| blob | d712583931906fc89cf16f8503f3202d11bc6dfa |
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);
2260 }
2262 /* Return the number of template headers we expect to see for a definition
2263 or specialization of CTYPE or one of its non-template members. */
2265 int
2267 {
2271 {
2272 /* You're supposed to have one `template <...>' for every
2273 template class, but you don't need one for a full
2274 specialization. For example:
2276 template <class T> struct S{};
2277 template <> struct S<int> { void f(); };
2278 void S<int>::f () {}
2280 is correct; there shouldn't be a `template <>' for the
2281 definition of `S<int>::f'. */
2283 /* If CTYPE does not have template information of any
2284 kind, then it is not a template, nor is it nested
2285 within a template. */
2293 }
2296 }
2298 /* Do a simple sanity check on the template headers that precede the
2299 variable declaration DECL. */
2301 void
2303 {
2310 {
2316 "members of an explicitly specialized class are defined "
2318 }
2319 }
2321 /* Check to see if the function just declared, as indicated in
2322 DECLARATOR, and in DECL, is a specialization of a function
2323 template. We may also discover that the declaration is an explicit
2324 instantiation at this point.
2326 Returns DECL, or an equivalent declaration that should be used
2327 instead if all goes well. Issues an error message if something is
2328 amiss. Returns error_mark_node if the error is not easily
2329 recoverable.
2331 FLAGS is a bitmask consisting of the following flags:
2333 2: The function has a definition.
2334 4: The function is a friend.
2336 The TEMPLATE_COUNT is the number of references to qualifying
2337 template classes that appeared in the name of the function. For
2338 example, in
2340 template <class T> struct S { void f(); };
2341 void S<int>::f();
2343 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2344 classes are not counted in the TEMPLATE_COUNT, so that in
2346 template <class T> struct S {};
2347 template <> struct S<int> { void f(); }
2348 template <> void S<int>::f();
2350 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2351 invalid; there should be no template <>.)
2353 If the function is a specialization, it is marked as such via
2354 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2355 is set up correctly, and it is added to the list of specializations
2356 for that template. */
2358 tree
2360 tree decl,
2363 {
2371 tmpl_spec_kind tsk;
2374 {
2377 else
2379 }
2380 else
2384 {
2387 {
2390 }
2392 {
2394 /* This could be something like:
2396 template <class T> void f(T);
2397 class S { friend void f<>(int); } */
2399 else
2400 {
2401 /* This case handles bogus declarations like template <>
2402 template <class T> void f<int>(); */
2405 declarator);
2407 }
2408 }
2412 /* The error has already been reported in
2413 check_specialization_scope. */
2419 /* Fall through. */
2432 decl);
2435 else
2439 /* Fall through. */
2444 else
2450 {
2451 /* This case handles bogus declarations like template <>
2452 template <class T> void f<int>(); */
2457 else
2459 declarator);
2461 }
2464 /* This is a specialization of a member template, without
2465 specialization the containing class. Something like:
2467 template <class T> struct S {
2468 template <class U> void f (U);
2469 };
2470 template <> template <class U> void S<int>::f(U) {}
2472 That's a specialization -- but of the entire template. */
2478 }
2481 {
2485 {
2489 }
2490 }
2493 {
2497 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2499 {
2500 tree fns;
2505 else
2506 {
2507 /* If there is no class context, the explicit instantiation
2508 must be at namespace scope. */
2511 /* Find the namespace binding, using the declaration
2512 context. */
2516 {
2519 }
2520 else
2521 {
2527 }
2528 }
2531 }
2537 {
2539 /* A specialization in class scope. This is invalid,
2540 but the error will already have been flagged by
2541 check_specialization_scope. */
2543 else
2544 {
2545 /* It's not valid to write an explicit instantiation in
2546 class scope, e.g.:
2548 class C { template void f(); }
2550 This case is caught by the parser. However, on
2551 something like:
2553 template class C { void f(); };
2555 (which is invalid) we can get here. The error will be
2556 issued later. */
2557 ;
2558 }
2561 }
2564 {
2565 /* Find the list of functions in ctype that have the same
2566 name as the declared function. */
2572 {
2577 {
2578 /* From [temp.expl.spec]:
2580 If such an explicit specialization for the member
2581 of a class template names an implicitly-declared
2582 special member function (clause _special_), the
2583 program is ill-formed.
2585 Similar language is found in [temp.explicit]. */
2588 }
2591 }
2594 {
2598 }
2599 else
2600 {
2602 tree ovl;
2604 /* For a type-conversion operator, we cannot do a
2605 name-based lookup. We might be looking for `operator
2606 int' which will be a specialization of `operator T'.
2607 So, we find *all* the conversion operators, and then
2608 select from them. */
2616 {
2618 /* There are no more conversion functions. */
2621 /* Glue all these conversion functions together
2622 with those we already have. */
2625 }
2626 }
2629 {
2632 }
2633 else
2635 }
2637 /* Figure out what exactly is being specialized at this point.
2638 Note that for an explicit instantiation, even one for a
2639 member function, we cannot tell apriori whether the
2640 instantiation is for a member template, or just a member
2641 function of a template class. Even if a member template is
2642 being instantiated, the member template arguments may be
2643 elided if they can be deduced from the rest of the
2644 declaration. */
2647 member_specialization,
2648 template_count,
2649 tsk);
2652 /* We couldn't figure out what this declaration was
2653 specializing. */
2655 else
2656 {
2660 {
2661 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2662 is done by do_decl_instantiation later. */
2668 {
2669 /* If TMPL is not the most general template (for
2670 example, if TMPL is a friend template that is
2671 injected into namespace scope), then there will
2672 be too many levels of TARGS. Remove some of them
2673 here. */
2675 tree new_targs;
2682 }
2685 }
2687 /* If we thought that the DECL was a member function, but it
2688 turns out to be specializing a static member function,
2689 make DECL a static member function as well. */
2694 /* If this is a specialization of a member template of a
2695 template class, we want to return the TEMPLATE_DECL, not
2696 the specialization of it. */
2698 {
2703 {
2704 tree parm;
2708 /* We want to use the argument list specified in the
2709 definition, not in the original declaration. */
2714 }
2717 }
2719 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2722 /* Inherit default function arguments from the template
2723 DECL is specializing. */
2726 /* This specialization has the same protection as the
2727 template it specializes. */
2731 /* 7.1.1-1 [dcl.stc]
2733 A storage-class-specifier shall not be specified in an
2734 explicit specialization...
2736 The parser rejects these, so unless action is taken here,
2737 explicit function specializations will always appear with
2738 global linkage.
2740 The action recommended by the C++ CWG in response to C++
2741 defect report 605 is to make the storage class and linkage
2742 of the explicit specialization match the templated function:
2744 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2745 */
2747 {
2751 /* This specialization has the same linkage and visibility as
2752 the function template it specializes. */
2755 {
2758 }
2761 {
2764 }
2765 }
2767 /* If DECL is a friend declaration, declared using an
2768 unqualified name, the namespace associated with DECL may
2769 have been set incorrectly. For example, in:
2771 template <typename T> void f(T);
2772 namespace N {
2773 struct S { friend void f<int>(int); }
2774 }
2776 we will have set the DECL_CONTEXT for the friend
2777 declaration to N, rather than to the global namespace. */
2782 /* This is not really a declaration of a specialization.
2783 It's just the name of an instantiation. But, it's not
2784 a request for an instantiation, either. */
2787 /* Register this specialization so that we can find it
2788 again. */
2791 /* A 'structor should already have clones. */
2796 }
2797 }
2800 }
2802 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2803 parameters. These are represented in the same format used for
2804 DECL_TEMPLATE_PARMS. */
2806 int
2808 {
2809 const_tree p1;
2810 const_tree p2;
2818 {
2830 {
2834 /* If either of the template parameters are invalid, assume
2835 they match for the sake of error recovery. */
2848 }
2849 }
2852 /* One set of parameters has more parameters lists than the
2853 other. */
2857 }
2859 /* Determine whether PARM is a parameter pack. */
2861 bool
2863 {
2864 /* Determine if we have a non-type template parameter pack. */
2871 /* If this is a list of template parameters, we could get a
2872 TYPE_DECL or a TEMPLATE_DECL. */
2876 /* Otherwise it must be a type template parameter. */
2880 }
2882 /* Determine if T is a function parameter pack. */
2884 bool
2886 {
2890 }
2892 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2893 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2895 tree
2897 {
2904 }
2906 /* Return true iff the function parameter PARAM_DECL was expanded
2907 from the function parameter pack PACK. */
2909 bool
2911 {
2916 /* The parameter pack and its pack arguments have the same
2917 DECL_PARM_INDEX. */
2919 }
2921 /* Determine whether ARGS describes a variadic template args list,
2922 i.e., one that is terminated by a template argument pack. */
2924 static bool
2926 {
2928 tree last_parm;
2942 }
2944 /* Generate a new name for the parameter pack name NAME (an
2945 IDENTIFIER_NODE) that incorporates its */
2947 static tree
2949 {
2950 /* Munge the name to include the parameter index. */
2951 #define NUMBUF_LEN 128
2965 }
2967 /* Return true if T is a primary function, class or alias template
2968 instantiation. */
2970 bool
2972 {
2986 }
2988 /* Return true if PARM is a template template parameter. */
2990 bool
2992 {
2994 }
2996 /* Return true iff PARM is a DECL representing a type template
2997 parameter. */
2999 bool
3001 {
3006 }
3008 /* Return the template parameters of T if T is a
3009 primary template instantiation, NULL otherwise. */
3011 tree
3013 {
3018 parms = INNERMOST_TEMPLATE_PARMS
3022 }
3024 /* Return the template parameters of the LEVELth level from the full list
3025 of template parameters PARMS. */
3027 tree
3029 {
3030 tree p;
3041 }
3043 /* Returns the template arguments of T if T is a template instantiation,
3044 NULL otherwise. */
3046 tree
3048 {
3056 }
3058 /* Return the argument pack elements of T if T is a template argument pack,
3059 NULL otherwise. */
3061 tree
3063 {
3069 }
3071 /* Structure used to track the progress of find_parameter_packs_r. */
3072 struct find_parameter_pack_data
3073 {
3074 /* TREE_LIST that will contain all of the parameter packs found by
3075 the traversal. */
3078 /* Set of AST nodes that have been visited by the traversal. */
3080 };
3082 /* Identifies all of the argument packs that occur in a template
3083 argument and appends them to the TREE_LIST inside DATA, which is a
3084 find_parameter_pack_data structure. This is a subroutine of
3085 make_pack_expansion and uses_parameter_packs. */
3086 static tree
3088 {
3094 /* Handle type aliases/typedefs. */
3096 {
3103 }
3105 /* Identify whether this is a parameter pack or not. */
3107 {
3123 {
3124 /* We don't want to walk into the type of a PARM_DECL,
3125 because we don't want to see the type parameter pack. */
3128 }
3131 /* Look through a lambda capture proxy to the field pack. */
3134 {
3140 }
3147 /* Not a parameter pack. */
3149 }
3152 {
3153 /* Add this parameter pack to the list. */
3155 }
3161 /* This switch statement will return immediately if we don't find a
3162 parameter pack. */
3164 {
3169 /* Check the template itself. */
3172 /* Check the template arguments. */
3188 /* Fall through. */
3230 }
3233 }
3235 /* Determines if the expression or type T uses any parameter packs. */
3236 bool
3238 {
3246 }
3248 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3249 representation a base-class initializer into a parameter pack
3250 expansion. If all goes well, the resulting node will be an
3251 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3252 respectively. */
3253 tree
3255 {
3256 tree result;
3265 {
3266 /* The only time we will see a TREE_LIST here is for a base
3267 class initializer. In this case, the TREE_PURPOSE will be a
3268 _TYPE node (representing the base class expansion we're
3269 initializing) and the TREE_VALUE will be a TREE_LIST
3270 containing the initialization arguments.
3272 The resulting expansion looks somewhat different from most
3273 expansions. Rather than returning just one _EXPANSION, we
3274 return a TREE_LIST whose TREE_PURPOSE is a
3275 TYPE_PACK_EXPANSION containing the bases that will be
3276 initialized. The TREE_VALUE will be identical to the
3277 original TREE_VALUE, which is a list of arguments that will
3278 be passed to each base. We do not introduce any new pack
3279 expansion nodes into the TREE_VALUE (although it is possible
3280 that some already exist), because the TREE_PURPOSE and
3281 TREE_VALUE all need to be expanded together with the same
3282 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3283 resulting TREE_PURPOSE will mention the parameter packs in
3284 both the bases and the arguments to the bases. */
3285 tree purpose;
3286 tree value;
3289 /* Determine which parameter packs will be used by the base
3290 class expansion. */
3297 {
3301 }
3304 {
3305 /* Collect the sets of parameter packs used in each of the
3306 initialization arguments. */
3308 {
3309 /* Determine which parameter packs will be expanded in this
3310 argument. */
3313 }
3314 }
3318 /* Create the pack expansion type for the base type. */
3323 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3324 they will rarely be compared to anything. */
3328 }
3333 /* Build the PACK_EXPANSION_* node. */
3334 result = for_types
3339 {
3340 /* Propagate type and const-expression information. */
3343 }
3344 else
3345 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3346 they will rarely be compared to anything. */
3349 /* Determine which parameter packs will be expanded. */
3355 /* Make sure we found some parameter packs. */
3357 {
3360 else
3363 }
3369 }
3371 /* Checks T for any "bare" parameter packs, which have not yet been
3372 expanded, and issues an error if any are found. This operation can
3373 only be done on full expressions or types (e.g., an expression
3374 statement, "if" condition, etc.), because we could have expressions like:
3376 foo(f(g(h(args)))...)
3378 where "args" is a parameter pack. check_for_bare_parameter_packs
3379 should not be called for the subexpressions args, h(args),
3380 g(h(args)), or f(g(h(args))), because we would produce erroneous
3381 error messages.
3383 Returns TRUE and emits an error if there were bare parameter packs,
3384 returns FALSE otherwise. */
3385 bool
3387 {
3403 {
3406 {
3415 else
3420 else
3424 }
3427 }
3430 }
3432 /* Expand any parameter packs that occur in the template arguments in
3433 ARGS. */
3434 tree
3436 {
3442 /* First, determine if we need to expand anything, and the number of
3443 slots we'll need. */
3445 {
3450 {
3454 else
3456 }
3457 else
3458 {
3460 num_result_args++;
3461 }
3462 }
3464 /* If no expansion is necessary, we're done. */
3468 /* Expand arguments. */
3471 non_default_args_count =
3474 {
3477 {
3484 }
3485 else
3486 {
3489 }
3490 }
3494 }
3496 /* Checks if DECL shadows a template parameter.
3498 [temp.local]: A template-parameter shall not be redeclared within its
3499 scope (including nested scopes).
3501 Emits an error and returns TRUE if the DECL shadows a parameter,
3502 returns FALSE otherwise. */
3504 bool
3506 {
3507 tree olddecl;
3509 /* If we're not in a template, we can't possibly shadow a template
3510 parameter. */
3514 /* Figure out what we're shadowing. */
3519 /* If there's no previous binding for this name, we're not shadowing
3520 anything, let alone a template parameter. */
3524 /* If we're not shadowing a template parameter, we're done. Note
3525 that OLDDECL might be an OVERLOAD (or perhaps even an
3526 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3527 node. */
3531 /* We check for decl != olddecl to avoid bogus errors for using a
3532 name inside a class. We check TPFI to avoid duplicate errors for
3533 inline member templates. */
3539 /* Don't complain about the injected class name, as we've already
3540 complained about the class itself. */
3547 }
3549 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3550 ORIG_LEVEL, DECL, and TYPE. */
3552 static tree
3556 tree decl,
3557 tree type)
3558 {
3569 }
3571 /* Find the canonical type parameter for the given template type
3572 parameter. Returns the canonical type parameter, which may be TYPE
3573 if no such parameter existed. */
3575 static tree
3577 {
3578 tree list;
3592 else
3593 {
3598 }
3599 }
3601 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3602 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3603 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3604 new one is created. */
3606 static tree
3608 tsubst_flags_t complain)
3609 {
3614 {
3633 /* Template template parameters need this. */
3638 }
3641 }
3643 /* Process information from new template parameter PARM and append it
3644 to the LIST being built. This new parameter is a non-type
3645 parameter iff IS_NON_TYPE is true. This new parameter is a
3646 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3647 is in PARM_LOC. */
3649 tree
3652 {
3654 tree defval;
3661 {
3665 {
3669 else
3671 }
3674 }
3677 {
3683 {
3684 /* [temp.param]
3686 The top-level cv-qualifiers on the template-parameter are
3687 ignored when determining its type. */
3692 && !is_parameter_pack
3693 /* If we're in a nested template parameter list, the template
3694 template parameter could be a parameter pack. */
3696 {
3697 /* This template parameter is not a parameter pack, but it
3698 should be. Complain about "bare" parameter packs. */
3701 /* Recover by calling this a parameter pack. */
3703 }
3704 }
3706 /* A template parameter is not modifiable. */
3715 processing_template_decl,
3720 }
3721 else
3722 {
3723 tree t;
3727 {
3729 /* This is for distinguishing between real templates and template
3730 template parameters */
3734 }
3735 else
3736 {
3738 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3741 }
3748 processing_template_decl,
3752 }
3758 }
3760 /* The end of a template parameter list has been reached. Process the
3761 tree list into a parameter vector, converting each parameter into a more
3762 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3763 as PARM_DECLs. */
3765 tree
3767 {
3772 current_template_parms
3777 {
3781 }
3786 }
3788 /* end_template_decl is called after a template declaration is seen. */
3790 void
3792 {
3798 /* This matches the pushlevel in begin_template_parm_list. */
3803 }
3805 /* Takes a TREE_LIST representing a template parameter and convert it
3806 into an argument suitable to be passed to the type substitution
3807 functions. Note that If the TREE_LIST contains an error_mark
3808 node, the returned argument is error_mark_node. */
3810 static tree
3812 {
3825 {
3829 {
3830 /* Turn this argument into a TYPE_ARGUMENT_PACK
3831 with a single element, which expands T. */
3833 #ifdef ENABLE_CHECKING
3834 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3836 #endif
3841 }
3842 }
3843 else
3844 {
3848 {
3849 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3850 with a single element, which expands T. */
3853 #ifdef ENABLE_CHECKING
3854 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3856 #endif
3863 }
3864 else
3866 }
3868 }
3870 /* Given a set of template parameters, return them as a set of template
3871 arguments. The template parameters are represented as a TREE_VEC, in
3872 the form documented in cp-tree.h for template arguments. */
3874 static tree
3876 {
3877 tree header;
3882 /* If there is only one level of template parameters, we do not
3883 create a TREE_VEC of TREE_VECs. Instead, we return a single
3884 TREE_VEC containing the arguments. */
3889 {
3897 #ifdef ENABLE_CHECKING
3899 #endif
3903 else
3905 }
3908 /* This can happen for template parms of a template template
3909 parameter, e.g:
3911 template<template<class T, class U> class TT> struct S;
3913 Consider the level of the parms of TT; T and U both have
3914 level 2; TT has no template parm of level 1. So in this case
3915 the first element of full_template_args is NULL_TREE. If we
3916 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3917 of 2. This will make tsubst wrongly consider that T and U
3918 have level 1. Instead, let's create a dummy vector as the
3919 first element of full_template_args so that TMPL_ARGS_DEPTH
3920 returns the correct depth for args. */
3923 }
3925 /* Within the declaration of a template, return the currently active
3926 template parameters as an argument TREE_VEC. */
3928 static tree
3930 {
3932 }
3934 /* Update the declared TYPE by doing any lookups which were thought to be
3935 dependent, but are not now that we know the SCOPE of the declarator. */
3937 tree
3939 {
3950 /* Don't bother building up the args in this case. */
3952 {
3953 /* tsubst in the args corresponding to the template parameters,
3954 including auto if present. Most things will be unchanged, but
3955 make_typename_type and tsubst_qualified_id will resolve
3956 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3959 tree pushed;
3961 {
3965 }
3970 }
3976 {
3979 else
3981 }
3983 }
3985 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3986 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3987 a member template. Used by push_template_decl below. */
3989 static tree
3991 {
3999 }
4001 struct template_parm_data
4002 {
4003 /* The level of the template parameters we are currently
4004 processing. */
4007 /* The index of the specialization argument we are currently
4008 processing. */
4011 /* An array whose size is the number of template parameters. The
4012 elements are nonzero if the parameter has been used in any one
4013 of the arguments processed so far. */
4016 /* An array whose size is the number of template arguments. The
4017 elements are nonzero if the argument makes use of template
4018 parameters of this level. */
4020 };
4022 /* Subroutine of push_template_decl used to see if each template
4023 parameter in a partial specialization is used in the explicit
4024 argument list. If T is of the LEVEL given in DATA (which is
4025 treated as a template_parm_data*), then DATA->PARMS is marked
4026 appropriately. */
4028 static int
4030 {
4038 {
4041 }
4043 /* Return zero so that for_each_template_parm will continue the
4044 traversal of the tree; we want to mark *every* template parm. */
4046 }
4048 /* Process the partial specialization DECL. */
4050 static tree
4052 {
4058 tree inner_parms;
4059 tree inst;
4072 /* We check that each of the template parameters given in the
4073 partial specialization is used in the argument list to the
4074 specialization. For example:
4076 template <class T> struct S;
4077 template <class T> struct S<T*>;
4079 The second declaration is OK because `T*' uses the template
4080 parameter T, whereas
4082 template <class T> struct S<int>;
4084 is no good. Even trickier is:
4086 template <class T>
4087 struct S1
4088 {
4089 template <class U>
4090 struct S2;
4091 template <class U>
4092 struct S2<T>;
4093 };
4095 The S2<T> declaration is actually invalid; it is a
4096 full-specialization. Of course,
4098 template <class U>
4099 struct S2<T (*)(U)>;
4101 or some such would have been OK. */
4109 {
4114 NULL,
4116 }
4119 {
4120 /* One of the template parms was not used in a deduced context in the
4121 specialization. */
4123 {
4127 }
4131 }
4136 /* [temp.class.spec]
4138 The argument list of the specialization shall not be identical to
4139 the implicit argument list of the primary template. */
4146 /* A partial specialization that replaces multiple parameters of the
4147 primary template with a pack expansion is less specialized for those
4148 parameters. */
4150 {
4152 "primary template because it replaces multiple parameters "
4156 }
4158 /* [temp.class.spec]
4160 A partially specialized non-type argument expression shall not
4161 involve template parameters of the partial specialization except
4162 when the argument expression is a simple identifier.
4164 The type of a template parameter corresponding to a specialized
4165 non-type argument shall not be dependent on a parameter of the
4166 specialization.
4168 Also, we verify that pack expansions only occur at the
4169 end of the argument list. */
4173 {
4180 {
4181 /* Extract the arguments from the argument pack. We'll be
4182 iterating over these in the following loop. */
4185 }
4188 {
4190 /* Get the Jth argument in the parameter pack. */
4194 {
4195 /* Pack expansions must come at the end of the
4196 argument list. */
4199 {
4203 else
4206 }
4207 }
4210 /* We only care about the pattern. */
4216 /* This next two lines are the `argument expression is not just a
4217 simple identifier' condition and also the `specialized
4218 non-type argument' bit. */
4222 {
4226 arg);
4227 else
4228 {
4229 /* Look at the corresponding template parameter,
4230 marking which template parameters its type depends
4231 upon. */
4235 {
4236 /* We haven't yet initialized TPD2. Do so now. */
4238 /* The number of parameters here is the number in the
4239 main template, which, as checked in the assertion
4240 above, is NARGS. */
4244 }
4246 /* Mark the template parameters. But this time, we're
4247 looking for the template parameters of the main
4248 template, not in the specialization. */
4255 NULL,
4259 {
4260 /* The type depended on some template parameters.
4261 If they are fully specialized in the
4262 specialization, that's OK. */
4271 "type %qT of template argument %qE depends "
4273 "type %qT of template argument %qE depends "
4275 type,
4276 arg);
4277 }
4278 }
4279 }
4280 }
4281 }
4283 /* We should only get here once. */
4301 {
4305 {
4309 "partial specialization of %qT after instantiation "
4311 }
4312 }
4315 }
4317 /* PARM is a template parameter of some form; return the corresponding
4318 TEMPLATE_PARM_INDEX. */
4320 static tree
4322 {
4334 }
4336 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4337 parameter packs used by the template parameter PARM. */
4339 static void
4341 {
4342 /* A type parm can't refer to another parm. */
4346 {
4350 }
4357 }
4359 /* PARM is a template parameter pack. Return any parameter packs used in
4360 its type or the type of any of its template parameters. If there are
4361 any such packs, it will be instantiated into a fixed template parameter
4362 list by partial instantiation rather than be fully deduced. */
4364 tree
4366 {
4367 /* This can only be true in a member template. */
4370 /* This can only be true for a parameter pack. */
4373 /* A type parm can't refer to another parm. */
4386 }
4388 /* Check that a template declaration's use of default arguments and
4389 parameter packs is not invalid. Here, PARMS are the template
4390 parameters. IS_PRIMARY is true if DECL is the thing declared by
4391 a primary template. IS_PARTIAL is true if DECL is a partial
4392 specialization.
4394 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4395 declaration (but not a definition); 1 indicates a declaration, 2
4396 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4397 emitted for extraneous default arguments.
4399 Returns TRUE if there were no errors found, FALSE otherwise. */
4401 bool
4404 {
4407 tree parm_level;
4410 /* [temp.param]
4412 A default template-argument shall not be specified in a
4413 function template declaration or a function template definition, nor
4414 in the template-parameter-list of the definition of a member of a
4415 class template. */
4418 /* You can't have a function template declaration in a local
4419 scope, nor you can you define a member of a class template in a
4420 local scope. */
4426 /* A lambda doesn't have an explicit declaration; don't complain
4427 about the parms of the enclosing class. */
4434 /* If this is either a friend defined in the scope of the class
4435 or a member function. */
4441 /* And, if it was a member function, it really was defined in
4442 the scope of the class. */
4445 /* We already checked these parameters when the template was
4446 declared, so there's no need to do it again now. This function
4447 was defined in class scope, but we're processing its body now
4448 that the class is complete. */
4451 /* Core issue 226 (C++0x only): the following only applies to class
4452 templates. */
4455 {
4456 /* [temp.param]
4458 If a template-parameter has a default template-argument, all
4459 subsequent template-parameters shall have a default
4460 template-argument supplied. */
4462 {
4469 {
4479 {
4481 /* For better subsequent error-recovery, we indicate that
4482 there should have been a default argument. */
4485 }
4487 && !is_friend_decl
4488 /* Don't complain about an enclosing partial
4489 specialization. */
4494 /* A fixed parameter pack will be partially
4495 instantiated into a fixed length list. */
4497 {
4498 /* A primary class template can only have one
4499 parameter pack, at the end of the template
4500 parameter list. */
4505 else
4513 }
4514 }
4515 }
4516 }
4519 || is_partial
4520 || !is_primary
4522 /* For an ordinary class template, default template arguments are
4523 allowed at the innermost level, e.g.:
4524 template <class T = int>
4525 struct S {};
4526 but, in a partial specialization, they're not allowed even
4527 there, as we have in [temp.class.spec]:
4529 The template parameter list of a specialization shall not
4530 contain default template argument values.
4532 So, for a partial specialization, or for a function template
4533 (in C++98/C++03), we look at all of them. */
4534 ;
4535 else
4536 /* But, for a primary class template that is not a partial
4537 specialization we look at all template parameters except the
4538 innermost ones. */
4541 /* Figure out what error message to issue. */
4554 else
4558 /* If we're inside a class definition, there's no need to
4559 examine the parameters to the class itself. On the one
4560 hand, they will be checked when the class is defined, and,
4561 on the other, default arguments are valid in things like:
4562 template <class T = double>
4563 struct S { template <class U> void f(U); };
4564 Here the default argument for `S' has no bearing on the
4565 declaration of `f'. */
4567 else
4568 /* Check everything. */
4574 {
4581 {
4586 {
4588 {
4595 }
4597 /* Clear out the default argument so that we are not
4598 confused later. */
4600 }
4601 }
4603 /* At this point, if we're still interested in issuing messages,
4604 they must apply to classes surrounding the object declared. */
4608 }
4611 }
4613 /* Worker for push_template_decl_real, called via
4614 for_each_template_parm. DATA is really an int, indicating the
4615 level of the parameters we are interested in. If T is a template
4616 parameter of that level, return nonzero. */
4618 static int
4620 {
4626 else
4629 }
4631 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4632 parameters given by current_template_args, or reuses a
4633 previously existing one, if appropriate. Returns the DECL, or an
4634 equivalent one, if it is replaced via a call to duplicate_decls.
