| blob | c74e7ae7586088c1e56ca198e9d2b4ee3d718411 |
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;
470 {
475 {
478 }
481 }
483 /* Remember how many levels of template parameters we pushed so that
484 we can pop them later. */
486 }
488 /* Undo the effects of maybe_begin_member_template_processing. */
490 void
492 {
501 {
505 }
506 }
508 /* Return a new template argument vector which contains all of ARGS,
509 but has as its innermost set of arguments the EXTRA_ARGS. */
511 static tree
513 {
514 tree new_args;
532 }
534 /* Like add_to_template_args, but only the outermost ARGS are added to
535 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
536 (EXTRA_ARGS) levels are added. This function is used to combine
537 the template arguments from a partial instantiation with the
538 template arguments used to attain the full instantiation from the
539 partial instantiation. */
541 static tree
543 {
544 tree new_args;
546 /* If there are more levels of EXTRA_ARGS than there are ARGS,
547 something very fishy is going on. */
550 /* If *all* the new arguments will be the EXTRA_ARGS, just return
551 them. */
555 /* For the moment, we make ARGS look like it contains fewer levels. */
560 /* Now, we restore ARGS to its full dimensions. */
564 }
566 /* Return the N levels of innermost template arguments from the ARGS. */
568 tree
570 {
571 tree new_args;
577 /* If N is 1, just return the innermost set of template arguments. */
581 /* If we're not removing anything, just return the arguments we were
582 given. */
588 /* Make a new set of arguments, not containing the outer arguments. */
595 }
597 /* The inverse of get_innermost_template_args: Return all but the innermost
598 EXTRA_LEVELS levels of template arguments from the ARGS. */
600 static tree
602 {
603 tree new_args;
609 /* If N is 1, just return the outermost set of template arguments. */
613 /* If we're not removing anything, just return the arguments we were
614 given. */
619 /* Make a new set of arguments, not containing the inner arguments. */
626 }
628 /* We've got a template header coming up; push to a new level for storing
629 the parms. */
631 void
633 {
634 /* We use a non-tag-transparent scope here, which causes pushtag to
635 put tags in this scope, rather than in the enclosing class or
636 namespace scope. This is the right thing, since we want
637 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
638 global template class, push_template_decl handles putting the
639 TEMPLATE_DECL into top-level scope. For a nested template class,
640 e.g.:
642 template <class T> struct S1 {
643 template <class T> struct S2 {};
644 };
646 pushtag contains special code to call pushdecl_with_scope on the
647 TEMPLATE_DECL for S2. */
652 }
654 /* This routine is called when a specialization is declared. If it is
655 invalid to declare a specialization here, an error is reported and
656 false is returned, otherwise this routine will return true. */
658 static bool
660 {
663 /* [temp.expl.spec]
665 An explicit specialization shall be declared in the namespace of
666 which the template is a member, or, for member templates, in the
667 namespace of which the enclosing class or enclosing class
668 template is a member. An explicit specialization of a member
669 function, member class or static data member of a class template
670 shall be declared in the namespace of which the class template
671 is a member. */
673 {
676 }
678 /* [temp.expl.spec]
680 In an explicit specialization declaration for a member of a class
681 template or a member template that appears in namespace scope,
682 the member template and some of its enclosing class templates may
683 remain unspecialized, except that the declaration shall not
684 explicitly specialize a class member template if its enclosing
685 class templates are not explicitly specialized as well. */
687 {
690 }
693 }
695 /* We've just seen template <>. */
697 bool
699 {
703 }
705 /* Called at then end of processing a declaration preceded by
706 template<>. */
708 void
710 {
713 }
715 /* Any template <>'s that we have seen thus far are not referring to a
716 function specialization. */
718 void
720 {
723 }
725 /* We've just seen a template header. If SPECIALIZATION is nonzero,
726 it was of the form template <>. */
728 static void
730 {
732 template_header_count++;
733 }
735 /* We're beginning an explicit instantiation. */
737 void
739 {
742 }
745 void
747 {
750 }
752 /* An explicit specialization or partial specialization of TMPL is being
753 declared. Check that the namespace in which the specialization is
754 occurring is permissible. Returns false iff it is invalid to
755 specialize TMPL in the current namespace. */
757 static bool
759 {
762 /* [tmpl.expl.spec]
764 An explicit specialization shall be declared in the namespace of
765 which the template is a member, or, for member templates, in the
766 namespace of which the enclosing class or enclosing class
767 template is a member. An explicit specialization of a member
768 function, member class or static data member of a class template
769 shall be declared in the namespace of which the class template is
770 a member. */
773 {
776 }
778 /* Same or super-using namespace. */
780 else
781 {
785 }
786 }
788 /* SPEC is an explicit instantiation. Check that it is valid to
789 perform this explicit instantiation in the current namespace. */
791 static void
793 {
794 tree ns;
796 /* DR 275: An explicit instantiation shall appear in an enclosing
797 namespace of its template. */
803 }
805 /* The TYPE is being declared. If it is a template type, that means it
806 is a partial specialization. Do appropriate error-checking. */
808 tree
810 {
811 tree context;
816 /* A lambda that appears in specialization context is not itself a
817 specialization. */
822 {
826 }
831 {
836 else
839 }
841 {
842 /* This is for ordinary explicit specialization and partial
843 specialization of a template class such as:
845 template <> class C<int>;
847 or:
849 template <class T> class C<T*>;
851 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
855 {
862 {
866 }
867 }
873 /* Trying to define a specialization either without a template<> header
874 or in an inappropriate place. We've already given an error, so just
875 bail now so we don't actually define the specialization. */
877 }
883 {
884 /* This is for an explicit specialization of member class
885 template according to [temp.expl.spec/18]:
887 template <> template <class U> class C<int>::D;
889 The context `C<int>' must be an implicit instantiation.
890 Otherwise this is just a member class template declared
891 earlier like:
893 template <> class C<int> { template <class U> class D; };
894 template <> template <class U> class C<int>::D;
896 In the first case, `C<int>::D' is a specialization of `C<T>::D'
897 while in the second case, `C<int>::D' is a primary template
898 and `C<T>::D' may not exist. */
902 {
903 tree t;
908 {
911 }
913 /* Check for invalid specialization after instantiation:
915 template <> template <> class C<int>::D<int>;
916 template <> template <class U> class C<int>::D; */
920 {
924 {
925 /* We already have a full specialization of this partial
926 instantiation, or a full specialization has been
927 looked up but not instantiated. Reassign it to the
928 new member specialization template. */
929 spec_entry elt;
946 }
947 else
948 /* But if we've had an implicit instantiation, that's a
949 problem ([temp.expl.spec]/6). */
952 }
954 /* Mark TYPE as a specialization. And as a result, we only
955 have one level of template argument for the innermost
956 class template. */
961 }
962 }
964 {
965 /* Someday C++0x may allow for enum template specialization. */
970 else
971 {
974 }
975 }
978 }
980 /* Returns nonzero if we can optimize the retrieval of specializations
981 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
982 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
986 {
989 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
990 parameter. */
992 /* The optimized lookup depends on the fact that the
993 template arguments for the member function template apply
994 purely to the containing class, which is not true if the
995 containing class is an explicit or partial
996 specialization. */
1000 /* It is possible to have a template that is not a member
1001 template and is not a member of a template class:
1003 template <typename T>
1004 struct S { friend A::f(); };
1006 Here, the friend function is a template, but the context does
1007 not have template information. The optimized lookup relies
1008 on having ARGS be the template arguments for both the class
1009 and the function template. */
1011 }
1013 /* Retrieve the specialization (in the sense of [temp.spec] - a
1014 specialization is either an instantiation or an explicit
1015 specialization) of TMPL for the given template ARGS. If there is
1016 no such specialization, return NULL_TREE. The ARGS are a vector of
1017 arguments, or a vector of vectors of arguments, in the case of
1018 templates with more than one level of parameters.
1020 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1021 then we search for a partial specialization matching ARGS. This
1022 parameter is ignored if TMPL is not a class template.
1024 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1025 result is a NONTYPE_ARGUMENT_PACK. */
1027 static tree
1029 {
1039 /* There should be as many levels of arguments as there are
1040 levels of parameters. */
1047 {
1048 tree class_template;
1049 tree class_specialization;
1051 tree fns;
1054 /* The template arguments actually apply to the containing
1055 class. Find the class specialization with those
1056 arguments. */
1058 class_specialization
1062 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1063 for the specialization. */
1067 /* Iterate through the methods with the indicated name, looking
1068 for the one that has an instance of TMPL. */
1071 {
1074 /* using-declarations can add base methods to the method vec,
1075 and we don't want those here. */
1078 }
1080 }
1081 else
1082 {
1084 spec_entry elt;
1085 htab_t specializations;
1093 else
1101 }
1104 }
1106 /* Like retrieve_specialization, but for local declarations. */
1108 static tree
1110 {
1118 }
1120 /* Returns nonzero iff DECL is a specialization of TMPL. */
1122 int
1124 {
1125 tree t;
1128 {
1134 }
1135 else
1136 {
1145 }
1148 }
1150 /* Returns nonzero iff DECL is a specialization of friend declaration
1151 FRIEND_DECL according to [temp.friend]. */
1153 bool
1155 {
1162 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1163 of a template class, we want to check if DECL is a specialization
1164 if this. */
1168 {
1169 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1172 }
1177 /* There is nothing to do if this is not a template friend. */
1184 /* [temp.friend/6]
1185 A member of a class template may be declared to be a friend of a
1186 non-template class. In this case, the corresponding member of
1187 every specialization of the class template is a friend of the
1188 class granting friendship.
1190 For example, given a template friend declaration
1192 template <class T> friend void A<T>::f();
1194 the member function below is considered a friend
1196 template <> struct A<int> {
1197 void f();
1198 };
1200 For this type of template friend, TEMPLATE_DEPTH below will be
1201 nonzero. To determine if DECL is a friend of FRIEND, we first
1202 check if the enclosing class is a specialization of another. */
1209 {
1210 /* Next, we check the members themselves. In order to handle
1211 a few tricky cases, such as when FRIEND_DECL's are
1213 template <class T> friend void A<T>::g(T t);
1214 template <class T> template <T t> friend void A<T>::h();
1216 and DECL's are
1218 void A<int>::g(int);
1219 template <int> void A<int>::h();
1221 we need to figure out ARGS, the template arguments from
1222 the context of DECL. This is required for template substitution
1223 of `T' in the function parameter of `g' and template parameter
1224 of `h' in the above examples. Here ARGS corresponds to `int'. */
1231 {
1233 {
1236 else
1238 current_depth++;
1239 }
1241 }
1244 {
1246 tree friend_type;
1247 tree decl_type;
1248 tree friend_args_type;
1249 tree decl_args_type;
1251 /* Make sure that both DECL and FRIEND_DECL are templates or
1252 non-templates. */
1258 {
1259 /* If both are templates, check template parameter list. */
1260 tree friend_parms
1265 friend_parms))
1269 }
1270 else
1278 /* Check if return types match. */
1282 /* Check if function parameter types match, ignoring the
1283 `this' parameter. */
1292 }
1293 else
1294 {
1295 /* DECL is a TYPE_DECL */
1299 /* Make sure that both DECL and FRIEND_DECL are templates or
1300 non-templates. */
1301 is_template
1308 {
1309 tree friend_parms;
1310 /* If both are templates, check the name of the two
1311 TEMPLATE_DECL's first because is_friend didn't. */
1316 /* Now check template parameter list. */
1317 friend_parms
1320 return comp_template_parms
1322 friend_parms);
1323 }
1324 else
1327 }
1328 }
1330 }
1332 /* Register the specialization SPEC as a specialization of TMPL with
1333 the indicated ARGS. IS_FRIEND indicates whether the specialization
1334 is actually just a friend declaration. Returns SPEC, or an
1335 equivalent prior declaration, if available.
1337 We also store instantiations of field packs in the hash table, even
1338 though they are not themselves templates, to make lookup easier. */
1340 static tree
1342 hashval_t hash)
1343 {
1344 tree fn;
1346 spec_entry elt;
1354 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1355 register it; we want the corresponding TEMPLATE_DECL instead.
1356 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1357 the more obvious `uses_template_parms (spec)' to avoid problems
1358 with default function arguments. In particular, given
1359 something like this:
1361 template <class T> void f(T t1, T t = T())
1363 the default argument expression is not substituted for in an
1364 instantiation unless and until it is actually needed. */
1368 /* We don't put these specializations in the hash table, but we might
1369 want to give an error about a mismatch. */
1371 else
1372 {
1380 slot =
1384 else
1386 }
1388 /* We can sometimes try to re-register a specialization that we've
1389 already got. In particular, regenerate_decl_from_template calls
1390 duplicate_decls which will update the specialization list. But,
1391 we'll still get called again here anyhow. It's more convenient
1392 to simply allow this than to try to prevent it. */
1396 {
1398 {
1401 {
1403 fn);
1405 }
1406 else
1407 {
1408 tree clone;
1409 /* This situation should occur only if the first
1410 specialization is an implicit instantiation, the
1411 second is an explicit specialization, and the
1412 implicit instantiation has not yet been used. That
1413 situation can occur if we have implicitly
1414 instantiated a member function and then specialized
1415 it later.
1417 We can also wind up here if a friend declaration that
1418 looked like an instantiation turns out to be a
1419 specialization:
1421 template <class T> void foo(T);
1422 class S { friend void foo<>(int) };
1423 template <> void foo(int);
1425 We transform the existing DECL in place so that any
1426 pointers to it become pointers to the updated
1427 declaration.
1429 If there was a definition for the template, but not
1430 for the specialization, we want this to look as if
1431 there were no definition, and vice versa. */
1434 /* The call to duplicate_decls will have applied
1435 [temp.expl.spec]:
1437 An explicit specialization of a function template
1438 is inline only if it is explicitly declared to be,
1439 and independently of whether its function template
1440 is.
1442 to the primary function; now copy the inline bits to
1443 the various clones. */
1445 {
1452 }
1456 }
1457 }
1459 {
1461 /* Dup decl failed, but this is a new definition. Set the
1462 line number so any errors match this new
1463 definition. */
1467 }
1468 }
1472 /* A specialization must be declared in the same namespace as the
1473 template it is specializing. */
1479 {
1487 /* TMPL is a forward declaration of a template function; keep a list
1488 of all specializations in case we need to reassign them to a friend
1489 template later in tsubst_friend_function. */
1492 }
1495 }
1497 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1498 TMPL and ARGS members, ignores SPEC. */
1502 static int
1504 {
1515 }
1517 /* Returns a hash for a template TMPL and template arguments ARGS. */
1519 static hashval_t
1521 {
1524 }
1526 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1527 ignoring SPEC. */
1529 static hashval_t
1531 {
1534 }
1536 /* Recursively calculate a hash value for a template argument ARG, for use
1537 in the hash tables of template specializations. */
1539 hashval_t
1541 {
1553 /* We can get one of these when re-hashing a previous entry in the middle
1554 of substituting into a pack expansion. Just look through it. */
1563 {
1571 {
1576 }
1598 {
1601 {
1604 }
1606 }
1610 {
1613 }
1624 val = iterative_hash_template_arg
1636 val);
1638 val);
1647 /* A lambda can't appear in a template arg, but don't crash on
1648 erroneous input. */
1660 /* Now hash operands as usual. */
1665 }
1668 {
1672 val);
1675 /* Otherwise just compare the types during lookup. */
1684 {
1689 }
1690 }
1693 }
1695 /* Unregister the specialization SPEC as a specialization of TMPL.
1696 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1697 if the SPEC was listed as a specialization of TMPL.
1699 Note that SPEC has been ggc_freed, so we can't look inside it. */
1701 bool
1703 {
1705 spec_entry elt;
1713 {
1718 }
1721 }
1723 /* Like register_specialization, but for local declarations. We are
1724 registering SPEC, an instantiation of TMPL. */
1726 static void
1728 {
1733 }
1735 /* TYPE is a class type. Returns true if TYPE is an explicitly
1736 specialized class. */
1738 bool
1740 {
1744 }
1746 /* Print the list of functions at FNS, going through all the overloads
1747 for each element of the list. Alternatively, FNS can not be a
1748 TREE_LIST, in which case it will be printed together with all the
1749 overloads.
1751 MORE and *STR should respectively be FALSE and NULL when the function
1752 is called from the outside. They are used internally on recursive
1753 calls. print_candidates manages the two parameters and leaves NULL
1754 in *STR when it ends. */
1756 static void
1758 {
1764 {
1768 }
1769 else
1770 {
1773 {
1774 /* Pick the prefix string. */
1776 {
1780 }
1784 }
1787 }
1790 {
1793 }
1794 }
1796 /* Print the list of candidate FNS in an error message. FNS can also
1797 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1799 void
1801 {
1805 }
1807 /* Returns the template (one of the functions given by TEMPLATE_ID)
1808 which can be specialized to match the indicated DECL with the
1809 explicit template args given in TEMPLATE_ID. The DECL may be
1810 NULL_TREE if none is available. In that case, the functions in
1811 TEMPLATE_ID are non-members.
1813 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1814 specialization of a member template.
1816 The TEMPLATE_COUNT is the number of references to qualifying
1817 template classes that appeared in the name of the function. See
1818 check_explicit_specialization for a more accurate description.
1820 TSK indicates what kind of template declaration (if any) is being
1821 declared. TSK_TEMPLATE indicates that the declaration given by
1822 DECL, though a FUNCTION_DECL, has template parameters, and is
1823 therefore a template function.
1825 The template args (those explicitly specified and those deduced)
1826 are output in a newly created vector *TARGS_OUT.
1828 If it is impossible to determine the result, an error message is
1829 issued. The error_mark_node is returned to indicate failure. */
1831 static tree
1833 tree decl,
1837 tmpl_spec_kind tsk)
1838 {
1839 tree fns;
1840 tree targs;
1841 tree explicit_targs;
1843 /* A TREE_LIST of templates of which DECL may be a specialization.
1844 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1845 corresponding TREE_PURPOSE is the set of template arguments that,
1846 when used to instantiate the template, would produce a function
1847 with the signature of DECL. */
1857 /* We shouldn't be specializing a member template of an
1858 unspecialized class template; we already gave an error in
1859 check_specialization_scope, now avoid crashing. */
1862 {
1865 }
1873 /* Check for baselinks. */
1878 {
1881 }
1883 /* Count the number of template headers specified for this
1884 specialization. */
1892 {
1896 {
1897 tree decl_arg_types;
1898 tree fn_arg_types;
1899 tree insttype;
1901 /* In case of explicit specialization, we need to check if
1902 the number of template headers appearing in the specialization
1903 is correct. This is usually done in check_explicit_specialization,
1904 but the check done there cannot be exhaustive when specializing
1905 member functions. Consider the following code:
1907 template <> void A<int>::f(int);
1908 template <> template <> void A<int>::f(int);
1910 Assuming that A<int> is not itself an explicit specialization
1911 already, the first line specializes "f" which is a non-template
1912 member function, whilst the second line specializes "f" which
1913 is a template member function. So both lines are syntactically
1914 correct, and check_explicit_specialization does not reject
1915 them.
1917 Here, we can do better, as we are matching the specialization
1918 against the declarations. We count the number of template
1919 headers, and we check if they match TEMPLATE_COUNT + 1
1920 (TEMPLATE_COUNT is the number of qualifying template classes,
1921 plus there must be another header for the member template
1922 itself).
1924 Notice that if header_count is zero, this is not a
1925 specialization but rather a template instantiation, so there
1926 is no check we can perform here. */
1930 /* Check that the number of template arguments at the
1931 innermost level for DECL is the same as for FN. */
1939 /* DECL might be a specialization of FN. */
1943 /* For a non-static member function, we need to make sure
1944 that the const qualification is the same. Since
1945 get_bindings does not try to merge the "this" parameter,
1946 we must do the comparison explicitly. */
1952 /* Skip the "this" parameter and, for constructors of
1953 classes with virtual bases, the VTT parameter. A
1954 full specialization of a constructor will have a VTT
1955 parameter, but a template never will. */
1956 decl_arg_types
1958 fn_arg_types
1961 /* Function templates cannot be specializations; there are
1962 no partial specializations of functions. Therefore, if
1963 the type of DECL does not match FN, there is no
1964 match. */
1966 {
1970 }
1972 /* See whether this function might be a specialization of this
1973 template. Suppress access control because we might be trying
1974 to make this specialization a friend, and we have already done
1975 access control for the declaration of the specialization. */
1981 /* We cannot deduce template arguments that when used to
1982 specialize TMPL will produce DECL. */
1985 /* Make sure that the deduced arguments actually work. */
1989 fn_arg_types
1994 /* Save this template, and the arguments deduced. */
1996 }
1998 /* FN is an ordinary member function, and we need a
1999 specialization of a member template. */
2000 ;
2002 /* We can get IDENTIFIER_NODEs here in certain erroneous
2003 cases. */
2004 ;
2006 /* This is just an ordinary non-member function. Nothing can
2007 be a specialization of that. */
2008 ;
2010 /* Cannot specialize functions that are created implicitly. */
2011 ;
2012 else
2013 {
2014 tree decl_arg_types;
2016 /* This is an ordinary member function. However, since
2017 we're here, we can assume its enclosing class is a
2018 template class. For example,
2020 template <typename T> struct S { void f(); };
2021 template <> void S<int>::f() {}
2023 Here, S<int>::f is a non-template, but S<int> is a
2024 template class. If FN has the same type as DECL, we
2025 might be in business. */
2028 /* Its enclosing class is an explicit specialization
2029 of a template class. This is not a candidate. */
2034 /* The return types differ. */
2037 /* Adjust the type of DECL in case FN is a static member. */
2044 decl_arg_types))
2045 /* They match! */
2047 }
2048 }
2051 {
2052 /* We have:
2054 [temp.expl.spec]
2056 It is possible for a specialization with a given function
2057 signature to be instantiated from more than one function
2058 template. In such cases, explicit specification of the
2059 template arguments must be used to uniquely identify the
2060 function template specialization being specialized.
2062 Note that here, there's no suggestion that we're supposed to
2063 determine which of the candidate templates is most
2064 specialized. However, we, also have:
2066 [temp.func.order]
2068 Partial ordering of overloaded function template
2069 declarations is used in the following contexts to select
2070 the function template to which a function template
2071 specialization refers:
2073 -- when an explicit specialization refers to a function
2074 template.
2076 So, we do use the partial ordering rules, at least for now.
2077 This extension can only serve to make invalid programs valid,
2078 so it's safe. And, there is strong anecdotal evidence that
2079 the committee intended the partial ordering rules to apply;
2080 the EDG front end has that behavior, and John Spicer claims
2081 that the committee simply forgot to delete the wording in
2082 [temp.expl.spec]. */
2085 {
2088 }
2089 }
2092 {
2100 }
2104 {
2110 }
2112 /* We have one, and exactly one, match. */
2114 {
2117 /* DECL is a re-declaration or partial instantiation of a template
2118 function. */
2121 /* It was a specialization of an ordinary member function in a
2122 template class. */
2124 }
2126 /* It was a specialization of a template. */
2129 {
2134 }
2135 else
2138 }
2140 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2141 but with the default argument values filled in from those in the
2142 TMPL_TYPES. */
2144 static tree
2146 tree tmpl_types)
2147 {
2148 tree new_spec_types;
2156 /* Substitute into the rest of the list. */
2157 new_spec_types =
2161 /* Add the default argument for this parameter. */
2164 new_spec_types);
2165 }
2167 /* DECL is an explicit specialization. Replicate default arguments
2168 from the template it specializes. (That way, code like:
2170 template <class T> void f(T = 3);
2171 template <> void f(double);
2172 void g () { f (); }
2174 works, as required.) An alternative approach would be to look up
2175 the correct default arguments at the call-site, but this approach
2176 is consistent with how implicit instantiations are handled. */
2178 static void
2180 {
2181 tree tmpl;
2182 tree spec_types;
2183 tree tmpl_types;
2184 tree new_spec_types;
2185 tree old_type;
2186 tree new_type;
2187 tree t;
2192 /* See if there's anything we need to do. */
2205 {
2206 /* Remove the this pointer, but remember the object's type for
2207 CV quals. */
2213 {
2214 /* DECL may contain more parameters than TMPL due to the extra
2215 in-charge parameter in constructors and destructors. */
2218 }
2220 {
2223 }
2224 }
2226 /* Compute the merged default arguments. */
2227 new_spec_types =
2230 /* Compute the new FUNCTION_TYPE. */
2232 {
2236 new_spec_types);
2239 /* Put the in-charge parameter back. */
2242 new_spec_types);
2246 new_spec_types);
2247 }
2248 else
2250 new_spec_types);
2256 }
2258 /* Return the number of template headers we expect to see for a definition
2259 or specialization of CTYPE or one of its non-template members. */
2261 int
2263 {
2267 {
2268 /* You're supposed to have one `template <...>' for every
2269 template class, but you don't need one for a full
2270 specialization. For example:
2272 template <class T> struct S{};
2273 template <> struct S<int> { void f(); };
2274 void S<int>::f () {}
2276 is correct; there shouldn't be a `template <>' for the
2277 definition of `S<int>::f'. */
2279 /* If CTYPE does not have template information of any
2280 kind, then it is not a template, nor is it nested
2281 within a template. */
2289 }
2292 }
2294 /* Do a simple sanity check on the template headers that precede the
2295 variable declaration DECL. */
2297 void
2299 {
2306 {
2312 "members of an explicitly specialized class are defined "
2314 }
2315 }
2317 /* Check to see if the function just declared, as indicated in
2318 DECLARATOR, and in DECL, is a specialization of a function
2319 template. We may also discover that the declaration is an explicit
2320 instantiation at this point.
2322 Returns DECL, or an equivalent declaration that should be used
2323 instead if all goes well. Issues an error message if something is
2324 amiss. Returns error_mark_node if the error is not easily
2325 recoverable.
2327 FLAGS is a bitmask consisting of the following flags:
2329 2: The function has a definition.
2330 4: The function is a friend.
2332 The TEMPLATE_COUNT is the number of references to qualifying
2333 template classes that appeared in the name of the function. For
2334 example, in
2336 template <class T> struct S { void f(); };
2337 void S<int>::f();
2339 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2340 classes are not counted in the TEMPLATE_COUNT, so that in
2342 template <class T> struct S {};
2343 template <> struct S<int> { void f(); }
2344 template <> void S<int>::f();
2346 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2347 invalid; there should be no template <>.)
2349 If the function is a specialization, it is marked as such via
2350 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2351 is set up correctly, and it is added to the list of specializations
2352 for that template. */
2354 tree
2356 tree decl,
2359 {
2367 tmpl_spec_kind tsk;
2370 {
2373 else
2375 }
2376 else
2380 {
2383 {
2386 }
2388 {
2390 /* This could be something like:
2392 template <class T> void f(T);
2393 class S { friend void f<>(int); } */
2395 else
2396 {
2397 /* This case handles bogus declarations like template <>
2398 template <class T> void f<int>(); */
2401 declarator);
2403 }
2404 }
2408 /* The error has already been reported in
2409 check_specialization_scope. */
2415 /* Fall through. */
2428 decl);
2431 else
2435 /* Fall through. */
2440 else
2446 {
2447 /* This case handles bogus declarations like template <>
2448 template <class T> void f<int>(); */
2453 else
2455 declarator);
2457 }
2460 /* This is a specialization of a member template, without
2461 specialization the containing class. Something like:
2463 template <class T> struct S {
2464 template <class U> void f (U);
2465 };
2466 template <> template <class U> void S<int>::f(U) {}
2468 That's a specialization -- but of the entire template. */
2474 }
2477 {
2481 {
2485 }
2486 }
2489 {
2493 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2495 {
2496 tree fns;
2501 else
2502 {
2503 /* If there is no class context, the explicit instantiation
2504 must be at namespace scope. */
2507 /* Find the namespace binding, using the declaration
2508 context. */
2512 {
2515 }
2516 else
2517 {
2523 }
2524 }
2527 }
2533 {
2535 /* A specialization in class scope. This is invalid,
2536 but the error will already have been flagged by
2537 check_specialization_scope. */
2539 else
2540 {
2541 /* It's not valid to write an explicit instantiation in
2542 class scope, e.g.:
2544 class C { template void f(); }
2546 This case is caught by the parser. However, on
2547 something like:
2549 template class C { void f(); };
2551 (which is invalid) we can get here. The error will be
2552 issued later. */
2553 ;
2554 }
2557 }
2560 {
2561 /* Find the list of functions in ctype that have the same
2562 name as the declared function. */
2568 {
2573 {
2574 /* From [temp.expl.spec]:
2576 If such an explicit specialization for the member
2577 of a class template names an implicitly-declared
2578 special member function (clause _special_), the
2579 program is ill-formed.
2581 Similar language is found in [temp.explicit]. */
2584 }
2587 }
2590 {
2594 }
2595 else
2596 {
2598 tree ovl;
2600 /* For a type-conversion operator, we cannot do a
2601 name-based lookup. We might be looking for `operator
2602 int' which will be a specialization of `operator T'.
2603 So, we find *all* the conversion operators, and then
2604 select from them. */
2612 {
2614 /* There are no more conversion functions. */
2617 /* Glue all these conversion functions together
2618 with those we already have. */
2621 }
2622 }
2625 {
2628 }
2629 else
2631 }
2633 /* Figure out what exactly is being specialized at this point.
2634 Note that for an explicit instantiation, even one for a
2635 member function, we cannot tell apriori whether the
2636 instantiation is for a member template, or just a member
2637 function of a template class. Even if a member template is
2638 being instantiated, the member template arguments may be
2639 elided if they can be deduced from the rest of the
2640 declaration. */
2643 member_specialization,
2644 template_count,
2645 tsk);
2648 /* We couldn't figure out what this declaration was
2649 specializing. */
2651 else
2652 {
2656 {
2657 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2658 is done by do_decl_instantiation later. */
2664 {
2665 /* If TMPL is not the most general template (for
2666 example, if TMPL is a friend template that is
2667 injected into namespace scope), then there will
2668 be too many levels of TARGS. Remove some of them
2669 here. */
2671 tree new_targs;
2678 }
2681 }
2683 /* If we thought that the DECL was a member function, but it
2684 turns out to be specializing a static member function,
2685 make DECL a static member function as well. */
2690 /* If this is a specialization of a member template of a
2691 template class, we want to return the TEMPLATE_DECL, not
2692 the specialization of it. */
2694 {
2699 {
2700 tree parm;
2704 /* We want to use the argument list specified in the
2705 definition, not in the original declaration. */
2710 }
2713 }
2715 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2718 /* Inherit default function arguments from the template
2719 DECL is specializing. */
2722 /* This specialization has the same protection as the
2723 template it specializes. */
2727 /* 7.1.1-1 [dcl.stc]
2729 A storage-class-specifier shall not be specified in an
2730 explicit specialization...
2732 The parser rejects these, so unless action is taken here,
2733 explicit function specializations will always appear with
2734 global linkage.
2736 The action recommended by the C++ CWG in response to C++
2737 defect report 605 is to make the storage class and linkage
2738 of the explicit specialization match the templated function:
2740 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2741 */
2743 {
2747 /* This specialization has the same linkage and visibility as
2748 the function template it specializes. */
2751 {
2754 }
2757 {
2760 }
2761 }
2763 /* If DECL is a friend declaration, declared using an
2764 unqualified name, the namespace associated with DECL may
2765 have been set incorrectly. For example, in:
2767 template <typename T> void f(T);
2768 namespace N {
2769 struct S { friend void f<int>(int); }
2770 }
2772 we will have set the DECL_CONTEXT for the friend
2773 declaration to N, rather than to the global namespace. */
2778 /* This is not really a declaration of a specialization.
