| blob | d5cc2576f9de2110c61ad4b764e25084badbf435 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2014 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". */
51 /* The type of functions taking a tree, and some additional data, and
52 returning an int. */
55 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
56 instantiations have been deferred, either because their definitions
57 were not yet available, or because we were putting off doing the work. */
61 };
76 /* Live only within one (recursive) call to tsubst_expr. We use
77 this to pass the statement expression node from the STMT_EXPR
78 to the EXPR_STMT that is its result. */
81 /* True if we've recursed into fn_type_unification too many times. */
85 {
86 tree tmpl;
87 tree args;
88 tree spec;
92 htab_t decl_specializations;
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
113 tbr_incomplete_type,
114 tbr_ambiguous_baseclass,
115 tbr_success
116 };
139 tree);
202 location_t);
210 /* Make the current scope suitable for access checking when we are
211 processing T. T can be FUNCTION_DECL for instantiated function
212 template, VAR_DECL for static member variable, or TYPE_DECL for
213 alias template (needed by instantiate_decl). */
215 static void
217 {
225 else
229 {
230 saved_access_scope = tree_cons
233 }
234 }
236 /* Restore the scope set up by push_access_scope. T is the node we
237 are processing. */
239 static void
241 {
243 {
246 }
250 else
252 }
254 /* Do any processing required when DECL (a member template
255 declaration) is finished. Returns the TEMPLATE_DECL corresponding
256 to DECL, unless it is a specialization, in which case the DECL
257 itself is returned. */
259 tree
261 {
268 {
269 tree type;
277 {
281 }
283 }
287 {
289 {
292 }
293 else
295 }
296 else
300 }
302 /* Create a template info node. */
304 tree
306 {
311 }
313 /* Return the template info node corresponding to T, whatever T is. */
315 tree
317 {
338 }
340 /* Returns the template nesting level of the indicated class TYPE.
342 For example, in:
343 template <class T>
344 struct A
345 {
346 template <class U>
347 struct B {};
348 };
350 A<T>::B<U> has depth two, while A<T> has depth one.
351 Both A<T>::B<int> and A<int>::B<U> have depth one, if
352 they are instantiations, not specializations.
354 This function is guaranteed to return 0 if passed NULL_TREE so
355 that, for example, `template_class_depth (current_class_type)' is
356 always safe. */
358 int
360 {
367 {
373 }
376 }
378 /* Subroutine of maybe_begin_member_template_processing.
379 Returns true if processing DECL needs us to push template parms. */
381 static bool
383 {
389 }
391 /* Subroutine of maybe_begin_member_template_processing.
392 Push the template parms in PARMS, starting from LEVELS steps into the
393 chain, and ending at the beginning, since template parms are listed
394 innermost first. */
396 static void
398 {
406 current_template_parms
412 NULL);
414 {
423 {
430 {
431 /* Make a CONST_DECL as is done in process_template_parm.
432 It is ugly that we recreate this here; the original
433 version built in process_template_parm is no longer
434 available. */
444 }
449 }
450 }
451 }
453 /* Restore the template parameter context for a member template, a
454 friend template defined in a class definition, or a non-template
455 member of template class. */
457 void
459 {
460 tree parms;
465 {
468 /* Disregard full specializations (c++/60999). */
471 }
474 {
479 {
482 }
485 }
487 /* Remember how many levels of template parameters we pushed so that
488 we can pop them later. */
490 }
492 /* Undo the effects of maybe_begin_member_template_processing. */
494 void
496 {
505 {
509 }
510 }
512 /* Return a new template argument vector which contains all of ARGS,
513 but has as its innermost set of arguments the EXTRA_ARGS. */
515 static tree
517 {
518 tree new_args;
536 }
538 /* Like add_to_template_args, but only the outermost ARGS are added to
539 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
540 (EXTRA_ARGS) levels are added. This function is used to combine
541 the template arguments from a partial instantiation with the
542 template arguments used to attain the full instantiation from the
543 partial instantiation. */
545 static tree
547 {
548 tree new_args;
550 /* If there are more levels of EXTRA_ARGS than there are ARGS,
551 something very fishy is going on. */
554 /* If *all* the new arguments will be the EXTRA_ARGS, just return
555 them. */
559 /* For the moment, we make ARGS look like it contains fewer levels. */
564 /* Now, we restore ARGS to its full dimensions. */
568 }
570 /* Return the N levels of innermost template arguments from the ARGS. */
572 tree
574 {
575 tree new_args;
581 /* If N is 1, just return the innermost set of template arguments. */
585 /* If we're not removing anything, just return the arguments we were
586 given. */
592 /* Make a new set of arguments, not containing the outer arguments. */
599 }
601 /* The inverse of get_innermost_template_args: Return all but the innermost
602 EXTRA_LEVELS levels of template arguments from the ARGS. */
604 static tree
606 {
607 tree new_args;
613 /* If N is 1, just return the outermost set of template arguments. */
617 /* If we're not removing anything, just return the arguments we were
618 given. */
623 /* Make a new set of arguments, not containing the inner arguments. */
630 }
632 /* We've got a template header coming up; push to a new level for storing
633 the parms. */
635 void
637 {
638 /* We use a non-tag-transparent scope here, which causes pushtag to
639 put tags in this scope, rather than in the enclosing class or
640 namespace scope. This is the right thing, since we want
641 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
642 global template class, push_template_decl handles putting the
643 TEMPLATE_DECL into top-level scope. For a nested template class,
644 e.g.:
646 template <class T> struct S1 {
647 template <class T> struct S2 {};
648 };
650 pushtag contains special code to call pushdecl_with_scope on the
651 TEMPLATE_DECL for S2. */
656 }
658 /* This routine is called when a specialization is declared. If it is
659 invalid to declare a specialization here, an error is reported and
660 false is returned, otherwise this routine will return true. */
662 static bool
664 {
667 /* [temp.expl.spec]
669 An explicit specialization shall be declared in the namespace of
670 which the template is a member, or, for member templates, in the
671 namespace of which the enclosing class or enclosing class
672 template is a member. An explicit specialization of a member
673 function, member class or static data member of a class template
674 shall be declared in the namespace of which the class template
675 is a member. */
677 {
680 }
682 /* [temp.expl.spec]
684 In an explicit specialization declaration for a member of a class
685 template or a member template that appears in namespace scope,
686 the member template and some of its enclosing class templates may
687 remain unspecialized, except that the declaration shall not
688 explicitly specialize a class member template if its enclosing
689 class templates are not explicitly specialized as well. */
691 {
694 }
697 }
699 /* We've just seen template <>. */
701 bool
703 {
707 }
709 /* Called at then end of processing a declaration preceded by
710 template<>. */
712 void
714 {
717 }
719 /* Any template <>'s that we have seen thus far are not referring to a
720 function specialization. */
722 void
724 {
727 }
729 /* We've just seen a template header. If SPECIALIZATION is nonzero,
730 it was of the form template <>. */
732 static void
734 {
736 template_header_count++;
737 }
739 /* We're beginning an explicit instantiation. */
741 void
743 {
746 }
749 void
751 {
754 }
756 /* An explicit specialization or partial specialization of TMPL is being
757 declared. Check that the namespace in which the specialization is
758 occurring is permissible. Returns false iff it is invalid to
759 specialize TMPL in the current namespace. */
761 static bool
763 {
766 /* [tmpl.expl.spec]
768 An explicit specialization shall be declared in the namespace of
769 which the template is a member, or, for member templates, in the
770 namespace of which the enclosing class or enclosing class
771 template is a member. An explicit specialization of a member
772 function, member class or static data member of a class template
773 shall be declared in the namespace of which the class template is
774 a member. */
777 {
780 }
782 /* Same or super-using namespace. */
784 else
785 {
789 }
790 }
792 /* SPEC is an explicit instantiation. Check that it is valid to
793 perform this explicit instantiation in the current namespace. */
795 static void
797 {
798 tree ns;
800 /* DR 275: An explicit instantiation shall appear in an enclosing
801 namespace of its template. */
807 }
809 /* The TYPE is being declared. If it is a template type, that means it
810 is a partial specialization. Do appropriate error-checking. */
812 tree
814 {
815 tree context;
820 /* A lambda that appears in specialization context is not itself a
821 specialization. */
826 {
830 }
835 {
840 else
843 }
845 {
846 /* This is for ordinary explicit specialization and partial
847 specialization of a template class such as:
849 template <> class C<int>;
851 or:
853 template <class T> class C<T*>;
855 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
859 {
866 {
870 }
871 }
877 /* Trying to define a specialization either without a template<> header
878 or in an inappropriate place. We've already given an error, so just
879 bail now so we don't actually define the specialization. */
881 }
887 {
888 /* This is for an explicit specialization of member class
889 template according to [temp.expl.spec/18]:
891 template <> template <class U> class C<int>::D;
893 The context `C<int>' must be an implicit instantiation.
894 Otherwise this is just a member class template declared
895 earlier like:
897 template <> class C<int> { template <class U> class D; };
898 template <> template <class U> class C<int>::D;
900 In the first case, `C<int>::D' is a specialization of `C<T>::D'
901 while in the second case, `C<int>::D' is a primary template
902 and `C<T>::D' may not exist. */
906 {
907 tree t;
912 {
915 }
917 /* Check for invalid specialization after instantiation:
919 template <> template <> class C<int>::D<int>;
920 template <> template <class U> class C<int>::D; */
924 {
928 {
929 /* We already have a full specialization of this partial
930 instantiation, or a full specialization has been
931 looked up but not instantiated. Reassign it to the
932 new member specialization template. */
933 spec_entry elt;
950 }
951 else
952 /* But if we've had an implicit instantiation, that's a
953 problem ([temp.expl.spec]/6). */
956 }
958 /* Mark TYPE as a specialization. And as a result, we only
959 have one level of template argument for the innermost
960 class template. */
965 }
966 }
968 {
969 /* Someday C++0x may allow for enum template specialization. */
974 else
975 {
978 }
979 }
982 }
984 /* Returns nonzero if we can optimize the retrieval of specializations
985 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
986 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
990 {
993 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
994 parameter. */
996 /* The optimized lookup depends on the fact that the
997 template arguments for the member function template apply
998 purely to the containing class, which is not true if the
999 containing class is an explicit or partial
1000 specialization. */
1004 /* It is possible to have a template that is not a member
1005 template and is not a member of a template class:
1007 template <typename T>
1008 struct S { friend A::f(); };
1010 Here, the friend function is a template, but the context does
1011 not have template information. The optimized lookup relies
1012 on having ARGS be the template arguments for both the class
1013 and the function template. */
1015 }
1017 /* Retrieve the specialization (in the sense of [temp.spec] - a
1018 specialization is either an instantiation or an explicit
1019 specialization) of TMPL for the given template ARGS. If there is
1020 no such specialization, return NULL_TREE. The ARGS are a vector of
1021 arguments, or a vector of vectors of arguments, in the case of
1022 templates with more than one level of parameters.
1024 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1025 then we search for a partial specialization matching ARGS. This
1026 parameter is ignored if TMPL is not a class template.
1028 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1029 result is a NONTYPE_ARGUMENT_PACK. */
1031 static tree
1033 {
1043 /* There should be as many levels of arguments as there are
1044 levels of parameters. */
1051 {
1052 tree class_template;
1053 tree class_specialization;
1055 tree fns;
1058 /* The template arguments actually apply to the containing
1059 class. Find the class specialization with those
1060 arguments. */
1062 class_specialization
1066 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1067 for the specialization. */
1071 /* Iterate through the methods with the indicated name, looking
1072 for the one that has an instance of TMPL. */
1075 {
1078 /* using-declarations can add base methods to the method vec,
1079 and we don't want those here. */
1082 }
1084 }
1085 else
1086 {
1088 spec_entry elt;
1089 htab_t specializations;
1097 else
1105 }
1108 }
1110 /* Like retrieve_specialization, but for local declarations. */
1112 static tree
1114 {
1122 }
1124 /* Returns nonzero iff DECL is a specialization of TMPL. */
1126 int
1128 {
1129 tree t;
1132 {
1138 }
1139 else
1140 {
1149 }
1152 }
1154 /* Returns nonzero iff DECL is a specialization of friend declaration
1155 FRIEND_DECL according to [temp.friend]. */
1157 bool
1159 {
1166 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1167 of a template class, we want to check if DECL is a specialization
1168 if this. */
1172 {
1173 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1176 }
1181 /* There is nothing to do if this is not a template friend. */
1188 /* [temp.friend/6]
1189 A member of a class template may be declared to be a friend of a
1190 non-template class. In this case, the corresponding member of
1191 every specialization of the class template is a friend of the
1192 class granting friendship.
1194 For example, given a template friend declaration
1196 template <class T> friend void A<T>::f();
1198 the member function below is considered a friend
1200 template <> struct A<int> {
1201 void f();
1202 };
1204 For this type of template friend, TEMPLATE_DEPTH below will be
1205 nonzero. To determine if DECL is a friend of FRIEND, we first
1206 check if the enclosing class is a specialization of another. */
1213 {
1214 /* Next, we check the members themselves. In order to handle
1215 a few tricky cases, such as when FRIEND_DECL's are
1217 template <class T> friend void A<T>::g(T t);
1218 template <class T> template <T t> friend void A<T>::h();
1220 and DECL's are
1222 void A<int>::g(int);
1223 template <int> void A<int>::h();
1225 we need to figure out ARGS, the template arguments from
1226 the context of DECL. This is required for template substitution
1227 of `T' in the function parameter of `g' and template parameter
1228 of `h' in the above examples. Here ARGS corresponds to `int'. */
1235 {
1237 {
1240 else
1242 current_depth++;
1243 }
1245 }
1248 {
1250 tree friend_type;
1251 tree decl_type;
1252 tree friend_args_type;
1253 tree decl_args_type;
1255 /* Make sure that both DECL and FRIEND_DECL are templates or
1256 non-templates. */
1262 {
1263 /* If both are templates, check template parameter list. */
1264 tree friend_parms
1269 friend_parms))
1273 }
1274 else
1282 /* Check if return types match. */
1286 /* Check if function parameter types match, ignoring the
1287 `this' parameter. */
1296 }
1297 else
1298 {
1299 /* DECL is a TYPE_DECL */
1303 /* Make sure that both DECL and FRIEND_DECL are templates or
1304 non-templates. */
1305 is_template
1312 {
1313 tree friend_parms;
1314 /* If both are templates, check the name of the two
1315 TEMPLATE_DECL's first because is_friend didn't. */
1320 /* Now check template parameter list. */
1321 friend_parms
1324 return comp_template_parms
1326 friend_parms);
1327 }
1328 else
1331 }
1332 }
1334 }
1336 /* Register the specialization SPEC as a specialization of TMPL with
1337 the indicated ARGS. IS_FRIEND indicates whether the specialization
1338 is actually just a friend declaration. Returns SPEC, or an
1339 equivalent prior declaration, if available.
1341 We also store instantiations of field packs in the hash table, even
1342 though they are not themselves templates, to make lookup easier. */
1344 static tree
1346 hashval_t hash)
1347 {
1348 tree fn;
1350 spec_entry elt;
1358 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1359 register it; we want the corresponding TEMPLATE_DECL instead.
1360 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1361 the more obvious `uses_template_parms (spec)' to avoid problems
1362 with default function arguments. In particular, given
1363 something like this:
1365 template <class T> void f(T t1, T t = T())
1367 the default argument expression is not substituted for in an
1368 instantiation unless and until it is actually needed. */
1372 /* We don't put these specializations in the hash table, but we might
1373 want to give an error about a mismatch. */
1375 else
1376 {
1384 slot =
1388 else
1390 }
1392 /* We can sometimes try to re-register a specialization that we've
1393 already got. In particular, regenerate_decl_from_template calls
1394 duplicate_decls which will update the specialization list. But,
1395 we'll still get called again here anyhow. It's more convenient
1396 to simply allow this than to try to prevent it. */
1400 {
1402 {
1405 {
1407 fn);
1409 }
1410 else
1411 {
1412 tree clone;
1413 /* This situation should occur only if the first
1414 specialization is an implicit instantiation, the
1415 second is an explicit specialization, and the
1416 implicit instantiation has not yet been used. That
1417 situation can occur if we have implicitly
1418 instantiated a member function and then specialized
1419 it later.
1421 We can also wind up here if a friend declaration that
1422 looked like an instantiation turns out to be a
1423 specialization:
1425 template <class T> void foo(T);
1426 class S { friend void foo<>(int) };
1427 template <> void foo(int);
1429 We transform the existing DECL in place so that any
1430 pointers to it become pointers to the updated
1431 declaration.
1433 If there was a definition for the template, but not
1434 for the specialization, we want this to look as if
1435 there were no definition, and vice versa. */
1438 /* The call to duplicate_decls will have applied
1439 [temp.expl.spec]:
1441 An explicit specialization of a function template
1442 is inline only if it is explicitly declared to be,
1443 and independently of whether its function template
1444 is.
1446 to the primary function; now copy the inline bits to
1447 the various clones. */
1449 {
1456 }
1460 }
1461 }
1463 {
1465 /* Dup decl failed, but this is a new definition. Set the
1466 line number so any errors match this new
1467 definition. */
1471 }
1472 }
1476 /* A specialization must be declared in the same namespace as the
1477 template it is specializing. */
1483 {
1491 /* TMPL is a forward declaration of a template function; keep a list
1492 of all specializations in case we need to reassign them to a friend
1493 template later in tsubst_friend_function. */
1496 }
1499 }
1501 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1502 TMPL and ARGS members, ignores SPEC. */
1506 static int
1508 {
1519 }
1521 /* Returns a hash for a template TMPL and template arguments ARGS. */
1523 static hashval_t
1525 {
1528 }
1530 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1531 ignoring SPEC. */
1533 static hashval_t
1535 {
1538 }
1540 /* Recursively calculate a hash value for a template argument ARG, for use
1541 in the hash tables of template specializations. */
1543 hashval_t
1545 {
1557 /* We can get one of these when re-hashing a previous entry in the middle
1558 of substituting into a pack expansion. Just look through it. */
1567 {
1575 {
1580 }
1602 {
1605 {
1608 }
1610 }
1614 {
1617 }
1628 val = iterative_hash_template_arg
1640 val);
1642 val);
1651 /* A lambda can't appear in a template arg, but don't crash on
1652 erroneous input. */
1664 /* Now hash operands as usual. */
1669 }
1672 {
1676 val);
1679 /* Otherwise just compare the types during lookup. */
1688 {
1693 }
1694 }
1697 }
1699 /* Unregister the specialization SPEC as a specialization of TMPL.
1700 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1701 if the SPEC was listed as a specialization of TMPL.
1703 Note that SPEC has been ggc_freed, so we can't look inside it. */
1705 bool
1707 {
1709 spec_entry elt;
1717 {
1722 }
1725 }
1727 /* Like register_specialization, but for local declarations. We are
1728 registering SPEC, an instantiation of TMPL. */
1730 static void
1732 {
1737 }
1739 /* TYPE is a class type. Returns true if TYPE is an explicitly
1740 specialized class. */
1742 bool
1744 {
1748 }
1750 /* Print the list of functions at FNS, going through all the overloads
1751 for each element of the list. Alternatively, FNS can not be a
1752 TREE_LIST, in which case it will be printed together with all the
1753 overloads.
1755 MORE and *STR should respectively be FALSE and NULL when the function
1756 is called from the outside. They are used internally on recursive
1757 calls. print_candidates manages the two parameters and leaves NULL
1758 in *STR when it ends. */
1760 static void
1762 {
1768 {
1772 }
1773 else
1774 {
1777 {
1778 /* Pick the prefix string. */
1780 {
1784 }
1788 }
1791 }
1794 {
1797 }
1798 }
1800 /* Print the list of candidate FNS in an error message. FNS can also
1801 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1803 void
1805 {
1809 }
1811 /* Returns the template (one of the functions given by TEMPLATE_ID)
1812 which can be specialized to match the indicated DECL with the
1813 explicit template args given in TEMPLATE_ID. The DECL may be
1814 NULL_TREE if none is available. In that case, the functions in
1815 TEMPLATE_ID are non-members.
1817 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1818 specialization of a member template.
1820 The TEMPLATE_COUNT is the number of references to qualifying
1821 template classes that appeared in the name of the function. See
1822 check_explicit_specialization for a more accurate description.
1824 TSK indicates what kind of template declaration (if any) is being
1825 declared. TSK_TEMPLATE indicates that the declaration given by
1826 DECL, though a FUNCTION_DECL, has template parameters, and is
1827 therefore a template function.
1829 The template args (those explicitly specified and those deduced)
1830 are output in a newly created vector *TARGS_OUT.
1832 If it is impossible to determine the result, an error message is
1833 issued. The error_mark_node is returned to indicate failure. */
1835 static tree
1837 tree decl,
1841 tmpl_spec_kind tsk)
1842 {
1843 tree fns;
1844 tree targs;
1845 tree explicit_targs;
1847 /* A TREE_LIST of templates of which DECL may be a specialization.
1848 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1849 corresponding TREE_PURPOSE is the set of template arguments that,
1850 when used to instantiate the template, would produce a function
1851 with the signature of DECL. */
1861 /* We shouldn't be specializing a member template of an
1862 unspecialized class template; we already gave an error in
1863 check_specialization_scope, now avoid crashing. */
1866 {
1869 }
1877 /* Check for baselinks. */
1882 {
1885 }
1887 /* Count the number of template headers specified for this
1888 specialization. */
1896 {
1900 {
1901 tree decl_arg_types;
1902 tree fn_arg_types;
1903 tree insttype;
1905 /* In case of explicit specialization, we need to check if
1906 the number of template headers appearing in the specialization
1907 is correct. This is usually done in check_explicit_specialization,
1908 but the check done there cannot be exhaustive when specializing
1909 member functions. Consider the following code:
1911 template <> void A<int>::f(int);
1912 template <> template <> void A<int>::f(int);
1914 Assuming that A<int> is not itself an explicit specialization
1915 already, the first line specializes "f" which is a non-template
1916 member function, whilst the second line specializes "f" which
1917 is a template member function. So both lines are syntactically
1918 correct, and check_explicit_specialization does not reject
1919 them.
1921 Here, we can do better, as we are matching the specialization
1922 against the declarations. We count the number of template
1923 headers, and we check if they match TEMPLATE_COUNT + 1
1924 (TEMPLATE_COUNT is the number of qualifying template classes,
1925 plus there must be another header for the member template
1926 itself).
1928 Notice that if header_count is zero, this is not a
1929 specialization but rather a template instantiation, so there
1930 is no check we can perform here. */
1934 /* Check that the number of template arguments at the
1935 innermost level for DECL is the same as for FN. */
1943 /* DECL might be a specialization of FN. */
1947 /* For a non-static member function, we need to make sure
1948 that the const qualification is the same. Since
1949 get_bindings does not try to merge the "this" parameter,
1950 we must do the comparison explicitly. */
1956 /* Skip the "this" parameter and, for constructors of
1957 classes with virtual bases, the VTT parameter. A
1958 full specialization of a constructor will have a VTT
1959 parameter, but a template never will. */
1960 decl_arg_types
1962 fn_arg_types
1965 /* Function templates cannot be specializations; there are
1966 no partial specializations of functions. Therefore, if
1967 the type of DECL does not match FN, there is no
1968 match. */
1970 {
1974 }
1976 /* See whether this function might be a specialization of this
1977 template. Suppress access control because we might be trying
1978 to make this specialization a friend, and we have already done
1979 access control for the declaration of the specialization. */
1985 /* We cannot deduce template arguments that when used to
1986 specialize TMPL will produce DECL. */
1989 /* Make sure that the deduced arguments actually work. */
1993 fn_arg_types
1998 /* Save this template, and the arguments deduced. */
2000 }
2002 /* FN is an ordinary member function, and we need a
2003 specialization of a member template. */
2004 ;
2006 /* We can get IDENTIFIER_NODEs here in certain erroneous
2007 cases. */
2008 ;
2010 /* This is just an ordinary non-member function. Nothing can
2011 be a specialization of that. */
2012 ;
2014 /* Cannot specialize functions that are created implicitly. */
2015 ;
2016 else
2017 {
2018 tree decl_arg_types;
2020 /* This is an ordinary member function. However, since
2021 we're here, we can assume its enclosing class is a
2022 template class. For example,
2024 template <typename T> struct S { void f(); };
2025 template <> void S<int>::f() {}
2027 Here, S<int>::f is a non-template, but S<int> is a
2028 template class. If FN has the same type as DECL, we
2029 might be in business. */
2032 /* Its enclosing class is an explicit specialization
2033 of a template class. This is not a candidate. */
2038 /* The return types differ. */
2041 /* Adjust the type of DECL in case FN is a static member. */
2048 decl_arg_types))
2049 /* They match! */
2051 }
2052 }
2055 {
2056 /* We have:
2058 [temp.expl.spec]
2060 It is possible for a specialization with a given function
2061 signature to be instantiated from more than one function
2062 template. In such cases, explicit specification of the
2063 template arguments must be used to uniquely identify the
2064 function template specialization being specialized.
2066 Note that here, there's no suggestion that we're supposed to
2067 determine which of the candidate templates is most
2068 specialized. However, we, also have:
2070 [temp.func.order]
2072 Partial ordering of overloaded function template
2073 declarations is used in the following contexts to select
2074 the function template to which a function template
2075 specialization refers:
2077 -- when an explicit specialization refers to a function
2078 template.
2080 So, we do use the partial ordering rules, at least for now.
2081 This extension can only serve to make invalid programs valid,
2082 so it's safe. And, there is strong anecdotal evidence that
2083 the committee intended the partial ordering rules to apply;
2084 the EDG front end has that behavior, and John Spicer claims
2085 that the committee simply forgot to delete the wording in
2086 [temp.expl.spec]. */
2089 {
2092 }
2093 }
2096 {
2104 }
2108 {
2114 }
2116 /* We have one, and exactly one, match. */
2118 {
2121 /* DECL is a re-declaration or partial instantiation of a template
2122 function. */
2125 /* It was a specialization of an ordinary member function in a
2126 template class. */
2128 }
2130 /* It was a specialization of a template. */
2133 {
2138 }
2139 else
2142 }
2144 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2145 but with the default argument values filled in from those in the
2146 TMPL_TYPES. */
2148 static tree
2150 tree tmpl_types)
2151 {
2152 tree new_spec_types;
2160 /* Substitute into the rest of the list. */
2161 new_spec_types =
2165 /* Add the default argument for this parameter. */
2168 new_spec_types);
2169 }
2171 /* DECL is an explicit specialization. Replicate default arguments
2172 from the template it specializes. (That way, code like:
2174 template <class T> void f(T = 3);
2175 template <> void f(double);
2176 void g () { f (); }
2178 works, as required.) An alternative approach would be to look up
2179 the correct default arguments at the call-site, but this approach
2180 is consistent with how implicit instantiations are handled. */
2182 static void
2184 {
2185 tree tmpl;
2186 tree spec_types;
2187 tree tmpl_types;
2188 tree new_spec_types;
2189 tree old_type;
2190 tree new_type;
2191 tree t;
2196 /* See if there's anything we need to do. */
2209 {
2210 /* Remove the this pointer, but remember the object's type for
2211 CV quals. */
2217 {
2218 /* DECL may contain more parameters than TMPL due to the extra
2219 in-charge parameter in constructors and destructors. */
2222 }
2224 {
2227 }
2228 }
2230 /* Compute the merged default arguments. */
2231 new_spec_types =
2234 /* Compute the new FUNCTION_TYPE. */
2236 {
2240 new_spec_types);
2243 /* Put the in-charge parameter back. */
2246 new_spec_types);
2250 new_spec_types);
2251 }
2252 else
2254 new_spec_types);
2264 }
2266 /* Return the number of template headers we expect to see for a definition
2267 or specialization of CTYPE or one of its non-template members. */
2269 int
2271 {
2275 {
2276 /* You're supposed to have one `template <...>' for every
2277 template class, but you don't need one for a full
2278 specialization. For example:
2280 template <class T> struct S{};
2281 template <> struct S<int> { void f(); };
2282 void S<int>::f () {}
2284 is correct; there shouldn't be a `template <>' for the
2285 definition of `S<int>::f'. */
2287 /* If CTYPE does not have template information of any
2288 kind, then it is not a template, nor is it nested
2289 within a template. */
2297 }
2300 }
2302 /* Do a simple sanity check on the template headers that precede the
2303 variable declaration DECL. */
2305 void
2307 {
2314 {
2320 "members of an explicitly specialized class are defined "
2322 }
2323 }
2325 /* Check to see if the function just declared, as indicated in
2326 DECLARATOR, and in DECL, is a specialization of a function
2327 template. We may also discover that the declaration is an explicit
2328 instantiation at this point.
2330 Returns DECL, or an equivalent declaration that should be used
2331 instead if all goes well. Issues an error message if something is
2332 amiss. Returns error_mark_node if the error is not easily
2333 recoverable.
2335 FLAGS is a bitmask consisting of the following flags:
2337 2: The function has a definition.
2338 4: The function is a friend.
2340 The TEMPLATE_COUNT is the number of references to qualifying
2341 template classes that appeared in the name of the function. For
2342 example, in
2344 template <class T> struct S { void f(); };
2345 void S<int>::f();
2347 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2348 classes are not counted in the TEMPLATE_COUNT, so that in
2350 template <class T> struct S {};
2351 template <> struct S<int> { void f(); }
2352 template <> void S<int>::f();
2354 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2355 invalid; there should be no template <>.)
2357 If the function is a specialization, it is marked as such via
2358 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2359 is set up correctly, and it is added to the list of specializations
2360 for that template. */
2362 tree
2364 tree decl,
2367 {
2375 tmpl_spec_kind tsk;
2378 {
2381 else
2383 }
2384 else
2388 {
2391 {
2394 }
2396 {
2398 /* This could be something like:
2400 template <class T> void f(T);
2401 class S { friend void f<>(int); } */
2403 else
2404 {
2405 /* This case handles bogus declarations like template <>
2406 template <class T> void f<int>(); */
2409 declarator);
2411 }
2412 }
2416 /* The error has already been reported in
2417 check_specialization_scope. */
2423 /* Fall through. */
2436 decl);
2439 else
2443 /* Fall through. */
2448 else
2454 {
2455 /* This case handles bogus declarations like template <>
2456 template <class T> void f<int>(); */
2461 else
2463 declarator);
2465 }
2468 /* This is a specialization of a member template, without
2469 specialization the containing class. Something like:
2471 template <class T> struct S {
2472 template <class U> void f (U);
2473 };
2474 template <> template <class U> void S<int>::f(U) {}
2476 That's a specialization -- but of the entire template. */
2482 }
2485 {
2489 {
2493 }
2494 }
2497 {
2501 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2503 {
2504 tree fns;
2509 else
2510 {
2511 /* If there is no class context, the explicit instantiation
2512 must be at namespace scope. */
2515 /* Find the namespace binding, using the declaration
2516 context. */
2520 {
2523 }
2524 else
2525 {
2531 }
2532 }
2535 }
2541 {
2543 /* A specialization in class scope. This is invalid,
2544 but the error will already have been flagged by
2545 check_specialization_scope. */
2547 else
2548 {
2549 /* It's not valid to write an explicit instantiation in
2550 class scope, e.g.:
2552 class C { template void f(); }
2554 This case is caught by the parser. However, on
2555 something like:
2557 template class C { void f(); };
2559 (which is invalid) we can get here. The error will be
2560 issued later. */
2561 ;
2562 }
2565 }
2568 {
2569 /* Find the list of functions in ctype that have the same
2570 name as the declared function. */
2576 {
2581 {
2582 /* From [temp.expl.spec]:
2584 If such an explicit specialization for the member
2585 of a class template names an implicitly-declared
2586 special member function (clause _special_), the
2587 program is ill-formed.
2589 Similar language is found in [temp.explicit]. */
2592 }
2595 }
2598 {
2602 }
2603 else
2604 {
2606 tree ovl;
2608 /* For a type-conversion operator, we cannot do a
2609 name-based lookup. We might be looking for `operator
2610 int' which will be a specialization of `operator T'.
2611 So, we find *all* the conversion operators, and then
2612 select from them. */
2620 {
2622 /* There are no more conversion functions. */
2625 /* Glue all these conversion functions together
2626 with those we already have. */
2629 }
2630 }
2633 {
2636 }
2637 else
2639 }
2641 /* Figure out what exactly is being specialized at this point.