4636 If IS_FRIEND is true, DECL is a friend declaration. */
4638 tree
4640 {
4641 tree tmpl;
4642 tree args;
4643 tree info;
4644 tree ctx;
4648 /* True if the template is a member template, in the sense of
4649 [temp.mem]. */
4655 /* See if this is a partial specialization. */
4664 /* For a friend, we want the context of the friend function, not
4665 the type of which it is a friend. */
4669 /* In the case of a virtual function, we want the class in which
4670 it is defined. */
4672 else
4673 /* Otherwise, if we're currently defining some class, the DECL
4674 is assumed to be a member of the class. */
4683 /* See if this is a primary template. */
4686 /* A friend template that specifies a class context, i.e.
4687 template <typename T> friend void A<T>::f();
4688 is not primary. */
4690 else
4694 {
4699 {
4702 }
4704 {
4706 {
4707 /* [temp.mem]
4709 A destructor shall not be a member template. */
4712 }
4719 {
4720 /* [basic.stc.dynamic.allocation]
4722 An allocation function can be a function
4723 template. ... Template allocation functions shall
4724 have two or more parameters. */
4727 }
4728 }
4734 /* alias-declaration */
4736 else
4737 {
4740 }
4741 }
4743 /* Check to see that the rules regarding the use of default
4744 arguments are not being violated. */
4748 /* Ensure that there are no parameter packs in the type of this
4749 declaration that have not been expanded. */
4751 {
4752 /* Check each of the arguments individually to see if there are
4753 any bare parameter packs. */
4759 {
4762 {
4763 /* This is a PARM_DECL that contains unexpanded parameter
4764 packs. We have already complained about this in the
4765 check_for_bare_parameter_packs call, so just replace
4766 these types with ERROR_MARK_NODE. */
4769 }
4773 }
4775 /* Check for bare parameter packs in the return type and the
4776 exception specifiers. */
4778 /* Errors were already issued, set return type to int
4779 as the frontend doesn't expect error_mark_node as
4780 the return type. */
4784 }
4789 {
4792 }
4805 {
4810 /* If DECL is a TYPE_DECL for a class-template, then there won't
4811 be DECL_LANG_SPECIFIC. The information equivalent to
4812 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4816 {
4817 /* Since a template declaration already existed for this
4818 class-type, we must be redeclaring it here. Make sure
4819 that the redeclaration is valid. */
4821 current_template_parms);
4822 /* We don't need to create a new TEMPLATE_DECL; just use the
4823 one we already had. */
4825 }
4826 else
4827 {
4829 member_template_p);
4834 {
4835 /* A specialization of a member template of a template
4836 class. */
4840 }
4841 }
4842 }
4843 else
4844 {
4850 {
4853 }
4861 {
4862 tree new_tmpl;
4864 /* The declaration is a specialization of a member
4865 template, declared outside the class. Therefore, the
4866 innermost template arguments will be NULL, so we
4867 replace them with the arguments determined by the
4868 earlier call to check_explicit_specialization. */
4871 new_tmpl
4873 member_template_p);
4883 args,
4886 }
4888 /* Make sure the template headers we got make sense. */
4893 {
4898 }
4899 else
4901 {
4906 {
4910 else
4914 /* Avoid crash in import_export_decl. */
4917 }
4922 /* Can happen in erroneous input. */
4924 else
4926 }
4928 /* Check that the parms are used in the appropriate qualifying scopes
4929 in the declarator. */
4933 {
4939 /* Avoid crash in import_export_decl. */
4942 }
4943 }
4948 /* Push template declarations for global functions and types. Note
4949 that we do not try to push a global template friend declared in a
4950 template class; such a thing may well depend on the template
4951 parameters of the class. */
4954 {
4959 /* Hide template friend classes that haven't been declared yet. */
4961 {
4964 }
4965 }
4968 {
4974 {
4977 /* It is a conversion operator. See if the type converted to
4978 depends on innermost template operands. */
4981 depth))
4983 }
4985 /* Give template template parms a DECL_CONTEXT of the template
4986 for which they are a parameter. */
4989 {
4993 }
4994 }
4996 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4997 back to its most general template. If TMPL is a specialization,
4998 ARGS may only have the innermost set of arguments. Add the missing
4999 argument levels if necessary. */
5007 else
5008 {
5013 }
5016 }
5018 tree
5020 {
5022 }
5024 /* FN is an inheriting constructor that inherits from the constructor
5025 template INHERITED; turn FN into a constructor template with a matching
5026 template header. */
5028 tree
5030 {
5031 tree inner_parms
5034 tree parms
5045 }
5047 /* Called when a class template TYPE is redeclared with the indicated
5048 template PARMS, e.g.:
5050 template <class T> struct S;
5051 template <class T> struct S {}; */
5053 bool
5055 {
5056 tree tmpl;
5057 tree tmpl_parms;
5061 {
5064 }
5068 /* The type is nested in some template class. Nothing to worry
5069 about here; there are no new template parameters for the nested
5070 type. */
5074 {
5076 tmpl);
5078 }
5084 {
5094 }
5097 {
5098 tree tmpl_parm;
5099 tree parm;
5100 tree tmpl_default;
5101 tree parm_default;
5115 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5116 TEMPLATE_DECL. */
5126 {
5130 }
5133 {
5134 /* We have in [temp.param]:
5136 A template-parameter may not be given default arguments
5137 by two different declarations in the same scope. */
5142 }
5145 /* Update the previous template parameters (which are the ones
5146 that will really count) with the new default value. */
5149 /* Update the new parameters, too; they'll be used as the
5150 parameters for any members. */
5152 }
5155 }
5157 /* Simplify EXPR if it is a non-dependent expression. Returns the
5158 (possibly simplified) expression. */
5160 tree
5162 {
5166 /* If we're in a template, but EXPR isn't value dependent, simplify
5167 it. We're supposed to treat:
5169 template <typename T> void f(T[1 + 1]);
5170 template <typename T> void f(T[2]);
5172 as two declarations of the same function, for example. */
5176 {
5177 HOST_WIDE_INT saved_processing_template_decl;
5183 complain,
5188 }
5190 }
5192 tree
5194 {
5196 }
5198 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5199 template declaration, or a TYPE_DECL for an alias declaration. */
5201 bool
5203 {
5211 }
5213 /* Return TRUE iff is a specialization of an alias template. */
5215 bool
5217 {
5225 }
5227 /* Return the number of innermost template parameters in TMPL. */
5229 static int
5231 {
5234 }
5236 /* Return either TMPL or another template that it is equivalent to under DR
5237 1286: An alias that just changes the name of a template is equivalent to
5238 the other template. */
5240 static tree
5242 {
5245 {
5248 {
5253 {
5254 tree alias_args = INNERMOST_TEMPLATE_ARGS
5258 /* The alias type is equivalent to the pattern of the
5259 underlying template, so strip the alias. */
5262 }
5263 }
5265 }
5267 }
5269 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5270 must be a function or a pointer-to-function type, as specified
5271 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5272 and check that the resulting function has external linkage. */
5274 static tree
5276 tsubst_flags_t complain)
5277 {
5280 linkage_kind linkage;
5292 /* [temp.arg.nontype]/1
5294 A template-argument for a non-type, non-template template-parameter
5295 shall be one of:
5296 [...]
5297 -- the address of an object or function with external [C++11: or
5298 internal] linkage. */
5301 {
5303 {
5309 else
5312 }
5314 }
5318 {
5320 {
5325 else
5329 }
5331 }
5334 }
5336 /* Subroutine of convert_nontype_argument.
5337 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5338 Emit an error otherwise. */
5340 static bool
5342 tsubst_flags_t complain)
5343 {
5350 {
5354 }
5356 }
5358 /* Returns TRUE iff the address of OP is value-dependent.
5360 14.6.2.4 [temp.dep.temp]:
5361 A non-integral non-type template-argument is dependent if its type is
5362 dependent or it has either of the following forms
5363 qualified-id
5364 & qualified-id
5365 and contains a nested-name-specifier which specifies a class-name that
5366 names a dependent type.
5368 We generalize this to just say that the address of a member of a
5369 dependent class is value-dependent; the above doesn't cover the
5370 address of a static data member named with an unqualified-id. */
5372 static bool
5374 {
5375 /* We could use get_inner_reference here, but there's no need;
5376 this is only relevant for template non-type arguments, which
5377 can only be expressed as &id-expression. */
5379 {
5383 }
5386 }
5388 /* The next set of functions are used for providing helpful explanatory
5389 diagnostics for failed overload resolution. Their messages should be
5390 indented by two spaces for consistency with the messages in
5391 call.c */
5393 static int
5395 {
5397 }
5399 static int
5401 {
5406 }
5408 static int
5410 {
5412 }
5414 static int
5416 {
5422 }
5424 static int
5426 {
5430 }
5432 static int
5434 {
5437 " template parameter %qD is not a parameter pack, but "
5441 }
5443 static int
5445 {
5448 " template argument %qE does not match "
5452 }
5454 static int
5456 {
5460 }
5462 static int
5464 {
5470 }
5472 static int
5474 {
5476 {
5481 else
5483 " deduced conflicting values for non-type parameter "
5485 }
5487 }
5489 static int
5491 {
5494 " variable-sized array type %qT is not "
5496 arg);
5498 }
5500 static int
5502 {
5506 arg);
5508 }
5510 static int
5512 {
5519 }
5521 static int
5523 {
5525 }
5527 static int
5529 {
5531 }
5533 static int
5536 {
5542 }
5544 static int
5547 {
5550 {
5558 }
5560 }
5562 static int
5564 {
5567 " template parameters of a template template argument are "
5570 }
5572 static int
5574 {
5580 }
5582 static int
5584 {
5589 }
5591 static int
5593 {
5597 arg);
5599 }
5601 /* Attempt to convert the non-type template parameter EXPR to the
5602 indicated TYPE. If the conversion is successful, return the
5603 converted value. If the conversion is unsuccessful, return
5604 NULL_TREE if we issued an error message, or error_mark_node if we
5605 did not. We issue error messages for out-and-out bad template
5606 parameters, but not simply because the conversion failed, since we
5607 might be just trying to do argument deduction. Both TYPE and EXPR
5608 must be non-dependent.
5610 The conversion follows the special rules described in
5611 [temp.arg.nontype], and it is much more strict than an implicit
5612 conversion.
5614 This function is called twice for each template argument (see
5615 lookup_template_class for a more accurate description of this
5616 problem). This means that we need to handle expressions which
5617 are not valid in a C++ source, but can be created from the
5618 first call (for instance, casts to perform conversions). These
5619 hacks can go away after we fix the double coercion problem. */
5621 static tree
5623 {
5624 tree expr_type;
5626 /* Detect immediately string literals as invalid non-type argument.
5627 This special-case is not needed for correctness (we would easily
5628 catch this later), but only to provide better diagnostic for this
5629 common user mistake. As suggested by DR 100, we do not mention
5630 linkage issues in the diagnostic as this is not the point. */
5631 /* FIXME we're making this OK. */
5633 {
5639 }
5641 /* Add the ADDR_EXPR now for the benefit of
5642 value_dependent_expression_p. */
5645 {
5649 }
5651 /* If we are in a template, EXPR may be non-dependent, but still
5652 have a syntactic, rather than semantic, form. For example, EXPR
5653 might be a SCOPE_REF, rather than the VAR_DECL to which the
5654 SCOPE_REF refers. Preserving the qualifying scope is necessary
5655 so that access checking can be performed when the template is
5656 instantiated -- but here we need the resolved form so that we can
5657 convert the argument. */
5668 else
5671 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5672 to a non-type argument of "nullptr". */
5676 /* In C++11, integral or enumeration non-type template arguments can be
5677 arbitrary constant expressions. Pointer and pointer to
5678 member arguments can be general constant expressions that evaluate
5679 to a null value, but otherwise still need to be of a specific form. */
5681 {
5683 /* A PTRMEM_CST is already constant, and a valid template
5684 argument for a parameter of pointer to member type, we just want
5685 to leave it in that form rather than lower it to a
5690 {
5695 }
5696 }
5698 /* HACK: Due to double coercion, we can get a
5699 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5700 which is the tree that we built on the first call (see
5701 below when coercing to reference to object or to reference to
5702 function). We just strip everything and get to the arg.
5703 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5704 for examples. */
5706 {
5712 {
5713 /* ??? Maybe we could use convert_from_reference here, but we
5714 would need to relax its constraints because the NOP_EXPR
5715 could actually change the type to something more cv-qualified,
5716 and this is not folded by convert_from_reference. */
5721 && (same_type_ignoring_top_level_qualifiers_p
5724 {
5727 }
5728 }
5729 }
5731 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5732 parameter is a pointer to object, through decay and
5733 qualification conversion. Let's strip everything. */
5735 {
5740 {
5741 /* Skip the ADDR_EXPR only if it is part of the decay for
5742 an array. Otherwise, it is part of the original argument
5743 in the source code. */
5748 }
5749 }
5751 /* [temp.arg.nontype]/5, bullet 1
5753 For a non-type template-parameter of integral or enumeration type,
5754 integral promotions (_conv.prom_) and integral conversions
5755 (_conv.integral_) are applied. */
5757 {
5766 /* Notice that there are constant expressions like '4 % 0' which
5767 do not fold into integer constants. */
5769 {
5771 {
5782 /* else cxx_constant_value complained but gave us
5783 a real constant, so go ahead. */
5785 }
5786 else
5788 }
5790 /* Avoid typedef problems. */
5793 }
5794 /* [temp.arg.nontype]/5, bullet 2
5796 For a non-type template-parameter of type pointer to object,
5797 qualification conversions (_conv.qual_) and the array-to-pointer
5798 conversion (_conv.array_) are applied. */
5800 {
5801 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5803 A template-argument for a non-type, non-template template-parameter
5804 shall be one of: [...]
5806 -- the name of a non-type template-parameter;
5807 -- the address of an object or function with external linkage, [...]
5808 expressed as "& id-expression" where the & is optional if the name
5809 refers to a function or array, or if the corresponding
5810 template-parameter is a reference.
5812 Here, we do not care about functions, as they are invalid anyway
5813 for a parameter of type pointer-to-object. */
5816 /* Non-type template parameters are OK. */
5817 ;
5822 {
5824 {
5827 "because %qD is a variable, not the address of "
5830 }
5832 {
5838 }
5839 /* Other values, like integer constants, might be valid
5840 non-type arguments of some other type. */
5842 }
5843 else
5844 {
5845 tree decl;
5850 {
5855 }
5857 {
5863 }
5865 {
5870 }
5871 }
5880 }
5881 /* [temp.arg.nontype]/5, bullet 3
5883 For a non-type template-parameter of type reference to object, no
5884 conversions apply. The type referred to by the reference may be more
5885 cv-qualified than the (otherwise identical) type of the
5886 template-argument. The template-parameter is bound directly to the
5887 template-argument, which must be an lvalue. */
5889 {
5891 expr_type))
5895 {
5900 }
5903 {
5908 }
5910 /* [temp.arg.nontype]/1
5912 A template-argument for a non-type, non-template template-parameter
5913 shall be one of: [...]
5915 -- the address of an object or function with external linkage. */
5918 {
5921 {
5924 "because a reference variable does not have a constant "
5927 }
5928 }
5931 {
5937 }
5940 {
5946 }
5949 }
5950 /* [temp.arg.nontype]/5, bullet 4
5952 For a non-type template-parameter of type pointer to function, only
5953 the function-to-pointer conversion (_conv.func_) is applied. If the
5954 template-argument represents a set of overloaded functions (or a
5955 pointer to such), the matching function is selected from the set
5956 (_over.over_). */
5958 {
5959 /* If the argument is a template-id, we might not have enough
5960 context information to decay the pointer. */
5962 {
5966 }
5969 /* Null pointer values are OK in C++11. */
5975 }
5976 /* [temp.arg.nontype]/5, bullet 5
5978 For a non-type template-parameter of type reference to function, no
5979 conversions apply. If the template-argument represents a set of
5980 overloaded functions, the matching function is selected from the set
5981 (_over.over_). */
5983 {
5985 {
5987 {
5992 }
5994 }
6001 }
6002 /* [temp.arg.nontype]/5, bullet 6
6004 For a non-type template-parameter of type pointer to member function,
6005 no conversions apply. If the template-argument represents a set of
6006 overloaded member functions, the matching member function is selected
6007 from the set (_over.over_). */
6009 {
6014 /* [temp.arg.nontype] bullet 1 says the pointer to member
6015 expression must be a pointer-to-member constant. */
6019 /* There is no way to disable standard conversions in
6020 resolve_address_of_overloaded_function (called by
6021 instantiate_type). It is possible that the call succeeded by
6022 converting &B::I to &D::I (where B is a base of D), so we need
6023 to reject this conversion here.
6025 Actually, even if there was a way to disable standard conversions,
6026 it would still be better to reject them here so that we can
6027 provide a superior diagnostic. */
6029 {
6031 {
6035 /* If we are just one standard conversion off, explain. */
6039 }
6041 }
6042 }
6043 /* [temp.arg.nontype]/5, bullet 7
6045 For a non-type template-parameter of type pointer to data member,
6046 qualification conversions (_conv.qual_) are applied. */
6048 {
6049 /* [temp.arg.nontype] bullet 1 says the pointer to member
6050 expression must be a pointer-to-member constant. */
6057 }
6059 {
6061 {
6066 }
6068 }
6069 /* A template non-type parameter must be one of the above. */
6070 else
6073 /* Sanity check: did we actually convert the argument to the
6074 right type? */
6078 }
6080 /* Subroutine of coerce_template_template_parms, which returns 1 if
6081 PARM_PARM and ARG_PARM match using the rule for the template
6082 parameters of template template parameters. Both PARM and ARG are
6083 template parameters; the rest of the arguments are the same as for
6084 coerce_template_template_parms.
6085 */
6086 static int
6088 tree arg,
6089 tsubst_flags_t complain,
6090 tree in_decl,
6091 tree outer_args)
6092 {
6101 {
6103 /* We encounter instantiations of templates like
6104 template <template <template <class> class> class TT>
6105 class C; */
6106 {
6113 }
6114 /* Fall through. */
6119 /* Argument is a parameter pack but parameter is not. */
6124 /* The tsubst call is used to handle cases such as
6126 template <int> class C {};
6127 template <class T, template <T> class TT> class D {};
6128 D<int, C> d;
6130 i.e. the parameter list of TT depends on earlier parameters. */
6132 && !same_type_p
6139 /* Argument is a parameter pack but parameter is not. */
6146 }
6149 }
6152 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6153 template template parameters. Both PARM_PARMS and ARG_PARMS are
6154 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6155 or PARM_DECL.
6157 Consider the example:
6158 template <class T> class A;
6159 template<template <class U> class TT> class B;
6161 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6162 the parameters to A, and OUTER_ARGS contains A. */
6164 static int
6166 tree arg_parms,
6167 tsubst_flags_t complain,
6168 tree in_decl,
6169 tree outer_args)
6170 {
6181 /* Determine whether we have a parameter pack at the end of the
6182 template template parameter's template parameter list. */
6184 {
6191 {
6205 }
6206 }
6212 /* Check all of the template parameters except the parameter pack at
6213 the end (if any). */
6215 {
6224 outer_args))
6227 }
6230 {
6231 /* Check each of the template parameters in the template
6232 argument against the template parameter pack at the end of
6233 the template template parameter. */
6240 {
6247 outer_args))
6249 }
6250 }
6253 }
6255 /* Verifies that the deduced template arguments (in TARGS) for the
6256 template template parameters (in TPARMS) represent valid bindings,
6257 by comparing the template parameter list of each template argument
6258 to the template parameter list of its corresponding template
6259 template parameter, in accordance with DR150. This
6260 routine can only be called after all template arguments have been
6261 deduced. It will return TRUE if all of the template template
6262 parameter bindings are okay, FALSE otherwise. */
6263 bool
6265 {
6269 /* We're dealing with template parms in this process. */
6275 {
6280 {
6285 {
6286 /* Look inside the argument pack. */
6289 }
6292 {
6296 /* Extract the next argument from the argument
6297 pack. */
6301 /* Look at the pattern of the pack expansion. */
6304 /* Extract the template parameters from the template
6305 argument. */
6311 /* Verify that we can coerce the template template
6312 parameters from the template argument to the template
6313 parameter. This requires an exact match. */
6315 && !coerce_template_template_parms
6317 targ_parms,
6318 tf_none,
6319 tparm,
6320 targs))
6321 {
6324 }
6325 }
6326 }
6327 }
6329 out:
6333 }
6335 /* Since type attributes aren't mangled, we need to strip them from
6336 template type arguments. */
6338 static tree
6340 {
6341 tree mv;
6348 {
6353 }
6355 }
6357 /* Convert the indicated template ARG as necessary to match the
6358 indicated template PARM. Returns the converted ARG, or
6359 error_mark_node if the conversion was unsuccessful. Error and
6360 warning messages are issued under control of COMPLAIN. This
6361 conversion is for the Ith parameter in the parameter list. ARGS is
6362 the full set of template arguments deduced so far. */
6364 static tree
6366 tree arg,
6367 tree args,
6368 tsubst_flags_t complain,
6370 tree in_decl)
6371 {
6372 tree orig_arg;
6373 tree val;
6378 {
6379 /* The template argument was the name of some
6380 member function. That's usually
6381 invalid, but static members are OK. In any
6382 case, grab the underlying fields/functions
6383 and issue an error later if required. */
6386 }
6394 /* When determining whether an argument pack expansion is a template,
6395 look at the pattern. */
6399 /* Deal with an injected-class-name used as a template template arg. */
6401 {
6404 {
6414 }
6415 }
6417 is_tmpl_type =
6433 {
6435 {
6439 }
6442 "to refer to a type member of a template parameter, "
6447 typename_type,
6448 complain);
6451 }
6453 {
6455 {
6457 {
6467 else
6469 }
6470 }
6472 }
6474 {
6476 {
6482 else
6484 }
6486 }
6489 {
6491 {
6495 /* The number of argument required is not known yet.
6496 Just accept it for now. */
6498 else
6499 {
6501 tree argparm;
6503 /* Strip alias templates that are equivalent to another
6504 template. */
6510 args))
6511 {
6514 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6515 TEMPLATE_DECL. */
6517 {
6522 }
6523 }
6524 else
6525 {
6527 {
6533 }
6536 }
6537 }
6538 }
6539 else
6541 /* We only form one instance of each template specialization.
6542 Therefore, if we use a non-canonical variant (i.e., a
6543 typedef), any future messages referring to the type will use
6544 the typedef, which is confusing if those future uses do not
6545 themselves also use the typedef. */
6548 }
6549 else
6550 {
6557 {
6560 else
6561 {
6562 /* Not sure if this is reachable, but it doesn't hurt
6563 to be robust. */
6566 }
6567 }
6570 /* We used to call digest_init here. However, digest_init
6571 will report errors, which we don't want when complain
6572 is zero. More importantly, digest_init will try too
6573 hard to convert things: for example, `0' should not be
6574 converted to pointer type at this point according to
6575 the standard. Accepting this is not merely an
6576 extension, since deciding whether or not these
6577 conversions can occur is part of determining which
6578 function template to call, or whether a given explicit
6579 argument specification is valid. */
6581 else
6590 {
6591 /* Strip typedefs from the SCOPE_REF. */
6594 complain);
6597 }
6598 }
6601 }
6603 /* Coerces the remaining template arguments in INNER_ARGS (from
6604 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6605 Returns the coerced argument pack. PARM_IDX is the position of this
6606 parameter in the template parameter list. ARGS is the original
6607 template argument list. */
6608 static tree
6611 tree args,
6612 tree inner_args,
6614 tree new_args,
6616 tree in_decl,
6617 tsubst_flags_t complain)
6618 {
6621 tree packed_args;
6622 tree argument_pack;
6629 {
6630 /* When the template parameter is a non-type template parameter pack
6631 or template template parameter pack whose type or template
6632 parameters use parameter packs, we know exactly how many arguments
6633 we are looking for. Build a vector of the instantiated decls for
6634 these template parameters in PACKED_PARMS. */
6635 /* We can't use make_pack_expansion here because it would interpret a
6636 _DECL as a use rather than a declaration. */
6650 /* If we're doing a partial instantiation of a member template,
6651 verify that all of the types used for the non-type
6652 template parameter pack are, in fact, valid for non-type
6653 template parameters. */
6656 {
6659 {
6663 }
6664 }
6667 }
6668 else
6671 /* Convert the remaining arguments, which will be a part of the
6672 parameter pack "parm". */
6674 {
6680 {
6681 /* Once we've packed as many args as we have types, stop. */
6685 /* We don't know how many args we have yet, just
6686 use the unconverted ones for now. */
6688 else
6690 }
6693 {
6696 }
6697 else
6700 in_decl);
6704 }
6708 {
6713 }
6718 else
6719 {
6724 }
6727 #ifdef ENABLE_CHECKING
6730 #endif
6732 }
6734 /* Returns the number of pack expansions in the template argument vector
6735 ARGS. */
6737 static int
6739 {
6744 {
6748 }
6750 }
6752 /* Convert all template arguments to their appropriate types, and
6753 return a vector containing the innermost resulting template
6754 arguments. If any error occurs, return error_mark_node. Error and
6755 warning messages are issued under control of COMPLAIN.
6757 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6758 for arguments not specified in ARGS. Otherwise, if
6759 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6760 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6761 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6762 ARGS. */
6764 static tree
6766 tree args,
6767 tree in_decl,
6768 tsubst_flags_t complain,
6771 {
6773 tree orig_inner_args;
6774 tree inner_args;
6775 tree new_args;
6776 tree new_inner_args;
6780 /* When used as a boolean value, indicates whether this is a
6781 variadic template parameter list. Since it's an int, we can also
6782 subtract it from nparms to get the number of non-variadic
6783 parameters. */
6793 /* Determine if there are any parameter packs. */
6795 {
6801 }
6804 /* If there are no parameters that follow a parameter pack, we need to
6805 expand any argument packs so that we can deduce a parameter pack from
6806 some non-packed args followed by an argument pack, as in variadic85.C.
6807 If there are such parameters, we need to leave argument packs intact
6808 so the arguments are assigned properly. This can happen when dealing
6809 with a nested class inside a partial specialization of a class
6810 template, as in variadic92.C, or when deducing a template parameter pack
6811 from a sub-declarator, as in variadic114.C. */
6815 /* Count any pack expansion args. */
6821 && require_all_args
6822 && !variadic_args_p
6823 && (!use_default_args
6826 {
6828 {
6830 {
6834 }
6835 else
6841 }
6844 }
6845 /* We can't pass a pack expansion to a non-pack parameter of an alias
6846 template (DR 1430). */
6848 && variadic_args_p
6850 {
6852 {
6854 {
6860 {
6865 }
6866 }
6868 found:;
6869 }
6871 }
6873 /* We need to evaluate the template arguments, even though this
6874 template-id may be nested within a "sizeof". */
6883 {
6884 tree arg;
6885 tree parm;
6887 /* Get the Ith template parameter. */
6891 {
6894 }
6896 /* Calculate the next argument. */
6899 else
6904 {
6905 /* Some arguments will be placed in the
6906 template parameter pack PARM. */
6913 {
6914 /* We don't know how many args we have yet, just use the
6915 unconverted (and still packed) ones for now. */
6919 }
6923 /* Store this argument. */
6925 {
6926 lost++;
6927 /* We are done with all of the arguments. */
6929 }
6930 else
6931 {
6934 }
6937 }
6939 {
6941 {
6942 /* "If every valid specialization of a variadic template
6943 requires an empty template parameter pack, the template is
6944 ill-formed, no diagnostic required." So check that the
6945 pattern works with this parameter. */
6950 in_decl);
6952 {
6956 }
6958 /* Recover from missing typename. */
6962 /* We don't know how many args we have yet, just
6963 use the unconverted ones for now. */
6967 }
6968 }
6970 {
6971 /* There must be a default arg in this case. */
6974 /* The position of the first default template argument,
6975 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6976 Record that. */
6980 }
6981 else
6985 {
6988 }
6990 /* This only occurs if there was an error in the template
6991 parameter list itself (which we would already have
6992 reported) that we are trying to recover from, e.g., a class
6993 template with a parameter list such as
6994 template<typename..., typename>. */
6996 else
7002 lost++;
7004 }
7009 {
7011 {
7016 }
7018 }
7023 #ifdef ENABLE_CHECKING
7027 #endif
7030 }
7032 /* Like coerce_template_parms. If PARMS represents all template
7033 parameters levels, this function returns a vector of vectors
7034 representing all the resulting argument levels. Note that in this
7035 case, only the innermost arguments are coerced because the
7036 outermost ones are supposed to have been coerced already.
