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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 /* A map from local variable declarations in the body of the template
82 presently being instantiated to the corresponding instantiated
83 local variables. */
86 /* True if we've recursed into fn_type_unification too many times. */
90 {
91 tree tmpl;
92 tree args;
93 tree spec;
97 htab_t decl_specializations;
100 htab_t type_specializations;
102 /* Contains canonical template parameter types. The vector is indexed by
103 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
104 TREE_LIST, whose TREE_VALUEs contain the canonical template
105 parameters of various types and levels. */
108 #define UNIFY_ALLOW_NONE 0
109 #define UNIFY_ALLOW_MORE_CV_QUAL 1
110 #define UNIFY_ALLOW_LESS_CV_QUAL 2
111 #define UNIFY_ALLOW_DERIVED 4
112 #define UNIFY_ALLOW_INTEGER 8
113 #define UNIFY_ALLOW_OUTER_LEVEL 16
114 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
115 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
118 tbr_incomplete_type,
119 tbr_ambiguous_baseclass,
120 tbr_success
121 };
144 tree);
207 location_t);
215 /* Make the current scope suitable for access checking when we are
216 processing T. T can be FUNCTION_DECL for instantiated function
217 template, VAR_DECL for static member variable, or TYPE_DECL for
218 alias template (needed by instantiate_decl). */
220 static void
222 {
230 else
234 {
235 saved_access_scope = tree_cons
238 }
239 }
241 /* Restore the scope set up by push_access_scope. T is the node we
242 are processing. */
244 static void
246 {
248 {
251 }
255 else
257 }
259 /* Do any processing required when DECL (a member template
260 declaration) is finished. Returns the TEMPLATE_DECL corresponding
261 to DECL, unless it is a specialization, in which case the DECL
262 itself is returned. */
264 tree
266 {
273 {
274 tree type;
282 {
286 }
288 }
292 {
294 {
297 }
298 else
300 }
301 else
305 }
307 /* Create a template info node. */
309 tree
311 {
316 }
318 /* Return the template info node corresponding to T, whatever T is. */
320 tree
322 {
340 }
342 /* Returns the template nesting level of the indicated class TYPE.
344 For example, in:
345 template <class T>
346 struct A
347 {
348 template <class U>
349 struct B {};
350 };
352 A<T>::B<U> has depth two, while A<T> has depth one.
353 Both A<T>::B<int> and A<int>::B<U> have depth one, if
354 they are instantiations, not specializations.
356 This function is guaranteed to return 0 if passed NULL_TREE so
357 that, for example, `template_class_depth (current_class_type)' is
358 always safe. */
360 int
362 {
369 {
375 }
378 }
380 /* Subroutine of maybe_begin_member_template_processing.
381 Returns true if processing DECL needs us to push template parms. */
383 static bool
385 {
391 }
393 /* Subroutine of maybe_begin_member_template_processing.
394 Push the template parms in PARMS, starting from LEVELS steps into the
395 chain, and ending at the beginning, since template parms are listed
396 innermost first. */
398 static void
400 {
408 current_template_parms
414 NULL);
416 {
425 {
432 {
433 /* Make a CONST_DECL as is done in process_template_parm.
434 It is ugly that we recreate this here; the original
435 version built in process_template_parm is no longer
436 available. */
446 }
451 }
452 }
453 }
455 /* Restore the template parameter context for a member template, a
456 friend template defined in a class definition, or a non-template
457 member of template class. */
459 void
461 {
462 tree parms;
472 {
477 {
480 }
483 }
485 /* Remember how many levels of template parameters we pushed so that
486 we can pop them later. */
488 }
490 /* Undo the effects of maybe_begin_member_template_processing. */
492 void
494 {
503 {
507 }
508 }
510 /* Return a new template argument vector which contains all of ARGS,
511 but has as its innermost set of arguments the EXTRA_ARGS. */
513 static tree
515 {
516 tree new_args;
534 }
536 /* Like add_to_template_args, but only the outermost ARGS are added to
537 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
538 (EXTRA_ARGS) levels are added. This function is used to combine
539 the template arguments from a partial instantiation with the
540 template arguments used to attain the full instantiation from the
541 partial instantiation. */
543 static tree
545 {
546 tree new_args;
548 /* If there are more levels of EXTRA_ARGS than there are ARGS,
549 something very fishy is going on. */
552 /* If *all* the new arguments will be the EXTRA_ARGS, just return
553 them. */
557 /* For the moment, we make ARGS look like it contains fewer levels. */
562 /* Now, we restore ARGS to its full dimensions. */
566 }
568 /* Return the N levels of innermost template arguments from the ARGS. */
570 tree
572 {
573 tree new_args;
579 /* If N is 1, just return the innermost set of template arguments. */
583 /* If we're not removing anything, just return the arguments we were
584 given. */
590 /* Make a new set of arguments, not containing the outer arguments. */
597 }
599 /* The inverse of get_innermost_template_args: Return all but the innermost
600 EXTRA_LEVELS levels of template arguments from the ARGS. */
602 static tree
604 {
605 tree new_args;
611 /* If N is 1, just return the outermost set of template arguments. */
615 /* If we're not removing anything, just return the arguments we were
616 given. */
621 /* Make a new set of arguments, not containing the inner arguments. */
628 }
630 /* We've got a template header coming up; push to a new level for storing
631 the parms. */
633 void
635 {
636 /* We use a non-tag-transparent scope here, which causes pushtag to
637 put tags in this scope, rather than in the enclosing class or
638 namespace scope. This is the right thing, since we want
639 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
640 global template class, push_template_decl handles putting the
641 TEMPLATE_DECL into top-level scope. For a nested template class,
642 e.g.:
644 template <class T> struct S1 {
645 template <class T> struct S2 {};
646 };
648 pushtag contains special code to call pushdecl_with_scope on the
649 TEMPLATE_DECL for S2. */
654 }
656 /* This routine is called when a specialization is declared. If it is
657 invalid to declare a specialization here, an error is reported and
658 false is returned, otherwise this routine will return true. */
660 static bool
662 {
665 /* [temp.expl.spec]
667 An explicit specialization shall be declared in the namespace of
668 which the template is a member, or, for member templates, in the
669 namespace of which the enclosing class or enclosing class
670 template is a member. An explicit specialization of a member
671 function, member class or static data member of a class template
672 shall be declared in the namespace of which the class template
673 is a member. */
675 {
678 }
680 /* [temp.expl.spec]
682 In an explicit specialization declaration for a member of a class
683 template or a member template that appears in namespace scope,
684 the member template and some of its enclosing class templates may
685 remain unspecialized, except that the declaration shall not
686 explicitly specialize a class member template if its enclosing
687 class templates are not explicitly specialized as well. */
689 {
692 }
695 }
697 /* We've just seen template <>. */
699 bool
701 {
705 }
707 /* Called at then end of processing a declaration preceded by
708 template<>. */
710 void
712 {
715 }
717 /* Any template <>'s that we have seen thus far are not referring to a
718 function specialization. */
720 void
722 {
725 }
727 /* We've just seen a template header. If SPECIALIZATION is nonzero,
728 it was of the form template <>. */
730 static void
732 {
734 template_header_count++;
735 }
737 /* We're beginning an explicit instantiation. */
739 void
741 {
744 }
747 void
749 {
752 }
754 /* An explicit specialization or partial specialization of TMPL is being
755 declared. Check that the namespace in which the specialization is
756 occurring is permissible. Returns false iff it is invalid to
757 specialize TMPL in the current namespace. */
759 static bool
761 {
764 /* [tmpl.expl.spec]
766 An explicit specialization shall be declared in the namespace of
767 which the template is a member, or, for member templates, in the
768 namespace of which the enclosing class or enclosing class
769 template is a member. An explicit specialization of a member
770 function, member class or static data member of a class template
771 shall be declared in the namespace of which the class template is
772 a member. */
775 {
778 }
780 /* Same or super-using namespace. */
782 else
783 {
787 }
788 }
790 /* SPEC is an explicit instantiation. Check that it is valid to
791 perform this explicit instantiation in the current namespace. */
793 static void
795 {
796 tree ns;
798 /* DR 275: An explicit instantiation shall appear in an enclosing
799 namespace of its template. */
805 }
807 /* The TYPE is being declared. If it is a template type, that means it
808 is a partial specialization. Do appropriate error-checking. */
810 tree
812 {
813 tree context;
818 /* A lambda that appears in specialization context is not itself a
819 specialization. */
824 {
828 }
833 {
838 else
841 }
843 {
844 /* This is for ordinary explicit specialization and partial
845 specialization of a template class such as:
847 template <> class C<int>;
849 or:
851 template <class T> class C<T*>;
853 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
857 {
862 {
866 }
867 }
873 /* Trying to define a specialization either without a template<> header
874 or in an inappropriate place. We've already given an error, so just
875 bail now so we don't actually define the specialization. */
877 }
883 {
884 /* This is for an explicit specialization of member class
885 template according to [temp.expl.spec/18]:
887 template <> template <class U> class C<int>::D;
889 The context `C<int>' must be an implicit instantiation.
890 Otherwise this is just a member class template declared
891 earlier like:
893 template <> class C<int> { template <class U> class D; };
894 template <> template <class U> class C<int>::D;
896 In the first case, `C<int>::D' is a specialization of `C<T>::D'
897 while in the second case, `C<int>::D' is a primary template
898 and `C<T>::D' may not exist. */
902 {
903 tree t;
908 {
911 }
913 /* Check for invalid specialization after instantiation:
915 template <> template <> class C<int>::D<int>;
916 template <> template <class U> class C<int>::D; */
920 {
923 {
924 /* We already have a full specialization of this partial
925 instantiation. Reassign it to the new member
926 specialization template. */
927 spec_entry elt;
944 }
946 /* But if we've had an implicit instantiation, that's a
947 problem ([temp.expl.spec]/6). */
950 }
952 /* Mark TYPE as a specialization. And as a result, we only
953 have one level of template argument for the innermost
954 class template. */
959 }
960 }
962 {
963 /* Someday C++0x may allow for enum template specialization. */
968 else
969 {
972 }
973 }
976 }
978 /* Returns nonzero if we can optimize the retrieval of specializations
979 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
980 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
984 {
987 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
988 parameter. */
990 /* The optimized lookup depends on the fact that the
991 template arguments for the member function template apply
992 purely to the containing class, which is not true if the
993 containing class is an explicit or partial
994 specialization. */
998 /* It is possible to have a template that is not a member
999 template and is not a member of a template class:
1001 template <typename T>
1002 struct S { friend A::f(); };
1004 Here, the friend function is a template, but the context does
1005 not have template information. The optimized lookup relies
1006 on having ARGS be the template arguments for both the class
1007 and the function template. */
1009 }
1011 /* Retrieve the specialization (in the sense of [temp.spec] - a
1012 specialization is either an instantiation or an explicit
1013 specialization) of TMPL for the given template ARGS. If there is
1014 no such specialization, return NULL_TREE. The ARGS are a vector of
1015 arguments, or a vector of vectors of arguments, in the case of
1016 templates with more than one level of parameters.
1018 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1019 then we search for a partial specialization matching ARGS. This
1020 parameter is ignored if TMPL is not a class template.
1022 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1023 result is a NONTYPE_ARGUMENT_PACK. */
1025 static tree
1027 {
1037 /* There should be as many levels of arguments as there are
1038 levels of parameters. */
1045 {
1046 tree class_template;
1047 tree class_specialization;
1049 tree fns;
1052 /* The template arguments actually apply to the containing
1053 class. Find the class specialization with those
1054 arguments. */
1056 class_specialization
1060 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1061 for the specialization. */
1065 /* Iterate through the methods with the indicated name, looking
1066 for the one that has an instance of TMPL. */
1069 {
1072 /* using-declarations can add base methods to the method vec,
1073 and we don't want those here. */
1076 }
1078 }
1079 else
1080 {
1082 spec_entry elt;
1083 htab_t specializations;
1091 else
1099 }
1102 }
1104 /* Like retrieve_specialization, but for local declarations. */
1106 static tree
1108 {
1116 }
1118 /* Returns nonzero iff DECL is a specialization of TMPL. */
1120 int
1122 {
1123 tree t;
1126 {
1132 }
1133 else
1134 {
1143 }
1146 }
1148 /* Returns nonzero iff DECL is a specialization of friend declaration
1149 FRIEND_DECL according to [temp.friend]. */
1151 bool
1153 {
1160 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1161 of a template class, we want to check if DECL is a specialization
1162 if this. */
1166 {
1167 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1170 }
1175 /* There is nothing to do if this is not a template friend. */
1182 /* [temp.friend/6]
1183 A member of a class template may be declared to be a friend of a
1184 non-template class. In this case, the corresponding member of
1185 every specialization of the class template is a friend of the
1186 class granting friendship.
1188 For example, given a template friend declaration
1190 template <class T> friend void A<T>::f();
1192 the member function below is considered a friend
1194 template <> struct A<int> {
1195 void f();
1196 };
1198 For this type of template friend, TEMPLATE_DEPTH below will be
1199 nonzero. To determine if DECL is a friend of FRIEND, we first
1200 check if the enclosing class is a specialization of another. */
1207 {
1208 /* Next, we check the members themselves. In order to handle
1209 a few tricky cases, such as when FRIEND_DECL's are
1211 template <class T> friend void A<T>::g(T t);
1212 template <class T> template <T t> friend void A<T>::h();
1214 and DECL's are
1216 void A<int>::g(int);
1217 template <int> void A<int>::h();
1219 we need to figure out ARGS, the template arguments from
1220 the context of DECL. This is required for template substitution
1221 of `T' in the function parameter of `g' and template parameter
1222 of `h' in the above examples. Here ARGS corresponds to `int'. */
1229 {
1231 {
1234 else
1236 current_depth++;
1237 }
1239 }
1242 {
1244 tree friend_type;
1245 tree decl_type;
1246 tree friend_args_type;
1247 tree decl_args_type;
1249 /* Make sure that both DECL and FRIEND_DECL are templates or
1250 non-templates. */
1256 {
1257 /* If both are templates, check template parameter list. */
1258 tree friend_parms
1263 friend_parms))
1267 }
1268 else
1276 /* Check if return types match. */
1280 /* Check if function parameter types match, ignoring the
1281 `this' parameter. */
1290 }
1291 else
1292 {
1293 /* DECL is a TYPE_DECL */
1297 /* Make sure that both DECL and FRIEND_DECL are templates or
1298 non-templates. */
1299 is_template
1306 {
1307 tree friend_parms;
1308 /* If both are templates, check the name of the two
1309 TEMPLATE_DECL's first because is_friend didn't. */
1314 /* Now check template parameter list. */
1315 friend_parms
1318 return comp_template_parms
1320 friend_parms);
1321 }
1322 else
1325 }
1326 }
1328 }
1330 /* Register the specialization SPEC as a specialization of TMPL with
1331 the indicated ARGS. IS_FRIEND indicates whether the specialization
1332 is actually just a friend declaration. Returns SPEC, or an
1333 equivalent prior declaration, if available.
1335 We also store instantiations of field packs in the hash table, even
1336 though they are not themselves templates, to make lookup easier. */
1338 static tree
1340 hashval_t hash)
1341 {
1342 tree fn;
1344 spec_entry elt;
1352 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1353 register it; we want the corresponding TEMPLATE_DECL instead.
1354 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1355 the more obvious `uses_template_parms (spec)' to avoid problems
1356 with default function arguments. In particular, given
1357 something like this:
1359 template <class T> void f(T t1, T t = T())
1361 the default argument expression is not substituted for in an
1362 instantiation unless and until it is actually needed. */
1366 /* We don't put these specializations in the hash table, but we might
1367 want to give an error about a mismatch. */
1369 else
1370 {
1378 slot =
1382 else
1384 }
1386 /* We can sometimes try to re-register a specialization that we've
1387 already got. In particular, regenerate_decl_from_template calls
1388 duplicate_decls which will update the specialization list. But,
1389 we'll still get called again here anyhow. It's more convenient
1390 to simply allow this than to try to prevent it. */
1394 {
1396 {
1399 {
1401 fn);
1403 }
1404 else
1405 {
1406 tree clone;
1407 /* This situation should occur only if the first
1408 specialization is an implicit instantiation, the
1409 second is an explicit specialization, and the
1410 implicit instantiation has not yet been used. That
1411 situation can occur if we have implicitly
1412 instantiated a member function and then specialized
1413 it later.
1415 We can also wind up here if a friend declaration that
1416 looked like an instantiation turns out to be a
1417 specialization:
1419 template <class T> void foo(T);
1420 class S { friend void foo<>(int) };
1421 template <> void foo(int);
1423 We transform the existing DECL in place so that any
1424 pointers to it become pointers to the updated
1425 declaration.
1427 If there was a definition for the template, but not
1428 for the specialization, we want this to look as if
1429 there were no definition, and vice versa. */
1432 /* The call to duplicate_decls will have applied
1433 [temp.expl.spec]:
1435 An explicit specialization of a function template
1436 is inline only if it is explicitly declared to be,
1437 and independently of whether its function template
1438 is.
1440 to the primary function; now copy the inline bits to
1441 the various clones. */
1443 {
1448 }
1452 }
1453 }
1455 {
1457 /* Dup decl failed, but this is a new definition. Set the
1458 line number so any errors match this new
1459 definition. */
1463 }
1464 }
1468 /* A specialization must be declared in the same namespace as the
1469 template it is specializing. */
1475 {
1483 /* TMPL is a forward declaration of a template function; keep a list
1484 of all specializations in case we need to reassign them to a friend
1485 template later in tsubst_friend_function. */
1488 }
1491 }
1493 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1494 TMPL and ARGS members, ignores SPEC. */
1498 static int
1500 {
1511 }
1513 /* Returns a hash for a template TMPL and template arguments ARGS. */
1515 static hashval_t
1517 {
1520 }
1522 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1523 ignoring SPEC. */
1525 static hashval_t
1527 {
1530 }
1532 /* Recursively calculate a hash value for a template argument ARG, for use
1533 in the hash tables of template specializations. */
1535 hashval_t
1537 {
1549 /* We can get one of these when re-hashing a previous entry in the middle
1550 of substituting into a pack expansion. Just look through it. */
1559 {
1567 {
1572 }
1594 {
1597 {
1600 }
1602 }
1606 {
1609 }
1620 val = iterative_hash_template_arg
1632 val);
1634 val);
1643 /* A lambda can't appear in a template arg, but don't crash on
1644 erroneous input. */
1656 /* Now hash operands as usual. */
1661 }
1664 {
1668 val);
1671 /* Otherwise just compare the types during lookup. */
1680 {
1685 }
1686 }
1689 }
1691 /* Unregister the specialization SPEC as a specialization of TMPL.
1692 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1693 if the SPEC was listed as a specialization of TMPL.
1695 Note that SPEC has been ggc_freed, so we can't look inside it. */
1697 bool
1699 {
1701 spec_entry elt;
1709 {
1714 }
1717 }
1719 /* Like register_specialization, but for local declarations. We are
1720 registering SPEC, an instantiation of TMPL. */
1722 static void
1724 {
1729 }
1731 /* TYPE is a class type. Returns true if TYPE is an explicitly
1732 specialized class. */
1734 bool
1736 {
1740 }
1742 /* Print the list of functions at FNS, going through all the overloads
1743 for each element of the list. Alternatively, FNS can not be a
1744 TREE_LIST, in which case it will be printed together with all the
1745 overloads.
1747 MORE and *STR should respectively be FALSE and NULL when the function
1748 is called from the outside. They are used internally on recursive
1749 calls. print_candidates manages the two parameters and leaves NULL
1750 in *STR when it ends. */
1752 static void
1754 {
1760 {
1764 }
1765 else
1766 {
1769 {
1770 /* Pick the prefix string. */
1772 {
1776 }
1780 }
1783 }
1786 {
1789 }
1790 }
1792 /* Print the list of candidate FNS in an error message. FNS can also
1793 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1795 void
1797 {
1801 }
1803 /* Returns the template (one of the functions given by TEMPLATE_ID)
1804 which can be specialized to match the indicated DECL with the
1805 explicit template args given in TEMPLATE_ID. The DECL may be
1806 NULL_TREE if none is available. In that case, the functions in
1807 TEMPLATE_ID are non-members.
1809 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1810 specialization of a member template.
1812 The TEMPLATE_COUNT is the number of references to qualifying
1813 template classes that appeared in the name of the function. See
1814 check_explicit_specialization for a more accurate description.
1816 TSK indicates what kind of template declaration (if any) is being
1817 declared. TSK_TEMPLATE indicates that the declaration given by
1818 DECL, though a FUNCTION_DECL, has template parameters, and is
1819 therefore a template function.
1821 The template args (those explicitly specified and those deduced)
1822 are output in a newly created vector *TARGS_OUT.
1824 If it is impossible to determine the result, an error message is
1825 issued. The error_mark_node is returned to indicate failure. */
1827 static tree
1829 tree decl,
1833 tmpl_spec_kind tsk)
1834 {
1835 tree fns;
1836 tree targs;
1837 tree explicit_targs;
1839 /* A TREE_LIST of templates of which DECL may be a specialization.
1840 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1841 corresponding TREE_PURPOSE is the set of template arguments that,
1842 when used to instantiate the template, would produce a function
1843 with the signature of DECL. */
1853 /* We shouldn't be specializing a member template of an
1854 unspecialized class template; we already gave an error in
1855 check_specialization_scope, now avoid crashing. */
1858 {
1861 }
1869 /* Check for baselinks. */
1874 {
1877 }
1879 /* Count the number of template headers specified for this
1880 specialization. */
1888 {
1892 {
1893 tree decl_arg_types;
1894 tree fn_arg_types;
1895 tree insttype;
1897 /* In case of explicit specialization, we need to check if
1898 the number of template headers appearing in the specialization
1899 is correct. This is usually done in check_explicit_specialization,
1900 but the check done there cannot be exhaustive when specializing
1901 member functions. Consider the following code:
1903 template <> void A<int>::f(int);
1904 template <> template <> void A<int>::f(int);
1906 Assuming that A<int> is not itself an explicit specialization
1907 already, the first line specializes "f" which is a non-template
1908 member function, whilst the second line specializes "f" which
1909 is a template member function. So both lines are syntactically
1910 correct, and check_explicit_specialization does not reject
1911 them.
1913 Here, we can do better, as we are matching the specialization
1914 against the declarations. We count the number of template
1915 headers, and we check if they match TEMPLATE_COUNT + 1
1916 (TEMPLATE_COUNT is the number of qualifying template classes,
1917 plus there must be another header for the member template
1918 itself).
1920 Notice that if header_count is zero, this is not a
1921 specialization but rather a template instantiation, so there
1922 is no check we can perform here. */
1926 /* Check that the number of template arguments at the
1927 innermost level for DECL is the same as for FN. */
1935 /* DECL might be a specialization of FN. */
1939 /* For a non-static member function, we need to make sure
1940 that the const qualification is the same. Since
1941 get_bindings does not try to merge the "this" parameter,
1942 we must do the comparison explicitly. */
1948 /* Skip the "this" parameter and, for constructors of
1949 classes with virtual bases, the VTT parameter. A
1950 full specialization of a constructor will have a VTT
1951 parameter, but a template never will. */
1952 decl_arg_types
1954 fn_arg_types
1957 /* Function templates cannot be specializations; there are
1958 no partial specializations of functions. Therefore, if
1959 the type of DECL does not match FN, there is no
1960 match. */
1962 {
1966 }
1968 /* See whether this function might be a specialization of this
1969 template. Suppress access control because we might be trying
1970 to make this specialization a friend, and we have already done
1971 access control for the declaration of the specialization. */
1977 /* We cannot deduce template arguments that when used to
1978 specialize TMPL will produce DECL. */
1981 /* Make sure that the deduced arguments actually work. */
1985 fn_arg_types
1990 /* Save this template, and the arguments deduced. */
1992 }
1994 /* FN is an ordinary member function, and we need a
1995 specialization of a member template. */
1996 ;
1998 /* We can get IDENTIFIER_NODEs here in certain erroneous
1999 cases. */
2000 ;
2002 /* This is just an ordinary non-member function. Nothing can
2003 be a specialization of that. */
2004 ;
2006 /* Cannot specialize functions that are created implicitly. */
2007 ;
2008 else
2009 {
2010 tree decl_arg_types;
2012 /* This is an ordinary member function. However, since
2013 we're here, we can assume its enclosing class is a
2014 template class. For example,
2016 template <typename T> struct S { void f(); };
2017 template <> void S<int>::f() {}
2019 Here, S<int>::f is a non-template, but S<int> is a
2020 template class. If FN has the same type as DECL, we
2021 might be in business. */
2024 /* Its enclosing class is an explicit specialization
2025 of a template class. This is not a candidate. */
2030 /* The return types differ. */
2033 /* Adjust the type of DECL in case FN is a static member. */
2040 decl_arg_types))
2041 /* They match! */
2043 }
2044 }
2047 {
2048 /* We have:
2050 [temp.expl.spec]
2052 It is possible for a specialization with a given function
2053 signature to be instantiated from more than one function
2054 template. In such cases, explicit specification of the
2055 template arguments must be used to uniquely identify the
2056 function template specialization being specialized.
2058 Note that here, there's no suggestion that we're supposed to
2059 determine which of the candidate templates is most
2060 specialized. However, we, also have:
2062 [temp.func.order]
2064 Partial ordering of overloaded function template
2065 declarations is used in the following contexts to select
2066 the function template to which a function template
2067 specialization refers:
2069 -- when an explicit specialization refers to a function
2070 template.
2072 So, we do use the partial ordering rules, at least for now.
2073 This extension can only serve to make invalid programs valid,
2074 so it's safe. And, there is strong anecdotal evidence that
2075 the committee intended the partial ordering rules to apply;
2076 the EDG front end has that behavior, and John Spicer claims
2077 that the committee simply forgot to delete the wording in
2078 [temp.expl.spec]. */
2081 {
2084 }
2085 }
2088 {
2096 }
2100 {
2106 }
2108 /* We have one, and exactly one, match. */
2110 {
2113 /* DECL is a re-declaration or partial instantiation of a template
2114 function. */
2117 /* It was a specialization of an ordinary member function in a
2118 template class. */
2120 }
2122 /* It was a specialization of a template. */
2125 {
2130 }
2131 else
2134 }
2136 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2137 but with the default argument values filled in from those in the
2138 TMPL_TYPES. */
2140 static tree
2142 tree tmpl_types)
2143 {
2144 tree new_spec_types;
2152 /* Substitute into the rest of the list. */
2153 new_spec_types =
2157 /* Add the default argument for this parameter. */
2160 new_spec_types);
2161 }
2163 /* DECL is an explicit specialization. Replicate default arguments
2164 from the template it specializes. (That way, code like:
2166 template <class T> void f(T = 3);
2167 template <> void f(double);
2168 void g () { f (); }
2170 works, as required.) An alternative approach would be to look up
2171 the correct default arguments at the call-site, but this approach
2172 is consistent with how implicit instantiations are handled. */
2174 static void
2176 {
2177 tree tmpl;
2178 tree spec_types;
2179 tree tmpl_types;
2180 tree new_spec_types;
2181 tree old_type;
2182 tree new_type;
2183 tree t;
2188 /* See if there's anything we need to do. */
2201 {
2202 /* Remove the this pointer, but remember the object's type for
2203 CV quals. */
2209 {
2210 /* DECL may contain more parameters than TMPL due to the extra
2211 in-charge parameter in constructors and destructors. */
2214 }
2216 {
2219 }
2220 }
2222 /* Compute the merged default arguments. */
2223 new_spec_types =
2226 /* Compute the new FUNCTION_TYPE. */
2228 {
2232 new_spec_types);
2235 /* Put the in-charge parameter back. */
2238 new_spec_types);
2242 new_spec_types);
2243 }
2244 else
2246 new_spec_types);
2252 }
2254 /* Return the number of template headers we expect to see for a definition
2255 or specialization of CTYPE or one of its non-template members. */
2257 int
2259 {
2263 {
2264 /* You're supposed to have one `template <...>' for every
2265 template class, but you don't need one for a full
2266 specialization. For example:
2268 template <class T> struct S{};
2269 template <> struct S<int> { void f(); };
2270 void S<int>::f () {}
2272 is correct; there shouldn't be a `template <>' for the
2273 definition of `S<int>::f'. */
2275 /* If CTYPE does not have template information of any
2276 kind, then it is not a template, nor is it nested
2277 within a template. */
2285 }
2288 }
2290 /* Do a simple sanity check on the template headers that precede the
2291 variable declaration DECL. */
2293 void
2295 {
2302 {
2308 "members of an explicitly specialized class are defined "
2310 }
2311 }
2313 /* Check to see if the function just declared, as indicated in
2314 DECLARATOR, and in DECL, is a specialization of a function
2315 template. We may also discover that the declaration is an explicit
2316 instantiation at this point.
2318 Returns DECL, or an equivalent declaration that should be used
2319 instead if all goes well. Issues an error message if something is
2320 amiss. Returns error_mark_node if the error is not easily
2321 recoverable.
2323 FLAGS is a bitmask consisting of the following flags:
2325 2: The function has a definition.
2326 4: The function is a friend.
2328 The TEMPLATE_COUNT is the number of references to qualifying
2329 template classes that appeared in the name of the function. For
2330 example, in
2332 template <class T> struct S { void f(); };
2333 void S<int>::f();
2335 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2336 classes are not counted in the TEMPLATE_COUNT, so that in
2338 template <class T> struct S {};
2339 template <> struct S<int> { void f(); }
2340 template <> void S<int>::f();
2342 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2343 invalid; there should be no template <>.)
2345 If the function is a specialization, it is marked as such via
2346 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2347 is set up correctly, and it is added to the list of specializations
2348 for that template. */
2350 tree
2352 tree decl,
2355 {
2363 tmpl_spec_kind tsk;
2366 {
2369 else
2371 }
2372 else
2376 {
2379 {
2382 }
2384 {
2386 /* This could be something like:
2388 template <class T> void f(T);
2389 class S { friend void f<>(int); } */
2391 else
2392 {
2393 /* This case handles bogus declarations like template <>
2394 template <class T> void f<int>(); */
2397 declarator);
2399 }
2400 }
2404 /* The error has already been reported in
2405 check_specialization_scope. */
2411 /* Fall through. */
2424 decl);
2427 else
2431 /* Fall through. */
2436 else
2442 {
2443 /* This case handles bogus declarations like template <>
2444 template <class T> void f<int>(); */
2449 else
2451 declarator);
2453 }
2456 /* This is a specialization of a member template, without
2457 specialization the containing class. Something like:
2459 template <class T> struct S {
2460 template <class U> void f (U);
2461 };
2462 template <> template <class U> void S<int>::f(U) {}
2464 That's a specialization -- but of the entire template. */
2470 }
2473 {
2477 {
2481 }
2482 }
2485 {
2489 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2491 {
2492 tree fns;
2497 else
2498 {
2499 /* If there is no class context, the explicit instantiation
2500 must be at namespace scope. */
2503 /* Find the namespace binding, using the declaration
2504 context. */
2508 {
2511 }
2512 else
2513 {
2519 }
2520 }
2523 }
2529 {
2531 /* A specialization in class scope. This is invalid,
2532 but the error will already have been flagged by
2533 check_specialization_scope. */
2535 else
2536 {
2537 /* It's not valid to write an explicit instantiation in
2538 class scope, e.g.:
2540 class C { template void f(); }
2542 This case is caught by the parser. However, on
2543 something like:
2545 template class C { void f(); };
2547 (which is invalid) we can get here. The error will be
2548 issued later. */
2549 ;
2550 }
2553 }
2556 {
2557 /* Find the list of functions in ctype that have the same
2558 name as the declared function. */
2564 {
2569 {
2570 /* From [temp.expl.spec]:
2572 If such an explicit specialization for the member
2573 of a class template names an implicitly-declared
2574 special member function (clause _special_), the
2575 program is ill-formed.