2642 Note that for an explicit instantiation, even one for a
2643 member function, we cannot tell apriori whether the
2644 instantiation is for a member template, or just a member
2645 function of a template class. Even if a member template is
2646 being instantiated, the member template arguments may be
2647 elided if they can be deduced from the rest of the
2648 declaration. */
2651 member_specialization,
2652 template_count,
2653 tsk);
2656 /* We couldn't figure out what this declaration was
2657 specializing. */
2659 else
2660 {
2664 {
2665 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2666 is done by do_decl_instantiation later. */
2672 {
2673 /* If TMPL is not the most general template (for
2674 example, if TMPL is a friend template that is
2675 injected into namespace scope), then there will
2676 be too many levels of TARGS. Remove some of them
2677 here. */
2679 tree new_targs;
2686 }
2689 }
2691 /* If we thought that the DECL was a member function, but it
2692 turns out to be specializing a static member function,
2693 make DECL a static member function as well. */
2698 /* If this is a specialization of a member template of a
2699 template class, we want to return the TEMPLATE_DECL, not
2700 the specialization of it. */
2702 {
2707 {
2708 tree parm;
2712 /* We want to use the argument list specified in the
2713 definition, not in the original declaration. */
2718 }
2721 }
2723 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2726 /* Inherit default function arguments from the template
2727 DECL is specializing. */
2730 /* This specialization has the same protection as the
2731 template it specializes. */
2735 /* 7.1.1-1 [dcl.stc]
2737 A storage-class-specifier shall not be specified in an
2738 explicit specialization...
2740 The parser rejects these, so unless action is taken here,
2741 explicit function specializations will always appear with
2742 global linkage.
2744 The action recommended by the C++ CWG in response to C++
2745 defect report 605 is to make the storage class and linkage
2746 of the explicit specialization match the templated function:
2748 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2749 */
2751 {
2755 /* This specialization has the same linkage and visibility as
2756 the function template it specializes. */
2759 {
2762 }
2765 {
2768 }
2769 }
2771 /* If DECL is a friend declaration, declared using an
2772 unqualified name, the namespace associated with DECL may
2773 have been set incorrectly. For example, in:
2775 template <typename T> void f(T);
2776 namespace N {
2777 struct S { friend void f<int>(int); }
2778 }
2780 we will have set the DECL_CONTEXT for the friend
2781 declaration to N, rather than to the global namespace. */
2786 /* This is not really a declaration of a specialization.
2787 It's just the name of an instantiation. But, it's not
2788 a request for an instantiation, either. */
2791 /* Register this specialization so that we can find it
2792 again. */
2795 /* A 'structor should already have clones. */
2800 }
2801 }
2804 }
2806 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2807 parameters. These are represented in the same format used for
2808 DECL_TEMPLATE_PARMS. */
2810 int
2812 {
2813 const_tree p1;
2814 const_tree p2;
2822 {
2834 {
2838 /* If either of the template parameters are invalid, assume
2839 they match for the sake of error recovery. */
2852 }
2853 }
2856 /* One set of parameters has more parameters lists than the
2857 other. */
2861 }
2863 /* Determine whether PARM is a parameter pack. */
2865 bool
2867 {
2868 /* Determine if we have a non-type template parameter pack. */
2875 /* If this is a list of template parameters, we could get a
2876 TYPE_DECL or a TEMPLATE_DECL. */
2880 /* Otherwise it must be a type template parameter. */
2884 }
2886 /* Determine if T is a function parameter pack. */
2888 bool
2890 {
2894 }
2896 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2897 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2899 tree
2901 {
2908 }
2910 /* Return true iff the function parameter PARAM_DECL was expanded
2911 from the function parameter pack PACK. */
2913 bool
2915 {
2920 /* The parameter pack and its pack arguments have the same
2921 DECL_PARM_INDEX. */
2923 }
2925 /* Determine whether ARGS describes a variadic template args list,
2926 i.e., one that is terminated by a template argument pack. */
2928 static bool
2930 {
2932 tree last_parm;
2946 }
2948 /* Generate a new name for the parameter pack name NAME (an
2949 IDENTIFIER_NODE) that incorporates its */
2951 static tree
2953 {
2954 /* Munge the name to include the parameter index. */
2955 #define NUMBUF_LEN 128
2969 }
2971 /* Return true if T is a primary function, class or alias template
2972 instantiation. */
2974 bool
2976 {
2990 }
2992 /* Return true if PARM is a template template parameter. */
2994 bool
2996 {
2998 }
3000 /* Return true iff PARM is a DECL representing a type template
3001 parameter. */
3003 bool
3005 {
3010 }
3012 /* Return the template parameters of T if T is a
3013 primary template instantiation, NULL otherwise. */
3015 tree
3017 {
3022 parms = INNERMOST_TEMPLATE_PARMS
3026 }
3028 /* Return the template parameters of the LEVELth level from the full list
3029 of template parameters PARMS. */
3031 tree
3033 {
3034 tree p;
3045 }
3047 /* Returns the template arguments of T if T is a template instantiation,
3048 NULL otherwise. */
3050 tree
3052 {
3060 }
3062 /* Return the argument pack elements of T if T is a template argument pack,
3063 NULL otherwise. */
3065 tree
3067 {
3073 }
3075 /* Structure used to track the progress of find_parameter_packs_r. */
3076 struct find_parameter_pack_data
3077 {
3078 /* TREE_LIST that will contain all of the parameter packs found by
3079 the traversal. */
3082 /* Set of AST nodes that have been visited by the traversal. */
3084 };
3086 /* Identifies all of the argument packs that occur in a template
3087 argument and appends them to the TREE_LIST inside DATA, which is a
3088 find_parameter_pack_data structure. This is a subroutine of
3089 make_pack_expansion and uses_parameter_packs. */
3090 static tree
3092 {
3098 /* Handle type aliases/typedefs. */
3100 {
3107 }
3109 /* Identify whether this is a parameter pack or not. */
3111 {
3127 {
3128 /* We don't want to walk into the type of a PARM_DECL,
3129 because we don't want to see the type parameter pack. */
3132 }
3135 /* Look through a lambda capture proxy to the field pack. */
3138 {
3144 }
3151 /* Not a parameter pack. */
3153 }
3156 {
3157 /* Add this parameter pack to the list. */
3159 }
3165 /* This switch statement will return immediately if we don't find a
3166 parameter pack. */
3168 {
3173 /* Check the template itself. */
3176 /* Check the template arguments. */
3192 /* Fall through. */
3234 }
3237 }
3239 /* Determines if the expression or type T uses any parameter packs. */
3240 bool
3242 {
3250 }
3252 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3253 representation a base-class initializer into a parameter pack
3254 expansion. If all goes well, the resulting node will be an
3255 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3256 respectively. */
3257 tree
3259 {
3260 tree result;
3269 {
3270 /* The only time we will see a TREE_LIST here is for a base
3271 class initializer. In this case, the TREE_PURPOSE will be a
3272 _TYPE node (representing the base class expansion we're
3273 initializing) and the TREE_VALUE will be a TREE_LIST
3274 containing the initialization arguments.
3276 The resulting expansion looks somewhat different from most
3277 expansions. Rather than returning just one _EXPANSION, we
3278 return a TREE_LIST whose TREE_PURPOSE is a
3279 TYPE_PACK_EXPANSION containing the bases that will be
3280 initialized. The TREE_VALUE will be identical to the
3281 original TREE_VALUE, which is a list of arguments that will
3282 be passed to each base. We do not introduce any new pack
3283 expansion nodes into the TREE_VALUE (although it is possible
3284 that some already exist), because the TREE_PURPOSE and
3285 TREE_VALUE all need to be expanded together with the same
3286 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3287 resulting TREE_PURPOSE will mention the parameter packs in
3288 both the bases and the arguments to the bases. */
3289 tree purpose;
3290 tree value;
3293 /* Determine which parameter packs will be used by the base
3294 class expansion. */
3301 {
3305 }
3308 {
3309 /* Collect the sets of parameter packs used in each of the
3310 initialization arguments. */
3312 {
3313 /* Determine which parameter packs will be expanded in this
3314 argument. */
3317 }
3318 }
3322 /* Create the pack expansion type for the base type. */
3327 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3328 they will rarely be compared to anything. */
3332 }
3337 /* Build the PACK_EXPANSION_* node. */
3338 result = for_types
3343 {
3344 /* Propagate type and const-expression information. */
3347 }
3348 else
3349 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3350 they will rarely be compared to anything. */
3353 /* Determine which parameter packs will be expanded. */
3359 /* Make sure we found some parameter packs. */
3361 {
3364 else
3367 }
3373 }
3375 /* Checks T for any "bare" parameter packs, which have not yet been
3376 expanded, and issues an error if any are found. This operation can
3377 only be done on full expressions or types (e.g., an expression
3378 statement, "if" condition, etc.), because we could have expressions like:
3380 foo(f(g(h(args)))...)
3382 where "args" is a parameter pack. check_for_bare_parameter_packs
3383 should not be called for the subexpressions args, h(args),
3384 g(h(args)), or f(g(h(args))), because we would produce erroneous
3385 error messages.
3387 Returns TRUE and emits an error if there were bare parameter packs,
3388 returns FALSE otherwise. */
3389 bool
3391 {
3407 {
3410 {
3419 else
3424 else
3428 }
3431 }
3434 }
3436 /* Expand any parameter packs that occur in the template arguments in
3437 ARGS. */
3438 tree
3440 {
3446 /* First, determine if we need to expand anything, and the number of
3447 slots we'll need. */
3449 {
3454 {
3458 else
3460 }
3461 else
3462 {
3464 num_result_args++;
3465 }
3466 }
3468 /* If no expansion is necessary, we're done. */
3472 /* Expand arguments. */
3475 non_default_args_count =
3478 {
3481 {
3488 }
3489 else
3490 {
3493 }
3494 }
3498 }
3500 /* Checks if DECL shadows a template parameter.
3502 [temp.local]: A template-parameter shall not be redeclared within its
3503 scope (including nested scopes).
3505 Emits an error and returns TRUE if the DECL shadows a parameter,
3506 returns FALSE otherwise. */
3508 bool
3510 {
3511 tree olddecl;
3513 /* If we're not in a template, we can't possibly shadow a template
3514 parameter. */
3518 /* Figure out what we're shadowing. */
3523 /* If there's no previous binding for this name, we're not shadowing
3524 anything, let alone a template parameter. */
3528 /* If we're not shadowing a template parameter, we're done. Note
3529 that OLDDECL might be an OVERLOAD (or perhaps even an
3530 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3531 node. */
3535 /* We check for decl != olddecl to avoid bogus errors for using a
3536 name inside a class. We check TPFI to avoid duplicate errors for
3537 inline member templates. */
3543 /* Don't complain about the injected class name, as we've already
3544 complained about the class itself. */
3551 }
3553 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3554 ORIG_LEVEL, DECL, and TYPE. */
3556 static tree
3560 tree decl,
3561 tree type)
3562 {
3573 }
3575 /* Find the canonical type parameter for the given template type
3576 parameter. Returns the canonical type parameter, which may be TYPE
3577 if no such parameter existed. */
3579 static tree
3581 {
3582 tree list;
3596 else
3597 {
3602 }
3603 }
3605 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3606 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3607 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3608 new one is created. */
3610 static tree
3612 tsubst_flags_t complain)
3613 {
3618 {
3637 /* Template template parameters need this. */
3642 }
3645 }
3647 /* Process information from new template parameter PARM and append it
3648 to the LIST being built. This new parameter is a non-type
3649 parameter iff IS_NON_TYPE is true. This new parameter is a
3650 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3651 is in PARM_LOC. */
3653 tree
3656 {
3658 tree defval;
3665 {
3669 {
3673 else
3675 }
3678 }
3681 {
3687 {
3688 /* [temp.param]
3690 The top-level cv-qualifiers on the template-parameter are
3691 ignored when determining its type. */
3696 && !is_parameter_pack
3697 /* If we're in a nested template parameter list, the template
3698 template parameter could be a parameter pack. */
3700 {
3701 /* This template parameter is not a parameter pack, but it
3702 should be. Complain about "bare" parameter packs. */
3705 /* Recover by calling this a parameter pack. */
3707 }
3708 }
3710 /* A template parameter is not modifiable. */
3719 processing_template_decl,
3724 }
3725 else
3726 {
3727 tree t;
3731 {
3733 /* This is for distinguishing between real templates and template
3734 template parameters */
3738 }
3739 else
3740 {
3742 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3745 }
3752 processing_template_decl,
3756 }
3762 }
3764 /* The end of a template parameter list has been reached. Process the
3765 tree list into a parameter vector, converting each parameter into a more
3766 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3767 as PARM_DECLs. */
3769 tree
3771 {
3776 current_template_parms
3781 {
3785 }
3790 }
3792 /* end_template_decl is called after a template declaration is seen. */
3794 void
3796 {
3802 /* This matches the pushlevel in begin_template_parm_list. */
3807 }
3809 /* Takes a TREE_LIST representing a template parameter and convert it
3810 into an argument suitable to be passed to the type substitution
3811 functions. Note that If the TREE_LIST contains an error_mark
3812 node, the returned argument is error_mark_node. */
3814 static tree
3816 {
3829 {
3833 {
3834 /* Turn this argument into a TYPE_ARGUMENT_PACK
3835 with a single element, which expands T. */
3837 #ifdef ENABLE_CHECKING
3838 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3840 #endif
3845 }
3846 }
3847 else
3848 {
3852 {
3853 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3854 with a single element, which expands T. */
3857 #ifdef ENABLE_CHECKING
3858 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3860 #endif
3867 }
3868 else
3870 }
3872 }
3874 /* Given a set of template parameters, return them as a set of template
3875 arguments. The template parameters are represented as a TREE_VEC, in
3876 the form documented in cp-tree.h for template arguments. */
3878 static tree
3880 {
3881 tree header;
3886 /* If there is only one level of template parameters, we do not
3887 create a TREE_VEC of TREE_VECs. Instead, we return a single
3888 TREE_VEC containing the arguments. */
3893 {
3901 #ifdef ENABLE_CHECKING
3903 #endif
3907 else
3909 }
3912 /* This can happen for template parms of a template template
3913 parameter, e.g:
3915 template<template<class T, class U> class TT> struct S;
3917 Consider the level of the parms of TT; T and U both have
3918 level 2; TT has no template parm of level 1. So in this case
3919 the first element of full_template_args is NULL_TREE. If we
3920 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3921 of 2. This will make tsubst wrongly consider that T and U
3922 have level 1. Instead, let's create a dummy vector as the
3923 first element of full_template_args so that TMPL_ARGS_DEPTH
3924 returns the correct depth for args. */
3927 }
3929 /* Within the declaration of a template, return the currently active
3930 template parameters as an argument TREE_VEC. */
3932 static tree
3934 {
3936 }
3938 /* Update the declared TYPE by doing any lookups which were thought to be
3939 dependent, but are not now that we know the SCOPE of the declarator. */
3941 tree
3943 {
3954 /* Don't bother building up the args in this case. */
3956 {
3957 /* tsubst in the args corresponding to the template parameters,
3958 including auto if present. Most things will be unchanged, but
3959 make_typename_type and tsubst_qualified_id will resolve
3960 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3963 tree pushed;
3965 {
3969 }
3974 }
3980 {
3983 else
3985 }
3987 }
3989 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3990 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3991 a member template. Used by push_template_decl below. */
3993 static tree
3995 {
4003 }
4005 struct template_parm_data
4006 {
4007 /* The level of the template parameters we are currently
4008 processing. */
4011 /* The index of the specialization argument we are currently
4012 processing. */
4015 /* An array whose size is the number of template parameters. The
4016 elements are nonzero if the parameter has been used in any one
4017 of the arguments processed so far. */
4020 /* An array whose size is the number of template arguments. The
4021 elements are nonzero if the argument makes use of template
4022 parameters of this level. */
4024 };
4026 /* Subroutine of push_template_decl used to see if each template
4027 parameter in a partial specialization is used in the explicit
4028 argument list. If T is of the LEVEL given in DATA (which is
4029 treated as a template_parm_data*), then DATA->PARMS is marked
4030 appropriately. */
4032 static int
4034 {
4042 {
4045 }
4047 /* Return zero so that for_each_template_parm will continue the
4048 traversal of the tree; we want to mark *every* template parm. */
4050 }
4052 /* Process the partial specialization DECL. */
4054 static tree
4056 {
4062 tree inner_parms;
4063 tree inst;
4076 /* We check that each of the template parameters given in the
4077 partial specialization is used in the argument list to the
4078 specialization. For example:
4080 template <class T> struct S;
4081 template <class T> struct S<T*>;
4083 The second declaration is OK because `T*' uses the template
4084 parameter T, whereas
4086 template <class T> struct S<int>;
4088 is no good. Even trickier is:
4090 template <class T>
4091 struct S1
4092 {
4093 template <class U>
4094 struct S2;
4095 template <class U>
4096 struct S2<T>;
4097 };
4099 The S2<T> declaration is actually invalid; it is a
4100 full-specialization. Of course,
4102 template <class U>
4103 struct S2<T (*)(U)>;
4105 or some such would have been OK. */
4113 {
4118 NULL,
4120 }
4123 {
4124 /* One of the template parms was not used in a deduced context in the
4125 specialization. */
4127 {
4131 }
4135 }
4140 /* [temp.class.spec]
4142 The argument list of the specialization shall not be identical to
4143 the implicit argument list of the primary template. */
4150 /* A partial specialization that replaces multiple parameters of the
4151 primary template with a pack expansion is less specialized for those
4152 parameters. */
4154 {
4156 "primary template because it replaces multiple parameters "
4160 }
4162 /* [temp.class.spec]
4164 A partially specialized non-type argument expression shall not
4165 involve template parameters of the partial specialization except
4166 when the argument expression is a simple identifier.
4168 The type of a template parameter corresponding to a specialized
4169 non-type argument shall not be dependent on a parameter of the
4170 specialization.
4172 Also, we verify that pack expansions only occur at the
4173 end of the argument list. */
4177 {
4184 {
4185 /* Extract the arguments from the argument pack. We'll be
4186 iterating over these in the following loop. */
4189 }
4192 {
4194 /* Get the Jth argument in the parameter pack. */
4198 {
4199 /* Pack expansions must come at the end of the
4200 argument list. */
4203 {
4207 else
4210 }
4211 }
4214 /* We only care about the pattern. */
4220 /* This next two lines are the `argument expression is not just a
4221 simple identifier' condition and also the `specialized
4222 non-type argument' bit. */
4226 {
4230 arg);
4231 else
4232 {
4233 /* Look at the corresponding template parameter,
4234 marking which template parameters its type depends
4235 upon. */
4239 {
4240 /* We haven't yet initialized TPD2. Do so now. */
4242 /* The number of parameters here is the number in the
4243 main template, which, as checked in the assertion
4244 above, is NARGS. */
4248 }
4250 /* Mark the template parameters. But this time, we're
4251 looking for the template parameters of the main
4252 template, not in the specialization. */
4259 NULL,
4263 {
4264 /* The type depended on some template parameters.
4265 If they are fully specialized in the
4266 specialization, that's OK. */
4275 "type %qT of template argument %qE depends "
4277 "type %qT of template argument %qE depends "
4279 type,
4280 arg);
4281 }
4282 }
4283 }
4284 }
4285 }
4287 /* We should only get here once. */
4305 {
4309 {
4313 "partial specialization of %qT after instantiation "
4315 }
4316 }
4319 }
4321 /* PARM is a template parameter of some form; return the corresponding
4322 TEMPLATE_PARM_INDEX. */
4324 static tree
4326 {
4338 }
4340 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4341 parameter packs used by the template parameter PARM. */
4343 static void
4345 {
4346 /* A type parm can't refer to another parm. */
4350 {
4354 }
4361 }
4363 /* PARM is a template parameter pack. Return any parameter packs used in
4364 its type or the type of any of its template parameters. If there are
4365 any such packs, it will be instantiated into a fixed template parameter
4366 list by partial instantiation rather than be fully deduced. */
4368 tree
4370 {
4371 /* This can only be true in a member template. */
4374 /* This can only be true for a parameter pack. */
4377 /* A type parm can't refer to another parm. */
4390 }
4392 /* Check that a template declaration's use of default arguments and
4393 parameter packs is not invalid. Here, PARMS are the template
4394 parameters. IS_PRIMARY is true if DECL is the thing declared by
4395 a primary template. IS_PARTIAL is true if DECL is a partial
4396 specialization.
4398 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4399 declaration (but not a definition); 1 indicates a declaration, 2
4400 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4401 emitted for extraneous default arguments.
4403 Returns TRUE if there were no errors found, FALSE otherwise. */
4405 bool
4408 {
4411 tree parm_level;
4414 /* [temp.param]
4416 A default template-argument shall not be specified in a
4417 function template declaration or a function template definition, nor
4418 in the template-parameter-list of the definition of a member of a
4419 class template. */
4423 /* You can't have a function template declaration in a local
4424 scope, nor you can you define a member of a class template in a
4425 local scope. */
4431 /* A lambda doesn't have an explicit declaration; don't complain
4432 about the parms of the enclosing class. */
4439 /* If this is either a friend defined in the scope of the class
4440 or a member function. */
4446 /* And, if it was a member function, it really was defined in
4447 the scope of the class. */
4450 /* We already checked these parameters when the template was
4451 declared, so there's no need to do it again now. This function
4452 was defined in class scope, but we're processing its body now
4453 that the class is complete. */
4456 /* Core issue 226 (C++0x only): the following only applies to class
4457 templates. */
4460 {
4461 /* [temp.param]
4463 If a template-parameter has a default template-argument, all
4464 subsequent template-parameters shall have a default
4465 template-argument supplied. */
4467 {
4474 {
4484 {
4486 /* For better subsequent error-recovery, we indicate that
4487 there should have been a default argument. */
4490 }
4492 && !is_friend_decl
4493 /* Don't complain about an enclosing partial
4494 specialization. */
4499 /* A fixed parameter pack will be partially
4500 instantiated into a fixed length list. */
4502 {
4503 /* A primary class template can only have one
4504 parameter pack, at the end of the template
4505 parameter list. */
4510 else
4518 }
4519 }
4520 }
4521 }
4524 || is_partial
4525 || !is_primary
4527 /* For an ordinary class template, default template arguments are
4528 allowed at the innermost level, e.g.:
4529 template <class T = int>
4530 struct S {};
4531 but, in a partial specialization, they're not allowed even
4532 there, as we have in [temp.class.spec]:
4534 The template parameter list of a specialization shall not
4535 contain default template argument values.
4537 So, for a partial specialization, or for a function template
4538 (in C++98/C++03), we look at all of them. */
4539 ;
4540 else
4541 /* But, for a primary class template that is not a partial
4542 specialization we look at all template parameters except the
4543 innermost ones. */
4546 /* Figure out what error message to issue. */
4559 else
4563 /* If we're inside a class definition, there's no need to
4564 examine the parameters to the class itself. On the one
4565 hand, they will be checked when the class is defined, and,
4566 on the other, default arguments are valid in things like:
4567 template <class T = double>
4568 struct S { template <class U> void f(U); };
4569 Here the default argument for `S' has no bearing on the
4570 declaration of `f'. */
4572 else
4573 /* Check everything. */
4579 {
4586 {
4591 {
4593 {
4600 }
4602 /* Clear out the default argument so that we are not
4603 confused later. */
4605 }
4606 }
4608 /* At this point, if we're still interested in issuing messages,
4609 they must apply to classes surrounding the object declared. */
4613 }
4616 }
4618 /* Worker for push_template_decl_real, called via
4619 for_each_template_parm. DATA is really an int, indicating the
4620 level of the parameters we are interested in. If T is a template
4621 parameter of that level, return nonzero. */
4623 static int
4625 {
4631 else
4634 }
4636 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4637 parameters given by current_template_args, or reuses a
4638 previously existing one, if appropriate. Returns the DECL, or an
4639 equivalent one, if it is replaced via a call to duplicate_decls.
4641 If IS_FRIEND is true, DECL is a friend declaration. */
4643 tree
4645 {
4646 tree tmpl;
4647 tree args;
4648 tree info;
4649 tree ctx;
4653 /* True if the template is a member template, in the sense of
4654 [temp.mem]. */
4660 /* See if this is a partial specialization. */
4669 /* For a friend, we want the context of the friend function, not
4670 the type of which it is a friend. */
4674 /* In the case of a virtual function, we want the class in which
4675 it is defined. */
4677 else
4678 /* Otherwise, if we're currently defining some class, the DECL
4679 is assumed to be a member of the class. */
4688 /* See if this is a primary template. */
4691 /* A friend template that specifies a class context, i.e.
4692 template <typename T> friend void A<T>::f();
4693 is not primary. */
4695 else
4699 {
4704 {
4707 }
4709 {
4711 {
4712 /* [temp.mem]
4714 A destructor shall not be a member template. */
4717 }
4724 {
4725 /* [basic.stc.dynamic.allocation]
4727 An allocation function can be a function
4728 template. ... Template allocation functions shall
4729 have two or more parameters. */
4732 }
4733 }
4739 /* alias-declaration */
4741 else
4742 {
4745 }
4746 }
4748 /* Check to see that the rules regarding the use of default
4749 arguments are not being violated. */
4753 /* Ensure that there are no parameter packs in the type of this
4754 declaration that have not been expanded. */
4756 {
4757 /* Check each of the arguments individually to see if there are
4758 any bare parameter packs. */
4764 {
4767 {
4768 /* This is a PARM_DECL that contains unexpanded parameter
4769 packs. We have already complained about this in the
4770 check_for_bare_parameter_packs call, so just replace
4771 these types with ERROR_MARK_NODE. */
4774 }
4778 }
4780 /* Check for bare parameter packs in the return type and the
4781 exception specifiers. */
4783 /* Errors were already issued, set return type to int
4784 as the frontend doesn't expect error_mark_node as
4785 the return type. */
4789 }
4794 {
4797 }
4810 {
4815 /* If DECL is a TYPE_DECL for a class-template, then there won't
4816 be DECL_LANG_SPECIFIC. The information equivalent to
4817 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4821 {
4822 /* Since a template declaration already existed for this
4823 class-type, we must be redeclaring it here. Make sure
4824 that the redeclaration is valid. */
4826 current_template_parms);
4827 /* We don't need to create a new TEMPLATE_DECL; just use the
4828 one we already had. */
4830 }
4831 else
4832 {
4834 member_template_p);
4839 {
4840 /* A specialization of a member template of a template
4841 class. */
4845 }
4846 }
4847 }
4848 else
4849 {
4855 {
4858 }
4866 {
4867 tree new_tmpl;
4869 /* The declaration is a specialization of a member
4870 template, declared outside the class. Therefore, the
4871 innermost template arguments will be NULL, so we
4872 replace them with the arguments determined by the
4873 earlier call to check_explicit_specialization. */
4876 new_tmpl
4878 member_template_p);
4888 args,
4891 }
4893 /* Make sure the template headers we got make sense. */
4898 {
4903 }
4904 else
4906 {
4911 {
4915 else
4919 /* Avoid crash in import_export_decl. */
4922 }
4927 /* Can happen in erroneous input. */
4929 else
4931 }
4933 /* Check that the parms are used in the appropriate qualifying scopes
4934 in the declarator. */
4938 {
4944 /* Avoid crash in import_export_decl. */
4947 }
4948 }
4953 /* Push template declarations for global functions and types. Note
4954 that we do not try to push a global template friend declared in a
4955 template class; such a thing may well depend on the template
4956 parameters of the class. */
4959 {
4964 /* Hide template friend classes that haven't been declared yet. */
4966 {
4969 }
4970 }
4973 {
4979 {
4982 /* It is a conversion operator. See if the type converted to
4983 depends on innermost template operands. */
4986 depth))
4988 }
4990 /* Give template template parms a DECL_CONTEXT of the template
4991 for which they are a parameter. */
4994 {
4998 }
4999 }
5001 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5002 back to its most general template. If TMPL is a specialization,
5003 ARGS may only have the innermost set of arguments. Add the missing
5004 argument levels if necessary. */
5012 else
5013 {
5018 }
5021 }
5023 tree
5025 {
5027 }
5029 /* FN is an inheriting constructor that inherits from the constructor
5030 template INHERITED; turn FN into a constructor template with a matching
5031 template header. */
5033 tree
5035 {
5036 tree inner_parms
5039 tree parms
5050 }
5052 /* Called when a class template TYPE is redeclared with the indicated
5053 template PARMS, e.g.:
5055 template <class T> struct S;
5056 template <class T> struct S {}; */
5058 bool
5060 {
5061 tree tmpl;
5062 tree tmpl_parms;
5066 {
5069 }
5073 /* The type is nested in some template class. Nothing to worry
5074 about here; there are no new template parameters for the nested
5075 type. */
5079 {
5081 tmpl);
5083 }
5089 {
5099 }
5102 {
5103 tree tmpl_parm;
5104 tree parm;
5105 tree tmpl_default;
5106 tree parm_default;
5120 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5121 TEMPLATE_DECL. */
5131 {
5135 }
5138 {
5139 /* We have in [temp.param]:
5141 A template-parameter may not be given default arguments
5142 by two different declarations in the same scope. */
5147 }
5150 /* Update the previous template parameters (which are the ones
5151 that will really count) with the new default value. */
5154 /* Update the new parameters, too; they'll be used as the
5155 parameters for any members. */
5157 }
5160 }
5162 /* Simplify EXPR if it is a non-dependent expression. Returns the
5163 (possibly simplified) expression. */
5165 tree
5167 {
5171 /* If we're in a template, but EXPR isn't value dependent, simplify
5172 it. We're supposed to treat:
5174 template <typename T> void f(T[1 + 1]);
5175 template <typename T> void f(T[2]);
5177 as two declarations of the same function, for example. */
5181 {
5182 HOST_WIDE_INT saved_processing_template_decl;
5188 complain,
5193 }
5195 }
5197 tree
5199 {
5201 }
5203 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5204 template declaration, or a TYPE_DECL for an alias declaration. */
5206 bool
5208 {
5216 }
5218 /* Return TRUE iff is a specialization of an alias template. */
5220 bool
5222 {
5230 }
5232 /* Return the number of innermost template parameters in TMPL. */
5234 static int
5236 {
5239 }
5241 /* Return either TMPL or another template that it is equivalent to under DR
5242 1286: An alias that just changes the name of a template is equivalent to
5243 the other template. */
5245 static tree
5247 {
5250 {
5253 {
5258 {
5259 tree alias_args = INNERMOST_TEMPLATE_ARGS
5263 /* The alias type is equivalent to the pattern of the
5264 underlying template, so strip the alias. */
5267 }
5268 }
5270 }
5272 }
5274 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5275 must be a function or a pointer-to-function type, as specified
5276 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5277 and check that the resulting function has external linkage. */
5279 static tree
5281 tsubst_flags_t complain)
5282 {
5285 linkage_kind linkage;
5297 /* [temp.arg.nontype]/1
5299 A template-argument for a non-type, non-template template-parameter
5300 shall be one of:
5301 [...]
5302 -- the address of an object or function with external [C++11: or
5303 internal] linkage. */
5306 {
5308 {
5314 else
5317 }
5319 }
5323 {
5325 {
5330 else
5334 }
5336 }
5339 }
5341 /* Subroutine of convert_nontype_argument.
5342 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5343 Emit an error otherwise. */
5345 static bool
5347 tsubst_flags_t complain)
5348 {
5359 {
5363 }
5365 }
5367 /* Returns TRUE iff the address of OP is value-dependent.
5369 14.6.2.4 [temp.dep.temp]:
5370 A non-integral non-type template-argument is dependent if its type is
5371 dependent or it has either of the following forms
5372 qualified-id
5373 & qualified-id
5374 and contains a nested-name-specifier which specifies a class-name that
5375 names a dependent type.
