| blob | dd453c526cc18a353b968dd7dcc582c8333853cf |
1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
50 /* The type of functions taking a tree, and some additional data, and
51 returning an int. */
54 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
55 instantiations have been deferred, either because their definitions
56 were not yet available, or because we were putting off doing the work. */
60 };
75 /* Live only within one (recursive) call to tsubst_expr. We use
76 this to pass the statement expression node from the STMT_EXPR
77 to the EXPR_STMT that is its result. */
80 /* A map from local variable declarations in the body of the template
81 presently being instantiated to the corresponding instantiated
82 local variables. */
86 {
87 tree tmpl;
88 tree args;
89 tree spec;
93 htab_t decl_specializations;
96 htab_t type_specializations;
98 /* Contains canonical template parameter types. The vector is indexed by
99 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
100 TREE_LIST, whose TREE_VALUEs contain the canonical template
101 parameters of various types and levels. */
104 #define UNIFY_ALLOW_NONE 0
105 #define UNIFY_ALLOW_MORE_CV_QUAL 1
106 #define UNIFY_ALLOW_LESS_CV_QUAL 2
107 #define UNIFY_ALLOW_DERIVED 4
108 #define UNIFY_ALLOW_INTEGER 8
109 #define UNIFY_ALLOW_OUTER_LEVEL 16
110 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
111 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
133 tree);
198 /* Make the current scope suitable for access checking when we are
199 processing T. T can be FUNCTION_DECL for instantiated function
200 template, or VAR_DECL for static member variable (need by
201 instantiate_decl). */
203 static void
205 {
213 else
217 {
218 saved_access_scope = tree_cons
221 }
222 }
224 /* Restore the scope set up by push_access_scope. T is the node we
225 are processing. */
227 static void
229 {
231 {
234 }
238 else
240 }
242 /* Do any processing required when DECL (a member template
243 declaration) is finished. Returns the TEMPLATE_DECL corresponding
244 to DECL, unless it is a specialization, in which case the DECL
245 itself is returned. */
247 tree
249 {
256 {
257 tree type;
265 {
269 }
271 }
275 {
277 {
280 }
281 else
283 }
284 else
288 }
290 /* Return the template info node corresponding to T, whatever T is. */
292 tree
294 {
310 }
312 /* Returns the template nesting level of the indicated class TYPE.
314 For example, in:
315 template <class T>
316 struct A
317 {
318 template <class U>
319 struct B {};
320 };
322 A<T>::B<U> has depth two, while A<T> has depth one.
323 Both A<T>::B<int> and A<int>::B<U> have depth one, if
324 they are instantiations, not specializations.
326 This function is guaranteed to return 0 if passed NULL_TREE so
327 that, for example, `template_class_depth (current_class_type)' is
328 always safe. */
330 int
332 {
339 {
345 }
348 }
350 /* Subroutine of maybe_begin_member_template_processing.
351 Returns true if processing DECL needs us to push template parms. */
353 static bool
355 {
361 }
363 /* Subroutine of maybe_begin_member_template_processing.
364 Push the template parms in PARMS, starting from LEVELS steps into the
365 chain, and ending at the beginning, since template parms are listed
366 innermost first. */
368 static void
370 {
378 current_template_parms
384 NULL);
386 {
395 {
402 {
403 /* Make a CONST_DECL as is done in process_template_parm.
404 It is ugly that we recreate this here; the original
405 version built in process_template_parm is no longer
406 available. */
416 }
421 }
422 }
423 }
425 /* Restore the template parameter context for a member template or
426 a friend template defined in a class definition. */
428 void
430 {
431 tree parms;
435 {
440 {
443 }
446 }
448 /* Remember how many levels of template parameters we pushed so that
449 we can pop them later. */
451 }
453 /* Undo the effects of maybe_begin_member_template_processing. */
455 void
457 {
466 {
470 }
471 }
473 /* Return a new template argument vector which contains all of ARGS,
474 but has as its innermost set of arguments the EXTRA_ARGS. */
476 static tree
478 {
479 tree new_args;
494 }
496 /* Like add_to_template_args, but only the outermost ARGS are added to
497 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
498 (EXTRA_ARGS) levels are added. This function is used to combine
499 the template arguments from a partial instantiation with the
500 template arguments used to attain the full instantiation from the
501 partial instantiation. */
503 static tree
505 {
506 tree new_args;
508 /* If there are more levels of EXTRA_ARGS than there are ARGS,
509 something very fishy is going on. */
512 /* If *all* the new arguments will be the EXTRA_ARGS, just return
513 them. */
517 /* For the moment, we make ARGS look like it contains fewer levels. */
522 /* Now, we restore ARGS to its full dimensions. */
526 }
528 /* Return the N levels of innermost template arguments from the ARGS. */
530 tree
532 {
533 tree new_args;
539 /* If N is 1, just return the innermost set of template arguments. */
543 /* If we're not removing anything, just return the arguments we were
544 given. */
550 /* Make a new set of arguments, not containing the outer arguments. */
557 }
559 /* The inverse of get_innermost_template_args: Return all but the innermost
560 EXTRA_LEVELS levels of template arguments from the ARGS. */
562 static tree
564 {
565 tree new_args;
571 /* If N is 1, just return the outermost set of template arguments. */
575 /* If we're not removing anything, just return the arguments we were
576 given. */
581 /* Make a new set of arguments, not containing the inner arguments. */
588 }
590 /* We've got a template header coming up; push to a new level for storing
591 the parms. */
593 void
595 {
596 /* We use a non-tag-transparent scope here, which causes pushtag to
597 put tags in this scope, rather than in the enclosing class or
598 namespace scope. This is the right thing, since we want
599 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
600 global template class, push_template_decl handles putting the
601 TEMPLATE_DECL into top-level scope. For a nested template class,
602 e.g.:
604 template <class T> struct S1 {
605 template <class T> struct S2 {};
606 };
608 pushtag contains special code to call pushdecl_with_scope on the
609 TEMPLATE_DECL for S2. */
614 }
616 /* This routine is called when a specialization is declared. If it is
617 invalid to declare a specialization here, an error is reported and
618 false is returned, otherwise this routine will return true. */
620 static bool
622 {
625 /* [temp.expl.spec]
627 An explicit specialization shall be declared in the namespace of
628 which the template is a member, or, for member templates, in the
629 namespace of which the enclosing class or enclosing class
630 template is a member. An explicit specialization of a member
631 function, member class or static data member of a class template
632 shall be declared in the namespace of which the class template
633 is a member. */
635 {
638 }
640 /* [temp.expl.spec]
642 In an explicit specialization declaration for a member of a class
643 template or a member template that appears in namespace scope,
644 the member template and some of its enclosing class templates may
645 remain unspecialized, except that the declaration shall not
646 explicitly specialize a class member template if its enclosing
647 class templates are not explicitly specialized as well. */
649 {
652 }
655 }
657 /* We've just seen template <>. */
659 bool
661 {
665 }
667 /* Called at then end of processing a declaration preceded by
668 template<>. */
670 void
672 {
675 }
677 /* Any template <>'s that we have seen thus far are not referring to a
678 function specialization. */
680 void
682 {
685 }
687 /* We've just seen a template header. If SPECIALIZATION is nonzero,
688 it was of the form template <>. */
690 static void
692 {
694 template_header_count++;
695 }
697 /* We're beginning an explicit instantiation. */
699 void
701 {
704 }
707 void
709 {
712 }
714 /* An explicit specialization or partial specialization TMPL is being
715 declared. Check that the namespace in which the specialization is
716 occurring is permissible. Returns false iff it is invalid to
717 specialize TMPL in the current namespace. */
719 static bool
721 {
724 /* [tmpl.expl.spec]
726 An explicit specialization shall be declared in the namespace of
727 which the template is a member, or, for member templates, in the
728 namespace of which the enclosing class or enclosing class
729 template is a member. An explicit specialization of a member
730 function, member class or static data member of a class template
731 shall be declared in the namespace of which the class template is
732 a member. */
734 /* Same or super-using namespace. */
736 else
737 {
741 }
742 }
744 /* SPEC is an explicit instantiation. Check that it is valid to
745 perform this explicit instantiation in the current namespace. */
747 static void
749 {
750 tree ns;
752 /* DR 275: An explicit instantiation shall appear in an enclosing
753 namespace of its template. */
759 }
761 /* The TYPE is being declared. If it is a template type, that means it
762 is a partial specialization. Do appropriate error-checking. */
764 tree
766 {
767 tree context;
773 {
777 }
782 {
783 /* This is for ordinary explicit specialization and partial
784 specialization of a template class such as:
786 template <> class C<int>;
788 or:
790 template <class T> class C<T*>;
792 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
796 {
800 {
804 }
805 }
808 }
814 {
815 /* This is for an explicit specialization of member class
816 template according to [temp.expl.spec/18]:
818 template <> template <class U> class C<int>::D;
820 The context `C<int>' must be an implicit instantiation.
821 Otherwise this is just a member class template declared
822 earlier like:
824 template <> class C<int> { template <class U> class D; };
825 template <> template <class U> class C<int>::D;
827 In the first case, `C<int>::D' is a specialization of `C<T>::D'
828 while in the second case, `C<int>::D' is a primary template
829 and `C<T>::D' may not exist. */
833 {
834 tree t;
839 {
842 }
844 /* Check for invalid specialization after instantiation:
846 template <> template <> class C<int>::D<int>;
847 template <> template <class U> class C<int>::D; */
851 {
854 {
855 /* We already have a full specialization of this partial
856 instantiation. Reassign it to the new member
857 specialization template. */
858 spec_entry elt;
874 }
876 /* But if we've had an implicit instantiation, that's a
877 problem ([temp.expl.spec]/6). */
880 }
882 /* Mark TYPE as a specialization. And as a result, we only
883 have one level of template argument for the innermost
884 class template. */
888 }
889 }
891 {
894 }
897 }
899 /* Returns nonzero if we can optimize the retrieval of specializations
900 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
901 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
905 {
908 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
909 parameter. */
911 /* The optimized lookup depends on the fact that the
912 template arguments for the member function template apply
913 purely to the containing class, which is not true if the
914 containing class is an explicit or partial
915 specialization. */
919 /* It is possible to have a template that is not a member
920 template and is not a member of a template class:
922 template <typename T>
923 struct S { friend A::f(); };
925 Here, the friend function is a template, but the context does
926 not have template information. The optimized lookup relies
927 on having ARGS be the template arguments for both the class
928 and the function template. */
930 }
932 /* Retrieve the specialization (in the sense of [temp.spec] - a
933 specialization is either an instantiation or an explicit
934 specialization) of TMPL for the given template ARGS. If there is
935 no such specialization, return NULL_TREE. The ARGS are a vector of
936 arguments, or a vector of vectors of arguments, in the case of
937 templates with more than one level of parameters.
939 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
940 then we search for a partial specialization matching ARGS. This
941 parameter is ignored if TMPL is not a class template. */
943 static tree
945 {
951 /* There should be as many levels of arguments as there are
952 levels of parameters. */
957 {
958 tree class_template;
959 tree class_specialization;
961 tree fns;
964 /* The template arguments actually apply to the containing
965 class. Find the class specialization with those
966 arguments. */
968 class_specialization
972 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
973 for the specialization. */
977 /* Iterate through the methods with the indicated name, looking
978 for the one that has an instance of TMPL. */
981 {
984 /* using-declarations can add base methods to the method vec,
985 and we don't want those here. */
988 }
990 }
991 else
992 {
994 spec_entry elt;
995 htab_t specializations;
1003 else
1011 }
1014 }
1016 /* Like retrieve_specialization, but for local declarations. */
1018 static tree
1020 {
1021 tree spec;
1029 }
1031 /* Returns nonzero iff DECL is a specialization of TMPL. */
1033 int
1035 {
1036 tree t;
1039 {
1045 }
1046 else
1047 {
1056 }
1059 }
1061 /* Returns nonzero iff DECL is a specialization of friend declaration
1062 FRIEND_DECL according to [temp.friend]. */
1064 bool
1066 {
1073 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1074 of a template class, we want to check if DECL is a specialization
1075 if this. */
1079 {
1080 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1083 }
1088 /* There is nothing to do if this is not a template friend. */
1095 /* [temp.friend/6]
1096 A member of a class template may be declared to be a friend of a
1097 non-template class. In this case, the corresponding member of
1098 every specialization of the class template is a friend of the
1099 class granting friendship.
1101 For example, given a template friend declaration
1103 template <class T> friend void A<T>::f();
1105 the member function below is considered a friend
1107 template <> struct A<int> {
1108 void f();
1109 };
1111 For this type of template friend, TEMPLATE_DEPTH below will be
1112 nonzero. To determine if DECL is a friend of FRIEND, we first
1113 check if the enclosing class is a specialization of another. */
1120 {
1121 /* Next, we check the members themselves. In order to handle
1122 a few tricky cases, such as when FRIEND_DECL's are
1124 template <class T> friend void A<T>::g(T t);
1125 template <class T> template <T t> friend void A<T>::h();
1127 and DECL's are
1129 void A<int>::g(int);
1130 template <int> void A<int>::h();
1132 we need to figure out ARGS, the template arguments from
1133 the context of DECL. This is required for template substitution
1134 of `T' in the function parameter of `g' and template parameter
1135 of `h' in the above examples. Here ARGS corresponds to `int'. */
1142 {
1144 {
1147 else
1149 current_depth++;
1150 }
1152 }
1155 {
1157 tree friend_type;
1158 tree decl_type;
1159 tree friend_args_type;
1160 tree decl_args_type;
1162 /* Make sure that both DECL and FRIEND_DECL are templates or
1163 non-templates. */
1169 {
1170 /* If both are templates, check template parameter list. */
1171 tree friend_parms
1176 friend_parms))
1180 }
1181 else
1189 /* Check if return types match. */
1193 /* Check if function parameter types match, ignoring the
1194 `this' parameter. */
1203 }
1204 else
1205 {
1206 /* DECL is a TYPE_DECL */
1210 /* Make sure that both DECL and FRIEND_DECL are templates or
1211 non-templates. */
1212 is_template
1219 {
1220 tree friend_parms;
1221 /* If both are templates, check the name of the two
1222 TEMPLATE_DECL's first because is_friend didn't. */
1227 /* Now check template parameter list. */
1228 friend_parms
1231 return comp_template_parms
1233 friend_parms);
1234 }
1235 else
1238 }
1239 }
1241 }
1243 /* Register the specialization SPEC as a specialization of TMPL with
1244 the indicated ARGS. IS_FRIEND indicates whether the specialization
1245 is actually just a friend declaration. Returns SPEC, or an
1246 equivalent prior declaration, if available. */
1248 static tree
1250 hashval_t hash)
1251 {
1252 tree fn;
1254 spec_entry elt;
1260 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1261 register it; we want the corresponding TEMPLATE_DECL instead.
1262 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1263 the more obvious `uses_template_parms (spec)' to avoid problems
1264 with default function arguments. In particular, given
1265 something like this:
1267 template <class T> void f(T t1, T t = T())
1269 the default argument expression is not substituted for in an
1270 instantiation unless and until it is actually needed. */
1274 /* We don't put these specializations in the hash table, but we might
1275 want to give an error about a mismatch. */
1277 else
1278 {
1290 else
1292 }
1294 /* We can sometimes try to re-register a specialization that we've
1295 already got. In particular, regenerate_decl_from_template calls
1296 duplicate_decls which will update the specialization list. But,
1297 we'll still get called again here anyhow. It's more convenient
1298 to simply allow this than to try to prevent it. */
1302 {
1304 {
1307 {
1309 fn);
1311 }
1312 else
1313 {
1314 tree clone;
1315 /* This situation should occur only if the first
1316 specialization is an implicit instantiation, the
1317 second is an explicit specialization, and the
1318 implicit instantiation has not yet been used. That
1319 situation can occur if we have implicitly
1320 instantiated a member function and then specialized
1321 it later.
1323 We can also wind up here if a friend declaration that
1324 looked like an instantiation turns out to be a
1325 specialization:
1327 template <class T> void foo(T);
1328 class S { friend void foo<>(int) };
1329 template <> void foo(int);
1331 We transform the existing DECL in place so that any
1332 pointers to it become pointers to the updated
1333 declaration.
1335 If there was a definition for the template, but not
1336 for the specialization, we want this to look as if
1337 there were no definition, and vice versa. */
1340 /* The call to duplicate_decls will have applied
1341 [temp.expl.spec]:
1343 An explicit specialization of a function template
1344 is inline only if it is explicitly declared to be,
1345 and independently of whether its function template
1346 is.
1348 to the primary function; now copy the inline bits to
1349 the various clones. */
1351 {
1356 }
1360 }
1361 }
1363 {
1365 /* Dup decl failed, but this is a new definition. Set the
1366 line number so any errors match this new
1367 definition. */
1371 }
1372 }
1376 /* A specialization must be declared in the same namespace as the
1377 template it is specializing. */
1383 {
1390 /* TMPL is a forward declaration of a template function; keep a list
1391 of all specializations in case we need to reassign them to a friend
1392 template later in tsubst_friend_function. */
1395 }
1398 }
1400 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1401 TMPL and ARGS members, ignores SPEC. */
1403 static int
1405 {
1411 }
1413 /* Returns a hash for a template TMPL and template arguments ARGS. */
1415 static hashval_t
1417 {
1420 }
1422 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1423 ignoring SPEC. */
1425 static hashval_t
1427 {
1430 }
1432 /* Recursively calculate a hash value for a template argument ARG, for use
1433 in the hash tables of template specializations. */
1435 static hashval_t
1437 {
1454 {
1462 {
1467 }
1474 /* We can get one of these when re-hashing a previous entry in the middle
1475 of substituting into a pack expansion. Just look through it... */
1477 /* ...and fall through. */
1493 {
1496 {
1499 }
1501 }
1516 val = iterative_hash_template_arg
1528 val);
1530 val);
1540 {
1544 val);
1547 /* Otherwise just compare the types during lookup. */
1556 {
1561 }
1562 }
1563 }
1566 }
1568 /* Unregister the specialization SPEC as a specialization of TMPL.