2577 Similar language is found in [temp.explicit]. */
2580 }
2583 }
2586 {
2590 }
2591 else
2592 {
2594 tree ovl;
2596 /* For a type-conversion operator, we cannot do a
2597 name-based lookup. We might be looking for `operator
2598 int' which will be a specialization of `operator T'.
2599 So, we find *all* the conversion operators, and then
2600 select from them. */
2608 {
2610 /* There are no more conversion functions. */
2613 /* Glue all these conversion functions together
2614 with those we already have. */
2617 }
2618 }
2621 {
2624 }
2625 else
2627 }
2629 /* Figure out what exactly is being specialized at this point.
2630 Note that for an explicit instantiation, even one for a
2631 member function, we cannot tell apriori whether the
2632 instantiation is for a member template, or just a member
2633 function of a template class. Even if a member template is
2634 being instantiated, the member template arguments may be
2635 elided if they can be deduced from the rest of the
2636 declaration. */
2639 member_specialization,
2640 template_count,
2641 tsk);
2644 /* We couldn't figure out what this declaration was
2645 specializing. */
2647 else
2648 {
2652 {
2653 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2654 is done by do_decl_instantiation later. */
2660 {
2661 /* If TMPL is not the most general template (for
2662 example, if TMPL is a friend template that is
2663 injected into namespace scope), then there will
2664 be too many levels of TARGS. Remove some of them
2665 here. */
2667 tree new_targs;
2674 }
2677 }
2679 /* If we thought that the DECL was a member function, but it
2680 turns out to be specializing a static member function,
2681 make DECL a static member function as well. */
2686 /* If this is a specialization of a member template of a
2687 template class, we want to return the TEMPLATE_DECL, not
2688 the specialization of it. */
2690 {
2695 {
2696 tree parm;
2700 /* We want to use the argument list specified in the
2701 definition, not in the original declaration. */
2706 }
2709 }
2711 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2714 /* Inherit default function arguments from the template
2715 DECL is specializing. */
2718 /* This specialization has the same protection as the
2719 template it specializes. */
2723 /* 7.1.1-1 [dcl.stc]
2725 A storage-class-specifier shall not be specified in an
2726 explicit specialization...
2728 The parser rejects these, so unless action is taken here,
2729 explicit function specializations will always appear with
2730 global linkage.
2732 The action recommended by the C++ CWG in response to C++
2733 defect report 605 is to make the storage class and linkage
2734 of the explicit specialization match the templated function:
2736 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2737 */
2739 {
2743 /* This specialization has the same linkage and visibility as
2744 the function template it specializes. */
2747 {
2750 }
2753 {
2756 }
2757 }
2759 /* If DECL is a friend declaration, declared using an
2760 unqualified name, the namespace associated with DECL may
2761 have been set incorrectly. For example, in:
2763 template <typename T> void f(T);
2764 namespace N {
2765 struct S { friend void f<int>(int); }
2766 }
2768 we will have set the DECL_CONTEXT for the friend
2769 declaration to N, rather than to the global namespace. */
2774 /* This is not really a declaration of a specialization.
2775 It's just the name of an instantiation. But, it's not
2776 a request for an instantiation, either. */
2779 /* This is indeed a specialization. In case of constructors
2780 and destructors, we need in-charge and not-in-charge
2781 versions in V3 ABI. */
2784 /* Register this specialization so that we can find it
2785 again. */
2787 }
2788 }
2791 }
2793 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2794 parameters. These are represented in the same format used for
2795 DECL_TEMPLATE_PARMS. */
2797 int
2799 {
2800 const_tree p1;
2801 const_tree p2;
2809 {
2821 {
2825 /* If either of the template parameters are invalid, assume
2826 they match for the sake of error recovery. */
2839 }
2840 }
2843 /* One set of parameters has more parameters lists than the
2844 other. */
2848 }
2850 /* Determine whether PARM is a parameter pack. */
2852 bool
2854 {
2855 /* Determine if we have a non-type template parameter pack. */
2862 /* If this is a list of template parameters, we could get a
2863 TYPE_DECL or a TEMPLATE_DECL. */
2867 /* Otherwise it must be a type template parameter. */
2871 }
2873 /* Determine if T is a function parameter pack. */
2875 bool
2877 {
2881 }
2883 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2884 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2886 tree
2888 {
2895 }
2897 /* Return true iff the function parameter PARAM_DECL was expanded
2898 from the function parameter pack PACK. */
2900 bool
2902 {
2907 /* The parameter pack and its pack arguments have the same
2908 DECL_PARM_INDEX. */
2910 }
2912 /* Determine whether ARGS describes a variadic template args list,
2913 i.e., one that is terminated by a template argument pack. */
2915 static bool
2917 {
2919 tree last_parm;
2933 }
2935 /* Generate a new name for the parameter pack name NAME (an
2936 IDENTIFIER_NODE) that incorporates its */
2938 static tree
2940 {
2941 /* Munge the name to include the parameter index. */
2942 #define NUMBUF_LEN 128
2956 }
2958 /* Return true if T is a primary function, class or alias template
2959 instantiation. */
2961 bool
2963 {
2977 }
2979 /* Return true if PARM is a template template parameter. */
2981 bool
2983 {
2985 }
2987 /* Return true iff PARM is a DECL representing a type template
2988 parameter. */
2990 bool
2992 {
2997 }
2999 /* Return the template parameters of T if T is a
3000 primary template instantiation, NULL otherwise. */
3002 tree
3004 {
3009 parms = INNERMOST_TEMPLATE_PARMS
3013 }
3015 /* Return the template parameters of the LEVELth level from the full list
3016 of template parameters PARMS. */
3018 tree
3020 {
3021 tree p;
3032 }
3034 /* Returns the template arguments of T if T is a template instantiation,
3035 NULL otherwise. */
3037 tree
3039 {
3047 }
3049 /* Return the argument pack elements of T if T is a template argument pack,
3050 NULL otherwise. */
3052 tree
3054 {
3060 }
3062 /* Structure used to track the progress of find_parameter_packs_r. */
3063 struct find_parameter_pack_data
3064 {
3065 /* TREE_LIST that will contain all of the parameter packs found by
3066 the traversal. */
3069 /* Set of AST nodes that have been visited by the traversal. */
3071 };
3073 /* Identifies all of the argument packs that occur in a template
3074 argument and appends them to the TREE_LIST inside DATA, which is a
3075 find_parameter_pack_data structure. This is a subroutine of
3076 make_pack_expansion and uses_parameter_packs. */
3077 static tree
3079 {
3085 /* Handle type aliases/typedefs. */
3087 {
3094 }
3096 /* Identify whether this is a parameter pack or not. */
3098 {
3114 {
3115 /* We don't want to walk into the type of a PARM_DECL,
3116 because we don't want to see the type parameter pack. */
3119 }
3122 /* Look through a lambda capture proxy to the field pack. */
3125 {
3131 }
3138 /* Not a parameter pack. */
3140 }
3143 {
3144 /* Add this parameter pack to the list. */
3146 }
3152 /* This switch statement will return immediately if we don't find a
3153 parameter pack. */
3155 {
3160 /* Check the template itself. */
3163 /* Check the template arguments. */
3179 /* Fall through. */
3221 }
3224 }
3226 /* Determines if the expression or type T uses any parameter packs. */
3227 bool
3229 {
3237 }
3239 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3240 representation a base-class initializer into a parameter pack
3241 expansion. If all goes well, the resulting node will be an
3242 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3243 respectively. */
3244 tree
3246 {
3247 tree result;
3256 {
3257 /* The only time we will see a TREE_LIST here is for a base
3258 class initializer. In this case, the TREE_PURPOSE will be a
3259 _TYPE node (representing the base class expansion we're
3260 initializing) and the TREE_VALUE will be a TREE_LIST
3261 containing the initialization arguments.
3263 The resulting expansion looks somewhat different from most
3264 expansions. Rather than returning just one _EXPANSION, we
3265 return a TREE_LIST whose TREE_PURPOSE is a
3266 TYPE_PACK_EXPANSION containing the bases that will be
3267 initialized. The TREE_VALUE will be identical to the
3268 original TREE_VALUE, which is a list of arguments that will
3269 be passed to each base. We do not introduce any new pack
3270 expansion nodes into the TREE_VALUE (although it is possible
3271 that some already exist), because the TREE_PURPOSE and
3272 TREE_VALUE all need to be expanded together with the same
3273 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3274 resulting TREE_PURPOSE will mention the parameter packs in
3275 both the bases and the arguments to the bases. */
3276 tree purpose;
3277 tree value;
3280 /* Determine which parameter packs will be used by the base
3281 class expansion. */
3288 {
3292 }
3295 {
3296 /* Collect the sets of parameter packs used in each of the
3297 initialization arguments. */
3299 {
3300 /* Determine which parameter packs will be expanded in this
3301 argument. */
3304 }
3305 }
3309 /* Create the pack expansion type for the base type. */
3314 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3315 they will rarely be compared to anything. */
3319 }
3324 /* Build the PACK_EXPANSION_* node. */
3325 result = for_types
3330 {
3331 /* Propagate type and const-expression information. */
3334 }
3335 else
3336 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3337 they will rarely be compared to anything. */
3340 /* Determine which parameter packs will be expanded. */
3346 /* Make sure we found some parameter packs. */
3348 {
3351 else
3354 }
3360 }
3362 /* Checks T for any "bare" parameter packs, which have not yet been
3363 expanded, and issues an error if any are found. This operation can
3364 only be done on full expressions or types (e.g., an expression
3365 statement, "if" condition, etc.), because we could have expressions like:
3367 foo(f(g(h(args)))...)
3369 where "args" is a parameter pack. check_for_bare_parameter_packs
3370 should not be called for the subexpressions args, h(args),
3371 g(h(args)), or f(g(h(args))), because we would produce erroneous
3372 error messages.
3374 Returns TRUE and emits an error if there were bare parameter packs,
3375 returns FALSE otherwise. */
3376 bool
3378 {
3394 {
3397 {
3406 else
3411 else
3415 }
3418 }
3421 }
3423 /* Expand any parameter packs that occur in the template arguments in
3424 ARGS. */
3425 tree
3427 {
3433 /* First, determine if we need to expand anything, and the number of
3434 slots we'll need. */
3436 {
3441 {
3445 else
3447 }
3448 else
3449 {
3451 num_result_args++;
3452 }
3453 }
3455 /* If no expansion is necessary, we're done. */
3459 /* Expand arguments. */
3462 non_default_args_count =
3465 {
3468 {
3475 }
3476 else
3477 {
3480 }
3481 }
3485 }
3487 /* Checks if DECL shadows a template parameter.
3489 [temp.local]: A template-parameter shall not be redeclared within its
3490 scope (including nested scopes).
3492 Emits an error and returns TRUE if the DECL shadows a parameter,
3493 returns FALSE otherwise. */
3495 bool
3497 {
3498 tree olddecl;
3500 /* If we're not in a template, we can't possibly shadow a template
3501 parameter. */
3505 /* Figure out what we're shadowing. */
3510 /* If there's no previous binding for this name, we're not shadowing
3511 anything, let alone a template parameter. */
3515 /* If we're not shadowing a template parameter, we're done. Note
3516 that OLDDECL might be an OVERLOAD (or perhaps even an
3517 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3518 node. */
3522 /* We check for decl != olddecl to avoid bogus errors for using a
3523 name inside a class. We check TPFI to avoid duplicate errors for
3524 inline member templates. */
3530 /* Don't complain about the injected class name, as we've already
3531 complained about the class itself. */
3538 }
3540 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3541 ORIG_LEVEL, DECL, and TYPE. */
3543 static tree
3547 tree decl,
3548 tree type)
3549 {
3560 }
3562 /* Find the canonical type parameter for the given template type
3563 parameter. Returns the canonical type parameter, which may be TYPE
3564 if no such parameter existed. */
3566 static tree
3568 {
3569 tree list;
3583 else
3584 {
3589 }
3590 }
3592 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3593 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3594 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3595 new one is created. */
3597 static tree
3599 tsubst_flags_t complain)
3600 {
3605 {
3624 /* Template template parameters need this. */
3629 }
3632 }
3634 /* Process information from new template parameter PARM and append it
3635 to the LIST being built. This new parameter is a non-type
3636 parameter iff IS_NON_TYPE is true. This new parameter is a
3637 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3638 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3639 parameter list PARM belongs to. This is used used to create a
3640 proper canonical type for the type of PARM that is to be created,
3641 iff PARM is a type. If the size is not known, this parameter shall
3642 be set to 0. */
3644 tree
3647 {
3649 tree defval;
3650 tree err_parm_list;
3657 {
3661 {
3665 else
3667 }
3670 }
3671 else
3675 {
3681 {
3685 }
3686 else
3687 {
3688 /* [temp.param]
3690 The top-level cv-qualifiers on the template-parameter are
3691 ignored when determining its type. */
3694 {
3698 }
3701 {
3702 /* This template parameter is not a parameter pack, but it
3703 should be. Complain about "bare" parameter packs. */
3706 /* Recover by calling this a parameter pack. */
3708 }
3709 }
3711 /* A template parameter is not modifiable. */
3720 processing_template_decl,
3725 }
3726 else
3727 {
3728 tree t;
3732 {
3734 /* This is for distinguishing between real templates and template
3735 template parameters */
3739 }
3740 else
3741 {
3743 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3746 }
3753 processing_template_decl,
3757 }
3763 }
3765 /* The end of a template parameter list has been reached. Process the
3766 tree list into a parameter vector, converting each parameter into a more
3767 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3768 as PARM_DECLs. */
3770 tree
3772 {
3777 current_template_parms
3782 {
3786 }
3791 }
3793 /* end_template_decl is called after a template declaration is seen. */
3795 void
3797 {
3803 /* This matches the pushlevel in begin_template_parm_list. */
3808 }
3810 /* Takes a TREE_LIST representing a template parameter and convert it
3811 into an argument suitable to be passed to the type substitution
3812 functions. Note that If the TREE_LIST contains an error_mark
3813 node, the returned argument is error_mark_node. */
3815 static tree
3817 {
3830 {
3834 {
3835 /* Turn this argument into a TYPE_ARGUMENT_PACK
3836 with a single element, which expands T. */
3838 #ifdef ENABLE_CHECKING
3839 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3841 #endif
3846 }
3847 }
3848 else
3849 {
3853 {
3854 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3855 with a single element, which expands T. */
3858 #ifdef ENABLE_CHECKING
3859 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3861 #endif
3868 }
3869 }
3871 }
3873 /* Given a set of template parameters, return them as a set of template
3874 arguments. The template parameters are represented as a TREE_VEC, in
3875 the form documented in cp-tree.h for template arguments. */
3877 static tree
3879 {
3880 tree header;
3885 /* If there is only one level of template parameters, we do not
3886 create a TREE_VEC of TREE_VECs. Instead, we return a single
3887 TREE_VEC containing the arguments. */
3892 {
3900 #ifdef ENABLE_CHECKING
3902 #endif
3906 else
3908 }
3911 /* This can happen for template parms of a template template
3912 parameter, e.g:
3914 template<template<class T, class U> class TT> struct S;
3916 Consider the level of the parms of TT; T and U both have
3917 level 2; TT has no template parm of level 1. So in this case
3918 the first element of full_template_args is NULL_TREE. If we
3919 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3920 of 2. This will make tsubst wrongly consider that T and U
3921 have level 1. Instead, let's create a dummy vector as the
3922 first element of full_template_args so that TMPL_ARGS_DEPTH
3923 returns the correct depth for args. */
3926 }
3928 /* Within the declaration of a template, return the currently active
3929 template parameters as an argument TREE_VEC. */
3931 static tree
3933 {
3935 }
3937 /* Update the declared TYPE by doing any lookups which were thought to be
3938 dependent, but are not now that we know the SCOPE of the declarator. */
3940 tree
3942 {
3953 /* Don't bother building up the args in this case. */
3955 {
3956 /* tsubst in the args corresponding to the template parameters,
3957 including auto if present. Most things will be unchanged, but
3958 make_typename_type and tsubst_qualified_id will resolve
3959 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3962 tree pushed;
3964 {
3968 }
3973 }
3979 {
3982 else
3984 }
3986 }
3988 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3989 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3990 a member template. Used by push_template_decl below. */
3992 static tree
3994 {
4002 }
4004 struct template_parm_data
4005 {
4006 /* The level of the template parameters we are currently
4007 processing. */
4010 /* The index of the specialization argument we are currently
4011 processing. */
4014 /* An array whose size is the number of template parameters. The
4015 elements are nonzero if the parameter has been used in any one
4016 of the arguments processed so far. */
4019 /* An array whose size is the number of template arguments. The
4020 elements are nonzero if the argument makes use of template
4021 parameters of this level. */
4023 };
4025 /* Subroutine of push_template_decl used to see if each template
4026 parameter in a partial specialization is used in the explicit
4027 argument list. If T is of the LEVEL given in DATA (which is
4028 treated as a template_parm_data*), then DATA->PARMS is marked
4029 appropriately. */
4031 static int
4033 {
4039 {
4042 }
4043 else
4044 {
4047 }
4050 {
4053 }
4055 /* Return zero so that for_each_template_parm will continue the
4056 traversal of the tree; we want to mark *every* template parm. */
4058 }
4060 /* Process the partial specialization DECL. */
4062 static tree
4064 {
4070 tree inner_parms;
4071 tree inst;
4084 /* We check that each of the template parameters given in the
4085 partial specialization is used in the argument list to the
4086 specialization. For example:
4088 template <class T> struct S;
4089 template <class T> struct S<T*>;
4091 The second declaration is OK because `T*' uses the template
4092 parameter T, whereas
4094 template <class T> struct S<int>;
4096 is no good. Even trickier is:
4098 template <class T>
4099 struct S1
4100 {
4101 template <class U>
4102 struct S2;
4103 template <class U>
4104 struct S2<T>;
4105 };
4107 The S2<T> declaration is actually invalid; it is a
4108 full-specialization. Of course,
4110 template <class U>
4111 struct S2<T (*)(U)>;
4113 or some such would have been OK. */
4121 {
4126 NULL,
4128 }
4131 {
4132 /* One of the template parms was not used in the
4133 specialization. */
4135 {
4138 }
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 line is the `argument expression is not just a
4227 simple identifier' condition and also the `specialized
4228 non-type argument' bit. */
4230 {
4234 arg);
4235 else
4236 {
4237 /* Look at the corresponding template parameter,
4238 marking which template parameters its type depends
4239 upon. */
4243 {
4244 /* We haven't yet initialized TPD2. Do so now. */
4246 /* The number of parameters here is the number in the
4247 main template, which, as checked in the assertion
4248 above, is NARGS. */
4252 }
4254 /* Mark the template parameters. But this time, we're
4255 looking for the template parameters of the main
4256 template, not in the specialization. */
4263 NULL,
4267 {
4268 /* The type depended on some template parameters.
4269 If they are fully specialized in the
4270 specialization, that's OK. */
4279 "type %qT of template argument %qE depends "
4281 "type %qT of template argument %qE depends "
4283 type,
4284 arg);
4285 }
4286 }
4287 }
4288 }
4289 }
4291 /* We should only get here once. */
4309 {
4313 {
4317 "partial specialization of %qT after instantiation "
4319 }
4320 }
4323 }
4325 /* Check that a template declaration's use of default arguments and
4326 parameter packs is not invalid. Here, PARMS are the template
4327 parameters. IS_PRIMARY is true if DECL is the thing declared by
4328 a primary template. IS_PARTIAL is true if DECL is a partial
4329 specialization.
4331 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4332 declaration (but not a definition); 1 indicates a declaration, 2
4333 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4334 emitted for extraneous default arguments.
4336 Returns TRUE if there were no errors found, FALSE otherwise. */
4338 bool
4341 {
4344 tree parm_level;
4347 /* [temp.param]
4349 A default template-argument shall not be specified in a
4350 function template declaration or a function template definition, nor
4351 in the template-parameter-list of the definition of a member of a
4352 class template. */
4355 /* You can't have a function template declaration in a local
4356 scope, nor you can you define a member of a class template in a
4357 local scope. */
4363 /* A lambda doesn't have an explicit declaration; don't complain
4364 about the parms of the enclosing class. */
4371 /* If this is either a friend defined in the scope of the class
4372 or a member function. */
4378 /* And, if it was a member function, it really was defined in
4379 the scope of the class. */
4382 /* We already checked these parameters when the template was
4383 declared, so there's no need to do it again now. This function
4384 was defined in class scope, but we're processing its body now
4385 that the class is complete. */
4388 /* Core issue 226 (C++0x only): the following only applies to class
4389 templates. */
4392 {
4393 /* [temp.param]
4395 If a template-parameter has a default template-argument, all
4396 subsequent template-parameters shall have a default
4397 template-argument supplied. */
4399 {
4406 {
4416 {
4418 /* For better subsequent error-recovery, we indicate that
4419 there should have been a default argument. */
4422 }
4424 && !is_friend_decl
4425 /* Don't complain about an enclosing partial
4426 specialization. */
4431 {
4432 /* A primary class template can only have one
4433 parameter pack, at the end of the template
4434 parameter list. */
4439 else
4447 }
4448 }
4449 }
4450 }
4453 || is_partial
4454 || !is_primary
4456 /* For an ordinary class template, default template arguments are
4457 allowed at the innermost level, e.g.:
4458 template <class T = int>
4459 struct S {};
4460 but, in a partial specialization, they're not allowed even
4461 there, as we have in [temp.class.spec]:
4463 The template parameter list of a specialization shall not
4464 contain default template argument values.
4466 So, for a partial specialization, or for a function template
4467 (in C++98/C++03), we look at all of them. */
4468 ;
4469 else
4470 /* But, for a primary class template that is not a partial
4471 specialization we look at all template parameters except the
4472 innermost ones. */
4475 /* Figure out what error message to issue. */
4488 else
4492 /* If we're inside a class definition, there's no need to
4493 examine the parameters to the class itself. On the one
4494 hand, they will be checked when the class is defined, and,
4495 on the other, default arguments are valid in things like:
4496 template <class T = double>
4497 struct S { template <class U> void f(U); };
4498 Here the default argument for `S' has no bearing on the
4499 declaration of `f'. */
4501 else
4502 /* Check everything. */
4508 {
4515 {
4520 {
4522 {
4529 }
4531 /* Clear out the default argument so that we are not
4532 confused later. */
4534 }
4535 }
4537 /* At this point, if we're still interested in issuing messages,
4538 they must apply to classes surrounding the object declared. */
4542 }
4545 }
4547 /* Worker for push_template_decl_real, called via
4548 for_each_template_parm. DATA is really an int, indicating the
4549 level of the parameters we are interested in. If T is a template
4550 parameter of that level, return nonzero. */
4552 static int
4554 {
4560 else
4563 }
4565 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4566 parameters given by current_template_args, or reuses a
4567 previously existing one, if appropriate. Returns the DECL, or an
4568 equivalent one, if it is replaced via a call to duplicate_decls.
4570 If IS_FRIEND is true, DECL is a friend declaration. */
4572 tree
4574 {
4575 tree tmpl;
4576 tree args;
4577 tree info;
4578 tree ctx;
4582 /* True if the template is a member template, in the sense of
4583 [temp.mem]. */
4589 /* See if this is a partial specialization. */
4598 /* For a friend, we want the context of the friend function, not
4599 the type of which it is a friend. */
4603 /* In the case of a virtual function, we want the class in which
4604 it is defined. */
4606 else
4607 /* Otherwise, if we're currently defining some class, the DECL
4608 is assumed to be a member of the class. */
4617 /* See if this is a primary template. */
4619 /* A friend template that specifies a class context, i.e.
4620 template <typename T> friend void A<T>::f();
4621 is not primary. */
4623 else
4627 {
4632 {
4635 }
4637 {
4639 {
4640 /* [temp.mem]
4642 A destructor shall not be a member template. */
4645 }
4652 {
4653 /* [basic.stc.dynamic.allocation]
4655 An allocation function can be a function
4656 template. ... Template allocation functions shall
4657 have two or more parameters. */
4660 }
4661 }
4667 /* alias-declaration */
4669 else
4670 {
4673 }
4674 }
4676 /* Check to see that the rules regarding the use of default
4677 arguments are not being violated. */
4681 /* Ensure that there are no parameter packs in the type of this
4682 declaration that have not been expanded. */
4684 {
4685 /* Check each of the arguments individually to see if there are
4686 any bare parameter packs. */
4692 {
4695 {
4696 /* This is a PARM_DECL that contains unexpanded parameter
4697 packs. We have already complained about this in the
4698 check_for_bare_parameter_packs call, so just replace
4699 these types with ERROR_MARK_NODE. */
4702 }
4706 }
4708 /* Check for bare parameter packs in the return type and the
4709 exception specifiers. */
4711 /* Errors were already issued, set return type to int
4712 as the frontend doesn't expect error_mark_node as
4713 the return type. */
4717 }
4722 {
4725 }
4738 {
4743 /* If DECL is a TYPE_DECL for a class-template, then there won't
4744 be DECL_LANG_SPECIFIC. The information equivalent to
4745 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4749 {
4750 /* Since a template declaration already existed for this
4751 class-type, we must be redeclaring it here. Make sure
4752 that the redeclaration is valid. */
4754 current_template_parms);
4755 /* We don't need to create a new TEMPLATE_DECL; just use the
4756 one we already had. */
4758 }
4759 else
4760 {
4762 member_template_p);
4767 {
4768 /* A specialization of a member template of a template
4769 class. */
4773 }
4774 }
4775 }
4776 else
4777 {
4783 {
4786 }
4794 {
4795 tree new_tmpl;
4797 /* The declaration is a specialization of a member
4798 template, declared outside the class. Therefore, the
4799 innermost template arguments will be NULL, so we
4800 replace them with the arguments determined by the
4801 earlier call to check_explicit_specialization. */
4804 new_tmpl
4806 member_template_p);
4816 args,
4819 }
4821 /* Make sure the template headers we got make sense. */
4826 {
4829 }
4830 else
4832 {
4837 {
4841 else
4845 /* Avoid crash in import_export_decl. */
4848 }
4853 /* Can happen in erroneous input. */
4855 else
4857 }
4859 /* Check that the parms are used in the appropriate qualifying scopes
4860 in the declarator. */
4864 {
4870 /* Avoid crash in import_export_decl. */
4873 }
4874 }
4879 /* Push template declarations for global functions and types. Note
4880 that we do not try to push a global template friend declared in a
4881 template class; such a thing may well depend on the template
4882 parameters of the class. */
4885 {
4890 /* Hide template friend classes that haven't been declared yet. */
4892 {
4895 }
4896 }
4899 {
4905 {
4908 /* It is a conversion operator. See if the type converted to
4909 depends on innermost template operands. */
4912 depth))
4914 }
4916 /* Give template template parms a DECL_CONTEXT of the template
4917 for which they are a parameter. */
4920 {
4924 }
4925 }
4927 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4928 back to its most general template. If TMPL is a specialization,
4929 ARGS may only have the innermost set of arguments. Add the missing
4930 argument levels if necessary. */
4938 else
4939 {
4944 }
4947 }
4949 tree
4951 {
4953 }
4955 /* FN is an inheriting constructor that inherits from the constructor
4956 template INHERITED; turn FN into a constructor template with a matching
4957 template header. */
4959 tree
4961 {
4962 tree inner_parms
4965 tree parms
4976 }
4978 /* Called when a class template TYPE is redeclared with the indicated
4979 template PARMS, e.g.:
4981 template <class T> struct S;
4982 template <class T> struct S {}; */
4984 bool
4986 {
4987 tree tmpl;
4988 tree tmpl_parms;
4992 {
4995 }
4999 /* The type is nested in some template class. Nothing to worry
5000 about here; there are no new template parameters for the nested
5001 type. */
5005 {
5007 tmpl);
5009 }
5015 {
5025 }
5028 {
5029 tree tmpl_parm;
5030 tree parm;
5031 tree tmpl_default;
5032 tree parm_default;
5046 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5047 TEMPLATE_DECL. */
5057 {
5061 }
5064 {
5065 /* We have in [temp.param]:
5067 A template-parameter may not be given default arguments
5068 by two different declarations in the same scope. */
5073 }
5076 /* Update the previous template parameters (which are the ones
5077 that will really count) with the new default value. */
5080 /* Update the new parameters, too; they'll be used as the
5081 parameters for any members. */
5083 }
5086 }
5088 /* Simplify EXPR if it is a non-dependent expression. Returns the
5089 (possibly simplified) expression. */
5091 tree
5093 {
5097 /* If we're in a template, but EXPR isn't value dependent, simplify
5098 it. We're supposed to treat:
5100 template <typename T> void f(T[1 + 1]);
5101 template <typename T> void f(T[2]);
5103 as two declarations of the same function, for example. */
5107 {
5108 HOST_WIDE_INT saved_processing_template_decl;
5114 complain,
5119 }
5121 }
5123 tree
5125 {
5127 }
5129 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5130 template declaration, or a TYPE_DECL for an alias declaration. */
5132 bool
5134 {
5142 }
5144 /* Return TRUE iff is a specialization of an alias template. */
5146 bool
5148 {
5156 }
5158 /* Return the number of innermost template parameters in TMPL. */
5160 static int
5162 {
5165 }
5167 /* Return either TMPL or another template that it is equivalent to under DR
5168 1286: An alias that just changes the name of a template is equivalent to
5169 the other template. */
5171 static tree
5173 {
5176 {
5179 {
5185 {
5186 /* The alias type is equivalent to the pattern of the
5187 underlying template, so strip the alias. */
5190 }
5191 }
5193 }
5195 }
5197 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5198 must be a function or a pointer-to-function type, as specified
5199 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5200 and check that the resulting function has external linkage. */
5202 static tree
5204 {
5207 linkage_kind linkage;
5219 /* [temp.arg.nontype]/1
5221 A template-argument for a non-type, non-template template-parameter
5222 shall be one of:
5223 [...]
5224 -- the address of an object or function with external [C++11: or
5225 internal] linkage. */
5228 {
5232 else
5235 }
5239 {
5244 else
5249 }
5252 }
5254 /* Subroutine of convert_nontype_argument.
5255 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5256 Emit an error otherwise. */
5258 static bool
5260 tsubst_flags_t complain)
5261 {
5268 {
5272 }
5274 }
5276 /* Returns TRUE iff the address of OP is value-dependent.
5278 14.6.2.4 [temp.dep.temp]:
5279 A non-integral non-type template-argument is dependent if its type is
5280 dependent or it has either of the following forms
5281 qualified-id
5282 & qualified-id
5283 and contains a nested-name-specifier which specifies a class-name that
5284 names a dependent type.