5377 We generalize this to just say that the address of a member of a
5378 dependent class is value-dependent; the above doesn't cover the
5379 address of a static data member named with an unqualified-id. */
5381 static bool
5383 {
5384 /* We could use get_inner_reference here, but there's no need;
5385 this is only relevant for template non-type arguments, which
5386 can only be expressed as &id-expression. */
5388 {
5392 }
5395 }
5397 /* The next set of functions are used for providing helpful explanatory
5398 diagnostics for failed overload resolution. Their messages should be
5399 indented by two spaces for consistency with the messages in
5400 call.c */
5402 static int
5404 {
5406 }
5408 static int
5410 {
5415 }
5417 static int
5419 {
5421 }
5423 static int
5425 {
5431 }
5433 static int
5435 {
5439 }
5441 static int
5443 {
5446 " template parameter %qD is not a parameter pack, but "
5450 }
5452 static int
5454 {
5457 " template argument %qE does not match "
5461 }
5463 static int
5465 {
5469 }
5471 static int
5473 {
5479 }
5481 static int
5483 {
5485 {
5490 else
5492 " deduced conflicting values for non-type parameter "
5494 }
5496 }
5498 static int
5500 {
5503 " variable-sized array type %qT is not "
5505 arg);
5507 }
5509 static int
5511 {
5515 arg);
5517 }
5519 static int
5521 {
5528 }
5530 static int
5532 {
5534 }
5536 static int
5538 {
5540 }
5542 static int
5545 {
5551 }
5553 static int
5556 {
5559 {
5567 }
5569 }
5571 static int
5573 {
5576 " template parameters of a template template argument are "
5579 }
5581 static int
5583 {
5589 }
5591 static int
5593 {
5598 }
5600 static int
5602 {
5606 arg);
5608 }
5610 /* Attempt to convert the non-type template parameter EXPR to the
5611 indicated TYPE. If the conversion is successful, return the
5612 converted value. If the conversion is unsuccessful, return
5613 NULL_TREE if we issued an error message, or error_mark_node if we
5614 did not. We issue error messages for out-and-out bad template
5615 parameters, but not simply because the conversion failed, since we
5616 might be just trying to do argument deduction. Both TYPE and EXPR
5617 must be non-dependent.
5619 The conversion follows the special rules described in
5620 [temp.arg.nontype], and it is much more strict than an implicit
5621 conversion.
5623 This function is called twice for each template argument (see
5624 lookup_template_class for a more accurate description of this
5625 problem). This means that we need to handle expressions which
5626 are not valid in a C++ source, but can be created from the
5627 first call (for instance, casts to perform conversions). These
5628 hacks can go away after we fix the double coercion problem. */
5630 static tree
5632 {
5633 tree expr_type;
5635 /* Detect immediately string literals as invalid non-type argument.
5636 This special-case is not needed for correctness (we would easily
5637 catch this later), but only to provide better diagnostic for this
5638 common user mistake. As suggested by DR 100, we do not mention
5639 linkage issues in the diagnostic as this is not the point. */
5640 /* FIXME we're making this OK. */
5642 {
5648 }
5650 /* Add the ADDR_EXPR now for the benefit of
5651 value_dependent_expression_p. */
5654 {
5658 }
5660 /* If we are in a template, EXPR may be non-dependent, but still
5661 have a syntactic, rather than semantic, form. For example, EXPR
5662 might be a SCOPE_REF, rather than the VAR_DECL to which the
5663 SCOPE_REF refers. Preserving the qualifying scope is necessary
5664 so that access checking can be performed when the template is
5665 instantiated -- but here we need the resolved form so that we can
5666 convert the argument. */
5677 else
5680 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5681 to a non-type argument of "nullptr". */
5685 /* In C++11, integral or enumeration non-type template arguments can be
5686 arbitrary constant expressions. Pointer and pointer to
5687 member arguments can be general constant expressions that evaluate
5688 to a null value, but otherwise still need to be of a specific form. */
5690 {
5692 /* A PTRMEM_CST is already constant, and a valid template
5693 argument for a parameter of pointer to member type, we just want
5694 to leave it in that form rather than lower it to a
5699 {
5704 }
5705 }
5707 /* HACK: Due to double coercion, we can get a
5708 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5709 which is the tree that we built on the first call (see
5710 below when coercing to reference to object or to reference to
5711 function). We just strip everything and get to the arg.
5712 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5713 for examples. */
5715 {
5721 {
5722 /* ??? Maybe we could use convert_from_reference here, but we
5723 would need to relax its constraints because the NOP_EXPR
5724 could actually change the type to something more cv-qualified,
5725 and this is not folded by convert_from_reference. */
5730 && (same_type_ignoring_top_level_qualifiers_p
5733 {
5736 }
5737 }
5738 }
5740 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5741 parameter is a pointer to object, through decay and
5742 qualification conversion. Let's strip everything. */
5744 {
5749 {
5750 /* Skip the ADDR_EXPR only if it is part of the decay for
5751 an array. Otherwise, it is part of the original argument
5752 in the source code. */
5757 }
5758 }
5760 /* [temp.arg.nontype]/5, bullet 1
5762 For a non-type template-parameter of integral or enumeration type,
5763 integral promotions (_conv.prom_) and integral conversions
5764 (_conv.integral_) are applied. */
5766 {
5775 /* Notice that there are constant expressions like '4 % 0' which
5776 do not fold into integer constants. */
5778 {
5780 {
5791 /* else cxx_constant_value complained but gave us
5792 a real constant, so go ahead. */
5794 }
5795 else
5797 }
5799 /* Avoid typedef problems. */
5802 }
5803 /* [temp.arg.nontype]/5, bullet 2
5805 For a non-type template-parameter of type pointer to object,
5806 qualification conversions (_conv.qual_) and the array-to-pointer
5807 conversion (_conv.array_) are applied. */
5809 {
5810 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5812 A template-argument for a non-type, non-template template-parameter
5813 shall be one of: [...]
5815 -- the name of a non-type template-parameter;
5816 -- the address of an object or function with external linkage, [...]
5817 expressed as "& id-expression" where the & is optional if the name
5818 refers to a function or array, or if the corresponding
5819 template-parameter is a reference.
5821 Here, we do not care about functions, as they are invalid anyway
5822 for a parameter of type pointer-to-object. */
5825 /* Non-type template parameters are OK. */
5826 ;
5831 {
5833 {
5836 "because %qD is a variable, not the address of "
5839 }
5841 {
5847 }
5848 /* Other values, like integer constants, might be valid
5849 non-type arguments of some other type. */
5851 }
5852 else
5853 {
5854 tree decl;
5859 {
5864 }
5866 {
5872 }
5874 {
5879 }
5880 }
5889 }
5890 /* [temp.arg.nontype]/5, bullet 3
5892 For a non-type template-parameter of type reference to object, no
5893 conversions apply. The type referred to by the reference may be more
5894 cv-qualified than the (otherwise identical) type of the
5895 template-argument. The template-parameter is bound directly to the
5896 template-argument, which must be an lvalue. */
5898 {
5900 expr_type))
5904 {
5909 }
5912 {
5917 }
5919 /* [temp.arg.nontype]/1
5921 A template-argument for a non-type, non-template template-parameter
5922 shall be one of: [...]
5924 -- the address of an object or function with external linkage. */
5927 {
5930 {
5933 "because a reference variable does not have a constant "
5936 }
5937 }
5940 {
5946 }
5949 {
5955 }
5958 }
5959 /* [temp.arg.nontype]/5, bullet 4
5961 For a non-type template-parameter of type pointer to function, only
5962 the function-to-pointer conversion (_conv.func_) is applied. If the
5963 template-argument represents a set of overloaded functions (or a
5964 pointer to such), the matching function is selected from the set
5965 (_over.over_). */
5967 {
5968 /* If the argument is a template-id, we might not have enough
5969 context information to decay the pointer. */
5971 {
5975 }
5978 /* Null pointer values are OK in C++11. */
5984 }
5985 /* [temp.arg.nontype]/5, bullet 5
5987 For a non-type template-parameter of type reference to function, no
5988 conversions apply. If the template-argument represents a set of
5989 overloaded functions, the matching function is selected from the set
5990 (_over.over_). */
5992 {
5994 {
5996 {
6001 }
6003 }
6010 }
6011 /* [temp.arg.nontype]/5, bullet 6
6013 For a non-type template-parameter of type pointer to member function,
6014 no conversions apply. If the template-argument represents a set of
6015 overloaded member functions, the matching member function is selected
6016 from the set (_over.over_). */
6018 {
6023 /* [temp.arg.nontype] bullet 1 says the pointer to member
6024 expression must be a pointer-to-member constant. */
6028 /* There is no way to disable standard conversions in
6029 resolve_address_of_overloaded_function (called by
6030 instantiate_type). It is possible that the call succeeded by
6031 converting &B::I to &D::I (where B is a base of D), so we need
6032 to reject this conversion here.
6034 Actually, even if there was a way to disable standard conversions,
6035 it would still be better to reject them here so that we can
6036 provide a superior diagnostic. */
6038 {
6040 {
6044 /* If we are just one standard conversion off, explain. */
6048 }
6050 }
6051 }
6052 /* [temp.arg.nontype]/5, bullet 7
6054 For a non-type template-parameter of type pointer to data member,
6055 qualification conversions (_conv.qual_) are applied. */
6057 {
6058 /* [temp.arg.nontype] bullet 1 says the pointer to member
6059 expression must be a pointer-to-member constant. */
6066 }
6068 {
6070 {
6075 }
6077 }
6078 /* A template non-type parameter must be one of the above. */
6079 else
6082 /* Sanity check: did we actually convert the argument to the
6083 right type? */
6087 }
6089 /* Subroutine of coerce_template_template_parms, which returns 1 if
6090 PARM_PARM and ARG_PARM match using the rule for the template
6091 parameters of template template parameters. Both PARM and ARG are
6092 template parameters; the rest of the arguments are the same as for
6093 coerce_template_template_parms.
6094 */
6095 static int
6097 tree arg,
6098 tsubst_flags_t complain,
6099 tree in_decl,
6100 tree outer_args)
6101 {
6110 {
6112 /* We encounter instantiations of templates like
6113 template <template <template <class> class> class TT>
6114 class C; */
6115 {
6122 }
6123 /* Fall through. */
6128 /* Argument is a parameter pack but parameter is not. */
6133 /* The tsubst call is used to handle cases such as
6135 template <int> class C {};
6136 template <class T, template <T> class TT> class D {};
6137 D<int, C> d;
6139 i.e. the parameter list of TT depends on earlier parameters. */
6141 && !same_type_p
6148 /* Argument is a parameter pack but parameter is not. */
6155 }
6158 }
6161 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6162 template template parameters. Both PARM_PARMS and ARG_PARMS are
6163 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6164 or PARM_DECL.
6166 Consider the example:
6167 template <class T> class A;
6168 template<template <class U> class TT> class B;
6170 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6171 the parameters to A, and OUTER_ARGS contains A. */
6173 static int
6175 tree arg_parms,
6176 tsubst_flags_t complain,
6177 tree in_decl,
6178 tree outer_args)
6179 {
6190 /* Determine whether we have a parameter pack at the end of the
6191 template template parameter's template parameter list. */
6193 {
6200 {
6214 }
6215 }
6221 /* Check all of the template parameters except the parameter pack at
6222 the end (if any). */
6224 {
6233 outer_args))
6236 }
6239 {
6240 /* Check each of the template parameters in the template
6241 argument against the template parameter pack at the end of
6242 the template template parameter. */
6249 {
6256 outer_args))
6258 }
6259 }
6262 }
6264 /* Verifies that the deduced template arguments (in TARGS) for the
6265 template template parameters (in TPARMS) represent valid bindings,
6266 by comparing the template parameter list of each template argument
6267 to the template parameter list of its corresponding template
6268 template parameter, in accordance with DR150. This
6269 routine can only be called after all template arguments have been
6270 deduced. It will return TRUE if all of the template template
6271 parameter bindings are okay, FALSE otherwise. */
6272 bool
6274 {
6278 /* We're dealing with template parms in this process. */
6284 {
6289 {
6294 {
6295 /* Look inside the argument pack. */
6298 }
6301 {
6305 /* Extract the next argument from the argument
6306 pack. */
6310 /* Look at the pattern of the pack expansion. */
6313 /* Extract the template parameters from the template
6314 argument. */
6320 /* Verify that we can coerce the template template
6321 parameters from the template argument to the template
6322 parameter. This requires an exact match. */
6324 && !coerce_template_template_parms
6326 targ_parms,
6327 tf_none,
6328 tparm,
6329 targs))
6330 {
6333 }
6334 }
6335 }
6336 }
6338 out:
6342 }
6344 /* Since type attributes aren't mangled, we need to strip them from
6345 template type arguments. */
6347 static tree
6349 {
6350 tree mv;
6357 {
6362 }
6364 }
6366 /* Convert the indicated template ARG as necessary to match the
6367 indicated template PARM. Returns the converted ARG, or
6368 error_mark_node if the conversion was unsuccessful. Error and
6369 warning messages are issued under control of COMPLAIN. This
6370 conversion is for the Ith parameter in the parameter list. ARGS is
6371 the full set of template arguments deduced so far. */
6373 static tree
6375 tree arg,
6376 tree args,
6377 tsubst_flags_t complain,
6379 tree in_decl)
6380 {
6381 tree orig_arg;
6382 tree val;
6387 {
6388 /* The template argument was the name of some
6389 member function. That's usually
6390 invalid, but static members are OK. In any
6391 case, grab the underlying fields/functions
6392 and issue an error later if required. */
6395 }
6403 /* When determining whether an argument pack expansion is a template,
6404 look at the pattern. */
6408 /* Deal with an injected-class-name used as a template template arg. */
6410 {
6413 {
6423 }
6424 }
6426 is_tmpl_type =
6442 {
6444 {
6448 }
6451 "to refer to a type member of a template parameter, "
6456 typename_type,
6457 complain);
6460 }
6462 {
6464 {
6466 {
6476 else
6478 }
6479 }
6481 }
6483 {
6485 {
6491 else
6493 }
6495 }
6498 {
6500 {
6504 /* The number of argument required is not known yet.
6505 Just accept it for now. */
6507 else
6508 {
6510 tree argparm;
6512 /* Strip alias templates that are equivalent to another
6513 template. */
6519 args))
6520 {
6523 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6524 TEMPLATE_DECL. */
6526 {
6531 }
6532 }
6533 else
6534 {
6536 {
6542 }
6545 }
6546 }
6547 }
6548 else
6550 /* We only form one instance of each template specialization.
6551 Therefore, if we use a non-canonical variant (i.e., a
6552 typedef), any future messages referring to the type will use
6553 the typedef, which is confusing if those future uses do not
6554 themselves also use the typedef. */
6557 }
6558 else
6559 {
6566 {
6569 else
6570 {
6571 /* Not sure if this is reachable, but it doesn't hurt
6572 to be robust. */
6575 }
6576 }
6579 /* We used to call digest_init here. However, digest_init
6580 will report errors, which we don't want when complain
6581 is zero. More importantly, digest_init will try too
6582 hard to convert things: for example, `0' should not be
6583 converted to pointer type at this point according to
6584 the standard. Accepting this is not merely an
6585 extension, since deciding whether or not these
6586 conversions can occur is part of determining which
6587 function template to call, or whether a given explicit
6588 argument specification is valid. */
6590 else
6599 {
6600 /* Strip typedefs from the SCOPE_REF. */
6603 complain);
6606 }
6607 }
6610 }
6612 /* Coerces the remaining template arguments in INNER_ARGS (from
6613 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6614 Returns the coerced argument pack. PARM_IDX is the position of this
6615 parameter in the template parameter list. ARGS is the original
6616 template argument list. */
6617 static tree
6620 tree args,
6621 tree inner_args,
6623 tree new_args,
6625 tree in_decl,
6626 tsubst_flags_t complain)
6627 {
6630 tree packed_args;
6631 tree argument_pack;
6638 {
6639 /* When the template parameter is a non-type template parameter pack
6640 or template template parameter pack whose type or template
6641 parameters use parameter packs, we know exactly how many arguments
6642 we are looking for. Build a vector of the instantiated decls for
6643 these template parameters in PACKED_PARMS. */
6644 /* We can't use make_pack_expansion here because it would interpret a
6645 _DECL as a use rather than a declaration. */
6659 /* If we're doing a partial instantiation of a member template,
6660 verify that all of the types used for the non-type
6661 template parameter pack are, in fact, valid for non-type
6662 template parameters. */
6665 {
6668 {
6672 }
6673 }
6676 }
6677 else
6680 /* Convert the remaining arguments, which will be a part of the
6681 parameter pack "parm". */
6683 {
6689 {
6690 /* Once we've packed as many args as we have types, stop. */
6694 /* We don't know how many args we have yet, just
6695 use the unconverted ones for now. */
6697 else
6699 }
6702 {
6705 }
6706 else
6709 in_decl);
6713 }
6717 {
6722 }
6727 else
6728 {
6733 }
6736 #ifdef ENABLE_CHECKING
6739 #endif
6741 }
6743 /* Returns the number of pack expansions in the template argument vector
6744 ARGS. */
6746 static int
6748 {
6753 {
6757 }
6759 }
6761 /* Convert all template arguments to their appropriate types, and
6762 return a vector containing the innermost resulting template
6763 arguments. If any error occurs, return error_mark_node. Error and
6764 warning messages are issued under control of COMPLAIN.
6766 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6767 for arguments not specified in ARGS. Otherwise, if
6768 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6769 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6770 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6771 ARGS. */
6773 static tree
6775 tree args,
6776 tree in_decl,
6777 tsubst_flags_t complain,
6780 {
6782 tree orig_inner_args;
6783 tree inner_args;
6784 tree new_args;
6785 tree new_inner_args;
6789 /* When used as a boolean value, indicates whether this is a
6790 variadic template parameter list. Since it's an int, we can also
6791 subtract it from nparms to get the number of non-variadic
6792 parameters. */
6802 /* Determine if there are any parameter packs. */
6804 {
6810 }
6813 /* If there are no parameters that follow a parameter pack, we need to
6814 expand any argument packs so that we can deduce a parameter pack from
6815 some non-packed args followed by an argument pack, as in variadic85.C.
6816 If there are such parameters, we need to leave argument packs intact
6817 so the arguments are assigned properly. This can happen when dealing
6818 with a nested class inside a partial specialization of a class
6819 template, as in variadic92.C, or when deducing a template parameter pack
6820 from a sub-declarator, as in variadic114.C. */
6824 /* Count any pack expansion args. */
6830 && require_all_args
6831 && !variadic_args_p
6832 && (!use_default_args
6835 {
6837 {
6839 {
6843 }
6844 else
6850 }
6853 }
6854 /* We can't pass a pack expansion to a non-pack parameter of an alias
6855 template (DR 1430). */
6857 && variadic_args_p
6859 {
6861 {
6863 {
6869 {
6874 }
6875 }
6877 found:;
6878 }
6880 }
6882 /* We need to evaluate the template arguments, even though this
6883 template-id may be nested within a "sizeof". */
6892 {
6893 tree arg;
6894 tree parm;
6896 /* Get the Ith template parameter. */
6900 {
6903 }
6905 /* Calculate the next argument. */
6908 else
6913 {
6914 /* Some arguments will be placed in the
6915 template parameter pack PARM. */
6922 {
6923 /* We don't know how many args we have yet, just use the
6924 unconverted (and still packed) ones for now. */
6928 }
6932 /* Store this argument. */
6934 {
6935 lost++;
6936 /* We are done with all of the arguments. */
6938 }
6939 else
6940 {
6943 }
6946 }
6948 {
6950 {
6951 /* "If every valid specialization of a variadic template
6952 requires an empty template parameter pack, the template is
6953 ill-formed, no diagnostic required." So check that the
6954 pattern works with this parameter. */
6959 in_decl);
6961 {
6965 }
6967 /* Recover from missing typename. */
6971 /* We don't know how many args we have yet, just
6972 use the unconverted ones for now. */
6976 }
6977 }
6979 {
6980 /* There must be a default arg in this case. */
6983 /* The position of the first default template argument,
6984 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6985 Record that. */
6989 }
6990 else
6994 {
6997 }
6999 /* This only occurs if there was an error in the template
7000 parameter list itself (which we would already have
7001 reported) that we are trying to recover from, e.g., a class
7002 template with a parameter list such as
7003 template<typename..., typename>. */
7005 else
7011 lost++;
7013 }
7018 {
7020 {
7025 }
7027 }
7032 #ifdef ENABLE_CHECKING
7036 #endif
7039 }
7041 /* Like coerce_template_parms. If PARMS represents all template
7042 parameters levels, this function returns a vector of vectors
7043 representing all the resulting argument levels. Note that in this
7044 case, only the innermost arguments are coerced because the
7045 outermost ones are supposed to have been coerced already.
7047 Otherwise, if PARMS represents only (the innermost) vector of
7048 parameters, this function returns a vector containing just the
7049 innermost resulting arguments. */
7051 static tree
7053 tree args,
7054 tree in_decl,
7055 tsubst_flags_t complain,
7058 {
7061 tree coerced_args;
7064 {
7066 tree level;
7072 {
7073 tree l;
7077 require_all_args,
7078 use_default_args);
7079 else
7086 }
7087 }
7088 else
7091 require_all_args,
7092 use_default_args);
7094 }
7096 /* Returns 1 if template args OT and NT are equivalent. */
7098 static int
7100 {
7107 /* For member templates */
7116 {
7133 }
7135 {
7136 /* We get here probably because we are in the middle of substituting
7137 into the pattern of a pack expansion. In that case the
7138 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7139 interested in. So we want to use the initial pack argument for
7140 the comparison. */
7145 }
7150 else
7152 }
7154 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7155 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7156 NEWARG_PTR with the offending arguments if they are non-NULL. */
7158 static int
7161 {
7174 {
7179 {
7185 }
7186 }
7188 }
7190 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7191 of template arguments. Returns 0 otherwise. */
7193 int
7195 {
7197 }
7199 static void
7201 {
7211 /* We are called both from instantiate_decl, where we've already had a
7212 tinst_level pushed, and instantiate_template, where we haven't.
7213 Compensate. */
7224 else
7233 }
7236 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7237 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7238 documentation for TEMPLATE_ID_EXPR. */
7240 tree
7242 {
7243 tree type;
7251 {
7254 }
7257 {
7259 unknown_type_node,
7261 arglist);
7263 }
7270 }
7272 /* Within the scope of a template class S<T>, the name S gets bound
7273 (in build_self_reference) to a TYPE_DECL for the class, not a
7274 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7275 or one of its enclosing classes, and that type is a template,
7276 return the associated TEMPLATE_DECL. Otherwise, the original
7277 DECL is returned.
7279 Also handle the case when DECL is a TREE_LIST of ambiguous
7280 injected-class-names from different bases. */
7282 tree
7284 {
7288 /* DR 176: A lookup that finds an injected-class-name (10.2
7289 [class.member.lookup]) can result in an ambiguity in certain cases
7290 (for example, if it is found in more than one base class). If all of
7291 the injected-class-names that are found refer to specializations of
7292 the same class template, and if the name is followed by a
7293 template-argument-list, the reference refers to the class template
7294 itself and not a specialization thereof, and is not ambiguous. */
7296 {
7299 {
7305 }
7308 else
7310 }
7316 }
7318 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7319 parameters, find the desired type.
7321 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7323 IN_DECL, if non-NULL, is the template declaration we are trying to
7324 instantiate.
7326 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7327 the class we are looking up.
7329 Issue error and warning messages under control of COMPLAIN.
7331 If the template class is really a local class in a template
7332 function, then the FUNCTION_CONTEXT is the function in which it is
7333 being instantiated.
7335 ??? Note that this function is currently called *twice* for each
7336 template-id: the first time from the parser, while creating the
7337 incomplete type (finish_template_type), and the second type during the
7338 real instantiation (instantiate_template_class). This is surely something
7339 that we want to avoid. It also causes some problems with argument
7340 coercion (see convert_nontype_argument for more information on this). */
7342 static tree
7345 {
7347 tree t;
7350 spec_entry elt;
7351 hashval_t hash;
7354 {
7358 else
7359 {
7366 }
7369 }
7371 {
7374 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7375 an implicit typename for the second A. Deal with it. */
7380 {
7383 }
7384 }
7387 {
7390 }
7394 {
7398 }
7400 {
7403 }
7405 /* Issue an error message if we didn't find a template. */
7407 {
7411 }
7414 /* Make sure it's a user visible template, if it was named by
7415 the user. */
7418 {
7420 {
7424 }
7426 }
7430 /* An alias that just changes the name of a template is equivalent to the
7431 other template, so if any of the arguments are pack expansions, strip
7432 the alias to avoid problems with a pack expansion passed to a non-pack
7433 alias template parameter (DR 1430). */
7438 {
7439 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7440 template arguments */
7442 tree parm;
7443 tree arglist2;
7444 tree outer;
7448 /* Consider an example where a template template parameter declared as
7450 template <class T, class U = std::allocator<T> > class TT
7452 The template parameter level of T and U are one level larger than
7453 of TT. To proper process the default argument of U, say when an
7454 instantiation `TT<int>' is seen, we need to build the full
7455 arguments containing {int} as the innermost level. Outer levels,
7456 available when not appearing as default template argument, can be
7457 obtained from the arguments of the enclosing template.
7459 Suppose that TT is later substituted with std::vector. The above
7460 instantiation is `TT<int, std::allocator<T> >' with TT at
7461 level 1, and T at level 2, while the template arguments at level 1
7462 becomes {std::vector} and the inner level 2 is {int}. */
7468 /* This is an argument of the current template, so we haven't set
7469 DECL_CONTEXT yet. */
7476 complain,
7486 }
7487 else
7488 {
7490 tree gen_tmpl;
7491 tree type_decl;
7499 /* An error occurred while building the template TEMPL, and a
7500 diagnostic has most certainly been emitted for that
7501 already. Let's propagate that error. */
7510 {
7511 /* We've been given an incomplete set of template arguments.
7512 For example, given:
7514 template <class T> struct S1 {
7515 template <class U> struct S2 {};
7516 template <class U> struct S2<U*> {};
7517 };
7519 we will be called with an ARGLIST of `U*', but the
7520 TEMPLATE will be `template <class T> template
7521 <class U> struct S1<T>::S2'. We must fill in the missing
7522 arguments. */
7523 arglist
7525 arglist);
7527 }
7529 /* Now we should have enough arguments. */
7532 /* From here on, we're only interested in the most general
7533 template. */
7535 /* Calculate the BOUND_ARGS. These will be the args that are
7536 actually tsubst'd into the definition to create the
7537 instantiation. */
7539 {
7540 /* We have multiple levels of arguments to coerce, at once. */
7550 {
7551 tree a;
7555 complain,
7558 else
7559 /* Outer levels should have already been coerced. */
7562 /* Don't process further if one of the levels fails. */
7564 {
7565 /* Restore the ARGLIST to its full size. */
7568 }
7572 /* We temporarily reduce the length of the ARGLIST so
7573 that coerce_template_parms will see only the arguments
7574 corresponding to the template parameters it is
7575 examining. */
7577 }
7579 /* Restore the ARGLIST to its full size. */
7583 }
7584 else
7585 arglist
7588 gen_tmpl,
7589 complain,
7594 /* We were unable to bind the arguments. */
7597 /* In the scope of a template class, explicit references to the
7598 template class refer to the type of the template, not any
7599 instantiation of it. For example, in:
7601 template <class T> class C { void f(C<T>); }
7603 the `C<T>' is just the same as `C'. Outside of the
7604 class, however, such a reference is an instantiation. */
7608 /* comp_template_args is expensive, check it last. */
7610 arglist))
7613 /* If we already have this specialization, return it. */
7625 /* If the deduced arguments are invalid, then the binding
7626 failed. */
7630 complain))
7637 {
7642 }
7652 /* Create the type. */
7654 {
7655 /* The user referred to a specialization of an alias
7656 template represented by GEN_TMPL.
7658 [temp.alias]/2 says:
7660 When a template-id refers to the specialization of an
7661 alias template, it is equivalent to the associated
7662 type obtained by substitution of its
7663 template-arguments for the template-parameters in the
7664 type-id of the alias template. */
7667 /* Note that the call above (by indirectly calling
7668 register_specialization in tsubst_decl) registers the
7669 TYPE_DECL representing the specialization of the alias
7670 template. So next time someone substitutes ARGLIST for
7671 the template parms into the alias template (GEN_TMPL),
7672 she'll get that TYPE_DECL back. */
7676 }
7678 {
7680 {
7689 }
7690 else
7691 {
7692 /* We don't want to call start_enum for this type, since
7693 the values for the enumeration constants may involve
7694 template parameters. And, no one should be interested
7695 in the enumeration constants for such a type. */
7698 }
7702 }
7704 {
7711 /* A local class. Make sure the decl gets registered properly. */
7716 /* This instantiation is another name for the primary
7717 template type. Set the TYPE_CANONICAL field
7718 appropriately. */
7721 /* Some of the template arguments require structural
7722 equality testing, so this template class requires
7723 structural equality testing. */
7725 }
7726 else
7729 /* If we called start_enum or pushtag above, this information
7730 will already be set up. */
7732 {
7739 }
7740 else
7744 {
7750 {
7753 }
7754 }
7756 /* Let's consider the explicit specialization of a member
7757 of a class template specialization that is implicitly instantiated,
7758 e.g.:
7759 template<class T>
7760 struct S
7761 {
7762 template<class U> struct M {}; //#0
7763 };
7765 template<>
7766 template<>
7767 struct S<int>::M<char> //#1
7768 {
7769 int i;
7770 };
7771 [temp.expl.spec]/4 says this is valid.
7773 In this case, when we write:
7774 S<int>::M<char> m;
7776 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7777 the one of #0.
7779 When we encounter #1, we want to store the partial instantiation
7780 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7782 For all cases other than this "explicit specialization of member of a
7783 class template", we just want to store the most general template into
7784 the CLASSTYPE_TI_TEMPLATE of M.
7786 This case of "explicit specialization of member of a class template"
7787 only happens when:
7788 1/ the enclosing class is an instantiation of, and therefore not
7789 the same as, the context of the most general template, and
7790 2/ we aren't looking at the partial instantiation itself, i.e.
7791 the innermost arguments are not the same as the innermost parms of
7792 the most general template.
7794 So it's only when 1/ and 2/ happens that we want to use the partial
7795 instantiation of the member template in lieu of its most general
7796 template. */
7800 /* the enclosing class must be an instantiation... */
7803 {
7804 tree partial_inst_args;
7807 partial_inst_args =
7813 use_partial_inst_tmpl =
7814 /*...and we must not be looking at the partial instantiation
7815 itself. */
7817 partial_inst_args);
7818 }
7821 /* This case is easy; there are no member templates involved. */
7823 else
7824 {
7825 /* This is a full instantiation of a member template. Find
7826 the partial instantiation of which this is an instance. */
7828 /* Temporarily reduce by one the number of levels in the ARGLIST
7829 so as to avoid comparing the last set of arguments. */
7833 /* FOUND is either a proper class type, or an alias
7834 template specialization. In the later case, it's a
7835 TYPE_DECL, resulting from the substituting of arguments
7836 for parameters in the TYPE_DECL of the alias template
7837 done earlier. So be careful while getting the template
7838 of FOUND. */
7842 }
7853 /* Note this use of the partial instantiation so we can check it
7854 later in maybe_process_partial_specialization. */
7861 /* Now that the type has been registered on the instantiations
7862 list, we set up the enumerators. Because the enumeration
7863 constants may involve the enumeration type itself, we make
7864 sure to register the type first, and then create the
7865 constants. That way, doing tsubst_expr for the enumeration
7866 constants won't result in recursive calls here; we'll find
7867 the instantiation and exit above. */
7871 /* If the type makes use of template parameters, the
7872 code that generates debugging information will crash. */
7875 /* Possibly limit visibility based on template args. */
7880 }
7881 }
7883 /* Wrapper for lookup_template_class_1. */
7885 tree
7888 {
7889 tree ret;
7895 }
7896 \f
7897 struct pair_fn_data
7898 {
7899 tree_fn_t fn;
7901 /* True when we should also visit template parameters that occur in
7902 non-deduced contexts. */
7905 };
7907 /* Called from for_each_template_parm via walk_tree. */
7909 static tree
7911 {
7924 {
7928 /* Fall through. */
7951 /* Since we're not going to walk subtrees, we have to do this
7952 explicitly here. */
7956 /* Fall through. */
7959 /* Check the return type. */
7964 /* Check the parameter types. Since default arguments are not
7965 instantiated until they are needed, the TYPE_ARG_TYPES may
7966 contain expressions that involve template parameters. But,
7967 no-one should be looking at them yet. And, once they're
7968 instantiated, they don't contain template parameters, so
7969 there's no point in looking at them then, either. */
7970 {
7971 tree parm;
7978 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7979 want walk_tree walking into them itself. */
7981 }
7999 /* Fall through. */
8015 /* Record template parameters such as `T' inside `TT<T>'. */
8019 /* Fall through. */
8031 /* A template template parameter is encountered. */
8037 /* Already substituted template template parameter */
8060 /* If there's no type, then this thing must be some expression
8061 involving template parameters. */
8083 }
8085 /* We didn't find any template parameters we liked. */
8087 }
8089 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8090 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8091 call FN with the parameter and the DATA.