2779 It's just the name of an instantiation. But, it's not
2780 a request for an instantiation, either. */
2783 /* Register this specialization so that we can find it
2784 again. */
2787 /* A 'structor should already have clones. */
2792 }
2793 }
2796 }
2798 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2799 parameters. These are represented in the same format used for
2800 DECL_TEMPLATE_PARMS. */
2802 int
2804 {
2805 const_tree p1;
2806 const_tree p2;
2814 {
2826 {
2830 /* If either of the template parameters are invalid, assume
2831 they match for the sake of error recovery. */
2844 }
2845 }
2848 /* One set of parameters has more parameters lists than the
2849 other. */
2853 }
2855 /* Determine whether PARM is a parameter pack. */
2857 bool
2859 {
2860 /* Determine if we have a non-type template parameter pack. */
2867 /* If this is a list of template parameters, we could get a
2868 TYPE_DECL or a TEMPLATE_DECL. */
2872 /* Otherwise it must be a type template parameter. */
2876 }
2878 /* Determine if T is a function parameter pack. */
2880 bool
2882 {
2886 }
2888 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2889 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2891 tree
2893 {
2900 }
2902 /* Return true iff the function parameter PARAM_DECL was expanded
2903 from the function parameter pack PACK. */
2905 bool
2907 {
2912 /* The parameter pack and its pack arguments have the same
2913 DECL_PARM_INDEX. */
2915 }
2917 /* Determine whether ARGS describes a variadic template args list,
2918 i.e., one that is terminated by a template argument pack. */
2920 static bool
2922 {
2924 tree last_parm;
2938 }
2940 /* Generate a new name for the parameter pack name NAME (an
2941 IDENTIFIER_NODE) that incorporates its */
2943 static tree
2945 {
2946 /* Munge the name to include the parameter index. */
2947 #define NUMBUF_LEN 128
2961 }
2963 /* Return true if T is a primary function, class or alias template
2964 instantiation. */
2966 bool
2968 {
2982 }
2984 /* Return true if PARM is a template template parameter. */
2986 bool
2988 {
2990 }
2992 /* Return true iff PARM is a DECL representing a type template
2993 parameter. */
2995 bool
2997 {
3002 }
3004 /* Return the template parameters of T if T is a
3005 primary template instantiation, NULL otherwise. */
3007 tree
3009 {
3014 parms = INNERMOST_TEMPLATE_PARMS
3018 }
3020 /* Return the template parameters of the LEVELth level from the full list
3021 of template parameters PARMS. */
3023 tree
3025 {
3026 tree p;
3037 }
3039 /* Returns the template arguments of T if T is a template instantiation,
3040 NULL otherwise. */
3042 tree
3044 {
3052 }
3054 /* Return the argument pack elements of T if T is a template argument pack,
3055 NULL otherwise. */
3057 tree
3059 {
3065 }
3067 /* Structure used to track the progress of find_parameter_packs_r. */
3068 struct find_parameter_pack_data
3069 {
3070 /* TREE_LIST that will contain all of the parameter packs found by
3071 the traversal. */
3074 /* Set of AST nodes that have been visited by the traversal. */
3076 };
3078 /* Identifies all of the argument packs that occur in a template
3079 argument and appends them to the TREE_LIST inside DATA, which is a
3080 find_parameter_pack_data structure. This is a subroutine of
3081 make_pack_expansion and uses_parameter_packs. */
3082 static tree
3084 {
3090 /* Handle type aliases/typedefs. */
3092 {
3099 }
3101 /* Identify whether this is a parameter pack or not. */
3103 {
3119 {
3120 /* We don't want to walk into the type of a PARM_DECL,
3121 because we don't want to see the type parameter pack. */
3124 }
3127 /* Look through a lambda capture proxy to the field pack. */
3130 {
3136 }
3143 /* Not a parameter pack. */
3145 }
3148 {
3149 /* Add this parameter pack to the list. */
3151 }
3157 /* This switch statement will return immediately if we don't find a
3158 parameter pack. */
3160 {
3165 /* Check the template itself. */
3168 /* Check the template arguments. */
3184 /* Fall through. */
3226 }
3229 }
3231 /* Determines if the expression or type T uses any parameter packs. */
3232 bool
3234 {
3242 }
3244 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3245 representation a base-class initializer into a parameter pack
3246 expansion. If all goes well, the resulting node will be an
3247 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3248 respectively. */
3249 tree
3251 {
3252 tree result;
3261 {
3262 /* The only time we will see a TREE_LIST here is for a base
3263 class initializer. In this case, the TREE_PURPOSE will be a
3264 _TYPE node (representing the base class expansion we're
3265 initializing) and the TREE_VALUE will be a TREE_LIST
3266 containing the initialization arguments.
3268 The resulting expansion looks somewhat different from most
3269 expansions. Rather than returning just one _EXPANSION, we
3270 return a TREE_LIST whose TREE_PURPOSE is a
3271 TYPE_PACK_EXPANSION containing the bases that will be
3272 initialized. The TREE_VALUE will be identical to the
3273 original TREE_VALUE, which is a list of arguments that will
3274 be passed to each base. We do not introduce any new pack
3275 expansion nodes into the TREE_VALUE (although it is possible
3276 that some already exist), because the TREE_PURPOSE and
3277 TREE_VALUE all need to be expanded together with the same
3278 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3279 resulting TREE_PURPOSE will mention the parameter packs in
3280 both the bases and the arguments to the bases. */
3281 tree purpose;
3282 tree value;
3285 /* Determine which parameter packs will be used by the base
3286 class expansion. */
3293 {
3297 }
3300 {
3301 /* Collect the sets of parameter packs used in each of the
3302 initialization arguments. */
3304 {
3305 /* Determine which parameter packs will be expanded in this
3306 argument. */
3309 }
3310 }
3314 /* Create the pack expansion type for the base type. */
3319 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3320 they will rarely be compared to anything. */
3324 }
3329 /* Build the PACK_EXPANSION_* node. */
3330 result = for_types
3335 {
3336 /* Propagate type and const-expression information. */
3339 }
3340 else
3341 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3342 they will rarely be compared to anything. */
3345 /* Determine which parameter packs will be expanded. */
3351 /* Make sure we found some parameter packs. */
3353 {
3356 else
3359 }
3365 }
3367 /* Checks T for any "bare" parameter packs, which have not yet been
3368 expanded, and issues an error if any are found. This operation can
3369 only be done on full expressions or types (e.g., an expression
3370 statement, "if" condition, etc.), because we could have expressions like:
3372 foo(f(g(h(args)))...)
3374 where "args" is a parameter pack. check_for_bare_parameter_packs
3375 should not be called for the subexpressions args, h(args),
3376 g(h(args)), or f(g(h(args))), because we would produce erroneous
3377 error messages.
3379 Returns TRUE and emits an error if there were bare parameter packs,
3380 returns FALSE otherwise. */
3381 bool
3383 {
3399 {
3402 {
3411 else
3416 else
3420 }
3423 }
3426 }
3428 /* Expand any parameter packs that occur in the template arguments in
3429 ARGS. */
3430 tree
3432 {
3438 /* First, determine if we need to expand anything, and the number of
3439 slots we'll need. */
3441 {
3446 {
3450 else
3452 }
3453 else
3454 {
3456 num_result_args++;
3457 }
3458 }
3460 /* If no expansion is necessary, we're done. */
3464 /* Expand arguments. */
3467 non_default_args_count =
3470 {
3473 {
3480 }
3481 else
3482 {
3485 }
3486 }
3490 }
3492 /* Checks if DECL shadows a template parameter.
3494 [temp.local]: A template-parameter shall not be redeclared within its
3495 scope (including nested scopes).
3497 Emits an error and returns TRUE if the DECL shadows a parameter,
3498 returns FALSE otherwise. */
3500 bool
3502 {
3503 tree olddecl;
3505 /* If we're not in a template, we can't possibly shadow a template
3506 parameter. */
3510 /* Figure out what we're shadowing. */
3515 /* If there's no previous binding for this name, we're not shadowing
3516 anything, let alone a template parameter. */
3520 /* If we're not shadowing a template parameter, we're done. Note
3521 that OLDDECL might be an OVERLOAD (or perhaps even an
3522 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3523 node. */
3527 /* We check for decl != olddecl to avoid bogus errors for using a
3528 name inside a class. We check TPFI to avoid duplicate errors for
3529 inline member templates. */
3535 /* Don't complain about the injected class name, as we've already
3536 complained about the class itself. */
3543 }
3545 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3546 ORIG_LEVEL, DECL, and TYPE. */
3548 static tree
3552 tree decl,
3553 tree type)
3554 {
3565 }
3567 /* Find the canonical type parameter for the given template type
3568 parameter. Returns the canonical type parameter, which may be TYPE
3569 if no such parameter existed. */
3571 static tree
3573 {
3574 tree list;
3588 else
3589 {
3594 }
3595 }
3597 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3598 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3599 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3600 new one is created. */
3602 static tree
3604 tsubst_flags_t complain)
3605 {
3610 {
3629 /* Template template parameters need this. */
3634 }
3637 }
3639 /* Process information from new template parameter PARM and append it
3640 to the LIST being built. This new parameter is a non-type
3641 parameter iff IS_NON_TYPE is true. This new parameter is a
3642 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3643 is in PARM_LOC. */
3645 tree
3648 {
3650 tree defval;
3657 {
3661 {
3665 else
3667 }
3670 }
3673 {
3679 {
3680 /* [temp.param]
3682 The top-level cv-qualifiers on the template-parameter are
3683 ignored when determining its type. */
3688 && !is_parameter_pack
3689 /* If we're in a nested template parameter list, the template
3690 template parameter could be a parameter pack. */
3692 {
3693 /* This template parameter is not a parameter pack, but it
3694 should be. Complain about "bare" parameter packs. */
3697 /* Recover by calling this a parameter pack. */
3699 }
3700 }
3702 /* A template parameter is not modifiable. */
3711 processing_template_decl,
3716 }
3717 else
3718 {
3719 tree t;
3723 {
3725 /* This is for distinguishing between real templates and template
3726 template parameters */
3730 }
3731 else
3732 {
3734 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3737 }
3744 processing_template_decl,
3748 }
3754 }
3756 /* The end of a template parameter list has been reached. Process the
3757 tree list into a parameter vector, converting each parameter into a more
3758 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3759 as PARM_DECLs. */
3761 tree
3763 {
3768 current_template_parms
3773 {
3777 }
3782 }
3784 /* end_template_decl is called after a template declaration is seen. */
3786 void
3788 {
3794 /* This matches the pushlevel in begin_template_parm_list. */
3799 }
3801 /* Takes a TREE_LIST representing a template parameter and convert it
3802 into an argument suitable to be passed to the type substitution
3803 functions. Note that If the TREE_LIST contains an error_mark
3804 node, the returned argument is error_mark_node. */
3806 static tree
3808 {
3821 {
3825 {
3826 /* Turn this argument into a TYPE_ARGUMENT_PACK
3827 with a single element, which expands T. */
3829 #ifdef ENABLE_CHECKING
3830 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3832 #endif
3837 }
3838 }
3839 else
3840 {
3844 {
3845 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3846 with a single element, which expands T. */
3849 #ifdef ENABLE_CHECKING
3850 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3852 #endif
3859 }
3860 else
3862 }
3864 }
3866 /* Given a set of template parameters, return them as a set of template
3867 arguments. The template parameters are represented as a TREE_VEC, in
3868 the form documented in cp-tree.h for template arguments. */
3870 static tree
3872 {
3873 tree header;
3878 /* If there is only one level of template parameters, we do not
3879 create a TREE_VEC of TREE_VECs. Instead, we return a single
3880 TREE_VEC containing the arguments. */
3885 {
3893 #ifdef ENABLE_CHECKING
3895 #endif
3899 else
3901 }
3904 /* This can happen for template parms of a template template
3905 parameter, e.g:
3907 template<template<class T, class U> class TT> struct S;
3909 Consider the level of the parms of TT; T and U both have
3910 level 2; TT has no template parm of level 1. So in this case
3911 the first element of full_template_args is NULL_TREE. If we
3912 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3913 of 2. This will make tsubst wrongly consider that T and U
3914 have level 1. Instead, let's create a dummy vector as the
3915 first element of full_template_args so that TMPL_ARGS_DEPTH
3916 returns the correct depth for args. */
3919 }
3921 /* Within the declaration of a template, return the currently active
3922 template parameters as an argument TREE_VEC. */
3924 static tree
3926 {
3928 }
3930 /* Update the declared TYPE by doing any lookups which were thought to be
3931 dependent, but are not now that we know the SCOPE of the declarator. */
3933 tree
3935 {
3946 /* Don't bother building up the args in this case. */
3948 {
3949 /* tsubst in the args corresponding to the template parameters,
3950 including auto if present. Most things will be unchanged, but
3951 make_typename_type and tsubst_qualified_id will resolve
3952 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3955 tree pushed;
3957 {
3961 }
3966 }
3972 {
3975 else
3977 }
3979 }
3981 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3982 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3983 a member template. Used by push_template_decl below. */
3985 static tree
3987 {
3995 }
3997 struct template_parm_data
3998 {
3999 /* The level of the template parameters we are currently
4000 processing. */
4003 /* The index of the specialization argument we are currently
4004 processing. */
4007 /* An array whose size is the number of template parameters. The
4008 elements are nonzero if the parameter has been used in any one
4009 of the arguments processed so far. */
4012 /* An array whose size is the number of template arguments. The
4013 elements are nonzero if the argument makes use of template
4014 parameters of this level. */
4016 };
4018 /* Subroutine of push_template_decl used to see if each template
4019 parameter in a partial specialization is used in the explicit
4020 argument list. If T is of the LEVEL given in DATA (which is
4021 treated as a template_parm_data*), then DATA->PARMS is marked
4022 appropriately. */
4024 static int
4026 {
4034 {
4037 }
4039 /* Return zero so that for_each_template_parm will continue the
4040 traversal of the tree; we want to mark *every* template parm. */
4042 }
4044 /* Process the partial specialization DECL. */
4046 static tree
4048 {
4054 tree inner_parms;
4055 tree inst;
4068 /* We check that each of the template parameters given in the
4069 partial specialization is used in the argument list to the
4070 specialization. For example:
4072 template <class T> struct S;
4073 template <class T> struct S<T*>;
4075 The second declaration is OK because `T*' uses the template
4076 parameter T, whereas
4078 template <class T> struct S<int>;
4080 is no good. Even trickier is:
4082 template <class T>
4083 struct S1
4084 {
4085 template <class U>
4086 struct S2;
4087 template <class U>
4088 struct S2<T>;
4089 };
4091 The S2<T> declaration is actually invalid; it is a
4092 full-specialization. Of course,
4094 template <class U>
4095 struct S2<T (*)(U)>;
4097 or some such would have been OK. */
4105 {
4110 NULL,
4112 }
4115 {
4116 /* One of the template parms was not used in a deduced context in the
4117 specialization. */
4119 {
4123 }
4127 }
4132 /* [temp.class.spec]
4134 The argument list of the specialization shall not be identical to
4135 the implicit argument list of the primary template. */
4142 /* A partial specialization that replaces multiple parameters of the
4143 primary template with a pack expansion is less specialized for those
4144 parameters. */
4146 {
4148 "primary template because it replaces multiple parameters "
4152 }
4154 /* [temp.class.spec]
4156 A partially specialized non-type argument expression shall not
4157 involve template parameters of the partial specialization except
4158 when the argument expression is a simple identifier.
4160 The type of a template parameter corresponding to a specialized
4161 non-type argument shall not be dependent on a parameter of the
4162 specialization.
4164 Also, we verify that pack expansions only occur at the
4165 end of the argument list. */
4169 {
4176 {
4177 /* Extract the arguments from the argument pack. We'll be
4178 iterating over these in the following loop. */
4181 }
4184 {
4186 /* Get the Jth argument in the parameter pack. */
4190 {
4191 /* Pack expansions must come at the end of the
4192 argument list. */
4195 {
4199 else
4202 }
4203 }
4206 /* We only care about the pattern. */
4212 /* This next two lines are the `argument expression is not just a
4213 simple identifier' condition and also the `specialized
4214 non-type argument' bit. */
4218 {
4222 arg);
4223 else
4224 {
4225 /* Look at the corresponding template parameter,
4226 marking which template parameters its type depends
4227 upon. */
4231 {
4232 /* We haven't yet initialized TPD2. Do so now. */
4234 /* The number of parameters here is the number in the
4235 main template, which, as checked in the assertion
4236 above, is NARGS. */
4240 }
4242 /* Mark the template parameters. But this time, we're
4243 looking for the template parameters of the main
4244 template, not in the specialization. */
4251 NULL,
4255 {
4256 /* The type depended on some template parameters.
4257 If they are fully specialized in the
4258 specialization, that's OK. */
4267 "type %qT of template argument %qE depends "
4269 "type %qT of template argument %qE depends "
4271 type,
4272 arg);
4273 }
4274 }
4275 }
4276 }
4277 }
4279 /* We should only get here once. */
4297 {
4301 {
4305 "partial specialization of %qT after instantiation "
4307 }
4308 }
4311 }
4313 /* PARM is a template parameter of some form; return the corresponding
4314 TEMPLATE_PARM_INDEX. */
4316 static tree
4318 {
4330 }
4332 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4333 parameter packs used by the template parameter PARM. */
4335 static void
4337 {
4338 /* A type parm can't refer to another parm. */
4342 {
4346 }
4353 }
4355 /* PARM is a template parameter pack. Return any parameter packs used in
4356 its type or the type of any of its template parameters. If there are
4357 any such packs, it will be instantiated into a fixed template parameter
4358 list by partial instantiation rather than be fully deduced. */
4360 tree
4362 {
4363 /* This can only be true in a member template. */
4366 /* This can only be true for a parameter pack. */
4369 /* A type parm can't refer to another parm. */
4382 }
4384 /* Check that a template declaration's use of default arguments and
4385 parameter packs is not invalid. Here, PARMS are the template
4386 parameters. IS_PRIMARY is true if DECL is the thing declared by
4387 a primary template. IS_PARTIAL is true if DECL is a partial
4388 specialization.
4390 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4391 declaration (but not a definition); 1 indicates a declaration, 2
4392 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4393 emitted for extraneous default arguments.
4395 Returns TRUE if there were no errors found, FALSE otherwise. */
4397 bool
4400 {
4403 tree parm_level;
4406 /* [temp.param]
4408 A default template-argument shall not be specified in a
4409 function template declaration or a function template definition, nor
4410 in the template-parameter-list of the definition of a member of a
4411 class template. */
4414 /* You can't have a function template declaration in a local
4415 scope, nor you can you define a member of a class template in a
4416 local scope. */
4422 /* A lambda doesn't have an explicit declaration; don't complain
4423 about the parms of the enclosing class. */
4430 /* If this is either a friend defined in the scope of the class
4431 or a member function. */
4437 /* And, if it was a member function, it really was defined in
4438 the scope of the class. */
4441 /* We already checked these parameters when the template was
4442 declared, so there's no need to do it again now. This function
4443 was defined in class scope, but we're processing its body now
4444 that the class is complete. */
4447 /* Core issue 226 (C++0x only): the following only applies to class
4448 templates. */
4451 {
4452 /* [temp.param]
4454 If a template-parameter has a default template-argument, all
4455 subsequent template-parameters shall have a default
4456 template-argument supplied. */
4458 {
4465 {
4475 {
4477 /* For better subsequent error-recovery, we indicate that
4478 there should have been a default argument. */
4481 }
4483 && !is_friend_decl
4484 /* Don't complain about an enclosing partial
4485 specialization. */
4490 /* A fixed parameter pack will be partially
4491 instantiated into a fixed length list. */
4493 {
4494 /* A primary class template can only have one
4495 parameter pack, at the end of the template
4496 parameter list. */
4501 else
4509 }
4510 }
4511 }
4512 }
4515 || is_partial
4516 || !is_primary
4518 /* For an ordinary class template, default template arguments are
4519 allowed at the innermost level, e.g.:
4520 template <class T = int>
4521 struct S {};
4522 but, in a partial specialization, they're not allowed even
4523 there, as we have in [temp.class.spec]:
4525 The template parameter list of a specialization shall not
4526 contain default template argument values.
4528 So, for a partial specialization, or for a function template
4529 (in C++98/C++03), we look at all of them. */
4530 ;
4531 else
4532 /* But, for a primary class template that is not a partial
4533 specialization we look at all template parameters except the
4534 innermost ones. */
4537 /* Figure out what error message to issue. */
4550 else
4554 /* If we're inside a class definition, there's no need to
4555 examine the parameters to the class itself. On the one
4556 hand, they will be checked when the class is defined, and,
4557 on the other, default arguments are valid in things like:
4558 template <class T = double>
4559 struct S { template <class U> void f(U); };
4560 Here the default argument for `S' has no bearing on the
4561 declaration of `f'. */
4563 else
4564 /* Check everything. */
4570 {
4577 {
4582 {
4584 {
4591 }
4593 /* Clear out the default argument so that we are not
4594 confused later. */
4596 }
4597 }
4599 /* At this point, if we're still interested in issuing messages,
4600 they must apply to classes surrounding the object declared. */
4604 }
4607 }
4609 /* Worker for push_template_decl_real, called via
4610 for_each_template_parm. DATA is really an int, indicating the
4611 level of the parameters we are interested in. If T is a template
4612 parameter of that level, return nonzero. */
4614 static int
4616 {
4622 else
4625 }
4627 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4628 parameters given by current_template_args, or reuses a
4629 previously existing one, if appropriate. Returns the DECL, or an
4630 equivalent one, if it is replaced via a call to duplicate_decls.
4632 If IS_FRIEND is true, DECL is a friend declaration. */
4634 tree
4636 {
4637 tree tmpl;
4638 tree args;
4639 tree info;
4640 tree ctx;
4644 /* True if the template is a member template, in the sense of
4645 [temp.mem]. */
4651 /* See if this is a partial specialization. */
4660 /* For a friend, we want the context of the friend function, not
4661 the type of which it is a friend. */
4665 /* In the case of a virtual function, we want the class in which
4666 it is defined. */
4668 else
4669 /* Otherwise, if we're currently defining some class, the DECL
4670 is assumed to be a member of the class. */
4679 /* See if this is a primary template. */
4682 /* A friend template that specifies a class context, i.e.
4683 template <typename T> friend void A<T>::f();
4684 is not primary. */
4686 else
4690 {
4695 {
4698 }
4700 {
4702 {
4703 /* [temp.mem]
4705 A destructor shall not be a member template. */
4708 }
4715 {
4716 /* [basic.stc.dynamic.allocation]
4718 An allocation function can be a function
4719 template. ... Template allocation functions shall
4720 have two or more parameters. */
4723 }
4724 }
4730 /* alias-declaration */
4732 else
4733 {
4736 }
4737 }
4739 /* Check to see that the rules regarding the use of default
4740 arguments are not being violated. */
4744 /* Ensure that there are no parameter packs in the type of this
4745 declaration that have not been expanded. */
4747 {
4748 /* Check each of the arguments individually to see if there are
4749 any bare parameter packs. */
4755 {
4758 {
4759 /* This is a PARM_DECL that contains unexpanded parameter
4760 packs. We have already complained about this in the
4761 check_for_bare_parameter_packs call, so just replace
4762 these types with ERROR_MARK_NODE. */
4765 }
4769 }
4771 /* Check for bare parameter packs in the return type and the
4772 exception specifiers. */
4774 /* Errors were already issued, set return type to int
4775 as the frontend doesn't expect error_mark_node as
4776 the return type. */
4780 }
4785 {
4788 }
4801 {
4806 /* If DECL is a TYPE_DECL for a class-template, then there won't
4807 be DECL_LANG_SPECIFIC. The information equivalent to
4808 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4812 {
4813 /* Since a template declaration already existed for this
4814 class-type, we must be redeclaring it here. Make sure
4815 that the redeclaration is valid. */
4817 current_template_parms);
4818 /* We don't need to create a new TEMPLATE_DECL; just use the
4819 one we already had. */
4821 }
4822 else
4823 {
4825 member_template_p);
4830 {
4831 /* A specialization of a member template of a template
4832 class. */
4836 }
4837 }
4838 }
4839 else
4840 {
4846 {
4849 }
4857 {
4858 tree new_tmpl;
4860 /* The declaration is a specialization of a member
4861 template, declared outside the class. Therefore, the
4862 innermost template arguments will be NULL, so we
4863 replace them with the arguments determined by the
4864 earlier call to check_explicit_specialization. */
4867 new_tmpl
4869 member_template_p);
4879 args,
4882 }
4884 /* Make sure the template headers we got make sense. */
4889 {
4894 }
4895 else
4897 {
4902 {
4906 else
4910 /* Avoid crash in import_export_decl. */
4913 }
4918 /* Can happen in erroneous input. */
4920 else
4922 }
4924 /* Check that the parms are used in the appropriate qualifying scopes
4925 in the declarator. */
4929 {
4935 /* Avoid crash in import_export_decl. */
4938 }
4939 }
4944 /* Push template declarations for global functions and types. Note
4945 that we do not try to push a global template friend declared in a
4946 template class; such a thing may well depend on the template
4947 parameters of the class. */
4950 {
4955 /* Hide template friend classes that haven't been declared yet. */
4957 {
4960 }
4961 }
4964 {
4970 {
4973 /* It is a conversion operator. See if the type converted to
4974 depends on innermost template operands. */
4977 depth))
4979 }
4981 /* Give template template parms a DECL_CONTEXT of the template
4982 for which they are a parameter. */
4985 {
4989 }
4990 }
4992 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4993 back to its most general template. If TMPL is a specialization,
4994 ARGS may only have the innermost set of arguments. Add the missing
4995 argument levels if necessary. */
5003 else
5004 {
5009 }
5012 }
5014 tree
5016 {
5018 }
5020 /* FN is an inheriting constructor that inherits from the constructor
5021 template INHERITED; turn FN into a constructor template with a matching
5022 template header. */
5024 tree
5026 {
5027 tree inner_parms
5030 tree parms
5041 }
5043 /* Called when a class template TYPE is redeclared with the indicated
5044 template PARMS, e.g.:
5046 template <class T> struct S;
5047 template <class T> struct S {}; */
5049 bool
5051 {
5052 tree tmpl;
5053 tree tmpl_parms;
5057 {
5060 }
5064 /* The type is nested in some template class. Nothing to worry
5065 about here; there are no new template parameters for the nested
5066 type. */
5070 {
5072 tmpl);
5074 }
5080 {
5090 }
5093 {
5094 tree tmpl_parm;
5095 tree parm;
5096 tree tmpl_default;
5097 tree parm_default;
5111 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5112 TEMPLATE_DECL. */
5122 {
5126 }
5129 {
5130 /* We have in [temp.param]:
5132 A template-parameter may not be given default arguments
5133 by two different declarations in the same scope. */
5138 }
5141 /* Update the previous template parameters (which are the ones
5142 that will really count) with the new default value. */
5145 /* Update the new parameters, too; they'll be used as the
5146 parameters for any members. */
5148 }
5151 }
5153 /* Simplify EXPR if it is a non-dependent expression. Returns the
5154 (possibly simplified) expression. */
5156 tree
5158 {
5162 /* If we're in a template, but EXPR isn't value dependent, simplify
5163 it. We're supposed to treat:
5165 template <typename T> void f(T[1 + 1]);
5166 template <typename T> void f(T[2]);
5168 as two declarations of the same function, for example. */
5172 {
5173 HOST_WIDE_INT saved_processing_template_decl;
5179 complain,
5184 }
5186 }
5188 tree
5190 {
5192 }
5194 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5195 template declaration, or a TYPE_DECL for an alias declaration. */
5197 bool
5199 {
5207 }
5209 /* Return TRUE iff is a specialization of an alias template. */
5211 bool
5213 {
5221 }
5223 /* Return the number of innermost template parameters in TMPL. */
5225 static int
5227 {
5230 }
5232 /* Return either TMPL or another template that it is equivalent to under DR
5233 1286: An alias that just changes the name of a template is equivalent to
5234 the other template. */
5236 static tree
5238 {
5241 {
5244 {
5249 {
5250 tree alias_args = INNERMOST_TEMPLATE_ARGS
5254 /* The alias type is equivalent to the pattern of the
5255 underlying template, so strip the alias. */
5258 }
5259 }
5261 }
5263 }
5265 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5266 must be a function or a pointer-to-function type, as specified
5267 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5268 and check that the resulting function has external linkage. */
5270 static tree
5272 {
5275 linkage_kind linkage;
5287 /* [temp.arg.nontype]/1
5289 A template-argument for a non-type, non-template template-parameter
5290 shall be one of:
5291 [...]
5292 -- the address of an object or function with external [C++11: or
5293 internal] linkage. */
5296 {
5300 else
5303 }
5307 {
5312 else
5317 }
5320 }
5322 /* Subroutine of convert_nontype_argument.
5323 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5324 Emit an error otherwise. */
5326 static bool
5328 tsubst_flags_t complain)
5329 {
5336 {
5340 }
5342 }
5344 /* Returns TRUE iff the address of OP is value-dependent.
5346 14.6.2.4 [temp.dep.temp]:
5347 A non-integral non-type template-argument is dependent if its type is
5348 dependent or it has either of the following forms
5349 qualified-id
5350 & qualified-id
5351 and contains a nested-name-specifier which specifies a class-name that
5352 names a dependent type.
5354 We generalize this to just say that the address of a member of a
5355 dependent class is value-dependent; the above doesn't cover the
5356 address of a static data member named with an unqualified-id. */
5358 static bool
5360 {
5361 /* We could use get_inner_reference here, but there's no need;
5362 this is only relevant for template non-type arguments, which
5363 can only be expressed as &id-expression. */
5365 {
5369 }
5372 }
5374 /* The next set of functions are used for providing helpful explanatory
5375 diagnostics for failed overload resolution. Their messages should be
5376 indented by two spaces for consistency with the messages in
5377 call.c */
5379 static int
5381 {
5383 }
5385 static int
5387 {
5392 }
5394 static int
5396 {
5398 }
5400 static int
5402 {
5408 }
5410 static int
5412 {
5416 }
5418 static int
5420 {
5423 " template parameter %qD is not a parameter pack, but "
5427 }
5429 static int
5431 {
5434 " template argument %qE does not match "
5438 }
5440 static int
5442 {
5446 }
5448 static int
5450 {
5456 }
5458 static int
5460 {
5462 {
5467 else
5469 " deduced conflicting values for non-type parameter "
5471 }
5473 }
5475 static int
5477 {
5480 " variable-sized array type %qT is not "
5482 arg);
5484 }
5486 static int
5488 {
5492 arg);
5494 }
5496 static int
5498 {
5505 }
5507 static int
5509 {
5511 }
5513 static int
5515 {
5517 }
5519 static int
5522 {
5528 }
5530 static int
5533 {
5536 {
5544 }
5546 }
5548 static int
5550 {
5553 " template parameters of a template template argument are "
5556 }
5558 static int
5560 {
5566 }
5568 static int
5570 {
5575 }
5577 static int
5579 {
5583 arg);
5585 }
5587 /* Attempt to convert the non-type template parameter EXPR to the
5588 indicated TYPE. If the conversion is successful, return the
5589 converted value. If the conversion is unsuccessful, return
5590 NULL_TREE if we issued an error message, or error_mark_node if we
5591 did not. We issue error messages for out-and-out bad template
5592 parameters, but not simply because the conversion failed, since we
5593 might be just trying to do argument deduction. Both TYPE and EXPR
5594 must be non-dependent.
5596 The conversion follows the special rules described in
5597 [temp.arg.nontype], and it is much more strict than an implicit
5598 conversion.