7038 Otherwise, if PARMS represents only (the innermost) vector of
7039 parameters, this function returns a vector containing just the
7040 innermost resulting arguments. */
7042 static tree
7044 tree args,
7045 tree in_decl,
7046 tsubst_flags_t complain,
7049 {
7052 tree coerced_args;
7055 {
7057 tree level;
7063 {
7064 tree l;
7068 require_all_args,
7069 use_default_args);
7070 else
7077 }
7078 }
7079 else
7082 require_all_args,
7083 use_default_args);
7085 }
7087 /* Returns 1 if template args OT and NT are equivalent. */
7089 static int
7091 {
7098 /* For member templates */
7107 {
7124 }
7126 {
7127 /* We get here probably because we are in the middle of substituting
7128 into the pattern of a pack expansion. In that case the
7129 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7130 interested in. So we want to use the initial pack argument for
7131 the comparison. */
7136 }
7141 else
7143 }
7145 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7146 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7147 NEWARG_PTR with the offending arguments if they are non-NULL. */
7149 static int
7152 {
7165 {
7170 {
7176 }
7177 }
7179 }
7181 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7182 of template arguments. Returns 0 otherwise. */
7184 int
7186 {
7188 }
7190 static void
7192 {
7202 /* We are called both from instantiate_decl, where we've already had a
7203 tinst_level pushed, and instantiate_template, where we haven't.
7204 Compensate. */
7215 else
7224 }
7227 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7228 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7229 documentation for TEMPLATE_ID_EXPR. */
7231 tree
7233 {
7234 tree type;
7242 {
7245 }
7248 {
7250 unknown_type_node,
7252 arglist);
7254 }
7261 }
7263 /* Within the scope of a template class S<T>, the name S gets bound
7264 (in build_self_reference) to a TYPE_DECL for the class, not a
7265 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7266 or one of its enclosing classes, and that type is a template,
7267 return the associated TEMPLATE_DECL. Otherwise, the original
7268 DECL is returned.
7270 Also handle the case when DECL is a TREE_LIST of ambiguous
7271 injected-class-names from different bases. */
7273 tree
7275 {
7279 /* DR 176: A lookup that finds an injected-class-name (10.2
7280 [class.member.lookup]) can result in an ambiguity in certain cases
7281 (for example, if it is found in more than one base class). If all of
7282 the injected-class-names that are found refer to specializations of
7283 the same class template, and if the name is followed by a
7284 template-argument-list, the reference refers to the class template
7285 itself and not a specialization thereof, and is not ambiguous. */
7287 {
7290 {
7296 }
7299 else
7301 }
7307 }
7309 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7310 parameters, find the desired type.
7312 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7314 IN_DECL, if non-NULL, is the template declaration we are trying to
7315 instantiate.
7317 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7318 the class we are looking up.
7320 Issue error and warning messages under control of COMPLAIN.
7322 If the template class is really a local class in a template
7323 function, then the FUNCTION_CONTEXT is the function in which it is
7324 being instantiated.
7326 ??? Note that this function is currently called *twice* for each
7327 template-id: the first time from the parser, while creating the
7328 incomplete type (finish_template_type), and the second type during the
7329 real instantiation (instantiate_template_class). This is surely something
7330 that we want to avoid. It also causes some problems with argument
7331 coercion (see convert_nontype_argument for more information on this). */
7333 static tree
7336 {
7338 tree t;
7341 spec_entry elt;
7342 hashval_t hash;
7345 {
7349 else
7350 {
7357 }
7360 }
7362 {
7365 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7366 an implicit typename for the second A. Deal with it. */
7371 {
7374 }
7375 }
7378 {
7381 }
7385 {
7389 }
7391 {
7394 }
7396 /* Issue an error message if we didn't find a template. */
7398 {
7402 }
7405 /* Make sure it's a user visible template, if it was named by
7406 the user. */
7409 {
7411 {
7415 }
7417 }
7421 /* An alias that just changes the name of a template is equivalent to the
7422 other template, so if any of the arguments are pack expansions, strip
7423 the alias to avoid problems with a pack expansion passed to a non-pack
7424 alias template parameter (DR 1430). */
7429 {
7430 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7431 template arguments */
7433 tree parm;
7434 tree arglist2;
7435 tree outer;
7439 /* Consider an example where a template template parameter declared as
7441 template <class T, class U = std::allocator<T> > class TT
7443 The template parameter level of T and U are one level larger than
7444 of TT. To proper process the default argument of U, say when an
7445 instantiation `TT<int>' is seen, we need to build the full
7446 arguments containing {int} as the innermost level. Outer levels,
7447 available when not appearing as default template argument, can be
7448 obtained from the arguments of the enclosing template.
7450 Suppose that TT is later substituted with std::vector. The above
7451 instantiation is `TT<int, std::allocator<T> >' with TT at
7452 level 1, and T at level 2, while the template arguments at level 1
7453 becomes {std::vector} and the inner level 2 is {int}. */
7459 /* This is an argument of the current template, so we haven't set
7460 DECL_CONTEXT yet. */
7467 complain,
7477 }
7478 else
7479 {
7481 tree gen_tmpl;
7482 tree type_decl;
7490 /* An error occurred while building the template TEMPL, and a
7491 diagnostic has most certainly been emitted for that
7492 already. Let's propagate that error. */
7501 {
7502 /* We've been given an incomplete set of template arguments.
7503 For example, given:
7505 template <class T> struct S1 {
7506 template <class U> struct S2 {};
7507 template <class U> struct S2<U*> {};
7508 };
7510 we will be called with an ARGLIST of `U*', but the
7511 TEMPLATE will be `template <class T> template
7512 <class U> struct S1<T>::S2'. We must fill in the missing
7513 arguments. */
7514 arglist
7516 arglist);
7518 }
7520 /* Now we should have enough arguments. */
7523 /* From here on, we're only interested in the most general
7524 template. */
7526 /* Calculate the BOUND_ARGS. These will be the args that are
7527 actually tsubst'd into the definition to create the
7528 instantiation. */
7530 {
7531 /* We have multiple levels of arguments to coerce, at once. */
7541 {
7542 tree a;
7546 complain,
7549 else
7550 /* Outer levels should have already been coerced. */
7553 /* Don't process further if one of the levels fails. */
7555 {
7556 /* Restore the ARGLIST to its full size. */
7559 }
7563 /* We temporarily reduce the length of the ARGLIST so
7564 that coerce_template_parms will see only the arguments
7565 corresponding to the template parameters it is
7566 examining. */
7568 }
7570 /* Restore the ARGLIST to its full size. */
7574 }
7575 else
7576 arglist
7579 gen_tmpl,
7580 complain,
7585 /* We were unable to bind the arguments. */
7588 /* In the scope of a template class, explicit references to the
7589 template class refer to the type of the template, not any
7590 instantiation of it. For example, in:
7592 template <class T> class C { void f(C<T>); }
7594 the `C<T>' is just the same as `C'. Outside of the
7595 class, however, such a reference is an instantiation. */
7599 /* comp_template_args is expensive, check it last. */
7601 arglist))
7604 /* If we already have this specialization, return it. */
7616 /* If the deduced arguments are invalid, then the binding
7617 failed. */
7621 complain))
7628 {
7633 }
7643 /* Create the type. */
7645 {
7646 /* The user referred to a specialization of an alias
7647 template represented by GEN_TMPL.
7649 [temp.alias]/2 says:
7651 When a template-id refers to the specialization of an
7652 alias template, it is equivalent to the associated
7653 type obtained by substitution of its
7654 template-arguments for the template-parameters in the
7655 type-id of the alias template. */
7658 /* Note that the call above (by indirectly calling
7659 register_specialization in tsubst_decl) registers the
7660 TYPE_DECL representing the specialization of the alias
7661 template. So next time someone substitutes ARGLIST for
7662 the template parms into the alias template (GEN_TMPL),
7663 she'll get that TYPE_DECL back. */
7667 }
7669 {
7671 {
7680 }
7681 else
7682 {
7683 /* We don't want to call start_enum for this type, since
7684 the values for the enumeration constants may involve
7685 template parameters. And, no one should be interested
7686 in the enumeration constants for such a type. */
7689 }
7693 }
7695 {
7702 /* A local class. Make sure the decl gets registered properly. */
7707 /* This instantiation is another name for the primary
7708 template type. Set the TYPE_CANONICAL field
7709 appropriately. */
7712 /* Some of the template arguments require structural
7713 equality testing, so this template class requires
7714 structural equality testing. */
7716 }
7717 else
7720 /* If we called start_enum or pushtag above, this information
7721 will already be set up. */
7723 {
7730 }
7731 else
7735 {
7741 {
7744 }
7745 }
7747 /* Let's consider the explicit specialization of a member
7748 of a class template specialization that is implicitly instantiated,
7749 e.g.:
7750 template<class T>
7751 struct S
7752 {
7753 template<class U> struct M {}; //#0
7754 };
7756 template<>
7757 template<>
7758 struct S<int>::M<char> //#1
7759 {
7760 int i;
7761 };
7762 [temp.expl.spec]/4 says this is valid.
7764 In this case, when we write:
7765 S<int>::M<char> m;
7767 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7768 the one of #0.
7770 When we encounter #1, we want to store the partial instantiation
7771 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7773 For all cases other than this "explicit specialization of member of a
7774 class template", we just want to store the most general template into
7775 the CLASSTYPE_TI_TEMPLATE of M.
7777 This case of "explicit specialization of member of a class template"
7778 only happens when:
7779 1/ the enclosing class is an instantiation of, and therefore not
7780 the same as, the context of the most general template, and
7781 2/ we aren't looking at the partial instantiation itself, i.e.
7782 the innermost arguments are not the same as the innermost parms of
7783 the most general template.
7785 So it's only when 1/ and 2/ happens that we want to use the partial
7786 instantiation of the member template in lieu of its most general
7787 template. */
7791 /* the enclosing class must be an instantiation... */
7794 {
7795 tree partial_inst_args;
7798 partial_inst_args =
7804 use_partial_inst_tmpl =
7805 /*...and we must not be looking at the partial instantiation
7806 itself. */
7808 partial_inst_args);
7809 }
7812 /* This case is easy; there are no member templates involved. */
7814 else
7815 {
7816 /* This is a full instantiation of a member template. Find
7817 the partial instantiation of which this is an instance. */
7819 /* Temporarily reduce by one the number of levels in the ARGLIST
7820 so as to avoid comparing the last set of arguments. */
7824 /* FOUND is either a proper class type, or an alias
7825 template specialization. In the later case, it's a
7826 TYPE_DECL, resulting from the substituting of arguments
7827 for parameters in the TYPE_DECL of the alias template
7828 done earlier. So be careful while getting the template
7829 of FOUND. */
7833 }
7844 /* Note this use of the partial instantiation so we can check it
7845 later in maybe_process_partial_specialization. */
7852 /* Now that the type has been registered on the instantiations
7853 list, we set up the enumerators. Because the enumeration
7854 constants may involve the enumeration type itself, we make
7855 sure to register the type first, and then create the
7856 constants. That way, doing tsubst_expr for the enumeration
7857 constants won't result in recursive calls here; we'll find
7858 the instantiation and exit above. */
7862 /* If the type makes use of template parameters, the
7863 code that generates debugging information will crash. */
7866 /* Possibly limit visibility based on template args. */
7871 }
7872 }
7874 /* Wrapper for lookup_template_class_1. */
7876 tree
7879 {
7880 tree ret;
7886 }
7887 \f
7888 struct pair_fn_data
7889 {
7890 tree_fn_t fn;
7892 /* True when we should also visit template parameters that occur in
7893 non-deduced contexts. */
7896 };
7898 /* Called from for_each_template_parm via walk_tree. */
7900 static tree
7902 {
7915 {
7919 /* Fall through. */
7942 /* Since we're not going to walk subtrees, we have to do this
7943 explicitly here. */
7947 /* Fall through. */
7950 /* Check the return type. */
7955 /* Check the parameter types. Since default arguments are not
7956 instantiated until they are needed, the TYPE_ARG_TYPES may
7957 contain expressions that involve template parameters. But,
7958 no-one should be looking at them yet. And, once they're
7959 instantiated, they don't contain template parameters, so
7960 there's no point in looking at them then, either. */
7961 {
7962 tree parm;
7969 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7970 want walk_tree walking into them itself. */
7972 }
7990 /* Fall through. */
8006 /* Record template parameters such as `T' inside `TT<T>'. */
8010 /* Fall through. */
8022 /* A template template parameter is encountered. */
8028 /* Already substituted template template parameter */
8051 /* If there's no type, then this thing must be some expression
8052 involving template parameters. */
8074 }
8076 /* We didn't find any template parameters we liked. */
8078 }
8080 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8081 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8082 call FN with the parameter and the DATA.
8083 If FN returns nonzero, the iteration is terminated, and
8084 for_each_template_parm returns 1. Otherwise, the iteration
8085 continues. If FN never returns a nonzero value, the value
8086 returned by for_each_template_parm is 0. If FN is NULL, it is
8087 considered to be the function which always returns 1.
8089 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8090 parameters that occur in non-deduced contexts. When false, only
8091 visits those template parameters that can be deduced. */
8093 static int
8097 {
8101 /* Set up. */
8106 /* Walk the tree. (Conceptually, we would like to walk without
8107 duplicates, but for_each_template_parm_r recursively calls
8108 for_each_template_parm, so we would need to reorganize a fair
8109 bit to use walk_tree_without_duplicates, so we keep our own
8110 visited list.) */
8113 else
8116 for_each_template_parm_r,
8120 /* Clean up. */
8122 {
8125 }
8128 }
8130 /* Returns true if T depends on any template parameter. */
8132 int
8134 {
8161 else
8162 {
8165 }
8170 }
8172 /* Returns true iff current_function_decl is an incompletely instantiated
8173 template. Useful instead of processing_template_decl because the latter
8174 is set to 0 during fold_non_dependent_expr. */
8176 bool
8178 {
8187 }
8189 /* Returns true if T depends on any template parameter with level LEVEL. */
8191 int
8193 {
8196 }
8198 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8199 ill-formed translation unit, i.e. a variable or function that isn't
8200 usable in a constant expression. */
8204 {
8208 }
8210 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8211 neglectable and instantiated from within an erroneous instantiation. */
8213 static bool
8215 {
8226 }
8234 /* We're starting to instantiate D; record the template instantiation context
8235 for diagnostics and to restore it later. */
8237 int
8239 {
8243 {
8249 else
8257 }
8259 /* If the current instantiation caused problems, don't let it instantiate
8260 anything else. Do allow deduction substitution and decls usable in
8261 constant expressions. */
8278 }
8280 /* We're done instantiating this template; return to the instantiation
8281 context. */
8283 void
8285 {
8286 /* Restore the filename and line number stashed away when we started
8287 this instantiation. */
8291 }
8293 /* We're instantiating a deferred template; restore the template
8294 instantiation context in which the instantiation was requested, which
8295 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8297 static tree
8299 {
8311 }
8313 /* Returns the TINST_LEVEL which gives the original instantiation
8314 context. */
8318 {
8324 }
8326 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8327 vector of template arguments, as for tsubst.
8329 Returns an appropriate tsubst'd friend declaration. */
8331 static tree
8333 {
8334 tree new_friend;
8339 /* This was a friend declared with an explicit template
8340 argument list, e.g.:
8342 friend void f<>(T);
8344 to indicate that f was a template instantiation, not a new
8345 function declaration. Now, we have to figure out what
8346 instantiation of what template. */
8347 {
8349 tree new_args;
8350 tree tmpl;
8353 /* Friend functions are looked up in the containing namespace scope.
8354 We must enter that scope, to avoid finding member functions of the
8355 current class with same name. */
8370 tsk_none);
8372 }
8376 /* The NEW_FRIEND will look like an instantiation, to the
8377 compiler, but is not an instantiation from the point of view of
8378 the language. For example, we might have had:
8380 template <class T> struct S {
8381 template <class U> friend void f(T, U);
8382 };
8384 Then, in S<int>, template <class U> void f(int, U) is not an
8385 instantiation of anything. */
8391 {
8395 }
8397 /* The mangled name for the NEW_FRIEND is incorrect. The function
8398 is not a template instantiation and should not be mangled like
8399 one. Therefore, we forget the mangling here; we'll recompute it
8400 later if we need it. */
8402 {
8405 }
8408 {
8409 tree old_decl;
8410 tree new_friend_template_info;
8411 tree new_friend_result_template_info;
8412 tree ns;
8415 /* We must save some information from NEW_FRIEND before calling
8416 duplicate decls since that function will free NEW_FRIEND if
8417 possible. */
8419 new_friend_is_defn =
8424 {
8425 /* This declaration is a `primary' template. */
8428 new_friend_result_template_info
8430 }
8431 else
8434 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8438 /* Inside pushdecl_namespace_level, we will push into the
8439 current namespace. However, the friend function should go
8440 into the namespace of the template. */
8450 {
8451 /* This new friend declaration matched an existing
8452 declaration. For example, given:
8454 template <class T> void f(T);
8455 template <class U> class C {
8456 template <class T> friend void f(T) {}
8457 };
8459 the friend declaration actually provides the definition
8460 of `f', once C has been instantiated for some type. So,
8461 old_decl will be the out-of-class template declaration,
8462 while new_friend is the in-class definition.
8464 But, if `f' was called before this point, the
8465 instantiation of `f' will have DECL_TI_ARGS corresponding
8466 to `T' but not to `U', references to which might appear
8467 in the definition of `f'. Previously, the most general
8468 template for an instantiation of `f' was the out-of-class
8469 version; now it is the in-class version. Therefore, we
8470 run through all specialization of `f', adding to their
8471 DECL_TI_ARGS appropriately. In particular, they need a
8472 new set of outer arguments, corresponding to the
8473 arguments for this class instantiation.
8475 The same situation can arise with something like this:
8477 friend void f(int);
8478 template <class T> class C {
8479 friend void f(T) {}
8480 };
8482 when `C<int>' is instantiated. Now, `f(int)' is defined
8483 in the class. */
8486 /* On the other hand, if the in-class declaration does
8487 *not* provide a definition, then we don't want to alter
8488 existing definitions. We can just leave everything
8489 alone. */
8490 ;
8491 else
8492 {
8496 /* Overwrite whatever template info was there before, if
8497 any, with the new template information pertaining to
8498 the declaration. */
8502 {
8503 /* We should have called reregister_specialization in
8504 duplicate_decls. */
8509 /* Instantiate it if the global has already been used. */
8513 }
8514 else
8515 {
8516 tree t;
8518 /* Indicate that the old function template is a partial
8519 instantiation. */
8527 /* Reassign any specializations already in the hash table
8528 to the new more general template, and add the
8529 additional template args. */
8533 {
8535 spec_entry elt;
8547 register_specialization
8550 }
8552 }
8553 }
8555 /* The information from NEW_FRIEND has been merged into OLD_DECL
8556 by duplicate_decls. */
8558 }
8559 }
8560 else
8561 {
8565 /* In the code
8566 template <class T> class C {
8567 template <class U> friend void C1<U>::f (); // case 1
8568 friend void C2<T>::f (); // case 2
8569 };
8570 we only need to make sure CONTEXT is a complete type for
8571 case 2. To distinguish between the two cases, we note that
8572 CONTEXT of case 1 remains dependent type after tsubst while
8573 this isn't true for case 2. */
8583 {
8585 /* do_friend adds the TEMPLATE_DECL for any member friend
8586 template even if it isn't a member template, i.e.
8587 template <class T> friend A<T>::f();
8588 Look through it in that case. */
8592 /* Check to see that the declaration is really present, and,
8593 possibly obtain an improved declaration. */
8598 }
8599 }
8602 }
8604 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8605 template arguments, as for tsubst.
8607 Returns an appropriate tsubst'd friend type or error_mark_node on
8608 failure. */
8610 static tree
8612 {
8613 tree friend_type;
8614 tree tmpl;
8615 tree context;
8618 {
8621 }
8626 {
8629 else
8631 }
8633 /* Look for a class template declaration. We look for hidden names
8634 because two friend declarations of the same template are the
8635 same. For example, in:
8637 struct A {
8638 template <typename> friend class F;
8639 };
8640 template <typename> struct B {
8641 template <typename> friend class F;
8642 };
8644 both F templates are the same. */
8648 /* But, if we don't find one, it might be because we're in a
8649 situation like this:
8651 template <class T>
8652 struct S {
8653 template <class U>
8654 friend struct S;
8655 };
8657 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8658 for `S<int>', not the TEMPLATE_DECL. */
8660 {
8663 }
8666 {
8667 /* The friend template has already been declared. Just
8668 check to see that the declarations match, and install any new
8669 default parameters. We must tsubst the default parameters,
8670 of course. We only need the innermost template parameters
8671 because that is all that redeclare_class_template will look
8672 at. */
8675 {
8676 tree parms;
8677 location_t saved_input_location;
8686 }
8689 }
8690 else
8691 {
8692 /* The friend template has not already been declared. In this
8693 case, the instantiation of the template class will cause the
8694 injection of this template into the global scope. */
8699 /* The new TMPL is not an instantiation of anything, so we
8700 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8701 the new type because that is supposed to be the corresponding
8702 template decl, i.e., TMPL. */
8709 /* Inject this template into the global scope. */
8711 }
8714 {
8717 else
8719 }
8722 }
8724 /* Returns zero if TYPE cannot be completed later due to circularity.
8725 Otherwise returns one. */
8727 static int
8729 {
8739 else
8741 }
8745 /* Apply any attributes which had to be deferred until instantiation
8746 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8747 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8749 static void
8752 {
8754 tree t;
8759 {
8763 }
8766 {
8770 }
8771 else
8775 {
8780 {
8783 {
8790 {
8797 clauses
8801 else
8803 }
8804 /* If the first attribute argument is an identifier, don't
8805 pass it through tsubst. Attributes like mode, format,
8806 cleanup and several target specific attributes expect it
8807 unmodified. */
8810 {
8811 tree chain
8813 in_decl,
8818 chain);
8819 }
8820 else
8826 }
8827 else
8829 }
8832 }
8833 }
8835 /* Perform (or defer) access check for typedefs that were referenced
8836 from within the template TMPL code.
8837 This is a subroutine of instantiate_decl and instantiate_class_template.
8838 TMPL is the template to consider and TARGS is the list of arguments of
8839 that template. */
8841 static void
8843 {
8844 location_t saved_location;
8855 {
8867 /* Make access check error messages point to the location
8868 of the use of the typedef. */
8872 tf_warning_or_error);
8873 }
8875 }
8877 static tree
8879 {
8881 tree typedecl;
8882 tree pbinfo;
8883 tree base_list;
8885 tree fn_context;
8894 /* Figure out which template is being instantiated. */
8898 /* Determine what specialization of the original template to
8899 instantiate. */
8902 {
8905 }
8907 {
8908 /* This TYPE is actually an instantiation of a partial
8909 specialization. We replace the innermost set of ARGS with
8910 the arguments appropriate for substitution. For example,
8911 given:
8913 template <class T> struct S {};
8914 template <class T> struct S<T*> {};
8916 and supposing that we are instantiating S<int*>, ARGS will
8917 presently be {int*} -- but we need {int}. */
8920 }
8921 else
8922 {
8925 }
8927 /* If the template we're instantiating is incomplete, then clearly
8928 there's nothing we can do. */
8932 /* If we've recursively instantiated too many templates, stop. */
8936 /* Now we're really doing the instantiation. Mark the type as in
8937 the process of being defined. */
8940 /* We may be in the middle of deferred access check. Disable
8941 it now. */
8945 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
8950 /* Use #pragma pack from the template context. */
8956 /* Set the input location to the most specialized template definition.
8957 This is needed if tsubsting causes an error. */
8969 {
8972 /* Adjust visibility for template arguments. */
8974 }
8980 /* We should never instantiate a nested class before its enclosing
8981 class; we need to look up the nested class by name before we can
8982 instantiate it, and that lookup should instantiate the enclosing
8983 class. */
8989 {
8990 tree pbase_binfo;
8991 tree pushed_scope;
8994 /* We must enter the scope containing the type, as that is where
8995 the accessibility of types named in dependent bases are
8996 looked up from. */
8999 /* Substitute into each of the bases to determine the actual
9000 basetypes. */
9002 {
9003 tree base;
9009 {
9010 expanded_bases =
9017 }
9020 {
9022 /* Extract the already-expanded base class. */
9024 else
9025 /* Substitute to figure out the base class. */
9027 NULL_TREE);
9035 }
9036 }
9038 /* The list is now in reverse order; correct that. */
9043 }
9044 /* Now call xref_basetypes to set up all the base-class
9045 information. */
9053 /* Now that our base classes are set up, enter the scope of the
9054 class, so that name lookups into base classes, etc. will work
9055 correctly. This is precisely analogous to what we do in
9056 begin_class_definition when defining an ordinary non-template
9057 class, except we also need to push the enclosing classes. */
9060 /* Now members are processed in the order of declaration. */
9063 {
9067 {
9069 {
9070 /* Build new CLASSTYPE_NESTED_UTDS. */
9072 tree newtag;
9078 /* If the member is a class template, then -- even after
9079 substitution -- there may be dependent types in the
9080 template argument list for the class. We increment
9081 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9082 that function will assume that no types are dependent
9083 when outside of a template. */
9093 {
9097 /* Unfortunately, lookup_template_class sets
9098 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9099 instantiation (i.e., for the type of a member
9100 template class nested within a template class.)
9101 This behavior is required for
9102 maybe_process_partial_specialization to work
9103 correctly, but is not accurate in this case;
9104 the TAG is not an instantiation of anything.
9105 (The corresponding TEMPLATE_DECL is an
9106 instantiation, but the TYPE is not.) */
9109 /* Now, we call pushtag to put this NEWTAG into the scope of
9110 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9111 pushtag calling push_template_decl. We don't have to do
9112 this for enums because it will already have been done in
9113 tsubst_enum. */
9117 }
9118 }
9120 {
9121 /* Build new TYPE_METHODS. */
9122 tree r;
9131 /* Instantiate members marked with attribute used. */
9137 }
9138 else
9139 {
9140 /* Build new TYPE_FIELDS. */
9142 {
9143 tree condition;
9146 condition =
9156 }
9158 {
9159 tree r;
9163 /* The file and line for this declaration, to
9164 assist in error message reporting. Since we
9165 called push_tinst_level above, we don't need to
9166 restore these. */
9176 {
9177 /* A capture pack became multiple fields. */
9180 }
9183 {
9187 {
9188 /* In [temp.inst]:
9190 [t]he initialization (and any associated
9191 side-effects) of a static data member does
9192 not occur unless the static data member is
9193 itself used in a way that requires the
9194 definition of the static data member to
9195 exist.