8092 If FN returns nonzero, the iteration is terminated, and
8093 for_each_template_parm returns 1. Otherwise, the iteration
8094 continues. If FN never returns a nonzero value, the value
8095 returned by for_each_template_parm is 0. If FN is NULL, it is
8096 considered to be the function which always returns 1.
8098 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8099 parameters that occur in non-deduced contexts. When false, only
8100 visits those template parameters that can be deduced. */
8102 static int
8106 {
8110 /* Set up. */
8115 /* Walk the tree. (Conceptually, we would like to walk without
8116 duplicates, but for_each_template_parm_r recursively calls
8117 for_each_template_parm, so we would need to reorganize a fair
8118 bit to use walk_tree_without_duplicates, so we keep our own
8119 visited list.) */
8122 else
8125 for_each_template_parm_r,
8129 /* Clean up. */
8131 {
8134 }
8137 }
8139 /* Returns true if T depends on any template parameter. */
8141 int
8143 {
8170 else
8171 {
8174 }
8179 }
8181 /* Returns true iff current_function_decl is an incompletely instantiated
8182 template. Useful instead of processing_template_decl because the latter
8183 is set to 0 during fold_non_dependent_expr. */
8185 bool
8187 {
8196 }
8198 /* Returns true if T depends on any template parameter with level LEVEL. */
8200 int
8202 {
8205 }
8207 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8208 ill-formed translation unit, i.e. a variable or function that isn't
8209 usable in a constant expression. */
8213 {
8217 }
8219 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8220 neglectable and instantiated from within an erroneous instantiation. */
8222 static bool
8224 {
8235 }
8243 /* We're starting to instantiate D; record the template instantiation context
8244 for diagnostics and to restore it later. */
8246 int
8248 {
8252 {
8258 else
8266 }
8268 /* If the current instantiation caused problems, don't let it instantiate
8269 anything else. Do allow deduction substitution and decls usable in
8270 constant expressions. */
8287 }
8289 /* We're done instantiating this template; return to the instantiation
8290 context. */
8292 void
8294 {
8295 /* Restore the filename and line number stashed away when we started
8296 this instantiation. */
8300 }
8302 /* We're instantiating a deferred template; restore the template
8303 instantiation context in which the instantiation was requested, which
8304 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8306 static tree
8308 {
8320 }
8322 /* Returns the TINST_LEVEL which gives the original instantiation
8323 context. */
8327 {
8333 }
8335 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8336 vector of template arguments, as for tsubst.
8338 Returns an appropriate tsubst'd friend declaration. */
8340 static tree
8342 {
8343 tree new_friend;
8348 /* This was a friend declared with an explicit template
8349 argument list, e.g.:
8351 friend void f<>(T);
8353 to indicate that f was a template instantiation, not a new
8354 function declaration. Now, we have to figure out what
8355 instantiation of what template. */
8356 {
8358 tree new_args;
8359 tree tmpl;
8362 /* Friend functions are looked up in the containing namespace scope.
8363 We must enter that scope, to avoid finding member functions of the
8364 current class with same name. */
8379 tsk_none);
8381 }
8385 /* The NEW_FRIEND will look like an instantiation, to the
8386 compiler, but is not an instantiation from the point of view of
8387 the language. For example, we might have had:
8389 template <class T> struct S {
8390 template <class U> friend void f(T, U);
8391 };
8393 Then, in S<int>, template <class U> void f(int, U) is not an
8394 instantiation of anything. */
8400 {
8404 }
8406 /* The mangled name for the NEW_FRIEND is incorrect. The function
8407 is not a template instantiation and should not be mangled like
8408 one. Therefore, we forget the mangling here; we'll recompute it
8409 later if we need it. */
8411 {
8414 }
8417 {
8418 tree old_decl;
8419 tree new_friend_template_info;
8420 tree new_friend_result_template_info;
8421 tree ns;
8424 /* We must save some information from NEW_FRIEND before calling
8425 duplicate decls since that function will free NEW_FRIEND if
8426 possible. */
8428 new_friend_is_defn =
8433 {
8434 /* This declaration is a `primary' template. */
8437 new_friend_result_template_info
8439 }
8440 else
8443 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8447 /* Inside pushdecl_namespace_level, we will push into the
8448 current namespace. However, the friend function should go
8449 into the namespace of the template. */
8459 {
8460 /* This new friend declaration matched an existing
8461 declaration. For example, given:
8463 template <class T> void f(T);
8464 template <class U> class C {
8465 template <class T> friend void f(T) {}
8466 };
8468 the friend declaration actually provides the definition
8469 of `f', once C has been instantiated for some type. So,
8470 old_decl will be the out-of-class template declaration,
8471 while new_friend is the in-class definition.
8473 But, if `f' was called before this point, the
8474 instantiation of `f' will have DECL_TI_ARGS corresponding
8475 to `T' but not to `U', references to which might appear
8476 in the definition of `f'. Previously, the most general
8477 template for an instantiation of `f' was the out-of-class
8478 version; now it is the in-class version. Therefore, we
8479 run through all specialization of `f', adding to their
8480 DECL_TI_ARGS appropriately. In particular, they need a
8481 new set of outer arguments, corresponding to the
8482 arguments for this class instantiation.
8484 The same situation can arise with something like this:
8486 friend void f(int);
8487 template <class T> class C {
8488 friend void f(T) {}
8489 };
8491 when `C<int>' is instantiated. Now, `f(int)' is defined
8492 in the class. */
8495 /* On the other hand, if the in-class declaration does
8496 *not* provide a definition, then we don't want to alter
8497 existing definitions. We can just leave everything
8498 alone. */
8499 ;
8500 else
8501 {
8505 /* Overwrite whatever template info was there before, if
8506 any, with the new template information pertaining to
8507 the declaration. */
8511 {
8512 /* We should have called reregister_specialization in
8513 duplicate_decls. */
8518 /* Instantiate it if the global has already been used. */
8522 }
8523 else
8524 {
8525 tree t;
8527 /* Indicate that the old function template is a partial
8528 instantiation. */
8536 /* Reassign any specializations already in the hash table
8537 to the new more general template, and add the
8538 additional template args. */
8542 {
8544 spec_entry elt;
8556 register_specialization
8559 }
8561 }
8562 }
8564 /* The information from NEW_FRIEND has been merged into OLD_DECL
8565 by duplicate_decls. */
8567 }
8568 }
8569 else
8570 {
8574 /* In the code
8575 template <class T> class C {
8576 template <class U> friend void C1<U>::f (); // case 1
8577 friend void C2<T>::f (); // case 2
8578 };
8579 we only need to make sure CONTEXT is a complete type for
8580 case 2. To distinguish between the two cases, we note that
8581 CONTEXT of case 1 remains dependent type after tsubst while
8582 this isn't true for case 2. */
8592 {
8594 /* do_friend adds the TEMPLATE_DECL for any member friend
8595 template even if it isn't a member template, i.e.
8596 template <class T> friend A<T>::f();
8597 Look through it in that case. */
8601 /* Check to see that the declaration is really present, and,
8602 possibly obtain an improved declaration. */
8607 }
8608 }
8611 }
8613 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8614 template arguments, as for tsubst.
8616 Returns an appropriate tsubst'd friend type or error_mark_node on
8617 failure. */
8619 static tree
8621 {
8622 tree friend_type;
8623 tree tmpl;
8624 tree context;
8627 {
8630 }
8635 {
8638 else
8640 }
8642 /* Look for a class template declaration. We look for hidden names
8643 because two friend declarations of the same template are the
8644 same. For example, in:
8646 struct A {
8647 template <typename> friend class F;
8648 };
8649 template <typename> struct B {
8650 template <typename> friend class F;
8651 };
8653 both F templates are the same. */
8657 /* But, if we don't find one, it might be because we're in a
8658 situation like this:
8660 template <class T>
8661 struct S {
8662 template <class U>
8663 friend struct S;
8664 };
8666 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8667 for `S<int>', not the TEMPLATE_DECL. */
8669 {
8672 }
8675 {
8676 /* The friend template has already been declared. Just
8677 check to see that the declarations match, and install any new
8678 default parameters. We must tsubst the default parameters,
8679 of course. We only need the innermost template parameters
8680 because that is all that redeclare_class_template will look
8681 at. */
8684 {
8685 tree parms;
8686 location_t saved_input_location;
8695 }
8698 }
8699 else
8700 {
8701 /* The friend template has not already been declared. In this
8702 case, the instantiation of the template class will cause the
8703 injection of this template into the global scope. */
8708 /* The new TMPL is not an instantiation of anything, so we
8709 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8710 the new type because that is supposed to be the corresponding
8711 template decl, i.e., TMPL. */
8718 /* Inject this template into the global scope. */
8720 }
8723 {
8726 else
8728 }
8731 }
8733 /* Returns zero if TYPE cannot be completed later due to circularity.
8734 Otherwise returns one. */
8736 static int
8738 {
8748 else
8750 }
8754 /* Apply any attributes which had to be deferred until instantiation
8755 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8756 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8758 static void
8761 {
8763 tree t;
8768 {
8772 }
8775 {
8779 }
8780 else
8784 {
8789 {
8792 {
8799 {
8806 clauses
8810 else
8812 }
8813 /* If the first attribute argument is an identifier, don't
8814 pass it through tsubst. Attributes like mode, format,
8815 cleanup and several target specific attributes expect it
8816 unmodified. */
8819 {
8820 tree chain
8822 in_decl,
8827 chain);
8828 }
8829 else
8835 }
8836 else
8838 }
8841 }
8842 }
8844 /* Perform (or defer) access check for typedefs that were referenced
8845 from within the template TMPL code.
8846 This is a subroutine of instantiate_decl and instantiate_class_template.
8847 TMPL is the template to consider and TARGS is the list of arguments of
8848 that template. */
8850 static void
8852 {
8853 location_t saved_location;
8864 {
8876 /* Make access check error messages point to the location
8877 of the use of the typedef. */
8881 tf_warning_or_error);
8882 }
8884 }
8886 static tree
8888 {
8890 tree typedecl;
8891 tree pbinfo;
8892 tree base_list;
8894 tree fn_context;
8903 /* Figure out which template is being instantiated. */
8907 /* Determine what specialization of the original template to
8908 instantiate. */
8911 {
8914 }
8916 {
8917 /* This TYPE is actually an instantiation of a partial
8918 specialization. We replace the innermost set of ARGS with
8919 the arguments appropriate for substitution. For example,
8920 given:
8922 template <class T> struct S {};
8923 template <class T> struct S<T*> {};
8925 and supposing that we are instantiating S<int*>, ARGS will
8926 presently be {int*} -- but we need {int}. */
8929 }
8930 else
8931 {
8934 }
8936 /* If the template we're instantiating is incomplete, then clearly
8937 there's nothing we can do. */
8941 /* If we've recursively instantiated too many templates, stop. */
8945 /* Now we're really doing the instantiation. Mark the type as in
8946 the process of being defined. */
8949 /* We may be in the middle of deferred access check. Disable
8950 it now. */
8954 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
8959 /* Use #pragma pack from the template context. */
8965 /* Set the input location to the most specialized template definition.
8966 This is needed if tsubsting causes an error. */
8978 {
8981 /* Adjust visibility for template arguments. */
8983 }
8989 /* We should never instantiate a nested class before its enclosing
8990 class; we need to look up the nested class by name before we can
8991 instantiate it, and that lookup should instantiate the enclosing
8992 class. */
8998 {
8999 tree pbase_binfo;
9000 tree pushed_scope;
9003 /* We must enter the scope containing the type, as that is where
9004 the accessibility of types named in dependent bases are
9005 looked up from. */
9008 /* Substitute into each of the bases to determine the actual
9009 basetypes. */
9011 {
9012 tree base;
9018 {
9019 expanded_bases =
9026 }
9029 {
9031 /* Extract the already-expanded base class. */
9033 else
9034 /* Substitute to figure out the base class. */
9036 NULL_TREE);
9044 }
9045 }
9047 /* The list is now in reverse order; correct that. */
9052 }
9053 /* Now call xref_basetypes to set up all the base-class
9054 information. */
9062 /* Now that our base classes are set up, enter the scope of the
9063 class, so that name lookups into base classes, etc. will work
9064 correctly. This is precisely analogous to what we do in
9065 begin_class_definition when defining an ordinary non-template
9066 class, except we also need to push the enclosing classes. */
9069 /* Now members are processed in the order of declaration. */
9072 {
9076 {
9078 {
9079 /* Build new CLASSTYPE_NESTED_UTDS. */
9081 tree newtag;
9087 /* If the member is a class template, then -- even after
9088 substitution -- there may be dependent types in the
9089 template argument list for the class. We increment
9090 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9091 that function will assume that no types are dependent
9092 when outside of a template. */
9102 {
9106 /* Unfortunately, lookup_template_class sets
9107 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9108 instantiation (i.e., for the type of a member
9109 template class nested within a template class.)
9110 This behavior is required for
9111 maybe_process_partial_specialization to work
9112 correctly, but is not accurate in this case;
9113 the TAG is not an instantiation of anything.
9114 (The corresponding TEMPLATE_DECL is an
9115 instantiation, but the TYPE is not.) */
9118 /* Now, we call pushtag to put this NEWTAG into the scope of
9119 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9120 pushtag calling push_template_decl. We don't have to do
9121 this for enums because it will already have been done in
9122 tsubst_enum. */
9126 }
9127 }
9129 {
9130 /* Build new TYPE_METHODS. */
9131 tree r;
9140 /* Instantiate members marked with attribute used. */
9146 }
9147 else
9148 {
9149 /* Build new TYPE_FIELDS. */
9151 {
9152 tree condition;
9155 condition =
9165 }
9167 {
9168 tree r;
9172 /* The file and line for this declaration, to
9173 assist in error message reporting. Since we
9174 called push_tinst_level above, we don't need to
9175 restore these. */
9185 {
9186 /* A capture pack became multiple fields. */
9189 }
9192 {
9196 {
9197 /* In [temp.inst]:
9199 [t]he initialization (and any associated
9200 side-effects) of a static data member does
9201 not occur unless the static data member is
9202 itself used in a way that requires the
9203 definition of the static data member to
9204 exist.
9206 Therefore, we do not substitute into the
9207 initialized for the static data member here. */
9208 finish_static_data_member_decl
9214 /* Instantiate members marked with attribute used. */
9217 }
9219 {
9220 /* Determine whether R has a valid type and can be
9221 completed later. If R is invalid, then its type
9222 is replaced by error_mark_node. */
9228 {
9231 }
9232 }
9234 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9235 such a thing will already have been added to the field
9236 list by tsubst_enum in finish_member_declaration in the
9237 CLASSTYPE_NESTED_UTDS case above. */
9241 {
9244 }
9245 }
9246 }
9247 }
9248 }
9249 else
9250 {
9253 {
9254 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9260 {
9261 /* template <class T> friend class C; */
9264 }
9266 {
9267 /* template <class T> friend class C::D; */
9273 }
9276 {
9277 /* This could be either
9279 friend class T::C;
9281 when dependent_type_p is false or
9283 template <class U> friend class T::C;
9285 otherwise. */
9288 /* Bump processing_template_decl for correct
9289 dependent_type_p calculation. */
9294 }
9297 {
9298 /* friend class C;
9300 where C hasn't been declared yet. Let's lookup name
9301 from namespace scope directly, bypassing any name that
9302 come from dependent base class. */
9305 /* The call to xref_tag_from_type does injection for friend
9306 classes. */
9308 friend_type =
9312 }
9314 /* friend class C<T>; */
9317 /* Otherwise it's
9319 friend class C;
9321 where C is already declared or
9323 friend class C<int>;
9325 We don't have to do anything in these cases. */
9328 /* Trick make_friend_class into realizing that the friend
9329 we're adding is a template, not an ordinary class. It's
9330 important that we use make_friend_class since it will
9331 perform some error-checking and output cross-reference
9332 information. */
9340 }
9341 else
9342 {
9343 /* Build new DECL_FRIENDLIST. */
9344 tree r;
9346 /* The file and line for this declaration, to
9347 assist in error message reporting. Since we
9348 called push_tinst_level above, we don't need to
9349 restore these. */
9353 {
9356 }
9361 {
9364 }
9365 }
9366 }
9367 }
9370 {
9373 {
9378 /* We need to instantiate the capture list from the template
9379 after we've instantiated the closure members, but before we
9380 consider adding the conversion op. Also keep any captures
9381 that may have been added during instantiation of the op(). */
9383 tree tmpl_cap
9392 }
9393 else
9395 }
9397 /* Set the file and line number information to whatever is given for
9398 the class itself. This puts error messages involving generated
9399 implicit functions at a predictable point, and the same point
9400 that would be used for non-template classes. */
9407 /* We don't instantiate default arguments for member functions. 14.7.1:
9409 The implicit instantiation of a class template specialization causes
9410 the implicit instantiation of the declarations, but not of the
9411 definitions or default arguments, of the class member functions,
9412 member classes, static data members and member templates.... */
9414 /* Some typedefs referenced from within the template code need to be access
9415 checked at template instantiation time, i.e now. These types were
9416 added to the template at parsing time. Let's get those and perform
9417 the access checks then. */
9427 /* The vtable for a template class can be emitted in any translation
9428 unit in which the class is instantiated. When there is no key
9429 method, however, finish_struct_1 will already have added TYPE to
9430 the keyed_classes list. */
9435 }
9437 /* Wrapper for instantiate_class_template_1. */
9439 tree
9441 {
9442 tree ret;
9447 }
9449 static tree
9451 {
9452 tree r;
9458 else
9459 {
9466 }
9468 }
9470 /* Given a function parameter pack TMPL_PARM and some function parameters
9471 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9472 and set *SPEC_P to point at the next point in the list. */
9474 static tree
9476 {
9477 /* Collect all of the extra "packed" parameters into an
9478 argument pack. */
9479 tree parmvec;
9480 tree parmtypevec;
9491 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9496 {
9499 }
9501 /* Build the argument packs. */
9508 }
9510 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9511 NONTYPE_ARGUMENT_PACK. */
9513 static tree
9515 {
9517 }
9519 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9520 pack expansion. */
9522 static bool
9524 {
9529 }
9532 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9534 static tree
9536 {
9543 }
9545 /* This is a subroutine of tsubst_pack_expansion.
9547 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9548 mechanism to store the (non complete list of) arguments of the
9549 substitution and return a non substituted pack expansion, in order
9550 to wait for when we have enough arguments to really perform the
9551 substitution. */
9553 static bool
9557 {
9558 /* If one pack has an expansion and another pack has a normal
9559 argument or if one pack has an empty argument and an another
9560 one hasn't then tsubst_pack_expansion cannot perform the
9561 substitution and need to fall back on the
9562 PACK_EXPANSION_EXTRA mechanism. */
9570 {
9573 parm_pack;
9575 {
9580 else
9582 }
9586 }
9588 }
9590 /* [temp.variadic]/6 says that:
9592 The instantiation of a pack expansion [...]
9593 produces a list E1,E2, ..., En, where N is the number of elements
9594 in the pack expansion parameters.
9596 This subroutine of tsubst_pack_expansion produces one of these Ei.
9598 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9599 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9600 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9601 INDEX is the index 'i' of the element Ei to produce. ARGS,
9602 COMPLAIN, and IN_DECL are the same parameters as for the
9603 tsubst_pack_expansion function.
9605 The function returns the resulting Ei upon successful completion,
9606 or error_mark_node.
9608 Note that this function possibly modifies the ARGS parameter, so
9609 it's the responsibility of the caller to restore it. */
9611 static tree
9613 tree parm_packs,
9615 tree args /* This parm gets
9617 tsubst_flags_t complain,
9618 tree in_decl)
9619 {
9620 tree t;
9623 /* For each parameter pack, change the substitution of the parameter
9624 pack to the ith argument in its argument pack, then expand the
9625 pattern. */
9627 {
9632 ith_elem_is_expansion |=
9635 /* Select the Ith argument from the pack. */
9638 {
9640 {
9644 }
9645 else
9647 }
9648 else
9649 {
9654 {
9656 /* Update the corresponding argument. */
9658 }
9659 else
9660 /* Re-use the ARGUMENT_PACK_SELECT. */
9662 }
9664 }
9666 /* Substitute into the PATTERN with the (possibly altered)
9667 arguments. */
9669 /* Expanding a fixed parameter pack from
9670 coerce_template_parameter_pack. */
9675 else
9678 /* If the Ith argument pack element is a pack expansion, then
9679 the Ith element resulting from the substituting is going to
9680 be a pack expansion as well. */
9685 }
9687 /* Substitute ARGS into T, which is an pack expansion
9688 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9689 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9690 (if only a partial substitution could be performed) or
9691 ERROR_MARK_NODE if there was an error. */
9692 tree
9694 tree in_decl)
9695 {
9696 tree pattern;
9700 tree result;
9708 /* Add in any args remembered from an earlier partial instantiation. */
9713 /* Determine the argument packs that will instantiate the parameter
9714 packs used in the expansion expression. While we're at it,
9715 compute the number of arguments to be expanded and make sure it
9716 is consistent. */
9719 {
9726 {
9730 else
9733 }
9735 {
9738 else
9739 {
9740 /* We can't rely on local_specializations for a parameter
9741 name used later in a function declaration (such as in a
9742 late-specified return type). Even if it exists, it might
9743 have the wrong value for a recursive call. Just make a
9744 dummy decl, since it's only used for its type. */
9747 /* Partial instantiation of the parm_pack, we can't build
9748 up an argument pack yet. */
9750 else
9753 }
9754 }
9757 else
9758 {
9764 }
9771 /* This can only happen if we forget to expand an argument
9772 pack somewhere else. Just return an error, silently. */
9773 {
9777 }
9780 {
9784 /* Don't bother trying to do a partial substitution with
9785 incomplete packs; we'll try again after deduction. */
9792 {
9798 pattern);
9799 else
9802 pattern);
9804 }
9806 /* Keep track of the parameter packs and their corresponding
9807 argument packs. */
9810 }
9811 else
9812 {
9813 /* We can't substitute for this parameter pack. We use a flag as
9814 well as the missing_level counter because function parameter
9815 packs don't have a level. */
9817 }
9818 }
9820 /* We cannot expand this expansion expression, because we don't have
9821 all of the argument packs we need. */
9823 {
9824 /* We got some full packs, but we can't substitute them in until we
9825 have values for all the packs. So remember these until then. */
9830 }
9832 {
9833 /* There were no real arguments, we're just replacing a parameter
9834 pack with another version of itself. Substitute into the
9835 pattern and return a PACK_EXPANSION_*. The caller will need to
9836 deal with that. */
9840 else
9844 }
9849 {
9850 /* We're in a late-specified return type, so create our own local
9851 specializations map; the current map is either NULL or (in the
9852 case of recursive unification) might have bindings that we don't
9853 want to use or alter. */
9856 }
9858 /* For each argument in each argument pack, substitute into the
9859 pattern. */
9862 {
9864 i,
9866 in_decl);
9869 {
9872 }
9873 }
9875 /* Update ARGS to restore the substitution from parameter packs to
9876 their argument packs. */
9878 {
9884 else
9885 {
9893 /* Update the corresponding argument. */
9897 else
9899 }
9900 }
9903 {
9906 }
9909 }
9911 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9912 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9913 parameter packs; all parms generated from a function parameter pack will
9914 have the same DECL_PARM_INDEX. */
9916 tree
9918 {
9920 tree patparm;
9923 {
9929 }
9930 else
9931 {
9936 }
9939 }
9941 /* Substitute ARGS into the vector or list of template arguments T. */
9943 static tree
9945 {
9957 {
9959 tree new_arg;
9964 {
9965 /* Substitute into an expansion expression. */
9969 /* Add to the expanded length adjustment the number of
9970 expanded arguments. We subtract one from this
9971 measurement, because the argument pack expression
9972 itself is already counted as 1 in
9973 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9974 the argument pack is empty. */
9976 }
9978 {
9979 /* Substitute into each of the arguments. */
9985 new_arg,
9999 }
10000 }
10001 else
10010 }
10015 /* Make space for the expanded arguments coming from template
10016 argument packs. */
10018 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10019 arguments for a member template.
10020 In that case each TREE_VEC in ORIG_T represents a level of template
10021 arguments, and ORIG_T won't carry any non defaulted argument count.
10022 It will rather be the nested TREE_VECs that will carry one.
10023 In other words, ORIG_T carries a non defaulted argument count only
10024 if it doesn't contain any nested TREE_VEC. */
10026 {
10030 }
10032 {
10036 {
10039 /* Now expand the template argument pack "in place". */
10042 }
10043 else
10044 {
10046 out++;
10047 }
10048 }
10051 }
10053 /* Return the result of substituting ARGS into the template parameters
10054 given by PARMS. If there are m levels of ARGS and m + n levels of
10055 PARMS, then the result will contain n levels of PARMS. For
10056 example, if PARMS is `template <class T> template <class U>
10057 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10058 result will be `template <int*, double, class V>'. */
10060 static tree
10062 {
10066 /* When substituting into a template, we must set
10067 PROCESSING_TEMPLATE_DECL as the template parameters may be
10068 dependent if they are based on one-another, and the dependency
10069 predicates are short-circuit outside of templates. */
10076 {
10077 tree new_vec =
10082 {
10083 tree tuple;
10095 }
10101 }
10106 }
10108 /* Return the result of substituting ARGS into one template parameter
10109 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10110 parameter and which TREE_PURPOSE is the default argument of the
10111 template parameter. */
10113 static tree
10115 {
10136 }
10138 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10139 type T. If T is not an aggregate or enumeration type, it is
10140 handled as if by tsubst. IN_DECL is as for tsubst. If
10141 ENTERING_SCOPE is nonzero, T is the context for a template which
10142 we are presently tsubst'ing. Return the substituted value. */
10144 static tree
10146 tree args,
10147 tsubst_flags_t complain,
10148 tree in_decl,
10150 {
10155 {
10160 /* Else fall through. */
10164 {
10165 tree argvec;
10166 tree context;
10167 tree r;
10171 /* In "sizeof(X<I>)" we need to evaluate "I". */
10177 /* First, determine the context for the type we are looking
10178 up. */
10181 {
10184 /* If context is a nested class inside a class template,
10185 it may still need to be instantiated (c++/33959). */
10187 }
10189 /* Then, figure out what arguments are appropriate for the
10190 type we are trying to find. For example, given:
10192 template <class T> struct S;
10193 template <class T, class U> void f(T, U) { S<U> su; }
10195 and supposing that we are instantiating f<int, double>,
10196 then our ARGS will be {int, double}, but, when looking up
10197 S we only want {double}. */
10202 else
10203 {
10207 }
10213 }
10214 else
10215 /* This is not a template type, so there's nothing to do. */
10220 }
10221 }
10223 /* Substitute into the default argument ARG (a default argument for
10224 FN), which has the indicated TYPE. */
10226 tree
10228 {
10233 /* This can happen in invalid code. */
10237 /* This default argument came from a template. Instantiate the
10238 default argument here, not in tsubst. In the case of
10239 something like:
10241 template <class T>
10242 struct S {
10243 static T t();
10244 void f(T = t());
10245 };
10247 we must be careful to do name lookup in the scope of S<T>,
10248 rather than in the current class. */
10250 /* The "this" pointer is not valid in a default argument. */
10252 {
10257 }
10260 /* The default argument expression may cause implicitly defined
10261 member functions to be synthesized, which will result in garbage
10262 collection. We must treat this situation as if we were within
10263 the body of function so as to avoid collecting live data on the
10264 stack. */
10272 /* Restore the "this" pointer. */
10274 {
10277 }
10284 /* Make sure the default argument is reasonable. */
10290 }
10292 /* Substitute into all the default arguments for FN. */
10294 static void
10296 {
10297 tree arg;
10298 tree tmpl_args;
10302 /* If this function is not yet instantiated, we certainly don't need
10303 its default arguments. */
10306 /* Don't do this again for clones. */
10311 arg;
10317 complain);
10318 }
10320 /* Substitute the ARGS into the T, which is a _DECL. Return the
10321 result of the substitution. Issue error and warning messages under
10322 control of COMPLAIN. */
10324 static tree
10326 {
10327 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10328 location_t saved_loc;
10333 /* Set the filename and linenumber to improve error-reporting. */
10338 {
10340 {
10341 /* We can get here when processing a member function template,
10342 member class template, or template template parameter. */
10344 tree spec;
10345 tree tmpl_args;
10346 tree full_args;
10349 {
10350 /* Template template parameter is treated here. */
10354 /* If we get a real template back, return it. This can happen in
10355 the context of most_specialized_class. */
10367 complain);
10370 }
10372 /* We might already have an instance of this template.
10373 The ARGS are for the surrounding class type, so the
10374 full args contain the tsubst'd args for the context,
10375 plus the innermost args from the template decl. */
10379 /* Because this is a template, the arguments will still be
10380 dependent, even after substitution. If
10381 PROCESSING_TEMPLATE_DECL is not set, the dependency
10382 predicates will short-circuit. */
10390 /* If this is a default template template argument,
10391 tsubst might not have changed anything. */
10398 {
10401 }
10403 /* Make a new template decl. It will be similar to the
10404 original, but will record the current template arguments.
10405 We also create a new function declaration, which is just
10406 like the old one, but points to this new template, rather
10407 than the old one. */
10416 {
10417 tree new_type;
10425 /* For a partial specialization, we need to keep pointing to
10426 the primary template. */
10432 }
10433 else
10434 {
10435 tree new_decl;
10447 }
10453 /* The template parameters for this new template are all the
10454 template parameters for the old template, except the
10455 outermost level of parameters. */
10458 complain);
10464 /* Record this non-type partial instantiation. */
10468 }
10472 {
10473 tree ctx;
10476 tree gen_tmpl;
10477 tree type;
10482 /* Nobody should be tsubst'ing into non-template functions. */
10486 {
10487 tree spec;
10490 /* If T is not dependent, just return it. We have to
10491 increment PROCESSING_TEMPLATE_DECL because
10492 value_dependent_expression_p assumes that nothing is
10493 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10500 /* Calculate the most general template of which R is a
10501 specialization, and the complete set of arguments used to
10502 specialize R. */
10505 (DECL_TEMPLATE_RESULT
10511 /* Check to see if we already have this specialization. */
10516 {
10519 }
10521 /* We can see more levels of arguments than parameters if
10522 there was a specialization of a member template, like
10523 this:
10525 template <class T> struct S { template <class U> void f(); }
10526 template <> template <class U> void S<int>::f(U);
10528 Here, we'll be substituting into the specialization,
10529 because that's where we can find the code we actually
10530 want to generate, but we'll have enough arguments for
10531 the most general template.