5600 This function is called twice for each template argument (see
5601 lookup_template_class for a more accurate description of this
5602 problem). This means that we need to handle expressions which
5603 are not valid in a C++ source, but can be created from the
5604 first call (for instance, casts to perform conversions). These
5605 hacks can go away after we fix the double coercion problem. */
5607 static tree
5609 {
5610 tree expr_type;
5612 /* Detect immediately string literals as invalid non-type argument.
5613 This special-case is not needed for correctness (we would easily
5614 catch this later), but only to provide better diagnostic for this
5615 common user mistake. As suggested by DR 100, we do not mention
5616 linkage issues in the diagnostic as this is not the point. */
5617 /* FIXME we're making this OK. */
5619 {
5625 }
5627 /* Add the ADDR_EXPR now for the benefit of
5628 value_dependent_expression_p. */
5631 {
5635 }
5637 /* If we are in a template, EXPR may be non-dependent, but still
5638 have a syntactic, rather than semantic, form. For example, EXPR
5639 might be a SCOPE_REF, rather than the VAR_DECL to which the
5640 SCOPE_REF refers. Preserving the qualifying scope is necessary
5641 so that access checking can be performed when the template is
5642 instantiated -- but here we need the resolved form so that we can
5643 convert the argument. */
5654 else
5657 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5658 to a non-type argument of "nullptr". */
5662 /* In C++11, integral or enumeration non-type template arguments can be
5663 arbitrary constant expressions. Pointer and pointer to
5664 member arguments can be general constant expressions that evaluate
5665 to a null value, but otherwise still need to be of a specific form. */
5667 {
5669 /* A PTRMEM_CST is already constant, and a valid template
5670 argument for a parameter of pointer to member type, we just want
5671 to leave it in that form rather than lower it to a
5676 {
5681 }
5682 }
5684 /* HACK: Due to double coercion, we can get a
5685 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5686 which is the tree that we built on the first call (see
5687 below when coercing to reference to object or to reference to
5688 function). We just strip everything and get to the arg.
5689 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5690 for examples. */
5692 {
5698 {
5699 /* ??? Maybe we could use convert_from_reference here, but we
5700 would need to relax its constraints because the NOP_EXPR
5701 could actually change the type to something more cv-qualified,
5702 and this is not folded by convert_from_reference. */
5707 && (same_type_ignoring_top_level_qualifiers_p
5710 {
5713 }
5714 }
5715 }
5717 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5718 parameter is a pointer to object, through decay and
5719 qualification conversion. Let's strip everything. */
5721 {
5726 {
5727 /* Skip the ADDR_EXPR only if it is part of the decay for
5728 an array. Otherwise, it is part of the original argument
5729 in the source code. */
5734 }
5735 }
5737 /* [temp.arg.nontype]/5, bullet 1
5739 For a non-type template-parameter of integral or enumeration type,
5740 integral promotions (_conv.prom_) and integral conversions
5741 (_conv.integral_) are applied. */
5743 {
5752 /* Notice that there are constant expressions like '4 % 0' which
5753 do not fold into integer constants. */
5755 {
5757 {
5768 /* else cxx_constant_value complained but gave us
5769 a real constant, so go ahead. */
5771 }
5772 else
5774 }
5776 /* Avoid typedef problems. */
5779 }
5780 /* [temp.arg.nontype]/5, bullet 2
5782 For a non-type template-parameter of type pointer to object,
5783 qualification conversions (_conv.qual_) and the array-to-pointer
5784 conversion (_conv.array_) are applied. */
5786 {
5787 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5789 A template-argument for a non-type, non-template template-parameter
5790 shall be one of: [...]
5792 -- the name of a non-type template-parameter;
5793 -- the address of an object or function with external linkage, [...]
5794 expressed as "& id-expression" where the & is optional if the name
5795 refers to a function or array, or if the corresponding
5796 template-parameter is a reference.
5798 Here, we do not care about functions, as they are invalid anyway
5799 for a parameter of type pointer-to-object. */
5802 /* Non-type template parameters are OK. */
5803 ;
5808 {
5810 {
5812 "because %qD is a variable, not the address of "
5816 }
5818 {
5823 }
5824 /* Other values, like integer constants, might be valid
5825 non-type arguments of some other type. */
5827 }
5828 else
5829 {
5830 tree decl;
5835 {
5840 }
5842 {
5847 }
5849 {
5854 }
5855 }
5864 }
5865 /* [temp.arg.nontype]/5, bullet 3
5867 For a non-type template-parameter of type reference to object, no
5868 conversions apply. The type referred to by the reference may be more
5869 cv-qualified than the (otherwise identical) type of the
5870 template-argument. The template-parameter is bound directly to the
5871 template-argument, which must be an lvalue. */
5873 {
5875 expr_type))
5879 {
5883 }
5886 {
5890 }
5892 /* [temp.arg.nontype]/1
5894 A template-argument for a non-type, non-template template-parameter
5895 shall be one of: [...]
5897 -- the address of an object or function with external linkage. */
5900 {
5903 {
5905 "because a reference variable does not have a constant "
5908 }
5909 }
5912 {
5917 }
5920 {
5925 }
5928 }
5929 /* [temp.arg.nontype]/5, bullet 4
5931 For a non-type template-parameter of type pointer to function, only
5932 the function-to-pointer conversion (_conv.func_) is applied. If the
5933 template-argument represents a set of overloaded functions (or a
5934 pointer to such), the matching function is selected from the set
5935 (_over.over_). */
5937 {
5938 /* If the argument is a template-id, we might not have enough
5939 context information to decay the pointer. */
5941 {
5945 }
5948 /* Null pointer values are OK in C++11. */
5954 }
5955 /* [temp.arg.nontype]/5, bullet 5
5957 For a non-type template-parameter of type reference to function, no
5958 conversions apply. If the template-argument represents a set of
5959 overloaded functions, the matching function is selected from the set
5960 (_over.over_). */
5962 {
5964 {
5969 }
5976 }
5977 /* [temp.arg.nontype]/5, bullet 6
5979 For a non-type template-parameter of type pointer to member function,
5980 no conversions apply. If the template-argument represents a set of
5981 overloaded member functions, the matching member function is selected
5982 from the set (_over.over_). */
5984 {
5989 /* [temp.arg.nontype] bullet 1 says the pointer to member
5990 expression must be a pointer-to-member constant. */
5994 /* There is no way to disable standard conversions in
5995 resolve_address_of_overloaded_function (called by
5996 instantiate_type). It is possible that the call succeeded by
5997 converting &B::I to &D::I (where B is a base of D), so we need
5998 to reject this conversion here.
6000 Actually, even if there was a way to disable standard conversions,
6001 it would still be better to reject them here so that we can
6002 provide a superior diagnostic. */
6004 {
6008 /* If we are just one standard conversion off, explain. */
6013 }
6014 }
6015 /* [temp.arg.nontype]/5, bullet 7
6017 For a non-type template-parameter of type pointer to data member,
6018 qualification conversions (_conv.qual_) are applied. */
6020 {
6021 /* [temp.arg.nontype] bullet 1 says the pointer to member
6022 expression must be a pointer-to-member constant. */
6029 }
6031 {
6033 {
6037 }
6039 }
6040 /* A template non-type parameter must be one of the above. */
6041 else
6044 /* Sanity check: did we actually convert the argument to the
6045 right type? */
6049 }
6051 /* Subroutine of coerce_template_template_parms, which returns 1 if
6052 PARM_PARM and ARG_PARM match using the rule for the template
6053 parameters of template template parameters. Both PARM and ARG are
6054 template parameters; the rest of the arguments are the same as for
6055 coerce_template_template_parms.
6056 */
6057 static int
6059 tree arg,
6060 tsubst_flags_t complain,
6061 tree in_decl,
6062 tree outer_args)
6063 {
6072 {
6074 /* We encounter instantiations of templates like
6075 template <template <template <class> class> class TT>
6076 class C; */
6077 {
6084 }
6085 /* Fall through. */
6090 /* Argument is a parameter pack but parameter is not. */
6095 /* The tsubst call is used to handle cases such as
6097 template <int> class C {};
6098 template <class T, template <T> class TT> class D {};
6099 D<int, C> d;
6101 i.e. the parameter list of TT depends on earlier parameters. */
6103 && !same_type_p
6110 /* Argument is a parameter pack but parameter is not. */
6117 }
6120 }
6123 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6124 template template parameters. Both PARM_PARMS and ARG_PARMS are
6125 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6126 or PARM_DECL.
6128 Consider the example:
6129 template <class T> class A;
6130 template<template <class U> class TT> class B;
6132 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6133 the parameters to A, and OUTER_ARGS contains A. */
6135 static int
6137 tree arg_parms,
6138 tsubst_flags_t complain,
6139 tree in_decl,
6140 tree outer_args)
6141 {
6152 /* Determine whether we have a parameter pack at the end of the
6153 template template parameter's template parameter list. */
6155 {
6162 {
6176 }
6177 }
6183 /* Check all of the template parameters except the parameter pack at
6184 the end (if any). */
6186 {
6195 outer_args))
6198 }
6201 {
6202 /* Check each of the template parameters in the template
6203 argument against the template parameter pack at the end of
6204 the template template parameter. */
6211 {
6218 outer_args))
6220 }
6221 }
6224 }
6226 /* Verifies that the deduced template arguments (in TARGS) for the
6227 template template parameters (in TPARMS) represent valid bindings,
6228 by comparing the template parameter list of each template argument
6229 to the template parameter list of its corresponding template
6230 template parameter, in accordance with DR150. This
6231 routine can only be called after all template arguments have been
6232 deduced. It will return TRUE if all of the template template
6233 parameter bindings are okay, FALSE otherwise. */
6234 bool
6236 {
6240 /* We're dealing with template parms in this process. */
6246 {
6251 {
6256 {
6257 /* Look inside the argument pack. */
6260 }
6263 {
6267 /* Extract the next argument from the argument
6268 pack. */
6272 /* Look at the pattern of the pack expansion. */
6275 /* Extract the template parameters from the template
6276 argument. */
6282 /* Verify that we can coerce the template template
6283 parameters from the template argument to the template
6284 parameter. This requires an exact match. */
6286 && !coerce_template_template_parms
6288 targ_parms,
6289 tf_none,
6290 tparm,
6291 targs))
6292 {
6295 }
6296 }
6297 }
6298 }
6300 out:
6304 }
6306 /* Since type attributes aren't mangled, we need to strip them from
6307 template type arguments. */
6309 static tree
6311 {
6312 tree mv;
6319 {
6324 }
6326 }
6328 /* Convert the indicated template ARG as necessary to match the
6329 indicated template PARM. Returns the converted ARG, or
6330 error_mark_node if the conversion was unsuccessful. Error and
6331 warning messages are issued under control of COMPLAIN. This
6332 conversion is for the Ith parameter in the parameter list. ARGS is
6333 the full set of template arguments deduced so far. */
6335 static tree
6337 tree arg,
6338 tree args,
6339 tsubst_flags_t complain,
6341 tree in_decl)
6342 {
6343 tree orig_arg;
6344 tree val;
6349 {
6350 /* The template argument was the name of some
6351 member function. That's usually
6352 invalid, but static members are OK. In any
6353 case, grab the underlying fields/functions
6354 and issue an error later if required. */
6357 }
6365 /* When determining whether an argument pack expansion is a template,
6366 look at the pattern. */
6370 /* Deal with an injected-class-name used as a template template arg. */
6372 {
6375 {
6385 }
6386 }
6388 is_tmpl_type =
6404 {
6406 {
6410 }
6413 "to refer to a type member of a template parameter, "
6418 typename_type,
6419 complain);
6422 }
6424 {
6426 {
6428 {
6438 else
6440 }
6441 }
6443 }
6445 {
6447 {
6453 else
6455 }
6457 }
6460 {
6462 {
6466 /* The number of argument required is not known yet.
6467 Just accept it for now. */
6469 else
6470 {
6472 tree argparm;
6474 /* Strip alias templates that are equivalent to another
6475 template. */
6481 args))
6482 {
6485 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6486 TEMPLATE_DECL. */
6488 {
6493 }
6494 }
6495 else
6496 {
6498 {
6504 }
6507 }
6508 }
6509 }
6510 else
6512 /* We only form one instance of each template specialization.
6513 Therefore, if we use a non-canonical variant (i.e., a
6514 typedef), any future messages referring to the type will use
6515 the typedef, which is confusing if those future uses do not
6516 themselves also use the typedef. */
6519 }
6520 else
6521 {
6528 {
6531 else
6532 {
6533 /* Not sure if this is reachable, but it doesn't hurt
6534 to be robust. */
6537 }
6538 }
6541 /* We used to call digest_init here. However, digest_init
6542 will report errors, which we don't want when complain
6543 is zero. More importantly, digest_init will try too
6544 hard to convert things: for example, `0' should not be
6545 converted to pointer type at this point according to
6546 the standard. Accepting this is not merely an
6547 extension, since deciding whether or not these
6548 conversions can occur is part of determining which
6549 function template to call, or whether a given explicit
6550 argument specification is valid. */
6552 else
6561 {
6562 /* Strip typedefs from the SCOPE_REF. */
6565 complain);
6568 }
6569 }
6572 }
6574 /* Coerces the remaining template arguments in INNER_ARGS (from
6575 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6576 Returns the coerced argument pack. PARM_IDX is the position of this
6577 parameter in the template parameter list. ARGS is the original
6578 template argument list. */
6579 static tree
6582 tree args,
6583 tree inner_args,
6585 tree new_args,
6587 tree in_decl,
6588 tsubst_flags_t complain)
6589 {
6592 tree packed_args;
6593 tree argument_pack;
6600 {
6601 /* When the template parameter is a non-type template parameter pack
6602 or template template parameter pack whose type or template
6603 parameters use parameter packs, we know exactly how many arguments
6604 we are looking for. Build a vector of the instantiated decls for
6605 these template parameters in PACKED_PARMS. */
6606 /* We can't use make_pack_expansion here because it would interpret a
6607 _DECL as a use rather than a declaration. */
6621 /* If we're doing a partial instantiation of a member template,
6622 verify that all of the types used for the non-type
6623 template parameter pack are, in fact, valid for non-type
6624 template parameters. */
6627 {
6630 {
6634 }
6635 }
6638 }
6639 else
6642 /* Convert the remaining arguments, which will be a part of the
6643 parameter pack "parm". */
6645 {
6651 {
6652 /* Once we've packed as many args as we have types, stop. */
6656 /* We don't know how many args we have yet, just
6657 use the unconverted ones for now. */
6659 else
6661 }
6664 {
6667 }
6668 else
6671 in_decl);
6675 }
6679 {
6683 }
6688 else
6689 {
6694 }
6697 #ifdef ENABLE_CHECKING
6700 #endif
6702 }
6704 /* Returns the number of pack expansions in the template argument vector
6705 ARGS. */
6707 static int
6709 {
6714 {
6718 }
6720 }
6722 /* Convert all template arguments to their appropriate types, and
6723 return a vector containing the innermost resulting template
6724 arguments. If any error occurs, return error_mark_node. Error and
6725 warning messages are issued under control of COMPLAIN.
6727 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6728 for arguments not specified in ARGS. Otherwise, if
6729 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6730 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6731 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6732 ARGS. */
6734 static tree
6736 tree args,
6737 tree in_decl,
6738 tsubst_flags_t complain,
6741 {
6743 tree orig_inner_args;
6744 tree inner_args;
6745 tree new_args;
6746 tree new_inner_args;
6750 /* When used as a boolean value, indicates whether this is a
6751 variadic template parameter list. Since it's an int, we can also
6752 subtract it from nparms to get the number of non-variadic
6753 parameters. */
6763 /* Determine if there are any parameter packs. */
6765 {
6771 }
6774 /* If there are no parameters that follow a parameter pack, we need to
6775 expand any argument packs so that we can deduce a parameter pack from
6776 some non-packed args followed by an argument pack, as in variadic85.C.
6777 If there are such parameters, we need to leave argument packs intact
6778 so the arguments are assigned properly. This can happen when dealing
6779 with a nested class inside a partial specialization of a class
6780 template, as in variadic92.C, or when deducing a template parameter pack
6781 from a sub-declarator, as in variadic114.C. */
6785 /* Count any pack expansion args. */
6791 && require_all_args
6792 && !variadic_args_p
6793 && (!use_default_args
6796 {
6798 {
6800 {
6804 }
6805 else
6811 }
6814 }
6815 /* We can't pass a pack expansion to a non-pack parameter of an alias
6816 template (DR 1430). */
6818 && variadic_args_p
6820 {
6822 {
6824 {
6830 {
6835 }
6836 }
6838 found:;
6839 }
6841 }
6843 /* We need to evaluate the template arguments, even though this
6844 template-id may be nested within a "sizeof". */
6853 {
6854 tree arg;
6855 tree parm;
6857 /* Get the Ith template parameter. */
6861 {
6864 }
6866 /* Calculate the next argument. */
6869 else
6874 {
6875 /* Some arguments will be placed in the
6876 template parameter pack PARM. */
6883 {
6884 /* We don't know how many args we have yet, just use the
6885 unconverted (and still packed) ones for now. */
6889 }
6893 /* Store this argument. */
6895 {
6896 lost++;
6897 /* We are done with all of the arguments. */
6899 }
6900 else
6901 {
6904 }
6907 }
6909 {
6911 {
6912 /* "If every valid specialization of a variadic template
6913 requires an empty template parameter pack, the template is
6914 ill-formed, no diagnostic required." So check that the
6915 pattern works with this parameter. */
6920 in_decl);
6922 {
6926 }
6928 /* Recover from missing typename. */
6932 /* We don't know how many args we have yet, just
6933 use the unconverted ones for now. */
6937 }
6938 }
6940 {
6941 /* There must be a default arg in this case. */
6944 /* The position of the first default template argument,
6945 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6946 Record that. */
6950 }
6951 else
6955 {
6958 }
6960 /* This only occurs if there was an error in the template
6961 parameter list itself (which we would already have
6962 reported) that we are trying to recover from, e.g., a class
6963 template with a parameter list such as
6964 template<typename..., typename>. */
6966 else
6972 lost++;
6974 }
6979 {
6981 {
6986 }
6988 }
6993 #ifdef ENABLE_CHECKING
6997 #endif
7000 }
7002 /* Like coerce_template_parms. If PARMS represents all template
7003 parameters levels, this function returns a vector of vectors
7004 representing all the resulting argument levels. Note that in this
7005 case, only the innermost arguments are coerced because the
7006 outermost ones are supposed to have been coerced already.
7008 Otherwise, if PARMS represents only (the innermost) vector of
7009 parameters, this function returns a vector containing just the
7010 innermost resulting arguments. */
7012 static tree
7014 tree args,
7015 tree in_decl,
7016 tsubst_flags_t complain,
7019 {
7022 tree coerced_args;
7025 {
7027 tree level;
7033 {
7034 tree l;
7038 require_all_args,
7039 use_default_args);
7040 else
7047 }
7048 }
7049 else
7052 require_all_args,
7053 use_default_args);
7055 }
7057 /* Returns 1 if template args OT and NT are equivalent. */
7059 static int
7061 {
7068 /* For member templates */
7077 {
7094 }
7096 {
7097 /* We get here probably because we are in the middle of substituting
7098 into the pattern of a pack expansion. In that case the
7099 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7100 interested in. So we want to use the initial pack argument for
7101 the comparison. */
7106 }
7111 else
7113 }
7115 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7116 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7117 NEWARG_PTR with the offending arguments if they are non-NULL. */
7119 static int
7122 {
7135 {
7140 {
7146 }
7147 }
7149 }
7151 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7152 of template arguments. Returns 0 otherwise. */
7154 int
7156 {
7158 }
7160 static void
7162 {
7172 /* We are called both from instantiate_decl, where we've already had a
7173 tinst_level pushed, and instantiate_template, where we haven't.
7174 Compensate. */
7185 else
7194 }
7197 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7198 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7199 documentation for TEMPLATE_ID_EXPR. */
7201 tree
7203 {
7204 tree type;
7212 {
7215 }
7218 {
7220 unknown_type_node,
7222 arglist);
7224 }
7231 }
7233 /* Within the scope of a template class S<T>, the name S gets bound
7234 (in build_self_reference) to a TYPE_DECL for the class, not a
7235 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7236 or one of its enclosing classes, and that type is a template,
7237 return the associated TEMPLATE_DECL. Otherwise, the original
7238 DECL is returned.
7240 Also handle the case when DECL is a TREE_LIST of ambiguous
7241 injected-class-names from different bases. */
7243 tree
7245 {
7249 /* DR 176: A lookup that finds an injected-class-name (10.2
7250 [class.member.lookup]) can result in an ambiguity in certain cases
7251 (for example, if it is found in more than one base class). If all of
7252 the injected-class-names that are found refer to specializations of
7253 the same class template, and if the name is followed by a
7254 template-argument-list, the reference refers to the class template
7255 itself and not a specialization thereof, and is not ambiguous. */
7257 {
7260 {
7266 }
7269 else
7271 }
7277 }
7279 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7280 parameters, find the desired type.
7282 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7284 IN_DECL, if non-NULL, is the template declaration we are trying to
7285 instantiate.
7287 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7288 the class we are looking up.
7290 Issue error and warning messages under control of COMPLAIN.
7292 If the template class is really a local class in a template
7293 function, then the FUNCTION_CONTEXT is the function in which it is
7294 being instantiated.
7296 ??? Note that this function is currently called *twice* for each
7297 template-id: the first time from the parser, while creating the
7298 incomplete type (finish_template_type), and the second type during the
7299 real instantiation (instantiate_template_class). This is surely something
7300 that we want to avoid. It also causes some problems with argument
7301 coercion (see convert_nontype_argument for more information on this). */
7303 static tree
7306 {
7308 tree t;
7311 spec_entry elt;
7312 hashval_t hash;
7315 {
7319 else
7320 {
7327 }
7330 }
7332 {
7335 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7336 an implicit typename for the second A. Deal with it. */
7341 {
7344 }
7345 }
7348 {
7351 }
7355 {
7359 }
7361 {
7364 }
7366 /* Issue an error message if we didn't find a template. */
7368 {
7372 }
7375 /* Make sure it's a user visible template, if it was named by
7376 the user. */
7379 {
7381 {
7385 }
7387 }
7391 /* An alias that just changes the name of a template is equivalent to the
7392 other template, so if any of the arguments are pack expansions, strip
7393 the alias to avoid problems with a pack expansion passed to a non-pack
7394 alias template parameter (DR 1430). */
7399 {
7400 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7401 template arguments */
7403 tree parm;
7404 tree arglist2;
7405 tree outer;
7409 /* Consider an example where a template template parameter declared as
7411 template <class T, class U = std::allocator<T> > class TT
7413 The template parameter level of T and U are one level larger than
7414 of TT. To proper process the default argument of U, say when an
7415 instantiation `TT<int>' is seen, we need to build the full
7416 arguments containing {int} as the innermost level. Outer levels,
7417 available when not appearing as default template argument, can be
7418 obtained from the arguments of the enclosing template.
7420 Suppose that TT is later substituted with std::vector. The above
7421 instantiation is `TT<int, std::allocator<T> >' with TT at
7422 level 1, and T at level 2, while the template arguments at level 1
7423 becomes {std::vector} and the inner level 2 is {int}. */
7429 /* This is an argument of the current template, so we haven't set
7430 DECL_CONTEXT yet. */
7437 complain,
7447 }
7448 else
7449 {
7451 tree gen_tmpl;
7452 tree type_decl;
7460 /* An error occurred while building the template TEMPL, and a
7461 diagnostic has most certainly been emitted for that
7462 already. Let's propagate that error. */
7471 {
7472 /* We've been given an incomplete set of template arguments.
7473 For example, given:
7475 template <class T> struct S1 {
7476 template <class U> struct S2 {};
7477 template <class U> struct S2<U*> {};
7478 };
7480 we will be called with an ARGLIST of `U*', but the
7481 TEMPLATE will be `template <class T> template
7482 <class U> struct S1<T>::S2'. We must fill in the missing
7483 arguments. */
7484 arglist
7486 arglist);
7488 }
7490 /* Now we should have enough arguments. */
7493 /* From here on, we're only interested in the most general
7494 template. */
7496 /* Calculate the BOUND_ARGS. These will be the args that are
7497 actually tsubst'd into the definition to create the
7498 instantiation. */
7500 {
7501 /* We have multiple levels of arguments to coerce, at once. */
7511 {
7512 tree a;
7516 complain,
7519 else
7520 /* Outer levels should have already been coerced. */
7523 /* Don't process further if one of the levels fails. */
7525 {
7526 /* Restore the ARGLIST to its full size. */
7529 }
7533 /* We temporarily reduce the length of the ARGLIST so
7534 that coerce_template_parms will see only the arguments
7535 corresponding to the template parameters it is
7536 examining. */
7538 }
7540 /* Restore the ARGLIST to its full size. */
7544 }
7545 else
7546 arglist
7549 gen_tmpl,
7550 complain,
7555 /* We were unable to bind the arguments. */
7558 /* In the scope of a template class, explicit references to the
7559 template class refer to the type of the template, not any
7560 instantiation of it. For example, in:
7562 template <class T> class C { void f(C<T>); }
7564 the `C<T>' is just the same as `C'. Outside of the
7565 class, however, such a reference is an instantiation. */
7569 /* comp_template_args is expensive, check it last. */
7571 arglist))
7574 /* If we already have this specialization, return it. */
7586 /* If the deduced arguments are invalid, then the binding
7587 failed. */
7591 complain))
7598 {
7603 }
7613 /* Create the type. */
7615 {
7616 /* The user referred to a specialization of an alias
7617 template represented by GEN_TMPL.
7619 [temp.alias]/2 says:
7621 When a template-id refers to the specialization of an
7622 alias template, it is equivalent to the associated
7623 type obtained by substitution of its
7624 template-arguments for the template-parameters in the
7625 type-id of the alias template. */
7628 /* Note that the call above (by indirectly calling
7629 register_specialization in tsubst_decl) registers the
7630 TYPE_DECL representing the specialization of the alias
7631 template. So next time someone substitutes ARGLIST for
7632 the template parms into the alias template (GEN_TMPL),
7633 she'll get that TYPE_DECL back. */
7637 }
7639 {
7641 {
7650 }
7651 else
7652 {
7653 /* We don't want to call start_enum for this type, since
7654 the values for the enumeration constants may involve
7655 template parameters. And, no one should be interested
7656 in the enumeration constants for such a type. */
7659 }
7663 }
7665 {
7672 /* A local class. Make sure the decl gets registered properly. */
7677 /* This instantiation is another name for the primary
7678 template type. Set the TYPE_CANONICAL field
7679 appropriately. */
7682 /* Some of the template arguments require structural
7683 equality testing, so this template class requires
7684 structural equality testing. */
7686 }
7687 else
7690 /* If we called start_enum or pushtag above, this information
7691 will already be set up. */
7693 {
7700 }
7701 else
7705 {
7711 {
7714 }
7715 }
7717 /* Let's consider the explicit specialization of a member
7718 of a class template specialization that is implicitly instantiated,
7719 e.g.:
7720 template<class T>
7721 struct S
7722 {
7723 template<class U> struct M {}; //#0
7724 };
7726 template<>
7727 template<>
7728 struct S<int>::M<char> //#1
7729 {
7730 int i;
7731 };
7732 [temp.expl.spec]/4 says this is valid.
7734 In this case, when we write:
7735 S<int>::M<char> m;
7737 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7738 the one of #0.
7740 When we encounter #1, we want to store the partial instantiation
7741 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7743 For all cases other than this "explicit specialization of member of a
7744 class template", we just want to store the most general template into
7745 the CLASSTYPE_TI_TEMPLATE of M.
7747 This case of "explicit specialization of member of a class template"
7748 only happens when:
7749 1/ the enclosing class is an instantiation of, and therefore not
7750 the same as, the context of the most general template, and
7751 2/ we aren't looking at the partial instantiation itself, i.e.
7752 the innermost arguments are not the same as the innermost parms of
7753 the most general template.
7755 So it's only when 1/ and 2/ happens that we want to use the partial
7756 instantiation of the member template in lieu of its most general
7757 template. */
7761 /* the enclosing class must be an instantiation... */
7764 {
7765 tree partial_inst_args;
7768 partial_inst_args =
7774 use_partial_inst_tmpl =
7775 /*...and we must not be looking at the partial instantiation
7776 itself. */
7778 partial_inst_args);
7779 }
7782 /* This case is easy; there are no member templates involved. */
7784 else
7785 {
7786 /* This is a full instantiation of a member template. Find
7787 the partial instantiation of which this is an instance. */
7789 /* Temporarily reduce by one the number of levels in the ARGLIST
7790 so as to avoid comparing the last set of arguments. */
7794 /* FOUND is either a proper class type, or an alias
7795 template specialization. In the later case, it's a
7796 TYPE_DECL, resulting from the substituting of arguments
7797 for parameters in the TYPE_DECL of the alias template
7798 done earlier. So be careful while getting the template
7799 of FOUND. */
7803 }
7814 /* Note this use of the partial instantiation so we can check it
7815 later in maybe_process_partial_specialization. */
7822 /* Now that the type has been registered on the instantiations
7823 list, we set up the enumerators. Because the enumeration
7824 constants may involve the enumeration type itself, we make
7825 sure to register the type first, and then create the
7826 constants. That way, doing tsubst_expr for the enumeration
7827 constants won't result in recursive calls here; we'll find
7828 the instantiation and exit above. */
7832 /* If the type makes use of template parameters, the
7833 code that generates debugging information will crash. */
7836 /* Possibly limit visibility based on template args. */
7841 }
7842 }
7844 /* Wrapper for lookup_template_class_1. */
7846 tree
7849 {
7850 tree ret;
7856 }
7857 \f
7858 struct pair_fn_data
7859 {
7860 tree_fn_t fn;
7862 /* True when we should also visit template parameters that occur in
7863 non-deduced contexts. */
7866 };
7868 /* Called from for_each_template_parm via walk_tree. */
7870 static tree
7872 {
7885 {
7889 /* Fall through. */
7912 /* Since we're not going to walk subtrees, we have to do this
7913 explicitly here. */
7917 /* Fall through. */
7920 /* Check the return type. */
7925 /* Check the parameter types. Since default arguments are not
7926 instantiated until they are needed, the TYPE_ARG_TYPES may
7927 contain expressions that involve template parameters. But,
7928 no-one should be looking at them yet. And, once they're
7929 instantiated, they don't contain template parameters, so
7930 there's no point in looking at them then, either. */
7931 {
7932 tree parm;
7939 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7940 want walk_tree walking into them itself. */
7942 }
7960 /* Fall through. */
7976 /* Record template parameters such as `T' inside `TT<T>'. */
7980 /* Fall through. */
7992 /* A template template parameter is encountered. */
7998 /* Already substituted template template parameter */
8021 /* If there's no type, then this thing must be some expression
8022 involving template parameters. */
8044 }
8046 /* We didn't find any template parameters we liked. */
8048 }
8050 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8051 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8052 call FN with the parameter and the DATA.
8053 If FN returns nonzero, the iteration is terminated, and
8054 for_each_template_parm returns 1. Otherwise, the iteration
8055 continues. If FN never returns a nonzero value, the value
8056 returned by for_each_template_parm is 0. If FN is NULL, it is
8057 considered to be the function which always returns 1.
