional template args. */
9736 {
9738 spec_entry elt;
9750 register_specialization
9753 }
9755 }
9756 }
9758 /* The information from NEW_FRIEND has been merged into OLD_DECL
9759 by duplicate_decls. */
9761 }
9762 }
9763 else
9764 {
9768 /* In the code
9769 template <class T> class C {
9770 template <class U> friend void C1<U>::f (); // case 1
9771 friend void C2<T>::f (); // case 2
9772 };
9773 we only need to make sure CONTEXT is a complete type for
9774 case 2. To distinguish between the two cases, we note that
9775 CONTEXT of case 1 remains dependent type after tsubst while
9776 this isn't true for case 2. */
9786 {
9788 /* do_friend adds the TEMPLATE_DECL for any member friend
9789 template even if it isn't a member template, i.e.
9790 template <class T> friend A<T>::f();
9791 Look through it in that case. */
9795 /* Check to see that the declaration is really present, and,
9796 possibly obtain an improved declaration. */
9801 }
9802 }
9805 }
9807 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9808 template arguments, as for tsubst.
9810 Returns an appropriate tsubst'd friend type or error_mark_node on
9811 failure. */
9813 static tree
9815 {
9816 tree friend_type;
9817 tree tmpl;
9818 tree context;
9821 {
9824 }
9829 {
9832 else
9834 }
9836 /* Look for a class template declaration. We look for hidden names
9837 because two friend declarations of the same template are the
9838 same. For example, in:
9840 struct A {
9841 template <typename> friend class F;
9842 };
9843 template <typename> struct B {
9844 template <typename> friend class F;
9845 };
9847 both F templates are the same. */
9851 /* But, if we don't find one, it might be because we're in a
9852 situation like this:
9854 template <class T>
9855 struct S {
9856 template <class U>
9857 friend struct S;
9858 };
9860 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
9861 for `S<int>', not the TEMPLATE_DECL. */
9863 {
9866 }
9869 {
9870 /* The friend template has already been declared. Just
9871 check to see that the declarations match, and install any new
9872 default parameters. We must tsubst the default parameters,
9873 of course. We only need the innermost template parameters
9874 because that is all that redeclare_class_template will look
9875 at. */
9878 {
9879 tree parms;
9880 location_t saved_input_location;
9890 }
9893 }
9894 else
9895 {
9896 /* The friend template has not already been declared. In this
9897 case, the instantiation of the template class will cause the
9898 injection of this template into the global scope. */
9903 /* The new TMPL is not an instantiation of anything, so we
9904 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
9905 the new type because that is supposed to be the corresponding
9906 template decl, i.e., TMPL. */
9913 /* Inject this template into the global scope. */
9915 }
9918 {
9921 else
9923 }
9926 }
9928 /* Returns zero if TYPE cannot be completed later due to circularity.
9929 Otherwise returns one. */
9931 static int
9933 {
9943 else
9945 }
9950 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
9951 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
9953 static tree
9956 {
9965 {
9972 clauses
9976 else
9978 }
9979 /* If the first attribute argument is an identifier, don't
9980 pass it through tsubst. Attributes like mode, format,
9981 cleanup and several target specific attributes expect it
9982 unmodified. */
9984 {
9985 tree chain
9990 }
9992 {
9993 /* An attribute pack expansion. */
10002 {
10006 }
10008 }
10009 else
10016 }
10018 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10019 unchanged or a new TREE_LIST chain. */
10021 static tree
10024 {
10029 {
10033 }
10037 {
10040 {
10043 {
10045 do
10050 }
10051 }
10053 }
10056 }
10058 /* Apply any attributes which had to be deferred until instantiation
10059 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10060 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10062 static void
10065 {
10067 tree t;
10074 {
10078 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10079 to our attributes parameter. */
10081 }
10082 else
10083 {
10085 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10086 lookup_template_class_1, and should be preserved. */
10090 }
10094 {
10098 }
10102 {
10107 {
10110 {
10114 do
10117 }
10118 else
10120 }
10123 }
10124 }
10126 /* Perform (or defer) access check for typedefs that were referenced
10127 from within the template TMPL code.
10128 This is a subroutine of instantiate_decl and instantiate_class_template.
10129 TMPL is the template to consider and TARGS is the list of arguments of
10130 that template. */
10132 static void
10134 {
10135 location_t saved_location;
10146 {
10158 /* Make access check error messages point to the location
10159 of the use of the typedef. */
10163 tf_warning_or_error);
10164 }
10166 }
10168 static tree
10170 {
10172 tree typedecl;
10173 tree pbinfo;
10174 tree base_list;
10176 tree fn_context;
10185 /* Figure out which template is being instantiated. */
10189 /* Determine what specialization of the original template to
10190 instantiate. */
10193 {
10196 }
10198 {
10199 /* This TYPE is actually an instantiation of a partial
10200 specialization. We replace the innermost set of ARGS with
10201 the arguments appropriate for substitution. For example,
10202 given:
10204 template <class T> struct S {};
10205 template <class T> struct S<T*> {};
10207 and supposing that we are instantiating S<int*>, ARGS will
10208 presently be {int*} -- but we need {int}. */
10211 }
10212 else
10213 {
10216 }
10218 /* If the template we're instantiating is incomplete, then clearly
10219 there's nothing we can do. */
10223 /* If we've recursively instantiated too many templates, stop. */
10227 /* Now we're really doing the instantiation. Mark the type as in
10228 the process of being defined. */
10231 /* We may be in the middle of deferred access check. Disable
10232 it now. */
10239 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10244 else
10245 {
10248 }
10249 /* Use #pragma pack from the template context. */
10255 /* Set the input location to the most specialized template definition.
10256 This is needed if tsubsting causes an error. */
10268 {
10271 /* Adjust visibility for template arguments. */
10273 }
10279 /* We should never instantiate a nested class before its enclosing
10280 class; we need to look up the nested class by name before we can
10281 instantiate it, and that lookup should instantiate the enclosing
10282 class. */
10288 {
10289 tree pbase_binfo;
10290 tree pushed_scope;
10293 /* We must enter the scope containing the type, as that is where
10294 the accessibility of types named in dependent bases are
10295 looked up from. */
10298 /* Substitute into each of the bases to determine the actual
10299 basetypes. */
10301 {
10302 tree base;
10308 {
10309 expanded_bases =
10316 }
10319 {
10321 /* Extract the already-expanded base class. */
10323 else
10324 /* Substitute to figure out the base class. */
10326 NULL_TREE);
10334 }
10335 }
10337 /* The list is now in reverse order; correct that. */
10342 }
10343 /* Now call xref_basetypes to set up all the base-class
10344 information. */
10352 /* Now that our base classes are set up, enter the scope of the
10353 class, so that name lookups into base classes, etc. will work
10354 correctly. This is precisely analogous to what we do in
10355 begin_class_definition when defining an ordinary non-template
10356 class, except we also need to push the enclosing classes. */
10359 /* Now members are processed in the order of declaration. */
10362 {
10366 {
10368 {
10369 /* Build new CLASSTYPE_NESTED_UTDS. */
10371 tree newtag;
10377 /* If the member is a class template, then -- even after
10378 substitution -- there may be dependent types in the
10379 template argument list for the class. We increment
10380 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10381 that function will assume that no types are dependent
10382 when outside of a template. */
10392 {
10396 /* Unfortunately, lookup_template_class sets
10397 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10398 instantiation (i.e., for the type of a member
10399 template class nested within a template class.)
10400 This behavior is required for
10401 maybe_process_partial_specialization to work
10402 correctly, but is not accurate in this case;
10403 the TAG is not an instantiation of anything.
10404 (The corresponding TEMPLATE_DECL is an
10405 instantiation, but the TYPE is not.) */
10408 /* Now, we call pushtag to put this NEWTAG into the scope of
10409 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10410 pushtag calling push_template_decl. We don't have to do
10411 this for enums because it will already have been done in
10412 tsubst_enum. */
10416 }
10417 }
10419 {
10420 /* Build new TYPE_METHODS. */
10421 tree r;
10430 /* Instantiate members marked with attribute used. */
10436 }
10439 /* A closure type for a lambda in a default argument for a
10440 member template. Ignore it; it will be instantiated with
10442 else
10443 {
10444 /* Build new TYPE_FIELDS. */
10446 {
10447 tree condition;
10450 condition =
10460 }
10462 {
10463 tree r;
10467 /* The file and line for this declaration, to
10468 assist in error message reporting. Since we
10469 called push_tinst_level above, we don't need to
10470 restore these. */
10480 {
10481 /* A capture pack became multiple fields. */
10484 }
10487 {
10491 {
10492 /* In [temp.inst]:
10494 [t]he initialization (and any associated
10495 side-effects) of a static data member does
10496 not occur unless the static data member is
10497 itself used in a way that requires the
10498 definition of the static data member to
10499 exist.
10501 Therefore, we do not substitute into the
10502 initialized for the static data member here. */
10503 finish_static_data_member_decl
10509 /* Instantiate members marked with attribute used. */
10512 }
10514 {
10515 /* Determine whether R has a valid type and can be
10516 completed later. If R is invalid, then its type
10517 is replaced by error_mark_node. */
10523 {
10524 /* If R's type couldn't be completed and
10525 it isn't a flexible array member (whose
10526 type is incomplete by definition) give
10527 an error. */
10530 }
10531 }
10533 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10534 such a thing will already have been added to the field
10535 list by tsubst_enum in finish_member_declaration in the
10536 CLASSTYPE_NESTED_UTDS case above. */
10540 {
10543 }
10544 }
10545 }
10546 }
10547 }
10548 else
10549 {
10552 {
10553 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10559 {
10560 /* template <class T> friend class C; */
10563 }
10565 {
10566 /* template <class T> friend class C::D; */
10572 }
10575 {
10576 /* This could be either
10578 friend class T::C;
10580 when dependent_type_p is false or
10582 template <class U> friend class T::C;
10584 otherwise. */
10585 /* Bump processing_template_decl in case this is something like
10586 template <class T> friend struct A<T>::B. */
10593 }
10596 {
10597 /* friend class C;
10599 where C hasn't been declared yet. Let's lookup name
10600 from namespace scope directly, bypassing any name that
10601 come from dependent base class. */
10604 /* The call to xref_tag_from_type does injection for friend
10605 classes. */
10607 friend_type =
10611 }
10613 /* friend class C<T>; */
10616 /* Otherwise it's
10618 friend class C;
10620 where C is already declared or
10622 friend class C<int>;
10624 We don't have to do anything in these cases. */
10627 /* Trick make_friend_class into realizing that the friend
10628 we're adding is a template, not an ordinary class. It's
10629 important that we use make_friend_class since it will
10630 perform some error-checking and output cross-reference
10631 information. */
10639 }
10640 else
10641 {
10642 /* Build new DECL_FRIENDLIST. */
10643 tree r;
10645 /* The file and line for this declaration, to
10646 assist in error message reporting. Since we
10647 called push_tinst_level above, we don't need to
10648 restore these. */
10652 {
10655 }
10660 {
10663 }
10664 }
10665 }
10666 }
10669 {
10670 /* Restore these before substituting into the lambda capture
10671 initializers. */
10674 }
10677 {
10680 {
10686 {
10687 /* Set function_depth to avoid garbage collection. */
10691 }
10693 /* We need to instantiate the capture list from the template
10694 after we've instantiated the closure members, but before we
10695 consider adding the conversion op. Also keep any captures
10696 that may have been added during instantiation of the op(). */
10698 tree tmpl_cap
10707 }
10708 else
10710 }
10712 /* Set the file and line number information to whatever is given for
10713 the class itself. This puts error messages involving generated
10714 implicit functions at a predictable point, and the same point
10715 that would be used for non-template classes. */
10722 /* We don't instantiate default arguments for member functions. 14.7.1:
10724 The implicit instantiation of a class template specialization causes
10725 the implicit instantiation of the declarations, but not of the
10726 definitions or default arguments, of the class member functions,
10727 member classes, static data members and member templates.... */
10729 /* Some typedefs referenced from within the template code need to be access
10730 checked at template instantiation time, i.e now. These types were
10731 added to the template at parsing time. Let's get those and perform
10732 the access checks then. */
10742 /* The vtable for a template class can be emitted in any translation
10743 unit in which the class is instantiated. When there is no key
10744 method, however, finish_struct_1 will already have added TYPE to
10745 the keyed_classes list. */
10750 }
10752 /* Wrapper for instantiate_class_template_1. */
10754 tree
10756 {
10757 tree ret;
10762 }
10764 static tree
10766 {
10767 tree r;
10773 else
10774 {
10781 }
10783 }
10785 /* Given a function parameter pack TMPL_PARM and some function parameters
10786 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10787 and set *SPEC_P to point at the next point in the list. */
10789 tree
10791 {
10792 /* Collect all of the extra "packed" parameters into an
10793 argument pack. */
10794 tree parmvec;
10804 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10810 /* Build the argument packs. */
10815 }
10817 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10818 NONTYPE_ARGUMENT_PACK. */
10820 static tree
10822 {
10824 }
10826 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10827 pack expansion with no extra args, 2 if it has extra args, or 0
10828 if it is not a pack expansion. */
10830 static int
10832 {
10838 /* A decl pack is itself an expansion. */
10845 }
10848 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
10850 static tree
10852 {
10859 }
10861 /* This is a subroutine of tsubst_pack_expansion.
10863 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
10864 mechanism to store the (non complete list of) arguments of the
10865 substitution and return a non substituted pack expansion, in order
10866 to wait for when we have enough arguments to really perform the
10867 substitution. */
10869 static bool
10873 {
10874 /* If one pack has an expansion and another pack has a normal
10875 argument or if one pack has an empty argument and an another
10876 one hasn't then tsubst_pack_expansion cannot perform the
10877 substitution and need to fall back on the
10878 PACK_EXPANSION_EXTRA mechanism. */
10886 {
10889 parm_pack;
10891 {
10896 /* We can't substitute a pack expansion with extra args into
10897 our pattern. */
10901 else
10903 }
10907 }
10909 }
10911 /* [temp.variadic]/6 says that:
10913 The instantiation of a pack expansion [...]
10914 produces a list E1,E2, ..., En, where N is the number of elements
10915 in the pack expansion parameters.
10917 This subroutine of tsubst_pack_expansion produces one of these Ei.
10919 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
10920 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
10921 PATTERN, and each TREE_VALUE is its corresponding argument pack.
10922 INDEX is the index 'i' of the element Ei to produce. ARGS,
10923 COMPLAIN, and IN_DECL are the same parameters as for the
10924 tsubst_pack_expansion function.
10926 The function returns the resulting Ei upon successful completion,
10927 or error_mark_node.
10929 Note that this function possibly modifies the ARGS parameter, so
10930 it's the responsibility of the caller to restore it. */
10932 static tree
10934 tree parm_packs,
10936 tree args /* This parm gets
10938 tsubst_flags_t complain,
10939 tree in_decl)
10940 {
10941 tree t;
10944 /* For each parameter pack, change the substitution of the parameter
10945 pack to the ith argument in its argument pack, then expand the
10946 pattern. */
10948 {
10953 ith_elem_is_expansion |=
10956 /* Select the Ith argument from the pack. */
10959 {
10961 {
10966 }
10967 else
10969 }
10970 else
10971 {
10976 {
10978 /* Update the corresponding argument. */
10980 }
10981 else
10982 /* Re-use the ARGUMENT_PACK_SELECT. */
10984 }
10986 }
10988 /* Substitute into the PATTERN with the (possibly altered)
10989 arguments. */
10991 /* Expanding a fixed parameter pack from
10992 coerce_template_parameter_pack. */
10997 {
11000 else
11003 }
11007 else
11010 /* If the Ith argument pack element is a pack expansion, then
11011 the Ith element resulting from the substituting is going to
11012 be a pack expansion as well. */
11017 }
11019 /* When the unexpanded parameter pack in a fold expression expands to an empty
11020 sequence, the value of the expression is as follows; the program is
11021 ill-formed if the operator is not listed in this table.
11023 && true
11024 || false
11025 , void() */
11027 tree
11029 {
11033 {
11042 }
11048 }
11050 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11051 form an expression that combines the two terms using the
11052 operator of T. */
11054 static tree
11056 {
11060 // Handle compound assignment operators.
11065 {
11075 complain);
11076 }
11077 }
11079 /* Substitute ARGS into the pack of a fold expression T. */
11083 {
11085 }
11087 /* Substitute ARGS into the pack of a fold expression T. */
11091 {
11093 }
11095 /* Expand a PACK of arguments into a grouped as left fold.
11096 Given a pack containing elements A0, A1, ..., An and an
11097 operator @, this builds the expression:
11099 ((A0 @ A1) @ A2) ... @ An
11101 Note that PACK must not be empty.
11103 The operator is defined by the original fold expression T. */
11105 static tree
11107 {
11110 {
11113 }
11115 }
11117 /* Substitute into a unary left fold expression. */
11119 static tree
11121 tree in_decl)
11122 {
11127 {
11131 }
11134 else
11136 }
11138 /* Substitute into a binary left fold expression.
11140 Do ths by building a single (non-empty) vector of argumnts and
11141 building the expression from those elements. */
11143 static tree
11145 tree in_decl)
11146 {
11155 {
11160 }
11168 }
11170 /* Expand a PACK of arguments into a grouped as right fold.
11171 Given a pack containing elementns A0, A1, ..., and an
11172 operator @, this builds the expression:
11174 A0@ ... (An-2 @ (An-1 @ An))
11176 Note that PACK must not be empty.
11178 The operator is defined by the original fold expression T. */
11180 tree
11182 {
11183 // Build the expression.
11187 {
11190 }
11192 }
11194 /* Substitute into a unary right fold expression. */
11196 static tree
11198 tree in_decl)
11199 {
11204 {
11208 }
11211 else
11213 }
11215 /* Substitute into a binary right fold expression.
11217 Do ths by building a single (non-empty) vector of arguments and
11218 building the expression from those elements. */
11220 static tree
11222 tree in_decl)
11223 {
11232 {
11237 }
11246 }
11249 /* Substitute ARGS into T, which is an pack expansion
11250 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11251 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11252 (if only a partial substitution could be performed) or
11253 ERROR_MARK_NODE if there was an error. */
11254 tree
11256 tree in_decl)
11257 {
11258 tree pattern;
11262 tree result;
11270 /* Add in any args remembered from an earlier partial instantiation. */
11275 /* Determine the argument packs that will instantiate the parameter
11276 packs used in the expansion expression. While we're at it,
11277 compute the number of arguments to be expanded and make sure it
11278 is consistent. */
11281 {
11288 {
11292 else
11295 }
11297 {
11298 /* We know we have correct local_specializations if this
11299 expansion is at function scope, or if we're dealing with a
11300 local parameter in a requires expression; for the latter,
11301 tsubst_requires_expr set it up appropriately. */
11304 else
11305 /* We can't rely on local_specializations for a parameter
11306 name used later in a function declaration (such as in a
11307 late-specified return type). Even if it exists, it might
11308 have the wrong value for a recursive call. */
11312 {
11313 /* This parameter pack was used in an unevaluated context. Just
11314 make a dummy decl, since it's only used for its type. */
11317 /* Partial instantiation of the parm_pack, we can't build
11318 up an argument pack yet. */
11320 else
11322 }
11323 }
11326 else
11327 {
11333 }
11340 /* This can only happen if we forget to expand an argument
11341 pack somewhere else. Just return an error, silently. */
11342 {
11346 }
11349 {
11353 /* Don't bother trying to do a partial substitution with
11354 incomplete packs; we'll try again after deduction. */
11361 {
11366 pattern);
11367 else
11369 pattern);
11371 }
11373 /* Keep track of the parameter packs and their corresponding
11374 argument packs. */
11377 }
11378 else
11379 {
11380 /* We can't substitute for this parameter pack. We use a flag as
11381 well as the missing_level counter because function parameter
11382 packs don't have a level. */
11385 }
11386 }
11388 /* If the expansion is just T..., return the matching argument pack, unless
11389 we need to call convert_from_reference on all the elements. This is an
11390 important optimization; see c++/68422. */
11393 {
11395 /* Types need no adjustment, nor does sizeof..., and if we still have
11396 some pack expansion args we won't do anything yet. */
11401 /* Also optimize expression pack expansions if we can tell that the
11402 elements won't have reference type. */
11408 /* Otherwise use the normal path so we get convert_from_reference. */
11409 }
11411 /* We cannot expand this expansion expression, because we don't have
11412 all of the argument packs we need. */
11414 {
11415 /* We got some full packs, but we can't substitute them in until we
11416 have values for all the packs. So remember these until then. */
11421 }
11423 {
11424 /* There were no real arguments, we're just replacing a parameter
11425 pack with another version of itself. Substitute into the
11426 pattern and return a PACK_EXPANSION_*. The caller will need to
11427 deal with that. */
11431 else
11435 }
11440 {
11441 /* We're in a late-specified return type, so create our own local
11442 specializations map; the current map is either NULL or (in the
11443 case of recursive unification) might have bindings that we don't
11444 want to use or alter. */
11447 }
11449 /* For each argument in each argument pack, substitute into the
11450 pattern. */
11454 {
11456 i,
11458 in_decl);
11461 {
11464 }
11465 }
11467 /* Update ARGS to restore the substitution from parameter packs to
11468 their argument packs. */
11470 {
11476 else
11477 {
11485 /* Update the corresponding argument. */
11489 else
11491 }
11492 }
11495 {
11498 }
11500 /* If the dependent pack arguments were such that we end up with only a
11501 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11507 }
11509 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11510 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11511 parameter packs; all parms generated from a function parameter pack will
11512 have the same DECL_PARM_INDEX. */
11514 tree
11516 {
11518 tree patparm;
11521 {
11527 }
11528 else
11529 {
11534 }
11537 }
11539 /* Make an argument pack out of the TREE_VEC VEC. */
11541 static tree
11543 {
11544 tree pack;
11548 else
11549 {
11552 }
11555 }
11557 /* Return an exact copy of template args T that can be modified
11558 independently. */
11560 static tree
11562 {
11570 {
11575 }
11581 }
11583 /* Substitute ARGS into the vector or list of template arguments T. */
11585 static tree
11587 {
11599 {
11601 tree new_arg;
11606 {
11607 /* Substitute into an expansion expression. */
11611 /* Add to the expanded length adjustment the number of
11612 expanded arguments. We subtract one from this
11613 measurement, because the argument pack expression
11614 itself is already counted as 1 in
11615 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11616 the argument pack is empty. */
11618 }
11620 {
11621 /* Substitute into each of the arguments. */
11630 else
11635 }
11636 else
11645 }
11650 /* Make space for the expanded arguments coming from template
11651 argument packs. */
11653 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11654 arguments for a member template.