5286 We generalize this to just say that the address of a member of a
5287 dependent class is value-dependent; the above doesn't cover the
5288 address of a static data member named with an unqualified-id. */
5290 static bool
5292 {
5293 /* We could use get_inner_reference here, but there's no need;
5294 this is only relevant for template non-type arguments, which
5295 can only be expressed as &id-expression. */
5297 {
5301 }
5304 }
5306 /* The next set of functions are used for providing helpful explanatory
5307 diagnostics for failed overload resolution. Their messages should be
5308 indented by two spaces for consistency with the messages in
5309 call.c */
5311 static int
5313 {
5315 }
5317 static int
5319 {
5324 }
5326 static int
5328 {
5330 }
5332 static int
5334 {
5340 }
5342 static int
5344 {
5348 }
5350 static int
5352 {
5355 " template parameter %qD is not a parameter pack, but "
5359 }
5361 static int
5363 {
5366 " template argument %qE does not match "
5370 }
5372 static int
5374 {
5378 }
5380 static int
5382 {
5388 }
5390 static int
5392 {
5394 {
5399 else
5401 " deduced conflicting values for non-type parameter "
5403 }
5405 }
5407 static int
5409 {
5412 " variable-sized array type %qT is not "
5414 arg);
5416 }
5418 static int
5420 {
5424 arg);
5426 }
5428 static int
5430 {
5437 }
5439 static int
5441 {
5443 }
5445 static int
5447 {
5449 }
5451 static int
5454 {
5460 }
5462 static int
5465 {
5468 {
5476 }
5478 }
5480 static int
5482 {
5485 " template parameters of a template template argument are "
5488 }
5490 static int
5492 {
5498 }
5500 static int
5502 {
5507 }
5509 static int
5511 {
5515 arg);
5517 }
5519 /* Attempt to convert the non-type template parameter EXPR to the
5520 indicated TYPE. If the conversion is successful, return the
5521 converted value. If the conversion is unsuccessful, return
5522 NULL_TREE if we issued an error message, or error_mark_node if we
5523 did not. We issue error messages for out-and-out bad template
5524 parameters, but not simply because the conversion failed, since we
5525 might be just trying to do argument deduction. Both TYPE and EXPR
5526 must be non-dependent.
5528 The conversion follows the special rules described in
5529 [temp.arg.nontype], and it is much more strict than an implicit
5530 conversion.
5532 This function is called twice for each template argument (see
5533 lookup_template_class for a more accurate description of this
5534 problem). This means that we need to handle expressions which
5535 are not valid in a C++ source, but can be created from the
5536 first call (for instance, casts to perform conversions). These
5537 hacks can go away after we fix the double coercion problem. */
5539 static tree
5541 {
5542 tree expr_type;
5544 /* Detect immediately string literals as invalid non-type argument.
5545 This special-case is not needed for correctness (we would easily
5546 catch this later), but only to provide better diagnostic for this
5547 common user mistake. As suggested by DR 100, we do not mention
5548 linkage issues in the diagnostic as this is not the point. */
5549 /* FIXME we're making this OK. */
5551 {
5557 }
5559 /* Add the ADDR_EXPR now for the benefit of
5560 value_dependent_expression_p. */
5563 {
5567 }
5569 /* If we are in a template, EXPR may be non-dependent, but still
5570 have a syntactic, rather than semantic, form. For example, EXPR
5571 might be a SCOPE_REF, rather than the VAR_DECL to which the
5572 SCOPE_REF refers. Preserving the qualifying scope is necessary
5573 so that access checking can be performed when the template is
5574 instantiated -- but here we need the resolved form so that we can
5575 convert the argument. */
5586 else
5589 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5590 to a non-type argument of "nullptr". */
5594 /* In C++11, integral or enumeration non-type template arguments can be
5595 arbitrary constant expressions. Pointer and pointer to
5596 member arguments can be general constant expressions that evaluate
5597 to a null value, but otherwise still need to be of a specific form. */
5599 {
5601 /* A PTRMEM_CST is already constant, and a valid template
5602 argument for a parameter of pointer to member type, we just want
5603 to leave it in that form rather than lower it to a
5608 {
5613 }
5614 }
5616 /* HACK: Due to double coercion, we can get a
5617 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5618 which is the tree that we built on the first call (see
5619 below when coercing to reference to object or to reference to
5620 function). We just strip everything and get to the arg.
5621 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5622 for examples. */
5624 {
5630 {
5631 /* ??? Maybe we could use convert_from_reference here, but we
5632 would need to relax its constraints because the NOP_EXPR
5633 could actually change the type to something more cv-qualified,
5634 and this is not folded by convert_from_reference. */
5639 && (same_type_ignoring_top_level_qualifiers_p
5642 {
5645 }
5646 }
5647 }
5649 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5650 parameter is a pointer to object, through decay and
5651 qualification conversion. Let's strip everything. */
5653 {
5658 {
5659 /* Skip the ADDR_EXPR only if it is part of the decay for
5660 an array. Otherwise, it is part of the original argument
5661 in the source code. */
5666 }
5667 }
5669 /* [temp.arg.nontype]/5, bullet 1
5671 For a non-type template-parameter of integral or enumeration type,
5672 integral promotions (_conv.prom_) and integral conversions
5673 (_conv.integral_) are applied. */
5675 {
5684 /* Notice that there are constant expressions like '4 % 0' which
5685 do not fold into integer constants. */
5687 {
5689 {
5700 /* else cxx_constant_value complained but gave us
5701 a real constant, so go ahead. */
5703 }
5704 else
5706 }
5708 /* Avoid typedef problems. */
5711 }
5712 /* [temp.arg.nontype]/5, bullet 2
5714 For a non-type template-parameter of type pointer to object,
5715 qualification conversions (_conv.qual_) and the array-to-pointer
5716 conversion (_conv.array_) are applied. */
5718 {
5719 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5721 A template-argument for a non-type, non-template template-parameter
5722 shall be one of: [...]
5724 -- the name of a non-type template-parameter;
5725 -- the address of an object or function with external linkage, [...]
5726 expressed as "& id-expression" where the & is optional if the name
5727 refers to a function or array, or if the corresponding
5728 template-parameter is a reference.
5730 Here, we do not care about functions, as they are invalid anyway
5731 for a parameter of type pointer-to-object. */
5734 /* Non-type template parameters are OK. */
5735 ;
5740 {
5742 {
5744 "because %qD is a variable, not the address of "
5748 }
5750 {
5755 }
5756 /* Other values, like integer constants, might be valid
5757 non-type arguments of some other type. */
5759 }
5760 else
5761 {
5762 tree decl;
5767 {
5772 }
5774 {
5779 }
5781 {
5786 }
5787 }
5796 }
5797 /* [temp.arg.nontype]/5, bullet 3
5799 For a non-type template-parameter of type reference to object, no
5800 conversions apply. The type referred to by the reference may be more
5801 cv-qualified than the (otherwise identical) type of the
5802 template-argument. The template-parameter is bound directly to the
5803 template-argument, which must be an lvalue. */
5805 {
5807 expr_type))
5811 {
5815 }
5818 {
5822 }
5824 /* [temp.arg.nontype]/1
5826 A template-argument for a non-type, non-template template-parameter
5827 shall be one of: [...]
5829 -- the address of an object or function with external linkage. */
5832 {
5835 {
5837 "because a reference variable does not have a constant "
5840 }
5841 }
5844 {
5849 }
5852 {
5857 }
5860 }
5861 /* [temp.arg.nontype]/5, bullet 4
5863 For a non-type template-parameter of type pointer to function, only
5864 the function-to-pointer conversion (_conv.func_) is applied. If the
5865 template-argument represents a set of overloaded functions (or a
5866 pointer to such), the matching function is selected from the set
5867 (_over.over_). */
5869 {
5870 /* If the argument is a template-id, we might not have enough
5871 context information to decay the pointer. */
5873 {
5877 }
5880 /* Null pointer values are OK in C++11. */
5886 }
5887 /* [temp.arg.nontype]/5, bullet 5
5889 For a non-type template-parameter of type reference to function, no
5890 conversions apply. If the template-argument represents a set of
5891 overloaded functions, the matching function is selected from the set
5892 (_over.over_). */
5894 {
5896 {
5901 }
5908 }
5909 /* [temp.arg.nontype]/5, bullet 6
5911 For a non-type template-parameter of type pointer to member function,
5912 no conversions apply. If the template-argument represents a set of
5913 overloaded member functions, the matching member function is selected
5914 from the set (_over.over_). */
5916 {
5921 /* [temp.arg.nontype] bullet 1 says the pointer to member
5922 expression must be a pointer-to-member constant. */
5926 /* There is no way to disable standard conversions in
5927 resolve_address_of_overloaded_function (called by
5928 instantiate_type). It is possible that the call succeeded by
5929 converting &B::I to &D::I (where B is a base of D), so we need
5930 to reject this conversion here.
5932 Actually, even if there was a way to disable standard conversions,
5933 it would still be better to reject them here so that we can
5934 provide a superior diagnostic. */
5936 {
5940 /* If we are just one standard conversion off, explain. */
5945 }
5946 }
5947 /* [temp.arg.nontype]/5, bullet 7
5949 For a non-type template-parameter of type pointer to data member,
5950 qualification conversions (_conv.qual_) are applied. */
5952 {
5953 /* [temp.arg.nontype] bullet 1 says the pointer to member
5954 expression must be a pointer-to-member constant. */
5961 }
5963 {
5965 {
5969 }
5971 }
5972 /* A template non-type parameter must be one of the above. */
5973 else
5976 /* Sanity check: did we actually convert the argument to the
5977 right type? */
5981 }
5983 /* Subroutine of coerce_template_template_parms, which returns 1 if
5984 PARM_PARM and ARG_PARM match using the rule for the template
5985 parameters of template template parameters. Both PARM and ARG are
5986 template parameters; the rest of the arguments are the same as for
5987 coerce_template_template_parms.
5988 */
5989 static int
5991 tree arg,
5992 tsubst_flags_t complain,
5993 tree in_decl,
5994 tree outer_args)
5995 {
6004 {
6006 /* We encounter instantiations of templates like
6007 template <template <template <class> class> class TT>
6008 class C; */
6009 {
6016 }
6017 /* Fall through. */
6022 /* Argument is a parameter pack but parameter is not. */
6027 /* The tsubst call is used to handle cases such as
6029 template <int> class C {};
6030 template <class T, template <T> class TT> class D {};
6031 D<int, C> d;
6033 i.e. the parameter list of TT depends on earlier parameters. */
6035 && !same_type_p
6042 /* Argument is a parameter pack but parameter is not. */
6049 }
6052 }
6055 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6056 template template parameters. Both PARM_PARMS and ARG_PARMS are
6057 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6058 or PARM_DECL.
6060 Consider the example:
6061 template <class T> class A;
6062 template<template <class U> class TT> class B;
6064 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6065 the parameters to A, and OUTER_ARGS contains A. */
6067 static int
6069 tree arg_parms,
6070 tsubst_flags_t complain,
6071 tree in_decl,
6072 tree outer_args)
6073 {
6084 /* Determine whether we have a parameter pack at the end of the
6085 template template parameter's template parameter list. */
6087 {
6094 {
6108 }
6109 }
6115 /* Check all of the template parameters except the parameter pack at
6116 the end (if any). */
6118 {
6127 outer_args))
6130 }
6133 {
6134 /* Check each of the template parameters in the template
6135 argument against the template parameter pack at the end of
6136 the template template parameter. */
6143 {
6150 outer_args))
6152 }
6153 }
6156 }
6158 /* Verifies that the deduced template arguments (in TARGS) for the
6159 template template parameters (in TPARMS) represent valid bindings,
6160 by comparing the template parameter list of each template argument
6161 to the template parameter list of its corresponding template
6162 template parameter, in accordance with DR150. This
6163 routine can only be called after all template arguments have been
6164 deduced. It will return TRUE if all of the template template
6165 parameter bindings are okay, FALSE otherwise. */
6166 bool
6168 {
6172 /* We're dealing with template parms in this process. */
6178 {
6183 {
6188 {
6189 /* Look inside the argument pack. */
6192 }
6195 {
6199 /* Extract the next argument from the argument
6200 pack. */
6204 /* Look at the pattern of the pack expansion. */
6207 /* Extract the template parameters from the template
6208 argument. */
6214 /* Verify that we can coerce the template template
6215 parameters from the template argument to the template
6216 parameter. This requires an exact match. */
6218 && !coerce_template_template_parms
6220 targ_parms,
6221 tf_none,
6222 tparm,
6223 targs))
6224 {
6227 }
6228 }
6229 }
6230 }
6232 out:
6236 }
6238 /* Since type attributes aren't mangled, we need to strip them from
6239 template type arguments. */
6241 static tree
6243 {
6244 tree mv;
6251 {
6256 }
6258 }
6260 /* Convert the indicated template ARG as necessary to match the
6261 indicated template PARM. Returns the converted ARG, or
6262 error_mark_node if the conversion was unsuccessful. Error and
6263 warning messages are issued under control of COMPLAIN. This
6264 conversion is for the Ith parameter in the parameter list. ARGS is
6265 the full set of template arguments deduced so far. */
6267 static tree
6269 tree arg,
6270 tree args,
6271 tsubst_flags_t complain,
6273 tree in_decl)
6274 {
6275 tree orig_arg;
6276 tree val;
6281 {
6282 /* The template argument was the name of some
6283 member function. That's usually
6284 invalid, but static members are OK. In any
6285 case, grab the underlying fields/functions
6286 and issue an error later if required. */
6289 }
6297 /* When determining whether an argument pack expansion is a template,
6298 look at the pattern. */
6302 /* Deal with an injected-class-name used as a template template arg. */
6304 {
6307 {
6317 }
6318 }
6320 is_tmpl_type =
6336 {
6338 {
6342 }
6345 "to refer to a type member of a template parameter, "
6350 typename_type,
6351 complain);
6354 }
6356 {
6358 {
6360 {
6370 else
6372 }
6373 }
6375 }
6377 {
6379 {
6385 else
6387 }
6389 }
6392 {
6394 {
6398 /* The number of argument required is not known yet.
6399 Just accept it for now. */
6401 else
6402 {
6404 tree argparm;
6406 /* Strip alias templates that are equivalent to another
6407 template. */
6413 args))
6414 {
6417 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6418 TEMPLATE_DECL. */
6420 {
6425 }
6426 }
6427 else
6428 {
6430 {
6436 }
6439 }
6440 }
6441 }
6442 else
6444 /* We only form one instance of each template specialization.
6445 Therefore, if we use a non-canonical variant (i.e., a
6446 typedef), any future messages referring to the type will use
6447 the typedef, which is confusing if those future uses do not
6448 themselves also use the typedef. */
6451 }
6452 else
6453 {
6460 {
6463 else
6464 {
6465 /* Not sure if this is reachable, but it doesn't hurt
6466 to be robust. */
6469 }
6470 }
6473 /* We used to call digest_init here. However, digest_init
6474 will report errors, which we don't want when complain
6475 is zero. More importantly, digest_init will try too
6476 hard to convert things: for example, `0' should not be
6477 converted to pointer type at this point according to
6478 the standard. Accepting this is not merely an
6479 extension, since deciding whether or not these
6480 conversions can occur is part of determining which
6481 function template to call, or whether a given explicit
6482 argument specification is valid. */
6484 else
6493 {
6494 /* Strip typedefs from the SCOPE_REF. */
6497 complain);
6500 }
6501 }
6504 }
6506 /* Coerces the remaining template arguments in INNER_ARGS (from
6507 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6508 Returns the coerced argument pack. PARM_IDX is the position of this
6509 parameter in the template parameter list. ARGS is the original
6510 template argument list. */
6511 static tree
6514 tree args,
6515 tree inner_args,
6517 tree new_args,
6519 tree in_decl,
6520 tsubst_flags_t complain)
6521 {
6524 tree packed_args;
6525 tree argument_pack;
6535 {
6536 /* When the template parameter is a non-type template
6537 parameter pack whose type uses parameter packs, we need
6538 to look at each of the template arguments
6539 separately. Build a vector of the types for these
6540 non-type template parameters in PACKED_TYPES. */
6541 tree expansion
6549 /* Check that we have the right number of arguments. */
6553 {
6554 int needed_parms
6559 }
6561 /* If we aren't able to check the actual arguments now
6562 (because they haven't been expanded yet), we can at least
6563 verify that all of the types used for the non-type
6564 template parameter pack are, in fact, valid for non-type
6565 template parameters. */
6568 {
6571 {
6575 }
6576 }
6577 }
6579 /* Convert the remaining arguments, which will be a part of the
6580 parameter pack "parm". */
6582 {
6587 {
6588 /* When we have a vector of types (corresponding to the
6589 non-type template parameter pack that uses parameter
6590 packs in its type, as mention above), and the
6591 argument is not an expansion (which expands to a
6592 currently unknown number of arguments), clone the
6593 parm and give it the next type in PACKED_TYPES. */
6597 }
6600 {
6603 }
6604 else
6607 in_decl);
6611 }
6616 else
6617 {
6622 }
6625 #ifdef ENABLE_CHECKING
6628 #endif
6630 }
6632 /* Returns the number of pack expansions in the template argument vector
6633 ARGS. */
6635 static int
6637 {
6642 {
6646 }
6648 }
6650 /* Convert all template arguments to their appropriate types, and
6651 return a vector containing the innermost resulting template
6652 arguments. If any error occurs, return error_mark_node. Error and
6653 warning messages are issued under control of COMPLAIN.
6655 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6656 for arguments not specified in ARGS. Otherwise, if
6657 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6658 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6659 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6660 ARGS. */
6662 static tree
6664 tree args,
6665 tree in_decl,
6666 tsubst_flags_t complain,
6669 {
6671 tree inner_args;
6672 tree new_args;
6673 tree new_inner_args;
6677 /* When used as a boolean value, indicates whether this is a
6678 variadic template parameter list. Since it's an int, we can also
6679 subtract it from nparms to get the number of non-variadic
6680 parameters. */
6690 /* Determine if there are any parameter packs. */
6692 {
6698 }
6701 /* If there are no parameters that follow a parameter pack, we need to
6702 expand any argument packs so that we can deduce a parameter pack from
6703 some non-packed args followed by an argument pack, as in variadic85.C.
6704 If there are such parameters, we need to leave argument packs intact
6705 so the arguments are assigned properly. This can happen when dealing
6706 with a nested class inside a partial specialization of a class
6707 template, as in variadic92.C, or when deducing a template parameter pack
6708 from a sub-declarator, as in variadic114.C. */
6712 /* Count any pack expansion args. */
6718 && require_all_args
6719 && !variadic_args_p
6720 && (!use_default_args
6723 {
6725 {
6727 {
6731 }
6732 else
6738 }
6741 }
6742 /* We can't pass a pack expansion to a non-pack parameter of an alias
6743 template (DR 1430). */
6745 && variadic_args_p
6747 {
6749 {
6751 {
6757 {
6762 }
6763 }
6765 found:;
6766 }
6768 }
6770 /* We need to evaluate the template arguments, even though this
6771 template-id may be nested within a "sizeof". */
6779 {
6780 tree arg;
6781 tree parm;
6783 /* Get the Ith template parameter. */
6787 {
6790 }
6792 /* Calculate the next argument. */
6795 else
6800 {
6801 /* All remaining arguments will be placed in the
6802 template parameter pack PARM. */
6808 /* Store this argument. */
6810 lost++;
6813 /* We are done with all of the arguments. */
6817 }
6819 {
6821 {
6822 /* We don't know how many args we have yet, just
6823 use the unconverted ones for now. */
6826 }
6827 }
6829 {
6830 /* There must be a default arg in this case. */
6833 /* The position of the first default template argument,
6834 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6835 Record that. */
6838 }
6839 else
6843 {
6846 }
6848 /* This only occurs if there was an error in the template
6849 parameter list itself (which we would already have
6850 reported) that we are trying to recover from, e.g., a class
6851 template with a parameter list such as
6852 template<typename..., typename>. */
6854 else
6860 lost++;
6862 }
6869 #ifdef ENABLE_CHECKING
6873 #endif
6876 }
6878 /* Like coerce_template_parms. If PARMS represents all template
6879 parameters levels, this function returns a vector of vectors
6880 representing all the resulting argument levels. Note that in this
6881 case, only the innermost arguments are coerced because the
6882 outermost ones are supposed to have been coerced already.
6884 Otherwise, if PARMS represents only (the innermost) vector of
6885 parameters, this function returns a vector containing just the
6886 innermost resulting arguments. */
6888 static tree
6890 tree args,
6891 tree in_decl,
6892 tsubst_flags_t complain,
6895 {
6898 tree coerced_args;
6901 {
6903 tree level;
6909 {
6910 tree l;
6914 require_all_args,
6915 use_default_args);
6916 else
6923 }
6924 }
6925 else
6928 require_all_args,
6929 use_default_args);
6931 }
6933 /* Returns 1 if template args OT and NT are equivalent. */
6935 static int
6937 {
6944 /* For member templates */
6953 {
6970 }
6972 {
6973 /* We get here probably because we are in the middle of substituting
6974 into the pattern of a pack expansion. In that case the
6975 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6976 interested in. So we want to use the initial pack argument for
6977 the comparison. */
6982 }
6987 else
6989 }
6991 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6992 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6993 NEWARG_PTR with the offending arguments if they are non-NULL. */
6995 static int
6998 {
7011 {
7016 {
7022 }
7023 }
7025 }
7027 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7028 of template arguments. Returns 0 otherwise. */
7030 int
7032 {
7034 }
7036 static void
7038 {
7048 /* We are called both from instantiate_decl, where we've already had a
7049 tinst_level pushed, and instantiate_template, where we haven't.
7050 Compensate. */
7061 else
7070 }
7073 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7074 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7075 documentation for TEMPLATE_ID_EXPR. */
7077 tree
7079 {
7080 tree type;
7088 {
7091 }
7094 {
7096 unknown_type_node,
7098 arglist);
7100 }
7107 }
7109 /* Within the scope of a template class S<T>, the name S gets bound
7110 (in build_self_reference) to a TYPE_DECL for the class, not a
7111 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7112 or one of its enclosing classes, and that type is a template,
7113 return the associated TEMPLATE_DECL. Otherwise, the original
7114 DECL is returned.
7116 Also handle the case when DECL is a TREE_LIST of ambiguous
7117 injected-class-names from different bases. */
7119 tree
7121 {
7125 /* DR 176: A lookup that finds an injected-class-name (10.2
7126 [class.member.lookup]) can result in an ambiguity in certain cases
7127 (for example, if it is found in more than one base class). If all of
7128 the injected-class-names that are found refer to specializations of
7129 the same class template, and if the name is followed by a
7130 template-argument-list, the reference refers to the class template
7131 itself and not a specialization thereof, and is not ambiguous. */
7133 {
7136 {
7142 }
7145 else
7147 }
7153 }
7155 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7156 parameters, find the desired type.
7158 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7160 IN_DECL, if non-NULL, is the template declaration we are trying to
7161 instantiate.
7163 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7164 the class we are looking up.
7166 Issue error and warning messages under control of COMPLAIN.
7168 If the template class is really a local class in a template
7169 function, then the FUNCTION_CONTEXT is the function in which it is
7170 being instantiated.
7172 ??? Note that this function is currently called *twice* for each
7173 template-id: the first time from the parser, while creating the
7174 incomplete type (finish_template_type), and the second type during the
7175 real instantiation (instantiate_template_class). This is surely something
7176 that we want to avoid. It also causes some problems with argument
7177 coercion (see convert_nontype_argument for more information on this). */
7179 static tree
7182 {
7184 tree t;
7187 spec_entry elt;
7188 hashval_t hash;
7191 {
7195 else
7196 {
7203 }
7206 }
7208 {
7211 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7212 an implicit typename for the second A. Deal with it. */
7217 {
7220 }
7221 }
7224 {
7227 }
7231 {
7235 }
7237 {
7240 }
7242 /* Issue an error message if we didn't find a template. */
7244 {
7248 }
7251 /* Make sure it's a user visible template, if it was named by
7252 the user. */
7255 {
7257 {
7261 }
7263 }
7267 /* An alias that just changes the name of a template is equivalent to the
7268 other template, so if any of the arguments are pack expansions, strip
7269 the alias to avoid problems with a pack expansion passed to a non-pack
7270 alias template parameter (DR 1430). */
7275 {
7276 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7277 template arguments */
7279 tree parm;
7280 tree arglist2;
7281 tree outer;
7285 /* Consider an example where a template template parameter declared as
7287 template <class T, class U = std::allocator<T> > class TT
7289 The template parameter level of T and U are one level larger than
7290 of TT. To proper process the default argument of U, say when an
7291 instantiation `TT<int>' is seen, we need to build the full
7292 arguments containing {int} as the innermost level. Outer levels,
7293 available when not appearing as default template argument, can be
7294 obtained from the arguments of the enclosing template.
7296 Suppose that TT is later substituted with std::vector. The above
7297 instantiation is `TT<int, std::allocator<T> >' with TT at
7298 level 1, and T at level 2, while the template arguments at level 1
7299 becomes {std::vector} and the inner level 2 is {int}. */
7305 /* This is an argument of the current template, so we haven't set
7306 DECL_CONTEXT yet. */
7313 complain,
7323 }
7324 else
7325 {
7327 tree gen_tmpl;
7328 tree type_decl;
7336 /* An error occurred while building the template TEMPL, and a
7337 diagnostic has most certainly been emitted for that
7338 already. Let's propagate that error. */
7347 {
7348 /* We've been given an incomplete set of template arguments.
7349 For example, given:
7351 template <class T> struct S1 {
7352 template <class U> struct S2 {};
7353 template <class U> struct S2<U*> {};
7354 };
7356 we will be called with an ARGLIST of `U*', but the
7357 TEMPLATE will be `template <class T> template
7358 <class U> struct S1<T>::S2'. We must fill in the missing
7359 arguments. */
7360 arglist
7362 arglist);
7364 }
7366 /* Now we should have enough arguments. */
7369 /* From here on, we're only interested in the most general
7370 template. */
7372 /* Calculate the BOUND_ARGS. These will be the args that are
7373 actually tsubst'd into the definition to create the
7374 instantiation. */
7376 {
7377 /* We have multiple levels of arguments to coerce, at once. */
7387 {
7388 tree a;
7392 complain,
7395 else
7396 /* Outer levels should have already been coerced. */
7399 /* Don't process further if one of the levels fails. */
7401 {
7402 /* Restore the ARGLIST to its full size. */
7405 }
7409 /* We temporarily reduce the length of the ARGLIST so
7410 that coerce_template_parms will see only the arguments
7411 corresponding to the template parameters it is
7412 examining. */
7414 }
7416 /* Restore the ARGLIST to its full size. */
7420 }
7421 else
7422 arglist
7425 gen_tmpl,
7426 complain,
7431 /* We were unable to bind the arguments. */
7434 /* In the scope of a template class, explicit references to the
7435 template class refer to the type of the template, not any
7436 instantiation of it. For example, in:
7438 template <class T> class C { void f(C<T>); }
7440 the `C<T>' is just the same as `C'. Outside of the
7441 class, however, such a reference is an instantiation. */
7445 /* comp_template_args is expensive, check it last. */
7447 arglist))
7450 /* If we already have this specialization, return it. */
7462 /* If the deduced arguments are invalid, then the binding
7463 failed. */
7467 complain))
7474 {
7479 }
7489 /* Create the type. */
7491 {
7492 /* The user referred to a specialization of an alias
7493 template represented by GEN_TMPL.
7495 [temp.alias]/2 says:
7497 When a template-id refers to the specialization of an
7498 alias template, it is equivalent to the associated
7499 type obtained by substitution of its
7500 template-arguments for the template-parameters in the
7501 type-id of the alias template. */
7504 /* Note that the call above (by indirectly calling
7505 register_specialization in tsubst_decl) registers the
7506 TYPE_DECL representing the specialization of the alias
7507 template. So next time someone substitutes ARGLIST for
7508 the template parms into the alias template (GEN_TMPL),
7509 she'll get that TYPE_DECL back. */
7513 }
7515 {
7517 {
7523 }
7524 else
7525 {
7526 /* We don't want to call start_enum for this type, since
7527 the values for the enumeration constants may involve
7528 template parameters. And, no one should be interested
7529 in the enumeration constants for such a type. */
7532 }
7536 }
7538 {
7545 /* A local class. Make sure the decl gets registered properly. */
7550 /* This instantiation is another name for the primary
7551 template type. Set the TYPE_CANONICAL field
7552 appropriately. */
7555 /* Some of the template arguments require structural
7556 equality testing, so this template class requires
7557 structural equality testing. */
7559 }
7560 else
7563 /* If we called start_enum or pushtag above, this information
7564 will already be set up. */
7566 {
7573 }
7574 else
7578 {
7584 {
7587 }
7588 }
7590 /* Let's consider the explicit specialization of a member
7591 of a class template specialization that is implicitely instantiated,
7592 e.g.:
7593 template<class T>
7594 struct S
7595 {
7596 template<class U> struct M {}; //#0
7597 };
7599 template<>
7600 template<>
7601 struct S<int>::M<char> //#1
7602 {
7603 int i;
7604 };
7605 [temp.expl.spec]/4 says this is valid.
7607 In this case, when we write:
7608 S<int>::M<char> m;
7610 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7611 the one of #0.
7613 When we encounter #1, we want to store the partial instantiation
7614 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7616 For all cases other than this "explicit specialization of member of a
7617 class template", we just want to store the most general template into
7618 the CLASSTYPE_TI_TEMPLATE of M.
7620 This case of "explicit specialization of member of a class template"
7621 only happens when:
7622 1/ the enclosing class is an instantiation of, and therefore not
7623 the same as, the context of the most general template, and
7624 2/ we aren't looking at the partial instantiation itself, i.e.
7625 the innermost arguments are not the same as the innermost parms of
7626 the most general template.
7628 So it's only when 1/ and 2/ happens that we want to use the partial
7629 instantiation of the member template in lieu of its most general
7630 template. */
7634 /* the enclosing class must be an instantiation... */
7637 {
7638 tree partial_inst_args;
7641 partial_inst_args =
7647 use_partial_inst_tmpl =
7648 /*...and we must not be looking at the partial instantiation
7649 itself. */
7651 partial_inst_args);
7652 }
7655 /* This case is easy; there are no member templates involved. */
7657 else
7658 {
7659 /* This is a full instantiation of a member template. Find
7660 the partial instantiation of which this is an instance. */
7662 /* Temporarily reduce by one the number of levels in the ARGLIST
7663 so as to avoid comparing the last set of arguments. */
7667 /* FOUND is either a proper class type, or an alias
7668 template specialization. In the later case, it's a
7669 TYPE_DECL, resulting from the substituting of arguments
7670 for parameters in the TYPE_DECL of the alias template
7671 done earlier. So be careful while getting the template
7672 of FOUND. */
7676 }
7687 /* Note this use of the partial instantiation so we can check it
7688 later in maybe_process_partial_specialization. */
7695 /* Now that the type has been registered on the instantiations
7696 list, we set up the enumerators. Because the enumeration
7697 constants may involve the enumeration type itself, we make
7698 sure to register the type first, and then create the
7699 constants. That way, doing tsubst_expr for the enumeration
7700 constants won't result in recursive calls here; we'll find
7701 the instantiation and exit above. */
7705 /* If the type makes use of template parameters, the
7706 code that generates debugging information will crash. */
7709 /* Possibly limit visibility based on template args. */
7714 }
7715 }
7717 /* Wrapper for lookup_template_class_1. */
7719 tree
7722 {
7723 tree ret;
7729 }
7730 \f
7731 struct pair_fn_data
7732 {
7733 tree_fn_t fn;
7735 /* True when we should also visit template parameters that occur in
7736 non-deduced contexts. */
7739 };
7741 /* Called from for_each_template_parm via walk_tree. */
7743 static tree
7745 {
7758 {
7762 /* Fall through. */
7785 /* Since we're not going to walk subtrees, we have to do this
7786 explicitly here. */
7790 /* Fall through. */
7793 /* Check the return type. */
7798 /* Check the parameter types. Since default arguments are not
7799 instantiated until they are needed, the TYPE_ARG_TYPES may
7800 contain expressions that involve template parameters. But,
7801 no-one should be looking at them yet. And, once they're
7802 instantiated, they don't contain template parameters, so
7803 there's no point in looking at them then, either. */
7804 {
7805 tree parm;
7812 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7813 want walk_tree walking into them itself. */
7815 }
7833 /* Fall through. */
7849 /* Record template parameters such as `T' inside `TT<T>'. */
7853 /* Fall through. */
7865 /* A template template parameter is encountered. */
7871 /* Already substituted template template parameter */
7894 /* If there's no type, then this thing must be some expression
7895 involving template parameters. */
7917 }
7919 /* We didn't find any template parameters we liked. */
7921 }
7923 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7924 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7925 call FN with the parameter and the DATA.