8059 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8060 parameters that occur in non-deduced contexts. When false, only
8061 visits those template parameters that can be deduced. */
8063 static int
8067 {
8071 /* Set up. */
8076 /* Walk the tree. (Conceptually, we would like to walk without
8077 duplicates, but for_each_template_parm_r recursively calls
8078 for_each_template_parm, so we would need to reorganize a fair
8079 bit to use walk_tree_without_duplicates, so we keep our own
8080 visited list.) */
8083 else
8086 for_each_template_parm_r,
8090 /* Clean up. */
8092 {
8095 }
8098 }
8100 /* Returns true if T depends on any template parameter. */
8102 int
8104 {
8131 else
8132 {
8135 }
8140 }
8142 /* Returns true iff current_function_decl is an incompletely instantiated
8143 template. Useful instead of processing_template_decl because the latter
8144 is set to 0 during fold_non_dependent_expr. */
8146 bool
8148 {
8157 }
8159 /* Returns true if T depends on any template parameter with level LEVEL. */
8161 int
8163 {
8166 }
8168 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8169 ill-formed translation unit, i.e. a variable or function that isn't
8170 usable in a constant expression. */
8174 {
8178 }
8180 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8181 neglectable and instantiated from within an erroneous instantiation. */
8183 static bool
8185 {
8196 }
8204 /* We're starting to instantiate D; record the template instantiation context
8205 for diagnostics and to restore it later. */
8207 int
8209 {
8213 {
8219 else
8227 }
8229 /* If the current instantiation caused problems, don't let it instantiate
8230 anything else. Do allow deduction substitution and decls usable in
8231 constant expressions. */
8248 }
8250 /* We're done instantiating this template; return to the instantiation
8251 context. */
8253 void
8255 {
8256 /* Restore the filename and line number stashed away when we started
8257 this instantiation. */
8261 }
8263 /* We're instantiating a deferred template; restore the template
8264 instantiation context in which the instantiation was requested, which
8265 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8267 static tree
8269 {
8281 }
8283 /* Returns the TINST_LEVEL which gives the original instantiation
8284 context. */
8288 {
8294 }
8296 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8297 vector of template arguments, as for tsubst.
8299 Returns an appropriate tsubst'd friend declaration. */
8301 static tree
8303 {
8304 tree new_friend;
8309 /* This was a friend declared with an explicit template
8310 argument list, e.g.:
8312 friend void f<>(T);
8314 to indicate that f was a template instantiation, not a new
8315 function declaration. Now, we have to figure out what
8316 instantiation of what template. */
8317 {
8319 tree new_args;
8320 tree tmpl;
8323 /* Friend functions are looked up in the containing namespace scope.
8324 We must enter that scope, to avoid finding member functions of the
8325 current class with same name. */
8340 tsk_none);
8342 }
8346 /* The NEW_FRIEND will look like an instantiation, to the
8347 compiler, but is not an instantiation from the point of view of
8348 the language. For example, we might have had:
8350 template <class T> struct S {
8351 template <class U> friend void f(T, U);
8352 };
8354 Then, in S<int>, template <class U> void f(int, U) is not an
8355 instantiation of anything. */
8361 {
8365 }
8367 /* The mangled name for the NEW_FRIEND is incorrect. The function
8368 is not a template instantiation and should not be mangled like
8369 one. Therefore, we forget the mangling here; we'll recompute it
8370 later if we need it. */
8372 {
8375 }
8378 {
8379 tree old_decl;
8380 tree new_friend_template_info;
8381 tree new_friend_result_template_info;
8382 tree ns;
8385 /* We must save some information from NEW_FRIEND before calling
8386 duplicate decls since that function will free NEW_FRIEND if
8387 possible. */
8389 new_friend_is_defn =
8394 {
8395 /* This declaration is a `primary' template. */
8398 new_friend_result_template_info
8400 }
8401 else
8404 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8408 /* Inside pushdecl_namespace_level, we will push into the
8409 current namespace. However, the friend function should go
8410 into the namespace of the template. */
8420 {
8421 /* This new friend declaration matched an existing
8422 declaration. For example, given:
8424 template <class T> void f(T);
8425 template <class U> class C {
8426 template <class T> friend void f(T) {}
8427 };
8429 the friend declaration actually provides the definition
8430 of `f', once C has been instantiated for some type. So,
8431 old_decl will be the out-of-class template declaration,
8432 while new_friend is the in-class definition.
8434 But, if `f' was called before this point, the
8435 instantiation of `f' will have DECL_TI_ARGS corresponding
8436 to `T' but not to `U', references to which might appear
8437 in the definition of `f'. Previously, the most general
8438 template for an instantiation of `f' was the out-of-class
8439 version; now it is the in-class version. Therefore, we
8440 run through all specialization of `f', adding to their
8441 DECL_TI_ARGS appropriately. In particular, they need a
8442 new set of outer arguments, corresponding to the
8443 arguments for this class instantiation.
8445 The same situation can arise with something like this:
8447 friend void f(int);
8448 template <class T> class C {
8449 friend void f(T) {}
8450 };
8452 when `C<int>' is instantiated. Now, `f(int)' is defined
8453 in the class. */
8456 /* On the other hand, if the in-class declaration does
8457 *not* provide a definition, then we don't want to alter
8458 existing definitions. We can just leave everything
8459 alone. */
8460 ;
8461 else
8462 {
8466 /* Overwrite whatever template info was there before, if
8467 any, with the new template information pertaining to
8468 the declaration. */
8472 {
8473 /* We should have called reregister_specialization in
8474 duplicate_decls. */
8479 /* Instantiate it if the global has already been used. */
8483 }
8484 else
8485 {
8486 tree t;
8488 /* Indicate that the old function template is a partial
8489 instantiation. */
8497 /* Reassign any specializations already in the hash table
8498 to the new more general template, and add the
8499 additional template args. */
8503 {
8505 spec_entry elt;
8517 register_specialization
8520 }
8522 }
8523 }
8525 /* The information from NEW_FRIEND has been merged into OLD_DECL
8526 by duplicate_decls. */
8528 }
8529 }
8530 else
8531 {
8535 /* In the code
8536 template <class T> class C {
8537 template <class U> friend void C1<U>::f (); // case 1
8538 friend void C2<T>::f (); // case 2
8539 };
8540 we only need to make sure CONTEXT is a complete type for
8541 case 2. To distinguish between the two cases, we note that
8542 CONTEXT of case 1 remains dependent type after tsubst while
8543 this isn't true for case 2. */
8553 {
8555 /* do_friend adds the TEMPLATE_DECL for any member friend
8556 template even if it isn't a member template, i.e.
8557 template <class T> friend A<T>::f();
8558 Look through it in that case. */
8562 /* Check to see that the declaration is really present, and,
8563 possibly obtain an improved declaration. */
8568 }
8569 }
8572 }
8574 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8575 template arguments, as for tsubst.
8577 Returns an appropriate tsubst'd friend type or error_mark_node on
8578 failure. */
8580 static tree
8582 {
8583 tree friend_type;
8584 tree tmpl;
8585 tree context;
8588 {
8591 }
8596 {
8599 else
8601 }
8603 /* Look for a class template declaration. We look for hidden names
8604 because two friend declarations of the same template are the
8605 same. For example, in:
8607 struct A {
8608 template <typename> friend class F;
8609 };
8610 template <typename> struct B {
8611 template <typename> friend class F;
8612 };
8614 both F templates are the same. */
8618 /* But, if we don't find one, it might be because we're in a
8619 situation like this:
8621 template <class T>
8622 struct S {
8623 template <class U>
8624 friend struct S;
8625 };
8627 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8628 for `S<int>', not the TEMPLATE_DECL. */
8630 {
8633 }
8636 {
8637 /* The friend template has already been declared. Just
8638 check to see that the declarations match, and install any new
8639 default parameters. We must tsubst the default parameters,
8640 of course. We only need the innermost template parameters
8641 because that is all that redeclare_class_template will look
8642 at. */
8645 {
8646 tree parms;
8647 location_t saved_input_location;
8656 }
8659 }
8660 else
8661 {
8662 /* The friend template has not already been declared. In this
8663 case, the instantiation of the template class will cause the
8664 injection of this template into the global scope. */
8669 /* The new TMPL is not an instantiation of anything, so we
8670 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8671 the new type because that is supposed to be the corresponding
8672 template decl, i.e., TMPL. */
8679 /* Inject this template into the global scope. */
8681 }
8684 {
8687 else
8689 }
8692 }
8694 /* Returns zero if TYPE cannot be completed later due to circularity.
8695 Otherwise returns one. */
8697 static int
8699 {
8709 else
8711 }
8715 /* Apply any attributes which had to be deferred until instantiation
8716 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8717 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8719 static void
8722 {
8724 tree t;
8729 {
8733 }
8736 {
8740 }
8741 else
8745 {
8750 {
8753 {
8760 {
8767 clauses
8771 else
8773 }
8774 /* If the first attribute argument is an identifier, don't
8775 pass it through tsubst. Attributes like mode, format,
8776 cleanup and several target specific attributes expect it
8777 unmodified. */
8780 {
8781 tree chain
8783 in_decl,
8788 chain);
8789 }
8790 else
8796 }
8797 else
8799 }
8802 }
8803 }
8805 /* Perform (or defer) access check for typedefs that were referenced
8806 from within the template TMPL code.
8807 This is a subroutine of instantiate_decl and instantiate_class_template.
8808 TMPL is the template to consider and TARGS is the list of arguments of
8809 that template. */
8811 static void
8813 {
8814 location_t saved_location;
8825 {
8837 /* Make access check error messages point to the location
8838 of the use of the typedef. */
8842 tf_warning_or_error);
8843 }
8845 }
8847 static tree
8849 {
8851 tree typedecl;
8852 tree pbinfo;
8853 tree base_list;
8855 tree fn_context;
8864 /* Figure out which template is being instantiated. */
8868 /* Determine what specialization of the original template to
8869 instantiate. */
8872 {
8875 }
8877 {
8878 /* This TYPE is actually an instantiation of a partial
8879 specialization. We replace the innermost set of ARGS with
8880 the arguments appropriate for substitution. For example,
8881 given:
8883 template <class T> struct S {};
8884 template <class T> struct S<T*> {};
8886 and supposing that we are instantiating S<int*>, ARGS will
8887 presently be {int*} -- but we need {int}. */
8890 }
8891 else
8892 {
8895 }
8897 /* If the template we're instantiating is incomplete, then clearly
8898 there's nothing we can do. */
8902 /* If we've recursively instantiated too many templates, stop. */
8906 /* Now we're really doing the instantiation. Mark the type as in
8907 the process of being defined. */
8910 /* We may be in the middle of deferred access check. Disable
8911 it now. */
8917 /* Use #pragma pack from the template context. */
8923 /* Set the input location to the most specialized template definition.
8924 This is needed if tsubsting causes an error. */
8936 {
8939 /* Adjust visibility for template arguments. */
8941 }
8947 /* We should never instantiate a nested class before its enclosing
8948 class; we need to look up the nested class by name before we can
8949 instantiate it, and that lookup should instantiate the enclosing
8950 class. */
8956 {
8957 tree pbase_binfo;
8958 tree pushed_scope;
8961 /* We must enter the scope containing the type, as that is where
8962 the accessibility of types named in dependent bases are
8963 looked up from. */
8966 /* Substitute into each of the bases to determine the actual
8967 basetypes. */
8969 {
8970 tree base;
8976 {
8977 expanded_bases =
8984 }
8987 {
8989 /* Extract the already-expanded base class. */
8991 else
8992 /* Substitute to figure out the base class. */
8994 NULL_TREE);
9002 }
9003 }
9005 /* The list is now in reverse order; correct that. */
9010 }
9011 /* Now call xref_basetypes to set up all the base-class
9012 information. */
9020 /* Now that our base classes are set up, enter the scope of the
9021 class, so that name lookups into base classes, etc. will work
9022 correctly. This is precisely analogous to what we do in
9023 begin_class_definition when defining an ordinary non-template
9024 class, except we also need to push the enclosing classes. */
9027 /* Now members are processed in the order of declaration. */
9030 {
9034 {
9036 {
9037 /* Build new CLASSTYPE_NESTED_UTDS. */
9039 tree newtag;
9045 /* If the member is a class template, then -- even after
9046 substitution -- there may be dependent types in the
9047 template argument list for the class. We increment
9048 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9049 that function will assume that no types are dependent
9050 when outside of a template. */
9060 {
9064 /* Unfortunately, lookup_template_class sets
9065 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9066 instantiation (i.e., for the type of a member
9067 template class nested within a template class.)
9068 This behavior is required for
9069 maybe_process_partial_specialization to work
9070 correctly, but is not accurate in this case;
9071 the TAG is not an instantiation of anything.
9072 (The corresponding TEMPLATE_DECL is an
9073 instantiation, but the TYPE is not.) */
9076 /* Now, we call pushtag to put this NEWTAG into the scope of
9077 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9078 pushtag calling push_template_decl. We don't have to do
9079 this for enums because it will already have been done in
9080 tsubst_enum. */
9084 }
9085 }
9087 {
9088 /* Build new TYPE_METHODS. */
9089 tree r;
9098 /* Instantiate members marked with attribute used. */
9104 }
9105 else
9106 {
9107 /* Build new TYPE_FIELDS. */
9109 {
9110 tree condition;
9113 condition =
9123 }
9125 {
9126 tree r;
9130 /* The file and line for this declaration, to
9131 assist in error message reporting. Since we
9132 called push_tinst_level above, we don't need to
9133 restore these. */
9143 {
9144 /* A capture pack became multiple fields. */
9147 }
9150 {
9154 {
9155 /* In [temp.inst]:
9157 [t]he initialization (and any associated
9158 side-effects) of a static data member does
9159 not occur unless the static data member is
9160 itself used in a way that requires the
9161 definition of the static data member to
9162 exist.
9164 Therefore, we do not substitute into the
9165 initialized for the static data member here. */
9166 finish_static_data_member_decl
9172 /* Instantiate members marked with attribute used. */
9175 }
9177 {
9178 /* Determine whether R has a valid type and can be
9179 completed later. If R is invalid, then its type
9180 is replaced by error_mark_node. */
9186 {
9189 }
9190 }
9192 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9193 such a thing will already have been added to the field
9194 list by tsubst_enum in finish_member_declaration in the
9195 CLASSTYPE_NESTED_UTDS case above. */
9199 {
9202 }
9203 }
9204 }
9205 }
9206 }
9207 else
9208 {
9211 {
9212 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9218 {
9219 /* template <class T> friend class C; */
9222 }
9224 {
9225 /* template <class T> friend class C::D; */
9231 }
9234 {
9235 /* This could be either
9237 friend class T::C;
9239 when dependent_type_p is false or
9241 template <class U> friend class T::C;
9243 otherwise. */
9246 /* Bump processing_template_decl for correct
9247 dependent_type_p calculation. */
9252 }
9255 {
9256 /* friend class C;
9258 where C hasn't been declared yet. Let's lookup name
9259 from namespace scope directly, bypassing any name that
9260 come from dependent base class. */
9263 /* The call to xref_tag_from_type does injection for friend
9264 classes. */
9266 friend_type =
9270 }
9272 /* friend class C<T>; */
9275 /* Otherwise it's
9277 friend class C;
9279 where C is already declared or
9281 friend class C<int>;
9283 We don't have to do anything in these cases. */
9286 /* Trick make_friend_class into realizing that the friend
9287 we're adding is a template, not an ordinary class. It's
9288 important that we use make_friend_class since it will
9289 perform some error-checking and output cross-reference
9290 information. */
9298 }
9299 else
9300 {
9301 /* Build new DECL_FRIENDLIST. */
9302 tree r;
9304 /* The file and line for this declaration, to
9305 assist in error message reporting. Since we
9306 called push_tinst_level above, we don't need to
9307 restore these. */
9311 {
9314 }
9319 {
9322 }
9323 }
9324 }
9325 }
9328 {
9331 {
9336 /* We need to instantiate the capture list from the template
9337 after we've instantiated the closure members, but before we
9338 consider adding the conversion op. Also keep any captures
9339 that may have been added during instantiation of the op(). */
9341 tree tmpl_cap
9350 }
9351 else
9353 }
9355 /* Set the file and line number information to whatever is given for
9356 the class itself. This puts error messages involving generated
9357 implicit functions at a predictable point, and the same point
9358 that would be used for non-template classes. */
9365 /* We don't instantiate default arguments for member functions. 14.7.1:
9367 The implicit instantiation of a class template specialization causes
9368 the implicit instantiation of the declarations, but not of the
9369 definitions or default arguments, of the class member functions,
9370 member classes, static data members and member templates.... */
9372 /* Some typedefs referenced from within the template code need to be access
9373 checked at template instantiation time, i.e now. These types were
9374 added to the template at parsing time. Let's get those and perform
9375 the access checks then. */
9385 /* The vtable for a template class can be emitted in any translation
9386 unit in which the class is instantiated. When there is no key
9387 method, however, finish_struct_1 will already have added TYPE to
9388 the keyed_classes list. */
9393 }
9395 /* Wrapper for instantiate_class_template_1. */
9397 tree
9399 {
9400 tree ret;
9405 }
9407 static tree
9409 {
9410 tree r;
9416 else
9417 {
9424 }
9426 }
9428 /* Given a function parameter pack TMPL_PARM and some function parameters
9429 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9430 and set *SPEC_P to point at the next point in the list. */
9432 static tree
9434 {
9435 /* Collect all of the extra "packed" parameters into an
9436 argument pack. */
9437 tree parmvec;
9438 tree parmtypevec;
9449 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9454 {
9457 }
9459 /* Build the argument packs. */
9466 }
9468 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9469 NONTYPE_ARGUMENT_PACK. */
9471 static tree
9473 {
9475 }
9477 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9478 pack expansion. */
9480 static bool
9482 {
9487 }
9490 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9492 static tree
9494 {
9501 }
9503 /* This is a subroutine of tsubst_pack_expansion.
9505 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9506 mechanism to store the (non complete list of) arguments of the
9507 substitution and return a non substituted pack expansion, in order
9508 to wait for when we have enough arguments to really perform the
9509 substitution. */
9511 static bool
9515 {
9516 /* If one pack has an expansion and another pack has a normal
9517 argument or if one pack has an empty argument and an another
9518 one hasn't then tsubst_pack_expansion cannot perform the
9519 substitution and need to fall back on the
9520 PACK_EXPANSION_EXTRA mechanism. */
9528 {
9531 parm_pack;
9533 {
9538 else
9540 }
9544 }
9546 }
9548 /* [temp.variadic]/6 says that:
9550 The instantiation of a pack expansion [...]
9551 produces a list E1,E2, ..., En, where N is the number of elements
9552 in the pack expansion parameters.
9554 This subroutine of tsubst_pack_expansion produces one of these Ei.
9556 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9557 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9558 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9559 INDEX is the index 'i' of the element Ei to produce. ARGS,
9560 COMPLAIN, and IN_DECL are the same parameters as for the
9561 tsubst_pack_expansion function.
9563 The function returns the resulting Ei upon successful completion,
9564 or error_mark_node.
9566 Note that this function possibly modifies the ARGS parameter, so
9567 it's the responsibility of the caller to restore it. */
9569 static tree
9571 tree parm_packs,
9573 tree args /* This parm gets
9575 tsubst_flags_t complain,
9576 tree in_decl)
9577 {
9578 tree t;
9581 /* For each parameter pack, change the substitution of the parameter
9582 pack to the ith argument in its argument pack, then expand the
9583 pattern. */
9585 {
9590 ith_elem_is_expansion |=
9593 /* Select the Ith argument from the pack. */
9596 {
9598 {
9602 }
9603 else
9605 }
9606 else
9607 {
9612 {
9614 /* Update the corresponding argument. */
9616 }
9617 else
9618 /* Re-use the ARGUMENT_PACK_SELECT. */
9620 }
9622 }
9624 /* Substitute into the PATTERN with the (possibly altered)
9625 arguments. */
9627 /* Expanding a fixed parameter pack from
9628 coerce_template_parameter_pack. */
9633 else
9636 /* If the Ith argument pack element is a pack expansion, then
9637 the Ith element resulting from the substituting is going to
9638 be a pack expansion as well. */
9643 }
9645 /* Substitute ARGS into T, which is an pack expansion
9646 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9647 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9648 (if only a partial substitution could be performed) or
9649 ERROR_MARK_NODE if there was an error. */
9650 tree
9652 tree in_decl)
9653 {
9654 tree pattern;
9658 tree result;
9666 /* Add in any args remembered from an earlier partial instantiation. */
9671 /* Determine the argument packs that will instantiate the parameter
9672 packs used in the expansion expression. While we're at it,
9673 compute the number of arguments to be expanded and make sure it
9674 is consistent. */
9677 {
9684 {
9688 else
9691 }
9693 {
9696 else
9697 {
9698 /* We can't rely on local_specializations for a parameter
9699 name used later in a function declaration (such as in a
9700 late-specified return type). Even if it exists, it might
9701 have the wrong value for a recursive call. Just make a
9702 dummy decl, since it's only used for its type. */
9705 /* Partial instantiation of the parm_pack, we can't build
9706 up an argument pack yet. */
9708 else
9711 }
9712 }
9715 else
9716 {
9722 }
9729 /* This can only happen if we forget to expand an argument
9730 pack somewhere else. Just return an error, silently. */
9731 {
9735 }
9738 {
9742 /* Don't bother trying to do a partial substitution with
9743 incomplete packs; we'll try again after deduction. */
9750 {
9756 pattern);
9757 else
9760 pattern);
9762 }
9764 /* Keep track of the parameter packs and their corresponding
9765 argument packs. */
9768 }
9769 else
9770 {
9771 /* We can't substitute for this parameter pack. We use a flag as
9772 well as the missing_level counter because function parameter
9773 packs don't have a level. */
9775 }
9776 }
9778 /* We cannot expand this expansion expression, because we don't have
9779 all of the argument packs we need. */
9781 {
9782 /* We got some full packs, but we can't substitute them in until we
9783 have values for all the packs. So remember these until then. */
9788 }
9790 {
9791 /* There were no real arguments, we're just replacing a parameter
9792 pack with another version of itself. Substitute into the
9793 pattern and return a PACK_EXPANSION_*. The caller will need to
9794 deal with that. */
9798 else
9802 }
9807 {
9808 /* We're in a late-specified return type, so create our own local
9809 specializations map; the current map is either NULL or (in the
9810 case of recursive unification) might have bindings that we don't
9811 want to use or alter. */
9814 }
9816 /* For each argument in each argument pack, substitute into the
9817 pattern. */
9820 {
9822 i,
9824 in_decl);
9827 {
9830 }
9831 }
9833 /* Update ARGS to restore the substitution from parameter packs to
9834 their argument packs. */
9836 {
9842 else
9843 {
9851 /* Update the corresponding argument. */
9855 else
9857 }
9858 }
9861 {
9864 }
9867 }
9869 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9870 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9871 parameter packs; all parms generated from a function parameter pack will
9872 have the same DECL_PARM_INDEX. */
9874 tree
9876 {
9878 tree patparm;
9881 {
9887 }
9888 else
9889 {
9894 }
9897 }
9899 /* Substitute ARGS into the vector or list of template arguments T. */
9901 static tree
9903 {
9915 {
9917 tree new_arg;
9922 {
9923 /* Substitute into an expansion expression. */
9927 /* Add to the expanded length adjustment the number of
9928 expanded arguments. We subtract one from this
9929 measurement, because the argument pack expression
9930 itself is already counted as 1 in
9931 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9932 the argument pack is empty. */
9934 }
9936 {
9937 /* Substitute into each of the arguments. */
9943 new_arg,
9957 }
9958 }
9959 else
9968 }
9973 /* Make space for the expanded arguments coming from template
9974 argument packs. */
9976 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9977 arguments for a member template.
9978 In that case each TREE_VEC in ORIG_T represents a level of template
9979 arguments, and ORIG_T won't carry any non defaulted argument count.
9980 It will rather be the nested TREE_VECs that will carry one.
9981 In other words, ORIG_T carries a non defaulted argument count only
9982 if it doesn't contain any nested TREE_VEC. */
9984 {
9988 }
9990 {
9994 {
9997 /* Now expand the template argument pack "in place". */
10000 }
10001 else
10002 {
10004 out++;
10005 }
10006 }
10009 }
10011 /* Return the result of substituting ARGS into the template parameters
10012 given by PARMS. If there are m levels of ARGS and m + n levels of
10013 PARMS, then the result will contain n levels of PARMS. For
10014 example, if PARMS is `template <class T> template <class U>
10015 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10016 result will be `template <int*, double, class V>'. */
10018 static tree
10020 {
10024 /* When substituting into a template, we must set
10025 PROCESSING_TEMPLATE_DECL as the template parameters may be
10026 dependent if they are based on one-another, and the dependency
10027 predicates are short-circuit outside of templates. */
10034 {
10035 tree new_vec =
10040 {
10041 tree tuple;
10053 }
10059 }
10064 }
10066 /* Return the result of substituting ARGS into one template parameter
10067 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10068 parameter and which TREE_PURPOSE is the default argument of the
10069 template parameter. */
10071 static tree
10073 {
10094 }
10096 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10097 type T. If T is not an aggregate or enumeration type, it is
10098 handled as if by tsubst. IN_DECL is as for tsubst. If
10099 ENTERING_SCOPE is nonzero, T is the context for a template which
10100 we are presently tsubst'ing. Return the substituted value. */
10102 static tree
10104 tree args,
10105 tsubst_flags_t complain,
10106 tree in_decl,
10108 {
10113 {
10118 /* Else fall through. */
10122 {
10123 tree argvec;
10124 tree context;
10125 tree r;
10129 /* In "sizeof(X<I>)" we need to evaluate "I". */
10135 /* First, determine the context for the type we are looking
10136 up. */
10139 {
10142 /* If context is a nested class inside a class template,
10143 it may still need to be instantiated (c++/33959). */
10145 }
10147 /* Then, figure out what arguments are appropriate for the
10148 type we are trying to find. For example, given:
10150 template <class T> struct S;
10151 template <class T, class U> void f(T, U) { S<U> su; }
10153 and supposing that we are instantiating f<int, double>,
10154 then our ARGS will be {int, double}, but, when looking up
10155 S we only want {double}. */
10160 else
10161 {
10165 }
10171 }
10172 else
10173 /* This is not a template type, so there's nothing to do. */
10178 }
10179 }
10181 /* Substitute into the default argument ARG (a default argument for
10182 FN), which has the indicated TYPE. */
10184 tree
10186 {
10191 /* This can happen in invalid code. */
10195 /* This default argument came from a template. Instantiate the
10196 default argument here, not in tsubst. In the case of
10197 something like:
10199 template <class T>
10200 struct S {
10201 static T t();
10202 void f(T = t());
10203 };
10205 we must be careful to do name lookup in the scope of S<T>,
10206 rather than in the current class. */
10208 /* The "this" pointer is not valid in a default argument. */
10210 {
10215 }
10218 /* The default argument expression may cause implicitly defined
10219 member functions to be synthesized, which will result in garbage
10220 collection. We must treat this situation as if we were within
10221 the body of function so as to avoid collecting live data on the
10222 stack. */
10230 /* Restore the "this" pointer. */
10232 {
10235 }
10242 /* Make sure the default argument is reasonable. */
10248 }
10250 /* Substitute into all the default arguments for FN. */
10252 static void
10254 {
10255 tree arg;
10256 tree tmpl_args;
10260 /* If this function is not yet instantiated, we certainly don't need
10261 its default arguments. */
10264 /* Don't do this again for clones. */
10269 arg;
10275 complain);
10276 }
10278 /* Substitute the ARGS into the T, which is a _DECL. Return the
10279 result of the substitution. Issue error and warning messages under
10280 control of COMPLAIN. */
10282 static tree
10284 {
10285 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10286 location_t saved_loc;
10291 /* Set the filename and linenumber to improve error-reporting. */
10296 {
10298 {
10299 /* We can get here when processing a member function template,
10300 member class template, or template template parameter. */
10302 tree spec;
10303 tree tmpl_args;
10304 tree full_args;
10307 {
10308 /* Template template parameter is treated here. */
10312 /* If we get a real template back, return it. This can happen in
10313 the context of most_specialized_class. */
10325 complain);
10328 }
10330 /* We might already have an instance of this template.
10331 The ARGS are for the surrounding class type, so the
10332 full args contain the tsubst'd args for the context,
10333 plus the innermost args from the template decl. */
10337 /* Because this is a template, the arguments will still be
10338 dependent, even after substitution. If
10339 PROCESSING_TEMPLATE_DECL is not set, the dependency
10340 predicates will short-circuit. */
10348 /* If this is a default template template argument,
10349 tsubst might not have changed anything. */
10356 {
10359 }
10361 /* Make a new template decl. It will be similar to the
10362 original, but will record the current template arguments.
10363 We also create a new function declaration, which is just
10364 like the old one, but points to this new template, rather
10365 than the old one. */
10374 {
10375 tree new_type;
10383 /* For a partial specialization, we need to keep pointing to
10384 the primary template. */
10390 }
10391 else
10392 {
10393 tree new_decl;
10405 }
10411 /* The template parameters for this new template are all the
10412 template parameters for the old template, except the
10413 outermost level of parameters. */
10416 complain);
10422 /* Record this non-type partial instantiation. */
10426 }
10430 {
10431 tree ctx;
10434 tree gen_tmpl;
10435 tree type;
10440 /* Nobody should be tsubst'ing into non-template functions. */
10444 {
10445 tree spec;
10448 /* If T is not dependent, just return it. We have to
10449 increment PROCESSING_TEMPLATE_DECL because
10450 value_dependent_expression_p assumes that nothing is
10451 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10458 /* Calculate the most general template of which R is a
10459 specialization, and the complete set of arguments used to
10460 specialize R. */
10463 (DECL_TEMPLATE_RESULT
10469 /* Check to see if we already have this specialization. */
10474 {
10477 }
10479 /* We can see more levels of arguments than parameters if
10480 there was a specialization of a member template, like
10481 this:
10483 template <class T> struct S { template <class U> void f(); }
10484 template <> template <class U> void S<int>::f(U);
10486 Here, we'll be substituting into the specialization,
10487 because that's where we can find the code we actually
10488 want to generate, but we'll have enough arguments for
10489 the most general template.
10491 We also deal with the peculiar case:
10493 template <class T> struct S {
10494 template <class U> friend void f();
10495 };
10496 template <class U> void f() {}
10497 template S<int>;
10498 template void f<double>();
10500 Here, the ARGS for the instantiation of will be {int,
10501 double}. But, we only need as many ARGS as there are
10502 levels of template parameters in CODE_PATTERN. We are
10503 careful not to get fooled into reducing the ARGS in
10504 situations like:
10506 template <class T> struct S { template <class U> void f(U); }
10507 template <class T> template <> void S<T>::f(int) {}
10509 which we can spot because the pattern will be a
10510 specialization in this case. */
10512 parms_depth =
10517 }
10518 else
10519 {
10520 /* This special case arises when we have something like this:
10522 template <class T> struct S {
10523 friend void f<int>(int, double);
10524 };
10526 Here, the DECL_TI_TEMPLATE for the friend declaration
10527 will be an IDENTIFIER_NODE. We are being called from
10528 tsubst_friend_function, and we want only to create a
10529 new decl (R) with appropriate types so that we can call
10530 determine_specialization. */
10532 }
10535 {
10538 else
10542 }
10543 else
10544 {
10547 }
10552 /* If we hit excessive deduction depth, the type is bogus even if
10553 it isn't error_mark_node, so don't build a decl. */
10557 /* We do NOT check for matching decls pushed separately at this
10558 point, as they may not represent instantiations of this
10559 template, and in any case are considered separate under the
10560 discrete model. */
10564 /* Clear out the mangled name and RTL for the instantiation. */
10567 /* Leave DECL_INITIAL set on deleted instantiations. */
10572 /* OpenMP UDRs have the only argument a reference to the declared
10573 type. We want to diagnose if the declared type is a reference,
10574 which is invalid, but as references to references are usually
10575 quietly merged, diagnose it here. */
10577 {
10578 tree argtype
10583 "reference type %qT in "
10587 argtype);
10588 }
10591 /* Type-conversion operator. Reconstruct the name, in
10592 case it's the name of one of the template's parameters. */
10602 /* If this is an instantiation of a function with internal
10603 linkage, we already know what object file linkage will be
10604 assigned to the instantiation. */
10613 /* We'll re-clone as appropriate in instantiate_template. */
10616 /* If we aren't complaining now, return on error before we register
10617 the specialization so that we'll complain eventually. */
10623 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10624 this in the special friend case mentioned above where
10625 GEN_TMPL is NULL. */
10627 {
10632 tree new_r
10635 /* We instantiated this while substituting into
10636 the type earlier (template/friend54.C). */
10639 /* We're not supposed to instantiate default arguments
10640 until they are called, for a template. But, for a
10641 declaration like:
10643 template <class T> void f ()
10644 { extern void g(int i = T()); }
10646 we should do the substitution when the template is
10647 instantiated. We handle the member function case in
10648 instantiate_class_template since the default arguments
10649 might refer to other members of the class. */
10654 }
10655 else
10658 /* Copy the list of befriending classes. */
10662 {
10666 in_decl);
10667 }
10670 {
10676 /* If this is an instantiation of a member template, clone it.