11655 In that case each TREE_VEC in ORIG_T represents a level of template
11656 arguments, and ORIG_T won't carry any non defaulted argument count.
11657 It will rather be the nested TREE_VECs that will carry one.
11658 In other words, ORIG_T carries a non defaulted argument count only
11659 if it doesn't contain any nested TREE_VEC. */
11661 {
11665 }
11667 {
11671 {
11674 /* Now expand the template argument pack "in place". */
11677 }
11678 else
11679 {
11681 out++;
11682 }
11683 }
11686 }
11688 /* Substitute ARGS into one level PARMS of template parameters. */
11690 static tree
11692 {
11699 {
11707 }
11710 }
11712 /* Return the result of substituting ARGS into the template parameters
11713 given by PARMS. If there are m levels of ARGS and m + n levels of
11714 PARMS, then the result will contain n levels of PARMS. For
11715 example, if PARMS is `template <class T> template <class U>
11716 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11717 result will be `template <int*, double, class V>'. */
11719 static tree
11721 {
11725 /* When substituting into a template, we must set
11726 PROCESSING_TEMPLATE_DECL as the template parameters may be
11727 dependent if they are based on one-another, and the dependency
11728 predicates are short-circuit outside of templates. */
11735 {
11742 }
11747 }
11749 /* Return the result of substituting ARGS into one template parameter
11750 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11751 parameter and which TREE_PURPOSE is the default argument of the
11752 template parameter. */
11754 static tree
11756 {
11777 }
11779 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11780 type T. If T is not an aggregate or enumeration type, it is
11781 handled as if by tsubst. IN_DECL is as for tsubst. If
11782 ENTERING_SCOPE is nonzero, T is the context for a template which
11783 we are presently tsubst'ing. Return the substituted value. */
11785 static tree
11787 tree args,
11788 tsubst_flags_t complain,
11789 tree in_decl,
11791 {
11796 {
11801 /* Fall through. */
11805 {
11806 tree argvec;
11807 tree context;
11808 tree r;
11812 /* In "sizeof(X<I>)" we need to evaluate "I". */
11818 /* First, determine the context for the type we are looking
11819 up. */
11822 {
11825 /* If context is a nested class inside a class template,
11826 it may still need to be instantiated (c++/33959). */
11828 }
11830 /* Then, figure out what arguments are appropriate for the
11831 type we are trying to find. For example, given:
11833 template <class T> struct S;
11834 template <class T, class U> void f(T, U) { S<U> su; }
11836 and supposing that we are instantiating f<int, double>,
11837 then our ARGS will be {int, double}, but, when looking up
11838 S we only want {double}. */
11843 else
11844 {
11848 }
11854 }
11855 else
11856 /* This is not a template type, so there's nothing to do. */
11861 }
11862 }
11864 /* Substitute into the default argument ARG (a default argument for
11865 FN), which has the indicated TYPE. */
11867 tree
11869 {
11874 /* This can happen in invalid code. */
11878 /* This default argument came from a template. Instantiate the
11879 default argument here, not in tsubst. In the case of
11880 something like:
11882 template <class T>
11883 struct S {
11884 static T t();
11885 void f(T = t());
11886 };
11888 we must be careful to do name lookup in the scope of S<T>,
11889 rather than in the current class. */
11891 /* The "this" pointer is not valid in a default argument. */
11893 {
11898 }
11901 /* The default argument expression may cause implicitly defined
11902 member functions to be synthesized, which will result in garbage
11903 collection. We must treat this situation as if we were within
11904 the body of function so as to avoid collecting live data on the
11905 stack. */
11913 /* Restore the "this" pointer. */
11915 {
11918 }
11925 /* Make sure the default argument is reasonable. */
11931 }
11933 /* Substitute into all the default arguments for FN. */
11935 static void
11937 {
11938 tree arg;
11939 tree tmpl_args;
11943 /* If this function is not yet instantiated, we certainly don't need
11944 its default arguments. */
11947 /* Don't do this again for clones. */
11952 arg;
11958 complain);
11959 }
11961 /* Substitute the ARGS into the T, which is a _DECL. Return the
11962 result of the substitution. Issue error and warning messages under
11963 control of COMPLAIN. */
11965 static tree
11967 {
11968 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
11969 location_t saved_loc;
11974 /* Set the filename and linenumber to improve error-reporting. */
11979 {
11981 {
11982 /* We can get here when processing a member function template,
11983 member class template, or template template parameter. */
11985 tree spec;
11986 tree tmpl_args;
11987 tree full_args;
11990 {
11991 /* Template template parameter is treated here. */
11995 /* If we get a real template back, return it. This can happen in
11996 the context of most_specialized_partial_spec. */
11999 else
12000 /* The new TEMPLATE_DECL was built in
12001 reduce_template_parm_level. */
12004 }
12006 /* We might already have an instance of this template.
12007 The ARGS are for the surrounding class type, so the
12008 full args contain the tsubst'd args for the context,
12009 plus the innermost args from the template decl. */
12013 /* Because this is a template, the arguments will still be
12014 dependent, even after substitution. If
12015 PROCESSING_TEMPLATE_DECL is not set, the dependency
12016 predicates will short-circuit. */
12024 /* If this is a default template template argument,
12025 tsubst might not have changed anything. */
12032 {
12035 }
12037 /* Make a new template decl. It will be similar to the
12038 original, but will record the current template arguments.
12039 We also create a new function declaration, which is just
12040 like the old one, but points to this new template, rather
12041 than the old one. */
12046 // Build new template info linking to the original template decl.
12051 {
12052 tree new_type;
12060 /* For a partial specialization, we need to keep pointing to
12061 the primary template. */
12067 }
12068 else
12069 {
12070 tree new_decl;
12082 }
12088 /* The template parameters for this new template are all the
12089 template parameters for the old template, except the
12090 outermost level of parameters. */
12093 complain);
12099 /* Record this non-type partial instantiation. */
12103 }
12107 {
12108 tree ctx;
12111 tree gen_tmpl;
12112 tree type;
12117 /* Nobody should be tsubst'ing into non-template functions. */
12121 {
12122 tree spec;
12124 /* If T is not dependent, just return it. */
12128 /* Calculate the most general template of which R is a
12129 specialization, and the complete set of arguments used to
12130 specialize R. */
12133 (DECL_TEMPLATE_RESULT
12139 /* Check to see if we already have this specialization. */
12144 {
12147 }
12149 /* We can see more levels of arguments than parameters if
12150 there was a specialization of a member template, like
12151 this:
12153 template <class T> struct S { template <class U> void f(); }
12154 template <> template <class U> void S<int>::f(U);
12156 Here, we'll be substituting into the specialization,
12157 because that's where we can find the code we actually
12158 want to generate, but we'll have enough arguments for
12159 the most general template.
12161 We also deal with the peculiar case:
12163 template <class T> struct S {
12164 template <class U> friend void f();
12165 };
12166 template <class U> void f() {}
12167 template S<int>;
12168 template void f<double>();
12170 Here, the ARGS for the instantiation of will be {int,
12171 double}. But, we only need as many ARGS as there are
12172 levels of template parameters in CODE_PATTERN. We are
12173 careful not to get fooled into reducing the ARGS in
12174 situations like:
12176 template <class T> struct S { template <class U> void f(U); }
12177 template <class T> template <> void S<T>::f(int) {}
12179 which we can spot because the pattern will be a
12180 specialization in this case. */
12182 parms_depth =
12187 }
12188 else
12189 {
12190 /* This special case arises when we have something like this:
12192 template <class T> struct S {
12193 friend void f<int>(int, double);
12194 };
12196 Here, the DECL_TI_TEMPLATE for the friend declaration
12197 will be an IDENTIFIER_NODE. We are being called from
12198 tsubst_friend_function, and we want only to create a
12199 new decl (R) with appropriate types so that we can call
12200 determine_specialization. */
12202 }
12205 {
12208 else
12212 }
12213 else
12214 {
12217 }
12222 /* If we hit excessive deduction depth, the type is bogus even if
12223 it isn't error_mark_node, so don't build a decl. */
12227 /* We do NOT check for matching decls pushed separately at this
12228 point, as they may not represent instantiations of this
12229 template, and in any case are considered separate under the
12230 discrete model. */
12234 /* Clear out the mangled name and RTL for the instantiation. */
12237 /* Leave DECL_INITIAL set on deleted instantiations. */
12242 /* OpenMP UDRs have the only argument a reference to the declared
12243 type. We want to diagnose if the declared type is a reference,
12244 which is invalid, but as references to references are usually
12245 quietly merged, diagnose it here. */
12247 {
12248 tree argtype
12253 "reference type %qT in "
12257 argtype);
12258 }
12261 /* Type-conversion operator. Reconstruct the name, in
12262 case it's the name of one of the template's parameters. */
12272 /* If this is an instantiation of a function with internal
12273 linkage, we already know what object file linkage will be
12274 assigned to the instantiation. */
12283 /* We'll re-clone as appropriate in instantiate_template. */
12286 /* If we aren't complaining now, return on error before we register
12287 the specialization so that we'll complain eventually. */
12293 /* When instantiating a constrained member, substitute
12294 into the constraints to create a new constraint. */
12297 {
12300 }
12302 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12303 this in the special friend case mentioned above where
12304 GEN_TMPL is NULL. */
12306 {
12311 tree new_r
12314 /* We instantiated this while substituting into
12315 the type earlier (template/friend54.C). */
12318 /* We're not supposed to instantiate default arguments
12319 until they are called, for a template. But, for a
12320 declaration like:
12322 template <class T> void f ()
12323 { extern void g(int i = T()); }
12325 we should do the substitution when the template is
12326 instantiated. We handle the member function case in
12327 instantiate_class_template since the default arguments
12328 might refer to other members of the class. */
12333 }
12334 else
12337 /* Copy the list of befriending classes. */
12341 {
12345 in_decl);
12346 }
12349 {
12353 /* If this is an instantiation of a member template, clone it.
12354 If it isn't, that'll be handled by
12355 clone_constructors_and_destructors. */
12358 }
12369 /* Possibly limit visibility based on template args. */
12372 {
12376 }
12384 }
12388 {
12396 {
12397 /* If there is a local specialization that isn't a
12398 parameter pack, it means that we're doing a "simple"
12399 substitution from inside tsubst_pack_expansion. Just
12400 return the local specialization (which will be a single
12401 parm). */
12408 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12409 the parameters in this function parameter pack. */
12413 {
12416 /* Zero-length parameter packs are boring. Just substitute
12417 into the chain. */
12421 }
12422 else
12423 {
12424 /* All we did was update the type. Make a note of that. */
12427 }
12428 }
12430 /* Loop through all of the parameters we'll build. When T is
12431 a function parameter pack, LEN is the number of expanded
12432 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12435 {
12442 /* We're on the Ith parameter of the function parameter
12443 pack. */
12444 {
12445 /* Get the Ith type. */
12448 /* Rename the parameter to include the index. */
12451 }
12453 /* We're dealing with a normal parameter. */
12461 {
12464 else
12467 }
12477 /* Keep track of the first new parameter we
12478 generate. That's what will be returned to the
12479 caller. */
12483 /* Build a proper chain of parameters when substituting
12484 into a function parameter pack. */
12487 }
12489 /* If cp_unevaluated_operand is set, we're just looking for a
12490 single dummy parameter, so don't keep going. */
12495 /* FIRST_R contains the start of the chain we've built. */
12497 }
12501 {
12508 {
12509 /* This field is a lambda capture pack. Return a TREE_VEC of
12510 the expanded fields to instantiate_class_template_1 and
12511 store them in the specializations hash table as a
12512 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12516 {
12519 }
12520 else
12521 {
12522 /* All we did was update the type. Make a note of that. */
12525 }
12526 }
12529 {
12532 {
12536 }
12546 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12547 non-bit-fields DECL_INITIAL is a non-static data member
12548 initializer, which gets deferred instantiation. */
12554 {
12555 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12556 NSDMI in perform_member_init. Still set DECL_INITIAL
12557 so that we know there is one. */
12562 }
12563 /* We don't have to set DECL_CONTEXT here; it is set by
12564 finish_member_declaration. */
12572 }
12575 {
12580 }
12581 }
12585 /* We reach here only for member using decls. We also need to check
12586 uses_template_parms because DECL_DEPENDENT_P is not set for a
12587 using-declaration that designates a member of the current
12588 instantiation (c++/53549). */
12591 {
12595 {
12600 {
12604 {
12607 }
12608 else
12609 {
12612 }
12614 }
12615 }
12616 else
12617 {
12623 else
12624 {
12627 }
12628 }
12629 }
12630 else
12631 {
12634 }
12639 {
12642 tree spec;
12644 tree ctx;
12653 {
12654 /* If this is the canonical decl, we don't have to
12655 mess with instantiations, and often we can't (for
12656 typename, template type parms and such). Note that
12657 TYPE_NAME is not correct for the above test if
12658 we've copied the type for a typedef. */
12664 }
12666 /* Check to see if we already have the specialization we
12667 need. */
12670 {
12671 /* T is a static data member or namespace-scope entity.
12672 We have to substitute into namespace-scope variables
12673 (not just variable templates) because of cases like:
12675 template <class T> void f() { extern T t; }
12677 where the entity referenced is not known until
12678 instantiation time. */
12682 {
12684 complain,
12686 /* If CTX is unchanged, then T is in fact the
12687 specialization we want. That situation occurs when
12688 referencing a static data member within in its own
12689 class. We can use pointer equality, rather than
12690 same_type_p, because DECL_CONTEXT is always
12691 canonical... */
12693 /* ... unless T is a member template; in which
12694 case our caller can be willing to create a
12695 specialization of that template represented
12696 by T. */
12700 }
12703 {
12708 argvec = (coerce_innermost_template_parms
12716 }
12717 }
12718 else
12719 {
12720 /* A local variable. */
12722 /* Subsequent calls to pushdecl will fill this in. */
12724 /* Unless this is a reference to a static variable from an
12725 enclosing function, in which case we need to fill it in now. */
12727 {
12731 }
12733 }
12734 /* If we already have the specialization we need, there is
12735 nothing more to do. */
12737 {
12740 }
12742 /* Create a new node for the specialization we need. */
12745 {
12748 else
12755 }
12757 {
12758 /* Even if the original location is out of scope, the
12759 newly substituted one is not. */
12766 {
12767 /* It may seem that this case cannot occur, since:
12769 typedef void f();
12770 void g() { f x; }
12772 declares a function, not a variable. However:
12774 typedef void f();
12775 template <typename T> void g() { T t; }
12776 template void g<f>();
12778 is an attempt to declare a variable with function
12779 type. */
12781 /* R is not yet sufficiently initialized, so we
12782 just use its name. */
12785 }
12787 /* Wait until cp_finish_decl to set this again, to handle
12788 circular dependency (template/instantiate6.C). */
12793 {
12798 {
12801 }
12803 }
12807 }
12813 /* Clear out the mangled name and RTL for the instantiation. */
12817 /* The initializer must not be expanded until it is required;
12818 see [temp.inst]. */
12826 {
12827 /* Possibly limit visibility based on template args. */
12830 {
12834 }
12836 }
12839 {
12840 /* A static data member declaration is always marked
12841 external when it is declared in-class, even if an
12842 initializer is present. We mimic the non-template
12843 processing here. */
12851 }
12852 else
12853 {
12858 }
12866 /* Preserve a typedef that names a type. */
12868 {
12872 /* An alias template specialization can be dependent
12873 even if its underlying type is not. */
12875 }
12878 }
12883 }
12884 #undef RETURN
12886 out:
12887 /* Restore the file and line information. */
12891 }
12893 /* Substitute into the ARG_TYPES of a function type.
12894 If END is a TREE_CHAIN, leave it and any following types
12895 un-substituted. */
12897 static tree
12899 tree args,
12900 tree end,
12901 tsubst_flags_t complain,
12902 tree in_decl)
12903 {
12904 tree remaining_arg_types;
12908 tree default_arg;
12919 {
12920 /* For a pack expansion, perform substitution on the
12921 entire expression. Later on, we'll handle the arguments
12922 one-by-one. */
12927 /* So that we'll spin through the parameters, one by one. */
12929 else
12930 {
12931 /* We only partially substituted into the parameter
12932 pack. Our type is TYPE_PACK_EXPANSION. */
12935 }
12936 }
12949 {
12951 {
12955 }
12957 }
12958 /* DR 657. */
12962 /* Do array-to-pointer, function-to-pointer conversion, and ignore
12963 top-level qualifiers as required. */
12966 /* We do not substitute into default arguments here. The standard
12967 mandates that they be instantiated only when needed, which is
12968 done in build_over_call. */
12972 {
12973 /* We've instantiated a template before its default arguments
12974 have been parsed. This can happen for a nested template
12975 class, and is not an error unless we require the default
12976 argument in a call of this function. */
12977 remaining_arg_types =
12980 }
12981 else
12982 remaining_arg_types =
12984 }
12987 }
12989 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
12990 *not* handle the exception-specification for FNTYPE, because the
12991 initial substitution of explicitly provided template parameters
12992 during argument deduction forbids substitution into the
12993 exception-specification:
12995 [temp.deduct]
12997 All references in the function type of the function template to the
12998 corresponding template parameters are replaced by the specified tem-
12999 plate argument values. If a substitution in a template parameter or
13000 in the function type of the function template results in an invalid
13001 type, type deduction fails. [Note: The equivalent substitution in
13002 exception specifications is done only when the function is instanti-
13003 ated, at which point a program is ill-formed if the substitution
13004 results in an invalid type.] */
13006 static tree
13008 tree args,
13009 tsubst_flags_t complain,
13010 tree in_decl)
13011 {
13012 tree return_type;
13014 tree fntype;
13016 /* The TYPE_CONTEXT is not used for function/method types. */
13019 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13020 failure. */
13024 {
13025 /* Substitute the argument types. */
13037 {
13038 /* DR 1207: 'this' is in scope in the trailing return type. */
13040 }
13042 /* Substitute the return type. */
13046 {
13049 }
13050 }
13051 else
13052 /* Substitute the return type. */
13057 /* DR 486 clarifies that creation of a function type with an
13058 invalid return type is a deduction failure. */
13061 {
13063 {
13066 else
13068 }
13070 }
13071 /* And DR 657. */
13076 {
13077 /* Substitute the argument types. */
13082 }
13084 /* Construct a new type node and return it. */
13086 {
13091 }
13092 else
13093 {
13095 /* Don't pick up extra function qualifiers from the basetype. */
13098 {
13099 /* [temp.deduct]
13101 Type deduction may fail for any of the following
13102 reasons:
13104 -- Attempting to create "pointer to member of T" when T
13105 is not a class type. */
13108 r);
13110 }
13115 }
13122 }
13124 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13125 ARGS into that specification, and return the substituted
13126 specification. If there is no specification, return NULL_TREE. */
13128 static tree
13130 tree args,
13131 tsubst_flags_t complain,
13132 tree in_decl,
13134 {
13135 tree specs;
13136 tree new_specs;
13141 {
13142 /* A noexcept-specifier. */
13147 {
13148 /* Defer instantiation of noexcept-specifiers to avoid
13149 excessive instantiations (c++/49107). */
13152 {
13153 /* We already partially instantiated this member template,
13154 so combine the new args with the old. */
13159 }
13160 else
13161 {
13164 }
13165 }
13166 else
13167 new_specs = tsubst_copy_and_build
13171 }
13173 {
13176 else
13178 {
13179 tree spec;
13184 {
13185 /* Expand the pack expansion type. */
13188 in_decl);
13194 else
13195 {
13196 /* We're substituting into a member template, so
13197 we got a TYPE_PACK_EXPANSION back. Add that
13198 expansion and move on. */
13202 expanded_specs,
13203 complain);
13206 }
13207 }
13210 {
13213 else
13218 complain);
13219 }
13222 }
13223 }
13225 }
13227 /* Take the tree structure T and replace template parameters used
13228 therein with the argument vector ARGS. IN_DECL is an associated
13229 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13230 Issue error and warning messages under control of COMPLAIN. Note
13231 that we must be relatively non-tolerant of extensions here, in
13232 order to preserve conformance; if we allow substitutions that
13233 should not be allowed, we may allow argument deductions that should
13234 not succeed, and therefore report ambiguous overload situations
13235 where there are none. In theory, we could allow the substitution,
13236 but indicate that it should have failed, and allow our caller to
13237 make sure that the right thing happens, but we don't try to do this
13238 yet.
