| blob | 60e96710eb638327258baade207f58a849633de7 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2014 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
51 /* The type of functions taking a tree, and some additional data, and
52 returning an int. */
55 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
56 instantiations have been deferred, either because their definitions
57 were not yet available, or because we were putting off doing the work. */
61 };
76 /* Live only within one (recursive) call to tsubst_expr. We use
77 this to pass the statement expression node from the STMT_EXPR
78 to the EXPR_STMT that is its result. */
81 /* True if we've recursed into fn_type_unification too many times. */
85 {
86 tree tmpl;
87 tree args;
88 tree spec;
92 htab_t decl_specializations;
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
113 tbr_incomplete_type,
114 tbr_ambiguous_baseclass,
115 tbr_success
116 };
139 tree);
202 location_t);
210 /* Make the current scope suitable for access checking when we are
211 processing T. T can be FUNCTION_DECL for instantiated function
212 template, VAR_DECL for static member variable, or TYPE_DECL for
213 alias template (needed by instantiate_decl). */
215 static void
217 {
225 else
229 {
230 saved_access_scope = tree_cons
233 }
234 }
236 /* Restore the scope set up by push_access_scope. T is the node we
237 are processing. */
239 static void
241 {
243 {
246 }
250 else
252 }
254 /* Do any processing required when DECL (a member template
255 declaration) is finished. Returns the TEMPLATE_DECL corresponding
256 to DECL, unless it is a specialization, in which case the DECL
257 itself is returned. */
259 tree
261 {
268 {
269 tree type;
277 {
281 }
283 }
287 {
289 {
292 }
293 else
295 }
296 else
300 }
302 /* Create a template info node. */
304 tree
306 {
311 }
313 /* Return the template info node corresponding to T, whatever T is. */
315 tree
317 {
338 }
340 /* Returns the template nesting level of the indicated class TYPE.
342 For example, in:
343 template <class T>
344 struct A
345 {
346 template <class U>
347 struct B {};
348 };
350 A<T>::B<U> has depth two, while A<T> has depth one.
351 Both A<T>::B<int> and A<int>::B<U> have depth one, if
352 they are instantiations, not specializations.
354 This function is guaranteed to return 0 if passed NULL_TREE so
355 that, for example, `template_class_depth (current_class_type)' is
356 always safe. */
358 int
360 {
367 {
373 }
376 }
378 /* Subroutine of maybe_begin_member_template_processing.
379 Returns true if processing DECL needs us to push template parms. */
381 static bool
383 {
389 }
391 /* Subroutine of maybe_begin_member_template_processing.
392 Push the template parms in PARMS, starting from LEVELS steps into the
393 chain, and ending at the beginning, since template parms are listed
394 innermost first. */
396 static void
398 {
406 current_template_parms
412 NULL);
414 {
423 {
430 {
431 /* Make a CONST_DECL as is done in process_template_parm.
432 It is ugly that we recreate this here; the original
433 version built in process_template_parm is no longer
434 available. */
444 }
449 }
450 }
451 }
453 /* Restore the template parameter context for a member template, a
454 friend template defined in a class definition, or a non-template
455 member of template class. */
457 void
459 {
460 tree parms;
465 {
468 /* Disregard full specializations (c++/60999). */
471 }
474 {
479 {
482 }
485 }
487 /* Remember how many levels of template parameters we pushed so that
488 we can pop them later. */
490 }
492 /* Undo the effects of maybe_begin_member_template_processing. */
494 void
496 {
505 {
509 }
510 }
512 /* Return a new template argument vector which contains all of ARGS,
513 but has as its innermost set of arguments the EXTRA_ARGS. */
515 static tree
517 {
518 tree new_args;
536 }
538 /* Like add_to_template_args, but only the outermost ARGS are added to
539 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
540 (EXTRA_ARGS) levels are added. This function is used to combine
541 the template arguments from a partial instantiation with the
542 template arguments used to attain the full instantiation from the
543 partial instantiation. */
545 static tree
547 {
548 tree new_args;
550 /* If there are more levels of EXTRA_ARGS than there are ARGS,
551 something very fishy is going on. */
554 /* If *all* the new arguments will be the EXTRA_ARGS, just return
555 them. */
559 /* For the moment, we make ARGS look like it contains fewer levels. */
564 /* Now, we restore ARGS to its full dimensions. */
568 }
570 /* Return the N levels of innermost template arguments from the ARGS. */
572 tree
574 {
575 tree new_args;
581 /* If N is 1, just return the innermost set of template arguments. */
585 /* If we're not removing anything, just return the arguments we were
586 given. */
592 /* Make a new set of arguments, not containing the outer arguments. */
599 }
601 /* The inverse of get_innermost_template_args: Return all but the innermost
602 EXTRA_LEVELS levels of template arguments from the ARGS. */
604 static tree
606 {
607 tree new_args;
613 /* If N is 1, just return the outermost set of template arguments. */
617 /* If we're not removing anything, just return the arguments we were
618 given. */
623 /* Make a new set of arguments, not containing the inner arguments. */
630 }
632 /* We've got a template header coming up; push to a new level for storing
633 the parms. */
635 void
637 {
638 /* We use a non-tag-transparent scope here, which causes pushtag to
639 put tags in this scope, rather than in the enclosing class or
640 namespace scope. This is the right thing, since we want
641 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
642 global template class, push_template_decl handles putting the
643 TEMPLATE_DECL into top-level scope. For a nested template class,
644 e.g.:
646 template <class T> struct S1 {
647 template <class T> struct S2 {};
648 };
650 pushtag contains special code to call pushdecl_with_scope on the
651 TEMPLATE_DECL for S2. */
656 }
658 /* This routine is called when a specialization is declared. If it is
659 invalid to declare a specialization here, an error is reported and
660 false is returned, otherwise this routine will return true. */
662 static bool
664 {
667 /* [temp.expl.spec]
669 An explicit specialization shall be declared in the namespace of
670 which the template is a member, or, for member templates, in the
671 namespace of which the enclosing class or enclosing class
672 template is a member. An explicit specialization of a member
673 function, member class or static data member of a class template
674 shall be declared in the namespace of which the class template
675 is a member. */
677 {
680 }
682 /* [temp.expl.spec]
684 In an explicit specialization declaration for a member of a class
685 template or a member template that appears in namespace scope,
686 the member template and some of its enclosing class templates may
687 remain unspecialized, except that the declaration shall not
688 explicitly specialize a class member template if its enclosing
689 class templates are not explicitly specialized as well. */
691 {
694 }
697 }
699 /* We've just seen template <>. */
701 bool
703 {
707 }
709 /* Called at then end of processing a declaration preceded by
710 template<>. */
712 void
714 {
717 }
719 /* Any template <>'s that we have seen thus far are not referring to a
720 function specialization. */
722 void
724 {
727 }
729 /* We've just seen a template header. If SPECIALIZATION is nonzero,
730 it was of the form template <>. */
732 static void
734 {
736 template_header_count++;
737 }
739 /* We're beginning an explicit instantiation. */
741 void
743 {
746 }
749 void
751 {
754 }
756 /* An explicit specialization or partial specialization of TMPL is being
757 declared. Check that the namespace in which the specialization is
758 occurring is permissible. Returns false iff it is invalid to
759 specialize TMPL in the current namespace. */
761 static bool
763 {
766 /* [tmpl.expl.spec]
768 An explicit specialization shall be declared in the namespace of
769 which the template is a member, or, for member templates, in the
770 namespace of which the enclosing class or enclosing class
771 template is a member. An explicit specialization of a member
772 function, member class or static data member of a class template
773 shall be declared in the namespace of which the class template is
774 a member. */
777 {
780 }
782 /* Same or super-using namespace. */
784 else
785 {
789 }
790 }
792 /* SPEC is an explicit instantiation. Check that it is valid to
793 perform this explicit instantiation in the current namespace. */
795 static void
797 {
798 tree ns;
800 /* DR 275: An explicit instantiation shall appear in an enclosing
801 namespace of its template. */
807 }
809 /* The TYPE is being declared. If it is a template type, that means it
810 is a partial specialization. Do appropriate error-checking. */
812 tree
814 {
815 tree context;
820 /* A lambda that appears in specialization context is not itself a
821 specialization. */
826 {
830 }
835 {
840 else
843 }
845 {
846 /* This is for ordinary explicit specialization and partial
847 specialization of a template class such as:
849 template <> class C<int>;
851 or:
853 template <class T> class C<T*>;
855 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
859 {
866 {
870 }
871 }
877 /* Trying to define a specialization either without a template<> header
878 or in an inappropriate place. We've already given an error, so just
879 bail now so we don't actually define the specialization. */
881 }
887 {
888 /* This is for an explicit specialization of member class
889 template according to [temp.expl.spec/18]:
891 template <> template <class U> class C<int>::D;
893 The context `C<int>' must be an implicit instantiation.
894 Otherwise this is just a member class template declared
895 earlier like:
897 template <> class C<int> { template <class U> class D; };
898 template <> template <class U> class C<int>::D;
900 In the first case, `C<int>::D' is a specialization of `C<T>::D'
901 while in the second case, `C<int>::D' is a primary template
902 and `C<T>::D' may not exist. */
906 {
907 tree t;
912 {
915 }
917 /* Check for invalid specialization after instantiation:
919 template <> template <> class C<int>::D<int>;
920 template <> template <class U> class C<int>::D; */
924 {
928 {
929 /* We already have a full specialization of this partial
930 instantiation, or a full specialization has been
931 looked up but not instantiated. Reassign it to the
932 new member specialization template. */
933 spec_entry elt;
950 }
951 else
952 /* But if we've had an implicit instantiation, that's a
953 problem ([temp.expl.spec]/6). */
956 }
958 /* Mark TYPE as a specialization. And as a result, we only
959 have one level of template argument for the innermost
960 class template. */
965 }
966 }
968 {
969 /* Someday C++0x may allow for enum template specialization. */
974 else
975 {
978 }
979 }
982 }
984 /* Returns nonzero if we can optimize the retrieval of specializations
985 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
986 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
990 {
993 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
994 parameter. */
996 /* The optimized lookup depends on the fact that the
997 template arguments for the member function template apply
998 purely to the containing class, which is not true if the
999 containing class is an explicit or partial
1000 specialization. */
1004 /* It is possible to have a template that is not a member
1005 template and is not a member of a template class:
1007 template <typename T>
1008 struct S { friend A::f(); };
1010 Here, the friend function is a template, but the context does
1011 not have template information. The optimized lookup relies
1012 on having ARGS be the template arguments for both the class
1013 and the function template. */
1015 }
1017 /* Retrieve the specialization (in the sense of [temp.spec] - a
1018 specialization is either an instantiation or an explicit
1019 specialization) of TMPL for the given template ARGS. If there is
1020 no such specialization, return NULL_TREE. The ARGS are a vector of
1021 arguments, or a vector of vectors of arguments, in the case of
1022 templates with more than one level of parameters.
1024 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1025 then we search for a partial specialization matching ARGS. This
1026 parameter is ignored if TMPL is not a class template.
1028 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1029 result is a NONTYPE_ARGUMENT_PACK. */
1031 static tree
1033 {
1043 /* There should be as many levels of arguments as there are
1044 levels of parameters. */
1051 {
1052 tree class_template;
1053 tree class_specialization;
1055 tree fns;
1058 /* The template arguments actually apply to the containing
1059 class. Find the class specialization with those
1060 arguments. */
1062 class_specialization
1066 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1067 for the specialization. */
1071 /* Iterate through the methods with the indicated name, looking
1072 for the one that has an instance of TMPL. */
1075 {
1078 /* using-declarations can add base methods to the method vec,
1079 and we don't want those here. */
1082 }
1084 }
1085 else
1086 {
1088 spec_entry elt;
1089 htab_t specializations;
1097 else
1105 }
1108 }
1110 /* Like retrieve_specialization, but for local declarations. */
1112 static tree
1114 {
1122 }
1124 /* Returns nonzero iff DECL is a specialization of TMPL. */
1126 int
1128 {
1129 tree t;
1132 {
1138 }
1139 else
1140 {
1149 }
1152 }
1154 /* Returns nonzero iff DECL is a specialization of friend declaration
1155 FRIEND_DECL according to [temp.friend]. */
1157 bool
1159 {
1166 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1167 of a template class, we want to check if DECL is a specialization
1168 if this. */
1172 {
1173 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1176 }
1181 /* There is nothing to do if this is not a template friend. */
1188 /* [temp.friend/6]
1189 A member of a class template may be declared to be a friend of a
1190 non-template class. In this case, the corresponding member of
1191 every specialization of the class template is a friend of the
1192 class granting friendship.
1194 For example, given a template friend declaration
1196 template <class T> friend void A<T>::f();
1198 the member function below is considered a friend
1200 template <> struct A<int> {
1201 void f();
1202 };
1204 For this type of template friend, TEMPLATE_DEPTH below will be
1205 nonzero. To determine if DECL is a friend of FRIEND, we first
1206 check if the enclosing class is a specialization of another. */
1213 {
1214 /* Next, we check the members themselves. In order to handle
1215 a few tricky cases, such as when FRIEND_DECL's are
1217 template <class T> friend void A<T>::g(T t);
1218 template <class T> template <T t> friend void A<T>::h();
1220 and DECL's are
1222 void A<int>::g(int);
1223 template <int> void A<int>::h();
1225 we need to figure out ARGS, the template arguments from
1226 the context of DECL. This is required for template substitution
1227 of `T' in the function parameter of `g' and template parameter
1228 of `h' in the above examples. Here ARGS corresponds to `int'. */
1235 {
1237 {
1240 else
1242 current_depth++;
1243 }
1245 }
1248 {
1250 tree friend_type;
1251 tree decl_type;
1252 tree friend_args_type;
1253 tree decl_args_type;
1255 /* Make sure that both DECL and FRIEND_DECL are templates or
1256 non-templates. */
1262 {
1263 /* If both are templates, check template parameter list. */
1264 tree friend_parms
1269 friend_parms))
1273 }
1274 else
1282 /* Check if return types match. */
1286 /* Check if function parameter types match, ignoring the
1287 `this' parameter. */
1296 }
1297 else
1298 {
1299 /* DECL is a TYPE_DECL */
1303 /* Make sure that both DECL and FRIEND_DECL are templates or
1304 non-templates. */
1305 is_template
1312 {
1313 tree friend_parms;
1314 /* If both are templates, check the name of the two
1315 TEMPLATE_DECL's first because is_friend didn't. */
1320 /* Now check template parameter list. */
1321 friend_parms
1324 return comp_template_parms
1326 friend_parms);
1327 }
1328 else
1331 }
1332 }
1334 }
1336 /* Register the specialization SPEC as a specialization of TMPL with
1337 the indicated ARGS. IS_FRIEND indicates whether the specialization
1338 is actually just a friend declaration. Returns SPEC, or an
1339 equivalent prior declaration, if available.
1341 We also store instantiations of field packs in the hash table, even
1342 though they are not themselves templates, to make lookup easier. */
1344 static tree
1346 hashval_t hash)
1347 {
1348 tree fn;
1350 spec_entry elt;
1358 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1359 register it; we want the corresponding TEMPLATE_DECL instead.
1360 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1361 the more obvious `uses_template_parms (spec)' to avoid problems
1362 with default function arguments. In particular, given
1363 something like this:
1365 template <class T> void f(T t1, T t = T())
1367 the default argument expression is not substituted for in an
1368 instantiation unless and until it is actually needed. */
1372 /* We don't put these specializations in the hash table, but we might
1373 want to give an error about a mismatch. */
1375 else
1376 {
1384 slot =
1388 else
1390 }
1392 /* We can sometimes try to re-register a specialization that we've
1393 already got. In particular, regenerate_decl_from_template calls
1394 duplicate_decls which will update the specialization list. But,
1395 we'll still get called again here anyhow. It's more convenient
1396 to simply allow this than to try to prevent it. */
1400 {
1402 {
1405 {
1407 fn);
1409 }
1410 else
1411 {
1412 tree clone;
1413 /* This situation should occur only if the first
1414 specialization is an implicit instantiation, the
1415 second is an explicit specialization, and the
1416 implicit instantiation has not yet been used. That
1417 situation can occur if we have implicitly
1418 instantiated a member function and then specialized
1419 it later.
1421 We can also wind up here if a friend declaration that
1422 looked like an instantiation turns out to be a
1423 specialization:
1425 template <class T> void foo(T);
1426 class S { friend void foo<>(int) };
1427 template <> void foo(int);
1429 We transform the existing DECL in place so that any
1430 pointers to it become pointers to the updated
1431 declaration.
1433 If there was a definition for the template, but not
1434 for the specialization, we want this to look as if
1435 there were no definition, and vice versa. */
1438 /* The call to duplicate_decls will have applied
1439 [temp.expl.spec]:
1441 An explicit specialization of a function template
1442 is inline only if it is explicitly declared to be,
1443 and independently of whether its function template
1444 is.
1446 to the primary function; now copy the inline bits to
1447 the various clones. */
1449 {
1456 }
1460 }
1461 }
1463 {
1465 /* Dup decl failed, but this is a new definition. Set the
1466 line number so any errors match this new
1467 definition. */
1471 }
1472 }
1476 /* A specialization must be declared in the same namespace as the
1477 template it is specializing. */
1483 {
1491 /* TMPL is a forward declaration of a template function; keep a list
1492 of all specializations in case we need to reassign them to a friend
1493 template later in tsubst_friend_function. */
1496 }
1499 }
1501 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1502 TMPL and ARGS members, ignores SPEC. */
1506 static int
1508 {
1519 }
1521 /* Returns a hash for a template TMPL and template arguments ARGS. */
1523 static hashval_t
1525 {
1528 }
1530 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1531 ignoring SPEC. */
1533 static hashval_t
1535 {
1538 }
1540 /* Recursively calculate a hash value for a template argument ARG, for use
1541 in the hash tables of template specializations. */
1543 hashval_t
1545 {
1557 /* We can get one of these when re-hashing a previous entry in the middle
1558 of substituting into a pack expansion. Just look through it. */
1567 {
1575 {
1580 }
1602 {
1606 {
1609 }
1611 }
1615 {
1618 }
1629 val = iterative_hash_template_arg
1641 val);
1643 val);
1652 /* A lambda can't appear in a template arg, but don't crash on
1653 erroneous input. */
1665 /* Now hash operands as usual. */
1670 }
1673 {
1677 val);
1680 /* Otherwise just compare the types during lookup. */
1689 {
1694 }
1695 }
1698 }
1700 /* Unregister the specialization SPEC as a specialization of TMPL.
1701 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1702 if the SPEC was listed as a specialization of TMPL.
1704 Note that SPEC has been ggc_freed, so we can't look inside it. */
1706 bool
1708 {
1710 spec_entry elt;
1718 {
1723 }
1726 }
1728 /* Like register_specialization, but for local declarations. We are
1729 registering SPEC, an instantiation of TMPL. */
1731 static void
1733 {
1738 }
1740 /* TYPE is a class type. Returns true if TYPE is an explicitly
1741 specialized class. */
1743 bool
1745 {
1749 }
1751 /* Print the list of functions at FNS, going through all the overloads
1752 for each element of the list. Alternatively, FNS can not be a
1753 TREE_LIST, in which case it will be printed together with all the
1754 overloads.
1756 MORE and *STR should respectively be FALSE and NULL when the function
1757 is called from the outside. They are used internally on recursive
1758 calls. print_candidates manages the two parameters and leaves NULL
1759 in *STR when it ends. */
1761 static void
1763 {
1769 {
1773 }
1774 else
1775 {
1778 {
1779 /* Pick the prefix string. */
1781 {
1785 }
1789 }
1792 }
1795 {
1798 }
1799 }
1801 /* Print the list of candidate FNS in an error message. FNS can also
1802 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1804 void
1806 {
1810 }
1812 /* Returns the template (one of the functions given by TEMPLATE_ID)
1813 which can be specialized to match the indicated DECL with the
1814 explicit template args given in TEMPLATE_ID. The DECL may be
1815 NULL_TREE if none is available. In that case, the functions in
1816 TEMPLATE_ID are non-members.
1818 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1819 specialization of a member template.
1821 The TEMPLATE_COUNT is the number of references to qualifying
1822 template classes that appeared in the name of the function. See
1823 check_explicit_specialization for a more accurate description.
1825 TSK indicates what kind of template declaration (if any) is being
1826 declared. TSK_TEMPLATE indicates that the declaration given by
1827 DECL, though a FUNCTION_DECL, has template parameters, and is
1828 therefore a template function.
1830 The template args (those explicitly specified and those deduced)
1831 are output in a newly created vector *TARGS_OUT.
1833 If it is impossible to determine the result, an error message is
1834 issued. The error_mark_node is returned to indicate failure. */
1836 static tree
1838 tree decl,
1842 tmpl_spec_kind tsk)
1843 {
1844 tree fns;
1845 tree targs;
1846 tree explicit_targs;
1848 /* A TREE_LIST of templates of which DECL may be a specialization.
1849 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1850 corresponding TREE_PURPOSE is the set of template arguments that,
1851 when used to instantiate the template, would produce a function
1852 with the signature of DECL. */
1862 /* We shouldn't be specializing a member template of an
1863 unspecialized class template; we already gave an error in
1864 check_specialization_scope, now avoid crashing. */
1867 {
1870 }
1878 /* Check for baselinks. */
1883 {
1886 }
1888 /* Count the number of template headers specified for this
1889 specialization. */
1897 {
1901 {
1902 tree decl_arg_types;
1903 tree fn_arg_types;
1904 tree insttype;
1906 /* In case of explicit specialization, we need to check if
1907 the number of template headers appearing in the specialization
1908 is correct. This is usually done in check_explicit_specialization,
1909 but the check done there cannot be exhaustive when specializing
1910 member functions. Consider the following code:
1912 template <> void A<int>::f(int);
1913 template <> template <> void A<int>::f(int);
1915 Assuming that A<int> is not itself an explicit specialization
1916 already, the first line specializes "f" which is a non-template
1917 member function, whilst the second line specializes "f" which
1918 is a template member function. So both lines are syntactically
1919 correct, and check_explicit_specialization does not reject
1920 them.
1922 Here, we can do better, as we are matching the specialization
1923 against the declarations. We count the number of template
1924 headers, and we check if they match TEMPLATE_COUNT + 1
1925 (TEMPLATE_COUNT is the number of qualifying template classes,
1926 plus there must be another header for the member template
1927 itself).
1929 Notice that if header_count is zero, this is not a
1930 specialization but rather a template instantiation, so there
1931 is no check we can perform here. */
1935 /* Check that the number of template arguments at the
1936 innermost level for DECL is the same as for FN. */
1944 /* DECL might be a specialization of FN. */
1948 /* For a non-static member function, we need to make sure
1949 that the const qualification is the same. Since
1950 get_bindings does not try to merge the "this" parameter,
1951 we must do the comparison explicitly. */
1957 /* Skip the "this" parameter and, for constructors of
1958 classes with virtual bases, the VTT parameter. A
1959 full specialization of a constructor will have a VTT
1960 parameter, but a template never will. */
1961 decl_arg_types
1963 fn_arg_types
1966 /* Function templates cannot be specializations; there are
1967 no partial specializations of functions. Therefore, if
1968 the type of DECL does not match FN, there is no
1969 match. */
1971 {
1975 }
1977 /* See whether this function might be a specialization of this
1978 template. Suppress access control because we might be trying
1979 to make this specialization a friend, and we have already done
1980 access control for the declaration of the specialization. */
1986 /* We cannot deduce template arguments that when used to
1987 specialize TMPL will produce DECL. */
1990 /* Make sure that the deduced arguments actually work. */
1994 fn_arg_types
1999 /* Save this template, and the arguments deduced. */
2001 }
2003 /* FN is an ordinary member function, and we need a
2004 specialization of a member template. */
2005 ;
2007 /* We can get IDENTIFIER_NODEs here in certain erroneous
2008 cases. */
2009 ;
2011 /* This is just an ordinary non-member function. Nothing can
2012 be a specialization of that. */
2013 ;
2015 /* Cannot specialize functions that are created implicitly. */
2016 ;
2017 else
2018 {
2019 tree decl_arg_types;
2021 /* This is an ordinary member function. However, since
2022 we're here, we can assume its enclosing class is a
2023 template class. For example,
2025 template <typename T> struct S { void f(); };
2026 template <> void S<int>::f() {}
2028 Here, S<int>::f is a non-template, but S<int> is a
2029 template class. If FN has the same type as DECL, we
2030 might be in business. */
2033 /* Its enclosing class is an explicit specialization
2034 of a template class. This is not a candidate. */
2039 /* The return types differ. */
2042 /* Adjust the type of DECL in case FN is a static member. */
2049 decl_arg_types))
2050 /* They match! */
2052 }
2053 }
2056 {
2057 /* We have:
2059 [temp.expl.spec]
2061 It is possible for a specialization with a given function
2062 signature to be instantiated from more than one function
2063 template. In such cases, explicit specification of the
2064 template arguments must be used to uniquely identify the
2065 function template specialization being specialized.
2067 Note that here, there's no suggestion that we're supposed to
2068 determine which of the candidate templates is most
2069 specialized. However, we, also have:
2071 [temp.func.order]
2073 Partial ordering of overloaded function template
2074 declarations is used in the following contexts to select
2075 the function template to which a function template
2076 specialization refers:
2078 -- when an explicit specialization refers to a function
2079 template.
2081 So, we do use the partial ordering rules, at least for now.
2082 This extension can only serve to make invalid programs valid,
2083 so it's safe. And, there is strong anecdotal evidence that
2084 the committee intended the partial ordering rules to apply;
2085 the EDG front end has that behavior, and John Spicer claims
2086 that the committee simply forgot to delete the wording in
2087 [temp.expl.spec]. */
2090 {
2093 }
2094 }
2097 {
2105 }
2109 {
2115 }
2117 /* We have one, and exactly one, match. */
2119 {
2122 /* DECL is a re-declaration or partial instantiation of a template
2123 function. */
2126 /* It was a specialization of an ordinary member function in a
2127 template class. */
2129 }
2131 /* It was a specialization of a template. */
2134 {
2139 }
2140 else
2143 }
2145 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2146 but with the default argument values filled in from those in the
2147 TMPL_TYPES. */
2149 static tree
2151 tree tmpl_types)
2152 {
2153 tree new_spec_types;
2161 /* Substitute into the rest of the list. */
2162 new_spec_types =
2166 /* Add the default argument for this parameter. */
2169 new_spec_types);
2170 }
2172 /* DECL is an explicit specialization. Replicate default arguments
2173 from the template it specializes. (That way, code like:
2175 template <class T> void f(T = 3);
2176 template <> void f(double);
2177 void g () { f (); }
2179 works, as required.) An alternative approach would be to look up
2180 the correct default arguments at the call-site, but this approach
2181 is consistent with how implicit instantiations are handled. */
2183 static void
2185 {
2186 tree tmpl;
2187 tree spec_types;
2188 tree tmpl_types;
2189 tree new_spec_types;
2190 tree old_type;
2191 tree new_type;
2192 tree t;
2197 /* See if there's anything we need to do. */
2210 {
2211 /* Remove the this pointer, but remember the object's type for
2212 CV quals. */
2218 {
2219 /* DECL may contain more parameters than TMPL due to the extra
2220 in-charge parameter in constructors and destructors. */
2223 }
2225 {
2228 }
2229 }
2231 /* Compute the merged default arguments. */
2232 new_spec_types =
2235 /* Compute the new FUNCTION_TYPE. */
2237 {
2241 new_spec_types);
2244 /* Put the in-charge parameter back. */
2247 new_spec_types);
2251 new_spec_types);
2252 }
2253 else
2255 new_spec_types);
2261 }
2263 /* Return the number of template headers we expect to see for a definition
2264 or specialization of CTYPE or one of its non-template members. */
2266 int
2268 {
2272 {
2273 /* You're supposed to have one `template <...>' for every
2274 template class, but you don't need one for a full
2275 specialization. For example:
2277 template <class T> struct S{};
2278 template <> struct S<int> { void f(); };
2279 void S<int>::f () {}
2281 is correct; there shouldn't be a `template <>' for the
2282 definition of `S<int>::f'. */
2284 /* If CTYPE does not have template information of any
2285 kind, then it is not a template, nor is it nested
2286 within a template. */
2294 }
2297 }
2299 /* Do a simple sanity check on the template headers that precede the
2300 variable declaration DECL. */
2302 void
2304 {
2311 {
2317 "members of an explicitly specialized class are defined "
2319 }
2320 }
2322 /* Check to see if the function just declared, as indicated in
2323 DECLARATOR, and in DECL, is a specialization of a function
2324 template. We may also discover that the declaration is an explicit
2325 instantiation at this point.
2327 Returns DECL, or an equivalent declaration that should be used
2328 instead if all goes well. Issues an error message if something is
2329 amiss. Returns error_mark_node if the error is not easily
2330 recoverable.
2332 FLAGS is a bitmask consisting of the following flags:
2334 2: The function has a definition.
2335 4: The function is a friend.
2337 The TEMPLATE_COUNT is the number of references to qualifying
2338 template classes that appeared in the name of the function. For
2339 example, in
2341 template <class T> struct S { void f(); };
2342 void S<int>::f();
2344 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2345 classes are not counted in the TEMPLATE_COUNT, so that in
2347 template <class T> struct S {};
2348 template <> struct S<int> { void f(); }
2349 template <> void S<int>::f();
2351 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2352 invalid; there should be no template <>.)
2354 If the function is a specialization, it is marked as such via
2355 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2356 is set up correctly, and it is added to the list of specializations
2357 for that template. */
2359 tree
2361 tree decl,
2364 {
2372 tmpl_spec_kind tsk;
2375 {
2378 else
2380 }
2381 else
2385 {
2388 {
2391 }
2393 {
2395 /* This could be something like:
2397 template <class T> void f(T);
2398 class S { friend void f<>(int); } */
2400 else
2401 {
2402 /* This case handles bogus declarations like template <>
2403 template <class T> void f<int>(); */
2406 declarator);
2408 }
2409 }
2413 /* The error has already been reported in
2414 check_specialization_scope. */
2420 /* Fall through. */
2433 decl);
2436 else
2440 /* Fall through. */
2445 else
2451 {
2452 /* This case handles bogus declarations like template <>
2453 template <class T> void f<int>(); */
2458 else
2460 declarator);
2462 }
2465 /* This is a specialization of a member template, without
2466 specialization the containing class. Something like:
2468 template <class T> struct S {
2469 template <class U> void f (U);
2470 };
2471 template <> template <class U> void S<int>::f(U) {}
2473 That's a specialization -- but of the entire template. */
2479 }
2482 {
2486 {
2490 }
2491 }
2494 {
2498 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2500 {
2501 tree fns;
2506 else
2507 {
2508 /* If there is no class context, the explicit instantiation
2509 must be at namespace scope. */
2512 /* Find the namespace binding, using the declaration
2513 context. */
2517 {
2520 }
2521 else
2522 {
2528 }
2529 }
2532 }
2538 {
2540 /* A specialization in class scope. This is invalid,
2541 but the error will already have been flagged by
2542 check_specialization_scope. */
2544 else
2545 {
2546 /* It's not valid to write an explicit instantiation in
2547 class scope, e.g.:
2549 class C { template void f(); }
2551 This case is caught by the parser. However, on
2552 something like:
2554 template class C { void f(); };
2556 (which is invalid) we can get here. The error will be
2557 issued later. */
2558 ;
2559 }
2562 }
2565 {
2566 /* Find the list of functions in ctype that have the same
2567 name as the declared function. */
2573 {
2578 {
2579 /* From [temp.expl.spec]:
2581 If such an explicit specialization for the member
2582 of a class template names an implicitly-declared
2583 special member function (clause _special_), the
2584 program is ill-formed.
2586 Similar language is found in [temp.explicit]. */
2589 }
2592 }
2595 {
2599 }
2600 else
2601 {
2603 tree ovl;
2605 /* For a type-conversion operator, we cannot do a
2606 name-based lookup. We might be looking for `operator
2607 int' which will be a specialization of `operator T'.
2608 So, we find *all* the conversion operators, and then
2609 select from them. */
2617 {
2619 /* There are no more conversion functions. */
2622 /* Glue all these conversion functions together
2623 with those we already have. */
2626 }
2627 }
2630 {
2633 }
2634 else
2636 }
2638 /* Figure out what exactly is being specialized at this point.