7926 If FN returns nonzero, the iteration is terminated, and
7927 for_each_template_parm returns 1. Otherwise, the iteration
7928 continues. If FN never returns a nonzero value, the value
7929 returned by for_each_template_parm is 0. If FN is NULL, it is
7930 considered to be the function which always returns 1.
7932 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7933 parameters that occur in non-deduced contexts. When false, only
7934 visits those template parameters that can be deduced. */
7936 static int
7940 {
7944 /* Set up. */
7949 /* Walk the tree. (Conceptually, we would like to walk without
7950 duplicates, but for_each_template_parm_r recursively calls
7951 for_each_template_parm, so we would need to reorganize a fair
7952 bit to use walk_tree_without_duplicates, so we keep our own
7953 visited list.) */
7956 else
7959 for_each_template_parm_r,
7963 /* Clean up. */
7965 {
7968 }
7971 }
7973 /* Returns true if T depends on any template parameter. */
7975 int
7977 {
8004 else
8005 {
8008 }
8013 }
8015 /* Returns true iff current_function_decl is an incompletely instantiated
8016 template. Useful instead of processing_template_decl because the latter
8017 is set to 0 during fold_non_dependent_expr. */
8019 bool
8021 {
8030 }
8032 /* Returns true if T depends on any template parameter with level LEVEL. */
8034 int
8036 {
8039 }
8041 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8042 ill-formed translation unit, i.e. a variable or function that isn't
8043 usable in a constant expression. */
8047 {
8051 }
8053 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8054 neglectable and instantiated from within an erroneous instantiation. */
8056 static bool
8058 {
8069 }
8077 /* We're starting to instantiate D; record the template instantiation context
8078 for diagnostics and to restore it later. */
8080 int
8082 {
8086 {
8092 else
8100 }
8102 /* If the current instantiation caused problems, don't let it instantiate
8103 anything else. Do allow deduction substitution and decls usable in
8104 constant expressions. */
8121 }
8123 /* We're done instantiating this template; return to the instantiation
8124 context. */
8126 void
8128 {
8129 /* Restore the filename and line number stashed away when we started
8130 this instantiation. */
8134 }
8136 /* We're instantiating a deferred template; restore the template
8137 instantiation context in which the instantiation was requested, which
8138 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8140 static tree
8142 {
8154 }
8156 /* Returns the TINST_LEVEL which gives the original instantiation
8157 context. */
8161 {
8167 }
8169 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8170 vector of template arguments, as for tsubst.
8172 Returns an appropriate tsubst'd friend declaration. */
8174 static tree
8176 {
8177 tree new_friend;
8182 /* This was a friend declared with an explicit template
8183 argument list, e.g.:
8185 friend void f<>(T);
8187 to indicate that f was a template instantiation, not a new
8188 function declaration. Now, we have to figure out what
8189 instantiation of what template. */
8190 {
8192 tree new_args;
8193 tree tmpl;
8196 /* Friend functions are looked up in the containing namespace scope.
8197 We must enter that scope, to avoid finding member functions of the
8198 current class with same name. */
8213 tsk_none);
8215 }
8219 /* The NEW_FRIEND will look like an instantiation, to the
8220 compiler, but is not an instantiation from the point of view of
8221 the language. For example, we might have had:
8223 template <class T> struct S {
8224 template <class U> friend void f(T, U);
8225 };
8227 Then, in S<int>, template <class U> void f(int, U) is not an
8228 instantiation of anything. */
8234 {
8238 }
8240 /* The mangled name for the NEW_FRIEND is incorrect. The function
8241 is not a template instantiation and should not be mangled like
8242 one. Therefore, we forget the mangling here; we'll recompute it
8243 later if we need it. */
8245 {
8248 }
8251 {
8252 tree old_decl;
8253 tree new_friend_template_info;
8254 tree new_friend_result_template_info;
8255 tree ns;
8258 /* We must save some information from NEW_FRIEND before calling
8259 duplicate decls since that function will free NEW_FRIEND if
8260 possible. */
8262 new_friend_is_defn =
8267 {
8268 /* This declaration is a `primary' template. */
8271 new_friend_result_template_info
8273 }
8274 else
8277 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8281 /* Inside pushdecl_namespace_level, we will push into the
8282 current namespace. However, the friend function should go
8283 into the namespace of the template. */
8293 {
8294 /* This new friend declaration matched an existing
8295 declaration. For example, given:
8297 template <class T> void f(T);
8298 template <class U> class C {
8299 template <class T> friend void f(T) {}
8300 };
8302 the friend declaration actually provides the definition
8303 of `f', once C has been instantiated for some type. So,
8304 old_decl will be the out-of-class template declaration,
8305 while new_friend is the in-class definition.
8307 But, if `f' was called before this point, the
8308 instantiation of `f' will have DECL_TI_ARGS corresponding
8309 to `T' but not to `U', references to which might appear
8310 in the definition of `f'. Previously, the most general
8311 template for an instantiation of `f' was the out-of-class
8312 version; now it is the in-class version. Therefore, we
8313 run through all specialization of `f', adding to their
8314 DECL_TI_ARGS appropriately. In particular, they need a
8315 new set of outer arguments, corresponding to the
8316 arguments for this class instantiation.
8318 The same situation can arise with something like this:
8320 friend void f(int);
8321 template <class T> class C {
8322 friend void f(T) {}
8323 };
8325 when `C<int>' is instantiated. Now, `f(int)' is defined
8326 in the class. */
8329 /* On the other hand, if the in-class declaration does
8330 *not* provide a definition, then we don't want to alter
8331 existing definitions. We can just leave everything
8332 alone. */
8333 ;
8334 else
8335 {
8339 /* Overwrite whatever template info was there before, if
8340 any, with the new template information pertaining to
8341 the declaration. */
8345 {
8346 /* We should have called reregister_specialization in
8347 duplicate_decls. */
8352 /* Instantiate it if the global has already been used. */
8356 }
8357 else
8358 {
8359 tree t;
8361 /* Indicate that the old function template is a partial
8362 instantiation. */
8370 /* Reassign any specializations already in the hash table
8371 to the new more general template, and add the
8372 additional template args. */
8376 {
8378 spec_entry elt;
8390 register_specialization
8393 }
8395 }
8396 }
8398 /* The information from NEW_FRIEND has been merged into OLD_DECL
8399 by duplicate_decls. */
8401 }
8402 }
8403 else
8404 {
8408 /* In the code
8409 template <class T> class C {
8410 template <class U> friend void C1<U>::f (); // case 1
8411 friend void C2<T>::f (); // case 2
8412 };
8413 we only need to make sure CONTEXT is a complete type for
8414 case 2. To distinguish between the two cases, we note that
8415 CONTEXT of case 1 remains dependent type after tsubst while
8416 this isn't true for case 2. */
8426 {
8427 /* Check to see that the declaration is really present, and,
8428 possibly obtain an improved declaration. */
8434 }
8435 }
8438 }
8440 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8441 template arguments, as for tsubst.
8443 Returns an appropriate tsubst'd friend type or error_mark_node on
8444 failure. */
8446 static tree
8448 {
8449 tree friend_type;
8450 tree tmpl;
8451 tree context;
8454 {
8457 }
8462 {
8465 else
8467 }
8469 /* Look for a class template declaration. We look for hidden names
8470 because two friend declarations of the same template are the
8471 same. For example, in:
8473 struct A {
8474 template <typename> friend class F;
8475 };
8476 template <typename> struct B {
8477 template <typename> friend class F;
8478 };
8480 both F templates are the same. */
8484 /* But, if we don't find one, it might be because we're in a
8485 situation like this:
8487 template <class T>
8488 struct S {
8489 template <class U>
8490 friend struct S;
8491 };
8493 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8494 for `S<int>', not the TEMPLATE_DECL. */
8496 {
8499 }
8502 {
8503 /* The friend template has already been declared. Just
8504 check to see that the declarations match, and install any new
8505 default parameters. We must tsubst the default parameters,
8506 of course. We only need the innermost template parameters
8507 because that is all that redeclare_class_template will look
8508 at. */
8511 {
8512 tree parms;
8513 location_t saved_input_location;
8522 }
8525 }
8526 else
8527 {
8528 /* The friend template has not already been declared. In this
8529 case, the instantiation of the template class will cause the
8530 injection of this template into the global scope. */
8535 /* The new TMPL is not an instantiation of anything, so we
8536 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8537 the new type because that is supposed to be the corresponding
8538 template decl, i.e., TMPL. */
8545 /* Inject this template into the global scope. */
8547 }
8550 {
8553 else
8555 }
8558 }
8560 /* Returns zero if TYPE cannot be completed later due to circularity.
8561 Otherwise returns one. */
8563 static int
8565 {
8575 else
8577 }
8581 /* Apply any attributes which had to be deferred until instantiation
8582 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8583 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8585 static void
8588 {
8590 tree t;
8595 {
8599 }
8602 {
8606 }
8607 else
8611 {
8616 {
8619 {
8626 {
8633 clauses
8637 else
8639 }
8640 /* If the first attribute argument is an identifier, don't
8641 pass it through tsubst. Attributes like mode, format,
8642 cleanup and several target specific attributes expect it
8643 unmodified. */
8646 {
8647 tree chain
8649 in_decl,
8654 chain);
8655 }
8656 else
8662 }
8663 else
8665 }
8668 }
8669 }
8671 /* Perform (or defer) access check for typedefs that were referenced
8672 from within the template TMPL code.
8673 This is a subroutine of instantiate_decl and instantiate_class_template.
8674 TMPL is the template to consider and TARGS is the list of arguments of
8675 that template. */
8677 static void
8679 {
8680 location_t saved_location;
8691 {
8703 /* Make access check error messages point to the location
8704 of the use of the typedef. */
8708 tf_warning_or_error);
8709 }
8711 }
8713 static tree
8715 {
8717 tree typedecl;
8718 tree pbinfo;
8719 tree base_list;
8721 tree fn_context;
8730 /* Figure out which template is being instantiated. */
8734 /* Determine what specialization of the original template to
8735 instantiate. */
8738 {
8741 }
8743 {
8744 /* This TYPE is actually an instantiation of a partial
8745 specialization. We replace the innermost set of ARGS with
8746 the arguments appropriate for substitution. For example,
8747 given:
8749 template <class T> struct S {};
8750 template <class T> struct S<T*> {};
8752 and supposing that we are instantiating S<int*>, ARGS will
8753 presently be {int*} -- but we need {int}. */
8756 }
8757 else
8758 {
8761 }
8763 /* If the template we're instantiating is incomplete, then clearly
8764 there's nothing we can do. */
8768 /* If we've recursively instantiated too many templates, stop. */
8772 /* Now we're really doing the instantiation. Mark the type as in
8773 the process of being defined. */
8776 /* We may be in the middle of deferred access check. Disable
8777 it now. */
8783 /* Use #pragma pack from the template context. */
8789 /* Set the input location to the most specialized template definition.
8790 This is needed if tsubsting causes an error. */
8802 {
8805 /* Adjust visibility for template arguments. */
8807 }
8813 /* We should never instantiate a nested class before its enclosing
8814 class; we need to look up the nested class by name before we can
8815 instantiate it, and that lookup should instantiate the enclosing
8816 class. */
8822 {
8823 tree pbase_binfo;
8824 tree pushed_scope;
8827 /* We must enter the scope containing the type, as that is where
8828 the accessibility of types named in dependent bases are
8829 looked up from. */
8832 /* Substitute into each of the bases to determine the actual
8833 basetypes. */
8835 {
8836 tree base;
8842 {
8843 expanded_bases =
8850 }
8853 {
8855 /* Extract the already-expanded base class. */
8857 else
8858 /* Substitute to figure out the base class. */
8860 NULL_TREE);
8868 }
8869 }
8871 /* The list is now in reverse order; correct that. */
8876 }
8877 /* Now call xref_basetypes to set up all the base-class
8878 information. */
8886 /* Now that our base classes are set up, enter the scope of the
8887 class, so that name lookups into base classes, etc. will work
8888 correctly. This is precisely analogous to what we do in
8889 begin_class_definition when defining an ordinary non-template
8890 class, except we also need to push the enclosing classes. */
8893 /* Now members are processed in the order of declaration. */
8896 {
8900 {
8902 {
8903 /* Build new CLASSTYPE_NESTED_UTDS. */
8905 tree newtag;
8911 /* If the member is a class template, then -- even after
8912 substitution -- there may be dependent types in the
8913 template argument list for the class. We increment
8914 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8915 that function will assume that no types are dependent
8916 when outside of a template. */
8926 {
8930 /* Unfortunately, lookup_template_class sets
8931 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8932 instantiation (i.e., for the type of a member
8933 template class nested within a template class.)
8934 This behavior is required for
8935 maybe_process_partial_specialization to work
8936 correctly, but is not accurate in this case;
8937 the TAG is not an instantiation of anything.
8938 (The corresponding TEMPLATE_DECL is an
8939 instantiation, but the TYPE is not.) */
8942 /* Now, we call pushtag to put this NEWTAG into the scope of
8943 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8944 pushtag calling push_template_decl. We don't have to do
8945 this for enums because it will already have been done in
8946 tsubst_enum. */
8950 }
8951 }
8953 {
8954 /* Build new TYPE_METHODS. */
8955 tree r;
8964 /* Instantiate members marked with attribute used. */
8970 }
8971 else
8972 {
8973 /* Build new TYPE_FIELDS. */
8975 {
8976 tree condition;
8979 condition =
8989 }
8991 {
8992 tree r;
8996 /* The file and line for this declaration, to
8997 assist in error message reporting. Since we
8998 called push_tinst_level above, we don't need to
8999 restore these. */
9009 {
9010 /* A capture pack became multiple fields. */
9013 }
9016 {
9020 {
9021 /* In [temp.inst]:
9023 [t]he initialization (and any associated
9024 side-effects) of a static data member does
9025 not occur unless the static data member is
9026 itself used in a way that requires the
9027 definition of the static data member to
9028 exist.
9030 Therefore, we do not substitute into the
9031 initialized for the static data member here. */
9032 finish_static_data_member_decl
9038 /* Instantiate members marked with attribute used. */
9041 }
9043 {
9044 /* Determine whether R has a valid type and can be
9045 completed later. If R is invalid, then its type
9046 is replaced by error_mark_node. */
9052 {
9055 }
9056 }
9058 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9059 such a thing will already have been added to the field
9060 list by tsubst_enum in finish_member_declaration in the
9061 CLASSTYPE_NESTED_UTDS case above. */
9065 {
9068 }
9069 }
9070 }
9071 }
9072 }
9073 else
9074 {
9077 {
9078 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9084 {
9085 /* template <class T> friend class C; */
9088 }
9090 {
9091 /* template <class T> friend class C::D; */
9097 }
9100 {
9101 /* This could be either
9103 friend class T::C;
9105 when dependent_type_p is false or
9107 template <class U> friend class T::C;
9109 otherwise. */
9112 /* Bump processing_template_decl for correct
9113 dependent_type_p calculation. */
9118 }
9121 {
9122 /* friend class C;
9124 where C hasn't been declared yet. Let's lookup name
9125 from namespace scope directly, bypassing any name that
9126 come from dependent base class. */
9129 /* The call to xref_tag_from_type does injection for friend
9130 classes. */
9132 friend_type =
9136 }
9138 /* friend class C<T>; */
9141 /* Otherwise it's
9143 friend class C;
9145 where C is already declared or
9147 friend class C<int>;
9149 We don't have to do anything in these cases. */
9152 /* Trick make_friend_class into realizing that the friend
9153 we're adding is a template, not an ordinary class. It's
9154 important that we use make_friend_class since it will
9155 perform some error-checking and output cross-reference
9156 information. */
9164 }
9165 else
9166 {
9167 /* Build new DECL_FRIENDLIST. */
9168 tree r;
9170 /* The file and line for this declaration, to
9171 assist in error message reporting. Since we
9172 called push_tinst_level above, we don't need to
9173 restore these. */
9177 {
9180 }
9185 {
9188 }
9189 }
9190 }
9191 }
9194 {
9197 {
9202 /* We need to instantiate the capture list from the template
9203 after we've instantiated the closure members, but before we
9204 consider adding the conversion op. Also keep any captures
9205 that may have been added during instantiation of the op(). */
9207 tree tmpl_cap
9216 }
9217 else
9219 }
9221 /* Set the file and line number information to whatever is given for
9222 the class itself. This puts error messages involving generated
9223 implicit functions at a predictable point, and the same point
9224 that would be used for non-template classes. */
9231 /* We don't instantiate default arguments for member functions. 14.7.1:
9233 The implicit instantiation of a class template specialization causes
9234 the implicit instantiation of the declarations, but not of the
9235 definitions or default arguments, of the class member functions,
9236 member classes, static data members and member templates.... */
9238 /* Some typedefs referenced from within the template code need to be access
9239 checked at template instantiation time, i.e now. These types were
9240 added to the template at parsing time. Let's get those and perform
9241 the access checks then. */
9251 /* The vtable for a template class can be emitted in any translation
9252 unit in which the class is instantiated. When there is no key
9253 method, however, finish_struct_1 will already have added TYPE to
9254 the keyed_classes list. */
9259 }
9261 /* Wrapper for instantiate_class_template_1. */
9263 tree
9265 {
9266 tree ret;
9271 }
9273 static tree
9275 {
9276 tree r;
9282 else
9283 {
9290 }
9292 }
9294 /* Given a function parameter pack TMPL_PARM and some function parameters
9295 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9296 and set *SPEC_P to point at the next point in the list. */
9298 static tree
9300 {
9301 /* Collect all of the extra "packed" parameters into an
9302 argument pack. */
9303 tree parmvec;
9304 tree parmtypevec;
9315 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9320 {
9323 }
9325 /* Build the argument packs. */
9332 }
9334 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9335 NONTYPE_ARGUMENT_PACK. */
9337 static tree
9339 {
9341 }
9343 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9344 pack expansion. */
9346 static bool
9348 {
9353 }
9356 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9358 static tree
9360 {
9367 }
9369 /* This is a subroutine of tsubst_pack_expansion.
9371 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9372 mechanism to store the (non complete list of) arguments of the
9373 substitution and return a non substituted pack expansion, in order
9374 to wait for when we have enough arguments to really perform the
9375 substitution. */
9377 static bool
9381 {
9382 /* If one pack has an expansion and another pack has a normal
9383 argument or if one pack has an empty argument and an another
9384 one hasn't then tsubst_pack_expansion cannot perform the
9385 substitution and need to fall back on the
9386 PACK_EXPANSION_EXTRA mechanism. */
9394 {
9397 parm_pack;
9399 {
9404 else
9406 }
9410 }
9412 }
9414 /* [temp.variadic]/6 says that:
9416 The instantiation of a pack expansion [...]
9417 produces a list E1,E2, ..., En, where N is the number of elements
9418 in the pack expansion parameters.
9420 This subroutine of tsubst_pack_expansion produces one of these Ei.
9422 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9423 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9424 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9425 INDEX is the index 'i' of the element Ei to produce. ARGS,
9426 COMPLAIN, and IN_DECL are the same parameters as for the
9427 tsubst_pack_expansion function.
9429 The function returns the resulting Ei upon successful completion,
9430 or error_mark_node.
9432 Note that this function possibly modifies the ARGS parameter, so
9433 it's the responsibility of the caller to restore it. */
9435 static tree
9437 tree parm_packs,
9439 tree args /* This parm gets
9441 tsubst_flags_t complain,
9442 tree in_decl)
9443 {
9444 tree t;
9447 /* For each parameter pack, change the substitution of the parameter
9448 pack to the ith argument in its argument pack, then expand the
9449 pattern. */
9451 {
9456 ith_elem_is_expansion |=
9459 /* Select the Ith argument from the pack. */
9462 {
9464 {
9468 }
9469 else
9471 }
9472 else
9473 {
9478 {
9480 /* Update the corresponding argument. */
9482 }
9483 else
9484 /* Re-use the ARGUMENT_PACK_SELECT. */
9486 }
9488 }
9490 /* Substitute into the PATTERN with the (possibly altered)
9491 arguments. */
9495 else
9498 /* If the Ith argument pack element is a pack expansion, then
9499 the Ith element resulting from the substituting is going to
9500 be a pack expansion as well. */
9505 }
9507 /* Substitute ARGS into T, which is an pack expansion
9508 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9509 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9510 (if only a partial substitution could be performed) or
9511 ERROR_MARK_NODE if there was an error. */
9512 tree
9514 tree in_decl)
9515 {
9516 tree pattern;
9520 tree result;
9528 /* Add in any args remembered from an earlier partial instantiation. */
9533 /* Determine the argument packs that will instantiate the parameter
9534 packs used in the expansion expression. While we're at it,
9535 compute the number of arguments to be expanded and make sure it
9536 is consistent. */
9539 {
9546 {
9550 else
9553 }
9555 {
9558 else
9559 {
9560 /* We can't rely on local_specializations for a parameter
9561 name used later in a function declaration (such as in a
9562 late-specified return type). Even if it exists, it might
9563 have the wrong value for a recursive call. Just make a
9564 dummy decl, since it's only used for its type. */
9567 /* Partial instantiation of the parm_pack, we can't build
9568 up an argument pack yet. */
9570 else
9573 }
9574 }
9577 else
9578 {
9584 }
9591 /* This can only happen if we forget to expand an argument
9592 pack somewhere else. Just return an error, silently. */
9593 {
9597 }
9600 {
9604 /* Don't bother trying to do a partial substitution with
9605 incomplete packs; we'll try again after deduction. */
9612 {
9618 pattern);
9619 else
9622 pattern);
9624 }
9626 /* Keep track of the parameter packs and their corresponding
9627 argument packs. */
9630 }
9631 else
9632 {
9633 /* We can't substitute for this parameter pack. We use a flag as
9634 well as the missing_level counter because function parameter
9635 packs don't have a level. */
9637 }
9638 }
9640 /* We cannot expand this expansion expression, because we don't have
9641 all of the argument packs we need. */
9643 {
9644 /* We got some full packs, but we can't substitute them in until we
9645 have values for all the packs. So remember these until then. */
9650 }
9652 {
9653 /* There were no real arguments, we're just replacing a parameter
9654 pack with another version of itself. Substitute into the
9655 pattern and return a PACK_EXPANSION_*. The caller will need to
9656 deal with that. */
9660 else
9664 }
9669 {
9670 /* We're in a late-specified return type, so create our own local
9671 specializations map; the current map is either NULL or (in the
9672 case of recursive unification) might have bindings that we don't
9673 want to use or alter. */
9676 }
9678 /* For each argument in each argument pack, substitute into the
9679 pattern. */
9682 {
9684 i,
9686 in_decl);
9689 {
9692 }
9693 }
9695 /* Update ARGS to restore the substitution from parameter packs to
9696 their argument packs. */
9698 {
9704 else
9705 {
9713 /* Update the corresponding argument. */
9717 else
9719 }
9720 }
9723 {
9726 }
9729 }
9731 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9732 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9733 parameter packs; all parms generated from a function parameter pack will
9734 have the same DECL_PARM_INDEX. */
9736 tree
9738 {
9740 tree patparm;
9743 {
9749 }
9750 else
9751 {
9756 }
9759 }
9761 /* Substitute ARGS into the vector or list of template arguments T. */
9763 static tree
9765 {
9777 {
9779 tree new_arg;
9784 {
9785 /* Substitute into an expansion expression. */
9789 /* Add to the expanded length adjustment the number of
9790 expanded arguments. We subtract one from this
9791 measurement, because the argument pack expression
9792 itself is already counted as 1 in
9793 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9794 the argument pack is empty. */
9796 }
9798 {
9799 /* Substitute into each of the arguments. */
9805 new_arg,
9819 }
9820 }
9821 else
9830 }
9835 /* Make space for the expanded arguments coming from template
9836 argument packs. */
9838 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9839 arguments for a member template.
9840 In that case each TREE_VEC in ORIG_T represents a level of template
9841 arguments, and ORIG_T won't carry any non defaulted argument count.
9842 It will rather be the nested TREE_VECs that will carry one.
9843 In other words, ORIG_T carries a non defaulted argument count only
9844 if it doesn't contain any nested TREE_VEC. */
9846 {
9850 }
9852 {
9856 {
9859 /* Now expand the template argument pack "in place". */
9862 }
9863 else
9864 {
9866 out++;
9867 }
9868 }
9871 }
9873 /* Return the result of substituting ARGS into the template parameters
9874 given by PARMS. If there are m levels of ARGS and m + n levels of
9875 PARMS, then the result will contain n levels of PARMS. For
9876 example, if PARMS is `template <class T> template <class U>
9877 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9878 result will be `template <int*, double, class V>'. */
9880 static tree
9882 {
9886 /* When substituting into a template, we must set
9887 PROCESSING_TEMPLATE_DECL as the template parameters may be
9888 dependent if they are based on one-another, and the dependency
9889 predicates are short-circuit outside of templates. */
9896 {
9897 tree new_vec =
9902 {
9903 tree tuple;
9915 }
9921 }
9926 }
9928 /* Return the result of substituting ARGS into one template parameter
9929 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9930 parameter and which TREE_PURPOSE is the default argument of the
9931 template parameter. */
9933 static tree
9935 {
9956 }
9958 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9959 type T. If T is not an aggregate or enumeration type, it is
9960 handled as if by tsubst. IN_DECL is as for tsubst. If
9961 ENTERING_SCOPE is nonzero, T is the context for a template which
9962 we are presently tsubst'ing. Return the substituted value. */
9964 static tree
9966 tree args,
9967 tsubst_flags_t complain,
9968 tree in_decl,
9970 {
9975 {
9980 /* Else fall through. */
9984 {
9985 tree argvec;
9986 tree context;
9987 tree r;
9991 /* In "sizeof(X<I>)" we need to evaluate "I". */
9997 /* First, determine the context for the type we are looking
9998 up. */
10001 {
10004 /* If context is a nested class inside a class template,
10005 it may still need to be instantiated (c++/33959). */
10007 }
10009 /* Then, figure out what arguments are appropriate for the
10010 type we are trying to find. For example, given:
10012 template <class T> struct S;
10013 template <class T, class U> void f(T, U) { S<U> su; }
10015 and supposing that we are instantiating f<int, double>,
10016 then our ARGS will be {int, double}, but, when looking up
10017 S we only want {double}. */
10022 else
10023 {
10027 }
10033 }
10034 else
10035 /* This is not a template type, so there's nothing to do. */
10040 }
10041 }
10043 /* Substitute into the default argument ARG (a default argument for
10044 FN), which has the indicated TYPE. */
10046 tree
10048 {
10053 /* This can happen in invalid code. */
10057 /* This default argument came from a template. Instantiate the
10058 default argument here, not in tsubst. In the case of
10059 something like:
10061 template <class T>
10062 struct S {
10063 static T t();
10064 void f(T = t());
10065 };
10067 we must be careful to do name lookup in the scope of S<T>,
10068 rather than in the current class. */
10070 /* The "this" pointer is not valid in a default argument. */
10072 {
10077 }
10080 /* The default argument expression may cause implicitly defined
10081 member functions to be synthesized, which will result in garbage
10082 collection. We must treat this situation as if we were within
10083 the body of function so as to avoid collecting live data on the
10084 stack. */
10092 /* Restore the "this" pointer. */
10094 {
10097 }
10104 /* Make sure the default argument is reasonable. */
10110 }
10112 /* Substitute into all the default arguments for FN. */
10114 static void
10116 {
10117 tree arg;
10118 tree tmpl_args;
10122 /* If this function is not yet instantiated, we certainly don't need
10123 its default arguments. */
10126 /* Don't do this again for clones. */
10131 arg;
10137 complain);
10138 }
10140 /* Substitute the ARGS into the T, which is a _DECL. Return the
10141 result of the substitution. Issue error and warning messages under
10142 control of COMPLAIN. */
10144 static tree
10146 {
10147 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10148 location_t saved_loc;
10153 /* Set the filename and linenumber to improve error-reporting. */
10158 {
10160 {
10161 /* We can get here when processing a member function template,
10162 member class template, or template template parameter. */
10164 tree spec;
10165 tree tmpl_args;
10166 tree full_args;
10169 {
10170 /* Template template parameter is treated here. */
10174 /* If we get a real template back, return it. This can happen in
10175 the context of most_specialized_class. */
10187 complain);
10190 }
10192 /* We might already have an instance of this template.
10193 The ARGS are for the surrounding class type, so the
10194 full args contain the tsubst'd args for the context,
10195 plus the innermost args from the template decl. */
10199 /* Because this is a template, the arguments will still be
10200 dependent, even after substitution. If
10201 PROCESSING_TEMPLATE_DECL is not set, the dependency
10202 predicates will short-circuit. */
10210 /* If this is a default template template argument,
10211 tsubst might not have changed anything. */
10218 {
10221 }
10223 /* Make a new template decl. It will be similar to the
10224 original, but will record the current template arguments.
10225 We also create a new function declaration, which is just
10226 like the old one, but points to this new template, rather
10227 than the old one. */
10236 {
10237 tree new_type;
10245 /* For a partial specialization, we need to keep pointing to
10246 the primary template. */
10252 }
10253 else
10254 {
10255 tree new_decl;
10267 }
10273 /* The template parameters for this new template are all the
10274 template parameters for the old template, except the
10275 outermost level of parameters. */
10278 complain);
10284 /* Record this non-type partial instantiation. */
10288 }
10292 {
10293 tree ctx;
10296 tree gen_tmpl;
10297 tree type;
10302 /* Nobody should be tsubst'ing into non-template functions. */
10306 {
10307 tree spec;
10310 /* If T is not dependent, just return it. We have to
10311 increment PROCESSING_TEMPLATE_DECL because
10312 value_dependent_expression_p assumes that nothing is
10313 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10320 /* Calculate the most general template of which R is a
10321 specialization, and the complete set of arguments used to
10322 specialize R. */
10325 (DECL_TEMPLATE_RESULT
10331 /* Check to see if we already have this specialization. */
10336 {
10339 }
10341 /* We can see more levels of arguments than parameters if
10342 there was a specialization of a member template, like
10343 this:
10345 template <class T> struct S { template <class U> void f(); }
10346 template <> template <class U> void S<int>::f(U);
10348 Here, we'll be substituting into the specialization,
10349 because that's where we can find the code we actually
10350 want to generate, but we'll have enough arguments for
10351 the most general template.