1569 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1570 if the SPEC was listed as a specialization of TMPL.
1572 Note that SPEC has been ggc_freed, so we can't look inside it. */
1574 bool
1576 {
1578 spec_entry elt;
1586 {
1591 }
1594 }
1596 /* Compare an entry in the local specializations hash table P1 (which
1597 is really a pointer to a TREE_LIST) with P2 (which is really a
1598 DECL). */
1600 static int
1602 {
1604 }
1606 /* Hash P1, an entry in the local specializations table. */
1608 static hashval_t
1610 {
1612 }
1614 /* Like register_specialization, but for local declarations. We are
1615 registering SPEC, an instantiation of TMPL. */
1617 static void
1619 {
1625 }
1627 /* TYPE is a class type. Returns true if TYPE is an explicitly
1628 specialized class. */
1630 bool
1632 {
1636 }
1638 /* Print the list of candidate FNS in an error message. */
1640 void
1642 {
1643 tree fn;
1644 tree f;
1649 {
1651 {
1654 }
1655 }
1657 {
1661 }
1662 }
1664 /* Returns the template (one of the functions given by TEMPLATE_ID)
1665 which can be specialized to match the indicated DECL with the
1666 explicit template args given in TEMPLATE_ID. The DECL may be
1667 NULL_TREE if none is available. In that case, the functions in
1668 TEMPLATE_ID are non-members.
1670 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1671 specialization of a member template.
1673 The TEMPLATE_COUNT is the number of references to qualifying
1674 template classes that appeared in the name of the function. See
1675 check_explicit_specialization for a more accurate description.
1677 TSK indicates what kind of template declaration (if any) is being
1678 declared. TSK_TEMPLATE indicates that the declaration given by
1679 DECL, though a FUNCTION_DECL, has template parameters, and is
1680 therefore a template function.
1682 The template args (those explicitly specified and those deduced)
1683 are output in a newly created vector *TARGS_OUT.
1685 If it is impossible to determine the result, an error message is
1686 issued. The error_mark_node is returned to indicate failure. */
1688 static tree
1690 tree decl,
1694 tmpl_spec_kind tsk)
1695 {
1696 tree fns;
1697 tree targs;
1698 tree explicit_targs;
1700 /* A TREE_LIST of templates of which DECL may be a specialization.
1701 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1702 corresponding TREE_PURPOSE is the set of template arguments that,
1703 when used to instantiate the template, would produce a function
1704 with the signature of DECL. */
1720 /* Check for baselinks. */
1725 {
1728 }
1730 /* Count the number of template headers specified for this
1731 specialization. */
1739 {
1743 {
1744 tree decl_arg_types;
1745 tree fn_arg_types;
1747 /* In case of explicit specialization, we need to check if
1748 the number of template headers appearing in the specialization
1749 is correct. This is usually done in check_explicit_specialization,
1750 but the check done there cannot be exhaustive when specializing
1751 member functions. Consider the following code:
1753 template <> void A<int>::f(int);
1754 template <> template <> void A<int>::f(int);
1756 Assuming that A<int> is not itself an explicit specialization
1757 already, the first line specializes "f" which is a non-template
1758 member function, whilst the second line specializes "f" which
1759 is a template member function. So both lines are syntactically
1760 correct, and check_explicit_specialization does not reject
1761 them.
1763 Here, we can do better, as we are matching the specialization
1764 against the declarations. We count the number of template
1765 headers, and we check if they match TEMPLATE_COUNT + 1
1766 (TEMPLATE_COUNT is the number of qualifying template classes,
1767 plus there must be another header for the member template
1768 itself).
1770 Notice that if header_count is zero, this is not a
1771 specialization but rather a template instantiation, so there
1772 is no check we can perform here. */
1776 /* Check that the number of template arguments at the
1777 innermost level for DECL is the same as for FN. */
1785 /* DECL might be a specialization of FN. */
1789 /* For a non-static member function, we need to make sure
1790 that the const qualification is the same. Since
1791 get_bindings does not try to merge the "this" parameter,
1792 we must do the comparison explicitly. */
1798 /* Skip the "this" parameter and, for constructors of
1799 classes with virtual bases, the VTT parameter. A
1800 full specialization of a constructor will have a VTT
1801 parameter, but a template never will. */
1802 decl_arg_types
1804 fn_arg_types
1807 /* Check that the number of function parameters matches.
1808 For example,
1809 template <class T> void f(int i = 0);
1810 template <> void f<int>();
1811 The specialization f<int> is invalid but is not caught
1812 by get_bindings below. */
1816 /* Function templates cannot be specializations; there are
1817 no partial specializations of functions. Therefore, if
1818 the type of DECL does not match FN, there is no
1819 match. */
1821 {
1825 }
1827 /* See whether this function might be a specialization of this
1828 template. */
1832 /* We cannot deduce template arguments that when used to
1833 specialize TMPL will produce DECL. */
1836 /* Save this template, and the arguments deduced. */
1838 }
1840 /* FN is an ordinary member function, and we need a
1841 specialization of a member template. */
1842 ;
1844 /* We can get IDENTIFIER_NODEs here in certain erroneous
1845 cases. */
1846 ;
1848 /* This is just an ordinary non-member function. Nothing can
1849 be a specialization of that. */
1850 ;
1852 /* Cannot specialize functions that are created implicitly. */
1853 ;
1854 else
1855 {
1856 tree decl_arg_types;
1858 /* This is an ordinary member function. However, since
1859 we're here, we can assume it's enclosing class is a
1860 template class. For example,
1862 template <typename T> struct S { void f(); };
1863 template <> void S<int>::f() {}
1865 Here, S<int>::f is a non-template, but S<int> is a
1866 template class. If FN has the same type as DECL, we
1867 might be in business. */
1870 /* Its enclosing class is an explicit specialization
1871 of a template class. This is not a candidate. */
1876 /* The return types differ. */
1879 /* Adjust the type of DECL in case FN is a static member. */
1886 decl_arg_types))
1887 /* They match! */
1889 }
1890 }
1893 {
1894 /* We have:
1896 [temp.expl.spec]
1898 It is possible for a specialization with a given function
1899 signature to be instantiated from more than one function
1900 template. In such cases, explicit specification of the
1901 template arguments must be used to uniquely identify the
1902 function template specialization being specialized.
1904 Note that here, there's no suggestion that we're supposed to
1905 determine which of the candidate templates is most
1906 specialized. However, we, also have:
1908 [temp.func.order]
1910 Partial ordering of overloaded function template
1911 declarations is used in the following contexts to select
1912 the function template to which a function template
1913 specialization refers:
1915 -- when an explicit specialization refers to a function
1916 template.
1918 So, we do use the partial ordering rules, at least for now.
1919 This extension can only serve to make invalid programs valid,
1920 so it's safe. And, there is strong anecdotal evidence that
1921 the committee intended the partial ordering rules to apply;
1922 the EDG front end has that behavior, and John Spicer claims
1923 that the committee simply forgot to delete the wording in
1924 [temp.expl.spec]. */
1927 {
1930 }
1931 }
1934 {
1938 }
1942 {
1948 }
1950 /* We have one, and exactly one, match. */
1952 {
1955 /* DECL is a re-declaration or partial instantiation of a template
1956 function. */
1959 /* It was a specialization of an ordinary member function in a
1960 template class. */
1962 }
1964 /* It was a specialization of a template. */
1967 {
1972 }
1973 else
1976 }
1978 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
1979 but with the default argument values filled in from those in the
1980 TMPL_TYPES. */
1982 static tree
1984 tree tmpl_types)
1985 {
1986 tree new_spec_types;
1994 /* Substitute into the rest of the list. */
1995 new_spec_types =
1999 /* Add the default argument for this parameter. */
2002 new_spec_types);
2003 }
2005 /* DECL is an explicit specialization. Replicate default arguments
2006 from the template it specializes. (That way, code like:
2008 template <class T> void f(T = 3);
2009 template <> void f(double);
2010 void g () { f (); }
2012 works, as required.) An alternative approach would be to look up
2013 the correct default arguments at the call-site, but this approach
2014 is consistent with how implicit instantiations are handled. */
2016 static void
2018 {
2019 tree tmpl;
2020 tree spec_types;
2021 tree tmpl_types;
2022 tree new_spec_types;
2023 tree old_type;
2024 tree new_type;
2025 tree t;
2030 /* See if there's anything we need to do. */
2043 {
2044 /* Remove the this pointer, but remember the object's type for
2045 CV quals. */
2051 {
2052 /* DECL may contain more parameters than TMPL due to the extra
2053 in-charge parameter in constructors and destructors. */
2056 }
2058 {
2061 }
2062 }
2064 /* Compute the merged default arguments. */
2065 new_spec_types =
2068 /* Compute the new FUNCTION_TYPE. */
2070 {
2074 new_spec_types);
2077 /* Put the in-charge parameter back. */
2080 new_spec_types);
2084 new_spec_types);
2085 }
2086 else
2088 new_spec_types);
2094 }
2096 /* Check to see if the function just declared, as indicated in
2097 DECLARATOR, and in DECL, is a specialization of a function
2098 template. We may also discover that the declaration is an explicit
2099 instantiation at this point.
2101 Returns DECL, or an equivalent declaration that should be used
2102 instead if all goes well. Issues an error message if something is
2103 amiss. Returns error_mark_node if the error is not easily
2104 recoverable.
2106 FLAGS is a bitmask consisting of the following flags:
2108 2: The function has a definition.
2109 4: The function is a friend.
2111 The TEMPLATE_COUNT is the number of references to qualifying
2112 template classes that appeared in the name of the function. For
2113 example, in
2115 template <class T> struct S { void f(); };
2116 void S<int>::f();
2118 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2119 classes are not counted in the TEMPLATE_COUNT, so that in
2121 template <class T> struct S {};
2122 template <> struct S<int> { void f(); }
2123 template <> void S<int>::f();
2125 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2126 invalid; there should be no template <>.)
2128 If the function is a specialization, it is marked as such via
2129 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2130 is set up correctly, and it is added to the list of specializations
2131 for that template. */
2133 tree
2135 tree decl,
2138 {
2146 tmpl_spec_kind tsk;
2149 {
2152 else
2154 }
2155 else
2159 {
2162 {
2165 }
2167 {
2169 /* This could be something like:
2171 template <class T> void f(T);
2172 class S { friend void f<>(int); } */
2174 else
2175 {
2176 /* This case handles bogus declarations like template <>
2177 template <class T> void f<int>(); */
2180 declarator);
2182 }
2183 }
2187 /* The error has already been reported in
2188 check_specialization_scope. */
2194 /* Fall through. */
2207 decl);
2210 else
2214 /* Fall through. */
2219 else
2225 {
2226 /* This case handles bogus declarations like template <>
2227 template <class T> void f<int>(); */
2232 else
2234 declarator);
2236 }
2239 /* This is a specialization of a member template, without
2240 specialization the containing class. Something like:
2242 template <class T> struct S {
2243 template <class U> void f (U);
2244 };
2245 template <> template <class U> void S<int>::f(U) {}
2247 That's a specialization -- but of the entire template. */
2253 }
2256 {
2260 {
2264 }
2265 }
2268 {
2272 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2274 {
2275 tree fns;
2280 else
2281 {
2282 /* If there is no class context, the explicit instantiation
2283 must be at namespace scope. */
2286 /* Find the namespace binding, using the declaration
2287 context. */
2291 {
2294 }
2295 else
2296 {
2302 }
2303 }
2306 }
2312 {
2314 /* A specialization in class scope. This is invalid,
2315 but the error will already have been flagged by
2316 check_specialization_scope. */
2318 else
2319 {
2320 /* It's not valid to write an explicit instantiation in
2321 class scope, e.g.:
2323 class C { template void f(); }
2325 This case is caught by the parser. However, on
2326 something like:
2328 template class C { void f(); };
2330 (which is invalid) we can get here. The error will be
2331 issued later. */
2332 ;
2333 }
2336 }
2339 IDENTIFIER_NODE))
2340 {
2341 /* Find the list of functions in ctype that have the same
2342 name as the declared function. */
2348 {
2353 {
2354 /* From [temp.expl.spec]:
2356 If such an explicit specialization for the member
2357 of a class template names an implicitly-declared
2358 special member function (clause _special_), the
2359 program is ill-formed.
2361 Similar language is found in [temp.explicit]. */
2364 }
2367 }
2370 {
2374 }
2375 else
2376 {
2378 tree ovl;
2380 /* For a type-conversion operator, we cannot do a
2381 name-based lookup. We might be looking for `operator
2382 int' which will be a specialization of `operator T'.
2383 So, we find *all* the conversion operators, and then
2384 select from them. */
2392 {
2394 /* There are no more conversion functions. */
2397 /* Glue all these conversion functions together
2398 with those we already have. */
2401 }
2402 }
2405 {
2408 }
2409 else
2411 }
2413 /* Figure out what exactly is being specialized at this point.
2414 Note that for an explicit instantiation, even one for a
2415 member function, we cannot tell apriori whether the
2416 instantiation is for a member template, or just a member
2417 function of a template class. Even if a member template is
2418 being instantiated, the member template arguments may be
2419 elided if they can be deduced from the rest of the
2420 declaration. */
2423 member_specialization,
2424 template_count,
2425 tsk);
2428 /* We couldn't figure out what this declaration was
2429 specializing. */
2431 else
2432 {
2436 {
2437 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2438 is done by do_decl_instantiation later. */
2444 {
2445 /* If TMPL is not the most general template (for
2446 example, if TMPL is a friend template that is
2447 injected into namespace scope), then there will
2448 be too many levels of TARGS. Remove some of them
2449 here. */
2451 tree new_targs;
2458 }
2461 }
2463 /* If we thought that the DECL was a member function, but it
2464 turns out to be specializing a static member function,
2465 make DECL a static member function as well. */
2470 /* If this is a specialization of a member template of a
2471 template class, we want to return the TEMPLATE_DECL, not
2472 the specialization of it. */
2474 {
2479 {
2480 tree parm;
2484 /* We want to use the argument list specified in the
2485 definition, not in the original declaration. */
2490 }
2493 }
2495 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2498 /* Inherit default function arguments from the template
2499 DECL is specializing. */
2502 /* This specialization has the same protection as the
2503 template it specializes. */
2507 /* 7.1.1-1 [dcl.stc]
2509 A storage-class-specifier shall not be specified in an
2510 explicit specialization...
2512 The parser rejects these, so unless action is taken here,
2513 explicit function specializations will always appear with
2514 global linkage.
2516 The action recommended by the C++ CWG in response to C++
2517 defect report 605 is to make the storage class and linkage
2518 of the explicit specialization match the templated function:
2520 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2521 */
2523 {
2527 /* This specialization has the same linkage and visibility as
2528 the function template it specializes. */
2531 {
2534 }
2537 {
2540 }
2541 }
2543 /* If DECL is a friend declaration, declared using an
2544 unqualified name, the namespace associated with DECL may
2545 have been set incorrectly. For example, in:
2547 template <typename T> void f(T);
2548 namespace N {
2549 struct S { friend void f<int>(int); }
2550 }
2552 we will have set the DECL_CONTEXT for the friend
2553 declaration to N, rather than to the global namespace. */
2558 /* This is not really a declaration of a specialization.
2559 It's just the name of an instantiation. But, it's not
2560 a request for an instantiation, either. */
2563 /* This is indeed a specialization. In case of constructors
2564 and destructors, we need in-charge and not-in-charge
2565 versions in V3 ABI. */
2568 /* Register this specialization so that we can find it
2569 again. */
2571 }
2572 }
2575 }
2577 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2578 parameters. These are represented in the same format used for
2579 DECL_TEMPLATE_PARMS. */
2581 int
2583 {
2584 const_tree p1;
2585 const_tree p2;
2593 {
2605 {
2609 /* If either of the template parameters are invalid, assume
2610 they match for the sake of error recovery. */
2623 }
2624 }
2627 /* One set of parameters has more parameters lists than the
2628 other. */
2632 }
2634 /* Determine whether PARM is a parameter pack. */
2636 bool
2638 {
2639 /* Determine if we have a non-type template parameter pack. */
2644 /* If this is a list of template parameters, we could get a
2645 TYPE_DECL or a TEMPLATE_DECL. */
2652 }
2654 /* Determine if T is a function parameter pack. */
2656 bool
2658 {
2662 }
2664 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2665 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2667 tree
2669 {
2676 }
2678 /* Return true iff the function parameter PARAM_DECL was expanded
2679 from the function parameter pack PACK. */
2681 bool
2683 {
2690 /* The parameter pack and its pack arguments have the same
2691 DECL_PARM_INDEX. */
2693 }
2695 /* Determine whether ARGS describes a variadic template args list,
2696 i.e., one that is terminated by a template argument pack. */
2698 static bool
2700 {
2702 tree last_parm;
2716 }
2718 /* Generate a new name for the parameter pack name NAME (an
2719 IDENTIFIER_NODE) that incorporates its */
2721 static tree
2723 {
2724 /* Munge the name to include the parameter index. */
2725 #define NUMBUF_LEN 128
2737 }
2739 /* Return true if T is a primary function
2740 or class template instantiation. */
2742 static bool
2744 {
2756 }
2758 /* Return true if PARM is a template template parameter. */
2760 bool
2762 {
2764 }
2766 /* Return the template parameters of T if T is a
2767 primary template instantiation, NULL otherwise. */
2769 tree
2771 {
2776 parms = INNERMOST_TEMPLATE_PARMS
2780 }
2782 /* Returns the template arguments of T if T is a template instantiation,
2783 NULL otherwise. */
2785 tree
2787 {
2795 }
2797 /* Return the argument pack elements of T if T is a template argument pack,
2798 NULL otherwise. */
2800 tree
2802 {
2808 }
2810 /* Structure used to track the progress of find_parameter_packs_r. */
2811 struct find_parameter_pack_data
2812 {
2813 /* TREE_LIST that will contain all of the parameter packs found by
2814 the traversal. */
2817 /* Set of AST nodes that have been visited by the traversal. */
2819 };
2821 /* Identifies all of the argument packs that occur in a template
2822 argument and appends them to the TREE_LIST inside DATA, which is a
2823 find_parameter_pack_data structure. This is a subroutine of
2824 make_pack_expansion and uses_parameter_packs. */
2825 static tree
2827 {
2833 /* Identify whether this is a parameter pack or not. */
2835 {
2849 {
2850 /* We don't want to walk into the type of a PARM_DECL,
2851 because we don't want to see the type parameter pack. */
2854 }
2858 /* Not a parameter pack. */
2860 }
2863 {
2864 /* Add this parameter pack to the list. */
2866 }
2872 /* This switch statement will return immediately if we don't find a
2873 parameter pack. */
2875 {
2880 /* Check the template itself. */
2883 /* Check the template arguments. */
2899 /* Fall through. */
2940 }
2943 }
2945 /* Determines if the expression or type T uses any parameter packs. */
2946 bool
2948 {
2956 }
2958 /* Turn ARG, which may be an expression, type, or a TREE_LIST
2959 representation a base-class initializer into a parameter pack
2960 expansion. If all goes well, the resulting node will be an
2961 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
2962 respectively. */
2963 tree
2965 {
2966 tree result;
2975 {
2976 /* The only time we will see a TREE_LIST here is for a base
2977 class initializer. In this case, the TREE_PURPOSE will be a
2978 _TYPE node (representing the base class expansion we're
2979 initializing) and the TREE_VALUE will be a TREE_LIST
2980 containing the initialization arguments.