2639 Note that for an explicit instantiation, even one for a
2640 member function, we cannot tell apriori whether the
2641 instantiation is for a member template, or just a member
2642 function of a template class. Even if a member template is
2643 being instantiated, the member template arguments may be
2644 elided if they can be deduced from the rest of the
2645 declaration. */
2648 member_specialization,
2649 template_count,
2650 tsk);
2653 /* We couldn't figure out what this declaration was
2654 specializing. */
2656 else
2657 {
2661 {
2662 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2663 is done by do_decl_instantiation later. */
2669 {
2670 /* If TMPL is not the most general template (for
2671 example, if TMPL is a friend template that is
2672 injected into namespace scope), then there will
2673 be too many levels of TARGS. Remove some of them
2674 here. */
2676 tree new_targs;
2683 }
2686 }
2688 /* If we thought that the DECL was a member function, but it
2689 turns out to be specializing a static member function,
2690 make DECL a static member function as well. */
2695 /* If this is a specialization of a member template of a
2696 template class, we want to return the TEMPLATE_DECL, not
2697 the specialization of it. */
2699 {
2704 {
2705 tree parm;
2709 /* We want to use the argument list specified in the
2710 definition, not in the original declaration. */
2715 }
2718 }
2720 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2723 /* Inherit default function arguments from the template
2724 DECL is specializing. */
2727 /* This specialization has the same protection as the
2728 template it specializes. */
2732 /* 7.1.1-1 [dcl.stc]
2734 A storage-class-specifier shall not be specified in an
2735 explicit specialization...
2737 The parser rejects these, so unless action is taken here,
2738 explicit function specializations will always appear with
2739 global linkage.
2741 The action recommended by the C++ CWG in response to C++
2742 defect report 605 is to make the storage class and linkage
2743 of the explicit specialization match the templated function:
2745 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2746 */
2748 {
2752 /* This specialization has the same linkage and visibility as
2753 the function template it specializes. */
2756 {
2759 }
2762 {
2765 }
2766 }
2768 /* If DECL is a friend declaration, declared using an
2769 unqualified name, the namespace associated with DECL may
2770 have been set incorrectly. For example, in:
2772 template <typename T> void f(T);
2773 namespace N {
2774 struct S { friend void f<int>(int); }
2775 }
2777 we will have set the DECL_CONTEXT for the friend
2778 declaration to N, rather than to the global namespace. */
2783 /* This is not really a declaration of a specialization.
2784 It's just the name of an instantiation. But, it's not
2785 a request for an instantiation, either. */
2788 /* Register this specialization so that we can find it
2789 again. */
2792 /* A 'structor should already have clones. */
2797 }
2798 }
2801 }
2803 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2804 parameters. These are represented in the same format used for
2805 DECL_TEMPLATE_PARMS. */
2807 int
2809 {
2810 const_tree p1;
2811 const_tree p2;
2819 {
2831 {
2835 /* If either of the template parameters are invalid, assume
2836 they match for the sake of error recovery. */
2849 }
2850 }
2853 /* One set of parameters has more parameters lists than the
2854 other. */
2858 }
2860 /* Determine whether PARM is a parameter pack. */
2862 bool
2864 {
2865 /* Determine if we have a non-type template parameter pack. */
2872 /* If this is a list of template parameters, we could get a
2873 TYPE_DECL or a TEMPLATE_DECL. */
2877 /* Otherwise it must be a type template parameter. */
2881 }
2883 /* Determine if T is a function parameter pack. */
2885 bool
2887 {
2891 }
2893 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2894 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2896 tree
2898 {
2905 }
2907 /* Return true iff the function parameter PARAM_DECL was expanded
2908 from the function parameter pack PACK. */
2910 bool
2912 {
2917 /* The parameter pack and its pack arguments have the same
2918 DECL_PARM_INDEX. */
2920 }
2922 /* Determine whether ARGS describes a variadic template args list,
2923 i.e., one that is terminated by a template argument pack. */
2925 static bool
2927 {
2929 tree last_parm;
2943 }
2945 /* Generate a new name for the parameter pack name NAME (an
2946 IDENTIFIER_NODE) that incorporates its */
2948 static tree
2950 {
2951 /* Munge the name to include the parameter index. */
2952 #define NUMBUF_LEN 128
2966 }
2968 /* Return true if T is a primary function, class or alias template
2969 instantiation. */
2971 bool
2973 {
2987 }
2989 /* Return true if PARM is a template template parameter. */
2991 bool
2993 {
2995 }
2997 /* Return true iff PARM is a DECL representing a type template
2998 parameter. */
3000 bool
3002 {
3007 }
3009 /* Return the template parameters of T if T is a
3010 primary template instantiation, NULL otherwise. */
3012 tree
3014 {
3019 parms = INNERMOST_TEMPLATE_PARMS
3023 }
3025 /* Return the template parameters of the LEVELth level from the full list
3026 of template parameters PARMS. */
3028 tree
3030 {
3031 tree p;
3042 }
3044 /* Returns the template arguments of T if T is a template instantiation,
3045 NULL otherwise. */
3047 tree
3049 {
3057 }
3059 /* Return the argument pack elements of T if T is a template argument pack,
3060 NULL otherwise. */
3062 tree
3064 {
3070 }
3072 /* Structure used to track the progress of find_parameter_packs_r. */
3073 struct find_parameter_pack_data
3074 {
3075 /* TREE_LIST that will contain all of the parameter packs found by
3076 the traversal. */
3079 /* Set of AST nodes that have been visited by the traversal. */
3081 };
3083 /* Identifies all of the argument packs that occur in a template
3084 argument and appends them to the TREE_LIST inside DATA, which is a
3085 find_parameter_pack_data structure. This is a subroutine of
3086 make_pack_expansion and uses_parameter_packs. */
3087 static tree
3089 {
3095 /* Handle type aliases/typedefs. */
3097 {
3104 }
3106 /* Identify whether this is a parameter pack or not. */
3108 {
3124 {
3125 /* We don't want to walk into the type of a PARM_DECL,
3126 because we don't want to see the type parameter pack. */
3129 }
3132 /* Look through a lambda capture proxy to the field pack. */
3135 {
3141 }
3148 /* Not a parameter pack. */
3150 }
3153 {
3154 /* Add this parameter pack to the list. */
3156 }
3162 /* This switch statement will return immediately if we don't find a
3163 parameter pack. */
3165 {
3170 /* Check the template itself. */
3173 /* Check the template arguments. */
3189 /* Fall through. */
3231 }
3234 }
3236 /* Determines if the expression or type T uses any parameter packs. */
3237 bool
3239 {
3247 }
3249 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3250 representation a base-class initializer into a parameter pack
3251 expansion. If all goes well, the resulting node will be an
3252 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3253 respectively. */
3254 tree
3256 {
3257 tree result;
3266 {
3267 /* The only time we will see a TREE_LIST here is for a base
3268 class initializer. In this case, the TREE_PURPOSE will be a
3269 _TYPE node (representing the base class expansion we're
3270 initializing) and the TREE_VALUE will be a TREE_LIST
3271 containing the initialization arguments.
3273 The resulting expansion looks somewhat different from most
3274 expansions. Rather than returning just one _EXPANSION, we
3275 return a TREE_LIST whose TREE_PURPOSE is a
3276 TYPE_PACK_EXPANSION containing the bases that will be
3277 initialized. The TREE_VALUE will be identical to the
3278 original TREE_VALUE, which is a list of arguments that will
3279 be passed to each base. We do not introduce any new pack
3280 expansion nodes into the TREE_VALUE (although it is possible
3281 that some already exist), because the TREE_PURPOSE and
3282 TREE_VALUE all need to be expanded together with the same
3283 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3284 resulting TREE_PURPOSE will mention the parameter packs in
3285 both the bases and the arguments to the bases. */
3286 tree purpose;
3287 tree value;
3290 /* Determine which parameter packs will be used by the base
3291 class expansion. */
3298 {
3302 }
3305 {
3306 /* Collect the sets of parameter packs used in each of the
3307 initialization arguments. */
3309 {
3310 /* Determine which parameter packs will be expanded in this
3311 argument. */
3314 }
3315 }
3319 /* Create the pack expansion type for the base type. */
3324 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3325 they will rarely be compared to anything. */
3329 }
3334 /* Build the PACK_EXPANSION_* node. */
3335 result = for_types
3340 {
3341 /* Propagate type and const-expression information. */
3344 }
3345 else
3346 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3347 they will rarely be compared to anything. */
3350 /* Determine which parameter packs will be expanded. */
3356 /* Make sure we found some parameter packs. */
3358 {
3361 else
3364 }
3370 }
3372 /* Checks T for any "bare" parameter packs, which have not yet been
3373 expanded, and issues an error if any are found. This operation can
3374 only be done on full expressions or types (e.g., an expression
3375 statement, "if" condition, etc.), because we could have expressions like:
3377 foo(f(g(h(args)))...)
3379 where "args" is a parameter pack. check_for_bare_parameter_packs
3380 should not be called for the subexpressions args, h(args),
3381 g(h(args)), or f(g(h(args))), because we would produce erroneous
3382 error messages.
3384 Returns TRUE and emits an error if there were bare parameter packs,
3385 returns FALSE otherwise. */
3386 bool
3388 {
3404 {
3407 {
3416 else
3421 else
3425 }
3428 }
3431 }
3433 /* Expand any parameter packs that occur in the template arguments in
3434 ARGS. */
3435 tree
3437 {
3443 /* First, determine if we need to expand anything, and the number of
3444 slots we'll need. */
3446 {
3451 {
3455 else
3457 }
3458 else
3459 {
3461 num_result_args++;
3462 }
3463 }
3465 /* If no expansion is necessary, we're done. */
3469 /* Expand arguments. */
3472 non_default_args_count =
3475 {
3478 {
3485 }
3486 else
3487 {
3490 }
3491 }
3495 }
3497 /* Checks if DECL shadows a template parameter.
3499 [temp.local]: A template-parameter shall not be redeclared within its
3500 scope (including nested scopes).
3502 Emits an error and returns TRUE if the DECL shadows a parameter,
3503 returns FALSE otherwise. */
3505 bool
3507 {
3508 tree olddecl;
3510 /* If we're not in a template, we can't possibly shadow a template
3511 parameter. */
3515 /* Figure out what we're shadowing. */
3520 /* If there's no previous binding for this name, we're not shadowing
3521 anything, let alone a template parameter. */
3525 /* If we're not shadowing a template parameter, we're done. Note
3526 that OLDDECL might be an OVERLOAD (or perhaps even an
3527 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3528 node. */
3532 /* We check for decl != olddecl to avoid bogus errors for using a
3533 name inside a class. We check TPFI to avoid duplicate errors for
3534 inline member templates. */
3540 /* Don't complain about the injected class name, as we've already
3541 complained about the class itself. */
3548 }
3550 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3551 ORIG_LEVEL, DECL, and TYPE. */
3553 static tree
3557 tree decl,
3558 tree type)
3559 {
3570 }
3572 /* Find the canonical type parameter for the given template type
3573 parameter. Returns the canonical type parameter, which may be TYPE
3574 if no such parameter existed. */
3576 static tree
3578 {
3579 tree list;
3593 else
3594 {
3599 }
3600 }
3602 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3603 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3604 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3605 new one is created. */
3607 static tree
3609 tsubst_flags_t complain)
3610 {
3615 {
3634 /* Template template parameters need this. */
3639 }
3642 }
3644 /* Process information from new template parameter PARM and append it
3645 to the LIST being built. This new parameter is a non-type
3646 parameter iff IS_NON_TYPE is true. This new parameter is a
3647 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3648 is in PARM_LOC. */
3650 tree
3653 {
3655 tree defval;
3662 {
3666 {
3670 else
3672 }
3675 }
3678 {
3684 {
3685 /* [temp.param]
3687 The top-level cv-qualifiers on the template-parameter are
3688 ignored when determining its type. */
3693 && !is_parameter_pack
3694 /* If we're in a nested template parameter list, the template
3695 template parameter could be a parameter pack. */
3697 {
3698 /* This template parameter is not a parameter pack, but it
3699 should be. Complain about "bare" parameter packs. */
3702 /* Recover by calling this a parameter pack. */
3704 }
3705 }
3707 /* A template parameter is not modifiable. */
3716 processing_template_decl,
3721 }
3722 else
3723 {
3724 tree t;
3728 {
3730 /* This is for distinguishing between real templates and template
3731 template parameters */
3735 }
3736 else
3737 {
3739 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3742 }
3749 processing_template_decl,
3753 }
3759 }
3761 /* The end of a template parameter list has been reached. Process the
3762 tree list into a parameter vector, converting each parameter into a more
3763 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3764 as PARM_DECLs. */
3766 tree
3768 {
3773 current_template_parms
3778 {
3782 }
3787 }
3789 /* end_template_decl is called after a template declaration is seen. */
3791 void
3793 {
3799 /* This matches the pushlevel in begin_template_parm_list. */
3804 }
3806 /* Takes a TREE_LIST representing a template parameter and convert it
3807 into an argument suitable to be passed to the type substitution
3808 functions. Note that If the TREE_LIST contains an error_mark
3809 node, the returned argument is error_mark_node. */
3811 static tree
3813 {
3826 {
3830 {
3831 /* Turn this argument into a TYPE_ARGUMENT_PACK
3832 with a single element, which expands T. */
3834 #ifdef ENABLE_CHECKING
3835 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3837 #endif
3842 }
3843 }
3844 else
3845 {
3849 {
3850 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3851 with a single element, which expands T. */
3854 #ifdef ENABLE_CHECKING
3855 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3857 #endif
3864 }
3865 else
3867 }
3869 }
3871 /* Given a set of template parameters, return them as a set of template
3872 arguments. The template parameters are represented as a TREE_VEC, in
3873 the form documented in cp-tree.h for template arguments. */
3875 static tree
3877 {
3878 tree header;
3883 /* If there is only one level of template parameters, we do not
3884 create a TREE_VEC of TREE_VECs. Instead, we return a single
3885 TREE_VEC containing the arguments. */
3890 {
3898 #ifdef ENABLE_CHECKING
3900 #endif
3904 else
3906 }
3909 /* This can happen for template parms of a template template
3910 parameter, e.g:
3912 template<template<class T, class U> class TT> struct S;
3914 Consider the level of the parms of TT; T and U both have
3915 level 2; TT has no template parm of level 1. So in this case
3916 the first element of full_template_args is NULL_TREE. If we
3917 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3918 of 2. This will make tsubst wrongly consider that T and U
3919 have level 1. Instead, let's create a dummy vector as the
3920 first element of full_template_args so that TMPL_ARGS_DEPTH
3921 returns the correct depth for args. */
3924 }
3926 /* Within the declaration of a template, return the currently active
3927 template parameters as an argument TREE_VEC. */
3929 static tree
3931 {
3933 }
3935 /* Update the declared TYPE by doing any lookups which were thought to be
3936 dependent, but are not now that we know the SCOPE of the declarator. */
3938 tree
3940 {
3951 /* Don't bother building up the args in this case. */
3953 {
3954 /* tsubst in the args corresponding to the template parameters,
3955 including auto if present. Most things will be unchanged, but
3956 make_typename_type and tsubst_qualified_id will resolve
3957 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3960 tree pushed;
3962 {
3966 }
3971 }
3977 {
3980 else
3982 }
3984 }
3986 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3987 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3988 a member template. Used by push_template_decl below. */
3990 static tree
3992 {
4000 }
4002 struct template_parm_data
4003 {
4004 /* The level of the template parameters we are currently
4005 processing. */
4008 /* The index of the specialization argument we are currently
4009 processing. */
4012 /* An array whose size is the number of template parameters. The
4013 elements are nonzero if the parameter has been used in any one
4014 of the arguments processed so far. */
4017 /* An array whose size is the number of template arguments. The
4018 elements are nonzero if the argument makes use of template
4019 parameters of this level. */
4021 };
4023 /* Subroutine of push_template_decl used to see if each template
4024 parameter in a partial specialization is used in the explicit
4025 argument list. If T is of the LEVEL given in DATA (which is
4026 treated as a template_parm_data*), then DATA->PARMS is marked
4027 appropriately. */
4029 static int
4031 {
4037 {
4040 }
4041 else
4042 {
4045 }
4048 {
4051 }
4053 /* Return zero so that for_each_template_parm will continue the
4054 traversal of the tree; we want to mark *every* template parm. */
4056 }
4058 /* Process the partial specialization DECL. */
4060 static tree
4062 {
4068 tree inner_parms;
4069 tree inst;
4082 /* We check that each of the template parameters given in the
4083 partial specialization is used in the argument list to the
4084 specialization. For example:
4086 template <class T> struct S;
4087 template <class T> struct S<T*>;
4089 The second declaration is OK because `T*' uses the template
4090 parameter T, whereas
4092 template <class T> struct S<int>;
4094 is no good. Even trickier is:
4096 template <class T>
4097 struct S1
4098 {
4099 template <class U>
4100 struct S2;
4101 template <class U>
4102 struct S2<T>;
4103 };
4105 The S2<T> declaration is actually invalid; it is a
4106 full-specialization. Of course,
4108 template <class U>
4109 struct S2<T (*)(U)>;
4111 or some such would have been OK. */
4119 {
4124 NULL,
4126 }
4129 {
4130 /* One of the template parms was not used in a deduced context in the
4131 specialization. */
4133 {
4137 }
4141 }
4146 /* [temp.class.spec]
4148 The argument list of the specialization shall not be identical to
4149 the implicit argument list of the primary template. */
4156 /* A partial specialization that replaces multiple parameters of the
4157 primary template with a pack expansion is less specialized for those
4158 parameters. */
4160 {
4162 "primary template because it replaces multiple parameters "
4166 }
4168 /* [temp.class.spec]
4170 A partially specialized non-type argument expression shall not
4171 involve template parameters of the partial specialization except
4172 when the argument expression is a simple identifier.
4174 The type of a template parameter corresponding to a specialized
4175 non-type argument shall not be dependent on a parameter of the
4176 specialization.
4178 Also, we verify that pack expansions only occur at the
4179 end of the argument list. */
4183 {
4190 {
4191 /* Extract the arguments from the argument pack. We'll be
4192 iterating over these in the following loop. */
4195 }
4198 {
4200 /* Get the Jth argument in the parameter pack. */
4204 {
4205 /* Pack expansions must come at the end of the
4206 argument list. */
4209 {
4213 else
4216 }
4217 }
4220 /* We only care about the pattern. */
4226 /* This next two lines are the `argument expression is not just a
4227 simple identifier' condition and also the `specialized
4228 non-type argument' bit. */
4232 {
4236 arg);
4237 else
4238 {
4239 /* Look at the corresponding template parameter,
4240 marking which template parameters its type depends
4241 upon. */
4245 {
4246 /* We haven't yet initialized TPD2. Do so now. */
4248 /* The number of parameters here is the number in the
4249 main template, which, as checked in the assertion
4250 above, is NARGS. */
4254 }
4256 /* Mark the template parameters. But this time, we're
4257 looking for the template parameters of the main
4258 template, not in the specialization. */
4265 NULL,
4269 {
4270 /* The type depended on some template parameters.
4271 If they are fully specialized in the
4272 specialization, that's OK. */
4281 "type %qT of template argument %qE depends "
4283 "type %qT of template argument %qE depends "
4285 type,
4286 arg);
4287 }
4288 }
4289 }
4290 }
4291 }
4293 /* We should only get here once. */
4311 {
4315 {
4319 "partial specialization of %qT after instantiation "
4321 }
4322 }
4325 }
4327 /* PARM is a template parameter of some form; return the corresponding
4328 TEMPLATE_PARM_INDEX. */
4330 static tree
4332 {
4344 }
4346 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4347 parameter packs used by the template parameter PARM. */
4349 static void
4351 {
4352 /* A type parm can't refer to another parm. */
4356 {
4360 }
4367 }
4369 /* PARM is a template parameter pack. Return any parameter packs used in
4370 its type or the type of any of its template parameters. If there are
4371 any such packs, it will be instantiated into a fixed template parameter
4372 list by partial instantiation rather than be fully deduced. */
4374 tree
4376 {
4377 /* This can only be true in a member template. */
4380 /* This can only be true for a parameter pack. */
4383 /* A type parm can't refer to another parm. */
4396 }
4398 /* Check that a template declaration's use of default arguments and
4399 parameter packs is not invalid. Here, PARMS are the template
4400 parameters. IS_PRIMARY is true if DECL is the thing declared by
4401 a primary template. IS_PARTIAL is true if DECL is a partial
4402 specialization.
4404 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4405 declaration (but not a definition); 1 indicates a declaration, 2
4406 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4407 emitted for extraneous default arguments.
4409 Returns TRUE if there were no errors found, FALSE otherwise. */
4411 bool
4414 {
4417 tree parm_level;
4420 /* [temp.param]
4422 A default template-argument shall not be specified in a
4423 function template declaration or a function template definition, nor
4424 in the template-parameter-list of the definition of a member of a
4425 class template. */
4429 /* You can't have a function template declaration in a local
4430 scope, nor you can you define a member of a class template in a
4431 local scope. */
4439 /* A lambda doesn't have an explicit declaration; don't complain
4440 about the parms of the enclosing class. */
4447 /* If this is either a friend defined in the scope of the class
4448 or a member function. */
4454 /* And, if it was a member function, it really was defined in
4455 the scope of the class. */
4458 /* We already checked these parameters when the template was
4459 declared, so there's no need to do it again now. This function
4460 was defined in class scope, but we're processing its body now
4461 that the class is complete. */
4464 /* Core issue 226 (C++0x only): the following only applies to class
4465 templates. */
4468 {
4469 /* [temp.param]
4471 If a template-parameter has a default template-argument, all
4472 subsequent template-parameters shall have a default
4473 template-argument supplied. */
4475 {
4482 {
4492 {
4494 /* For better subsequent error-recovery, we indicate that
4495 there should have been a default argument. */
4498 }
4500 && !is_friend_decl
4501 /* Don't complain about an enclosing partial
4502 specialization. */
4507 /* A fixed parameter pack will be partially
4508 instantiated into a fixed length list. */
4510 {
4511 /* A primary class template can only have one
4512 parameter pack, at the end of the template
4513 parameter list. */
4518 else
4526 }
4527 }
4528 }
4529 }
4532 || is_partial
4533 || !is_primary
4535 /* For an ordinary class template, default template arguments are
4536 allowed at the innermost level, e.g.:
4537 template <class T = int>
4538 struct S {};
4539 but, in a partial specialization, they're not allowed even
4540 there, as we have in [temp.class.spec]:
4542 The template parameter list of a specialization shall not
4543 contain default template argument values.
4545 So, for a partial specialization, or for a function template
4546 (in C++98/C++03), we look at all of them. */
4547 ;
4548 else
4549 /* But, for a primary class template that is not a partial
4550 specialization we look at all template parameters except the
4551 innermost ones. */
4554 /* Figure out what error message to issue. */
4567 else
4571 /* If we're inside a class definition, there's no need to
4572 examine the parameters to the class itself. On the one
4573 hand, they will be checked when the class is defined, and,
4574 on the other, default arguments are valid in things like:
4575 template <class T = double>
4576 struct S { template <class U> void f(U); };
4577 Here the default argument for `S' has no bearing on the
4578 declaration of `f'. */
4580 else
4581 /* Check everything. */
4587 {
4594 {
4599 {
4601 {
4608 }
4610 /* Clear out the default argument so that we are not
4611 confused later. */
4613 }
4614 }
4616 /* At this point, if we're still interested in issuing messages,
4617 they must apply to classes surrounding the object declared. */
4621 }
4624 }
4626 /* Worker for push_template_decl_real, called via
4627 for_each_template_parm. DATA is really an int, indicating the
4628 level of the parameters we are interested in. If T is a template
4629 parameter of that level, return nonzero. */
4631 static int
4633 {
4639 else
4642 }
4644 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4645 parameters given by current_template_args, or reuses a
4646 previously existing one, if appropriate. Returns the DECL, or an
4647 equivalent one, if it is replaced via a call to duplicate_decls.
4649 If IS_FRIEND is true, DECL is a friend declaration. */
4651 tree
4653 {
4654 tree tmpl;
4655 tree args;
4656 tree info;
4657 tree ctx;
4661 /* True if the template is a member template, in the sense of
4662 [temp.mem]. */
4668 /* See if this is a partial specialization. */
4677 /* For a friend, we want the context of the friend function, not
4678 the type of which it is a friend. */
4682 /* In the case of a virtual function, we want the class in which
4683 it is defined. */
4685 else
4686 /* Otherwise, if we're currently defining some class, the DECL
4687 is assumed to be a member of the class. */
4696 /* See if this is a primary template. */
4699 /* A friend template that specifies a class context, i.e.
4700 template <typename T> friend void A<T>::f();
4701 is not primary. */
4706 else
4710 {
4715 {
4718 }
4720 {
4722 {
4723 /* [temp.mem]
4725 A destructor shall not be a member template. */
4728 }
4735 {
4736 /* [basic.stc.dynamic.allocation]
4738 An allocation function can be a function
4739 template. ... Template allocation functions shall
4740 have two or more parameters. */
4743 }
4744 }
4750 /* alias-declaration */
4752 else
4753 {
4756 }
4757 }
4759 /* Check to see that the rules regarding the use of default
4760 arguments are not being violated. */
4764 /* Ensure that there are no parameter packs in the type of this
4765 declaration that have not been expanded. */
4767 {
4768 /* Check each of the arguments individually to see if there are
4769 any bare parameter packs. */
4775 {
4778 {
4779 /* This is a PARM_DECL that contains unexpanded parameter
4780 packs. We have already complained about this in the
4781 check_for_bare_parameter_packs call, so just replace
4782 these types with ERROR_MARK_NODE. */
4785 }
4789 }
4791 /* Check for bare parameter packs in the return type and the
4792 exception specifiers. */
4794 /* Errors were already issued, set return type to int
4795 as the frontend doesn't expect error_mark_node as
4796 the return type. */
4800 }
4805 {
4808 }
4821 {
4826 /* If DECL is a TYPE_DECL for a class-template, then there won't
4827 be DECL_LANG_SPECIFIC. The information equivalent to
4828 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4832 {
4833 /* Since a template declaration already existed for this
4834 class-type, we must be redeclaring it here. Make sure
4835 that the redeclaration is valid. */
4837 current_template_parms);
4838 /* We don't need to create a new TEMPLATE_DECL; just use the
4839 one we already had. */
4841 }
4842 else
4843 {
4845 member_template_p);
4850 {
4851 /* A specialization of a member template of a template
4852 class. */
4856 }
4857 }
4858 }
4859 else
4860 {
4866 {
4869 }
4877 {
4878 tree new_tmpl;
4880 /* The declaration is a specialization of a member
4881 template, declared outside the class. Therefore, the
4882 innermost template arguments will be NULL, so we
4883 replace them with the arguments determined by the
4884 earlier call to check_explicit_specialization. */
4887 new_tmpl
4889 member_template_p);
4899 args,
4902 }
4904 /* Make sure the template headers we got make sense. */
4909 {
4914 }
4915 else
4917 {
4922 {
4926 else
4930 /* Avoid crash in import_export_decl. */
4933 }
4938 /* Can happen in erroneous input. */
4940 else
4942 }
4944 /* Check that the parms are used in the appropriate qualifying scopes
4945 in the declarator. */
4949 {
4955 /* Avoid crash in import_export_decl. */
4958 }
4959 }
4964 /* Push template declarations for global functions and types. Note
4965 that we do not try to push a global template friend declared in a
4966 template class; such a thing may well depend on the template
4967 parameters of the class. */
4970 {
4975 /* Hide template friend classes that haven't been declared yet. */
4977 {
4980 }
4981 }
4984 {
4990 {
4993 /* It is a conversion operator. See if the type converted to
4994 depends on innermost template operands. */
4997 depth))
4999 }
5001 /* Give template template parms a DECL_CONTEXT of the template
5002 for which they are a parameter. */
5005 {
5009 }
5010 }
5012 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5013 back to its most general template. If TMPL is a specialization,
5014 ARGS may only have the innermost set of arguments. Add the missing
5015 argument levels if necessary. */
5023 else
5024 {
5029 }
5032 }
5034 tree
5036 {
5038 }
5040 /* FN is an inheriting constructor that inherits from the constructor
5041 template INHERITED; turn FN into a constructor template with a matching
5042 template header. */
5044 tree
5046 {
5047 tree inner_parms
5050 tree parms
5061 }
5063 /* Called when a class template TYPE is redeclared with the indicated
5064 template PARMS, e.g.:
5066 template <class T> struct S;
5067 template <class T> struct S {}; */
5069 bool
5071 {
5072 tree tmpl;
5073 tree tmpl_parms;
5077 {
5080 }
5084 /* The type is nested in some template class. Nothing to worry
5085 about here; there are no new template parameters for the nested
5086 type. */
5090 {
5092 tmpl);
5094 }
5100 {
5110 }
5113 {
5114 tree tmpl_parm;
5115 tree parm;
5116 tree tmpl_default;
5117 tree parm_default;
5131 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5132 TEMPLATE_DECL. */
5142 {
5146 }
5149 {
5150 /* We have in [temp.param]:
5152 A template-parameter may not be given default arguments
5153 by two different declarations in the same scope. */
5158 }
5161 /* Update the previous template parameters (which are the ones
5162 that will really count) with the new default value. */
5165 /* Update the new parameters, too; they'll be used as the
5166 parameters for any members. */
5168 }
5171 }
5173 /* Simplify EXPR if it is a non-dependent expression. Returns the
5174 (possibly simplified) expression. */
5176 tree
5178 {
5182 /* If we're in a template, but EXPR isn't value dependent, simplify
5183 it. We're supposed to treat:
5185 template <typename T> void f(T[1 + 1]);
5186 template <typename T> void f(T[2]);
5188 as two declarations of the same function, for example. */
5192 {
5193 HOST_WIDE_INT saved_processing_template_decl;
5199 complain,
5204 }
5206 }
5208 tree
5210 {
5212 }
5214 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5215 template declaration, or a TYPE_DECL for an alias declaration. */
5217 bool
5219 {
5227 }
5229 /* Return TRUE iff is a specialization of an alias template. */
5231 bool
5233 {
5241 }
5243 /* Return the number of innermost template parameters in TMPL. */
5245 static int
5247 {
5250 }
5252 /* Return either TMPL or another template that it is equivalent to under DR
5253 1286: An alias that just changes the name of a template is equivalent to
5254 the other template. */
5256 static tree
5258 {
5261 {
5264 {
5269 {
5270 tree alias_args = INNERMOST_TEMPLATE_ARGS
5274 /* The alias type is equivalent to the pattern of the
5275 underlying template, so strip the alias. */
5278 }
5279 }
5281 }
5283 }
5285 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5286 must be a function or a pointer-to-function type, as specified
5287 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5288 and check that the resulting function has external linkage. */
5290 static tree
5292 {
5295 linkage_kind linkage;
5307 /* [temp.arg.nontype]/1
5309 A template-argument for a non-type, non-template template-parameter
5310 shall be one of:
5311 [...]
5312 -- the address of an object or function with external [C++11: or
5313 internal] linkage. */
5316 {
5320 else
5323 }
5327 {
5332 else
5337 }
5340 }
5342 /* Subroutine of convert_nontype_argument.
5343 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5344 Emit an error otherwise. */
5346 static bool
5348 tsubst_flags_t complain)
5349 {
5360 {
5364 }
5366 }
5368 /* Returns TRUE iff the address of OP is value-dependent.
5370 14.6.2.4 [temp.dep.temp]:
5371 A non-integral non-type template-argument is dependent if its type is
5372 dependent or it has either of the following forms
5373 qualified-id
5374 & qualified-id
5375 and contains a nested-name-specifier which specifies a class-name that
5376 names a dependent type.