10533 We also deal with the peculiar case:
10535 template <class T> struct S {
10536 template <class U> friend void f();
10537 };
10538 template <class U> void f() {}
10539 template S<int>;
10540 template void f<double>();
10542 Here, the ARGS for the instantiation of will be {int,
10543 double}. But, we only need as many ARGS as there are
10544 levels of template parameters in CODE_PATTERN. We are
10545 careful not to get fooled into reducing the ARGS in
10546 situations like:
10548 template <class T> struct S { template <class U> void f(U); }
10549 template <class T> template <> void S<T>::f(int) {}
10551 which we can spot because the pattern will be a
10552 specialization in this case. */
10554 parms_depth =
10559 }
10560 else
10561 {
10562 /* This special case arises when we have something like this:
10564 template <class T> struct S {
10565 friend void f<int>(int, double);
10566 };
10568 Here, the DECL_TI_TEMPLATE for the friend declaration
10569 will be an IDENTIFIER_NODE. We are being called from
10570 tsubst_friend_function, and we want only to create a
10571 new decl (R) with appropriate types so that we can call
10572 determine_specialization. */
10574 }
10577 {
10580 else
10584 }
10585 else
10586 {
10589 }
10594 /* If we hit excessive deduction depth, the type is bogus even if
10595 it isn't error_mark_node, so don't build a decl. */
10599 /* We do NOT check for matching decls pushed separately at this
10600 point, as they may not represent instantiations of this
10601 template, and in any case are considered separate under the
10602 discrete model. */
10606 /* Clear out the mangled name and RTL for the instantiation. */
10609 /* Leave DECL_INITIAL set on deleted instantiations. */
10614 /* OpenMP UDRs have the only argument a reference to the declared
10615 type. We want to diagnose if the declared type is a reference,
10616 which is invalid, but as references to references are usually
10617 quietly merged, diagnose it here. */
10619 {
10620 tree argtype
10625 "reference type %qT in "
10629 argtype);
10630 }
10633 /* Type-conversion operator. Reconstruct the name, in
10634 case it's the name of one of the template's parameters. */
10644 /* If this is an instantiation of a function with internal
10645 linkage, we already know what object file linkage will be
10646 assigned to the instantiation. */
10655 /* We'll re-clone as appropriate in instantiate_template. */
10658 /* If we aren't complaining now, return on error before we register
10659 the specialization so that we'll complain eventually. */
10665 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10666 this in the special friend case mentioned above where
10667 GEN_TMPL is NULL. */
10669 {
10674 tree new_r
10677 /* We instantiated this while substituting into
10678 the type earlier (template/friend54.C). */
10681 /* We're not supposed to instantiate default arguments
10682 until they are called, for a template. But, for a
10683 declaration like:
10685 template <class T> void f ()
10686 { extern void g(int i = T()); }
10688 we should do the substitution when the template is
10689 instantiated. We handle the member function case in
10690 instantiate_class_template since the default arguments
10691 might refer to other members of the class. */
10696 }
10697 else
10700 /* Copy the list of befriending classes. */
10704 {
10708 in_decl);
10709 }
10712 {
10718 /* If this is an instantiation of a member template, clone it.
10719 If it isn't, that'll be handled by
10720 clone_constructors_and_destructors. */
10723 }
10734 /* Possibly limit visibility based on template args. */
10737 {
10741 }
10749 }
10753 {
10761 {
10762 /* If there is a local specialization that isn't a
10763 parameter pack, it means that we're doing a "simple"
10764 substitution from inside tsubst_pack_expansion. Just
10765 return the local specialization (which will be a single
10766 parm). */
10773 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10774 the parameters in this function parameter pack. */
10778 {
10781 /* Zero-length parameter packs are boring. Just substitute
10782 into the chain. */
10786 }
10787 else
10788 {
10789 /* All we did was update the type. Make a note of that. */
10792 }
10793 }
10795 /* Loop through all of the parameters we'll build. When T is
10796 a function parameter pack, LEN is the number of expanded
10797 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10800 {
10807 /* We're on the Ith parameter of the function parameter
10808 pack. */
10809 {
10810 /* Get the Ith type. */
10813 /* Rename the parameter to include the index. */
10816 }
10818 /* We're dealing with a normal parameter. */
10826 {
10829 else
10832 }
10842 /* Keep track of the first new parameter we
10843 generate. That's what will be returned to the
10844 caller. */
10848 /* Build a proper chain of parameters when substituting
10849 into a function parameter pack. */
10852 }
10854 /* If cp_unevaluated_operand is set, we're just looking for a
10855 single dummy parameter, so don't keep going. */
10860 /* FIRST_R contains the start of the chain we've built. */
10862 }
10866 {
10873 {
10874 /* This field is a lambda capture pack. Return a TREE_VEC of
10875 the expanded fields to instantiate_class_template_1 and
10876 store them in the specializations hash table as a
10877 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10881 {
10884 }
10885 else
10886 {
10887 /* All we did was update the type. Make a note of that. */
10890 }
10891 }
10894 {
10897 {
10901 }
10911 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10912 non-bit-fields DECL_INITIAL is a non-static data member
10913 initializer, which gets deferred instantiation. */
10919 {
10920 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10921 NSDMI in perform_member_init. Still set DECL_INITIAL
10922 so that we know there is one. */
10927 }
10928 /* We don't have to set DECL_CONTEXT here; it is set by
10929 finish_member_declaration. */
10937 }
10940 {
10948 }
10949 }
10953 /* We reach here only for member using decls. We also need to check
10954 uses_template_parms because DECL_DEPENDENT_P is not set for a
10955 using-declaration that designates a member of the current
10956 instantiation (c++/53549). */
10959 {
10966 else
10967 {
10970 }
10971 }
10972 else
10973 {
10976 }
10981 {
10984 tree spec;
10986 tree ctx;
10995 {
10996 /* If this is the canonical decl, we don't have to
10997 mess with instantiations, and often we can't (for
10998 typename, template type parms and such). Note that
10999 TYPE_NAME is not correct for the above test if
11000 we've copied the type for a typedef. */
11006 }
11008 /* Check to see if we already have the specialization we
11009 need. */
11012 {
11013 /* T is a static data member or namespace-scope entity.
11014 We have to substitute into namespace-scope variables
11015 (even though such entities are never templates) because
11016 of cases like:
11018 template <class T> void f() { extern T t; }
11020 where the entity referenced is not known until
11021 instantiation time. */
11025 {
11027 complain,
11029 /* If CTX is unchanged, then T is in fact the
11030 specialization we want. That situation occurs when
11031 referencing a static data member within in its own
11032 class. We can use pointer equality, rather than
11033 same_type_p, because DECL_CONTEXT is always
11034 canonical... */
11037 /* ... unless T is a member template; in which
11038 case our caller can be willing to create a
11039 specialization of that template represented
11040 by T. */
11044 }
11047 {
11055 }
11056 }
11057 else
11058 {
11059 /* A local variable. */
11061 /* Subsequent calls to pushdecl will fill this in. */
11064 }
11065 /* If we already have the specialization we need, there is
11066 nothing more to do. */
11068 {
11071 }
11073 /* Create a new node for the specialization we need. */
11076 {
11079 else
11086 }
11088 {
11089 /* Even if the original location is out of scope, the
11090 newly substituted one is not. */
11097 {
11098 /* It may seem that this case cannot occur, since:
11100 typedef void f();
11101 void g() { f x; }
11103 declares a function, not a variable. However:
11105 typedef void f();
11106 template <typename T> void g() { T t; }
11107 template void g<f>();
11109 is an attempt to declare a variable with function
11110 type. */
11112 /* R is not yet sufficiently initialized, so we
11113 just use its name. */
11116 }
11118 /* Wait until cp_finish_decl to set this again, to handle
11119 circular dependency (template/instantiate6.C). */
11124 {
11129 {
11132 }
11134 }
11135 }
11141 /* Clear out the mangled name and RTL for the instantiation. */
11145 /* The initializer must not be expanded until it is required;
11146 see [temp.inst]. */
11152 {
11153 /* Possibly limit visibility based on template args. */
11156 {
11160 }
11162 }
11165 {
11166 /* A static data member declaration is always marked
11167 external when it is declared in-class, even if an
11168 initializer is present. We mimic the non-template
11169 processing here. */
11175 }
11185 /* Preserve a typedef that names a type. */
11187 {
11190 }
11193 }
11198 }
11199 #undef RETURN
11201 out:
11202 /* Restore the file and line information. */
11206 }
11208 /* Substitute into the ARG_TYPES of a function type.
11209 If END is a TREE_CHAIN, leave it and any following types
11210 un-substituted. */
11212 static tree
11214 tree args,
11215 tree end,
11216 tsubst_flags_t complain,
11217 tree in_decl)
11218 {
11219 tree remaining_arg_types;
11223 tree default_arg;
11234 {
11235 /* For a pack expansion, perform substitution on the
11236 entire expression. Later on, we'll handle the arguments
11237 one-by-one. */
11242 /* So that we'll spin through the parameters, one by one. */
11244 else
11245 {
11246 /* We only partially substituted into the parameter
11247 pack. Our type is TYPE_PACK_EXPANSION. */
11250 }
11251 }
11264 {
11266 {
11270 }
11272 }
11273 /* DR 657. */
11277 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11278 top-level qualifiers as required. */
11281 /* We do not substitute into default arguments here. The standard
11282 mandates that they be instantiated only when needed, which is
11283 done in build_over_call. */
11287 {
11288 /* We've instantiated a template before its default arguments
11289 have been parsed. This can happen for a nested template
11290 class, and is not an error unless we require the default
11291 argument in a call of this function. */
11292 remaining_arg_types =
11295 }
11296 else
11297 remaining_arg_types =
11299 }
11302 }
11304 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11305 *not* handle the exception-specification for FNTYPE, because the
11306 initial substitution of explicitly provided template parameters
11307 during argument deduction forbids substitution into the
11308 exception-specification:
11310 [temp.deduct]
11312 All references in the function type of the function template to the
11313 corresponding template parameters are replaced by the specified tem-
11314 plate argument values. If a substitution in a template parameter or
11315 in the function type of the function template results in an invalid
11316 type, type deduction fails. [Note: The equivalent substitution in
11317 exception specifications is done only when the function is instanti-
11318 ated, at which point a program is ill-formed if the substitution
11319 results in an invalid type.] */
11321 static tree
11323 tree args,
11324 tsubst_flags_t complain,
11325 tree in_decl)
11326 {
11327 tree return_type;
11329 tree fntype;
11331 /* The TYPE_CONTEXT is not used for function/method types. */
11334 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
11335 failure. */
11339 {
11340 /* Substitute the argument types. */
11352 {
11353 /* DR 1207: 'this' is in scope in the trailing return type. */
11355 }
11357 /* Substitute the return type. */
11361 {
11364 }
11365 }
11366 else
11367 /* Substitute the return type. */
11372 /* DR 486 clarifies that creation of a function type with an
11373 invalid return type is a deduction failure. */
11376 {
11378 {
11381 else
11383 }
11385 }
11386 /* And DR 657. */
11391 {
11392 /* Substitute the argument types. */
11397 }
11399 /* Construct a new type node and return it. */
11401 {
11406 }
11407 else
11408 {
11410 /* Don't pick up extra function qualifiers from the basetype. */
11413 {
11414 /* [temp.deduct]
11416 Type deduction may fail for any of the following
11417 reasons:
11419 -- Attempting to create "pointer to member of T" when T
11420 is not a class type. */
11423 r);
11425 }
11430 }
11437 }
11439 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11440 ARGS into that specification, and return the substituted
11441 specification. If there is no specification, return NULL_TREE. */
11443 static tree
11445 tree args,
11446 tsubst_flags_t complain,
11447 tree in_decl,
11449 {
11450 tree specs;
11451 tree new_specs;
11456 {
11457 /* A noexcept-specifier. */
11462 {
11463 /* Defer instantiation of noexcept-specifiers to avoid
11464 excessive instantiations (c++/49107). */
11467 {
11468 /* We already partially instantiated this member template,
11469 so combine the new args with the old. */
11474 }
11475 else
11476 {
11479 }
11480 }
11481 else
11482 new_specs = tsubst_copy_and_build
11486 }
11488 {
11491 else
11493 {
11494 tree spec;
11499 {
11500 /* Expand the pack expansion type. */
11503 in_decl);
11509 else
11510 {
11511 /* We're substituting into a member template, so
11512 we got a TYPE_PACK_EXPANSION back. Add that
11513 expansion and move on. */
11517 expanded_specs,
11518 complain);
11521 }
11522 }
11525 {
11528 else
11533 complain);
11534 }
11537 }
11538 }
11540 }
11542 /* Take the tree structure T and replace template parameters used
11543 therein with the argument vector ARGS. IN_DECL is an associated
11544 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11545 Issue error and warning messages under control of COMPLAIN. Note
11546 that we must be relatively non-tolerant of extensions here, in
11547 order to preserve conformance; if we allow substitutions that
11548 should not be allowed, we may allow argument deductions that should
11549 not succeed, and therefore report ambiguous overload situations
11550 where there are none. In theory, we could allow the substitution,
11551 but indicate that it should have failed, and allow our caller to
11552 make sure that the right thing happens, but we don't try to do this
11553 yet.
11555 This function is used for dealing with types, decls and the like;
11556 for expressions, use tsubst_expr or tsubst_copy. */
11558 tree
11560 {
11583 else
11588 /* Reuse typedefs. We need to do this to handle dependent attributes,
11589 such as attribute aligned. */
11592 {
11596 {
11597 /* DECL represents an alias template and we want to
11598 instantiate it. */
11602 }
11606 {
11610 }
11615 else
11616 /* The typedef is from a non-template context. */
11620 {
11622 r = cp_build_qualified_type_real
11626 }
11627 else
11628 {
11629 /* We don't have an instantiation yet, so drop the typedef. */
11634 }
11635 }
11648 {
11674 {
11680 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11681 needed. */
11687 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11688 with TREE_SIDE_EFFECTS that indicates this is not an integral
11689 constant expression. */
11692 {
11695 }
11698 }
11704 {
11717 {
11721 {
11722 /* See through ARGUMENT_PACK_SELECT arguments. */
11724 /* If the selected argument is an expansion E, that most
11725 likely means we were called from
11726 gen_elem_of_pack_expansion_instantiation during the
11727 substituting of pack an argument pack (which Ith
11728 element is a pack expansion, where I is
11729 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11730 In this case, the Ith element resulting from this
11731 substituting is going to be a pack expansion, which
11732 pattern is the pattern of E. Let's return the
11733 pattern of E, and
11734 gen_elem_of_pack_expansion_instantiation will
11735 build the resulting pack expansion from it. */
11738 }
11739 }
11744 {
11746 /* If ARG is an argument pack, we don't actually want to
11747 perform a substitution here, because substitutions
11748 for argument packs are only done
11749 element-by-element. We can get to this point when
11750 substituting the type of a non-type template
11751 parameter pack, when that type actually contains
11752 template parameter packs from an outer template, e.g.,
11754 template<typename... Types> struct A {
11755 template<Types... Values> struct B { };
11756 }; */
11760 {
11766 return cp_build_qualified_type_real
11768 }
11770 {
11771 /* We are processing a type constructed from a
11772 template template parameter. */
11783 /* Consider this code:
11785 template <template <class> class Template>
11786 struct Internal {
11787 template <class Arg> using Bind = Template<Arg>;
11788 };
11790 template <template <class> class Template, class Arg>
11791 using Instantiate = Template<Arg>; //#0
11793 template <template <class> class Template,
11794 class Argument>
11795 using Bind =
11796 Instantiate<Internal<Template>::template Bind,
11797 Argument>; //#1
11799 When #1 is parsed, the
11800 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11801 parameter `Template' in #0 matches the
11802 UNBOUND_CLASS_TEMPLATE representing the argument
11803 `Internal<Template>::template Bind'; We then want
11804 to assemble the type `Bind<Argument>' that can't
11805 be fully created right now, because
11806 `Internal<Template>' not being complete, the Bind
11807 template cannot be looked up in that context. So
11808 we need to "store" `Bind<Argument>' for later
11809 when the context of Bind becomes complete. Let's
11810 store that in a TYPENAME_TYPE. */
11814 argvec),
11815 typename_type,
11816 complain);
11818 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11819 are resolving nested-types in the signature of a
11820 member function templates. Otherwise ARG is a
11821 TEMPLATE_DECL and is the real template to be
11822 instantiated. */
11830 complain);
11831 return cp_build_qualified_type_real
11833 }
11834 else
11835 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11837 }
11840 /* This can happen during the attempted tsubst'ing in
11841 unify. This means that we don't yet have any information
11842 about the template parameter in question. */
11845 /* Early in template argument deduction substitution, we don't
11846 want to reduce the level of 'auto', or it will be confused
11847 with a normal template parm in subsequent deduction. */
11851 /* If we get here, we must have been looking at a parm for a
11852 more deeply nested template. Make a new version of this
11853 template parameter, but with a lower level. */
11855 {
11860 {
11862 r = cp_build_qualified_type_real
11866 }
11867 else
11868 {
11879 /* We have reduced the level of the template
11880 template parameter, but not the levels of its
11881 template parameters, so canonical_type_parameter
11882 will not be able to find the canonical template
11883 template parameter for this level. Thus, we
11884 require structural equality checking to compare
11885 TEMPLATE_TEMPLATE_PARMs. */
11889 else
11893 {
11901 }
11902 }
11911 }
11914 }
11917 {
11925 {
11929 }
11932 {
11936 }
11939 {
11943 }
11949 }
11952 /* We should never be tsubsting a binfo. */
11956 /* A vector of template arguments. */
11962 {
11966 /* [temp.deduct]
11968 Type deduction may fail for any of the following
11969 reasons:
11971 -- Attempting to create a pointer to reference type.
11972 -- Attempting to create a reference to a reference type or
11973 a reference to void.
11975 Core issue 106 says that creating a reference to a reference
11976 during instantiation is no longer a cause for failure. We
11977 only enforce this check in strict C++98 mode. */
11981 {
11984 /* We keep track of the last time we issued this error
11985 message to avoid spewing a ton of messages during a
11986 single bad template instantiation. */
11989 {
11994 else
11997 }
12000 }
12004 {
12006 {
12009 type);
12010 else
12012 type);
12013 }
12015 }
12017 {
12021 }
12023 /* In C++0x, during template argument substitution, when there is an
12024 attempt to create a reference to a reference type, reference
12025 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
12027 "If a template-argument for a template-parameter T names a type
12028 that is a reference to a type A, an attempt to create the type
12029 'lvalue reference to cv T' creates the type 'lvalue reference to
12030 A,' while an attempt to create the type type rvalue reference to
12031 cv T' creates the type T"
12032 */
12033 r = cp_build_reference_type
12036 else
12044 {
12046 pedwarn
12048 code == REFERENCE_TYPE
12051 else
12053 }
12056 /* Will this ever be needed for TYPE_..._TO values? */
12060 }
12062 {
12065 {
12066 /* [temp.deduct]
12068 Type deduction may fail for any of the following
12069 reasons:
12071 -- Attempting to create "pointer to member of T" when T
12072 is not a class type. */
12076 }
12078 {
12082 }
12084 {
12088 }
12091 {
12092 /* The type of the implicit object parameter gets its
12093 cv-qualifiers from the FUNCTION_TYPE. */
12094 tree memptr;
12095 tree method_type
12100 complain);
12101 }
12102 else
12105 complain);
12106 }
12109 {
12110 tree fntype;
12111 tree specs;
12116 /* Substitute the exception specification. */
12124 }
12126 {
12131 /* As an optimization, we avoid regenerating the array type if
12132 it will obviously be the same as T. */
12136 /* These checks should match the ones in create_array_type_for_decl.
12138 [temp.deduct]
12140 The deduction may fail for any of the following reasons:
12142 -- Attempting to create an array with an element type that
12143 is void, a function type, or a reference type, or [DR337]
12144 an abstract class type. */
12150 {
12154 }
12162 {
12165 }
12168 }
12171 {
12181 {
12185 }
12187 {
12188 /* Normally, make_typename_type does not require that the CTX
12189 have complete type in order to allow things like:
12191 template <class T> struct S { typename S<T>::X Y; };
12193 But, such constructs have already been resolved by this
12194 point, so here CTX really should have complete type, unless
12195 it's a partial instantiation. */
12198 {
12202 }
12203 }
12210 {
12213 }
12216 {
12218 {
12222 else
12224 }
12226 {
12230 else
12232 }
12233 }
12235 return cp_build_qualified_type_real
12237 }
12240 {
12252 }
12255 {
12256 tree type;
12272 complain);
12273 }
12276 {
12277 tree type;
12295 else
12296 {
12300 /* In a template ~id could be either a complement expression
12301 or an unqualified-id naming a destructor; if instantiating
12302 it produces an expression, it's not an id-expression or
12303 member access. */
12306 }
12310 complain);
12311 }
12314 {
12318 }
12322 {
12324 tree packed_out =
12326 args,
12327 complain,
12328 in_decl);
12331 /* For template nontype argument packs, also substitute into
12332 the type. */
12337 }
12353 /* We should use one of the expression tsubsts for these codes. */
12359 }
12360 }
12362 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12363 type of the expression on the left-hand side of the "." or "->"
12364 operator. */
12366 static tree
12369 {
12370 tree name;
12371 tree qualifying_scope;
12372 tree fns;
12373 tree optype;
12378 /* A baselink indicates a function from a base class. Both the
12379 BASELINK_ACCESS_BINFO and the base class referenced may
12380 indicate bases of the template class, rather than the
12381 instantiated class. In addition, lookups that were not
12382 ambiguous before may be ambiguous now. Therefore, we perform
12383 the lookup again. */
12390 {
12397 }
12405 /* If lookup found a single function, mark it as used at this
12406 point. (If it lookup found multiple functions the one selected
12407 later by overload resolution will be marked as used at that
12408 point.) */
12414 /* Add back the template arguments, if present. */
12419 template_args);
12420 /* Update the conversion operator type. */
12428 qualifying_scope,
12429 object_type);
12431 }
12433 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12434 true if the qualified-id will be a postfix-expression in-and-of
12435 itself; false if more of the postfix-expression follows the
12436 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12437 of "&". */
12439 static tree
12443 {
12444 tree expr;
12445 tree scope;
12446 tree name;
12448 tree template_args;
12453 /* Figure out what name to look up. */
12456 {
12464 }
12465 else
12466 {
12469 }
12471 /* Substitute into the qualifying scope. When there are no ARGS, we
12472 are just trying to simplify a non-dependent expression. In that
12473 case the qualifying scope may be dependent, and, in any case,
12474 substituting will not help. */
12477 {
12480 }
12481 else
12485 {
12490 }
12493 {
12495 {
12496 /* A BIT_NOT_EXPR is used to represent a destructor. */
12498 {
12502 }
12503 else
12506 }
12507 else
12511 {
12513 {
12517 }
12519 }
12520 }
12523 {
12525 scope);
12526 /* Remember that there was a reference to this entity. */
12528 }
12531 {
12537 }
12546 {
12547 expr = (adjust_result_of_qualified_name_lookup
12549 expr = (finish_qualified_id_expr
12553 }
12555 /* Expressions do not generally have reference type. */
12557 /* However, if we're about to form a pointer-to-member, we just
12558 want the referenced member referenced. */
12563 }
12565 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
12566 initializer, DECL is the substituted VAR_DECL. Other arguments are as
12567 for tsubst. */
12569 static tree
12572 {
12579 {
12580 /* If we had an initializer but it
12581 instantiated to nothing,
12582 value-initialize the object. This will
12583 only occur when the initializer was a
12584 pack expansion where the parameter packs
12585 used in that expansion were of length
12586 zero. */
12588 complain);
12591 }
12594 }
12596 /* Like tsubst, but deals with expressions. This function just replaces
12597 template parms; to finish processing the resultant expression, use
12598 tsubst_copy_and_build or tsubst_expr. */
12600 static tree
12602 {
12604 tree r;
12612 {
12617 {
12618 /* We get here for a use of 'this' in an NSDMI. */
12620 && current_function_decl
12624 /* This can happen for a parameter name used later in a function
12625 declaration (such as in a late-specified return type). Just
12626 make a dummy decl, since it's only used for its type. */
12629 /* Give it the template pattern as its context; its true context
12630 hasn't been instantiated yet and this is good enough for
12631 mangling. */
12633 }
12641 {
12642 tree enum_type;
12643 tree v;
12647 /* There is no need to substitute into namespace-scope
12648 enumerators. */
12651 /* If ARGS is NULL, then T is known to be non-dependent. */
12655 /* Unfortunately, we cannot just call lookup_name here.
12656 Consider:
12658 template <int I> int f() {
12659 enum E { a = I };
12660 struct S { void g() { E e = a; } };
12661 };
12663 When we instantiate f<7>::S::g(), say, lookup_name is not
12664 clever enough to find f<7>::a. */
12665 enum_type
12675 /* We didn't find the name. That should never happen; if
12676 name-lookup found it during preliminary parsing, we
12677 should find it again here during instantiation. */
12679 }
12684 {
12685 /* Check for a local specialization set up by
12686 tsubst_pack_expansion. */
12688 {
12692 }
12694 /* When retrieving a capture pack from a generic lambda, remove the
12695 lambda call op's own template argument list from ARGS. Only the
12696 template arguments active for the closure type should be used to
12697 retrieve the pack specialization. */
12703 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12704 tsubst_decl put in the hash table. */
12706 }
12709 {
12710 tree ctx;
12715 {
12718 {
12722 }
12724 }
12725 }
12734 {
12737 {
12738 /* First try name lookup to find the instantiation. */
12741 {
12742 /* Make sure that the one we found is the one we want. */
12747 }
12751 else
12752 {
12753 /* This can happen for a variable used in a
12754 late-specified return type of a local lambda, or for a
12755 local static or constant. Building a new VAR_DECL
12756 should be OK in all those cases. */
12759 {
12760 /* We can't call cp_finish_decl, so handle the
12761 initializer by hand. */
12772 }
12777 {
12780 at_eof);
12782 /* A use of a local constant decays to its value.
12783 FIXME update for core DR 696. */
12785 }
12786 }
12787 /* Remember this for subsequent uses. */
12790 }
12791 }
12792 else
12801 /* An OVERLOAD will always be a non-dependent overload set; an
12802 overload set from function scope will just be represented with an
12803 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12819 {
12820 /* Template template argument like the following example need
12821 special treatment:
12823 template <template <class> class TT> struct C {};
12824 template <class T> struct D {
12825 template <class U> struct E {};
12826 C<E> c; // #1
12827 };
12828 D<int> d; // #2
12830 We are processing the template argument `E' in #1 for
12831 the template instantiation #2. Originally, `E' is a
12832 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12833 have to substitute this with one having context `D<int>'. */
12837 }
12838 else
12839 /* Ordinary template template argument. */
12850 {
12854 }
12858 {
12868 /* We only want to compute the number of arguments. */
12882 {
12889 else
12892 }
12893 else
12895 }
12897 {
12905 }
12906 /* Fall through */
12922 {
12926 }
12929 {
12930 tree object;
12931 tree name;
12936 {
12940 }
12943 {
12953 }
12958 in_decl);
12959 else
12962 }
13000 {
13004 }
13007 {
13012 }
13015 {
13019 }
13022 {
13030 }
13036 {
13043 }
13046 {
13053 }
13056 {
13063 }
13066 {
13067 /* Substituted template arguments */
13076 }
13079 {
13099 }
13124 /* Fall through. */
13127 {
13130 }
13131 else
13135 /* This is handled by tsubst_copy_and_build. */
13139 {
13143 }
13146 /* We shouldn't have built any of these during initial template
13147 generation. Instead, they should be built during instantiation
13148 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13152 {
13160 }
13178 {
13179 /* Instantiate any typedefs in the type. */
13184 }
13187 /* These can sometimes show up in a partial instantiation, but never
13188 involve template parms. */
13193 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13196 }
13197 }
13199 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13201 static tree
13204 {
13208 {
13214 {
13217 {
13223 }
13224 /* FALLTHRU */
13252 {
13255 {
13262 }
13263 else
13265 }
13295 }
13296 }
13302 }
13304 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13306 static tree
13308 tree in_decl)
13309 {
13310 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13330 {
13333 else
13334 {
13338 }
13339 }
13344 #undef RECUR
13345 }
13347 /* Substitute one OMP_FOR iterator. */
13349 static void
13354 {
13355 #define RECUR(NODE) \
13356 tsubst_expr ((NODE), args, complain, in_decl, \
13357 integral_constant_expression_p)
13366 {
13367 /* We need to jump through some hoops to handle declarations in the
13368 for-init-statement, since we might need to handle auto deduction,
13369 but we need to keep control of initialization. */
13373 }
13374 else
13386 {
13388 {
13389 /* Declare the variable, but don't let that initialize it. */
13394 }
13399 {
13404 }
13405 else
13412 }
13415 {
13416 /* Declare and initialize the variable. */
13419 }
13421 {
13422 tree c;
13424 {
13435 }
13437 {
13442 {
13445 }
13446 }
13447 }
13450 {
13454 }
13455 else
13459 {
13470 {
13478 }
13479 else
13485 {
13491 }
13495 {
13503 }
13504 else
13510 }
13516 #undef RECUR
13517 }
13519 /* Like tsubst_copy for expressions, etc. but also does semantic
13520 processing. */
13522 static tree
13525 {
13526 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13527 #define RECUR(NODE) \
13528 tsubst_expr ((NODE), args, complain, in_decl, \
13529 integral_constant_expression_p)
13532 tree r;
13533 location_t loc;
13545 {
13547 {
13548 tree_stmt_iterator i;
13552 }
13567 else
13576 {
13578 tree init;
13584 {
13587 tree decl;
13595 else
13597 }
13599 {
13600 /* Don't build up decls for a variadic capture proxy, we'll
13601 instantiate the elements directly as needed. */
13603 }
13604 else
13605 {
13609 {
13610 /* By marking the declaration as instantiated, we avoid
13611 trying to instantiate it. Since instantiate_decl can't
13612 handle local variables, and since we've already done
13613 all that needs to be done, that's the right thing to
13614 do. */
13619 /* Anonymous aggregates are a special case. */
13622 {
13625 {
13629 }
13631 }
13637 {
13642 }
13643 else
13644 {
13649 {
13650 /* For __PRETTY_FUNCTION__ we have to adjust the
13651 initializer. */
13655 }
13656 else
13660 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13663 }
13664 }
13665 }
13668 }
13683 {
13693 }
13720 {
13724 }
13732 else
13740 else
13761 {
13765 }
13769 {
13771 tree label;
13776 }
13782 /* Computed goto's must be tsubst'd into. On the other hand,
13783 non-computed gotos must not be; the identifier in question
13784 will have no binding. */
13786 else
13792 {
13808 }
13813 {
13818 }
13819 else
13820 {
13825 else
13832 else
13838 else
13840 }
13844 {
13848 {
13850 /* Prevent instantiate_decl from trying to instantiate
13851 this variable. We've already done all that needs to be
13852 done. */
13855 }
13860 }
13866 {
13867 /* Local classes are not independent templates; they are
13868 instantiated along with their containing function. And this
13869 way we don't have to deal with pushing out of one local class
13870 to instantiate a member of another local class. */
13871 tree fn;
13872 /* Closures are handled by the LAMBDA_EXPR. */
13878 }
13882 {
13883 tree condition;
13886 condition =
13888 args,
13897 }
13921 {
13930 {
13935 }
13947 integral_constant_expression_p);
13956 else
13957 {
13965 }
13968 }
14013 {
14018 {
14021 }
14027 }
14028 else
14029 {
14036 {
14039 }
14042 {
14047 {
14050 }
14056 }
14057 else
14058 {
14062 }
14065 }
14069 {
14075 {
14079 {
14084 }
14088 }
14089 else
14090 {
14095 }
14096 }
14100 {
14104 }
14124 /* If the first operand was a statement, we're done with it. */
14128 complain));
14140 integral_constant_expression_p));
14141 }
14144 out:
14147 #undef RECUR
14148 #undef RETURN
14149 }
14151 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14152 function. For description of the body see comment above
14153 cp_parser_omp_declare_reduction_exprs. */
14155 static void
14157 {
14163 tree_stmt_iterator tsi;
14174 {
14193 }
14195 {
14215 }
14216 }
14218 /* T is a postfix-expression that is not being used in a function
14219 call. Return the substituted version of T. */
14221 static tree
14223 tsubst_flags_t complain,
14224 tree in_decl)
14225 {
14229 else
14235 }
14237 /* Sentinel to disable certain warnings during template substitution. */
14245 };
14247 /* Like tsubst but deals with expressions and performs semantic
14248 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14250 tree
14252 tree args,
14253 tsubst_flags_t complain,
14254 tree in_decl,
14257 {
14258 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14259 #define RECUR(NODE) \
14260 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14262 integral_constant_expression_p)
14265 location_t loc;
14274 /* N3276 decltype magic only applies to calls at the top level or on the
14275 right side of a comma. */
14280 {
14283 /* Fall through. */
14285 {
14286 tree decl;
14287 cp_id_kind idk;
14292 {
14295 }
14297 /* Look up the name. */
14300 /* By convention, expressions use ERROR_MARK_NODE to indicate
14301 failure, not NULL_TREE. */
14307 integral_constant_expression_p,
14315 input_location);
14319 {
14323 }
14325 }
14328 {
14329 tree object;
14337 {
14340 }
14341 else
14348 else
14350 }
14353 {
14357 {
14358 /* A type conversion to reference type will be enclosed in
14359 such an indirect ref, but the substitution of the cast
14360 will have also added such an indirect ref. */
14363 }
14364 else
14368 }
14371 {
14375 }
14378 {
14385 flags));
14386 }
14389 {
14393 }
14400 {
14401 tree type;
14407 {
14412 }
14418 {
14436 }
14439 }
14473 else
14475 in_decl);
14510 {
14515 tree r = build_x_binary_op
14517 op0,
14519 ? ERROR_MARK
14521 op1,
14523 ? ERROR_MARK
14531 }
14534 {
14538 }
14551 {
14560 }
14564 /* Fall through */
14567 {
14568 tree r;
14574 {
14575 /* When there are no ARGS, we are trying to evaluate a
14576 non-dependent expression from the parser. Trying to do
14577 the substitutions may not work. */
14580 }
14581 else
14582 {
14587 else
14590 /*integral_constant_expression_p=*/
14594 }
14598 else
14602 {
14604 {
14606 {
14610 }
14611 else
14615 }
14617 }
14619 }
14622 {
14632 }
14646 {
14650 tree r = build_x_modify_expr
14653 /* TREE_NO_WARNING must be set if either the expression was
14654 parenthesized or it uses an operator such as >>= rather
14655 than plain assignment. In the former case, it was already
14656 set and must be copied. In the latter case,
14657 build_x_modify_expr sets it and it must not be reset
14658 here. */
14663 }
14668 /* Remember that there was a reference to this entity. */
14674 {
14679 tree ret;
14683 else
14684 {
14688 }
14690 /* If there was an initializer in the original tree, but it
14691 instantiated to an empty list, then we should pass a
14692 non-NULL empty vector to tell build_new that it was an
14693 empty initializer() rather than no initializer. This can
14694 only happen when the initializer is a pack expansion whose
14695 parameter packs are of length zero. */
14698 else
14699 {
14703 else
14704 {
14707 }
14708 }
14714 complain);
14722 }
14725 {
14731 complain));
14732 }
14735 {
14739 integral_constant_expression_p);
14741 op0,
14744 }
14747 {
14748 tree function;
14753 tree ret;
14756 /* When we parsed the expression, we determined whether or
14757 not Koenig lookup should be performed. */
14760 {
14765 }
14767 {
14768 /* Do nothing; calling tsubst_copy_and_build on an identifier
14769 would incorrectly perform unqualified lookup again.