2982 The resulting expansion looks somewhat different from most
2983 expansions. Rather than returning just one _EXPANSION, we
2984 return a TREE_LIST whose TREE_PURPOSE is a
2985 TYPE_PACK_EXPANSION containing the bases that will be
2986 initialized. The TREE_VALUE will be identical to the
2987 original TREE_VALUE, which is a list of arguments that will
2988 be passed to each base. We do not introduce any new pack
2989 expansion nodes into the TREE_VALUE (although it is possible
2990 that some already exist), because the TREE_PURPOSE and
2991 TREE_VALUE all need to be expanded together with the same
2992 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
2993 resulting TREE_PURPOSE will mention the parameter packs in
2994 both the bases and the arguments to the bases. */
2995 tree purpose;
2996 tree value;
2999 /* Determine which parameter packs will be used by the base
3000 class expansion. */
3007 {
3011 }
3014 {
3015 /* Collect the sets of parameter packs used in each of the
3016 initialization arguments. */
3018 {
3019 /* Determine which parameter packs will be expanded in this
3020 argument. */
3023 }
3024 }
3028 /* Create the pack expansion type for the base type. */
3033 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3034 they will rarely be compared to anything. */
3038 }
3043 /* Build the PACK_EXPANSION_* node. */
3044 result = for_types
3049 {
3050 /* Propagate type and const-expression information. */
3053 }
3054 else
3055 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3056 they will rarely be compared to anything. */
3059 /* Determine which parameter packs will be expanded. */
3065 /* Make sure we found some parameter packs. */
3067 {
3070 else
3073 }
3077 }
3079 /* Checks T for any "bare" parameter packs, which have not yet been
3080 expanded, and issues an error if any are found. This operation can
3081 only be done on full expressions or types (e.g., an expression
3082 statement, "if" condition, etc.), because we could have expressions like:
3084 foo(f(g(h(args)))...)
3086 where "args" is a parameter pack. check_for_bare_parameter_packs
3087 should not be called for the subexpressions args, h(args),
3088 g(h(args)), or f(g(h(args))), because we would produce erroneous
3089 error messages.
3091 Returns TRUE and emits an error if there were bare parameter packs,
3092 returns FALSE otherwise. */
3093 bool
3095 {
3111 {
3114 {
3123 else
3128 else
3132 }
3135 }
3138 }
3140 /* Expand any parameter packs that occur in the template arguments in
3141 ARGS. */
3142 tree
3144 {
3149 /* First, determine if we need to expand anything, and the number of
3150 slots we'll need. */
3152 {
3155 {
3159 else
3161 }
3162 else
3163 {
3165 num_result_args++;
3166 }
3167 }
3169 /* If no expansion is necessary, we're done. */
3173 /* Expand arguments. */
3176 {
3179 {
3184 }
3185 else
3186 {
3189 }
3190 }
3193 }
3195 /* Checks if DECL shadows a template parameter.
3197 [temp.local]: A template-parameter shall not be redeclared within its
3198 scope (including nested scopes).
3200 Emits an error and returns TRUE if the DECL shadows a parameter,
3201 returns FALSE otherwise. */
3203 bool
3205 {
3206 tree olddecl;
3208 /* If we're not in a template, we can't possibly shadow a template
3209 parameter. */
3213 /* Figure out what we're shadowing. */
3218 /* If there's no previous binding for this name, we're not shadowing
3219 anything, let alone a template parameter. */
3223 /* If we're not shadowing a template parameter, we're done. Note
3224 that OLDDECL might be an OVERLOAD (or perhaps even an
3225 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3226 node. */
3230 /* We check for decl != olddecl to avoid bogus errors for using a
3231 name inside a class. We check TPFI to avoid duplicate errors for
3232 inline member templates. */
3240 }
3242 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3243 ORIG_LEVEL, DECL, and TYPE. */
3245 static tree
3249 tree decl,
3250 tree type)
3251 {
3262 }
3264 /* Find the canonical type parameter for the given template type
3265 parameter. Returns the canonical type parameter, which may be TYPE
3266 if no such parameter existed. */
3267 static tree
3269 {
3270 tree list;
3284 else
3285 {
3290 }
3291 }
3293 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3294 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3295 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3296 new one is created. */
3298 static tree
3300 tsubst_flags_t complain)
3301 {
3305 {
3324 /* Template template parameters need this. */
3329 }
3332 }
3334 /* Process information from new template parameter PARM and append it to the
3335 LIST being built. This new parameter is a non-type parameter iff
3336 IS_NON_TYPE is true. This new parameter is a parameter
3337 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3338 PARM_LOC. */
3340 tree
3343 {
3345 tree defval;
3346 tree err_parm_list;
3353 {
3357 {
3361 else
3363 }
3366 }
3367 else
3371 {
3377 {
3381 }
3382 else
3383 {
3384 /* [temp.param]
3386 The top-level cv-qualifiers on the template-parameter are
3387 ignored when determining its type. */
3390 {
3394 }
3397 {
3398 /* This template parameter is not a parameter pack, but it
3399 should be. Complain about "bare" parameter packs. */
3402 /* Recover by calling this a parameter pack. */
3404 }
3405 }
3407 /* A template parameter is not modifiable. */
3416 processing_template_decl,
3421 }
3422 else
3423 {
3424 tree t;
3428 {
3430 /* This is for distinguishing between real templates and template
3431 template parameters */
3435 }
3436 else
3437 {
3439 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3442 }
3449 processing_template_decl,
3453 }
3459 }
3461 /* The end of a template parameter list has been reached. Process the
3462 tree list into a parameter vector, converting each parameter into a more
3463 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3464 as PARM_DECLs. */
3466 tree
3468 {
3473 current_template_parms
3478 {
3482 }
3487 }
3489 /* end_template_decl is called after a template declaration is seen. */
3491 void
3493 {
3499 /* This matches the pushlevel in begin_template_parm_list. */
3504 }
3506 /* Within the declaration of a template, return all levels of template
3507 parameters that apply. The template parameters are represented as
3508 a TREE_VEC, in the form documented in cp-tree.h for template
3509 arguments. */
3511 static tree
3513 {
3514 tree header;
3519 /* If there is only one level of template parameters, we do not
3520 create a TREE_VEC of TREE_VECs. Instead, we return a single
3521 TREE_VEC containing the arguments. */
3526 {
3532 {
3535 /* T will be a list if we are called from within a
3536 begin/end_template_parm_list pair, but a vector directly
3537 if within a begin/end_member_template_processing pair. */
3539 {
3543 {
3546 {
3550 {
3551 /* Turn this argument into a TYPE_ARGUMENT_PACK
3552 with a single element, which expands T. */
3558 }
3559 }
3560 else
3561 {
3565 {
3566 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3567 with a single element, which expands T. */
3575 }
3576 }
3578 }
3579 }
3580 }
3584 else
3586 }
3589 }
3591 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3592 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3593 a member template. Used by push_template_decl below. */
3595 static tree
3597 {
3604 }
3606 struct template_parm_data
3607 {
3608 /* The level of the template parameters we are currently
3609 processing. */
3612 /* The index of the specialization argument we are currently
3613 processing. */
3616 /* An array whose size is the number of template parameters. The
3617 elements are nonzero if the parameter has been used in any one
3618 of the arguments processed so far. */
3621 /* An array whose size is the number of template arguments. The
3622 elements are nonzero if the argument makes use of template
3623 parameters of this level. */
3625 };
3627 /* Subroutine of push_template_decl used to see if each template
3628 parameter in a partial specialization is used in the explicit
3629 argument list. If T is of the LEVEL given in DATA (which is
3630 treated as a template_parm_data*), then DATA->PARMS is marked
3631 appropriately. */
3633 static int
3635 {
3641 {
3644 }
3645 else
3646 {
3649 }
3652 {
3655 }
3657 /* Return zero so that for_each_template_parm will continue the
3658 traversal of the tree; we want to mark *every* template parm. */
3660 }
3662 /* Process the partial specialization DECL. */
3664 static tree
3666 {
3672 tree inner_parms;
3685 /* We check that each of the template parameters given in the
3686 partial specialization is used in the argument list to the
3687 specialization. For example:
3689 template <class T> struct S;
3690 template <class T> struct S<T*>;
3692 The second declaration is OK because `T*' uses the template
3693 parameter T, whereas
3695 template <class T> struct S<int>;
3697 is no good. Even trickier is:
3699 template <class T>
3700 struct S1
3701 {
3702 template <class U>
3703 struct S2;
3704 template <class U>
3705 struct S2<T>;
3706 };
3708 The S2<T> declaration is actually invalid; it is a
3709 full-specialization. Of course,
3711 template <class U>
3712 struct S2<T (*)(U)>;
3714 or some such would have been OK. */
3722 {
3727 NULL,
3729 }
3732 {
3733 /* One of the template parms was not used in the
3734 specialization. */
3736 {
3739 }
3742 }
3744 /* [temp.class.spec]
3746 The argument list of the specialization shall not be identical to
3747 the implicit argument list of the primary template. */
3754 /* [temp.class.spec]
3756 A partially specialized non-type argument expression shall not
3757 involve template parameters of the partial specialization except
3758 when the argument expression is a simple identifier.
3760 The type of a template parameter corresponding to a specialized
3761 non-type argument shall not be dependent on a parameter of the
3762 specialization.
3764 Also, we verify that pack expansions only occur at the
3765 end of the argument list. */
3769 {
3776 {
3777 /* Extract the arguments from the argument pack. We'll be
3778 iterating over these in the following loop. */
3781 }
3784 {
3786 /* Get the Jth argument in the parameter pack. */
3790 {
3791 /* Pack expansions must come at the end of the
3792 argument list. */
3795 {
3798 else
3803 }
3804 }
3807 /* We only care about the pattern. */
3813 /* This next line is the `argument expression is not just a
3814 simple identifier' condition and also the `specialized
3815 non-type argument' bit. */
3817 {
3821 arg);
3822 else
3823 {
3824 /* Look at the corresponding template parameter,
3825 marking which template parameters its type depends
3826 upon. */
3830 {
3831 /* We haven't yet initialized TPD2. Do so now. */
3832 tpd2.arg_uses_template_parms
3834 /* The number of parameters here is the number in the
3835 main template, which, as checked in the assertion
3836 above, is NARGS. */
3840 }
3842 /* Mark the template parameters. But this time, we're
3843 looking for the template parameters of the main
3844 template, not in the specialization. */
3851 NULL,
3855 {
3856 /* The type depended on some template parameters.
3857 If they are fully specialized in the
3858 specialization, that's OK. */
3863 {
3866 type,
3867 arg);
3869 }
3870 }
3871 }
3872 }
3873 }
3874 }
3876 /* We should only get here once. */
3884 }
3886 /* Check that a template declaration's use of default arguments and
3887 parameter packs is not invalid. Here, PARMS are the template
3888 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
3889 a primary template. IS_PARTIAL is nonzero if DECL is a partial
3890 specialization.
3893 IS_FRIEND_DECL is nonzero if DECL is a friend function template
3894 declaration (but not a definition); 1 indicates a declaration, 2
3895 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
3896 emitted for extraneous default arguments.
3898 Returns TRUE if there were no errors found, FALSE otherwise. */
3900 bool
3903 {
3906 tree parm_level;
3909 /* [temp.param]
3911 A default template-argument shall not be specified in a
3912 function template declaration or a function template definition, nor
3913 in the template-parameter-list of the definition of a member of a
3914 class template. */
3917 /* You can't have a function template declaration in a local
3918 scope, nor you can you define a member of a class template in a
3919 local scope. */
3926 /* If this is either a friend defined in the scope of the class
3927 or a member function. */
3933 /* And, if it was a member function, it really was defined in
3934 the scope of the class. */
3937 /* We already checked these parameters when the template was
3938 declared, so there's no need to do it again now. This function
3939 was defined in class scope, but we're processing it's body now
3940 that the class is complete. */
3943 /* Core issue 226 (C++0x only): the following only applies to class
3944 templates. */
3946 {
3947 /* [temp.param]
3949 If a template-parameter has a default template-argument, all
3950 subsequent template-parameters shall have a default
3951 template-argument supplied. */
3953 {
3960 {
3970 {
3972 /* For better subsequent error-recovery, we indicate that
3973 there should have been a default argument. */
3976 }
3978 && !is_partial
3979 && !is_friend_decl
3980 /* Don't complain about an enclosing partial
3981 specialization. */
3986 {
3987 /* A primary class template can only have one
3988 parameter pack, at the end of the template
3989 parameter list. */
3994 else
4002 }
4003 }
4004 }
4005 }
4008 || is_partial
4009 || !is_primary
4011 /* For an ordinary class template, default template arguments are
4012 allowed at the innermost level, e.g.:
4013 template <class T = int>
4014 struct S {};
4015 but, in a partial specialization, they're not allowed even
4016 there, as we have in [temp.class.spec]:
4018 The template parameter list of a specialization shall not
4019 contain default template argument values.
4021 So, for a partial specialization, or for a function template
4022 (in C++98/C++03), we look at all of them. */
4023 ;
4024 else
4025 /* But, for a primary class template that is not a partial
4026 specialization we look at all template parameters except the
4027 innermost ones. */
4030 /* Figure out what error message to issue. */
4040 else
4044 /* If we're inside a class definition, there's no need to
4045 examine the parameters to the class itself. On the one
4046 hand, they will be checked when the class is defined, and,
4047 on the other, default arguments are valid in things like:
4048 template <class T = double>
4049 struct S { template <class U> void f(U); };
4050 Here the default argument for `S' has no bearing on the
4051 declaration of `f'. */
4053 else
4054 /* Check everything. */
4060 {
4067 {
4072 {
4074 {
4081 }
4083 /* Clear out the default argument so that we are not
4084 confused later. */
4086 }
4087 }
4089 /* At this point, if we're still interested in issuing messages,
4090 they must apply to classes surrounding the object declared. */
4093 }
4096 }
4098 /* Worker for push_template_decl_real, called via
4099 for_each_template_parm. DATA is really an int, indicating the
4100 level of the parameters we are interested in. If T is a template
4101 parameter of that level, return nonzero. */
4103 static int
4105 {
4111 else
4114 }
4116 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4117 parameters given by current_template_args, or reuses a
4118 previously existing one, if appropriate. Returns the DECL, or an
4119 equivalent one, if it is replaced via a call to duplicate_decls.
4121 If IS_FRIEND is true, DECL is a friend declaration. */
4123 tree
4125 {
4126 tree tmpl;
4127 tree args;
4128 tree info;
4129 tree ctx;
4133 /* True if the template is a member template, in the sense of
4134 [temp.mem]. */
4140 /* See if this is a partial specialization. */
4149 /* For a friend, we want the context of the friend function, not
4150 the type of which it is a friend. */
4154 /* In the case of a virtual function, we want the class in which
4155 it is defined. */
4157 else
4158 /* Otherwise, if we're currently defining some class, the DECL
4159 is assumed to be a member of the class. */
4168 /* See if this is a primary template. */
4170 /* A friend template that specifies a class context, i.e.