10353 We also deal with the peculiar case:
10355 template <class T> struct S {
10356 template <class U> friend void f();
10357 };
10358 template <class U> void f() {}
10359 template S<int>;
10360 template void f<double>();
10362 Here, the ARGS for the instantiation of will be {int,
10363 double}. But, we only need as many ARGS as there are
10364 levels of template parameters in CODE_PATTERN. We are
10365 careful not to get fooled into reducing the ARGS in
10366 situations like:
10368 template <class T> struct S { template <class U> void f(U); }
10369 template <class T> template <> void S<T>::f(int) {}
10371 which we can spot because the pattern will be a
10372 specialization in this case. */
10374 parms_depth =
10379 }
10380 else
10381 {
10382 /* This special case arises when we have something like this:
10384 template <class T> struct S {
10385 friend void f<int>(int, double);
10386 };
10388 Here, the DECL_TI_TEMPLATE for the friend declaration
10389 will be an IDENTIFIER_NODE. We are being called from
10390 tsubst_friend_function, and we want only to create a
10391 new decl (R) with appropriate types so that we can call
10392 determine_specialization. */
10394 }
10397 {
10400 else
10404 }
10405 else
10406 {
10409 }
10414 /* If we hit excessive deduction depth, the type is bogus even if
10415 it isn't error_mark_node, so don't build a decl. */
10419 /* We do NOT check for matching decls pushed separately at this
10420 point, as they may not represent instantiations of this
10421 template, and in any case are considered separate under the
10422 discrete model. */
10426 /* Clear out the mangled name and RTL for the instantiation. */
10429 /* Leave DECL_INITIAL set on deleted instantiations. */
10434 /* OpenMP UDRs have the only argument a reference to the declared
10435 type. We want to diagnose if the declared type is a reference,
10436 which is invalid, but as references to references are usually
10437 quietly merged, diagnose it here. */
10439 {
10440 tree argtype
10445 "reference type %qT in "
10449 argtype);
10450 }
10453 /* Type-conversion operator. Reconstruct the name, in
10454 case it's the name of one of the template's parameters. */
10464 /* If this is an instantiation of a function with internal
10465 linkage, we already know what object file linkage will be
10466 assigned to the instantiation. */
10475 /* We'll re-clone as appropriate in instantiate_template. */
10478 /* If we aren't complaining now, return on error before we register
10479 the specialization so that we'll complain eventually. */
10485 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10486 this in the special friend case mentioned above where
10487 GEN_TMPL is NULL. */
10489 {
10494 tree new_r
10497 /* We instantiated this while substituting into
10498 the type earlier (template/friend54.C). */
10501 /* We're not supposed to instantiate default arguments
10502 until they are called, for a template. But, for a
10503 declaration like:
10505 template <class T> void f ()
10506 { extern void g(int i = T()); }
10508 we should do the substitution when the template is
10509 instantiated. We handle the member function case in
10510 instantiate_class_template since the default arguments
10511 might refer to other members of the class. */
10516 }
10517 else
10520 /* Copy the list of befriending classes. */
10524 {
10528 in_decl);
10529 }
10532 {
10538 /* If this is an instantiation of a member template, clone it.
10539 If it isn't, that'll be handled by
10540 clone_constructors_and_destructors. */
10543 }
10554 /* Possibly limit visibility based on template args. */
10557 {
10561 }
10569 }
10573 {
10581 {
10582 /* If there is a local specialization that isn't a
10583 parameter pack, it means that we're doing a "simple"
10584 substitution from inside tsubst_pack_expansion. Just
10585 return the local specialization (which will be a single
10586 parm). */
10593 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10594 the parameters in this function parameter pack. */
10598 {
10601 /* Zero-length parameter packs are boring. Just substitute
10602 into the chain. */
10606 }
10607 else
10608 {
10609 /* All we did was update the type. Make a note of that. */
10612 }
10613 }
10615 /* Loop through all of the parameters we'll build. When T is
10616 a function parameter pack, LEN is the number of expanded
10617 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10620 {
10627 /* We're on the Ith parameter of the function parameter
10628 pack. */
10629 {
10630 /* Get the Ith type. */
10633 /* Rename the parameter to include the index. */
10636 }
10638 /* We're dealing with a normal parameter. */
10646 {
10649 else
10652 }
10662 /* Keep track of the first new parameter we
10663 generate. That's what will be returned to the
10664 caller. */
10668 /* Build a proper chain of parameters when substituting
10669 into a function parameter pack. */
10672 }
10674 /* If cp_unevaluated_operand is set, we're just looking for a
10675 single dummy parameter, so don't keep going. */
10680 /* FIRST_R contains the start of the chain we've built. */
10682 }
10686 {
10693 {
10694 /* This field is a lambda capture pack. Return a TREE_VEC of
10695 the expanded fields to instantiate_class_template_1 and
10696 store them in the specializations hash table as a
10697 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10701 {
10704 }
10705 else
10706 {
10707 /* All we did was update the type. Make a note of that. */
10710 }
10711 }
10714 {
10717 {
10721 }
10731 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10732 non-bit-fields DECL_INITIAL is a non-static data member
10733 initializer, which gets deferred instantiation. */
10739 {
10740 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10741 NSDMI in perform_member_init. Still set DECL_INITIAL
10742 so that we know there is one. */
10747 }
10748 /* We don't have to set DECL_CONTEXT here; it is set by
10749 finish_member_declaration. */
10757 }
10760 {
10768 }
10769 }
10773 /* We reach here only for member using decls. We also need to check
10774 uses_template_parms because DECL_DEPENDENT_P is not set for a
10775 using-declaration that designates a member of the current
10776 instantiation (c++/53549). */
10779 {
10786 else
10787 {
10790 }
10791 }
10792 else
10793 {
10796 }
10801 {
10804 tree spec;
10806 tree ctx;
10812 {
10813 /* If this is the canonical decl, we don't have to
10814 mess with instantiations, and often we can't (for
10815 typename, template type parms and such). Note that
10816 TYPE_NAME is not correct for the above test if
10817 we've copied the type for a typedef. */
10823 }
10825 /* Check to see if we already have the specialization we
10826 need. */
10829 {
10830 /* T is a static data member or namespace-scope entity.
10831 We have to substitute into namespace-scope variables
10832 (even though such entities are never templates) because
10833 of cases like:
10835 template <class T> void f() { extern T t; }
10837 where the entity referenced is not known until
10838 instantiation time. */
10842 {
10844 complain,
10846 /* If CTX is unchanged, then T is in fact the
10847 specialization we want. That situation occurs when
10848 referencing a static data member within in its own
10849 class. We can use pointer equality, rather than
10850 same_type_p, because DECL_CONTEXT is always
10851 canonical... */
10854 /* ... unless T is a member template; in which
10855 case our caller can be willing to create a
10856 specialization of that template represented
10857 by T. */
10861 }
10864 {
10872 }
10873 }
10874 else
10875 {
10876 /* A local variable. */
10878 /* Subsequent calls to pushdecl will fill this in. */
10881 }
10882 /* If we already have the specialization we need, there is
10883 nothing more to do. */
10885 {
10888 }
10890 /* Create a new node for the specialization we need. */
10893 {
10896 else
10903 }
10905 {
10906 /* Even if the original location is out of scope, the
10907 newly substituted one is not. */
10914 {
10915 /* It may seem that this case cannot occur, since:
10917 typedef void f();
10918 void g() { f x; }
10920 declares a function, not a variable. However:
10922 typedef void f();
10923 template <typename T> void g() { T t; }
10924 template void g<f>();
10926 is an attempt to declare a variable with function
10927 type. */
10929 /* R is not yet sufficiently initialized, so we
10930 just use its name. */
10933 }
10935 /* Wait until cp_finish_decl to set this again, to handle
10936 circular dependency (template/instantiate6.C). */
10941 {
10946 {
10949 }
10951 }
10952 }
10958 /* Clear out the mangled name and RTL for the instantiation. */
10962 /* The initializer must not be expanded until it is required;
10963 see [temp.inst]. */
10969 {
10970 /* Possibly limit visibility based on template args. */
10973 {
10977 }
10979 }
10982 {
10983 /* A static data member declaration is always marked
10984 external when it is declared in-class, even if an
10985 initializer is present. We mimic the non-template
10986 processing here. */
10992 }
11002 /* Preserve a typedef that names a type. */
11004 {
11007 }
11010 }
11015 }
11016 #undef RETURN
11018 out:
11019 /* Restore the file and line information. */
11023 }
11025 /* Substitute into the ARG_TYPES of a function type.
11026 If END is a TREE_CHAIN, leave it and any following types
11027 un-substituted. */
11029 static tree
11031 tree args,
11032 tree end,
11033 tsubst_flags_t complain,
11034 tree in_decl)
11035 {
11036 tree remaining_arg_types;
11040 tree default_arg;
11051 {
11052 /* For a pack expansion, perform substitution on the
11053 entire expression. Later on, we'll handle the arguments
11054 one-by-one. */
11059 /* So that we'll spin through the parameters, one by one. */
11061 else
11062 {
11063 /* We only partially substituted into the parameter
11064 pack. Our type is TYPE_PACK_EXPANSION. */
11067 }
11068 }
11081 {
11083 {
11087 }
11089 }
11090 /* DR 657. */
11094 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11095 top-level qualifiers as required. */
11098 /* We do not substitute into default arguments here. The standard
11099 mandates that they be instantiated only when needed, which is
11100 done in build_over_call. */
11104 {
11105 /* We've instantiated a template before its default arguments
11106 have been parsed. This can happen for a nested template
11107 class, and is not an error unless we require the default
11108 argument in a call of this function. */
11109 remaining_arg_types =
11112 }
11113 else
11114 remaining_arg_types =
11116 }
11119 }
11121 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11122 *not* handle the exception-specification for FNTYPE, because the
11123 initial substitution of explicitly provided template parameters
11124 during argument deduction forbids substitution into the
11125 exception-specification:
11127 [temp.deduct]
11129 All references in the function type of the function template to the
11130 corresponding template parameters are replaced by the specified tem-
11131 plate argument values. If a substitution in a template parameter or
11132 in the function type of the function template results in an invalid
11133 type, type deduction fails. [Note: The equivalent substitution in
11134 exception specifications is done only when the function is instanti-
11135 ated, at which point a program is ill-formed if the substitution
11136 results in an invalid type.] */
11138 static tree
11140 tree args,
11141 tsubst_flags_t complain,
11142 tree in_decl)
11143 {
11144 tree return_type;
11145 tree arg_types;
11146 tree fntype;
11148 /* The TYPE_CONTEXT is not used for function/method types. */
11151 /* Substitute the return type. */
11155 /* DR 486 clarifies that creation of a function type with an
11156 invalid return type is a deduction failure. */
11159 {
11161 {
11164 else
11166 }
11168 }
11169 /* And DR 657. */
11173 /* Substitute the argument types. */
11179 /* Construct a new type node and return it. */
11181 {
11186 }
11187 else
11188 {
11190 /* Don't pick up extra function qualifiers from the basetype. */
11193 {
11194 /* [temp.deduct]
11196 Type deduction may fail for any of the following
11197 reasons:
11199 -- Attempting to create "pointer to member of T" when T
11200 is not a class type. */
11203 r);
11205 }
11210 }
11214 }
11216 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11217 ARGS into that specification, and return the substituted
11218 specification. If there is no specification, return NULL_TREE. */
11220 static tree
11222 tree args,
11223 tsubst_flags_t complain,
11224 tree in_decl,
11226 {
11227 tree specs;
11228 tree new_specs;
11233 {
11234 /* A noexcept-specifier. */
11239 {
11240 /* Defer instantiation of noexcept-specifiers to avoid
11241 excessive instantiations (c++/49107). */
11244 {
11245 /* We already partially instantiated this member template,
11246 so combine the new args with the old. */
11251 }
11252 else
11253 {
11256 }
11257 }
11258 else
11259 new_specs = tsubst_copy_and_build
11263 }
11265 {
11268 else
11270 {
11271 tree spec;
11276 {
11277 /* Expand the pack expansion type. */
11280 in_decl);
11286 else
11287 {
11288 /* We're substituting into a member template, so
11289 we got a TYPE_PACK_EXPANSION back. Add that
11290 expansion and move on. */
11294 expanded_specs,
11295 complain);
11298 }
11299 }
11302 {
11305 else
11310 complain);
11311 }
11314 }
11315 }
11317 }
11319 /* Take the tree structure T and replace template parameters used
11320 therein with the argument vector ARGS. IN_DECL is an associated
11321 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11322 Issue error and warning messages under control of COMPLAIN. Note
11323 that we must be relatively non-tolerant of extensions here, in
11324 order to preserve conformance; if we allow substitutions that
11325 should not be allowed, we may allow argument deductions that should
11326 not succeed, and therefore report ambiguous overload situations
11327 where there are none. In theory, we could allow the substitution,
11328 but indicate that it should have failed, and allow our caller to
11329 make sure that the right thing happens, but we don't try to do this
11330 yet.
11332 This function is used for dealing with types, decls and the like;
11333 for expressions, use tsubst_expr or tsubst_copy. */
11335 tree
11337 {
11360 else
11365 /* Reuse typedefs. We need to do this to handle dependent attributes,
11366 such as attribute aligned. */
11369 {
11373 {
11374 /* DECL represents an alias template and we want to
11375 instantiate it. */
11379 }
11383 {
11387 }
11392 else
11393 /* The typedef is from a non-template context. */
11397 {
11399 r = cp_build_qualified_type_real
11403 }
11404 else
11405 {
11406 /* We don't have an instantiation yet, so drop the typedef. */
11411 }
11412 }
11425 {
11451 {
11457 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11458 needed. */
11464 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11465 with TREE_SIDE_EFFECTS that indicates this is not an integral
11466 constant expression. */
11469 {
11472 }
11475 }
11481 {
11494 {
11498 {
11499 /* See through ARGUMENT_PACK_SELECT arguments. */
11501 /* If the selected argument is an expansion E, that most
11502 likely means we were called from
11503 gen_elem_of_pack_expansion_instantiation during the
11504 substituting of pack an argument pack (which Ith
11505 element is a pack expansion, where I is
11506 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11507 In this case, the Ith element resulting from this
11508 substituting is going to be a pack expansion, which
11509 pattern is the pattern of E. Let's return the
11510 pattern of E, and
11511 gen_elem_of_pack_expansion_instantiation will
11512 build the resulting pack expansion from it. */
11515 }
11516 }
11521 {
11523 /* If ARG is an argument pack, we don't actually want to
11524 perform a substitution here, because substitutions
11525 for argument packs are only done
11526 element-by-element. We can get to this point when
11527 substituting the type of a non-type template
11528 parameter pack, when that type actually contains
11529 template parameter packs from an outer template, e.g.,
11531 template<typename... Types> struct A {
11532 template<Types... Values> struct B { };
11533 }; */
11537 {
11543 return cp_build_qualified_type_real
11545 }
11547 {
11548 /* We are processing a type constructed from a
11549 template template parameter. */
11560 /* Consider this code:
11562 template <template <class> class Template>
11563 struct Internal {
11564 template <class Arg> using Bind = Template<Arg>;
11565 };
11567 template <template <class> class Template, class Arg>
11568 using Instantiate = Template<Arg>; //#0
11570 template <template <class> class Template,
11571 class Argument>
11572 using Bind =
11573 Instantiate<Internal<Template>::template Bind,
11574 Argument>; //#1
11576 When #1 is parsed, the
11577 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11578 parameter `Template' in #0 matches the
11579 UNBOUND_CLASS_TEMPLATE representing the argument
11580 `Internal<Template>::template Bind'; We then want
11581 to assemble the type `Bind<Argument>' that can't
11582 be fully created right now, because
11583 `Internal<Template>' not being complete, the Bind
11584 template cannot be looked up in that context. So
11585 we need to "store" `Bind<Argument>' for later
11586 when the context of Bind becomes complete. Let's
11587 store that in a TYPENAME_TYPE. */
11591 argvec),
11592 typename_type,
11593 complain);
11595 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11596 are resolving nested-types in the signature of a
11597 member function templates. Otherwise ARG is a
11598 TEMPLATE_DECL and is the real template to be
11599 instantiated. */
11607 complain);
11608 return cp_build_qualified_type_real
11610 }
11611 else
11612 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11614 }
11617 /* This can happen during the attempted tsubst'ing in
11618 unify. This means that we don't yet have any information
11619 about the template parameter in question. */
11622 /* Early in template argument deduction substitution, we don't
11623 want to reduce the level of 'auto', or it will be confused
11624 with a normal template parm in subsequent deduction. */
11628 /* If we get here, we must have been looking at a parm for a
11629 more deeply nested template. Make a new version of this
11630 template parameter, but with a lower level. */
11632 {
11637 {
11639 r = cp_build_qualified_type_real
11643 }
11644 else
11645 {
11656 /* We have reduced the level of the template
11657 template parameter, but not the levels of its
11658 template parameters, so canonical_type_parameter
11659 will not be able to find the canonical template
11660 template parameter for this level. Thus, we
11661 require structural equality checking to compare
11662 TEMPLATE_TEMPLATE_PARMs. */
11666 else
11670 {
11678 }
11679 }
11688 }
11691 }
11694 {
11702 {
11706 }
11709 {
11713 }
11716 {
11720 }
11726 }
11729 /* We should never be tsubsting a binfo. */
11733 /* A vector of template arguments. */
11739 {
11743 /* [temp.deduct]
11745 Type deduction may fail for any of the following
11746 reasons:
11748 -- Attempting to create a pointer to reference type.
11749 -- Attempting to create a reference to a reference type or
11750 a reference to void.
11752 Core issue 106 says that creating a reference to a reference
11753 during instantiation is no longer a cause for failure. We
11754 only enforce this check in strict C++98 mode. */
11758 {
11761 /* We keep track of the last time we issued this error
11762 message to avoid spewing a ton of messages during a
11763 single bad template instantiation. */
11766 {
11771 else
11774 }
11777 }
11781 {
11783 {
11786 type);
11787 else
11789 type);
11790 }
11792 }
11794 {
11798 }
11800 /* In C++0x, during template argument substitution, when there is an
11801 attempt to create a reference to a reference type, reference
11802 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11804 "If a template-argument for a template-parameter T names a type
11805 that is a reference to a type A, an attempt to create the type
11806 'lvalue reference to cv T' creates the type 'lvalue reference to
11807 A,' while an attempt to create the type type rvalue reference to
11808 cv T' creates the type T"
11809 */
11810 r = cp_build_reference_type
11813 else
11820 {
11822 pedwarn
11824 code == REFERENCE_TYPE
11827 else
11829 }
11832 /* Will this ever be needed for TYPE_..._TO values? */
11836 }
11838 {
11841 {
11842 /* [temp.deduct]
11844 Type deduction may fail for any of the following
11845 reasons:
11847 -- Attempting to create "pointer to member of T" when T
11848 is not a class type. */
11852 }
11854 {
11858 }
11860 {
11864 }
11867 {
11868 /* The type of the implicit object parameter gets its
11869 cv-qualifiers from the FUNCTION_TYPE. */
11870 tree memptr;
11871 tree method_type
11876 complain);
11877 }
11878 else
11881 complain);
11882 }
11885 {
11886 tree fntype;
11887 tree specs;
11892 /* Substitute the exception specification. */
11900 }
11902 {
11907 /* As an optimization, we avoid regenerating the array type if
11908 it will obviously be the same as T. */
11912 /* These checks should match the ones in grokdeclarator.
11914 [temp.deduct]
11916 The deduction may fail for any of the following reasons:
11918 -- Attempting to create an array with an element type that
11919 is void, a function type, or a reference type, or [DR337]
11920 an abstract class type. */
11924 {
11928 }
11936 {
11939 }
11942 }
11945 {
11955 {
11959 }
11961 {
11962 /* Normally, make_typename_type does not require that the CTX
11963 have complete type in order to allow things like:
11965 template <class T> struct S { typename S<T>::X Y; };
11967 But, such constructs have already been resolved by this
11968 point, so here CTX really should have complete type, unless
11969 it's a partial instantiation. */
11972 {
11976 }
11977 }
11984 {
11987 }
11990 {
11992 {
11996 else
11998 }
12000 {
12004 else
12006 }
12007 }
12009 return cp_build_qualified_type_real
12011 }
12014 {
12026 }
12029 {
12030 tree type;
12046 complain);
12047 }
12050 {
12051 tree type;
12069 else
12070 {
12074 /* In a template ~id could be either a complement expression
12075 or an unqualified-id naming a destructor; if instantiating
12076 it produces an expression, it's not an id-expression or
12077 member access. */
12080 }
12084 complain);
12085 }
12088 {
12092 }
12096 {
12098 tree packed_out =
12100 args,
12101 complain,
12102 in_decl);
12105 /* For template nontype argument packs, also substitute into
12106 the type. */
12111 }
12126 /* We should use one of the expression tsubsts for these codes. */
12132 }
12133 }
12135 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12136 type of the expression on the left-hand side of the "." or "->"
12137 operator. */
12139 static tree
12142 {
12143 tree name;
12144 tree qualifying_scope;
12145 tree fns;
12146 tree optype;
12151 /* A baselink indicates a function from a base class. Both the
12152 BASELINK_ACCESS_BINFO and the base class referenced may
12153 indicate bases of the template class, rather than the
12154 instantiated class. In addition, lookups that were not
12155 ambiguous before may be ambiguous now. Therefore, we perform
12156 the lookup again. */
12163 {
12170 }
12178 /* If lookup found a single function, mark it as used at this
12179 point. (If it lookup found multiple functions the one selected
12180 later by overload resolution will be marked as used at that
12181 point.) */
12187 /* Add back the template arguments, if present. */
12192 template_args);
12193 /* Update the conversion operator type. */
12201 qualifying_scope,
12202 object_type);
12204 }
12206 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12207 true if the qualified-id will be a postfix-expression in-and-of
12208 itself; false if more of the postfix-expression follows the
12209 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12210 of "&". */
12212 static tree
12216 {
12217 tree expr;
12218 tree scope;
12219 tree name;
12221 tree template_args;
12226 /* Figure out what name to look up. */
12229 {
12237 }
12238 else
12239 {
12242 }
12244 /* Substitute into the qualifying scope. When there are no ARGS, we
12245 are just trying to simplify a non-dependent expression. In that
12246 case the qualifying scope may be dependent, and, in any case,
12247 substituting will not help. */
12250 {
12253 }
12254 else
12258 {
12263 }
12266 {
12268 {
12269 /* A BIT_NOT_EXPR is used to represent a destructor. */
12271 {
12275 }
12276 else
12279 }
12280 else
12284 {
12286 {
12290 }
12292 }
12293 }
12296 {
12298 scope);
12299 /* Remember that there was a reference to this entity. */
12301 }
12304 {
12310 }
12319 {
12320 expr = (adjust_result_of_qualified_name_lookup
12322 expr = (finish_qualified_id_expr
12326 }
12328 /* Expressions do not generally have reference type. */
12330 /* However, if we're about to form a pointer-to-member, we just
12331 want the referenced member referenced. */
12336 }
12338 /* Like tsubst, but deals with expressions. This function just replaces
12339 template parms; to finish processing the resultant expression, use
12340 tsubst_copy_and_build or tsubst_expr. */
12342 static tree
12344 {
12346 tree r;
12354 {
12359 {
12360 /* We get here for a use of 'this' in an NSDMI. */
12366 /* This can happen for a parameter name used later in a function
12367 declaration (such as in a late-specified return type). Just
12368 make a dummy decl, since it's only used for its type. */
12371 /* Give it the template pattern as its context; its true context
12372 hasn't been instantiated yet and this is good enough for
12373 mangling. */
12375 }
12383 {
12384 tree enum_type;
12385 tree v;
12389 /* There is no need to substitute into namespace-scope
12390 enumerators. */
12393 /* If ARGS is NULL, then T is known to be non-dependent. */
12397 /* Unfortunately, we cannot just call lookup_name here.
12398 Consider:
12400 template <int I> int f() {
12401 enum E { a = I };
12402 struct S { void g() { E e = a; } };
12403 };
12405 When we instantiate f<7>::S::g(), say, lookup_name is not
12406 clever enough to find f<7>::a. */
12407 enum_type
12417 /* We didn't find the name. That should never happen; if
12418 name-lookup found it during preliminary parsing, we
12419 should find it again here during instantiation. */
12421 }
12426 {
12427 /* Check for a local specialization set up by
12428 tsubst_pack_expansion. */
12431 {
12435 }
12437 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12438 tsubst_decl put in the hash table. */
12440 }
12443 {
12444 tree ctx;
12449 {
12452 {
12456 }
12458 }
12459 }
12468 {
12471 {
12473 {
12474 /* Just use name lookup to find a member alias for an
12475 anonymous union, but then add it to the hash table. */
12479 }
12480 else
12481 {
12482 /* This can happen for a variable used in a late-specified
12483 return type of a local lambda. Just make a dummy decl
12484 since it's only used for its type. */
12489 }
12490 }
12491 }
12492 else
12501 /* An OVERLOAD will always be a non-dependent overload set; an
12502 overload set from function scope will just be represented with an
12503 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12519 {
12520 /* Template template argument like the following example need
12521 special treatment:
12523 template <template <class> class TT> struct C {};
12524 template <class T> struct D {
12525 template <class U> struct E {};
12526 C<E> c; // #1
12527 };
12528 D<int> d; // #2
12530 We are processing the template argument `E' in #1 for
12531 the template instantiation #2. Originally, `E' is a
12532 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12533 have to substitute this with one having context `D<int>'. */
12537 }
12538 else
12539 /* Ordinary template template argument. */
12550 return build1
12556 {
12566 /* We only want to compute the number of arguments. */
12580 {
12587 else
12590 }
12591 else
12593 }
12595 {
12603 }
12604 /* Fall through */
12620 return build1
12625 {
12626 tree object;
12627 tree name;
12632 {
12636 }
12639 {
12649 }
12654 in_decl);
12655 else
12658 }
12696 return build_nt
12709 return build_nt
12716 {
12724 }
12730 {
12731 r = build_nt
12737 }
12740 {
12741 r = build_nt
12747 }
12750 {
12751 r = build_nt
12757 }
12760 {
12761 /* Substituted template arguments */
12770 }
12773 {
12793 }
12818 /* Fall through. */
12821 {
12824 }
12825 else
12829 /* This is handled by tsubst_copy_and_build. */
12835 in_decl),
12839 /* We shouldn't have built any of these during initial template
12840 generation. Instead, they should be built during instantiation
12841 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12845 r = build2
12865 {
12866 /* Instantiate any typedefs in the type. */
12871 }
12874 /* These can sometimes show up in a partial instantiation, but never
12875 involve template parms. */
12880 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12883 }
12884 }
12886 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12888 static tree
12891 {
12895 {
12901 {
12904 {
12910 }
12911 /* FALLTHRU */
12939 {
12942 {
12949 }
12950 else
12952 }
12982 }
12983 }
12989 }
12991 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12993 static tree
12995 tree in_decl)
12996 {
12997 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13017 {
13020 else
13021 {
13025 }
13026 }
13031 #undef RECUR
13032 }
13034 /* Substitute one OMP_FOR iterator. */
13036 static void
13041 {
13042 #define RECUR(NODE) \
13043 tsubst_expr ((NODE), args, complain, in_decl, \
13044 integral_constant_expression_p)
13052 /* Do this before substituting into decl to handle 'auto'. */
13061 {
13065 }
13070 {
13077 complain);
13078 else
13085 }
13088 {
13089 tree c;
13091 {
13102 }
13104 {
13109 {
13112 }
13113 }
13114 }
13120 else
13124 {
13135 {
13142 }
13143 else
13149 {
13155 }
13159 {
13166 }
13167 else
13173 }
13179 #undef RECUR
13180 }
13182 /* Like tsubst_copy for expressions, etc. but also does semantic
13183 processing. */
13185 static tree
13188 {
13189 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13190 #define RECUR(NODE) \
13191 tsubst_expr ((NODE), args, complain, in_decl, \
13192 integral_constant_expression_p)
13195 tree r;
13196 location_t loc;
13208 {
13210 {
13211 tree_stmt_iterator i;
13215 }
13230 else
13239 {
13241 tree init;
13247 {
13250 tree decl;
13258 else
13260 }
13262 {
13263 /* Don't build up decls for a variadic capture proxy, we'll
13264 instantiate the elements directly as needed. */
13266 }
13267 else
13268 {
13272 {
13273 /* By marking the declaration as instantiated, we avoid
13274 trying to instantiate it. Since instantiate_decl can't
13275 handle local variables, and since we've already done
13276 all that needs to be done, that's the right thing to
13277 do. */
13282 /* Anonymous aggregates are a special case. */
13285 {
13288 {
13292 }
13294 }
13300 {
13305 }
13306 else
13307 {
13312 {
13313 /* For __PRETTY_FUNCTION__ we have to adjust the
13314 initializer. */
13318 }
13319 else
13320 {
13324 {
13325 /* If we had an initializer but it
13326 instantiated to nothing,
13327 value-initialize the object. This will
13328 only occur when the initializer was a
13329 pack expansion where the parameter packs
13330 used in that expansion were of length
13331 zero. */
13333 complain);
13336 }
13337 else
13339 }
13342 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13345 }
13346 }
13347 }
13350 }
13365 {
13375 }
13402 {
13406 }
13414 else
13422 else
13449 {
13451 tree label;
13456 }
13462 /* Computed goto's must be tsubst'd into. On the other hand,
13463 non-computed gotos must not be; the identifier in question
13464 will have no binding. */
13466 else
13472 tmp = finish_asm_stmt
13479 {
13484 }
13489 {
13494 }
13495 else
13496 {
13501 else
13508 else
13514 else
13516 }
13520 {
13524 {
13526 /* Prevent instantiate_decl from trying to instantiate
13527 this variable. We've already done all that needs to be
13528 done. */
13531 }
13536 }
13542 {
13543 /* Local classes are not independent templates; they are
13544 instantiated along with their containing function. And this
13545 way we don't have to deal with pushing out of one local class
13546 to instantiate a member of another local class. */
13547 tree fn;
13548 /* Closures are handled by the LAMBDA_EXPR. */
13554 }
13558 {
13559 tree condition;
13562 condition =
13564 args,
13573 }
13597 {
13606 {
13611 }
13623 integral_constant_expression_p);
13632 else
13633 {
13641 }
13644 }
13689 {
13694 {
13697 }
13703 }
13704 else
13705 {
13712 {
13715 }
13718 {
13723 {
13726 }
13732 }
13733 else
13734 {
13738 }
13741 }
13745 {
13751 {
13755 {
13760 }
13764 }
13765 else
13766 {
13771 }
13772 }
13797 /* If the first operand was a statement, we're done with it. */
13801 complain));
13808 integral_constant_expression_p));
13809 }
13812 out:
13815 #undef RECUR
13816 #undef RETURN
13817 }
13819 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
13820 function. For description of the body see comment above
13821 cp_parser_omp_declare_reduction_exprs. */
13823 static void
13825 {
13831 tree_stmt_iterator tsi;
13842 {
13861 }
13863 {
13883 }
13884 }
13886 /* T is a postfix-expression that is not being used in a function
13887 call. Return the substituted version of T. */
13889 static tree
13891 tsubst_flags_t complain,
13892 tree in_decl)
13893 {
13897 else
13903 }
13905 /* Like tsubst but deals with expressions and performs semantic
13906 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13908 tree
13910 tree args,
13911 tsubst_flags_t complain,
13912 tree in_decl,
13915 {
13916 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
13917 #define RECUR(NODE) \
13918 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13920 integral_constant_expression_p)
13923 location_t loc;
13932 /* N3276 decltype magic only applies to calls at the top level or on the
13933 right side of a comma. */
13938 {
13941 /* Fall through. */
13943 {
13944 tree decl;
13945 cp_id_kind idk;
13950 {
13953 }
13955 /* Look up the name. */
13958 /* By convention, expressions use ERROR_MARK_NODE to indicate
13959 failure, not NULL_TREE. */
13965 integral_constant_expression_p,
13973 input_location);
13977 {
13981 }
13983 }
13986 {
13987 tree object;
13995 {
13998 }
13999 else
14006 else
14008 }
14011 {
14015 {
14016 /* A type conversion to reference type will be enclosed in
14017 such an indirect ref, but the substitution of the cast
14018 will have also added such an indirect ref. */
14021 }
14022 else
14026 }
14034 {
14041 flags));
14042 }
14055 {
14056 tree type;
14062 {
14067 }
14073 {
14091 }
14095 }
14129 else
14131 in_decl);
14166 {
14167 tree r;
14171 r = build_x_binary_op
14175 ? ERROR_MARK
14179 ? ERROR_MARK
14189 }
14206 {
14215 }
14219 /* Fall through */
14222 {
14223 tree r;
14229 {
14230 /* When there are no ARGS, we are trying to evaluate a
14231 non-dependent expression from the parser. Trying to do
14232 the substitutions may not work. */
14235 }
14236 else
14237 {
14242 else
14245 /*integral_constant_expression_p=*/
14249 }
14253 else
14257 {
14259 {
14261 {
14265 }
14266 else
14270 }
14272 }
14274 }
14277 {
14287 }
14301 {
14302 tree r;
14306 r = build_x_modify_expr
14312 /* TREE_NO_WARNING must be set if either the expression was
14313 parenthesized or it uses an operator such as >>= rather
14314 than plain assignment. In the former case, it was already
14315 set and must be copied. In the latter case,
14316 build_x_modify_expr sets it and it must not be reset
14317 here. */
14324 }
14329 /* Remember that there was a reference to this entity. */
14335 {
14340 tree ret;
14344 else
14345 {
14349 }
14351 /* If there was an initializer in the original tree, but it
14352 instantiated to an empty list, then we should pass a
14353 non-NULL empty vector to tell build_new that it was an
14354 empty initializer() rather than no initializer. This can
14355 only happen when the initializer is a pack expansion whose
14356 parameter packs are of length zero. */
14359 else
14360 {
14364 else
14365 {
14368 }
14369 }
14376 complain);
14384 }
14392 complain));
14395 {
14399 integral_constant_expression_p);
14401 op0,
14404 }
14407 {
14408 tree function;
14413 tree ret;
14416 /* When we parsed the expression, we determined whether or
14417 not Koenig lookup should be performed. */
14420 {
14425 }
14427 {
14428 /* Do nothing; calling tsubst_copy_and_build on an identifier
14429 would incorrectly perform unqualified lookup again.