9197 Therefore, we do not substitute into the
9198 initialized for the static data member here. */
9199 finish_static_data_member_decl
9205 /* Instantiate members marked with attribute used. */
9208 }
9210 {
9211 /* Determine whether R has a valid type and can be
9212 completed later. If R is invalid, then its type
9213 is replaced by error_mark_node. */
9219 {
9222 }
9223 }
9225 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9226 such a thing will already have been added to the field
9227 list by tsubst_enum in finish_member_declaration in the
9228 CLASSTYPE_NESTED_UTDS case above. */
9232 {
9235 }
9236 }
9237 }
9238 }
9239 }
9240 else
9241 {
9244 {
9245 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9251 {
9252 /* template <class T> friend class C; */
9255 }
9257 {
9258 /* template <class T> friend class C::D; */
9264 }
9267 {
9268 /* This could be either
9270 friend class T::C;
9272 when dependent_type_p is false or
9274 template <class U> friend class T::C;
9276 otherwise. */
9279 /* Bump processing_template_decl for correct
9280 dependent_type_p calculation. */
9285 }
9288 {
9289 /* friend class C;
9291 where C hasn't been declared yet. Let's lookup name
9292 from namespace scope directly, bypassing any name that
9293 come from dependent base class. */
9296 /* The call to xref_tag_from_type does injection for friend
9297 classes. */
9299 friend_type =
9303 }
9305 /* friend class C<T>; */
9308 /* Otherwise it's
9310 friend class C;
9312 where C is already declared or
9314 friend class C<int>;
9316 We don't have to do anything in these cases. */
9319 /* Trick make_friend_class into realizing that the friend
9320 we're adding is a template, not an ordinary class. It's
9321 important that we use make_friend_class since it will
9322 perform some error-checking and output cross-reference
9323 information. */
9331 }
9332 else
9333 {
9334 /* Build new DECL_FRIENDLIST. */
9335 tree r;
9337 /* The file and line for this declaration, to
9338 assist in error message reporting. Since we
9339 called push_tinst_level above, we don't need to
9340 restore these. */
9344 {
9347 }
9352 {
9355 }
9356 }
9357 }
9358 }
9361 {
9364 {
9369 /* We need to instantiate the capture list from the template
9370 after we've instantiated the closure members, but before we
9371 consider adding the conversion op. Also keep any captures
9372 that may have been added during instantiation of the op(). */
9374 tree tmpl_cap
9383 }
9384 else
9386 }
9388 /* Set the file and line number information to whatever is given for
9389 the class itself. This puts error messages involving generated
9390 implicit functions at a predictable point, and the same point
9391 that would be used for non-template classes. */
9398 /* We don't instantiate default arguments for member functions. 14.7.1:
9400 The implicit instantiation of a class template specialization causes
9401 the implicit instantiation of the declarations, but not of the
9402 definitions or default arguments, of the class member functions,
9403 member classes, static data members and member templates.... */
9405 /* Some typedefs referenced from within the template code need to be access
9406 checked at template instantiation time, i.e now. These types were
9407 added to the template at parsing time. Let's get those and perform
9408 the access checks then. */
9418 /* The vtable for a template class can be emitted in any translation
9419 unit in which the class is instantiated. When there is no key
9420 method, however, finish_struct_1 will already have added TYPE to
9421 the keyed_classes list. */
9426 }
9428 /* Wrapper for instantiate_class_template_1. */
9430 tree
9432 {
9433 tree ret;
9438 }
9440 static tree
9442 {
9443 tree r;
9449 else
9450 {
9457 }
9459 }
9461 /* Given a function parameter pack TMPL_PARM and some function parameters
9462 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9463 and set *SPEC_P to point at the next point in the list. */
9465 static tree
9467 {
9468 /* Collect all of the extra "packed" parameters into an
9469 argument pack. */
9470 tree parmvec;
9471 tree parmtypevec;
9482 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9487 {
9490 }
9492 /* Build the argument packs. */
9499 }
9501 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9502 NONTYPE_ARGUMENT_PACK. */
9504 static tree
9506 {
9508 }
9510 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9511 pack expansion. */
9513 static bool
9515 {
9520 }
9523 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9525 static tree
9527 {
9534 }
9536 /* This is a subroutine of tsubst_pack_expansion.
9538 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9539 mechanism to store the (non complete list of) arguments of the
9540 substitution and return a non substituted pack expansion, in order
9541 to wait for when we have enough arguments to really perform the
9542 substitution. */
9544 static bool
9548 {
9549 /* If one pack has an expansion and another pack has a normal
9550 argument or if one pack has an empty argument and an another
9551 one hasn't then tsubst_pack_expansion cannot perform the
9552 substitution and need to fall back on the
9553 PACK_EXPANSION_EXTRA mechanism. */
9561 {
9564 parm_pack;
9566 {
9571 else
9573 }
9577 }
9579 }
9581 /* [temp.variadic]/6 says that:
9583 The instantiation of a pack expansion [...]
9584 produces a list E1,E2, ..., En, where N is the number of elements
9585 in the pack expansion parameters.
9587 This subroutine of tsubst_pack_expansion produces one of these Ei.
9589 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9590 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9591 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9592 INDEX is the index 'i' of the element Ei to produce. ARGS,
9593 COMPLAIN, and IN_DECL are the same parameters as for the
9594 tsubst_pack_expansion function.
9596 The function returns the resulting Ei upon successful completion,
9597 or error_mark_node.
9599 Note that this function possibly modifies the ARGS parameter, so
9600 it's the responsibility of the caller to restore it. */
9602 static tree
9604 tree parm_packs,
9606 tree args /* This parm gets
9608 tsubst_flags_t complain,
9609 tree in_decl)
9610 {
9611 tree t;
9614 /* For each parameter pack, change the substitution of the parameter
9615 pack to the ith argument in its argument pack, then expand the
9616 pattern. */
9618 {
9623 ith_elem_is_expansion |=
9626 /* Select the Ith argument from the pack. */
9629 {
9631 {
9635 }
9636 else
9638 }
9639 else
9640 {
9645 {
9647 /* Update the corresponding argument. */
9649 }
9650 else
9651 /* Re-use the ARGUMENT_PACK_SELECT. */
9653 }
9655 }
9657 /* Substitute into the PATTERN with the (possibly altered)
9658 arguments. */
9660 /* Expanding a fixed parameter pack from
9661 coerce_template_parameter_pack. */
9666 else
9669 /* If the Ith argument pack element is a pack expansion, then
9670 the Ith element resulting from the substituting is going to
9671 be a pack expansion as well. */
9676 }
9678 /* Substitute ARGS into T, which is an pack expansion
9679 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9680 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9681 (if only a partial substitution could be performed) or
9682 ERROR_MARK_NODE if there was an error. */
9683 tree
9685 tree in_decl)
9686 {
9687 tree pattern;
9691 tree result;
9699 /* Add in any args remembered from an earlier partial instantiation. */
9704 /* Determine the argument packs that will instantiate the parameter
9705 packs used in the expansion expression. While we're at it,
9706 compute the number of arguments to be expanded and make sure it
9707 is consistent. */
9710 {
9717 {
9721 else
9724 }
9726 {
9729 else
9730 {
9731 /* We can't rely on local_specializations for a parameter
9732 name used later in a function declaration (such as in a
9733 late-specified return type). Even if it exists, it might
9734 have the wrong value for a recursive call. Just make a
9735 dummy decl, since it's only used for its type. */
9738 /* Partial instantiation of the parm_pack, we can't build
9739 up an argument pack yet. */
9741 else
9744 }
9745 }
9748 else
9749 {
9755 }
9762 /* This can only happen if we forget to expand an argument
9763 pack somewhere else. Just return an error, silently. */
9764 {
9768 }
9771 {
9775 /* Don't bother trying to do a partial substitution with
9776 incomplete packs; we'll try again after deduction. */
9783 {
9789 pattern);
9790 else
9793 pattern);
9795 }
9797 /* Keep track of the parameter packs and their corresponding
9798 argument packs. */
9801 }
9802 else
9803 {
9804 /* We can't substitute for this parameter pack. We use a flag as
9805 well as the missing_level counter because function parameter
9806 packs don't have a level. */
9808 }
9809 }
9811 /* We cannot expand this expansion expression, because we don't have
9812 all of the argument packs we need. */
9814 {
9815 /* We got some full packs, but we can't substitute them in until we
9816 have values for all the packs. So remember these until then. */
9821 }
9823 {
9824 /* There were no real arguments, we're just replacing a parameter
9825 pack with another version of itself. Substitute into the
9826 pattern and return a PACK_EXPANSION_*. The caller will need to
9827 deal with that. */
9831 else
9835 }
9840 {
9841 /* We're in a late-specified return type, so create our own local
9842 specializations map; the current map is either NULL or (in the
9843 case of recursive unification) might have bindings that we don't
9844 want to use or alter. */
9847 }
9849 /* For each argument in each argument pack, substitute into the
9850 pattern. */
9853 {
9855 i,
9857 in_decl);
9860 {
9863 }
9864 }
9866 /* Update ARGS to restore the substitution from parameter packs to
9867 their argument packs. */
9869 {
9875 else
9876 {
9884 /* Update the corresponding argument. */
9888 else
9890 }
9891 }
9894 {
9897 }
9900 }
9902 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9903 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9904 parameter packs; all parms generated from a function parameter pack will
9905 have the same DECL_PARM_INDEX. */
9907 tree
9909 {
9911 tree patparm;
9914 {
9920 }
9921 else
9922 {
9927 }
9930 }
9932 /* Substitute ARGS into the vector or list of template arguments T. */
9934 static tree
9936 {
9948 {
9950 tree new_arg;
9955 {
9956 /* Substitute into an expansion expression. */
9960 /* Add to the expanded length adjustment the number of
9961 expanded arguments. We subtract one from this
9962 measurement, because the argument pack expression
9963 itself is already counted as 1 in
9964 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9965 the argument pack is empty. */
9967 }
9969 {
9970 /* Substitute into each of the arguments. */
9976 new_arg,
9990 }
9991 }
9992 else
10001 }
10006 /* Make space for the expanded arguments coming from template
10007 argument packs. */
10009 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10010 arguments for a member template.
10011 In that case each TREE_VEC in ORIG_T represents a level of template
10012 arguments, and ORIG_T won't carry any non defaulted argument count.
10013 It will rather be the nested TREE_VECs that will carry one.
10014 In other words, ORIG_T carries a non defaulted argument count only
10015 if it doesn't contain any nested TREE_VEC. */
10017 {
10021 }
10023 {
10027 {
10030 /* Now expand the template argument pack "in place". */
10033 }
10034 else
10035 {
10037 out++;
10038 }
10039 }
10042 }
10044 /* Return the result of substituting ARGS into the template parameters
10045 given by PARMS. If there are m levels of ARGS and m + n levels of
10046 PARMS, then the result will contain n levels of PARMS. For
10047 example, if PARMS is `template <class T> template <class U>
10048 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10049 result will be `template <int*, double, class V>'. */
10051 static tree
10053 {
10057 /* When substituting into a template, we must set
10058 PROCESSING_TEMPLATE_DECL as the template parameters may be
10059 dependent if they are based on one-another, and the dependency
10060 predicates are short-circuit outside of templates. */
10067 {
10068 tree new_vec =
10073 {
10074 tree tuple;
10086 }
10092 }
10097 }
10099 /* Return the result of substituting ARGS into one template parameter
10100 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10101 parameter and which TREE_PURPOSE is the default argument of the
10102 template parameter. */
10104 static tree
10106 {
10127 }
10129 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10130 type T. If T is not an aggregate or enumeration type, it is
10131 handled as if by tsubst. IN_DECL is as for tsubst. If
10132 ENTERING_SCOPE is nonzero, T is the context for a template which
10133 we are presently tsubst'ing. Return the substituted value. */
10135 static tree
10137 tree args,
10138 tsubst_flags_t complain,
10139 tree in_decl,
10141 {
10146 {
10151 /* Else fall through. */
10155 {
10156 tree argvec;
10157 tree context;
10158 tree r;
10162 /* In "sizeof(X<I>)" we need to evaluate "I". */
10168 /* First, determine the context for the type we are looking
10169 up. */
10172 {
10175 /* If context is a nested class inside a class template,
10176 it may still need to be instantiated (c++/33959). */
10178 }
10180 /* Then, figure out what arguments are appropriate for the
10181 type we are trying to find. For example, given:
10183 template <class T> struct S;
10184 template <class T, class U> void f(T, U) { S<U> su; }
10186 and supposing that we are instantiating f<int, double>,
10187 then our ARGS will be {int, double}, but, when looking up
10188 S we only want {double}. */
10193 else
10194 {
10198 }
10204 }
10205 else
10206 /* This is not a template type, so there's nothing to do. */
10211 }
10212 }
10214 /* Substitute into the default argument ARG (a default argument for
10215 FN), which has the indicated TYPE. */
10217 tree
10219 {
10224 /* This can happen in invalid code. */
10228 /* This default argument came from a template. Instantiate the
10229 default argument here, not in tsubst. In the case of
10230 something like:
10232 template <class T>
10233 struct S {
10234 static T t();
10235 void f(T = t());
10236 };
10238 we must be careful to do name lookup in the scope of S<T>,
10239 rather than in the current class. */
10241 /* The "this" pointer is not valid in a default argument. */
10243 {
10248 }
10251 /* The default argument expression may cause implicitly defined
10252 member functions to be synthesized, which will result in garbage
10253 collection. We must treat this situation as if we were within
10254 the body of function so as to avoid collecting live data on the
10255 stack. */
10263 /* Restore the "this" pointer. */
10265 {
10268 }
10275 /* Make sure the default argument is reasonable. */
10281 }
10283 /* Substitute into all the default arguments for FN. */
10285 static void
10287 {
10288 tree arg;
10289 tree tmpl_args;
10293 /* If this function is not yet instantiated, we certainly don't need
10294 its default arguments. */
10297 /* Don't do this again for clones. */
10302 arg;
10308 complain);
10309 }
10311 /* Substitute the ARGS into the T, which is a _DECL. Return the
10312 result of the substitution. Issue error and warning messages under
10313 control of COMPLAIN. */
10315 static tree
10317 {
10318 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10319 location_t saved_loc;
10324 /* Set the filename and linenumber to improve error-reporting. */
10329 {
10331 {
10332 /* We can get here when processing a member function template,
10333 member class template, or template template parameter. */
10335 tree spec;
10336 tree tmpl_args;
10337 tree full_args;
10340 {
10341 /* Template template parameter is treated here. */
10345 /* If we get a real template back, return it. This can happen in
10346 the context of most_specialized_class. */
10358 complain);
10361 }
10363 /* We might already have an instance of this template.
10364 The ARGS are for the surrounding class type, so the
10365 full args contain the tsubst'd args for the context,
10366 plus the innermost args from the template decl. */
10370 /* Because this is a template, the arguments will still be
10371 dependent, even after substitution. If
10372 PROCESSING_TEMPLATE_DECL is not set, the dependency
10373 predicates will short-circuit. */
10381 /* If this is a default template template argument,
10382 tsubst might not have changed anything. */
10389 {
10392 }
10394 /* Make a new template decl. It will be similar to the
10395 original, but will record the current template arguments.
10396 We also create a new function declaration, which is just
10397 like the old one, but points to this new template, rather
10398 than the old one. */
10407 {
10408 tree new_type;
10416 /* For a partial specialization, we need to keep pointing to
10417 the primary template. */
10423 }
10424 else
10425 {
10426 tree new_decl;
10438 }
10444 /* The template parameters for this new template are all the
10445 template parameters for the old template, except the
10446 outermost level of parameters. */
10449 complain);
10455 /* Record this non-type partial instantiation. */
10459 }
10463 {
10464 tree ctx;
10467 tree gen_tmpl;
10468 tree type;
10473 /* Nobody should be tsubst'ing into non-template functions. */
10477 {
10478 tree spec;
10481 /* If T is not dependent, just return it. We have to
10482 increment PROCESSING_TEMPLATE_DECL because
10483 value_dependent_expression_p assumes that nothing is
10484 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10491 /* Calculate the most general template of which R is a
10492 specialization, and the complete set of arguments used to
10493 specialize R. */
10496 (DECL_TEMPLATE_RESULT
10502 /* Check to see if we already have this specialization. */
10507 {
10510 }
10512 /* We can see more levels of arguments than parameters if
10513 there was a specialization of a member template, like
10514 this:
10516 template <class T> struct S { template <class U> void f(); }
10517 template <> template <class U> void S<int>::f(U);
10519 Here, we'll be substituting into the specialization,
10520 because that's where we can find the code we actually
10521 want to generate, but we'll have enough arguments for
10522 the most general template.
10524 We also deal with the peculiar case:
10526 template <class T> struct S {
10527 template <class U> friend void f();
10528 };
10529 template <class U> void f() {}
10530 template S<int>;
10531 template void f<double>();
10533 Here, the ARGS for the instantiation of will be {int,
10534 double}. But, we only need as many ARGS as there are
10535 levels of template parameters in CODE_PATTERN. We are
10536 careful not to get fooled into reducing the ARGS in
10537 situations like:
10539 template <class T> struct S { template <class U> void f(U); }
10540 template <class T> template <> void S<T>::f(int) {}
10542 which we can spot because the pattern will be a
10543 specialization in this case. */
10545 parms_depth =
10550 }
10551 else
10552 {
10553 /* This special case arises when we have something like this:
10555 template <class T> struct S {
10556 friend void f<int>(int, double);
10557 };
10559 Here, the DECL_TI_TEMPLATE for the friend declaration
10560 will be an IDENTIFIER_NODE. We are being called from
10561 tsubst_friend_function, and we want only to create a
10562 new decl (R) with appropriate types so that we can call
10563 determine_specialization. */
10565 }
10568 {
10571 else
10575 }
10576 else
10577 {
10580 }
10585 /* If we hit excessive deduction depth, the type is bogus even if
10586 it isn't error_mark_node, so don't build a decl. */
10590 /* We do NOT check for matching decls pushed separately at this
10591 point, as they may not represent instantiations of this
10592 template, and in any case are considered separate under the
10593 discrete model. */
10597 /* Clear out the mangled name and RTL for the instantiation. */
10600 /* Leave DECL_INITIAL set on deleted instantiations. */
10605 /* OpenMP UDRs have the only argument a reference to the declared
10606 type. We want to diagnose if the declared type is a reference,
10607 which is invalid, but as references to references are usually
10608 quietly merged, diagnose it here. */
10610 {
10611 tree argtype
10616 "reference type %qT in "
10620 argtype);
10621 }
10624 /* Type-conversion operator. Reconstruct the name, in
10625 case it's the name of one of the template's parameters. */
10635 /* If this is an instantiation of a function with internal
10636 linkage, we already know what object file linkage will be
10637 assigned to the instantiation. */
10646 /* We'll re-clone as appropriate in instantiate_template. */
10649 /* If we aren't complaining now, return on error before we register
10650 the specialization so that we'll complain eventually. */
10656 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10657 this in the special friend case mentioned above where
10658 GEN_TMPL is NULL. */
10660 {
10665 tree new_r
10668 /* We instantiated this while substituting into
10669 the type earlier (template/friend54.C). */
10672 /* We're not supposed to instantiate default arguments
10673 until they are called, for a template. But, for a
10674 declaration like:
10676 template <class T> void f ()
10677 { extern void g(int i = T()); }
10679 we should do the substitution when the template is
10680 instantiated. We handle the member function case in
10681 instantiate_class_template since the default arguments
10682 might refer to other members of the class. */
10687 }
10688 else
10691 /* Copy the list of befriending classes. */
10695 {
10699 in_decl);
10700 }
10703 {
10709 /* If this is an instantiation of a member template, clone it.
10710 If it isn't, that'll be handled by
10711 clone_constructors_and_destructors. */
10714 }
10725 /* Possibly limit visibility based on template args. */
10728 {
10732 }
10740 }
10744 {
10752 {
10753 /* If there is a local specialization that isn't a
10754 parameter pack, it means that we're doing a "simple"
10755 substitution from inside tsubst_pack_expansion. Just
10756 return the local specialization (which will be a single
10757 parm). */
10764 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10765 the parameters in this function parameter pack. */
10769 {
10772 /* Zero-length parameter packs are boring. Just substitute
10773 into the chain. */
10777 }
10778 else
10779 {
10780 /* All we did was update the type. Make a note of that. */
10783 }
10784 }
10786 /* Loop through all of the parameters we'll build. When T is
10787 a function parameter pack, LEN is the number of expanded
10788 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10791 {
10798 /* We're on the Ith parameter of the function parameter
10799 pack. */
10800 {
10801 /* Get the Ith type. */
10804 /* Rename the parameter to include the index. */
10807 }
10809 /* We're dealing with a normal parameter. */
10817 {
10820 else
10823 }
10833 /* Keep track of the first new parameter we
10834 generate. That's what will be returned to the
10835 caller. */
10839 /* Build a proper chain of parameters when substituting
10840 into a function parameter pack. */
10843 }
10845 /* If cp_unevaluated_operand is set, we're just looking for a
10846 single dummy parameter, so don't keep going. */
10851 /* FIRST_R contains the start of the chain we've built. */
10853 }
10857 {
10864 {
10865 /* This field is a lambda capture pack. Return a TREE_VEC of
10866 the expanded fields to instantiate_class_template_1 and
10867 store them in the specializations hash table as a
10868 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10872 {
10875 }
10876 else
10877 {
10878 /* All we did was update the type. Make a note of that. */
10881 }
10882 }
10885 {
10888 {
10892 }
10902 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10903 non-bit-fields DECL_INITIAL is a non-static data member
10904 initializer, which gets deferred instantiation. */
10910 {
10911 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10912 NSDMI in perform_member_init. Still set DECL_INITIAL
10913 so that we know there is one. */
10918 }
10919 /* We don't have to set DECL_CONTEXT here; it is set by
10920 finish_member_declaration. */
10928 }
10931 {
10939 }
10940 }
10944 /* We reach here only for member using decls. We also need to check
10945 uses_template_parms because DECL_DEPENDENT_P is not set for a
10946 using-declaration that designates a member of the current
10947 instantiation (c++/53549). */
10950 {
10957 else
10958 {
10961 }
10962 }
10963 else
10964 {
10967 }
10972 {
10975 tree spec;
10977 tree ctx;
10986 {
10987 /* If this is the canonical decl, we don't have to
10988 mess with instantiations, and often we can't (for
10989 typename, template type parms and such). Note that
10990 TYPE_NAME is not correct for the above test if
10991 we've copied the type for a typedef. */
10997 }
10999 /* Check to see if we already have the specialization we
11000 need. */
11003 {
11004 /* T is a static data member or namespace-scope entity.
11005 We have to substitute into namespace-scope variables
11006 (even though such entities are never templates) because
11007 of cases like:
11009 template <class T> void f() { extern T t; }
11011 where the entity referenced is not known until
11012 instantiation time. */
11016 {
11018 complain,
11020 /* If CTX is unchanged, then T is in fact the
11021 specialization we want. That situation occurs when
11022 referencing a static data member within in its own
11023 class. We can use pointer equality, rather than
11024 same_type_p, because DECL_CONTEXT is always
11025 canonical... */
11028 /* ... unless T is a member template; in which
11029 case our caller can be willing to create a
11030 specialization of that template represented
11031 by T. */
11035 }
11038 {
11046 }
11047 }
11048 else
11049 {
11050 /* A local variable. */
11052 /* Subsequent calls to pushdecl will fill this in. */
11055 }
11056 /* If we already have the specialization we need, there is
11057 nothing more to do. */
11059 {
11062 }
11064 /* Create a new node for the specialization we need. */
11067 {
11070 else
11077 }
11079 {
11080 /* Even if the original location is out of scope, the
11081 newly substituted one is not. */
11088 {
11089 /* It may seem that this case cannot occur, since:
11091 typedef void f();
11092 void g() { f x; }
11094 declares a function, not a variable. However:
11096 typedef void f();
11097 template <typename T> void g() { T t; }
11098 template void g<f>();
11100 is an attempt to declare a variable with function
11101 type. */
11103 /* R is not yet sufficiently initialized, so we
11104 just use its name. */
11107 }
11109 /* Wait until cp_finish_decl to set this again, to handle
11110 circular dependency (template/instantiate6.C). */
11115 {
11120 {
11123 }
11125 }
11126 }
11132 /* Clear out the mangled name and RTL for the instantiation. */
11136 /* The initializer must not be expanded until it is required;
11137 see [temp.inst]. */
11143 {
11144 /* Possibly limit visibility based on template args. */
11147 {
11151 }
11153 }
11156 {
11157 /* A static data member declaration is always marked
11158 external when it is declared in-class, even if an
11159 initializer is present. We mimic the non-template
11160 processing here. */
11166 }
11176 /* Preserve a typedef that names a type. */
11178 {
11181 }
11184 }
11189 }
11190 #undef RETURN
11192 out:
11193 /* Restore the file and line information. */
11197 }
11199 /* Substitute into the ARG_TYPES of a function type.
11200 If END is a TREE_CHAIN, leave it and any following types
11201 un-substituted. */
11203 static tree
11205 tree args,
11206 tree end,
11207 tsubst_flags_t complain,
11208 tree in_decl)
11209 {
11210 tree remaining_arg_types;
11214 tree default_arg;
11225 {
11226 /* For a pack expansion, perform substitution on the
11227 entire expression. Later on, we'll handle the arguments
11228 one-by-one. */
11233 /* So that we'll spin through the parameters, one by one. */
11235 else
11236 {
11237 /* We only partially substituted into the parameter
11238 pack. Our type is TYPE_PACK_EXPANSION. */
11241 }
11242 }
11255 {
11257 {
11261 }
11263 }
11264 /* DR 657. */
11268 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11269 top-level qualifiers as required. */
11272 /* We do not substitute into default arguments here. The standard
11273 mandates that they be instantiated only when needed, which is
11274 done in build_over_call. */
11278 {
11279 /* We've instantiated a template before its default arguments
11280 have been parsed. This can happen for a nested template
11281 class, and is not an error unless we require the default
11282 argument in a call of this function. */
11283 remaining_arg_types =
11286 }
11287 else
11288 remaining_arg_types =
11290 }
11293 }
11295 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11296 *not* handle the exception-specification for FNTYPE, because the
11297 initial substitution of explicitly provided template parameters
11298 during argument deduction forbids substitution into the
11299 exception-specification:
11301 [temp.deduct]
11303 All references in the function type of the function template to the
11304 corresponding template parameters are replaced by the specified tem-
11305 plate argument values. If a substitution in a template parameter or
11306 in the function type of the function template results in an invalid
11307 type, type deduction fails. [Note: The equivalent substitution in
11308 exception specifications is done only when the function is instanti-
11309 ated, at which point a program is ill-formed if the substitution
11310 results in an invalid type.] */
11312 static tree
11314 tree args,
11315 tsubst_flags_t complain,
11316 tree in_decl)
11317 {
11318 tree return_type;
11319 tree arg_types;
11320 tree fntype;
11322 /* The TYPE_CONTEXT is not used for function/method types. */
11325 /* Substitute the return type. */
11329 /* DR 486 clarifies that creation of a function type with an
11330 invalid return type is a deduction failure. */
11333 {
11335 {
11338 else
11340 }
11342 }
11343 /* And DR 657. */
11347 /* Substitute the argument types. */
11353 /* Construct a new type node and return it. */
11355 {
11360 }
11361 else
11362 {
11364 /* Don't pick up extra function qualifiers from the basetype. */
11367 {
11368 /* [temp.deduct]
11370 Type deduction may fail for any of the following
11371 reasons:
11373 -- Attempting to create "pointer to member of T" when T
11374 is not a class type. */
11377 r);
11379 }
11384 }
11388 }
11390 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11391 ARGS into that specification, and return the substituted
11392 specification. If there is no specification, return NULL_TREE. */
11394 static tree
11396 tree args,
11397 tsubst_flags_t complain,
11398 tree in_decl,
11400 {
11401 tree specs;
11402 tree new_specs;
11407 {
11408 /* A noexcept-specifier. */
11413 {
11414 /* Defer instantiation of noexcept-specifiers to avoid
11415 excessive instantiations (c++/49107). */
11418 {
11419 /* We already partially instantiated this member template,
11420 so combine the new args with the old. */
11425 }
11426 else
11427 {
11430 }
11431 }
11432 else
11433 new_specs = tsubst_copy_and_build
11437 }
11439 {
11442 else
11444 {
11445 tree spec;
11450 {
11451 /* Expand the pack expansion type. */
11454 in_decl);
11460 else
11461 {
11462 /* We're substituting into a member template, so
11463 we got a TYPE_PACK_EXPANSION back. Add that
11464 expansion and move on. */
11468 expanded_specs,
11469 complain);
11472 }
11473 }
11476 {
11479 else
11484 complain);
11485 }
11488 }
11489 }
11491 }
11493 /* Take the tree structure T and replace template parameters used
11494 therein with the argument vector ARGS. IN_DECL is an associated
11495 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11496 Issue error and warning messages under control of COMPLAIN. Note
11497 that we must be relatively non-tolerant of extensions here, in
11498 order to preserve conformance; if we allow substitutions that
11499 should not be allowed, we may allow argument deductions that should
11500 not succeed, and therefore report ambiguous overload situations
11501 where there are none. In theory, we could allow the substitution,
11502 but indicate that it should have failed, and allow our caller to
11503 make sure that the right thing happens, but we don't try to do this
11504 yet.