13240 This function is used for dealing with types, decls and the like;
13241 for expressions, use tsubst_expr or tsubst_copy. */
13243 tree
13245 {
13268 else
13273 /* Reuse typedefs. We need to do this to handle dependent attributes,
13274 such as attribute aligned. */
13277 {
13281 {
13282 /* DECL represents an alias template and we want to
13283 instantiate it. */
13287 }
13291 {
13295 }
13300 else
13301 /* The typedef is from a non-template context. */
13305 {
13307 r = cp_build_qualified_type_real
13311 }
13312 else
13313 {
13314 /* We don't have an instantiation yet, so drop the typedef. */
13319 }
13320 }
13337 {
13363 {
13369 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13370 needed. */
13376 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13377 with TREE_SIDE_EFFECTS that indicates this is not an integral
13378 constant expression. */
13381 {
13384 }
13387 }
13393 {
13399 /* Early in template argument deduction substitution, we don't
13400 want to reduce the level of 'auto', or it will be confused
13401 with a normal template parm in subsequent deduction. */
13413 {
13417 {
13418 /* See through ARGUMENT_PACK_SELECT arguments. */
13420 /* If the selected argument is an expansion E, that most
13421 likely means we were called from
13422 gen_elem_of_pack_expansion_instantiation during the
13423 substituting of pack an argument pack (which Ith
13424 element is a pack expansion, where I is
13425 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13426 In this case, the Ith element resulting from this
13427 substituting is going to be a pack expansion, which
13428 pattern is the pattern of E. Let's return the
13429 pattern of E, and
13430 gen_elem_of_pack_expansion_instantiation will
13431 build the resulting pack expansion from it. */
13433 {
13434 /* Make sure we aren't throwing away arg info. */
13437 }
13438 }
13439 }
13444 {
13446 /* If ARG is an argument pack, we don't actually want to
13447 perform a substitution here, because substitutions
13448 for argument packs are only done
13449 element-by-element. We can get to this point when
13450 substituting the type of a non-type template
13451 parameter pack, when that type actually contains
13452 template parameter packs from an outer template, e.g.,
13454 template<typename... Types> struct A {
13455 template<Types... Values> struct B { };
13456 }; */
13460 {
13466 return cp_build_qualified_type_real
13468 }
13470 {
13471 /* We are processing a type constructed from a
13472 template template parameter. */
13483 /* Consider this code:
13485 template <template <class> class Template>
13486 struct Internal {
13487 template <class Arg> using Bind = Template<Arg>;
13488 };
13490 template <template <class> class Template, class Arg>
13491 using Instantiate = Template<Arg>; //#0
13493 template <template <class> class Template,
13494 class Argument>
13495 using Bind =
13496 Instantiate<Internal<Template>::template Bind,
13497 Argument>; //#1
13499 When #1 is parsed, the
13500 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13501 parameter `Template' in #0 matches the
13502 UNBOUND_CLASS_TEMPLATE representing the argument
13503 `Internal<Template>::template Bind'; We then want
13504 to assemble the type `Bind<Argument>' that can't
13505 be fully created right now, because
13506 `Internal<Template>' not being complete, the Bind
13507 template cannot be looked up in that context. So
13508 we need to "store" `Bind<Argument>' for later
13509 when the context of Bind becomes complete. Let's
13510 store that in a TYPENAME_TYPE. */
13514 argvec),
13515 typename_type,
13516 complain);
13518 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13519 are resolving nested-types in the signature of a
13520 member function templates. Otherwise ARG is a
13521 TEMPLATE_DECL and is the real template to be
13522 instantiated. */
13530 complain);
13531 return cp_build_qualified_type_real
13533 }
13536 else
13537 /* TEMPLATE_PARM_INDEX. */
13539 }
13542 /* This can happen during the attempted tsubst'ing in
13543 unify. This means that we don't yet have any information
13544 about the template parameter in question. */
13547 /* If we get here, we must have been looking at a parm for a
13548 more deeply nested template. Make a new version of this
13549 template parameter, but with a lower level. */
13551 {
13556 {
13558 r = cp_build_qualified_type_real
13562 }
13569 /* Break infinite recursion when substituting the constraints
13571 else
13572 {
13583 {
13584 /* Propagate constraints on placeholders. */
13589 {
13593 }
13594 }
13597 /* We have reduced the level of the template
13598 template parameter, but not the levels of its
13599 template parameters, so canonical_type_parameter
13600 will not be able to find the canonical template
13601 template parameter for this level. Thus, we
13602 require structural equality checking to compare
13603 TEMPLATE_TEMPLATE_PARMs. */
13607 else
13611 {
13613 /* We might need to substitute into the types of non-type
13614 template parameters. */
13626 }
13627 }
13631 /* OK, now substitute the type of the non-type parameter. We
13632 couldn't do it earlier because it might be an auto parameter,
13633 and we wouldn't need to if we had an argument. */
13640 }
13643 }
13646 {
13654 {
13658 }
13661 {
13665 }
13668 {
13672 }
13678 }
13681 /* We should never be tsubsting a binfo. */
13685 /* A vector of template arguments. */
13691 {
13695 /* [temp.deduct]
13697 Type deduction may fail for any of the following
13698 reasons:
13700 -- Attempting to create a pointer to reference type.
13701 -- Attempting to create a reference to a reference type or
13702 a reference to void.
13704 Core issue 106 says that creating a reference to a reference
13705 during instantiation is no longer a cause for failure. We
13706 only enforce this check in strict C++98 mode. */
13710 {
13713 /* We keep track of the last time we issued this error
13714 message to avoid spewing a ton of messages during a
13715 single bad template instantiation. */
13718 {
13723 else
13726 }
13729 }
13733 {
13735 {
13738 type);
13739 else
13741 type);
13742 }
13744 }
13746 {
13750 }
13752 /* In C++0x, during template argument substitution, when there is an
13753 attempt to create a reference to a reference type, reference
13754 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13756 "If a template-argument for a template-parameter T names a type
13757 that is a reference to a type A, an attempt to create the type
13758 'lvalue reference to cv T' creates the type 'lvalue reference to
13759 A,' while an attempt to create the type type rvalue reference to
13760 cv T' creates the type T"
13761 */
13762 r = cp_build_reference_type
13765 else
13770 /* Will this ever be needed for TYPE_..._TO values? */
13774 }
13776 {
13779 {
13780 /* [temp.deduct]
13782 Type deduction may fail for any of the following
13783 reasons:
13785 -- Attempting to create "pointer to member of T" when T
13786 is not a class type. */
13790 }
13792 {
13796 }
13798 {
13802 }
13805 {
13806 /* The type of the implicit object parameter gets its
13807 cv-qualifiers from the FUNCTION_TYPE. */
13808 tree memptr;
13809 tree method_type
13814 complain);
13815 }
13816 else
13819 complain);
13820 }
13823 {
13824 tree fntype;
13825 tree specs;
13830 /* Substitute the exception specification. */
13838 }
13840 {
13845 /* As an optimization, we avoid regenerating the array type if
13846 it will obviously be the same as T. */
13850 /* These checks should match the ones in create_array_type_for_decl.
13852 [temp.deduct]
13854 The deduction may fail for any of the following reasons:
13856 -- Attempting to create an array with an element type that
13857 is void, a function type, or a reference type, or [DR337]
13858 an abstract class type. */
13864 {
13868 }
13876 {
13879 }
13882 }
13885 {
13897 {
13901 }
13903 {
13904 /* Normally, make_typename_type does not require that the CTX
13905 have complete type in order to allow things like:
13907 template <class T> struct S { typename S<T>::X Y; };
13909 But, such constructs have already been resolved by this
13910 point, so here CTX really should have complete type, unless
13911 it's a partial instantiation. */
13914 {
13918 }
13919 }
13926 {
13929 }
13932 {
13934 {
13938 else
13940 }
13942 {
13946 else
13948 }
13949 }
13951 return cp_build_qualified_type_real
13953 }
13956 {
13968 }
13971 {
13972 tree type;
13988 complain);
13989 }
13992 {
13993 tree type;
14004 {
14006 {
14010 }
14013 }
14024 else
14025 {
14029 /* In a template ~id could be either a complement expression
14030 or an unqualified-id naming a destructor; if instantiating
14031 it produces an expression, it's not an id-expression or
14032 member access. */
14035 }
14040 }
14043 {
14047 }
14051 {
14052 tree r;
14056 else
14064 }
14079 /* We should use one of the expression tsubsts for these codes. */
14085 }
14086 }
14088 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
14089 type of the expression on the left-hand side of the "." or "->"
14090 operator. */
14092 static tree
14095 {
14096 tree name;
14097 tree qualifying_scope;
14098 tree fns;
14099 tree optype;
14104 /* A baselink indicates a function from a base class. Both the
14105 BASELINK_ACCESS_BINFO and the base class referenced may
14106 indicate bases of the template class, rather than the
14107 instantiated class. In addition, lookups that were not
14108 ambiguous before may be ambiguous now. Therefore, we perform
14109 the lookup again. */
14116 {
14123 }
14129 {
14131 {
14135 }
14137 }
14139 /* If lookup found a single function, mark it as used at this
14140 point. (If it lookup found multiple functions the one selected
14141 later by overload resolution will be marked as used at that
14142 point.) */
14149 /* Add back the template arguments, if present. */
14153 unknown_type_node,
14155 template_args);
14156 /* Update the conversion operator type. */
14164 {
14166 qualifying_scope,
14167 object_type);
14169 /* We need to call adjust_result_of_qualified_name_lookup in case the
14170 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14171 so that we still get virtual function binding. */
14173 }
14175 }
14177 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14178 true if the qualified-id will be a postfix-expression in-and-of
14179 itself; false if more of the postfix-expression follows the
14180 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14181 of "&". */
14183 static tree
14187 {
14188 tree expr;
14189 tree scope;
14190 tree name;
14192 tree template_args;
14197 /* Figure out what name to look up. */
14200 {
14210 }
14211 else
14212 {
14215 }
14217 /* Substitute into the qualifying scope. When there are no ARGS, we
14218 are just trying to simplify a non-dependent expression. In that
14219 case the qualifying scope may be dependent, and, in any case,
14220 substituting will not help. */
14223 {
14226 }
14227 else
14231 {
14238 }
14241 {
14243 {
14244 /* A BIT_NOT_EXPR is used to represent a destructor. */
14246 {
14250 }
14251 else
14254 }
14255 else
14259 {
14261 {
14265 }
14267 }
14268 }
14271 {
14273 scope);
14274 /* Remember that there was a reference to this entity. */
14277 }
14280 {
14286 }
14289 {
14292 complain);
14293 else
14295 }
14301 {
14302 expr = (adjust_result_of_qualified_name_lookup
14304 expr = (finish_qualified_id_expr
14308 }
14310 /* Expressions do not generally have reference type. */
14312 /* However, if we're about to form a pointer-to-member, we just
14313 want the referenced member referenced. */
14321 }
14323 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14324 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14325 for tsubst. */
14327 static tree
14330 {
14337 {
14338 /* If we had an initializer but it
14339 instantiated to nothing,
14340 value-initialize the object. This will
14341 only occur when the initializer was a
14342 pack expansion where the parameter packs
14343 used in that expansion were of length
14344 zero. */
14346 complain);
14351 }
14354 }
14356 /* Like tsubst, but deals with expressions. This function just replaces
14357 template parms; to finish processing the resultant expression, use
14358 tsubst_copy_and_build or tsubst_expr. */
14360 static tree
14362 {
14364 tree r;
14372 {
14377 {
14378 /* We get here for a use of 'this' in an NSDMI as part of a
14379 constructor call or as part of an aggregate initialization. */
14381 && ((current_function_decl
14383 || (current_class_ref
14387 /* This can happen for a parameter name used later in a function
14388 declaration (such as in a late-specified return type). Just
14389 make a dummy decl, since it's only used for its type. */
14392 /* Give it the template pattern as its context; its true context
14393 hasn't been instantiated yet and this is good enough for
14394 mangling. */
14396 }
14405 {
14406 tree enum_type;
14407 tree v;
14411 /* There is no need to substitute into namespace-scope
14412 enumerators. */
14415 /* If ARGS is NULL, then T is known to be non-dependent. */
14419 /* Unfortunately, we cannot just call lookup_name here.
14420 Consider:
14422 template <int I> int f() {
14423 enum E { a = I };
14424 struct S { void g() { E e = a; } };
14425 };
14427 When we instantiate f<7>::S::g(), say, lookup_name is not
14428 clever enough to find f<7>::a. */
14429 enum_type
14439 /* We didn't find the name. That should never happen; if
14440 name-lookup found it during preliminary parsing, we
14441 should find it again here during instantiation. */
14443 }
14448 {
14449 /* Check for a local specialization set up by
14450 tsubst_pack_expansion. */
14452 {
14456 }
14458 /* When retrieving a capture pack from a generic lambda, remove the
14459 lambda call op's own template argument list from ARGS. Only the
14460 template arguments active for the closure type should be used to
14461 retrieve the pack specialization. */
14467 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14468 tsubst_decl put in the hash table. */
14470 }
14473 {
14474 tree ctx;
14479 {
14482 {
14486 }
14488 }
14489 }
14499 {
14502 {
14503 /* First try name lookup to find the instantiation. */
14506 {
14507 /* Make sure that the one we found is the one we want. */
14513 }
14517 else
14518 {
14519 /* This can happen for a variable used in a
14520 late-specified return type of a local lambda, or for a
14521 local static or constant. Building a new VAR_DECL
14522 should be OK in all those cases. */
14525 /* Avoid infinite recursion (79640). */
14528 {
14529 /* We can't call cp_finish_decl, so handle the
14530 initializer by hand. */
14541 }
14548 }
14549 /* Remember this for subsequent uses. */
14552 }
14553 }
14554 else
14564 /* An OVERLOAD will always be a non-dependent overload set; an
14565 overload set from function scope will just be represented with an
14566 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14568 /* We must have marked any lookups as persistent. */
14584 {
14585 /* Template template argument like the following example need
14586 special treatment:
14588 template <template <class> class TT> struct C {};
14589 template <class T> struct D {
14590 template <class U> struct E {};
14591 C<E> c; // #1
14592 };
14593 D<int> d; // #2
14595 We are processing the template argument `E' in #1 for
14596 the template instantiation #2. Originally, `E' is a
14597 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14598 have to substitute this with one having context `D<int>'. */
14602 {
14603 /* When rewriting a constructor into a deduction guide, a
14604 non-dependent name can become dependent, so memtmpl<args>
14605 becomes context::template memtmpl<args>. */
14609 }
14611 }
14612 else
14613 /* Ordinary template template argument. */
14624 {
14628 }
14633 {
14642 /* We only want to compute the number of arguments. */
14645 else
14652 {
14654 /* Set TREE_USED for the benefit of -Wunused. */
14658 }
14666 {
14671 else
14677 else
14680 }
14681 else
14683 }
14685 {
14693 }
14694 /* Fall through */
14710 {
14714 }
14717 {
14718 tree object;
14719 tree name;
14724 {
14728 }
14731 {
14741 }
14746 in_decl);
14747 else
14750 }
14788 {
14792 }
14795 {
14800 }
14803 {
14807 }
14810 {
14818 }
14824 {
14831 }
14834 {
14841 }
14844 {
14851 }
14854 {
14855 /* Substituted template arguments */
14864 }
14867 {
14887 }
14912 /* Fall through. */
14915 {
14918 }
14919 else
14923 /* This is handled by tsubst_copy_and_build. */
14927 {
14931 }
14934 /* We shouldn't have built any of these during initial template
14935 generation. Instead, they should be built during instantiation
14936 in response to the saved STMT_IS_FULL_EXPR_P setting. */
14940 {
14950 }
14968 {
14969 /* Instantiate any typedefs in the type. */
14974 }
14977 /* These can sometimes show up in a partial instantiation, but never
14978 involve template parms. */
14992 /* We shouldn't get here, but keep going if !flag_checking. */
14996 }
14997 }
14999 /* Helper function for tsubst_omp_clauses, used for instantiation of
15000 OMP_CLAUSE_DECL of clauses. */
15002 static tree
15004 tree in_decl)
15005 {
15009 /* Handle an OpenMP array section represented as a TREE_LIST (or
15010 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15011 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15012 TREE_LIST. We can handle it exactly the same as an array section
15013 (purpose, value, and a chain), even though the nomenclature
15014 (low_bound, length, etc) is different. */
15016 {
15017 tree low_bound
15023 in_decl);
15032 }
15035 /* Undo convert_from_reference tsubst_expr could have called. */
15041 }
15043 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15045 static tree
15048 {
15053 {
15059 {
15062 {
15068 }
15069 /* FALLTHRU */
15084 in_decl);
15116 {
15119 {
15126 }
15127 else
15129 }
15132 in_decl);
15138 in_decl);
15146 in_decl);
15148 {
15151 }
15156 else
15159 in_decl,
15183 }
15186 {
15196 /* tsubst_expr on SCOPE_REF results in returning
15197 finish_non_static_data_member result. Undo that here. */
15201 {
15206 {
15210 CASE_CONVERT:
15219 /* FALLTHRU */
15223 }
15224 }
15230 {
15233 {
15236 }
15237 }
15241 }
15242 }
15246 {
15251 {
15254 }
15255 }
15257 }
15259 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15261 static tree
15263 tree in_decl)
15264 {
15265 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15285 {
15288 else
15289 {
15293 }
15294 }
15299 #undef RECUR
15300 }
15302 /* Used to temporarily communicate the list of #pragma omp parallel
15303 clauses to #pragma omp for instantiation if they are combined
15304 together. */
15308 /* Substitute one OMP_FOR iterator. */
15310 static void
15315 {
15316 #define RECUR(NODE) \
15317 tsubst_expr ((NODE), args, complain, in_decl, \
15318 integral_constant_expression_p)
15325 {
15328 }
15334 {
15335 /* We need to jump through some hoops to handle declarations in the
15336 init-statement, since we might need to handle auto deduction,
15337 but we need to keep control of initialization. */
15341 }
15342 else
15343 {
15345 {
15348 {
15352 {
15356 CASE_CONVERT:
15364 {
15367 }
15368 /* FALLTHRU */
15372 }
15373 }
15374 }
15375 else
15377 }
15388 {
15390 {
15391 /* Declare the variable, but don't let that initialize it. */
15396 }
15401 {
15406 }
15407 else
15414 }
15417 {
15418 /* Declare and initialize the variable. */
15421 }
15423 {
15427 {
15429 {
15435 {
15438 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15443 }
15446 {
15448 decl);
15450 }
15453 {
15455 decl);
15457 }
15458 else
15460 }
15463 }
15465 {
15470 {
15473 }
15474 }
15475 }
15478 {
15482 }
15483 else
15487 {
15498 {
15506 }
15507 else
15513 {
15519 }
15523 {
15531 }
15532 else
15538 }
15544 #undef RECUR
15545 }
15547 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15548 of OMP_TARGET's body. */
15550 static tree
15552 {
15555 {
15564 }
15566 }
15568 /* Helper function for tsubst_expr. For decomposition declaration
15569 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15570 also the corresponding decls representing the identifiers
15571 of the decomposition declaration. Return DECL if successful
15572 or error_mark_node otherwise, set *FIRST to the first decl
15573 in the list chained through DECL_CHAIN and *CNT to the number
15574 of such decls. */
15576 static tree
15580 {
15585 decl2
15590 {
15592 {
15595 }
15611 {
15614 }
15615 else
15617 }
15620 }
15622 /* Like tsubst_copy for expressions, etc. but also does semantic
15623 processing. */
15625 tree
15628 {
15629 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15630 #define RECUR(NODE) \
15631 tsubst_expr ((NODE), args, complain, in_decl, \
15632 integral_constant_expression_p)
15635 tree r;
15636 location_t loc;
15648 {
15650 {
15651 tree_stmt_iterator i;
15655 }
15670 else
15679 {
15681 tree init;
15687 {
15697 else
15699 }
15701 {
15702 /* Don't build up decls for a variadic capture proxy, we'll
15703 instantiate the elements directly as needed. */
15705 }
15706 else
15707 {
15711 {
15712 /* By marking the declaration as instantiated, we avoid
15713 trying to instantiate it. Since instantiate_decl can't
15714 handle local variables, and since we've already done
15715 all that needs to be done, that's the right thing to
15716 do. */
15721 /* Anonymous aggregates are a special case. */
15724 {
15727 {
15731 }
15733 }
15739 {
15744 }
15745 else
15746 {
15751 {
15752 /* For __PRETTY_FUNCTION__ we have to adjust the
15753 initializer. */
15757 }
15758 else
15762 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
15768 {
15770 tree first;
15776 }
15777 }
15778 }
15779 }
15782 }
15797 {
15805 {
15807 tree first;
15812 }
15813 else
15818 }
15844 else
15845 {
15852 }
15858 {
15867 }
15875 else
15883 else
15904 {
15911 }
15915 {
15917 tree label;
15924 }
15930 /* Computed goto's must be tsubst'd into. On the other hand,
15931 non-computed gotos must not be; the identifier in question
15932 will have no binding. */
15934 else
15940 {
15956 }
15961 {
15966 }
15967 else
15968 {
15973 else
15980 else
15986 else
15988 }
15992 {
15996 {
15998 /* Prevent instantiate_decl from trying to instantiate
15999 this variable. We've already done all that needs to be
16000 done. */
16003 }
16008 }
16014 {
16015 /* Local classes are not independent templates; they are
16016 instantiated along with their containing function. And this
16017 way we don't have to deal with pushing out of one local class
16018 to instantiate a member of another local class. */
16019 tree fn;
16020 /* Closures are handled by the LAMBDA_EXPR. */
16027 }
16031 {
16032 tree condition;
16035 condition =
16037 args,
16046 }
16052 in_decl);
16089 {
16104 in_decl);
16106 {
16113 }
16125 integral_constant_expression_p);
16136 else
16137 {
16145 }
16149 }
16154 /* FALLTHRU */
16161 in_decl);
16178 in_decl);
16189 {
16192 {
16193 /* For combined target teams, ensure the num_teams and
16194 thread_limit clause expressions are evaluated on the host,
16195 before entering the target construct. */
16196 tree c;
16202 {
16211 OMP_CLAUSE_FIRSTPRIVATE);
16215 }
16216 }
16217 }
16277 {
16282 {
16285 }
16291 }
16292 else
16293 {
16300 {
16303 }
16306 {
16311 {
16314 }
16320 }
16321 else
16322 {
16326 }
16329 }
16333 {
16339 {
16343 {
16348 }
16352 }
16353 else
16354 {
16359 }
16360 }
16364 {
16368 }
16388 /* If the first operand was a statement, we're done with it. */
16392 complain));
16404 integral_constant_expression_p));
16405 }
16408 out:
16411 #undef RECUR
16412 #undef RETURN
16413 }
16415 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16416 function. For description of the body see comment above
16417 cp_parser_omp_declare_reduction_exprs. */
16419 static void
16421 {
16427 tree_stmt_iterator tsi;
16438 {
16457 }
16459 {
16479 }
16480 }
16482 /* T is a postfix-expression that is not being used in a function
16483 call. Return the substituted version of T. */
16485 static tree
16487 tsubst_flags_t complain,
16488 tree in_decl)
16489 {
16493 else
16499 }
16501 /* Like tsubst but deals with expressions and performs semantic
16502 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16504 tree
16506 tree args,
16507 tsubst_flags_t complain,
16508 tree in_decl,
16511 {
16512 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16513 #define RECUR(NODE) \
16514 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16516 integral_constant_expression_p)
16519 location_t loc;
16528 /* N3276 decltype magic only applies to calls at the top level or on the
16529 right side of a comma. */
16534 {
16537 /* Fall through. */
16539 {
16540 tree decl;
16541 cp_id_kind idk;
16546 {
16549 }
16551 /* Look up the name. */
16554 /* By convention, expressions use ERROR_MARK_NODE to indicate
16555 failure, not NULL_TREE. */
16561 integral_constant_expression_p,
16569 input_location);
16573 {
16577 }
16579 }
16582 {
16583 tree object;
16593 {
16598 }
16604 {
16607 }
16608 else
16615 else
16617 }
16620 {
16624 {
16625 /* A type conversion to reference type will be enclosed in
16626 such an indirect ref, but the substitution of the cast
16627 will have also added such an indirect ref. */
16630 }
16631 else
16639 }
16642 {
16646 }
16649 {
16656 flags));
16657 }
16660 {
16664 }
16671 {
16672 tree type;
16678 {
16683 }
16689 {
16707 }
16710 }
16744 else
16746 in_decl);
16781 {
16788 tree r = build_x_binary_op
16790 op0,
16792 ? ERROR_MARK
16794 op1,
16796 ? ERROR_MARK
16804 }
16807 {
16811 }
16824 {
16833 }
16838 /* Fall through */
16841 {
16842 tree r;
16848 {
16849 /* When there are no ARGS, we are trying to evaluate a
16850 non-dependent expression from the parser. Trying to do
16851 the substitutions may not work. */
16854 }
16855 else
16856 {
16861 else
16864 /*integral_constant_expression_p=*/
16868 }
16872 else
16876 {
16878 {
16880 {
16884 }
16885 else
16889 }
16891 }
16893 }
16896 {
16906 }
16922 {
16926 tree r = build_x_modify_expr
16929 /* TREE_NO_WARNING must be set if either the expression was
16930 parenthesized or it uses an operator such as >>= rather
16931 than plain assignment. In the former case, it was already
16932 set and must be copied. In the latter case,
16933 build_x_modify_expr sets it and it must not be reset
16934 here. */
16939 }
16944 /* Remember that there was a reference to this entity. */
16951 {
16956 tree ret;
16960 else
16961 {
16965 }
16967 /* If there was an initializer in the original tree, but it
16968 instantiated to an empty list, then we should pass a
16969 non-NULL empty vector to tell build_new that it was an
16970 empty initializer() rather than no initializer. This can
16971 only happen when the initializer is a pack expansion whose
16972 parameter packs are of length zero. */
16975 else
16976 {
16980 else
16981 {
16984 }
16985 }
16991 complain);
16999 }
17002 {
17008 complain));
17009 }
17012 {
17016 integral_constant_expression_p);
17018 op0,
17021 }
17024 {
17025 tree function;
17030 tree ret;
17033 /* Internal function with no arguments. */
17037 /* When we parsed the expression, we determined whether or
17038 not Koenig lookup should be performed. */
17041 {
17044 }
17046 {
17051 }
17053 {
17054 /* Do nothing; calling tsubst_copy_and_build on an identifier
17055 would incorrectly perform unqualified lookup again.