5378 We generalize this to just say that the address of a member of a
5379 dependent class is value-dependent; the above doesn't cover the
5380 address of a static data member named with an unqualified-id. */
5382 static bool
5384 {
5385 /* We could use get_inner_reference here, but there's no need;
5386 this is only relevant for template non-type arguments, which
5387 can only be expressed as &id-expression. */
5389 {
5393 }
5396 }
5398 /* The next set of functions are used for providing helpful explanatory
5399 diagnostics for failed overload resolution. Their messages should be
5400 indented by two spaces for consistency with the messages in
5401 call.c */
5403 static int
5405 {
5407 }
5409 static int
5411 {
5416 }
5418 static int
5420 {
5422 }
5424 static int
5426 {
5432 }
5434 static int
5436 {
5440 }
5442 static int
5444 {
5447 " template parameter %qD is not a parameter pack, but "
5451 }
5453 static int
5455 {
5458 " template argument %qE does not match "
5462 }
5464 static int
5466 {
5470 }
5472 static int
5474 {
5480 }
5482 static int
5484 {
5486 {
5491 else
5493 " deduced conflicting values for non-type parameter "
5495 }
5497 }
5499 static int
5501 {
5504 " variable-sized array type %qT is not "
5506 arg);
5508 }
5510 static int
5512 {
5516 arg);
5518 }
5520 static int
5522 {
5529 }
5531 static int
5533 {
5535 }
5537 static int
5539 {
5541 }
5543 static int
5546 {
5552 }
5554 static int
5557 {
5560 {
5568 }
5570 }
5572 static int
5574 {
5577 " template parameters of a template template argument are "
5580 }
5582 static int
5584 {
5590 }
5592 static int
5594 {
5599 }
5601 static int
5603 {
5607 arg);
5609 }
5611 /* Attempt to convert the non-type template parameter EXPR to the
5612 indicated TYPE. If the conversion is successful, return the
5613 converted value. If the conversion is unsuccessful, return
5614 NULL_TREE if we issued an error message, or error_mark_node if we
5615 did not. We issue error messages for out-and-out bad template
5616 parameters, but not simply because the conversion failed, since we
5617 might be just trying to do argument deduction. Both TYPE and EXPR
5618 must be non-dependent.
5620 The conversion follows the special rules described in
5621 [temp.arg.nontype], and it is much more strict than an implicit
5622 conversion.
5624 This function is called twice for each template argument (see
5625 lookup_template_class for a more accurate description of this
5626 problem). This means that we need to handle expressions which
5627 are not valid in a C++ source, but can be created from the
5628 first call (for instance, casts to perform conversions). These
5629 hacks can go away after we fix the double coercion problem. */
5631 static tree
5633 {
5634 tree expr_type;
5636 /* Detect immediately string literals as invalid non-type argument.
5637 This special-case is not needed for correctness (we would easily
5638 catch this later), but only to provide better diagnostic for this
5639 common user mistake. As suggested by DR 100, we do not mention
5640 linkage issues in the diagnostic as this is not the point. */
5641 /* FIXME we're making this OK. */
5643 {
5649 }
5651 /* Add the ADDR_EXPR now for the benefit of
5652 value_dependent_expression_p. */
5655 {
5659 }
5661 /* If we are in a template, EXPR may be non-dependent, but still
5662 have a syntactic, rather than semantic, form. For example, EXPR
5663 might be a SCOPE_REF, rather than the VAR_DECL to which the
5664 SCOPE_REF refers. Preserving the qualifying scope is necessary
5665 so that access checking can be performed when the template is
5666 instantiated -- but here we need the resolved form so that we can
5667 convert the argument. */
5678 else
5681 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5682 to a non-type argument of "nullptr". */
5686 /* In C++11, integral or enumeration non-type template arguments can be
5687 arbitrary constant expressions. Pointer and pointer to
5688 member arguments can be general constant expressions that evaluate
5689 to a null value, but otherwise still need to be of a specific form. */
5691 {
5693 /* A PTRMEM_CST is already constant, and a valid template
5694 argument for a parameter of pointer to member type, we just want
5695 to leave it in that form rather than lower it to a
5700 {
5705 }
5706 }
5708 /* HACK: Due to double coercion, we can get a
5709 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5710 which is the tree that we built on the first call (see
5711 below when coercing to reference to object or to reference to
5712 function). We just strip everything and get to the arg.
5713 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5714 for examples. */
5716 {
5722 {
5723 /* ??? Maybe we could use convert_from_reference here, but we
5724 would need to relax its constraints because the NOP_EXPR
5725 could actually change the type to something more cv-qualified,
5726 and this is not folded by convert_from_reference. */
5731 && (same_type_ignoring_top_level_qualifiers_p
5734 {
5737 }
5738 }
5739 }
5741 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5742 parameter is a pointer to object, through decay and
5743 qualification conversion. Let's strip everything. */
5745 {
5750 {
5751 /* Skip the ADDR_EXPR only if it is part of the decay for
5752 an array. Otherwise, it is part of the original argument
5753 in the source code. */
5758 }
5759 }
5761 /* [temp.arg.nontype]/5, bullet 1
5763 For a non-type template-parameter of integral or enumeration type,
5764 integral promotions (_conv.prom_) and integral conversions
5765 (_conv.integral_) are applied. */
5767 {
5776 /* Notice that there are constant expressions like '4 % 0' which
5777 do not fold into integer constants. */
5779 {
5781 {
5792 /* else cxx_constant_value complained but gave us
5793 a real constant, so go ahead. */
5795 }
5796 else
5798 }
5800 /* Avoid typedef problems. */
5803 }
5804 /* [temp.arg.nontype]/5, bullet 2
5806 For a non-type template-parameter of type pointer to object,
5807 qualification conversions (_conv.qual_) and the array-to-pointer
5808 conversion (_conv.array_) are applied. */
5810 {
5811 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5813 A template-argument for a non-type, non-template template-parameter
5814 shall be one of: [...]
5816 -- the name of a non-type template-parameter;
5817 -- the address of an object or function with external linkage, [...]
5818 expressed as "& id-expression" where the & is optional if the name
5819 refers to a function or array, or if the corresponding
5820 template-parameter is a reference.
5822 Here, we do not care about functions, as they are invalid anyway
5823 for a parameter of type pointer-to-object. */
5826 /* Non-type template parameters are OK. */
5827 ;
5832 {
5834 {
5837 "because %qD is a variable, not the address of "
5840 }
5842 {
5848 }
5849 /* Other values, like integer constants, might be valid
5850 non-type arguments of some other type. */
5852 }
5853 else
5854 {
5855 tree decl;
5860 {
5865 }
5867 {
5873 }
5875 {
5880 }
5881 }
5890 }
5891 /* [temp.arg.nontype]/5, bullet 3
5893 For a non-type template-parameter of type reference to object, no
5894 conversions apply. The type referred to by the reference may be more
5895 cv-qualified than the (otherwise identical) type of the
5896 template-argument. The template-parameter is bound directly to the
5897 template-argument, which must be an lvalue. */
5899 {
5901 expr_type))
5905 {
5910 }
5913 {
5918 }
5920 /* [temp.arg.nontype]/1
5922 A template-argument for a non-type, non-template template-parameter
5923 shall be one of: [...]
5925 -- the address of an object or function with external linkage. */
5928 {
5931 {
5934 "because a reference variable does not have a constant "
5937 }
5938 }
5941 {
5947 }
5950 {
5956 }
5959 }
5960 /* [temp.arg.nontype]/5, bullet 4
5962 For a non-type template-parameter of type pointer to function, only
5963 the function-to-pointer conversion (_conv.func_) is applied. If the
5964 template-argument represents a set of overloaded functions (or a
5965 pointer to such), the matching function is selected from the set
5966 (_over.over_). */
5968 {
5969 /* If the argument is a template-id, we might not have enough
5970 context information to decay the pointer. */
5972 {
5976 }
5979 /* Null pointer values are OK in C++11. */
5985 }
5986 /* [temp.arg.nontype]/5, bullet 5
5988 For a non-type template-parameter of type reference to function, no
5989 conversions apply. If the template-argument represents a set of
5990 overloaded functions, the matching function is selected from the set
5991 (_over.over_). */
5993 {
5995 {
5997 {
6002 }
6004 }
6011 }
6012 /* [temp.arg.nontype]/5, bullet 6
6014 For a non-type template-parameter of type pointer to member function,
6015 no conversions apply. If the template-argument represents a set of
6016 overloaded member functions, the matching member function is selected
6017 from the set (_over.over_). */
6019 {
6024 /* [temp.arg.nontype] bullet 1 says the pointer to member
6025 expression must be a pointer-to-member constant. */
6029 /* There is no way to disable standard conversions in
6030 resolve_address_of_overloaded_function (called by
6031 instantiate_type). It is possible that the call succeeded by
6032 converting &B::I to &D::I (where B is a base of D), so we need
6033 to reject this conversion here.
6035 Actually, even if there was a way to disable standard conversions,
6036 it would still be better to reject them here so that we can
6037 provide a superior diagnostic. */
6039 {
6041 {
6045 /* If we are just one standard conversion off, explain. */
6049 }
6051 }
6052 }
6053 /* [temp.arg.nontype]/5, bullet 7
6055 For a non-type template-parameter of type pointer to data member,
6056 qualification conversions (_conv.qual_) are applied. */
6058 {
6059 /* [temp.arg.nontype] bullet 1 says the pointer to member
6060 expression must be a pointer-to-member constant. */
6067 }
6069 {
6071 {
6076 }
6078 }
6079 /* A template non-type parameter must be one of the above. */
6080 else
6083 /* Sanity check: did we actually convert the argument to the
6084 right type? */
6088 }
6090 /* Subroutine of coerce_template_template_parms, which returns 1 if
6091 PARM_PARM and ARG_PARM match using the rule for the template
6092 parameters of template template parameters. Both PARM and ARG are
6093 template parameters; the rest of the arguments are the same as for
6094 coerce_template_template_parms.
6095 */
6096 static int
6098 tree arg,
6099 tsubst_flags_t complain,
6100 tree in_decl,
6101 tree outer_args)
6102 {
6111 {
6113 /* We encounter instantiations of templates like
6114 template <template <template <class> class> class TT>
6115 class C; */
6116 {
6123 }
6124 /* Fall through. */
6129 /* Argument is a parameter pack but parameter is not. */
6134 /* The tsubst call is used to handle cases such as
6136 template <int> class C {};
6137 template <class T, template <T> class TT> class D {};
6138 D<int, C> d;
6140 i.e. the parameter list of TT depends on earlier parameters. */
6142 && !same_type_p
6149 /* Argument is a parameter pack but parameter is not. */
6156 }
6159 }
6162 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6163 template template parameters. Both PARM_PARMS and ARG_PARMS are
6164 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6165 or PARM_DECL.
6167 Consider the example:
6168 template <class T> class A;
6169 template<template <class U> class TT> class B;
6171 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6172 the parameters to A, and OUTER_ARGS contains A. */
6174 static int
6176 tree arg_parms,
6177 tsubst_flags_t complain,
6178 tree in_decl,
6179 tree outer_args)
6180 {
6191 /* Determine whether we have a parameter pack at the end of the
6192 template template parameter's template parameter list. */
6194 {
6201 {
6215 }
6216 }
6222 /* Check all of the template parameters except the parameter pack at
6223 the end (if any). */
6225 {
6234 outer_args))
6237 }
6240 {
6241 /* Check each of the template parameters in the template
6242 argument against the template parameter pack at the end of
6243 the template template parameter. */
6250 {
6257 outer_args))
6259 }
6260 }
6263 }
6265 /* Verifies that the deduced template arguments (in TARGS) for the
6266 template template parameters (in TPARMS) represent valid bindings,
6267 by comparing the template parameter list of each template argument
6268 to the template parameter list of its corresponding template
6269 template parameter, in accordance with DR150. This
6270 routine can only be called after all template arguments have been
6271 deduced. It will return TRUE if all of the template template
6272 parameter bindings are okay, FALSE otherwise. */
6273 bool
6275 {
6279 /* We're dealing with template parms in this process. */
6285 {
6290 {
6295 {
6296 /* Look inside the argument pack. */
6299 }
6302 {
6306 /* Extract the next argument from the argument
6307 pack. */
6311 /* Look at the pattern of the pack expansion. */
6314 /* Extract the template parameters from the template
6315 argument. */
6321 /* Verify that we can coerce the template template
6322 parameters from the template argument to the template
6323 parameter. This requires an exact match. */
6325 && !coerce_template_template_parms
6327 targ_parms,
6328 tf_none,
6329 tparm,
6330 targs))
6331 {
6334 }
6335 }
6336 }
6337 }
6339 out:
6343 }
6345 /* Since type attributes aren't mangled, we need to strip them from
6346 template type arguments. */
6348 static tree
6350 {
6351 tree mv;
6358 {
6363 }
6365 }
6367 /* Convert the indicated template ARG as necessary to match the
6368 indicated template PARM. Returns the converted ARG, or
6369 error_mark_node if the conversion was unsuccessful. Error and
6370 warning messages are issued under control of COMPLAIN. This
6371 conversion is for the Ith parameter in the parameter list. ARGS is
6372 the full set of template arguments deduced so far. */
6374 static tree
6376 tree arg,
6377 tree args,
6378 tsubst_flags_t complain,
6380 tree in_decl)
6381 {
6382 tree orig_arg;
6383 tree val;
6388 {
6389 /* The template argument was the name of some
6390 member function. That's usually
6391 invalid, but static members are OK. In any
6392 case, grab the underlying fields/functions
6393 and issue an error later if required. */
6396 }
6404 /* When determining whether an argument pack expansion is a template,
6405 look at the pattern. */
6409 /* Deal with an injected-class-name used as a template template arg. */
6411 {
6414 {
6424 }
6425 }
6427 is_tmpl_type =
6443 {
6445 {
6449 }
6452 "to refer to a type member of a template parameter, "
6457 typename_type,
6458 complain);
6461 }
6463 {
6465 {
6467 {
6477 else
6479 }
6480 }
6482 }
6484 {
6486 {
6492 else
6494 }
6496 }
6499 {
6501 {
6505 /* The number of argument required is not known yet.
6506 Just accept it for now. */
6508 else
6509 {
6511 tree argparm;
6513 /* Strip alias templates that are equivalent to another
6514 template. */
6520 args))
6521 {
6524 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6525 TEMPLATE_DECL. */
6527 {
6532 }
6533 }
6534 else
6535 {
6537 {
6543 }
6546 }
6547 }
6548 }
6549 else
6551 /* We only form one instance of each template specialization.
6552 Therefore, if we use a non-canonical variant (i.e., a
6553 typedef), any future messages referring to the type will use
6554 the typedef, which is confusing if those future uses do not
6555 themselves also use the typedef. */
6558 }
6559 else
6560 {
6567 {
6570 else
6571 {
6572 /* Not sure if this is reachable, but it doesn't hurt
6573 to be robust. */
6576 }
6577 }
6580 /* We used to call digest_init here. However, digest_init
6581 will report errors, which we don't want when complain
6582 is zero. More importantly, digest_init will try too
6583 hard to convert things: for example, `0' should not be
6584 converted to pointer type at this point according to
6585 the standard. Accepting this is not merely an
6586 extension, since deciding whether or not these
6587 conversions can occur is part of determining which
6588 function template to call, or whether a given explicit
6589 argument specification is valid. */
6591 else
6600 {
6601 /* Strip typedefs from the SCOPE_REF. */
6604 complain);
6607 }
6608 }
6611 }
6613 /* Coerces the remaining template arguments in INNER_ARGS (from
6614 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6615 Returns the coerced argument pack. PARM_IDX is the position of this
6616 parameter in the template parameter list. ARGS is the original
6617 template argument list. */
6618 static tree
6621 tree args,
6622 tree inner_args,
6624 tree new_args,
6626 tree in_decl,
6627 tsubst_flags_t complain)
6628 {
6631 tree packed_args;
6632 tree argument_pack;
6639 {
6640 /* When the template parameter is a non-type template parameter pack
6641 or template template parameter pack whose type or template
6642 parameters use parameter packs, we know exactly how many arguments
6643 we are looking for. Build a vector of the instantiated decls for
6644 these template parameters in PACKED_PARMS. */
6645 /* We can't use make_pack_expansion here because it would interpret a
6646 _DECL as a use rather than a declaration. */
6660 /* If we're doing a partial instantiation of a member template,
6661 verify that all of the types used for the non-type
6662 template parameter pack are, in fact, valid for non-type
6663 template parameters. */
6666 {
6669 {
6673 }
6674 /* We don't know how many args we have yet, just
6675 use the unconverted ones for now. */
6677 }
6680 }
6681 else
6684 /* Convert the remaining arguments, which will be a part of the
6685 parameter pack "parm". */
6687 {
6693 {
6694 /* Once we've packed as many args as we have types, stop. */
6698 /* We don't know how many args we have yet, just
6699 use the unconverted ones for now. */
6701 else
6703 }
6706 {
6709 }
6710 else
6713 in_decl);
6717 }
6721 {
6725 }
6730 else
6731 {
6736 }
6739 #ifdef ENABLE_CHECKING
6742 #endif
6744 }
6746 /* Returns the number of pack expansions in the template argument vector
6747 ARGS. */
6749 static int
6751 {
6756 {
6760 }
6762 }
6764 /* Convert all template arguments to their appropriate types, and
6765 return a vector containing the innermost resulting template
6766 arguments. If any error occurs, return error_mark_node. Error and
6767 warning messages are issued under control of COMPLAIN.
6769 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6770 for arguments not specified in ARGS. Otherwise, if
6771 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6772 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6773 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6774 ARGS. */
6776 static tree
6778 tree args,
6779 tree in_decl,
6780 tsubst_flags_t complain,
6783 {
6785 tree orig_inner_args;
6786 tree inner_args;
6787 tree new_args;
6788 tree new_inner_args;
6792 /* When used as a boolean value, indicates whether this is a
6793 variadic template parameter list. Since it's an int, we can also
6794 subtract it from nparms to get the number of non-variadic
6795 parameters. */
6805 /* Determine if there are any parameter packs. */
6807 {
6813 }
6816 /* If there are no parameters that follow a parameter pack, we need to
6817 expand any argument packs so that we can deduce a parameter pack from
6818 some non-packed args followed by an argument pack, as in variadic85.C.
6819 If there are such parameters, we need to leave argument packs intact
6820 so the arguments are assigned properly. This can happen when dealing
6821 with a nested class inside a partial specialization of a class
6822 template, as in variadic92.C, or when deducing a template parameter pack
6823 from a sub-declarator, as in variadic114.C. */
6827 /* Count any pack expansion args. */
6833 && require_all_args
6834 && !variadic_args_p
6835 && (!use_default_args
6838 {
6840 {
6842 {
6846 }
6847 else
6853 }
6856 }
6857 /* We can't pass a pack expansion to a non-pack parameter of an alias
6858 template (DR 1430). */
6860 && variadic_args_p
6862 {
6864 {
6866 {
6872 {
6877 }
6878 }
6880 found:;
6881 }
6883 }
6885 /* We need to evaluate the template arguments, even though this
6886 template-id may be nested within a "sizeof". */
6895 {
6896 tree arg;
6897 tree parm;
6899 /* Get the Ith template parameter. */
6903 {
6906 }
6908 /* Calculate the next argument. */
6911 else
6916 {
6917 /* Some arguments will be placed in the
6918 template parameter pack PARM. */
6925 {
6926 /* We don't know how many args we have yet, just use the
6927 unconverted (and still packed) ones for now. */
6931 }
6935 /* Store this argument. */
6937 {
6938 lost++;
6939 /* We are done with all of the arguments. */
6941 }
6942 else
6943 {
6946 }
6949 }
6951 {
6953 {
6954 /* "If every valid specialization of a variadic template
6955 requires an empty template parameter pack, the template is
6956 ill-formed, no diagnostic required." So check that the
6957 pattern works with this parameter. */
6962 in_decl);
6964 {
6968 }
6970 /* Recover from missing typename. */
6974 /* We don't know how many args we have yet, just
6975 use the unconverted ones for now. */
6979 }
6980 }
6982 {
6983 /* There must be a default arg in this case. */
6986 /* The position of the first default template argument,
6987 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6988 Record that. */
6992 }
6993 else
6997 {
7000 }
7002 /* This only occurs if there was an error in the template
7003 parameter list itself (which we would already have
7004 reported) that we are trying to recover from, e.g., a class
7005 template with a parameter list such as
7006 template<typename..., typename>. */
7008 else
7014 lost++;
7016 }
7021 {
7023 {
7028 }
7030 }
7035 #ifdef ENABLE_CHECKING
7039 #endif
7042 }
7044 /* Like coerce_template_parms. If PARMS represents all template
7045 parameters levels, this function returns a vector of vectors
7046 representing all the resulting argument levels. Note that in this
7047 case, only the innermost arguments are coerced because the
7048 outermost ones are supposed to have been coerced already.
7050 Otherwise, if PARMS represents only (the innermost) vector of
7051 parameters, this function returns a vector containing just the
7052 innermost resulting arguments. */
7054 static tree
7056 tree args,
7057 tree in_decl,
7058 tsubst_flags_t complain,
7061 {
7064 tree coerced_args;
7067 {
7069 tree level;
7075 {
7076 tree l;
7080 require_all_args,
7081 use_default_args);
7082 else
7089 }
7090 }
7091 else
7094 require_all_args,
7095 use_default_args);
7097 }
7099 /* Returns 1 if template args OT and NT are equivalent. */
7101 static int
7103 {
7110 /* For member templates */
7119 {
7136 }
7138 {
7139 /* We get here probably because we are in the middle of substituting
7140 into the pattern of a pack expansion. In that case the
7141 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7142 interested in. So we want to use the initial pack argument for
7143 the comparison. */
7148 }
7153 else
7155 }
7157 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7158 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7159 NEWARG_PTR with the offending arguments if they are non-NULL. */
7161 static int
7164 {
7177 {
7182 {
7188 }
7189 }
7191 }
7193 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7194 of template arguments. Returns 0 otherwise. */
7196 int
7198 {
7200 }
7202 static void
7204 {
7214 /* We are called both from instantiate_decl, where we've already had a
7215 tinst_level pushed, and instantiate_template, where we haven't.
7216 Compensate. */
7227 else
7236 }
7239 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7240 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7241 documentation for TEMPLATE_ID_EXPR. */
7243 tree
7245 {
7246 tree type;
7254 {
7257 }
7260 {
7262 unknown_type_node,
7264 arglist);
7266 }
7273 }
7275 /* Within the scope of a template class S<T>, the name S gets bound
7276 (in build_self_reference) to a TYPE_DECL for the class, not a
7277 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7278 or one of its enclosing classes, and that type is a template,
7279 return the associated TEMPLATE_DECL. Otherwise, the original
7280 DECL is returned.
7282 Also handle the case when DECL is a TREE_LIST of ambiguous
7283 injected-class-names from different bases. */
7285 tree
7287 {
7291 /* DR 176: A lookup that finds an injected-class-name (10.2
7292 [class.member.lookup]) can result in an ambiguity in certain cases
7293 (for example, if it is found in more than one base class). If all of
7294 the injected-class-names that are found refer to specializations of
7295 the same class template, and if the name is followed by a
7296 template-argument-list, the reference refers to the class template
7297 itself and not a specialization thereof, and is not ambiguous. */
7299 {
7302 {
7308 }
7311 else
7313 }
7319 }
7321 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7322 parameters, find the desired type.
7324 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7326 IN_DECL, if non-NULL, is the template declaration we are trying to
7327 instantiate.
7329 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7330 the class we are looking up.
7332 Issue error and warning messages under control of COMPLAIN.
7334 If the template class is really a local class in a template
7335 function, then the FUNCTION_CONTEXT is the function in which it is
7336 being instantiated.
7338 ??? Note that this function is currently called *twice* for each
7339 template-id: the first time from the parser, while creating the
7340 incomplete type (finish_template_type), and the second type during the
7341 real instantiation (instantiate_template_class). This is surely something
7342 that we want to avoid. It also causes some problems with argument
7343 coercion (see convert_nontype_argument for more information on this). */
7345 static tree
7348 {
7350 tree t;
7353 spec_entry elt;
7354 hashval_t hash;
7357 {
7361 else
7362 {
7369 }
7372 }
7374 {
7377 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7378 an implicit typename for the second A. Deal with it. */
7383 {
7386 }
7387 }
7390 {
7393 }
7397 {
7401 }
7403 {
7406 }
7408 /* Issue an error message if we didn't find a template. */
7410 {
7414 }
7417 /* Make sure it's a user visible template, if it was named by
7418 the user. */
7421 {
7423 {
7427 }
7429 }
7433 /* An alias that just changes the name of a template is equivalent to the
7434 other template, so if any of the arguments are pack expansions, strip
7435 the alias to avoid problems with a pack expansion passed to a non-pack
7436 alias template parameter (DR 1430). */
7441 {
7442 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7443 template arguments */
7445 tree parm;
7446 tree arglist2;
7447 tree outer;
7451 /* Consider an example where a template template parameter declared as
7453 template <class T, class U = std::allocator<T> > class TT
7455 The template parameter level of T and U are one level larger than
7456 of TT. To proper process the default argument of U, say when an
7457 instantiation `TT<int>' is seen, we need to build the full
7458 arguments containing {int} as the innermost level. Outer levels,
7459 available when not appearing as default template argument, can be
7460 obtained from the arguments of the enclosing template.
7462 Suppose that TT is later substituted with std::vector. The above
7463 instantiation is `TT<int, std::allocator<T> >' with TT at
7464 level 1, and T at level 2, while the template arguments at level 1
7465 becomes {std::vector} and the inner level 2 is {int}. */
7471 /* This is an argument of the current template, so we haven't set
7472 DECL_CONTEXT yet. */
7479 complain,
7489 }
7490 else
7491 {
7493 tree gen_tmpl;
7494 tree type_decl;
7502 /* An error occurred while building the template TEMPL, and a
7503 diagnostic has most certainly been emitted for that
7504 already. Let's propagate that error. */
7513 {
7514 /* We've been given an incomplete set of template arguments.
7515 For example, given:
7517 template <class T> struct S1 {
7518 template <class U> struct S2 {};
7519 template <class U> struct S2<U*> {};
7520 };
7522 we will be called with an ARGLIST of `U*', but the
7523 TEMPLATE will be `template <class T> template
7524 <class U> struct S1<T>::S2'. We must fill in the missing
7525 arguments. */
7526 arglist
7528 arglist);
7530 }
7532 /* Now we should have enough arguments. */
7535 /* From here on, we're only interested in the most general
7536 template. */
7538 /* Calculate the BOUND_ARGS. These will be the args that are
7539 actually tsubst'd into the definition to create the
7540 instantiation. */
7542 {
7543 /* We have multiple levels of arguments to coerce, at once. */
7553 {
7554 tree a;
7558 complain,
7561 else
7562 /* Outer levels should have already been coerced. */
7565 /* Don't process further if one of the levels fails. */
7567 {
7568 /* Restore the ARGLIST to its full size. */
7571 }
7575 /* We temporarily reduce the length of the ARGLIST so
7576 that coerce_template_parms will see only the arguments
7577 corresponding to the template parameters it is
7578 examining. */
7580 }
7582 /* Restore the ARGLIST to its full size. */
7586 }
7587 else
7588 arglist
7591 gen_tmpl,
7592 complain,
7597 /* We were unable to bind the arguments. */
7600 /* In the scope of a template class, explicit references to the
7601 template class refer to the type of the template, not any
7602 instantiation of it. For example, in:
7604 template <class T> class C { void f(C<T>); }
7606 the `C<T>' is just the same as `C'. Outside of the
7607 class, however, such a reference is an instantiation. */
7611 /* comp_template_args is expensive, check it last. */
7613 arglist))
7616 /* If we already have this specialization, return it. */
7628 /* If the deduced arguments are invalid, then the binding
7629 failed. */
7633 complain))
7640 {
7645 }
7655 /* Create the type. */
7657 {
7658 /* The user referred to a specialization of an alias
7659 template represented by GEN_TMPL.
7661 [temp.alias]/2 says:
7663 When a template-id refers to the specialization of an
7664 alias template, it is equivalent to the associated
7665 type obtained by substitution of its
7666 template-arguments for the template-parameters in the
7667 type-id of the alias template. */
7670 /* Note that the call above (by indirectly calling
7671 register_specialization in tsubst_decl) registers the
7672 TYPE_DECL representing the specialization of the alias
7673 template. So next time someone substitutes ARGLIST for
7674 the template parms into the alias template (GEN_TMPL),
7675 she'll get that TYPE_DECL back. */
7679 }
7681 {
7683 {
7692 }
7693 else
7694 {
7695 /* We don't want to call start_enum for this type, since
7696 the values for the enumeration constants may involve
7697 template parameters. And, no one should be interested
7698 in the enumeration constants for such a type. */
7701 }
7705 }
7707 {
7714 /* A local class. Make sure the decl gets registered properly. */
7719 /* This instantiation is another name for the primary
7720 template type. Set the TYPE_CANONICAL field
7721 appropriately. */
7724 /* Some of the template arguments require structural
7725 equality testing, so this template class requires
7726 structural equality testing. */
7728 }
7729 else
7732 /* If we called start_enum or pushtag above, this information
7733 will already be set up. */
7735 {
7742 }
7743 else
7747 {
7753 {
7756 }
7757 }
7759 /* Let's consider the explicit specialization of a member
7760 of a class template specialization that is implicitly instantiated,
7761 e.g.:
7762 template<class T>
7763 struct S
7764 {
7765 template<class U> struct M {}; //#0
7766 };
7768 template<>
7769 template<>
7770 struct S<int>::M<char> //#1
7771 {
7772 int i;
7773 };
7774 [temp.expl.spec]/4 says this is valid.
7776 In this case, when we write:
7777 S<int>::M<char> m;
7779 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7780 the one of #0.
7782 When we encounter #1, we want to store the partial instantiation
7783 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7785 For all cases other than this "explicit specialization of member of a
7786 class template", we just want to store the most general template into
7787 the CLASSTYPE_TI_TEMPLATE of M.
7789 This case of "explicit specialization of member of a class template"
7790 only happens when:
7791 1/ the enclosing class is an instantiation of, and therefore not
7792 the same as, the context of the most general template, and
7793 2/ we aren't looking at the partial instantiation itself, i.e.
7794 the innermost arguments are not the same as the innermost parms of
7795 the most general template.
7797 So it's only when 1/ and 2/ happens that we want to use the partial
7798 instantiation of the member template in lieu of its most general
7799 template. */
7803 /* the enclosing class must be an instantiation... */
7806 {
7807 tree partial_inst_args;
7810 partial_inst_args =
7816 use_partial_inst_tmpl =
7817 /*...and we must not be looking at the partial instantiation
7818 itself. */
7820 partial_inst_args);
7821 }
7824 /* This case is easy; there are no member templates involved. */
7826 else
7827 {
7828 /* This is a full instantiation of a member template. Find
7829 the partial instantiation of which this is an instance. */
7831 /* Temporarily reduce by one the number of levels in the ARGLIST
7832 so as to avoid comparing the last set of arguments. */
7836 /* FOUND is either a proper class type, or an alias
7837 template specialization. In the later case, it's a
7838 TYPE_DECL, resulting from the substituting of arguments
7839 for parameters in the TYPE_DECL of the alias template
7840 done earlier. So be careful while getting the template
7841 of FOUND. */
7845 }
7856 /* Note this use of the partial instantiation so we can check it
7857 later in maybe_process_partial_specialization. */
7864 /* Now that the type has been registered on the instantiations
7865 list, we set up the enumerators. Because the enumeration
7866 constants may involve the enumeration type itself, we make
7867 sure to register the type first, and then create the
7868 constants. That way, doing tsubst_expr for the enumeration
7869 constants won't result in recursive calls here; we'll find
7870 the instantiation and exit above. */
7874 /* If the type makes use of template parameters, the
7875 code that generates debugging information will crash. */
7878 /* Possibly limit visibility based on template args. */
7883 }
7884 }
7886 /* Wrapper for lookup_template_class_1. */
7888 tree
7891 {
7892 tree ret;
7898 }
7899 \f
7900 struct pair_fn_data
7901 {
7902 tree_fn_t fn;
7904 /* True when we should also visit template parameters that occur in
7905 non-deduced contexts. */
7908 };
7910 /* Called from for_each_template_parm via walk_tree. */
7912 static tree
7914 {
7927 {
7931 /* Fall through. */
7954 /* Since we're not going to walk subtrees, we have to do this
7955 explicitly here. */
7959 /* Fall through. */
7962 /* Check the return type. */
7967 /* Check the parameter types. Since default arguments are not
7968 instantiated until they are needed, the TYPE_ARG_TYPES may
7969 contain expressions that involve template parameters. But,
7970 no-one should be looking at them yet. And, once they're
7971 instantiated, they don't contain template parameters, so
7972 there's no point in looking at them then, either. */
7973 {
7974 tree parm;
7981 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7982 want walk_tree walking into them itself. */
7984 }
8002 /* Fall through. */
8018 /* Record template parameters such as `T' inside `TT<T>'. */
8022 /* Fall through. */
8034 /* A template template parameter is encountered. */
8040 /* Already substituted template template parameter */
8063 /* If there's no type, then this thing must be some expression
8064 involving template parameters. */
8086 }
8088 /* We didn't find any template parameters we liked. */
8090 }
8092 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8093 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8094 call FN with the parameter and the DATA.