11506 This function is used for dealing with types, decls and the like;
11507 for expressions, use tsubst_expr or tsubst_copy. */
11509 tree
11511 {
11534 else
11539 /* Reuse typedefs. We need to do this to handle dependent attributes,
11540 such as attribute aligned. */
11543 {
11547 {
11548 /* DECL represents an alias template and we want to
11549 instantiate it. */
11553 }
11557 {
11561 }
11566 else
11567 /* The typedef is from a non-template context. */
11571 {
11573 r = cp_build_qualified_type_real
11577 }
11578 else
11579 {
11580 /* We don't have an instantiation yet, so drop the typedef. */
11585 }
11586 }
11599 {
11625 {
11631 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11632 needed. */
11638 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11639 with TREE_SIDE_EFFECTS that indicates this is not an integral
11640 constant expression. */
11643 {
11646 }
11649 }
11655 {
11668 {
11672 {
11673 /* See through ARGUMENT_PACK_SELECT arguments. */
11675 /* If the selected argument is an expansion E, that most
11676 likely means we were called from
11677 gen_elem_of_pack_expansion_instantiation during the
11678 substituting of pack an argument pack (which Ith
11679 element is a pack expansion, where I is
11680 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11681 In this case, the Ith element resulting from this
11682 substituting is going to be a pack expansion, which
11683 pattern is the pattern of E. Let's return the
11684 pattern of E, and
11685 gen_elem_of_pack_expansion_instantiation will
11686 build the resulting pack expansion from it. */
11689 }
11690 }
11695 {
11697 /* If ARG is an argument pack, we don't actually want to
11698 perform a substitution here, because substitutions
11699 for argument packs are only done
11700 element-by-element. We can get to this point when
11701 substituting the type of a non-type template
11702 parameter pack, when that type actually contains
11703 template parameter packs from an outer template, e.g.,
11705 template<typename... Types> struct A {
11706 template<Types... Values> struct B { };
11707 }; */
11711 {
11717 return cp_build_qualified_type_real
11719 }
11721 {
11722 /* We are processing a type constructed from a
11723 template template parameter. */
11734 /* Consider this code:
11736 template <template <class> class Template>
11737 struct Internal {
11738 template <class Arg> using Bind = Template<Arg>;
11739 };
11741 template <template <class> class Template, class Arg>
11742 using Instantiate = Template<Arg>; //#0
11744 template <template <class> class Template,
11745 class Argument>
11746 using Bind =
11747 Instantiate<Internal<Template>::template Bind,
11748 Argument>; //#1
11750 When #1 is parsed, the
11751 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11752 parameter `Template' in #0 matches the
11753 UNBOUND_CLASS_TEMPLATE representing the argument
11754 `Internal<Template>::template Bind'; We then want
11755 to assemble the type `Bind<Argument>' that can't
11756 be fully created right now, because
11757 `Internal<Template>' not being complete, the Bind
11758 template cannot be looked up in that context. So
11759 we need to "store" `Bind<Argument>' for later
11760 when the context of Bind becomes complete. Let's
11761 store that in a TYPENAME_TYPE. */
11765 argvec),
11766 typename_type,
11767 complain);
11769 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11770 are resolving nested-types in the signature of a
11771 member function templates. Otherwise ARG is a
11772 TEMPLATE_DECL and is the real template to be
11773 instantiated. */
11781 complain);
11782 return cp_build_qualified_type_real
11784 }
11785 else
11786 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11788 }
11791 /* This can happen during the attempted tsubst'ing in
11792 unify. This means that we don't yet have any information
11793 about the template parameter in question. */
11796 /* Early in template argument deduction substitution, we don't
11797 want to reduce the level of 'auto', or it will be confused
11798 with a normal template parm in subsequent deduction. */
11802 /* If we get here, we must have been looking at a parm for a
11803 more deeply nested template. Make a new version of this
11804 template parameter, but with a lower level. */
11806 {
11811 {
11813 r = cp_build_qualified_type_real
11817 }
11818 else
11819 {
11830 /* We have reduced the level of the template
11831 template parameter, but not the levels of its
11832 template parameters, so canonical_type_parameter
11833 will not be able to find the canonical template
11834 template parameter for this level. Thus, we
11835 require structural equality checking to compare
11836 TEMPLATE_TEMPLATE_PARMs. */
11840 else
11844 {
11852 }
11853 }
11862 }
11865 }
11868 {
11876 {
11880 }
11883 {
11887 }
11890 {
11894 }
11900 }
11903 /* We should never be tsubsting a binfo. */
11907 /* A vector of template arguments. */
11913 {
11917 /* [temp.deduct]
11919 Type deduction may fail for any of the following
11920 reasons:
11922 -- Attempting to create a pointer to reference type.
11923 -- Attempting to create a reference to a reference type or
11924 a reference to void.
11926 Core issue 106 says that creating a reference to a reference
11927 during instantiation is no longer a cause for failure. We
11928 only enforce this check in strict C++98 mode. */
11932 {
11935 /* We keep track of the last time we issued this error
11936 message to avoid spewing a ton of messages during a
11937 single bad template instantiation. */
11940 {
11945 else
11948 }
11951 }
11955 {
11957 {
11960 type);
11961 else
11963 type);
11964 }
11966 }
11968 {
11972 }
11974 /* In C++0x, during template argument substitution, when there is an
11975 attempt to create a reference to a reference type, reference
11976 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11978 "If a template-argument for a template-parameter T names a type
11979 that is a reference to a type A, an attempt to create the type
11980 'lvalue reference to cv T' creates the type 'lvalue reference to
11981 A,' while an attempt to create the type type rvalue reference to
11982 cv T' creates the type T"
11983 */
11984 r = cp_build_reference_type
11987 else
11995 {
11997 pedwarn
11999 code == REFERENCE_TYPE
12002 else
12004 }
12007 /* Will this ever be needed for TYPE_..._TO values? */
12011 }
12013 {
12016 {
12017 /* [temp.deduct]
12019 Type deduction may fail for any of the following
12020 reasons:
12022 -- Attempting to create "pointer to member of T" when T
12023 is not a class type. */
12027 }
12029 {
12033 }
12035 {
12039 }
12042 {
12043 /* The type of the implicit object parameter gets its
12044 cv-qualifiers from the FUNCTION_TYPE. */
12045 tree memptr;
12046 tree method_type
12051 complain);
12052 }
12053 else
12056 complain);
12057 }
12060 {
12061 tree fntype;
12062 tree specs;
12067 /* Substitute the exception specification. */
12075 }
12077 {
12082 /* As an optimization, we avoid regenerating the array type if
12083 it will obviously be the same as T. */
12087 /* These checks should match the ones in grokdeclarator.
12089 [temp.deduct]
12091 The deduction may fail for any of the following reasons:
12093 -- Attempting to create an array with an element type that
12094 is void, a function type, or a reference type, or [DR337]
12095 an abstract class type. */
12099 {
12103 }
12111 {
12114 }
12117 }
12120 {
12130 {
12134 }
12136 {
12137 /* Normally, make_typename_type does not require that the CTX
12138 have complete type in order to allow things like:
12140 template <class T> struct S { typename S<T>::X Y; };
12142 But, such constructs have already been resolved by this
12143 point, so here CTX really should have complete type, unless
12144 it's a partial instantiation. */
12147 {
12151 }
12152 }
12159 {
12162 }
12165 {
12167 {
12171 else
12173 }
12175 {
12179 else
12181 }
12182 }
12184 return cp_build_qualified_type_real
12186 }
12189 {
12201 }
12204 {
12205 tree type;
12221 complain);
12222 }
12225 {
12226 tree type;
12244 else
12245 {
12249 /* In a template ~id could be either a complement expression
12250 or an unqualified-id naming a destructor; if instantiating
12251 it produces an expression, it's not an id-expression or
12252 member access. */
12255 }
12259 complain);
12260 }
12263 {
12267 }
12271 {
12273 tree packed_out =
12275 args,
12276 complain,
12277 in_decl);
12280 /* For template nontype argument packs, also substitute into
12281 the type. */
12286 }
12301 /* We should use one of the expression tsubsts for these codes. */
12307 }
12308 }
12310 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12311 type of the expression on the left-hand side of the "." or "->"
12312 operator. */
12314 static tree
12317 {
12318 tree name;
12319 tree qualifying_scope;
12320 tree fns;
12321 tree optype;
12326 /* A baselink indicates a function from a base class. Both the
12327 BASELINK_ACCESS_BINFO and the base class referenced may
12328 indicate bases of the template class, rather than the
12329 instantiated class. In addition, lookups that were not
12330 ambiguous before may be ambiguous now. Therefore, we perform
12331 the lookup again. */
12338 {
12345 }
12353 /* If lookup found a single function, mark it as used at this
12354 point. (If it lookup found multiple functions the one selected
12355 later by overload resolution will be marked as used at that
12356 point.) */
12362 /* Add back the template arguments, if present. */
12367 template_args);
12368 /* Update the conversion operator type. */
12376 qualifying_scope,
12377 object_type);
12379 }
12381 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12382 true if the qualified-id will be a postfix-expression in-and-of
12383 itself; false if more of the postfix-expression follows the
12384 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12385 of "&". */
12387 static tree
12391 {
12392 tree expr;
12393 tree scope;
12394 tree name;
12396 tree template_args;
12401 /* Figure out what name to look up. */
12404 {
12412 }
12413 else
12414 {
12417 }
12419 /* Substitute into the qualifying scope. When there are no ARGS, we
12420 are just trying to simplify a non-dependent expression. In that
12421 case the qualifying scope may be dependent, and, in any case,
12422 substituting will not help. */
12425 {
12428 }
12429 else
12433 {
12438 }
12441 {
12443 {
12444 /* A BIT_NOT_EXPR is used to represent a destructor. */
12446 {
12450 }
12451 else
12454 }
12455 else
12459 {
12461 {
12465 }
12467 }
12468 }
12471 {
12473 scope);
12474 /* Remember that there was a reference to this entity. */
12476 }
12479 {
12485 }
12494 {
12495 expr = (adjust_result_of_qualified_name_lookup
12497 expr = (finish_qualified_id_expr
12501 }
12503 /* Expressions do not generally have reference type. */
12505 /* However, if we're about to form a pointer-to-member, we just
12506 want the referenced member referenced. */
12511 }
12513 /* Like tsubst, but deals with expressions. This function just replaces
12514 template parms; to finish processing the resultant expression, use
12515 tsubst_copy_and_build or tsubst_expr. */
12517 static tree
12519 {
12521 tree r;
12529 {
12534 {
12535 /* We get here for a use of 'this' in an NSDMI. */
12537 && current_function_decl
12541 /* This can happen for a parameter name used later in a function
12542 declaration (such as in a late-specified return type). Just
12543 make a dummy decl, since it's only used for its type. */
12546 /* Give it the template pattern as its context; its true context
12547 hasn't been instantiated yet and this is good enough for
12548 mangling. */
12550 }
12558 {
12559 tree enum_type;
12560 tree v;
12564 /* There is no need to substitute into namespace-scope
12565 enumerators. */
12568 /* If ARGS is NULL, then T is known to be non-dependent. */
12572 /* Unfortunately, we cannot just call lookup_name here.
12573 Consider:
12575 template <int I> int f() {
12576 enum E { a = I };
12577 struct S { void g() { E e = a; } };
12578 };
12580 When we instantiate f<7>::S::g(), say, lookup_name is not
12581 clever enough to find f<7>::a. */
12582 enum_type
12592 /* We didn't find the name. That should never happen; if
12593 name-lookup found it during preliminary parsing, we
12594 should find it again here during instantiation. */
12596 }
12601 {
12602 /* Check for a local specialization set up by
12603 tsubst_pack_expansion. */
12605 {
12609 }
12611 /* When retrieving a capture pack from a generic lambda, remove the
12612 lambda call op's own template argument list from ARGS. Only the
12613 template arguments active for the closure type should be used to
12614 retrieve the pack specialization. */
12620 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12621 tsubst_decl put in the hash table. */
12623 }
12626 {
12627 tree ctx;
12632 {
12635 {
12639 }
12641 }
12642 }
12651 {
12654 {
12656 {
12657 /* Just use name lookup to find a member alias for an
12658 anonymous union, but then add it to the hash table. */
12662 }
12663 else
12664 {
12665 /* This can happen for a variable used in a
12666 late-specified return type of a local lambda, or for a
12667 local static or constant. Building a new VAR_DECL
12668 should be OK in all those cases. */
12671 /* A use of a local constant must decay to its value. */
12676 }
12677 }
12678 }
12679 else
12688 /* An OVERLOAD will always be a non-dependent overload set; an
12689 overload set from function scope will just be represented with an
12690 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12706 {
12707 /* Template template argument like the following example need
12708 special treatment:
12710 template <template <class> class TT> struct C {};
12711 template <class T> struct D {
12712 template <class U> struct E {};
12713 C<E> c; // #1
12714 };
12715 D<int> d; // #2
12717 We are processing the template argument `E' in #1 for
12718 the template instantiation #2. Originally, `E' is a
12719 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12720 have to substitute this with one having context `D<int>'. */
12724 }
12725 else
12726 /* Ordinary template template argument. */
12737 return build1
12743 {
12753 /* We only want to compute the number of arguments. */
12767 {
12774 else
12777 }
12778 else
12780 }
12782 {
12790 }
12791 /* Fall through */
12807 return build1
12812 {
12813 tree object;
12814 tree name;
12819 {
12823 }
12826 {
12836 }
12841 in_decl);
12842 else
12845 }
12883 return build_nt
12896 return build_nt
12903 {
12911 }
12917 {
12918 r = build_nt
12924 }
12927 {
12928 r = build_nt
12934 }
12937 {
12938 r = build_nt
12944 }
12947 {
12948 /* Substituted template arguments */
12957 }
12960 {
12980 }
13005 /* Fall through. */
13008 {
13011 }
13012 else
13016 /* This is handled by tsubst_copy_and_build. */
13022 in_decl),
13026 /* We shouldn't have built any of these during initial template
13027 generation. Instead, they should be built during instantiation
13028 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13032 r = build2
13052 {
13053 /* Instantiate any typedefs in the type. */
13058 }
13061 /* These can sometimes show up in a partial instantiation, but never
13062 involve template parms. */
13067 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13070 }
13071 }
13073 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13075 static tree
13078 {
13082 {
13088 {
13091 {
13097 }
13098 /* FALLTHRU */
13126 {
13129 {
13136 }
13137 else
13139 }
13169 }
13170 }
13176 }
13178 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13180 static tree
13182 tree in_decl)
13183 {
13184 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13204 {
13207 else
13208 {
13212 }
13213 }
13218 #undef RECUR
13219 }
13221 /* Substitute one OMP_FOR iterator. */
13223 static void
13228 {
13229 #define RECUR(NODE) \
13230 tsubst_expr ((NODE), args, complain, in_decl, \
13231 integral_constant_expression_p)
13240 {
13241 /* We need to jump through some hoops to handle declarations in the
13242 for-init-statement, since we might need to handle auto deduction,
13243 but we need to keep control of initialization. */
13247 }
13248 else
13260 {
13262 {
13263 /* Declare the variable, but don't let that initialize it. */
13268 }
13276 complain);
13277 else
13284 }
13287 {
13288 /* Declare and initialize the variable. */
13291 }
13293 {
13294 tree c;
13296 {
13307 }
13309 {
13314 {
13317 }
13318 }
13319 }
13325 else
13329 {
13340 {
13347 }
13348 else
13354 {
13360 }
13364 {
13371 }
13372 else
13378 }
13384 #undef RECUR
13385 }
13387 /* Like tsubst_copy for expressions, etc. but also does semantic
13388 processing. */
13390 static tree
13393 {
13394 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13395 #define RECUR(NODE) \
13396 tsubst_expr ((NODE), args, complain, in_decl, \
13397 integral_constant_expression_p)
13400 tree r;
13401 location_t loc;
13413 {
13415 {
13416 tree_stmt_iterator i;
13420 }
13435 else
13444 {
13446 tree init;
13452 {
13455 tree decl;
13463 else
13465 }
13467 {
13468 /* Don't build up decls for a variadic capture proxy, we'll
13469 instantiate the elements directly as needed. */
13471 }
13472 else
13473 {
13477 {
13478 /* By marking the declaration as instantiated, we avoid
13479 trying to instantiate it. Since instantiate_decl can't
13480 handle local variables, and since we've already done
13481 all that needs to be done, that's the right thing to
13482 do. */
13487 /* Anonymous aggregates are a special case. */
13490 {
13493 {
13497 }
13499 }
13505 {
13510 }
13511 else
13512 {
13517 {
13518 /* For __PRETTY_FUNCTION__ we have to adjust the
13519 initializer. */
13523 }
13524 else
13525 {
13529 {
13530 /* If we had an initializer but it
13531 instantiated to nothing,
13532 value-initialize the object. This will
13533 only occur when the initializer was a
13534 pack expansion where the parameter packs
13535 used in that expansion were of length
13536 zero. */
13538 complain);
13541 }
13542 else
13544 }
13547 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13550 }
13551 }
13552 }
13555 }
13570 {
13580 }
13607 {
13611 }
13619 else
13627 else
13654 {
13656 tree label;
13661 }
13667 /* Computed goto's must be tsubst'd into. On the other hand,
13668 non-computed gotos must not be; the identifier in question
13669 will have no binding. */
13671 else
13677 tmp = finish_asm_stmt
13684 {
13689 }
13694 {
13699 }
13700 else
13701 {
13706 else
13713 else
13719 else
13721 }
13725 {
13729 {
13731 /* Prevent instantiate_decl from trying to instantiate
13732 this variable. We've already done all that needs to be
13733 done. */
13736 }
13741 }
13747 {
13748 /* Local classes are not independent templates; they are
13749 instantiated along with their containing function. And this
13750 way we don't have to deal with pushing out of one local class
13751 to instantiate a member of another local class. */
13752 tree fn;
13753 /* Closures are handled by the LAMBDA_EXPR. */
13759 }
13763 {
13764 tree condition;
13767 condition =
13769 args,
13778 }
13802 {
13811 {
13816 }
13828 integral_constant_expression_p);
13837 else
13838 {
13846 }
13849 }
13894 {
13899 {
13902 }
13908 }
13909 else
13910 {
13917 {
13920 }
13923 {
13928 {
13931 }
13937 }
13938 else
13939 {
13943 }
13946 }
13950 {
13956 {
13960 {
13965 }
13969 }
13970 else
13971 {
13976 }
13977 }
14002 /* If the first operand was a statement, we're done with it. */
14006 complain));
14018 integral_constant_expression_p));
14019 }
14022 out:
14025 #undef RECUR
14026 #undef RETURN
14027 }
14029 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14030 function. For description of the body see comment above
14031 cp_parser_omp_declare_reduction_exprs. */
14033 static void
14035 {
14041 tree_stmt_iterator tsi;
14052 {
14071 }
14073 {
14093 }
14094 }
14096 /* T is a postfix-expression that is not being used in a function
14097 call. Return the substituted version of T. */
14099 static tree
14101 tsubst_flags_t complain,
14102 tree in_decl)
14103 {
14107 else
14113 }
14115 /* Sentinel to disable certain warnings during template substitution. */
14123 };
14125 /* Like tsubst but deals with expressions and performs semantic
14126 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14128 tree
14130 tree args,
14131 tsubst_flags_t complain,
14132 tree in_decl,
14135 {
14136 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14137 #define RECUR(NODE) \
14138 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14140 integral_constant_expression_p)
14143 location_t loc;
14152 /* N3276 decltype magic only applies to calls at the top level or on the
14153 right side of a comma. */
14158 {
14161 /* Fall through. */
14163 {
14164 tree decl;
14165 cp_id_kind idk;
14170 {
14173 }
14175 /* Look up the name. */
14178 /* By convention, expressions use ERROR_MARK_NODE to indicate
14179 failure, not NULL_TREE. */
14185 integral_constant_expression_p,
14193 input_location);
14197 {
14201 }
14203 }
14206 {
14207 tree object;
14215 {
14218 }
14219 else
14226 else
14228 }
14231 {
14235 {
14236 /* A type conversion to reference type will be enclosed in
14237 such an indirect ref, but the substitution of the cast
14238 will have also added such an indirect ref. */
14241 }
14242 else
14246 }
14254 {
14261 flags));
14262 }
14275 {
14276 tree type;
14282 {
14287 }
14293 {
14311 }
14314 }
14348 else
14350 in_decl);
14385 {
14388 tree r = build_x_binary_op
14392 ? ERROR_MARK
14396 ? ERROR_MARK
14404 }
14421 {
14430 }
14434 /* Fall through */
14437 {
14438 tree r;
14444 {
14445 /* When there are no ARGS, we are trying to evaluate a
14446 non-dependent expression from the parser. Trying to do
14447 the substitutions may not work. */
14450 }
14451 else
14452 {
14457 else
14460 /*integral_constant_expression_p=*/
14464 }
14468 else
14472 {
14474 {
14476 {
14480 }
14481 else
14485 }
14487 }
14489 }
14492 {
14502 }
14516 {
14518 tree r = build_x_modify_expr
14524 /* TREE_NO_WARNING must be set if either the expression was
14525 parenthesized or it uses an operator such as >>= rather
14526 than plain assignment. In the former case, it was already
14527 set and must be copied. In the latter case,
14528 build_x_modify_expr sets it and it must not be reset
14529 here. */
14534 }
14539 /* Remember that there was a reference to this entity. */
14545 {
14550 tree ret;
14554 else
14555 {
14559 }
14561 /* If there was an initializer in the original tree, but it
14562 instantiated to an empty list, then we should pass a
14563 non-NULL empty vector to tell build_new that it was an
14564 empty initializer() rather than no initializer. This can
14565 only happen when the initializer is a pack expansion whose
14566 parameter packs are of length zero. */
14569 else
14570 {
14574 else
14575 {
14578 }
14579 }
14586 complain);
14594 }
14602 complain));
14605 {
14609 integral_constant_expression_p);
14611 op0,
14614 }
14617 {
14618 tree function;
14623 tree ret;
14626 /* When we parsed the expression, we determined whether or
14627 not Koenig lookup should be performed. */
14630 {
14635 }
14637 {
14638 /* Do nothing; calling tsubst_copy_and_build on an identifier
14639 would incorrectly perform unqualified lookup again.
14641 Note that we can also have an IDENTIFIER_NODE if the earlier
14642 unqualified lookup found a member function; in that case
14643 koenig_p will be false and we do want to do the lookup
14644 again to find the instantiated member function.
14646 FIXME but doing that causes c++/15272, so we need to stop
14647 using IDENTIFIER_NODE in that situation. */
14649 }
14650 else
14651 {
14653 {
14659 }
14660 else
14665 /* Avoid error about taking the address of a constructor. */
14669 in_decl,
14671 integral_constant_expression_p);
14675 }
14680 {
14685 else
14686 {
14687 /* Expand the pack expansion and push each entry onto
14688 CALL_ARGS. */
14691 {
14696 {
14701 }
14702 }
14703 else
14704 {
14705 /* A partial substitution. Add one entry. */
14707 }
14708 }
14709 }
14711 /* We do not perform argument-dependent lookup if normal
14712 lookup finds a non-function, in accordance with the
14713 expected resolution of DR 218. */
14716 /* If lookup found a member function, the Koenig lookup is
14717 not appropriate, even if an unqualified-name was used
14718 to denote the function. */
14721 /* Only do this when substitution turns a dependent call
14722 into a non-dependent call. */
14729 {
14731 {
14732 /* For backwards compatibility and good diagnostics, try
14733 the unqualified lookup again if we aren't in SFINAE
14734 context. */
14735 tree unq = (tsubst_copy_and_build
14737 integral_constant_expression_p));
14742 {
14751 "%qD was not declared in this scope, "
14752 "and no declarations were found by "
14753 "argument-dependent lookup at the point "
14755 {
14759 {
14761 input_location);
14763 "declarations in dependent base %qT are "
14769 else
14773 }
14774 else
14777 }
14779 }
14780 }
14782 {
14787 }
14788 }
14790 /* Remember that there was a reference to this entity. */
14794 /* Put back tf_decltype for the actual call. */
14799 complain);
14801 {
14816 complain);
14817 else
14818 ret = (build_new_method_call
14823 complain));
14824 }
14825 else
14828 koenig_p,
14829 complain);
14834 }
14837 {
14842 {
14844 {
14849 }
14850 else
14851 {
14856 }
14857 }
14858 else
14859 {
14862 }
14866 }
14873 input_location));
14876 {
14884 {
14885 /* We have pack expansions, so expand those and
14886 create a new list out of it. */
14889 tree chain;
14892 /* Expand the argument expressions. */
14900 /* Build the rest of the list. */
14905 /* Determine the number of arguments. */
14907 {
14910 }
14913 else
14914 {
14915 /* Since we only performed a partial substitution into
14916 the argument pack, we only RETURN (a single list
14917 node. */
14924 }
14926 /* Convert the argument vectors into a TREE_LIST */
14929 {
14930 /* Grab the Ith values. */
14931 i--;
14934 value
14938 /* Build the list (backwards). */
14940 }
14943 }
14959 }
14962 {
14963 tree object;
14964 tree object_type;
14965 tree member;
14966 tree r;
14970 /* Remember that there was a reference to this entity. */
14980 else
14988 {
14990 {
14995 {
14998 }
15000 {
15005 }
15006 }
15007 }
15010 {
15011 /* Lookup the template functions now that we know what the
15012 scope is. */
15020 {
15023 args);
15024 member = (adjust_result_of_qualified_name_lookup
15026 object_type));
15027 }
15028 else
15029 {
15031 input_location);
15033 }
15034 }
15038 {
15040 {
15044 else
15047 }
15049 }
15051 {
15056 }
15060 complain);
15064 }
15071 {
15079 tree r;
15084 /* digest_init will do the wrong thing if we let it. */
15088 /* We do not want to process the index of aggregate
15089 initializers as they are identifier nodes which will be
15090 looked up by digest_init. */
15096 {
15098 /* An identifier index is looked up in the type
15099 being initialized, not the current scope. */
15104 {
15105 /* Substitute into the pack expansion. */
15107 in_decl);
15111 ;
15113 /* Just move the argument into place. */
15115 else
15116 {
15117 /* Update the length of the final CONSTRUCTOR
15118 arguments vector, and note that we will need to
15119 copy.*/
15122 }
15123 }
15124 else
15126 }
15129 {
15134 {
15136 {
15141 }
15142 else
15144 }
15145 }
15155 }
15158 {
15161 {
15164 }
15165 else
15166 {
15169 }
15170 }
15176 {
15177 /* We don't build decls for an instantiation of a
15178 variadic capture proxy, we instantiate the elements
15179 when needed. */
15182 }
15183 /* Fall through */
15186 {
15190 /* If the original type was a reference, we'll be wrapped in
15191 the appropriate INDIRECT_REF. */
15194 }
15205 {
15214 }
15217 {
15223 integral_constant_expression_p);
15227 /* If the resulting list of expression statement is empty,
15228 fold it further into void_zero_node. */
15233 }
15236 {
15250 /* For a function scope, we want to use tsubst so that we don't
15251 complain about referring to an auto function before its return
15252 type has been deduced. Otherwise, we want to use tsubst_copy so
15253 that we look up the existing field/parameter/variable rather
15254 than build a new one. */
15259 {
15260 /* Look up the parameter we want directly, as tsubst_copy
15261 doesn't do what we need. */
15267 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15270 }
15271 else
15280 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15282 /* Now that we know visibility, instantiate the type so we have a
15283 declaration of the op() for later calls to lambda_function. */
15289 }
15292 /* We can get here for a constant initializer of non-dependent type.
15293 FIXME stop folding in cp_parser_initializer_clause. */
15294 {
15296 complain);
15298 }
15302 integral_constant_expression_p));
15312 complain));
15315 /* Handle Objective-C++ constructs, if appropriate. */
15316 {
15317 tree subst
15322 }
15324 }
15326 #undef RECUR
15327 #undef RETURN
15328 out:
15331 }
15333 /* Verify that the instantiated ARGS are valid. For type arguments,
15334 make sure that the type's linkage is ok. For non-type arguments,
15335 make sure they are constants if they are integral or enumerations.
15336 Emit an error under control of COMPLAIN, and return TRUE on error. */
15338 static bool
15340 {
15344 {
15354 }
15356 {
15357 /* [basic.link]: A name with no linkage (notably, the name
15358 of a class or enumeration declared in a local scope)
15359 shall not be used to declare an entity with linkage.