14431 Note that we can also have an IDENTIFIER_NODE if the earlier
14432 unqualified lookup found a member function; in that case
14433 koenig_p will be false and we do want to do the lookup
14434 again to find the instantiated member function.
14436 FIXME but doing that causes c++/15272, so we need to stop
14437 using IDENTIFIER_NODE in that situation. */
14439 }
14440 else
14441 {
14443 {
14449 }
14450 else
14455 /* Avoid error about taking the address of a constructor. */
14459 in_decl,
14461 integral_constant_expression_p);
14465 }
14470 {
14475 else
14476 {
14477 /* Expand the pack expansion and push each entry onto
14478 CALL_ARGS. */
14481 {
14486 {
14491 }
14492 }
14493 else
14494 {
14495 /* A partial substitution. Add one entry. */
14497 }
14498 }
14499 }
14501 /* We do not perform argument-dependent lookup if normal
14502 lookup finds a non-function, in accordance with the
14503 expected resolution of DR 218. */
14506 /* If lookup found a member function, the Koenig lookup is
14507 not appropriate, even if an unqualified-name was used
14508 to denote the function. */
14511 /* Only do this when substitution turns a dependent call
14512 into a non-dependent call. */
14519 {
14521 {
14522 /* For backwards compatibility and good diagnostics, try
14523 the unqualified lookup again if we aren't in SFINAE
14524 context. */
14525 tree unq = (tsubst_copy_and_build
14527 integral_constant_expression_p));
14532 {
14541 "%qD was not declared in this scope, "
14542 "and no declarations were found by "
14543 "argument-dependent lookup at the point "
14545 {
14549 {
14551 input_location);
14553 "declarations in dependent base %qT are "
14559 else
14563 }
14564 else
14567 }
14569 }
14570 }
14572 {
14577 }
14578 }
14580 /* Remember that there was a reference to this entity. */
14584 /* Put back tf_decltype for the actual call. */
14589 complain);
14591 {
14606 complain);
14607 else
14608 ret = (build_new_method_call
14613 complain));
14614 }
14615 else
14618 koenig_p,
14619 complain);
14624 }
14627 {
14632 {
14634 {
14639 }
14640 else
14641 {
14646 }
14647 }
14648 else
14649 {
14652 }
14656 }
14663 input_location));
14666 {
14674 {
14675 /* We have pack expansions, so expand those and
14676 create a new list out of it. */
14679 tree chain;
14682 /* Expand the argument expressions. */
14690 /* Build the rest of the list. */
14695 /* Determine the number of arguments. */
14697 {
14700 }
14703 else
14704 {
14705 /* Since we only performed a partial substitution into
14706 the argument pack, we only RETURN (a single list
14707 node. */
14714 }
14716 /* Convert the argument vectors into a TREE_LIST */
14719 {
14720 /* Grab the Ith values. */
14721 i--;
14724 value
14728 /* Build the list (backwards). */
14730 }
14733 }
14749 }
14752 {
14753 tree object;
14754 tree object_type;
14755 tree member;
14759 /* Remember that there was a reference to this entity. */
14769 else
14777 {
14779 {
14784 {
14787 }
14789 {
14794 }
14795 }
14796 }
14799 {
14800 /* Lookup the template functions now that we know what the
14801 scope is. */
14809 {
14812 args);
14813 member = (adjust_result_of_qualified_name_lookup
14815 object_type));
14816 }
14817 else
14818 {
14820 input_location);
14822 }
14823 }
14827 {
14829 {
14833 else
14836 }
14838 }
14844 complain));
14845 }
14852 {
14860 tree r;
14865 /* digest_init will do the wrong thing if we let it. */
14869 /* We do not want to process the index of aggregate
14870 initializers as they are identifier nodes which will be
14871 looked up by digest_init. */
14877 {
14879 /* An identifier index is looked up in the type
14880 being initialized, not the current scope. */
14885 {
14886 /* Substitute into the pack expansion. */
14888 in_decl);
14892 ;
14894 /* Just move the argument into place. */
14896 else
14897 {
14898 /* Update the length of the final CONSTRUCTOR
14899 arguments vector, and note that we will need to
14900 copy.*/
14903 }
14904 }
14905 else
14907 }
14910 {
14915 {
14917 {
14922 }
14923 else
14925 }
14926 }
14936 }
14939 {
14942 {
14945 }
14946 else
14947 {
14950 }
14951 }
14957 {
14958 /* We don't build decls for an instantiation of a
14959 variadic capture proxy, we instantiate the elements
14960 when needed. */
14963 }
14964 /* Fall through */
14967 {
14971 /* If the original type was a reference, we'll be wrapped in
14972 the appropriate INDIRECT_REF. */
14975 }
14986 {
14995 }
14998 {
15004 integral_constant_expression_p);
15008 /* If the resulting list of expression statement is empty,
15009 fold it further into void_zero_node. */
15014 }
15017 {
15031 /* For a function scope, we want to use tsubst so that we don't
15032 complain about referring to an auto function before its return
15033 type has been deduced. Otherwise, we want to use tsubst_copy so
15034 that we look up the existing field/parameter/variable rather
15035 than build a new one. */
15040 {
15041 /* Look up the parameter we want directly, as tsubst_copy
15042 doesn't do what we need. */
15048 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15051 }
15052 else
15061 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15063 /* Now that we know visibility, instantiate the type so we have a
15064 declaration of the op() for later calls to lambda_function. */
15070 }
15073 /* We can get here for a constant initializer of non-dependent type.
15074 FIXME stop folding in cp_parser_initializer_clause. */
15075 {
15077 complain);
15079 }
15083 integral_constant_expression_p));
15093 complain));
15096 /* Handle Objective-C++ constructs, if appropriate. */
15097 {
15098 tree subst
15103 }
15105 }
15107 #undef RECUR
15108 #undef RETURN
15109 out:
15112 }
15114 /* Verify that the instantiated ARGS are valid. For type arguments,
15115 make sure that the type's linkage is ok. For non-type arguments,
15116 make sure they are constants if they are integral or enumerations.
15117 Emit an error under control of COMPLAIN, and return TRUE on error. */
15119 static bool
15121 {
15125 {
15135 }
15137 {
15138 /* [basic.link]: A name with no linkage (notably, the name
15139 of a class or enumeration declared in a local scope)
15140 shall not be used to declare an entity with linkage.
15141 This implies that names with no linkage cannot be used as
15142 template arguments
15144 DR 757 relaxes this restriction for C++0x. */
15149 {
15150 /* DR 488 makes use of a type with no linkage cause
15151 type deduction to fail. */
15153 {
15156 else
15159 }
15161 }
15162 /* In order to avoid all sorts of complications, we do not
15163 allow variably-modified types as template arguments. */
15165 {
15169 }
15170 }
15171 /* Class template and alias template arguments should be OK. */
15173 ;
15174 /* A non-type argument of integral or enumerated type must be a
15175 constant. */
15179 {
15183 }
15185 }
15187 static bool
15189 {
15194 {
15197 }
15201 }
15203 /* We're out of SFINAE context now, so generate diagnostics for the access
15204 errors we saw earlier when instantiating D from TMPL and ARGS. */
15206 static void
15208 {
15220 }
15222 /* Instantiate the indicated variable, function, or alias template TMPL with
15223 the template arguments in TARG_PTR. */
15225 static tree
15227 {
15229 tree fndecl;
15230 tree gen_tmpl;
15231 tree spec;
15239 /* If this function is a clone, handle it specially. */
15241 {
15242 tree spec;
15243 tree clone;
15245 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15246 DECL_CLONED_FUNCTION. */
15252 /* Look for the clone. */
15256 /* We should always have found the clone by now. */
15259 }
15264 /* Check to see if we already have this specialization. */
15267 /* The TMPL is a partial instantiation. To get a full set of
15268 arguments we must add the arguments used to perform the
15269 partial instantiation. */
15271 targ_ptr);
15273 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15274 but it doesn't seem to be on the hot path. */
15283 {
15285 {
15289 }
15291 }
15294 complain))
15297 /* We are building a FUNCTION_DECL, during which the access of its
15298 parameters and return types have to be checked. However this
15299 FUNCTION_DECL which is the desired context for access checking
15300 is not built yet. We solve this chicken-and-egg problem by
15301 deferring all checks until we have the FUNCTION_DECL. */
15304 /* Instantiation of the function happens in the context of the function
15305 template, not the context of the overload resolution we're doing. */
15307 /* If there are dependent arguments, e.g. because we're doing partial
15308 ordering, make sure processing_template_decl stays set. */
15312 {
15316 }
15317 /* Substitute template parameters to obtain the specialization. */
15325 {
15328 }
15330 /* The DECL_TI_TEMPLATE should always be the immediate parent
15331 template, not the most general template. */
15334 /* Now we know the specialization, compute access previously
15335 deferred. */
15342 /* If we've just instantiated the main entry point for a function,
15343 instantiate all the alternate entry points as well. We do this
15344 by cloning the instantiation of the main entry point, not by
15345 instantiating the template clones. */
15350 {
15352 {
15353 /* Remember to reinstantiate when we're out of SFINAE so the user
15354 can see the errors. */
15356 }
15358 }
15360 }
15362 /* Wrapper for instantiate_template_1. */
15364 tree
15366 {
15367 tree ret;
15372 }
15374 /* Instantiate the alias template TMPL with ARGS. Also push a template
15375 instantiation level, which instantiate_template doesn't do because
15376 functions and variables have sufficient context established by the
15377 callers. */
15379 static tree
15381 {
15388 {
15391 }
15393 args =
15401 /* We can't free this if a pending_template entry or last_error_tinst_level
15402 is pointing at it. */
15408 }
15410 /* PARM is a template parameter pack for FN. Returns true iff
15411 PARM is used in a deducible way in the argument list of FN. */
15413 static bool
15415 {
15418 {
15420 tree packs;
15426 {
15427 /* The template parameter pack is used in a function parameter
15428 pack. If this is the end of the parameter list, the
15429 template parameter pack is deducible. */
15432 else
15433 /* Otherwise, not. Well, it could be deduced from
15434 a non-pack parameter, but doing so would end up with
15435 a deduction mismatch, so don't bother. */
15437 }
15438 }
15439 /* The template parameter pack isn't used in any function parameter
15440 packs, but it might be used deeper, e.g. tuple<Args...>. */
15442 }
15444 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15445 NARGS elements of the arguments that are being used when calling
15446 it. TARGS is a vector into which the deduced template arguments
15447 are placed.
15449 Returns either a FUNCTION_DECL for the matching specialization of FN or
15450 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
15451 true, diagnostics will be printed to explain why it failed.
15453 If FN is a conversion operator, or we are trying to produce a specific
15454 specialization, RETURN_TYPE is the return type desired.
15456 The EXPLICIT_TARGS are explicit template arguments provided via a
15457 template-id.
15459 The parameter STRICT is one of:
15461 DEDUCE_CALL:
15462 We are deducing arguments for a function call, as in
15463 [temp.deduct.call].
15465 DEDUCE_CONV:
15466 We are deducing arguments for a conversion function, as in
15467 [temp.deduct.conv].
15469 DEDUCE_EXACT:
15470 We are deducing arguments when doing an explicit instantiation
15471 as in [temp.explicit], when determining an explicit specialization
15472 as in [temp.expl.spec], or when taking the address of a function
15473 template, as in [temp.deduct.funcaddr]. */
15475 tree
15477 tree explicit_targs,
15478 tree targs,
15481 tree return_type,
15482 unification_kind_t strict,
15486 {
15487 tree parms;
15488 tree fntype;
15496 tree tinst;
15502 /* In C++0x, it's possible to have a function template whose type depends
15503 on itself recursively. This is most obvious with decltype, but can also
15504 occur with enumeration scope (c++/48969). So we need to catch infinite
15505 recursion and reject the substitution at deduction time; this function
15506 will return error_mark_node for any repeated substitution.
15508 This also catches excessive recursion such as when f<N> depends on
15509 f<N-1> across all integers, and returns error_mark_node for all the
15510 substitutions back up to the initial one.
15512 This is, of course, not reentrant. */
15522 {
15523 /* [temp.deduct]
15525 The specified template arguments must match the template
15526 parameters in kind (i.e., type, nontype, template), and there
15527 must not be more arguments than there are parameters;
15528 otherwise type deduction fails.
15530 Nontype arguments must match the types of the corresponding
15531 nontype template parameters, or must be convertible to the
15532 types of the corresponding nontype parameters as specified in
15533 _temp.arg.nontype_, otherwise type deduction fails.
15535 All references in the function type of the function template
15536 to the corresponding template parameters are replaced by the
15537 specified template argument values. If a substitution in a
15538 template parameter or in the function type of the function
15539 template results in an invalid type, type deduction fails. */
15544 /* Adjust any explicit template arguments before entering the
15545 substitution context. */
15546 explicit_targs
15548 complain,
15554 /* Substitute the explicit args into the function type. This is
15555 necessary so that, for instance, explicitly declared function
15556 arguments can match null pointed constants. If we were given
15557 an incomplete set of explicit args, we must not do semantic
15558 processing during substitution as we could create partial
15559 instantiations. */
15561 {
15566 /* Dig out the actual parm. */
15569 {
15572 }
15574 {
15577 }
15580 /* No explicit argument for this template parameter. */
15584 {
15585 /* Mark the argument pack as "incomplete". We could
15586 still deduce more arguments during unification.
15587 We remove this mark in type_unification_real. */
15589 {
15593 }
15595 /* We have some incomplete argument packs. */
15597 }
15598 }
15602 {
15605 }
15608 /* Ignore any access checks; we'll see them again in
15609 instantiate_template and they might have the wrong
15610 access path at this point. */
15622 /* Place the explicitly specified arguments in TARGS. */
15625 }
15627 /* Never do unification on the 'this' parameter. */
15631 {
15640 }
15642 /* We allow incomplete unification without an error message here
15643 because the standard doesn't seem to explicitly prohibit it. Our
15644 callers must be ready to deal with unification failures in any
15645 event. */
15648 /* If we aren't explaining yet, push tinst context so we can see where
15649 any errors (e.g. from class instantiations triggered by instantiation
15650 of default template arguments) come from. If we are explaining, this
15651 context is redundant. */
15653 {
15656 }
15658 /* type_unification_real will pass back any access checks from default
15659 template argument substitution. */
15671 /* Now that we have bindings for all of the template arguments,
15672 ensure that the arguments deduced for the template template
15673 parameters have compatible template parameter lists. We cannot
15674 check this property before we have deduced all template
15675 arguments, because the template parameter types of a template
15676 template parameter might depend on prior template parameters
15677 deduced after the template template parameter. The following
15678 ill-formed example illustrates this issue:
15680 template<typename T, template<T> class C> void f(C<5>, T);
15682 template<int N> struct X {};
15684 void g() {
15685 f(X<5>(), 5l); // error: template argument deduction fails
15686 }
15688 The template parameter list of 'C' depends on the template type
15689 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15690 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15691 time that we deduce 'C'. */
15694 {
15697 }
15699 /* All is well so far. Now, check:
15701 [temp.deduct]
15703 When all template arguments have been deduced, all uses of
15704 template parameters in nondeduced contexts are replaced with
15705 the corresponding deduced argument values. If the
15706 substitution results in an invalid type, as described above,
15707 type deduction fails. */
15710 {
15713 }
15715 /* Also collect access checks from the instantiation. */
15728 /* Now perform any access checks encountered during substitution. */
15735 /* If we're looking for an exact match, check that what we got
15736 is indeed an exact match. It might not be if some template
15737 parameters are used in non-deduced contexts. */
15739 {
15743 tree sarg
15749 {
15753 }
15754 }
15758 fail:
15761 {
15763 /* Reset once we're all the way out. */
15765 }
15767 /* We can't free this if a pending_template entry or last_error_tinst_level
15768 is pointing at it. */
15774 }
15776 /* Adjust types before performing type deduction, as described in
15777 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15778 sections are symmetric. PARM is the type of a function parameter
15779 or the return type of the conversion function. ARG is the type of
15780 the argument passed to the call, or the type of the value
15781 initialized with the result of the conversion function.
15782 ARG_EXPR is the original argument expression, which may be null. */
15784 static int
15788 tree arg_expr)
15789 {
15793 {
15798 {
15799 /* Swap PARM and ARG throughout the remainder of this
15800 function; the handling is precisely symmetric since PARM
15801 will initialize ARG rather than vice versa. */
15806 }
15809 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15810 too, but here handle it by stripping the reference from PARM
15811 rather than by adding it to ARG. */
15819 /* Nothing else to do in this case. */
15824 }
15827 {
15828 /* [temp.deduct.call]
15830 If P is not a reference type:
15832 --If A is an array type, the pointer type produced by the
15833 array-to-pointer standard conversion (_conv.array_) is
15834 used in place of A for type deduction; otherwise,
15836 --If A is a function type, the pointer type produced by
15837 the function-to-pointer standard conversion
15838 (_conv.func_) is used in place of A for type deduction;
15839 otherwise,
15841 --If A is a cv-qualified type, the top level
15842 cv-qualifiers of A's type are ignored for type
15843 deduction. */
15848 else
15850 }
15852 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15853 of the form T&&, where T is a template parameter, and the argument
15854 is an lvalue, T is deduced as A& */
15860 /* try_one_overload doesn't provide an arg_expr, but
15861 functions are always lvalues. */
15865 /* [temp.deduct.call]
15867 If P is a cv-qualified type, the top level cv-qualifiers
15868 of P's type are ignored for type deduction. If P is a
15869 reference type, the type referred to by P is used for
15870 type deduction. */
15873 {
15876 }
15878 /* DR 322. For conversion deduction, remove a reference type on parm
15879 too (which has been swapped into ARG). */
15884 }
15886 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15887 template which does contain any deducible template parameters; check if
15888 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15889 unify_one_argument. */
15891 static int
15894 {
15895 tree type;
15899 else
15906 {
15910 }
15912 {
15917 }
15921 else
15923 }
15927 /* Returns true iff the expression EXPR is one from which a template
15928 argument can be deduced. In other words, if it's an undecorated
15929 use of a template non-type parameter. */
15931 static bool
15933 {
15935 }
15937 /* Returns true iff the array domain DOMAIN uses a template parameter in a
15938 deducible way; that is, if it has a max value of <PARM> - 1. */
15940 static bool
15942 {
15951 }
15953 /* Returns true iff the template arguments ARGS use a template parameter
15954 in a deducible way. */
15956 static bool
15958 {
15960 {
15965 else
15966 {
15973 else
15975 }
15978 }
15980 }
15982 /* Returns true iff TYPE contains any deducible references to template
15983 parameters, as per 14.8.2.5. */
15985 static bool
15987 {
15991 /* T
15992 cv-list T
15993 TT<T>
15994 TT<i>
15995 TT<> */
16000 /* T*
16001 T&
16002 T&& */
16006 /* T[integer-constant ]
16007 type [i] */
16012 /* T type ::*
16013 type T::*
16014 T T::*
16015 T (type ::*)()
16016 type (T::*)()
16017 type (type ::*)(T)
16018 type (T::*)(T)
16019 T (type ::*)(T)
16020 T (T::*)()
16021 T (T::*)(T) */
16024 || (uses_deducible_template_parms
16027 /* template-name <T> (where template-name refers to a class template)
16028 template-name <i> (where template-name refers to a class template) */
16035 /* type (T)
16036 T()
16037 T(T) */
16040 {
16049 }
16052 }
16054 /* Subroutine of type_unification_real and unify_pack_expansion to
16055 handle unification of a single P/A pair. Parameters are as
16056 for those functions. */
16058 static int
16062 {
16069 /* We can't deduce anything from this, but we might get all the
16070 template args from other function args. */
16073 /* Implicit conversions (Clause 4) will be performed on a function
16074 argument to convert it to the type of the corresponding function
16075 parameter if the parameter type contains no template-parameters that
16076 participate in template argument deduction. */
16078 /* For function parameters that contain no template-parameters at all,
16079 we have historically checked for convertibility in order to shortcut
16080 consideration of this candidate. */
16082 explain_p);
16085 /* For function parameters with only non-deducible template parameters,
16086 just return. */
16090 {
16092 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16093 | UNIFY_ALLOW_MORE_CV_QUAL
16107 }
16109 /* We only do these transformations if this is the top-level
16110 parameter_type_list in a call or declaration matching; in other
16111 situations (nested function declarators, template argument lists) we
16112 won't be comparing a type to an expression, and we don't do any type
16113 adjustments. */
16115 {
16117 {
16120 {
16121 /* [temp.deduct.type] A template-argument can be
16122 deduced from a pointer to function or pointer
16123 to member function argument if the set of
16124 overloaded functions does not contain function
16125 templates and at most one of a set of
16126 overloaded functions provides a unique
16127 match. */
16134 }
16140 }
16142 arg_strict |=
16144 }
16145 else
16149 /* For deduction from an init-list we need the actual list. */
16153 }
16155 /* Most parms like fn_type_unification.
16157 If SUBR is 1, we're being called recursively (to unify the
16158 arguments of a function or method parameter of a function
16159 template).
16161 CHECKS is a pointer to a vector of access checks encountered while
16162 substituting default template arguments. */
16164 static int
16166 tree targs,
16167 tree xparms,
16171 unification_kind_t strict,
16175 {
16180 tree parms;
16189 /* Reset the number of non-defaulted template arguments contained
16190 in TARGS. */
16193 again:
16201 {
16206 /* For a function parameter pack that occurs at the end of the
16207 parameter-declaration-list, the type A of each remaining
16208 argument of the call is compared with the type P of the
16209 declarator-id of the function parameter pack. */
16215 /* For a function parameter pack that does not occur at the
16216 end of the parameter-declaration-list, the type of the
16217 parameter pack is a non-deduced context. */
16226 }
16231 {
16232 /* Unify the remaining arguments with the pack expansion type. */
16233 tree argvec;
16236 /* Allocate a TREE_VEC and copy in all of the arguments */
16241 /* Copy the parameter into parmvec. */
16247 /* Advance to the end of the list of parameters. */
16249 }
16251 /* Fail if we've reached the end of the parm list, and more args
16252 are present, and the parm list isn't variadic. */
16255 /* Fail if parms are left and they don't have default values. */
16258 {
16262 {
16263 count++;
16265 }
16267 }
16270 {
16271 tsubst_flags_t complain = (explain_p
16272 ? tf_warning_or_error
16276 {
16280 /* Clear the "incomplete" flags on all argument packs now so that
16281 substituting them into later default arguments works. */
16283 {
16286 }
16292 /* If this is an undeduced nontype parameter that depends on
16293 a type parameter, try another pass; its type may have been
16294 deduced from a later argument than the one from which
16295 this parameter can be deduced. */
16301 /* Core issue #226 (C++0x) [temp.deduct]:
16303 If a template argument has not been deduced, its
16304 default template argument, if any, is used.
16306 When we are in C++98 mode, TREE_PURPOSE will either
16307 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16308 to explicitly check cxx_dialect here. */
16310 {
16325 else
16326 {
16328 /* The position of the first default template argument,
16329 is also the number of non-defaulted arguments in TARGS.
16330 Record that. */
16334 }
16335 }
16337 /* If the type parameter is a parameter pack, then it will
16338 be deduced to an empty parameter pack. */
16340 {
16341 tree arg;
16344 {
16348 }
16349 else
16356 }
16359 }
16360 }
16361 #ifdef ENABLE_CHECKING
16364 #endif
16367 }
16369 /* Subroutine of type_unification_real. Args are like the variables
16370 at the call site. ARG is an overloaded function (or template-id);
16371 we try deducing template args from each of the overloads, and if
16372 only one succeeds, we go with that. Modifies TARGS and returns
16373 true on success. */
16375 static bool
16377 tree targs,
16378 tree parm,
16379 tree arg,
16380 unification_kind_t strict,
16383 {
16390 {
16393 }
16394 else
16398 /* Handle `&x' where `x' is some static or non-static member
16399 function name. */
16405 /* Strip baselink information. */
16410 {
16411 /* If we got some explicit template args, we need to plug them into
16412 the affected templates before we try to unify, in case the
16413 explicit args will completely resolve the templates in question. */
16420 {
16433 {
16438 {
16441 }
16442 }
16445 }
16446 /* If no templates (or more than one) are fully resolved by the
16447 explicit arguments, this template-id is a non-deduced context; it
16448 could still be OK if we deduce all template arguments for the
16449 enclosing call through other arguments. */
16452 }
16455 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16456 -- but the deduction does not succeed because the expression is
16457 not just the function on its own. */
16459 else
16465 {
16468 }
16470 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16471 to function or pointer to member function argument if the set of
16472 overloaded functions does not contain function templates and at most
16473 one of a set of overloaded functions provides a unique match.
16475 So if we found multiple possibilities, we return success but don't
16476 deduce anything. */
16479 {
16484 }
16489 }
16491 /* Core DR 115: In contexts where deduction is done and fails, or in
16492 contexts where deduction is not done, if a template argument list is
16493 specified and it, along with any default template arguments, identifies
16494 a single function template specialization, then the template-id is an
16495 lvalue for the function template specialization. */
16497 tree
16499 {
16512 {
16515 }
16517 {
16520 }
16522 {
16525 }
16528 {
16532 /* If we got some explicit template args, we need to plug them into
16533 the affected templates before we try to unify, in case the
16534 explicit args will completely resolve the templates in question. */
16542 {
16555 {
16558 {
16561 }
16563 {
16566 }
16567 }
16568 }
16570 {
16578 {
16579 tree base
16582 }
16586 }
16588 /* There were no good options and at least one bad one, so let the
16589 user know what the problem is. */
16591 }
16593 }
16595 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16596 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16597 different overloads deduce different arguments for a given parm.
16598 ADDR_P is true if the expression for which deduction is being
16599 performed was of the form "& fn" rather than simply "fn".
16601 Returns 1 on success. */
16603 static int
16605 tree orig_targs,
16606 tree targs,
16607 tree parm,
16608 tree arg,
16609 unification_kind_t strict,
16613 {
16615 tree tempargs;
16621 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16622 to function or pointer to member function argument if the set of
16623 overloaded functions does not contain function templates and at most
16624 one of a set of overloaded functions provides a unique match.
16626 So if this is a template, just return success. */
16638 /* We don't copy orig_targs for this because if we have already deduced
16639 some template args from previous args, unify would complain when we
16640 try to deduce a template parameter for the same argument, even though
16641 there isn't really a conflict. */
16648 /* First make sure we didn't deduce anything that conflicts with
16649 explicitly specified args. */
16651 {
16658 /* Since we're unifying against ourselves, we will fill in
16659 template args used in the function parm list with our own
16660 template parms. Discard them. */
16664 }
16667 {
16672 }
16675 }
16677 /* PARM is a template class (perhaps with unbound template
16678 parameters). ARG is a fully instantiated type. If ARG can be
16679 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16680 TARGS are as for unify. */
16682 static tree
16685 {
16686 tree copy_of_targs;
16693 /* We need to make a new template argument vector for the call to
16694 unify. If we used TARGS, we'd clutter it up with the result of
16695 the attempted unification, even if this class didn't work out.
16696 We also don't want to commit ourselves to all the unifications
16697 we've already done, since unification is supposed to be done on
16698 an argument-by-argument basis. In other words, consider the
16699 following pathological case:
16701 template <int I, int J, int K>
16702 struct S {};
16704 template <int I, int J>
16705 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16707 template <int I, int J, int K>
16708 void f(S<I, J, K>, S<I, I, I>);
16710 void g() {
16711 S<0, 0, 0> s0;
16712 S<0, 1, 2> s2;
16714 f(s0, s2);
16715 }
16717 Now, by the time we consider the unification involving `s2', we
16718 already know that we must have `f<0, 0, 0>'. But, even though
16719 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
16720 because there are two ways to unify base classes of S<0, 1, 2>
16721 with S<I, I, I>. If we kept the already deduced knowledge, we
16722 would reject the possibility I=1. */
16725 /* If unification failed, we're done. */
16731 }
16733 /* Given a template type PARM and a class type ARG, find the unique
16734 base type in ARG that is an instance of PARM. We do not examine
16735 ARG itself; only its base-classes. If there is not exactly one
16736 appropriate base class, return NULL_TREE. PARM may be the type of
16737 a partial specialization, as well as a plain template type. Used
16738 by unify. */
16740 static enum template_base_result
16743 {
16745 tree binfo;
16751 {
16752 /* The type could not be completed. */
16755 }
16757 /* Walk in inheritance graph order. The search order is not
16758 important, and this avoids multiple walks of virtual bases. */
16760 {
16765 {
16766 /* If there is more than one satisfactory baseclass, then:
16768 [temp.deduct.call]
16770 If they yield more than one possible deduced A, the type
16771 deduction fails.
16773 applies. */
16775 {
16778 }
16781 }
16782 }
16786 }
16788 /* Returns the level of DECL, which declares a template parameter. */
16790 static int
16792 {
16794 {
16804 }
16806 }
16808 /* Decide whether ARG can be unified with PARM, considering only the
16809 cv-qualifiers of each type, given STRICT as documented for unify.
16810 Returns nonzero iff the unification is OK on that basis. */
16812 static int
16814 {
16820 {
16821 /* Although a CVR qualifier is ignored when being applied to a
16822 substituted template parameter ([8.3.2]/1 for example), that
16823 does not allow us to unify "const T" with "int&" because both
16824 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
16825 It is ok when we're allowing additional CV qualifiers
16826 at the outer level [14.8.2.1]/3,1st bullet. */
16836 }
16847 }
16849 /* Determines the LEVEL and INDEX for the template parameter PARM. */
16850 void
16852 {
16856 {
16859 }
16860 else
16861 {
16864 }
16865 }
16867 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
16868 do { \
16869 if (unify (TP, TA, P, A, S, EP)) \
16870 return 1; \
16871 } while (0);
16873 /* Unifies the remaining arguments in PACKED_ARGS with the pack
16874 expansion at the end of PACKED_PARMS. Returns 0 if the type
16875 deduction succeeds, 1 otherwise. STRICT is the same as in
16876 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
16877 call argument list. We'll need to adjust the arguments to make them
16878 types. SUBR tells us if this is from a recursive call to
16879 type_unification_real, or for comparing two template argument
16880 lists. */
16882 static int
16886 {
16887 tree parm
16894 /* Determine the parameter packs we will be deducing from the
16895 pattern, and record their current deductions. */
16898 {
16902 /* Determine the index and level of this parameter pack. */
16905 /* Keep track of the parameter packs and their corresponding
16906 argument packs. */
16909 }
16911 /* Loop through all of the arguments that have not yet been
16912 unified and unify each with the pattern. */
16914 {
16915 tree parm;
16919 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
16920 or the element of its argument pack at the current index if
16921 this argument was explicitly specified. */
16923 {
16932 {
16935 }
16937 }
16939 /* If we had explicit template arguments, substitute them into the
16940 pattern before deduction. */
16942 {
16943 /* Some arguments might still be unspecified or dependent. */
16951 NULL_TREE);
16956 }
16957 else
16960 /* Unify the pattern with the current argument. */
16965 /* For each parameter pack, collect the deduced value. */
16967 {
16973 }
16974 }
16976 /* Verify that the results of unification with the parameter packs
16977 produce results consistent with what we've seen before, and make
16978 the deduced argument packs available. */
16980 {
16987 /* By default keep the original deduced argument pack.