8095 If FN returns nonzero, the iteration is terminated, and
8096 for_each_template_parm returns 1. Otherwise, the iteration
8097 continues. If FN never returns a nonzero value, the value
8098 returned by for_each_template_parm is 0. If FN is NULL, it is
8099 considered to be the function which always returns 1.
8101 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8102 parameters that occur in non-deduced contexts. When false, only
8103 visits those template parameters that can be deduced. */
8105 static int
8109 {
8113 /* Set up. */
8118 /* Walk the tree. (Conceptually, we would like to walk without
8119 duplicates, but for_each_template_parm_r recursively calls
8120 for_each_template_parm, so we would need to reorganize a fair
8121 bit to use walk_tree_without_duplicates, so we keep our own
8122 visited list.) */
8125 else
8128 for_each_template_parm_r,
8132 /* Clean up. */
8134 {
8137 }
8140 }
8142 /* Returns true if T depends on any template parameter. */
8144 int
8146 {
8173 else
8174 {
8177 }
8182 }
8184 /* Returns true iff current_function_decl is an incompletely instantiated
8185 template. Useful instead of processing_template_decl because the latter
8186 is set to 0 during fold_non_dependent_expr. */
8188 bool
8190 {
8199 }
8201 /* Returns true if T depends on any template parameter with level LEVEL. */
8203 int
8205 {
8208 }
8210 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8211 ill-formed translation unit, i.e. a variable or function that isn't
8212 usable in a constant expression. */
8216 {
8220 }
8222 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8223 neglectable and instantiated from within an erroneous instantiation. */
8225 static bool
8227 {
8238 }
8246 /* We're starting to instantiate D; record the template instantiation context
8247 for diagnostics and to restore it later. */
8249 int
8251 {
8255 {
8261 else
8269 }
8271 /* If the current instantiation caused problems, don't let it instantiate
8272 anything else. Do allow deduction substitution and decls usable in
8273 constant expressions. */
8290 }
8292 /* We're done instantiating this template; return to the instantiation
8293 context. */
8295 void
8297 {
8298 /* Restore the filename and line number stashed away when we started
8299 this instantiation. */
8303 }
8305 /* We're instantiating a deferred template; restore the template
8306 instantiation context in which the instantiation was requested, which
8307 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8309 static tree
8311 {
8323 }
8325 /* Returns the TINST_LEVEL which gives the original instantiation
8326 context. */
8330 {
8336 }
8338 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8339 vector of template arguments, as for tsubst.
8341 Returns an appropriate tsubst'd friend declaration. */
8343 static tree
8345 {
8346 tree new_friend;
8351 /* This was a friend declared with an explicit template
8352 argument list, e.g.:
8354 friend void f<>(T);
8356 to indicate that f was a template instantiation, not a new
8357 function declaration. Now, we have to figure out what
8358 instantiation of what template. */
8359 {
8361 tree new_args;
8362 tree tmpl;
8365 /* Friend functions are looked up in the containing namespace scope.
8366 We must enter that scope, to avoid finding member functions of the
8367 current class with same name. */
8382 tsk_none);
8384 }
8388 /* The NEW_FRIEND will look like an instantiation, to the
8389 compiler, but is not an instantiation from the point of view of
8390 the language. For example, we might have had:
8392 template <class T> struct S {
8393 template <class U> friend void f(T, U);
8394 };
8396 Then, in S<int>, template <class U> void f(int, U) is not an
8397 instantiation of anything. */
8403 {
8407 }
8409 /* The mangled name for the NEW_FRIEND is incorrect. The function
8410 is not a template instantiation and should not be mangled like
8411 one. Therefore, we forget the mangling here; we'll recompute it
8412 later if we need it. */
8414 {
8417 }
8420 {
8421 tree old_decl;
8422 tree new_friend_template_info;
8423 tree new_friend_result_template_info;
8424 tree ns;
8427 /* We must save some information from NEW_FRIEND before calling
8428 duplicate decls since that function will free NEW_FRIEND if
8429 possible. */
8431 new_friend_is_defn =
8436 {
8437 /* This declaration is a `primary' template. */
8440 new_friend_result_template_info
8442 }
8443 else
8446 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8450 /* Inside pushdecl_namespace_level, we will push into the
8451 current namespace. However, the friend function should go
8452 into the namespace of the template. */
8462 {
8463 /* This new friend declaration matched an existing
8464 declaration. For example, given:
8466 template <class T> void f(T);
8467 template <class U> class C {
8468 template <class T> friend void f(T) {}
8469 };
8471 the friend declaration actually provides the definition
8472 of `f', once C has been instantiated for some type. So,
8473 old_decl will be the out-of-class template declaration,
8474 while new_friend is the in-class definition.
8476 But, if `f' was called before this point, the
8477 instantiation of `f' will have DECL_TI_ARGS corresponding
8478 to `T' but not to `U', references to which might appear
8479 in the definition of `f'. Previously, the most general
8480 template for an instantiation of `f' was the out-of-class
8481 version; now it is the in-class version. Therefore, we
8482 run through all specialization of `f', adding to their
8483 DECL_TI_ARGS appropriately. In particular, they need a
8484 new set of outer arguments, corresponding to the
8485 arguments for this class instantiation.
8487 The same situation can arise with something like this:
8489 friend void f(int);
8490 template <class T> class C {
8491 friend void f(T) {}
8492 };
8494 when `C<int>' is instantiated. Now, `f(int)' is defined
8495 in the class. */
8498 /* On the other hand, if the in-class declaration does
8499 *not* provide a definition, then we don't want to alter
8500 existing definitions. We can just leave everything
8501 alone. */
8502 ;
8503 else
8504 {
8508 /* Overwrite whatever template info was there before, if
8509 any, with the new template information pertaining to
8510 the declaration. */
8514 {
8515 /* We should have called reregister_specialization in
8516 duplicate_decls. */
8521 /* Instantiate it if the global has already been used. */
8525 }
8526 else
8527 {
8528 tree t;
8530 /* Indicate that the old function template is a partial
8531 instantiation. */
8539 /* Reassign any specializations already in the hash table
8540 to the new more general template, and add the
8541 additional template args. */
8545 {
8547 spec_entry elt;
8559 register_specialization
8562 }
8564 }
8565 }
8567 /* The information from NEW_FRIEND has been merged into OLD_DECL
8568 by duplicate_decls. */
8570 }
8571 }
8572 else
8573 {
8577 /* In the code
8578 template <class T> class C {
8579 template <class U> friend void C1<U>::f (); // case 1
8580 friend void C2<T>::f (); // case 2
8581 };
8582 we only need to make sure CONTEXT is a complete type for
8583 case 2. To distinguish between the two cases, we note that
8584 CONTEXT of case 1 remains dependent type after tsubst while
8585 this isn't true for case 2. */
8595 {
8597 /* do_friend adds the TEMPLATE_DECL for any member friend
8598 template even if it isn't a member template, i.e.
8599 template <class T> friend A<T>::f();
8600 Look through it in that case. */
8604 /* Check to see that the declaration is really present, and,
8605 possibly obtain an improved declaration. */
8610 }
8611 }
8614 }
8616 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8617 template arguments, as for tsubst.
8619 Returns an appropriate tsubst'd friend type or error_mark_node on
8620 failure. */
8622 static tree
8624 {
8625 tree friend_type;
8626 tree tmpl;
8627 tree context;
8630 {
8633 }
8638 {
8641 else
8643 }
8645 /* Look for a class template declaration. We look for hidden names
8646 because two friend declarations of the same template are the
8647 same. For example, in:
8649 struct A {
8650 template <typename> friend class F;
8651 };
8652 template <typename> struct B {
8653 template <typename> friend class F;
8654 };
8656 both F templates are the same. */
8660 /* But, if we don't find one, it might be because we're in a
8661 situation like this:
8663 template <class T>
8664 struct S {
8665 template <class U>
8666 friend struct S;
8667 };
8669 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8670 for `S<int>', not the TEMPLATE_DECL. */
8672 {
8675 }
8678 {
8679 /* The friend template has already been declared. Just
8680 check to see that the declarations match, and install any new
8681 default parameters. We must tsubst the default parameters,
8682 of course. We only need the innermost template parameters
8683 because that is all that redeclare_class_template will look
8684 at. */
8687 {
8688 tree parms;
8689 location_t saved_input_location;
8698 }
8701 }
8702 else
8703 {
8704 /* The friend template has not already been declared. In this
8705 case, the instantiation of the template class will cause the
8706 injection of this template into the global scope. */
8711 /* The new TMPL is not an instantiation of anything, so we
8712 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8713 the new type because that is supposed to be the corresponding
8714 template decl, i.e., TMPL. */
8721 /* Inject this template into the global scope. */
8723 }
8726 {
8729 else
8731 }
8734 }
8736 /* Returns zero if TYPE cannot be completed later due to circularity.
8737 Otherwise returns one. */
8739 static int
8741 {
8751 else
8753 }
8757 /* Apply any attributes which had to be deferred until instantiation
8758 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8759 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8761 static void
8764 {
8766 tree t;
8771 {
8775 }
8778 {
8782 }
8783 else
8787 {
8792 {
8795 {
8802 {
8809 clauses
8813 else
8815 }
8816 /* If the first attribute argument is an identifier, don't
8817 pass it through tsubst. Attributes like mode, format,
8818 cleanup and several target specific attributes expect it
8819 unmodified. */
8822 {
8823 tree chain
8825 in_decl,
8830 chain);
8831 }
8832 else
8838 }
8839 else
8841 }
8844 }
8845 }
8847 /* Perform (or defer) access check for typedefs that were referenced
8848 from within the template TMPL code.
8849 This is a subroutine of instantiate_decl and instantiate_class_template.
8850 TMPL is the template to consider and TARGS is the list of arguments of
8851 that template. */
8853 static void
8855 {
8856 location_t saved_location;
8867 {
8879 /* Make access check error messages point to the location
8880 of the use of the typedef. */
8884 tf_warning_or_error);
8885 }
8887 }
8889 static tree
8891 {
8893 tree typedecl;
8894 tree pbinfo;
8895 tree base_list;
8897 tree fn_context;
8906 /* Figure out which template is being instantiated. */
8910 /* Determine what specialization of the original template to
8911 instantiate. */
8914 {
8917 }
8919 {
8920 /* This TYPE is actually an instantiation of a partial
8921 specialization. We replace the innermost set of ARGS with
8922 the arguments appropriate for substitution. For example,
8923 given:
8925 template <class T> struct S {};
8926 template <class T> struct S<T*> {};
8928 and supposing that we are instantiating S<int*>, ARGS will
8929 presently be {int*} -- but we need {int}. */
8932 }
8933 else
8934 {
8937 }
8939 /* If the template we're instantiating is incomplete, then clearly
8940 there's nothing we can do. */
8944 /* If we've recursively instantiated too many templates, stop. */
8948 /* Now we're really doing the instantiation. Mark the type as in
8949 the process of being defined. */
8952 /* We may be in the middle of deferred access check. Disable
8953 it now. */
8959 /* Use #pragma pack from the template context. */
8965 /* Set the input location to the most specialized template definition.
8966 This is needed if tsubsting causes an error. */
8978 {
8981 /* Adjust visibility for template arguments. */
8983 }
8989 /* We should never instantiate a nested class before its enclosing
8990 class; we need to look up the nested class by name before we can
8991 instantiate it, and that lookup should instantiate the enclosing
8992 class. */
8998 {
8999 tree pbase_binfo;
9000 tree pushed_scope;
9003 /* We must enter the scope containing the type, as that is where
9004 the accessibility of types named in dependent bases are
9005 looked up from. */
9008 /* Substitute into each of the bases to determine the actual
9009 basetypes. */
9011 {
9012 tree base;
9018 {
9019 expanded_bases =
9026 }
9029 {
9031 /* Extract the already-expanded base class. */
9033 else
9034 /* Substitute to figure out the base class. */
9036 NULL_TREE);
9044 }
9045 }
9047 /* The list is now in reverse order; correct that. */
9052 }
9053 /* Now call xref_basetypes to set up all the base-class
9054 information. */
9062 /* Now that our base classes are set up, enter the scope of the
9063 class, so that name lookups into base classes, etc. will work
9064 correctly. This is precisely analogous to what we do in
9065 begin_class_definition when defining an ordinary non-template
9066 class, except we also need to push the enclosing classes. */
9069 /* Now members are processed in the order of declaration. */
9072 {
9076 {
9078 {
9079 /* Build new CLASSTYPE_NESTED_UTDS. */
9081 tree newtag;
9087 /* If the member is a class template, then -- even after
9088 substitution -- there may be dependent types in the
9089 template argument list for the class. We increment
9090 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9091 that function will assume that no types are dependent
9092 when outside of a template. */
9102 {
9106 /* Unfortunately, lookup_template_class sets
9107 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9108 instantiation (i.e., for the type of a member
9109 template class nested within a template class.)
9110 This behavior is required for
9111 maybe_process_partial_specialization to work
9112 correctly, but is not accurate in this case;
9113 the TAG is not an instantiation of anything.
9114 (The corresponding TEMPLATE_DECL is an
9115 instantiation, but the TYPE is not.) */
9118 /* Now, we call pushtag to put this NEWTAG into the scope of
9119 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9120 pushtag calling push_template_decl. We don't have to do
9121 this for enums because it will already have been done in
9122 tsubst_enum. */
9126 }
9127 }
9129 {
9130 /* Build new TYPE_METHODS. */
9131 tree r;
9140 /* Instantiate members marked with attribute used. */
9146 }
9149 /* A closure type for a lambda in a default argument for a
9150 member template. Ignore it; it will be instantiated with
9152 else
9153 {
9154 /* Build new TYPE_FIELDS. */
9156 {
9157 tree condition;
9160 condition =
9170 }
9172 {
9173 tree r;
9177 /* The file and line for this declaration, to
9178 assist in error message reporting. Since we
9179 called push_tinst_level above, we don't need to
9180 restore these. */
9190 {
9191 /* A capture pack became multiple fields. */
9194 }
9197 {
9201 {
9202 /* In [temp.inst]:
9204 [t]he initialization (and any associated
9205 side-effects) of a static data member does
9206 not occur unless the static data member is
9207 itself used in a way that requires the
9208 definition of the static data member to
9209 exist.
9211 Therefore, we do not substitute into the
9212 initialized for the static data member here. */
9213 finish_static_data_member_decl
9219 /* Instantiate members marked with attribute used. */
9222 }
9224 {
9225 /* Determine whether R has a valid type and can be
9226 completed later. If R is invalid, then its type
9227 is replaced by error_mark_node. */
9233 {
9236 }
9237 }
9239 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9240 such a thing will already have been added to the field
9241 list by tsubst_enum in finish_member_declaration in the
9242 CLASSTYPE_NESTED_UTDS case above. */
9246 {
9249 }
9250 }
9251 }
9252 }
9253 }
9254 else
9255 {
9258 {
9259 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9265 {
9266 /* template <class T> friend class C; */
9269 }
9271 {
9272 /* template <class T> friend class C::D; */
9278 }
9281 {
9282 /* This could be either
9284 friend class T::C;
9286 when dependent_type_p is false or
9288 template <class U> friend class T::C;
9290 otherwise. */
9293 /* Bump processing_template_decl for correct
9294 dependent_type_p calculation. */
9299 }
9302 {
9303 /* friend class C;
9305 where C hasn't been declared yet. Let's lookup name
9306 from namespace scope directly, bypassing any name that
9307 come from dependent base class. */
9310 /* The call to xref_tag_from_type does injection for friend
9311 classes. */
9313 friend_type =
9317 }
9319 /* friend class C<T>; */
9322 /* Otherwise it's
9324 friend class C;
9326 where C is already declared or
9328 friend class C<int>;
9330 We don't have to do anything in these cases. */
9333 /* Trick make_friend_class into realizing that the friend
9334 we're adding is a template, not an ordinary class. It's
9335 important that we use make_friend_class since it will
9336 perform some error-checking and output cross-reference
9337 information. */
9345 }
9346 else
9347 {
9348 /* Build new DECL_FRIENDLIST. */
9349 tree r;
9351 /* The file and line for this declaration, to
9352 assist in error message reporting. Since we
9353 called push_tinst_level above, we don't need to
9354 restore these. */
9358 {
9361 }
9366 {
9369 }
9370 }
9371 }
9372 }
9375 {
9378 {
9383 /* We need to instantiate the capture list from the template
9384 after we've instantiated the closure members, but before we
9385 consider adding the conversion op. Also keep any captures
9386 that may have been added during instantiation of the op(). */
9388 tree tmpl_cap
9397 }
9398 else
9400 }
9402 /* Set the file and line number information to whatever is given for
9403 the class itself. This puts error messages involving generated
9404 implicit functions at a predictable point, and the same point
9405 that would be used for non-template classes. */
9412 /* We don't instantiate default arguments for member functions. 14.7.1:
9414 The implicit instantiation of a class template specialization causes
9415 the implicit instantiation of the declarations, but not of the
9416 definitions or default arguments, of the class member functions,
9417 member classes, static data members and member templates.... */
9419 /* Some typedefs referenced from within the template code need to be access
9420 checked at template instantiation time, i.e now. These types were
9421 added to the template at parsing time. Let's get those and perform
9422 the access checks then. */
9432 /* The vtable for a template class can be emitted in any translation
9433 unit in which the class is instantiated. When there is no key
9434 method, however, finish_struct_1 will already have added TYPE to
9435 the keyed_classes list. */
9440 }
9442 /* Wrapper for instantiate_class_template_1. */
9444 tree
9446 {
9447 tree ret;
9452 }
9454 static tree
9456 {
9457 tree r;
9463 else
9464 {
9471 }
9473 }
9475 /* Given a function parameter pack TMPL_PARM and some function parameters
9476 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9477 and set *SPEC_P to point at the next point in the list. */
9479 static tree
9481 {
9482 /* Collect all of the extra "packed" parameters into an
9483 argument pack. */
9484 tree parmvec;
9485 tree parmtypevec;
9496 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9501 {
9504 }
9506 /* Build the argument packs. */
9513 }
9515 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9516 NONTYPE_ARGUMENT_PACK. */
9518 static tree
9520 {
9522 }
9524 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9525 pack expansion. */
9527 static bool
9529 {
9534 }
9537 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9539 static tree
9541 {
9548 }
9550 /* This is a subroutine of tsubst_pack_expansion.
9552 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9553 mechanism to store the (non complete list of) arguments of the
9554 substitution and return a non substituted pack expansion, in order
9555 to wait for when we have enough arguments to really perform the
9556 substitution. */
9558 static bool
9562 {
9563 /* If one pack has an expansion and another pack has a normal
9564 argument or if one pack has an empty argument and an another
9565 one hasn't then tsubst_pack_expansion cannot perform the
9566 substitution and need to fall back on the
9567 PACK_EXPANSION_EXTRA mechanism. */
9575 {
9578 parm_pack;
9580 {
9585 else
9587 }
9591 }
9593 }
9595 /* [temp.variadic]/6 says that:
9597 The instantiation of a pack expansion [...]
9598 produces a list E1,E2, ..., En, where N is the number of elements
9599 in the pack expansion parameters.
9601 This subroutine of tsubst_pack_expansion produces one of these Ei.
9603 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9604 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9605 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9606 INDEX is the index 'i' of the element Ei to produce. ARGS,
9607 COMPLAIN, and IN_DECL are the same parameters as for the
9608 tsubst_pack_expansion function.
9610 The function returns the resulting Ei upon successful completion,
9611 or error_mark_node.
9613 Note that this function possibly modifies the ARGS parameter, so
9614 it's the responsibility of the caller to restore it. */
9616 static tree
9618 tree parm_packs,
9620 tree args /* This parm gets
9622 tsubst_flags_t complain,
9623 tree in_decl)
9624 {
9625 tree t;
9628 /* For each parameter pack, change the substitution of the parameter
9629 pack to the ith argument in its argument pack, then expand the
9630 pattern. */
9632 {
9637 ith_elem_is_expansion |=
9640 /* Select the Ith argument from the pack. */
9643 {
9645 {
9649 }
9650 else
9652 }
9653 else
9654 {
9659 {
9661 /* Update the corresponding argument. */
9663 }
9664 else
9665 /* Re-use the ARGUMENT_PACK_SELECT. */
9667 }
9669 }
9671 /* Substitute into the PATTERN with the (possibly altered)
9672 arguments. */
9674 /* Expanding a fixed parameter pack from
9675 coerce_template_parameter_pack. */
9680 else
9683 /* If the Ith argument pack element is a pack expansion, then
9684 the Ith element resulting from the substituting is going to
9685 be a pack expansion as well. */
9690 }
9692 /* Substitute ARGS into T, which is an pack expansion
9693 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9694 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9695 (if only a partial substitution could be performed) or
9696 ERROR_MARK_NODE if there was an error. */
9697 tree
9699 tree in_decl)
9700 {
9701 tree pattern;
9705 tree result;
9713 /* Add in any args remembered from an earlier partial instantiation. */
9718 /* Determine the argument packs that will instantiate the parameter
9719 packs used in the expansion expression. While we're at it,
9720 compute the number of arguments to be expanded and make sure it
9721 is consistent. */
9724 {
9731 {
9735 else
9738 }
9740 {
9743 else
9744 {
9745 /* We can't rely on local_specializations for a parameter
9746 name used later in a function declaration (such as in a
9747 late-specified return type). Even if it exists, it might
9748 have the wrong value for a recursive call. Just make a
9749 dummy decl, since it's only used for its type. */
9752 /* Partial instantiation of the parm_pack, we can't build
9753 up an argument pack yet. */
9755 else
9758 }
9759 }
9762 else
9763 {
9769 }
9776 /* This can only happen if we forget to expand an argument
9777 pack somewhere else. Just return an error, silently. */
9778 {
9782 }
9785 {
9789 /* Don't bother trying to do a partial substitution with
9790 incomplete packs; we'll try again after deduction. */
9797 {
9803 pattern);
9804 else
9807 pattern);
9809 }
9811 /* Keep track of the parameter packs and their corresponding
9812 argument packs. */
9815 }
9816 else
9817 {
9818 /* We can't substitute for this parameter pack. We use a flag as
9819 well as the missing_level counter because function parameter
9820 packs don't have a level. */
9822 }
9823 }
9825 /* If the expansion is just T..., return the matching argument pack. */
9828 {
9833 /* Otherwise use the normal path so we get convert_from_reference. */
9834 }
9836 /* We cannot expand this expansion expression, because we don't have
9837 all of the argument packs we need. */
9839 {
9840 /* We got some full packs, but we can't substitute them in until we
9841 have values for all the packs. So remember these until then. */
9846 }
9848 {
9849 /* There were no real arguments, we're just replacing a parameter
9850 pack with another version of itself. Substitute into the
9851 pattern and return a PACK_EXPANSION_*. The caller will need to
9852 deal with that. */
9856 else
9860 }
9865 {
9866 /* We're in a late-specified return type, so create our own local
9867 specializations map; the current map is either NULL or (in the
9868 case of recursive unification) might have bindings that we don't
9869 want to use or alter. */
9872 }
9874 /* For each argument in each argument pack, substitute into the
9875 pattern. */
9878 {
9880 i,
9882 in_decl);
9885 {
9888 }
9889 }
9891 /* Update ARGS to restore the substitution from parameter packs to
9892 their argument packs. */
9894 {
9900 else
9901 {
9909 /* Update the corresponding argument. */
9913 else
9915 }
9916 }
9919 {
9922 }
9925 }
9927 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9928 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9929 parameter packs; all parms generated from a function parameter pack will
9930 have the same DECL_PARM_INDEX. */
9932 tree
9934 {
9936 tree patparm;
9939 {
9945 }
9946 else
9947 {
9952 }
9955 }
9957 /* Substitute ARGS into the vector or list of template arguments T. */
9959 static tree
9961 {
9973 {
9975 tree new_arg;
9980 {
9981 /* Substitute into an expansion expression. */
9985 /* Add to the expanded length adjustment the number of
9986 expanded arguments. We subtract one from this
9987 measurement, because the argument pack expression
9988 itself is already counted as 1 in
9989 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9990 the argument pack is empty. */
9992 }
9994 {
9995 /* Substitute into each of the arguments. */
10001 new_arg,
10015 }
10016 }
10017 else
10026 }
10031 /* Make space for the expanded arguments coming from template
10032 argument packs. */
10034 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10035 arguments for a member template.
10036 In that case each TREE_VEC in ORIG_T represents a level of template
10037 arguments, and ORIG_T won't carry any non defaulted argument count.
10038 It will rather be the nested TREE_VECs that will carry one.
10039 In other words, ORIG_T carries a non defaulted argument count only
10040 if it doesn't contain any nested TREE_VEC. */
10042 {
10046 }
10048 {
10052 {
10055 /* Now expand the template argument pack "in place". */
10058 }
10059 else
10060 {
10062 out++;
10063 }
10064 }
10067 }
10069 /* Return the result of substituting ARGS into the template parameters
10070 given by PARMS. If there are m levels of ARGS and m + n levels of
10071 PARMS, then the result will contain n levels of PARMS. For
10072 example, if PARMS is `template <class T> template <class U>
10073 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10074 result will be `template <int*, double, class V>'. */
10076 static tree
10078 {
10082 /* When substituting into a template, we must set
10083 PROCESSING_TEMPLATE_DECL as the template parameters may be
10084 dependent if they are based on one-another, and the dependency
10085 predicates are short-circuit outside of templates. */
10092 {
10093 tree new_vec =
10098 {
10099 tree tuple;
10111 }
10117 }
10122 }
10124 /* Return the result of substituting ARGS into one template parameter
10125 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10126 parameter and which TREE_PURPOSE is the default argument of the
10127 template parameter. */
10129 static tree
10131 {
10152 }
10154 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10155 type T. If T is not an aggregate or enumeration type, it is
10156 handled as if by tsubst. IN_DECL is as for tsubst. If
10157 ENTERING_SCOPE is nonzero, T is the context for a template which
10158 we are presently tsubst'ing. Return the substituted value. */
10160 static tree
10162 tree args,
10163 tsubst_flags_t complain,
10164 tree in_decl,
10166 {
10171 {
10176 /* Else fall through. */
10180 {
10181 tree argvec;
10182 tree context;
10183 tree r;
10187 /* In "sizeof(X<I>)" we need to evaluate "I". */
10193 /* First, determine the context for the type we are looking
10194 up. */
10197 {
10200 /* If context is a nested class inside a class template,
10201 it may still need to be instantiated (c++/33959). */
10203 }
10205 /* Then, figure out what arguments are appropriate for the
10206 type we are trying to find. For example, given:
10208 template <class T> struct S;
10209 template <class T, class U> void f(T, U) { S<U> su; }
10211 and supposing that we are instantiating f<int, double>,
10212 then our ARGS will be {int, double}, but, when looking up
10213 S we only want {double}. */
10218 else
10219 {
10223 }
10229 }
10230 else
10231 /* This is not a template type, so there's nothing to do. */
10236 }
10237 }
10239 /* Substitute into the default argument ARG (a default argument for
10240 FN), which has the indicated TYPE. */
10242 tree
10244 {
10249 /* This can happen in invalid code. */
10253 /* This default argument came from a template. Instantiate the
10254 default argument here, not in tsubst. In the case of
10255 something like:
10257 template <class T>
10258 struct S {
10259 static T t();
10260 void f(T = t());
10261 };
10263 we must be careful to do name lookup in the scope of S<T>,
10264 rather than in the current class. */
10266 /* The "this" pointer is not valid in a default argument. */
10268 {
10273 }
10276 /* The default argument expression may cause implicitly defined
10277 member functions to be synthesized, which will result in garbage
10278 collection. We must treat this situation as if we were within
10279 the body of function so as to avoid collecting live data on the
10280 stack. */
10288 /* Restore the "this" pointer. */
10290 {
10293 }
10300 /* Make sure the default argument is reasonable. */
10306 }
10308 /* Substitute into all the default arguments for FN. */
10310 static void
10312 {
10313 tree arg;
10314 tree tmpl_args;
10318 /* If this function is not yet instantiated, we certainly don't need
10319 its default arguments. */
10322 /* Don't do this again for clones. */
10327 arg;
10333 complain);
10334 }
10336 /* Substitute the ARGS into the T, which is a _DECL. Return the
10337 result of the substitution. Issue error and warning messages under
10338 control of COMPLAIN. */
10340 static tree
10342 {
10343 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10344 location_t saved_loc;
10349 /* Set the filename and linenumber to improve error-reporting. */
10354 {
10356 {
10357 /* We can get here when processing a member function template,
10358 member class template, or template template parameter. */
10360 tree spec;
10361 tree tmpl_args;
10362 tree full_args;
10365 {
10366 /* Template template parameter is treated here. */
10370 /* If we get a real template back, return it. This can happen in
10371 the context of most_specialized_class. */
10383 complain);
10386 }
10388 /* We might already have an instance of this template.
10389 The ARGS are for the surrounding class type, so the
10390 full args contain the tsubst'd args for the context,
10391 plus the innermost args from the template decl. */
10395 /* Because this is a template, the arguments will still be
10396 dependent, even after substitution. If
10397 PROCESSING_TEMPLATE_DECL is not set, the dependency
10398 predicates will short-circuit. */
10406 /* If this is a default template template argument,
10407 tsubst might not have changed anything. */
10414 {
10417 }
10419 /* Make a new template decl. It will be similar to the
10420 original, but will record the current template arguments.
10421 We also create a new function declaration, which is just
10422 like the old one, but points to this new template, rather
10423 than the old one. */
10432 {
10433 tree new_type;
10441 /* For a partial specialization, we need to keep pointing to
10442 the primary template. */
10448 }
10449 else
10450 {
10451 tree new_decl;
10463 }
10469 /* The template parameters for this new template are all the
10470 template parameters for the old template, except the
10471 outermost level of parameters. */
10474 complain);
10480 /* Record this non-type partial instantiation. */
10484 }
10488 {
10489 tree ctx;
10492 tree gen_tmpl;
10493 tree type;
10498 /* Nobody should be tsubst'ing into non-template functions. */
10502 {
10503 tree spec;
10506 /* If T is not dependent, just return it. We have to
10507 increment PROCESSING_TEMPLATE_DECL because
10508 value_dependent_expression_p assumes that nothing is
10509 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10516 /* Calculate the most general template of which R is a
10517 specialization, and the complete set of arguments used to
10518 specialize R. */
10521 (DECL_TEMPLATE_RESULT
10527 /* Check to see if we already have this specialization. */
10532 {
10535 }
10537 /* We can see more levels of arguments than parameters if
10538 there was a specialization of a member template, like
10539 this:
10541 template <class T> struct S { template <class U> void f(); }
10542 template <> template <class U> void S<int>::f(U);
10544 Here, we'll be substituting into the specialization,
10545 because that's where we can find the code we actually
10546 want to generate, but we'll have enough arguments for
10547 the most general template.