14771 Note that we can also have an IDENTIFIER_NODE if the earlier
14772 unqualified lookup found a member function; in that case
14773 koenig_p will be false and we do want to do the lookup
14774 again to find the instantiated member function.
14776 FIXME but doing that causes c++/15272, so we need to stop
14777 using IDENTIFIER_NODE in that situation. */
14779 }
14780 else
14781 {
14783 {
14789 }
14790 else
14795 /* Avoid error about taking the address of a constructor. */
14799 in_decl,
14801 integral_constant_expression_p);
14805 }
14810 {
14815 else
14816 {
14817 /* Expand the pack expansion and push each entry onto
14818 CALL_ARGS. */
14821 {
14826 {
14831 }
14832 }
14833 else
14834 {
14835 /* A partial substitution. Add one entry. */
14837 }
14838 }
14839 }
14841 /* We do not perform argument-dependent lookup if normal
14842 lookup finds a non-function, in accordance with the
14843 expected resolution of DR 218. */
14846 /* If lookup found a member function, the Koenig lookup is
14847 not appropriate, even if an unqualified-name was used
14848 to denote the function. */
14851 /* Only do this when substitution turns a dependent call
14852 into a non-dependent call. */
14859 {
14861 {
14862 /* For backwards compatibility and good diagnostics, try
14863 the unqualified lookup again if we aren't in SFINAE
14864 context. */
14865 tree unq = (tsubst_copy_and_build
14867 integral_constant_expression_p));
14872 {
14881 "%qD was not declared in this scope, "
14882 "and no declarations were found by "
14883 "argument-dependent lookup at the point "
14885 {
14889 {
14891 input_location);
14893 "declarations in dependent base %qT are "
14899 else
14903 }
14904 else
14907 }
14909 }
14910 }
14912 {
14917 }
14918 }
14920 /* Remember that there was a reference to this entity. */
14924 /* Put back tf_decltype for the actual call. */
14929 complain);
14931 {
14946 complain);
14947 else
14948 ret = (build_new_method_call
14953 complain));
14954 }
14955 else
14958 koenig_p,
14959 complain);
14964 }
14967 {
14972 {
14974 {
14979 }
14980 else
14981 {
14986 }
14987 }
14988 else
14989 {
14992 }
14996 }
14999 {
15004 input_location));
15005 }
15008 {
15016 {
15017 /* We have pack expansions, so expand those and
15018 create a new list out of it. */
15021 tree chain;
15024 /* Expand the argument expressions. */
15032 /* Build the rest of the list. */
15037 /* Determine the number of arguments. */
15039 {
15042 }
15045 else
15046 {
15047 /* Since we only performed a partial substitution into
15048 the argument pack, we only RETURN (a single list
15049 node. */
15056 }
15058 /* Convert the argument vectors into a TREE_LIST */
15061 {
15062 /* Grab the Ith values. */
15063 i--;
15066 value
15070 /* Build the list (backwards). */
15072 }
15075 }
15091 }
15094 {
15095 tree object;
15096 tree object_type;
15097 tree member;
15098 tree r;
15102 /* Remember that there was a reference to this entity. */
15112 else
15120 {
15122 {
15127 {
15130 }
15132 {
15137 }
15138 }
15139 }
15142 {
15143 /* Lookup the template functions now that we know what the
15144 scope is. */
15152 {
15155 args);
15156 member = (adjust_result_of_qualified_name_lookup
15158 object_type));
15159 }
15160 else
15161 {
15163 input_location);
15165 }
15166 }
15170 {
15172 {
15176 else
15179 }
15181 }
15183 {
15188 }
15192 complain);
15196 }
15203 {
15211 tree r;
15216 /* digest_init will do the wrong thing if we let it. */
15220 /* We do not want to process the index of aggregate
15221 initializers as they are identifier nodes which will be
15222 looked up by digest_init. */
15228 {
15230 /* An identifier index is looked up in the type
15231 being initialized, not the current scope. */
15236 {
15237 /* Substitute into the pack expansion. */
15239 in_decl);
15243 ;
15245 /* Just move the argument into place. */
15247 else
15248 {
15249 /* Update the length of the final CONSTRUCTOR
15250 arguments vector, and note that we will need to
15251 copy.*/
15254 }
15255 }
15256 else
15258 }
15261 {
15266 {
15268 {
15273 }
15274 else
15276 }
15277 }
15287 }
15290 {
15293 {
15296 }
15297 else
15298 {
15301 }
15302 }
15308 {
15309 /* We don't build decls for an instantiation of a
15310 variadic capture proxy, we instantiate the elements
15311 when needed. */
15314 }
15315 /* Fall through */
15318 {
15322 /* If the original type was a reference, we'll be wrapped in
15323 the appropriate INDIRECT_REF. */
15326 }
15329 {
15333 }
15339 {
15348 }
15351 {
15357 integral_constant_expression_p);
15361 /* If the resulting list of expression statement is empty,
15362 fold it further into void_node. */
15367 }
15370 {
15384 /* For a function scope, we want to use tsubst so that we don't
15385 complain about referring to an auto function before its return
15386 type has been deduced. Otherwise, we want to use tsubst_copy so
15387 that we look up the existing field/parameter/variable rather
15388 than build a new one. */
15393 {
15394 /* Look up the parameter we want directly, as tsubst_copy
15395 doesn't do what we need. */
15401 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15404 }
15405 else
15414 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15416 /* Now that we know visibility, instantiate the type so we have a
15417 declaration of the op() for later calls to lambda_function. */
15423 }
15426 /* We can get here for a constant initializer of non-dependent type.
15427 FIXME stop folding in cp_parser_initializer_clause. */
15428 {
15430 complain);
15432 }
15436 integral_constant_expression_p));
15442 {
15447 complain));
15448 }
15451 /* Handle Objective-C++ constructs, if appropriate. */
15452 {
15453 tree subst
15458 }
15460 }
15462 #undef RECUR
15463 #undef RETURN
15464 out:
15467 }
15469 /* Verify that the instantiated ARGS are valid. For type arguments,
15470 make sure that the type's linkage is ok. For non-type arguments,
15471 make sure they are constants if they are integral or enumerations.
15472 Emit an error under control of COMPLAIN, and return TRUE on error. */
15474 static bool
15476 {
15480 {
15490 }
15492 {
15493 /* [basic.link]: A name with no linkage (notably, the name
15494 of a class or enumeration declared in a local scope)
15495 shall not be used to declare an entity with linkage.
15496 This implies that names with no linkage cannot be used as
15497 template arguments
15499 DR 757 relaxes this restriction for C++0x. */
15504 {
15505 /* DR 488 makes use of a type with no linkage cause
15506 type deduction to fail. */
15508 {
15511 else
15514 }
15516 }
15517 /* In order to avoid all sorts of complications, we do not
15518 allow variably-modified types as template arguments. */
15520 {
15524 }
15525 }
15526 /* Class template and alias template arguments should be OK. */
15528 ;
15529 /* A non-type argument of integral or enumerated type must be a
15530 constant. */
15534 {
15538 }
15540 }
15542 static bool
15544 {
15549 {
15552 }
15556 }
15558 /* We're out of SFINAE context now, so generate diagnostics for the access
15559 errors we saw earlier when instantiating D from TMPL and ARGS. */
15561 static void
15563 {
15575 }
15577 /* Instantiate the indicated variable, function, or alias template TMPL with
15578 the template arguments in TARG_PTR. */
15580 static tree
15582 {
15584 tree fndecl;
15585 tree gen_tmpl;
15586 tree spec;
15594 /* If this function is a clone, handle it specially. */
15596 {
15597 tree spec;
15598 tree clone;
15600 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15601 DECL_CLONED_FUNCTION. */
15607 /* Look for the clone. */
15611 /* We should always have found the clone by now. */
15614 }
15619 /* Check to see if we already have this specialization. */
15622 /* The TMPL is a partial instantiation. To get a full set of
15623 arguments we must add the arguments used to perform the
15624 partial instantiation. */
15626 targ_ptr);
15628 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15629 but it doesn't seem to be on the hot path. */
15638 {
15640 {
15644 }
15646 }
15649 complain))
15652 /* We are building a FUNCTION_DECL, during which the access of its
15653 parameters and return types have to be checked. However this
15654 FUNCTION_DECL which is the desired context for access checking
15655 is not built yet. We solve this chicken-and-egg problem by
15656 deferring all checks until we have the FUNCTION_DECL. */
15659 /* Instantiation of the function happens in the context of the function
15660 template, not the context of the overload resolution we're doing. */
15662 /* If there are dependent arguments, e.g. because we're doing partial
15663 ordering, make sure processing_template_decl stays set. */
15667 {
15671 }
15672 /* Substitute template parameters to obtain the specialization. */
15680 {
15683 }
15685 /* The DECL_TI_TEMPLATE should always be the immediate parent
15686 template, not the most general template. */
15689 /* Now we know the specialization, compute access previously
15690 deferred. */
15697 /* If we've just instantiated the main entry point for a function,
15698 instantiate all the alternate entry points as well. We do this
15699 by cloning the instantiation of the main entry point, not by
15700 instantiating the template clones. */
15705 {
15707 {
15708 /* Remember to reinstantiate when we're out of SFINAE so the user
15709 can see the errors. */
15711 }
15713 }
15715 }
15717 /* Wrapper for instantiate_template_1. */
15719 tree
15721 {
15722 tree ret;
15727 }
15729 /* Instantiate the alias template TMPL with ARGS. Also push a template
15730 instantiation level, which instantiate_template doesn't do because
15731 functions and variables have sufficient context established by the
15732 callers. */
15734 static tree
15736 {
15743 {
15746 }
15748 args =
15756 /* We can't free this if a pending_template entry or last_error_tinst_level
15757 is pointing at it. */
15763 }
15765 /* PARM is a template parameter pack for FN. Returns true iff
15766 PARM is used in a deducible way in the argument list of FN. */
15768 static bool
15770 {
15773 {
15775 tree packs;
15781 {
15782 /* The template parameter pack is used in a function parameter
15783 pack. If this is the end of the parameter list, the
15784 template parameter pack is deducible. */
15787 else
15788 /* Otherwise, not. Well, it could be deduced from
15789 a non-pack parameter, but doing so would end up with
15790 a deduction mismatch, so don't bother. */
15792 }
15793 }
15794 /* The template parameter pack isn't used in any function parameter
15795 packs, but it might be used deeper, e.g. tuple<Args...>. */
15797 }
15799 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15800 NARGS elements of the arguments that are being used when calling
15801 it. TARGS is a vector into which the deduced template arguments
15802 are placed.
15804 Returns either a FUNCTION_DECL for the matching specialization of FN or
15805 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
15806 true, diagnostics will be printed to explain why it failed.
15808 If FN is a conversion operator, or we are trying to produce a specific
15809 specialization, RETURN_TYPE is the return type desired.
15811 The EXPLICIT_TARGS are explicit template arguments provided via a
15812 template-id.
15814 The parameter STRICT is one of:
15816 DEDUCE_CALL:
15817 We are deducing arguments for a function call, as in
15818 [temp.deduct.call].
15820 DEDUCE_CONV:
15821 We are deducing arguments for a conversion function, as in
15822 [temp.deduct.conv].
15824 DEDUCE_EXACT:
15825 We are deducing arguments when doing an explicit instantiation
15826 as in [temp.explicit], when determining an explicit specialization
15827 as in [temp.expl.spec], or when taking the address of a function
15828 template, as in [temp.deduct.funcaddr]. */
15830 tree
15832 tree explicit_targs,
15833 tree targs,
15836 tree return_type,
15837 unification_kind_t strict,
15841 {
15842 tree parms;
15843 tree fntype;
15851 tree tinst;
15857 /* In C++0x, it's possible to have a function template whose type depends
15858 on itself recursively. This is most obvious with decltype, but can also
15859 occur with enumeration scope (c++/48969). So we need to catch infinite
15860 recursion and reject the substitution at deduction time; this function
15861 will return error_mark_node for any repeated substitution.
15863 This also catches excessive recursion such as when f<N> depends on
15864 f<N-1> across all integers, and returns error_mark_node for all the
15865 substitutions back up to the initial one.
15867 This is, of course, not reentrant. */
15877 {
15878 /* [temp.deduct]
15880 The specified template arguments must match the template
15881 parameters in kind (i.e., type, nontype, template), and there
15882 must not be more arguments than there are parameters;
15883 otherwise type deduction fails.
15885 Nontype arguments must match the types of the corresponding
15886 nontype template parameters, or must be convertible to the
15887 types of the corresponding nontype parameters as specified in
15888 _temp.arg.nontype_, otherwise type deduction fails.
15890 All references in the function type of the function template
15891 to the corresponding template parameters are replaced by the
15892 specified template argument values. If a substitution in a
15893 template parameter or in the function type of the function
15894 template results in an invalid type, type deduction fails. */
15899 /* Adjust any explicit template arguments before entering the
15900 substitution context. */
15901 explicit_targs
15903 complain,
15909 /* Substitute the explicit args into the function type. This is
15910 necessary so that, for instance, explicitly declared function
15911 arguments can match null pointed constants. If we were given
15912 an incomplete set of explicit args, we must not do semantic
15913 processing during substitution as we could create partial
15914 instantiations. */
15916 {
15921 /* Dig out the actual parm. */
15924 {
15927 }
15929 {
15932 }
15935 /* No explicit argument for this template parameter. */
15939 {
15940 /* Mark the argument pack as "incomplete". We could
15941 still deduce more arguments during unification.
15942 We remove this mark in type_unification_real. */
15944 {
15948 }
15950 /* We have some incomplete argument packs. */
15952 }
15953 }
15957 {
15960 }
15963 /* Ignore any access checks; we'll see them again in
15964 instantiate_template and they might have the wrong
15965 access path at this point. */
15977 /* Place the explicitly specified arguments in TARGS. */
15980 }
15982 /* Never do unification on the 'this' parameter. */
15986 {
15995 }
15997 /* We allow incomplete unification without an error message here
15998 because the standard doesn't seem to explicitly prohibit it. Our
15999 callers must be ready to deal with unification failures in any
16000 event. */
16003 /* If we aren't explaining yet, push tinst context so we can see where
16004 any errors (e.g. from class instantiations triggered by instantiation
16005 of default template arguments) come from. If we are explaining, this
16006 context is redundant. */
16008 {
16011 }
16013 /* type_unification_real will pass back any access checks from default
16014 template argument substitution. */
16026 /* Now that we have bindings for all of the template arguments,
16027 ensure that the arguments deduced for the template template
16028 parameters have compatible template parameter lists. We cannot
16029 check this property before we have deduced all template
16030 arguments, because the template parameter types of a template
16031 template parameter might depend on prior template parameters
16032 deduced after the template template parameter. The following
16033 ill-formed example illustrates this issue:
16035 template<typename T, template<T> class C> void f(C<5>, T);
16037 template<int N> struct X {};
16039 void g() {
16040 f(X<5>(), 5l); // error: template argument deduction fails
16041 }
16043 The template parameter list of 'C' depends on the template type
16044 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
16045 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
16046 time that we deduce 'C'. */
16049 {
16052 }
16054 /* All is well so far. Now, check:
16056 [temp.deduct]
16058 When all template arguments have been deduced, all uses of
16059 template parameters in nondeduced contexts are replaced with
16060 the corresponding deduced argument values. If the
16061 substitution results in an invalid type, as described above,
16062 type deduction fails. */
16065 {
16068 }
16070 /* Also collect access checks from the instantiation. */
16083 /* Now perform any access checks encountered during substitution. */
16090 /* If we're looking for an exact match, check that what we got
16091 is indeed an exact match. It might not be if some template
16092 parameters are used in non-deduced contexts. But don't check
16093 for an exact match if we have dependent template arguments;
16094 in that case we're doing partial ordering, and we already know
16095 that we have two candidates that will provide the actual type. */
16097 {
16101 tree sarg
16107 {
16111 }
16112 }
16116 fail:
16119 {
16121 /* Reset once we're all the way out. */
16123 }
16125 /* We can't free this if a pending_template entry or last_error_tinst_level
16126 is pointing at it. */
16132 }
16134 /* Adjust types before performing type deduction, as described in
16135 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16136 sections are symmetric. PARM is the type of a function parameter
16137 or the return type of the conversion function. ARG is the type of
16138 the argument passed to the call, or the type of the value
16139 initialized with the result of the conversion function.
16140 ARG_EXPR is the original argument expression, which may be null. */
16142 static int
16146 tree arg_expr)
16147 {
16151 {
16156 {
16157 /* Swap PARM and ARG throughout the remainder of this
16158 function; the handling is precisely symmetric since PARM
16159 will initialize ARG rather than vice versa. */
16164 }
16167 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16168 too, but here handle it by stripping the reference from PARM
16169 rather than by adding it to ARG. */
16177 /* Nothing else to do in this case. */
16182 }
16185 {
16186 /* [temp.deduct.call]
16188 If P is not a reference type:
16190 --If A is an array type, the pointer type produced by the
16191 array-to-pointer standard conversion (_conv.array_) is
16192 used in place of A for type deduction; otherwise,
16194 --If A is a function type, the pointer type produced by
16195 the function-to-pointer standard conversion
16196 (_conv.func_) is used in place of A for type deduction;
16197 otherwise,
16199 --If A is a cv-qualified type, the top level
16200 cv-qualifiers of A's type are ignored for type
16201 deduction. */
16206 else
16208 }
16210 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16211 of the form T&&, where T is a template parameter, and the argument
16212 is an lvalue, T is deduced as A& */
16218 /* try_one_overload doesn't provide an arg_expr, but
16219 functions are always lvalues. */
16223 /* [temp.deduct.call]
16225 If P is a cv-qualified type, the top level cv-qualifiers
16226 of P's type are ignored for type deduction. If P is a
16227 reference type, the type referred to by P is used for
16228 type deduction. */
16231 {
16234 }
16236 /* DR 322. For conversion deduction, remove a reference type on parm
16237 too (which has been swapped into ARG). */
16242 }
16244 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16245 template which does contain any deducible template parameters; check if
16246 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16247 unify_one_argument. */
16249 static int
16252 {
16253 tree type;
16257 else
16264 {
16268 }
16270 {
16275 }
16279 else
16281 }
16285 /* Returns true iff the expression EXPR is one from which a template
16286 argument can be deduced. In other words, if it's an undecorated
16287 use of a template non-type parameter. */
16289 static bool
16291 {
16293 }
16295 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16296 deducible way; that is, if it has a max value of <PARM> - 1. */
16298 static bool
16300 {
16309 }
16311 /* Returns true iff the template arguments ARGS use a template parameter
16312 in a deducible way. */
16314 static bool
16316 {
16318 {
16323 else
16324 {
16331 else
16333 }
16336 }
16338 }
16340 /* Returns true iff TYPE contains any deducible references to template
16341 parameters, as per 14.8.2.5. */
16343 static bool
16345 {
16349 /* T
16350 cv-list T
16351 TT<T>
16352 TT<i>
16353 TT<> */
16358 /* T*
16359 T&
16360 T&& */
16364 /* T[integer-constant ]
16365 type [i] */
16370 /* T type ::*
16371 type T::*
16372 T T::*
16373 T (type ::*)()
16374 type (T::*)()
16375 type (type ::*)(T)
16376 type (T::*)(T)
16377 T (type ::*)(T)
16378 T (T::*)()
16379 T (T::*)(T) */
16382 || (uses_deducible_template_parms
16385 /* template-name <T> (where template-name refers to a class template)
16386 template-name <i> (where template-name refers to a class template) */
16393 /* type (T)
16394 T()
16395 T(T) */
16398 {
16407 }
16410 }
16412 /* Subroutine of type_unification_real and unify_pack_expansion to
16413 handle unification of a single P/A pair. Parameters are as
16414 for those functions. */
16416 static int
16420 {
16427 /* We can't deduce anything from this, but we might get all the
16428 template args from other function args. */
16431 /* Implicit conversions (Clause 4) will be performed on a function
16432 argument to convert it to the type of the corresponding function
16433 parameter if the parameter type contains no template-parameters that
16434 participate in template argument deduction. */
16436 /* For function parameters that contain no template-parameters at all,
16437 we have historically checked for convertibility in order to shortcut
16438 consideration of this candidate. */
16440 explain_p);
16443 /* For function parameters with only non-deducible template parameters,
16444 just return. */
16448 {
16450 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16451 | UNIFY_ALLOW_MORE_CV_QUAL
16465 }
16467 /* We only do these transformations if this is the top-level
16468 parameter_type_list in a call or declaration matching; in other
16469 situations (nested function declarators, template argument lists) we
16470 won't be comparing a type to an expression, and we don't do any type
16471 adjustments. */
16473 {
16475 {
16478 {
16479 /* [temp.deduct.type] A template-argument can be
16480 deduced from a pointer to function or pointer
16481 to member function argument if the set of
16482 overloaded functions does not contain function
16483 templates and at most one of a set of
16484 overloaded functions provides a unique
16485 match. */
16492 }
16498 }
16500 arg_strict |=
16502 }
16503 else
16507 /* For deduction from an init-list we need the actual list. */
16511 }
16513 /* Most parms like fn_type_unification.
16515 If SUBR is 1, we're being called recursively (to unify the
16516 arguments of a function or method parameter of a function
16517 template).
16519 CHECKS is a pointer to a vector of access checks encountered while
16520 substituting default template arguments. */
16522 static int
16524 tree targs,
16525 tree xparms,
16529 unification_kind_t strict,
16533 {
16538 tree parms;
16547 /* Reset the number of non-defaulted template arguments contained
16548 in TARGS. */
16551 again:
16559 {
16564 /* For a function parameter pack that occurs at the end of the
16565 parameter-declaration-list, the type A of each remaining
16566 argument of the call is compared with the type P of the
16567 declarator-id of the function parameter pack. */
16573 /* For a function parameter pack that does not occur at the
16574 end of the parameter-declaration-list, the type of the
16575 parameter pack is a non-deduced context. */
16584 }
16589 {
16590 /* Unify the remaining arguments with the pack expansion type. */
16591 tree argvec;
16594 /* Allocate a TREE_VEC and copy in all of the arguments */
16599 /* Copy the parameter into parmvec. */
16605 /* Advance to the end of the list of parameters. */
16607 }
16609 /* Fail if we've reached the end of the parm list, and more args
16610 are present, and the parm list isn't variadic. */
16613 /* Fail if parms are left and they don't have default values. */
16616 {
16620 {
16621 count++;
16623 }
16625 }
16628 {
16629 tsubst_flags_t complain = (explain_p
16630 ? tf_warning_or_error
16634 {
16638 /* Clear the "incomplete" flags on all argument packs now so that
16639 substituting them into later default arguments works. */
16641 {
16644 }
16650 /* If this is an undeduced nontype parameter that depends on
16651 a type parameter, try another pass; its type may have been
16652 deduced from a later argument than the one from which
16653 this parameter can be deduced. */
16659 /* Core issue #226 (C++0x) [temp.deduct]:
16661 If a template argument has not been deduced, its
16662 default template argument, if any, is used.
16664 When we are in C++98 mode, TREE_PURPOSE will either
16665 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16666 to explicitly check cxx_dialect here. */
16668 {
16683 else
16684 {
16686 /* The position of the first default template argument,
16687 is also the number of non-defaulted arguments in TARGS.
16688 Record that. */
16692 }
16693 }
16695 /* If the type parameter is a parameter pack, then it will
16696 be deduced to an empty parameter pack. */
16698 {
16699 tree arg;
16702 {
16706 }
16707 else
16714 }
16717 }
16718 }
16719 #ifdef ENABLE_CHECKING
16722 #endif
16725 }
16727 /* Subroutine of type_unification_real. Args are like the variables
16728 at the call site. ARG is an overloaded function (or template-id);
16729 we try deducing template args from each of the overloads, and if
16730 only one succeeds, we go with that. Modifies TARGS and returns
16731 true on success. */
16733 static bool
16735 tree targs,
16736 tree parm,
16737 tree arg,
16738 unification_kind_t strict,
16741 {
16748 {
16751 }
16752 else
16756 /* Handle `&x' where `x' is some static or non-static member
16757 function name. */
16763 /* Strip baselink information. */
16768 {
16769 /* If we got some explicit template args, we need to plug them into
16770 the affected templates before we try to unify, in case the
16771 explicit args will completely resolve the templates in question. */
16778 {
16791 {
16796 {
16799 }
16800 }
16803 }
16804 /* If no templates (or more than one) are fully resolved by the
16805 explicit arguments, this template-id is a non-deduced context; it
16806 could still be OK if we deduce all template arguments for the
16807 enclosing call through other arguments. */
16810 }
16813 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16814 -- but the deduction does not succeed because the expression is
16815 not just the function on its own. */
16817 else
16823 {
16826 }
16828 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16829 to function or pointer to member function argument if the set of
16830 overloaded functions does not contain function templates and at most
16831 one of a set of overloaded functions provides a unique match.
16833 So if we found multiple possibilities, we return success but don't
16834 deduce anything. */
16837 {
16842 }
16847 }
16849 /* Core DR 115: In contexts where deduction is done and fails, or in
16850 contexts where deduction is not done, if a template argument list is
16851 specified and it, along with any default template arguments, identifies
16852 a single function template specialization, then the template-id is an
16853 lvalue for the function template specialization. */
16855 tree
16857 {
16870 {
16873 }
16875 {
16878 }
16880 {
16883 }
16886 {
16890 /* If we got some explicit template args, we need to plug them into
16891 the affected templates before we try to unify, in case the
16892 explicit args will completely resolve the templates in question. */
16900 {
16913 {
16916 {
16919 }
16921 {
16924 }
16925 }
16926 }
16928 {
16936 {
16937 tree base
16940 }
16944 }
16946 /* There were no good options and at least one bad one, so let the
16947 user know what the problem is. */
16949 }
16951 }
16953 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16954 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16955 different overloads deduce different arguments for a given parm.
16956 ADDR_P is true if the expression for which deduction is being
16957 performed was of the form "& fn" rather than simply "fn".
16959 Returns 1 on success. */
16961 static int
16963 tree orig_targs,
16964 tree targs,
16965 tree parm,
16966 tree arg,
16967 unification_kind_t strict,
16971 {
16973 tree tempargs;
16979 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16980 to function or pointer to member function argument if the set of
16981 overloaded functions does not contain function templates and at most
16982 one of a set of overloaded functions provides a unique match.
16984 So if this is a template, just return success. */
16996 /* We don't copy orig_targs for this because if we have already deduced
16997 some template args from previous args, unify would complain when we
16998 try to deduce a template parameter for the same argument, even though
16999 there isn't really a conflict. */
17006 /* First make sure we didn't deduce anything that conflicts with
17007 explicitly specified args. */
17009 {
17016 /* Since we're unifying against ourselves, we will fill in
17017 template args used in the function parm list with our own
17018 template parms. Discard them. */
17022 }
17025 {
17030 }
17033 }
17035 /* PARM is a template class (perhaps with unbound template
17036 parameters). ARG is a fully instantiated type. If ARG can be
17037 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
17038 TARGS are as for unify. */
17040 static tree
17043 {
17044 tree copy_of_targs;
17051 /* We need to make a new template argument vector for the call to
17052 unify. If we used TARGS, we'd clutter it up with the result of
17053 the attempted unification, even if this class didn't work out.
17054 We also don't want to commit ourselves to all the unifications
17055 we've already done, since unification is supposed to be done on
17056 an argument-by-argument basis. In other words, consider the
17057 following pathological case:
17059 template <int I, int J, int K>
17060 struct S {};
17062 template <int I, int J>
17063 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
17065 template <int I, int J, int K>
17066 void f(S<I, J, K>, S<I, I, I>);
17068 void g() {
17069 S<0, 0, 0> s0;
17070 S<0, 1, 2> s2;
17072 f(s0, s2);
17073 }
17075 Now, by the time we consider the unification involving `s2', we
17076 already know that we must have `f<0, 0, 0>'. But, even though
17077 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
17078 because there are two ways to unify base classes of S<0, 1, 2>
17079 with S<I, I, I>. If we kept the already deduced knowledge, we
17080 would reject the possibility I=1. */
17083 /* If unification failed, we're done. */
17089 }
17091 /* Given a template type PARM and a class type ARG, find the unique
17092 base type in ARG that is an instance of PARM. We do not examine
17093 ARG itself; only its base-classes. If there is not exactly one
17094 appropriate base class, return NULL_TREE. PARM may be the type of
17095 a partial specialization, as well as a plain template type. Used
17096 by unify. */
17098 static enum template_base_result
17101 {
17103 tree binfo;
17109 {
17110 /* The type could not be completed. */
17113 }
17115 /* Walk in inheritance graph order. The search order is not
17116 important, and this avoids multiple walks of virtual bases. */
17118 {
17123 {
17124 /* If there is more than one satisfactory baseclass, then:
17126 [temp.deduct.call]
17128 If they yield more than one possible deduced A, the type
17129 deduction fails.
17131 applies. */
17133 {
17136 }
17139 }
17140 }
17144 }
17146 /* Returns the level of DECL, which declares a template parameter. */
17148 static int
17150 {
17152 {
17162 }
17164 }
17166 /* Decide whether ARG can be unified with PARM, considering only the
17167 cv-qualifiers of each type, given STRICT as documented for unify.