10677 If it isn't, that'll be handled by
10678 clone_constructors_and_destructors. */
10681 }
10692 /* Possibly limit visibility based on template args. */
10695 {
10699 }
10707 }
10711 {
10719 {
10720 /* If there is a local specialization that isn't a
10721 parameter pack, it means that we're doing a "simple"
10722 substitution from inside tsubst_pack_expansion. Just
10723 return the local specialization (which will be a single
10724 parm). */
10731 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10732 the parameters in this function parameter pack. */
10736 {
10739 /* Zero-length parameter packs are boring. Just substitute
10740 into the chain. */
10744 }
10745 else
10746 {
10747 /* All we did was update the type. Make a note of that. */
10750 }
10751 }
10753 /* Loop through all of the parameters we'll build. When T is
10754 a function parameter pack, LEN is the number of expanded
10755 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10758 {
10765 /* We're on the Ith parameter of the function parameter
10766 pack. */
10767 {
10768 /* Get the Ith type. */
10771 /* Rename the parameter to include the index. */
10774 }
10776 /* We're dealing with a normal parameter. */
10784 {
10787 else
10790 }
10800 /* Keep track of the first new parameter we
10801 generate. That's what will be returned to the
10802 caller. */
10806 /* Build a proper chain of parameters when substituting
10807 into a function parameter pack. */
10810 }
10812 /* If cp_unevaluated_operand is set, we're just looking for a
10813 single dummy parameter, so don't keep going. */
10818 /* FIRST_R contains the start of the chain we've built. */
10820 }
10824 {
10831 {
10832 /* This field is a lambda capture pack. Return a TREE_VEC of
10833 the expanded fields to instantiate_class_template_1 and
10834 store them in the specializations hash table as a
10835 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10839 {
10842 }
10843 else
10844 {
10845 /* All we did was update the type. Make a note of that. */
10848 }
10849 }
10852 {
10855 {
10859 }
10869 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10870 non-bit-fields DECL_INITIAL is a non-static data member
10871 initializer, which gets deferred instantiation. */
10877 {
10878 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10879 NSDMI in perform_member_init. Still set DECL_INITIAL
10880 so that we know there is one. */
10885 }
10886 /* We don't have to set DECL_CONTEXT here; it is set by
10887 finish_member_declaration. */
10895 }
10898 {
10906 }
10907 }
10911 /* We reach here only for member using decls. We also need to check
10912 uses_template_parms because DECL_DEPENDENT_P is not set for a
10913 using-declaration that designates a member of the current
10914 instantiation (c++/53549). */
10917 {
10924 else
10925 {
10928 }
10929 }
10930 else
10931 {
10934 }
10939 {
10942 tree spec;
10944 tree ctx;
10953 {
10954 /* If this is the canonical decl, we don't have to
10955 mess with instantiations, and often we can't (for
10956 typename, template type parms and such). Note that
10957 TYPE_NAME is not correct for the above test if
10958 we've copied the type for a typedef. */
10964 }
10966 /* Check to see if we already have the specialization we
10967 need. */
10970 {
10971 /* T is a static data member or namespace-scope entity.
10972 We have to substitute into namespace-scope variables
10973 (even though such entities are never templates) because
10974 of cases like:
10976 template <class T> void f() { extern T t; }
10978 where the entity referenced is not known until
10979 instantiation time. */
10983 {
10985 complain,
10987 /* If CTX is unchanged, then T is in fact the
10988 specialization we want. That situation occurs when
10989 referencing a static data member within in its own
10990 class. We can use pointer equality, rather than
10991 same_type_p, because DECL_CONTEXT is always
10992 canonical... */
10995 /* ... unless T is a member template; in which
10996 case our caller can be willing to create a
10997 specialization of that template represented
10998 by T. */
11002 }
11005 {
11013 }
11014 }
11015 else
11016 {
11017 /* A local variable. */
11019 /* Subsequent calls to pushdecl will fill this in. */
11022 }
11023 /* If we already have the specialization we need, there is
11024 nothing more to do. */
11026 {
11029 }
11031 /* Create a new node for the specialization we need. */
11034 {
11037 else
11044 }
11046 {
11047 /* Even if the original location is out of scope, the
11048 newly substituted one is not. */
11055 {
11056 /* It may seem that this case cannot occur, since:
11058 typedef void f();
11059 void g() { f x; }
11061 declares a function, not a variable. However:
11063 typedef void f();
11064 template <typename T> void g() { T t; }
11065 template void g<f>();
11067 is an attempt to declare a variable with function
11068 type. */
11070 /* R is not yet sufficiently initialized, so we
11071 just use its name. */
11074 }
11076 /* Wait until cp_finish_decl to set this again, to handle
11077 circular dependency (template/instantiate6.C). */
11082 {
11087 {
11090 }
11092 }
11093 }
11099 /* Clear out the mangled name and RTL for the instantiation. */
11103 /* The initializer must not be expanded until it is required;
11104 see [temp.inst]. */
11110 {
11111 /* Possibly limit visibility based on template args. */
11114 {
11118 }
11120 }
11123 {
11124 /* A static data member declaration is always marked
11125 external when it is declared in-class, even if an
11126 initializer is present. We mimic the non-template
11127 processing here. */
11133 }
11143 /* Preserve a typedef that names a type. */
11145 {
11148 }
11151 }
11156 }
11157 #undef RETURN
11159 out:
11160 /* Restore the file and line information. */
11164 }
11166 /* Substitute into the ARG_TYPES of a function type.
11167 If END is a TREE_CHAIN, leave it and any following types
11168 un-substituted. */
11170 static tree
11172 tree args,
11173 tree end,
11174 tsubst_flags_t complain,
11175 tree in_decl)
11176 {
11177 tree remaining_arg_types;
11181 tree default_arg;
11192 {
11193 /* For a pack expansion, perform substitution on the
11194 entire expression. Later on, we'll handle the arguments
11195 one-by-one. */
11200 /* So that we'll spin through the parameters, one by one. */
11202 else
11203 {
11204 /* We only partially substituted into the parameter
11205 pack. Our type is TYPE_PACK_EXPANSION. */
11208 }
11209 }
11222 {
11224 {
11228 }
11230 }
11231 /* DR 657. */
11235 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11236 top-level qualifiers as required. */
11239 /* We do not substitute into default arguments here. The standard
11240 mandates that they be instantiated only when needed, which is
11241 done in build_over_call. */
11245 {
11246 /* We've instantiated a template before its default arguments
11247 have been parsed. This can happen for a nested template
11248 class, and is not an error unless we require the default
11249 argument in a call of this function. */
11250 remaining_arg_types =
11253 }
11254 else
11255 remaining_arg_types =
11257 }
11260 }
11262 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11263 *not* handle the exception-specification for FNTYPE, because the
11264 initial substitution of explicitly provided template parameters
11265 during argument deduction forbids substitution into the
11266 exception-specification:
11268 [temp.deduct]
11270 All references in the function type of the function template to the
11271 corresponding template parameters are replaced by the specified tem-
11272 plate argument values. If a substitution in a template parameter or
11273 in the function type of the function template results in an invalid
11274 type, type deduction fails. [Note: The equivalent substitution in
11275 exception specifications is done only when the function is instanti-
11276 ated, at which point a program is ill-formed if the substitution
11277 results in an invalid type.] */
11279 static tree
11281 tree args,
11282 tsubst_flags_t complain,
11283 tree in_decl)
11284 {
11285 tree return_type;
11286 tree arg_types;
11287 tree fntype;
11289 /* The TYPE_CONTEXT is not used for function/method types. */
11292 /* Substitute the return type. */
11296 /* DR 486 clarifies that creation of a function type with an
11297 invalid return type is a deduction failure. */
11300 {
11302 {
11305 else
11307 }
11309 }
11310 /* And DR 657. */
11314 /* Substitute the argument types. */
11320 /* Construct a new type node and return it. */
11322 {
11327 }
11328 else
11329 {
11331 /* Don't pick up extra function qualifiers from the basetype. */
11334 {
11335 /* [temp.deduct]
11337 Type deduction may fail for any of the following
11338 reasons:
11340 -- Attempting to create "pointer to member of T" when T
11341 is not a class type. */
11344 r);
11346 }
11351 }
11355 }
11357 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11358 ARGS into that specification, and return the substituted
11359 specification. If there is no specification, return NULL_TREE. */
11361 static tree
11363 tree args,
11364 tsubst_flags_t complain,
11365 tree in_decl,
11367 {
11368 tree specs;
11369 tree new_specs;
11374 {
11375 /* A noexcept-specifier. */
11380 {
11381 /* Defer instantiation of noexcept-specifiers to avoid
11382 excessive instantiations (c++/49107). */
11385 {
11386 /* We already partially instantiated this member template,
11387 so combine the new args with the old. */
11392 }
11393 else
11394 {
11397 }
11398 }
11399 else
11400 new_specs = tsubst_copy_and_build
11404 }
11406 {
11409 else
11411 {
11412 tree spec;
11417 {
11418 /* Expand the pack expansion type. */
11421 in_decl);
11427 else
11428 {
11429 /* We're substituting into a member template, so
11430 we got a TYPE_PACK_EXPANSION back. Add that
11431 expansion and move on. */
11435 expanded_specs,
11436 complain);
11439 }
11440 }
11443 {
11446 else
11451 complain);
11452 }
11455 }
11456 }
11458 }
11460 /* Take the tree structure T and replace template parameters used
11461 therein with the argument vector ARGS. IN_DECL is an associated
11462 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11463 Issue error and warning messages under control of COMPLAIN. Note
11464 that we must be relatively non-tolerant of extensions here, in
11465 order to preserve conformance; if we allow substitutions that
11466 should not be allowed, we may allow argument deductions that should
11467 not succeed, and therefore report ambiguous overload situations
11468 where there are none. In theory, we could allow the substitution,
11469 but indicate that it should have failed, and allow our caller to
11470 make sure that the right thing happens, but we don't try to do this
11471 yet.
11473 This function is used for dealing with types, decls and the like;
11474 for expressions, use tsubst_expr or tsubst_copy. */
11476 tree
11478 {
11501 else
11506 /* Reuse typedefs. We need to do this to handle dependent attributes,
11507 such as attribute aligned. */
11510 {
11514 {
11515 /* DECL represents an alias template and we want to
11516 instantiate it. */
11520 }
11524 {
11528 }
11533 else
11534 /* The typedef is from a non-template context. */
11538 {
11540 r = cp_build_qualified_type_real
11544 }
11545 else
11546 {
11547 /* We don't have an instantiation yet, so drop the typedef. */
11552 }
11553 }
11566 {
11592 {
11598 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11599 needed. */
11605 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11606 with TREE_SIDE_EFFECTS that indicates this is not an integral
11607 constant expression. */
11610 {
11613 }
11616 }
11622 {
11635 {
11639 {
11640 /* See through ARGUMENT_PACK_SELECT arguments. */
11642 /* If the selected argument is an expansion E, that most
11643 likely means we were called from
11644 gen_elem_of_pack_expansion_instantiation during the
11645 substituting of pack an argument pack (which Ith
11646 element is a pack expansion, where I is
11647 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11648 In this case, the Ith element resulting from this
11649 substituting is going to be a pack expansion, which
11650 pattern is the pattern of E. Let's return the
11651 pattern of E, and
11652 gen_elem_of_pack_expansion_instantiation will
11653 build the resulting pack expansion from it. */
11656 }
11657 }
11662 {
11664 /* If ARG is an argument pack, we don't actually want to
11665 perform a substitution here, because substitutions
11666 for argument packs are only done
11667 element-by-element. We can get to this point when
11668 substituting the type of a non-type template
11669 parameter pack, when that type actually contains
11670 template parameter packs from an outer template, e.g.,
11672 template<typename... Types> struct A {
11673 template<Types... Values> struct B { };
11674 }; */
11678 {
11684 return cp_build_qualified_type_real
11686 }
11688 {
11689 /* We are processing a type constructed from a
11690 template template parameter. */
11701 /* Consider this code:
11703 template <template <class> class Template>
11704 struct Internal {
11705 template <class Arg> using Bind = Template<Arg>;
11706 };
11708 template <template <class> class Template, class Arg>
11709 using Instantiate = Template<Arg>; //#0
11711 template <template <class> class Template,
11712 class Argument>
11713 using Bind =
11714 Instantiate<Internal<Template>::template Bind,
11715 Argument>; //#1
11717 When #1 is parsed, the
11718 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11719 parameter `Template' in #0 matches the
11720 UNBOUND_CLASS_TEMPLATE representing the argument
11721 `Internal<Template>::template Bind'; We then want
11722 to assemble the type `Bind<Argument>' that can't
11723 be fully created right now, because
11724 `Internal<Template>' not being complete, the Bind
11725 template cannot be looked up in that context. So
11726 we need to "store" `Bind<Argument>' for later
11727 when the context of Bind becomes complete. Let's
11728 store that in a TYPENAME_TYPE. */
11732 argvec),
11733 typename_type,
11734 complain);
11736 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11737 are resolving nested-types in the signature of a
11738 member function templates. Otherwise ARG is a
11739 TEMPLATE_DECL and is the real template to be
11740 instantiated. */
11748 complain);
11749 return cp_build_qualified_type_real
11751 }
11752 else
11753 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11755 }
11758 /* This can happen during the attempted tsubst'ing in
11759 unify. This means that we don't yet have any information
11760 about the template parameter in question. */
11763 /* Early in template argument deduction substitution, we don't
11764 want to reduce the level of 'auto', or it will be confused
11765 with a normal template parm in subsequent deduction. */
11769 /* If we get here, we must have been looking at a parm for a
11770 more deeply nested template. Make a new version of this
11771 template parameter, but with a lower level. */
11773 {
11778 {
11780 r = cp_build_qualified_type_real
11784 }
11785 else
11786 {
11797 /* We have reduced the level of the template
11798 template parameter, but not the levels of its
11799 template parameters, so canonical_type_parameter
11800 will not be able to find the canonical template
11801 template parameter for this level. Thus, we
11802 require structural equality checking to compare
11803 TEMPLATE_TEMPLATE_PARMs. */
11807 else
11811 {
11819 }
11820 }
11829 }
11832 }
11835 {
11843 {
11847 }
11850 {
11854 }
11857 {
11861 }
11867 }
11870 /* We should never be tsubsting a binfo. */
11874 /* A vector of template arguments. */
11880 {
11884 /* [temp.deduct]
11886 Type deduction may fail for any of the following
11887 reasons:
11889 -- Attempting to create a pointer to reference type.
11890 -- Attempting to create a reference to a reference type or
11891 a reference to void.
11893 Core issue 106 says that creating a reference to a reference
11894 during instantiation is no longer a cause for failure. We
11895 only enforce this check in strict C++98 mode. */
11899 {
11902 /* We keep track of the last time we issued this error
11903 message to avoid spewing a ton of messages during a
11904 single bad template instantiation. */
11907 {
11912 else
11915 }
11918 }
11922 {
11924 {
11927 type);
11928 else
11930 type);
11931 }
11933 }
11935 {
11939 }
11941 /* In C++0x, during template argument substitution, when there is an
11942 attempt to create a reference to a reference type, reference
11943 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11945 "If a template-argument for a template-parameter T names a type
11946 that is a reference to a type A, an attempt to create the type
11947 'lvalue reference to cv T' creates the type 'lvalue reference to
11948 A,' while an attempt to create the type type rvalue reference to
11949 cv T' creates the type T"
11950 */
11951 r = cp_build_reference_type
11954 else
11962 {
11964 pedwarn
11966 code == REFERENCE_TYPE
11969 else
11971 }
11974 /* Will this ever be needed for TYPE_..._TO values? */
11978 }
11980 {
11983 {
11984 /* [temp.deduct]
11986 Type deduction may fail for any of the following
11987 reasons:
11989 -- Attempting to create "pointer to member of T" when T
11990 is not a class type. */
11994 }
11996 {
12000 }
12002 {
12006 }
12009 {
12010 /* The type of the implicit object parameter gets its
12011 cv-qualifiers from the FUNCTION_TYPE. */
12012 tree memptr;
12013 tree method_type
12018 complain);
12019 }
12020 else
12023 complain);
12024 }
12027 {
12028 tree fntype;
12029 tree specs;
12034 /* Substitute the exception specification. */
12042 }
12044 {
12049 /* As an optimization, we avoid regenerating the array type if
12050 it will obviously be the same as T. */
12054 /* These checks should match the ones in grokdeclarator.
12056 [temp.deduct]
12058 The deduction may fail for any of the following reasons:
12060 -- Attempting to create an array with an element type that
12061 is void, a function type, or a reference type, or [DR337]
12062 an abstract class type. */
12066 {
12070 }
12078 {
12081 }
12084 }
12087 {
12097 {
12101 }
12103 {
12104 /* Normally, make_typename_type does not require that the CTX
12105 have complete type in order to allow things like:
12107 template <class T> struct S { typename S<T>::X Y; };
12109 But, such constructs have already been resolved by this
12110 point, so here CTX really should have complete type, unless
12111 it's a partial instantiation. */
12114 {
12118 }
12119 }
12126 {
12129 }
12132 {
12134 {
12138 else
12140 }
12142 {
12146 else
12148 }
12149 }
12151 return cp_build_qualified_type_real
12153 }
12156 {
12168 }
12171 {
12172 tree type;
12188 complain);
12189 }
12192 {
12193 tree type;
12211 else
12212 {
12216 /* In a template ~id could be either a complement expression
12217 or an unqualified-id naming a destructor; if instantiating
12218 it produces an expression, it's not an id-expression or
12219 member access. */
12222 }
12226 complain);
12227 }
12230 {
12234 }
12238 {
12240 tree packed_out =
12242 args,
12243 complain,
12244 in_decl);
12247 /* For template nontype argument packs, also substitute into
12248 the type. */
12253 }
12268 /* We should use one of the expression tsubsts for these codes. */
12274 }
12275 }
12277 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12278 type of the expression on the left-hand side of the "." or "->"
12279 operator. */
12281 static tree
12284 {
12285 tree name;
12286 tree qualifying_scope;
12287 tree fns;
12288 tree optype;
12293 /* A baselink indicates a function from a base class. Both the
12294 BASELINK_ACCESS_BINFO and the base class referenced may
12295 indicate bases of the template class, rather than the
12296 instantiated class. In addition, lookups that were not
12297 ambiguous before may be ambiguous now. Therefore, we perform
12298 the lookup again. */
12305 {
12312 }
12320 /* If lookup found a single function, mark it as used at this
12321 point. (If it lookup found multiple functions the one selected
12322 later by overload resolution will be marked as used at that
12323 point.) */
12329 /* Add back the template arguments, if present. */
12334 template_args);
12335 /* Update the conversion operator type. */
12343 qualifying_scope,
12344 object_type);
12346 }
12348 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12349 true if the qualified-id will be a postfix-expression in-and-of
12350 itself; false if more of the postfix-expression follows the
12351 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12352 of "&". */
12354 static tree
12358 {
12359 tree expr;
12360 tree scope;
12361 tree name;
12363 tree template_args;
12368 /* Figure out what name to look up. */
12371 {
12379 }
12380 else
12381 {
12384 }
12386 /* Substitute into the qualifying scope. When there are no ARGS, we
12387 are just trying to simplify a non-dependent expression. In that
12388 case the qualifying scope may be dependent, and, in any case,
12389 substituting will not help. */
12392 {
12395 }
12396 else
12400 {
12405 }
12408 {
12410 {
12411 /* A BIT_NOT_EXPR is used to represent a destructor. */
12413 {
12417 }
12418 else
12421 }
12422 else
12426 {
12428 {
12432 }
12434 }
12435 }
12438 {
12440 scope);
12441 /* Remember that there was a reference to this entity. */
12443 }
12446 {
12452 }
12461 {
12462 expr = (adjust_result_of_qualified_name_lookup
12464 expr = (finish_qualified_id_expr
12468 }
12470 /* Expressions do not generally have reference type. */
12472 /* However, if we're about to form a pointer-to-member, we just
12473 want the referenced member referenced. */
12478 }
12480 /* Like tsubst, but deals with expressions. This function just replaces
12481 template parms; to finish processing the resultant expression, use
12482 tsubst_copy_and_build or tsubst_expr. */
12484 static tree
12486 {
12488 tree r;
12496 {
12501 {
12502 /* We get here for a use of 'this' in an NSDMI. */
12508 /* This can happen for a parameter name used later in a function
12509 declaration (such as in a late-specified return type). Just
12510 make a dummy decl, since it's only used for its type. */
12513 /* Give it the template pattern as its context; its true context
12514 hasn't been instantiated yet and this is good enough for
12515 mangling. */
12517 }
12525 {
12526 tree enum_type;
12527 tree v;
12531 /* There is no need to substitute into namespace-scope
12532 enumerators. */
12535 /* If ARGS is NULL, then T is known to be non-dependent. */
12539 /* Unfortunately, we cannot just call lookup_name here.
12540 Consider:
12542 template <int I> int f() {
12543 enum E { a = I };
12544 struct S { void g() { E e = a; } };
12545 };
12547 When we instantiate f<7>::S::g(), say, lookup_name is not
12548 clever enough to find f<7>::a. */
12549 enum_type
12559 /* We didn't find the name. That should never happen; if
12560 name-lookup found it during preliminary parsing, we
12561 should find it again here during instantiation. */
12563 }
12568 {
12569 /* Check for a local specialization set up by
12570 tsubst_pack_expansion. */
12572 {
12576 }
12578 /* When retrieving a capture pack from a generic lambda, remove the
12579 lambda call op's own template argument list from ARGS. Only the
12580 template arguments active for the closure type should be used to
12581 retrieve the pack specialization. */
12587 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12588 tsubst_decl put in the hash table. */
12590 }
12593 {
12594 tree ctx;
12599 {
12602 {
12606 }
12608 }
12609 }
12618 {
12621 {
12623 {
12624 /* Just use name lookup to find a member alias for an
12625 anonymous union, but then add it to the hash table. */
12629 }
12630 else
12631 {
12632 /* This can happen for a variable used in a late-specified
12633 return type of a local lambda. Just make a dummy decl
12634 since it's only used for its type. */
12639 }
12640 }
12641 }
12642 else
12651 /* An OVERLOAD will always be a non-dependent overload set; an
12652 overload set from function scope will just be represented with an
12653 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12669 {
12670 /* Template template argument like the following example need
12671 special treatment:
12673 template <template <class> class TT> struct C {};
12674 template <class T> struct D {
12675 template <class U> struct E {};
12676 C<E> c; // #1
12677 };
12678 D<int> d; // #2
12680 We are processing the template argument `E' in #1 for
12681 the template instantiation #2. Originally, `E' is a
12682 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12683 have to substitute this with one having context `D<int>'. */
12687 }
12688 else
12689 /* Ordinary template template argument. */
12700 return build1
12706 {
12716 /* We only want to compute the number of arguments. */
12730 {
12737 else
12740 }
12741 else
12743 }
12745 {
12753 }
12754 /* Fall through */
12770 return build1
12775 {
12776 tree object;
12777 tree name;
12782 {
12786 }
12789 {
12799 }
12804 in_decl);
12805 else
12808 }
12846 return build_nt
12859 return build_nt
12866 {
12874 }
12880 {
12881 r = build_nt
12887 }
12890 {
12891 r = build_nt
12897 }
12900 {
12901 r = build_nt
12907 }
12910 {
12911 /* Substituted template arguments */
12920 }
12923 {
12943 }
12968 /* Fall through. */
12971 {
12974 }
12975 else
12979 /* This is handled by tsubst_copy_and_build. */
12985 in_decl),
12989 /* We shouldn't have built any of these during initial template
12990 generation. Instead, they should be built during instantiation
12991 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12995 r = build2
13015 {
13016 /* Instantiate any typedefs in the type. */
13021 }
13024 /* These can sometimes show up in a partial instantiation, but never
13025 involve template parms. */
13030 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13033 }
13034 }
13036 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13038 static tree
13041 {
13045 {
13051 {
13054 {
13060 }
13061 /* FALLTHRU */
13089 {
13092 {
13099 }
13100 else
13102 }
13132 }
13133 }
13139 }
13141 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13143 static tree
13145 tree in_decl)
13146 {
13147 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13167 {
13170 else
13171 {
13175 }
13176 }
13181 #undef RECUR
13182 }
13184 /* Substitute one OMP_FOR iterator. */
13186 static void
13191 {
13192 #define RECUR(NODE) \
13193 tsubst_expr ((NODE), args, complain, in_decl, \
13194 integral_constant_expression_p)
13203 {
13204 /* We need to jump through some hoops to handle declarations in the
13205 for-init-statement, since we might need to handle auto deduction,
13206 but we need to keep control of initialization. */
13210 }
13211 else
13223 {
13225 {
13226 /* Declare the variable, but don't let that initialize it. */
13231 }
13239 complain);
13240 else
13247 }
13250 {
13251 /* Declare and initialize the variable. */
13254 }
13256 {
13257 tree c;
13259 {
13270 }
13272 {
13277 {
13280 }
13281 }
13282 }
13288 else
13292 {
13303 {
13310 }
13311 else
13317 {
13323 }
13327 {
13334 }
13335 else
13341 }
13347 #undef RECUR
13348 }
13350 /* Like tsubst_copy for expressions, etc. but also does semantic
13351 processing. */
13353 static tree
13356 {
13357 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13358 #define RECUR(NODE) \
13359 tsubst_expr ((NODE), args, complain, in_decl, \
13360 integral_constant_expression_p)
13363 tree r;
13364 location_t loc;
13376 {
13378 {
13379 tree_stmt_iterator i;
13383 }
13398 else
13407 {
13409 tree init;
13415 {
13418 tree decl;
13426 else
13428 }
13430 {
13431 /* Don't build up decls for a variadic capture proxy, we'll
13432 instantiate the elements directly as needed. */
13434 }
13435 else
13436 {
13440 {
13441 /* By marking the declaration as instantiated, we avoid
13442 trying to instantiate it. Since instantiate_decl can't
13443 handle local variables, and since we've already done
13444 all that needs to be done, that's the right thing to
13445 do. */
13450 /* Anonymous aggregates are a special case. */
13453 {
13456 {
13460 }
13462 }
13468 {
13473 }
13474 else
13475 {
13480 {
13481 /* For __PRETTY_FUNCTION__ we have to adjust the
13482 initializer. */
13486 }
13487 else
13488 {
13492 {
13493 /* If we had an initializer but it
13494 instantiated to nothing,
13495 value-initialize the object. This will
13496 only occur when the initializer was a
13497 pack expansion where the parameter packs
13498 used in that expansion were of length
13499 zero. */
13501 complain);
13504 }
13505 else
13507 }
13510 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13513 }
13514 }
13515 }
13518 }
13533 {
13543 }
13570 {
13574 }
13582 else
13590 else
13617 {
13619 tree label;
13624 }
13630 /* Computed goto's must be tsubst'd into. On the other hand,
13631 non-computed gotos must not be; the identifier in question
13632 will have no binding. */
13634 else
13640 tmp = finish_asm_stmt
13647 {
13652 }
13657 {
13662 }
13663 else
13664 {
13669 else
13676 else
13682 else
13684 }
13688 {
13692 {
13694 /* Prevent instantiate_decl from trying to instantiate
13695 this variable. We've already done all that needs to be
13696 done. */
13699 }
13704 }
13710 {
13711 /* Local classes are not independent templates; they are
13712 instantiated along with their containing function. And this
13713 way we don't have to deal with pushing out of one local class
13714 to instantiate a member of another local class. */
13715 tree fn;
13716 /* Closures are handled by the LAMBDA_EXPR. */
13722 }
13726 {
13727 tree condition;
13730 condition =
13732 args,
13741 }
13765 {
13774 {
13779 }
13791 integral_constant_expression_p);
13800 else
13801 {
13809 }
13812 }
13857 {
13862 {
13865 }
13871 }
13872 else
13873 {
13880 {
13883 }
13886 {
13891 {
13894 }
13900 }
13901 else
13902 {
13906 }
13909 }
13913 {
13919 {
13923 {
13928 }
13932 }
13933 else
13934 {
13939 }
13940 }
13965 /* If the first operand was a statement, we're done with it. */
13969 complain));
13981 integral_constant_expression_p));
13982 }
13985 out:
13988 #undef RECUR
13989 #undef RETURN
13990 }
13992 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
13993 function. For description of the body see comment above
13994 cp_parser_omp_declare_reduction_exprs. */
13996 static void
13998 {
14004 tree_stmt_iterator tsi;
14015 {
14034 }
14036 {
14056 }
14057 }
14059 /* T is a postfix-expression that is not being used in a function
14060 call. Return the substituted version of T. */
14062 static tree
14064 tsubst_flags_t complain,
14065 tree in_decl)
14066 {
14070 else
14076 }
14078 /* Sentinel to disable certain warnings during template substitution. */
14086 };
14088 /* Like tsubst but deals with expressions and performs semantic
14089 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14091 tree
14093 tree args,
14094 tsubst_flags_t complain,
14095 tree in_decl,
14098 {
14099 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14100 #define RECUR(NODE) \
14101 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14103 integral_constant_expression_p)
14106 location_t loc;
14115 /* N3276 decltype magic only applies to calls at the top level or on the
14116 right side of a comma. */
14121 {
14124 /* Fall through. */
14126 {
14127 tree decl;
14128 cp_id_kind idk;
14133 {
14136 }
14138 /* Look up the name. */
14141 /* By convention, expressions use ERROR_MARK_NODE to indicate
14142 failure, not NULL_TREE. */
14148 integral_constant_expression_p,
14156 input_location);
14160 {
14164 }
14166 }
14169 {
14170 tree object;
14178 {
14181 }
14182 else
14189 else
14191 }
14194 {
14198 {
14199 /* A type conversion to reference type will be enclosed in
14200 such an indirect ref, but the substitution of the cast
14201 will have also added such an indirect ref. */
14204 }
14205 else
14209 }
14217 {
14224 flags));
14225 }
14238 {
14239 tree type;
14245 {
14250 }
14256 {
14274 }
14277 }
14311 else
14313 in_decl);
14348 {
14351 tree r = build_x_binary_op
14355 ? ERROR_MARK
14359 ? ERROR_MARK
14367 }
14384 {
14393 }
14397 /* Fall through */
14400 {
14401 tree r;
14407 {
14408 /* When there are no ARGS, we are trying to evaluate a
14409 non-dependent expression from the parser. Trying to do
14410 the substitutions may not work. */
14413 }
14414 else
14415 {
14420 else
14423 /*integral_constant_expression_p=*/
14427 }
14431 else
14435 {
14437 {
14439 {
14443 }
14444 else
14448 }
14450 }
14452 }
14455 {
14465 }
14479 {
14481 tree r = build_x_modify_expr
14487 /* TREE_NO_WARNING must be set if either the expression was
14488 parenthesized or it uses an operator such as >>= rather
14489 than plain assignment. In the former case, it was already
14490 set and must be copied. In the latter case,
14491 build_x_modify_expr sets it and it must not be reset
14492 here. */
14497 }
14502 /* Remember that there was a reference to this entity. */
14508 {
14513 tree ret;
14517 else
14518 {
14522 }
14524 /* If there was an initializer in the original tree, but it
14525 instantiated to an empty list, then we should pass a
14526 non-NULL empty vector to tell build_new that it was an
14527 empty initializer() rather than no initializer. This can
14528 only happen when the initializer is a pack expansion whose
14529 parameter packs are of length zero. */
14532 else
14533 {
14537 else
14538 {
14541 }
14542 }
14549 complain);
14557 }
14565 complain));
14568 {
14572 integral_constant_expression_p);
14574 op0,
14577 }
14580 {
14581 tree function;
14586 tree ret;
14589 /* When we parsed the expression, we determined whether or
14590 not Koenig lookup should be performed. */
14593 {
14598 }
14600 {
14601 /* Do nothing; calling tsubst_copy_and_build on an identifier
14602 would incorrectly perform unqualified lookup again.