10549 We also deal with the peculiar case:
10551 template <class T> struct S {
10552 template <class U> friend void f();
10553 };
10554 template <class U> void f() {}
10555 template S<int>;
10556 template void f<double>();
10558 Here, the ARGS for the instantiation of will be {int,
10559 double}. But, we only need as many ARGS as there are
10560 levels of template parameters in CODE_PATTERN. We are
10561 careful not to get fooled into reducing the ARGS in
10562 situations like:
10564 template <class T> struct S { template <class U> void f(U); }
10565 template <class T> template <> void S<T>::f(int) {}
10567 which we can spot because the pattern will be a
10568 specialization in this case. */
10570 parms_depth =
10575 }
10576 else
10577 {
10578 /* This special case arises when we have something like this:
10580 template <class T> struct S {
10581 friend void f<int>(int, double);
10582 };
10584 Here, the DECL_TI_TEMPLATE for the friend declaration
10585 will be an IDENTIFIER_NODE. We are being called from
10586 tsubst_friend_function, and we want only to create a
10587 new decl (R) with appropriate types so that we can call
10588 determine_specialization. */
10590 }
10593 {
10596 else
10600 }
10601 else
10602 {
10605 }
10610 /* If we hit excessive deduction depth, the type is bogus even if
10611 it isn't error_mark_node, so don't build a decl. */
10615 /* We do NOT check for matching decls pushed separately at this
10616 point, as they may not represent instantiations of this
10617 template, and in any case are considered separate under the
10618 discrete model. */
10622 /* Clear out the mangled name and RTL for the instantiation. */
10625 /* Leave DECL_INITIAL set on deleted instantiations. */
10630 /* OpenMP UDRs have the only argument a reference to the declared
10631 type. We want to diagnose if the declared type is a reference,
10632 which is invalid, but as references to references are usually
10633 quietly merged, diagnose it here. */
10635 {
10636 tree argtype
10641 "reference type %qT in "
10645 argtype);
10646 }
10649 /* Type-conversion operator. Reconstruct the name, in
10650 case it's the name of one of the template's parameters. */
10660 /* If this is an instantiation of a function with internal
10661 linkage, we already know what object file linkage will be
10662 assigned to the instantiation. */
10671 /* We'll re-clone as appropriate in instantiate_template. */
10674 /* If we aren't complaining now, return on error before we register
10675 the specialization so that we'll complain eventually. */
10681 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10682 this in the special friend case mentioned above where
10683 GEN_TMPL is NULL. */
10685 {
10690 tree new_r
10693 /* We instantiated this while substituting into
10694 the type earlier (template/friend54.C). */
10700 /* We're not supposed to instantiate default arguments
10701 until they are called, for a template. But, for a
10702 declaration like:
10704 template <class T> void f ()
10705 { extern void g(int i = T()); }
10707 we should do the substitution when the template is
10708 instantiated. We handle the member function case in
10709 instantiate_class_template since the default arguments
10710 might refer to other members of the class. */
10715 }
10716 else
10719 /* Copy the list of befriending classes. */
10723 {
10727 in_decl);
10728 }
10731 {
10737 /* If this is an instantiation of a member template, clone it.
10738 If it isn't, that'll be handled by
10739 clone_constructors_and_destructors. */
10742 }
10753 /* Possibly limit visibility based on template args. */
10756 {
10760 }
10768 }
10772 {
10780 {
10781 /* If there is a local specialization that isn't a
10782 parameter pack, it means that we're doing a "simple"
10783 substitution from inside tsubst_pack_expansion. Just
10784 return the local specialization (which will be a single
10785 parm). */
10792 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10793 the parameters in this function parameter pack. */
10797 {
10800 /* Zero-length parameter packs are boring. Just substitute
10801 into the chain. */
10805 }
10806 else
10807 {
10808 /* All we did was update the type. Make a note of that. */
10811 }
10812 }
10814 /* Loop through all of the parameters we'll build. When T is
10815 a function parameter pack, LEN is the number of expanded
10816 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10819 {
10826 /* We're on the Ith parameter of the function parameter
10827 pack. */
10828 {
10829 /* Get the Ith type. */
10832 /* Rename the parameter to include the index. */
10835 }
10837 /* We're dealing with a normal parameter. */
10845 {
10848 else
10851 }
10861 /* Keep track of the first new parameter we
10862 generate. That's what will be returned to the
10863 caller. */
10867 /* Build a proper chain of parameters when substituting
10868 into a function parameter pack. */
10871 }
10873 /* If cp_unevaluated_operand is set, we're just looking for a
10874 single dummy parameter, so don't keep going. */
10879 /* FIRST_R contains the start of the chain we've built. */
10881 }
10885 {
10892 {
10893 /* This field is a lambda capture pack. Return a TREE_VEC of
10894 the expanded fields to instantiate_class_template_1 and
10895 store them in the specializations hash table as a
10896 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10900 {
10903 }
10904 else
10905 {
10906 /* All we did was update the type. Make a note of that. */
10909 }
10910 }
10913 {
10916 {
10920 }
10930 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10931 non-bit-fields DECL_INITIAL is a non-static data member
10932 initializer, which gets deferred instantiation. */
10938 {
10939 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10940 NSDMI in perform_member_init. Still set DECL_INITIAL
10941 so that we know there is one. */
10946 }
10947 /* We don't have to set DECL_CONTEXT here; it is set by
10948 finish_member_declaration. */
10956 }
10959 {
10967 }
10968 }
10972 /* We reach here only for member using decls. We also need to check
10973 uses_template_parms because DECL_DEPENDENT_P is not set for a
10974 using-declaration that designates a member of the current
10975 instantiation (c++/53549). */
10978 {
10985 else
10986 {
10989 }
10990 }
10991 else
10992 {
10995 }
11000 {
11003 tree spec;
11005 tree ctx;
11014 {
11015 /* If this is the canonical decl, we don't have to
11016 mess with instantiations, and often we can't (for
11017 typename, template type parms and such). Note that
11018 TYPE_NAME is not correct for the above test if
11019 we've copied the type for a typedef. */
11025 }
11027 /* Check to see if we already have the specialization we
11028 need. */
11031 {
11032 /* T is a static data member or namespace-scope entity.
11033 We have to substitute into namespace-scope variables
11034 (even though such entities are never templates) because
11035 of cases like:
11037 template <class T> void f() { extern T t; }
11039 where the entity referenced is not known until
11040 instantiation time. */
11044 {
11046 complain,
11048 /* If CTX is unchanged, then T is in fact the
11049 specialization we want. That situation occurs when
11050 referencing a static data member within in its own
11051 class. We can use pointer equality, rather than
11052 same_type_p, because DECL_CONTEXT is always
11053 canonical... */
11056 /* ... unless T is a member template; in which
11057 case our caller can be willing to create a
11058 specialization of that template represented
11059 by T. */
11063 }
11066 {
11074 }
11075 }
11076 else
11077 {
11078 /* A local variable. */
11080 /* Subsequent calls to pushdecl will fill this in. */
11083 }
11084 /* If we already have the specialization we need, there is
11085 nothing more to do. */
11087 {
11090 }
11092 /* Create a new node for the specialization we need. */
11095 {
11098 else
11105 }
11107 {
11108 /* Even if the original location is out of scope, the
11109 newly substituted one is not. */
11116 {
11117 /* It may seem that this case cannot occur, since:
11119 typedef void f();
11120 void g() { f x; }
11122 declares a function, not a variable. However:
11124 typedef void f();
11125 template <typename T> void g() { T t; }
11126 template void g<f>();
11128 is an attempt to declare a variable with function
11129 type. */
11131 /* R is not yet sufficiently initialized, so we
11132 just use its name. */
11135 }
11137 /* Wait until cp_finish_decl to set this again, to handle
11138 circular dependency (template/instantiate6.C). */
11143 {
11148 {
11151 }
11153 }
11154 }
11160 /* Clear out the mangled name and RTL for the instantiation. */
11164 /* The initializer must not be expanded until it is required;
11165 see [temp.inst]. */
11171 {
11172 /* Possibly limit visibility based on template args. */
11175 {
11179 }
11181 }
11184 {
11185 /* A static data member declaration is always marked
11186 external when it is declared in-class, even if an
11187 initializer is present. We mimic the non-template
11188 processing here. */
11194 }
11204 /* Preserve a typedef that names a type. */
11206 {
11209 }
11212 }
11217 }
11218 #undef RETURN
11220 out:
11221 /* Restore the file and line information. */
11225 }
11227 /* Substitute into the ARG_TYPES of a function type.
11228 If END is a TREE_CHAIN, leave it and any following types
11229 un-substituted. */
11231 static tree
11233 tree args,
11234 tree end,
11235 tsubst_flags_t complain,
11236 tree in_decl)
11237 {
11238 tree remaining_arg_types;
11242 tree default_arg;
11253 {
11254 /* For a pack expansion, perform substitution on the
11255 entire expression. Later on, we'll handle the arguments
11256 one-by-one. */
11261 /* So that we'll spin through the parameters, one by one. */
11263 else
11264 {
11265 /* We only partially substituted into the parameter
11266 pack. Our type is TYPE_PACK_EXPANSION. */
11269 }
11270 }
11283 {
11285 {
11289 }
11291 }
11292 /* DR 657. */
11296 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11297 top-level qualifiers as required. */
11300 /* We do not substitute into default arguments here. The standard
11301 mandates that they be instantiated only when needed, which is
11302 done in build_over_call. */
11306 {
11307 /* We've instantiated a template before its default arguments
11308 have been parsed. This can happen for a nested template
11309 class, and is not an error unless we require the default
11310 argument in a call of this function. */
11311 remaining_arg_types =
11314 }
11315 else
11316 remaining_arg_types =
11318 }
11321 }
11323 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11324 *not* handle the exception-specification for FNTYPE, because the
11325 initial substitution of explicitly provided template parameters
11326 during argument deduction forbids substitution into the
11327 exception-specification:
11329 [temp.deduct]
11331 All references in the function type of the function template to the
11332 corresponding template parameters are replaced by the specified tem-
11333 plate argument values. If a substitution in a template parameter or
11334 in the function type of the function template results in an invalid
11335 type, type deduction fails. [Note: The equivalent substitution in
11336 exception specifications is done only when the function is instanti-
11337 ated, at which point a program is ill-formed if the substitution
11338 results in an invalid type.] */
11340 static tree
11342 tree args,
11343 tsubst_flags_t complain,
11344 tree in_decl)
11345 {
11346 tree return_type;
11347 tree arg_types;
11348 tree fntype;
11350 /* The TYPE_CONTEXT is not used for function/method types. */
11353 /* Substitute the return type. */
11357 /* DR 486 clarifies that creation of a function type with an
11358 invalid return type is a deduction failure. */
11361 {
11363 {
11366 else
11368 }
11370 }
11371 /* And DR 657. */
11375 /* Substitute the argument types. */
11381 /* Construct a new type node and return it. */
11383 {
11388 }
11389 else
11390 {
11392 /* Don't pick up extra function qualifiers from the basetype. */
11395 {
11396 /* [temp.deduct]
11398 Type deduction may fail for any of the following
11399 reasons:
11401 -- Attempting to create "pointer to member of T" when T
11402 is not a class type. */
11405 r);
11407 }
11412 }
11416 }
11418 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11419 ARGS into that specification, and return the substituted
11420 specification. If there is no specification, return NULL_TREE. */
11422 static tree
11424 tree args,
11425 tsubst_flags_t complain,
11426 tree in_decl,
11428 {
11429 tree specs;
11430 tree new_specs;
11435 {
11436 /* A noexcept-specifier. */
11441 {
11442 /* Defer instantiation of noexcept-specifiers to avoid
11443 excessive instantiations (c++/49107). */
11446 {
11447 /* We already partially instantiated this member template,
11448 so combine the new args with the old. */
11453 }
11454 else
11455 {
11458 }
11459 }
11460 else
11461 new_specs = tsubst_copy_and_build
11465 }
11467 {
11470 else
11472 {
11473 tree spec;
11478 {
11479 /* Expand the pack expansion type. */
11482 in_decl);
11488 else
11489 {
11490 /* We're substituting into a member template, so
11491 we got a TYPE_PACK_EXPANSION back. Add that
11492 expansion and move on. */
11496 expanded_specs,
11497 complain);
11500 }
11501 }
11504 {
11507 else
11512 complain);
11513 }
11516 }
11517 }
11519 }
11521 /* Take the tree structure T and replace template parameters used
11522 therein with the argument vector ARGS. IN_DECL is an associated
11523 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11524 Issue error and warning messages under control of COMPLAIN. Note
11525 that we must be relatively non-tolerant of extensions here, in
11526 order to preserve conformance; if we allow substitutions that
11527 should not be allowed, we may allow argument deductions that should
11528 not succeed, and therefore report ambiguous overload situations
11529 where there are none. In theory, we could allow the substitution,
11530 but indicate that it should have failed, and allow our caller to
11531 make sure that the right thing happens, but we don't try to do this
11532 yet.
11534 This function is used for dealing with types, decls and the like;
11535 for expressions, use tsubst_expr or tsubst_copy. */
11537 tree
11539 {
11562 else
11567 /* Reuse typedefs. We need to do this to handle dependent attributes,
11568 such as attribute aligned. */
11571 {
11575 {
11576 /* DECL represents an alias template and we want to
11577 instantiate it. */
11581 }
11585 {
11589 }
11594 else
11595 /* The typedef is from a non-template context. */
11599 {
11601 r = cp_build_qualified_type_real
11605 }
11606 else
11607 {
11608 /* We don't have an instantiation yet, so drop the typedef. */
11613 }
11614 }
11627 {
11653 {
11659 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11660 needed. */
11666 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11667 with TREE_SIDE_EFFECTS that indicates this is not an integral
11668 constant expression. */
11671 {
11674 }
11677 }
11683 {
11696 {
11700 {
11701 /* See through ARGUMENT_PACK_SELECT arguments. */
11703 /* If the selected argument is an expansion E, that most
11704 likely means we were called from
11705 gen_elem_of_pack_expansion_instantiation during the
11706 substituting of pack an argument pack (which Ith
11707 element is a pack expansion, where I is
11708 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11709 In this case, the Ith element resulting from this
11710 substituting is going to be a pack expansion, which
11711 pattern is the pattern of E. Let's return the
11712 pattern of E, and
11713 gen_elem_of_pack_expansion_instantiation will
11714 build the resulting pack expansion from it. */
11717 }
11718 }
11723 {
11725 /* If ARG is an argument pack, we don't actually want to
11726 perform a substitution here, because substitutions
11727 for argument packs are only done
11728 element-by-element. We can get to this point when
11729 substituting the type of a non-type template
11730 parameter pack, when that type actually contains
11731 template parameter packs from an outer template, e.g.,
11733 template<typename... Types> struct A {
11734 template<Types... Values> struct B { };
11735 }; */
11739 {
11745 return cp_build_qualified_type_real
11747 }
11749 {
11750 /* We are processing a type constructed from a
11751 template template parameter. */
11762 /* Consider this code:
11764 template <template <class> class Template>
11765 struct Internal {
11766 template <class Arg> using Bind = Template<Arg>;
11767 };
11769 template <template <class> class Template, class Arg>
11770 using Instantiate = Template<Arg>; //#0
11772 template <template <class> class Template,
11773 class Argument>
11774 using Bind =
11775 Instantiate<Internal<Template>::template Bind,
11776 Argument>; //#1
11778 When #1 is parsed, the
11779 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11780 parameter `Template' in #0 matches the
11781 UNBOUND_CLASS_TEMPLATE representing the argument
11782 `Internal<Template>::template Bind'; We then want
11783 to assemble the type `Bind<Argument>' that can't
11784 be fully created right now, because
11785 `Internal<Template>' not being complete, the Bind
11786 template cannot be looked up in that context. So
11787 we need to "store" `Bind<Argument>' for later
11788 when the context of Bind becomes complete. Let's
11789 store that in a TYPENAME_TYPE. */
11793 argvec),
11794 typename_type,
11795 complain);
11797 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11798 are resolving nested-types in the signature of a
11799 member function templates. Otherwise ARG is a
11800 TEMPLATE_DECL and is the real template to be
11801 instantiated. */
11809 complain);
11810 return cp_build_qualified_type_real
11812 }
11813 else
11814 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11816 }
11819 /* This can happen during the attempted tsubst'ing in
11820 unify. This means that we don't yet have any information
11821 about the template parameter in question. */
11824 /* Early in template argument deduction substitution, we don't
11825 want to reduce the level of 'auto', or it will be confused
11826 with a normal template parm in subsequent deduction. */
11830 /* If we get here, we must have been looking at a parm for a
11831 more deeply nested template. Make a new version of this
11832 template parameter, but with a lower level. */
11834 {
11839 {
11841 r = cp_build_qualified_type_real
11845 }
11846 else
11847 {
11858 /* We have reduced the level of the template
11859 template parameter, but not the levels of its
11860 template parameters, so canonical_type_parameter
11861 will not be able to find the canonical template
11862 template parameter for this level. Thus, we
11863 require structural equality checking to compare
11864 TEMPLATE_TEMPLATE_PARMs. */
11868 else
11872 {
11880 }
11881 }
11890 }
11893 }
11896 {
11904 {
11908 }
11911 {
11915 }
11918 {
11922 }
11928 }
11931 /* We should never be tsubsting a binfo. */
11935 /* A vector of template arguments. */
11941 {
11945 /* [temp.deduct]
11947 Type deduction may fail for any of the following
11948 reasons:
11950 -- Attempting to create a pointer to reference type.
11951 -- Attempting to create a reference to a reference type or
11952 a reference to void.
11954 Core issue 106 says that creating a reference to a reference
11955 during instantiation is no longer a cause for failure. We
11956 only enforce this check in strict C++98 mode. */
11960 {
11963 /* We keep track of the last time we issued this error
11964 message to avoid spewing a ton of messages during a
11965 single bad template instantiation. */
11968 {
11973 else
11976 }
11979 }
11983 {
11985 {
11988 type);
11989 else
11991 type);
11992 }
11994 }
11996 {
12000 }
12002 /* In C++0x, during template argument substitution, when there is an
12003 attempt to create a reference to a reference type, reference
12004 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
12006 "If a template-argument for a template-parameter T names a type
12007 that is a reference to a type A, an attempt to create the type
12008 'lvalue reference to cv T' creates the type 'lvalue reference to
12009 A,' while an attempt to create the type type rvalue reference to
12010 cv T' creates the type T"
12011 */
12012 r = cp_build_reference_type
12015 else
12023 {
12025 pedwarn
12027 code == REFERENCE_TYPE
12030 else
12032 }
12035 /* Will this ever be needed for TYPE_..._TO values? */
12039 }
12041 {
12044 {
12045 /* [temp.deduct]
12047 Type deduction may fail for any of the following
12048 reasons:
12050 -- Attempting to create "pointer to member of T" when T
12051 is not a class type. */
12055 }
12057 {
12061 }
12063 {
12067 }
12070 {
12071 /* The type of the implicit object parameter gets its
12072 cv-qualifiers from the FUNCTION_TYPE. */
12073 tree memptr;
12074 tree method_type
12079 complain);
12080 }
12081 else
12084 complain);
12085 }
12088 {
12089 tree fntype;
12090 tree specs;
12095 /* Substitute the exception specification. */
12103 }
12105 {
12110 /* As an optimization, we avoid regenerating the array type if
12111 it will obviously be the same as T. */
12115 /* These checks should match the ones in grokdeclarator.
12117 [temp.deduct]
12119 The deduction may fail for any of the following reasons:
12121 -- Attempting to create an array with an element type that
12122 is void, a function type, or a reference type, or [DR337]
12123 an abstract class type. */
12127 {
12131 }
12139 {
12142 }
12145 }
12148 {
12158 {
12162 }
12164 {
12165 /* Normally, make_typename_type does not require that the CTX
12166 have complete type in order to allow things like:
12168 template <class T> struct S { typename S<T>::X Y; };
12170 But, such constructs have already been resolved by this
12171 point, so here CTX really should have complete type, unless
12172 it's a partial instantiation. */
12175 {
12179 }
12180 }
12187 {
12190 }
12193 {
12195 {
12199 else
12201 }
12203 {
12207 else
12209 }
12210 }
12212 return cp_build_qualified_type_real
12214 }
12217 {
12229 }
12232 {
12233 tree type;
12249 complain);
12250 }
12253 {
12254 tree type;
12272 else
12273 {
12277 /* In a template ~id could be either a complement expression
12278 or an unqualified-id naming a destructor; if instantiating
12279 it produces an expression, it's not an id-expression or
12280 member access. */
12283 }
12287 complain);
12288 }
12291 {
12295 }
12299 {
12301 tree packed_out =
12303 args,
12304 complain,
12305 in_decl);
12308 /* For template nontype argument packs, also substitute into
12309 the type. */
12314 }
12329 /* We should use one of the expression tsubsts for these codes. */
12335 }
12336 }
12338 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12339 type of the expression on the left-hand side of the "." or "->"
12340 operator. */
12342 static tree
12345 {
12346 tree name;
12347 tree qualifying_scope;
12348 tree fns;
12349 tree optype;
12354 /* A baselink indicates a function from a base class. Both the
12355 BASELINK_ACCESS_BINFO and the base class referenced may
12356 indicate bases of the template class, rather than the
12357 instantiated class. In addition, lookups that were not
12358 ambiguous before may be ambiguous now. Therefore, we perform
12359 the lookup again. */
12366 {
12373 }
12381 /* If lookup found a single function, mark it as used at this
12382 point. (If it lookup found multiple functions the one selected
12383 later by overload resolution will be marked as used at that
12384 point.) */
12390 /* Add back the template arguments, if present. */
12395 template_args);
12396 /* Update the conversion operator type. */
12404 qualifying_scope,
12405 object_type);
12407 }
12409 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12410 true if the qualified-id will be a postfix-expression in-and-of
12411 itself; false if more of the postfix-expression follows the
12412 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12413 of "&". */
12415 static tree
12419 {
12420 tree expr;
12421 tree scope;
12422 tree name;
12424 tree template_args;
12429 /* Figure out what name to look up. */
12432 {
12440 }
12441 else
12442 {
12445 }
12447 /* Substitute into the qualifying scope. When there are no ARGS, we
12448 are just trying to simplify a non-dependent expression. In that
12449 case the qualifying scope may be dependent, and, in any case,
12450 substituting will not help. */
12453 {
12456 }
12457 else
12461 {
12466 }
12469 {
12471 {
12472 /* A BIT_NOT_EXPR is used to represent a destructor. */
12474 {
12478 }
12479 else
12482 }
12483 else
12487 {
12489 {
12493 }
12495 }
12496 }
12499 {
12501 scope);
12502 /* Remember that there was a reference to this entity. */
12504 }
12507 {
12513 }
12522 {
12523 expr = (adjust_result_of_qualified_name_lookup
12525 expr = (finish_qualified_id_expr
12529 }
12531 /* Expressions do not generally have reference type. */
12533 /* However, if we're about to form a pointer-to-member, we just
12534 want the referenced member referenced. */
12539 }
12541 /* Like tsubst, but deals with expressions. This function just replaces
12542 template parms; to finish processing the resultant expression, use
12543 tsubst_copy_and_build or tsubst_expr. */
12545 static tree
12547 {
12549 tree r;
12557 {
12562 {
12563 /* We get here for a use of 'this' in an NSDMI. */
12569 /* This can happen for a parameter name used later in a function
12570 declaration (such as in a late-specified return type). Just
12571 make a dummy decl, since it's only used for its type. */
12574 /* Give it the template pattern as its context; its true context
12575 hasn't been instantiated yet and this is good enough for
12576 mangling. */
12578 }
12586 {
12587 tree enum_type;
12588 tree v;
12592 /* There is no need to substitute into namespace-scope
12593 enumerators. */
12596 /* If ARGS is NULL, then T is known to be non-dependent. */
12600 /* Unfortunately, we cannot just call lookup_name here.
12601 Consider:
12603 template <int I> int f() {
12604 enum E { a = I };
12605 struct S { void g() { E e = a; } };
12606 };
12608 When we instantiate f<7>::S::g(), say, lookup_name is not
12609 clever enough to find f<7>::a. */
12610 enum_type
12620 /* We didn't find the name. That should never happen; if
12621 name-lookup found it during preliminary parsing, we
12622 should find it again here during instantiation. */
12624 }
12629 {
12630 /* Check for a local specialization set up by
12631 tsubst_pack_expansion. */
12633 {
12637 }
12639 /* When retrieving a capture pack from a generic lambda, remove the
12640 lambda call op's own template argument list from ARGS. Only the
12641 template arguments active for the closure type should be used to
12642 retrieve the pack specialization. */
12648 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12649 tsubst_decl put in the hash table. */
12651 }
12654 {
12655 tree ctx;
12660 {
12663 {
12667 }
12669 }
12670 }
12679 {
12682 {
12684 {
12685 /* Just use name lookup to find a member alias for an
12686 anonymous union, but then add it to the hash table. */
12690 }
12691 else
12692 {
12693 /* This can happen for a variable used in a
12694 late-specified return type of a local lambda, or for a
12695 local static or constant. Building a new VAR_DECL
12696 should be OK in all those cases. */
12699 /* A use of a local constant must decay to its value. */
12704 }
12705 }
12706 }
12707 else
12716 /* An OVERLOAD will always be a non-dependent overload set; an
12717 overload set from function scope will just be represented with an
12718 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12734 {
12735 /* Template template argument like the following example need
12736 special treatment:
12738 template <template <class> class TT> struct C {};
12739 template <class T> struct D {
12740 template <class U> struct E {};
12741 C<E> c; // #1
12742 };
12743 D<int> d; // #2
12745 We are processing the template argument `E' in #1 for
12746 the template instantiation #2. Originally, `E' is a
12747 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12748 have to substitute this with one having context `D<int>'. */
12752 }
12753 else
12754 /* Ordinary template template argument. */
12765 return build1
12771 {
12781 /* We only want to compute the number of arguments. */
12795 {
12802 else
12805 }
12806 else
12808 }
12810 {
12818 }
12819 /* Fall through */
12835 return build1
12840 {
12841 tree object;
12842 tree name;
12847 {
12851 }
12854 {
12864 }
12869 in_decl);
12870 else
12873 }
12911 return build_nt
12924 return build_nt
12931 {
12939 }
12945 {
12946 r = build_nt
12952 }
12955 {
12956 r = build_nt
12962 }
12965 {
12966 r = build_nt
12972 }
12975 {
12976 /* Substituted template arguments */
12985 }
12988 {
13008 }
13033 /* Fall through. */
13036 {
13039 }
13040 else
13044 /* This is handled by tsubst_copy_and_build. */
13050 in_decl),
13054 /* We shouldn't have built any of these during initial template
13055 generation. Instead, they should be built during instantiation
13056 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13060 r = build2
13080 {
13081 /* Instantiate any typedefs in the type. */
13086 }
13089 /* These can sometimes show up in a partial instantiation, but never
13090 involve template parms. */
13095 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13098 }
13099 }
13101 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13103 static tree
13106 {
13110 {
13116 {
13119 {
13125 }
13126 /* FALLTHRU */
13154 {
13157 {
13164 }
13165 else
13167 }
13197 }
13198 }
13204 }
13206 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13208 static tree
13210 tree in_decl)
13211 {
13212 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13232 {
13235 else
13236 {
13240 }
13241 }
13246 #undef RECUR
13247 }
13249 /* Substitute one OMP_FOR iterator. */
13251 static void
13256 {
13257 #define RECUR(NODE) \
13258 tsubst_expr ((NODE), args, complain, in_decl, \
13259 integral_constant_expression_p)
13268 {
13269 /* We need to jump through some hoops to handle declarations in the
13270 for-init-statement, since we might need to handle auto deduction,
13271 but we need to keep control of initialization. */
13275 }
13276 else
13288 {
13290 {
13291 /* Declare the variable, but don't let that initialize it. */
13296 }
13304 complain);
13305 else
13312 }
13315 {
13316 /* Declare and initialize the variable. */
13319 }
13321 {
13322 tree c;
13324 {
13335 }
13337 {
13342 {
13345 }
13346 }
13347 }
13353 else
13357 {
13368 {
13375 }
13376 else
13382 {
13388 }
13392 {
13399 }
13400 else
13406 }
13412 #undef RECUR
13413 }
13415 /* Like tsubst_copy for expressions, etc. but also does semantic
13416 processing. */
13418 static tree
13421 {
13422 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13423 #define RECUR(NODE) \
13424 tsubst_expr ((NODE), args, complain, in_decl, \
13425 integral_constant_expression_p)
13428 tree r;
13429 location_t loc;
13441 {
13443 {
13444 tree_stmt_iterator i;
13448 }
13463 else
13472 {
13474 tree init;
13480 {
13483 tree decl;
13491 else
13493 }
13495 {
13496 /* Don't build up decls for a variadic capture proxy, we'll
13497 instantiate the elements directly as needed. */
13499 }
13500 else
13501 {
13505 {
13506 /* By marking the declaration as instantiated, we avoid
13507 trying to instantiate it. Since instantiate_decl can't
13508 handle local variables, and since we've already done
13509 all that needs to be done, that's the right thing to
13510 do. */
13515 /* Anonymous aggregates are a special case. */
13518 {
13521 {
13525 }
13527 }
13533 {
13538 }
13539 else
13540 {
13545 {
13546 /* For __PRETTY_FUNCTION__ we have to adjust the
13547 initializer. */
13551 }
13552 else
13553 {
13557 {
13558 /* If we had an initializer but it
13559 instantiated to nothing,
13560 value-initialize the object. This will
13561 only occur when the initializer was a
13562 pack expansion where the parameter packs
13563 used in that expansion were of length
13564 zero. */
13566 complain);
13569 }
13570 else
13572 }
13575 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13578 }
13579 }
13580 }
13583 }
13598 {
13608 }
13635 {
13639 }
13647 else
13655 else
13682 {
13684 tree label;
13689 }
13695 /* Computed goto's must be tsubst'd into. On the other hand,
13696 non-computed gotos must not be; the identifier in question
13697 will have no binding. */
13699 else
13705 tmp = finish_asm_stmt
13712 {
13717 }
13722 {
13727 }
13728 else
13729 {
13734 else
13741 else
13747 else
13749 }
13753 {
13757 {
13759 /* Prevent instantiate_decl from trying to instantiate
13760 this variable. We've already done all that needs to be
13761 done. */
13764 }
13769 }
13775 {
13776 /* Local classes are not independent templates; they are
13777 instantiated along with their containing function. And this
13778 way we don't have to deal with pushing out of one local class
13779 to instantiate a member of another local class. */
13780 tree fn;
13781 /* Closures are handled by the LAMBDA_EXPR. */
13787 }
13791 {
13792 tree condition;
13795 condition =
13797 args,
13806 }
13830 {
13839 {
13844 }
13856 integral_constant_expression_p);
13865 else
13866 {
13874 }
13877 }
13936 {
13941 {
13944 }
13950 }
13951 else
13952 {
13959 {
13962 }
13965 {
13970 {
13973 }
13979 }
13980 else
13981 {
13985 }
13988 }
13992 {
13998 {
14002 {
14007 }
14011 }
14012 else
14013 {
14018 }
14019 }
14044 /* If the first operand was a statement, we're done with it. */
14048 complain));
14060 integral_constant_expression_p));
14061 }
14064 out:
14067 #undef RECUR
14068 #undef RETURN
14069 }
14071 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14072 function. For description of the body see comment above
14073 cp_parser_omp_declare_reduction_exprs. */
14075 static void
14077 {
14083 tree_stmt_iterator tsi;
14094 {
14113 }
14115 {
14135 }
14136 }
14138 /* T is a postfix-expression that is not being used in a function
14139 call. Return the substituted version of T. */
14141 static tree
14143 tsubst_flags_t complain,
14144 tree in_decl)
14145 {
14149 else
14155 }
14157 /* Like tsubst but deals with expressions and performs semantic
14158 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14160 tree
14162 tree args,
14163 tsubst_flags_t complain,
14164 tree in_decl,
14167 {
14168 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14169 #define RECUR(NODE) \
14170 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14172 integral_constant_expression_p)
14175 location_t loc;
14184 /* N3276 decltype magic only applies to calls at the top level or on the
14185 right side of a comma. */
14190 {
14193 /* Fall through. */
14195 {
14196 tree decl;
14197 cp_id_kind idk;
14202 {
14205 }
14207 /* Look up the name. */
14210 /* By convention, expressions use ERROR_MARK_NODE to indicate
14211 failure, not NULL_TREE. */
14217 integral_constant_expression_p,
14225 input_location);
14229 {
14233 }
14235 }
14238 {
14239 tree object;
14247 {
14250 }
14251 else
14258 else
14260 }
14263 {
14267 {
14268 /* A type conversion to reference type will be enclosed in
14269 such an indirect ref, but the substitution of the cast
14270 will have also added such an indirect ref. */
14273 }
14274 else
14278 }
14286 {
14293 flags));
14294 }
14307 {
14308 tree type;
14314 {
14319 }
14325 {
14343 }
14346 }
14380 else
14382 in_decl);
14417 {
14420 tree r = build_x_binary_op
14424 ? ERROR_MARK
14428 ? ERROR_MARK
14436 }
14453 {
14462 }
14466 /* Fall through */
14469 {
14470 tree r;
14476 {
14477 /* When there are no ARGS, we are trying to evaluate a
14478 non-dependent expression from the parser. Trying to do
14479 the substitutions may not work. */
14482 }
14483 else
14484 {
14489 else
14492 /*integral_constant_expression_p=*/
14496 }
14500 else
14504 {
14506 {
14508 {
14512 }
14513 else
14517 }
14519 }
14521 }
14524 {
14534 }
14548 {
14550 tree r = build_x_modify_expr
14556 /* TREE_NO_WARNING must be set if either the expression was
14557 parenthesized or it uses an operator such as >>= rather
14558 than plain assignment. In the former case, it was already
14559 set and must be copied. In the latter case,
14560 build_x_modify_expr sets it and it must not be reset
14561 here. */
14566 }
14571 /* Remember that there was a reference to this entity. */
14577 {
14582 tree ret;
14586 else
14587 {
14591 }
14593 /* If there was an initializer in the original tree, but it
14594 instantiated to an empty list, then we should pass a
14595 non-NULL empty vector to tell build_new that it was an
14596 empty initializer() rather than no initializer. This can
14597 only happen when the initializer is a pack expansion whose
14598 parameter packs are of length zero. */
14601 else
14602 {
14606 else
14607 {
14610 }
14611 }
14618 complain);
14626 }
14634 complain));
14637 {
14641 integral_constant_expression_p);
14643 op0,
14646 }
14649 {
14650 tree function;
14655 tree ret;
14658 /* When we parsed the expression, we determined whether or
14659 not Koenig lookup should be performed. */
14662 {
14667 }
14669 {
14670 /* Do nothing; calling tsubst_copy_and_build on an identifier
14671 would incorrectly perform unqualified lookup again.