4171 template <typename T> friend void A<T>::f();
4172 is not primary. */
4174 else
4178 {
4183 {
4186 }
4188 {
4190 {
4191 /* [temp.mem]
4193 A destructor shall not be a member template. */
4196 }
4203 {
4204 /* [basic.stc.dynamic.allocation]
4206 An allocation function can be a function
4207 template. ... Template allocation functions shall
4208 have two or more parameters. */
4211 }
4212 }
4216 else
4217 {
4220 }
4221 }
4223 /* Check to see that the rules regarding the use of default
4224 arguments are not being violated. */
4228 /* Ensure that there are no parameter packs in the type of this
4229 declaration that have not been expanded. */
4231 {
4232 /* Check each of the arguments individually to see if there are
4233 any bare parameter packs. */
4239 {
4242 {
4243 /* This is a PARM_DECL that contains unexpanded parameter
4244 packs. We have already complained about this in the
4245 check_for_bare_parameter_packs call, so just replace
4246 these types with ERROR_MARK_NODE. */
4249 }
4253 }
4255 /* Check for bare parameter packs in the return type and the
4256 exception specifiers. */
4258 /* Errors were already issued, set return type to int
4259 as the frontend doesn't expect error_mark_node as
4260 the return type. */
4264 }
4266 {
4269 }
4280 {
4285 /* If DECL is a TYPE_DECL for a class-template, then there won't
4286 be DECL_LANG_SPECIFIC. The information equivalent to
4287 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4291 {
4292 /* Since a template declaration already existed for this
4293 class-type, we must be redeclaring it here. Make sure
4294 that the redeclaration is valid. */
4296 current_template_parms);
4297 /* We don't need to create a new TEMPLATE_DECL; just use the
4298 one we already had. */
4300 }
4301 else
4302 {
4304 member_template_p);
4309 {
4310 /* A specialization of a member template of a template
4311 class. */
4315 }
4316 }
4317 }
4318 else
4319 {
4325 {
4328 }
4336 {
4337 tree new_tmpl;
4339 /* The declaration is a specialization of a member
4340 template, declared outside the class. Therefore, the
4341 innermost template arguments will be NULL, so we
4342 replace them with the arguments determined by the
4343 earlier call to check_explicit_specialization. */
4346 new_tmpl
4348 member_template_p);
4358 args,
4361 }
4363 /* Make sure the template headers we got make sense. */
4368 {
4371 }
4372 else
4374 {
4379 {
4383 else
4388 }
4392 else
4396 }
4398 /* Check that the parms are used in the appropriate qualifying scopes
4399 in the declarator. */
4403 {
4409 /* Avoid crash in import_export_decl. */
4412 }
4413 }
4418 /* Push template declarations for global functions and types. Note
4419 that we do not try to push a global template friend declared in a
4420 template class; such a thing may well depend on the template
4421 parameters of the class. */
4424 {
4429 /* Hide template friend classes that haven't been declared yet. */
4431 {
4434 }
4435 }
4438 {
4444 {
4447 /* It is a conversion operator. See if the type converted to
4448 depends on innermost template operands. */
4451 depth))
4453 }
4455 /* Give template template parms a DECL_CONTEXT of the template
4456 for which they are a parameter. */
4459 {
4463 }
4464 }
4466 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4467 back to its most general template. If TMPL is a specialization,
4468 ARGS may only have the innermost set of arguments. Add the missing
4469 argument levels if necessary. */
4481 }
4483 tree
4485 {
4487 }
4489 /* Called when a class template TYPE is redeclared with the indicated
4490 template PARMS, e.g.:
4492 template <class T> struct S;
4493 template <class T> struct S {}; */
4495 bool
4497 {
4498 tree tmpl;
4499 tree tmpl_parms;
4503 {
4506 }
4510 /* The type is nested in some template class. Nothing to worry
4511 about here; there are no new template parameters for the nested
4512 type. */
4516 {
4518 tmpl);
4520 }
4526 {
4532 }
4535 {
4536 tree tmpl_parm;
4537 tree parm;
4538 tree tmpl_default;
4539 tree parm_default;
4550 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4551 TEMPLATE_DECL. */
4562 {
4566 }
4569 {
4570 /* We have in [temp.param]:
4572 A template-parameter may not be given default arguments
4573 by two different declarations in the same scope. */
4578 }
4581 /* Update the previous template parameters (which are the ones
4582 that will really count) with the new default value. */
4585 /* Update the new parameters, too; they'll be used as the
4586 parameters for any members. */
4588 }
4591 }
4593 /* Simplify EXPR if it is a non-dependent expression. Returns the
4594 (possibly simplified) expression. */
4596 tree
4598 {
4602 /* If we're in a template, but EXPR isn't value dependent, simplify
4603 it. We're supposed to treat:
4605 template <typename T> void f(T[1 + 1]);
4606 template <typename T> void f(T[2]);
4608 as two declarations of the same function, for example. */
4612 {
4613 HOST_WIDE_INT saved_processing_template_decl;
4619 tf_error,
4624 }
4626 }
4628 /* EXPR is an expression which is used in a constant-expression context.
4629 For instance, it could be a VAR_DECL with a constant initializer.
4630 Extract the innermost constant expression.
4632 This is basically a more powerful version of
4633 integral_constant_value, which can be used also in templates where
4634 initializers can maintain a syntactic rather than semantic form
4635 (even if they are non-dependent, for access-checking purposes). */
4637 static tree
4639 {
4641 do
4642 {
4645 }
4649 }
4651 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4652 must be a function or a pointer-to-function type, as specified
4653 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4654 and check that the resulting function has external linkage. */
4656 static tree
4658 {
4672 /* [temp.arg.nontype]/1
4674 A template-argument for a non-type, non-template template-parameter
4675 shall be one of:
4676 [...]
4677 -- the address of an object or function with external linkage. */
4679 {
4684 }
4687 }
4689 /* Subroutine of convert_nontype_argument.
4690 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4691 Emit an error otherwise. */
4693 static bool
4695 {
4703 }
4705 /* Attempt to convert the non-type template parameter EXPR to the
4706 indicated TYPE. If the conversion is successful, return the
4707 converted value. If the conversion is unsuccessful, return
4708 NULL_TREE if we issued an error message, or error_mark_node if we
4709 did not. We issue error messages for out-and-out bad template
4710 parameters, but not simply because the conversion failed, since we
4711 might be just trying to do argument deduction. Both TYPE and EXPR
4712 must be non-dependent.
4714 The conversion follows the special rules described in
4715 [temp.arg.nontype], and it is much more strict than an implicit
4716 conversion.
4718 This function is called twice for each template argument (see
4719 lookup_template_class for a more accurate description of this
4720 problem). This means that we need to handle expressions which
4721 are not valid in a C++ source, but can be created from the
4722 first call (for instance, casts to perform conversions). These
4723 hacks can go away after we fix the double coercion problem. */
4725 static tree
4727 {
4728 tree expr_type;
4730 /* Detect immediately string literals as invalid non-type argument.
4731 This special-case is not needed for correctness (we would easily
4732 catch this later), but only to provide better diagnostic for this
4733 common user mistake. As suggested by DR 100, we do not mention
4734 linkage issues in the diagnostic as this is not the point. */
4736 {
4741 }
4743 /* If we are in a template, EXPR may be non-dependent, but still
4744 have a syntactic, rather than semantic, form. For example, EXPR
4745 might be a SCOPE_REF, rather than the VAR_DECL to which the
4746 SCOPE_REF refers. Preserving the qualifying scope is necessary
4747 so that access checking can be performed when the template is
4748 instantiated -- but here we need the resolved form so that we can
4749 convert the argument. */
4755 /* HACK: Due to double coercion, we can get a
4756 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4757 which is the tree that we built on the first call (see
4758 below when coercing to reference to object or to reference to
4759 function). We just strip everything and get to the arg.
4760 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4761 for examples. */
4763 {
4765 {
4766 /* ??? Maybe we could use convert_from_reference here, but we
4767 would need to relax its constraints because the NOP_EXPR
4768 could actually change the type to something more cv-qualified,
4769 and this is not folded by convert_from_reference. */
4780 }
4782 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4783 parameter is a pointer to object, through decay and
4784 qualification conversion. Let's strip everything. */
4786 {
4790 /* Skip the ADDR_EXPR only if it is part of the decay for
4791 an array. Otherwise, it is part of the original argument
4792 in the source code. */
4796 }
4797 }
4799 /* [temp.arg.nontype]/5, bullet 1
4801 For a non-type template-parameter of integral or enumeration type,
4802 integral promotions (_conv.prom_) and integral conversions
4803 (_conv.integral_) are applied. */
4805 {
4810 /* Notice that there are constant expressions like '4 % 0' which
4811 do not fold into integer constants. */
4813 {
4817 }
4819 /* At this point, an implicit conversion does what we want,
4820 because we already know that the expression is of integral
4821 type. */
4826 /* Conversion was allowed: fold it to a bare integer constant. */
4828 }
4829 /* [temp.arg.nontype]/5, bullet 2
4831 For a non-type template-parameter of type pointer to object,
4832 qualification conversions (_conv.qual_) and the array-to-pointer
4833 conversion (_conv.array_) are applied. */
4835 {
4836 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
4838 A template-argument for a non-type, non-template template-parameter
4839 shall be one of: [...]
4841 -- the name of a non-type template-parameter;
4842 -- the address of an object or function with external linkage, [...]
4843 expressed as "& id-expression" where the & is optional if the name
4844 refers to a function or array, or if the corresponding
4845 template-parameter is a reference.
4847 Here, we do not care about functions, as they are invalid anyway
4848 for a parameter of type pointer-to-object. */
4851 /* Non-type template parameters are OK. */
4852 ;
4855 {
4857 {
4859 "because %qD is a variable, not the address of "
4863 }
4864 /* Other values, like integer constants, might be valid
4865 non-type arguments of some other type. */
4867 }
4868 else
4869 {
4870 tree decl;
4875 {
4880 }
4882 {
4887 }
4888 }
4897 }
4898 /* [temp.arg.nontype]/5, bullet 3
4900 For a non-type template-parameter of type reference to object, no
4901 conversions apply. The type referred to by the reference may be more
4902 cv-qualified than the (otherwise identical) type of the
4903 template-argument. The template-parameter is bound directly to the
4904 template-argument, which must be an lvalue. */
4906 {
4908 expr_type))
4912 {
4916 }
4919 {
4923 }
4925 /* [temp.arg.nontype]/1
4927 A template-argument for a non-type, non-template template-parameter
4928 shall be one of: [...]
4930 -- the address of an object or function with external linkage. */
4932 {
4937 }
4940 }
4941 /* [temp.arg.nontype]/5, bullet 4
4943 For a non-type template-parameter of type pointer to function, only
4944 the function-to-pointer conversion (_conv.func_) is applied. If the
4945 template-argument represents a set of overloaded functions (or a
4946 pointer to such), the matching function is selected from the set
4947 (_over.over_). */
4949 {
4950 /* If the argument is a template-id, we might not have enough
4951 context information to decay the pointer. */
4953 {
4957 }
4964 {
4968 }
4969 }
4970 /* [temp.arg.nontype]/5, bullet 5
4972 For a non-type template-parameter of type reference to function, no
4973 conversions apply. If the template-argument represents a set of
4974 overloaded functions, the matching function is selected from the set
4975 (_over.over_). */
4977 {
4979 {
4984 }
4991 }
4992 /* [temp.arg.nontype]/5, bullet 6
4994 For a non-type template-parameter of type pointer to member function,
4995 no conversions apply. If the template-argument represents a set of
4996 overloaded member functions, the matching member function is selected
4997 from the set (_over.over_). */
4999 {
5004 /* [temp.arg.nontype] bullet 1 says the pointer to member
5005 expression must be a pointer-to-member constant. */
5009 /* There is no way to disable standard conversions in
5010 resolve_address_of_overloaded_function (called by
5011 instantiate_type). It is possible that the call succeeded by
5012 converting &B::I to &D::I (where B is a base of D), so we need
5013 to reject this conversion here.
5015 Actually, even if there was a way to disable standard conversions,
5016 it would still be better to reject them here so that we can
5017 provide a superior diagnostic. */
5019 {
5020 /* Make sure we are just one standard conversion off. */
5027 }
5028 }
5029 /* [temp.arg.nontype]/5, bullet 7
5031 For a non-type template-parameter of type pointer to data member,
5032 qualification conversions (_conv.qual_) are applied. */
5034 {
5035 /* [temp.arg.nontype] bullet 1 says the pointer to member
5036 expression must be a pointer-to-member constant. */
5043 }
5044 /* A template non-type parameter must be one of the above. */
5045 else
5048 /* Sanity check: did we actually convert the argument to the
5049 right type? */
5052 }
5054 /* Subroutine of coerce_template_template_parms, which returns 1 if
5055 PARM_PARM and ARG_PARM match using the rule for the template
5056 parameters of template template parameters. Both PARM and ARG are
5057 template parameters; the rest of the arguments are the same as for
5058 coerce_template_template_parms.
5059 */
5060 static int
5062 tree arg,
5063 tsubst_flags_t complain,
5064 tree in_decl,
5065 tree outer_args)
5066 {
5075 {
5077 /* We encounter instantiations of templates like
5078 template <template <template <class> class> class TT>
5079 class C; */
5080 {
5087 }
5088 /* Fall through. */
5093 /* Argument is a parameter pack but parameter is not. */
5098 /* The tsubst call is used to handle cases such as
5100 template <int> class C {};
5101 template <class T, template <T> class TT> class D {};
5102 D<int, C> d;
5104 i.e. the parameter list of TT depends on earlier parameters. */
5106 && !same_type_p
5113 /* Argument is a parameter pack but parameter is not. */
5120 }
5123 }
5126 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5127 template template parameters. Both PARM_PARMS and ARG_PARMS are
5128 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5129 or PARM_DECL.
5131 Consider the example:
5132 template <class T> class A;
5133 template<template <class U> class TT> class B;
5135 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5136 the parameters to A, and OUTER_ARGS contains A. */
5138 static int
5140 tree arg_parms,
5141 tsubst_flags_t complain,
5142 tree in_decl,
5143 tree outer_args)
5144 {
5155 /* Determine whether we have a parameter pack at the end of the
5156 template template parameter's template parameter list. */
5158 {
5165 {
5179 }
5180 }
5186 /* Check all of the template parameters except the parameter pack at
5187 the end (if any). */
5189 {
5198 outer_args))
5201 }
5204 {
5205 /* Check each of the template parameters in the template
5206 argument against the template parameter pack at the end of
5207 the template template parameter. */
5214 {
5221 outer_args))
5223 }
5224 }
5227 }
5229 /* Verifies that the deduced template arguments (in TARGS) for the
5230 template template parameters (in TPARMS) represent valid bindings,
5231 by comparing the template parameter list of each template argument
5232 to the template parameter list of its corresponding template
5233 template parameter, in accordance with DR150. This
5234 routine can only be called after all template arguments have been
5235 deduced. It will return TRUE if all of the template template
5236 parameter bindings are okay, FALSE otherwise. */
5237 bool
5239 {
5243 /* We're dealing with template parms in this process. */
5249 {
5254 {
5259 {
5260 /* Look inside the argument pack. */
5263 }
5266 {
5270 /* Extract the next argument from the argument
5271 pack. */
5275 /* Look at the pattern of the pack expansion. */
5278 /* Extract the template parameters from the template
5279 argument. */
5285 /* Verify that we can coerce the template template
5286 parameters from the template argument to the template
5287 parameter. This requires an exact match. */
5289 && !coerce_template_template_parms
5291 targ_parms,
5292 tf_none,
5293 tparm,
5294 targs))
5295 {
5298 }
5299 }
5300 }
5301 }
5303 out:
5307 }
5309 /* Convert the indicated template ARG as necessary to match the
5310 indicated template PARM. Returns the converted ARG, or
5311 error_mark_node if the conversion was unsuccessful. Error and
5312 warning messages are issued under control of COMPLAIN. This
5313 conversion is for the Ith parameter in the parameter list. ARGS is
5314 the full set of template arguments deduced so far. */
5316 static tree
5318 tree arg,
5319 tree args,
5320 tsubst_flags_t complain,
5322 tree in_decl)
5323 {
5324 tree orig_arg;
5325 tree val;
5330 {
5331 /* The template argument was the name of some
5332 member function. That's usually
5333 invalid, but static members are OK. In any
5334 case, grab the underlying fields/functions
5335 and issue an error later if required. */
5338 }
5346 /* When determining whether an argument pack expansion is a template,
5347 look at the pattern. */
5351 is_tmpl_type =
5366 {
5372 typename_type,
5376 }
5378 {
5380 {
5382 {
5392 else
5394 }
5395 }
5397 }
5399 {
5401 {
5407 else
5409 }
5411 }
5414 {
5416 {
5418 /* The number of argument required is not known yet.
5419 Just accept it for now. */
5421 else
5422 {
5424 tree argparm;
5430 args))
5431 {
5434 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5435 TEMPLATE_DECL. */
5437 {
5442 {
5445 }
5446 }
5447 }
5448 else
5449 {
5451 {
5457 }
5460 }
5461 }
5462 }
5463 else
5465 /* We only form one instance of each template specialization.
5466 Therefore, if we use a non-canonical variant (i.e., a
5467 typedef), any future messages referring to the type will use
5468 the typedef, which is confusing if those future uses do not
5469 themselves also use the typedef. */
5472 }
5473 else
5474 {
5481 {
5484 else
5485 {
5486 /* Not sure if this is reachable, but it doesn't hurt
5487 to be robust. */
5490 }
5491 }
5493 /* We used to call digest_init here. However, digest_init
5494 will report errors, which we don't want when complain
5495 is zero. More importantly, digest_init will try too
5496 hard to convert things: for example, `0' should not be
5497 converted to pointer type at this point according to
5498 the standard. Accepting this is not merely an
5499 extension, since deciding whether or not these
5500 conversions can occur is part of determining which
5501 function template to call, or whether a given explicit
5502 argument specification is valid. */
5504 else
5511 }
5514 }
5516 /* Coerces the remaining template arguments in INNER_ARGS (from
5517 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5518 Returns the coerced argument pack. PARM_IDX is the position of this
5519 parameter in the template parameter list. ARGS is the original
5520 template argument list. */
5521 static tree
5524 tree args,
5525 tree inner_args,
5527 tree new_args,
5529 tree in_decl,
5530 tsubst_flags_t complain)
5531 {
5534 tree packed_args;
5535 tree argument_pack;
5545 {
5546 /* When the template parameter is a non-type template
5547 parameter pack whose type uses parameter packs, we need
5548 to look at each of the template arguments
5549 separately. Build a vector of the types for these
5550 non-type template parameters in PACKED_TYPES. */
5551 tree expansion
5559 /* Check that we have the right number of arguments. */
5563 {
5564 int needed_parms
5569 }
5571 /* If we aren't able to check the actual arguments now
5572 (because they haven't been expanded yet), we can at least
5573 verify that all of the types used for the non-type
5574 template parameter pack are, in fact, valid for non-type
5575 template parameters. */
5578 {
5581 {
5585 }
5586 }
5587 }
5589 /* Convert the remaining arguments, which will be a part of the
5590 parameter pack "parm". */
5592 {
5597 {
5598 /* When we have a vector of types (corresponding to the
5599 non-type template parameter pack that uses parameter
5600 packs in its type, as mention above), and the
5601 argument is not an expansion (which expands to a
5602 currently unknown number of arguments), clone the
5603 parm and give it the next type in PACKED_TYPES. */
5607 }
5612 in_decl);
5616 }
5621 else
5622 {
5627 }
5631 }
5633 /* Convert all template arguments to their appropriate types, and
5634 return a vector containing the innermost resulting template
5635 arguments. If any error occurs, return error_mark_node. Error and
5636 warning messages are issued under control of COMPLAIN.