17168 Returns nonzero iff the unification is OK on that basis. */
17170 static int
17172 {
17178 {
17179 /* Although a CVR qualifier is ignored when being applied to a
17180 substituted template parameter ([8.3.2]/1 for example), that
17181 does not allow us to unify "const T" with "int&" because both
17182 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17183 It is ok when we're allowing additional CV qualifiers
17184 at the outer level [14.8.2.1]/3,1st bullet. */
17194 }
17205 }
17207 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17208 void
17210 {
17214 {
17217 }
17218 else
17219 {
17222 }
17223 }
17225 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17226 do { \
17227 if (unify (TP, TA, P, A, S, EP)) \
17228 return 1; \
17229 } while (0);
17231 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17232 expansion at the end of PACKED_PARMS. Returns 0 if the type
17233 deduction succeeds, 1 otherwise. STRICT is the same as in
17234 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17235 call argument list. We'll need to adjust the arguments to make them
17236 types. SUBR tells us if this is from a recursive call to
17237 type_unification_real, or for comparing two template argument
17238 lists. */
17240 static int
17244 {
17245 tree parm
17255 /* Determine the parameter packs we will be deducing from the
17256 pattern, and record their current deductions. */
17259 {
17263 /* Determine the index and level of this parameter pack. */
17266 /* Keep track of the parameter packs and their corresponding
17267 argument packs. */
17270 }
17272 /* Loop through all of the arguments that have not yet been
17273 unified and unify each with the pattern. */
17275 {
17276 tree parm;
17280 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17281 or the element of its argument pack at the current index if
17282 this argument was explicitly specified. */
17284 {
17293 {
17296 }
17298 }
17300 /* If we had explicit template arguments, substitute them into the
17301 pattern before deduction. */
17303 {
17304 /* Some arguments might still be unspecified or dependent. */
17312 NULL_TREE);
17317 }
17318 else
17321 /* Unify the pattern with the current argument. */
17326 /* For each parameter pack, collect the deduced value. */
17328 {
17334 }
17335 }
17337 /* Verify that the results of unification with the parameter packs
17338 produce results consistent with what we've seen before, and make
17339 the deduced argument packs available. */
17341 {
17348 /* By default keep the original deduced argument pack.
17349 If necessary, more specific code is going to update the
17350 resulting deduced argument later down in this function. */
17354 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17355 actually deduce anything. */
17363 {
17364 /* If we had fewer function args than explicit template args,
17365 just use the explicits. */
17370 }
17373 {
17374 tree result;
17375 /* Build the deduced *_ARGUMENT_PACK. */
17377 {
17382 }
17383 else
17388 /* Note the deduced argument packs for this parameter
17389 pack. */
17391 }
17395 {
17396 /* We only had the explicitly-provided arguments before, but
17397 now we have a complete set of arguments. */
17403 }
17404 else
17405 {
17411 /* Inconsistent unification of this parameter pack. */
17413 bad_old_arg,
17414 bad_new_arg);
17415 }
17416 }
17419 }
17421 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17422 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17423 parameters and return value are as for unify. */
17425 static int
17429 {
17430 tree parm_max;
17431 tree arg_max;
17435 /* Our representation of array types uses "N - 1" as the
17436 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17437 not an integer constant. We cannot unify arbitrarily
17438 complex expressions, so we eliminate the MINUS_EXPRs
17439 here. */
17443 {
17446 }
17450 {
17451 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17452 trying to unify the type of a variable with the type
17453 of a template parameter. For example:
17455 template <unsigned int N>
17456 void f (char (&) [N]);
17457 int g();
17458 void h(int i) {
17459 char a[g(i)];
17460 f(a);
17461 }
17463 Here, the type of the ARG will be "int [g(i)]", and
17464 may be a SAVE_EXPR, etc. */
17468 }
17470 /* If only one of the bounds used a MINUS_EXPR, compensate
17471 by adding one to the other bound. */
17474 integer_type_node,
17475 parm_max,
17476 integer_one_node);
17479 integer_type_node,
17480 arg_max,
17481 integer_one_node);
17485 }
17487 /* Deduce the value of template parameters. TPARMS is the (innermost)
17488 set of template parameters to a template. TARGS is the bindings
17489 for those template parameters, as determined thus far; TARGS may
17490 include template arguments for outer levels of template parameters
17491 as well. PARM is a parameter to a template function, or a
17492 subcomponent of that parameter; ARG is the corresponding argument.
17493 This function attempts to match PARM with ARG in a manner
17494 consistent with the existing assignments in TARGS. If more values
17495 are deduced, then TARGS is updated.
17497 Returns 0 if the type deduction succeeds, 1 otherwise. The
17498 parameter STRICT is a bitwise or of the following flags:
17500 UNIFY_ALLOW_NONE:
17501 Require an exact match between PARM and ARG.
17502 UNIFY_ALLOW_MORE_CV_QUAL:
17503 Allow the deduced ARG to be more cv-qualified (by qualification
17504 conversion) than ARG.
17505 UNIFY_ALLOW_LESS_CV_QUAL:
17506 Allow the deduced ARG to be less cv-qualified than ARG.
17507 UNIFY_ALLOW_DERIVED:
17508 Allow the deduced ARG to be a template base class of ARG,
17509 or a pointer to a template base class of the type pointed to by
17510 ARG.
17511 UNIFY_ALLOW_INTEGER:
17512 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17513 case for more information.
17514 UNIFY_ALLOW_OUTER_LEVEL:
17515 This is the outermost level of a deduction. Used to determine validity
17516 of qualification conversions. A valid qualification conversion must
17517 have const qualified pointers leading up to the inner type which
17518 requires additional CV quals, except at the outer level, where const
17519 is not required [conv.qual]. It would be normal to set this flag in
17520 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17521 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17522 This is the outermost level of a deduction, and PARM can be more CV
17523 qualified at this point.
17524 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17525 This is the outermost level of a deduction, and PARM can be less CV
17526 qualified at this point. */
17528 static int
17531 {
17533 tree targ;
17534 tree tparm;
17537 /* I don't think this will do the right thing with respect to types.
17538 But the only case I've seen it in so far has been array bounds, where
17539 signedness is the only information lost, and I think that will be
17540 okay. */
17548 /* We can't deduce anything from this, but we might get all the
17549 template args from other function args. */
17552 /* If PARM uses template parameters, then we can't bail out here,
17553 even if ARG == PARM, since we won't record unifications for the
17554 template parameters. We might need them if we're trying to
17555 figure out which of two things is more specialized. */
17559 /* Handle init lists early, so the rest of the function can assume
17560 we're dealing with a type. */
17562 {
17567 /* Replace T with std::initializer_list<T> for deduction. */
17574 /* We can only deduce from an initializer list argument if the
17575 parameter is std::initializer_list or an array; otherwise this
17576 is a non-deduced context. */
17581 else
17585 {
17592 {
17594 /* It should only be possible to get here for a call. */
17596 elt_strict |= maybe_adjust_types_for_deduction
17599 }
17602 explain_p);
17603 }
17607 {
17608 /* Also deduce from the length of the initializer list. */
17615 }
17617 /* If the std::initializer_list<T> deduction worked, replace the
17618 deduced A with std::initializer_list<A>. */
17620 {
17625 }
17627 }
17629 /* Immediately reject some pairs that won't unify because of
17630 cv-qualification mismatches. */
17633 /* It is the elements of the array which hold the cv quals of an array
17634 type, and the elements might be template type parms. We'll check
17635 when we recurse. */
17637 /* We check the cv-qualifiers when unifying with template type
17638 parameters below. We want to allow ARG `const T' to unify with
17639 PARM `T' for example, when computing which of two templates
17640 is more specialized, for example. */
17654 {
17658 /* In a type which contains a nested-name-specifier, template
17659 argument values cannot be deduced for template parameters used
17660 within the nested-name-specifier. */
17672 /* The PARM is not one we're trying to unify. Just check
17673 to see if it matches ARG. */
17674 {
17679 else
17681 }
17688 /* Check for mixed types and values. */
17696 {
17697 /* ARG must be constructed from a template class or a template
17698 template parameter. */
17702 {
17704 /* An alias template name is never deduced. */
17709 tree parm_parms
17710 = DECL_INNERMOST_TEMPLATE_PARMS
17715 /* The resolution to DR150 makes clear that default
17716 arguments for an N-argument may not be used to bind T
17717 to a template template parameter with fewer than N
17718 parameters. It is not safe to permit the binding of
17719 default arguments as an extension, as that may change
17720 the meaning of a conforming program. Consider:
17722 struct Dense { static const unsigned int dim = 1; };
17724 template <template <typename> class View,
17725 typename Block>
17726 void operator+(float, View<Block> const&);
17728 template <typename Block,
17729 unsigned int Dim = Block::dim>
17730 struct Lvalue_proxy { operator float() const; };
17732 void
17733 test_1d (void) {
17734 Lvalue_proxy<Dense> p;
17735 float b;
17736 b + p;
17737 }
17739 Here, if Lvalue_proxy is permitted to bind to View, then
17740 the global operator+ will be used; if they are not, the
17741 Lvalue_proxy will be converted to float. */
17743 full_argvec,
17745 (explain_p
17746 ? tf_warning_or_error
17753 /* Deduce arguments T, i from TT<T> or TT<i>.
17754 We check each element of PARMVEC and ARGVEC individually
17755 rather than the whole TREE_VEC since they can have
17756 different number of elements. */
17763 /* Check if the parameters end in a pack, making them
17764 variadic. */
17770 /* If the template argument list of P contains a pack
17771 expansion that is not the last template argument, the
17772 entire template argument list is a non-deduced
17773 context. */
17782 {
17787 }
17792 DEDUCE_EXACT,
17795 }
17798 /* Fall through to deduce template name. */
17799 }
17803 {
17804 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17806 /* Simple cases: Value already set, does match or doesn't. */
17811 }
17812 else
17813 {
17814 /* If PARM is `const T' and ARG is only `int', we don't have
17815 a match unless we are allowing additional qualification.
17816 If ARG is `const int' and PARM is just `T' that's OK;
17817 that binds `const int' to `T'. */
17822 /* Consider the case where ARG is `const volatile int' and
17823 PARM is `const T'. Then, T should be `volatile int'. */
17824 arg = cp_build_qualified_type_real
17829 /* Simple cases: Value already set, does match or doesn't. */
17835 /* Make sure that ARG is not a variable-sized array. (Note
17836 that were talking about variable-sized arrays (like
17837 `int[n]'), rather than arrays of unknown size (like
17838 `int[]').) We'll get very confused by such a type since
17839 the bound of the array is not constant, and therefore
17840 not mangleable. Besides, such types are not allowed in
17841 ISO C++, so we can do as we please here. We do allow
17842 them for 'auto' deduction, since that isn't ABI-exposed. */
17846 /* Strip typedefs as in convert_template_argument. */
17848 }
17850 /* If ARG is a parameter pack or an expansion, we cannot unify
17851 against it unless PARM is also a parameter pack. */
17856 /* If the argument deduction results is a METHOD_TYPE,
17857 then there is a problem.
17858 METHOD_TYPE doesn't map to any real C++ type the result of
17859 the deduction can not be of that type. */
17873 {
17874 /* The PARM is not one we're trying to unify. Just check
17875 to see if it matches ARG. */
17881 }
17887 {
17892 }
17894 /* [temp.deduct.type] If, in the declaration of a function template
17895 with a non-type template-parameter, the non-type
17896 template-parameter is used in an expression in the function
17897 parameter-list and, if the corresponding template-argument is
17898 deduced, the template-argument type shall match the type of the
17899 template-parameter exactly, except that a template-argument
17900 deduced from an array bound may be of any integral type.
17901 The non-type parameter might use already deduced type parameters. */
17904 /* Template-parameter dependent expression. Just accept it for now.
17905 It will later be processed in convert_template_argument. */
17906 ;
17911 /* Convert the ARG to the type of PARM; the deduced non-type
17912 template argument must exactly match the types of the
17913 corresponding parameter. */
17916 /* We haven't deduced the type of this parameter yet. Try again
17917 later. */
17919 else
17922 /* If ARG is a parameter pack or an expansion, we cannot unify
17923 against it unless PARM is also a parameter pack. */
17933 {
17934 /* A pointer-to-member constant can be unified only with
17935 another constant. */
17939 /* Just unify the class member. It would be useless (and possibly
17940 wrong, depending on the strict flags) to unify also
17941 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17942 arg refer to the same variable, even if through different
17943 classes. For instance:
17945 struct A { int x; };
17946 struct B : A { };
17948 Unification of &A::x and &B::x must succeed. */
17951 }
17954 {
17958 /* [temp.deduct.call]
17960 A can be another pointer or pointer to member type that can
17961 be converted to the deduced A via a qualification
17962 conversion (_conv.qual_).
17964 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17965 This will allow for additional cv-qualification of the
17966 pointed-to types if appropriate. */
17969 /* The derived-to-base conversion only persists through one
17970 level of pointers. */
17975 }
18007 /* We have already checked cv-qualification at the top of the
18008 function. */
18012 /* As far as unification is concerned, this wins. Later checks
18013 will invalidate it if necessary. */
18016 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
18017 /* Type INTEGER_CST can come from ordinary constant template args. */
18029 {
18039 /* Check for pack expansions in the parameters. */
18041 {
18043 {
18045 /* We can unify against something with a trailing
18046 parameter pack. */
18048 else
18049 /* [temp.deduct.type]/9: If the template argument list of
18050 P contains a pack expansion that is not the last
18051 template argument, the entire template argument list
18052 is a non-deduced context. */
18054 }
18055 }
18057 /* If we don't have enough arguments to satisfy the parameters
18058 (not counting the pack expression at the end), or we have
18059 too many arguments for a parameter list that doesn't end in
18060 a pack expression, we can't unify. */
18066 /* Unify all of the parameters that precede the (optional)
18067 pack expression. */
18069 {
18074 }
18077 DEDUCE_EXACT,
18080 }
18088 {
18096 }
18099 {
18103 {
18104 /* First, we try to unify the PARM and ARG directly. */
18109 {
18110 /* Fallback to the special case allowed in
18111 [temp.deduct.call]:
18113 If P is a class, and P has the form
18114 template-id, then A can be a derived class of
18115 the deduced A. Likewise, if P is a pointer to
18116 a class of the form template-id, A can be a
18117 pointer to a derived class pointed to by the
18118 deduced A. */
18125 }
18126 }
18130 /* Perhaps PARM is something like S<U> and ARG is S<int>.
18131 Then, we should unify `int' and `U'. */
18133 else
18134 /* There's no chance of unification succeeding. */
18139 }
18146 {
18149 tree a;
18155 /* CV qualifications for methods can never be deduced, they must
18156 match exactly. We need to check them explicitly here,
18157 because type_unification_real treats them as any other
18158 cv-qualified parameter. */
18160 && (!check_cv_quals_for_unify
18180 }
18183 /* Unify a pointer to member with a pointer to member function, which
18184 deduces the type of the member as a function type. */
18186 {
18187 /* Check top-level cv qualifiers */
18195 /* Determine the type of the function we are unifying against. */
18199 }
18218 /* Matched cases are handled by the ARG == PARM test above. */
18222 /* A non-type template parameter that is a variable should be a
18223 an integral constant, in which case, it whould have been
18224 folded into its (constant) value. So we should not be getting
18225 a variable here. */
18236 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18237 or UNDERLYING_TYPE nodes. */
18241 /* Unification fails if we hit an error node. */
18248 /* FALLTHRU */
18251 /* An unresolved overload is a nondeduced context. */
18256 /* We must be looking at an expression. This can happen with
18257 something like:
18259 template <int I>
18260 void foo(S<I>, S<I + 2>);
18262 This is a "nondeduced context":
18264 [deduct.type]
18266 The nondeduced contexts are:
18268 --A type that is a template-id in which one or more of
18269 the template-arguments is an expression that references
18270 a template-parameter.
18272 In these cases, we assume deduction succeeded, but don't
18273 actually infer any unifications. */
18278 else
18280 }
18281 }
18282 #undef RECUR_AND_CHECK_FAILURE
18283 \f
18284 /* Note that DECL can be defined in this translation unit, if
18285 required. */
18287 static void
18289 {
18290 tree clone;
18294 }
18296 /* Called if RESULT is explicitly instantiated, or is a member of an
18297 explicitly instantiated class. */
18299 void
18301 {
18304 /* If this entity has already been written out, it's too late to
18305 make any modifications. */
18309 /* For anonymous namespace we don't need to do anything. */
18311 {
18314 }
18317 /* The TREE_PUBLIC flag for function declarations will have been
18318 set correctly by tsubst. */
18321 /* This might have been set by an earlier implicit instantiation. */
18326 else
18327 {
18330 /* Always make artificials weak. */
18333 /* For WIN32 we also want to put explicit instantiations in
18334 linkonce sections. */
18337 }
18339 /* If EXTERN_P, then this function will not be emitted -- unless
18340 followed by an explicit instantiation, at which point its linkage
18341 will be adjusted. If !EXTERN_P, then this function will be
18342 emitted here. In neither circumstance do we want
18343 import_export_decl to adjust the linkage. */
18345 }
18347 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18348 important template arguments. If any are missing, we check whether
18349 they're important by using error_mark_node for substituting into any
18350 args that were used for partial ordering (the ones between ARGS and END)
18351 and seeing if it bubbles up. */
18353 static bool
18355 {
18360 {
18363 }
18365 {
18369 }
18371 }
18373 /* Given two function templates PAT1 and PAT2, return:
18375 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18376 -1 if PAT2 is more specialized than PAT1.
18377 0 if neither is more specialized.
18379 LEN indicates the number of parameters we should consider
18380 (defaulted parameters should not be considered).
18382 The 1998 std underspecified function template partial ordering, and
18383 DR214 addresses the issue. We take pairs of arguments, one from
18384 each of the templates, and deduce them against each other. One of
18385 the templates will be more specialized if all the *other*
18386 template's arguments deduce against its arguments and at least one
18387 of its arguments *does* *not* deduce against the other template's
18388 corresponding argument. Deduction is done as for class templates.
18389 The arguments used in deduction have reference and top level cv
18390 qualifiers removed. Iff both arguments were originally reference
18391 types *and* deduction succeeds in both directions, an lvalue reference
18392 wins against an rvalue reference and otherwise the template
18393 with the more cv-qualified argument wins for that pairing (if
18394 neither is more cv-qualified, they both are equal). Unlike regular
18395 deduction, after all the arguments have been deduced in this way,
18396 we do *not* verify the deduced template argument values can be
18397 substituted into non-deduced contexts.
18399 The logic can be a bit confusing here, because we look at deduce1 and
18400 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18401 can find template arguments for pat1 to make arg1 look like arg2, that
18402 means that arg2 is at least as specialized as arg1. */
18404 int
18406 {
18419 /* Remove the this parameter from non-static member functions. If
18420 one is a non-static member function and the other is not a static
18421 member function, remove the first parameter from that function
18422 also. This situation occurs for operator functions where we
18423 locate both a member function (with this pointer) and non-member
18424 operator (with explicit first operand). */
18426 {
18431 }
18433 {
18436 {
18437 len--;
18439 }
18440 }
18442 /* If only one is a conversion operator, they are unordered. */
18446 /* Consider the return type for a conversion function */
18448 {
18451 len++;
18452 }
18454 processing_template_decl++;
18460 /* Stop when an ellipsis is seen. */
18462 {
18473 {
18474 /* When both arguments are pack expansions, we need only
18475 unify the patterns themselves. */
18479 /* This is the last comparison we need to do. */
18481 }
18484 {
18488 }
18491 {
18495 }
18501 {
18507 /* Setup the parameter vector, which contains only ARG1. */
18510 /* Setup the argument vector, which contains the remaining
18511 arguments. */
18520 /* We cannot deduce in the other direction, because ARG1 is
18521 a pack expansion but ARG2 is not. */
18523 }
18525 {
18531 /* Setup the parameter vector, which contains only ARG1. */
18534 /* Setup the argument vector, which contains the remaining
18535 arguments. */
18544 /* We cannot deduce in the other direction, because ARG2 is
18545 a pack expansion but ARG1 is not.*/
18547 }
18549 else
18550 {
18551 /* The normal case, where neither argument is a pack
18552 expansion. */
18559 }
18561 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18562 arg2, then arg2 is not as specialized as arg1. */
18568 /* "If, for a given type, deduction succeeds in both directions
18569 (i.e., the types are identical after the transformations above)
18570 and both P and A were reference types (before being replaced with
18571 the type referred to above):
18572 - if the type from the argument template was an lvalue reference and
18573 the type from the parameter template was not, the argument type is
18574 considered to be more specialized than the other; otherwise,
18575 - if the type from the argument template is more cv-qualified
18576 than the type from the parameter template (as described above),
18577 the argument type is considered to be more specialized than the other;
18578 otherwise,
18579 - neither type is more specialized than the other." */
18582 {
18584 {
18587 else
18589 }
18591 {
18596 }
18597 }
18600 /* We've failed to deduce something in either direction.
18601 These must be unordered. */
18606 /* We have already processed all of the arguments in our
18607 handing of the pack expansion type. */
18612 }
18614 /* "In most cases, all template parameters must have values in order for
18615 deduction to succeed, but for partial ordering purposes a template
18616 parameter may remain without a value provided it is not used in the
18617 types being used for partial ordering."
18619 Thus, if we are missing any of the targs1 we need to substitute into
18620 origs1, then pat2 is not as specialized as pat1. This can happen when
18621 there is a nondeduced context. */
18627 processing_template_decl--;
18629 /* All things being equal, if the next argument is a pack expansion
18630 for one function but not for the other, prefer the
18631 non-variadic function. FIXME this is bogus; see c++/41958. */
18635 {
18638 }
18644 else
18646 }
18648 /* Determine which of two partial specializations of TMPL is more
18649 specialized.
18651 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18652 to the first partial specialization. The TREE_VALUE is the
18653 innermost set of template parameters for the partial
18654 specialization. PAT2 is similar, but for the second template.
18656 Return 1 if the first partial specialization is more specialized;
18657 -1 if the second is more specialized; 0 if neither is more
18658 specialized.
18660 See [temp.class.order] for information about determining which of
18661 two templates is more specialized. */
18663 static int
18665 {
18666 tree targs;
18674 /* Just like what happens for functions, if we are ordering between
18675 different class template specializations, we may encounter dependent
18676 types in the arguments, and we need our dependency check functions
18677 to behave correctly. */
18683 {
18686 }
18692 {
18695 }
18698 /* In the case of a tie where at least one of the class templates
18699 has a parameter pack at the end, the template with the most
18700 non-packed parameters wins. */
18702 && any_deductions
18705 {
18711 /* We don't count the pack expansion at the end. */
18721 }
18724 }
18726 /* Return the template arguments that will produce the function signature
18727 DECL from the function template FN, with the explicit template
18728 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18729 also match. Return NULL_TREE if no satisfactory arguments could be
18730 found. */
18732 static tree
18734 {
18738 tree decl_arg_types;
18741 tree arg;
18745 /* Never do unification on the 'this' parameter. */
18766 }
18768 /* Return the innermost template arguments that, when applied to a partial
18769 specialization of TMPL whose innermost template parameters are
18770 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18771 ARGS.
18773 For example, suppose we have:
18775 template <class T, class U> struct S {};
18776 template <class T> struct S<T*, int> {};
18778 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18779 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18780 int}. The resulting vector will be {double}, indicating that `T'
18781 is bound to `double'. */
18783 static tree
18785 {
18787 tree deduced_args;
18788 tree innermost_deduced_args;
18792 {
18796 innermost_deduced_args);
18797 }
18798 else
18811 /* Verify that nondeduced template arguments agree with the type
18812 obtained from argument deduction.
18814 For example:
18816 struct A { typedef int X; };
18817 template <class T, class U> struct C {};
18818 template <class T> struct C<T, typename T::X> {};
18820 Then with the instantiation `C<A, int>', we can deduce that
18821 `T' is `A' but unify () does not check whether `typename T::X'
18822 is `int'. */
18828 /* We only need to check the innermost arguments; the other
18829 arguments will always agree. */
18834 /* Now that we have bindings for all of the template arguments,
18835 ensure that the arguments deduced for the template template
18836 parameters have compatible template parameter lists. See the use
18837 of template_template_parm_bindings_ok_p in fn_type_unification
18838 for more information. */
18843 }
18845 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18846 Return the TREE_LIST node with the most specialized template, if
18847 any. If there is no most specialized template, the error_mark_node
18848 is returned.
18850 Note that this function does not look at, or modify, the
18851 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18852 returned is one of the elements of INSTANTIATIONS, callers may
18853 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18854 and retrieve it from the value returned. */
18856 tree
18858 {
18865 {
18871 fate--;
18876 fate++;
18881 {
18882 /* Equally specialized, move to next function. If there
18883 is no next function, nothing's most specialized. */
18888 }
18889 }
18892 /* Now verify that champ is better than everything earlier in the
18893 instantiation list. */
18901 {
18904 }
18906 processing_template_decl--;
18912 }
18914 /* If DECL is a specialization of some template, return the most
18915 general such template. Otherwise, returns NULL_TREE.
18917 For example, given:
18919 template <class T> struct S { template <class U> void f(U); };
18921 if TMPL is `template <class U> void S<int>::f(U)' this will return
18922 the full template. This function will not trace past partial
18923 specializations, however. For example, given in addition:
18925 template <class T> struct S<T*> { template <class U> void f(U); };
18927 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18928 `template <class T> template <class U> S<T*>::f(U)'. */
18930 tree
18932 {
18934 {
18937 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
18938 template friend, or a FIELD_DECL for a capture pack. */
18941 }
18943 /* Look for more and more general templates. */
18945 {
18946 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18947 (See cp-tree.h for details.) */
18955 /* Stop if we run into an explicitly specialized class template. */
18962 }
18965 }
18967 /* Return the most specialized of the class template partial
18968 specializations which can produce TYPE, a specialization of some class
18969 template. The value returned is actually a TREE_LIST; the TREE_TYPE is
18970 a _TYPE node corresponding to the partial specialization, while the
18971 TREE_PURPOSE is the set of template arguments that must be
18972 substituted into the TREE_TYPE in order to generate TYPE.
18974 If the choice of partial specialization is ambiguous, a diagnostic
18975 is issued, and the error_mark_node is returned. If there are no
18976 partial specializations matching TYPE, then NULL_TREE is
18977 returned, indicating that the primary template should be used. */
18979 static tree
18981 {
18983 tree t;
18984 tree champ;
18993 /* For determining which partial specialization to use, only the
18994 innermost args are interesting. */
18996 {
18999 }
19002 {
19003 tree partial_spec_args;
19004 tree spec_args;
19013 {
19014 /* Discard the outer levels of args, and then substitute in the
19015 template args from the enclosing class. */
19017 partial_spec_args = tsubst_template_args
19020 /* And the same for the partial specialization TEMPLATE_DECL. */
19022 }
19024 partial_spec_args =
19026 partial_spec_args,
19040 partial_spec_args,
19041 args);
19043 {
19048 }
19049 }
19059 {
19062 ;
19063 else
19064 {
19066 {
19069 {
19072 }
19073 }
19075 }
19076 }
19080 {
19083 {
19086 }
19087 }
19090 {
19098 {
19101 }
19104 }
19107 }
19109 /* Explicitly instantiate DECL. */
19111 void
19113 {
19118 /* An error occurred, for which grokdeclarator has already issued
19119 an appropriate message. */
19122 {
19125 }
19127 {
19128 /* There is an asymmetry here in the way VAR_DECLs and
19129 FUNCTION_DECLs are handled by grokdeclarator. In the case of
19130 the latter, the DECL we get back will be marked as a
19131 template instantiation, and the appropriate
19132 DECL_TEMPLATE_INFO will be set up. This does not happen for
19133 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
19134 should handle VAR_DECLs as it currently handles
19135 FUNCTION_DECLs. */
19137 {
19140 }
19143 {
19146 }
19148 {
19153 }
19154 }
19156 {
19159 }
19160 else
19163 /* Check for various error cases. Note that if the explicit
19164 instantiation is valid the RESULT will currently be marked as an
19165 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19166 until we get here. */
19169 {
19170 /* DR 259 [temp.spec].
19172 Both an explicit instantiation and a declaration of an explicit
19173 specialization shall not appear in a program unless the explicit
19174 instantiation follows a declaration of the explicit specialization.
19176 For a given set of template parameters, if an explicit
19177 instantiation of a template appears after a declaration of an
19178 explicit specialization for that template, the explicit
19179 instantiation has no effect. */
19181 }
19183 {
19184 /* [temp.spec]
19186 No program shall explicitly instantiate any template more
19187 than once.
19189 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19190 the first instantiation was `extern' and the second is not,
19191 and EXTERN_P for the opposite case. */
19194 /* If an "extern" explicit instantiation follows an ordinary
19195 explicit instantiation, the template is instantiated. */
19198 }
19200 {
19203 }
19205 {
19208 }
19211 ;
19213 {
19216 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19219 }
19220 else
19228 }
19230 static void
19232 {
19238 {
19241 }
19242 }
19244 /* Called from do_type_instantiation through binding_table_foreach to
19245 do recursive instantiation for the type bound in ENTRY. */
19246 static void
19248 {
19254 }
19256 /* Called from do_type_instantiation to instantiate a member
19257 (a member function or a static member variable) of an
19258 explicitly instantiated class template. */
19259 static void
19261 {
19266 }
19268 /* Perform an explicit instantiation of template class T. STORAGE, if
19269 non-null, is the RID for extern, inline or static. COMPLAIN is
19270 nonzero if this is called from the parser, zero if called recursively,
19271 since the standard is unclear (as detailed below). */
19273 void
19275 {
19285 {
19286 tree tmpl =
19290 else
19293 }
19298 {
19301 t);
19303 }
19306 {
19308 {
19310 {
19313 "ISO C++ 1998 forbids the use of %<extern%> on "
19315 }
19316 else
19318 "ISO C++ forbids the use of %qE"
19320 }
19328 else
19329 {
19331 storage);
19333 }
19334 }
19337 {
19338 /* DR 259 [temp.spec].
19340 Both an explicit instantiation and a declaration of an explicit
19341 specialization shall not appear in a program unless the explicit
19342 instantiation follows a declaration of the explicit specialization.
19344 For a given set of template parameters, if an explicit
19345 instantiation of a template appears after a declaration of an
19346 explicit specialization for that template, the explicit
19347 instantiation has no effect. */
19349 }
19351 {
19352 /* [temp.spec]
19354 No program shall explicitly instantiate any template more
19355 than once.
19357 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19358 instantiation was `extern'. If EXTERN_P then the second is.
19359 These cases are OK. */
19366 /* If we've already instantiated the template, just return now. */
19369 }
19377 {
19378 tree tmp;
19380 /* In contrast to implicit instantiation, where only the
19381 declarations, and not the definitions, of members are
19382 instantiated, we have here:
19384 [temp.explicit]
19386 The explicit instantiation of a class template specialization
19387 implies the instantiation of all of its members not
19388 previously explicitly specialized in the translation unit
19389 containing the explicit instantiation.
19391 Of course, we can't instantiate member template classes, since
19392 we don't have any arguments for them. Note that the standard
19393 is unclear on whether the instantiation of the members are
19394 *explicit* instantiations or not. However, the most natural
19395 interpretation is that it should be an explicit instantiation. */
19410 }
19411 }
19413 /* Given a function DECL, which is a specialization of TMPL, modify
19414 DECL to be a re-instantiation of TMPL with the same template
19415 arguments. TMPL should be the template into which tsubst'ing
19416 should occur for DECL, not the most general template.