14673 Note that we can also have an IDENTIFIER_NODE if the earlier
14674 unqualified lookup found a member function; in that case
14675 koenig_p will be false and we do want to do the lookup
14676 again to find the instantiated member function.
14678 FIXME but doing that causes c++/15272, so we need to stop
14679 using IDENTIFIER_NODE in that situation. */
14681 }
14682 else
14683 {
14685 {
14691 }
14692 else
14697 /* Avoid error about taking the address of a constructor. */
14701 in_decl,
14703 integral_constant_expression_p);
14707 }
14712 {
14717 else
14718 {
14719 /* Expand the pack expansion and push each entry onto
14720 CALL_ARGS. */
14723 {
14728 {
14733 }
14734 }
14735 else
14736 {
14737 /* A partial substitution. Add one entry. */
14739 }
14740 }
14741 }
14743 /* We do not perform argument-dependent lookup if normal
14744 lookup finds a non-function, in accordance with the
14745 expected resolution of DR 218. */
14748 /* If lookup found a member function, the Koenig lookup is
14749 not appropriate, even if an unqualified-name was used
14750 to denote the function. */
14753 /* Only do this when substitution turns a dependent call
14754 into a non-dependent call. */
14761 {
14763 {
14764 /* For backwards compatibility and good diagnostics, try
14765 the unqualified lookup again if we aren't in SFINAE
14766 context. */
14767 tree unq = (tsubst_copy_and_build
14769 integral_constant_expression_p));
14774 {
14783 "%qD was not declared in this scope, "
14784 "and no declarations were found by "
14785 "argument-dependent lookup at the point "
14787 {
14791 {
14793 input_location);
14795 "declarations in dependent base %qT are "
14801 else
14805 }
14806 else
14809 }
14811 }
14812 }
14814 {
14819 }
14820 }
14822 /* Remember that there was a reference to this entity. */
14826 /* Put back tf_decltype for the actual call. */
14831 complain);
14833 {
14848 complain);
14849 else
14850 ret = (build_new_method_call
14855 complain));
14856 }
14857 else
14860 koenig_p,
14861 complain);
14866 }
14869 {
14871 tree folded_cond = (maybe_constant_value
14876 {
14878 {
14883 }
14884 else
14885 {
14890 }
14892 }
14893 else
14894 {
14897 }
14901 }
14908 input_location));
14911 {
14919 {
14920 /* We have pack expansions, so expand those and
14921 create a new list out of it. */
14924 tree chain;
14927 /* Expand the argument expressions. */
14935 /* Build the rest of the list. */
14940 /* Determine the number of arguments. */
14942 {
14945 }
14948 else
14949 {
14950 /* Since we only performed a partial substitution into
14951 the argument pack, we only RETURN (a single list
14952 node. */
14959 }
14961 /* Convert the argument vectors into a TREE_LIST */
14964 {
14965 /* Grab the Ith values. */
14966 i--;
14969 value
14973 /* Build the list (backwards). */
14975 }
14978 }
14994 }
14997 {
14998 tree object;
14999 tree object_type;
15000 tree member;
15001 tree r;
15005 /* Remember that there was a reference to this entity. */
15015 else
15023 {
15025 {
15030 {
15033 }
15035 {
15040 }
15041 }
15042 }
15045 {
15046 /* Lookup the template functions now that we know what the
15047 scope is. */
15055 {
15058 args);
15059 member = (adjust_result_of_qualified_name_lookup
15061 object_type));
15062 }
15063 else
15064 {
15066 input_location);
15068 }
15069 }
15073 {
15075 {
15079 else
15082 }
15084 }
15086 {
15091 }
15095 complain);
15099 }
15106 {
15114 tree r;
15119 /* digest_init will do the wrong thing if we let it. */
15123 /* We do not want to process the index of aggregate
15124 initializers as they are identifier nodes which will be
15125 looked up by digest_init. */
15131 {
15133 /* An identifier index is looked up in the type
15134 being initialized, not the current scope. */
15139 {
15140 /* Substitute into the pack expansion. */
15142 in_decl);
15146 ;
15148 /* Just move the argument into place. */
15150 else
15151 {
15152 /* Update the length of the final CONSTRUCTOR
15153 arguments vector, and note that we will need to
15154 copy.*/
15157 }
15158 }
15159 else
15161 }
15164 {
15169 {
15171 {
15176 }
15177 else
15179 }
15180 }
15190 }
15193 {
15196 {
15199 }
15200 else
15201 {
15204 }
15205 }
15211 {
15212 /* We don't build decls for an instantiation of a
15213 variadic capture proxy, we instantiate the elements
15214 when needed. */
15217 }
15218 /* Fall through */
15221 {
15224 && !processing_template_decl
15225 && !cp_unevaluated_operand
15227 {
15229 /* Replace an evaluated use of the thread_local variable with
15230 a call to its wrapper. */
15232 }
15235 /* If the original type was a reference, we'll be wrapped in
15236 the appropriate INDIRECT_REF. */
15239 }
15250 {
15259 }
15262 {
15268 integral_constant_expression_p);
15272 /* If the resulting list of expression statement is empty,
15273 fold it further into void_zero_node. */
15278 }
15281 {
15295 /* For a function scope, we want to use tsubst so that we don't
15296 complain about referring to an auto function before its return
15297 type has been deduced. Otherwise, we want to use tsubst_copy so
15298 that we look up the existing field/parameter/variable rather
15299 than build a new one. */
15304 {
15305 /* Look up the parameter we want directly, as tsubst_copy
15306 doesn't do what we need. */
15312 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15315 }
15316 else
15325 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15327 /* Now that we know visibility, instantiate the type so we have a
15328 declaration of the op() for later calls to lambda_function. */
15334 }
15337 /* We can get here for a constant initializer of non-dependent type.
15338 FIXME stop folding in cp_parser_initializer_clause. */
15339 {
15341 complain);
15343 }
15347 integral_constant_expression_p));
15357 complain));
15360 /* Handle Objective-C++ constructs, if appropriate. */
15361 {
15362 tree subst
15367 }
15369 }
15371 #undef RECUR
15372 #undef RETURN
15373 out:
15376 }
15378 /* Verify that the instantiated ARGS are valid. For type arguments,
15379 make sure that the type's linkage is ok. For non-type arguments,
15380 make sure they are constants if they are integral or enumerations.
15381 Emit an error under control of COMPLAIN, and return TRUE on error. */
15383 static bool
15385 {
15389 {
15399 }
15401 {
15402 /* [basic.link]: A name with no linkage (notably, the name
15403 of a class or enumeration declared in a local scope)
15404 shall not be used to declare an entity with linkage.
15405 This implies that names with no linkage cannot be used as
15406 template arguments
15408 DR 757 relaxes this restriction for C++0x. */
15413 {
15414 /* DR 488 makes use of a type with no linkage cause
15415 type deduction to fail. */
15417 {
15420 else
15423 }
15425 }
15426 /* In order to avoid all sorts of complications, we do not
15427 allow variably-modified types as template arguments. */
15429 {
15433 }
15434 }
15435 /* Class template and alias template arguments should be OK. */
15437 ;
15438 /* A non-type argument of integral or enumerated type must be a
15439 constant. */
15444 {
15448 }
15450 }
15452 static bool
15454 {
15459 {
15462 }
15466 }
15468 /* We're out of SFINAE context now, so generate diagnostics for the access
15469 errors we saw earlier when instantiating D from TMPL and ARGS. */
15471 static void
15473 {
15485 }
15487 /* Instantiate the indicated variable, function, or alias template TMPL with
15488 the template arguments in TARG_PTR. */
15490 static tree
15492 {
15494 tree fndecl;
15495 tree gen_tmpl;
15496 tree spec;
15504 /* If this function is a clone, handle it specially. */
15506 {
15507 tree spec;
15508 tree clone;
15510 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15511 DECL_CLONED_FUNCTION. */
15517 /* Look for the clone. */
15521 /* We should always have found the clone by now. */
15524 }
15529 /* Check to see if we already have this specialization. */
15532 /* The TMPL is a partial instantiation. To get a full set of
15533 arguments we must add the arguments used to perform the
15534 partial instantiation. */
15536 targ_ptr);
15538 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15539 but it doesn't seem to be on the hot path. */
15548 {
15550 {
15554 }
15556 }
15559 complain))
15562 /* We are building a FUNCTION_DECL, during which the access of its
15563 parameters and return types have to be checked. However this
15564 FUNCTION_DECL which is the desired context for access checking
15565 is not built yet. We solve this chicken-and-egg problem by
15566 deferring all checks until we have the FUNCTION_DECL. */
15569 /* Instantiation of the function happens in the context of the function
15570 template, not the context of the overload resolution we're doing. */
15572 /* If there are dependent arguments, e.g. because we're doing partial
15573 ordering, make sure processing_template_decl stays set. */
15577 {
15581 }
15582 /* Substitute template parameters to obtain the specialization. */
15590 {
15593 }
15595 /* The DECL_TI_TEMPLATE should always be the immediate parent
15596 template, not the most general template. */
15599 /* Now we know the specialization, compute access previously
15600 deferred. */
15607 /* If we've just instantiated the main entry point for a function,
15608 instantiate all the alternate entry points as well. We do this
15609 by cloning the instantiation of the main entry point, not by
15610 instantiating the template clones. */
15615 {
15617 {
15618 /* Remember to reinstantiate when we're out of SFINAE so the user
15619 can see the errors. */
15621 }
15623 }
15625 }
15627 /* Wrapper for instantiate_template_1. */
15629 tree
15631 {
15632 tree ret;
15637 }
15639 /* Instantiate the alias template TMPL with ARGS. Also push a template
15640 instantiation level, which instantiate_template doesn't do because
15641 functions and variables have sufficient context established by the
15642 callers. */
15644 static tree
15646 {
15653 {
15656 }
15658 args =
15666 /* We can't free this if a pending_template entry or last_error_tinst_level
15667 is pointing at it. */
15673 }
15675 /* PARM is a template parameter pack for FN. Returns true iff
15676 PARM is used in a deducible way in the argument list of FN. */
15678 static bool
15680 {
15683 {
15685 tree packs;
15691 {
15692 /* The template parameter pack is used in a function parameter
15693 pack. If this is the end of the parameter list, the
15694 template parameter pack is deducible. */
15697 else
15698 /* Otherwise, not. Well, it could be deduced from
15699 a non-pack parameter, but doing so would end up with
15700 a deduction mismatch, so don't bother. */
15702 }
15703 }
15704 /* The template parameter pack isn't used in any function parameter
15705 packs, but it might be used deeper, e.g. tuple<Args...>. */
15707 }
15709 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15710 NARGS elements of the arguments that are being used when calling
15711 it. TARGS is a vector into which the deduced template arguments
15712 are placed.
15714 Returns either a FUNCTION_DECL for the matching specialization of FN or
15715 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
15716 true, diagnostics will be printed to explain why it failed.
15718 If FN is a conversion operator, or we are trying to produce a specific
15719 specialization, RETURN_TYPE is the return type desired.
15721 The EXPLICIT_TARGS are explicit template arguments provided via a
15722 template-id.
15724 The parameter STRICT is one of:
15726 DEDUCE_CALL:
15727 We are deducing arguments for a function call, as in
15728 [temp.deduct.call].
15730 DEDUCE_CONV:
15731 We are deducing arguments for a conversion function, as in
15732 [temp.deduct.conv].
15734 DEDUCE_EXACT:
15735 We are deducing arguments when doing an explicit instantiation
15736 as in [temp.explicit], when determining an explicit specialization
15737 as in [temp.expl.spec], or when taking the address of a function
15738 template, as in [temp.deduct.funcaddr]. */
15740 tree
15742 tree explicit_targs,
15743 tree targs,
15746 tree return_type,
15747 unification_kind_t strict,
15751 {
15752 tree parms;
15753 tree fntype;
15761 tree tinst;
15767 /* In C++0x, it's possible to have a function template whose type depends
15768 on itself recursively. This is most obvious with decltype, but can also
15769 occur with enumeration scope (c++/48969). So we need to catch infinite
15770 recursion and reject the substitution at deduction time; this function
15771 will return error_mark_node for any repeated substitution.
15773 This also catches excessive recursion such as when f<N> depends on
15774 f<N-1> across all integers, and returns error_mark_node for all the
15775 substitutions back up to the initial one.
15777 This is, of course, not reentrant. */
15787 {
15788 /* [temp.deduct]
15790 The specified template arguments must match the template
15791 parameters in kind (i.e., type, nontype, template), and there
15792 must not be more arguments than there are parameters;
15793 otherwise type deduction fails.
15795 Nontype arguments must match the types of the corresponding
15796 nontype template parameters, or must be convertible to the
15797 types of the corresponding nontype parameters as specified in
15798 _temp.arg.nontype_, otherwise type deduction fails.
15800 All references in the function type of the function template
15801 to the corresponding template parameters are replaced by the
15802 specified template argument values. If a substitution in a
15803 template parameter or in the function type of the function
15804 template results in an invalid type, type deduction fails. */
15809 /* Adjust any explicit template arguments before entering the
15810 substitution context. */
15811 explicit_targs
15813 complain,
15819 /* Substitute the explicit args into the function type. This is
15820 necessary so that, for instance, explicitly declared function
15821 arguments can match null pointed constants. If we were given
15822 an incomplete set of explicit args, we must not do semantic
15823 processing during substitution as we could create partial
15824 instantiations. */
15826 {
15831 /* Dig out the actual parm. */
15834 {
15837 }
15839 {
15842 }
15845 /* No explicit argument for this template parameter. */
15849 {
15850 /* Mark the argument pack as "incomplete". We could
15851 still deduce more arguments during unification.
15852 We remove this mark in type_unification_real. */
15854 {
15858 }
15860 /* We have some incomplete argument packs. */
15862 }
15863 }
15867 {
15870 }
15873 /* Ignore any access checks; we'll see them again in
15874 instantiate_template and they might have the wrong
15875 access path at this point. */
15887 /* Place the explicitly specified arguments in TARGS. */
15890 }
15892 /* Never do unification on the 'this' parameter. */
15896 {
15905 }
15907 /* We allow incomplete unification without an error message here
15908 because the standard doesn't seem to explicitly prohibit it. Our
15909 callers must be ready to deal with unification failures in any
15910 event. */
15913 /* If we aren't explaining yet, push tinst context so we can see where
15914 any errors (e.g. from class instantiations triggered by instantiation
15915 of default template arguments) come from. If we are explaining, this
15916 context is redundant. */
15918 {
15921 }
15923 /* type_unification_real will pass back any access checks from default
15924 template argument substitution. */
15936 /* Now that we have bindings for all of the template arguments,
15937 ensure that the arguments deduced for the template template
15938 parameters have compatible template parameter lists. We cannot
15939 check this property before we have deduced all template
15940 arguments, because the template parameter types of a template
15941 template parameter might depend on prior template parameters
15942 deduced after the template template parameter. The following
15943 ill-formed example illustrates this issue:
15945 template<typename T, template<T> class C> void f(C<5>, T);
15947 template<int N> struct X {};
15949 void g() {
15950 f(X<5>(), 5l); // error: template argument deduction fails
15951 }
15953 The template parameter list of 'C' depends on the template type
15954 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15955 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15956 time that we deduce 'C'. */
15959 {
15962 }
15964 /* All is well so far. Now, check:
15966 [temp.deduct]
15968 When all template arguments have been deduced, all uses of
15969 template parameters in nondeduced contexts are replaced with
15970 the corresponding deduced argument values. If the
15971 substitution results in an invalid type, as described above,
15972 type deduction fails. */
15975 {
15978 }
15980 /* Also collect access checks from the instantiation. */
15993 /* Now perform any access checks encountered during substitution. */
16000 /* If we're looking for an exact match, check that what we got
16001 is indeed an exact match. It might not be if some template
16002 parameters are used in non-deduced contexts. But don't check
16003 for an exact match if we have dependent template arguments;
16004 in that case we're doing partial ordering, and we already know
16005 that we have two candidates that will provide the actual type. */
16007 {
16011 tree sarg
16017 {
16021 }
16022 }
16026 fail:
16029 {
16031 /* Reset once we're all the way out. */
16033 }
16035 /* We can't free this if a pending_template entry or last_error_tinst_level
16036 is pointing at it. */
16042 }
16044 /* Adjust types before performing type deduction, as described in
16045 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16046 sections are symmetric. PARM is the type of a function parameter
16047 or the return type of the conversion function. ARG is the type of
16048 the argument passed to the call, or the type of the value
16049 initialized with the result of the conversion function.
16050 ARG_EXPR is the original argument expression, which may be null. */
16052 static int
16056 tree arg_expr)
16057 {
16061 {
16066 {
16067 /* Swap PARM and ARG throughout the remainder of this
16068 function; the handling is precisely symmetric since PARM
16069 will initialize ARG rather than vice versa. */
16074 }
16077 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16078 too, but here handle it by stripping the reference from PARM
16079 rather than by adding it to ARG. */
16087 /* Nothing else to do in this case. */
16092 }
16095 {
16096 /* [temp.deduct.call]
16098 If P is not a reference type:
16100 --If A is an array type, the pointer type produced by the
16101 array-to-pointer standard conversion (_conv.array_) is
16102 used in place of A for type deduction; otherwise,
16104 --If A is a function type, the pointer type produced by
16105 the function-to-pointer standard conversion
16106 (_conv.func_) is used in place of A for type deduction;
16107 otherwise,
16109 --If A is a cv-qualified type, the top level
16110 cv-qualifiers of A's type are ignored for type
16111 deduction. */
16116 else
16118 }
16120 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16121 of the form T&&, where T is a template parameter, and the argument
16122 is an lvalue, T is deduced as A& */
16128 /* try_one_overload doesn't provide an arg_expr, but
16129 functions are always lvalues. */
16133 /* [temp.deduct.call]
16135 If P is a cv-qualified type, the top level cv-qualifiers
16136 of P's type are ignored for type deduction. If P is a
16137 reference type, the type referred to by P is used for
16138 type deduction. */
16141 {
16144 }
16146 /* DR 322. For conversion deduction, remove a reference type on parm
16147 too (which has been swapped into ARG). */
16152 }
16154 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16155 template which does contain any deducible template parameters; check if
16156 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16157 unify_one_argument. */
16159 static int
16162 {
16163 tree type;
16167 else
16174 {
16178 }
16180 {
16185 }
16189 else
16191 }
16195 /* Returns true iff the expression EXPR is one from which a template
16196 argument can be deduced. In other words, if it's an undecorated
16197 use of a template non-type parameter. */
16199 static bool
16201 {
16203 }
16205 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16206 deducible way; that is, if it has a max value of <PARM> - 1. */
16208 static bool
16210 {
16219 }
16221 /* Returns true iff the template arguments ARGS use a template parameter
16222 in a deducible way. */
16224 static bool
16226 {
16228 {
16233 else
16234 {
16241 else
16243 }
16246 }
16248 }
16250 /* Returns true iff TYPE contains any deducible references to template
16251 parameters, as per 14.8.2.5. */
16253 static bool
16255 {
16259 /* T
16260 cv-list T
16261 TT<T>
16262 TT<i>
16263 TT<> */
16268 /* T*
16269 T&
16270 T&& */
16274 /* T[integer-constant ]
16275 type [i] */
16280 /* T type ::*
16281 type T::*
16282 T T::*
16283 T (type ::*)()
16284 type (T::*)()
16285 type (type ::*)(T)
16286 type (T::*)(T)
16287 T (type ::*)(T)
16288 T (T::*)()
16289 T (T::*)(T) */
16292 || (uses_deducible_template_parms
16295 /* template-name <T> (where template-name refers to a class template)
16296 template-name <i> (where template-name refers to a class template) */
16303 /* type (T)
16304 T()
16305 T(T) */
16308 {
16317 }
16320 }
16322 /* Subroutine of type_unification_real and unify_pack_expansion to
16323 handle unification of a single P/A pair. Parameters are as
16324 for those functions. */
16326 static int
16330 {
16337 /* We can't deduce anything from this, but we might get all the
16338 template args from other function args. */
16341 /* Implicit conversions (Clause 4) will be performed on a function
16342 argument to convert it to the type of the corresponding function
16343 parameter if the parameter type contains no template-parameters that
16344 participate in template argument deduction. */
16346 /* For function parameters that contain no template-parameters at all,
16347 we have historically checked for convertibility in order to shortcut
16348 consideration of this candidate. */
16350 explain_p);
16353 /* For function parameters with only non-deducible template parameters,
16354 just return. */
16358 {
16360 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16361 | UNIFY_ALLOW_MORE_CV_QUAL
16375 }
16377 /* We only do these transformations if this is the top-level
16378 parameter_type_list in a call or declaration matching; in other
16379 situations (nested function declarators, template argument lists) we
16380 won't be comparing a type to an expression, and we don't do any type
16381 adjustments. */
16383 {
16385 {
16388 {
16389 /* [temp.deduct.type] A template-argument can be
16390 deduced from a pointer to function or pointer
16391 to member function argument if the set of
16392 overloaded functions does not contain function
16393 templates and at most one of a set of
16394 overloaded functions provides a unique
16395 match. */
16402 }
16408 }
16410 arg_strict |=
16412 }
16413 else
16418 /* For deduction from an init-list we need the actual list. */
16422 }
16424 /* Most parms like fn_type_unification.
16426 If SUBR is 1, we're being called recursively (to unify the
16427 arguments of a function or method parameter of a function
16428 template).
16430 CHECKS is a pointer to a vector of access checks encountered while
16431 substituting default template arguments. */
16433 static int
16435 tree targs,
16436 tree xparms,
16440 unification_kind_t strict,
16444 {
16449 tree parms;
16458 /* Reset the number of non-defaulted template arguments contained
16459 in TARGS. */
16462 again:
16470 {
16475 /* For a function parameter pack that occurs at the end of the
16476 parameter-declaration-list, the type A of each remaining
16477 argument of the call is compared with the type P of the
16478 declarator-id of the function parameter pack. */
16484 /* For a function parameter pack that does not occur at the
16485 end of the parameter-declaration-list, the type of the
16486 parameter pack is a non-deduced context. */
16495 }
16500 {
16501 /* Unify the remaining arguments with the pack expansion type. */
16502 tree argvec;
16505 /* Allocate a TREE_VEC and copy in all of the arguments */
16510 /* Copy the parameter into parmvec. */
16516 /* Advance to the end of the list of parameters. */
16518 }
16520 /* Fail if we've reached the end of the parm list, and more args
16521 are present, and the parm list isn't variadic. */
16524 /* Fail if parms are left and they don't have default values. */
16527 {
16531 {
16532 count++;
16534 }
16536 }
16539 {
16540 tsubst_flags_t complain = (explain_p
16541 ? tf_warning_or_error
16545 {
16549 /* Clear the "incomplete" flags on all argument packs now so that
16550 substituting them into later default arguments works. */
16552 {
16555 }
16561 /* If this is an undeduced nontype parameter that depends on
16562 a type parameter, try another pass; its type may have been
16563 deduced from a later argument than the one from which
16564 this parameter can be deduced. */
16570 /* Core issue #226 (C++0x) [temp.deduct]:
16572 If a template argument has not been deduced, its
16573 default template argument, if any, is used.
16575 When we are in C++98 mode, TREE_PURPOSE will either
16576 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16577 to explicitly check cxx_dialect here. */
16579 {
16594 else
16595 {
16597 /* The position of the first default template argument,
16598 is also the number of non-defaulted arguments in TARGS.
16599 Record that. */
16603 }
16604 }
16606 /* If the type parameter is a parameter pack, then it will
16607 be deduced to an empty parameter pack. */
16609 {
16610 tree arg;
16613 {
16617 }
16618 else
16625 }
16628 }
16629 }
16630 #ifdef ENABLE_CHECKING
16633 #endif
16636 }
16638 /* Subroutine of type_unification_real. Args are like the variables
16639 at the call site. ARG is an overloaded function (or template-id);
16640 we try deducing template args from each of the overloads, and if
16641 only one succeeds, we go with that. Modifies TARGS and returns
16642 true on success. */
16644 static bool
16646 tree targs,
16647 tree parm,
16648 tree arg,
16649 unification_kind_t strict,
16652 {
16659 {
16662 }
16663 else
16667 /* Handle `&x' where `x' is some static or non-static member
16668 function name. */
16674 /* Strip baselink information. */
16679 {
16680 /* If we got some explicit template args, we need to plug them into
16681 the affected templates before we try to unify, in case the
16682 explicit args will completely resolve the templates in question. */
16689 {
16702 {
16707 {
16710 }
16711 }
16714 }
16715 /* If no templates (or more than one) are fully resolved by the
16716 explicit arguments, this template-id is a non-deduced context; it
16717 could still be OK if we deduce all template arguments for the
16718 enclosing call through other arguments. */
16721 }
16724 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16725 -- but the deduction does not succeed because the expression is
16726 not just the function on its own. */
16728 else
16734 {
16737 }
16739 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16740 to function or pointer to member function argument if the set of
16741 overloaded functions does not contain function templates and at most
16742 one of a set of overloaded functions provides a unique match.
16744 So if we found multiple possibilities, we return success but don't
16745 deduce anything. */
16748 {
16752 {
16757 /* Don't forget explicit template arguments in a pack. */
16761 }
16762 }
16767 }
16769 /* Core DR 115: In contexts where deduction is done and fails, or in
16770 contexts where deduction is not done, if a template argument list is
16771 specified and it, along with any default template arguments, identifies
16772 a single function template specialization, then the template-id is an
16773 lvalue for the function template specialization. */
16775 tree
16777 {
16790 {
16793 }
16795 {
16798 }
16800 {
16803 }
16806 {
16810 /* If we got some explicit template args, we need to plug them into
16811 the affected templates before we try to unify, in case the
16812 explicit args will completely resolve the templates in question. */
16820 {
16833 {
16836 {
16839 }
16841 {
16844 }
16845 }
16846 }
16848 {
16856 {
16857 tree base
16860 }
16864 }
16866 /* There were no good options and at least one bad one, so let the
16867 user know what the problem is. */
16869 }
16871 }
16873 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16874 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16875 different overloads deduce different arguments for a given parm.
16876 ADDR_P is true if the expression for which deduction is being
16877 performed was of the form "& fn" rather than simply "fn".
16879 Returns 1 on success. */
16881 static int
16883 tree orig_targs,
16884 tree targs,
16885 tree parm,
16886 tree arg,
16887 unification_kind_t strict,
16891 {
16893 tree tempargs;
16899 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16900 to function or pointer to member function argument if the set of
16901 overloaded functions does not contain function templates and at most
16902 one of a set of overloaded functions provides a unique match.
16904 So if this is a template, just return success. */
16916 /* We don't copy orig_targs for this because if we have already deduced
16917 some template args from previous args, unify would complain when we
16918 try to deduce a template parameter for the same argument, even though
16919 there isn't really a conflict. */
16926 /* First make sure we didn't deduce anything that conflicts with
16927 explicitly specified args. */
16929 {
16936 /* Since we're unifying against ourselves, we will fill in
16937 template args used in the function parm list with our own
16938 template parms. Discard them. */
16942 }
16945 {
16950 }
16953 }
16955 /* PARM is a template class (perhaps with unbound template
16956 parameters). ARG is a fully instantiated type. If ARG can be
16957 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16958 TARGS are as for unify. */
16960 static tree
16963 {
16964 tree copy_of_targs;
16971 /* We need to make a new template argument vector for the call to
16972 unify. If we used TARGS, we'd clutter it up with the result of
16973 the attempted unification, even if this class didn't work out.
16974 We also don't want to commit ourselves to all the unifications
16975 we've already done, since unification is supposed to be done on
16976 an argument-by-argument basis. In other words, consider the
16977 following pathological case:
16979 template <int I, int J, int K>
16980 struct S {};
16982 template <int I, int J>
16983 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16985 template <int I, int J, int K>
16986 void f(S<I, J, K>, S<I, I, I>);
16988 void g() {
16989 S<0, 0, 0> s0;
16990 S<0, 1, 2> s2;
16992 f(s0, s2);
16993 }
16995 Now, by the time we consider the unification involving `s2', we
16996 already know that we must have `f<0, 0, 0>'. But, even though
16997 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
16998 because there are two ways to unify base classes of S<0, 1, 2>
16999 with S<I, I, I>. If we kept the already deduced knowledge, we
17000 would reject the possibility I=1. */
17003 /* If unification failed, we're done. */
17009 }
17011 /* Given a template type PARM and a class type ARG, find the unique
17012 base type in ARG that is an instance of PARM. We do not examine
17013 ARG itself; only its base-classes. If there is not exactly one
17014 appropriate base class, return NULL_TREE. PARM may be the type of
17015 a partial specialization, as well as a plain template type. Used
17016 by unify. */
17018 static enum template_base_result
17021 {
17023 tree binfo;
17029 {
17030 /* The type could not be completed. */
17033 }
17035 /* Walk in inheritance graph order. The search order is not
17036 important, and this avoids multiple walks of virtual bases. */
17038 {
17043 {
17044 /* If there is more than one satisfactory baseclass, then:
17046 [temp.deduct.call]
17048 If they yield more than one possible deduced A, the type
17049 deduction fails.
17051 applies. */
17053 {
17056 }
17059 }
17060 }
17064 }
17066 /* Returns the level of DECL, which declares a template parameter. */
17068 static int
17070 {
17072 {
17082 }
17084 }
17086 /* Decide whether ARG can be unified with PARM, considering only the
17087 cv-qualifiers of each type, given STRICT as documented for unify.