5638 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5639 for arguments not specified in ARGS. Otherwise, if
5640 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5641 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5642 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5643 ARGS. */
5645 static tree
5647 tree args,
5648 tree in_decl,
5649 tsubst_flags_t complain,
5652 {
5654 tree inner_args;
5655 tree new_args;
5656 tree new_inner_args;
5660 /* When used as a boolean value, indicates whether this is a
5661 variadic template parameter list. Since it's an int, we can also
5662 subtract it from nparms to get the number of non-variadic
5663 parameters. */
5668 /* Determine if there are any parameter packs. */
5670 {
5674 }
5677 /* If there are 0 or 1 parameter packs, we need to expand any argument
5678 packs so that we can deduce a parameter pack from some non-packed args
5679 followed by an argument pack, as in variadic85.C. If there are more
5680 than that, we need to leave argument packs intact so the arguments are
5681 assigned to the right parameter packs. This should only happen when
5682 dealing with a nested class inside a partial specialization of a class
5683 template, as in variadic92.C. */
5690 && require_all_args
5691 && (!use_default_args
5694 {
5696 {
5699 {
5702 }
5709 }
5712 }
5714 /* We need to evaluate the template arguments, even though this
5715 template-id may be nested within a "sizeof". */
5723 {
5724 tree arg;
5725 tree parm;
5727 /* Get the Ith template parameter. */
5731 {
5734 }
5736 /* Calculate the next argument. */
5739 else
5744 {
5745 /* All remaining arguments will be placed in the
5746 template parameter pack PARM. */
5752 /* Store this argument. */
5754 lost++;
5757 /* We are done with all of the arguments. */
5761 }
5763 {
5765 {
5767 {
5768 /* FIXME this restriction was removed by N2555; see
5769 bug 35722. */
5770 /* If ARG is a pack expansion, but PARM is not a
5771 template parameter pack (if it were, we would have
5772 handled it above), we're trying to expand into a
5773 fixed-length argument list. */
5777 else
5780 }
5782 }
5783 }
5785 /* There must be a default arg in this case. */
5788 else
5792 {
5795 }
5797 /* This only occurs if there was an error in the template
5798 parameter list itself (which we would already have
5799 reported) that we are trying to recover from, e.g., a class
5800 template with a parameter list such as
5801 template<typename..., typename>. */
5803 else
5809 lost++;
5811 }
5819 }
5821 /* Returns 1 if template args OT and NT are equivalent. */
5823 static int
5825 {
5830 /* For member templates */
5837 {
5854 }
5856 {
5857 /* We get here probably because we are in the middle of substituting
5858 into the pattern of a pack expansion. In that case the
5859 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
5860 interested in. So we want to use the initial pack argument for
5861 the comparison. */
5866 }
5871 else
5873 }
5875 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
5876 of template arguments. Returns 0 otherwise. */
5878 int
5880 {
5887 {
5893 }
5895 }
5897 static void
5899 {
5909 /* We are called both from instantiate_decl, where we've already had a
5910 tinst_level pushed, and instantiate_template, where we haven't.
5911 Compensate. */
5922 else
5931 }
5934 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
5935 ARGLIST. Valid choices for FNS are given in the cp-tree.def
5936 documentation for TEMPLATE_ID_EXPR. */
5938 tree
5940 {
5941 tree type;
5951 {
5953 unknown_type_node,
5955 arglist);
5957 }
5964 }
5966 /* Within the scope of a template class S<T>, the name S gets bound
5967 (in build_self_reference) to a TYPE_DECL for the class, not a
5968 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
5969 or one of its enclosing classes, and that type is a template,
5970 return the associated TEMPLATE_DECL. Otherwise, the original
5971 DECL is returned. */
5973 tree
5975 {
5982 }
5984 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
5985 parameters, find the desired type.
5987 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
5989 IN_DECL, if non-NULL, is the template declaration we are trying to
5990 instantiate.
5992 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
5993 the class we are looking up.
5995 Issue error and warning messages under control of COMPLAIN.
5997 If the template class is really a local class in a template
5998 function, then the FUNCTION_CONTEXT is the function in which it is
5999 being instantiated.
6001 ??? Note that this function is currently called *twice* for each
6002 template-id: the first time from the parser, while creating the
6003 incomplete type (finish_template_type), and the second type during the
6004 real instantiation (instantiate_template_class). This is surely something
6005 that we want to avoid. It also causes some problems with argument
6006 coercion (see convert_nontype_argument for more information on this). */
6008 tree
6010 tree arglist,
6011 tree in_decl,
6012 tree context,
6014 tsubst_flags_t complain)
6015 {
6017 tree t;
6020 spec_entry elt;
6021 hashval_t hash;
6026 {
6030 else
6031 {
6038 }
6041 }
6043 {
6046 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6047 an implicit typename for the second A. Deal with it. */
6052 {
6055 }
6056 }
6059 {
6062 }
6066 {
6070 }
6072 /* Issue an error message if we didn't find a template. */
6074 {
6078 }
6081 /* Make sure it's a user visible template, if it was named by
6082 the user. */
6085 {
6087 {
6091 }
6093 }
6098 {
6099 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6100 template arguments */
6102 tree parm;
6103 tree arglist2;
6104 tree outer;
6108 /* Consider an example where a template template parameter declared as
6110 template <class T, class U = std::allocator<T> > class TT
6112 The template parameter level of T and U are one level larger than
6113 of TT. To proper process the default argument of U, say when an
6114 instantiation `TT<int>' is seen, we need to build the full
6115 arguments containing {int} as the innermost level. Outer levels,
6116 available when not appearing as default template argument, can be
6117 obtained from the arguments of the enclosing template.
6119 Suppose that TT is later substituted with std::vector. The above
6120 instantiation is `TT<int, std::allocator<T> >' with TT at
6121 level 1, and T at level 2, while the template arguments at level 1
6122 becomes {std::vector} and the inner level 2 is {int}. */
6128 /* This is an argument of the current template, so we haven't set
6129 DECL_CONTEXT yet. */
6136 complain,
6146 }
6147 else
6148 {
6150 tree gen_tmpl;
6151 tree type_decl;
6163 {
6164 /* We've been given an incomplete set of template arguments.
6165 For example, given:
6167 template <class T> struct S1 {
6168 template <class U> struct S2 {};
6169 template <class U> struct S2<U*> {};
6170 };
6172 we will be called with an ARGLIST of `U*', but the
6173 TEMPLATE will be `template <class T> template
6174 <class U> struct S1<T>::S2'. We must fill in the missing
6175 arguments. */
6176 arglist
6178 arglist);
6180 }
6182 /* Now we should have enough arguments. */
6185 /* From here on, we're only interested in the most general
6186 template. */
6188 /* Calculate the BOUND_ARGS. These will be the args that are
6189 actually tsubst'd into the definition to create the
6190 instantiation. */
6192 {
6193 /* We have multiple levels of arguments to coerce, at once. */
6203 {
6206 complain,
6210 /* Don't process further if one of the levels fails. */
6212 {
6213 /* Restore the ARGLIST to its full size. */
6216 }
6220 /* We temporarily reduce the length of the ARGLIST so
6221 that coerce_template_parms will see only the arguments
6222 corresponding to the template parameters it is
6223 examining. */
6225 }
6227 /* Restore the ARGLIST to its full size. */
6231 }
6232 else
6233 arglist
6236 gen_tmpl,
6237 complain,
6242 /* We were unable to bind the arguments. */
6245 /* In the scope of a template class, explicit references to the
6246 template class refer to the type of the template, not any
6247 instantiation of it. For example, in:
6249 template <class T> class C { void f(C<T>); }
6251 the `C<T>' is just the same as `C'. Outside of the
6252 class, however, such a reference is an instantiation. */
6256 /* comp_template_args is expensive, check it last. */
6258 arglist))
6261 /* If we already have this specialization, return it. */
6271 /* This type is a "partial instantiation" if any of the template
6272 arguments still involve template parameters. Note that we set
6273 IS_PARTIAL_INSTANTIATION for partial specializations as
6274 well. */
6277 /* If the deduced arguments are invalid, then the binding
6278 failed. */
6282 complain))
6289 {
6294 }
6301 /* Create the type. */
6303 {
6305 {
6311 }
6312 else
6313 {
6314 /* We don't want to call start_enum for this type, since
6315 the values for the enumeration constants may involve
6316 template parameters. And, no one should be interested
6317 in the enumeration constants for such a type. */
6320 }
6321 }
6322 else
6323 {
6330 /* A local class. Make sure the decl gets registered properly. */
6335 /* This instantiation is another name for the primary
6336 template type. Set the TYPE_CANONICAL field
6337 appropriately. */
6340 /* Some of the template arguments require structural
6341 equality testing, so this template class requires
6342 structural equality testing. */
6344 }
6346 /* If we called start_enum or pushtag above, this information
6347 will already be set up. */
6349 {
6357 }
6358 else
6366 {
6369 }
6371 /* Set up the template information. We have to figure out which
6372 template is the immediate parent if this is a full
6373 instantiation. */
6376 /* This case is easy; there are no member templates involved. */
6378 else
6379 {
6380 /* This is a full instantiation of a member template. Find
6381 the partial instantiation of which this is an instance. */
6383 /* Temporarily reduce by one the number of levels in the ARGLIST
6384 so as to avoid comparing the last set of arguments. */
6389 }
6399 /* Note this use of the partial instantiation so we can check it
6400 later in maybe_process_partial_specialization. */
6407 /* Now that the type has been registered on the instantiations
6408 list, we set up the enumerators. Because the enumeration
6409 constants may involve the enumeration type itself, we make
6410 sure to register the type first, and then create the
6411 constants. That way, doing tsubst_expr for the enumeration
6412 constants won't result in recursive calls here; we'll find
6413 the instantiation and exit above. */
6417 /* If the type makes use of template parameters, the
6418 code that generates debugging information will crash. */
6421 /* Possibly limit visibility based on template args. */
6426 }
6428 }
6429 \f
6430 struct pair_fn_data
6431 {
6432 tree_fn_t fn;
6434 /* True when we should also visit template parameters that occur in
6435 non-deduced contexts. */
6438 };
6440 /* Called from for_each_template_parm via walk_tree. */
6442 static tree
6444 {
6457 {
6461 /* Fall through. */
6484 /* Since we're not going to walk subtrees, we have to do this
6485 explicitly here. */
6489 /* Fall through. */
6492 /* Check the return type. */
6497 /* Check the parameter types. Since default arguments are not
6498 instantiated until they are needed, the TYPE_ARG_TYPES may
6499 contain expressions that involve template parameters. But,
6500 no-one should be looking at them yet. And, once they're
6501 instantiated, they don't contain template parameters, so
6502 there's no point in looking at them then, either. */
6503 {
6504 tree parm;
6511 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6512 want walk_tree walking into them itself. */
6514 }
6531 /* Fall through. */
6547 /* Record template parameters such as `T' inside `TT<T>'. */
6551 /* Fall through. */
6563 /* A template template parameter is encountered. */
6569 /* Already substituted template template parameter */
6592 /* If there's no type, then this thing must be some expression
6593 involving template parameters. */
6614 }
6616 /* We didn't find any template parameters we liked. */
6618 }
6620 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6621 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6622 call FN with the parameter and the DATA.
6623 If FN returns nonzero, the iteration is terminated, and
6624 for_each_template_parm returns 1. Otherwise, the iteration
6625 continues. If FN never returns a nonzero value, the value
6626 returned by for_each_template_parm is 0. If FN is NULL, it is
6627 considered to be the function which always returns 1.
6629 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6630 parameters that occur in non-deduced contexts. When false, only
6631 visits those template parameters that can be deduced. */
6633 static int
6637 {
6641 /* Set up. */
6646 /* Walk the tree. (Conceptually, we would like to walk without
6647 duplicates, but for_each_template_parm_r recursively calls
6648 for_each_template_parm, so we would need to reorganize a fair
6649 bit to use walk_tree_without_duplicates, so we keep our own
6650 visited list.) */
6653 else
6656 for_each_template_parm_r,
6660 /* Clean up. */
6662 {
6665 }
6668 }
6670 /* Returns true if T depends on any template parameter. */
6672 int
6674 {
6701 else
6702 {
6705 }
6710 }
6712 /* Returns true if T depends on any template parameter with level LEVEL. */
6714 int
6716 {
6719 }
6723 #ifdef GATHER_STATISTICS
6725 #endif
6729 /* We're starting to instantiate D; record the template instantiation context
6730 for diagnostics and to restore it later. */
6732 static int
6734 {
6738 {
6739 /* If the instantiation in question still has unbound template parms,
6740 we don't really care if we can't instantiate it, so just return.
6741 This happens with base instantiation for implicit `typename'. */
6753 }
6763 #ifdef GATHER_STATISTICS
6766 #endif
6770 }
6772 /* We're done instantiating this template; return to the instantiation
6773 context. */
6775 static void
6777 {
6778 /* Restore the filename and line number stashed away when we started
6779 this instantiation. */
6784 }
6786 /* We're instantiating a deferred template; restore the template
6787 instantiation context in which the instantiation was requested, which
6788 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
6790 static tree
6792 {
6802 }
6804 /* Returns the TINST_LEVEL which gives the original instantiation
6805 context. */
6809 {
6815 }
6817 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
6819 bool
6821 {
6822 tree parms;
6839 }
6841 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
6842 vector of template arguments, as for tsubst.
6844 Returns an appropriate tsubst'd friend declaration. */
6846 static tree
6848 {
6849 tree new_friend;
6854 /* This was a friend declared with an explicit template
6855 argument list, e.g.:
6857 friend void f<>(T);
6859 to indicate that f was a template instantiation, not a new
6860 function declaration. Now, we have to figure out what
6861 instantiation of what template. */
6862 {
6864 tree new_args;
6865 tree tmpl;
6868 /* Friend functions are looked up in the containing namespace scope.
6869 We must enter that scope, to avoid finding member functions of the
6870 current class with same name. */
6885 tsk_none);
6887 }
6891 /* The NEW_FRIEND will look like an instantiation, to the
6892 compiler, but is not an instantiation from the point of view of
6893 the language. For example, we might have had:
6895 template <class T> struct S {
6896 template <class U> friend void f(T, U);
6897 };
6899 Then, in S<int>, template <class U> void f(int, U) is not an
6900 instantiation of anything. */
6906 {
6910 }
6912 /* The mangled name for the NEW_FRIEND is incorrect. The function
6913 is not a template instantiation and should not be mangled like
6914 one. Therefore, we forget the mangling here; we'll recompute it
6915 later if we need it. */
6917 {
6920 }
6923 {
6924 tree old_decl;
6925 tree new_friend_template_info;
6926 tree new_friend_result_template_info;
6927 tree ns;
6930 /* We must save some information from NEW_FRIEND before calling
6931 duplicate decls since that function will free NEW_FRIEND if
6932 possible. */
6934 new_friend_is_defn =
6939 {
6940 /* This declaration is a `primary' template. */
6943 new_friend_result_template_info
6945 }
6946 else
6949 /* Make the init_value nonzero so pushdecl knows this is a defn. */
6953 /* Inside pushdecl_namespace_level, we will push into the
6954 current namespace. However, the friend function should go
6955 into the namespace of the template. */
6965 {
6966 /* This new friend declaration matched an existing
6967 declaration. For example, given:
6969 template <class T> void f(T);
6970 template <class U> class C {
6971 template <class T> friend void f(T) {}
6972 };
6974 the friend declaration actually provides the definition
6975 of `f', once C has been instantiated for some type. So,
6976 old_decl will be the out-of-class template declaration,
6977 while new_friend is the in-class definition.
6979 But, if `f' was called before this point, the
6980 instantiation of `f' will have DECL_TI_ARGS corresponding
6981 to `T' but not to `U', references to which might appear
6982 in the definition of `f'. Previously, the most general
6983 template for an instantiation of `f' was the out-of-class
6984 version; now it is the in-class version. Therefore, we
6985 run through all specialization of `f', adding to their
6986 DECL_TI_ARGS appropriately. In particular, they need a
6987 new set of outer arguments, corresponding to the
6988 arguments for this class instantiation.
6990 The same situation can arise with something like this:
6992 friend void f(int);
6993 template <class T> class C {
6994 friend void f(T) {}
6995 };
6997 when `C<int>' is instantiated. Now, `f(int)' is defined
6998 in the class. */
7001 /* On the other hand, if the in-class declaration does
7002 *not* provide a definition, then we don't want to alter
7003 existing definitions. We can just leave everything
7004 alone. */
7005 ;
7006 else
7007 {
7011 /* Overwrite whatever template info was there before, if
7012 any, with the new template information pertaining to
7013 the declaration. */
7017 /* We should have called reregister_specialization in
7018 duplicate_decls. */
7022 else
7023 {
7024 tree t;
7026 /* Indicate that the old function template is a partial
7027 instantiation. */
7035 /* Reassign any specializations already in the hash table
7036 to the new more general template, and add the
7037 additional template args. */
7041 {
7043 spec_entry elt;
7055 register_specialization
7058 }
7060 }
7061 }
7063 /* The information from NEW_FRIEND has been merged into OLD_DECL
7064 by duplicate_decls. */
7066 }
7067 }
7068 else
7069 {
7073 /* In the code
7074 template <class T> class C {
7075 template <class U> friend void C1<U>::f (); // case 1
7076 friend void C2<T>::f (); // case 2
7077 };
7078 we only need to make sure CONTEXT is a complete type for
7079 case 2. To distinguish between the two cases, we note that
7080 CONTEXT of case 1 remains dependent type after tsubst while
7081 this isn't true for case 2. */
7091 {
7092 /* Check to see that the declaration is really present, and,
7093 possibly obtain an improved declaration. */
7099 }
7100 }
7103 }
7105 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7106 template arguments, as for tsubst.