14604 Note that we can also have an IDENTIFIER_NODE if the earlier
14605 unqualified lookup found a member function; in that case
14606 koenig_p will be false and we do want to do the lookup
14607 again to find the instantiated member function.
14609 FIXME but doing that causes c++/15272, so we need to stop
14610 using IDENTIFIER_NODE in that situation. */
14612 }
14613 else
14614 {
14616 {
14622 }
14623 else
14628 /* Avoid error about taking the address of a constructor. */
14632 in_decl,
14634 integral_constant_expression_p);
14638 }
14643 {
14648 else
14649 {
14650 /* Expand the pack expansion and push each entry onto
14651 CALL_ARGS. */
14654 {
14659 {
14664 }
14665 }
14666 else
14667 {
14668 /* A partial substitution. Add one entry. */
14670 }
14671 }
14672 }
14674 /* We do not perform argument-dependent lookup if normal
14675 lookup finds a non-function, in accordance with the
14676 expected resolution of DR 218. */
14679 /* If lookup found a member function, the Koenig lookup is
14680 not appropriate, even if an unqualified-name was used
14681 to denote the function. */
14684 /* Only do this when substitution turns a dependent call
14685 into a non-dependent call. */
14692 {
14694 {
14695 /* For backwards compatibility and good diagnostics, try
14696 the unqualified lookup again if we aren't in SFINAE
14697 context. */
14698 tree unq = (tsubst_copy_and_build
14700 integral_constant_expression_p));
14705 {
14714 "%qD was not declared in this scope, "
14715 "and no declarations were found by "
14716 "argument-dependent lookup at the point "
14718 {
14722 {
14724 input_location);
14726 "declarations in dependent base %qT are "
14732 else
14736 }
14737 else
14740 }
14742 }
14743 }
14745 {
14750 }
14751 }
14753 /* Remember that there was a reference to this entity. */
14757 /* Put back tf_decltype for the actual call. */
14762 complain);
14764 {
14779 complain);
14780 else
14781 ret = (build_new_method_call
14786 complain));
14787 }
14788 else
14791 koenig_p,
14792 complain);
14797 }
14800 {
14805 {
14807 {
14812 }
14813 else
14814 {
14819 }
14820 }
14821 else
14822 {
14825 }
14829 }
14836 input_location));
14839 {
14847 {
14848 /* We have pack expansions, so expand those and
14849 create a new list out of it. */
14852 tree chain;
14855 /* Expand the argument expressions. */
14863 /* Build the rest of the list. */
14868 /* Determine the number of arguments. */
14870 {
14873 }
14876 else
14877 {
14878 /* Since we only performed a partial substitution into
14879 the argument pack, we only RETURN (a single list
14880 node. */
14887 }
14889 /* Convert the argument vectors into a TREE_LIST */
14892 {
14893 /* Grab the Ith values. */
14894 i--;
14897 value
14901 /* Build the list (backwards). */
14903 }
14906 }
14922 }
14925 {
14926 tree object;
14927 tree object_type;
14928 tree member;
14929 tree r;
14933 /* Remember that there was a reference to this entity. */
14943 else
14951 {
14953 {
14958 {
14961 }
14963 {
14968 }
14969 }
14970 }
14973 {
14974 /* Lookup the template functions now that we know what the
14975 scope is. */
14983 {
14986 args);
14987 member = (adjust_result_of_qualified_name_lookup
14989 object_type));
14990 }
14991 else
14992 {
14994 input_location);
14996 }
14997 }
15001 {
15003 {
15007 else
15010 }
15012 }
15014 {
15019 }
15023 complain);
15027 }
15034 {
15042 tree r;
15047 /* digest_init will do the wrong thing if we let it. */
15051 /* We do not want to process the index of aggregate
15052 initializers as they are identifier nodes which will be
15053 looked up by digest_init. */
15059 {
15061 /* An identifier index is looked up in the type
15062 being initialized, not the current scope. */
15067 {
15068 /* Substitute into the pack expansion. */
15070 in_decl);
15074 ;
15076 /* Just move the argument into place. */
15078 else
15079 {
15080 /* Update the length of the final CONSTRUCTOR
15081 arguments vector, and note that we will need to
15082 copy.*/
15085 }
15086 }
15087 else
15089 }
15092 {
15097 {
15099 {
15104 }
15105 else
15107 }
15108 }
15118 }
15121 {
15124 {
15127 }
15128 else
15129 {
15132 }
15133 }
15139 {
15140 /* We don't build decls for an instantiation of a
15141 variadic capture proxy, we instantiate the elements
15142 when needed. */
15145 }
15146 /* Fall through */
15149 {
15153 /* If the original type was a reference, we'll be wrapped in
15154 the appropriate INDIRECT_REF. */
15157 }
15168 {
15177 }
15180 {
15186 integral_constant_expression_p);
15190 /* If the resulting list of expression statement is empty,
15191 fold it further into void_zero_node. */
15196 }
15199 {
15213 /* For a function scope, we want to use tsubst so that we don't
15214 complain about referring to an auto function before its return
15215 type has been deduced. Otherwise, we want to use tsubst_copy so
15216 that we look up the existing field/parameter/variable rather
15217 than build a new one. */
15222 {
15223 /* Look up the parameter we want directly, as tsubst_copy
15224 doesn't do what we need. */
15230 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15233 }
15234 else
15243 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15245 /* Now that we know visibility, instantiate the type so we have a
15246 declaration of the op() for later calls to lambda_function. */
15252 }
15255 /* We can get here for a constant initializer of non-dependent type.
15256 FIXME stop folding in cp_parser_initializer_clause. */
15257 {
15259 complain);
15261 }
15265 integral_constant_expression_p));
15275 complain));
15278 /* Handle Objective-C++ constructs, if appropriate. */
15279 {
15280 tree subst
15285 }
15287 }
15289 #undef RECUR
15290 #undef RETURN
15291 out:
15294 }
15296 /* Verify that the instantiated ARGS are valid. For type arguments,
15297 make sure that the type's linkage is ok. For non-type arguments,
15298 make sure they are constants if they are integral or enumerations.
15299 Emit an error under control of COMPLAIN, and return TRUE on error. */
15301 static bool
15303 {
15307 {
15317 }
15319 {
15320 /* [basic.link]: A name with no linkage (notably, the name
15321 of a class or enumeration declared in a local scope)
15322 shall not be used to declare an entity with linkage.
15323 This implies that names with no linkage cannot be used as
15324 template arguments
15326 DR 757 relaxes this restriction for C++0x. */
15331 {
15332 /* DR 488 makes use of a type with no linkage cause
15333 type deduction to fail. */
15335 {
15338 else
15341 }
15343 }
15344 /* In order to avoid all sorts of complications, we do not
15345 allow variably-modified types as template arguments. */
15347 {
15351 }
15352 }
15353 /* Class template and alias template arguments should be OK. */
15355 ;
15356 /* A non-type argument of integral or enumerated type must be a
15357 constant. */
15361 {
15365 }
15367 }
15369 static bool
15371 {
15376 {
15379 }
15383 }
15385 /* We're out of SFINAE context now, so generate diagnostics for the access
15386 errors we saw earlier when instantiating D from TMPL and ARGS. */
15388 static void
15390 {
15402 }
15404 /* Instantiate the indicated variable, function, or alias template TMPL with
15405 the template arguments in TARG_PTR. */
15407 static tree
15409 {
15411 tree fndecl;
15412 tree gen_tmpl;
15413 tree spec;
15421 /* If this function is a clone, handle it specially. */
15423 {
15424 tree spec;
15425 tree clone;
15427 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15428 DECL_CLONED_FUNCTION. */
15434 /* Look for the clone. */
15438 /* We should always have found the clone by now. */
15441 }
15446 /* Check to see if we already have this specialization. */
15449 /* The TMPL is a partial instantiation. To get a full set of
15450 arguments we must add the arguments used to perform the
15451 partial instantiation. */
15453 targ_ptr);
15455 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15456 but it doesn't seem to be on the hot path. */
15465 {
15467 {
15471 }
15473 }
15476 complain))
15479 /* We are building a FUNCTION_DECL, during which the access of its
15480 parameters and return types have to be checked. However this
15481 FUNCTION_DECL which is the desired context for access checking
15482 is not built yet. We solve this chicken-and-egg problem by
15483 deferring all checks until we have the FUNCTION_DECL. */
15486 /* Instantiation of the function happens in the context of the function
15487 template, not the context of the overload resolution we're doing. */
15489 /* If there are dependent arguments, e.g. because we're doing partial
15490 ordering, make sure processing_template_decl stays set. */
15494 {
15498 }
15499 /* Substitute template parameters to obtain the specialization. */
15507 {
15510 }
15512 /* The DECL_TI_TEMPLATE should always be the immediate parent
15513 template, not the most general template. */
15516 /* Now we know the specialization, compute access previously
15517 deferred. */
15524 /* If we've just instantiated the main entry point for a function,
15525 instantiate all the alternate entry points as well. We do this
15526 by cloning the instantiation of the main entry point, not by
15527 instantiating the template clones. */
15532 {
15534 {
15535 /* Remember to reinstantiate when we're out of SFINAE so the user
15536 can see the errors. */
15538 }
15540 }
15542 }
15544 /* Wrapper for instantiate_template_1. */
15546 tree
15548 {
15549 tree ret;
15554 }
15556 /* Instantiate the alias template TMPL with ARGS. Also push a template
15557 instantiation level, which instantiate_template doesn't do because
15558 functions and variables have sufficient context established by the
15559 callers. */
15561 static tree
15563 {
15570 {
15573 }
15575 args =
15583 /* We can't free this if a pending_template entry or last_error_tinst_level
15584 is pointing at it. */
15590 }
15592 /* PARM is a template parameter pack for FN. Returns true iff
15593 PARM is used in a deducible way in the argument list of FN. */
15595 static bool
15597 {
15600 {
15602 tree packs;
15608 {
15609 /* The template parameter pack is used in a function parameter
15610 pack. If this is the end of the parameter list, the
15611 template parameter pack is deducible. */
15614 else
15615 /* Otherwise, not. Well, it could be deduced from
15616 a non-pack parameter, but doing so would end up with
15617 a deduction mismatch, so don't bother. */
15619 }
15620 }
15621 /* The template parameter pack isn't used in any function parameter
15622 packs, but it might be used deeper, e.g. tuple<Args...>. */
15624 }
15626 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15627 NARGS elements of the arguments that are being used when calling
15628 it. TARGS is a vector into which the deduced template arguments
15629 are placed.
15631 Returns either a FUNCTION_DECL for the matching specialization of FN or
15632 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
15633 true, diagnostics will be printed to explain why it failed.
15635 If FN is a conversion operator, or we are trying to produce a specific
15636 specialization, RETURN_TYPE is the return type desired.
15638 The EXPLICIT_TARGS are explicit template arguments provided via a
15639 template-id.
15641 The parameter STRICT is one of:
15643 DEDUCE_CALL:
15644 We are deducing arguments for a function call, as in
15645 [temp.deduct.call].
15647 DEDUCE_CONV:
15648 We are deducing arguments for a conversion function, as in
15649 [temp.deduct.conv].
15651 DEDUCE_EXACT:
15652 We are deducing arguments when doing an explicit instantiation
15653 as in [temp.explicit], when determining an explicit specialization
15654 as in [temp.expl.spec], or when taking the address of a function
15655 template, as in [temp.deduct.funcaddr]. */
15657 tree
15659 tree explicit_targs,
15660 tree targs,
15663 tree return_type,
15664 unification_kind_t strict,
15668 {
15669 tree parms;
15670 tree fntype;
15678 tree tinst;
15684 /* In C++0x, it's possible to have a function template whose type depends
15685 on itself recursively. This is most obvious with decltype, but can also
15686 occur with enumeration scope (c++/48969). So we need to catch infinite
15687 recursion and reject the substitution at deduction time; this function
15688 will return error_mark_node for any repeated substitution.
15690 This also catches excessive recursion such as when f<N> depends on
15691 f<N-1> across all integers, and returns error_mark_node for all the
15692 substitutions back up to the initial one.
15694 This is, of course, not reentrant. */
15704 {
15705 /* [temp.deduct]
15707 The specified template arguments must match the template
15708 parameters in kind (i.e., type, nontype, template), and there
15709 must not be more arguments than there are parameters;
15710 otherwise type deduction fails.
15712 Nontype arguments must match the types of the corresponding
15713 nontype template parameters, or must be convertible to the
15714 types of the corresponding nontype parameters as specified in
15715 _temp.arg.nontype_, otherwise type deduction fails.
15717 All references in the function type of the function template
15718 to the corresponding template parameters are replaced by the
15719 specified template argument values. If a substitution in a
15720 template parameter or in the function type of the function
15721 template results in an invalid type, type deduction fails. */
15726 /* Adjust any explicit template arguments before entering the
15727 substitution context. */
15728 explicit_targs
15730 complain,
15736 /* Substitute the explicit args into the function type. This is
15737 necessary so that, for instance, explicitly declared function
15738 arguments can match null pointed constants. If we were given
15739 an incomplete set of explicit args, we must not do semantic
15740 processing during substitution as we could create partial
15741 instantiations. */
15743 {
15748 /* Dig out the actual parm. */
15751 {
15754 }
15756 {
15759 }
15762 /* No explicit argument for this template parameter. */
15766 {
15767 /* Mark the argument pack as "incomplete". We could
15768 still deduce more arguments during unification.
15769 We remove this mark in type_unification_real. */
15771 {
15775 }
15777 /* We have some incomplete argument packs. */
15779 }
15780 }
15784 {
15787 }
15790 /* Ignore any access checks; we'll see them again in
15791 instantiate_template and they might have the wrong
15792 access path at this point. */
15804 /* Place the explicitly specified arguments in TARGS. */
15807 }
15809 /* Never do unification on the 'this' parameter. */
15813 {
15822 }
15824 /* We allow incomplete unification without an error message here
15825 because the standard doesn't seem to explicitly prohibit it. Our
15826 callers must be ready to deal with unification failures in any
15827 event. */
15830 /* If we aren't explaining yet, push tinst context so we can see where
15831 any errors (e.g. from class instantiations triggered by instantiation
15832 of default template arguments) come from. If we are explaining, this
15833 context is redundant. */
15835 {
15838 }
15840 /* type_unification_real will pass back any access checks from default
15841 template argument substitution. */
15853 /* Now that we have bindings for all of the template arguments,
15854 ensure that the arguments deduced for the template template
15855 parameters have compatible template parameter lists. We cannot
15856 check this property before we have deduced all template
15857 arguments, because the template parameter types of a template
15858 template parameter might depend on prior template parameters
15859 deduced after the template template parameter. The following
15860 ill-formed example illustrates this issue:
15862 template<typename T, template<T> class C> void f(C<5>, T);
15864 template<int N> struct X {};
15866 void g() {
15867 f(X<5>(), 5l); // error: template argument deduction fails
15868 }
15870 The template parameter list of 'C' depends on the template type
15871 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15872 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15873 time that we deduce 'C'. */
15876 {
15879 }
15881 /* All is well so far. Now, check:
15883 [temp.deduct]
15885 When all template arguments have been deduced, all uses of
15886 template parameters in nondeduced contexts are replaced with
15887 the corresponding deduced argument values. If the
15888 substitution results in an invalid type, as described above,
15889 type deduction fails. */
15892 {
15895 }
15897 /* Also collect access checks from the instantiation. */
15910 /* Now perform any access checks encountered during substitution. */
15917 /* If we're looking for an exact match, check that what we got
15918 is indeed an exact match. It might not be if some template
15919 parameters are used in non-deduced contexts. But don't check
15920 for an exact match if we have dependent template arguments;
15921 in that case we're doing partial ordering, and we already know
15922 that we have two candidates that will provide the actual type. */
15924 {
15928 tree sarg
15934 {
15938 }
15939 }
15943 fail:
15946 {
15948 /* Reset once we're all the way out. */
15950 }
15952 /* We can't free this if a pending_template entry or last_error_tinst_level
15953 is pointing at it. */
15959 }
15961 /* Adjust types before performing type deduction, as described in
15962 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15963 sections are symmetric. PARM is the type of a function parameter
15964 or the return type of the conversion function. ARG is the type of
15965 the argument passed to the call, or the type of the value
15966 initialized with the result of the conversion function.
15967 ARG_EXPR is the original argument expression, which may be null. */
15969 static int
15973 tree arg_expr)
15974 {
15978 {
15983 {
15984 /* Swap PARM and ARG throughout the remainder of this
15985 function; the handling is precisely symmetric since PARM
15986 will initialize ARG rather than vice versa. */
15991 }
15994 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15995 too, but here handle it by stripping the reference from PARM
15996 rather than by adding it to ARG. */
16004 /* Nothing else to do in this case. */
16009 }
16012 {
16013 /* [temp.deduct.call]
16015 If P is not a reference type:
16017 --If A is an array type, the pointer type produced by the
16018 array-to-pointer standard conversion (_conv.array_) is
16019 used in place of A for type deduction; otherwise,
16021 --If A is a function type, the pointer type produced by
16022 the function-to-pointer standard conversion
16023 (_conv.func_) is used in place of A for type deduction;
16024 otherwise,
16026 --If A is a cv-qualified type, the top level
16027 cv-qualifiers of A's type are ignored for type
16028 deduction. */
16033 else
16035 }
16037 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16038 of the form T&&, where T is a template parameter, and the argument
16039 is an lvalue, T is deduced as A& */
16045 /* try_one_overload doesn't provide an arg_expr, but
16046 functions are always lvalues. */
16050 /* [temp.deduct.call]
16052 If P is a cv-qualified type, the top level cv-qualifiers
16053 of P's type are ignored for type deduction. If P is a
16054 reference type, the type referred to by P is used for
16055 type deduction. */
16058 {
16061 }
16063 /* DR 322. For conversion deduction, remove a reference type on parm
16064 too (which has been swapped into ARG). */
16069 }
16071 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16072 template which does contain any deducible template parameters; check if
16073 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16074 unify_one_argument. */
16076 static int
16079 {
16080 tree type;
16084 else
16091 {
16095 }
16097 {
16102 }
16106 else
16108 }
16112 /* Returns true iff the expression EXPR is one from which a template
16113 argument can be deduced. In other words, if it's an undecorated
16114 use of a template non-type parameter. */
16116 static bool
16118 {
16120 }
16122 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16123 deducible way; that is, if it has a max value of <PARM> - 1. */
16125 static bool
16127 {
16136 }
16138 /* Returns true iff the template arguments ARGS use a template parameter
16139 in a deducible way. */
16141 static bool
16143 {
16145 {
16150 else
16151 {
16158 else
16160 }
16163 }
16165 }
16167 /* Returns true iff TYPE contains any deducible references to template
16168 parameters, as per 14.8.2.5. */
16170 static bool
16172 {
16176 /* T
16177 cv-list T
16178 TT<T>
16179 TT<i>
16180 TT<> */
16185 /* T*
16186 T&
16187 T&& */
16191 /* T[integer-constant ]
16192 type [i] */
16197 /* T type ::*
16198 type T::*
16199 T T::*
16200 T (type ::*)()
16201 type (T::*)()
16202 type (type ::*)(T)
16203 type (T::*)(T)
16204 T (type ::*)(T)
16205 T (T::*)()
16206 T (T::*)(T) */
16209 || (uses_deducible_template_parms
16212 /* template-name <T> (where template-name refers to a class template)
16213 template-name <i> (where template-name refers to a class template) */
16220 /* type (T)
16221 T()
16222 T(T) */
16225 {
16234 }
16237 }
16239 /* Subroutine of type_unification_real and unify_pack_expansion to
16240 handle unification of a single P/A pair. Parameters are as
16241 for those functions. */
16243 static int
16247 {
16254 /* We can't deduce anything from this, but we might get all the
16255 template args from other function args. */
16258 /* Implicit conversions (Clause 4) will be performed on a function
16259 argument to convert it to the type of the corresponding function
16260 parameter if the parameter type contains no template-parameters that
16261 participate in template argument deduction. */
16263 /* For function parameters that contain no template-parameters at all,
16264 we have historically checked for convertibility in order to shortcut
16265 consideration of this candidate. */
16267 explain_p);
16270 /* For function parameters with only non-deducible template parameters,
16271 just return. */
16275 {
16277 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16278 | UNIFY_ALLOW_MORE_CV_QUAL
16292 }
16294 /* We only do these transformations if this is the top-level
16295 parameter_type_list in a call or declaration matching; in other
16296 situations (nested function declarators, template argument lists) we
16297 won't be comparing a type to an expression, and we don't do any type
16298 adjustments. */
16300 {
16302 {
16305 {
16306 /* [temp.deduct.type] A template-argument can be
16307 deduced from a pointer to function or pointer
16308 to member function argument if the set of
16309 overloaded functions does not contain function
16310 templates and at most one of a set of
16311 overloaded functions provides a unique
16312 match. */
16319 }
16325 }
16327 arg_strict |=
16329 }
16330 else
16334 /* For deduction from an init-list we need the actual list. */
16338 }
16340 /* Most parms like fn_type_unification.
16342 If SUBR is 1, we're being called recursively (to unify the
16343 arguments of a function or method parameter of a function
16344 template).
16346 CHECKS is a pointer to a vector of access checks encountered while
16347 substituting default template arguments. */
16349 static int
16351 tree targs,
16352 tree xparms,
16356 unification_kind_t strict,
16360 {
16365 tree parms;
16374 /* Reset the number of non-defaulted template arguments contained
16375 in TARGS. */
16378 again:
16386 {
16391 /* For a function parameter pack that occurs at the end of the
16392 parameter-declaration-list, the type A of each remaining
16393 argument of the call is compared with the type P of the
16394 declarator-id of the function parameter pack. */
16400 /* For a function parameter pack that does not occur at the
16401 end of the parameter-declaration-list, the type of the
16402 parameter pack is a non-deduced context. */
16411 }
16416 {
16417 /* Unify the remaining arguments with the pack expansion type. */
16418 tree argvec;
16421 /* Allocate a TREE_VEC and copy in all of the arguments */
16426 /* Copy the parameter into parmvec. */
16432 /* Advance to the end of the list of parameters. */
16434 }
16436 /* Fail if we've reached the end of the parm list, and more args
16437 are present, and the parm list isn't variadic. */
16440 /* Fail if parms are left and they don't have default values. */
16443 {
16447 {
16448 count++;
16450 }
16452 }
16455 {
16456 tsubst_flags_t complain = (explain_p
16457 ? tf_warning_or_error
16461 {
16465 /* Clear the "incomplete" flags on all argument packs now so that
16466 substituting them into later default arguments works. */
16468 {
16471 }
16477 /* If this is an undeduced nontype parameter that depends on
16478 a type parameter, try another pass; its type may have been
16479 deduced from a later argument than the one from which
16480 this parameter can be deduced. */
16486 /* Core issue #226 (C++0x) [temp.deduct]:
16488 If a template argument has not been deduced, its
16489 default template argument, if any, is used.
16491 When we are in C++98 mode, TREE_PURPOSE will either
16492 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16493 to explicitly check cxx_dialect here. */
16495 {
16510 else
16511 {
16513 /* The position of the first default template argument,
16514 is also the number of non-defaulted arguments in TARGS.
16515 Record that. */
16519 }
16520 }
16522 /* If the type parameter is a parameter pack, then it will
16523 be deduced to an empty parameter pack. */
16525 {
16526 tree arg;
16529 {
16533 }
16534 else
16541 }
16544 }
16545 }
16546 #ifdef ENABLE_CHECKING
16549 #endif
16552 }
16554 /* Subroutine of type_unification_real. Args are like the variables
16555 at the call site. ARG is an overloaded function (or template-id);
16556 we try deducing template args from each of the overloads, and if
16557 only one succeeds, we go with that. Modifies TARGS and returns
16558 true on success. */
16560 static bool
16562 tree targs,
16563 tree parm,
16564 tree arg,
16565 unification_kind_t strict,
16568 {
16575 {
16578 }
16579 else
16583 /* Handle `&x' where `x' is some static or non-static member
16584 function name. */
16590 /* Strip baselink information. */
16595 {
16596 /* If we got some explicit template args, we need to plug them into
16597 the affected templates before we try to unify, in case the
16598 explicit args will completely resolve the templates in question. */
16605 {
16618 {
16623 {
16626 }
16627 }
16630 }
16631 /* If no templates (or more than one) are fully resolved by the
16632 explicit arguments, this template-id is a non-deduced context; it
16633 could still be OK if we deduce all template arguments for the
16634 enclosing call through other arguments. */
16637 }
16640 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16641 -- but the deduction does not succeed because the expression is
16642 not just the function on its own. */
16644 else
16650 {
16653 }
16655 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16656 to function or pointer to member function argument if the set of
16657 overloaded functions does not contain function templates and at most
16658 one of a set of overloaded functions provides a unique match.
16660 So if we found multiple possibilities, we return success but don't
16661 deduce anything. */
16664 {
16669 }
16674 }
16676 /* Core DR 115: In contexts where deduction is done and fails, or in
16677 contexts where deduction is not done, if a template argument list is
16678 specified and it, along with any default template arguments, identifies
16679 a single function template specialization, then the template-id is an
16680 lvalue for the function template specialization. */
16682 tree
16684 {
16697 {
16700 }
16702 {
16705 }
16707 {
16710 }
16713 {
16717 /* If we got some explicit template args, we need to plug them into
16718 the affected templates before we try to unify, in case the
16719 explicit args will completely resolve the templates in question. */
16727 {
16740 {
16743 {
16746 }
16748 {
16751 }
16752 }
16753 }
16755 {
16763 {
16764 tree base
16767 }
16771 }
16773 /* There were no good options and at least one bad one, so let the
16774 user know what the problem is. */
16776 }
16778 }
16780 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16781 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16782 different overloads deduce different arguments for a given parm.
16783 ADDR_P is true if the expression for which deduction is being
16784 performed was of the form "& fn" rather than simply "fn".
16786 Returns 1 on success. */
16788 static int
16790 tree orig_targs,
16791 tree targs,
16792 tree parm,
16793 tree arg,
16794 unification_kind_t strict,
16798 {
16800 tree tempargs;
16806 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16807 to function or pointer to member function argument if the set of
16808 overloaded functions does not contain function templates and at most
16809 one of a set of overloaded functions provides a unique match.
16811 So if this is a template, just return success. */
16823 /* We don't copy orig_targs for this because if we have already deduced
16824 some template args from previous args, unify would complain when we
16825 try to deduce a template parameter for the same argument, even though
16826 there isn't really a conflict. */
16833 /* First make sure we didn't deduce anything that conflicts with
16834 explicitly specified args. */
16836 {
16843 /* Since we're unifying against ourselves, we will fill in
16844 template args used in the function parm list with our own
16845 template parms. Discard them. */
16849 }
16852 {
16857 }
16860 }
16862 /* PARM is a template class (perhaps with unbound template
16863 parameters). ARG is a fully instantiated type. If ARG can be
16864 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16865 TARGS are as for unify. */
16867 static tree
16870 {
16871 tree copy_of_targs;
16878 /* We need to make a new template argument vector for the call to
16879 unify. If we used TARGS, we'd clutter it up with the result of
16880 the attempted unification, even if this class didn't work out.
16881 We also don't want to commit ourselves to all the unifications
16882 we've already done, since unification is supposed to be done on
16883 an argument-by-argument basis. In other words, consider the
16884 following pathological case:
16886 template <int I, int J, int K>
16887 struct S {};
16889 template <int I, int J>
16890 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16892 template <int I, int J, int K>
16893 void f(S<I, J, K>, S<I, I, I>);
16895 void g() {
16896 S<0, 0, 0> s0;
16897 S<0, 1, 2> s2;
16899 f(s0, s2);
16900 }
16902 Now, by the time we consider the unification involving `s2', we
16903 already know that we must have `f<0, 0, 0>'. But, even though
16904 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
16905 because there are two ways to unify base classes of S<0, 1, 2>
16906 with S<I, I, I>. If we kept the already deduced knowledge, we
16907 would reject the possibility I=1. */
16910 /* If unification failed, we're done. */
16916 }
16918 /* Given a template type PARM and a class type ARG, find the unique
16919 base type in ARG that is an instance of PARM. We do not examine
16920 ARG itself; only its base-classes. If there is not exactly one
16921 appropriate base class, return NULL_TREE. PARM may be the type of
16922 a partial specialization, as well as a plain template type. Used
16923 by unify. */
16925 static enum template_base_result
16928 {
16930 tree binfo;
16936 {
16937 /* The type could not be completed. */
16940 }
16942 /* Walk in inheritance graph order. The search order is not
16943 important, and this avoids multiple walks of virtual bases. */
16945 {
16950 {
16951 /* If there is more than one satisfactory baseclass, then:
16953 [temp.deduct.call]
16955 If they yield more than one possible deduced A, the type
16956 deduction fails.
16958 applies. */
16960 {
16963 }
16966 }
16967 }
16971 }
16973 /* Returns the level of DECL, which declares a template parameter. */
16975 static int
16977 {
16979 {
16989 }
16991 }
16993 /* Decide whether ARG can be unified with PARM, considering only the
16994 cv-qualifiers of each type, given STRICT as documented for unify.
16995 Returns nonzero iff the unification is OK on that basis. */
16997 static int
16999 {
17005 {
17006 /* Although a CVR qualifier is ignored when being applied to a
17007 substituted template parameter ([8.3.2]/1 for example), that
17008 does not allow us to unify "const T" with "int&" because both
17009 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17010 It is ok when we're allowing additional CV qualifiers
17011 at the outer level [14.8.2.1]/3,1st bullet. */
17021 }
17032 }
17034 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17035 void
17037 {
17041 {
17044 }
17045 else
17046 {
17049 }
17050 }
17052 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17053 do { \
17054 if (unify (TP, TA, P, A, S, EP)) \
17055 return 1; \
17056 } while (0);
17058 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17059 expansion at the end of PACKED_PARMS. Returns 0 if the type
17060 deduction succeeds, 1 otherwise. STRICT is the same as in
17061 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17062 call argument list. We'll need to adjust the arguments to make them
17063 types. SUBR tells us if this is from a recursive call to
17064 type_unification_real, or for comparing two template argument
17065 lists. */
17067 static int
17071 {
17072 tree parm
17082 /* Determine the parameter packs we will be deducing from the
17083 pattern, and record their current deductions. */
17086 {
17090 /* Determine the index and level of this parameter pack. */
17093 /* Keep track of the parameter packs and their corresponding
17094 argument packs. */
17097 }
17099 /* Loop through all of the arguments that have not yet been
17100 unified and unify each with the pattern. */
17102 {
17103 tree parm;
17107 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17108 or the element of its argument pack at the current index if
17109 this argument was explicitly specified. */
17111 {
17120 {
17123 }
17125 }
17127 /* If we had explicit template arguments, substitute them into the
17128 pattern before deduction. */
17130 {
17131 /* Some arguments might still be unspecified or dependent. */
17139 NULL_TREE);
17144 }
17145 else
17148 /* Unify the pattern with the current argument. */
17153 /* For each parameter pack, collect the deduced value. */
17155 {
17161 }
17162 }
17164 /* Verify that the results of unification with the parameter packs
17165 produce results consistent with what we've seen before, and make
17166 the deduced argument packs available. */
17168 {
17175 /* By default keep the original deduced argument pack.