15360 This implies that names with no linkage cannot be used as
15361 template arguments
15363 DR 757 relaxes this restriction for C++0x. */
15368 {
15369 /* DR 488 makes use of a type with no linkage cause
15370 type deduction to fail. */
15372 {
15375 else
15378 }
15380 }
15381 /* In order to avoid all sorts of complications, we do not
15382 allow variably-modified types as template arguments. */
15384 {
15388 }
15389 }
15390 /* Class template and alias template arguments should be OK. */
15392 ;
15393 /* A non-type argument of integral or enumerated type must be a
15394 constant. */
15398 {
15402 }
15404 }
15406 static bool
15408 {
15413 {
15416 }
15420 }
15422 /* We're out of SFINAE context now, so generate diagnostics for the access
15423 errors we saw earlier when instantiating D from TMPL and ARGS. */
15425 static void
15427 {
15439 }
15441 /* Instantiate the indicated variable, function, or alias template TMPL with
15442 the template arguments in TARG_PTR. */
15444 static tree
15446 {
15448 tree fndecl;
15449 tree gen_tmpl;
15450 tree spec;
15458 /* If this function is a clone, handle it specially. */
15460 {
15461 tree spec;
15462 tree clone;
15464 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15465 DECL_CLONED_FUNCTION. */
15471 /* Look for the clone. */
15475 /* We should always have found the clone by now. */
15478 }
15483 /* Check to see if we already have this specialization. */
15486 /* The TMPL is a partial instantiation. To get a full set of
15487 arguments we must add the arguments used to perform the
15488 partial instantiation. */
15490 targ_ptr);
15492 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15493 but it doesn't seem to be on the hot path. */
15502 {
15504 {
15508 }
15510 }
15513 complain))
15516 /* We are building a FUNCTION_DECL, during which the access of its
15517 parameters and return types have to be checked. However this
15518 FUNCTION_DECL which is the desired context for access checking
15519 is not built yet. We solve this chicken-and-egg problem by
15520 deferring all checks until we have the FUNCTION_DECL. */
15523 /* Instantiation of the function happens in the context of the function
15524 template, not the context of the overload resolution we're doing. */
15526 /* If there are dependent arguments, e.g. because we're doing partial
15527 ordering, make sure processing_template_decl stays set. */
15531 {
15535 }
15536 /* Substitute template parameters to obtain the specialization. */
15544 {
15547 }
15549 /* The DECL_TI_TEMPLATE should always be the immediate parent
15550 template, not the most general template. */
15553 /* Now we know the specialization, compute access previously
15554 deferred. */
15561 /* If we've just instantiated the main entry point for a function,
15562 instantiate all the alternate entry points as well. We do this
15563 by cloning the instantiation of the main entry point, not by
15564 instantiating the template clones. */
15569 {
15571 {
15572 /* Remember to reinstantiate when we're out of SFINAE so the user
15573 can see the errors. */
15575 }
15577 }
15579 }
15581 /* Wrapper for instantiate_template_1. */
15583 tree
15585 {
15586 tree ret;
15591 }
15593 /* Instantiate the alias template TMPL with ARGS. Also push a template
15594 instantiation level, which instantiate_template doesn't do because
15595 functions and variables have sufficient context established by the
15596 callers. */
15598 static tree
15600 {
15607 {
15610 }
15612 args =
15620 /* We can't free this if a pending_template entry or last_error_tinst_level
15621 is pointing at it. */
15627 }
15629 /* PARM is a template parameter pack for FN. Returns true iff
15630 PARM is used in a deducible way in the argument list of FN. */
15632 static bool
15634 {
15637 {
15639 tree packs;
15645 {
15646 /* The template parameter pack is used in a function parameter
15647 pack. If this is the end of the parameter list, the
15648 template parameter pack is deducible. */
15651 else
15652 /* Otherwise, not. Well, it could be deduced from
15653 a non-pack parameter, but doing so would end up with
15654 a deduction mismatch, so don't bother. */
15656 }
15657 }
15658 /* The template parameter pack isn't used in any function parameter
15659 packs, but it might be used deeper, e.g. tuple<Args...>. */
15661 }
15663 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15664 NARGS elements of the arguments that are being used when calling
15665 it. TARGS is a vector into which the deduced template arguments
15666 are placed.
15668 Returns either a FUNCTION_DECL for the matching specialization of FN or
15669 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
15670 true, diagnostics will be printed to explain why it failed.
15672 If FN is a conversion operator, or we are trying to produce a specific
15673 specialization, RETURN_TYPE is the return type desired.
15675 The EXPLICIT_TARGS are explicit template arguments provided via a
15676 template-id.
15678 The parameter STRICT is one of:
15680 DEDUCE_CALL:
15681 We are deducing arguments for a function call, as in
15682 [temp.deduct.call].
15684 DEDUCE_CONV:
15685 We are deducing arguments for a conversion function, as in
15686 [temp.deduct.conv].
15688 DEDUCE_EXACT:
15689 We are deducing arguments when doing an explicit instantiation
15690 as in [temp.explicit], when determining an explicit specialization
15691 as in [temp.expl.spec], or when taking the address of a function
15692 template, as in [temp.deduct.funcaddr]. */
15694 tree
15696 tree explicit_targs,
15697 tree targs,
15700 tree return_type,
15701 unification_kind_t strict,
15705 {
15706 tree parms;
15707 tree fntype;
15715 tree tinst;
15721 /* In C++0x, it's possible to have a function template whose type depends
15722 on itself recursively. This is most obvious with decltype, but can also
15723 occur with enumeration scope (c++/48969). So we need to catch infinite
15724 recursion and reject the substitution at deduction time; this function
15725 will return error_mark_node for any repeated substitution.
15727 This also catches excessive recursion such as when f<N> depends on
15728 f<N-1> across all integers, and returns error_mark_node for all the
15729 substitutions back up to the initial one.
15731 This is, of course, not reentrant. */
15741 {
15742 /* [temp.deduct]
15744 The specified template arguments must match the template
15745 parameters in kind (i.e., type, nontype, template), and there
15746 must not be more arguments than there are parameters;
15747 otherwise type deduction fails.
15749 Nontype arguments must match the types of the corresponding
15750 nontype template parameters, or must be convertible to the
15751 types of the corresponding nontype parameters as specified in
15752 _temp.arg.nontype_, otherwise type deduction fails.
15754 All references in the function type of the function template
15755 to the corresponding template parameters are replaced by the
15756 specified template argument values. If a substitution in a
15757 template parameter or in the function type of the function
15758 template results in an invalid type, type deduction fails. */
15763 /* Adjust any explicit template arguments before entering the
15764 substitution context. */
15765 explicit_targs
15767 complain,
15773 /* Substitute the explicit args into the function type. This is
15774 necessary so that, for instance, explicitly declared function
15775 arguments can match null pointed constants. If we were given
15776 an incomplete set of explicit args, we must not do semantic
15777 processing during substitution as we could create partial
15778 instantiations. */
15780 {
15785 /* Dig out the actual parm. */
15788 {
15791 }
15793 {
15796 }
15799 /* No explicit argument for this template parameter. */
15803 {
15804 /* Mark the argument pack as "incomplete". We could
15805 still deduce more arguments during unification.
15806 We remove this mark in type_unification_real. */
15808 {
15812 }
15814 /* We have some incomplete argument packs. */
15816 }
15817 }
15821 {
15824 }
15827 /* Ignore any access checks; we'll see them again in
15828 instantiate_template and they might have the wrong
15829 access path at this point. */
15841 /* Place the explicitly specified arguments in TARGS. */
15844 }
15846 /* Never do unification on the 'this' parameter. */
15850 {
15859 }
15861 /* We allow incomplete unification without an error message here
15862 because the standard doesn't seem to explicitly prohibit it. Our
15863 callers must be ready to deal with unification failures in any
15864 event. */
15867 /* If we aren't explaining yet, push tinst context so we can see where
15868 any errors (e.g. from class instantiations triggered by instantiation
15869 of default template arguments) come from. If we are explaining, this
15870 context is redundant. */
15872 {
15875 }
15877 /* type_unification_real will pass back any access checks from default
15878 template argument substitution. */
15890 /* Now that we have bindings for all of the template arguments,
15891 ensure that the arguments deduced for the template template
15892 parameters have compatible template parameter lists. We cannot
15893 check this property before we have deduced all template
15894 arguments, because the template parameter types of a template
15895 template parameter might depend on prior template parameters
15896 deduced after the template template parameter. The following
15897 ill-formed example illustrates this issue:
15899 template<typename T, template<T> class C> void f(C<5>, T);
15901 template<int N> struct X {};
15903 void g() {
15904 f(X<5>(), 5l); // error: template argument deduction fails
15905 }
15907 The template parameter list of 'C' depends on the template type
15908 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15909 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15910 time that we deduce 'C'. */
15913 {
15916 }
15918 /* All is well so far. Now, check:
15920 [temp.deduct]
15922 When all template arguments have been deduced, all uses of
15923 template parameters in nondeduced contexts are replaced with
15924 the corresponding deduced argument values. If the
15925 substitution results in an invalid type, as described above,
15926 type deduction fails. */
15929 {
15932 }
15934 /* Also collect access checks from the instantiation. */
15947 /* Now perform any access checks encountered during substitution. */
15954 /* If we're looking for an exact match, check that what we got
15955 is indeed an exact match. It might not be if some template
15956 parameters are used in non-deduced contexts. But don't check
15957 for an exact match if we have dependent template arguments;
15958 in that case we're doing partial ordering, and we already know
15959 that we have two candidates that will provide the actual type. */
15961 {
15965 tree sarg
15971 {
15975 }
15976 }
15980 fail:
15983 {
15985 /* Reset once we're all the way out. */
15987 }
15989 /* We can't free this if a pending_template entry or last_error_tinst_level
15990 is pointing at it. */
15996 }
15998 /* Adjust types before performing type deduction, as described in
15999 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16000 sections are symmetric. PARM is the type of a function parameter
16001 or the return type of the conversion function. ARG is the type of
16002 the argument passed to the call, or the type of the value
16003 initialized with the result of the conversion function.
16004 ARG_EXPR is the original argument expression, which may be null. */
16006 static int
16010 tree arg_expr)
16011 {
16015 {
16020 {
16021 /* Swap PARM and ARG throughout the remainder of this
16022 function; the handling is precisely symmetric since PARM
16023 will initialize ARG rather than vice versa. */
16028 }
16031 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16032 too, but here handle it by stripping the reference from PARM
16033 rather than by adding it to ARG. */
16041 /* Nothing else to do in this case. */
16046 }
16049 {
16050 /* [temp.deduct.call]
16052 If P is not a reference type:
16054 --If A is an array type, the pointer type produced by the
16055 array-to-pointer standard conversion (_conv.array_) is
16056 used in place of A for type deduction; otherwise,
16058 --If A is a function type, the pointer type produced by
16059 the function-to-pointer standard conversion
16060 (_conv.func_) is used in place of A for type deduction;
16061 otherwise,
16063 --If A is a cv-qualified type, the top level
16064 cv-qualifiers of A's type are ignored for type
16065 deduction. */
16070 else
16072 }
16074 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16075 of the form T&&, where T is a template parameter, and the argument
16076 is an lvalue, T is deduced as A& */
16082 /* try_one_overload doesn't provide an arg_expr, but
16083 functions are always lvalues. */
16087 /* [temp.deduct.call]
16089 If P is a cv-qualified type, the top level cv-qualifiers
16090 of P's type are ignored for type deduction. If P is a
16091 reference type, the type referred to by P is used for
16092 type deduction. */
16095 {
16098 }
16100 /* DR 322. For conversion deduction, remove a reference type on parm
16101 too (which has been swapped into ARG). */
16106 }
16108 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16109 template which does contain any deducible template parameters; check if
16110 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16111 unify_one_argument. */
16113 static int
16116 {
16117 tree type;
16121 else
16128 {
16132 }
16134 {
16139 }
16143 else
16145 }
16149 /* Returns true iff the expression EXPR is one from which a template
16150 argument can be deduced. In other words, if it's an undecorated
16151 use of a template non-type parameter. */
16153 static bool
16155 {
16157 }
16159 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16160 deducible way; that is, if it has a max value of <PARM> - 1. */
16162 static bool
16164 {
16173 }
16175 /* Returns true iff the template arguments ARGS use a template parameter
16176 in a deducible way. */
16178 static bool
16180 {
16182 {
16187 else
16188 {
16195 else
16197 }
16200 }
16202 }
16204 /* Returns true iff TYPE contains any deducible references to template
16205 parameters, as per 14.8.2.5. */
16207 static bool
16209 {
16213 /* T
16214 cv-list T
16215 TT<T>
16216 TT<i>
16217 TT<> */
16222 /* T*
16223 T&
16224 T&& */
16228 /* T[integer-constant ]
16229 type [i] */
16234 /* T type ::*
16235 type T::*
16236 T T::*
16237 T (type ::*)()
16238 type (T::*)()
16239 type (type ::*)(T)
16240 type (T::*)(T)
16241 T (type ::*)(T)
16242 T (T::*)()
16243 T (T::*)(T) */
16246 || (uses_deducible_template_parms
16249 /* template-name <T> (where template-name refers to a class template)
16250 template-name <i> (where template-name refers to a class template) */
16257 /* type (T)
16258 T()
16259 T(T) */
16262 {
16271 }
16274 }
16276 /* Subroutine of type_unification_real and unify_pack_expansion to
16277 handle unification of a single P/A pair. Parameters are as
16278 for those functions. */
16280 static int
16284 {
16291 /* We can't deduce anything from this, but we might get all the
16292 template args from other function args. */
16295 /* Implicit conversions (Clause 4) will be performed on a function
16296 argument to convert it to the type of the corresponding function
16297 parameter if the parameter type contains no template-parameters that
16298 participate in template argument deduction. */
16300 /* For function parameters that contain no template-parameters at all,
16301 we have historically checked for convertibility in order to shortcut
16302 consideration of this candidate. */
16304 explain_p);
16307 /* For function parameters with only non-deducible template parameters,
16308 just return. */
16312 {
16314 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16315 | UNIFY_ALLOW_MORE_CV_QUAL
16329 }
16331 /* We only do these transformations if this is the top-level
16332 parameter_type_list in a call or declaration matching; in other
16333 situations (nested function declarators, template argument lists) we
16334 won't be comparing a type to an expression, and we don't do any type
16335 adjustments. */
16337 {
16339 {
16342 {
16343 /* [temp.deduct.type] A template-argument can be
16344 deduced from a pointer to function or pointer
16345 to member function argument if the set of
16346 overloaded functions does not contain function
16347 templates and at most one of a set of
16348 overloaded functions provides a unique
16349 match. */
16356 }
16362 }
16364 arg_strict |=
16366 }
16367 else
16371 /* For deduction from an init-list we need the actual list. */
16375 }
16377 /* Most parms like fn_type_unification.
16379 If SUBR is 1, we're being called recursively (to unify the
16380 arguments of a function or method parameter of a function
16381 template).
16383 CHECKS is a pointer to a vector of access checks encountered while
16384 substituting default template arguments. */
16386 static int
16388 tree targs,
16389 tree xparms,
16393 unification_kind_t strict,
16397 {
16402 tree parms;
16411 /* Reset the number of non-defaulted template arguments contained
16412 in TARGS. */
16415 again:
16423 {
16428 /* For a function parameter pack that occurs at the end of the
16429 parameter-declaration-list, the type A of each remaining
16430 argument of the call is compared with the type P of the
16431 declarator-id of the function parameter pack. */
16437 /* For a function parameter pack that does not occur at the
16438 end of the parameter-declaration-list, the type of the
16439 parameter pack is a non-deduced context. */
16448 }
16453 {
16454 /* Unify the remaining arguments with the pack expansion type. */
16455 tree argvec;
16458 /* Allocate a TREE_VEC and copy in all of the arguments */
16463 /* Copy the parameter into parmvec. */
16469 /* Advance to the end of the list of parameters. */
16471 }
16473 /* Fail if we've reached the end of the parm list, and more args
16474 are present, and the parm list isn't variadic. */
16477 /* Fail if parms are left and they don't have default values. */
16480 {
16484 {
16485 count++;
16487 }
16489 }
16492 {
16493 tsubst_flags_t complain = (explain_p
16494 ? tf_warning_or_error
16498 {
16502 /* Clear the "incomplete" flags on all argument packs now so that
16503 substituting them into later default arguments works. */
16505 {
16508 }
16514 /* If this is an undeduced nontype parameter that depends on
16515 a type parameter, try another pass; its type may have been
16516 deduced from a later argument than the one from which
16517 this parameter can be deduced. */
16523 /* Core issue #226 (C++0x) [temp.deduct]:
16525 If a template argument has not been deduced, its
16526 default template argument, if any, is used.
16528 When we are in C++98 mode, TREE_PURPOSE will either
16529 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16530 to explicitly check cxx_dialect here. */
16532 {
16547 else
16548 {
16550 /* The position of the first default template argument,
16551 is also the number of non-defaulted arguments in TARGS.
16552 Record that. */
16556 }
16557 }
16559 /* If the type parameter is a parameter pack, then it will
16560 be deduced to an empty parameter pack. */
16562 {
16563 tree arg;
16566 {
16570 }
16571 else
16578 }
16581 }
16582 }
16583 #ifdef ENABLE_CHECKING
16586 #endif
16589 }
16591 /* Subroutine of type_unification_real. Args are like the variables
16592 at the call site. ARG is an overloaded function (or template-id);
16593 we try deducing template args from each of the overloads, and if
16594 only one succeeds, we go with that. Modifies TARGS and returns
16595 true on success. */
16597 static bool
16599 tree targs,
16600 tree parm,
16601 tree arg,
16602 unification_kind_t strict,
16605 {
16612 {
16615 }
16616 else
16620 /* Handle `&x' where `x' is some static or non-static member
16621 function name. */
16627 /* Strip baselink information. */
16632 {
16633 /* If we got some explicit template args, we need to plug them into
16634 the affected templates before we try to unify, in case the
16635 explicit args will completely resolve the templates in question. */
16642 {
16655 {
16660 {
16663 }
16664 }
16667 }
16668 /* If no templates (or more than one) are fully resolved by the
16669 explicit arguments, this template-id is a non-deduced context; it
16670 could still be OK if we deduce all template arguments for the
16671 enclosing call through other arguments. */
16674 }
16677 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16678 -- but the deduction does not succeed because the expression is
16679 not just the function on its own. */
16681 else
16687 {
16690 }
16692 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16693 to function or pointer to member function argument if the set of
16694 overloaded functions does not contain function templates and at most
16695 one of a set of overloaded functions provides a unique match.
16697 So if we found multiple possibilities, we return success but don't
16698 deduce anything. */
16701 {
16706 }
16711 }
16713 /* Core DR 115: In contexts where deduction is done and fails, or in
16714 contexts where deduction is not done, if a template argument list is
16715 specified and it, along with any default template arguments, identifies
16716 a single function template specialization, then the template-id is an
16717 lvalue for the function template specialization. */
16719 tree
16721 {
16734 {
16737 }
16739 {
16742 }
16744 {
16747 }
16750 {
16754 /* If we got some explicit template args, we need to plug them into
16755 the affected templates before we try to unify, in case the
16756 explicit args will completely resolve the templates in question. */
16764 {
16777 {
16780 {
16783 }
16785 {
16788 }
16789 }
16790 }
16792 {
16800 {
16801 tree base
16804 }
16808 }
16810 /* There were no good options and at least one bad one, so let the
16811 user know what the problem is. */
16813 }
16815 }
16817 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16818 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16819 different overloads deduce different arguments for a given parm.
16820 ADDR_P is true if the expression for which deduction is being
16821 performed was of the form "& fn" rather than simply "fn".
16823 Returns 1 on success. */
16825 static int
16827 tree orig_targs,
16828 tree targs,
16829 tree parm,
16830 tree arg,
16831 unification_kind_t strict,
16835 {
16837 tree tempargs;
16843 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16844 to function or pointer to member function argument if the set of
16845 overloaded functions does not contain function templates and at most
16846 one of a set of overloaded functions provides a unique match.
16848 So if this is a template, just return success. */
16860 /* We don't copy orig_targs for this because if we have already deduced
16861 some template args from previous args, unify would complain when we
16862 try to deduce a template parameter for the same argument, even though
16863 there isn't really a conflict. */
16870 /* First make sure we didn't deduce anything that conflicts with
16871 explicitly specified args. */
16873 {
16880 /* Since we're unifying against ourselves, we will fill in
16881 template args used in the function parm list with our own
16882 template parms. Discard them. */
16886 }
16889 {
16894 }
16897 }
16899 /* PARM is a template class (perhaps with unbound template
16900 parameters). ARG is a fully instantiated type. If ARG can be
16901 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16902 TARGS are as for unify. */
16904 static tree
16907 {
16908 tree copy_of_targs;
16915 /* We need to make a new template argument vector for the call to
16916 unify. If we used TARGS, we'd clutter it up with the result of
16917 the attempted unification, even if this class didn't work out.
16918 We also don't want to commit ourselves to all the unifications
16919 we've already done, since unification is supposed to be done on
16920 an argument-by-argument basis. In other words, consider the
16921 following pathological case:
16923 template <int I, int J, int K>
16924 struct S {};
16926 template <int I, int J>
16927 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16929 template <int I, int J, int K>
16930 void f(S<I, J, K>, S<I, I, I>);
16932 void g() {
16933 S<0, 0, 0> s0;
16934 S<0, 1, 2> s2;
16936 f(s0, s2);
16937 }
16939 Now, by the time we consider the unification involving `s2', we
16940 already know that we must have `f<0, 0, 0>'. But, even though
16941 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
16942 because there are two ways to unify base classes of S<0, 1, 2>
16943 with S<I, I, I>. If we kept the already deduced knowledge, we
16944 would reject the possibility I=1. */
16947 /* If unification failed, we're done. */
16953 }
16955 /* Given a template type PARM and a class type ARG, find the unique
16956 base type in ARG that is an instance of PARM. We do not examine
16957 ARG itself; only its base-classes. If there is not exactly one
16958 appropriate base class, return NULL_TREE. PARM may be the type of
16959 a partial specialization, as well as a plain template type. Used
16960 by unify. */
16962 static enum template_base_result
16965 {
16967 tree binfo;
16973 {
16974 /* The type could not be completed. */
16977 }
16979 /* Walk in inheritance graph order. The search order is not
16980 important, and this avoids multiple walks of virtual bases. */
16982 {
16987 {
16988 /* If there is more than one satisfactory baseclass, then:
16990 [temp.deduct.call]
16992 If they yield more than one possible deduced A, the type
16993 deduction fails.
16995 applies. */
16997 {
17000 }
17003 }
17004 }
17008 }
17010 /* Returns the level of DECL, which declares a template parameter. */
17012 static int
17014 {
17016 {
17026 }
17028 }
17030 /* Decide whether ARG can be unified with PARM, considering only the
17031 cv-qualifiers of each type, given STRICT as documented for unify.
17032 Returns nonzero iff the unification is OK on that basis. */
17034 static int
17036 {
17042 {
17043 /* Although a CVR qualifier is ignored when being applied to a
17044 substituted template parameter ([8.3.2]/1 for example), that
17045 does not allow us to unify "const T" with "int&" because both
17046 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17047 It is ok when we're allowing additional CV qualifiers
17048 at the outer level [14.8.2.1]/3,1st bullet. */
17058 }
17069 }
17071 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17072 void
17074 {
17078 {
17081 }
17082 else
17083 {
17086 }
17087 }
17089 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17090 do { \
17091 if (unify (TP, TA, P, A, S, EP)) \
17092 return 1; \
17093 } while (0);
17095 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17096 expansion at the end of PACKED_PARMS. Returns 0 if the type
17097 deduction succeeds, 1 otherwise. STRICT is the same as in
17098 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17099 call argument list. We'll need to adjust the arguments to make them
17100 types. SUBR tells us if this is from a recursive call to
17101 type_unification_real, or for comparing two template argument
17102 lists. */
17104 static int
17108 {
17109 tree parm
17119 /* Determine the parameter packs we will be deducing from the
17120 pattern, and record their current deductions. */
17123 {
17127 /* Determine the index and level of this parameter pack. */
17130 /* Keep track of the parameter packs and their corresponding
17131 argument packs. */
17134 }
17136 /* Loop through all of the arguments that have not yet been
17137 unified and unify each with the pattern. */
17139 {
17140 tree parm;
17144 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17145 or the element of its argument pack at the current index if
17146 this argument was explicitly specified. */
17148 {
17157 {
17160 }
17162 }
17164 /* If we had explicit template arguments, substitute them into the
17165 pattern before deduction. */
17167 {
17168 /* Some arguments might still be unspecified or dependent. */
17176 NULL_TREE);
17181 }
17182 else
17185 /* Unify the pattern with the current argument. */
17190 /* For each parameter pack, collect the deduced value. */
17192 {
17198 }
17199 }
17201 /* Verify that the results of unification with the parameter packs
17202 produce results consistent with what we've seen before, and make
17203 the deduced argument packs available. */
17205 {
17212 /* By default keep the original deduced argument pack.
17213 If necessary, more specific code is going to update the
17214 resulting deduced argument later down in this function. */
17218 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17219 actually deduce anything. */
17227 {
17228 /* If we had fewer function args than explicit template args,
17229 just use the explicits. */
17234 }
17237 {
17238 tree result;
17239 /* Build the deduced *_ARGUMENT_PACK. */
17241 {
17246 }
17247 else
17252 /* Note the deduced argument packs for this parameter
17253 pack. */
17255 }
17259 {
17260 /* We only had the explicitly-provided arguments before, but
17261 now we have a complete set of arguments. */
17267 }
17268 else
17269 {
17275 /* Inconsistent unification of this parameter pack. */
17277 bad_old_arg,
17278 bad_new_arg);
17279 }
17280 }
17283 }
17285 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17286 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17287 parameters and return value are as for unify. */
17289 static int
17293 {
17294 tree parm_max;
17295 tree arg_max;
17299 /* Our representation of array types uses "N - 1" as the
17300 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17301 not an integer constant. We cannot unify arbitrarily
17302 complex expressions, so we eliminate the MINUS_EXPRs
17303 here. */
17307 {
17310 }
17314 {
17315 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17316 trying to unify the type of a variable with the type
17317 of a template parameter. For example:
17319 template <unsigned int N>
17320 void f (char (&) [N]);
17321 int g();
17322 void h(int i) {
17323 char a[g(i)];
17324 f(a);
17325 }
17327 Here, the type of the ARG will be "int [g(i)]", and
17328 may be a SAVE_EXPR, etc. */
17332 }
17334 /* If only one of the bounds used a MINUS_EXPR, compensate
17335 by adding one to the other bound. */
17338 integer_type_node,
17339 parm_max,
17340 integer_one_node);
17343 integer_type_node,
17344 arg_max,
17345 integer_one_node);
17349 }
17351 /* Deduce the value of template parameters. TPARMS is the (innermost)
17352 set of template parameters to a template. TARGS is the bindings
17353 for those template parameters, as determined thus far; TARGS may
17354 include template arguments for outer levels of template parameters
17355 as well. PARM is a parameter to a template function, or a
17356 subcomponent of that parameter; ARG is the corresponding argument.
17357 This function attempts to match PARM with ARG in a manner
17358 consistent with the existing assignments in TARGS. If more values
17359 are deduced, then TARGS is updated.
17361 Returns 0 if the type deduction succeeds, 1 otherwise. The
17362 parameter STRICT is a bitwise or of the following flags:
17364 UNIFY_ALLOW_NONE:
17365 Require an exact match between PARM and ARG.
17366 UNIFY_ALLOW_MORE_CV_QUAL:
17367 Allow the deduced ARG to be more cv-qualified (by qualification
17368 conversion) than ARG.
17369 UNIFY_ALLOW_LESS_CV_QUAL:
17370 Allow the deduced ARG to be less cv-qualified than ARG.
17371 UNIFY_ALLOW_DERIVED:
17372 Allow the deduced ARG to be a template base class of ARG,
17373 or a pointer to a template base class of the type pointed to by
17374 ARG.
17375 UNIFY_ALLOW_INTEGER:
17376 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17377 case for more information.
17378 UNIFY_ALLOW_OUTER_LEVEL:
17379 This is the outermost level of a deduction. Used to determine validity
17380 of qualification conversions. A valid qualification conversion must
17381 have const qualified pointers leading up to the inner type which
17382 requires additional CV quals, except at the outer level, where const
17383 is not required [conv.qual]. It would be normal to set this flag in
17384 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17385 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17386 This is the outermost level of a deduction, and PARM can be more CV
17387 qualified at this point.
17388 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17389 This is the outermost level of a deduction, and PARM can be less CV
17390 qualified at this point. */
17392 static int
17395 {
17397 tree targ;
17398 tree tparm;
17401 /* I don't think this will do the right thing with respect to types.