7108 Returns an appropriate tsubst'd friend type or error_mark_node on
7109 failure. */
7111 static tree
7113 {
7114 tree friend_type;
7115 tree tmpl;
7116 tree context;
7121 {
7124 else
7126 }
7128 /* Look for a class template declaration. We look for hidden names
7129 because two friend declarations of the same template are the
7130 same. For example, in:
7132 struct A {
7133 template <typename> friend class F;
7134 };
7135 template <typename> struct B {
7136 template <typename> friend class F;
7137 };
7139 both F templates are the same. */
7144 /* But, if we don't find one, it might be because we're in a
7145 situation like this:
7147 template <class T>
7148 struct S {
7149 template <class U>
7150 friend struct S;
7151 };
7153 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7154 for `S<int>', not the TEMPLATE_DECL. */
7156 {
7159 }
7162 {
7163 /* The friend template has already been declared. Just
7164 check to see that the declarations match, and install any new
7165 default parameters. We must tsubst the default parameters,
7166 of course. We only need the innermost template parameters
7167 because that is all that redeclare_class_template will look
7168 at. */
7171 {
7172 tree parms;
7173 location_t saved_input_location;
7182 }
7185 }
7186 else
7187 {
7188 /* The friend template has not already been declared. In this
7189 case, the instantiation of the template class will cause the
7190 injection of this template into the global scope. */
7195 /* The new TMPL is not an instantiation of anything, so we
7196 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7197 the new type because that is supposed to be the corresponding
7198 template decl, i.e., TMPL. */
7205 /* Inject this template into the global scope. */
7207 }
7210 {
7213 else
7215 }
7218 }
7220 /* Returns zero if TYPE cannot be completed later due to circularity.
7221 Otherwise returns one. */
7223 static int
7225 {
7235 else
7237 }
7239 /* Apply any attributes which had to be deferred until instantiation
7240 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7241 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7243 static void
7246 {
7248 tree t;
7253 {
7257 }
7260 {
7264 }
7265 else
7269 {
7274 {
7277 {
7280 /* If the first attribute argument is an identifier, don't
7281 pass it through tsubst. Attributes like mode, format,
7282 cleanup and several target specific attributes expect it
7283 unmodified. */
7289 {
7290 tree chain
7292 in_decl,
7297 chain);
7298 }
7299 else
7305 }
7306 else
7308 }
7311 }
7312 }
7314 /* Perform (or defer) access check for typedefs that were referenced
7315 from within the template TMPL code.
7316 This is a subroutine of instantiate_template and instantiate_class_template.
7317 TMPL is the template to consider and TARGS is the list of arguments of
7318 that template. */
7320 static void
7322 {
7323 tree t;
7331 {
7345 }
7346 }
7348 tree
7350 {
7352 tree typedecl;
7353 tree pbinfo;
7354 tree base_list;
7365 /* Figure out which template is being instantiated. */
7369 /* Determine what specialization of the original template to
7370 instantiate. */
7373 {
7376 }
7378 {
7379 /* This TYPE is actually an instantiation of a partial
7380 specialization. We replace the innermost set of ARGS with
7381 the arguments appropriate for substitution. For example,
7382 given:
7384 template <class T> struct S {};
7385 template <class T> struct S<T*> {};
7387 and supposing that we are instantiating S<int*>, ARGS will
7388 presently be {int*} -- but we need {int}. */
7391 }
7392 else
7393 {
7396 }
7398 /* If the template we're instantiating is incomplete, then clearly
7399 there's nothing we can do. */
7403 /* If we've recursively instantiated too many templates, stop. */
7407 /* Now we're really doing the instantiation. Mark the type as in
7408 the process of being defined. */
7411 /* We may be in the middle of deferred access check. Disable
7412 it now. */
7416 /* Use #pragma pack from the template context. */
7422 /* Set the input location to the most specialized template definition.
7423 This is needed if tsubsting causes an error. */
7444 {
7447 }
7451 /* We should never instantiate a nested class before its enclosing
7452 class; we need to look up the nested class by name before we can
7453 instantiate it, and that lookup should instantiate the enclosing
7454 class. */
7461 {
7462 tree pbase_binfo;
7464 tree pushed_scope;
7467 /* We must enter the scope containing the type, as that is where
7468 the accessibility of types named in dependent bases are
7469 looked up from. */
7472 /* Substitute into each of the bases to determine the actual
7473 basetypes. */
7475 {
7476 tree base;
7482 {
7483 expanded_bases =
7490 }
7493 {
7495 /* Extract the already-expanded base class. */
7497 else
7498 /* Substitute to figure out the base class. */
7500 NULL_TREE);
7508 }
7509 }
7511 /* The list is now in reverse order; correct that. */
7516 }
7517 /* Now call xref_basetypes to set up all the base-class
7518 information. */
7525 /* Now that our base classes are set up, enter the scope of the
7526 class, so that name lookups into base classes, etc. will work
7527 correctly. This is precisely analogous to what we do in
7528 begin_class_definition when defining an ordinary non-template
7529 class, except we also need to push the enclosing classes. */
7532 /* Now members are processed in the order of declaration. */
7535 {
7539 {
7541 {
7542 /* Build new CLASSTYPE_NESTED_UTDS. */
7544 tree newtag;
7550 /* If the member is a class template, then -- even after
7551 substitution -- there may be dependent types in the
7552 template argument list for the class. We increment
7553 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7554 that function will assume that no types are dependent
7555 when outside of a template. */
7565 {
7569 /* Unfortunately, lookup_template_class sets
7570 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7571 instantiation (i.e., for the type of a member
7572 template class nested within a template class.)
7573 This behavior is required for
7574 maybe_process_partial_specialization to work
7575 correctly, but is not accurate in this case;
7576 the TAG is not an instantiation of anything.
7577 (The corresponding TEMPLATE_DECL is an
7578 instantiation, but the TYPE is not.) */
7581 /* Now, we call pushtag to put this NEWTAG into the scope of
7582 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7583 pushtag calling push_template_decl. We don't have to do
7584 this for enums because it will already have been done in
7585 tsubst_enum. */
7589 }
7590 }
7593 {
7594 /* Build new TYPE_METHODS. */
7595 tree r;
7604 }
7605 else
7606 {
7607 /* Build new TYPE_FIELDS. */
7609 {
7610 tree condition =
7618 }
7620 {
7621 tree r;
7623 /* The file and line for this declaration, to
7624 assist in error message reporting. Since we
7625 called push_tinst_level above, we don't need to
7626 restore these. */
7635 {
7636 /* In [temp.inst]:
7638 [t]he initialization (and any associated
7639 side-effects) of a static data member does
7640 not occur unless the static data member is
7641 itself used in a way that requires the
7642 definition of the static data member to
7643 exist.
7645 Therefore, we do not substitute into the
7646 initialized for the static data member here. */
7647 finish_static_data_member_decl
7655 }
7657 {
7658 /* Determine whether R has a valid type and can be
7659 completed later. If R is invalid, then it is
7660 replaced by error_mark_node so that it will not be
7661 added to TYPE_FIELDS. */
7667 {
7670 }
7671 }
7673 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
7674 such a thing will already have been added to the field
7675 list by tsubst_enum in finish_member_declaration in the
7676 CLASSTYPE_NESTED_UTDS case above. */
7680 {
7683 }
7684 }
7685 }
7686 }
7687 else
7688 {
7690 {
7691 /* Build new CLASSTYPE_FRIEND_CLASSES. */
7697 {
7698 /* template <class T> friend class C; */
7701 }
7703 {
7704 /* template <class T> friend class C::D; */
7710 }
7712 {
7713 /* This could be either
7715 friend class T::C;
7717 when dependent_type_p is false or
7719 template <class U> friend class T::C;
7721 otherwise. */
7724 /* Bump processing_template_decl for correct
7725 dependent_type_p calculation. */
7730 }
7733 {
7734 /* friend class C;
7736 where C hasn't been declared yet. Let's lookup name
7737 from namespace scope directly, bypassing any name that
7738 come from dependent base class. */
7741 /* The call to xref_tag_from_type does injection for friend
7742 classes. */
7744 friend_type =
7748 }
7750 /* friend class C<T>; */
7753 /* Otherwise it's
7755 friend class C;
7757 where C is already declared or
7759 friend class C<int>;
7761 We don't have to do anything in these cases. */
7764 /* Trick make_friend_class into realizing that the friend
7765 we're adding is a template, not an ordinary class. It's
7766 important that we use make_friend_class since it will
7767 perform some error-checking and output cross-reference
7768 information. */
7776 }
7777 else
7778 {
7779 /* Build new DECL_FRIENDLIST. */
7780 tree r;
7782 /* The file and line for this declaration, to
7783 assist in error message reporting. Since we
7784 called push_tinst_level above, we don't need to
7785 restore these. */
7789 {
7792 }
7797 {
7800 }
7801 }
7802 }
7803 }
7805 /* Set the file and line number information to whatever is given for
7806 the class itself. This puts error messages involving generated
7807 implicit functions at a predictable point, and the same point
7808 that would be used for non-template classes. */
7815 /* Now that the class is complete, instantiate default arguments for
7816 any member functions. We don't do this earlier because the
7817 default arguments may reference members of the class. */
7821 /* Implicitly generated member functions will not have template
7822 information; they are not instantiations, but instead are
7823 created "fresh" for each instantiation. */
7827 /* Some typedefs referenced from within the template code need to be access
7828 checked at template instantiation time, i.e now. These types were
7829 added to the template at parsing time. Let's get those and perform
7830 the access checks then. */
7839 /* The vtable for a template class can be emitted in any translation
7840 unit in which the class is instantiated. When there is no key
7841 method, however, finish_struct_1 will already have added TYPE to
7842 the keyed_classes list. */
7847 }
7849 static tree
7851 {
7852 tree r;
7858 else
7859 {
7863 }
7865 }
7867 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
7868 NONTYPE_ARGUMENT_PACK. */
7870 static tree
7872 {
7873 /* Collect all of the extra "packed" parameters into an
7874 argument pack. */
7875 tree parmvec;
7876 tree parmtypevec;
7881 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
7885 {
7888 }
7890 /* Build the argument packs. */
7896 }
7898 /* Substitute ARGS into T, which is an pack expansion
7899 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
7900 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
7901 (if only a partial substitution could be performed) or
7902 ERROR_MARK_NODE if there was an error. */
7903 tree
7905 tree in_decl)
7906 {
7907 tree pattern;
7910 tree result;
7917 /* Determine the argument packs that will instantiate the parameter
7918 packs used in the expansion expression. While we're at it,
7919 compute the number of arguments to be expanded and make sure it
7920 is consistent. */
7923 {
7929 {
7932 {
7933 /* This can happen for a parameter name used later in a function
7934 declaration (such as in a late-specified return type). Just
7935 make a dummy decl, since it's only used for its type. */
7939 }
7940 }
7941 else
7942 {
7949 }
7956 /* This can only happen if we forget to expand an argument
7957 pack somewhere else. Just return an error, silently. */
7958 {
7962 }
7967 {
7972 /* The argument pack that the parameter maps to is just an
7973 expansion of the parameter itself, such as one would
7974 find in the implicit typedef of a class inside the
7975 class itself. Consider this parameter "unsubstituted",
7976 so that we will maintain the outer pack expansion. */
7978 }
7981 {
7985 /* It's all-or-nothing with incomplete argument packs. */
7993 {
7996 }
7998 {
8000 /* We got explicit args for some packs but not others;
8001 do nothing now and try again after deduction. */
8006 pattern);
8007 else
8010 pattern);
8012 }
8014 /* Keep track of the parameter packs and their corresponding
8015 argument packs. */
8018 }
8019 else
8020 /* We can't substitute for this parameter pack. */
8023 unsubstituted_packs);
8024 }
8026 /* We cannot expand this expansion expression, because we don't have
8027 all of the argument packs we need. Substitute into the pattern
8028 and return a PACK_EXPANSION_*. The caller will need to deal with
8029 that. */
8031 {
8032 tree new_pat;
8036 else
8039 }
8041 /* We could not find any argument packs that work. */
8046 {
8047 /* We're in a late-specified return type, so we don't have a local
8048 specializations table. Create one for doing this expansion. */
8051 hash_local_specialization,
8052 eq_local_specializations,
8053 NULL);
8054 }
8056 /* For each argument in each argument pack, substitute into the
8057 pattern. */
8060 {
8061 /* For parameter pack, change the substitution of the parameter
8062 pack to the ith argument in its argument pack, then expand
8063 the pattern. */
8065 {
8069 {
8070 /* Select the Ith argument from the pack. */
8076 }
8077 else
8078 {
8084 {
8085 /* Select the Ith argument from the pack. */
8089 }
8091 /* Update the corresponding argument. */
8093 }
8094 }
8096 /* Substitute into the PATTERN with the altered arguments. */
8101 else
8105 /* When we have incomplete argument packs, the last "expanded"
8106 result is itself a pack expansion, which allows us
8107 to deduce more arguments. */
8112 {
8115 }
8116 }
8118 /* Update ARGS to restore the substitution from parameter packs to
8119 their argument packs. */
8121 {
8126 else
8127 {
8131 /* Update the corresponding argument. */
8135 else
8137 }
8138 }
8141 {
8144 }
8147 }
8149 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8150 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8151 parameter packs; all parms generated from a function parameter pack will
8152 have the same DECL_PARM_INDEX. */
8154 tree
8156 {
8158 tree patparm;
8161 {
8167 }
8168 else
8169 {
8174 }
8177 }
8179 /* Substitute ARGS into the vector or list of template arguments T. */
8181 static tree
8183 {
8190 {
8192 tree new_arg;
8197 {
8198 /* Substitute into an expansion expression. */
8202 /* Add to the expanded length adjustment the number of
8203 expanded arguments. We subtract one from this
8204 measurement, because the argument pack expression
8205 itself is already counted as 1 in
8206 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8207 the argument pack is empty. */
8209 }
8211 {
8212 /* Substitute into each of the arguments. */
8218 new_arg,
8232 }
8233 }
8234 else
8243 }
8248 /* Make space for the expanded arguments coming from template
8249 argument packs. */
8252 {
8256 {
8259 /* Now expand the template argument pack "in place". */
8262 }
8263 else
8264 {
8266 out++;
8267 }
8268 }
8271 }
8273 /* Return the result of substituting ARGS into the template parameters
8274 given by PARMS. If there are m levels of ARGS and m + n levels of
8275 PARMS, then the result will contain n levels of PARMS. For
8276 example, if PARMS is `template <class T> template <class U>
8277 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8278 result will be `template <int*, double, class V>'. */
8280 static tree
8282 {
8286 /* When substituting into a template, we must set
8287 PROCESSING_TEMPLATE_DECL as the template parameters may be
8288 dependent if they are based on one-another, and the dependency
8289 predicates are short-circuit outside of templates. */
8296 {
8297 tree new_vec =
8302 {
8303 tree tuple;
8304 tree default_value;
8305 tree parm_decl;
8327 }
8333 }
8338 }
8340 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8341 type T. If T is not an aggregate or enumeration type, it is
8342 handled as if by tsubst. IN_DECL is as for tsubst. If
8343 ENTERING_SCOPE is nonzero, T is the context for a template which
8344 we are presently tsubst'ing. Return the substituted value. */
8346 static tree
8348 tree args,
8349 tsubst_flags_t complain,
8350 tree in_decl,
8352 {
8357 {
8362 /* Else fall through. */
8366 {
8367 tree argvec;
8368 tree context;
8369 tree r;
8373 /* In "sizeof(X<I>)" we need to evaluate "I". */
8379 /* First, determine the context for the type we are looking
8380 up. */
8383 {
8386 /* If context is a nested class inside a class template,
8387 it may still need to be instantiated (c++/33959). */
8390 }
8392 /* Then, figure out what arguments are appropriate for the
8393 type we are trying to find. For example, given:
8395 template <class T> struct S;
8396 template <class T, class U> void f(T, U) { S<U> su; }
8398 and supposing that we are instantiating f<int, double>,
8399 then our ARGS will be {int, double}, but, when looking up
8400 S we only want {double}. */
8405 else
8406 {
8410 }
8416 }
8417 else
8418 /* This is not a template type, so there's nothing to do. */
8423 }
8424 }
8426 /* Substitute into the default argument ARG (a default argument for
8427 FN), which has the indicated TYPE. */
8429 tree
8431 {
8435 /* This default argument came from a template. Instantiate the
8436 default argument here, not in tsubst. In the case of
8437 something like:
8439 template <class T>
8440 struct S {
8441 static T t();
8442 void f(T = t());
8443 };
8445 we must be careful to do name lookup in the scope of S<T>,
8446 rather than in the current class. */
8448 /* The "this" pointer is not valid in a default argument. */
8450 {
8455 }
8458 /* The default argument expression may cause implicitly defined
8459 member functions to be synthesized, which will result in garbage
8460 collection. We must treat this situation as if we were within
8461 the body of function so as to avoid collecting live data on the
8462 stack. */
8470 /* Restore the "this" pointer. */
8472 {
8475 }
8477 /* Make sure the default argument is reasonable. */
8483 }
8485 /* Substitute into all the default arguments for FN. */
8487 static void
8489 {
8490 tree arg;
8491 tree tmpl_args;
8495 /* If this function is not yet instantiated, we certainly don't need
8496 its default arguments. */
8501 arg;
8507 }
8509 /* Substitute the ARGS into the T, which is a _DECL. Return the
8510 result of the substitution. Issue error and warning messages under
8511 control of COMPLAIN. */
8513 static tree
8515 {
8516 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8517 location_t saved_loc;
8522 /* Set the filename and linenumber to improve error-reporting. */
8527 {
8529 {
8530 /* We can get here when processing a member function template,
8531 member class template, or template template parameter. */
8533 tree spec;
8534 tree tmpl_args;
8535 tree full_args;
8538 {
8539 /* Template template parameter is treated here. */
8552 complain);
8555 }
8557 /* We might already have an instance of this template.