17176 If necessary, more specific code is going to update the
17177 resulting deduced argument later down in this function. */
17181 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17182 actually deduce anything. */
17190 {
17191 /* If we had fewer function args than explicit template args,
17192 just use the explicits. */
17197 }
17200 {
17201 tree result;
17202 /* Build the deduced *_ARGUMENT_PACK. */
17204 {
17209 }
17210 else
17215 /* Note the deduced argument packs for this parameter
17216 pack. */
17218 }
17222 {
17223 /* We only had the explicitly-provided arguments before, but
17224 now we have a complete set of arguments. */
17230 }
17231 else
17232 {
17238 /* Inconsistent unification of this parameter pack. */
17240 bad_old_arg,
17241 bad_new_arg);
17242 }
17243 }
17246 }
17248 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17249 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17250 parameters and return value are as for unify. */
17252 static int
17256 {
17257 tree parm_max;
17258 tree arg_max;
17262 /* Our representation of array types uses "N - 1" as the
17263 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17264 not an integer constant. We cannot unify arbitrarily
17265 complex expressions, so we eliminate the MINUS_EXPRs
17266 here. */
17270 {
17273 }
17277 {
17278 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17279 trying to unify the type of a variable with the type
17280 of a template parameter. For example:
17282 template <unsigned int N>
17283 void f (char (&) [N]);
17284 int g();
17285 void h(int i) {
17286 char a[g(i)];
17287 f(a);
17288 }
17290 Here, the type of the ARG will be "int [g(i)]", and
17291 may be a SAVE_EXPR, etc. */
17295 }
17297 /* If only one of the bounds used a MINUS_EXPR, compensate
17298 by adding one to the other bound. */
17301 integer_type_node,
17302 parm_max,
17303 integer_one_node);
17306 integer_type_node,
17307 arg_max,
17308 integer_one_node);
17312 }
17314 /* Deduce the value of template parameters. TPARMS is the (innermost)
17315 set of template parameters to a template. TARGS is the bindings
17316 for those template parameters, as determined thus far; TARGS may
17317 include template arguments for outer levels of template parameters
17318 as well. PARM is a parameter to a template function, or a
17319 subcomponent of that parameter; ARG is the corresponding argument.
17320 This function attempts to match PARM with ARG in a manner
17321 consistent with the existing assignments in TARGS. If more values
17322 are deduced, then TARGS is updated.
17324 Returns 0 if the type deduction succeeds, 1 otherwise. The
17325 parameter STRICT is a bitwise or of the following flags:
17327 UNIFY_ALLOW_NONE:
17328 Require an exact match between PARM and ARG.
17329 UNIFY_ALLOW_MORE_CV_QUAL:
17330 Allow the deduced ARG to be more cv-qualified (by qualification
17331 conversion) than ARG.
17332 UNIFY_ALLOW_LESS_CV_QUAL:
17333 Allow the deduced ARG to be less cv-qualified than ARG.
17334 UNIFY_ALLOW_DERIVED:
17335 Allow the deduced ARG to be a template base class of ARG,
17336 or a pointer to a template base class of the type pointed to by
17337 ARG.
17338 UNIFY_ALLOW_INTEGER:
17339 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17340 case for more information.
17341 UNIFY_ALLOW_OUTER_LEVEL:
17342 This is the outermost level of a deduction. Used to determine validity
17343 of qualification conversions. A valid qualification conversion must
17344 have const qualified pointers leading up to the inner type which
17345 requires additional CV quals, except at the outer level, where const
17346 is not required [conv.qual]. It would be normal to set this flag in
17347 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17348 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17349 This is the outermost level of a deduction, and PARM can be more CV
17350 qualified at this point.
17351 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17352 This is the outermost level of a deduction, and PARM can be less CV
17353 qualified at this point. */
17355 static int
17358 {
17360 tree targ;
17361 tree tparm;
17364 /* I don't think this will do the right thing with respect to types.
17365 But the only case I've seen it in so far has been array bounds, where
17366 signedness is the only information lost, and I think that will be
17367 okay. */
17375 /* We can't deduce anything from this, but we might get all the
17376 template args from other function args. */
17379 /* If PARM uses template parameters, then we can't bail out here,
17380 even if ARG == PARM, since we won't record unifications for the
17381 template parameters. We might need them if we're trying to
17382 figure out which of two things is more specialized. */
17386 /* Handle init lists early, so the rest of the function can assume
17387 we're dealing with a type. */
17389 {
17394 /* Replace T with std::initializer_list<T> for deduction. */
17401 /* We can only deduce from an initializer list argument if the
17402 parameter is std::initializer_list or an array; otherwise this
17403 is a non-deduced context. */
17408 else
17412 {
17419 {
17421 /* It should only be possible to get here for a call. */
17423 elt_strict |= maybe_adjust_types_for_deduction
17426 }
17429 explain_p);
17430 }
17434 {
17435 /* Also deduce from the length of the initializer list. */
17442 }
17444 /* If the std::initializer_list<T> deduction worked, replace the
17445 deduced A with std::initializer_list<A>. */
17447 {
17452 }
17454 }
17456 /* Immediately reject some pairs that won't unify because of
17457 cv-qualification mismatches. */
17460 /* It is the elements of the array which hold the cv quals of an array
17461 type, and the elements might be template type parms. We'll check
17462 when we recurse. */
17464 /* We check the cv-qualifiers when unifying with template type
17465 parameters below. We want to allow ARG `const T' to unify with
17466 PARM `T' for example, when computing which of two templates
17467 is more specialized, for example. */
17481 {
17485 /* In a type which contains a nested-name-specifier, template
17486 argument values cannot be deduced for template parameters used
17487 within the nested-name-specifier. */
17499 /* The PARM is not one we're trying to unify. Just check
17500 to see if it matches ARG. */
17501 {
17506 else
17508 }
17515 /* Check for mixed types and values. */
17523 {
17524 /* ARG must be constructed from a template class or a template
17525 template parameter. */
17529 {
17531 /* An alias template name is never deduced. */
17536 tree parm_parms
17537 = DECL_INNERMOST_TEMPLATE_PARMS
17542 /* The resolution to DR150 makes clear that default
17543 arguments for an N-argument may not be used to bind T
17544 to a template template parameter with fewer than N
17545 parameters. It is not safe to permit the binding of
17546 default arguments as an extension, as that may change
17547 the meaning of a conforming program. Consider:
17549 struct Dense { static const unsigned int dim = 1; };
17551 template <template <typename> class View,
17552 typename Block>
17553 void operator+(float, View<Block> const&);
17555 template <typename Block,
17556 unsigned int Dim = Block::dim>
17557 struct Lvalue_proxy { operator float() const; };
17559 void
17560 test_1d (void) {
17561 Lvalue_proxy<Dense> p;
17562 float b;
17563 b + p;
17564 }
17566 Here, if Lvalue_proxy is permitted to bind to View, then
17567 the global operator+ will be used; if they are not, the
17568 Lvalue_proxy will be converted to float. */
17570 full_argvec,
17572 (explain_p
17573 ? tf_warning_or_error
17580 /* Deduce arguments T, i from TT<T> or TT<i>.
17581 We check each element of PARMVEC and ARGVEC individually
17582 rather than the whole TREE_VEC since they can have
17583 different number of elements. */
17590 /* Check if the parameters end in a pack, making them
17591 variadic. */
17597 /* If the template argument list of P contains a pack
17598 expansion that is not the last template argument, the
17599 entire template argument list is a non-deduced
17600 context. */
17609 {
17614 }
17619 DEDUCE_EXACT,
17622 }
17625 /* Fall through to deduce template name. */
17626 }
17630 {
17631 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17633 /* Simple cases: Value already set, does match or doesn't. */
17638 }
17639 else
17640 {
17641 /* If PARM is `const T' and ARG is only `int', we don't have
17642 a match unless we are allowing additional qualification.
17643 If ARG is `const int' and PARM is just `T' that's OK;
17644 that binds `const int' to `T'. */
17649 /* Consider the case where ARG is `const volatile int' and
17650 PARM is `const T'. Then, T should be `volatile int'. */
17651 arg = cp_build_qualified_type_real
17656 /* Simple cases: Value already set, does match or doesn't. */
17662 /* Make sure that ARG is not a variable-sized array. (Note
17663 that were talking about variable-sized arrays (like
17664 `int[n]'), rather than arrays of unknown size (like
17665 `int[]').) We'll get very confused by such a type since
17666 the bound of the array is not constant, and therefore
17667 not mangleable. Besides, such types are not allowed in
17668 ISO C++, so we can do as we please here. We do allow
17669 them for 'auto' deduction, since that isn't ABI-exposed. */
17673 /* Strip typedefs as in convert_template_argument. */
17675 }
17677 /* If ARG is a parameter pack or an expansion, we cannot unify
17678 against it unless PARM is also a parameter pack. */
17683 /* If the argument deduction results is a METHOD_TYPE,
17684 then there is a problem.
17685 METHOD_TYPE doesn't map to any real C++ type the result of
17686 the deduction can not be of that type. */
17700 {
17701 /* The PARM is not one we're trying to unify. Just check
17702 to see if it matches ARG. */
17708 }
17714 {
17719 }
17721 /* [temp.deduct.type] If, in the declaration of a function template
17722 with a non-type template-parameter, the non-type
17723 template-parameter is used in an expression in the function
17724 parameter-list and, if the corresponding template-argument is
17725 deduced, the template-argument type shall match the type of the
17726 template-parameter exactly, except that a template-argument
17727 deduced from an array bound may be of any integral type.
17728 The non-type parameter might use already deduced type parameters. */
17731 /* Template-parameter dependent expression. Just accept it for now.
17732 It will later be processed in convert_template_argument. */
17733 ;
17738 /* Convert the ARG to the type of PARM; the deduced non-type
17739 template argument must exactly match the types of the
17740 corresponding parameter. */
17743 /* We haven't deduced the type of this parameter yet. Try again
17744 later. */
17746 else
17749 /* If ARG is a parameter pack or an expansion, we cannot unify
17750 against it unless PARM is also a parameter pack. */
17760 {
17761 /* A pointer-to-member constant can be unified only with
17762 another constant. */
17766 /* Just unify the class member. It would be useless (and possibly
17767 wrong, depending on the strict flags) to unify also
17768 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17769 arg refer to the same variable, even if through different
17770 classes. For instance:
17772 struct A { int x; };
17773 struct B : A { };
17775 Unification of &A::x and &B::x must succeed. */
17778 }
17781 {
17785 /* [temp.deduct.call]
17787 A can be another pointer or pointer to member type that can
17788 be converted to the deduced A via a qualification
17789 conversion (_conv.qual_).
17791 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17792 This will allow for additional cv-qualification of the
17793 pointed-to types if appropriate. */
17796 /* The derived-to-base conversion only persists through one
17797 level of pointers. */
17802 }
17834 /* We have already checked cv-qualification at the top of the
17835 function. */
17839 /* As far as unification is concerned, this wins. Later checks
17840 will invalidate it if necessary. */
17843 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17844 /* Type INTEGER_CST can come from ordinary constant template args. */
17856 {
17866 /* Check for pack expansions in the parameters. */
17868 {
17870 {
17872 /* We can unify against something with a trailing
17873 parameter pack. */
17875 else
17876 /* [temp.deduct.type]/9: If the template argument list of
17877 P contains a pack expansion that is not the last
17878 template argument, the entire template argument list
17879 is a non-deduced context. */
17881 }
17882 }
17884 /* If we don't have enough arguments to satisfy the parameters
17885 (not counting the pack expression at the end), or we have
17886 too many arguments for a parameter list that doesn't end in
17887 a pack expression, we can't unify. */
17893 /* Unify all of the parameters that precede the (optional)
17894 pack expression. */
17896 {
17901 }
17904 DEDUCE_EXACT,
17907 }
17915 {
17923 }
17926 {
17930 {
17931 /* First, we try to unify the PARM and ARG directly. */
17936 {
17937 /* Fallback to the special case allowed in
17938 [temp.deduct.call]:
17940 If P is a class, and P has the form
17941 template-id, then A can be a derived class of
17942 the deduced A. Likewise, if P is a pointer to
17943 a class of the form template-id, A can be a
17944 pointer to a derived class pointed to by the
17945 deduced A. */
17952 }
17953 }
17957 /* Perhaps PARM is something like S<U> and ARG is S<int>.
17958 Then, we should unify `int' and `U'. */
17960 else
17961 /* There's no chance of unification succeeding. */
17966 }
17973 {
17976 tree a;
17982 /* CV qualifications for methods can never be deduced, they must
17983 match exactly. We need to check them explicitly here,
17984 because type_unification_real treats them as any other
17985 cv-qualified parameter. */
17987 && (!check_cv_quals_for_unify
18007 }
18010 /* Unify a pointer to member with a pointer to member function, which
18011 deduces the type of the member as a function type. */
18013 {
18014 /* Check top-level cv qualifiers */
18022 /* Determine the type of the function we are unifying against. */
18026 }
18045 /* Matched cases are handled by the ARG == PARM test above. */
18049 /* A non-type template parameter that is a variable should be a
18050 an integral constant, in which case, it whould have been
18051 folded into its (constant) value. So we should not be getting
18052 a variable here. */
18063 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18064 or UNDERLYING_TYPE nodes. */
18068 /* Unification fails if we hit an error node. */
18075 /* FALLTHRU */
18078 /* An unresolved overload is a nondeduced context. */
18083 /* We must be looking at an expression. This can happen with
18084 something like:
18086 template <int I>
18087 void foo(S<I>, S<I + 2>);
18089 This is a "nondeduced context":
18091 [deduct.type]
18093 The nondeduced contexts are:
18095 --A type that is a template-id in which one or more of
18096 the template-arguments is an expression that references
18097 a template-parameter.
18099 In these cases, we assume deduction succeeded, but don't
18100 actually infer any unifications. */
18105 else
18107 }
18108 }
18109 #undef RECUR_AND_CHECK_FAILURE
18110 \f
18111 /* Note that DECL can be defined in this translation unit, if
18112 required. */
18114 static void
18116 {
18117 tree clone;
18121 }
18123 /* Called if RESULT is explicitly instantiated, or is a member of an
18124 explicitly instantiated class. */
18126 void
18128 {
18131 /* If this entity has already been written out, it's too late to
18132 make any modifications. */
18136 /* For anonymous namespace we don't need to do anything. */
18138 {
18141 }
18144 /* The TREE_PUBLIC flag for function declarations will have been
18145 set correctly by tsubst. */
18148 /* This might have been set by an earlier implicit instantiation. */
18153 else
18154 {
18157 /* Always make artificials weak. */
18160 /* For WIN32 we also want to put explicit instantiations in
18161 linkonce sections. */
18164 }
18166 /* If EXTERN_P, then this function will not be emitted -- unless
18167 followed by an explicit instantiation, at which point its linkage
18168 will be adjusted. If !EXTERN_P, then this function will be
18169 emitted here. In neither circumstance do we want
18170 import_export_decl to adjust the linkage. */
18172 }
18174 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18175 important template arguments. If any are missing, we check whether
18176 they're important by using error_mark_node for substituting into any
18177 args that were used for partial ordering (the ones between ARGS and END)
18178 and seeing if it bubbles up. */
18180 static bool
18182 {
18187 {
18190 }
18192 {
18196 }
18198 }
18200 /* Given two function templates PAT1 and PAT2, return:
18202 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18203 -1 if PAT2 is more specialized than PAT1.
18204 0 if neither is more specialized.
18206 LEN indicates the number of parameters we should consider
18207 (defaulted parameters should not be considered).
18209 The 1998 std underspecified function template partial ordering, and
18210 DR214 addresses the issue. We take pairs of arguments, one from
18211 each of the templates, and deduce them against each other. One of
18212 the templates will be more specialized if all the *other*
18213 template's arguments deduce against its arguments and at least one
18214 of its arguments *does* *not* deduce against the other template's
18215 corresponding argument. Deduction is done as for class templates.
18216 The arguments used in deduction have reference and top level cv
18217 qualifiers removed. Iff both arguments were originally reference
18218 types *and* deduction succeeds in both directions, an lvalue reference
18219 wins against an rvalue reference and otherwise the template
18220 with the more cv-qualified argument wins for that pairing (if
18221 neither is more cv-qualified, they both are equal). Unlike regular
18222 deduction, after all the arguments have been deduced in this way,
18223 we do *not* verify the deduced template argument values can be
18224 substituted into non-deduced contexts.
18226 The logic can be a bit confusing here, because we look at deduce1 and
18227 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18228 can find template arguments for pat1 to make arg1 look like arg2, that
18229 means that arg2 is at least as specialized as arg1. */
18231 int
18233 {
18246 /* Remove the this parameter from non-static member functions. If
18247 one is a non-static member function and the other is not a static
18248 member function, remove the first parameter from that function
18249 also. This situation occurs for operator functions where we
18250 locate both a member function (with this pointer) and non-member
18251 operator (with explicit first operand). */
18253 {
18258 }
18260 {
18263 {
18264 len--;
18266 }
18267 }
18269 /* If only one is a conversion operator, they are unordered. */
18273 /* Consider the return type for a conversion function */
18275 {
18278 len++;
18279 }
18281 processing_template_decl++;
18287 /* Stop when an ellipsis is seen. */
18289 {
18300 {
18301 /* When both arguments are pack expansions, we need only
18302 unify the patterns themselves. */
18306 /* This is the last comparison we need to do. */
18308 }
18311 {
18315 }
18318 {
18322 }
18328 {
18334 /* Setup the parameter vector, which contains only ARG1. */
18337 /* Setup the argument vector, which contains the remaining
18338 arguments. */
18347 /* We cannot deduce in the other direction, because ARG1 is
18348 a pack expansion but ARG2 is not. */
18350 }
18352 {
18358 /* Setup the parameter vector, which contains only ARG1. */
18361 /* Setup the argument vector, which contains the remaining
18362 arguments. */
18371 /* We cannot deduce in the other direction, because ARG2 is
18372 a pack expansion but ARG1 is not.*/
18374 }
18376 else
18377 {
18378 /* The normal case, where neither argument is a pack
18379 expansion. */
18386 }
18388 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18389 arg2, then arg2 is not as specialized as arg1. */
18395 /* "If, for a given type, deduction succeeds in both directions
18396 (i.e., the types are identical after the transformations above)
18397 and both P and A were reference types (before being replaced with
18398 the type referred to above):
18399 - if the type from the argument template was an lvalue reference and
18400 the type from the parameter template was not, the argument type is
18401 considered to be more specialized than the other; otherwise,
18402 - if the type from the argument template is more cv-qualified
18403 than the type from the parameter template (as described above),
18404 the argument type is considered to be more specialized than the other;
18405 otherwise,
18406 - neither type is more specialized than the other." */
18409 {
18411 {
18414 else
18416 }
18418 {
18423 }
18424 }
18427 /* We've failed to deduce something in either direction.
18428 These must be unordered. */
18433 /* We have already processed all of the arguments in our
18434 handing of the pack expansion type. */
18439 }
18441 /* "In most cases, all template parameters must have values in order for
18442 deduction to succeed, but for partial ordering purposes a template
18443 parameter may remain without a value provided it is not used in the
18444 types being used for partial ordering."
18446 Thus, if we are missing any of the targs1 we need to substitute into
18447 origs1, then pat2 is not as specialized as pat1. This can happen when
18448 there is a nondeduced context. */
18454 processing_template_decl--;
18456 /* All things being equal, if the next argument is a pack expansion
18457 for one function but not for the other, prefer the
18458 non-variadic function. FIXME this is bogus; see c++/41958. */
18462 {
18465 }
18471 else
18473 }
18475 /* Determine which of two partial specializations of TMPL is more
18476 specialized.
18478 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18479 to the first partial specialization. The TREE_VALUE is the
18480 innermost set of template parameters for the partial
18481 specialization. PAT2 is similar, but for the second template.
18483 Return 1 if the first partial specialization is more specialized;
18484 -1 if the second is more specialized; 0 if neither is more
18485 specialized.
18487 See [temp.class.order] for information about determining which of
18488 two templates is more specialized. */
18490 static int
18492 {
18493 tree targs;
18501 /* Just like what happens for functions, if we are ordering between
18502 different class template specializations, we may encounter dependent
18503 types in the arguments, and we need our dependency check functions
18504 to behave correctly. */
18510 {
18513 }
18519 {
18522 }
18525 /* In the case of a tie where at least one of the class templates
18526 has a parameter pack at the end, the template with the most
18527 non-packed parameters wins. */
18529 && any_deductions
18532 {
18538 /* We don't count the pack expansion at the end. */
18548 }
18551 }
18553 /* Return the template arguments that will produce the function signature
18554 DECL from the function template FN, with the explicit template
18555 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18556 also match. Return NULL_TREE if no satisfactory arguments could be
18557 found. */
18559 static tree
18561 {
18565 tree decl_arg_types;
18568 tree arg;
18572 /* Never do unification on the 'this' parameter. */
18593 }
18595 /* Return the innermost template arguments that, when applied to a partial
18596 specialization of TMPL whose innermost template parameters are
18597 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18598 ARGS.
18600 For example, suppose we have:
18602 template <class T, class U> struct S {};
18603 template <class T> struct S<T*, int> {};
18605 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18606 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18607 int}. The resulting vector will be {double}, indicating that `T'
18608 is bound to `double'. */
18610 static tree
18612 {
18614 tree deduced_args;
18615 tree innermost_deduced_args;
18619 {
18623 innermost_deduced_args);
18624 }
18625 else
18638 /* Verify that nondeduced template arguments agree with the type
18639 obtained from argument deduction.
18641 For example:
18643 struct A { typedef int X; };
18644 template <class T, class U> struct C {};
18645 template <class T> struct C<T, typename T::X> {};
18647 Then with the instantiation `C<A, int>', we can deduce that
18648 `T' is `A' but unify () does not check whether `typename T::X'
18649 is `int'. */
18655 /* We only need to check the innermost arguments; the other
18656 arguments will always agree. */
18661 /* Now that we have bindings for all of the template arguments,
18662 ensure that the arguments deduced for the template template
18663 parameters have compatible template parameter lists. See the use
18664 of template_template_parm_bindings_ok_p in fn_type_unification
18665 for more information. */
18670 }
18672 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18673 Return the TREE_LIST node with the most specialized template, if
18674 any. If there is no most specialized template, the error_mark_node
18675 is returned.
18677 Note that this function does not look at, or modify, the
18678 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18679 returned is one of the elements of INSTANTIATIONS, callers may
18680 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18681 and retrieve it from the value returned. */
18683 tree
18685 {
18692 {
18698 fate--;
18703 fate++;
18708 {
18709 /* Equally specialized, move to next function. If there
18710 is no next function, nothing's most specialized. */
18715 }
18716 }
18719 /* Now verify that champ is better than everything earlier in the
18720 instantiation list. */
18728 {
18731 }
18733 processing_template_decl--;
18739 }
18741 /* If DECL is a specialization of some template, return the most
18742 general such template. Otherwise, returns NULL_TREE.
18744 For example, given:
18746 template <class T> struct S { template <class U> void f(U); };
18748 if TMPL is `template <class U> void S<int>::f(U)' this will return
18749 the full template. This function will not trace past partial
18750 specializations, however. For example, given in addition:
18752 template <class T> struct S<T*> { template <class U> void f(U); };
18754 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18755 `template <class T> template <class U> S<T*>::f(U)'. */
18757 tree
18759 {
18761 {
18764 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
18765 template friend, or a FIELD_DECL for a capture pack. */
18768 }
18770 /* Look for more and more general templates. */
18772 {
18773 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18774 (See cp-tree.h for details.) */
18782 /* Stop if we run into an explicitly specialized class template. */
18789 }
18792 }
18794 /* Return the most specialized of the class template partial
18795 specializations which can produce TYPE, a specialization of some class
18796 template. The value returned is actually a TREE_LIST; the TREE_TYPE is
18797 a _TYPE node corresponding to the partial specialization, while the
18798 TREE_PURPOSE is the set of template arguments that must be
18799 substituted into the TREE_TYPE in order to generate TYPE.
18801 If the choice of partial specialization is ambiguous, a diagnostic
18802 is issued, and the error_mark_node is returned. If there are no
18803 partial specializations matching TYPE, then NULL_TREE is
18804 returned, indicating that the primary template should be used. */
18806 static tree
18808 {
18810 tree t;
18811 tree champ;
18820 /* For determining which partial specialization to use, only the
18821 innermost args are interesting. */
18823 {
18826 }
18829 {
18830 tree partial_spec_args;
18831 tree spec_args;
18840 {
18841 /* Discard the outer levels of args, and then substitute in the
18842 template args from the enclosing class. */
18844 partial_spec_args = tsubst_template_args
18847 /* And the same for the partial specialization TEMPLATE_DECL. */
18849 }
18851 partial_spec_args =
18853 partial_spec_args,
18867 partial_spec_args,
18868 args);
18870 {
18875 }
18876 }
18886 {
18889 ;
18890 else
18891 {
18893 {
18896 {
18899 }
18900 }
18902 }
18903 }
18907 {
18910 {
18913 }
18914 }
18917 {
18925 {
18928 }
18931 }
18934 }
18936 /* Explicitly instantiate DECL. */
18938 void
18940 {
18945 /* An error occurred, for which grokdeclarator has already issued
18946 an appropriate message. */
18949 {
18952 }
18954 {
18955 /* There is an asymmetry here in the way VAR_DECLs and
18956 FUNCTION_DECLs are handled by grokdeclarator. In the case of
18957 the latter, the DECL we get back will be marked as a
18958 template instantiation, and the appropriate
18959 DECL_TEMPLATE_INFO will be set up. This does not happen for
18960 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
18961 should handle VAR_DECLs as it currently handles
18962 FUNCTION_DECLs. */
18964 {
18967 }
18970 {
18973 }
18975 {
18980 }
18981 }
18983 {
18986 }
18987 else
18990 /* Check for various error cases. Note that if the explicit
18991 instantiation is valid the RESULT will currently be marked as an
18992 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
18993 until we get here. */
18996 {
18997 /* DR 259 [temp.spec].
18999 Both an explicit instantiation and a declaration of an explicit
19000 specialization shall not appear in a program unless the explicit
19001 instantiation follows a declaration of the explicit specialization.
19003 For a given set of template parameters, if an explicit
19004 instantiation of a template appears after a declaration of an
19005 explicit specialization for that template, the explicit
19006 instantiation has no effect. */
19008 }
19010 {
19011 /* [temp.spec]
19013 No program shall explicitly instantiate any template more
19014 than once.
19016 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19017 the first instantiation was `extern' and the second is not,
19018 and EXTERN_P for the opposite case. */
19021 /* If an "extern" explicit instantiation follows an ordinary
19022 explicit instantiation, the template is instantiated. */
19025 }
19027 {
19030 }
19032 {
19035 }
19038 ;
19040 {
19043 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19046 }
19047 else
19055 }
19057 static void
19059 {
19065 {
19068 }
19069 }
19071 /* Called from do_type_instantiation through binding_table_foreach to
19072 do recursive instantiation for the type bound in ENTRY. */
19073 static void
19075 {
19081 }
19083 /* Called from do_type_instantiation to instantiate a member
19084 (a member function or a static member variable) of an
19085 explicitly instantiated class template. */
19086 static void
19088 {
19093 }
19095 /* Perform an explicit instantiation of template class T. STORAGE, if
19096 non-null, is the RID for extern, inline or static. COMPLAIN is
19097 nonzero if this is called from the parser, zero if called recursively,
19098 since the standard is unclear (as detailed below). */
19100 void
19102 {
19112 {
19113 tree tmpl =
19117 else
19120 }
19125 {
19128 t);
19130 }
19133 {
19135 {
19137 {
19140 "ISO C++ 1998 forbids the use of %<extern%> on "
19142 }
19143 else
19145 "ISO C++ forbids the use of %qE"
19147 }
19155 else
19156 {
19158 storage);
19160 }
19161 }
19164 {
19165 /* DR 259 [temp.spec].
19167 Both an explicit instantiation and a declaration of an explicit
19168 specialization shall not appear in a program unless the explicit
19169 instantiation follows a declaration of the explicit specialization.
19171 For a given set of template parameters, if an explicit
19172 instantiation of a template appears after a declaration of an
19173 explicit specialization for that template, the explicit
19174 instantiation has no effect. */
19176 }
19178 {
19179 /* [temp.spec]
19181 No program shall explicitly instantiate any template more
19182 than once.
19184 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19185 instantiation was `extern'. If EXTERN_P then the second is.
19186 These cases are OK. */
19193 /* If we've already instantiated the template, just return now. */
19196 }
19204 {
19205 tree tmp;
19207 /* In contrast to implicit instantiation, where only the
19208 declarations, and not the definitions, of members are
19209 instantiated, we have here:
19211 [temp.explicit]
19213 The explicit instantiation of a class template specialization
19214 implies the instantiation of all of its members not
19215 previously explicitly specialized in the translation unit
19216 containing the explicit instantiation.
19218 Of course, we can't instantiate member template classes, since
19219 we don't have any arguments for them. Note that the standard
19220 is unclear on whether the instantiation of the members are
19221 *explicit* instantiations or not. However, the most natural
19222 interpretation is that it should be an explicit instantiation. */
19237 }
19238 }
19240 /* Given a function DECL, which is a specialization of TMPL, modify
19241 DECL to be a re-instantiation of TMPL with the same template
19242 arguments. TMPL should be the template into which tsubst'ing
19243 should occur for DECL, not the most general template.