17088 Returns nonzero iff the unification is OK on that basis. */
17090 static int
17092 {
17098 {
17099 /* Although a CVR qualifier is ignored when being applied to a
17100 substituted template parameter ([8.3.2]/1 for example), that
17101 does not allow us to unify "const T" with "int&" because both
17102 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17103 It is ok when we're allowing additional CV qualifiers
17104 at the outer level [14.8.2.1]/3,1st bullet. */
17114 }
17125 }
17127 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17128 void
17130 {
17134 {
17137 }
17138 else
17139 {
17142 }
17143 }
17145 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17146 do { \
17147 if (unify (TP, TA, P, A, S, EP)) \
17148 return 1; \
17149 } while (0);
17151 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17152 expansion at the end of PACKED_PARMS. Returns 0 if the type
17153 deduction succeeds, 1 otherwise. STRICT is the same as in
17154 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17155 call argument list. We'll need to adjust the arguments to make them
17156 types. SUBR tells us if this is from a recursive call to
17157 type_unification_real, or for comparing two template argument
17158 lists. */
17160 static int
17164 {
17165 tree parm
17175 /* Determine the parameter packs we will be deducing from the
17176 pattern, and record their current deductions. */
17179 {
17183 /* Determine the index and level of this parameter pack. */
17186 /* Keep track of the parameter packs and their corresponding
17187 argument packs. */
17190 }
17192 /* Loop through all of the arguments that have not yet been
17193 unified and unify each with the pattern. */
17195 {
17196 tree parm;
17200 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17201 or the element of its argument pack at the current index if
17202 this argument was explicitly specified. */
17204 {
17213 {
17216 }
17218 }
17220 /* If we had explicit template arguments, substitute them into the
17221 pattern before deduction. */
17223 {
17224 /* Some arguments might still be unspecified or dependent. */
17232 NULL_TREE);
17237 }
17238 else
17241 /* Unify the pattern with the current argument. */
17246 /* For each parameter pack, collect the deduced value. */
17248 {
17254 }
17255 }
17257 /* Verify that the results of unification with the parameter packs
17258 produce results consistent with what we've seen before, and make
17259 the deduced argument packs available. */
17261 {
17268 /* By default keep the original deduced argument pack.
17269 If necessary, more specific code is going to update the
17270 resulting deduced argument later down in this function. */
17274 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17275 actually deduce anything. */
17283 {
17284 /* If we had fewer function args than explicit template args,
17285 just use the explicits. */
17290 }
17293 {
17294 tree result;
17295 /* Build the deduced *_ARGUMENT_PACK. */
17297 {
17302 }
17303 else
17308 /* Note the deduced argument packs for this parameter
17309 pack. */
17311 }
17315 {
17316 /* We only had the explicitly-provided arguments before, but
17317 now we have a complete set of arguments. */
17323 }
17324 else
17325 {
17331 /* Inconsistent unification of this parameter pack. */
17333 bad_old_arg,
17334 bad_new_arg);
17335 }
17336 }
17339 }
17341 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17342 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17343 parameters and return value are as for unify. */
17345 static int
17349 {
17350 tree parm_max;
17351 tree arg_max;
17355 /* Our representation of array types uses "N - 1" as the
17356 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17357 not an integer constant. We cannot unify arbitrarily
17358 complex expressions, so we eliminate the MINUS_EXPRs
17359 here. */
17363 {
17366 }
17370 {
17371 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17372 trying to unify the type of a variable with the type
17373 of a template parameter. For example:
17375 template <unsigned int N>
17376 void f (char (&) [N]);
17377 int g();
17378 void h(int i) {
17379 char a[g(i)];
17380 f(a);
17381 }
17383 Here, the type of the ARG will be "int [g(i)]", and
17384 may be a SAVE_EXPR, etc. */
17388 }
17390 /* If only one of the bounds used a MINUS_EXPR, compensate
17391 by adding one to the other bound. */
17394 integer_type_node,
17395 parm_max,
17396 integer_one_node);
17399 integer_type_node,
17400 arg_max,
17401 integer_one_node);
17405 }
17407 /* Deduce the value of template parameters. TPARMS is the (innermost)
17408 set of template parameters to a template. TARGS is the bindings
17409 for those template parameters, as determined thus far; TARGS may
17410 include template arguments for outer levels of template parameters
17411 as well. PARM is a parameter to a template function, or a
17412 subcomponent of that parameter; ARG is the corresponding argument.
17413 This function attempts to match PARM with ARG in a manner
17414 consistent with the existing assignments in TARGS. If more values
17415 are deduced, then TARGS is updated.
17417 Returns 0 if the type deduction succeeds, 1 otherwise. The
17418 parameter STRICT is a bitwise or of the following flags:
17420 UNIFY_ALLOW_NONE:
17421 Require an exact match between PARM and ARG.
17422 UNIFY_ALLOW_MORE_CV_QUAL:
17423 Allow the deduced ARG to be more cv-qualified (by qualification
17424 conversion) than ARG.
17425 UNIFY_ALLOW_LESS_CV_QUAL:
17426 Allow the deduced ARG to be less cv-qualified than ARG.
17427 UNIFY_ALLOW_DERIVED:
17428 Allow the deduced ARG to be a template base class of ARG,
17429 or a pointer to a template base class of the type pointed to by
17430 ARG.
17431 UNIFY_ALLOW_INTEGER:
17432 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17433 case for more information.
17434 UNIFY_ALLOW_OUTER_LEVEL:
17435 This is the outermost level of a deduction. Used to determine validity
17436 of qualification conversions. A valid qualification conversion must
17437 have const qualified pointers leading up to the inner type which
17438 requires additional CV quals, except at the outer level, where const
17439 is not required [conv.qual]. It would be normal to set this flag in
17440 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17441 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17442 This is the outermost level of a deduction, and PARM can be more CV
17443 qualified at this point.
17444 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17445 This is the outermost level of a deduction, and PARM can be less CV
17446 qualified at this point. */
17448 static int
17451 {
17453 tree targ;
17454 tree tparm;
17457 /* I don't think this will do the right thing with respect to types.
17458 But the only case I've seen it in so far has been array bounds, where
17459 signedness is the only information lost, and I think that will be
17460 okay. */
17468 /* We can't deduce anything from this, but we might get all the
17469 template args from other function args. */
17472 /* If PARM uses template parameters, then we can't bail out here,
17473 even if ARG == PARM, since we won't record unifications for the
17474 template parameters. We might need them if we're trying to
17475 figure out which of two things is more specialized. */
17479 /* Handle init lists early, so the rest of the function can assume
17480 we're dealing with a type. */
17482 {
17487 /* Replace T with std::initializer_list<T> for deduction. */
17494 /* We can only deduce from an initializer list argument if the
17495 parameter is std::initializer_list or an array; otherwise this
17496 is a non-deduced context. */
17501 else
17505 {
17512 {
17514 /* It should only be possible to get here for a call. */
17516 elt_strict |= maybe_adjust_types_for_deduction
17519 }
17522 explain_p);
17523 }
17527 {
17528 /* Also deduce from the length of the initializer list. */
17535 }
17537 /* If the std::initializer_list<T> deduction worked, replace the
17538 deduced A with std::initializer_list<A>. */
17540 {
17545 }
17547 }
17549 /* Immediately reject some pairs that won't unify because of
17550 cv-qualification mismatches. */
17553 /* It is the elements of the array which hold the cv quals of an array
17554 type, and the elements might be template type parms. We'll check
17555 when we recurse. */
17557 /* We check the cv-qualifiers when unifying with template type
17558 parameters below. We want to allow ARG `const T' to unify with
17559 PARM `T' for example, when computing which of two templates
17560 is more specialized, for example. */
17574 {
17578 /* In a type which contains a nested-name-specifier, template
17579 argument values cannot be deduced for template parameters used
17580 within the nested-name-specifier. */
17592 /* The PARM is not one we're trying to unify. Just check
17593 to see if it matches ARG. */
17594 {
17599 else
17601 }
17608 /* Check for mixed types and values. */
17616 {
17617 /* ARG must be constructed from a template class or a template
17618 template parameter. */
17622 {
17624 /* An alias template name is never deduced. */
17629 tree parm_parms
17630 = DECL_INNERMOST_TEMPLATE_PARMS
17635 /* The resolution to DR150 makes clear that default
17636 arguments for an N-argument may not be used to bind T
17637 to a template template parameter with fewer than N
17638 parameters. It is not safe to permit the binding of
17639 default arguments as an extension, as that may change
17640 the meaning of a conforming program. Consider:
17642 struct Dense { static const unsigned int dim = 1; };
17644 template <template <typename> class View,
17645 typename Block>
17646 void operator+(float, View<Block> const&);
17648 template <typename Block,
17649 unsigned int Dim = Block::dim>
17650 struct Lvalue_proxy { operator float() const; };
17652 void
17653 test_1d (void) {
17654 Lvalue_proxy<Dense> p;
17655 float b;
17656 b + p;
17657 }
17659 Here, if Lvalue_proxy is permitted to bind to View, then
17660 the global operator+ will be used; if they are not, the
17661 Lvalue_proxy will be converted to float. */
17663 full_argvec,
17665 (explain_p
17666 ? tf_warning_or_error
17673 /* Deduce arguments T, i from TT<T> or TT<i>.
17674 We check each element of PARMVEC and ARGVEC individually
17675 rather than the whole TREE_VEC since they can have
17676 different number of elements. */
17683 /* Check if the parameters end in a pack, making them
17684 variadic. */
17690 /* If the template argument list of P contains a pack
17691 expansion that is not the last template argument, the
17692 entire template argument list is a non-deduced
17693 context. */
17702 {
17707 }
17712 DEDUCE_EXACT,
17715 }
17718 /* Fall through to deduce template name. */
17719 }
17723 {
17724 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17726 /* Simple cases: Value already set, does match or doesn't. */
17731 }
17732 else
17733 {
17734 /* If PARM is `const T' and ARG is only `int', we don't have
17735 a match unless we are allowing additional qualification.
17736 If ARG is `const int' and PARM is just `T' that's OK;
17737 that binds `const int' to `T'. */
17742 /* Consider the case where ARG is `const volatile int' and
17743 PARM is `const T'. Then, T should be `volatile int'. */
17744 arg = cp_build_qualified_type_real
17749 /* Simple cases: Value already set, does match or doesn't. */
17755 /* Make sure that ARG is not a variable-sized array. (Note
17756 that were talking about variable-sized arrays (like
17757 `int[n]'), rather than arrays of unknown size (like
17758 `int[]').) We'll get very confused by such a type since
17759 the bound of the array is not constant, and therefore
17760 not mangleable. Besides, such types are not allowed in
17761 ISO C++, so we can do as we please here. We do allow
17762 them for 'auto' deduction, since that isn't ABI-exposed. */
17766 /* Strip typedefs as in convert_template_argument. */
17768 }
17770 /* If ARG is a parameter pack or an expansion, we cannot unify
17771 against it unless PARM is also a parameter pack. */
17776 /* If the argument deduction results is a METHOD_TYPE,
17777 then there is a problem.
17778 METHOD_TYPE doesn't map to any real C++ type the result of
17779 the deduction can not be of that type. */
17793 {
17794 /* The PARM is not one we're trying to unify. Just check
17795 to see if it matches ARG. */
17801 }
17807 {
17812 }
17814 /* [temp.deduct.type] If, in the declaration of a function template
17815 with a non-type template-parameter, the non-type
17816 template-parameter is used in an expression in the function
17817 parameter-list and, if the corresponding template-argument is
17818 deduced, the template-argument type shall match the type of the
17819 template-parameter exactly, except that a template-argument
17820 deduced from an array bound may be of any integral type.
17821 The non-type parameter might use already deduced type parameters. */
17824 /* Template-parameter dependent expression. Just accept it for now.
17825 It will later be processed in convert_template_argument. */
17826 ;
17831 /* Convert the ARG to the type of PARM; the deduced non-type
17832 template argument must exactly match the types of the
17833 corresponding parameter. */
17836 /* We haven't deduced the type of this parameter yet. Try again
17837 later. */
17839 else
17842 /* If ARG is a parameter pack or an expansion, we cannot unify
17843 against it unless PARM is also a parameter pack. */
17853 {
17854 /* A pointer-to-member constant can be unified only with
17855 another constant. */
17859 /* Just unify the class member. It would be useless (and possibly
17860 wrong, depending on the strict flags) to unify also
17861 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17862 arg refer to the same variable, even if through different
17863 classes. For instance:
17865 struct A { int x; };
17866 struct B : A { };
17868 Unification of &A::x and &B::x must succeed. */
17871 }
17874 {
17878 /* [temp.deduct.call]
17880 A can be another pointer or pointer to member type that can
17881 be converted to the deduced A via a qualification
17882 conversion (_conv.qual_).
17884 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17885 This will allow for additional cv-qualification of the
17886 pointed-to types if appropriate. */
17889 /* The derived-to-base conversion only persists through one
17890 level of pointers. */
17895 }
17927 /* We have already checked cv-qualification at the top of the
17928 function. */
17932 /* As far as unification is concerned, this wins. Later checks
17933 will invalidate it if necessary. */
17936 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17937 /* Type INTEGER_CST can come from ordinary constant template args. */
17949 {
17959 /* Check for pack expansions in the parameters. */
17961 {
17963 {
17965 /* We can unify against something with a trailing
17966 parameter pack. */
17968 else
17969 /* [temp.deduct.type]/9: If the template argument list of
17970 P contains a pack expansion that is not the last
17971 template argument, the entire template argument list
17972 is a non-deduced context. */
17974 }
17975 }
17977 /* If we don't have enough arguments to satisfy the parameters
17978 (not counting the pack expression at the end), or we have
17979 too many arguments for a parameter list that doesn't end in
17980 a pack expression, we can't unify. */
17986 /* Unify all of the parameters that precede the (optional)
17987 pack expression. */
17989 {
17994 }
17997 DEDUCE_EXACT,
18000 }
18008 {
18016 }
18019 {
18023 {
18024 /* First, we try to unify the PARM and ARG directly. */
18029 {
18030 /* Fallback to the special case allowed in
18031 [temp.deduct.call]:
18033 If P is a class, and P has the form
18034 template-id, then A can be a derived class of
18035 the deduced A. Likewise, if P is a pointer to
18036 a class of the form template-id, A can be a
18037 pointer to a derived class pointed to by the
18038 deduced A. */
18045 }
18046 }
18050 /* Perhaps PARM is something like S<U> and ARG is S<int>.
18051 Then, we should unify `int' and `U'. */
18053 else
18054 /* There's no chance of unification succeeding. */
18059 }
18066 {
18069 tree a;
18075 /* CV qualifications for methods can never be deduced, they must
18076 match exactly. We need to check them explicitly here,
18077 because type_unification_real treats them as any other
18078 cv-qualified parameter. */
18080 && (!check_cv_quals_for_unify
18100 }
18103 /* Unify a pointer to member with a pointer to member function, which
18104 deduces the type of the member as a function type. */
18106 {
18107 /* Check top-level cv qualifiers */
18115 /* Determine the type of the function we are unifying against. */
18119 }
18138 /* Matched cases are handled by the ARG == PARM test above. */
18142 /* A non-type template parameter that is a variable should be a
18143 an integral constant, in which case, it whould have been
18144 folded into its (constant) value. So we should not be getting
18145 a variable here. */
18156 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18157 or UNDERLYING_TYPE nodes. */
18161 /* Unification fails if we hit an error node. */
18166 {
18171 }
18172 /* FALLTHRU */
18175 /* An unresolved overload is a nondeduced context. */
18180 /* We must be looking at an expression. This can happen with
18181 something like:
18183 template <int I>
18184 void foo(S<I>, S<I + 2>);
18186 This is a "nondeduced context":
18188 [deduct.type]
18190 The nondeduced contexts are:
18192 --A type that is a template-id in which one or more of
18193 the template-arguments is an expression that references
18194 a template-parameter.
18196 In these cases, we assume deduction succeeded, but don't
18197 actually infer any unifications. */
18202 else
18204 }
18205 }
18206 #undef RECUR_AND_CHECK_FAILURE
18207 \f
18208 /* Note that DECL can be defined in this translation unit, if
18209 required. */
18211 static void
18213 {
18214 tree clone;
18218 }
18220 /* Called if RESULT is explicitly instantiated, or is a member of an
18221 explicitly instantiated class. */
18223 void
18225 {
18228 /* If this entity has already been written out, it's too late to
18229 make any modifications. */
18233 /* For anonymous namespace we don't need to do anything. */
18235 {
18238 }
18241 /* The TREE_PUBLIC flag for function declarations will have been
18242 set correctly by tsubst. */
18245 /* This might have been set by an earlier implicit instantiation. */
18250 else
18251 {
18254 /* Always make artificials weak. */
18257 /* For WIN32 we also want to put explicit instantiations in
18258 linkonce sections. */
18261 }
18263 /* If EXTERN_P, then this function will not be emitted -- unless
18264 followed by an explicit instantiation, at which point its linkage
18265 will be adjusted. If !EXTERN_P, then this function will be
18266 emitted here. In neither circumstance do we want
18267 import_export_decl to adjust the linkage. */
18269 }
18271 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18272 important template arguments. If any are missing, we check whether
18273 they're important by using error_mark_node for substituting into any
18274 args that were used for partial ordering (the ones between ARGS and END)
18275 and seeing if it bubbles up. */
18277 static bool
18279 {
18284 {
18287 }
18289 {
18293 }
18295 }
18297 /* Given two function templates PAT1 and PAT2, return:
18299 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18300 -1 if PAT2 is more specialized than PAT1.
18301 0 if neither is more specialized.
18303 LEN indicates the number of parameters we should consider
18304 (defaulted parameters should not be considered).
18306 The 1998 std underspecified function template partial ordering, and
18307 DR214 addresses the issue. We take pairs of arguments, one from
18308 each of the templates, and deduce them against each other. One of
18309 the templates will be more specialized if all the *other*
18310 template's arguments deduce against its arguments and at least one
18311 of its arguments *does* *not* deduce against the other template's
18312 corresponding argument. Deduction is done as for class templates.
18313 The arguments used in deduction have reference and top level cv
18314 qualifiers removed. Iff both arguments were originally reference
18315 types *and* deduction succeeds in both directions, an lvalue reference
18316 wins against an rvalue reference and otherwise the template
18317 with the more cv-qualified argument wins for that pairing (if
18318 neither is more cv-qualified, they both are equal). Unlike regular
18319 deduction, after all the arguments have been deduced in this way,
18320 we do *not* verify the deduced template argument values can be
18321 substituted into non-deduced contexts.
18323 The logic can be a bit confusing here, because we look at deduce1 and
18324 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18325 can find template arguments for pat1 to make arg1 look like arg2, that
18326 means that arg2 is at least as specialized as arg1. */
18328 int
18330 {
18343 /* Remove the this parameter from non-static member functions. If
18344 one is a non-static member function and the other is not a static
18345 member function, remove the first parameter from that function
18346 also. This situation occurs for operator functions where we
18347 locate both a member function (with this pointer) and non-member
18348 operator (with explicit first operand). */
18350 {
18355 }
18357 {
18360 {
18361 len--;
18363 }
18364 }
18366 /* If only one is a conversion operator, they are unordered. */
18370 /* Consider the return type for a conversion function */
18372 {
18375 len++;
18376 }
18378 processing_template_decl++;
18384 /* Stop when an ellipsis is seen. */
18386 {
18397 {
18398 /* When both arguments are pack expansions, we need only
18399 unify the patterns themselves. */
18403 /* This is the last comparison we need to do. */
18405 }
18408 {
18412 }
18415 {
18419 }
18425 {
18431 /* Setup the parameter vector, which contains only ARG1. */
18434 /* Setup the argument vector, which contains the remaining
18435 arguments. */
18444 /* We cannot deduce in the other direction, because ARG1 is
18445 a pack expansion but ARG2 is not. */
18447 }
18449 {
18455 /* Setup the parameter vector, which contains only ARG1. */
18458 /* Setup the argument vector, which contains the remaining
18459 arguments. */
18468 /* We cannot deduce in the other direction, because ARG2 is
18469 a pack expansion but ARG1 is not.*/
18471 }
18473 else
18474 {
18475 /* The normal case, where neither argument is a pack
18476 expansion. */
18483 }
18485 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18486 arg2, then arg2 is not as specialized as arg1. */
18492 /* "If, for a given type, deduction succeeds in both directions
18493 (i.e., the types are identical after the transformations above)
18494 and both P and A were reference types (before being replaced with
18495 the type referred to above):
18496 - if the type from the argument template was an lvalue reference and
18497 the type from the parameter template was not, the argument type is
18498 considered to be more specialized than the other; otherwise,
18499 - if the type from the argument template is more cv-qualified
18500 than the type from the parameter template (as described above),
18501 the argument type is considered to be more specialized than the other;
18502 otherwise,
18503 - neither type is more specialized than the other." */
18506 {
18508 {
18511 else
18513 }
18515 {
18520 }
18521 }
18524 /* We've failed to deduce something in either direction.
18525 These must be unordered. */
18530 /* We have already processed all of the arguments in our
18531 handing of the pack expansion type. */
18536 }
18538 /* "In most cases, all template parameters must have values in order for
18539 deduction to succeed, but for partial ordering purposes a template
18540 parameter may remain without a value provided it is not used in the
18541 types being used for partial ordering."
18543 Thus, if we are missing any of the targs1 we need to substitute into
18544 origs1, then pat2 is not as specialized as pat1. This can happen when
18545 there is a nondeduced context. */
18551 processing_template_decl--;
18553 /* All things being equal, if the next argument is a pack expansion
18554 for one function but not for the other, prefer the
18555 non-variadic function. FIXME this is bogus; see c++/41958. */
18559 {
18562 }
18568 else
18570 }
18572 /* Determine which of two partial specializations of TMPL is more
18573 specialized.
18575 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18576 to the first partial specialization. The TREE_VALUE is the
18577 innermost set of template parameters for the partial
18578 specialization. PAT2 is similar, but for the second template.
18580 Return 1 if the first partial specialization is more specialized;
18581 -1 if the second is more specialized; 0 if neither is more
18582 specialized.
18584 See [temp.class.order] for information about determining which of
18585 two templates is more specialized. */
18587 static int
18589 {
18590 tree targs;
18598 /* Just like what happens for functions, if we are ordering between
18599 different class template specializations, we may encounter dependent
18600 types in the arguments, and we need our dependency check functions
18601 to behave correctly. */
18607 {
18610 }
18616 {
18619 }
18622 /* In the case of a tie where at least one of the class templates
18623 has a parameter pack at the end, the template with the most
18624 non-packed parameters wins. */
18626 && any_deductions
18629 {
18635 /* We don't count the pack expansion at the end. */
18645 }
18648 }
18650 /* Return the template arguments that will produce the function signature
18651 DECL from the function template FN, with the explicit template
18652 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18653 also match. Return NULL_TREE if no satisfactory arguments could be
18654 found. */
18656 static tree
18658 {
18662 tree decl_arg_types;
18665 tree arg;
18669 /* Never do unification on the 'this' parameter. */
18690 }
18692 /* Return the innermost template arguments that, when applied to a partial
18693 specialization of TMPL whose innermost template parameters are
18694 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18695 ARGS.
18697 For example, suppose we have:
18699 template <class T, class U> struct S {};
18700 template <class T> struct S<T*, int> {};
18702 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18703 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18704 int}. The resulting vector will be {double}, indicating that `T'
18705 is bound to `double'. */
18707 static tree
18709 {
18711 tree deduced_args;
18712 tree innermost_deduced_args;
18716 {
18720 innermost_deduced_args);
18721 }
18722 else
18735 /* Verify that nondeduced template arguments agree with the type
18736 obtained from argument deduction.
18738 For example:
18740 struct A { typedef int X; };
18741 template <class T, class U> struct C {};
18742 template <class T> struct C<T, typename T::X> {};
18744 Then with the instantiation `C<A, int>', we can deduce that
18745 `T' is `A' but unify () does not check whether `typename T::X'
18746 is `int'. */
18752 /* We only need to check the innermost arguments; the other
18753 arguments will always agree. */
18758 /* Now that we have bindings for all of the template arguments,
18759 ensure that the arguments deduced for the template template
18760 parameters have compatible template parameter lists. See the use
18761 of template_template_parm_bindings_ok_p in fn_type_unification
18762 for more information. */
18767 }
18769 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18770 Return the TREE_LIST node with the most specialized template, if
18771 any. If there is no most specialized template, the error_mark_node
18772 is returned.
18774 Note that this function does not look at, or modify, the
18775 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18776 returned is one of the elements of INSTANTIATIONS, callers may
18777 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18778 and retrieve it from the value returned. */
18780 tree
18782 {
18789 {
18795 fate--;
18800 fate++;
18805 {
18806 /* Equally specialized, move to next function. If there
18807 is no next function, nothing's most specialized. */
18812 }
18813 }
18816 /* Now verify that champ is better than everything earlier in the
18817 instantiation list. */
18825 {
18828 }
18830 processing_template_decl--;
18836 }
18838 /* If DECL is a specialization of some template, return the most
18839 general such template. Otherwise, returns NULL_TREE.
18841 For example, given:
18843 template <class T> struct S { template <class U> void f(U); };
18845 if TMPL is `template <class U> void S<int>::f(U)' this will return
18846 the full template. This function will not trace past partial
18847 specializations, however. For example, given in addition:
18849 template <class T> struct S<T*> { template <class U> void f(U); };
18851 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18852 `template <class T> template <class U> S<T*>::f(U)'. */
18854 tree
18856 {
18858 {
18861 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
18862 template friend, or a FIELD_DECL for a capture pack. */
18865 }
18867 /* Look for more and more general templates. */
18869 {
18870 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18871 (See cp-tree.h for details.) */
18879 /* Stop if we run into an explicitly specialized class template. */
18886 }
18889 }
18891 /* Return the most specialized of the class template partial
18892 specializations which can produce TYPE, a specialization of some class
18893 template. The value returned is actually a TREE_LIST; the TREE_TYPE is
18894 a _TYPE node corresponding to the partial specialization, while the
18895 TREE_PURPOSE is the set of template arguments that must be
18896 substituted into the TREE_TYPE in order to generate TYPE.
18898 If the choice of partial specialization is ambiguous, a diagnostic
18899 is issued, and the error_mark_node is returned. If there are no
18900 partial specializations matching TYPE, then NULL_TREE is
18901 returned, indicating that the primary template should be used. */
18903 static tree
18905 {
18907 tree t;
18908 tree champ;
18917 /* For determining which partial specialization to use, only the
18918 innermost args are interesting. */
18920 {
18923 }
18926 {
18927 tree partial_spec_args;
18928 tree spec_args;
18937 {
18938 /* Discard the outer levels of args, and then substitute in the
18939 template args from the enclosing class. */
18941 partial_spec_args = tsubst_template_args
18944 /* And the same for the partial specialization TEMPLATE_DECL. */
18946 }
18948 partial_spec_args =
18950 partial_spec_args,
18964 partial_spec_args,
18965 args);
18967 {
18972 }
18973 }
18983 {
18986 ;
18987 else
18988 {
18990 {
18993 {
18996 }
18997 }
18999 }
19000 }
19004 {
19007 {
19010 }
19011 }
19014 {
19022 {
19025 }
19028 }
19031 }
19033 /* Explicitly instantiate DECL. */
19035 void
19037 {
19042 /* An error occurred, for which grokdeclarator has already issued
19043 an appropriate message. */
19046 {
19049 }
19051 {
19052 /* There is an asymmetry here in the way VAR_DECLs and
19053 FUNCTION_DECLs are handled by grokdeclarator. In the case of
19054 the latter, the DECL we get back will be marked as a
19055 template instantiation, and the appropriate
19056 DECL_TEMPLATE_INFO will be set up. This does not happen for
19057 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
19058 should handle VAR_DECLs as it currently handles
19059 FUNCTION_DECLs. */
19061 {
19064 }
19067 {
19070 }
19072 {
19077 }
19078 }
19080 {
19083 }
19084 else
19087 /* Check for various error cases. Note that if the explicit
19088 instantiation is valid the RESULT will currently be marked as an
19089 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19090 until we get here. */
19093 {
19094 /* DR 259 [temp.spec].
19096 Both an explicit instantiation and a declaration of an explicit
19097 specialization shall not appear in a program unless the explicit
19098 instantiation follows a declaration of the explicit specialization.
19100 For a given set of template parameters, if an explicit
19101 instantiation of a template appears after a declaration of an
19102 explicit specialization for that template, the explicit
19103 instantiation has no effect. */
19105 }
19107 {
19108 /* [temp.spec]
19110 No program shall explicitly instantiate any template more
19111 than once.
19113 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19114 the first instantiation was `extern' and the second is not,
19115 and EXTERN_P for the opposite case. */
19118 /* If an "extern" explicit instantiation follows an ordinary
19119 explicit instantiation, the template is instantiated. */
19122 }
19124 {
19127 }
19129 {
19132 }
19135 ;
19137 {
19140 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19143 }
19144 else
19152 }
19154 static void
19156 {
19162 {
19165 }
19166 }
19168 /* Called from do_type_instantiation through binding_table_foreach to
19169 do recursive instantiation for the type bound in ENTRY. */
19170 static void
19172 {
19178 }
19180 /* Called from do_type_instantiation to instantiate a member
19181 (a member function or a static member variable) of an
19182 explicitly instantiated class template. */
19183 static void
19185 {
19190 }
19192 /* Perform an explicit instantiation of template class T. STORAGE, if
19193 non-null, is the RID for extern, inline or static. COMPLAIN is
19194 nonzero if this is called from the parser, zero if called recursively,
19195 since the standard is unclear (as detailed below). */
19197 void
19199 {
19209 {
19210 tree tmpl =
19214 else
19217 }
19222 {
19225 t);
19227 }
19230 {
19232 {
19234 {
19237 "ISO C++ 1998 forbids the use of %<extern%> on "
19239 }
19240 else
19242 "ISO C++ forbids the use of %qE"
19244 }
19252 else
19253 {
19255 storage);
19257 }
19258 }
19261 {
19262 /* DR 259 [temp.spec].
19264 Both an explicit instantiation and a declaration of an explicit
19265 specialization shall not appear in a program unless the explicit
19266 instantiation follows a declaration of the explicit specialization.
19268 For a given set of template parameters, if an explicit
19269 instantiation of a template appears after a declaration of an
19270 explicit specialization for that template, the explicit
19271 instantiation has no effect. */
19273 }
19275 {
19276 /* [temp.spec]
19278 No program shall explicitly instantiate any template more
19279 than once.
19281 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19282 instantiation was `extern'. If EXTERN_P then the second is.
19283 These cases are OK. */
19290 /* If we've already instantiated the template, just return now. */
19293 }
19301 {
19302 tree tmp;
19304 /* In contrast to implicit instantiation, where only the
19305 declarations, and not the definitions, of members are
19306 instantiated, we have here:
19308 [temp.explicit]
19310 The explicit instantiation of a class template specialization
19311 implies the instantiation of all of its members not
19312 previously explicitly specialized in the translation unit
19313 containing the explicit instantiation.
19315 Of course, we can't instantiate member template classes, since
19316 we don't have any arguments for them. Note that the standard
19317 is unclear on whether the instantiation of the members are
19318 *explicit* instantiations or not. However, the most natural
19319 interpretation is that it should be an explicit instantiation. */
19334 }
19335 }
19337 /* Given a function DECL, which is a specialization of TMPL, modify
19338 DECL to be a re-instantiation of TMPL with the same template
19339 arguments. TMPL should be the template into which tsubst'ing
19340 should occur for DECL, not the most general template.