17402 But the only case I've seen it in so far has been array bounds, where
17403 signedness is the only information lost, and I think that will be
17404 okay. */
17412 /* We can't deduce anything from this, but we might get all the
17413 template args from other function args. */
17416 /* If PARM uses template parameters, then we can't bail out here,
17417 even if ARG == PARM, since we won't record unifications for the
17418 template parameters. We might need them if we're trying to
17419 figure out which of two things is more specialized. */
17423 /* Handle init lists early, so the rest of the function can assume
17424 we're dealing with a type. */
17426 {
17431 /* Replace T with std::initializer_list<T> for deduction. */
17438 /* We can only deduce from an initializer list argument if the
17439 parameter is std::initializer_list or an array; otherwise this
17440 is a non-deduced context. */
17445 else
17449 {
17456 {
17458 /* It should only be possible to get here for a call. */
17460 elt_strict |= maybe_adjust_types_for_deduction
17463 }
17466 explain_p);
17467 }
17471 {
17472 /* Also deduce from the length of the initializer list. */
17479 }
17481 /* If the std::initializer_list<T> deduction worked, replace the
17482 deduced A with std::initializer_list<A>. */
17484 {
17489 }
17491 }
17493 /* Immediately reject some pairs that won't unify because of
17494 cv-qualification mismatches. */
17497 /* It is the elements of the array which hold the cv quals of an array
17498 type, and the elements might be template type parms. We'll check
17499 when we recurse. */
17501 /* We check the cv-qualifiers when unifying with template type
17502 parameters below. We want to allow ARG `const T' to unify with
17503 PARM `T' for example, when computing which of two templates
17504 is more specialized, for example. */
17518 {
17522 /* In a type which contains a nested-name-specifier, template
17523 argument values cannot be deduced for template parameters used
17524 within the nested-name-specifier. */
17536 /* The PARM is not one we're trying to unify. Just check
17537 to see if it matches ARG. */
17538 {
17543 else
17545 }
17552 /* Check for mixed types and values. */
17560 {
17561 /* ARG must be constructed from a template class or a template
17562 template parameter. */
17566 {
17568 /* An alias template name is never deduced. */
17573 tree parm_parms
17574 = DECL_INNERMOST_TEMPLATE_PARMS
17579 /* The resolution to DR150 makes clear that default
17580 arguments for an N-argument may not be used to bind T
17581 to a template template parameter with fewer than N
17582 parameters. It is not safe to permit the binding of
17583 default arguments as an extension, as that may change
17584 the meaning of a conforming program. Consider:
17586 struct Dense { static const unsigned int dim = 1; };
17588 template <template <typename> class View,
17589 typename Block>
17590 void operator+(float, View<Block> const&);
17592 template <typename Block,
17593 unsigned int Dim = Block::dim>
17594 struct Lvalue_proxy { operator float() const; };
17596 void
17597 test_1d (void) {
17598 Lvalue_proxy<Dense> p;
17599 float b;
17600 b + p;
17601 }
17603 Here, if Lvalue_proxy is permitted to bind to View, then
17604 the global operator+ will be used; if they are not, the
17605 Lvalue_proxy will be converted to float. */
17607 full_argvec,
17609 (explain_p
17610 ? tf_warning_or_error
17617 /* Deduce arguments T, i from TT<T> or TT<i>.
17618 We check each element of PARMVEC and ARGVEC individually
17619 rather than the whole TREE_VEC since they can have
17620 different number of elements. */
17627 /* Check if the parameters end in a pack, making them
17628 variadic. */
17634 /* If the template argument list of P contains a pack
17635 expansion that is not the last template argument, the
17636 entire template argument list is a non-deduced
17637 context. */
17646 {
17651 }
17656 DEDUCE_EXACT,
17659 }
17662 /* Fall through to deduce template name. */
17663 }
17667 {
17668 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17670 /* Simple cases: Value already set, does match or doesn't. */
17675 }
17676 else
17677 {
17678 /* If PARM is `const T' and ARG is only `int', we don't have
17679 a match unless we are allowing additional qualification.
17680 If ARG is `const int' and PARM is just `T' that's OK;
17681 that binds `const int' to `T'. */
17686 /* Consider the case where ARG is `const volatile int' and
17687 PARM is `const T'. Then, T should be `volatile int'. */
17688 arg = cp_build_qualified_type_real
17693 /* Simple cases: Value already set, does match or doesn't. */
17699 /* Make sure that ARG is not a variable-sized array. (Note
17700 that were talking about variable-sized arrays (like
17701 `int[n]'), rather than arrays of unknown size (like
17702 `int[]').) We'll get very confused by such a type since
17703 the bound of the array is not constant, and therefore
17704 not mangleable. Besides, such types are not allowed in
17705 ISO C++, so we can do as we please here. We do allow
17706 them for 'auto' deduction, since that isn't ABI-exposed. */
17710 /* Strip typedefs as in convert_template_argument. */
17712 }
17714 /* If ARG is a parameter pack or an expansion, we cannot unify
17715 against it unless PARM is also a parameter pack. */
17720 /* If the argument deduction results is a METHOD_TYPE,
17721 then there is a problem.
17722 METHOD_TYPE doesn't map to any real C++ type the result of
17723 the deduction can not be of that type. */
17737 {
17738 /* The PARM is not one we're trying to unify. Just check
17739 to see if it matches ARG. */
17745 }
17751 {
17756 }
17758 /* [temp.deduct.type] If, in the declaration of a function template
17759 with a non-type template-parameter, the non-type
17760 template-parameter is used in an expression in the function
17761 parameter-list and, if the corresponding template-argument is
17762 deduced, the template-argument type shall match the type of the
17763 template-parameter exactly, except that a template-argument
17764 deduced from an array bound may be of any integral type.
17765 The non-type parameter might use already deduced type parameters. */
17768 /* Template-parameter dependent expression. Just accept it for now.
17769 It will later be processed in convert_template_argument. */
17770 ;
17775 /* Convert the ARG to the type of PARM; the deduced non-type
17776 template argument must exactly match the types of the
17777 corresponding parameter. */
17780 /* We haven't deduced the type of this parameter yet. Try again
17781 later. */
17783 else
17786 /* If ARG is a parameter pack or an expansion, we cannot unify
17787 against it unless PARM is also a parameter pack. */
17797 {
17798 /* A pointer-to-member constant can be unified only with
17799 another constant. */
17803 /* Just unify the class member. It would be useless (and possibly
17804 wrong, depending on the strict flags) to unify also
17805 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17806 arg refer to the same variable, even if through different
17807 classes. For instance:
17809 struct A { int x; };
17810 struct B : A { };
17812 Unification of &A::x and &B::x must succeed. */
17815 }
17818 {
17822 /* [temp.deduct.call]
17824 A can be another pointer or pointer to member type that can
17825 be converted to the deduced A via a qualification
17826 conversion (_conv.qual_).
17828 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17829 This will allow for additional cv-qualification of the
17830 pointed-to types if appropriate. */
17833 /* The derived-to-base conversion only persists through one
17834 level of pointers. */
17839 }
17871 /* We have already checked cv-qualification at the top of the
17872 function. */
17876 /* As far as unification is concerned, this wins. Later checks
17877 will invalidate it if necessary. */
17880 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17881 /* Type INTEGER_CST can come from ordinary constant template args. */
17893 {
17903 /* Check for pack expansions in the parameters. */
17905 {
17907 {
17909 /* We can unify against something with a trailing
17910 parameter pack. */
17912 else
17913 /* [temp.deduct.type]/9: If the template argument list of
17914 P contains a pack expansion that is not the last
17915 template argument, the entire template argument list
17916 is a non-deduced context. */
17918 }
17919 }
17921 /* If we don't have enough arguments to satisfy the parameters
17922 (not counting the pack expression at the end), or we have
17923 too many arguments for a parameter list that doesn't end in
17924 a pack expression, we can't unify. */
17930 /* Unify all of the parameters that precede the (optional)
17931 pack expression. */
17933 {
17938 }
17941 DEDUCE_EXACT,
17944 }
17952 {
17960 }
17963 {
17967 {
17968 /* First, we try to unify the PARM and ARG directly. */
17973 {
17974 /* Fallback to the special case allowed in
17975 [temp.deduct.call]:
17977 If P is a class, and P has the form
17978 template-id, then A can be a derived class of
17979 the deduced A. Likewise, if P is a pointer to
17980 a class of the form template-id, A can be a
17981 pointer to a derived class pointed to by the
17982 deduced A. */
17989 }
17990 }
17994 /* Perhaps PARM is something like S<U> and ARG is S<int>.
17995 Then, we should unify `int' and `U'. */
17997 else
17998 /* There's no chance of unification succeeding. */
18003 }
18010 {
18013 tree a;
18019 /* CV qualifications for methods can never be deduced, they must
18020 match exactly. We need to check them explicitly here,
18021 because type_unification_real treats them as any other
18022 cv-qualified parameter. */
18024 && (!check_cv_quals_for_unify
18044 }
18047 /* Unify a pointer to member with a pointer to member function, which
18048 deduces the type of the member as a function type. */
18050 {
18051 /* Check top-level cv qualifiers */
18059 /* Determine the type of the function we are unifying against. */
18063 }
18082 /* Matched cases are handled by the ARG == PARM test above. */
18086 /* A non-type template parameter that is a variable should be a
18087 an integral constant, in which case, it whould have been
18088 folded into its (constant) value. So we should not be getting
18089 a variable here. */
18100 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18101 or UNDERLYING_TYPE nodes. */
18105 /* Unification fails if we hit an error node. */
18112 /* FALLTHRU */
18115 /* An unresolved overload is a nondeduced context. */
18120 /* We must be looking at an expression. This can happen with
18121 something like:
18123 template <int I>
18124 void foo(S<I>, S<I + 2>);
18126 This is a "nondeduced context":
18128 [deduct.type]
18130 The nondeduced contexts are:
18132 --A type that is a template-id in which one or more of
18133 the template-arguments is an expression that references
18134 a template-parameter.
18136 In these cases, we assume deduction succeeded, but don't
18137 actually infer any unifications. */
18142 else
18144 }
18145 }
18146 #undef RECUR_AND_CHECK_FAILURE
18147 \f
18148 /* Note that DECL can be defined in this translation unit, if
18149 required. */
18151 static void
18153 {
18154 tree clone;
18158 }
18160 /* Called if RESULT is explicitly instantiated, or is a member of an
18161 explicitly instantiated class. */
18163 void
18165 {
18168 /* If this entity has already been written out, it's too late to
18169 make any modifications. */
18173 /* For anonymous namespace we don't need to do anything. */
18175 {
18178 }
18181 /* The TREE_PUBLIC flag for function declarations will have been
18182 set correctly by tsubst. */
18185 /* This might have been set by an earlier implicit instantiation. */
18190 else
18191 {
18194 /* Always make artificials weak. */
18197 /* For WIN32 we also want to put explicit instantiations in
18198 linkonce sections. */
18201 }
18203 /* If EXTERN_P, then this function will not be emitted -- unless
18204 followed by an explicit instantiation, at which point its linkage
18205 will be adjusted. If !EXTERN_P, then this function will be
18206 emitted here. In neither circumstance do we want
18207 import_export_decl to adjust the linkage. */
18209 }
18211 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18212 important template arguments. If any are missing, we check whether
18213 they're important by using error_mark_node for substituting into any
18214 args that were used for partial ordering (the ones between ARGS and END)
18215 and seeing if it bubbles up. */
18217 static bool
18219 {
18224 {
18227 }
18229 {
18233 }
18235 }
18237 /* Given two function templates PAT1 and PAT2, return:
18239 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18240 -1 if PAT2 is more specialized than PAT1.
18241 0 if neither is more specialized.
18243 LEN indicates the number of parameters we should consider
18244 (defaulted parameters should not be considered).
18246 The 1998 std underspecified function template partial ordering, and
18247 DR214 addresses the issue. We take pairs of arguments, one from
18248 each of the templates, and deduce them against each other. One of
18249 the templates will be more specialized if all the *other*
18250 template's arguments deduce against its arguments and at least one
18251 of its arguments *does* *not* deduce against the other template's
18252 corresponding argument. Deduction is done as for class templates.
18253 The arguments used in deduction have reference and top level cv
18254 qualifiers removed. Iff both arguments were originally reference
18255 types *and* deduction succeeds in both directions, an lvalue reference
18256 wins against an rvalue reference and otherwise the template
18257 with the more cv-qualified argument wins for that pairing (if
18258 neither is more cv-qualified, they both are equal). Unlike regular
18259 deduction, after all the arguments have been deduced in this way,
18260 we do *not* verify the deduced template argument values can be
18261 substituted into non-deduced contexts.
18263 The logic can be a bit confusing here, because we look at deduce1 and
18264 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18265 can find template arguments for pat1 to make arg1 look like arg2, that
18266 means that arg2 is at least as specialized as arg1. */
18268 int
18270 {
18283 /* Remove the this parameter from non-static member functions. If
18284 one is a non-static member function and the other is not a static
18285 member function, remove the first parameter from that function
18286 also. This situation occurs for operator functions where we
18287 locate both a member function (with this pointer) and non-member
18288 operator (with explicit first operand). */
18290 {
18295 }
18297 {
18300 {
18301 len--;
18303 }
18304 }
18306 /* If only one is a conversion operator, they are unordered. */
18310 /* Consider the return type for a conversion function */
18312 {
18315 len++;
18316 }
18318 processing_template_decl++;
18324 /* Stop when an ellipsis is seen. */
18326 {
18337 {
18338 /* When both arguments are pack expansions, we need only
18339 unify the patterns themselves. */
18343 /* This is the last comparison we need to do. */
18345 }
18348 {
18352 }
18355 {
18359 }
18365 {
18371 /* Setup the parameter vector, which contains only ARG1. */
18374 /* Setup the argument vector, which contains the remaining
18375 arguments. */
18384 /* We cannot deduce in the other direction, because ARG1 is
18385 a pack expansion but ARG2 is not. */
18387 }
18389 {
18395 /* Setup the parameter vector, which contains only ARG1. */
18398 /* Setup the argument vector, which contains the remaining
18399 arguments. */
18408 /* We cannot deduce in the other direction, because ARG2 is
18409 a pack expansion but ARG1 is not.*/
18411 }
18413 else
18414 {
18415 /* The normal case, where neither argument is a pack
18416 expansion. */
18423 }
18425 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18426 arg2, then arg2 is not as specialized as arg1. */
18432 /* "If, for a given type, deduction succeeds in both directions
18433 (i.e., the types are identical after the transformations above)
18434 and both P and A were reference types (before being replaced with
18435 the type referred to above):
18436 - if the type from the argument template was an lvalue reference and
18437 the type from the parameter template was not, the argument type is
18438 considered to be more specialized than the other; otherwise,
18439 - if the type from the argument template is more cv-qualified
18440 than the type from the parameter template (as described above),
18441 the argument type is considered to be more specialized than the other;
18442 otherwise,
18443 - neither type is more specialized than the other." */
18446 {
18448 {
18451 else
18453 }
18455 {
18460 }
18461 }
18464 /* We've failed to deduce something in either direction.
18465 These must be unordered. */
18470 /* We have already processed all of the arguments in our
18471 handing of the pack expansion type. */
18476 }
18478 /* "In most cases, all template parameters must have values in order for
18479 deduction to succeed, but for partial ordering purposes a template
18480 parameter may remain without a value provided it is not used in the
18481 types being used for partial ordering."
18483 Thus, if we are missing any of the targs1 we need to substitute into
18484 origs1, then pat2 is not as specialized as pat1. This can happen when
18485 there is a nondeduced context. */
18491 processing_template_decl--;
18493 /* All things being equal, if the next argument is a pack expansion
18494 for one function but not for the other, prefer the
18495 non-variadic function. FIXME this is bogus; see c++/41958. */
18499 {
18502 }
18508 else
18510 }
18512 /* Determine which of two partial specializations of TMPL is more
18513 specialized.
18515 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18516 to the first partial specialization. The TREE_VALUE is the
18517 innermost set of template parameters for the partial
18518 specialization. PAT2 is similar, but for the second template.
18520 Return 1 if the first partial specialization is more specialized;
18521 -1 if the second is more specialized; 0 if neither is more
18522 specialized.
18524 See [temp.class.order] for information about determining which of
18525 two templates is more specialized. */
18527 static int
18529 {
18530 tree targs;
18538 /* Just like what happens for functions, if we are ordering between
18539 different class template specializations, we may encounter dependent
18540 types in the arguments, and we need our dependency check functions
18541 to behave correctly. */
18547 {
18550 }
18556 {
18559 }
18562 /* In the case of a tie where at least one of the class templates
18563 has a parameter pack at the end, the template with the most
18564 non-packed parameters wins. */
18566 && any_deductions
18569 {
18575 /* We don't count the pack expansion at the end. */
18585 }
18588 }
18590 /* Return the template arguments that will produce the function signature
18591 DECL from the function template FN, with the explicit template
18592 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18593 also match. Return NULL_TREE if no satisfactory arguments could be
18594 found. */
18596 static tree
18598 {
18602 tree decl_arg_types;
18605 tree arg;
18609 /* Never do unification on the 'this' parameter. */
18630 }
18632 /* Return the innermost template arguments that, when applied to a partial
18633 specialization of TMPL whose innermost template parameters are
18634 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18635 ARGS.
18637 For example, suppose we have:
18639 template <class T, class U> struct S {};
18640 template <class T> struct S<T*, int> {};
18642 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18643 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18644 int}. The resulting vector will be {double}, indicating that `T'
18645 is bound to `double'. */
18647 static tree
18649 {
18651 tree deduced_args;
18652 tree innermost_deduced_args;
18656 {
18660 innermost_deduced_args);
18661 }
18662 else
18675 /* Verify that nondeduced template arguments agree with the type
18676 obtained from argument deduction.
18678 For example:
18680 struct A { typedef int X; };
18681 template <class T, class U> struct C {};
18682 template <class T> struct C<T, typename T::X> {};
18684 Then with the instantiation `C<A, int>', we can deduce that
18685 `T' is `A' but unify () does not check whether `typename T::X'
18686 is `int'. */
18692 /* We only need to check the innermost arguments; the other
18693 arguments will always agree. */
18698 /* Now that we have bindings for all of the template arguments,
18699 ensure that the arguments deduced for the template template
18700 parameters have compatible template parameter lists. See the use
18701 of template_template_parm_bindings_ok_p in fn_type_unification
18702 for more information. */
18707 }
18709 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18710 Return the TREE_LIST node with the most specialized template, if
18711 any. If there is no most specialized template, the error_mark_node
18712 is returned.
18714 Note that this function does not look at, or modify, the
18715 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18716 returned is one of the elements of INSTANTIATIONS, callers may
18717 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18718 and retrieve it from the value returned. */
18720 tree
18722 {
18729 {
18735 fate--;
18740 fate++;
18745 {
18746 /* Equally specialized, move to next function. If there
18747 is no next function, nothing's most specialized. */
18752 }
18753 }
18756 /* Now verify that champ is better than everything earlier in the
18757 instantiation list. */
18765 {
18768 }
18770 processing_template_decl--;
18776 }
18778 /* If DECL is a specialization of some template, return the most
18779 general such template. Otherwise, returns NULL_TREE.
18781 For example, given:
18783 template <class T> struct S { template <class U> void f(U); };
18785 if TMPL is `template <class U> void S<int>::f(U)' this will return
18786 the full template. This function will not trace past partial
18787 specializations, however. For example, given in addition:
18789 template <class T> struct S<T*> { template <class U> void f(U); };
18791 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18792 `template <class T> template <class U> S<T*>::f(U)'. */
18794 tree
18796 {
18798 {
18801 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
18802 template friend, or a FIELD_DECL for a capture pack. */
18805 }
18807 /* Look for more and more general templates. */
18809 {
18810 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18811 (See cp-tree.h for details.) */
18819 /* Stop if we run into an explicitly specialized class template. */
18826 }
18829 }
18831 /* Return the most specialized of the class template partial
18832 specializations which can produce TYPE, a specialization of some class
18833 template. The value returned is actually a TREE_LIST; the TREE_TYPE is
18834 a _TYPE node corresponding to the partial specialization, while the
18835 TREE_PURPOSE is the set of template arguments that must be
18836 substituted into the TREE_TYPE in order to generate TYPE.
18838 If the choice of partial specialization is ambiguous, a diagnostic
18839 is issued, and the error_mark_node is returned. If there are no
18840 partial specializations matching TYPE, then NULL_TREE is
18841 returned, indicating that the primary template should be used. */
18843 static tree
18845 {
18847 tree t;
18848 tree champ;
18857 /* For determining which partial specialization to use, only the
18858 innermost args are interesting. */
18860 {
18863 }
18866 {
18867 tree partial_spec_args;
18868 tree spec_args;
18877 {
18878 /* Discard the outer levels of args, and then substitute in the
18879 template args from the enclosing class. */
18881 partial_spec_args = tsubst_template_args
18884 /* And the same for the partial specialization TEMPLATE_DECL. */
18886 }
18888 partial_spec_args =
18890 partial_spec_args,
18904 partial_spec_args,
18905 args);
18907 {
18912 }
18913 }
18923 {
18926 ;
18927 else
18928 {
18930 {
18933 {
18936 }
18937 }
18939 }
18940 }
18944 {
18947 {
18950 }
18951 }
18954 {
18962 {
18965 }
18968 }
18971 }
18973 /* Explicitly instantiate DECL. */
18975 void
18977 {
18982 /* An error occurred, for which grokdeclarator has already issued
18983 an appropriate message. */
18986 {
18989 }
18991 {
18992 /* There is an asymmetry here in the way VAR_DECLs and
18993 FUNCTION_DECLs are handled by grokdeclarator. In the case of
18994 the latter, the DECL we get back will be marked as a
18995 template instantiation, and the appropriate
18996 DECL_TEMPLATE_INFO will be set up. This does not happen for
18997 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
18998 should handle VAR_DECLs as it currently handles
18999 FUNCTION_DECLs. */
19001 {
19004 }
19007 {
19010 }
19012 {
19017 }
19018 }
19020 {
19023 }
19024 else
19027 /* Check for various error cases. Note that if the explicit
19028 instantiation is valid the RESULT will currently be marked as an
19029 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19030 until we get here. */
19033 {
19034 /* DR 259 [temp.spec].
19036 Both an explicit instantiation and a declaration of an explicit
19037 specialization shall not appear in a program unless the explicit
19038 instantiation follows a declaration of the explicit specialization.
19040 For a given set of template parameters, if an explicit
19041 instantiation of a template appears after a declaration of an
19042 explicit specialization for that template, the explicit
19043 instantiation has no effect. */
19045 }
19047 {
19048 /* [temp.spec]
19050 No program shall explicitly instantiate any template more
19051 than once.
19053 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19054 the first instantiation was `extern' and the second is not,
19055 and EXTERN_P for the opposite case. */
19058 /* If an "extern" explicit instantiation follows an ordinary
19059 explicit instantiation, the template is instantiated. */
19062 }
19064 {
19067 }
19069 {
19072 }
19075 ;
19077 {
19080 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19083 }
19084 else
19092 }
19094 static void
19096 {
19102 {
19105 }
19106 }
19108 /* Called from do_type_instantiation through binding_table_foreach to
19109 do recursive instantiation for the type bound in ENTRY. */
19110 static void
19112 {
19118 }
19120 /* Called from do_type_instantiation to instantiate a member
19121 (a member function or a static member variable) of an
19122 explicitly instantiated class template. */
19123 static void
19125 {
19130 }
19132 /* Perform an explicit instantiation of template class T. STORAGE, if
19133 non-null, is the RID for extern, inline or static. COMPLAIN is
19134 nonzero if this is called from the parser, zero if called recursively,
19135 since the standard is unclear (as detailed below). */
19137 void
19139 {
19149 {
19150 tree tmpl =
19154 else
19157 }
19162 {
19165 t);
19167 }
19170 {
19172 {
19174 {
19177 "ISO C++ 1998 forbids the use of %<extern%> on "
19179 }
19180 else
19182 "ISO C++ forbids the use of %qE"
19184 }
19192 else
19193 {
19195 storage);
19197 }
19198 }
19201 {
19202 /* DR 259 [temp.spec].
19204 Both an explicit instantiation and a declaration of an explicit
19205 specialization shall not appear in a program unless the explicit
19206 instantiation follows a declaration of the explicit specialization.
19208 For a given set of template parameters, if an explicit
19209 instantiation of a template appears after a declaration of an
19210 explicit specialization for that template, the explicit
19211 instantiation has no effect. */
19213 }
19215 {
19216 /* [temp.spec]
19218 No program shall explicitly instantiate any template more
19219 than once.
19221 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19222 instantiation was `extern'. If EXTERN_P then the second is.
19223 These cases are OK. */
19230 /* If we've already instantiated the template, just return now. */
19233 }
19241 {
19242 tree tmp;
19244 /* In contrast to implicit instantiation, where only the
19245 declarations, and not the definitions, of members are
19246 instantiated, we have here:
19248 [temp.explicit]
19250 The explicit instantiation of a class template specialization
19251 implies the instantiation of all of its members not
19252 previously explicitly specialized in the translation unit
19253 containing the explicit instantiation.
19255 Of course, we can't instantiate member template classes, since
19256 we don't have any arguments for them. Note that the standard
19257 is unclear on whether the instantiation of the members are
19258 *explicit* instantiations or not. However, the most natural
19259 interpretation is that it should be an explicit instantiation. */
19274 }
19275 }
19277 /* Given a function DECL, which is a specialization of TMPL, modify
19278 DECL to be a re-instantiation of TMPL with the same template
19279 arguments. TMPL should be the template into which tsubst'ing
19280 should occur for DECL, not the most general template.
19282 One reason for doing this is a scenario like this:
19284 template <class T>
19285 void f(const T&, int i);
19287 void g() { f(3, 7); }
19289 template <class T>
19290 void f(const T& t, const int i) { }
19292 Note that when the template is first instantiated, with
19293 instantiate_template, the resulting DECL will have no name for the
19294 first parameter, and the wrong type for the second. So, when we go
19295 to instantiate the DECL, we regenerate it. */
19297 static void
19299 {
19300 /* The arguments used to instantiate DECL, from the most general
19301 template. */
19302 tree args;
19303 tree code_pattern;
19308 /* Make sure that we can see identifiers, and compute access
19309 correctly. */
19313 {
19314 tree decl_parm;
19315 tree pattern_parm;
19316 tree specs;
19330 specs);
19332 /* Merge parameter declarations. */
19335 pattern_parm
19339 {
19340 tree parm_type;
19341 tree attributes;
19346 NULL_TREE);
19352 {
19355 }
19358 }
19359 /* Merge any parameters that match with the function parameter
19360 pack. */
19362 {
19364 tree expanded_types;
19365 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19366 the parameters in this function parameter pack. */
19371 {
19372 tree parm_type;
19373 tree attributes;
19376 /* Rename the parameter to include the index. */
19385 {
19388 }
19390 }
19391 }
19392 /* Merge additional specifiers from the CODE_PATTERN. */
19396 }
19398 {
19406 }
19407 else
19411 }
19413 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19414 substituted to get DECL. */
19416 tree
19418 {
19421 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19422 for the instantiation. This is not always the most general
19423 template. Consider, for example:
19425 template <class T>
19426 struct S { template <class U> void f();
19427 template <> void f<int>(); };
19429 and an instantiation of S<double>::f<int>. We want TD to be the
19430 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19432 more general template. */
19434 /* We must also deal with friend templates. Given:
19436 template <class T> struct S {
19437 template <class U> friend void f() {};
19438 };
19440 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19441 so far as the language is concerned, but that's still
19442 where we get the pattern for the instantiation from. On
19443 other hand, if the definition comes outside the class, say:
19445 template <class T> struct S {
19446 template <class U> friend void f();
19447 };
19448 template <class U> friend void f() {}
19450 we don't need to look any further. That's what the check for
19451 DECL_INITIAL is for. */
19455 {
19456 /* The present template, TD, should not be a definition. If it
19457 were a definition, we should be using it! Note that we
19458 cannot restructure the loop to just keep going until we find
19459 a template with a definition, since that might go too far if
19460 a specialization was declared, but not defined. */
19464 /* Fetch the more general template. */
19466 }
19469 }
19471 /* Returns true if we need to instantiate this template instance even if we
19472 know we aren't going to emit it.. */
19474 bool
19476 {
19477 /* We always instantiate inline functions so that we can inline them. An
19478 explicit instantiation declaration prohibits implicit instantiation of
19479 non-inline functions. With high levels of optimization, we would
19480 normally inline non-inline functions -- but we're not allowed to do
19481 that for "extern template" functions. Therefore, we check
19482 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19486 /* And we need to instantiate static data members so that
19487 their initializers are available in integral constant
19488 expressions. */
19491 }
19493 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19494 instantiate it now, modifying TREE_TYPE (fn). */
19496 void
19498 {
19501 /* Don't instantiate a noexcept-specification from template context. */
19516 {
19520 {
19535 }
19536 else
19540 }
19543 {
19546 else
19548 }
19549 }
19551 /* Produce the definition of D, a _DECL generated from a template. If
19552 DEFER_OK is nonzero, then we don't have to actually do the
19553 instantiation now; we just have to do it sometime. Normally it is
19554 an error if this is an explicit instantiation but D is undefined.
19555 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19556 explicitly instantiated class template. */
19558 tree
19561 {
19563 tree gen_args;
19564 tree args;
19565 tree td;
19566 tree code_pattern;
19567 tree spec;
19568 tree gen_tmpl;
19575 tree fn_context;
19578 /* This function should only be used to instantiate templates for
19579 functions and static member variables. */
19582 /* Variables are never deferred; if instantiation is required, they
19583 are instantiated right away. That allows for better code in the
19584 case that an expression refers to the value of the variable --
19585 if the variable has a constant value the referring expression can
19586 take advantage of that fact. */
19591 /* Don't instantiate cloned functions. Instead, instantiate the
19592 functions they cloned. */
19600 /* D has already been instantiated or explicitly specialized, so
19601 there's nothing for us to do here.