8558 The ARGS are for the surrounding class type, so the
8559 full args contain the tsubst'd args for the context,
8560 plus the innermost args from the template decl. */
8564 /* Because this is a template, the arguments will still be
8565 dependent, even after substitution. If
8566 PROCESSING_TEMPLATE_DECL is not set, the dependency
8567 predicates will short-circuit. */
8575 /* If this is a default template template argument,
8576 tsubst might not have changed anything. */
8583 {
8586 }
8588 /* Make a new template decl. It will be similar to the
8589 original, but will record the current template arguments.
8590 We also create a new function declaration, which is just
8591 like the old one, but points to this new template, rather
8592 than the old one. */
8600 {
8601 tree new_type;
8613 }
8614 else
8615 {
8616 tree new_decl;
8628 }
8634 /* The template parameters for this new template are all the
8635 template parameters for the old template, except the
8636 outermost level of parameters. */
8639 complain);
8645 /* Record this non-type partial instantiation. */
8649 }
8653 {
8654 tree ctx;
8657 tree gen_tmpl;
8658 tree type;
8663 /* Nobody should be tsubst'ing into non-template functions. */
8667 {
8668 tree spec;
8671 /* If T is not dependent, just return it. We have to
8672 increment PROCESSING_TEMPLATE_DECL because
8673 value_dependent_expression_p assumes that nothing is
8674 dependent when PROCESSING_TEMPLATE_DECL is zero. */
8681 /* Calculate the most general template of which R is a
8682 specialization, and the complete set of arguments used to
8683 specialize R. */
8689 /* Check to see if we already have this specialization. */
8694 {
8697 }
8699 /* We can see more levels of arguments than parameters if
8700 there was a specialization of a member template, like
8701 this:
8703 template <class T> struct S { template <class U> void f(); }
8704 template <> template <class U> void S<int>::f(U);
8706 Here, we'll be substituting into the specialization,
8707 because that's where we can find the code we actually
8708 want to generate, but we'll have enough arguments for
8709 the most general template.
8711 We also deal with the peculiar case:
8713 template <class T> struct S {
8714 template <class U> friend void f();
8715 };
8716 template <class U> void f() {}
8717 template S<int>;
8718 template void f<double>();
8720 Here, the ARGS for the instantiation of will be {int,
8721 double}. But, we only need as many ARGS as there are
8722 levels of template parameters in CODE_PATTERN. We are
8723 careful not to get fooled into reducing the ARGS in
8724 situations like:
8726 template <class T> struct S { template <class U> void f(U); }
8727 template <class T> template <> void S<T>::f(int) {}
8729 which we can spot because the pattern will be a
8730 specialization in this case. */
8732 parms_depth =
8737 }
8738 else
8739 {
8740 /* This special case arises when we have something like this:
8742 template <class T> struct S {
8743 friend void f<int>(int, double);
8744 };
8746 Here, the DECL_TI_TEMPLATE for the friend declaration
8747 will be an IDENTIFIER_NODE. We are being called from
8748 tsubst_friend_function, and we want only to create a
8749 new decl (R) with appropriate types so that we can call
8750 determine_specialization. */
8752 }
8755 {
8758 else
8762 }
8763 else
8764 {
8767 }
8772 /* We do NOT check for matching decls pushed separately at this
8773 point, as they may not represent instantiations of this
8774 template, and in any case are considered separate under the
8775 discrete model. */
8779 /* Clear out the mangled name and RTL for the instantiation. */
8782 /* Leave DECL_INITIAL set on deleted instantiations. */
8788 /* Type-conversion operator. Reconstruct the name, in
8789 case it's the name of one of the template's parameters. */
8799 /* If this is an instantiation of a function with internal
8800 linkage, we already know what object file linkage will be
8801 assigned to the instantiation. */
8810 /* We'll re-clone as appropriate in instantiate_template. */
8813 /* If we aren't complaining now, return on error before we register
8814 the specialization so that we'll complain eventually. */
8820 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
8821 this in the special friend case mentioned above where
8822 GEN_TMPL is NULL. */
8824 {
8830 /* We're not supposed to instantiate default arguments
8831 until they are called, for a template. But, for a
8832 declaration like:
8834 template <class T> void f ()
8835 { extern void g(int i = T()); }
8837 we should do the substitution when the template is
8838 instantiated. We handle the member function case in
8839 instantiate_class_template since the default arguments
8840 might refer to other members of the class. */
8845 }
8846 else
8849 /* Copy the list of befriending classes. */
8853 {
8857 in_decl);
8858 }
8861 {
8865 /* If this is an instantiation of a member template, clone it.
8866 If it isn't, that'll be handled by
8867 clone_constructors_and_destructors. */
8870 }
8881 /* Possibly limit visibility based on template args. */
8884 {
8888 }
8896 }
8900 {
8908 {
8909 /* If there is a local specialization that isn't a
8910 parameter pack, it means that we're doing a "simple"
8911 substitution from inside tsubst_pack_expansion. Just
8912 return the local specialization (which will be a single
8913 parm). */
8920 /* Expand the TYPE_PACK_EXPANSION that provides the types for
8921 the parameters in this function parameter pack. */
8925 {
8928 /* Zero-length parameter packs are boring. Just substitute
8929 into the chain. */
8933 }
8934 else
8935 {
8936 /* All we did was update the type. Make a note of that. */
8939 }
8940 }
8942 /* Loop through all of the parameter's we'll build. When T is
8943 a function parameter pack, LEN is the number of expanded
8944 types in EXPANDED_TYPES; otherwise, LEN is 1. */
8947 {
8953 /* An argument of a function parameter pack is not a parameter
8954 pack. */
8958 /* We're on the Ith parameter of the function parameter
8959 pack. */
8960 {
8961 /* Get the Ith type. */
8965 /* Rename the parameter to include the index. */
8968 }
8970 /* We're dealing with a normal parameter. */
8978 {
8981 else
8984 }
8994 /* Keep track of the first new parameter we
8995 generate. That's what will be returned to the
8996 caller. */
9000 /* Build a proper chain of parameters when substituting
9001 into a function parameter pack. */
9004 }
9010 /* FIRST_R contains the start of the chain we've built. */
9012 }
9016 {
9017 tree type;
9026 /* DECL_INITIAL gives the number of bits in a bit-field. */
9031 /* We don't have to set DECL_CONTEXT here; it is set by
9032 finish_member_declaration. */
9039 }
9043 /* We reach here only for member using decls. */
9045 {
9046 r = do_class_using_decl
9051 else
9052 {
9055 }
9056 }
9057 else
9058 {
9061 }
9066 {
9069 tree spec;
9071 tree ctx;
9077 {
9078 /* If this is the canonical decl, we don't have to
9079 mess with instantiations, and often we can't (for
9080 typename, template type parms and such). Note that
9081 TYPE_NAME is not correct for the above test if
9082 we've copied the type for a typedef. */
9088 }
9090 /* Check to see if we already have the specialization we
9091 need. */
9094 {
9095 /* T is a static data member or namespace-scope entity.
9096 We have to substitute into namespace-scope variables
9097 (even though such entities are never templates) because
9098 of cases like:
9100 template <class T> void f() { extern T t; }
9102 where the entity referenced is not known until
9103 instantiation time. */
9107 {
9109 complain,
9111 /* If CTX is unchanged, then T is in fact the
9112 specialization we want. That situation occurs when
9113 referencing a static data member within in its own
9114 class. We can use pointer equality, rather than
9115 same_type_p, because DECL_CONTEXT is always
9116 canonical. */
9119 }
9122 {
9128 }
9129 }
9130 else
9131 {
9132 /* A local variable. */
9134 /* Subsequent calls to pushdecl will fill this in. */
9137 }
9138 /* If we already have the specialization we need, there is
9139 nothing more to do. */
9141 {
9144 }
9146 /* Create a new node for the specialization we need. */
9151 {
9152 /* Even if the original location is out of scope, the
9153 newly substituted one is not. */
9160 {
9161 /* It may seem that this case cannot occur, since:
9163 typedef void f();
9164 void g() { f x; }
9166 declares a function, not a variable. However:
9168 typedef void f();
9169 template <typename T> void g() { T t; }
9170 template void g<f>();
9172 is an attempt to declare a variable with function
9173 type. */
9175 /* R is not yet sufficiently initialized, so we
9176 just use its name. */
9179 }
9186 {
9191 }
9192 }
9198 /* Clear out the mangled name and RTL for the instantiation. */
9202 /* The initializer must not be expanded until it is required;
9203 see [temp.inst]. */
9209 {
9210 /* Possibly limit visibility based on template args. */
9213 {
9217 }
9219 }
9220 /* Preserve a typedef that names a type. */
9224 {
9229 }
9232 {
9233 /* A static data member declaration is always marked
9234 external when it is declared in-class, even if an
9235 initializer is present. We mimic the non-template
9236 processing here. */
9242 }
9244 {
9245 /* We're substituting this var in a decltype outside of its
9246 scope, such as for a lambda return type. Don't add it to
9247 local_specializations, do perform auto deduction. */
9249 tree init
9254 {
9257 }
9258 }
9259 else
9268 }
9273 }
9274 #undef RETURN
9276 out:
9277 /* Restore the file and line information. */
9281 }
9283 /* Substitute into the ARG_TYPES of a function type. */
9285 static tree
9287 tree args,
9288 tsubst_flags_t complain,
9289 tree in_decl)
9290 {
9291 tree remaining_arg_types;
9295 tree default_arg;
9306 {
9307 /* For a pack expansion, perform substitution on the
9308 entire expression. Later on, we'll handle the arguments
9309 one-by-one. */
9314 /* So that we'll spin through the parameters, one by one. */
9316 else
9317 {
9318 /* We only partially substituted into the parameter
9319 pack. Our type is TYPE_PACK_EXPANSION. */
9322 }
9323 }
9336 {
9338 {
9342 }
9344 }
9346 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9347 top-level qualifiers as required. */
9350 /* We do not substitute into default arguments here. The standard
9351 mandates that they be instantiated only when needed, which is
9352 done in build_over_call. */
9356 {
9357 /* We've instantiated a template before its default arguments
9358 have been parsed. This can happen for a nested template
9359 class, and is not an error unless we require the default
9360 argument in a call of this function. */
9361 remaining_arg_types =
9364 remaining_arg_types);
9365 }
9366 else
9367 remaining_arg_types =
9369 }
9372 }
9374 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9375 *not* handle the exception-specification for FNTYPE, because the
9376 initial substitution of explicitly provided template parameters
9377 during argument deduction forbids substitution into the
9378 exception-specification:
9380 [temp.deduct]
9382 All references in the function type of the function template to the
9383 corresponding template parameters are replaced by the specified tem-
9384 plate argument values. If a substitution in a template parameter or
9385 in the function type of the function template results in an invalid
9386 type, type deduction fails. [Note: The equivalent substitution in
9387 exception specifications is done only when the function is instanti-
9388 ated, at which point a program is ill-formed if the substitution
9389 results in an invalid type.] */
9391 static tree
9393 tree args,
9394 tsubst_flags_t complain,
9395 tree in_decl)
9396 {
9397 tree return_type;
9398 tree arg_types;
9399 tree fntype;
9401 /* The TYPE_CONTEXT is not used for function/method types. */
9404 /* Substitute the return type. */
9408 /* The standard does not presently indicate that creation of a
9409 function type with an invalid return type is a deduction failure.
9410 However, that is clearly analogous to creating an array of "void"
9411 or a reference to a reference. This is core issue #486. */
9414 {
9416 {
9419 else
9421 }
9423 }
9425 /* Substitute the argument types. */
9431 /* Construct a new type node and return it. */
9434 else
9435 {
9438 {
9439 /* [temp.deduct]
9441 Type deduction may fail for any of the following
9442 reasons:
9444 -- Attempting to create "pointer to member of T" when T
9445 is not a class type. */
9448 r);
9450 }
9454 }
9459 }
9461 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9462 ARGS into that specification, and return the substituted
9463 specification. If there is no specification, return NULL_TREE. */
9465 static tree
9467 tree args,
9468 tsubst_flags_t complain,
9469 tree in_decl)
9470 {
9471 tree specs;
9472 tree new_specs;
9477 {
9480 else
9482 {
9483 tree spec;
9488 {
9489 /* Expand the pack expansion type. */
9492 in_decl);
9498 else
9499 {
9500 /* We're substituting into a member template, so
9501 we got a TYPE_PACK_EXPANSION back. Add that
9502 expansion and move on. */
9506 expanded_specs,
9507 complain);
9510 }
9511 }
9514 {
9517 else
9522 complain);
9523 }
9526 }
9527 }
9529 }
9531 /* Take the tree structure T and replace template parameters used
9532 therein with the argument vector ARGS. IN_DECL is an associated
9533 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9534 Issue error and warning messages under control of COMPLAIN. Note
9535 that we must be relatively non-tolerant of extensions here, in
9536 order to preserve conformance; if we allow substitutions that
9537 should not be allowed, we may allow argument deductions that should
9538 not succeed, and therefore report ambiguous overload situations
9539 where there are none. In theory, we could allow the substitution,
9540 but indicate that it should have failed, and allow our caller to
9541 make sure that the right thing happens, but we don't try to do this
9542 yet.
9544 This function is used for dealing with types, decls and the like;
9545 for expressions, use tsubst_expr or tsubst_copy. */
9547 tree
9549 {
9568 else
9573 /* Reuse typedefs. We need to do this to handle dependent attributes,
9574 such as attribute aligned. */
9578 {
9584 {
9588 }
9593 else
9594 /* The typedef is from a non-template context. */
9598 {
9600 r = cp_build_qualified_type_real
9604 }
9605 /* Else we must be instantiating the typedef, so fall through. */
9606 }
9618 {
9645 {
9651 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
9652 needed. */
9660 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
9661 with TREE_SIDE_EFFECTS that indicates this is not an integral
9662 constant expression. */
9665 {
9668 }
9674 {
9678 }
9680 /* [temp.deduct]
9682 Type deduction may fail for any of the following
9683 reasons:
9685 Attempting to create an array with a size that is
9686 zero or negative. */
9688 /* We must fail if performing argument deduction (as
9689 indicated by the state of complain), so that
9690 another substitution can be found. */
9694 {
9699 }
9702 }
9708 {
9721 {
9725 /* See through ARGUMENT_PACK_SELECT arguments. */
9727 }
9732 {
9734 /* If ARG is an argument pack, we don't actually want to
9735 perform a substitution here, because substitutions
9736 for argument packs are only done
9737 element-by-element. We can get to this point when
9738 substituting the type of a non-type template
9739 parameter pack, when that type actually contains
9740 template parameter packs from an outer template, e.g.,
9742 template<typename... Types> struct A {
9743 template<Types... Values> struct B { };
9744 }; */
9748 {
9752 /* cv-quals from the template are discarded when
9753 substituting in a function or reference type. */
9758 else
9761 return cp_build_qualified_type_real
9763 }
9765 {
9766 /* We are processing a type constructed from a
9767 template template parameter. */
9773 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
9774 are resolving nested-types in the signature of a
9775 member function templates. Otherwise ARG is a
9776 TEMPLATE_DECL and is the real template to be
9777 instantiated. */
9785 complain);
9786 return cp_build_qualified_type_real
9788 }
9789 else
9790 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
9792 }
9795 /* This can happen during the attempted tsubst'ing in
9796 unify. This means that we don't yet have any information
9797 about the template parameter in question. */
9800 /* If we get here, we must have been looking at a parm for a
9801 more deeply nested template. Make a new version of this
9802 template parameter, but with a lower level. */
9804 {
9809 {
9811 r = cp_build_qualified_type_real
9815 }
9816 else
9817 {
9828 /* We have reduced the level of the template
9829 template parameter, but not the levels of its
9830 template parameters, so canonical_type_parameter
9831 will not be able to find the canonical template
9832 template parameter for this level. Thus, we
9833 require structural equality checking to compare
9834 TEMPLATE_TEMPLATE_PARMs. */
9838 else
9842 {
9850 }
9851 }
9860 }
9863 }
9866 {
9874 {
9878 }
9881 {
9885 }
9888 {
9892 }
9898 }
9901 /* We should never be tsubsting a binfo. */
9905 /* A vector of template arguments. */
9911 {
9920 /* [temp.deduct]
9922 Type deduction may fail for any of the following
9923 reasons:
9925 -- Attempting to create a pointer to reference type.
9926 -- Attempting to create a reference to a reference type or
9927 a reference to void.
9929 Core issue 106 says that creating a reference to a reference
9930 during instantiation is no longer a cause for failure. We
9931 only enforce this check in strict C++98 mode. */
9935 {
9938 /* We keep track of the last time we issued this error
9939 message to avoid spewing a ton of messages during a
9940 single bad template instantiation. */
9943 {
9946 else
9949 type);
9951 }
9954 }
9956 {
9960 }
9962 /* In C++0x, during template argument substitution, when there is an
9963 attempt to create a reference to a reference type, reference
9964 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
9966 "If a template-argument for a template-parameter T names a type
9967 that is a reference to a type A, an attempt to create the type
9968 'lvalue reference to cv T' creates the type 'lvalue reference to
9969 A,' while an attempt to create the type type rvalue reference to
9970 cv T' creates the type T"
9971 */
9972 r = cp_build_reference_type
9975 else
9980 /* Will this ever be needed for TYPE_..._TO values? */
9984 }
9986 {
9989 {
9990 /* [temp.deduct]
9992 Type deduction may fail for any of the following
9993 reasons:
9995 -- Attempting to create "pointer to member of T" when T
9996 is not a class type. */
10000 }
10002 {
10006 }
10008 {
10012 }
10015 {
10016 /* The type of the implicit object parameter gets its
10017 cv-qualifiers from the FUNCTION_TYPE. */
10018 tree memptr;
10022 complain);
10023 }
10024 else
10027 complain);
10028 }
10031 {
10032 tree fntype;
10033 tree specs;
10038 /* Substitute the exception specification. */
10040 in_decl);
10046 }
10048 {
10053 /* As an optimization, we avoid regenerating the array type if
10054 it will obviously be the same as T. */
10058 /* These checks should match the ones in grokdeclarator.