17057 Note that we can also have an IDENTIFIER_NODE if the earlier
17058 unqualified lookup found a member function; in that case
17059 koenig_p will be false and we do want to do the lookup
17060 again to find the instantiated member function.
17062 FIXME but doing that causes c++/15272, so we need to stop
17063 using IDENTIFIER_NODE in that situation. */
17065 }
17066 else
17067 {
17069 {
17075 }
17076 else
17081 /* Avoid error about taking the address of a constructor. */
17085 in_decl,
17087 integral_constant_expression_p);
17091 }
17096 {
17101 else
17102 {
17103 /* Expand the pack expansion and push each entry onto
17104 CALL_ARGS. */
17107 {
17112 {
17117 }
17118 }
17119 else
17120 {
17121 /* A partial substitution. Add one entry. */
17123 }
17124 }
17125 }
17127 /* We do not perform argument-dependent lookup if normal
17128 lookup finds a non-function, in accordance with the
17129 expected resolution of DR 218. */
17132 /* If lookup found a member function, the Koenig lookup is
17133 not appropriate, even if an unqualified-name was used
17134 to denote the function. */
17137 /* Only do this when substitution turns a dependent call
17138 into a non-dependent call. */
17146 {
17148 {
17149 /* For backwards compatibility and good diagnostics, try
17150 the unqualified lookup again if we aren't in SFINAE
17151 context. */
17152 tree unq = (tsubst_copy_and_build
17154 integral_constant_expression_p));
17156 {
17159 }
17162 {
17163 /* In a lambda fn, we have to be careful to not
17164 introduce new this captures. Legacy code can't
17165 be using lambdas anyway, so it's ok to be
17166 stricter. */
17171 "and no declarations were found by "
17172 "argument-dependent lookup at the point "
17179 else
17183 {
17194 {
17196 input_location);
17198 "declarations in dependent base %qT are "
17204 else
17208 }
17209 else
17211 "%qD declared here, later in the "
17214 {
17217 }
17218 }
17221 }
17222 }
17224 {
17229 }
17230 }
17232 /* Remember that there was a reference to this entity. */
17236 {
17239 }
17241 /* Put back tf_decltype for the actual call. */
17246 {
17250 {
17252 "wrong number of arguments to "
17255 }
17256 else
17258 input_location),
17263 /* Unsupported internal function with arguments. */
17265 }
17268 complain);
17270 {
17285 complain);
17286 else
17287 ret = (build_new_method_call
17292 complain));
17293 }
17294 else
17297 koenig_p,
17298 complain);
17303 {
17309 {
17315 {
17317 /* The thunk location is not interesting. */
17319 }
17320 }
17321 }
17324 }
17327 {
17333 {
17335 {
17340 }
17341 else
17342 {
17347 }
17349 }
17350 else
17351 {
17354 }
17358 }
17361 {
17366 input_location));
17367 }
17370 {
17378 {
17379 /* We have pack expansions, so expand those and
17380 create a new list out of it. */
17383 tree chain;
17386 /* Expand the argument expressions. */
17394 /* Build the rest of the list. */
17399 /* Determine the number of arguments. */
17401 {
17404 }
17407 else
17408 {
17409 /* Since we only performed a partial substitution into
17410 the argument pack, we only RETURN (a single list
17411 node. */
17418 }
17420 /* Convert the argument vectors into a TREE_LIST */
17423 {
17424 /* Grab the Ith values. */
17425 i--;
17428 value
17432 /* Build the list (backwards). */
17434 }
17437 }
17453 }
17456 {
17457 tree object;
17458 tree object_type;
17459 tree member;
17460 tree r;
17464 /* Remember that there was a reference to this entity. */
17475 else
17481 {
17486 }
17490 {
17492 {
17497 {
17500 }
17502 {
17507 }
17508 }
17509 }
17512 {
17513 /* Lookup the template functions now that we know what the
17514 scope is. */
17522 {
17525 args);
17526 member = (adjust_result_of_qualified_name_lookup
17528 object_type));
17529 }
17530 else
17531 {
17533 input_location);
17535 }
17536 }
17540 {
17542 {
17546 else
17549 }
17551 }
17555 complain);
17559 }
17566 {
17574 tree r;
17579 /* digest_init will do the wrong thing if we let it. */
17583 /* We do not want to process the index of aggregate
17584 initializers as they are identifier nodes which will be
17585 looked up by digest_init. */
17591 {
17593 /* An identifier index is looked up in the type
17594 being initialized, not the current scope. */
17599 {
17600 /* Substitute into the pack expansion. */
17602 in_decl);
17606 ;
17608 /* Just move the argument into place. */
17610 else
17611 {
17612 /* Update the length of the final CONSTRUCTOR
17613 arguments vector, and note that we will need to
17614 copy.*/
17617 }
17618 }
17619 else
17621 }
17624 {
17629 {
17631 {
17636 }
17637 else
17639 }
17640 }
17646 {
17651 }
17655 }
17658 {
17661 {
17664 }
17665 else
17666 {
17669 }
17670 }
17676 {
17677 /* We don't build decls for an instantiation of a
17678 variadic capture proxy, we instantiate the elements
17679 when needed. */
17682 }
17683 /* Fall through */
17686 {
17688 /* ??? We're doing a subset of finish_id_expression here. */
17690 && !processing_template_decl
17691 && !cp_unevaluated_operand
17694 {
17696 /* Replace an evaluated use of the thread_local variable with
17697 a call to its wrapper. */
17699 }
17701 {
17705 }
17708 /* If the original type was a reference, we'll be wrapped in
17709 the appropriate INDIRECT_REF. */
17712 }
17715 {
17719 }
17722 {
17723 tree object_ptr
17730 }
17737 {
17748 }
17751 {
17757 integral_constant_expression_p);
17761 /* If the resulting list of expression statement is empty,
17762 fold it further into void_node. */
17767 }
17770 {
17788 /* For a function or variable scope, we want to use tsubst so that we
17789 don't complain about referring to an auto before deduction. */
17792 {
17793 /* Look up the parameter we want directly, as tsubst_copy
17794 doesn't do what we need. */
17800 /* FIXME Work around the parm not having DECL_CONTEXT set. */
17803 }
17805 /* For a field, use tsubst_copy so that we look up the existing field
17806 rather than build a new one. */
17808 else
17815 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17817 /* Now that we know visibility, instantiate the type so we have a
17818 declaration of the op() for later calls to lambda_function. */
17829 }
17832 /* We can get here for a constant initializer of non-dependent type.
17833 FIXME stop folding in cp_parser_initializer_clause. */
17834 {
17836 complain);
17838 }
17842 integral_constant_expression_p));
17848 {
17853 complain));
17854 }
17860 /* Handle Objective-C++ constructs, if appropriate. */
17861 {
17862 tree subst
17867 }
17869 }
17871 #undef RECUR
17872 #undef RETURN
17873 out:
17876 }
17878 /* Verify that the instantiated ARGS are valid. For type arguments,
17879 make sure that the type's linkage is ok. For non-type arguments,
17880 make sure they are constants if they are integral or enumerations.
17881 Emit an error under control of COMPLAIN, and return TRUE on error. */
17883 static bool
17885 {
17889 {
17899 }
17901 {
17902 /* [basic.link]: A name with no linkage (notably, the name
17903 of a class or enumeration declared in a local scope)
17904 shall not be used to declare an entity with linkage.
17905 This implies that names with no linkage cannot be used as
17906 template arguments
17908 DR 757 relaxes this restriction for C++0x. */
17913 {
17914 /* DR 488 makes use of a type with no linkage cause
17915 type deduction to fail. */
17917 {
17920 else
17923 }
17925 }
17926 /* In order to avoid all sorts of complications, we do not
17927 allow variably-modified types as template arguments. */
17929 {
17933 }
17934 }
17935 /* Class template and alias template arguments should be OK. */
17937 ;
17938 /* A non-type argument of integral or enumerated type must be a
17939 constant. */
17944 {
17948 }
17950 }
17952 static bool
17954 {
17959 {
17962 }
17966 }
17968 /* We're out of SFINAE context now, so generate diagnostics for the access
17969 errors we saw earlier when instantiating D from TMPL and ARGS. */
17971 static void
17973 {
17985 }
17987 /* Instantiate the indicated variable, function, or alias template TMPL with
17988 the template arguments in TARG_PTR. */
17990 static tree
17992 {
17994 tree fndecl;
17995 tree gen_tmpl;
17996 tree spec;
18004 /* If this function is a clone, handle it specially. */
18006 {
18007 tree spec;
18008 tree clone;
18010 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18011 DECL_CLONED_FUNCTION. */
18017 /* Look for the clone. */
18021 /* We should always have found the clone by now. */
18024 }
18029 /* Check to see if we already have this specialization. */
18033 /* targ_ptr only has the innermost template args, so add the outer ones
18034 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18035 the case of a non-dependent call within a template definition). */
18036 targ_ptr = (add_outermost_template_args
18038 targ_ptr));
18040 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18041 but it doesn't seem to be on the hot path. */
18050 {
18052 {
18056 }
18058 }
18061 complain))
18064 /* We are building a FUNCTION_DECL, during which the access of its
18065 parameters and return types have to be checked. However this
18066 FUNCTION_DECL which is the desired context for access checking
18067 is not built yet. We solve this chicken-and-egg problem by
18068 deferring all checks until we have the FUNCTION_DECL. */
18071 /* Instantiation of the function happens in the context of the function
18072 template, not the context of the overload resolution we're doing. */
18074 /* If there are dependent arguments, e.g. because we're doing partial
18075 ordering, make sure processing_template_decl stays set. */
18079 {
18083 }
18089 {
18090 /* We need to determine if we're using a partial or explicit
18091 specialization now, because the type of the variable could be
18092 different. */
18098 {
18103 }
18104 }
18106 /* Substitute template parameters to obtain the specialization. */
18114 {
18117 }
18119 /* The DECL_TI_TEMPLATE should always be the immediate parent
18120 template, not the most general template. */
18124 /* Now we know the specialization, compute access previously
18125 deferred. Do no access control for inheriting constructors,
18126 as we already checked access for the inherited constructor. */
18129 {
18134 }
18137 /* If we've just instantiated the main entry point for a function,
18138 instantiate all the alternate entry points as well. We do this
18139 by cloning the instantiation of the main entry point, not by
18140 instantiating the template clones. */
18145 {
18147 {
18148 /* Remember to reinstantiate when we're out of SFINAE so the user
18149 can see the errors. */
18151 }
18153 }
18155 }
18157 /* Wrapper for instantiate_template_1. */
18159 tree
18161 {
18162 tree ret;
18167 }
18169 /* Instantiate the alias template TMPL with ARGS. Also push a template
18170 instantiation level, which instantiate_template doesn't do because
18171 functions and variables have sufficient context established by the
18172 callers. */
18174 static tree
18176 {
18183 {
18186 }
18188 args =
18196 /* We can't free this if a pending_template entry or last_error_tinst_level
18197 is pointing at it. */
18203 }
18205 /* PARM is a template parameter pack for FN. Returns true iff
18206 PARM is used in a deducible way in the argument list of FN. */
18208 static bool
18210 {
18213 {
18215 tree packs;
18221 {
18222 /* The template parameter pack is used in a function parameter
18223 pack. If this is the end of the parameter list, the
18224 template parameter pack is deducible. */
18227 else
18228 /* Otherwise, not. Well, it could be deduced from
18229 a non-pack parameter, but doing so would end up with
18230 a deduction mismatch, so don't bother. */
18232 }
18233 }
18234 /* The template parameter pack isn't used in any function parameter
18235 packs, but it might be used deeper, e.g. tuple<Args...>. */
18237 }
18239 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18240 NARGS elements of the arguments that are being used when calling
18241 it. TARGS is a vector into which the deduced template arguments
18242 are placed.
18244 Returns either a FUNCTION_DECL for the matching specialization of FN or
18245 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18246 true, diagnostics will be printed to explain why it failed.
18248 If FN is a conversion operator, or we are trying to produce a specific
18249 specialization, RETURN_TYPE is the return type desired.
18251 The EXPLICIT_TARGS are explicit template arguments provided via a
18252 template-id.
18254 The parameter STRICT is one of:
18256 DEDUCE_CALL:
18257 We are deducing arguments for a function call, as in
18258 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18259 deducing arguments for a call to the result of a conversion
18260 function template, as in [over.call.object].
18262 DEDUCE_CONV:
18263 We are deducing arguments for a conversion function, as in
18264 [temp.deduct.conv].
18266 DEDUCE_EXACT:
18267 We are deducing arguments when doing an explicit instantiation
18268 as in [temp.explicit], when determining an explicit specialization
18269 as in [temp.expl.spec], or when taking the address of a function
18270 template, as in [temp.deduct.funcaddr]. */
18272 tree
18274 tree explicit_targs,
18275 tree targs,
18278 tree return_type,
18279 unification_kind_t strict,
18283 {
18284 tree parms;
18285 tree fntype;
18298 tree tinst;
18304 full_targs = (add_outermost_template_args
18306 targs));
18311 /* In C++0x, it's possible to have a function template whose type depends
18312 on itself recursively. This is most obvious with decltype, but can also
18313 occur with enumeration scope (c++/48969). So we need to catch infinite
18314 recursion and reject the substitution at deduction time; this function
18315 will return error_mark_node for any repeated substitution.
18317 This also catches excessive recursion such as when f<N> depends on
18318 f<N-1> across all integers, and returns error_mark_node for all the
18319 substitutions back up to the initial one.
18321 This is, of course, not reentrant. */
18331 {
18332 /* [temp.deduct]
18334 The specified template arguments must match the template
18335 parameters in kind (i.e., type, nontype, template), and there
18336 must not be more arguments than there are parameters;
18337 otherwise type deduction fails.
18339 Nontype arguments must match the types of the corresponding
18340 nontype template parameters, or must be convertible to the
18341 types of the corresponding nontype parameters as specified in
18342 _temp.arg.nontype_, otherwise type deduction fails.
18344 All references in the function type of the function template
18345 to the corresponding template parameters are replaced by the
18346 specified template argument values. If a substitution in a
18347 template parameter or in the function type of the function
18348 template results in an invalid type, type deduction fails. */
18359 explicit_targs);
18361 /* Adjust any explicit template arguments before entering the
18362 substitution context. */
18363 explicit_targs
18365 complain,
18371 /* Substitute the explicit args into the function type. This is
18372 necessary so that, for instance, explicitly declared function
18373 arguments can match null pointed constants. If we were given
18374 an incomplete set of explicit args, we must not do semantic
18375 processing during substitution as we could create partial
18376 instantiations. */
18378 {
18383 /* Dig out the actual parm. */
18386 {
18389 }
18391 {
18394 }
18397 /* No explicit argument for this template parameter. */
18401 {
18402 /* Mark the argument pack as "incomplete". We could
18403 still deduce more arguments during unification.
18404 We remove this mark in type_unification_real. */
18406 {
18410 }
18412 /* We have some incomplete argument packs. */
18414 }
18415 }
18419 {
18422 }
18425 /* Ignore any access checks; we'll see them again in
18426 instantiate_template and they might have the wrong
18427 access path at this point. */
18439 /* Place the explicitly specified arguments in TARGS. */
18443 }
18445 /* Never do unification on the 'this' parameter. */
18449 {
18450 /* We're deducing for a call to the result of a template conversion
18451 function. The parms we really want are in return_type. */
18455 }
18457 {
18466 }
18468 /* We allow incomplete unification without an error message here
18469 because the standard doesn't seem to explicitly prohibit it. Our
18470 callers must be ready to deal with unification failures in any
18471 event. */
18474 /* If we aren't explaining yet, push tinst context so we can see where
18475 any errors (e.g. from class instantiations triggered by instantiation
18476 of default template arguments) come from. If we are explaining, this
18477 context is redundant. */
18479 {
18482 }
18484 /* type_unification_real will pass back any access checks from default
18485 template argument substitution. */
18497 /* Now that we have bindings for all of the template arguments,
18498 ensure that the arguments deduced for the template template
18499 parameters have compatible template parameter lists. We cannot
18500 check this property before we have deduced all template
18501 arguments, because the template parameter types of a template
18502 template parameter might depend on prior template parameters
18503 deduced after the template template parameter. The following
18504 ill-formed example illustrates this issue:
18506 template<typename T, template<T> class C> void f(C<5>, T);
18508 template<int N> struct X {};
18510 void g() {
18511 f(X<5>(), 5l); // error: template argument deduction fails
18512 }
18514 The template parameter list of 'C' depends on the template type
18515 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18516 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18517 time that we deduce 'C'. */
18520 {
18523 }
18525 /* All is well so far. Now, check:
18527 [temp.deduct]
18529 When all template arguments have been deduced, all uses of
18530 template parameters in nondeduced contexts are replaced with
18531 the corresponding deduced argument values. If the
18532 substitution results in an invalid type, as described above,
18533 type deduction fails. */
18536 {
18539 }
18541 /* Also collect access checks from the instantiation. */
18554 /* Now perform any access checks encountered during substitution. */
18561 /* If we're looking for an exact match, check that what we got
18562 is indeed an exact match. It might not be if some template
18563 parameters are used in non-deduced contexts. But don't check
18564 for an exact match if we have dependent template arguments;
18565 in that case we're doing partial ordering, and we already know
18566 that we have two candidates that will provide the actual type. */
18568 {
18572 tree sarg
18578 {
18582 }
18583 }
18585 /* After doing deduction with the inherited constructor, actually return an
18586 instantiation of the inheriting constructor. */
18592 fail:
18595 {
18597 /* Reset once we're all the way out. */
18599 }
18601 /* We can't free this if a pending_template entry or last_error_tinst_level
18602 is pointing at it. */
18608 }
18610 /* Adjust types before performing type deduction, as described in
18611 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
18612 sections are symmetric. PARM is the type of a function parameter
18613 or the return type of the conversion function. ARG is the type of
18614 the argument passed to the call, or the type of the value
18615 initialized with the result of the conversion function.