16988 If necessary, more specific code is going to update the
16989 resulting deduced argument later down in this function. */
16993 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16994 actually deduce anything. */
17002 {
17003 /* If we had fewer function args than explicit template args,
17004 just use the explicits. */
17009 }
17012 {
17013 tree result;
17014 /* Build the deduced *_ARGUMENT_PACK. */
17016 {
17021 }
17022 else
17027 /* Note the deduced argument packs for this parameter
17028 pack. */
17030 }
17034 {
17035 /* We only had the explicitly-provided arguments before, but
17036 now we have a complete set of arguments. */
17042 }
17043 else
17044 {
17050 /* Inconsistent unification of this parameter pack. */
17052 bad_old_arg,
17053 bad_new_arg);
17054 }
17055 }
17058 }
17060 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17061 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17062 parameters and return value are as for unify. */
17064 static int
17068 {
17069 tree parm_max;
17070 tree arg_max;
17074 /* Our representation of array types uses "N - 1" as the
17075 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17076 not an integer constant. We cannot unify arbitrarily
17077 complex expressions, so we eliminate the MINUS_EXPRs
17078 here. */
17082 {
17085 }
17089 {
17090 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17091 trying to unify the type of a variable with the type
17092 of a template parameter. For example:
17094 template <unsigned int N>
17095 void f (char (&) [N]);
17096 int g();
17097 void h(int i) {
17098 char a[g(i)];
17099 f(a);
17100 }
17102 Here, the type of the ARG will be "int [g(i)]", and
17103 may be a SAVE_EXPR, etc. */
17107 }
17109 /* If only one of the bounds used a MINUS_EXPR, compensate
17110 by adding one to the other bound. */
17113 integer_type_node,
17114 parm_max,
17115 integer_one_node);
17118 integer_type_node,
17119 arg_max,
17120 integer_one_node);
17124 }
17126 /* Deduce the value of template parameters. TPARMS is the (innermost)
17127 set of template parameters to a template. TARGS is the bindings
17128 for those template parameters, as determined thus far; TARGS may
17129 include template arguments for outer levels of template parameters
17130 as well. PARM is a parameter to a template function, or a
17131 subcomponent of that parameter; ARG is the corresponding argument.
17132 This function attempts to match PARM with ARG in a manner
17133 consistent with the existing assignments in TARGS. If more values
17134 are deduced, then TARGS is updated.
17136 Returns 0 if the type deduction succeeds, 1 otherwise. The
17137 parameter STRICT is a bitwise or of the following flags:
17139 UNIFY_ALLOW_NONE:
17140 Require an exact match between PARM and ARG.
17141 UNIFY_ALLOW_MORE_CV_QUAL:
17142 Allow the deduced ARG to be more cv-qualified (by qualification
17143 conversion) than ARG.
17144 UNIFY_ALLOW_LESS_CV_QUAL:
17145 Allow the deduced ARG to be less cv-qualified than ARG.
17146 UNIFY_ALLOW_DERIVED:
17147 Allow the deduced ARG to be a template base class of ARG,
17148 or a pointer to a template base class of the type pointed to by
17149 ARG.
17150 UNIFY_ALLOW_INTEGER:
17151 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17152 case for more information.
17153 UNIFY_ALLOW_OUTER_LEVEL:
17154 This is the outermost level of a deduction. Used to determine validity
17155 of qualification conversions. A valid qualification conversion must
17156 have const qualified pointers leading up to the inner type which
17157 requires additional CV quals, except at the outer level, where const
17158 is not required [conv.qual]. It would be normal to set this flag in
17159 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17160 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17161 This is the outermost level of a deduction, and PARM can be more CV
17162 qualified at this point.
17163 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17164 This is the outermost level of a deduction, and PARM can be less CV
17165 qualified at this point. */
17167 static int
17170 {
17172 tree targ;
17173 tree tparm;
17176 /* I don't think this will do the right thing with respect to types.
17177 But the only case I've seen it in so far has been array bounds, where
17178 signedness is the only information lost, and I think that will be
17179 okay. */
17187 /* We can't deduce anything from this, but we might get all the
17188 template args from other function args. */
17191 /* If PARM uses template parameters, then we can't bail out here,
17192 even if ARG == PARM, since we won't record unifications for the
17193 template parameters. We might need them if we're trying to
17194 figure out which of two things is more specialized. */
17198 /* Handle init lists early, so the rest of the function can assume
17199 we're dealing with a type. */
17201 {
17206 /* Replace T with std::initializer_list<T> for deduction. */
17213 /* We can only deduce from an initializer list argument if the
17214 parameter is std::initializer_list or an array; otherwise this
17215 is a non-deduced context. */
17220 else
17224 {
17231 {
17233 /* It should only be possible to get here for a call. */
17235 elt_strict |= maybe_adjust_types_for_deduction
17238 }
17241 explain_p);
17242 }
17245 {
17246 /* Also deduce from the length of the initializer list. */
17252 }
17254 /* If the std::initializer_list<T> deduction worked, replace the
17255 deduced A with std::initializer_list<A>. */
17257 {
17262 }
17264 }
17266 /* Immediately reject some pairs that won't unify because of
17267 cv-qualification mismatches. */
17270 /* It is the elements of the array which hold the cv quals of an array
17271 type, and the elements might be template type parms. We'll check
17272 when we recurse. */
17274 /* We check the cv-qualifiers when unifying with template type
17275 parameters below. We want to allow ARG `const T' to unify with
17276 PARM `T' for example, when computing which of two templates
17277 is more specialized, for example. */
17291 {
17295 /* In a type which contains a nested-name-specifier, template
17296 argument values cannot be deduced for template parameters used
17297 within the nested-name-specifier. */
17309 /* The PARM is not one we're trying to unify. Just check
17310 to see if it matches ARG. */
17311 {
17316 else
17318 }
17325 /* Check for mixed types and values. */
17333 {
17334 /* ARG must be constructed from a template class or a template
17335 template parameter. */
17340 {
17344 tree parm_parms
17345 = DECL_INNERMOST_TEMPLATE_PARMS
17350 /* The resolution to DR150 makes clear that default
17351 arguments for an N-argument may not be used to bind T
17352 to a template template parameter with fewer than N
17353 parameters. It is not safe to permit the binding of
17354 default arguments as an extension, as that may change
17355 the meaning of a conforming program. Consider:
17357 struct Dense { static const unsigned int dim = 1; };
17359 template <template <typename> class View,
17360 typename Block>
17361 void operator+(float, View<Block> const&);
17363 template <typename Block,
17364 unsigned int Dim = Block::dim>
17365 struct Lvalue_proxy { operator float() const; };
17367 void
17368 test_1d (void) {
17369 Lvalue_proxy<Dense> p;
17370 float b;
17371 b + p;
17372 }
17374 Here, if Lvalue_proxy is permitted to bind to View, then
17375 the global operator+ will be used; if they are not, the
17376 Lvalue_proxy will be converted to float. */
17378 full_argvec,
17380 (explain_p
17381 ? tf_warning_or_error
17388 /* Deduce arguments T, i from TT<T> or TT<i>.
17389 We check each element of PARMVEC and ARGVEC individually
17390 rather than the whole TREE_VEC since they can have
17391 different number of elements. */
17398 /* Check if the parameters end in a pack, making them
17399 variadic. */
17405 /* If the template argument list of P contains a pack
17406 expansion that is not the last template argument, the
17407 entire template argument list is a non-deduced
17408 context. */
17417 {
17422 }
17427 DEDUCE_EXACT,
17430 }
17433 /* Fall through to deduce template name. */
17434 }
17438 {
17439 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17441 /* Simple cases: Value already set, does match or doesn't. */
17446 }
17447 else
17448 {
17449 /* If PARM is `const T' and ARG is only `int', we don't have
17450 a match unless we are allowing additional qualification.
17451 If ARG is `const int' and PARM is just `T' that's OK;
17452 that binds `const int' to `T'. */
17457 /* Consider the case where ARG is `const volatile int' and
17458 PARM is `const T'. Then, T should be `volatile int'. */
17459 arg = cp_build_qualified_type_real
17464 /* Simple cases: Value already set, does match or doesn't. */
17470 /* Make sure that ARG is not a variable-sized array. (Note
17471 that were talking about variable-sized arrays (like
17472 `int[n]'), rather than arrays of unknown size (like
17473 `int[]').) We'll get very confused by such a type since
17474 the bound of the array is not constant, and therefore
17475 not mangleable. Besides, such types are not allowed in
17476 ISO C++, so we can do as we please here. We do allow
17477 them for 'auto' deduction, since that isn't ABI-exposed. */
17481 /* Strip typedefs as in convert_template_argument. */
17483 }
17485 /* If ARG is a parameter pack or an expansion, we cannot unify
17486 against it unless PARM is also a parameter pack. */
17491 /* If the argument deduction results is a METHOD_TYPE,
17492 then there is a problem.
17493 METHOD_TYPE doesn't map to any real C++ type the result of
17494 the deduction can not be of that type. */
17508 {
17509 /* The PARM is not one we're trying to unify. Just check
17510 to see if it matches ARG. */
17516 }
17522 {
17527 }
17529 /* [temp.deduct.type] If, in the declaration of a function template
17530 with a non-type template-parameter, the non-type
17531 template-parameter is used in an expression in the function
17532 parameter-list and, if the corresponding template-argument is
17533 deduced, the template-argument type shall match the type of the
17534 template-parameter exactly, except that a template-argument
17535 deduced from an array bound may be of any integral type.
17536 The non-type parameter might use already deduced type parameters. */
17539 /* Template-parameter dependent expression. Just accept it for now.
17540 It will later be processed in convert_template_argument. */
17541 ;
17546 /* Convert the ARG to the type of PARM; the deduced non-type
17547 template argument must exactly match the types of the
17548 corresponding parameter. */
17551 /* We haven't deduced the type of this parameter yet. Try again
17552 later. */
17554 else
17557 /* If ARG is a parameter pack or an expansion, we cannot unify
17558 against it unless PARM is also a parameter pack. */
17568 {
17569 /* A pointer-to-member constant can be unified only with
17570 another constant. */
17574 /* Just unify the class member. It would be useless (and possibly
17575 wrong, depending on the strict flags) to unify also
17576 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17577 arg refer to the same variable, even if through different
17578 classes. For instance:
17580 struct A { int x; };
17581 struct B : A { };
17583 Unification of &A::x and &B::x must succeed. */
17586 }
17589 {
17593 /* [temp.deduct.call]
17595 A can be another pointer or pointer to member type that can
17596 be converted to the deduced A via a qualification
17597 conversion (_conv.qual_).
17599 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17600 This will allow for additional cv-qualification of the
17601 pointed-to types if appropriate. */
17604 /* The derived-to-base conversion only persists through one
17605 level of pointers. */
17610 }
17642 /* We have already checked cv-qualification at the top of the
17643 function. */
17647 /* As far as unification is concerned, this wins. Later checks
17648 will invalidate it if necessary. */
17651 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17652 /* Type INTEGER_CST can come from ordinary constant template args. */
17664 {
17674 /* Check for pack expansions in the parameters. */
17676 {
17678 {
17680 /* We can unify against something with a trailing
17681 parameter pack. */
17683 else
17684 /* [temp.deduct.type]/9: If the template argument list of
17685 P contains a pack expansion that is not the last
17686 template argument, the entire template argument list
17687 is a non-deduced context. */
17689 }
17690 }
17692 /* If we don't have enough arguments to satisfy the parameters
17693 (not counting the pack expression at the end), or we have
17694 too many arguments for a parameter list that doesn't end in
17695 a pack expression, we can't unify. */
17701 /* Unify all of the parameters that precede the (optional)
17702 pack expression. */
17704 {
17709 }
17712 DEDUCE_EXACT,
17715 }
17723 {
17731 }
17734 {
17738 {
17739 /* First, we try to unify the PARM and ARG directly. */
17744 {
17745 /* Fallback to the special case allowed in
17746 [temp.deduct.call]:
17748 If P is a class, and P has the form
17749 template-id, then A can be a derived class of
17750 the deduced A. Likewise, if P is a pointer to
17751 a class of the form template-id, A can be a
17752 pointer to a derived class pointed to by the
17753 deduced A. */
17760 }
17761 }
17765 /* Perhaps PARM is something like S<U> and ARG is S<int>.
17766 Then, we should unify `int' and `U'. */
17768 else
17769 /* There's no chance of unification succeeding. */
17774 }
17781 {
17784 tree a;
17790 /* CV qualifications for methods can never be deduced, they must
17791 match exactly. We need to check them explicitly here,
17792 because type_unification_real treats them as any other
17793 cv-qualified parameter. */
17795 && (!check_cv_quals_for_unify
17815 }
17818 /* Unify a pointer to member with a pointer to member function, which
17819 deduces the type of the member as a function type. */
17821 {
17822 /* Check top-level cv qualifiers */
17830 /* Determine the type of the function we are unifying against. */
17834 }
17853 /* Matched cases are handled by the ARG == PARM test above. */
17857 /* A non-type template parameter that is a variable should be a
17858 an integral constant, in which case, it whould have been
17859 folded into its (constant) value. So we should not be getting
17860 a variable here. */
17871 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
17872 or UNDERLYING_TYPE nodes. */
17876 /* Unification fails if we hit an error node. */
17880 /* An unresolved overload is a nondeduced context. */
17885 /* We must be looking at an expression. This can happen with
17886 something like:
17888 template <int I>
17889 void foo(S<I>, S<I + 2>);
17891 This is a "nondeduced context":
17893 [deduct.type]
17895 The nondeduced contexts are:
17897 --A type that is a template-id in which one or more of
17898 the template-arguments is an expression that references
17899 a template-parameter.
17901 In these cases, we assume deduction succeeded, but don't
17902 actually infer any unifications. */
17907 else
17909 }
17910 }
17911 #undef RECUR_AND_CHECK_FAILURE
17912 \f
17913 /* Note that DECL can be defined in this translation unit, if
17914 required. */
17916 static void
17918 {
17919 tree clone;
17923 }
17925 /* Called if RESULT is explicitly instantiated, or is a member of an
17926 explicitly instantiated class. */
17928 void
17930 {
17933 /* If this entity has already been written out, it's too late to
17934 make any modifications. */
17938 /* For anonymous namespace we don't need to do anything. */
17940 {
17943 }
17946 /* The TREE_PUBLIC flag for function declarations will have been
17947 set correctly by tsubst. */
17950 /* This might have been set by an earlier implicit instantiation. */
17955 else
17956 {
17958 /* Always make artificials weak. */
17961 /* For WIN32 we also want to put explicit instantiations in
17962 linkonce sections. */
17965 }
17967 /* If EXTERN_P, then this function will not be emitted -- unless
17968 followed by an explicit instantiation, at which point its linkage
17969 will be adjusted. If !EXTERN_P, then this function will be
17970 emitted here. In neither circumstance do we want
17971 import_export_decl to adjust the linkage. */
17973 }
17975 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17976 important template arguments. If any are missing, we check whether
17977 they're important by using error_mark_node for substituting into any
17978 args that were used for partial ordering (the ones between ARGS and END)
17979 and seeing if it bubbles up. */
17981 static bool
17983 {
17988 {
17991 }
17993 {
17997 }
17999 }
18001 /* Given two function templates PAT1 and PAT2, return:
18003 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18004 -1 if PAT2 is more specialized than PAT1.
18005 0 if neither is more specialized.
18007 LEN indicates the number of parameters we should consider
18008 (defaulted parameters should not be considered).
18010 The 1998 std underspecified function template partial ordering, and
18011 DR214 addresses the issue. We take pairs of arguments, one from
18012 each of the templates, and deduce them against each other. One of
18013 the templates will be more specialized if all the *other*
18014 template's arguments deduce against its arguments and at least one
18015 of its arguments *does* *not* deduce against the other template's
18016 corresponding argument. Deduction is done as for class templates.
18017 The arguments used in deduction have reference and top level cv
18018 qualifiers removed. Iff both arguments were originally reference
18019 types *and* deduction succeeds in both directions, an lvalue reference
18020 wins against an rvalue reference and otherwise the template
18021 with the more cv-qualified argument wins for that pairing (if
18022 neither is more cv-qualified, they both are equal). Unlike regular
18023 deduction, after all the arguments have been deduced in this way,
18024 we do *not* verify the deduced template argument values can be
18025 substituted into non-deduced contexts.
18027 The logic can be a bit confusing here, because we look at deduce1 and
18028 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18029 can find template arguments for pat1 to make arg1 look like arg2, that
18030 means that arg2 is at least as specialized as arg1. */
18032 int
18034 {
18047 /* Remove the this parameter from non-static member functions. If
18048 one is a non-static member function and the other is not a static
18049 member function, remove the first parameter from that function
18050 also. This situation occurs for operator functions where we
18051 locate both a member function (with this pointer) and non-member
18052 operator (with explicit first operand). */
18054 {
18059 }
18061 {
18064 {
18065 len--;
18067 }
18068 }
18070 /* If only one is a conversion operator, they are unordered. */
18074 /* Consider the return type for a conversion function */
18076 {
18079 len++;
18080 }
18082 processing_template_decl++;
18088 /* Stop when an ellipsis is seen. */
18090 {
18101 {
18102 /* When both arguments are pack expansions, we need only
18103 unify the patterns themselves. */
18107 /* This is the last comparison we need to do. */
18109 }
18112 {
18116 }
18119 {
18123 }
18129 {
18135 /* Setup the parameter vector, which contains only ARG1. */
18138 /* Setup the argument vector, which contains the remaining
18139 arguments. */
18148 /* We cannot deduce in the other direction, because ARG1 is
18149 a pack expansion but ARG2 is not. */
18151 }
18153 {
18159 /* Setup the parameter vector, which contains only ARG1. */
18162 /* Setup the argument vector, which contains the remaining
18163 arguments. */
18172 /* We cannot deduce in the other direction, because ARG2 is
18173 a pack expansion but ARG1 is not.*/
18175 }
18177 else
18178 {
18179 /* The normal case, where neither argument is a pack
18180 expansion. */
18187 }
18189 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18190 arg2, then arg2 is not as specialized as arg1. */
18196 /* "If, for a given type, deduction succeeds in both directions
18197 (i.e., the types are identical after the transformations above)
18198 and both P and A were reference types (before being replaced with
18199 the type referred to above):
18200 - if the type from the argument template was an lvalue reference and
18201 the type from the parameter template was not, the argument type is
18202 considered to be more specialized than the other; otherwise,
18203 - if the type from the argument template is more cv-qualified
18204 than the type from the parameter template (as described above),
18205 the argument type is considered to be more specialized than the other;
18206 otherwise,
18207 - neither type is more specialized than the other." */
18210 {
18212 {
18215 else
18217 }
18219 {
18224 }
18225 }
18228 /* We've failed to deduce something in either direction.
18229 These must be unordered. */
18234 /* We have already processed all of the arguments in our
18235 handing of the pack expansion type. */
18240 }
18242 /* "In most cases, all template parameters must have values in order for
18243 deduction to succeed, but for partial ordering purposes a template
18244 parameter may remain without a value provided it is not used in the
18245 types being used for partial ordering."
18247 Thus, if we are missing any of the targs1 we need to substitute into
18248 origs1, then pat2 is not as specialized as pat1. This can happen when
18249 there is a nondeduced context. */
18255 processing_template_decl--;
18257 /* All things being equal, if the next argument is a pack expansion
18258 for one function but not for the other, prefer the
18259 non-variadic function. FIXME this is bogus; see c++/41958. */
18263 {
18266 }
18272 else
18274 }
18276 /* Determine which of two partial specializations of TMPL is more
18277 specialized.
18279 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18280 to the first partial specialization. The TREE_VALUE is the
18281 innermost set of template parameters for the partial
18282 specialization. PAT2 is similar, but for the second template.
18284 Return 1 if the first partial specialization is more specialized;
18285 -1 if the second is more specialized; 0 if neither is more
18286 specialized.
18288 See [temp.class.order] for information about determining which of
18289 two templates is more specialized. */
18291 static int
18293 {
18294 tree targs;
18302 /* Just like what happens for functions, if we are ordering between
18303 different class template specializations, we may encounter dependent
18304 types in the arguments, and we need our dependency check functions
18305 to behave correctly. */
18311 {
18314 }
18320 {
18323 }
18326 /* In the case of a tie where at least one of the class templates
18327 has a parameter pack at the end, the template with the most
18328 non-packed parameters wins. */
18330 && any_deductions
18333 {
18339 /* We don't count the pack expansion at the end. */
18349 }
18352 }
18354 /* Return the template arguments that will produce the function signature
18355 DECL from the function template FN, with the explicit template
18356 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18357 also match. Return NULL_TREE if no satisfactory arguments could be
18358 found. */
18360 static tree
18362 {
18366 tree decl_arg_types;
18369 tree arg;
18373 /* Never do unification on the 'this' parameter. */
18394 }
18396 /* Return the innermost template arguments that, when applied to a partial
18397 specialization of TMPL whose innermost template parameters are
18398 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18399 ARGS.
18401 For example, suppose we have:
18403 template <class T, class U> struct S {};
18404 template <class T> struct S<T*, int> {};
18406 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18407 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18408 int}. The resulting vector will be {double}, indicating that `T'
18409 is bound to `double'. */
18411 static tree
18413 {
18415 tree deduced_args;
18416 tree innermost_deduced_args;
18420 {
18424 innermost_deduced_args);
18425 }
18426 else
18439 /* Verify that nondeduced template arguments agree with the type
18440 obtained from argument deduction.
18442 For example:
18444 struct A { typedef int X; };
18445 template <class T, class U> struct C {};
18446 template <class T> struct C<T, typename T::X> {};
18448 Then with the instantiation `C<A, int>', we can deduce that
18449 `T' is `A' but unify () does not check whether `typename T::X'
18450 is `int'. */
18456 /* We only need to check the innermost arguments; the other
18457 arguments will always agree. */
18462 /* Now that we have bindings for all of the template arguments,
18463 ensure that the arguments deduced for the template template
18464 parameters have compatible template parameter lists. See the use
18465 of template_template_parm_bindings_ok_p in fn_type_unification
18466 for more information. */
18471 }
18473 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18474 Return the TREE_LIST node with the most specialized template, if
18475 any. If there is no most specialized template, the error_mark_node
18476 is returned.
18478 Note that this function does not look at, or modify, the
18479 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18480 returned is one of the elements of INSTANTIATIONS, callers may
18481 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18482 and retrieve it from the value returned. */
18484 tree
18486 {
18493 {
18499 fate--;
18504 fate++;
18509 {
18510 /* Equally specialized, move to next function. If there
18511 is no next function, nothing's most specialized. */
18516 }
18517 }
18520 /* Now verify that champ is better than everything earlier in the
18521 instantiation list. */
18529 {
18532 }
18534 processing_template_decl--;
18540 }
18542 /* If DECL is a specialization of some template, return the most
18543 general such template. Otherwise, returns NULL_TREE.
18545 For example, given:
18547 template <class T> struct S { template <class U> void f(U); };
18549 if TMPL is `template <class U> void S<int>::f(U)' this will return
18550 the full template. This function will not trace past partial
18551 specializations, however. For example, given in addition:
18553 template <class T> struct S<T*> { template <class U> void f(U); };
18555 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18556 `template <class T> template <class U> S<T*>::f(U)'. */
18558 tree
18560 {
18561 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
18562 an immediate specialization. */
18564 {
18568 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
18569 template friend. */
18574 }
18576 /* Look for more and more general templates. */
18578 {
18579 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18580 (See cp-tree.h for details.) */
18588 /* Stop if we run into an explicitly specialized class template. */
18595 }
18598 }
18600 /* Return the most specialized of the class template partial
18601 specializations which can produce TYPE, a specialization of some class
18602 template. The value returned is actually a TREE_LIST; the TREE_TYPE is
18603 a _TYPE node corresponding to the partial specialization, while the
18604 TREE_PURPOSE is the set of template arguments that must be
18605 substituted into the TREE_TYPE in order to generate TYPE.
18607 If the choice of partial specialization is ambiguous, a diagnostic
18608 is issued, and the error_mark_node is returned. If there are no
18609 partial specializations matching TYPE, then NULL_TREE is
18610 returned, indicating that the primary template should be used. */
18612 static tree
18614 {
18616 tree t;
18617 tree champ;
18626 /* For determining which partial specialization to use, only the
18627 innermost args are interesting. */
18629 {
18632 }
18635 {
18636 tree partial_spec_args;
18637 tree spec_args;
18646 {
18647 /* Discard the outer levels of args, and then substitute in the
18648 template args from the enclosing class. */
18650 partial_spec_args = tsubst_template_args
18653 /* And the same for the partial specialization TEMPLATE_DECL. */
18655 }
18657 partial_spec_args =
18659 partial_spec_args,
18673 partial_spec_args,
18674 args);
18676 {
18681 }
18682 }
18692 {
18695 ;
18696 else
18697 {
18699 {
18702 {
18705 }
18706 }
18708 }
18709 }
18713 {
18716 {
18719 }
18720 }
18723 {
18731 {
18734 }
18737 }
18740 }
18742 /* Explicitly instantiate DECL. */
18744 void
18746 {
18751 /* An error occurred, for which grokdeclarator has already issued
18752 an appropriate message. */
18755 {
18758 }
18760 {
18761 /* There is an asymmetry here in the way VAR_DECLs and
18762 FUNCTION_DECLs are handled by grokdeclarator. In the case of
18763 the latter, the DECL we get back will be marked as a
18764 template instantiation, and the appropriate
18765 DECL_TEMPLATE_INFO will be set up. This does not happen for
18766 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
18767 should handle VAR_DECLs as it currently handles
18768 FUNCTION_DECLs. */
18770 {
18773 }
18776 {
18779 }
18781 {
18786 }
18787 }
18789 {
18792 }
18793 else
18796 /* Check for various error cases. Note that if the explicit
18797 instantiation is valid the RESULT will currently be marked as an
18798 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
18799 until we get here. */
18802 {
18803 /* DR 259 [temp.spec].
18805 Both an explicit instantiation and a declaration of an explicit
18806 specialization shall not appear in a program unless the explicit
18807 instantiation follows a declaration of the explicit specialization.
18809 For a given set of template parameters, if an explicit
18810 instantiation of a template appears after a declaration of an
18811 explicit specialization for that template, the explicit
18812 instantiation has no effect. */
18814 }
18816 {
18817 /* [temp.spec]
18819 No program shall explicitly instantiate any template more
18820 than once.
18822 We check DECL_NOT_REALLY_EXTERN so as not to complain when
18823 the first instantiation was `extern' and the second is not,
18824 and EXTERN_P for the opposite case. */
18827 /* If an "extern" explicit instantiation follows an ordinary
18828 explicit instantiation, the template is instantiated. */
18831 }
18833 {
18836 }
18838 {
18841 }
18844 ;
18846 {
18849 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
18852 }
18853 else
18861 }
18863 static void
18865 {
18871 {
18874 }
18875 }
18877 /* Called from do_type_instantiation through binding_table_foreach to
18878 do recursive instantiation for the type bound in ENTRY. */
18879 static void
18881 {
18887 }
18889 /* Called from do_type_instantiation to instantiate a member
18890 (a member function or a static member variable) of an
18891 explicitly instantiated class template. */
18892 static void
18894 {
18899 }
18901 /* Perform an explicit instantiation of template class T. STORAGE, if
18902 non-null, is the RID for extern, inline or static. COMPLAIN is
18903 nonzero if this is called from the parser, zero if called recursively,
18904 since the standard is unclear (as detailed below). */
18906 void
18908 {
18918 {
18919 tree tmpl =
18923 else
18926 }
18931 {
18934 t);
18936 }
18939 {
18941 {
18943 {
18946 "ISO C++ 1998 forbids the use of %<extern%> on "
18948 }
18949 else
18951 "ISO C++ forbids the use of %qE"
18953 }
18961 else
18962 {
18964 storage);
18966 }
18967 }
18970 {
18971 /* DR 259 [temp.spec].
18973 Both an explicit instantiation and a declaration of an explicit
18974 specialization shall not appear in a program unless the explicit
18975 instantiation follows a declaration of the explicit specialization.
18977 For a given set of template parameters, if an explicit
18978 instantiation of a template appears after a declaration of an
18979 explicit specialization for that template, the explicit
18980 instantiation has no effect. */
18982 }
18984 {
18985 /* [temp.spec]
18987 No program shall explicitly instantiate any template more
18988 than once.
18990 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18991 instantiation was `extern'. If EXTERN_P then the second is.
18992 These cases are OK. */
18999 /* If we've already instantiated the template, just return now. */
19002 }
19010 {
19011 tree tmp;
19013 /* In contrast to implicit instantiation, where only the
19014 declarations, and not the definitions, of members are
19015 instantiated, we have here:
19017 [temp.explicit]
19019 The explicit instantiation of a class template specialization
19020 implies the instantiation of all of its members not
19021 previously explicitly specialized in the translation unit
19022 containing the explicit instantiation.
19024 Of course, we can't instantiate member template classes, since
19025 we don't have any arguments for them. Note that the standard
19026 is unclear on whether the instantiation of the members are
19027 *explicit* instantiations or not. However, the most natural
19028 interpretation is that it should be an explicit instantiation. */
19043 }
19044 }
19046 /* Given a function DECL, which is a specialization of TMPL, modify
19047 DECL to be a re-instantiation of TMPL with the same template
19048 arguments. TMPL should be the template into which tsubst'ing
19049 should occur for DECL, not the most general template.