19418 One reason for doing this is a scenario like this:
19420 template <class T>
19421 void f(const T&, int i);
19423 void g() { f(3, 7); }
19425 template <class T>
19426 void f(const T& t, const int i) { }
19428 Note that when the template is first instantiated, with
19429 instantiate_template, the resulting DECL will have no name for the
19430 first parameter, and the wrong type for the second. So, when we go
19431 to instantiate the DECL, we regenerate it. */
19433 static void
19435 {
19436 /* The arguments used to instantiate DECL, from the most general
19437 template. */
19438 tree args;
19439 tree code_pattern;
19444 /* Make sure that we can see identifiers, and compute access
19445 correctly. */
19449 {
19450 tree decl_parm;
19451 tree pattern_parm;
19452 tree specs;
19466 specs);
19468 /* Merge parameter declarations. */
19471 pattern_parm
19475 {
19476 tree parm_type;
19477 tree attributes;
19482 NULL_TREE);
19488 {
19491 }
19494 }
19495 /* Merge any parameters that match with the function parameter
19496 pack. */
19498 {
19500 tree expanded_types;
19501 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19502 the parameters in this function parameter pack. */
19507 {
19508 tree parm_type;
19509 tree attributes;
19512 /* Rename the parameter to include the index. */
19521 {
19524 }
19526 }
19527 }
19528 /* Merge additional specifiers from the CODE_PATTERN. */
19532 }
19534 {
19542 }
19543 else
19547 }
19549 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19550 substituted to get DECL. */
19552 tree
19554 {
19557 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19558 for the instantiation. This is not always the most general
19559 template. Consider, for example:
19561 template <class T>
19562 struct S { template <class U> void f();
19563 template <> void f<int>(); };
19565 and an instantiation of S<double>::f<int>. We want TD to be the
19566 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19568 more general template. */
19570 /* We must also deal with friend templates. Given:
19572 template <class T> struct S {
19573 template <class U> friend void f() {};
19574 };
19576 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19577 so far as the language is concerned, but that's still
19578 where we get the pattern for the instantiation from. On
19579 other hand, if the definition comes outside the class, say:
19581 template <class T> struct S {
19582 template <class U> friend void f();
19583 };
19584 template <class U> friend void f() {}
19586 we don't need to look any further. That's what the check for
19587 DECL_INITIAL is for. */
19591 {
19592 /* The present template, TD, should not be a definition. If it
19593 were a definition, we should be using it! Note that we
19594 cannot restructure the loop to just keep going until we find
19595 a template with a definition, since that might go too far if
19596 a specialization was declared, but not defined. */
19600 /* Fetch the more general template. */
19602 }
19605 }
19607 /* Returns true if we need to instantiate this template instance even if we
19608 know we aren't going to emit it.. */
19610 bool
19612 {
19613 /* We always instantiate inline functions so that we can inline them. An
19614 explicit instantiation declaration prohibits implicit instantiation of
19615 non-inline functions. With high levels of optimization, we would
19616 normally inline non-inline functions -- but we're not allowed to do
19617 that for "extern template" functions. Therefore, we check
19618 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19622 /* And we need to instantiate static data members so that
19623 their initializers are available in integral constant
19624 expressions. */
19627 }
19629 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19630 instantiate it now, modifying TREE_TYPE (fn). */
19632 void
19634 {
19637 /* Don't instantiate a noexcept-specification from template context. */
19652 {
19656 {
19671 }
19672 else
19676 }
19679 {
19682 else
19684 }
19685 }
19687 /* Produce the definition of D, a _DECL generated from a template. If
19688 DEFER_OK is nonzero, then we don't have to actually do the
19689 instantiation now; we just have to do it sometime. Normally it is
19690 an error if this is an explicit instantiation but D is undefined.
19691 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19692 explicitly instantiated class template. */
19694 tree
19697 {
19699 tree gen_args;
19700 tree args;
19701 tree td;
19702 tree code_pattern;
19703 tree spec;
19704 tree gen_tmpl;
19711 tree fn_context;
19714 /* This function should only be used to instantiate templates for
19715 functions and static member variables. */
19718 /* Variables are never deferred; if instantiation is required, they
19719 are instantiated right away. That allows for better code in the
19720 case that an expression refers to the value of the variable --
19721 if the variable has a constant value the referring expression can
19722 take advantage of that fact. */
19727 /* Don't instantiate cloned functions. Instead, instantiate the
19728 functions they cloned. */
19736 /* D has already been instantiated or explicitly specialized, so
19737 there's nothing for us to do here.
19739 It might seem reasonable to check whether or not D is an explicit
19740 instantiation, and, if so, stop here. But when an explicit
19741 instantiation is deferred until the end of the compilation,
19742 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19743 the instantiation. */
19746 /* Check to see whether we know that this template will be
19747 instantiated in some other file, as with "extern template"
19748 extension. */
19751 /* In general, we do not instantiate such templates. */
19755 /* Any local class members should be instantiated from the TAG_DEFN
19756 with defer_ok == 0. */
19764 /* We should already have the extra args. */
19767 /* And what's in the hash table should match D. */
19771 /* This needs to happen before any tsubsting. */
19777 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19778 for the instantiation. */
19782 /* We should never be trying to instantiate a member of a class
19783 template or partial specialization. */
19788 /* In the case of a friend template whose definition is provided
19789 outside the class, we may have too many arguments. Drop the
19790 ones we don't need. The same is true for specializations. */
19791 args = get_innermost_template_args
19793 else
19797 {
19802 }
19803 else
19804 {
19807 }
19809 /* We may be in the middle of deferred access check. Disable it now. */
19812 /* Unless an explicit instantiation directive has already determined
19813 the linkage of D, remember that a definition is available for
19814 this entity. */
19824 /* If D is a member of an explicitly instantiated class template,
19825 and no definition is available, treat it like an implicit
19826 instantiation. */
19829 {
19830 /* Leave linkage flags alone on instantiations with anonymous
19831 visibility. */
19833 {
19836 }
19838 }
19840 /* Defer all other templates, unless we have been explicitly
19841 forbidden from doing so. */
19843 template. */
19844 ! pattern_defined
19845 /* If it's OK to postpone instantiation, do so. */
19846 || defer_ok
19847 /* If this is a static data member that will be defined
19848 elsewhere, we don't want to instantiate the entire data
19849 member, but we do want to instantiate the initializer so that
19850 we can substitute that elsewhere. */
19852 /* Handle here a deleted function too, avoid generating
19853 its body (c++/61080). */
19855 {
19856 /* The definition of the static data member is now required so
19857 we must substitute the initializer. */
19861 {
19862 tree ns;
19863 tree init;
19870 args,
19873 /* Make sure the initializer is still constant, in case of
19874 circular dependency (template/instantiate6.C). */
19875 const_init
19879 LOOKUP_ONLYCONVERTING);
19882 }
19884 /* We restore the source position here because it's used by
19885 add_pending_template. */
19891 /* [temp.explicit]
19893 The definition of a non-exported function template, a
19894 non-exported member function template, or a non-exported
19895 member function or static data member of a class template
19896 shall be present in every translation unit in which it is
19897 explicitly instantiated. */
19901 /* If we're in unevaluated context, we just wanted to get the
19902 constant value; this isn't an odr use, so don't queue
19903 a full instantiation. */
19906 /* ??? Historically, we have instantiated inline functions, even
19907 when marked as "extern template". */
19911 }
19912 /* Tell the repository that D is available in this translation unit
19913 -- and see if it is supposed to be instantiated here. */
19915 {
19916 /* In a PCH file, despite the fact that the repository hasn't
19917 requested instantiation in the PCH it is still possible that
19918 an instantiation will be required in a file that includes the
19919 PCH. */
19922 /* Instantiate inline functions so that the inliner can do its
19923 job, even though we'll not be emitting a copy of this
19924 function. */
19927 }
19933 else
19934 {
19939 }
19941 /* Mark D as instantiated so that recursive calls to
19942 instantiate_decl do not try to instantiate it again. */
19945 /* Regenerate the declaration in case the template has been modified
19946 by a subsequent redeclaration. */
19949 /* We already set the file and line above. Reset them now in case
19950 they changed as a result of calling regenerate_decl_from_template. */
19954 {
19955 tree init;
19958 /* Clear out DECL_RTL; whatever was there before may not be right
19959 since we've reset the type of the declaration. */
19963 /* The initializer is placed in DECL_INITIAL by
19964 regenerate_decl_from_template so we don't need to
19965 push/pop_access_scope again here. Pull it out so that
19966 cp_finish_decl can process it. */
19971 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19972 initializer. That function will defer actual emission until
19973 we have a chance to determine linkage. */
19976 /* Enter the scope of D so that access-checking works correctly. */
19981 }
19985 {
19987 tree subst_decl;
19988 tree tmpl_parm;
19989 tree spec_parm;
19992 /* Save away the current list, in case we are instantiating one
19993 template from within the body of another. */
19996 /* Set up the list of local specializations. */
19999 /* Set up context. */
20003 else
20006 /* Some typedefs referenced from within the template code need to be
20007 access checked at template instantiation time, i.e now. These
20008 types were added to the template at parsing time. Let's get those
20009 and perform the access checks then. */
20011 gen_args);
20013 /* Create substitution entries for the parameters. */
20018 {
20022 }
20024 {
20026 {
20029 }
20030 else
20031 {
20032 /* Register the (value) argument pack as a specialization of
20033 TMPL_PARM, then move on. */
20036 }
20037 }
20040 /* Substitute into the body of the function. */
20044 else
20045 {
20050 /* Set the current input_location to the end of the function
20051 so that finish_function knows where we are. */
20052 input_location
20055 /* Remember if we saw an infinite loop in the template. */
20056 current_function_infinite_loop
20058 }
20060 /* We don't need the local specializations any more. */
20064 /* Finish the function. */
20068 else
20069 {
20072 }
20076 }
20078 /* We're not deferring instantiation any more. */
20086 out:
20096 }
20098 /* Run through the list of templates that we wish we could
20099 instantiate, and instantiate any we can. RETRIES is the
20100 number of times we retry pending template instantiation. */
20102 void
20104 {
20108 /* Instantiating templates may trigger vtable generation. This in turn
20109 may require further template instantiations. We place a limit here
20110 to avoid infinite loop. */
20112 {
20116 " instantiating %q+D, possibly from virtual table generation"
20120 /* Pretend that we defined it. */
20123 }
20125 do
20126 {
20131 {
20136 {
20137 tree fn;
20140 {
20144 fn;
20152 }
20155 }
20156 else
20157 {
20160 {
20161 instantiation
20167 }
20171 }
20174 /* If INSTANTIATION has been instantiated, then we don't
20175 need to consider it again in the future. */
20177 else
20178 {
20181 }
20184 }
20186 }
20190 }
20192 /* Substitute ARGVEC into T, which is a list of initializers for
20193 either base class or a non-static data member. The TREE_PURPOSEs
20194 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20195 instantiate_decl. */
20197 static tree
20199 {
20203 {
20204 tree decl;
20205 tree init;
20211 {
20212 tree expr;
20213 tree arg;
20215 /* Expand the base class expansion type into separate base
20216 classes. */
20218 tf_warning_or_error,
20219 NULL_TREE);
20223 /* We'll be building separate TREE_LISTs of arguments for
20224 each base. */
20230 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20231 expand each argument in the TREE_VALUE of t. */
20238 /* VOID_TYPE_NODE is used to indicate
20239 value-initialization. */
20240 {
20243 }
20244 else
20245 {
20246 /* Substitute parameter packs into each argument in the
20247 TREE_LIST. */
20250 {
20251 tree expanded_exprs;
20253 /* Expand the argument. */
20255 expanded_exprs
20257 tf_warning_or_error,
20258 NULL_TREE);
20262 /* Prepend each of the expanded expressions to the
20263 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20265 {
20270 }
20271 }
20274 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20275 since we built them backwards. */
20277 {
20280 }
20281 }
20282 }
20285 {
20287 {
20291 }
20292 else
20293 {
20294 tree tmp;
20309 /* If we had an initializer but it instantiated to nothing,
20310 value-initialize the object. This will only occur when
20311 the initializer was a pack expansion where the parameter
20312 packs used in that expansion were of length zero. */
20315 }
20318 {
20322 }
20323 }
20324 }
20326 }
20328 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20330 static void
20332 {
20337 else
20339 }
20341 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20342 is the instantiation (which should have been created with
20343 start_enum) and ARGS are the template arguments to use. */
20345 static void
20347 {
20348 tree e;
20354 {
20355 tree value;
20356 tree decl;
20359 /* Note that in a template enum, the TREE_VALUE is the
20360 CONST_DECL, not the corresponding INTEGER_CST. */
20365 /* Give this enumeration constant the correct access. */
20368 /* Actually build the enumerator itself. */
20369 build_enumerator
20371 }
20381 }
20383 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20384 its type -- but without substituting the innermost set of template
20385 arguments. So, innermost set of template parameters will appear in
20386 the type. */
20388 tree
20390 {
20391 tree fn_type;
20392 tree tmpl;
20393 tree targs;
20394 tree tparms;
20402 /* There should be as many levels of arguments as there are levels
20403 of parameters. */
20409 /* No substitution is necessary. */
20410 ;
20411 else
20412 {
20414 tree partial_args;
20416 /* Replace the innermost level of the TARGS with NULL_TREEs to
20417 let tsubst know not to substitute for those parameters. */
20426 /* Make sure that we can see identifiers, and compute access
20427 correctly. */
20431 /* Now, do the (partial) substitution to figure out the
20432 appropriate function type. */
20436 /* Substitute into the template parameters to obtain the real
20437 innermost set of parameters. This step is important if the
20438 innermost set of template parameters contains value
20439 parameters whose types depend on outer template parameters. */
20444 }
20447 }
20449 /* Return truthvalue if we're processing a template different from
20450 the last one involved in diagnostics. */
20451 int
20453 {
20455 }
20457 /* Remember current template involved in diagnostics. */
20458 void
20460 {
20462 }
20466 {
20468 }
20470 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20471 type. Return zero for ok, nonzero for disallowed. Issue error and
20472 warning messages under control of COMPLAIN. */
20474 static int
20476 {
20493 {
20496 else
20498 type);
20499 }
20501 }
20503 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20504 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20506 static bool
20508 {
20509 tree scope;
20511 /* [temp.dep.type]
20513 A type is dependent if it is:
20515 -- a template parameter. Template template parameters are types
20516 for us (since TYPE_P holds true for them) so we handle
20517 them here. */
20521 /* -- a qualified-id with a nested-name-specifier which contains a
20522 class-name that names a dependent type or whose unqualified-id
20523 names a dependent type. */
20526 /* -- a cv-qualified type where the cv-unqualified type is
20527 dependent. */
20529 /* -- a compound type constructed from any dependent type. */
20539 {
20540 tree arg_type;
20545 arg_type;
20550 }
20551 /* -- an array type constructed from any dependent type or whose
20552 size is specified by a constant expression that is
20553 value-dependent.
20555 We checked for type- and value-dependence of the bounds in
20556 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20558 {
20563 }
20565 /* -- a template-id in which either the template name is a template
20566 parameter ... */
20569 /* ... or any of the template arguments is a dependent type or
20570 an expression that is type-dependent or value-dependent. */
20572 && (any_dependent_template_arguments_p
20576 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20577 dependent; if the argument of the `typeof' expression is not
20578 type-dependent, then it should already been have resolved. */
20584 /* A template argument pack is dependent if any of its packed
20585 arguments are. */
20587 {
20593 }
20595 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20596 be template parameters. */
20600 /* The standard does not specifically mention types that are local
20601 to template functions or local classes, but they should be
20602 considered dependent too. For example:
20604 template <int I> void f() {
20605 enum E { a = I };
20606 S<sizeof (E)> s;
20607 }
20609 The size of `E' cannot be known until the value of `I' has been
20610 determined. Therefore, `E' must be considered dependent. */
20614 /* Don't use type_dependent_expression_p here, as it can lead
20615 to infinite recursion trying to determine whether a lambda
20616 nested in a lambda is dependent (c++/47687). */
20620 && (any_dependent_template_arguments_p
20624 /* Other types are non-dependent. */
20626 }
20628 /* Returns TRUE if TYPE is dependent, in the sense of
20629 [temp.dep.type]. Note that a NULL type is considered dependent. */
20631 bool
20633 {
20634 /* If there are no template parameters in scope, then there can't be
20635 any dependent types. */
20637 {
20638 /* If we are not processing a template, then nobody should be
20639 providing us with a dependent type. */
20643 }
20645 /* If the type is NULL, we have not computed a type for the entity
20646 in question; in that case, the type is dependent. */
20650 /* Erroneous types can be considered non-dependent. */
20654 /* If we have not already computed the appropriate value for TYPE,
20655 do so now. */
20657 {
20660 }
20663 }
20665 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20666 lookup. In other words, a dependent type that is not the current
20667 instantiation. */
20669 bool
20671 {
20674 }
20676 /* T is a SCOPE_REF; return whether we need to consider it
20677 instantiation-dependent so that we can check access at instantiation
20678 time even though we know which member it resolves to. */
20680 static bool
20682 {
20688 else
20690 }
20692 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20693 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20694 expression. */
20696 /* Note that this predicate is not appropriate for general expressions;
20697 only constant expressions (that satisfy potential_constant_expression)
20698 can be tested for value dependence. */
20700 bool
20702 {
20706 /* A name declared with a dependent type. */
20711 {
20713 /* A name that has not been looked up -- must be dependent. */
20717 /* A non-type template parm. */
20721 /* A non-type template parm. */
20727 /* A constant with literal type and is initialized
20728 with an expression that is value-dependent.
20730 Note that a non-dependent parenthesized initializer will have
20731 already been replaced with its constant value, so if we see
20732 a TREE_LIST it must be dependent. */
20745 /* These expressions are value-dependent if the type to which
20746 the cast occurs is dependent or the expression being casted
20747 is value-dependent. */
20748 {
20754 /* A functional cast has a list of operands. */
20757 {
20758 /* If there are no operands, it must be an expression such
20759 as "int()". This should not happen for aggregate types
20760 because it would form non-constant expressions. */
20765 }
20771 }
20776 /* FALLTHRU */
20779 /* A `sizeof' expression is value-dependent if the operand is
20780 type-dependent or is a pack expansion. */
20789 /* An 'encode' expression is value-dependent if the operand is
20790 type-dependent. */
20799 /* All instantiation-dependent expressions should also be considered
20800 value-dependent. */
20808 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20809 is value-dependent. */
20810 {
20819 }
20822 {
20826 }
20837 {
20841 }
20844 {
20851 {
20853 /* In a call to a constexpr member function, look through the
20854 implicit ADDR_EXPR on the object argument so that it doesn't
20855 cause the call to be considered value-dependent. We also
20856 look through it in potential_constant_expression. */
20863 }
20865 }
20868 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20869 type-dependent. */
20873 {
20875 tree val;
20880 }
20883 /* Treat a GNU statement expression as dependent to avoid crashing
20884 under fold_non_dependent_expr; it can't be constant. */
20888 /* A constant expression is value-dependent if any subexpression is
20889 value-dependent. */
20891 {
20898 {
20902 {
20905 /* In some cases, some of the operands may be missing.l
20906 (For example, in the case of PREDECREMENT_EXPR, the
20907 amount to increment by may be missing.) That doesn't
20908 make the expression dependent. */
20911 }
20912 }
20916 }
20918 }
20920 /* The expression is not value-dependent. */
20922 }
20924 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20925 [temp.dep.expr]. Note that an expression with no type is
20926 considered dependent. Other parts of the compiler arrange for an
20927 expression with type-dependent subexpressions to have no type, so
20928 this function doesn't have to be fully recursive. */
20930 bool
20932 {
20939 /* An unresolved name is always dependent. */
20943 /* Some expression forms are never type-dependent. */
20956 /* The types of these expressions depends only on the type to which
20957 the cast occurs. */
20966 /* The types of these expressions depends only on the type created
20967 by the expression. */
20970 {
20971 /* For NEW_EXPR tree nodes created inside a template, either
20972 the object type itself or a TREE_LIST may appear as the
20973 operand 1. */
20976 /* This is an array type. We need to check array dimensions
20977 as well. */
20979 || value_dependent_expression_p
20981 else
20983 }
20986 {
20990 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20991 contains an identifier associated by name lookup with one or more
20992 declarations declared with a dependent type, or...a
20993 nested-name-specifier or qualified-id that names a member of an
20994 unknown specialization. */
20997 }
21002 && (any_dependent_template_arguments_p
21014 {
21015 tree elt;
21019 {
21022 }
21024 }
21026 /* A static data member of the current instantiation with incomplete
21027 array type is type-dependent, as the definition and specializations
21028 can have different bounds. */
21035 /* An array of unknown bound depending on a variadic parameter, eg:
21037 template<typename... Args>
21038 void foo (Args... args)
21039 {
21040 int arr[] = { args... };
21041 }
21043 template<int... vals>
21044 void bar ()
21045 {
21046 int arr[] = { vals... };
21047 }
21049 If the array has no length and has an initializer, it must be that
21050 we couldn't determine its length in cp_complete_array_type because
21051 it is dependent. */
21059 {
21064 {
21070 }
21071 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
21075 /* Always dependent, on the number of arguments if nothing else. */
21083 {
21088 }
21093 {
21097 }
21099 }
21104 }
21106 /* walk_tree callback function for instantiation_dependent_expression_p,
21107 below. Returns non-zero if a dependent subexpression is found. */
21109 static tree
21112 {
21114 {
21115 /* We don't have to worry about decltype currently because decltype
21116 of an instantiation-dependent expr is a dependent type. This
21117 might change depending on the resolution of DR 1172. */
21120 }
21123 {
21124 /* Don't treat an argument list as dependent just because it has no
21125 TREE_TYPE. */
21132 /* A constant with a dependent initializer is dependent. */
21140 /* Handle expressions with type operands. */
21145 {
21150 {
21153 else
21154 {
21157 }
21158 }
21160 }
21172 /* In a template, finish_class_member_access_expr creates a
21173 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21174 type-dependent, so that we can check access control at
21175 instantiation time (PR 42277). See also Core issue 1273. */
21182 else
21185 /* Treat statement-expressions as dependent. */
21191 }
21195 else
21197 }
21199 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21200 sense defined by the ABI:
21202 "An expression is instantiation-dependent if it is type-dependent
21203 or value-dependent, or it has a subexpression that is type-dependent
21204 or value-dependent." */
21206 bool
21208 {
21209 tree result;
21220 }
21222 /* Like type_dependent_expression_p, but it also works while not processing
21223 a template definition, i.e. during substitution or mangling. */
21225 bool
21227 {
21233 }
21235 /* Returns TRUE if ARGS contains a type-dependent expression. */
21237 bool
21239 {
21241 tree arg;
21244 {
21247 }
21249 }
21251 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21252 expressions) contains any type-dependent expressions. */
21254 bool
21256 {
21262 }
21264 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21265 expressions) contains any value-dependent expressions. */
21267 bool
21269 {
21275 }
21277 /* Returns TRUE if the ARG (a template argument) is dependent. */
21279 bool
21281 {
21285 /* Assume a template argument that was wrongly written by the user
21286 is dependent. This is consistent with what
21287 any_dependent_template_arguments_p [that calls this function]
21288 does. */
21299 {
21303 {
21306 }
21309 }
21312 else
21315 }
21317 /* Returns true if ARGS (a collection of template arguments) contains
21318 any types that require structural equality testing. */
21320 bool
21322 {
21332 {
21335 {
21341 {
21342 /* Look inside the argument pack. */
21345 }
21348 {
21361 }
21362 }
21363 }
21366 }
21368 /* Returns true if ARGS (a collection of template arguments) contains
21369 any dependent arguments. */
21371 bool
21373 {
21383 {
21388 }
21391 }
21393 /* Returns TRUE if the template TMPL is dependent. */
21395 bool
21397 {
21399 {
21401 {
21405 }
21407 }
21409 /* Template template parameters are dependent. */
21413 /* So are names that have not been looked up. */
21416 /* So are member templates of dependent classes. */
21420 }
21422 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21424 bool
21426 {
21429 }
21431 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21432 is dependent. */
21434 bool
21436 {
21443 {
21464 {
21468 }
21472 {
21476 {
21481 }
21482 }
21483 }
21486 }
21488 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21489 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21490 no such TYPE can be found. Note that this function peers inside
21491 uninstantiated templates and therefore should be used only in
21492 extremely limited situations. ONLY_CURRENT_P restricts this
21493 peering to the currently open classes hierarchy (which is required
21494 when comparing types). */
21496 tree
21498 {
21499 tree scope;
21500 tree name;
21501 tree decl;
21503 tree pushed_scope;
21504 tree result;
21509 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21510 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21511 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21512 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21513 identifier of the TYPENAME_TYPE anymore.
21514 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21515 TYPENAME_TYPE instead, we avoid messing up with a possible
21516 typedef variant case. */
21519 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21520 it first before we can figure out what NAME refers to. */
21522 {
21524 /* Given a class template A with a dependent base with nested type C,
21525 typedef typename A::C::C C will land us here, as trying to resolve
21526 the initial A::C leads to the local C typedef, which leads back to
21527 A::C::C. So we break the recursion now. */
21529 else
21531 }
21532 /* If we don't know what SCOPE refers to, then we cannot resolve the
21533 TYPENAME_TYPE. */
21536 /* If the SCOPE is a template type parameter, we have no way of
21537 resolving the name. */
21540 /* If the SCOPE is not the current instantiation, there's no reason
21541 to look inside it. */
21544 /* If this is a typedef, we don't want to look inside (c++/11987). */
21547 /* If SCOPE isn't the template itself, it will not have a valid
21548 TYPE_FIELDS list. */
21550 /* scope is either the template itself or a compatible instantiation
21551 like X<T>, so look up the name in the original template. */
21553 else
21554 /* scope is a partial instantiation, so we can't do the lookup or we
21555 will lose the template arguments. */
21557 /* Enter the SCOPE so that name lookup will be resolved as if we
21558 were in the class definition. In particular, SCOPE will no
21559 longer be considered a dependent type. */
21561 /* Look up the declaration. */
21563 tf_warning_or_error);
21567 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21568 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21573 {
21577 }
21580 {
21581 tree tmpl;
21582 tree args;
21583 /* Obtain the template and the arguments. */
21586 /* Instantiate the template. */
21592 }
21594 /* Leave the SCOPE. */
21598 /* If we failed to resolve it, return the original typename. */
21602 /* If lookup found a typename type, resolve that too. */
21604 {
21605 /* Ill-formed programs can cause infinite recursion here, so we
21606 must catch that. */
21610 }
21612 /* Qualify the resulting type. */
21618 }
21620 /* EXPR is an expression which is not type-dependent. Return a proxy
21621 for EXPR that can be used to compute the types of larger
21622 expressions containing EXPR. */
21624 tree
21626 {
21627 tree inner_expr;
21629 #ifdef ENABLE_CHECKING
21630 /* Try to get a constant value for all non-dependent expressions in
21631 order to expose bugs in *_dependent_expression_p and constexpr. */
21634 #endif
21636 /* Preserve OVERLOADs; the functions must be available to resolve
21637 types. */
21648 /* There is no need to return a proxy for a variable. */
21651 /* Preserve string constants; conversions from string constants to
21652 "char *" are allowed, even though normally a "const char *"
21653 cannot be used to initialize a "char *". */
21656 /* Preserve void and arithmetic constants, as an optimization -- there is no
21657 reason to create a new node. */
21662 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21663 There is at least one place where we want to know that a
21664 particular expression is a throw-expression: when checking a ?:
21665 expression, there are special rules if the second or third
21666 argument is a throw-expression. */
21670 /* Don't wrap an initializer list, we need to be able to look inside. */
21674 /* Don't wrap a dummy object, we need to be able to test for it. */
21693 /* If the type is unknown, it can't really be non-dependent */
21696 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21698 }
21700 /* ARGS is a vector of expressions as arguments to a function call.
21701 Replace the arguments with equivalent non-dependent expressions.
21702 This modifies ARGS in place. */
21704 void
21706 {
21708 tree arg;
21711 {
21715 }
21716 }
21718 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21719 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21720 parms. */
21722 static tree
21724 {
21737 }
21739 tree
21741 {
21743 }
21745 tree
21747 {
21749 }
21751 /* Given type ARG, return std::initializer_list<ARG>. */
21753 static tree
21755 {
21756 tree std_init_list = namespace_binding
21758 tree argvec;
21760 {
21764 }
21769 }
21771 /* Replace auto in TYPE with std::initializer_list<auto>. */
21773 static tree
21775 {
21782 }
21784 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21785 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21787 tree
21789 {
21790 tree targs;
21796 /* Defining a subset of type-dependent expressions that we can deduce
21797 from ahead of time isn't worth the trouble. */
21800 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21801 with either a new invented type template parameter U or, if the
21802 initializer is a braced-init-list (8.5.4), with
21803 std::initializer_list<U>. */
21811 {
21817 {
21820 }
21821 }
21822 else
21823 {
21834 {
21836 /* Try again at instantiation time. */
21839 /* If type is error_mark_node a diagnostic must have been
21840 emitted by now. Also, having a mention to '<type error>'
21841 in the diagnostic is not really useful to the user. */
21842 {
21846 else
21848 }
21850 }
21851 }
21853 /* If the list of declarators contains more than one declarator, the type
21854 of each declared variable is determined as described above. If the
21855 type deduced for the template parameter U is not the same in each
21856 deduction, the program is ill-formed. */
21859 {
21865 else
21869 }
21875 }
21877 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21878 result. */
21880 tree
21882 {
21883 tree argvec;
21890 /* For a late-specified return type in a template type-parameter, we
21891 need to add a dummy argument level for its parmlist. */
21892 argvec = add_to_template_args
21897 }
21899 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21900 'decltype(auto)'. */
21902 bool
21904 {
21909 else
21911 }
21913 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21914 a use of `auto'. Returns NULL_TREE otherwise. */
21916 tree
21918 {
21920 }
21922 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21923 'decltype(auto)' or a concept. */
21925 bool
21927 {
21929 }
21931 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21932 a concept identifier) iff TYPE contains a use of a generic type. Returns
21933 NULL_TREE otherwise. */
21935 tree
21937 {
21939 }
21942 /* For a given template T, return the vector of typedefs referenced
21943 in T for which access check is needed at T instantiation time.
21944 T is either a FUNCTION_DECL or a RECORD_TYPE.
21945 Those typedefs were added to T by the function
21946 append_type_to_template_for_access_check. */
21950 {
21951 tree ti;
21962 {
21967 }
21970 }
21972 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21973 tied to T. That list of typedefs will be access checked at
21974 T instantiation time.
21975 T is either a FUNCTION_DECL or a RECORD_TYPE.
21976 TYPE_DECL is a TYPE_DECL node representing a typedef.
21977 SCOPE is the scope through which TYPE_DECL is accessed.
21978 LOCATION is the location of the usage point of TYPE_DECL.
21980 This function is a subroutine of
21981 append_type_to_template_for_access_check. */
21983 static void
21985 tree type_decl,
21986 tree scope,
21987 location_t location)
21988 {
21989 qualified_typedef_usage_t typedef_usage;
21990 tree ti;
21997 && type_decl
22011 }
22013 /* Append TYPE_DECL to the template TEMPL.
22014 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
22015 At TEMPL instanciation time, TYPE_DECL will be checked to see
22016 if it can be accessed through SCOPE.
22017 LOCATION is the location of the usage point of TYPE_DECL.
22019 e.g. consider the following code snippet:
22021 class C
22022 {
22023 typedef int myint;
22024 };
22026 template<class U> struct S
22027 {
22028 C::myint mi; // <-- usage point of the typedef C::myint
22029 };
22031 S<char> s;
22033 At S<char> instantiation time, we need to check the access of C::myint
22034 In other words, we need to check the access of the myint typedef through
22035 the C scope. For that purpose, this function will add the myint typedef
22036 and the scope C through which its being accessed to a list of typedefs
22037 tied to the template S. That list will be walked at template instantiation
22038 time and access check performed on each typedefs it contains.
22039 Note that this particular code snippet should yield an error because
22040 myint is private to C. */
22042 void
22044 tree type_decl,
22045 tree scope,
22046 location_t location)
22047 {
22053 /* Make sure we don't append the type to the template twice. */
22060 }
22062 /* Convert the generic type parameters in PARM that match the types given in the
22063 range [START_IDX, END_IDX) from the current_template_parms into generic type
22064 packs. */
22066 tree
22068 {
22079 {
22080 /* Create a distinct parameter pack type from the current parm and add it
22081 to the replacement args to tsubst below into the generic function
22082 parameter. */
22097 }
22103 /* If there are more levels then build up the replacement with the outer
22104 template parms. */
22108 replacement);
22111 }
22114 /* Set up the hash tables for template instantiations. */
22116 void
22118 {
22120 hash_specialization,
22121 eq_specializations,
22122 ggc_free);
22124 hash_specialization,
22125 eq_specializations,
22126 ggc_free);
22127 }
22129 /* Print stats about the template hash tables for -fstats. */
22131 void
22133 {
22142 }