18616 ARG_EXPR is the original argument expression, which may be null. */
18618 static int
18622 tree arg_expr)
18623 {
18627 {
18632 /* Swap PARM and ARG throughout the remainder of this
18633 function; the handling is precisely symmetric since PARM
18634 will initialize ARG rather than vice versa. */
18639 /* Core issue #873: Do the DR606 thing (see below) for these cases,
18640 too, but here handle it by stripping the reference from PARM
18641 rather than by adding it to ARG. */
18649 /* Nothing else to do in this case. */
18654 }
18657 {
18658 /* [temp.deduct.call]
18660 If P is not a reference type:
18662 --If A is an array type, the pointer type produced by the
18663 array-to-pointer standard conversion (_conv.array_) is
18664 used in place of A for type deduction; otherwise,
18666 --If A is a function type, the pointer type produced by
18667 the function-to-pointer standard conversion
18668 (_conv.func_) is used in place of A for type deduction;
18669 otherwise,
18671 --If A is a cv-qualified type, the top level
18672 cv-qualifiers of A's type are ignored for type
18673 deduction. */
18678 else
18680 }
18682 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
18683 reference to a cv-unqualified template parameter that does not represent a
18684 template parameter of a class template (during class template argument
18685 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
18686 an lvalue, the type "lvalue reference to A" is used in place of A for type
18687 deduction. */
18694 /* try_one_overload doesn't provide an arg_expr, but
18695 functions are always lvalues. */
18699 /* [temp.deduct.call]
18701 If P is a cv-qualified type, the top level cv-qualifiers
18702 of P's type are ignored for type deduction. If P is a
18703 reference type, the type referred to by P is used for
18704 type deduction. */
18707 {
18710 }
18712 /* DR 322. For conversion deduction, remove a reference type on parm
18713 too (which has been swapped into ARG). */
18718 }
18720 /* Subroutine of unify_one_argument. PARM is a function parameter of a
18721 template which does contain any deducible template parameters; check if
18722 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
18723 unify_one_argument. */
18725 static int
18728 {
18729 tree type;
18733 else
18740 {
18744 }
18746 {
18751 }
18755 else
18757 }
18761 /* Returns true iff the expression EXPR is one from which a template
18762 argument can be deduced. In other words, if it's an undecorated
18763 use of a template non-type parameter. */
18765 static bool
18767 {
18768 /* Strip implicit conversions. */
18772 }
18774 /* Returns true iff the array domain DOMAIN uses a template parameter in a
18775 deducible way; that is, if it has a max value of <PARM> - 1. */
18777 static bool
18779 {
18788 }
18790 /* Returns true iff the template arguments ARGS use a template parameter
18791 in a deducible way. */
18793 static bool
18795 {
18797 {
18802 else
18803 {
18810 else
18812 }
18815 }
18817 }
18819 /* Returns true iff TYPE contains any deducible references to template
18820 parameters, as per 14.8.2.5. */
18822 static bool
18824 {
18828 /* T
18829 cv-list T
18830 TT<T>
18831 TT<i>
18832 TT<> */
18837 /* T*
18838 T&
18839 T&& */
18843 /* T[integer-constant ]
18844 type [i] */
18849 /* T type ::*
18850 type T::*
18851 T T::*
18852 T (type ::*)()
18853 type (T::*)()
18854 type (type ::*)(T)
18855 type (T::*)(T)
18856 T (type ::*)(T)
18857 T (T::*)()
18858 T (T::*)(T) */
18861 || (uses_deducible_template_parms
18864 /* template-name <T> (where template-name refers to a class template)
18865 template-name <i> (where template-name refers to a class template) */
18872 /* type (T)
18873 T()
18874 T(T) */
18877 {
18886 }
18889 }
18891 /* Subroutine of type_unification_real and unify_pack_expansion to
18892 handle unification of a single P/A pair. Parameters are as
18893 for those functions. */
18895 static int
18899 {
18906 /* We can't deduce anything from this, but we might get all the
18907 template args from other function args. */
18910 /* Implicit conversions (Clause 4) will be performed on a function
18911 argument to convert it to the type of the corresponding function
18912 parameter if the parameter type contains no template-parameters that
18913 participate in template argument deduction. */
18916 /* For function parameters with no deducible template parameters,
18917 just return. We'll check non-dependent conversions later. */
18921 {
18923 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
18924 | UNIFY_ALLOW_MORE_CV_QUAL
18938 }
18940 /* We only do these transformations if this is the top-level
18941 parameter_type_list in a call or declaration matching; in other
18942 situations (nested function declarators, template argument lists) we
18943 won't be comparing a type to an expression, and we don't do any type
18944 adjustments. */
18946 {
18948 {
18951 {
18952 /* [temp.deduct.type] A template-argument can be
18953 deduced from a pointer to function or pointer
18954 to member function argument if the set of
18955 overloaded functions does not contain function
18956 templates and at most one of a set of
18957 overloaded functions provides a unique
18958 match. */
18965 }
18971 }
18973 arg_strict |=
18975 }
18976 else
18981 /* For deduction from an init-list we need the actual list. */
18985 }
18987 /* for_each_template_parm callback that always returns 0. */
18989 static int
18991 {
18993 }
18995 /* for_each_template_parm any_fn callback to handle deduction of a template
18996 type argument from the type of an array bound. */
18998 static int
19000 {
19008 {
19014 }
19016 /* Keep walking. */
19018 }
19020 /* Try to deduce any not-yet-deduced template type arguments from the type of
19021 an array bound. This is handled separately from unify because 14.8.2.5 says
19022 "The type of a type parameter is only deduced from an array bound if it is
19023 not otherwise deduced." */
19025 static void
19027 {
19032 }
19034 /* Most parms like fn_type_unification.
19036 If SUBR is 1, we're being called recursively (to unify the
19037 arguments of a function or method parameter of a function
19038 template).
19040 CHECKS is a pointer to a vector of access checks encountered while
19041 substituting default template arguments. */
19043 static int
19045 tree full_targs,
19046 tree xparms,
19050 unification_kind_t strict,
19054 {
19059 tree parms;
19070 /* Reset the number of non-defaulted template arguments contained
19071 in TARGS. */
19074 again:
19082 {
19087 /* For a function parameter pack that occurs at the end of the
19088 parameter-declaration-list, the type A of each remaining
19089 argument of the call is compared with the type P of the
19090 declarator-id of the function parameter pack. */
19096 /* For a function parameter pack that does not occur at the
19097 end of the parameter-declaration-list, the type of the
19098 parameter pack is a non-deduced context. */
19105 explain_p))
19107 }
19112 {
19113 /* Unify the remaining arguments with the pack expansion type. */
19114 tree argvec;
19117 /* Allocate a TREE_VEC and copy in all of the arguments */
19122 /* Copy the parameter into parmvec. */
19128 /* Advance to the end of the list of parameters. */
19130 }
19132 /* Fail if we've reached the end of the parm list, and more args
19133 are present, and the parm list isn't variadic. */
19136 /* Fail if parms are left and they don't have default values and
19137 they aren't all deduced as empty packs (c++/57397). This is
19138 consistent with sufficient_parms_p. */
19141 {
19145 do
19146 {
19149 count++;
19151 }
19155 type_pack_p);
19156 }
19159 {
19160 tsubst_flags_t complain = (explain_p
19161 ? tf_warning_or_error
19166 {
19170 /* Clear the "incomplete" flags on all argument packs now so that
19171 substituting them into later default arguments works. */
19173 {
19176 }
19184 {
19189 }
19191 /* If this is an undeduced nontype parameter that depends on
19192 a type parameter, try another pass; its type may have been
19193 deduced from a later argument than the one from which
19194 this parameter can be deduced. */
19198 {
19201 }
19203 /* Core issue #226 (C++0x) [temp.deduct]:
19205 If a template argument has not been deduced, its
19206 default template argument, if any, is used.
19208 When we are in C++98 mode, TREE_PURPOSE will either
19209 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19210 to explicitly check cxx_dialect here. */
19212 /* OK, there is a default argument. Wait until after the
19213 conversion check to do substitution. */
19216 /* If the type parameter is a parameter pack, then it will
19217 be deduced to an empty parameter pack. */
19219 {
19220 tree arg;
19223 {
19226 }
19227 else
19234 }
19237 }
19239 /* DR 1391: All parameters have args, now check non-dependent parms for
19240 convertibility. */
19244 {
19250 /* For a function parameter pack that occurs at the end of the
19251 parameter-declaration-list, the type A of each remaining
19252 argument of the call is compared with the type P of the
19253 declarator-id of the function parameter pack. */
19259 /* For a function parameter pack that does not occur at the
19260 end of the parameter-declaration-list, the type of the
19261 parameter pack is a non-deduced context. */
19270 explain_p))
19272 }
19274 /* Now substitute into the default template arguments. */
19276 {
19300 else
19308 {
19310 /* The position of the first default template argument,
19311 is also the number of non-defaulted arguments in TARGS.
19312 Record that. */
19315 }
19316 }
19320 }
19326 }
19328 /* Subroutine of type_unification_real. Args are like the variables
19329 at the call site. ARG is an overloaded function (or template-id);
19330 we try deducing template args from each of the overloads, and if
19331 only one succeeds, we go with that. Modifies TARGS and returns
19332 true on success. */
19334 static bool
19336 tree targs,
19337 tree parm,
19338 tree arg,
19339 unification_kind_t strict,
19342 {
19349 {
19352 }
19353 else
19357 /* Handle `&x' where `x' is some static or non-static member
19358 function name. */
19364 /* Strip baselink information. */
19369 {
19370 /* If we got some explicit template args, we need to plug them into
19371 the affected templates before we try to unify, in case the
19372 explicit args will completely resolve the templates in question. */
19379 {
19392 {
19397 {
19400 }
19401 }
19404 }
19405 /* If no templates (or more than one) are fully resolved by the
19406 explicit arguments, this template-id is a non-deduced context; it
19407 could still be OK if we deduce all template arguments for the
19408 enclosing call through other arguments. */
19411 }
19414 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19415 -- but the deduction does not succeed because the expression is
19416 not just the function on its own. */
19418 else
19420 {
19425 {
19428 }
19429 }
19431 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19432 to function or pointer to member function argument if the set of
19433 overloaded functions does not contain function templates and at most
19434 one of a set of overloaded functions provides a unique match.
19436 So if we found multiple possibilities, we return success but don't
19437 deduce anything. */
19440 {
19444 {
19449 /* Don't forget explicit template arguments in a pack. */
19453 }
19454 }
19459 }
19461 /* Core DR 115: In contexts where deduction is done and fails, or in
19462 contexts where deduction is not done, if a template argument list is
19463 specified and it, along with any default template arguments, identifies
19464 a single function template specialization, then the template-id is an
19465 lvalue for the function template specialization. */
19467 tree
19469 {
19482 {
19485 }
19487 {
19490 }
19492 {
19495 }
19498 {
19502 /* If we got some explicit template args, we need to plug them into
19503 the affected templates before we try to unify, in case the
19504 explicit args will completely resolve the templates in question. */
19512 {
19525 {
19528 {
19531 }
19533 {
19536 }
19537 }
19538 }
19540 {
19548 {
19549 tree base
19552 }
19556 }
19558 /* There were no good options and at least one bad one, so let the
19559 user know what the problem is. */
19561 }
19563 }
19565 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19566 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19567 different overloads deduce different arguments for a given parm.
19568 ADDR_P is true if the expression for which deduction is being
19569 performed was of the form "& fn" rather than simply "fn".
19571 Returns 1 on success. */
19573 static int
19575 tree orig_targs,
19576 tree targs,
19577 tree parm,
19578 tree arg,
19579 unification_kind_t strict,
19583 {
19585 tree tempargs;
19591 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19592 to function or pointer to member function argument if the set of
19593 overloaded functions does not contain function templates and at most
19594 one of a set of overloaded functions provides a unique match.
19596 So if this is a template, just return success. */
19608 /* We don't copy orig_targs for this because if we have already deduced
19609 some template args from previous args, unify would complain when we
19610 try to deduce a template parameter for the same argument, even though
19611 there isn't really a conflict. */
19618 /* First make sure we didn't deduce anything that conflicts with
19619 explicitly specified args. */
19621 {
19628 /* Since we're unifying against ourselves, we will fill in
19629 template args used in the function parm list with our own
19630 template parms. Discard them. */
19633 {
19634 /* Check that the argument at each index of the deduced argument pack
19635 is equivalent to the corresponding explicitly specified argument.
19636 We may have deduced more arguments than were explicitly specified,
19637 and that's OK. */
19639 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
19640 that's wrong if we deduce the same argument pack from multiple
19641 function arguments: it's only incomplete the first time. */
19654 }
19657 }
19660 {
19665 }
19668 }
19670 /* PARM is a template class (perhaps with unbound template
19671 parameters). ARG is a fully instantiated type. If ARG can be
19672 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
19673 TARGS are as for unify. */
19675 static tree
19678 {
19679 tree copy_of_targs;
19689 /* We need to make a new template argument vector for the call to
19690 unify. If we used TARGS, we'd clutter it up with the result of
19691 the attempted unification, even if this class didn't work out.
19692 We also don't want to commit ourselves to all the unifications
19693 we've already done, since unification is supposed to be done on
19694 an argument-by-argument basis. In other words, consider the
19695 following pathological case:
19697 template <int I, int J, int K>
19698 struct S {};
19700 template <int I, int J>
19701 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
19703 template <int I, int J, int K>
19704 void f(S<I, J, K>, S<I, I, I>);
19706 void g() {
19707 S<0, 0, 0> s0;
19708 S<0, 1, 2> s2;
19710 f(s0, s2);
19711 }
19713 Now, by the time we consider the unification involving `s2', we
19714 already know that we must have `f<0, 0, 0>'. But, even though
19715 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
19716 because there are two ways to unify base classes of S<0, 1, 2>
19717 with S<I, I, I>. If we kept the already deduced knowledge, we
19718 would reject the possibility I=1. */
19722 {
19726 }
19728 /* If unification failed, we're done. */
19734 }
19736 /* Given a template type PARM and a class type ARG, find the unique
19737 base type in ARG that is an instance of PARM. We do not examine
19738 ARG itself; only its base-classes. If there is not exactly one
19739 appropriate base class, return NULL_TREE. PARM may be the type of
19740 a partial specialization, as well as a plain template type. Used
19741 by unify. */
19743 static enum template_base_result
19746 {
19748 tree binfo;
19754 {
19755 /* The type could not be completed. */
19758 }
19760 /* Walk in inheritance graph order. The search order is not
19761 important, and this avoids multiple walks of virtual bases. */
19763 {
19768 {
19769 /* If there is more than one satisfactory baseclass, then:
19771 [temp.deduct.call]
19773 If they yield more than one possible deduced A, the type
19774 deduction fails.
19776 applies. */
19778 {
19781 }
19784 }
19785 }
19789 }
19791 /* Returns the level of DECL, which declares a template parameter. */
19793 static int
19795 {
19797 {
19807 }
19809 }
19811 /* Decide whether ARG can be unified with PARM, considering only the
19812 cv-qualifiers of each type, given STRICT as documented for unify.
19813 Returns nonzero iff the unification is OK on that basis. */
19815 static int
19817 {
19823 {
19824 /* Although a CVR qualifier is ignored when being applied to a
19825 substituted template parameter ([8.3.2]/1 for example), that
19826 does not allow us to unify "const T" with "int&" because both
19827 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
19828 It is ok when we're allowing additional CV qualifiers
19829 at the outer level [14.8.2.1]/3,1st bullet. */
19839 }
19850 }
19852 /* Determines the LEVEL and INDEX for the template parameter PARM. */
19853 void
19855 {
19859 {
19862 }
19863 else
19864 {
19867 }
19868 }
19870 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
19871 do { \
19872 if (unify (TP, TA, P, A, S, EP)) \
19873 return 1; \
19874 } while (0)
19876 /* Unifies the remaining arguments in PACKED_ARGS with the pack
19877 expansion at the end of PACKED_PARMS. Returns 0 if the type
19878 deduction succeeds, 1 otherwise. STRICT is the same as in
19879 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
19880 function call argument list. We'll need to adjust the arguments to make them
19881 types. SUBR tells us if this is from a recursive call to
19882 type_unification_real, or for comparing two template argument
19883 lists. */
19885 static int
19889 {
19890 tree parm
19900 /* Determine the parameter packs we will be deducing from the
19901 pattern, and record their current deductions. */
19904 {
19908 /* Determine the index and level of this parameter pack. */
19911 /* Keep track of the parameter packs and their corresponding
19912 argument packs. */
19915 }
19917 /* Loop through all of the arguments that have not yet been
19918 unified and unify each with the pattern. */
19920 {
19921 tree parm;
19925 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
19926 or the element of its argument pack at the current index if
19927 this argument was explicitly specified. */
19929 {
19938 {
19941 }
19943 }
19945 /* If we had explicit template arguments, substitute them into the
19946 pattern before deduction. */
19948 {
19949 /* Some arguments might still be unspecified or dependent. */
19957 NULL_TREE);
19962 }
19963 else
19966 /* Unify the pattern with the current argument. */
19968 explain_p))
19971 /* For each parameter pack, collect the deduced value. */
19973 {
19979 }
19980 }
19982 /* Verify that the results of unification with the parameter packs
19983 produce results consistent with what we've seen before, and make
19984 the deduced argument packs available. */
19986 {
19993 /* By default keep the original deduced argument pack.
19994 If necessary, more specific code is going to update the
19995 resulting deduced argument later down in this function. */
19999 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20000 actually deduce anything. */
20008 {
20009 /* If we had fewer function args than explicit template args,
20010 just use the explicits. */
20015 }
20018 {
20019 tree result;
20020 /* Build the deduced *_ARGUMENT_PACK. */
20022 {
20025 }
20026 else
20031 /* Note the deduced argument packs for this parameter
20032 pack. */
20034 }
20038 {
20039 /* We only had the explicitly-provided arguments before, but
20040 now we have a complete set of arguments. */
20046 }
20047 else
20048 {
20054 /* Inconsistent unification of this parameter pack. */
20056 bad_old_arg,
20057 bad_new_arg);
20058 }
20059 }
20062 }
20064 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20065 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20066 parameters and return value are as for unify. */
20068 static int
20072 {
20073 tree parm_max;
20074 tree arg_max;
20078 /* Our representation of array types uses "N - 1" as the
20079 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20080 not an integer constant. We cannot unify arbitrarily
20081 complex expressions, so we eliminate the MINUS_EXPRs
20082 here. */
20086 {
20089 }
20093 {
20094 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20095 trying to unify the type of a variable with the type
20096 of a template parameter. For example:
20098 template <unsigned int N>
20099 void f (char (&) [N]);
20100 int g();
20101 void h(int i) {
20102 char a[g(i)];
20103 f(a);
20104 }
20106 Here, the type of the ARG will be "int [g(i)]", and
20107 may be a SAVE_EXPR, etc. */
20111 }
20113 /* If only one of the bounds used a MINUS_EXPR, compensate
20114 by adding one to the other bound. */
20117 integer_type_node,
20118 parm_max,
20119 integer_one_node);
20122 integer_type_node,
20123 arg_max,
20124 integer_one_node);
20128 }
20130 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20134 static pa_kind_t
20136 {
20145 else
20147 }
20149 /* Deduce the value of template parameters. TPARMS is the (innermost)
20150 set of template parameters to a template. TARGS is the bindings
20151 for those template parameters, as determined thus far; TARGS may
20152 include template arguments for outer levels of template parameters
20153 as well. PARM is a parameter to a template function, or a
20154 subcomponent of that parameter; ARG is the corresponding argument.
20155 This function attempts to match PARM with ARG in a manner
20156 consistent with the existing assignments in TARGS. If more values
20157 are deduced, then TARGS is updated.
20159 Returns 0 if the type deduction succeeds, 1 otherwise. The
20160 parameter STRICT is a bitwise or of the following flags:
20162 UNIFY_ALLOW_NONE:
20163 Require an exact match between PARM and ARG.
20164 UNIFY_ALLOW_MORE_CV_QUAL:
20165 Allow the deduced ARG to be more cv-qualified (by qualification
20166 conversion) than ARG.
20167 UNIFY_ALLOW_LESS_CV_QUAL:
20168 Allow the deduced ARG to be less cv-qualified than ARG.
20169 UNIFY_ALLOW_DERIVED:
20170 Allow the deduced ARG to be a template base class of ARG,
20171 or a pointer to a template base class of the type pointed to by
20172 ARG.
20173 UNIFY_ALLOW_INTEGER:
20174 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20175 case for more information.
20176 UNIFY_ALLOW_OUTER_LEVEL:
20177 This is the outermost level of a deduction. Used to determine validity
20178 of qualification conversions. A valid qualification conversion must
20179 have const qualified pointers leading up to the inner type which
20180 requires additional CV quals, except at the outer level, where const
20181 is not required [conv.qual]. It would be normal to set this flag in
20182 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20183 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20184 This is the outermost level of a deduction, and PARM can be more CV
20185 qualified at this point.
20186 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20187 This is the outermost level of a deduction, and PARM can be less CV
20188 qualified at this point. */
20190 static int
20193 {
20195 tree targ;
20196 tree tparm;
20198 tsubst_flags_t complain = (explain_p
20199 ? tf_warning_or_error
20202 /* I don't think this will do the right thing with respect to types.
20203 But the only case I've seen it in so far has been array bounds, where
20204 signedness is the only information lost, and I think that will be
20205 okay. */
20213 /* We can't deduce anything from this, but we might get all the
20214 template args from other function args. */
20220 /* If PARM uses template parameters, then we can't bail out here,
20221 even if ARG == PARM, since we won't record unifications for the
20222 template parameters. We might need them if we're trying to
20223 figure out which of two things is more specialized. */
20227 /* Handle init lists early, so the rest of the function can assume
20228 we're dealing with a type. */
20230 {
20235 /* Replace T with std::initializer_list<T> for deduction. */
20242 /* We can only deduce from an initializer list argument if the
20243 parameter is std::initializer_list or an array; otherwise this
20244 is a non-deduced context. */
20249 else
20250 {
20252 /* Deduction is defined in terms of a single type, so just punt
20253 on the (bizarre) std::initializer_list<T...>. */
20256 }
20259 {
20266 {
20270 /* It should only be possible to get here for a call. */
20272 elt_strict |= maybe_adjust_types_for_deduction
20275 }
20278 explain_p);
20279 }
20283 {
20284 /* Also deduce from the length of the initializer list. */
20291 }
20293 /* If the std::initializer_list<T> deduction worked, replace the
20294 deduced A with std::initializer_list<A>. */
20296 {
20301 }
20303 }
20305 /* If parm and arg aren't the same kind of thing (template, type, or
20306 expression), fail early. */
20310 /* Immediately reject some pairs that won't unify because of
20311 cv-qualification mismatches. */
20314 /* It is the elements of the array which hold the cv quals of an array
20315 type, and the elements might be template type parms. We'll check
20316 when we recurse. */
20318 /* We check the cv-qualifiers when unifying with template type
20319 parameters below. We want to allow ARG `const T' to unify with
20320 PARM `T' for example, when computing which of two templates
20321 is more specialized, for example. */
20335 {
20339 /* In a type which contains a nested-name-specifier, template
20340 argument values cannot be deduced for template parameters used
20341 within the nested-name-specifier. */
20353 /* The PARM is not one we're trying to unify. Just check
20354 to see if it matches ARG. */
20355 {
20360 else
20362 }
20369 /* Check for mixed types and values. */
20377 {
20380 {
20381 /* First try to match ARG directly. */
20383 explain_p);
20385 {
20386 /* Otherwise, look for a suitable base of ARG, as below. */
20393 }
20394 }
20395 /* ARG must be constructed from a template class or a template
20396 template parameter. */
20401 /* Deduce arguments T, i from TT<T> or TT<i>. */
20407 /* Fall through to deduce template name. */
20408 }
20412 {
20413 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20415 /* Simple cases: Value already set, does match or doesn't. */
20420 }
20421 else
20422 {
20423 /* If PARM is `const T' and ARG is only `int', we don't have
20424 a match unless we are allowing additional qualification.