19245 One reason for doing this is a scenario like this:
19247 template <class T>
19248 void f(const T&, int i);
19250 void g() { f(3, 7); }
19252 template <class T>
19253 void f(const T& t, const int i) { }
19255 Note that when the template is first instantiated, with
19256 instantiate_template, the resulting DECL will have no name for the
19257 first parameter, and the wrong type for the second. So, when we go
19258 to instantiate the DECL, we regenerate it. */
19260 static void
19262 {
19263 /* The arguments used to instantiate DECL, from the most general
19264 template. */
19265 tree args;
19266 tree code_pattern;
19271 /* Make sure that we can see identifiers, and compute access
19272 correctly. */
19276 {
19277 tree decl_parm;
19278 tree pattern_parm;
19279 tree specs;
19293 specs);
19295 /* Merge parameter declarations. */
19298 pattern_parm
19302 {
19303 tree parm_type;
19304 tree attributes;
19309 NULL_TREE);
19315 {
19318 }
19321 }
19322 /* Merge any parameters that match with the function parameter
19323 pack. */
19325 {
19327 tree expanded_types;
19328 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19329 the parameters in this function parameter pack. */
19334 {
19335 tree parm_type;
19336 tree attributes;
19339 /* Rename the parameter to include the index. */
19348 {
19351 }
19353 }
19354 }
19355 /* Merge additional specifiers from the CODE_PATTERN. */
19359 }
19361 {
19369 }
19370 else
19374 }
19376 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19377 substituted to get DECL. */
19379 tree
19381 {
19384 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19385 for the instantiation. This is not always the most general
19386 template. Consider, for example:
19388 template <class T>
19389 struct S { template <class U> void f();
19390 template <> void f<int>(); };
19392 and an instantiation of S<double>::f<int>. We want TD to be the
19393 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19395 more general template. */
19397 /* We must also deal with friend templates. Given:
19399 template <class T> struct S {
19400 template <class U> friend void f() {};
19401 };
19403 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19404 so far as the language is concerned, but that's still
19405 where we get the pattern for the instantiation from. On
19406 other hand, if the definition comes outside the class, say:
19408 template <class T> struct S {
19409 template <class U> friend void f();
19410 };
19411 template <class U> friend void f() {}
19413 we don't need to look any further. That's what the check for
19414 DECL_INITIAL is for. */
19418 {
19419 /* The present template, TD, should not be a definition. If it
19420 were a definition, we should be using it! Note that we
19421 cannot restructure the loop to just keep going until we find
19422 a template with a definition, since that might go too far if
19423 a specialization was declared, but not defined. */
19427 /* Fetch the more general template. */
19429 }
19432 }
19434 /* Returns true if we need to instantiate this template instance even if we
19435 know we aren't going to emit it.. */
19437 bool
19439 {
19440 /* We always instantiate inline functions so that we can inline them. An
19441 explicit instantiation declaration prohibits implicit instantiation of
19442 non-inline functions. With high levels of optimization, we would
19443 normally inline non-inline functions -- but we're not allowed to do
19444 that for "extern template" functions. Therefore, we check
19445 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19449 /* And we need to instantiate static data members so that
19450 their initializers are available in integral constant
19451 expressions. */
19454 }
19456 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19457 instantiate it now, modifying TREE_TYPE (fn). */
19459 void
19461 {
19464 /* Don't instantiate a noexcept-specification from template context. */
19479 {
19481 {
19496 }
19497 else
19499 }
19500 else
19501 {
19502 /* This is an implicitly declared function, so NOEX is a list of
19503 other functions to evaluate and merge. */
19504 tree elt;
19507 {
19509 tree subspec;
19513 }
19514 }
19519 {
19522 else
19524 }
19525 }
19527 /* Produce the definition of D, a _DECL generated from a template. If
19528 DEFER_OK is nonzero, then we don't have to actually do the
19529 instantiation now; we just have to do it sometime. Normally it is
19530 an error if this is an explicit instantiation but D is undefined.
19531 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19532 explicitly instantiated class template. */
19534 tree
19537 {
19539 tree gen_args;
19540 tree args;
19541 tree td;
19542 tree code_pattern;
19543 tree spec;
19544 tree gen_tmpl;
19550 tree fn_context;
19553 /* This function should only be used to instantiate templates for
19554 functions and static member variables. */
19557 /* Variables are never deferred; if instantiation is required, they
19558 are instantiated right away. That allows for better code in the
19559 case that an expression refers to the value of the variable --
19560 if the variable has a constant value the referring expression can
19561 take advantage of that fact. */
19566 /* Don't instantiate cloned functions. Instead, instantiate the
19567 functions they cloned. */
19575 /* D has already been instantiated or explicitly specialized, so
19576 there's nothing for us to do here.
19578 It might seem reasonable to check whether or not D is an explicit
19579 instantiation, and, if so, stop here. But when an explicit
19580 instantiation is deferred until the end of the compilation,
19581 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19582 the instantiation. */
19585 /* Check to see whether we know that this template will be
19586 instantiated in some other file, as with "extern template"
19587 extension. */
19590 /* In general, we do not instantiate such templates. */
19598 /* We should already have the extra args. */
19601 /* And what's in the hash table should match D. */
19605 /* This needs to happen before any tsubsting. */
19611 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19612 for the instantiation. */
19616 /* We should never be trying to instantiate a member of a class
19617 template or partial specialization. */
19622 /* In the case of a friend template whose definition is provided
19623 outside the class, we may have too many arguments. Drop the
19624 ones we don't need. The same is true for specializations. */
19625 args = get_innermost_template_args
19627 else
19633 else
19636 /* We may be in the middle of deferred access check. Disable it now. */
19639 /* Unless an explicit instantiation directive has already determined
19640 the linkage of D, remember that a definition is available for
19641 this entity. */
19651 /* If D is a member of an explicitly instantiated class template,
19652 and no definition is available, treat it like an implicit
19653 instantiation. */
19656 {
19657 /* Leave linkage flags alone on instantiations with anonymous
19658 visibility. */
19660 {
19663 }
19665 }
19670 /* Defer all other templates, unless we have been explicitly
19671 forbidden from doing so. */
19673 template. */
19674 ! pattern_defined
19675 /* If it's OK to postpone instantiation, do so. */
19676 || defer_ok
19677 /* If this is a static data member that will be defined
19678 elsewhere, we don't want to instantiate the entire data
19679 member, but we do want to instantiate the initializer so that
19680 we can substitute that elsewhere. */
19682 {
19683 /* The definition of the static data member is now required so
19684 we must substitute the initializer. */
19688 {
19689 tree ns;
19690 tree init;
19697 args,
19700 /* Make sure the initializer is still constant, in case of
19701 circular dependency (template/instantiate6.C). */
19702 const_init
19706 LOOKUP_ONLYCONVERTING);
19709 }
19711 /* We restore the source position here because it's used by
19712 add_pending_template. */
19718 /* [temp.explicit]
19720 The definition of a non-exported function template, a
19721 non-exported member function template, or a non-exported
19722 member function or static data member of a class template
19723 shall be present in every translation unit in which it is
19724 explicitly instantiated. */
19728 /* If we're in unevaluated context, we just wanted to get the
19729 constant value; this isn't an odr use, so don't queue
19730 a full instantiation. */
19733 /* ??? Historically, we have instantiated inline functions, even
19734 when marked as "extern template". */
19738 }
19739 /* Tell the repository that D is available in this translation unit
19740 -- and see if it is supposed to be instantiated here. */
19742 {
19743 /* In a PCH file, despite the fact that the repository hasn't
19744 requested instantiation in the PCH it is still possible that
19745 an instantiation will be required in a file that includes the
19746 PCH. */
19749 /* Instantiate inline functions so that the inliner can do its
19750 job, even though we'll not be emitting a copy of this
19751 function. */
19754 }
19760 else
19761 {
19766 }
19768 /* Mark D as instantiated so that recursive calls to
19769 instantiate_decl do not try to instantiate it again. */
19772 /* Regenerate the declaration in case the template has been modified
19773 by a subsequent redeclaration. */
19776 /* We already set the file and line above. Reset them now in case
19777 they changed as a result of calling regenerate_decl_from_template. */
19781 {
19782 tree init;
19785 /* Clear out DECL_RTL; whatever was there before may not be right
19786 since we've reset the type of the declaration. */
19790 /* The initializer is placed in DECL_INITIAL by
19791 regenerate_decl_from_template so we don't need to
19792 push/pop_access_scope again here. Pull it out so that
19793 cp_finish_decl can process it. */
19798 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19799 initializer. That function will defer actual emission until
19800 we have a chance to determine linkage. */
19803 /* Enter the scope of D so that access-checking works correctly. */
19808 }
19812 {
19814 tree subst_decl;
19815 tree tmpl_parm;
19816 tree spec_parm;
19819 /* Save away the current list, in case we are instantiating one
19820 template from within the body of another. */
19823 /* Set up the list of local specializations. */
19826 /* Set up context. */
19830 else
19833 /* Some typedefs referenced from within the template code need to be
19834 access checked at template instantiation time, i.e now. These
19835 types were added to the template at parsing time. Let's get those
19836 and perform the access checks then. */
19838 gen_args);
19840 /* Create substitution entries for the parameters. */
19845 {
19849 }
19851 {
19853 {
19856 }
19857 else
19858 {
19859 /* Register the (value) argument pack as a specialization of
19860 TMPL_PARM, then move on. */
19863 }
19864 }
19867 /* Substitute into the body of the function. */
19871 else
19872 {
19877 /* Set the current input_location to the end of the function
19878 so that finish_function knows where we are. */
19879 input_location
19882 /* Remember if we saw an infinite loop in the template. */
19883 current_function_infinite_loop
19885 }
19887 /* We don't need the local specializations any more. */
19891 /* Finish the function. */
19895 else
19896 {
19899 }
19903 }
19905 /* We're not deferring instantiation any more. */
19913 out:
19923 }
19925 /* Run through the list of templates that we wish we could
19926 instantiate, and instantiate any we can. RETRIES is the
19927 number of times we retry pending template instantiation. */
19929 void
19931 {
19935 /* Instantiating templates may trigger vtable generation. This in turn
19936 may require further template instantiations. We place a limit here
19937 to avoid infinite loop. */
19939 {
19943 " instantiating %q+D, possibly from virtual table generation"
19947 /* Pretend that we defined it. */
19950 }
19952 do
19953 {
19958 {
19963 {
19964 tree fn;
19967 {
19971 fn;
19979 }
19982 }
19983 else
19984 {
19987 {
19988 instantiation
19994 }
19998 }
20001 /* If INSTANTIATION has been instantiated, then we don't
20002 need to consider it again in the future. */
20004 else
20005 {
20008 }
20011 }
20013 }
20017 }
20019 /* Substitute ARGVEC into T, which is a list of initializers for
20020 either base class or a non-static data member. The TREE_PURPOSEs
20021 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20022 instantiate_decl. */
20024 static tree
20026 {
20030 {
20031 tree decl;
20032 tree init;
20038 {
20039 tree expr;
20040 tree arg;
20042 /* Expand the base class expansion type into separate base
20043 classes. */
20045 tf_warning_or_error,
20046 NULL_TREE);
20050 /* We'll be building separate TREE_LISTs of arguments for
20051 each base. */
20057 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20058 expand each argument in the TREE_VALUE of t. */
20065 /* VOID_TYPE_NODE is used to indicate
20066 value-initialization. */
20067 {
20070 }
20071 else
20072 {
20073 /* Substitute parameter packs into each argument in the
20074 TREE_LIST. */
20077 {
20078 tree expanded_exprs;
20080 /* Expand the argument. */
20082 expanded_exprs
20084 tf_warning_or_error,
20085 NULL_TREE);
20089 /* Prepend each of the expanded expressions to the
20090 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20092 {
20097 }
20098 }
20101 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20102 since we built them backwards. */
20104 {
20107 }
20108 }
20109 }
20112 {
20114 {
20118 }
20119 else
20120 {
20121 tree tmp;
20136 /* If we had an initializer but it instantiated to nothing,
20137 value-initialize the object. This will only occur when
20138 the initializer was a pack expansion where the parameter
20139 packs used in that expansion were of length zero. */
20142 }
20145 {
20149 }
20150 }
20151 }
20153 }
20155 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20157 static void
20159 {
20164 else
20166 }
20168 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20169 is the instantiation (which should have been created with
20170 start_enum) and ARGS are the template arguments to use. */
20172 static void
20174 {
20175 tree e;
20181 {
20182 tree value;
20183 tree decl;
20186 /* Note that in a template enum, the TREE_VALUE is the
20187 CONST_DECL, not the corresponding INTEGER_CST. */
20192 /* Give this enumeration constant the correct access. */
20195 /* Actually build the enumerator itself. */
20196 build_enumerator
20198 }
20208 }
20210 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20211 its type -- but without substituting the innermost set of template
20212 arguments. So, innermost set of template parameters will appear in
20213 the type. */
20215 tree
20217 {
20218 tree fn_type;
20219 tree tmpl;
20220 tree targs;
20221 tree tparms;
20229 /* There should be as many levels of arguments as there are levels
20230 of parameters. */
20236 /* No substitution is necessary. */
20237 ;
20238 else
20239 {
20241 tree partial_args;
20243 /* Replace the innermost level of the TARGS with NULL_TREEs to
20244 let tsubst know not to substitute for those parameters. */
20253 /* Make sure that we can see identifiers, and compute access
20254 correctly. */
20258 /* Now, do the (partial) substitution to figure out the
20259 appropriate function type. */
20263 /* Substitute into the template parameters to obtain the real
20264 innermost set of parameters. This step is important if the
20265 innermost set of template parameters contains value
20266 parameters whose types depend on outer template parameters. */
20271 }
20274 }
20276 /* Return truthvalue if we're processing a template different from
20277 the last one involved in diagnostics. */
20278 int
20280 {
20282 }
20284 /* Remember current template involved in diagnostics. */
20285 void
20287 {
20289 }
20293 {
20295 }
20297 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20298 type. Return zero for ok, nonzero for disallowed. Issue error and
20299 warning messages under control of COMPLAIN. */
20301 static int
20303 {
20320 {
20323 else
20325 type);
20326 }
20328 }
20330 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20331 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20333 static bool
20335 {
20336 tree scope;
20338 /* [temp.dep.type]
20340 A type is dependent if it is:
20342 -- a template parameter. Template template parameters are types
20343 for us (since TYPE_P holds true for them) so we handle
20344 them here. */
20348 /* -- a qualified-id with a nested-name-specifier which contains a
20349 class-name that names a dependent type or whose unqualified-id
20350 names a dependent type. */
20353 /* -- a cv-qualified type where the cv-unqualified type is
20354 dependent. */
20356 /* -- a compound type constructed from any dependent type. */
20366 {
20367 tree arg_type;
20372 arg_type;
20377 }
20378 /* -- an array type constructed from any dependent type or whose
20379 size is specified by a constant expression that is
20380 value-dependent.
20382 We checked for type- and value-dependence of the bounds in
20383 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20385 {
20390 }
20392 /* -- a template-id in which either the template name is a template
20393 parameter ... */
20396 /* ... or any of the template arguments is a dependent type or
20397 an expression that is type-dependent or value-dependent. */
20399 && (any_dependent_template_arguments_p
20403 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20404 dependent; if the argument of the `typeof' expression is not
20405 type-dependent, then it should already been have resolved. */
20411 /* A template argument pack is dependent if any of its packed
20412 arguments are. */
20414 {
20420 }
20422 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20423 be template parameters. */
20427 /* The standard does not specifically mention types that are local
20428 to template functions or local classes, but they should be
20429 considered dependent too. For example:
20431 template <int I> void f() {
20432 enum E { a = I };
20433 S<sizeof (E)> s;
20434 }
20436 The size of `E' cannot be known until the value of `I' has been
20437 determined. Therefore, `E' must be considered dependent. */
20441 /* Don't use type_dependent_expression_p here, as it can lead
20442 to infinite recursion trying to determine whether a lambda
20443 nested in a lambda is dependent (c++/47687). */
20447 && (any_dependent_template_arguments_p
20451 /* Other types are non-dependent. */
20453 }
20455 /* Returns TRUE if TYPE is dependent, in the sense of
20456 [temp.dep.type]. Note that a NULL type is considered dependent. */
20458 bool
20460 {
20461 /* If there are no template parameters in scope, then there can't be
20462 any dependent types. */
20464 {
20465 /* If we are not processing a template, then nobody should be
20466 providing us with a dependent type. */
20470 }
20472 /* If the type is NULL, we have not computed a type for the entity
20473 in question; in that case, the type is dependent. */
20477 /* Erroneous types can be considered non-dependent. */
20481 /* If we have not already computed the appropriate value for TYPE,
20482 do so now. */
20484 {
20487 }
20490 }
20492 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20493 lookup. In other words, a dependent type that is not the current
20494 instantiation. */
20496 bool
20498 {
20501 }
20503 /* T is a SCOPE_REF; return whether we need to consider it
20504 instantiation-dependent so that we can check access at instantiation
20505 time even though we know which member it resolves to. */
20507 static bool
20509 {
20515 else
20517 }
20519 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20520 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20521 expression. */
20523 /* Note that this predicate is not appropriate for general expressions;
20524 only constant expressions (that satisfy potential_constant_expression)
20525 can be tested for value dependence. */
20527 bool
20529 {
20533 /* A name declared with a dependent type. */
20538 {
20540 /* A name that has not been looked up -- must be dependent. */
20544 /* A non-type template parm. */
20548 /* A non-type template parm. */
20554 /* A constant with literal type and is initialized
20555 with an expression that is value-dependent.
20557 Note that a non-dependent parenthesized initializer will have
20558 already been replaced with its constant value, so if we see
20559 a TREE_LIST it must be dependent. */
20572 /* These expressions are value-dependent if the type to which
20573 the cast occurs is dependent or the expression being casted
20574 is value-dependent. */
20575 {
20581 /* A functional cast has a list of operands. */
20584 {
20585 /* If there are no operands, it must be an expression such
20586 as "int()". This should not happen for aggregate types
20587 because it would form non-constant expressions. */
20592 }
20598 }
20603 /* FALLTHRU */
20606 /* A `sizeof' expression is value-dependent if the operand is
20607 type-dependent or is a pack expansion. */
20616 /* An 'encode' expression is value-dependent if the operand is
20617 type-dependent. */
20626 /* All instantiation-dependent expressions should also be considered
20627 value-dependent. */
20635 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20636 is value-dependent. */
20637 {
20646 }
20649 {
20653 }
20664 {
20668 }
20671 {
20678 {
20680 /* In a call to a constexpr member function, look through the
20681 implicit ADDR_EXPR on the object argument so that it doesn't
20682 cause the call to be considered value-dependent. We also
20683 look through it in potential_constant_expression. */
20690 }
20692 }
20695 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20696 type-dependent. */
20700 {
20702 tree val;
20707 }
20710 /* Treat a GNU statement expression as dependent to avoid crashing
20711 under fold_non_dependent_expr; it can't be constant. */
20715 /* A constant expression is value-dependent if any subexpression is
20716 value-dependent. */
20718 {
20725 {
20729 {
20732 /* In some cases, some of the operands may be missing.l
20733 (For example, in the case of PREDECREMENT_EXPR, the
20734 amount to increment by may be missing.) That doesn't
20735 make the expression dependent. */
20738 }
20739 }
20743 }
20745 }
20747 /* The expression is not value-dependent. */
20749 }
20751 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20752 [temp.dep.expr]. Note that an expression with no type is
20753 considered dependent. Other parts of the compiler arrange for an
20754 expression with type-dependent subexpressions to have no type, so
20755 this function doesn't have to be fully recursive. */
20757 bool
20759 {
20766 /* An unresolved name is always dependent. */
20770 /* Some expression forms are never type-dependent. */
20783 /* The types of these expressions depends only on the type to which
20784 the cast occurs. */
20793 /* The types of these expressions depends only on the type created
20794 by the expression. */
20797 {
20798 /* For NEW_EXPR tree nodes created inside a template, either
20799 the object type itself or a TREE_LIST may appear as the
20800 operand 1. */
20803 /* This is an array type. We need to check array dimensions
20804 as well. */
20806 || value_dependent_expression_p
20808 else
20810 }
20813 {
20817 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20818 contains an identifier associated by name lookup with one or more
20819 declarations declared with a dependent type, or...a
20820 nested-name-specifier or qualified-id that names a member of an
20821 unknown specialization. */
20824 }
20829 && (any_dependent_template_arguments_p
20841 {
20842 tree elt;
20846 {
20849 }
20851 }
20853 /* A static data member of the current instantiation with incomplete
20854 array type is type-dependent, as the definition and specializations
20855 can have different bounds. */
20862 /* An array of unknown bound depending on a variadic parameter, eg:
20864 template<typename... Args>
20865 void foo (Args... args)
20866 {
20867 int arr[] = { args... };
20868 }
20870 template<int... vals>
20871 void bar ()
20872 {
20873 int arr[] = { vals... };
20874 }
20876 If the array has no length and has an initializer, it must be that
20877 we couldn't determine its length in cp_complete_array_type because
20878 it is dependent. */
20886 {
20891 {
20897 }
20898 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
20902 /* Always dependent, on the number of arguments if nothing else. */
20910 {
20915 }
20920 {
20924 }
20926 }
20931 }
20933 /* walk_tree callback function for instantiation_dependent_expression_p,
20934 below. Returns non-zero if a dependent subexpression is found. */
20936 static tree
20939 {
20941 {
20942 /* We don't have to worry about decltype currently because decltype
20943 of an instantiation-dependent expr is a dependent type. This
20944 might change depending on the resolution of DR 1172. */
20947 }
20950 {
20951 /* Don't treat an argument list as dependent just because it has no
20952 TREE_TYPE. */
20959 /* A constant with a dependent initializer is dependent. */
20967 /* Handle expressions with type operands. */
20972 {
20977 {
20980 else
20981 {
20984 }
20985 }
20987 }
20999 /* In a template, finish_class_member_access_expr creates a
21000 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21001 type-dependent, so that we can check access control at
21002 instantiation time (PR 42277). See also Core issue 1273. */
21009 else
21012 /* Treat statement-expressions as dependent. */
21018 }
21022 else
21024 }
21026 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21027 sense defined by the ABI:
21029 "An expression is instantiation-dependent if it is type-dependent
21030 or value-dependent, or it has a subexpression that is type-dependent
21031 or value-dependent." */
21033 bool
21035 {
21036 tree result;
21047 }
21049 /* Like type_dependent_expression_p, but it also works while not processing
21050 a template definition, i.e. during substitution or mangling. */
21052 bool
21054 {
21060 }
21062 /* Returns TRUE if ARGS contains a type-dependent expression. */
21064 bool
21066 {
21068 tree arg;
21071 {
21074 }
21076 }
21078 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21079 expressions) contains any type-dependent expressions. */
21081 bool
21083 {
21089 }
21091 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21092 expressions) contains any value-dependent expressions. */
21094 bool
21096 {
21102 }
21104 /* Returns TRUE if the ARG (a template argument) is dependent. */
21106 bool
21108 {
21112 /* Assume a template argument that was wrongly written by the user
21113 is dependent. This is consistent with what
21114 any_dependent_template_arguments_p [that calls this function]
21115 does. */
21126 {
21130 {
21133 }
21136 }
21139 else
21142 }
21144 /* Returns true if ARGS (a collection of template arguments) contains
21145 any types that require structural equality testing. */
21147 bool
21149 {
21159 {
21162 {
21168 {
21169 /* Look inside the argument pack. */
21172 }
21175 {
21188 }
21189 }
21190 }
21193 }
21195 /* Returns true if ARGS (a collection of template arguments) contains
21196 any dependent arguments. */
21198 bool
21200 {
21210 {
21215 }
21218 }
21220 /* Returns TRUE if the template TMPL is dependent. */
21222 bool
21224 {
21226 {
21228 {
21232 }
21234 }
21236 /* Template template parameters are dependent. */
21240 /* So are names that have not been looked up. */
21243 /* So are member templates of dependent classes. */
21247 }
21249 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21251 bool
21253 {
21256 }
21258 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21259 is dependent. */
21261 bool
21263 {
21270 {
21291 {
21295 }
21299 {
21303 {
21308 }
21309 }
21310 }
21313 }
21315 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21316 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21317 no such TYPE can be found. Note that this function peers inside
21318 uninstantiated templates and therefore should be used only in
21319 extremely limited situations. ONLY_CURRENT_P restricts this
21320 peering to the currently open classes hierarchy (which is required
21321 when comparing types). */
21323 tree
21325 {
21326 tree scope;
21327 tree name;
21328 tree decl;
21330 tree pushed_scope;
21331 tree result;
21336 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21337 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21338 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21339 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21340 identifier of the TYPENAME_TYPE anymore.
21341 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21342 TYPENAME_TYPE instead, we avoid messing up with a possible
21343 typedef variant case. */
21346 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21347 it first before we can figure out what NAME refers to. */
21349 {
21351 /* Given a class template A with a dependent base with nested type C,
21352 typedef typename A::C::C C will land us here, as trying to resolve
21353 the initial A::C leads to the local C typedef, which leads back to
21354 A::C::C. So we break the recursion now. */
21356 else
21358 }
21359 /* If we don't know what SCOPE refers to, then we cannot resolve the
21360 TYPENAME_TYPE. */
21363 /* If the SCOPE is a template type parameter, we have no way of
21364 resolving the name. */
21367 /* If the SCOPE is not the current instantiation, there's no reason
21368 to look inside it. */
21371 /* If this is a typedef, we don't want to look inside (c++/11987). */
21374 /* If SCOPE isn't the template itself, it will not have a valid
21375 TYPE_FIELDS list. */
21377 /* scope is either the template itself or a compatible instantiation
21378 like X<T>, so look up the name in the original template. */
21380 else
21381 /* scope is a partial instantiation, so we can't do the lookup or we
21382 will lose the template arguments. */
21384 /* Enter the SCOPE so that name lookup will be resolved as if we
21385 were in the class definition. In particular, SCOPE will no
21386 longer be considered a dependent type. */
21388 /* Look up the declaration. */
21390 tf_warning_or_error);
21394 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21395 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21400 {
21404 }
21407 {
21408 tree tmpl;
21409 tree args;
21410 /* Obtain the template and the arguments. */
21413 /* Instantiate the template. */
21419 }
21421 /* Leave the SCOPE. */
21425 /* If we failed to resolve it, return the original typename. */
21429 /* If lookup found a typename type, resolve that too. */
21431 {
21432 /* Ill-formed programs can cause infinite recursion here, so we
21433 must catch that. */
21437 }
21439 /* Qualify the resulting type. */
21445 }
21447 /* EXPR is an expression which is not type-dependent. Return a proxy
21448 for EXPR that can be used to compute the types of larger
21449 expressions containing EXPR. */
21451 tree
21453 {
21454 tree inner_expr;
21456 #ifdef ENABLE_CHECKING
21457 /* Try to get a constant value for all non-dependent expressions in
21458 order to expose bugs in *_dependent_expression_p and constexpr. */
21461 #endif
21463 /* Preserve OVERLOADs; the functions must be available to resolve
21464 types. */
21475 /* There is no need to return a proxy for a variable. */
21478 /* Preserve string constants; conversions from string constants to
21479 "char *" are allowed, even though normally a "const char *"
21480 cannot be used to initialize a "char *". */
21483 /* Preserve arithmetic constants, as an optimization -- there is no
21484 reason to create a new node. */
21487 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21488 There is at least one place where we want to know that a
21489 particular expression is a throw-expression: when checking a ?:
21490 expression, there are special rules if the second or third
21491 argument is a throw-expression. */
21495 /* Don't wrap an initializer list, we need to be able to look inside. */
21499 /* Don't wrap a dummy object, we need to be able to test for it. */
21518 /* If the type is unknown, it can't really be non-dependent */
21521 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21523 }
21525 /* ARGS is a vector of expressions as arguments to a function call.
21526 Replace the arguments with equivalent non-dependent expressions.
21527 This modifies ARGS in place. */
21529 void
21531 {
21533 tree arg;
21536 {
21540 }
21541 }
21543 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21544 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21545 parms. */
21547 static tree
21549 {
21562 }
21564 tree
21566 {
21568 }
21570 tree
21572 {
21574 }
21576 /* Given type ARG, return std::initializer_list<ARG>. */
21578 static tree
21580 {
21581 tree std_init_list = namespace_binding
21583 tree argvec;
21585 {
21589 }
21594 }
21596 /* Replace auto in TYPE with std::initializer_list<auto>. */
21598 static tree
21600 {
21607 }
21609 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21610 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21612 tree
21614 {
21615 tree targs;
21621 /* Defining a subset of type-dependent expressions that we can deduce
21622 from ahead of time isn't worth the trouble. */
21625 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21626 with either a new invented type template parameter U or, if the
21627 initializer is a braced-init-list (8.5.4), with
21628 std::initializer_list<U>. */
21636 {
21642 {
21645 }
21646 }
21647 else
21648 {
21659 {
21661 /* Try again at instantiation time. */
21664 /* If type is error_mark_node a diagnostic must have been
21665 emitted by now. Also, having a mention to '<type error>'
21666 in the diagnostic is not really useful to the user. */
21667 {
21671 else
21673 }
21675 }
21676 }
21678 /* If the list of declarators contains more than one declarator, the type
21679 of each declared variable is determined as described above. If the
21680 type deduced for the template parameter U is not the same in each
21681 deduction, the program is ill-formed. */
21684 {
21690 else
21694 }
21700 }
21702 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21703 result. */
21705 tree
21707 {
21708 tree argvec;
21715 /* For a late-specified return type in a template type-parameter, we
21716 need to add a dummy argument level for its parmlist. */
21717 argvec = add_to_template_args
21722 }
21724 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21725 'decltype(auto)'. */
21727 bool
21729 {
21734 else
21736 }
21738 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21739 a use of `auto'. Returns NULL_TREE otherwise. */
21741 tree
21743 {
21745 }
21747 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21748 'decltype(auto)' or a concept. */
21750 bool
21752 {
21754 }
21756 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21757 a concept identifier) iff TYPE contains a use of a generic type. Returns
21758 NULL_TREE otherwise. */
21760 tree
21762 {
21764 }
21767 /* For a given template T, return the vector of typedefs referenced
21768 in T for which access check is needed at T instantiation time.
21769 T is either a FUNCTION_DECL or a RECORD_TYPE.
21770 Those typedefs were added to T by the function
21771 append_type_to_template_for_access_check. */
21775 {
21776 tree ti;
21787 {
21792 }
21795 }
21797 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21798 tied to T. That list of typedefs will be access checked at
21799 T instantiation time.
21800 T is either a FUNCTION_DECL or a RECORD_TYPE.
21801 TYPE_DECL is a TYPE_DECL node representing a typedef.
21802 SCOPE is the scope through which TYPE_DECL is accessed.
21803 LOCATION is the location of the usage point of TYPE_DECL.
21805 This function is a subroutine of
21806 append_type_to_template_for_access_check. */
21808 static void
21810 tree type_decl,
21811 tree scope,
21812 location_t location)
21813 {
21814 qualified_typedef_usage_t typedef_usage;
21815 tree ti;
21822 && type_decl
21836 }
21838 /* Append TYPE_DECL to the template TEMPL.
21839 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21840 At TEMPL instanciation time, TYPE_DECL will be checked to see
21841 if it can be accessed through SCOPE.
21842 LOCATION is the location of the usage point of TYPE_DECL.
21844 e.g. consider the following code snippet:
21846 class C
21847 {
21848 typedef int myint;
21849 };
21851 template<class U> struct S
21852 {
21853 C::myint mi; // <-- usage point of the typedef C::myint
21854 };
21856 S<char> s;
21858 At S<char> instantiation time, we need to check the access of C::myint
21859 In other words, we need to check the access of the myint typedef through
21860 the C scope. For that purpose, this function will add the myint typedef
21861 and the scope C through which its being accessed to a list of typedefs
21862 tied to the template S. That list will be walked at template instantiation
21863 time and access check performed on each typedefs it contains.
21864 Note that this particular code snippet should yield an error because
21865 myint is private to C. */
21867 void
21869 tree type_decl,
21870 tree scope,
21871 location_t location)
21872 {
21878 /* Make sure we don't append the type to the template twice. */
21885 }
21887 /* Convert the generic type parameters in PARM that match the types given in the
21888 range [START_IDX, END_IDX) from the current_template_parms into generic type
21889 packs. */
21891 tree
21893 {
21904 {
21905 /* Create a distinct parameter pack type from the current parm and add it
21906 to the replacement args to tsubst below into the generic function
21907 parameter. */
21922 }
21928 /* If there are more levels then build up the replacement with the outer
21929 template parms. */
21933 replacement);
21936 }
21939 /* Set up the hash tables for template instantiations. */
21941 void
21943 {
21945 hash_specialization,
21946 eq_specializations,
21947 ggc_free);
21949 hash_specialization,
21950 eq_specializations,
21951 ggc_free);
21952 }
21954 /* Print stats about the template hash tables for -fstats. */
21956 void
21958 {
21967 }