19603 It might seem reasonable to check whether or not D is an explicit
19604 instantiation, and, if so, stop here. But when an explicit
19605 instantiation is deferred until the end of the compilation,
19606 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19607 the instantiation. */
19610 /* Check to see whether we know that this template will be
19611 instantiated in some other file, as with "extern template"
19612 extension. */
19615 /* In general, we do not instantiate such templates. */
19623 /* We should already have the extra args. */
19626 /* And what's in the hash table should match D. */
19630 /* This needs to happen before any tsubsting. */
19636 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19637 for the instantiation. */
19641 /* We should never be trying to instantiate a member of a class
19642 template or partial specialization. */
19647 /* In the case of a friend template whose definition is provided
19648 outside the class, we may have too many arguments. Drop the
19649 ones we don't need. The same is true for specializations. */
19650 args = get_innermost_template_args
19652 else
19656 {
19661 }
19662 else
19663 {
19666 }
19668 /* We may be in the middle of deferred access check. Disable it now. */
19671 /* Unless an explicit instantiation directive has already determined
19672 the linkage of D, remember that a definition is available for
19673 this entity. */
19683 /* If D is a member of an explicitly instantiated class template,
19684 and no definition is available, treat it like an implicit
19685 instantiation. */
19688 {
19689 /* Leave linkage flags alone on instantiations with anonymous
19690 visibility. */
19692 {
19695 }
19697 }
19699 /* Defer all other templates, unless we have been explicitly
19700 forbidden from doing so. */
19702 template. */
19703 ! pattern_defined
19704 /* If it's OK to postpone instantiation, do so. */
19705 || defer_ok
19706 /* If this is a static data member that will be defined
19707 elsewhere, we don't want to instantiate the entire data
19708 member, but we do want to instantiate the initializer so that
19709 we can substitute that elsewhere. */
19711 /* Handle here a deleted function too, avoid generating
19712 its body (c++/61080). */
19714 {
19715 /* The definition of the static data member is now required so
19716 we must substitute the initializer. */
19720 {
19721 tree ns;
19722 tree init;
19729 args,
19732 /* Make sure the initializer is still constant, in case of
19733 circular dependency (template/instantiate6.C). */
19734 const_init
19738 LOOKUP_ONLYCONVERTING);
19741 }
19743 /* We restore the source position here because it's used by
19744 add_pending_template. */
19750 /* [temp.explicit]
19752 The definition of a non-exported function template, a
19753 non-exported member function template, or a non-exported
19754 member function or static data member of a class template
19755 shall be present in every translation unit in which it is
19756 explicitly instantiated. */
19760 /* If we're in unevaluated context, we just wanted to get the
19761 constant value; this isn't an odr use, so don't queue
19762 a full instantiation. */
19765 /* ??? Historically, we have instantiated inline functions, even
19766 when marked as "extern template". */
19770 }
19771 /* Tell the repository that D is available in this translation unit
19772 -- and see if it is supposed to be instantiated here. */
19774 {
19775 /* In a PCH file, despite the fact that the repository hasn't
19776 requested instantiation in the PCH it is still possible that
19777 an instantiation will be required in a file that includes the
19778 PCH. */
19781 /* Instantiate inline functions so that the inliner can do its
19782 job, even though we'll not be emitting a copy of this
19783 function. */
19786 }
19792 else
19793 {
19798 }
19800 /* Mark D as instantiated so that recursive calls to
19801 instantiate_decl do not try to instantiate it again. */
19804 /* Regenerate the declaration in case the template has been modified
19805 by a subsequent redeclaration. */
19808 /* We already set the file and line above. Reset them now in case
19809 they changed as a result of calling regenerate_decl_from_template. */
19813 {
19814 tree init;
19817 /* Clear out DECL_RTL; whatever was there before may not be right
19818 since we've reset the type of the declaration. */
19822 /* The initializer is placed in DECL_INITIAL by
19823 regenerate_decl_from_template so we don't need to
19824 push/pop_access_scope again here. Pull it out so that
19825 cp_finish_decl can process it. */
19830 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19831 initializer. That function will defer actual emission until
19832 we have a chance to determine linkage. */
19835 /* Enter the scope of D so that access-checking works correctly. */
19840 }
19844 {
19846 tree subst_decl;
19847 tree tmpl_parm;
19848 tree spec_parm;
19851 /* Save away the current list, in case we are instantiating one
19852 template from within the body of another. */
19855 /* Set up the list of local specializations. */
19858 /* Set up context. */
19862 else
19865 /* Some typedefs referenced from within the template code need to be
19866 access checked at template instantiation time, i.e now. These
19867 types were added to the template at parsing time. Let's get those
19868 and perform the access checks then. */
19870 gen_args);
19872 /* Create substitution entries for the parameters. */
19877 {
19881 }
19883 {
19885 {
19888 }
19889 else
19890 {
19891 /* Register the (value) argument pack as a specialization of
19892 TMPL_PARM, then move on. */
19895 }
19896 }
19899 /* Substitute into the body of the function. */
19903 else
19904 {
19909 /* Set the current input_location to the end of the function
19910 so that finish_function knows where we are. */
19911 input_location
19914 /* Remember if we saw an infinite loop in the template. */
19915 current_function_infinite_loop
19917 }
19919 /* We don't need the local specializations any more. */
19923 /* Finish the function. */
19927 else
19928 {
19931 }
19935 }
19937 /* We're not deferring instantiation any more. */
19945 out:
19955 }
19957 /* Run through the list of templates that we wish we could
19958 instantiate, and instantiate any we can. RETRIES is the
19959 number of times we retry pending template instantiation. */
19961 void
19963 {
19967 /* Instantiating templates may trigger vtable generation. This in turn
19968 may require further template instantiations. We place a limit here
19969 to avoid infinite loop. */
19971 {
19975 " instantiating %q+D, possibly from virtual table generation"
19979 /* Pretend that we defined it. */
19982 }
19984 do
19985 {
19990 {
19995 {
19996 tree fn;
19999 {
20003 fn;
20011 }
20014 }
20015 else
20016 {
20019 {
20020 instantiation
20026 }
20030 }
20033 /* If INSTANTIATION has been instantiated, then we don't
20034 need to consider it again in the future. */
20036 else
20037 {
20040 }
20043 }
20045 }
20049 }
20051 /* Substitute ARGVEC into T, which is a list of initializers for
20052 either base class or a non-static data member. The TREE_PURPOSEs
20053 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20054 instantiate_decl. */
20056 static tree
20058 {
20062 {
20063 tree decl;
20064 tree init;
20070 {
20071 tree expr;
20072 tree arg;
20074 /* Expand the base class expansion type into separate base
20075 classes. */
20077 tf_warning_or_error,
20078 NULL_TREE);
20082 /* We'll be building separate TREE_LISTs of arguments for
20083 each base. */
20089 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20090 expand each argument in the TREE_VALUE of t. */
20097 /* VOID_TYPE_NODE is used to indicate
20098 value-initialization. */
20099 {
20102 }
20103 else
20104 {
20105 /* Substitute parameter packs into each argument in the
20106 TREE_LIST. */
20109 {
20110 tree expanded_exprs;
20112 /* Expand the argument. */
20114 expanded_exprs
20116 tf_warning_or_error,
20117 NULL_TREE);
20121 /* Prepend each of the expanded expressions to the
20122 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20124 {
20129 }
20130 }
20133 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20134 since we built them backwards. */
20136 {
20139 }
20140 }
20141 }
20144 {
20146 {
20150 }
20151 else
20152 {
20153 tree tmp;
20168 /* If we had an initializer but it instantiated to nothing,
20169 value-initialize the object. This will only occur when
20170 the initializer was a pack expansion where the parameter
20171 packs used in that expansion were of length zero. */
20174 }
20177 {
20181 }
20182 }
20183 }
20185 }
20187 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20189 static void
20191 {
20196 else
20198 }
20200 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20201 is the instantiation (which should have been created with
20202 start_enum) and ARGS are the template arguments to use. */
20204 static void
20206 {
20207 tree e;
20213 {
20214 tree value;
20215 tree decl;
20218 /* Note that in a template enum, the TREE_VALUE is the
20219 CONST_DECL, not the corresponding INTEGER_CST. */
20224 /* Give this enumeration constant the correct access. */
20227 /* Actually build the enumerator itself. */
20228 build_enumerator
20230 }
20240 }
20242 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20243 its type -- but without substituting the innermost set of template
20244 arguments. So, innermost set of template parameters will appear in
20245 the type. */
20247 tree
20249 {
20250 tree fn_type;
20251 tree tmpl;
20252 tree targs;
20253 tree tparms;
20261 /* There should be as many levels of arguments as there are levels
20262 of parameters. */
20268 /* No substitution is necessary. */
20269 ;
20270 else
20271 {
20273 tree partial_args;
20275 /* Replace the innermost level of the TARGS with NULL_TREEs to
20276 let tsubst know not to substitute for those parameters. */
20285 /* Make sure that we can see identifiers, and compute access
20286 correctly. */
20290 /* Now, do the (partial) substitution to figure out the
20291 appropriate function type. */
20295 /* Substitute into the template parameters to obtain the real
20296 innermost set of parameters. This step is important if the
20297 innermost set of template parameters contains value
20298 parameters whose types depend on outer template parameters. */
20303 }
20306 }
20308 /* Return truthvalue if we're processing a template different from
20309 the last one involved in diagnostics. */
20310 int
20312 {
20314 }
20316 /* Remember current template involved in diagnostics. */
20317 void
20319 {
20321 }
20325 {
20327 }
20329 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20330 type. Return zero for ok, nonzero for disallowed. Issue error and
20331 warning messages under control of COMPLAIN. */
20333 static int
20335 {
20352 {
20355 else
20357 type);
20358 }
20360 }
20362 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20363 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20365 static bool
20367 {
20368 tree scope;
20370 /* [temp.dep.type]
20372 A type is dependent if it is:
20374 -- a template parameter. Template template parameters are types
20375 for us (since TYPE_P holds true for them) so we handle
20376 them here. */
20380 /* -- a qualified-id with a nested-name-specifier which contains a
20381 class-name that names a dependent type or whose unqualified-id
20382 names a dependent type. */
20385 /* -- a cv-qualified type where the cv-unqualified type is
20386 dependent. */
20388 /* -- a compound type constructed from any dependent type. */
20398 {
20399 tree arg_type;
20404 arg_type;
20409 }
20410 /* -- an array type constructed from any dependent type or whose
20411 size is specified by a constant expression that is
20412 value-dependent.
20414 We checked for type- and value-dependence of the bounds in
20415 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20417 {
20422 }
20424 /* -- a template-id in which either the template name is a template
20425 parameter ... */
20428 /* ... or any of the template arguments is a dependent type or
20429 an expression that is type-dependent or value-dependent. */
20431 && (any_dependent_template_arguments_p
20435 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20436 dependent; if the argument of the `typeof' expression is not
20437 type-dependent, then it should already been have resolved. */
20443 /* A template argument pack is dependent if any of its packed
20444 arguments are. */
20446 {
20452 }
20454 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20455 be template parameters. */
20459 /* The standard does not specifically mention types that are local
20460 to template functions or local classes, but they should be
20461 considered dependent too. For example:
20463 template <int I> void f() {
20464 enum E { a = I };
20465 S<sizeof (E)> s;
20466 }
20468 The size of `E' cannot be known until the value of `I' has been
20469 determined. Therefore, `E' must be considered dependent. */
20473 /* Don't use type_dependent_expression_p here, as it can lead
20474 to infinite recursion trying to determine whether a lambda
20475 nested in a lambda is dependent (c++/47687). */
20479 && (any_dependent_template_arguments_p
20483 /* Other types are non-dependent. */
20485 }
20487 /* Returns TRUE if TYPE is dependent, in the sense of
20488 [temp.dep.type]. Note that a NULL type is considered dependent. */
20490 bool
20492 {
20493 /* If there are no template parameters in scope, then there can't be
20494 any dependent types. */
20496 {
20497 /* If we are not processing a template, then nobody should be
20498 providing us with a dependent type. */
20502 }
20504 /* If the type is NULL, we have not computed a type for the entity
20505 in question; in that case, the type is dependent. */
20509 /* Erroneous types can be considered non-dependent. */
20513 /* If we have not already computed the appropriate value for TYPE,
20514 do so now. */
20516 {
20519 }
20522 }
20524 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20525 lookup. In other words, a dependent type that is not the current
20526 instantiation. */
20528 bool
20530 {
20533 }
20535 /* T is a SCOPE_REF; return whether we need to consider it
20536 instantiation-dependent so that we can check access at instantiation
20537 time even though we know which member it resolves to. */
20539 static bool
20541 {
20547 else
20549 }
20551 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20552 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20553 expression. */
20555 /* Note that this predicate is not appropriate for general expressions;
20556 only constant expressions (that satisfy potential_constant_expression)
20557 can be tested for value dependence. */
20559 bool
20561 {
20565 /* A name declared with a dependent type. */
20570 {
20572 /* A name that has not been looked up -- must be dependent. */
20576 /* A non-type template parm. */
20580 /* A non-type template parm. */
20586 /* A constant with literal type and is initialized
20587 with an expression that is value-dependent.
20589 Note that a non-dependent parenthesized initializer will have
20590 already been replaced with its constant value, so if we see
20591 a TREE_LIST it must be dependent. */
20604 /* These expressions are value-dependent if the type to which
20605 the cast occurs is dependent or the expression being casted
20606 is value-dependent. */
20607 {
20613 /* A functional cast has a list of operands. */
20616 {
20617 /* If there are no operands, it must be an expression such
20618 as "int()". This should not happen for aggregate types
20619 because it would form non-constant expressions. */
20624 }
20630 }
20635 /* FALLTHRU */
20638 /* A `sizeof' expression is value-dependent if the operand is
20639 type-dependent or is a pack expansion. */
20648 /* An 'encode' expression is value-dependent if the operand is
20649 type-dependent. */
20658 /* All instantiation-dependent expressions should also be considered
20659 value-dependent. */
20667 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20668 is value-dependent. */
20669 {
20678 }
20681 {
20685 }
20696 {
20700 }
20703 {
20710 {
20712 /* In a call to a constexpr member function, look through the
20713 implicit ADDR_EXPR on the object argument so that it doesn't
20714 cause the call to be considered value-dependent. We also
20715 look through it in potential_constant_expression. */
20722 }
20724 }
20727 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20728 type-dependent. */
20732 {
20734 tree val;
20739 }
20742 /* Treat a GNU statement expression as dependent to avoid crashing
20743 under fold_non_dependent_expr; it can't be constant. */
20747 /* A constant expression is value-dependent if any subexpression is
20748 value-dependent. */
20750 {
20757 {
20761 {
20764 /* In some cases, some of the operands may be missing.l
20765 (For example, in the case of PREDECREMENT_EXPR, the
20766 amount to increment by may be missing.) That doesn't
20767 make the expression dependent. */
20770 }
20771 }
20775 }
20777 }
20779 /* The expression is not value-dependent. */
20781 }
20783 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20784 [temp.dep.expr]. Note that an expression with no type is
20785 considered dependent. Other parts of the compiler arrange for an
20786 expression with type-dependent subexpressions to have no type, so
20787 this function doesn't have to be fully recursive. */
20789 bool
20791 {
20798 /* An unresolved name is always dependent. */
20802 /* Some expression forms are never type-dependent. */
20815 /* The types of these expressions depends only on the type to which
20816 the cast occurs. */
20825 /* The types of these expressions depends only on the type created
20826 by the expression. */
20829 {
20830 /* For NEW_EXPR tree nodes created inside a template, either
20831 the object type itself or a TREE_LIST may appear as the
20832 operand 1. */
20835 /* This is an array type. We need to check array dimensions
20836 as well. */
20838 || value_dependent_expression_p
20840 else
20842 }
20845 {
20849 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20850 contains an identifier associated by name lookup with one or more
20851 declarations declared with a dependent type, or...a
20852 nested-name-specifier or qualified-id that names a member of an
20853 unknown specialization. */
20856 }
20861 && (any_dependent_template_arguments_p
20873 {
20874 tree elt;
20878 {
20881 }
20883 }
20885 /* A static data member of the current instantiation with incomplete
20886 array type is type-dependent, as the definition and specializations
20887 can have different bounds. */
20894 /* An array of unknown bound depending on a variadic parameter, eg:
20896 template<typename... Args>
20897 void foo (Args... args)
20898 {
20899 int arr[] = { args... };
20900 }
20902 template<int... vals>
20903 void bar ()
20904 {
20905 int arr[] = { vals... };
20906 }
20908 If the array has no length and has an initializer, it must be that
20909 we couldn't determine its length in cp_complete_array_type because
20910 it is dependent. */
20918 {
20923 {
20929 }
20930 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
20934 /* Always dependent, on the number of arguments if nothing else. */
20942 {
20947 }
20952 {
20956 }
20958 }
20963 }
20965 /* walk_tree callback function for instantiation_dependent_expression_p,
20966 below. Returns non-zero if a dependent subexpression is found. */
20968 static tree
20971 {
20973 {
20974 /* We don't have to worry about decltype currently because decltype
20975 of an instantiation-dependent expr is a dependent type. This
20976 might change depending on the resolution of DR 1172. */
20979 }
20982 {
20983 /* Don't treat an argument list as dependent just because it has no
20984 TREE_TYPE. */
20991 /* A constant with a dependent initializer is dependent. */
20999 /* Handle expressions with type operands. */
21004 {
21009 {
21012 else
21013 {
21016 }
21017 }
21019 }
21031 /* In a template, finish_class_member_access_expr creates a
21032 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21033 type-dependent, so that we can check access control at
21034 instantiation time (PR 42277). See also Core issue 1273. */
21041 else
21044 /* Treat statement-expressions as dependent. */
21050 }
21054 else
21056 }
21058 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21059 sense defined by the ABI:
21061 "An expression is instantiation-dependent if it is type-dependent
21062 or value-dependent, or it has a subexpression that is type-dependent
21063 or value-dependent." */
21065 bool
21067 {
21068 tree result;
21079 }
21081 /* Like type_dependent_expression_p, but it also works while not processing
21082 a template definition, i.e. during substitution or mangling. */
21084 bool
21086 {
21092 }
21094 /* Returns TRUE if ARGS contains a type-dependent expression. */
21096 bool
21098 {
21100 tree arg;
21103 {
21106 }
21108 }
21110 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21111 expressions) contains any type-dependent expressions. */
21113 bool
21115 {
21121 }
21123 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21124 expressions) contains any value-dependent expressions. */
21126 bool
21128 {
21134 }
21136 /* Returns TRUE if the ARG (a template argument) is dependent. */
21138 bool
21140 {
21144 /* Assume a template argument that was wrongly written by the user
21145 is dependent. This is consistent with what
21146 any_dependent_template_arguments_p [that calls this function]
21147 does. */
21158 {
21162 {
21165 }
21168 }
21171 else
21174 }
21176 /* Returns true if ARGS (a collection of template arguments) contains
21177 any types that require structural equality testing. */
21179 bool
21181 {
21191 {
21194 {
21200 {
21201 /* Look inside the argument pack. */
21204 }
21207 {
21220 }
21221 }
21222 }
21225 }
21227 /* Returns true if ARGS (a collection of template arguments) contains
21228 any dependent arguments. */
21230 bool
21232 {
21242 {
21247 }
21250 }
21252 /* Returns TRUE if the template TMPL is dependent. */
21254 bool
21256 {
21258 {
21260 {
21264 }
21266 }
21268 /* Template template parameters are dependent. */
21272 /* So are names that have not been looked up. */
21275 /* So are member templates of dependent classes. */
21279 }
21281 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21283 bool
21285 {
21288 }
21290 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21291 is dependent. */
21293 bool
21295 {
21302 {
21323 {
21327 }
21331 {
21335 {
21340 }
21341 }
21342 }
21345 }
21347 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21348 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21349 no such TYPE can be found. Note that this function peers inside
21350 uninstantiated templates and therefore should be used only in
21351 extremely limited situations. ONLY_CURRENT_P restricts this
21352 peering to the currently open classes hierarchy (which is required
21353 when comparing types). */
21355 tree
21357 {
21358 tree scope;
21359 tree name;
21360 tree decl;
21362 tree pushed_scope;
21363 tree result;
21368 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21369 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21370 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21371 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21372 identifier of the TYPENAME_TYPE anymore.
21373 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21374 TYPENAME_TYPE instead, we avoid messing up with a possible
21375 typedef variant case. */
21378 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21379 it first before we can figure out what NAME refers to. */
21381 {
21383 /* Given a class template A with a dependent base with nested type C,
21384 typedef typename A::C::C C will land us here, as trying to resolve
21385 the initial A::C leads to the local C typedef, which leads back to
21386 A::C::C. So we break the recursion now. */
21388 else
21390 }
21391 /* If we don't know what SCOPE refers to, then we cannot resolve the
21392 TYPENAME_TYPE. */
21395 /* If the SCOPE is a template type parameter, we have no way of
21396 resolving the name. */
21399 /* If the SCOPE is not the current instantiation, there's no reason
21400 to look inside it. */
21403 /* If this is a typedef, we don't want to look inside (c++/11987). */
21406 /* If SCOPE isn't the template itself, it will not have a valid
21407 TYPE_FIELDS list. */
21409 /* scope is either the template itself or a compatible instantiation
21410 like X<T>, so look up the name in the original template. */
21412 else
21413 /* scope is a partial instantiation, so we can't do the lookup or we
21414 will lose the template arguments. */
21416 /* Enter the SCOPE so that name lookup will be resolved as if we
21417 were in the class definition. In particular, SCOPE will no
21418 longer be considered a dependent type. */
21420 /* Look up the declaration. */
21422 tf_warning_or_error);
21426 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21427 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21432 {
21436 }
21439 {
21440 tree tmpl;
21441 tree args;
21442 /* Obtain the template and the arguments. */
21445 /* Instantiate the template. */
21451 }
21453 /* Leave the SCOPE. */
21457 /* If we failed to resolve it, return the original typename. */
21461 /* If lookup found a typename type, resolve that too. */
21463 {
21464 /* Ill-formed programs can cause infinite recursion here, so we
21465 must catch that. */
21469 }
21471 /* Qualify the resulting type. */
21477 }
21479 /* EXPR is an expression which is not type-dependent. Return a proxy
21480 for EXPR that can be used to compute the types of larger
21481 expressions containing EXPR. */
21483 tree
21485 {
21486 tree inner_expr;
21488 #ifdef ENABLE_CHECKING
21489 /* Try to get a constant value for all non-dependent expressions in
21490 order to expose bugs in *_dependent_expression_p and constexpr. */
21493 #endif
21495 /* Preserve OVERLOADs; the functions must be available to resolve
21496 types. */
21507 /* There is no need to return a proxy for a variable. */
21510 /* Preserve string constants; conversions from string constants to
21511 "char *" are allowed, even though normally a "const char *"
21512 cannot be used to initialize a "char *". */
21515 /* Preserve arithmetic constants, as an optimization -- there is no
21516 reason to create a new node. */
21519 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21520 There is at least one place where we want to know that a
21521 particular expression is a throw-expression: when checking a ?:
21522 expression, there are special rules if the second or third
21523 argument is a throw-expression. */
21527 /* Don't wrap an initializer list, we need to be able to look inside. */
21531 /* Don't wrap a dummy object, we need to be able to test for it. */
21550 /* If the type is unknown, it can't really be non-dependent */
21553 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21555 }
21557 /* ARGS is a vector of expressions as arguments to a function call.
21558 Replace the arguments with equivalent non-dependent expressions.
21559 This modifies ARGS in place. */
21561 void
21563 {
21565 tree arg;
21568 {
21572 }
21573 }
21575 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21576 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21577 parms. */
21579 static tree
21581 {
21594 }
21596 tree
21598 {
21600 }
21602 tree
21604 {
21606 }
21608 /* Given type ARG, return std::initializer_list<ARG>. */
21610 static tree
21612 {
21613 tree std_init_list = namespace_binding
21615 tree argvec;
21617 {
21621 }
21626 }
21628 /* Replace auto in TYPE with std::initializer_list<auto>. */
21630 static tree
21632 {
21639 }
21641 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21642 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21644 tree
21646 {
21647 tree targs;
21653 /* Defining a subset of type-dependent expressions that we can deduce
21654 from ahead of time isn't worth the trouble. */
21657 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21658 with either a new invented type template parameter U or, if the
21659 initializer is a braced-init-list (8.5.4), with
21660 std::initializer_list<U>. */
21668 {
21674 {
21677 }
21678 }
21679 else
21680 {
21691 {
21693 /* Try again at instantiation time. */
21696 /* If type is error_mark_node a diagnostic must have been
21697 emitted by now. Also, having a mention to '<type error>'
21698 in the diagnostic is not really useful to the user. */
21699 {
21703 else
21705 }
21707 }
21708 }
21710 /* If the list of declarators contains more than one declarator, the type
21711 of each declared variable is determined as described above. If the
21712 type deduced for the template parameter U is not the same in each
21713 deduction, the program is ill-formed. */
21716 {
21722 else
21726 }
21732 }
21734 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21735 result. */
21737 tree
21739 {
21740 tree argvec;
21747 /* For a late-specified return type in a template type-parameter, we
21748 need to add a dummy argument level for its parmlist. */
21749 argvec = add_to_template_args
21754 }
21756 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21757 'decltype(auto)'. */
21759 bool
21761 {
21766 else
21768 }
21770 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21771 a use of `auto'. Returns NULL_TREE otherwise. */
21773 tree
21775 {
21777 }
21779 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21780 'decltype(auto)' or a concept. */
21782 bool
21784 {
21786 }
21788 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21789 a concept identifier) iff TYPE contains a use of a generic type. Returns
21790 NULL_TREE otherwise. */
21792 tree
21794 {
21796 }
21799 /* For a given template T, return the vector of typedefs referenced
21800 in T for which access check is needed at T instantiation time.
21801 T is either a FUNCTION_DECL or a RECORD_TYPE.
21802 Those typedefs were added to T by the function
21803 append_type_to_template_for_access_check. */
21807 {
21808 tree ti;
21819 {
21824 }
21827 }
21829 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21830 tied to T. That list of typedefs will be access checked at
21831 T instantiation time.
21832 T is either a FUNCTION_DECL or a RECORD_TYPE.
21833 TYPE_DECL is a TYPE_DECL node representing a typedef.
21834 SCOPE is the scope through which TYPE_DECL is accessed.
21835 LOCATION is the location of the usage point of TYPE_DECL.
21837 This function is a subroutine of
21838 append_type_to_template_for_access_check. */
21840 static void
21842 tree type_decl,
21843 tree scope,
21844 location_t location)
21845 {
21846 qualified_typedef_usage_t typedef_usage;
21847 tree ti;
21854 && type_decl
21868 }
21870 /* Append TYPE_DECL to the template TEMPL.
21871 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21872 At TEMPL instanciation time, TYPE_DECL will be checked to see
21873 if it can be accessed through SCOPE.
21874 LOCATION is the location of the usage point of TYPE_DECL.
21876 e.g. consider the following code snippet:
21878 class C
21879 {
21880 typedef int myint;
21881 };
21883 template<class U> struct S
21884 {
21885 C::myint mi; // <-- usage point of the typedef C::myint
21886 };
21888 S<char> s;
21890 At S<char> instantiation time, we need to check the access of C::myint
21891 In other words, we need to check the access of the myint typedef through
21892 the C scope. For that purpose, this function will add the myint typedef
21893 and the scope C through which its being accessed to a list of typedefs
21894 tied to the template S. That list will be walked at template instantiation
21895 time and access check performed on each typedefs it contains.
21896 Note that this particular code snippet should yield an error because
21897 myint is private to C. */
21899 void
21901 tree type_decl,
21902 tree scope,
21903 location_t location)
21904 {
21910 /* Make sure we don't append the type to the template twice. */
21917 }
21919 /* Convert the generic type parameters in PARM that match the types given in the
21920 range [START_IDX, END_IDX) from the current_template_parms into generic type
21921 packs. */
21923 tree
21925 {
21936 {
21937 /* Create a distinct parameter pack type from the current parm and add it
21938 to the replacement args to tsubst below into the generic function
21939 parameter. */
21954 }
21960 /* If there are more levels then build up the replacement with the outer
21961 template parms. */
21965 replacement);
21968 }
21971 /* Set up the hash tables for template instantiations. */
21973 void
21975 {
21977 hash_specialization,
21978 eq_specializations,
21979 ggc_free);
21981 hash_specialization,
21982 eq_specializations,
21983 ggc_free);
21984 }
21986 /* Print stats about the template hash tables for -fstats. */
21988 void
21990 {
21999 }