20425 If ARG is `const int' and PARM is just `T' that's OK;
20426 that binds `const int' to `T'. */
20431 /* Consider the case where ARG is `const volatile int' and
20432 PARM is `const T'. Then, T should be `volatile int'. */
20433 arg = cp_build_qualified_type_real
20438 /* Simple cases: Value already set, does match or doesn't. */
20444 /* Make sure that ARG is not a variable-sized array. (Note
20445 that were talking about variable-sized arrays (like
20446 `int[n]'), rather than arrays of unknown size (like
20447 `int[]').) We'll get very confused by such a type since
20448 the bound of the array is not constant, and therefore
20449 not mangleable. Besides, such types are not allowed in
20450 ISO C++, so we can do as we please here. We do allow
20451 them for 'auto' deduction, since that isn't ABI-exposed. */
20455 /* Strip typedefs as in convert_template_argument. */
20457 }
20459 /* If ARG is a parameter pack or an expansion, we cannot unify
20460 against it unless PARM is also a parameter pack. */
20465 /* If the argument deduction results is a METHOD_TYPE,
20466 then there is a problem.
20467 METHOD_TYPE doesn't map to any real C++ type the result of
20468 the deduction can not be of that type. */
20482 {
20483 /* The PARM is not one we're trying to unify. Just check
20484 to see if it matches ARG. */
20490 }
20496 {
20501 }
20504 /* We deduce from array bounds in try_array_deduction. */
20508 {
20513 }
20515 /* [temp.deduct.type] If, in the declaration of a function template
20516 with a non-type template-parameter, the non-type
20517 template-parameter is used in an expression in the function
20518 parameter-list and, if the corresponding template-argument is
20519 deduced, the template-argument type shall match the type of the
20520 template-parameter exactly, except that a template-argument
20521 deduced from an array bound may be of any integral type.
20522 The non-type parameter might use already deduced type parameters. */
20525 {
20529 }
20532 /* Template-parameter dependent expression. Just accept it for now.
20533 It will later be processed in convert_template_argument. */
20534 ;
20539 /* Convert the ARG to the type of PARM; the deduced non-type
20540 template argument must exactly match the types of the
20541 corresponding parameter. */
20544 /* We haven't deduced the type of this parameter yet. Try again
20545 later. */
20547 else
20550 /* If ARG is a parameter pack or an expansion, we cannot unify
20551 against it unless PARM is also a parameter pack. */
20556 {
20559 }
20564 {
20565 /* A pointer-to-member constant can be unified only with
20566 another constant. */
20570 /* Just unify the class member. It would be useless (and possibly
20571 wrong, depending on the strict flags) to unify also
20572 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20573 arg refer to the same variable, even if through different
20574 classes. For instance:
20576 struct A { int x; };
20577 struct B : A { };
20579 Unification of &A::x and &B::x must succeed. */
20582 }
20585 {
20589 /* [temp.deduct.call]
20591 A can be another pointer or pointer to member type that can
20592 be converted to the deduced A via a qualification
20593 conversion (_conv.qual_).
20595 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
20596 This will allow for additional cv-qualification of the
20597 pointed-to types if appropriate. */
20600 /* The derived-to-base conversion only persists through one
20601 level of pointers. */
20606 }
20638 /* We have already checked cv-qualification at the top of the
20639 function. */
20643 /* As far as unification is concerned, this wins. Later checks
20644 will invalidate it if necessary. */
20647 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
20648 /* Type INTEGER_CST can come from ordinary constant template args. */
20660 {
20670 /* Check for pack expansions in the parameters. */
20672 {
20674 {
20676 /* We can unify against something with a trailing
20677 parameter pack. */
20679 else
20680 /* [temp.deduct.type]/9: If the template argument list of
20681 P contains a pack expansion that is not the last
20682 template argument, the entire template argument list
20683 is a non-deduced context. */
20685 }
20686 }
20688 /* If we don't have enough arguments to satisfy the parameters
20689 (not counting the pack expression at the end), or we have
20690 too many arguments for a parameter list that doesn't end in
20691 a pack expression, we can't unify. */
20697 /* Unify all of the parameters that precede the (optional)
20698 pack expression. */
20700 {
20705 }
20708 DEDUCE_EXACT,
20711 }
20719 {
20727 }
20732 {
20736 {
20737 /* First, we try to unify the PARM and ARG directly. */
20742 {
20743 /* Fallback to the special case allowed in
20744 [temp.deduct.call]:
20746 If P is a class, and P has the form
20747 template-id, then A can be a derived class of
20748 the deduced A. Likewise, if P is a pointer to
20749 a class of the form template-id, A can be a
20750 pointer to a derived class pointed to by the
20751 deduced A. */
20757 {
20758 /* Don't give the derived diagnostic if we're
20759 already dealing with the same template. */
20760 bool same_template
20766 }
20767 }
20768 }
20772 /* Perhaps PARM is something like S<U> and ARG is S<int>.
20773 Then, we should unify `int' and `U'. */
20775 else
20776 /* There's no chance of unification succeeding. */
20781 }
20788 {
20791 tree a;
20797 /* CV qualifications for methods can never be deduced, they must
20798 match exactly. We need to check them explicitly here,
20799 because type_unification_real treats them as any other
20800 cv-qualified parameter. */
20802 && (!check_cv_quals_for_unify
20830 {
20842 }
20845 }
20848 /* Unify a pointer to member with a pointer to member function, which
20849 deduces the type of the member as a function type. */
20851 {
20852 /* Check top-level cv qualifiers */
20860 /* Determine the type of the function we are unifying against. */
20864 }
20883 /* Matched cases are handled by the ARG == PARM test above. */
20887 /* We might get a variable as a non-type template argument in parm if the
20888 corresponding parameter is type-dependent. Make any necessary
20889 adjustments based on whether arg is a reference. */
20893 {
20898 }
20899 /* Now use the normal expression code to check whether they match. */
20910 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
20911 or UNDERLYING_TYPE nodes. */
20915 /* Unification fails if we hit an error node. */
20920 {
20930 }
20931 /* FALLTHRU */
20934 /* An unresolved overload is a nondeduced context. */
20938 expr:
20939 /* We must be looking at an expression. This can happen with
20940 something like:
20942 template <int I>
20943 void foo(S<I>, S<I + 2>);
20945 This is a "nondeduced context":
20947 [deduct.type]
20949 The nondeduced contexts are:
20951 --A type that is a template-id in which one or more of
20952 the template-arguments is an expression that references
20953 a template-parameter.
20955 In these cases, we assume deduction succeeded, but don't
20956 actually infer any unifications. */
20961 else
20963 }
20964 }
20965 #undef RECUR_AND_CHECK_FAILURE
20966 \f
20967 /* Note that DECL can be defined in this translation unit, if
20968 required. */
20970 static void
20972 {
20973 tree clone;
20977 }
20979 /* Called if RESULT is explicitly instantiated, or is a member of an
20980 explicitly instantiated class. */
20982 void
20984 {
20987 /* If this entity has already been written out, it's too late to
20988 make any modifications. */
20992 /* For anonymous namespace we don't need to do anything. */
20994 {
20997 }
21000 /* The TREE_PUBLIC flag for function declarations will have been
21001 set correctly by tsubst. */
21004 /* This might have been set by an earlier implicit instantiation. */
21009 else
21010 {
21013 /* Always make artificials weak. */
21016 /* For WIN32 we also want to put explicit instantiations in
21017 linkonce sections. */
21020 }
21022 /* If EXTERN_P, then this function will not be emitted -- unless
21023 followed by an explicit instantiation, at which point its linkage
21024 will be adjusted. If !EXTERN_P, then this function will be
21025 emitted here. In neither circumstance do we want
21026 import_export_decl to adjust the linkage. */
21028 }
21030 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21031 important template arguments. If any are missing, we check whether
21032 they're important by using error_mark_node for substituting into any
21033 args that were used for partial ordering (the ones between ARGS and END)
21034 and seeing if it bubbles up. */
21036 static bool
21038 {
21043 {
21046 }
21048 {
21052 }
21054 }
21056 /* Given two function templates PAT1 and PAT2, return:
21058 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21059 -1 if PAT2 is more specialized than PAT1.
21060 0 if neither is more specialized.
21062 LEN indicates the number of parameters we should consider
21063 (defaulted parameters should not be considered).
21065 The 1998 std underspecified function template partial ordering, and
21066 DR214 addresses the issue. We take pairs of arguments, one from
21067 each of the templates, and deduce them against each other. One of
21068 the templates will be more specialized if all the *other*
21069 template's arguments deduce against its arguments and at least one
21070 of its arguments *does* *not* deduce against the other template's
21071 corresponding argument. Deduction is done as for class templates.
21072 The arguments used in deduction have reference and top level cv
21073 qualifiers removed. Iff both arguments were originally reference
21074 types *and* deduction succeeds in both directions, an lvalue reference
21075 wins against an rvalue reference and otherwise the template
21076 with the more cv-qualified argument wins for that pairing (if
21077 neither is more cv-qualified, they both are equal). Unlike regular
21078 deduction, after all the arguments have been deduced in this way,
21079 we do *not* verify the deduced template argument values can be
21080 substituted into non-deduced contexts.
21082 The logic can be a bit confusing here, because we look at deduce1 and
21083 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21084 can find template arguments for pat1 to make arg1 look like arg2, that
21085 means that arg2 is at least as specialized as arg1. */
21087 int
21089 {
21102 /* Remove the this parameter from non-static member functions. If
21103 one is a non-static member function and the other is not a static
21104 member function, remove the first parameter from that function
21105 also. This situation occurs for operator functions where we
21106 locate both a member function (with this pointer) and non-member
21107 operator (with explicit first operand). */
21109 {
21114 }
21116 {
21119 {
21120 len--;
21122 }
21123 }
21125 /* If only one is a conversion operator, they are unordered. */
21129 /* Consider the return type for a conversion function */
21131 {
21134 len++;
21135 }
21137 processing_template_decl++;
21143 /* Stop when an ellipsis is seen. */
21145 {
21156 {
21157 /* When both arguments are pack expansions, we need only
21158 unify the patterns themselves. */
21162 /* This is the last comparison we need to do. */
21164 }
21166 /* DR 1847: If a particular P contains no template-parameters that
21167 participate in template argument deduction, that P is not used to
21168 determine the ordering. */
21174 {
21178 }
21181 {
21185 }
21191 {
21197 /* Setup the parameter vector, which contains only ARG1. */
21200 /* Setup the argument vector, which contains the remaining
21201 arguments. */
21210 /* We cannot deduce in the other direction, because ARG1 is
21211 a pack expansion but ARG2 is not. */
21213 }
21215 {
21221 /* Setup the parameter vector, which contains only ARG1. */
21224 /* Setup the argument vector, which contains the remaining
21225 arguments. */
21234 /* We cannot deduce in the other direction, because ARG2 is
21235 a pack expansion but ARG1 is not.*/
21237 }
21239 else
21240 {
21241 /* The normal case, where neither argument is a pack
21242 expansion. */
21249 }
21251 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21252 arg2, then arg2 is not as specialized as arg1. */
21258 /* "If, for a given type, deduction succeeds in both directions
21259 (i.e., the types are identical after the transformations above)
21260 and both P and A were reference types (before being replaced with
21261 the type referred to above):
21262 - if the type from the argument template was an lvalue reference and
21263 the type from the parameter template was not, the argument type is
21264 considered to be more specialized than the other; otherwise,
21265 - if the type from the argument template is more cv-qualified
21266 than the type from the parameter template (as described above),
21267 the argument type is considered to be more specialized than the other;
21268 otherwise,
21269 - neither type is more specialized than the other." */
21272 {
21274 {
21277 else
21279 }
21281 {
21286 }
21287 }
21290 /* We've failed to deduce something in either direction.
21291 These must be unordered. */
21294 next:
21298 /* We have already processed all of the arguments in our
21299 handing of the pack expansion type. */
21304 }
21306 /* "In most cases, all template parameters must have values in order for
21307 deduction to succeed, but for partial ordering purposes a template
21308 parameter may remain without a value provided it is not used in the
21309 types being used for partial ordering."
21311 Thus, if we are missing any of the targs1 we need to substitute into
21312 origs1, then pat2 is not as specialized as pat1. This can happen when
21313 there is a nondeduced context. */
21319 processing_template_decl--;
21321 /* If both deductions succeed, the partial ordering selects the more
21322 constrained template. */
21324 {
21329 }
21331 /* All things being equal, if the next argument is a pack expansion
21332 for one function but not for the other, prefer the
21333 non-variadic function. FIXME this is bogus; see c++/41958. */
21337 {
21340 }
21346 else
21348 }
21350 /* Determine which of two partial specializations of TMPL is more
21351 specialized.
21353 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21354 to the first partial specialization. The TREE_PURPOSE is the
21355 innermost set of template parameters for the partial
21356 specialization. PAT2 is similar, but for the second template.
21358 Return 1 if the first partial specialization is more specialized;
21359 -1 if the second is more specialized; 0 if neither is more
21360 specialized.
21362 See [temp.class.order] for information about determining which of
21363 two templates is more specialized. */
21365 static int
21367 {
21368 tree targs;
21377 /* Just like what happens for functions, if we are ordering between
21378 different template specializations, we may encounter dependent
21379 types in the arguments, and we need our dependency check functions
21380 to behave correctly. */
21384 {
21387 }
21391 {
21394 }
21397 /* If both deductions succeed, the partial ordering selects the more
21398 constrained template. */
21402 /* In the case of a tie where at least one of the templates
21403 has a parameter pack at the end, the template with the most
21404 non-packed parameters wins. */
21406 && any_deductions
21409 {
21415 /* We don't count the pack expansion at the end. */
21425 }
21428 }
21430 /* Return the template arguments that will produce the function signature
21431 DECL from the function template FN, with the explicit template
21432 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21433 also match. Return NULL_TREE if no satisfactory arguments could be
21434 found. */
21436 static tree
21438 {
21442 tree decl_arg_types;
21445 tree arg;
21449 /* Never do unification on the 'this' parameter. */
21470 }
21472 /* Return the innermost template arguments that, when applied to a partial
21473 specialization SPEC_TMPL of TMPL, yield the ARGS.
21475 For example, suppose we have:
21477 template <class T, class U> struct S {};
21478 template <class T> struct S<T*, int> {};
21480 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21481 partial specialization and the ARGS will be {double*, int}. The resulting
21482 vector will be {double}, indicating that `T' is bound to `double'. */
21484 static tree
21486 {
21488 tree spec_args
21491 tree deduced_args;
21492 tree innermost_deduced_args;
21496 {
21500 innermost_deduced_args);
21501 }
21502 else
21506 again:
21515 {
21517 {
21523 }
21525 }
21529 {
21532 }
21534 /* Verify that nondeduced template arguments agree with the type
21535 obtained from argument deduction.
21537 For example:
21539 struct A { typedef int X; };
21540 template <class T, class U> struct C {};
21541 template <class T> struct C<T, typename T::X> {};
21543 Then with the instantiation `C<A, int>', we can deduce that
21544 `T' is `A' but unify () does not check whether `typename T::X'
21545 is `int'. */
21554 /* We only need to check the innermost arguments; the other
21555 arguments will always agree. */
21560 /* Now that we have bindings for all of the template arguments,
21561 ensure that the arguments deduced for the template template
21562 parameters have compatible template parameter lists. See the use
21563 of template_template_parm_bindings_ok_p in fn_type_unification
21564 for more information. */
21569 }
21571 // Compare two function templates T1 and T2 by deducing bindings
21572 // from one against the other. If both deductions succeed, compare
21573 // constraints to see which is more constrained.
21574 static int
21576 {
21581 {
21584 }
21587 {
21590 }
21592 // If both deductions succeed, then one may be more constrained.
21597 }
21599 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
21600 Return the TREE_LIST node with the most specialized template, if
21601 any. If there is no most specialized template, the error_mark_node
21602 is returned.
21604 Note that this function does not look at, or modify, the
21605 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
21606 returned is one of the elements of INSTANTIATIONS, callers may
21607 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
21608 and retrieve it from the value returned. */
21610 tree
21612 {
21619 {
21624 {
21625 /* Equally specialized, move to next function. If there
21626 is no next function, nothing's most specialized. */
21631 }
21632 }
21635 /* Now verify that champ is better than everything earlier in the
21636 instantiation list. */
21639 {
21642 }
21643 }
21645 processing_template_decl--;
21651 }
21653 /* If DECL is a specialization of some template, return the most
21654 general such template. Otherwise, returns NULL_TREE.
21656 For example, given:
21658 template <class T> struct S { template <class U> void f(U); };
21660 if TMPL is `template <class U> void S<int>::f(U)' this will return
21661 the full template. This function will not trace past partial
21662 specializations, however. For example, given in addition:
21664 template <class T> struct S<T*> { template <class U> void f(U); };
21666 if TMPL is `template <class U> void S<int*>::f(U)' this will return
21667 `template <class T> template <class U> S<T*>::f(U)'. */
21669 tree
21671 {
21673 {
21676 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
21677 template friend, or a FIELD_DECL for a capture pack. */
21680 }
21682 /* Look for more and more general templates. */
21684 {
21685 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
21686 (See cp-tree.h for details.) */
21695 /* Stop if we run into an explicitly specialized class template. */
21702 }
21705 }
21707 /* Return the most specialized of the template partial specializations
21708 which can produce TARGET, a specialization of some class or variable
21709 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
21710 a TEMPLATE_DECL node corresponding to the partial specialization, while
21711 the TREE_PURPOSE is the set of template arguments that must be
21712 substituted into the template pattern in order to generate TARGET.
21714 If the choice of partial specialization is ambiguous, a diagnostic
21715 is issued, and the error_mark_node is returned. If there are no
21716 partial specializations matching TARGET, then NULL_TREE is
21717 returned, indicating that the primary template should be used. */
21719 static tree
21721 {
21723 tree t;
21724 tree champ;
21731 {
21735 }
21737 {
21740 }
21742 {
21746 }
21747 else
21752 /* For determining which partial specialization to use, only the
21753 innermost args are interesting. */
21755 {
21758 }
21761 {
21762 tree spec_args;
21766 {
21767 /* Substitute in the template args from the enclosing class. */
21771 }
21778 {
21782 /* Keep the candidate only if the constraints are satisfied,
21783 or if we're not compiling with concepts. */
21786 {
21789 }
21790 }
21791 }
21801 {
21804 ;
21805 else
21806 {
21808 {
21811 {
21814 }
21815 }
21817 }
21818 }
21822 {
21825 {
21828 }
21829 }
21832 {
21839 else
21843 {
21848 }
21851 }
21854 }
21856 /* Explicitly instantiate DECL. */
21858 void
21860 {
21865 /* An error occurred, for which grokdeclarator has already issued
21866 an appropriate message. */
21869 {
21872 }
21878 {
21879 /* There is an asymmetry here in the way VAR_DECLs and
21880 FUNCTION_DECLs are handled by grokdeclarator. In the case of
21881 the latter, the DECL we get back will be marked as a
21882 template instantiation, and the appropriate
21883 DECL_TEMPLATE_INFO will be set up. This does not happen for
21884 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
21885 should handle VAR_DECLs as it currently handles
21886 FUNCTION_DECLs. */
21888 {
21891 }
21894 {
21897 }
21899 {
21904 }
21905 }
21907 {
21910 }
21911 else
21914 /* Check for various error cases. Note that if the explicit
21915 instantiation is valid the RESULT will currently be marked as an
21916 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
21917 until we get here. */
21920 {
21921 /* DR 259 [temp.spec].
21923 Both an explicit instantiation and a declaration of an explicit
21924 specialization shall not appear in a program unless the explicit
21925 instantiation follows a declaration of the explicit specialization.
21927 For a given set of template parameters, if an explicit
21928 instantiation of a template appears after a declaration of an
21929 explicit specialization for that template, the explicit
21930 instantiation has no effect. */
21932 }
21934 {
21935 /* [temp.spec]
21937 No program shall explicitly instantiate any template more
21938 than once.
21940 We check DECL_NOT_REALLY_EXTERN so as not to complain when
21941 the first instantiation was `extern' and the second is not,
21942 and EXTERN_P for the opposite case. */
21945 /* If an "extern" explicit instantiation follows an ordinary
21946 explicit instantiation, the template is instantiated. */
21949 }
21951 {
21954 }
21956 {
21959 }
21962 ;
21964 {
21967 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
21970 }
21971 else
21979 }
21981 static void
21983 {
21989 {
21992 }
21993 }
21995 /* Called from do_type_instantiation through binding_table_foreach to
21996 do recursive instantiation for the type bound in ENTRY. */
21997 static void
21999 {
22005 }
22007 /* Called from do_type_instantiation to instantiate a member
22008 (a member function or a static member variable) of an
22009 explicitly instantiated class template. */
22010 static void
22012 {
22017 }
22019 /* Perform an explicit instantiation of template class T. STORAGE, if
22020 non-null, is the RID for extern, inline or static. COMPLAIN is
22021 nonzero if this is called from the parser, zero if called recursively,
22022 since the standard is unclear (as detailed below). */
22024 void
22026 {
22036 {
22037 tree tmpl =
22041 else
22044 }
22049 {
22052 t);
22054 }
22057 {
22059 {
22061 {
22064 "ISO C++ 1998 forbids the use of %<extern%> on "
22066 }
22067 else
22069 "ISO C++ forbids the use of %qE"
22071 }
22079 else
22080 {
22082 storage);
22084 }
22085 }
22088 {
22089 /* DR 259 [temp.spec].
22091 Both an explicit instantiation and a declaration of an explicit
22092 specialization shall not appear in a program unless the explicit
22093 instantiation follows a declaration of the explicit specialization.
22095 For a given set of template parameters, if an explicit
22096 instantiation of a template appears after a declaration of an
22097 explicit specialization for that template, the explicit
22098 instantiation has no effect. */
22100 }
22102 {
22103 /* [temp.spec]
22105 No program shall explicitly instantiate any template more
22106 than once.
22108 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22109 instantiation was `extern'. If EXTERN_P then the second is.
22110 These cases are OK. */
22117 /* If we've already instantiated the template, just return now. */
22120 }
22128 {
22129 tree tmp;
22131 /* In contrast to implicit instantiation, where only the
22132 declarations, and not the definitions, of members are
22133 instantiated, we have here:
22135 [temp.explicit]
22137 The explicit instantiation of a class template specialization
22138 implies the instantiation of all of its members not
22139 previously explicitly specialized in the translation unit
22140 containing the explicit instantiation.