19342 One reason for doing this is a scenario like this:
19344 template <class T>
19345 void f(const T&, int i);
19347 void g() { f(3, 7); }
19349 template <class T>
19350 void f(const T& t, const int i) { }
19352 Note that when the template is first instantiated, with
19353 instantiate_template, the resulting DECL will have no name for the
19354 first parameter, and the wrong type for the second. So, when we go
19355 to instantiate the DECL, we regenerate it. */
19357 static void
19359 {
19360 /* The arguments used to instantiate DECL, from the most general
19361 template. */
19362 tree args;
19363 tree code_pattern;
19368 /* Make sure that we can see identifiers, and compute access
19369 correctly. */
19373 {
19374 tree decl_parm;
19375 tree pattern_parm;
19376 tree specs;
19390 specs);
19392 /* Merge parameter declarations. */
19395 pattern_parm
19399 {
19400 tree parm_type;
19401 tree attributes;
19406 NULL_TREE);
19412 {
19415 }
19418 }
19419 /* Merge any parameters that match with the function parameter
19420 pack. */
19422 {
19424 tree expanded_types;
19425 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19426 the parameters in this function parameter pack. */
19431 {
19432 tree parm_type;
19433 tree attributes;
19436 /* Rename the parameter to include the index. */
19445 {
19448 }
19450 }
19451 }
19452 /* Merge additional specifiers from the CODE_PATTERN. */
19456 }
19458 {
19466 }
19467 else
19471 }
19473 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19474 substituted to get DECL. */
19476 tree
19478 {
19481 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19482 for the instantiation. This is not always the most general
19483 template. Consider, for example:
19485 template <class T>
19486 struct S { template <class U> void f();
19487 template <> void f<int>(); };
19489 and an instantiation of S<double>::f<int>. We want TD to be the
19490 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19492 more general template. */
19494 /* We must also deal with friend templates. Given:
19496 template <class T> struct S {
19497 template <class U> friend void f() {};
19498 };
19500 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19501 so far as the language is concerned, but that's still
19502 where we get the pattern for the instantiation from. On
19503 other hand, if the definition comes outside the class, say:
19505 template <class T> struct S {
19506 template <class U> friend void f();
19507 };
19508 template <class U> friend void f() {}
19510 we don't need to look any further. That's what the check for
19511 DECL_INITIAL is for. */
19515 {
19516 /* The present template, TD, should not be a definition. If it
19517 were a definition, we should be using it! Note that we
19518 cannot restructure the loop to just keep going until we find
19519 a template with a definition, since that might go too far if
19520 a specialization was declared, but not defined. */
19524 /* Fetch the more general template. */
19526 }
19529 }
19531 /* Returns true if we need to instantiate this template instance even if we
19532 know we aren't going to emit it.. */
19534 bool
19536 {
19537 /* We always instantiate inline functions so that we can inline them. An
19538 explicit instantiation declaration prohibits implicit instantiation of
19539 non-inline functions. With high levels of optimization, we would
19540 normally inline non-inline functions -- but we're not allowed to do
19541 that for "extern template" functions. Therefore, we check
19542 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19546 /* And we need to instantiate static data members so that
19547 their initializers are available in integral constant
19548 expressions. */
19551 }
19553 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19554 instantiate it now, modifying TREE_TYPE (fn). */
19556 void
19558 {
19561 /* Don't instantiate a noexcept-specification from template context. */
19576 {
19578 {
19593 }
19594 else
19596 }
19597 else
19598 {
19599 /* This is an implicitly declared function, so NOEX is a list of
19600 other functions to evaluate and merge. */
19601 tree elt;
19604 {
19606 tree subspec;
19610 }
19611 }
19616 {
19619 else
19621 }
19622 }
19624 /* Produce the definition of D, a _DECL generated from a template. If
19625 DEFER_OK is nonzero, then we don't have to actually do the
19626 instantiation now; we just have to do it sometime. Normally it is
19627 an error if this is an explicit instantiation but D is undefined.
19628 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19629 explicitly instantiated class template. */
19631 tree
19634 {
19636 tree gen_args;
19637 tree args;
19638 tree td;
19639 tree code_pattern;
19640 tree spec;
19641 tree gen_tmpl;
19647 tree fn_context;
19650 /* This function should only be used to instantiate templates for
19651 functions and static member variables. */
19654 /* Variables are never deferred; if instantiation is required, they
19655 are instantiated right away. That allows for better code in the
19656 case that an expression refers to the value of the variable --
19657 if the variable has a constant value the referring expression can
19658 take advantage of that fact. */
19663 /* Don't instantiate cloned functions. Instead, instantiate the
19664 functions they cloned. */
19672 /* D has already been instantiated or explicitly specialized, so
19673 there's nothing for us to do here.
19675 It might seem reasonable to check whether or not D is an explicit
19676 instantiation, and, if so, stop here. But when an explicit
19677 instantiation is deferred until the end of the compilation,
19678 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19679 the instantiation. */
19682 /* Check to see whether we know that this template will be
19683 instantiated in some other file, as with "extern template"
19684 extension. */
19687 /* In general, we do not instantiate such templates. */
19695 /* We should already have the extra args. */
19698 /* And what's in the hash table should match D. */
19702 /* This needs to happen before any tsubsting. */
19708 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19709 for the instantiation. */
19713 /* We should never be trying to instantiate a member of a class
19714 template or partial specialization. */
19719 /* In the case of a friend template whose definition is provided
19720 outside the class, we may have too many arguments. Drop the
19721 ones we don't need. The same is true for specializations. */
19722 args = get_innermost_template_args
19724 else
19730 else
19733 /* We may be in the middle of deferred access check. Disable it now. */
19736 /* Unless an explicit instantiation directive has already determined
19737 the linkage of D, remember that a definition is available for
19738 this entity. */
19748 /* If D is a member of an explicitly instantiated class template,
19749 and no definition is available, treat it like an implicit
19750 instantiation. */
19753 {
19754 /* Leave linkage flags alone on instantiations with anonymous
19755 visibility. */
19757 {
19760 }
19762 }
19767 /* Defer all other templates, unless we have been explicitly
19768 forbidden from doing so. */
19770 template. */
19771 ! pattern_defined
19772 /* If it's OK to postpone instantiation, do so. */
19773 || defer_ok
19774 /* If this is a static data member that will be defined
19775 elsewhere, we don't want to instantiate the entire data
19776 member, but we do want to instantiate the initializer so that
19777 we can substitute that elsewhere. */
19779 {
19780 /* The definition of the static data member is now required so
19781 we must substitute the initializer. */
19785 {
19786 tree ns;
19787 tree init;
19794 args,
19797 /* If instantiating the initializer involved instantiating this
19798 again, don't call cp_finish_decl twice. */
19800 {
19801 /* Make sure the initializer is still constant, in case of
19802 circular dependency (template/instantiate6.C). */
19803 const_init
19807 LOOKUP_ONLYCONVERTING);
19808 }
19811 }
19813 /* We restore the source position here because it's used by
19814 add_pending_template. */
19820 /* [temp.explicit]
19822 The definition of a non-exported function template, a
19823 non-exported member function template, or a non-exported
19824 member function or static data member of a class template
19825 shall be present in every translation unit in which it is
19826 explicitly instantiated. */
19830 /* If we're in unevaluated context, we just wanted to get the
19831 constant value; this isn't an odr use, so don't queue
19832 a full instantiation. */
19835 /* ??? Historically, we have instantiated inline functions, even
19836 when marked as "extern template". */
19840 }
19841 /* Tell the repository that D is available in this translation unit
19842 -- and see if it is supposed to be instantiated here. */
19844 {
19845 /* In a PCH file, despite the fact that the repository hasn't
19846 requested instantiation in the PCH it is still possible that
19847 an instantiation will be required in a file that includes the
19848 PCH. */
19851 /* Instantiate inline functions so that the inliner can do its
19852 job, even though we'll not be emitting a copy of this
19853 function. */
19856 }
19862 else
19863 {
19868 }
19870 /* Mark D as instantiated so that recursive calls to
19871 instantiate_decl do not try to instantiate it again. */
19874 /* Regenerate the declaration in case the template has been modified
19875 by a subsequent redeclaration. */
19878 /* We already set the file and line above. Reset them now in case
19879 they changed as a result of calling regenerate_decl_from_template. */
19883 {
19884 tree init;
19887 /* Clear out DECL_RTL; whatever was there before may not be right
19888 since we've reset the type of the declaration. */
19892 /* The initializer is placed in DECL_INITIAL by
19893 regenerate_decl_from_template so we don't need to
19894 push/pop_access_scope again here. Pull it out so that
19895 cp_finish_decl can process it. */
19900 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19901 initializer. That function will defer actual emission until
19902 we have a chance to determine linkage. */
19905 /* Enter the scope of D so that access-checking works correctly. */
19910 }
19914 {
19916 tree subst_decl;
19917 tree tmpl_parm;
19918 tree spec_parm;
19921 /* Save away the current list, in case we are instantiating one
19922 template from within the body of another. */
19925 /* Set up the list of local specializations. */
19928 /* Set up context. */
19932 else
19935 /* Some typedefs referenced from within the template code need to be
19936 access checked at template instantiation time, i.e now. These
19937 types were added to the template at parsing time. Let's get those
19938 and perform the access checks then. */
19940 gen_args);
19942 /* Create substitution entries for the parameters. */
19947 {
19951 }
19953 {
19955 {
19958 }
19959 else
19960 {
19961 /* Register the (value) argument pack as a specialization of
19962 TMPL_PARM, then move on. */
19965 }
19966 }
19969 /* Substitute into the body of the function. */
19973 else
19974 {
19979 /* Set the current input_location to the end of the function
19980 so that finish_function knows where we are. */
19981 input_location
19984 /* Remember if we saw an infinite loop in the template. */
19985 current_function_infinite_loop
19987 }
19989 /* We don't need the local specializations any more. */
19993 /* Finish the function. */
19997 else
19998 {
20001 }
20005 }
20007 /* We're not deferring instantiation any more. */
20015 out:
20025 }
20027 /* Run through the list of templates that we wish we could
20028 instantiate, and instantiate any we can. RETRIES is the
20029 number of times we retry pending template instantiation. */
20031 void
20033 {
20037 /* Instantiating templates may trigger vtable generation. This in turn
20038 may require further template instantiations. We place a limit here
20039 to avoid infinite loop. */
20041 {
20045 " instantiating %q+D, possibly from virtual table generation"
20049 /* Pretend that we defined it. */
20052 }
20054 do
20055 {
20060 {
20065 {
20066 tree fn;
20069 {
20073 fn;
20081 }
20084 }
20085 else
20086 {
20089 {
20090 instantiation
20096 }
20100 }
20103 /* If INSTANTIATION has been instantiated, then we don't
20104 need to consider it again in the future. */
20106 else
20107 {
20110 }
20113 }
20115 }
20119 }
20121 /* Substitute ARGVEC into T, which is a list of initializers for
20122 either base class or a non-static data member. The TREE_PURPOSEs
20123 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20124 instantiate_decl. */
20126 static tree
20128 {
20132 {
20133 tree decl;
20134 tree init;
20140 {
20141 tree expr;
20142 tree arg;
20144 /* Expand the base class expansion type into separate base
20145 classes. */
20147 tf_warning_or_error,
20148 NULL_TREE);
20152 /* We'll be building separate TREE_LISTs of arguments for
20153 each base. */
20159 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20160 expand each argument in the TREE_VALUE of t. */
20167 /* VOID_TYPE_NODE is used to indicate
20168 value-initialization. */
20169 {
20172 }
20173 else
20174 {
20175 /* Substitute parameter packs into each argument in the
20176 TREE_LIST. */
20179 {
20180 tree expanded_exprs;
20182 /* Expand the argument. */
20184 expanded_exprs
20186 tf_warning_or_error,
20187 NULL_TREE);
20191 /* Prepend each of the expanded expressions to the
20192 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20194 {
20199 }
20200 }
20203 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20204 since we built them backwards. */
20206 {
20209 }
20210 }
20211 }
20214 {
20216 {
20220 }
20221 else
20222 {
20223 tree tmp;
20238 /* If we had an initializer but it instantiated to nothing,
20239 value-initialize the object. This will only occur when
20240 the initializer was a pack expansion where the parameter
20241 packs used in that expansion were of length zero. */
20244 }
20247 {
20251 }
20252 }
20253 }
20255 }
20257 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20259 static void
20261 {
20266 else
20268 }
20270 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20271 is the instantiation (which should have been created with
20272 start_enum) and ARGS are the template arguments to use. */
20274 static void
20276 {
20277 tree e;
20283 {
20284 tree value;
20285 tree decl;
20288 /* Note that in a template enum, the TREE_VALUE is the
20289 CONST_DECL, not the corresponding INTEGER_CST. */
20294 /* Give this enumeration constant the correct access. */
20297 /* Actually build the enumerator itself. */
20298 build_enumerator
20300 }
20310 }
20312 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20313 its type -- but without substituting the innermost set of template
20314 arguments. So, innermost set of template parameters will appear in
20315 the type. */
20317 tree
20319 {
20320 tree fn_type;
20321 tree tmpl;
20322 tree targs;
20323 tree tparms;
20331 /* There should be as many levels of arguments as there are levels
20332 of parameters. */
20338 /* No substitution is necessary. */
20339 ;
20340 else
20341 {
20343 tree partial_args;
20345 /* Replace the innermost level of the TARGS with NULL_TREEs to
20346 let tsubst know not to substitute for those parameters. */
20355 /* Make sure that we can see identifiers, and compute access
20356 correctly. */
20360 /* Now, do the (partial) substitution to figure out the
20361 appropriate function type. */
20365 /* Substitute into the template parameters to obtain the real
20366 innermost set of parameters. This step is important if the
20367 innermost set of template parameters contains value
20368 parameters whose types depend on outer template parameters. */
20373 }
20376 }
20378 /* Return truthvalue if we're processing a template different from
20379 the last one involved in diagnostics. */
20380 int
20382 {
20384 }
20386 /* Remember current template involved in diagnostics. */
20387 void
20389 {
20391 }
20395 {
20397 }
20399 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20400 type. Return zero for ok, nonzero for disallowed. Issue error and
20401 warning messages under control of COMPLAIN. */
20403 static int
20405 {
20422 {
20425 else
20427 type);
20428 }
20430 }
20432 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20433 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20435 static bool
20437 {
20438 tree scope;
20440 /* [temp.dep.type]
20442 A type is dependent if it is:
20444 -- a template parameter. Template template parameters are types
20445 for us (since TYPE_P holds true for them) so we handle
20446 them here. */
20450 /* -- a qualified-id with a nested-name-specifier which contains a
20451 class-name that names a dependent type or whose unqualified-id
20452 names a dependent type. */
20455 /* -- a cv-qualified type where the cv-unqualified type is
20456 dependent. */
20458 /* -- a compound type constructed from any dependent type. */
20468 {
20469 tree arg_type;
20474 arg_type;
20479 }
20480 /* -- an array type constructed from any dependent type or whose
20481 size is specified by a constant expression that is
20482 value-dependent.
20484 We checked for type- and value-dependence of the bounds in
20485 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20487 {
20492 }
20494 /* -- a template-id in which either the template name is a template
20495 parameter ... */
20498 /* ... or any of the template arguments is a dependent type or
20499 an expression that is type-dependent or value-dependent. */
20501 && (any_dependent_template_arguments_p
20505 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20506 dependent; if the argument of the `typeof' expression is not
20507 type-dependent, then it should already been have resolved. */
20513 /* A template argument pack is dependent if any of its packed
20514 arguments are. */
20516 {
20522 }
20524 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20525 be template parameters. */
20529 /* The standard does not specifically mention types that are local
20530 to template functions or local classes, but they should be
20531 considered dependent too. For example:
20533 template <int I> void f() {
20534 enum E { a = I };
20535 S<sizeof (E)> s;
20536 }
20538 The size of `E' cannot be known until the value of `I' has been
20539 determined. Therefore, `E' must be considered dependent. */
20543 /* Don't use type_dependent_expression_p here, as it can lead
20544 to infinite recursion trying to determine whether a lambda
20545 nested in a lambda is dependent (c++/47687). */
20549 && (any_dependent_template_arguments_p
20553 /* Other types are non-dependent. */
20555 }
20557 /* Returns TRUE if TYPE is dependent, in the sense of
20558 [temp.dep.type]. Note that a NULL type is considered dependent. */
20560 bool
20562 {
20563 /* If there are no template parameters in scope, then there can't be
20564 any dependent types. */
20566 {
20567 /* If we are not processing a template, then nobody should be
20568 providing us with a dependent type. */
20572 }
20574 /* If the type is NULL, we have not computed a type for the entity
20575 in question; in that case, the type is dependent. */
20579 /* Erroneous types can be considered non-dependent. */
20583 /* If we have not already computed the appropriate value for TYPE,
20584 do so now. */
20586 {
20589 }
20592 }
20594 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20595 lookup. In other words, a dependent type that is not the current
20596 instantiation. */
20598 bool
20600 {
20603 }
20605 /* T is a SCOPE_REF; return whether we need to consider it
20606 instantiation-dependent so that we can check access at instantiation
20607 time even though we know which member it resolves to. */
20609 static bool
20611 {
20617 else
20619 }
20621 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20622 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20623 expression. */
20625 /* Note that this predicate is not appropriate for general expressions;
20626 only constant expressions (that satisfy potential_constant_expression)
20627 can be tested for value dependence. */
20629 bool
20631 {
20635 /* A name declared with a dependent type. */
20640 {
20642 /* A name that has not been looked up -- must be dependent. */
20646 /* A non-type template parm. */
20650 /* A non-type template parm. */
20656 /* A constant with literal type and is initialized
20657 with an expression that is value-dependent.
20659 Note that a non-dependent parenthesized initializer will have
20660 already been replaced with its constant value, so if we see
20661 a TREE_LIST it must be dependent. */
20674 /* These expressions are value-dependent if the type to which
20675 the cast occurs is dependent or the expression being casted
20676 is value-dependent. */
20677 {
20683 /* A functional cast has a list of operands. */
20686 {
20687 /* If there are no operands, it must be an expression such
20688 as "int()". This should not happen for aggregate types
20689 because it would form non-constant expressions. */
20694 }
20700 }
20705 /* FALLTHRU */
20708 /* A `sizeof' expression is value-dependent if the operand is
20709 type-dependent or is a pack expansion. */
20718 /* An 'encode' expression is value-dependent if the operand is
20719 type-dependent. */
20728 /* All instantiation-dependent expressions should also be considered
20729 value-dependent. */
20737 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20738 is value-dependent. */
20739 {
20748 }
20751 {
20755 }
20766 {
20770 }
20773 {
20780 {
20782 /* In a call to a constexpr member function, look through the
20783 implicit ADDR_EXPR on the object argument so that it doesn't
20784 cause the call to be considered value-dependent. We also
20785 look through it in potential_constant_expression. */
20792 }
20794 }
20797 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20798 type-dependent. */
20802 {
20804 tree val;
20811 }
20814 /* Treat a GNU statement expression as dependent to avoid crashing
20815 under fold_non_dependent_expr; it can't be constant. */
20819 /* A constant expression is value-dependent if any subexpression is
20820 value-dependent. */
20822 {
20829 {
20833 {
20836 /* In some cases, some of the operands may be missing.l
20837 (For example, in the case of PREDECREMENT_EXPR, the
20838 amount to increment by may be missing.) That doesn't
20839 make the expression dependent. */
20842 }
20843 }
20847 }
20849 }
20851 /* The expression is not value-dependent. */
20853 }
20855 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20856 [temp.dep.expr]. Note that an expression with no type is
20857 considered dependent. Other parts of the compiler arrange for an
20858 expression with type-dependent subexpressions to have no type, so
20859 this function doesn't have to be fully recursive. */
20861 bool
20863 {
20870 /* An unresolved name is always dependent. */
20874 /* Some expression forms are never type-dependent. */
20887 /* The types of these expressions depends only on the type to which
20888 the cast occurs. */
20897 /* The types of these expressions depends only on the type created
20898 by the expression. */
20901 {
20902 /* For NEW_EXPR tree nodes created inside a template, either
20903 the object type itself or a TREE_LIST may appear as the
20904 operand 1. */
20907 /* This is an array type. We need to check array dimensions
20908 as well. */
20910 || value_dependent_expression_p
20912 else
20914 }
20917 {
20921 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20922 contains an identifier associated by name lookup with one or more
20923 declarations declared with a dependent type, or...a
20924 nested-name-specifier or qualified-id that names a member of an
20925 unknown specialization. */
20928 }
20933 && (any_dependent_template_arguments_p
20945 {
20946 tree elt;
20950 {
20953 }
20955 }
20957 /* A static data member of the current instantiation with incomplete
20958 array type is type-dependent, as the definition and specializations
20959 can have different bounds. */
20966 /* An array of unknown bound depending on a variadic parameter, eg:
20968 template<typename... Args>
20969 void foo (Args... args)
20970 {
20971 int arr[] = { args... };
20972 }
20974 template<int... vals>
20975 void bar ()
20976 {
20977 int arr[] = { vals... };
20978 }
20980 If the array has no length and has an initializer, it must be that
20981 we couldn't determine its length in cp_complete_array_type because
20982 it is dependent. */
20990 {
20995 {
21001 }
21002 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
21006 /* Always dependent, on the number of arguments if nothing else. */
21011 {
21016 }
21019 {
21024 }
21029 {
21033 }
21035 }
21040 }
21042 /* walk_tree callback function for instantiation_dependent_expression_p,
21043 below. Returns non-zero if a dependent subexpression is found. */
21045 static tree
21048 {
21050 {
21051 /* We don't have to worry about decltype currently because decltype
21052 of an instantiation-dependent expr is a dependent type. This
21053 might change depending on the resolution of DR 1172. */
21056 }
21059 {
21060 /* Don't treat an argument list as dependent just because it has no
21061 TREE_TYPE. */
21068 /* A constant with a dependent initializer is dependent. */
21076 /* Handle expressions with type operands. */
21081 {
21086 {
21089 else
21090 {
21093 }
21094 }
21096 }
21108 /* In a template, finish_class_member_access_expr creates a
21109 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21110 type-dependent, so that we can check access control at
21111 instantiation time (PR 42277). See also Core issue 1273. */
21118 else
21121 /* Treat statement-expressions as dependent. */
21127 }
21131 else
21133 }
21135 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21136 sense defined by the ABI:
21138 "An expression is instantiation-dependent if it is type-dependent
21139 or value-dependent, or it has a subexpression that is type-dependent
21140 or value-dependent." */
21142 bool
21144 {
21145 tree result;
21156 }
21158 /* Like type_dependent_expression_p, but it also works while not processing
21159 a template definition, i.e. during substitution or mangling. */
21161 bool
21163 {
21169 }
21171 /* Returns TRUE if ARGS contains a type-dependent expression. */
21173 bool
21175 {
21177 tree arg;
21180 {
21183 }
21185 }
21187 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21188 expressions) contains any type-dependent expressions. */
21190 bool
21192 {
21198 }
21200 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21201 expressions) contains any value-dependent expressions. */
21203 bool
21205 {
21211 }
21213 /* Returns TRUE if the ARG (a template argument) is dependent. */
21215 bool
21217 {
21221 /* Assume a template argument that was wrongly written by the user
21222 is dependent. This is consistent with what
21223 any_dependent_template_arguments_p [that calls this function]
21224 does. */
21235 {
21239 {
21242 }
21245 }
21248 else
21251 }
21253 /* Returns true if ARGS (a collection of template arguments) contains
21254 any types that require structural equality testing. */
21256 bool
21258 {
21268 {
21271 {
21277 {
21278 /* Look inside the argument pack. */
21281 }
21284 {
21297 }
21298 }
21299 }
21302 }
21304 /* Returns true if ARGS (a collection of template arguments) contains
21305 any dependent arguments. */
21307 bool
21309 {
21319 {
21324 }
21327 }
21329 /* Returns TRUE if the template TMPL is dependent. */
21331 bool
21333 {
21335 {
21337 {
21341 }
21343 }
21345 /* Template template parameters are dependent. */
21349 /* So are names that have not been looked up. */
21352 /* So are member templates of dependent classes. */
21356 }
21358 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21360 bool
21362 {
21365 }
21367 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21368 is dependent. */
21370 bool
21372 {
21379 {
21400 {
21404 }
21408 {
21412 {
21417 }
21418 }
21419 }
21422 }
21424 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21425 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21426 no such TYPE can be found. Note that this function peers inside
21427 uninstantiated templates and therefore should be used only in
21428 extremely limited situations. ONLY_CURRENT_P restricts this
21429 peering to the currently open classes hierarchy (which is required
21430 when comparing types). */
21432 tree
21434 {
21435 tree scope;
21436 tree name;
21437 tree decl;
21439 tree pushed_scope;
21440 tree result;
21445 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21446 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21447 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21448 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21449 identifier of the TYPENAME_TYPE anymore.
21450 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21451 TYPENAME_TYPE instead, we avoid messing up with a possible
21452 typedef variant case. */
21455 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21456 it first before we can figure out what NAME refers to. */
21458 {
21460 /* Given a class template A with a dependent base with nested type C,
21461 typedef typename A::C::C C will land us here, as trying to resolve
21462 the initial A::C leads to the local C typedef, which leads back to
21463 A::C::C. So we break the recursion now. */
21465 else
21467 }
21468 /* If we don't know what SCOPE refers to, then we cannot resolve the
21469 TYPENAME_TYPE. */
21472 /* If the SCOPE is a template type parameter, we have no way of
21473 resolving the name. */
21476 /* If the SCOPE is not the current instantiation, there's no reason
21477 to look inside it. */
21480 /* If this is a typedef, we don't want to look inside (c++/11987). */
21483 /* If SCOPE isn't the template itself, it will not have a valid
21484 TYPE_FIELDS list. */
21486 /* scope is either the template itself or a compatible instantiation
21487 like X<T>, so look up the name in the original template. */
21489 else
21490 /* scope is a partial instantiation, so we can't do the lookup or we
21491 will lose the template arguments. */
21493 /* Enter the SCOPE so that name lookup will be resolved as if we
21494 were in the class definition. In particular, SCOPE will no
21495 longer be considered a dependent type. */
21497 /* Look up the declaration. */
21499 tf_warning_or_error);
21503 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21504 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21509 {
21513 }
21516 {
21517 tree tmpl;
21518 tree args;
21519 /* Obtain the template and the arguments. */
21522 /* Instantiate the template. */
21528 }
21530 /* Leave the SCOPE. */
21534 /* If we failed to resolve it, return the original typename. */
21538 /* If lookup found a typename type, resolve that too. */
21540 {
21541 /* Ill-formed programs can cause infinite recursion here, so we
21542 must catch that. */
21546 }
21548 /* Qualify the resulting type. */
21554 }
21556 /* EXPR is an expression which is not type-dependent. Return a proxy
21557 for EXPR that can be used to compute the types of larger
21558 expressions containing EXPR. */
21560 tree
21562 {
21563 tree inner_expr;
21565 #ifdef ENABLE_CHECKING
21566 /* Try to get a constant value for all non-dependent expressions in
21567 order to expose bugs in *_dependent_expression_p and constexpr. */
21570 #endif
21572 /* Preserve OVERLOADs; the functions must be available to resolve
21573 types. */
21584 /* There is no need to return a proxy for a variable. */
21587 /* Preserve string constants; conversions from string constants to
21588 "char *" are allowed, even though normally a "const char *"
21589 cannot be used to initialize a "char *". */
21592 /* Preserve arithmetic constants, as an optimization -- there is no
21593 reason to create a new node. */
21596 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21597 There is at least one place where we want to know that a
21598 particular expression is a throw-expression: when checking a ?:
21599 expression, there are special rules if the second or third
21600 argument is a throw-expression. */
21604 /* Don't wrap an initializer list, we need to be able to look inside. */
21608 /* Don't wrap a dummy object, we need to be able to test for it. */
21627 /* If the type is unknown, it can't really be non-dependent */
21630 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21632 }
21634 /* ARGS is a vector of expressions as arguments to a function call.
21635 Replace the arguments with equivalent non-dependent expressions.
21636 This modifies ARGS in place. */
21638 void
21640 {
21642 tree arg;
21645 {
21649 }
21650 }
21652 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21653 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21654 parms. */
21656 static tree
21658 {
21671 }
21673 tree
21675 {
21677 }
21679 tree
21681 {
21683 }
21685 /* Given type ARG, return std::initializer_list<ARG>. */
21687 static tree
21689 {
21690 tree std_init_list = namespace_binding
21692 tree argvec;
21694 {
21698 }
21703 }
21705 /* Replace auto in TYPE with std::initializer_list<auto>. */
21707 static tree
21709 {
21716 }
21718 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21719 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21721 tree
21723 {
21724 tree targs;
21730 /* Defining a subset of type-dependent expressions that we can deduce
21731 from ahead of time isn't worth the trouble. */
21734 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21735 with either a new invented type template parameter U or, if the
21736 initializer is a braced-init-list (8.5.4), with
21737 std::initializer_list<U>. */
21745 {
21751 {
21754 }
21755 }
21756 else
21757 {
21768 {
21770 /* Try again at instantiation time. */
21773 /* If type is error_mark_node a diagnostic must have been
21774 emitted by now. Also, having a mention to '<type error>'
21775 in the diagnostic is not really useful to the user. */
21776 {
21780 else
21782 }
21784 }
21785 }
21787 /* If the list of declarators contains more than one declarator, the type
21788 of each declared variable is determined as described above. If the
21789 type deduced for the template parameter U is not the same in each
21790 deduction, the program is ill-formed. */
21793 {
21799 else
21803 }
21809 }
21811 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21812 result. */
21814 tree
21816 {
21817 tree argvec;
21824 /* For a late-specified return type in a template type-parameter, we
21825 need to add a dummy argument level for its parmlist. */
21826 argvec = add_to_template_args
21831 }
21833 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21834 'decltype(auto)'. */
21836 bool
21838 {
21843 else
21845 }
21847 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21848 a use of `auto'. Returns NULL_TREE otherwise. */
21850 tree
21852 {
21854 }
21856 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21857 'decltype(auto)' or a concept. */
21859 bool
21861 {
21863 }
21865 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21866 a concept identifier) iff TYPE contains a use of a generic type. Returns
21867 NULL_TREE otherwise. */
21869 tree
21871 {
21873 }
21876 /* For a given template T, return the vector of typedefs referenced
21877 in T for which access check is needed at T instantiation time.
21878 T is either a FUNCTION_DECL or a RECORD_TYPE.
21879 Those typedefs were added to T by the function
21880 append_type_to_template_for_access_check. */
21884 {
21885 tree ti;
21896 {
21901 }
21904 }
21906 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21907 tied to T. That list of typedefs will be access checked at
21908 T instantiation time.
21909 T is either a FUNCTION_DECL or a RECORD_TYPE.
21910 TYPE_DECL is a TYPE_DECL node representing a typedef.
21911 SCOPE is the scope through which TYPE_DECL is accessed.
21912 LOCATION is the location of the usage point of TYPE_DECL.
21914 This function is a subroutine of
21915 append_type_to_template_for_access_check. */
21917 static void
21919 tree type_decl,
21920 tree scope,
21921 location_t location)
21922 {
21923 qualified_typedef_usage_t typedef_usage;
21924 tree ti;
21931 && type_decl
21945 }
21947 /* Append TYPE_DECL to the template TEMPL.
21948 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21949 At TEMPL instanciation time, TYPE_DECL will be checked to see
21950 if it can be accessed through SCOPE.
21951 LOCATION is the location of the usage point of TYPE_DECL.
21953 e.g. consider the following code snippet:
21955 class C
21956 {
21957 typedef int myint;
21958 };
21960 template<class U> struct S
21961 {
21962 C::myint mi; // <-- usage point of the typedef C::myint
21963 };
21965 S<char> s;
21967 At S<char> instantiation time, we need to check the access of C::myint
21968 In other words, we need to check the access of the myint typedef through
21969 the C scope. For that purpose, this function will add the myint typedef
21970 and the scope C through which its being accessed to a list of typedefs
21971 tied to the template S. That list will be walked at template instantiation
21972 time and access check performed on each typedefs it contains.
21973 Note that this particular code snippet should yield an error because
21974 myint is private to C. */
21976 void
21978 tree type_decl,
21979 tree scope,
21980 location_t location)
21981 {
21987 /* Make sure we don't append the type to the template twice. */
21994 }
21996 /* Convert the generic type parameters in PARM that match the types given in the
21997 range [START_IDX, END_IDX) from the current_template_parms into generic type
21998 packs. */
22000 tree
22002 {
22013 {
22014 /* Create a distinct parameter pack type from the current parm and add it
22015 to the replacement args to tsubst below into the generic function
22016 parameter. */
22031 }
22037 /* If there are more levels then build up the replacement with the outer
22038 template parms. */
22042 replacement);
22045 }
22048 /* Set up the hash tables for template instantiations. */
22050 void
22052 {
22054 hash_specialization,
22055 eq_specializations,
22056 ggc_free);
22058 hash_specialization,
22059 eq_specializations,
22060 ggc_free);
22061 }
22063 /* Print stats about the template hash tables for -fstats. */
22065 void
22067 {
22076 }