19051 One reason for doing this is a scenario like this:
19053 template <class T>
19054 void f(const T&, int i);
19056 void g() { f(3, 7); }
19058 template <class T>
19059 void f(const T& t, const int i) { }
19061 Note that when the template is first instantiated, with
19062 instantiate_template, the resulting DECL will have no name for the
19063 first parameter, and the wrong type for the second. So, when we go
19064 to instantiate the DECL, we regenerate it. */
19066 static void
19068 {
19069 /* The arguments used to instantiate DECL, from the most general
19070 template. */
19071 tree args;
19072 tree code_pattern;
19077 /* Make sure that we can see identifiers, and compute access
19078 correctly. */
19082 {
19083 tree decl_parm;
19084 tree pattern_parm;
19085 tree specs;
19099 specs);
19101 /* Merge parameter declarations. */
19104 pattern_parm
19108 {
19109 tree parm_type;
19110 tree attributes;
19115 NULL_TREE);
19121 {
19124 }
19127 }
19128 /* Merge any parameters that match with the function parameter
19129 pack. */
19131 {
19133 tree expanded_types;
19134 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19135 the parameters in this function parameter pack. */
19140 {
19141 tree parm_type;
19142 tree attributes;
19145 /* Rename the parameter to include the index. */
19154 {
19157 }
19159 }
19160 }
19161 /* Merge additional specifiers from the CODE_PATTERN. */
19165 }
19167 {
19175 }
19176 else
19180 }
19182 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19183 substituted to get DECL. */
19185 tree
19187 {
19190 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19191 for the instantiation. This is not always the most general
19192 template. Consider, for example:
19194 template <class T>
19195 struct S { template <class U> void f();
19196 template <> void f<int>(); };
19198 and an instantiation of S<double>::f<int>. We want TD to be the
19199 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19201 more general template. */
19203 /* We must also deal with friend templates. Given:
19205 template <class T> struct S {
19206 template <class U> friend void f() {};
19207 };
19209 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19210 so far as the language is concerned, but that's still
19211 where we get the pattern for the instantiation from. On
19212 other hand, if the definition comes outside the class, say:
19214 template <class T> struct S {
19215 template <class U> friend void f();
19216 };
19217 template <class U> friend void f() {}
19219 we don't need to look any further. That's what the check for
19220 DECL_INITIAL is for. */
19224 {
19225 /* The present template, TD, should not be a definition. If it
19226 were a definition, we should be using it! Note that we
19227 cannot restructure the loop to just keep going until we find
19228 a template with a definition, since that might go too far if
19229 a specialization was declared, but not defined. */
19233 /* Fetch the more general template. */
19235 }
19238 }
19240 /* Returns true if we need to instantiate this template instance even if we
19241 know we aren't going to emit it.. */
19243 bool
19245 {
19246 /* We always instantiate inline functions so that we can inline them. An
19247 explicit instantiation declaration prohibits implicit instantiation of
19248 non-inline functions. With high levels of optimization, we would
19249 normally inline non-inline functions -- but we're not allowed to do
19250 that for "extern template" functions. Therefore, we check
19251 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19255 /* And we need to instantiate static data members so that
19256 their initializers are available in integral constant
19257 expressions. */
19260 }
19262 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19263 instantiate it now, modifying TREE_TYPE (fn). */
19265 void
19267 {
19281 {
19283 {
19298 }
19299 else
19301 }
19302 else
19303 {
19304 /* This is an implicitly declared function, so NOEX is a list of
19305 other functions to evaluate and merge. */
19306 tree elt;
19309 {
19311 tree subspec;
19315 }
19316 }
19321 {
19324 else
19326 }
19327 }
19329 /* Produce the definition of D, a _DECL generated from a template. If
19330 DEFER_OK is nonzero, then we don't have to actually do the
19331 instantiation now; we just have to do it sometime. Normally it is
19332 an error if this is an explicit instantiation but D is undefined.
19333 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19334 explicitly instantiated class template. */
19336 tree
19339 {
19341 tree gen_args;
19342 tree args;
19343 tree td;
19344 tree code_pattern;
19345 tree spec;
19346 tree gen_tmpl;
19352 tree fn_context;
19355 /* This function should only be used to instantiate templates for
19356 functions and static member variables. */
19359 /* Variables are never deferred; if instantiation is required, they
19360 are instantiated right away. That allows for better code in the
19361 case that an expression refers to the value of the variable --
19362 if the variable has a constant value the referring expression can
19363 take advantage of that fact. */
19368 /* Don't instantiate cloned functions. Instead, instantiate the
19369 functions they cloned. */
19377 /* D has already been instantiated or explicitly specialized, so
19378 there's nothing for us to do here.
19380 It might seem reasonable to check whether or not D is an explicit
19381 instantiation, and, if so, stop here. But when an explicit
19382 instantiation is deferred until the end of the compilation,
19383 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19384 the instantiation. */
19387 /* Check to see whether we know that this template will be
19388 instantiated in some other file, as with "extern template"
19389 extension. */
19392 /* In general, we do not instantiate such templates. */
19400 /* We should already have the extra args. */
19403 /* And what's in the hash table should match D. */
19407 /* This needs to happen before any tsubsting. */
19413 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19414 for the instantiation. */
19418 /* We should never be trying to instantiate a member of a class
19419 template or partial specialization. */
19424 /* In the case of a friend template whose definition is provided
19425 outside the class, we may have too many arguments. Drop the
19426 ones we don't need. The same is true for specializations. */
19427 args = get_innermost_template_args
19429 else
19435 else
19438 /* We may be in the middle of deferred access check. Disable it now. */
19441 /* Unless an explicit instantiation directive has already determined
19442 the linkage of D, remember that a definition is available for
19443 this entity. */
19453 /* If D is a member of an explicitly instantiated class template,
19454 and no definition is available, treat it like an implicit
19455 instantiation. */
19458 {
19459 /* Leave linkage flags alone on instantiations with anonymous
19460 visibility. */
19462 {
19465 }
19467 }
19472 /* Defer all other templates, unless we have been explicitly
19473 forbidden from doing so. */
19475 template. */
19476 ! pattern_defined
19477 /* If it's OK to postpone instantiation, do so. */
19478 || defer_ok
19479 /* If this is a static data member that will be defined
19480 elsewhere, we don't want to instantiate the entire data
19481 member, but we do want to instantiate the initializer so that
19482 we can substitute that elsewhere. */
19484 {
19485 /* The definition of the static data member is now required so
19486 we must substitute the initializer. */
19490 {
19491 tree ns;
19492 tree init;
19499 args,
19502 /* Make sure the initializer is still constant, in case of
19503 circular dependency (template/instantiate6.C). */
19504 const_init
19508 LOOKUP_ONLYCONVERTING);
19511 }
19513 /* We restore the source position here because it's used by
19514 add_pending_template. */
19520 /* [temp.explicit]
19522 The definition of a non-exported function template, a
19523 non-exported member function template, or a non-exported
19524 member function or static data member of a class template
19525 shall be present in every translation unit in which it is
19526 explicitly instantiated. */
19530 /* If we're in unevaluated context, we just wanted to get the
19531 constant value; this isn't an odr use, so don't queue
19532 a full instantiation. */
19535 /* ??? Historically, we have instantiated inline functions, even
19536 when marked as "extern template". */
19540 }
19541 /* Tell the repository that D is available in this translation unit
19542 -- and see if it is supposed to be instantiated here. */
19544 {
19545 /* In a PCH file, despite the fact that the repository hasn't
19546 requested instantiation in the PCH it is still possible that
19547 an instantiation will be required in a file that includes the
19548 PCH. */
19551 /* Instantiate inline functions so that the inliner can do its
19552 job, even though we'll not be emitting a copy of this
19553 function. */
19556 }
19562 else
19563 {
19568 }
19570 /* Mark D as instantiated so that recursive calls to
19571 instantiate_decl do not try to instantiate it again. */
19574 /* Regenerate the declaration in case the template has been modified
19575 by a subsequent redeclaration. */
19578 /* We already set the file and line above. Reset them now in case
19579 they changed as a result of calling regenerate_decl_from_template. */
19583 {
19584 tree init;
19587 /* Clear out DECL_RTL; whatever was there before may not be right
19588 since we've reset the type of the declaration. */
19592 /* The initializer is placed in DECL_INITIAL by
19593 regenerate_decl_from_template so we don't need to
19594 push/pop_access_scope again here. Pull it out so that
19595 cp_finish_decl can process it. */
19600 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19601 initializer. That function will defer actual emission until
19602 we have a chance to determine linkage. */
19605 /* Enter the scope of D so that access-checking works correctly. */
19610 }
19614 {
19616 tree subst_decl;
19617 tree tmpl_parm;
19618 tree spec_parm;
19621 /* Save away the current list, in case we are instantiating one
19622 template from within the body of another. */
19625 /* Set up the list of local specializations. */
19628 /* Set up context. */
19632 else
19635 /* Some typedefs referenced from within the template code need to be
19636 access checked at template instantiation time, i.e now. These
19637 types were added to the template at parsing time. Let's get those
19638 and perform the access checks then. */
19640 gen_args);
19642 /* Create substitution entries for the parameters. */
19647 {
19651 }
19653 {
19655 {
19658 }
19659 else
19660 {
19661 /* Register the (value) argument pack as a specialization of
19662 TMPL_PARM, then move on. */
19665 }
19666 }
19669 /* Substitute into the body of the function. */
19673 else
19674 {
19679 /* Set the current input_location to the end of the function
19680 so that finish_function knows where we are. */
19681 input_location
19684 /* Remember if we saw an infinite loop in the template. */
19685 current_function_infinite_loop
19687 }
19689 /* We don't need the local specializations any more. */
19693 /* Finish the function. */
19697 else
19698 {
19701 }
19705 }
19707 /* We're not deferring instantiation any more. */
19715 out:
19725 }
19727 /* Run through the list of templates that we wish we could
19728 instantiate, and instantiate any we can. RETRIES is the
19729 number of times we retry pending template instantiation. */
19731 void
19733 {
19737 /* Instantiating templates may trigger vtable generation. This in turn
19738 may require further template instantiations. We place a limit here
19739 to avoid infinite loop. */
19741 {
19745 " instantiating %q+D, possibly from virtual table generation"
19749 /* Pretend that we defined it. */
19752 }
19754 do
19755 {
19760 {
19765 {
19766 tree fn;
19769 {
19773 fn;
19781 }
19784 }
19785 else
19786 {
19789 {
19790 instantiation
19796 }
19800 }
19803 /* If INSTANTIATION has been instantiated, then we don't
19804 need to consider it again in the future. */
19806 else
19807 {
19810 }
19813 }
19815 }
19819 }
19821 /* Substitute ARGVEC into T, which is a list of initializers for
19822 either base class or a non-static data member. The TREE_PURPOSEs
19823 are DECLs, and the TREE_VALUEs are the initializer values. Used by
19824 instantiate_decl. */
19826 static tree
19828 {
19832 {
19833 tree decl;
19834 tree init;
19840 {
19841 tree expr;
19842 tree arg;
19844 /* Expand the base class expansion type into separate base
19845 classes. */
19847 tf_warning_or_error,
19848 NULL_TREE);
19852 /* We'll be building separate TREE_LISTs of arguments for
19853 each base. */
19859 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
19860 expand each argument in the TREE_VALUE of t. */
19867 /* VOID_TYPE_NODE is used to indicate
19868 value-initialization. */
19869 {
19872 }
19873 else
19874 {
19875 /* Substitute parameter packs into each argument in the
19876 TREE_LIST. */
19879 {
19880 tree expanded_exprs;
19882 /* Expand the argument. */
19884 expanded_exprs
19886 tf_warning_or_error,
19887 NULL_TREE);
19891 /* Prepend each of the expanded expressions to the
19892 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
19894 {
19899 }
19900 }
19903 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
19904 since we built them backwards. */
19906 {
19909 }
19910 }
19911 }
19914 {
19916 {
19920 }
19921 else
19922 {
19923 tree tmp;
19938 /* If we had an initializer but it instantiated to nothing,
19939 value-initialize the object. This will only occur when
19940 the initializer was a pack expansion where the parameter
19941 packs used in that expansion were of length zero. */
19944 }
19947 {
19951 }
19952 }
19953 }
19955 }
19957 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19959 static void
19961 {
19966 else
19968 }
19970 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19971 is the instantiation (which should have been created with
19972 start_enum) and ARGS are the template arguments to use. */
19974 static void
19976 {
19977 tree e;
19983 {
19984 tree value;
19985 tree decl;
19988 /* Note that in a template enum, the TREE_VALUE is the
19989 CONST_DECL, not the corresponding INTEGER_CST. */
19994 /* Give this enumeration constant the correct access. */
19997 /* Actually build the enumerator itself. */
19998 build_enumerator
20000 }
20010 }
20012 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20013 its type -- but without substituting the innermost set of template
20014 arguments. So, innermost set of template parameters will appear in
20015 the type. */
20017 tree
20019 {
20020 tree fn_type;
20021 tree tmpl;
20022 tree targs;
20023 tree tparms;
20031 /* There should be as many levels of arguments as there are levels
20032 of parameters. */
20038 /* No substitution is necessary. */
20039 ;
20040 else
20041 {
20043 tree partial_args;
20045 /* Replace the innermost level of the TARGS with NULL_TREEs to
20046 let tsubst know not to substitute for those parameters. */
20055 /* Make sure that we can see identifiers, and compute access
20056 correctly. */
20060 /* Now, do the (partial) substitution to figure out the
20061 appropriate function type. */
20065 /* Substitute into the template parameters to obtain the real
20066 innermost set of parameters. This step is important if the
20067 innermost set of template parameters contains value
20068 parameters whose types depend on outer template parameters. */
20073 }
20076 }
20078 /* Return truthvalue if we're processing a template different from
20079 the last one involved in diagnostics. */
20080 int
20082 {
20084 }
20086 /* Remember current template involved in diagnostics. */
20087 void
20089 {
20091 }
20095 {
20097 }
20099 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20100 type. Return zero for ok, nonzero for disallowed. Issue error and
20101 warning messages under control of COMPLAIN. */
20103 static int
20105 {
20122 {
20125 else
20127 type);
20128 }
20130 }
20132 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20133 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20135 static bool
20137 {
20138 tree scope;
20140 /* [temp.dep.type]
20142 A type is dependent if it is:
20144 -- a template parameter. Template template parameters are types
20145 for us (since TYPE_P holds true for them) so we handle
20146 them here. */
20150 /* -- a qualified-id with a nested-name-specifier which contains a
20151 class-name that names a dependent type or whose unqualified-id
20152 names a dependent type. */
20155 /* -- a cv-qualified type where the cv-unqualified type is
20156 dependent. */
20158 /* -- a compound type constructed from any dependent type. */
20168 {
20169 tree arg_type;
20174 arg_type;
20179 }
20180 /* -- an array type constructed from any dependent type or whose
20181 size is specified by a constant expression that is
20182 value-dependent.
20184 We checked for type- and value-dependence of the bounds in
20185 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20187 {
20192 }
20194 /* -- a template-id in which either the template name is a template
20195 parameter ... */
20198 /* ... or any of the template arguments is a dependent type or
20199 an expression that is type-dependent or value-dependent. */
20201 && (any_dependent_template_arguments_p
20205 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20206 dependent; if the argument of the `typeof' expression is not
20207 type-dependent, then it should already been have resolved. */
20213 /* A template argument pack is dependent if any of its packed
20214 arguments are. */
20216 {
20222 }
20224 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20225 be template parameters. */
20229 /* The standard does not specifically mention types that are local
20230 to template functions or local classes, but they should be
20231 considered dependent too. For example:
20233 template <int I> void f() {
20234 enum E { a = I };
20235 S<sizeof (E)> s;
20236 }
20238 The size of `E' cannot be known until the value of `I' has been
20239 determined. Therefore, `E' must be considered dependent. */
20243 /* Don't use type_dependent_expression_p here, as it can lead
20244 to infinite recursion trying to determine whether a lambda
20245 nested in a lambda is dependent (c++/47687). */
20249 && (any_dependent_template_arguments_p
20253 /* Other types are non-dependent. */
20255 }
20257 /* Returns TRUE if TYPE is dependent, in the sense of
20258 [temp.dep.type]. Note that a NULL type is considered dependent. */
20260 bool
20262 {
20263 /* If there are no template parameters in scope, then there can't be
20264 any dependent types. */
20266 {
20267 /* If we are not processing a template, then nobody should be
20268 providing us with a dependent type. */
20272 }
20274 /* If the type is NULL, we have not computed a type for the entity
20275 in question; in that case, the type is dependent. */
20279 /* Erroneous types can be considered non-dependent. */
20283 /* If we have not already computed the appropriate value for TYPE,
20284 do so now. */
20286 {
20289 }
20292 }
20294 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20295 lookup. In other words, a dependent type that is not the current
20296 instantiation. */
20298 bool
20300 {
20303 }
20305 /* T is a SCOPE_REF; return whether we need to consider it
20306 instantiation-dependent so that we can check access at instantiation
20307 time even though we know which member it resolves to. */
20309 static bool
20311 {
20317 else
20319 }
20321 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20322 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20323 expression. */
20325 /* Note that this predicate is not appropriate for general expressions;
20326 only constant expressions (that satisfy potential_constant_expression)
20327 can be tested for value dependence. */
20329 bool
20331 {
20335 /* A name declared with a dependent type. */
20340 {
20342 /* A name that has not been looked up -- must be dependent. */
20346 /* A non-type template parm. */
20350 /* A non-type template parm. */
20356 /* A constant with literal type and is initialized
20357 with an expression that is value-dependent.
20359 Note that a non-dependent parenthesized initializer will have
20360 already been replaced with its constant value, so if we see
20361 a TREE_LIST it must be dependent. */
20374 /* These expressions are value-dependent if the type to which
20375 the cast occurs is dependent or the expression being casted
20376 is value-dependent. */
20377 {
20383 /* A functional cast has a list of operands. */
20386 {
20387 /* If there are no operands, it must be an expression such
20388 as "int()". This should not happen for aggregate types
20389 because it would form non-constant expressions. */
20394 }
20400 }
20405 /* FALLTHRU */
20408 /* A `sizeof' expression is value-dependent if the operand is
20409 type-dependent or is a pack expansion. */
20418 /* An 'encode' expression is value-dependent if the operand is
20419 type-dependent. */
20428 /* All instantiation-dependent expressions should also be considered
20429 value-dependent. */
20437 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20438 is value-dependent. */
20439 {
20448 }
20451 {
20455 }
20466 {
20470 }
20473 {
20480 {
20482 /* In a call to a constexpr member function, look through the
20483 implicit ADDR_EXPR on the object argument so that it doesn't
20484 cause the call to be considered value-dependent. We also
20485 look through it in potential_constant_expression. */
20492 }
20494 }
20497 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20498 type-dependent. */
20502 {
20504 tree val;
20509 }
20512 /* Treat a GNU statement expression as dependent to avoid crashing
20513 under fold_non_dependent_expr; it can't be constant. */
20517 /* A constant expression is value-dependent if any subexpression is
20518 value-dependent. */
20520 {
20527 {
20531 {
20534 /* In some cases, some of the operands may be missing.l
20535 (For example, in the case of PREDECREMENT_EXPR, the
20536 amount to increment by may be missing.) That doesn't
20537 make the expression dependent. */
20540 }
20541 }
20545 }
20547 }
20549 /* The expression is not value-dependent. */
20551 }
20553 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20554 [temp.dep.expr]. Note that an expression with no type is
20555 considered dependent. Other parts of the compiler arrange for an
20556 expression with type-dependent subexpressions to have no type, so
20557 this function doesn't have to be fully recursive. */
20559 bool
20561 {
20568 /* An unresolved name is always dependent. */
20572 /* Some expression forms are never type-dependent. */
20585 /* The types of these expressions depends only on the type to which
20586 the cast occurs. */
20595 /* The types of these expressions depends only on the type created
20596 by the expression. */
20599 {
20600 /* For NEW_EXPR tree nodes created inside a template, either
20601 the object type itself or a TREE_LIST may appear as the
20602 operand 1. */
20605 /* This is an array type. We need to check array dimensions
20606 as well. */
20608 || value_dependent_expression_p
20610 else
20612 }
20615 {
20619 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20620 contains an identifier associated by name lookup with one or more
20621 declarations declared with a dependent type, or...a
20622 nested-name-specifier or qualified-id that names a member of an
20623 unknown specialization. */
20626 }
20631 && (any_dependent_template_arguments_p
20643 {
20644 tree elt;
20648 {
20651 }
20653 }
20655 /* A static data member of the current instantiation with incomplete
20656 array type is type-dependent, as the definition and specializations
20657 can have different bounds. */
20664 /* An array of unknown bound depending on a variadic parameter, eg:
20666 template<typename... Args>
20667 void foo (Args... args)
20668 {
20669 int arr[] = { args... };
20670 }
20672 template<int... vals>
20673 void bar ()
20674 {
20675 int arr[] = { vals... };
20676 }
20678 If the array has no length and has an initializer, it must be that
20679 we couldn't determine its length in cp_complete_array_type because
20680 it is dependent. */
20688 {
20693 {
20699 }
20700 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
20704 /* Always dependent, on the number of arguments if nothing else. */
20712 {
20717 }
20722 {
20726 }
20728 }
20733 }
20735 /* walk_tree callback function for instantiation_dependent_expression_p,
20736 below. Returns non-zero if a dependent subexpression is found. */
20738 static tree
20741 {
20743 {
20744 /* We don't have to worry about decltype currently because decltype
20745 of an instantiation-dependent expr is a dependent type. This
20746 might change depending on the resolution of DR 1172. */
20749 }
20752 {
20753 /* Don't treat an argument list as dependent just because it has no
20754 TREE_TYPE. */
20761 /* A constant with a dependent initializer is dependent. */
20769 /* Handle expressions with type operands. */
20774 {
20779 {
20782 else
20783 {
20786 }
20787 }
20789 }
20801 /* In a template, finish_class_member_access_expr creates a
20802 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
20803 type-dependent, so that we can check access control at
20804 instantiation time (PR 42277). See also Core issue 1273. */
20811 else
20814 /* Treat statement-expressions as dependent. */
20820 }
20824 else
20826 }
20828 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
20829 sense defined by the ABI:
20831 "An expression is instantiation-dependent if it is type-dependent
20832 or value-dependent, or it has a subexpression that is type-dependent
20833 or value-dependent." */
20835 bool
20837 {
20838 tree result;
20849 }
20851 /* Like type_dependent_expression_p, but it also works while not processing
20852 a template definition, i.e. during substitution or mangling. */
20854 bool
20856 {
20862 }
20864 /* Returns TRUE if ARGS contains a type-dependent expression. */
20866 bool
20868 {
20870 tree arg;
20873 {
20876 }
20878 }
20880 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20881 expressions) contains any type-dependent expressions. */
20883 bool
20885 {
20891 }
20893 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20894 expressions) contains any value-dependent expressions. */
20896 bool
20898 {
20904 }
20906 /* Returns TRUE if the ARG (a template argument) is dependent. */
20908 bool
20910 {
20914 /* Assume a template argument that was wrongly written by the user
20915 is dependent. This is consistent with what
20916 any_dependent_template_arguments_p [that calls this function]
20917 does. */
20928 {
20932 {
20935 }
20938 }
20941 else
20944 }
20946 /* Returns true if ARGS (a collection of template arguments) contains
20947 any types that require structural equality testing. */
20949 bool
20951 {
20961 {
20964 {
20970 {
20971 /* Look inside the argument pack. */
20974 }
20977 {
20990 }
20991 }
20992 }
20995 }
20997 /* Returns true if ARGS (a collection of template arguments) contains
20998 any dependent arguments. */
21000 bool
21002 {
21012 {
21017 }
21020 }
21022 /* Returns TRUE if the template TMPL is dependent. */
21024 bool
21026 {
21028 {
21030 {
21034 }
21036 }
21038 /* Template template parameters are dependent. */
21042 /* So are names that have not been looked up. */
21045 /* So are member templates of dependent classes. */
21049 }
21051 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21053 bool
21055 {
21058 }
21060 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21061 is dependent. */
21063 bool
21065 {
21072 {
21093 {
21097 }
21101 {
21105 {
21110 }
21111 }
21112 }
21115 }
21117 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21118 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21119 no such TYPE can be found. Note that this function peers inside
21120 uninstantiated templates and therefore should be used only in
21121 extremely limited situations. ONLY_CURRENT_P restricts this
21122 peering to the currently open classes hierarchy (which is required
21123 when comparing types). */
21125 tree
21127 {
21128 tree scope;
21129 tree name;
21130 tree decl;
21132 tree pushed_scope;
21133 tree result;
21138 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21139 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21140 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21141 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21142 identifier of the TYPENAME_TYPE anymore.
21143 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21144 TYPENAME_TYPE instead, we avoid messing up with a possible
21145 typedef variant case. */
21148 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21149 it first before we can figure out what NAME refers to. */
21151 {
21153 /* Given a class template A with a dependent base with nested type C,
21154 typedef typename A::C::C C will land us here, as trying to resolve
21155 the initial A::C leads to the local C typedef, which leads back to
21156 A::C::C. So we break the recursion now. */
21158 else
21160 }
21161 /* If we don't know what SCOPE refers to, then we cannot resolve the
21162 TYPENAME_TYPE. */
21165 /* If the SCOPE is a template type parameter, we have no way of
21166 resolving the name. */
21169 /* If the SCOPE is not the current instantiation, there's no reason
21170 to look inside it. */
21173 /* If this is a typedef, we don't want to look inside (c++/11987). */
21176 /* If SCOPE isn't the template itself, it will not have a valid
21177 TYPE_FIELDS list. */
21179 /* scope is either the template itself or a compatible instantiation
21180 like X<T>, so look up the name in the original template. */
21182 else
21183 /* scope is a partial instantiation, so we can't do the lookup or we
21184 will lose the template arguments. */
21186 /* Enter the SCOPE so that name lookup will be resolved as if we
21187 were in the class definition. In particular, SCOPE will no
21188 longer be considered a dependent type. */
21190 /* Look up the declaration. */
21192 tf_warning_or_error);
21196 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21197 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21202 {
21206 }
21209 {
21210 tree tmpl;
21211 tree args;
21212 /* Obtain the template and the arguments. */
21215 /* Instantiate the template. */
21221 }
21223 /* Leave the SCOPE. */
21227 /* If we failed to resolve it, return the original typename. */
21231 /* If lookup found a typename type, resolve that too. */
21233 {
21234 /* Ill-formed programs can cause infinite recursion here, so we
21235 must catch that. */
21239 }
21241 /* Qualify the resulting type. */
21247 }
21249 /* EXPR is an expression which is not type-dependent. Return a proxy
21250 for EXPR that can be used to compute the types of larger
21251 expressions containing EXPR. */
21253 tree
21255 {
21256 tree inner_expr;
21258 #ifdef ENABLE_CHECKING
21259 /* Try to get a constant value for all non-dependent expressions in
21260 order to expose bugs in *_dependent_expression_p and constexpr. */
21263 #endif
21265 /* Preserve OVERLOADs; the functions must be available to resolve
21266 types. */
21277 /* There is no need to return a proxy for a variable. */
21280 /* Preserve string constants; conversions from string constants to
21281 "char *" are allowed, even though normally a "const char *"
21282 cannot be used to initialize a "char *". */
21285 /* Preserve arithmetic constants, as an optimization -- there is no
21286 reason to create a new node. */
21289 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21290 There is at least one place where we want to know that a
21291 particular expression is a throw-expression: when checking a ?:
21292 expression, there are special rules if the second or third
21293 argument is a throw-expression. */
21297 /* Don't wrap an initializer list, we need to be able to look inside. */
21301 /* Don't wrap a dummy object, we need to be able to test for it. */
21320 /* If the type is unknown, it can't really be non-dependent */
21323 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21325 }
21327 /* ARGS is a vector of expressions as arguments to a function call.
21328 Replace the arguments with equivalent non-dependent expressions.
21329 This modifies ARGS in place. */
21331 void
21333 {
21335 tree arg;
21338 {
21342 }
21343 }
21345 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21346 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21347 parms. */
21349 static tree
21351 {
21364 }
21366 tree
21368 {
21370 }
21372 tree
21374 {
21376 }
21378 /* Given type ARG, return std::initializer_list<ARG>. */
21380 static tree
21382 {
21383 tree std_init_list = namespace_binding
21385 tree argvec;
21387 {
21391 }
21396 }
21398 /* Replace auto in TYPE with std::initializer_list<auto>. */
21400 static tree
21402 {
21409 }
21411 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21412 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21414 tree
21416 {
21417 tree targs;
21423 /* Defining a subset of type-dependent expressions that we can deduce
21424 from ahead of time isn't worth the trouble. */
21427 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21428 with either a new invented type template parameter U or, if the
21429 initializer is a braced-init-list (8.5.4), with
21430 std::initializer_list<U>. */
21438 {
21443 {
21446 }
21447 }
21448 else
21449 {
21460 {
21462 /* Try again at instantiation time. */
21465 /* If type is error_mark_node a diagnostic must have been
21466 emitted by now. Also, having a mention to '<type error>'
21467 in the diagnostic is not really useful to the user. */
21468 {
21472 else
21474 }
21476 }
21477 }
21479 /* If the list of declarators contains more than one declarator, the type
21480 of each declared variable is determined as described above. If the
21481 type deduced for the template parameter U is not the same in each
21482 deduction, the program is ill-formed. */
21485 {
21491 else
21495 }
21501 }
21503 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21504 result. */
21506 tree
21508 {
21509 tree argvec;
21516 /* For a late-specified return type in a template type-parameter, we
21517 need to add a dummy argument level for its parmlist. */
21518 argvec = add_to_template_args
21523 }
21525 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21526 'decltype(auto)'. */
21528 bool
21530 {
21535 else
21537 }
21539 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21540 a use of `auto'. Returns NULL_TREE otherwise. */
21542 tree
21544 {
21546 }
21548 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21549 'decltype(auto)' or a concept. */
21551 bool
21553 {
21555 }
21557 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21558 a concept identifier) iff TYPE contains a use of a generic type. Returns
21559 NULL_TREE otherwise. */
21561 tree
21563 {
21565 }
21568 /* For a given template T, return the vector of typedefs referenced
21569 in T for which access check is needed at T instantiation time.
21570 T is either a FUNCTION_DECL or a RECORD_TYPE.
21571 Those typedefs were added to T by the function
21572 append_type_to_template_for_access_check. */
21576 {
21577 tree ti;
21588 {
21593 }
21596 }
21598 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21599 tied to T. That list of typedefs will be access checked at
21600 T instantiation time.
21601 T is either a FUNCTION_DECL or a RECORD_TYPE.
21602 TYPE_DECL is a TYPE_DECL node representing a typedef.
21603 SCOPE is the scope through which TYPE_DECL is accessed.
21604 LOCATION is the location of the usage point of TYPE_DECL.
21606 This function is a subroutine of
21607 append_type_to_template_for_access_check. */
21609 static void
21611 tree type_decl,
21612 tree scope,
21613 location_t location)
21614 {
21615 qualified_typedef_usage_t typedef_usage;
21616 tree ti;
21623 && type_decl
21637 }
21639 /* Append TYPE_DECL to the template TEMPL.
21640 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21641 At TEMPL instanciation time, TYPE_DECL will be checked to see
21642 if it can be accessed through SCOPE.
21643 LOCATION is the location of the usage point of TYPE_DECL.
21645 e.g. consider the following code snippet:
21647 class C
21648 {
21649 typedef int myint;
21650 };
21652 template<class U> struct S
21653 {
21654 C::myint mi; // <-- usage point of the typedef C::myint
21655 };
21657 S<char> s;
21659 At S<char> instantiation time, we need to check the access of C::myint
21660 In other words, we need to check the access of the myint typedef through
21661 the C scope. For that purpose, this function will add the myint typedef
21662 and the scope C through which its being accessed to a list of typedefs
21663 tied to the template S. That list will be walked at template instantiation
21664 time and access check performed on each typedefs it contains.
21665 Note that this particular code snippet should yield an error because
21666 myint is private to C. */
21668 void
21670 tree type_decl,
21671 tree scope,
21672 location_t location)
21673 {
21679 /* Make sure we don't append the type to the template twice. */
21686 }
21688 /* Convert the generic type parameters in PARM that match the types given in the
21689 range [START_IDX, END_IDX) from the current_template_parms into generic type
21690 packs. */
21692 tree
21694 {
21705 {
21706 /* Create a distinct parameter pack type from the current parm and add it
21707 to the replacement args to tsubst below into the generic function
21708 parameter. */
21723 }
21729 /* If there are more levels then build up the replacement with the outer
21730 template parms. */
21734 replacement);
21737 }
21740 /* Set up the hash tables for template instantiations. */
21742 void
21744 {
21746 hash_specialization,
21747 eq_specializations,
21748 ggc_free);
21750 hash_specialization,
21751 eq_specializations,
21752 ggc_free);
21753 }
21755 /* Print stats about the template hash tables for -fstats. */
21757 void
21759 {
21768 }