22142 Of course, we can't instantiate member template classes, since
22143 we don't have any arguments for them. Note that the standard
22144 is unclear on whether the instantiation of the members are
22145 *explicit* instantiations or not. However, the most natural
22146 interpretation is that it should be an explicit instantiation. */
22162 }
22163 }
22165 /* Given a function DECL, which is a specialization of TMPL, modify
22166 DECL to be a re-instantiation of TMPL with the same template
22167 arguments. TMPL should be the template into which tsubst'ing
22168 should occur for DECL, not the most general template.
22170 One reason for doing this is a scenario like this:
22172 template <class T>
22173 void f(const T&, int i);
22175 void g() { f(3, 7); }
22177 template <class T>
22178 void f(const T& t, const int i) { }
22180 Note that when the template is first instantiated, with
22181 instantiate_template, the resulting DECL will have no name for the
22182 first parameter, and the wrong type for the second. So, when we go
22183 to instantiate the DECL, we regenerate it. */
22185 static void
22187 {
22188 /* The arguments used to instantiate DECL, from the most general
22189 template. */
22190 tree code_pattern;
22194 /* Make sure that we can see identifiers, and compute access
22195 correctly. */
22199 {
22200 tree decl_parm;
22201 tree pattern_parm;
22202 tree specs;
22216 specs);
22218 /* Merge parameter declarations. */
22221 pattern_parm
22225 {
22226 tree parm_type;
22227 tree attributes;
22232 NULL_TREE);
22238 {
22241 }
22244 }
22245 /* Merge any parameters that match with the function parameter
22246 pack. */
22248 {
22250 tree expanded_types;
22251 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22252 the parameters in this function parameter pack. */
22257 {
22258 tree parm_type;
22259 tree attributes;
22262 /* Rename the parameter to include the index. */
22271 {
22274 }
22276 }
22277 }
22278 /* Merge additional specifiers from the CODE_PATTERN. */
22282 }
22284 {
22292 }
22293 else
22297 }
22299 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22300 substituted to get DECL. */
22302 tree
22304 {
22307 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22308 for the instantiation. This is not always the most general
22309 template. Consider, for example:
22311 template <class T>
22312 struct S { template <class U> void f();
22313 template <> void f<int>(); };
22315 and an instantiation of S<double>::f<int>. We want TD to be the
22316 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22318 more general template. */
22320 /* We must also deal with friend templates. Given:
22322 template <class T> struct S {
22323 template <class U> friend void f() {};
22324 };
22326 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22327 so far as the language is concerned, but that's still
22328 where we get the pattern for the instantiation from. On
22329 other hand, if the definition comes outside the class, say:
22331 template <class T> struct S {
22332 template <class U> friend void f();
22333 };
22334 template <class U> friend void f() {}
22336 we don't need to look any further. That's what the check for
22337 DECL_INITIAL is for. */
22341 {
22342 /* The present template, TD, should not be a definition. If it
22343 were a definition, we should be using it! Note that we
22344 cannot restructure the loop to just keep going until we find
22345 a template with a definition, since that might go too far if
22346 a specialization was declared, but not defined. */
22348 /* Fetch the more general template. */
22350 }
22353 }
22355 /* Returns true if we need to instantiate this template instance even if we
22356 know we aren't going to emit it. */
22358 bool
22360 {
22361 /* We always instantiate inline functions so that we can inline them. An
22362 explicit instantiation declaration prohibits implicit instantiation of
22363 non-inline functions. With high levels of optimization, we would
22364 normally inline non-inline functions -- but we're not allowed to do
22365 that for "extern template" functions. Therefore, we check
22366 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22370 /* And we need to instantiate static data members so that
22371 their initializers are available in integral constant
22372 expressions. */
22375 }
22377 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22378 instantiate it now, modifying TREE_TYPE (fn). */
22380 void
22382 {
22385 /* Don't instantiate a noexcept-specification from template context. */
22400 {
22404 {
22419 }
22420 else
22424 }
22427 {
22430 else
22432 }
22433 }
22435 /* Produce the definition of D, a _DECL generated from a template. If
22436 DEFER_OK is true, then we don't have to actually do the
22437 instantiation now; we just have to do it sometime. Normally it is
22438 an error if this is an explicit instantiation but D is undefined.
22439 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22440 instantiated class template. */
22442 tree
22444 {
22446 tree gen_args;
22447 tree args;
22448 tree td;
22449 tree code_pattern;
22450 tree spec;
22451 tree gen_tmpl;
22459 /* This function should only be used to instantiate templates for
22460 functions and static member variables. */
22463 /* A concept is never instantiated. */
22466 /* Variables are never deferred; if instantiation is required, they
22467 are instantiated right away. That allows for better code in the
22468 case that an expression refers to the value of the variable --
22469 if the variable has a constant value the referring expression can
22470 take advantage of that fact. */
22474 /* Don't instantiate cloned functions. Instead, instantiate the
22475 functions they cloned. */
22483 /* D has already been instantiated or explicitly specialized, so
22484 there's nothing for us to do here.
22486 It might seem reasonable to check whether or not D is an explicit
22487 instantiation, and, if so, stop here. But when an explicit
22488 instantiation is deferred until the end of the compilation,
22489 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22490 the instantiation. */
22493 /* Check to see whether we know that this template will be
22494 instantiated in some other file, as with "extern template"
22495 extension. */
22498 /* In general, we do not instantiate such templates. */
22506 /* We should already have the extra args. */
22509 /* And what's in the hash table should match D. */
22513 /* This needs to happen before any tsubsting. */
22519 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22520 for the instantiation. */
22525 {
22526 /* Look up an explicit specialization, if any. */
22530 {
22533 }
22534 }
22538 /* We should never be trying to instantiate a member of a class
22539 template or partial specialization. */
22544 /* In the case of a friend template whose definition is provided
22545 outside the class, we may have too many arguments. Drop the
22546 ones we don't need. The same is true for specializations. */
22547 args = get_innermost_template_args
22551 {
22557 }
22558 else
22559 {
22564 else
22566 }
22568 /* We may be in the middle of deferred access check. Disable it now. */
22571 /* Unless an explicit instantiation directive has already determined
22572 the linkage of D, remember that a definition is available for
22573 this entity. */
22583 /* If D is a member of an explicitly instantiated class template,
22584 and no definition is available, treat it like an implicit
22585 instantiation. */
22588 {
22589 /* Leave linkage flags alone on instantiations with anonymous
22590 visibility. */
22592 {
22595 }
22597 }
22599 /* Defer all other templates, unless we have been explicitly
22600 forbidden from doing so. */
22602 template. */
22603 ! pattern_defined
22604 /* If it's OK to postpone instantiation, do so. */
22605 || defer_ok
22606 /* If this is a static data member that will be defined
22607 elsewhere, we don't want to instantiate the entire data
22608 member, but we do want to instantiate the initializer so that
22609 we can substitute that elsewhere. */
22611 /* Handle here a deleted function too, avoid generating
22612 its body (c++/61080). */
22614 {
22615 /* The definition of the static data member is now required so
22616 we must substitute the initializer. */
22620 {
22621 tree ns;
22622 tree init;
22631 args,
22634 /* If instantiating the initializer involved instantiating this
22635 again, don't call cp_finish_decl twice. */
22637 {
22638 /* Make sure the initializer is still constant, in case of
22639 circular dependency (template/instantiate6.C). */
22640 const_init
22644 LOOKUP_ONLYCONVERTING);
22645 }
22649 }
22651 /* We restore the source position here because it's used by
22652 add_pending_template. */
22658 /* [temp.explicit]
22660 The definition of a non-exported function template, a
22661 non-exported member function template, or a non-exported
22662 member function or static data member of a class template
22663 shall be present in every translation unit in which it is
22664 explicitly instantiated. */
22668 /* If we're in unevaluated context, we just wanted to get the
22669 constant value; this isn't an odr use, so don't queue
22670 a full instantiation. */
22673 /* ??? Historically, we have instantiated inline functions, even
22674 when marked as "extern template". */
22678 }
22679 /* Tell the repository that D is available in this translation unit
22680 -- and see if it is supposed to be instantiated here. */
22682 {
22683 /* In a PCH file, despite the fact that the repository hasn't
22684 requested instantiation in the PCH it is still possible that
22685 an instantiation will be required in a file that includes the
22686 PCH. */
22689 /* Instantiate inline functions so that the inliner can do its
22690 job, even though we'll not be emitting a copy of this
22691 function. */
22694 }
22697 tree fn_context;
22708 else
22709 {
22713 }
22715 /* Mark D as instantiated so that recursive calls to
22716 instantiate_decl do not try to instantiate it again. */
22719 /* Regenerate the declaration in case the template has been modified
22720 by a subsequent redeclaration. */
22723 /* We already set the file and line above. Reset them now in case
22724 they changed as a result of calling regenerate_decl_from_template. */
22728 {
22729 tree init;
22732 /* Clear out DECL_RTL; whatever was there before may not be right
22733 since we've reset the type of the declaration. */
22737 /* The initializer is placed in DECL_INITIAL by
22738 regenerate_decl_from_template so we don't need to
22739 push/pop_access_scope again here. Pull it out so that
22740 cp_finish_decl can process it. */
22745 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
22746 initializer. That function will defer actual emission until
22747 we have a chance to determine linkage. */
22750 /* Enter the scope of D so that access-checking works correctly. */
22763 }
22767 {
22769 tree tmpl_parm;
22770 tree spec_parm;
22774 /* Save away the current list, in case we are instantiating one
22775 template from within the body of another. */
22778 /* Set up the list of local specializations. */
22781 /* Set up context. */
22785 else
22786 {
22788 {
22789 /* When instantiating a lambda's templated function
22790 operator, we need to push the non-lambda class scope
22791 of the lambda itself so that the nested function
22792 stack is sufficiently correct to deal with this
22793 capture. */
22795 do
22800 }
22802 }
22804 /* Some typedefs referenced from within the template code need to be
22805 access checked at template instantiation time, i.e now. These
22806 types were added to the template at parsing time. Let's get those
22807 and perform the access checks then. */
22809 args);
22811 /* Create substitution entries for the parameters. */
22815 {
22819 }
22821 {
22823 {
22826 }
22827 else
22828 {
22829 /* Register the (value) argument pack as a specialization of
22830 TMPL_PARM, then move on. */
22833 }
22834 }
22837 /* Substitute into the body of the function. */
22841 else
22842 {
22847 /* Set the current input_location to the end of the function
22848 so that finish_function knows where we are. */
22849 input_location
22852 /* Remember if we saw an infinite loop in the template. */
22853 current_function_infinite_loop
22855 }
22857 /* We don't need the local specializations any more. */
22861 /* Finish the function. */
22865 else
22866 {
22869 }
22875 }
22877 /* We're not deferring instantiation any more. */
22882 else
22888 out:
22897 }
22899 /* Run through the list of templates that we wish we could
22900 instantiate, and instantiate any we can. RETRIES is the
22901 number of times we retry pending template instantiation. */
22903 void
22905 {
22909 /* Instantiating templates may trigger vtable generation. This in turn
22910 may require further template instantiations. We place a limit here
22911 to avoid infinite loop. */
22913 {
22917 "template instantiation depth exceeds maximum of %d"
22918 " instantiating %q+D, possibly from virtual table generation"
22922 /* Pretend that we defined it. */
22925 }
22927 do
22928 {
22933 {
22938 {
22939 tree fn;
22942 {
22946 fn;
22954 }
22957 }
22958 else
22959 {
22962 {
22963 instantiation
22969 }
22973 }
22976 /* If INSTANTIATION has been instantiated, then we don't
22977 need to consider it again in the future. */
22979 else
22980 {
22983 }
22986 }
22988 }
22992 }
22994 /* Substitute ARGVEC into T, which is a list of initializers for
22995 either base class or a non-static data member. The TREE_PURPOSEs
22996 are DECLs, and the TREE_VALUEs are the initializer values. Used by
22997 instantiate_decl. */
22999 static tree
23001 {
23005 {
23006 tree decl;
23007 tree init;
23013 {
23014 tree expr;
23015 tree arg;
23017 /* Expand the base class expansion type into separate base
23018 classes. */
23020 tf_warning_or_error,
23021 NULL_TREE);
23025 /* We'll be building separate TREE_LISTs of arguments for
23026 each base. */
23032 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23033 expand each argument in the TREE_VALUE of t. */
23040 /* VOID_TYPE_NODE is used to indicate
23041 value-initialization. */
23042 {
23045 }
23046 else
23047 {
23048 /* Substitute parameter packs into each argument in the
23049 TREE_LIST. */
23052 {
23053 tree expanded_exprs;
23055 /* Expand the argument. */
23057 expanded_exprs
23059 tf_warning_or_error,
23060 NULL_TREE);
23064 /* Prepend each of the expanded expressions to the
23065 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23067 {
23072 }
23073 }
23076 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23077 since we built them backwards. */
23079 {
23082 }
23083 }
23084 }
23087 {
23089 {
23093 }
23094 else
23095 {
23096 tree tmp;
23111 /* If we had an initializer but it instantiated to nothing,
23112 value-initialize the object. This will only occur when
23113 the initializer was a pack expansion where the parameter
23114 packs used in that expansion were of length zero. */
23117 }
23120 {
23124 }
23125 }
23126 }
23128 }
23130 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23132 static void
23134 {
23139 else
23141 }
23143 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23144 is the instantiation (which should have been created with
23145 start_enum) and ARGS are the template arguments to use. */
23147 static void
23149 {
23150 tree e;
23156 {
23157 tree value;
23158 tree decl;
23161 /* Note that in a template enum, the TREE_VALUE is the
23162 CONST_DECL, not the corresponding INTEGER_CST. */
23167 /* Give this enumeration constant the correct access. */
23170 /* Actually build the enumerator itself. Here we're assuming that
23171 enumerators can't have dependent attributes. */
23174 }
23184 }
23186 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23187 its type -- but without substituting the innermost set of template
23188 arguments. So, innermost set of template parameters will appear in
23189 the type. */
23191 tree
23193 {
23194 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23196 }
23198 /* Return truthvalue if we're processing a template different from
23199 the last one involved in diagnostics. */
23200 bool
23202 {
23204 }
23206 /* Remember current template involved in diagnostics. */
23207 void
23209 {
23211 }
23215 {
23217 }
23219 /* Return TRUE if current_function_decl is being instantiated, false
23220 otherwise. */
23222 bool
23224 {
23227 }
23229 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23230 type. Return zero for ok, nonzero for disallowed. Issue error and
23231 warning messages under control of COMPLAIN. */
23233 static int
23235 {
23250 /* A bound template template parm could later be instantiated to have a valid
23251 nontype parm type via an alias template. */
23257 {
23260 else
23262 type);
23263 }
23265 }
23267 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23268 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23270 static bool
23272 {
23273 tree scope;
23275 /* [temp.dep.type]
23277 A type is dependent if it is:
23279 -- a template parameter. Template template parameters are types
23280 for us (since TYPE_P holds true for them) so we handle
23281 them here. */
23285 /* -- a qualified-id with a nested-name-specifier which contains a
23286 class-name that names a dependent type or whose unqualified-id
23287 names a dependent type. */
23291 /* An alias template specialization can be dependent even if the
23292 resulting type is not. */
23296 /* -- a cv-qualified type where the cv-unqualified type is
23297 dependent.
23298 No code is necessary for this bullet; the code below handles
23299 cv-qualified types, and we don't want to strip aliases with
23300 TYPE_MAIN_VARIANT because of DR 1558. */
23301 /* -- a compound type constructed from any dependent type. */
23311 {
23312 tree arg_type;
23317 arg_type;
23322 }
23323 /* -- an array type constructed from any dependent type or whose
23324 size is specified by a constant expression that is
23325 value-dependent.
23327 We checked for type- and value-dependence of the bounds in
23328 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23330 {
23335 }
23337 /* -- a template-id in which either the template name is a template
23338 parameter ... */
23341 /* ... or any of the template arguments is a dependent type or
23342 an expression that is type-dependent or value-dependent. */
23344 && (any_dependent_template_arguments_p
23348 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23349 dependent; if the argument of the `typeof' expression is not
23350 type-dependent, then it should already been have resolved. */
23356 /* A template argument pack is dependent if any of its packed
23357 arguments are. */
23359 {
23365 }
23367 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23368 be template parameters. */
23375 /* The standard does not specifically mention types that are local
23376 to template functions or local classes, but they should be
23377 considered dependent too. For example:
23379 template <int I> void f() {
23380 enum E { a = I };
23381 S<sizeof (E)> s;
23382 }
23384 The size of `E' cannot be known until the value of `I' has been
23385 determined. Therefore, `E' must be considered dependent. */
23389 /* Don't use type_dependent_expression_p here, as it can lead
23390 to infinite recursion trying to determine whether a lambda
23391 nested in a lambda is dependent (c++/47687). */
23395 && (any_dependent_template_arguments_p
23399 /* Other types are non-dependent. */
23401 }
23403 /* Returns TRUE if TYPE is dependent, in the sense of
23404 [temp.dep.type]. Note that a NULL type is considered dependent. */
23406 bool
23408 {
23409 /* If there are no template parameters in scope, then there can't be
23410 any dependent types. */
23412 {
23413 /* If we are not processing a template, then nobody should be
23414 providing us with a dependent type. */
23418 }
23420 /* If the type is NULL, we have not computed a type for the entity
23421 in question; in that case, the type is dependent. */
23425 /* Erroneous types can be considered non-dependent. */
23429 /* Getting here with global_type_node means we improperly called this
23430 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23433 /* If we have not already computed the appropriate value for TYPE,
23434 do so now. */
23436 {
23439 }
23442 }
23444 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23445 lookup. In other words, a dependent type that is not the current
23446 instantiation. */
23448 bool
23450 {
23453 }
23455 /* T is a SCOPE_REF; return whether we need to consider it
23456 instantiation-dependent so that we can check access at instantiation
23457 time even though we know which member it resolves to. */
23459 static bool
23461 {
23467 else
23469 }
23471 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23472 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23473 expression. */
23475 /* Note that this predicate is not appropriate for general expressions;
23476 only constant expressions (that satisfy potential_constant_expression)
23477 can be tested for value dependence. */
23479 bool
23481 {
23485 /* A name declared with a dependent type. */
23490 {
23492 /* A dependent member function of the current instantiation. */
23496 /* A dependent member function of the current instantiation. */
23503 /* A name that has not been looked up -- must be dependent. */
23507 /* A non-type template parm. */
23511 /* A non-type template parm. */
23517 /* A constant with literal type and is initialized
23518 with an expression that is value-dependent.
23520 Note that a non-dependent parenthesized initializer will have
23521 already been replaced with its constant value, so if we see
23522 a TREE_LIST it must be dependent. */
23526 /* cp_finish_decl doesn't fold reference initializers. */
23532 {
23536 }
23544 /* These expressions are value-dependent if the type to which
23545 the cast occurs is dependent or the expression being casted
23546 is value-dependent. */
23547 {
23553 /* A functional cast has a list of operands. */
23556 {
23557 /* If there are no operands, it must be an expression such
23558 as "int()". This should not happen for aggregate types
23559 because it would form non-constant expressions. */
23564 }
23570 }
23575 /* FALLTHRU */
23578 /* A `sizeof' expression is value-dependent if the operand is
23579 type-dependent or is a pack expansion. */
23588 /* An 'encode' expression is value-dependent if the operand is
23589 type-dependent. */
23598 /* All instantiation-dependent expressions should also be considered
23599 value-dependent. */
23607 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
23608 is value-dependent. */
23609 {
23618 }
23621 {
23625 }
23636 {
23640 }
23643 /* Treat all requires-expressions as value-dependent so
23644 we don't try to fold them. */
23651 {
23658 {
23660 /* In a call to a constexpr member function, look through the
23661 implicit ADDR_EXPR on the object argument so that it doesn't
23662 cause the call to be considered value-dependent. We also
23663 look through it in potential_constant_expression. */
23670 }
23672 }
23675 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
23676 type-dependent. */
23681 {
23683 tree val;
23690 }
23693 /* Treat a GNU statement expression as dependent to avoid crashing
23694 under instantiate_non_dependent_expr; it can't be constant. */
23698 /* A constant expression is value-dependent if any subexpression is
23699 value-dependent. */
23701 {
23708 {
23712 {
23715 /* In some cases, some of the operands may be missing.l
23716 (For example, in the case of PREDECREMENT_EXPR, the
23717 amount to increment by may be missing.) That doesn't
23718 make the expression dependent. */
23721 }
23722 }
23726 }
23728 }
23730 /* The expression is not value-dependent. */
23732 }
23734 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
23735 [temp.dep.expr]. Note that an expression with no type is
23736 considered dependent. Other parts of the compiler arrange for an
23737 expression with type-dependent subexpressions to have no type, so
23738 this function doesn't have to be fully recursive. */
23740 bool
23742 {
23749 /* An unresolved name is always dependent. */
23755 /* A fold expression is type-dependent. */
23762 /* Some expression forms are never type-dependent. */
23776 /* The types of these expressions depends only on the type to which
23777 the cast occurs. */
23786 /* The types of these expressions depends only on the type created
23787 by the expression. */
23790 {
23791 /* For NEW_EXPR tree nodes created inside a template, either
23792 the object type itself or a TREE_LIST may appear as the
23793 operand 1. */
23796 /* This is an array type. We need to check array dimensions
23797 as well. */
23799 || value_dependent_expression_p
23801 else
23803 }
23806 {
23810 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
23811 contains an identifier associated by name lookup with one or more
23812 declarations declared with a dependent type, or...a
23813 nested-name-specifier or qualified-id that names a member of an
23814 unknown specialization. */
23817 }
23827 {
23828 tree elt;
23832 {
23835 }
23837 }
23839 /* A static data member of the current instantiation with incomplete
23840 array type is type-dependent, as the definition and specializations
23841 can have different bounds. */
23848 /* An array of unknown bound depending on a variadic parameter, eg:
23850 template<typename... Args>
23851 void foo (Args... args)
23852 {
23853 int arr[] = { args... };
23854 }
23856 template<int... vals>
23857 void bar ()
23858 {
23859 int arr[] = { vals... };
23860 }
23862 If the array has no length and has an initializer, it must be that
23863 we couldn't determine its length in cp_complete_array_type because
23864 it is dependent. */
23872 /* A function or variable template-id is type-dependent if it has any
23873 dependent template arguments. Note that we only consider the innermost
23874 template arguments here, since those are the ones that come from the
23875 template-id; the template arguments for the enclosing class do not make it
23876 type-dependent, they only make a member function value-dependent. */
23881 && (any_dependent_template_arguments_p
23885 /* Always dependent, on the number of arguments if nothing else. */
23890 {
23895 {
23901 }
23902 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
23907 {
23912 }
23915 {
23922 }
23932 }
23936 /* Dependent type attributes might not have made it from the decl to
23937 the type yet. */
23943 }
23945 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
23946 type-dependent if the expression refers to a member of the current
23947 instantiation and the type of the referenced member is dependent, or the
23948 class member access expression refers to a member of an unknown
23949 specialization.
23951 This function returns true if the OBJECT in such a class member access
23952 expression is of an unknown specialization. */
23954 bool
23956 {
23957 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
23958 dependent. */
23963 }
23965 /* walk_tree callback function for instantiation_dependent_expression_p,
23966 below. Returns non-zero if a dependent subexpression is found. */
23968 static tree
23971 {
23973 {
23974 /* We don't have to worry about decltype currently because decltype
23975 of an instantiation-dependent expr is a dependent type. This
23976 might change depending on the resolution of DR 1172. */
23979 }
23982 {
23983 /* Don't treat an argument list as dependent just because it has no
23984 TREE_TYPE. */
23992 /* Handle expressions with type operands. */
23997 {
24002 {
24005 else
24006 {
24009 }
24010 }
24012 }
24016 /* In a template, finish_class_member_access_expr creates a
24017 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24018 type-dependent, so that we can check access control at
24019 instantiation time (PR 42277). See also Core issue 1273. */
24026 else
24029 /* Treat statement-expressions as dependent. */
24033 /* Treat requires-expressions as dependent. */
24038 /* Treat calls to function concepts as dependent. */
24044 /* And variable concepts. */
24051 }
24055 else
24057 }
24059 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24060 sense defined by the ABI:
24062 "An expression is instantiation-dependent if it is type-dependent
24063 or value-dependent, or it has a subexpression that is type-dependent
24064 or value-dependent."
24066 Except don't actually check value-dependence for unevaluated expressions,
24067 because in sizeof(i) we don't care about the value of i. Checking
24068 type-dependence will in turn check value-dependence of array bounds/template
24069 arguments as needed. */
24071 bool
24073 {
24074 tree result;
24085 }
24087 /* As above, but also check value-dependence of the expression as a whole. */
24089 bool
24091 {
24094 }
24096 /* Like type_dependent_expression_p, but it also works while not processing
24097 a template definition, i.e. during substitution or mangling. */
24099 bool
24101 {
24107 }
24109 /* Returns TRUE if ARGS contains a type-dependent expression. */
24111 bool
24113 {
24115 tree arg;
24118 {
24121 }
24123 }
24125 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24126 expressions) contains any type-dependent expressions. */
24128 bool
24130 {
24136 }
24138 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24139 expressions) contains any value-dependent expressions. */
24141 bool
24143 {
24149 }
24151 /* Returns TRUE if the ARG (a template argument) is dependent. */
24153 bool
24155 {
24159 /* Assume a template argument that was wrongly written by the user
24160 is dependent. This is consistent with what
24161 any_dependent_template_arguments_p [that calls this function]
24162 does. */
24172 {
24175 /* A member template of a dependent class is not necessarily
24176 type-dependent, but it is a dependent template argument because it
24177 will be a member of an unknown specialization to that template. */
24180 }
24182 {
24186 {
24189 }
24192 }
24195 else
24198 }
24200 /* Returns true if ARGS (a collection of template arguments) contains
24201 any types that require structural equality testing. */
24203 bool
24205 {
24215 {
24218 {
24224 {
24225 /* Look inside the argument pack. */
24228 }
24231 {
24244 }
24245 }
24246 }
24249 }
24251 /* Returns true if ARGS (a collection of template arguments) contains
24252 any dependent arguments. */
24254 bool
24256 {
24266 {
24271 }
24274 }
24276 /* Returns TRUE if the template TMPL is type-dependent. */
24278 bool
24280 {
24282 {
24287 }
24289 /* Template template parameters are dependent. */
24293 /* So are names that have not been looked up. */
24297 }
24299 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24301 bool
24303 {
24306 }
24308 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24309 are dependent. */
24311 bool
24313 {
24320 {
24342 {
24346 }
24350 {
24354 {
24359 }
24360 }
24361 }
24364 }
24366 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24367 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24368 no such TYPE can be found. Note that this function peers inside
24369 uninstantiated templates and therefore should be used only in
24370 extremely limited situations. ONLY_CURRENT_P restricts this
24371 peering to the currently open classes hierarchy (which is required
24372 when comparing types). */
24374 tree
24376 {
24377 tree scope;
24378 tree name;
24379 tree decl;
24381 tree pushed_scope;
24382 tree result;
24387 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24388 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24389 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24390 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24391 identifier of the TYPENAME_TYPE anymore.
24392 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24393 TYPENAME_TYPE instead, we avoid messing up with a possible
24394 typedef variant case. */
24397 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24398 it first before we can figure out what NAME refers to. */
24400 {
24402 /* Given a class template A with a dependent base with nested type C,
24403 typedef typename A::C::C C will land us here, as trying to resolve
24404 the initial A::C leads to the local C typedef, which leads back to
24405 A::C::C. So we break the recursion now. */
24407 else
24409 }
24410 /* If we don't know what SCOPE refers to, then we cannot resolve the
24411 TYPENAME_TYPE. */
24414 /* If this is a typedef, we don't want to look inside (c++/11987). */
24417 /* If SCOPE isn't the template itself, it will not have a valid
24418 TYPE_FIELDS list. */
24420 /* scope is either the template itself or a compatible instantiation
24421 like X<T>, so look up the name in the original template. */
24423 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24425 /* If scope has no fields, it can't be a current instantiation. Check this
24426 before currently_open_class to avoid infinite recursion (71515). */
24429 /* If the SCOPE is not the current instantiation, there's no reason
24430 to look inside it. */
24433 /* Enter the SCOPE so that name lookup will be resolved as if we
24434 were in the class definition. In particular, SCOPE will no
24435 longer be considered a dependent type. */
24437 /* Look up the declaration. */
24439 tf_warning_or_error);
24443 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24444 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24449 {
24453 }
24456 {
24457 tree tmpl;
24458 tree args;
24459 /* Obtain the template and the arguments. */
24462 /* Instantiate the template. */
24468 }
24470 /* Leave the SCOPE. */
24474 /* If we failed to resolve it, return the original typename. */
24478 /* If lookup found a typename type, resolve that too. */
24480 {
24481 /* Ill-formed programs can cause infinite recursion here, so we
24482 must catch that. */
24486 }
24488 /* Qualify the resulting type. */
24494 }
24496 /* EXPR is an expression which is not type-dependent. Return a proxy
24497 for EXPR that can be used to compute the types of larger
24498 expressions containing EXPR. */
24500 tree
24502 {
24503 tree inner_expr;
24505 /* When checking, try to get a constant value for all non-dependent
24506 expressions in order to expose bugs in *_dependent_expression_p
24507 and constexpr. This can affect code generation, see PR70704, so
24508 only do this for -fchecking=2. */
24511 /* Don't do this during nsdmi parsing as it can lead to
24512 unexpected recursive instantiations. */
24514 /* Don't do this during concept expansion either and for
24515 the same reason. */
24519 /* Preserve OVERLOADs; the functions must be available to resolve
24520 types. */
24531 /* There is no need to return a proxy for a variable. */
24534 /* Preserve string constants; conversions from string constants to
24535 "char *" are allowed, even though normally a "const char *"
24536 cannot be used to initialize a "char *". */
24539 /* Preserve void and arithmetic constants, as an optimization -- there is no
24540 reason to create a new node. */
24545 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24546 There is at least one place where we want to know that a
24547 particular expression is a throw-expression: when checking a ?:
24548 expression, there are special rules if the second or third
24549 argument is a throw-expression. */
24553 /* Don't wrap an initializer list, we need to be able to look inside. */
24557 /* Don't wrap a dummy object, we need to be able to test for it. */
24576 /* If the type is unknown, it can't really be non-dependent */
24579 /* Otherwise, build a NON_DEPENDENT_EXPR. */
24581 }
24583 /* ARGS is a vector of expressions as arguments to a function call.
24584 Replace the arguments with equivalent non-dependent expressions.
24585 This modifies ARGS in place. */
24587 void
24589 {
24591 tree arg;
24594 {
24598 }
24599 }
24601 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
24602 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
24603 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
24605 static tree
24607 {
24621 }
24623 tree
24625 {
24627 }
24629 tree
24631 {
24633 }
24635 /* Return a C++17 deduction placeholder for class template TMPL. */
24637 tree
24639 {
24643 }
24645 /* Make a "constrained auto" type-specifier. This is an
24646 auto type with constraints that must be associated after
24647 deduction. The constraint is formed from the given
24648 CONC and its optional sequence of arguments, which are
24649 non-null if written as partial-concept-id. */
24651 tree
24653 {
24656 /* Build the constraint. */
24664 /* Our canonical type depends on the constraint. */
24667 /* Attach the constraint to the type declaration. */
24670 }
24672 /* Given type ARG, return std::initializer_list<ARG>. */
24674 static tree
24676 {
24678 tree argvec;
24680 {
24684 }
24689 }
24691 /* Replace auto in TYPE with std::initializer_list<auto>. */
24693 static tree
24695 {
24702 }
24704 /* Hash traits for hashing possibly constrained 'auto'
24705 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
24708 {
24711 };
24713 /* Hash the 'auto' T. */
24715 inline hashval_t
24717 {
24719 /* Matching constrained-type-specifiers denote the same template
24720 parameter, so hash the constraint. */
24722 else
24723 /* But unconstrained autos are all separate, so just hash the pointer. */
24725 }
24727 /* Compare two 'auto's. */
24731 {
24738 /* Two unconstrained autos are distinct. */
24743 }
24745 /* for_each_template_parm callback for extract_autos: if t is a (possibly
24746 constrained) auto, add it to the vector. */
24748 static int
24750 {
24753 {
24754 /* All the autos were built with index 0; fix that up now. */
24758 /* If this is a repeated constrained-type-specifier, use the index we
24759 chose before. */
24761 else
24762 {
24763 /* Otherwise this is new, so use the current count. */
24766 }
24768 }
24770 /* Always keep walking. */
24772 }
24774 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
24775 says they can appear anywhere in the type. */
24777 static tree
24779 {
24788 {
24793 }
24796 }
24798 /* The stem for deduction guide names. */
24801 /* Return the name for a deduction guide for class template TMPL. */
24803 tree
24805 {
24816 }
24818 /* True if NAME is the name of a deduction guide. */
24820 bool
24822 {
24826 }
24828 /* True if FN is a deduction guide. */
24830 bool
24832 {
24837 }
24839 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
24841 bool
24843 {
24850 }
24852 /* True if FN is a guide generated from a constructor template. */
24854 bool
24856 {
24861 {
24864 }
24866 }
24868 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
24869 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
24870 template parameter types. Note that the handling of template template
24871 parameters relies on current_template_parms being set appropriately for the
24872 new template. */
24874 static tree
24877 {
24880 tree newtype;
24883 {
24890 }
24891 else
24895 tree newdecl
24900 tree newidx;
24903 {
24913 {
24918 // First create a copy (ttargs) of tsubst_args with an
24919 // additional level for the template template parameter's own
24920 // template parameters (ttparms).
24921 tree ttparms = (INNERMOST_TEMPLATE_PARMS
24929 // Substitute ttargs into ttparms to fix references to
24930 // other template parameters.
24932 complain);
24933 // Now substitute again with args based on tparms, to reduce
24934 // the level of the ttparms.
24937 complain);
24938 // Finally, tack the adjusted parms onto tparms.
24940 current_template_parms);
24942 }
24943 }
24944 else
24945 {
24947 tree newconst
24959 }
24962 }
24964 /* Returns a C++17 class deduction guide template based on the constructor
24965 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
24966 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
24968 static tree
24970 {
24974 location_t loc;
24977 {
24981 {
24984 }
24985 else
24995 }
24996 else
24997 {
25001 tree fn_tmpl;
25003 {
25006 }
25007 else
25011 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25012 fully specialized args for the enclosing class. Strip those off, as
25013 the deduction guide won't have those template parameters. */
25016 /* Discard the 'this' parameter. */
25024 {
25027 /* For a member template constructor, we need to flatten the two
25028 template parameter lists into one, and then adjust the function
25029 signature accordingly. This gets...complicated. */
25033 /* For a member template we should have two levels of parms/args, one
25034 for the class and one for the constructor. We stripped
25035 specialized args for further enclosing classes above. */
25039 /* Template args for translating references to the two-level template
25040 parameters into references to the one-level template parameters we
25041 are creating. */
25046 /* Template parms for the constructor template. */
25049 /* Template parms for the class template. */
25053 /* Template parms for the deduction guide start as a copy of the
25054 template parms for the class. We set current_template_parms for
25055 lookup_template_class_1. */
25061 /* Now we need to rewrite the constructor parms to append them to the
25062 class parms. */
25064 {
25079 }
25081 /* Now we have a final set of template parms to substitute into the
25082 function signature. */
25092 }
25093 }
25096 {
25097 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25101 }
25105 FUNCTION_DECL,
25122 }
25124 /* Deduce template arguments for the class template placeholder PTYPE for
25125 template TMPL based on the initializer INIT, and return the resulting
25126 type. */
25128 static tree
25130 tsubst_flags_t complain)
25131 {
25133 {
25134 /* We should have handled this in the caller. */
25140 }
25152 else
25163 /* Prune explicit deduction guides in copy-initialization context. */
25165 {
25171 {
25172 /* Found a nonconverting guide, prune the candidates. */
25179 }
25180 }
25185 {
25188 }
25192 // FIXME cache artificial deduction guides
25195 {
25200 else
25204 }
25207 {
25216 {
25221 else
25223 }
25224 }
25227 {
25229 " of %qT, as it has no non-explicit deduction guides or "
25232 }
25238 {
25244 }
25250 }
25252 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25253 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25255 tree
25257 {
25259 tf_warning_or_error,
25260 adc_unspecified);
25261 }
25263 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25264 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25265 The CONTEXT determines the context in which auto deduction is performed
25266 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25267 OUTER_TARGS are used during template argument deduction
25268 (context == adc_unify) to properly substitute the result, and is ignored
25269 in other contexts.
25271 For partial-concept-ids, extra args may be appended to the list of deduced
25272 template arguments prior to determining constraint satisfaction. */
25274 tree
25278 {
25279 tree targs;
25286 /* Defining a subset of type-dependent expressions that we can deduce
25287 from ahead of time isn't worth the trouble. */
25291 /* C++17 class template argument deduction. */
25295 /* Nothing we can do with this, even in deduction context. */
25298 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25299 with either a new invented type template parameter U or, if the
25300 initializer is a braced-init-list (8.5.4), with
25301 std::initializer_list<U>. */
25303 {
25308 else
25309 {
25311 {
25315 "for deduction to %<std::initializer_list%>, use copy-"
25317 }
25319 }
25320 }
25331 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25332 and initializer has array type, deduce cv-qualified array type. */
25334 complain);
25336 {
25345 {
25349 }
25350 }
25351 else
25352 {
25354 tree tparms;
25358 else
25359 {
25363 }
25370 {
25372 /* Try again at instantiation time. */
25376 /* If type is error_mark_node a diagnostic must have been
25377 emitted by now. Also, having a mention to '<type error>'
25378 in the diagnostic is not really useful to the user. */
25379 {
25383 else
25388 }
25390 }
25391 }
25393 /* Check any placeholder constraints against the deduced type. */
25396 {
25397 /* Use the deduced type to check the associated constraints. If we
25398 have a partial-concept-id, rebuild the argument list so that
25399 we check using the extra arguments. */
25403 {
25406 }
25407 else
25410 {
25412 {
25414 {
25432 }
25434 }
25436 }
25437 }
25443 }
25445 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25446 result. */
25448 tree
25450 {
25452 {
25458 /* In an abbreviated function template we didn't know we were dealing
25459 with a function template when we saw the auto return type, so update
25460 it to have the correct level. */
25462 }
25464 }
25466 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25467 'decltype(auto)' or a deduced class template. */
25469 bool
25471 {
25477 else
25479 }
25481 /* for_each_template_parm callback for type_uses_auto. */
25483 int
25485 {
25487 }
25489 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
25490 a use of `auto'. Returns NULL_TREE otherwise. */
25492 tree
25494 {
25498 {
25499 /* The Concepts TS allows multiple autos in one type-specifier; just
25500 return the first one we find, do_auto_deduction will collect all of
25501 them. */
25505 else
25507 }
25508 else
25510 }
25512 /* For a given template T, return the vector of typedefs referenced
25513 in T for which access check is needed at T instantiation time.
25514 T is either a FUNCTION_DECL or a RECORD_TYPE.
25515 Those typedefs were added to T by the function
25516 append_type_to_template_for_access_check. */
25520 {
25521 tree ti;
25532 {
25537 }
25540 }
25542 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
25543 tied to T. That list of typedefs will be access checked at
25544 T instantiation time.
25545 T is either a FUNCTION_DECL or a RECORD_TYPE.
25546 TYPE_DECL is a TYPE_DECL node representing a typedef.
25547 SCOPE is the scope through which TYPE_DECL is accessed.
25548 LOCATION is the location of the usage point of TYPE_DECL.
25550 This function is a subroutine of
25551 append_type_to_template_for_access_check. */
25553 static void
25555 tree type_decl,
25556 tree scope,
25557 location_t location)
25558 {
25559 qualified_typedef_usage_t typedef_usage;
25560 tree ti;
25567 && type_decl
25581 }
25583 /* Append TYPE_DECL to the template TEMPL.
25584 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
25585 At TEMPL instanciation time, TYPE_DECL will be checked to see
25586 if it can be accessed through SCOPE.
25587 LOCATION is the location of the usage point of TYPE_DECL.
25589 e.g. consider the following code snippet:
25591 class C
25592 {
25593 typedef int myint;
25594 };
25596 template<class U> struct S
25597 {
25598 C::myint mi; // <-- usage point of the typedef C::myint
25599 };
25601 S<char> s;
25603 At S<char> instantiation time, we need to check the access of C::myint
25604 In other words, we need to check the access of the myint typedef through
25605 the C scope. For that purpose, this function will add the myint typedef
25606 and the scope C through which its being accessed to a list of typedefs
25607 tied to the template S. That list will be walked at template instantiation
25608 time and access check performed on each typedefs it contains.
25609 Note that this particular code snippet should yield an error because
25610 myint is private to C. */
25612 void
25614 tree type_decl,
25615 tree scope,
25616 location_t location)
25617 {
25623 /* Make sure we don't append the type to the template twice. */
25630 }
25632 /* Convert the generic type parameters in PARM that match the types given in the
25633 range [START_IDX, END_IDX) from the current_template_parms into generic type
25634 packs. */
25636 tree
25638 {
25649 {
25650 /* Create a distinct parameter pack type from the current parm and add it
25651 to the replacement args to tsubst below into the generic function
25652 parameter. */
25667 }
25673 /* If there are more levels then build up the replacement with the outer
25674 template parms. */
25678 replacement);
25681 }
25683 /* Entries in the decl_constraint hash table. */
25685 {
25686 tree decl;
25687 tree ci;
25688 };
25690 /* Hashing function and equality for constraint entries. */
25692 {
25694 {
25696 }
25699 {
25701 }
25702 };
25704 /* A mapping from declarations to constraint information. Note that
25705 both templates and their underlying declarations are mapped to the
25706 same constraint information.
25708 FIXME: This is defined in pt.c because garbage collection
25709 code is not being generated for constraint.cc. */
25713 /* Returns the template constraints of declaration T. If T is not
25714 constrained, return NULL_TREE. Note that T must be non-null. */
25716 tree
25718 {
25729 else
25731 }
25733 /* Associate the given constraint information CI with the declaration
25734 T. If T is a template, then the constraints are associated with
25735 its underlying declaration. Don't build associations if CI is
25736 NULL_TREE. */
25738 void
25740 {
25752 }
25754 /* Remove the associated constraints of the declaration T. */
25756 void
25758 {
25767 }
25769 /* Memoized satisfaction results for declarations. This
25770 maps the pair (constraint_info, arguments) to the result computed
25771 by constraints_satisfied_p. */
25774 {
25775 tree ci;
25776 tree args;
25777 tree result;
25778 };
25780 /* Hashing function and equality for constraint entries. */
25783 {
25785 {
25788 }
25791 {
25793 }
25794 };
25796 /* Memoized satisfaction results for concept checks. */
25799 {
25800 tree tmpl;
25801 tree args;
25802 tree result;
25803 };
25805 /* Hashing function and equality for constraint entries. */
25808 {
25810 {
25812 }
25815 {
25820 }
25821 };
25826 /* Search for a memoized satisfaction result. Returns one of the
25827 truth value nodes if previously memoized, or NULL_TREE otherwise. */
25829 tree
25831 {
25836 else
25838 }
25840 /* Memoize the result of a satisfication test. Returns the saved result. */
25842 tree
25844 {
25851 }
25853 /* Search for a memoized satisfaction result for a concept. */
25855 tree
25857 {
25862 else
25864 }
25866 /* Memoize the result of a concept check. Returns the saved result. */
25868 tree
25870 {
25877 }
25881 /* Returns a prior concept specialization. This returns the substituted
25882 and normalized constraints defined by the concept. */
25884 tree
25886 {
25891 else
25893 }
25895 /* Save a concept expansion for later. */
25897 tree
25899 {
25906 }
25908 static hashval_t
25910 {
25919 }
25921 /* Compare the constraints of two subsumption entries. The LEFT1 and
25922 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
25923 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
25925 static bool
25927 {
25935 }
25937 /* Key/value pair for learning and memoizing subsumption results. This
25938 associates a pair of check constraints (including arguments) with
25939 a boolean value indicating the result. */
25942 {
25943 tree t1;
25944 tree t2;
25946 };
25948 /* Hashing function and equality for constraint entries. */
25951 {
25953 {
25955 }
25958 {
25963 }
25964 };
25968 /* Search for a previously cached subsumption result. */
25972 {
25977 else
25979 }
25981 /* Save a subsumption result. */
25983 bool
25985 {
25992 }
25994 /* Set up the hash table for constraint association. */
25996 void
25998 {
26007 }
26009 /* Set up the hash tables for template instantiations. */
26011 void
26013 {
26016 }
26018 /* Print stats about the template hash tables for -fstats. */
26020 void
26022 {
26031 }