10060 [temp.deduct]
10062 The deduction may fail for any of the following reasons:
10064 -- Attempting to create an array with an element type that
10065 is void, a function type, or a reference type, or [DR337]
10066 an abstract class type. */
10070 {
10074 }
10076 {
10079 type);
10081 }
10086 {
10089 }
10092 }
10096 {
10105 }
10109 {
10115 }
10118 {
10128 {
10132 }
10134 {
10135 /* Normally, make_typename_type does not require that the CTX
10136 have complete type in order to allow things like:
10138 template <class T> struct S { typename S<T>::X Y; };
10140 But, such constructs have already been resolved by this
10141 point, so here CTX really should have complete type, unless
10142 it's a partial instantiation. */
10146 {
10150 }
10151 }
10158 {
10161 }
10164 {
10171 }
10173 return cp_build_qualified_type_real
10175 }
10178 {
10190 }
10198 {
10206 }
10209 {
10217 }
10220 {
10221 tree type;
10230 complain);
10231 }
10234 {
10235 tree type;
10251 else
10252 type = finish_decltype_type
10257 complain);
10258 }
10262 {
10266 tree packed_out =
10268 args,
10269 complain,
10270 in_decl);
10273 /* For template nontype argument packs, also substitute into
10274 the type. */
10279 }
10286 }
10287 }
10289 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10290 type of the expression on the left-hand side of the "." or "->"
10291 operator. */
10293 static tree
10296 {
10297 tree name;
10298 tree qualifying_scope;
10299 tree fns;
10300 tree optype;
10304 /* A baselink indicates a function from a base class. Both the
10305 BASELINK_ACCESS_BINFO and the base class referenced may
10306 indicate bases of the template class, rather than the
10307 instantiated class. In addition, lookups that were not
10308 ambiguous before may be ambiguous now. Therefore, we perform
10309 the lookup again. */
10316 {
10323 }
10327 /* If lookup found a single function, mark it as used at this
10328 point. (If it lookup found multiple functions the one selected
10329 later by overload resolution will be marked as used at that
10330 point.) */
10336 /* Add back the template arguments, if present. */
10341 template_args);
10342 /* Update the conversion operator type. */
10349 qualifying_scope,
10350 object_type);
10351 }
10353 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10354 true if the qualified-id will be a postfix-expression in-and-of
10355 itself; false if more of the postfix-expression follows the
10356 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10357 of "&". */
10359 static tree
10363 {
10364 tree expr;
10365 tree scope;
10366 tree name;
10368 tree template_args;
10372 /* Figure out what name to look up. */
10375 {
10382 }
10383 else
10384 {
10387 }
10389 /* Substitute into the qualifying scope. When there are no ARGS, we
10390 are just trying to simplify a non-dependent expression. In that
10391 case the qualifying scope may be dependent, and, in any case,
10392 substituting will not help. */
10395 {
10398 }
10399 else
10403 {
10409 }
10412 {
10414 {
10415 /* A BIT_NOT_EXPR is used to represent a destructor. */
10417 {
10421 }
10422 else
10425 }
10426 else
10430 {
10432 {
10436 }
10438 }
10439 }
10442 {
10444 scope);
10445 /* Remember that there was a reference to this entity. */
10447 }
10450 {
10456 }
10465 {
10466 expr = (adjust_result_of_qualified_name_lookup
10468 expr = (finish_qualified_id_expr
10472 }
10474 /* Expressions do not generally have reference type. */
10476 /* However, if we're about to form a pointer-to-member, we just
10477 want the referenced member referenced. */
10482 }
10484 /* Like tsubst, but deals with expressions. This function just replaces
10485 template parms; to finish processing the resultant expression, use
10486 tsubst_expr. */
10488 static tree
10490 {
10492 tree r;
10500 {
10505 {
10506 tree c;
10507 /* This can happen for a parameter name used later in a function
10508 declaration (such as in a late-specified return type). Just
10509 make a dummy decl, since it's only used for its type. */
10511 /* We copy T because want to tsubst the PARM_DECL only,
10512 not the following PARM_DECLs that are chained to T. */
10515 /* Give it the template pattern as its context; its true context
10516 hasn't been instantiated yet and this is good enough for
10517 mangling. */
10519 }
10527 {
10528 tree enum_type;
10529 tree v;
10533 /* There is no need to substitute into namespace-scope
10534 enumerators. */
10537 /* If ARGS is NULL, then T is known to be non-dependent. */
10541 /* Unfortunately, we cannot just call lookup_name here.
10542 Consider:
10544 template <int I> int f() {
10545 enum E { a = I };
10546 struct S { void g() { E e = a; } };
10547 };
10549 When we instantiate f<7>::S::g(), say, lookup_name is not
10550 clever enough to find f<7>::a. */
10551 enum_type
10561 /* We didn't find the name. That should never happen; if
10562 name-lookup found it during preliminary parsing, we
10563 should find it again here during instantiation. */
10565 }
10570 {
10571 tree ctx;
10576 {
10579 {
10583 }
10585 }
10586 }
10609 {
10610 /* Template template argument like the following example need
10611 special treatment:
10613 template <template <class> class TT> struct C {};
10614 template <class T> struct D {
10615 template <class U> struct E {};
10616 C<E> c; // #1
10617 };
10618 D<int> d; // #2
10620 We are processing the template argument `E' in #1 for
10621 the template instantiation #2. Originally, `E' is a
10622 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10623 have to substitute this with one having context `D<int>'. */
10627 }
10628 else
10629 /* Ordinary template template argument. */
10638 return build1
10644 {
10645 /* We only want to compute the number of arguments. */
10659 {
10666 else
10669 }
10670 else
10672 }
10673 /* Fall through */
10687 return build1
10692 {
10693 tree object;
10694 tree name;
10699 {
10703 }
10706 {
10716 }
10721 in_decl);
10722 else
10725 }
10763 return build_nt
10776 return build_nt
10783 {
10791 }
10796 {
10797 r = build_nt
10803 }
10806 {
10807 r = build_nt
10813 }
10816 {
10817 r = build_nt
10823 }
10826 {
10827 /* Substituted template arguments */
10836 }
10839 {
10859 }
10884 {
10887 }
10888 else
10892 /* This is handled by tsubst_copy_and_build. */
10897 in_decl),
10901 /* We shouldn't have built any of these during initial template
10902 generation. Instead, they should be built during instantiation
10903 in response to the saved STMT_IS_FULL_EXPR_P setting. */
10920 }
10921 }
10923 /* Like tsubst_copy, but specifically for OpenMP clauses. */
10925 static tree
10927 tree in_decl)
10928 {
10932 {
10938 {
10941 {
10947 }
10948 /* FALLTHRU */
10970 }
10971 }
10974 }
10976 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
10978 static tree
10980 tree in_decl)
10981 {
10982 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11007 #undef RECUR
11008 }
11010 /* Substitute one OMP_FOR iterator. */
11012 static void
11017 {
11018 #define RECUR(NODE) \
11019 tsubst_expr ((NODE), args, complain, in_decl, \
11020 integral_constant_expression_p)
11029 {
11036 }
11040 {
11046 complain);
11047 else
11054 }
11057 {
11058 tree c;
11060 {
11071 }
11073 {
11078 {
11081 }
11082 }
11083 }
11089 else
11093 {
11104 {
11111 }
11112 else
11118 {
11124 }
11128 {
11135 }
11136 else
11142 }
11148 #undef RECUR
11149 }
11151 /* Like tsubst_copy for expressions, etc. but also does semantic
11152 processing. */
11154 static tree
11157 {
11158 #define RECUR(NODE) \
11159 tsubst_expr ((NODE), args, complain, in_decl, \
11160 integral_constant_expression_p)
11173 {
11175 {
11176 tree_stmt_iterator i;
11180 }
11195 else
11204 {
11205 tree decl;
11206 tree init;
11212 {
11215 tree decl;
11223 else
11225 }
11226 else
11227 {
11231 {
11232 /* By marking the declaration as instantiated, we avoid
11233 trying to instantiate it. Since instantiate_decl can't
11234 handle local variables, and since we've already done
11235 all that needs to be done, that's the right thing to
11236 do. */
11241 /* Anonymous aggregates are a special case. */
11243 else
11244 {
11248 {
11249 /* For __PRETTY_FUNCTION__ we have to adjust the
11250 initializer. */
11254 }
11255 else
11256 {
11260 /* If we had an initializer but it
11261 instantiated to nothing,
11262 value-initialize the object. This will
11263 only occur when the initializer was a
11264 pack expansion where the parameter packs
11265 used in that expansion were of length
11266 zero. */
11268 else
11270 }
11273 }
11274 }
11275 }
11277 /* A DECL_EXPR can also be used as an expression, in the condition
11278 clause of an if/for/while construct. */
11280 }
11318 {
11322 }
11330 else
11338 else
11365 {
11367 tree label;
11372 }
11378 /* Computed goto's must be tsubst'd into. On the other hand,
11379 non-computed gotos must not be; the identifier in question
11380 will have no binding. */
11382 else
11388 tmp = finish_asm_stmt
11395 {
11400 }
11405 {
11410 }
11411 else
11412 {
11417 else
11424 else
11430 else
11432 }
11436 {
11440 {
11442 /* Prevent instantiate_decl from trying to instantiate
11443 this variable. We've already done all that needs to be
11444 done. */
11447 }
11452 }
11460 {
11461 tree condition =
11463 args,
11470 }
11491 {
11506 integral_constant_expression_p);
11515 {
11519 }
11520 else
11521 {
11529 }
11543 }
11574 {
11579 }
11595 integral_constant_expression_p);
11596 }
11599 #undef RECUR
11600 }
11602 /* T is a postfix-expression that is not being used in a function
11603 call. Return the substituted version of T. */
11605 static tree
11607 tsubst_flags_t complain,
11608 tree in_decl)
11609 {
11613 else
11619 }
11621 /* Like tsubst but deals with expressions and performs semantic
11622 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11624 tree
11626 tree args,
11627 tsubst_flags_t complain,
11628 tree in_decl,
11631 {
11632 #define RECUR(NODE) \
11633 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11635 integral_constant_expression_p)
11637 tree op1;
11643 {
11646 /* Fall through. */
11648 {
11649 tree decl;
11650 cp_id_kind idk;
11655 {
11658 }
11660 /* Look up the name. */
11663 /* By convention, expressions use ERROR_MARK_NODE to indicate
11664 failure, not NULL_TREE. */
11670 integral_constant_expression_p,
11678 input_location);
11684 }
11687 {
11688 tree object;
11696 {
11699 }
11700 else
11707 else
11709 }
11712 {
11716 {
11717 /* A type conversion to reference type will be enclosed in
11718 such an indirect ref, but the substitution of the cast
11719 will have also added such an indirect ref. */
11722 }
11723 else
11726 }
11729 return build_nop
11738 {
11739 tree type;
11740 tree op;
11745 {
11750 }
11755 {
11768 }
11769 }
11787 complain);
11794 else
11796 in_decl);
11833 return build_x_binary_op
11837 ? ERROR_MARK
11841 ? ERROR_MARK
11844 complain);
11857 /* Fall through */
11862 {
11863 /* When there are no ARGS, we are trying to evaluate a
11864 non-dependent expression from the parser. Trying to do
11865 the substitutions may not work. */
11868 }
11869 else
11870 {
11878 }
11882 else
11887 {
11888 tree r = build_x_modify_expr
11892 complain);
11893 /* TREE_NO_WARNING must be set if either the expression was
11894 parenthesized or it uses an operator such as >>= rather
11895 than plain assignment. In the former case, it was already
11896 set and must be copied. In the latter case,
11897 build_x_modify_expr sets it and it must not be reset
11898 here. */
11902 }
11907 /* Remember that there was a reference to this entity. */
11913 {
11918 tree ret;
11922 else
11923 {
11927 }
11929 /* If there was an initializer in the original tree, but it
11930 instantiated to an empty list, then we should pass a
11931 non-NULL empty vector to tell build_new that it was an
11932 empty initializer() rather than no initializer. This can
11933 only happen when the initializer is a pack expansion whose
11934 parameter packs are of length zero. */
11937 else
11938 {
11942 else
11943 {
11946 }
11947 }
11954 complain);
11962 }
11965 return delete_sanity
11974 complain);
11977 {
11978 tree function;
11983 tree ret;
11986 /* When we parsed the expression, we determined whether or
11987 not Koenig lookup should be performed. */
11990 {
11995 }
11996 else
11997 {
11999 {
12005 }
12006 else
12010 in_decl,
12012 integral_constant_expression_p);
12016 }
12021 {
12027 else
12028 {
12029 /* Expand the pack expansion and push each entry onto
12030 CALL_ARGS. */
12033 {
12038 {
12043 }
12044 }
12045 else
12046 {
12047 /* A partial substitution. Add one entry. */
12049 }
12050 }
12051 }
12053 /* We do not perform argument-dependent lookup if normal
12054 lookup finds a non-function, in accordance with the
12055 expected resolution of DR 218. */
12058 /* If lookup found a member function, the Koenig lookup is
12059 not appropriate, even if an unqualified-name was used
12060 to denote the function. */
12063 /* Only do this when substitution turns a dependent call
12064 into a non-dependent call. */
12070 {
12074 }
12076 /* Remember that there was a reference to this entity. */
12083 {
12088 complain);
12089 else
12090 ret = (build_new_method_call
12096 complain));
12097 }
12098 else
12101 koenig_p,
12102 complain);
12107 }
12110 return build_x_conditional_expr
12114 complain);
12117 return finish_pseudo_destructor_expr
12123 {
12131 {
12132 /* We have pack expansions, so expand those and
12133 create a new list out of it. */
12136 tree chain;
12139 /* Expand the argument expressions. */
12147 /* Build the rest of the list. */
12152 /* Determine the number of arguments. */
12154 {
12157 }
12160 else
12161 {
12162 /* Since we only performed a partial substitution into
12163 the argument pack, we only return a single list
12164 node. */
12171 }
12173 /* Convert the argument vectors into a TREE_LIST */
12176 {
12177 /* Grab the Ith values. */
12178 i--;
12181 value
12185 /* Build the list (backwards). */
12187 }
12190 }
12206 }
12209 {
12210 tree object;
12211 tree object_type;
12212 tree member;
12216 /* Remember that there was a reference to this entity. */
12226 else
12232 {
12234 {
12239 {
12242 }
12244 {
12248 }
12249 }
12250 }
12253 {
12254 tree tmpl;
12255 tree args;
12257 /* Lookup the template functions now that we know what the
12258 scope is. */
12265 {
12268 args);
12269 member = (adjust_result_of_qualified_name_lookup
12271 object_type));
12272 }
12273 else
12274 {
12276 input_location);
12278 }
12279 }
12283 {
12285 {
12289 else
12292 }
12294 }
12300 complain);
12301 }
12304 return build_throw
12308 {
12316 tree r;
12321 /* digest_init will do the wrong thing if we let it. */
12325 /* We do not want to process the index of aggregate
12326 initializers as they are identifier nodes which will be
12327 looked up by digest_init. */
12333 {
12338 {
12339 /* Substitute into the pack expansion. */
12341 in_decl);
12344 ;
12346 /* Just move the argument into place. */
12348 else
12349 {
12350 /* Update the length of the final CONSTRUCTOR
12351 arguments vector, and note that we will need to
12352 copy.*/
12355 }
12356 }
12357 else
12359 }
12362 {
12367 idx++)
12368 {
12370 {
12375 }
12376 else
12378 }
12379 }
12388 }
12391 {
12396 }
12401 /* Fall through */
12404 {
12408 /* If the original type was a reference, we'll be wrapped in
12409 the appropriate INDIRECT_REF. */
12412 }
12417 in_decl));
12423 {
12432 }
12435 {
12441 integral_constant_expression_p);
12446 }
12450 /* As in finish_id_expression, we resolve enumeration constants
12451 to their underlying values. */
12453 {
12456 }
12460 {
12479 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12481 /* Now that we know visibility, instantiate the type so we have a
12482 declaration of the op() for later calls to lambda_function. */
12490 }
12493 /* Handle Objective-C++ constructs, if appropriate. */
12494 {
12495 tree subst
12500 }
12502 }
12504 #undef RECUR
12505 }
12507 /* Verify that the instantiated ARGS are valid. For type arguments,
12508 make sure that the type's linkage is ok. For non-type arguments,
12509 make sure they are constants if they are integral or enumerations.
12510 Emit an error under control of COMPLAIN, and return TRUE on error. */
12512 static bool
12514 {
12516 {
12526 }
12528 {
12529 /* [basic.link]: A name with no linkage (notably, the name
12530 of a class or enumeration declared in a local scope)
12531 shall not be used to declare an entity with linkage.
12532 This implies that names with no linkage cannot be used as
12533 template arguments
12535 DR 757 relaxes this restriction for C++0x. */
12540 {
12541 /* DR 488 makes use of a type with no linkage cause
12542 type deduction to fail. */
12544 {
12547 else
12550 }
12552 }
12553 /* In order to avoid all sorts of complications, we do not
12554 allow variably-modified types as template arguments. */
12556 {
12560 }
12561 }
12562 /* A non-type argument of integral or enumerated type must be a
12563 constant. */
12567 {
12571 }
12573 }
12575 static bool
12577 {
12582 {
12585 }
12589 }
12591 /* Instantiate the indicated variable or function template TMPL with
12592 the template arguments in TARG_PTR. */
12594 tree
12596 {
12598 tree fndecl;
12599 tree gen_tmpl;
12600 tree spec;
12601 HOST_WIDE_INT saved_processing_template_decl;
12608 /* If this function is a clone, handle it specially. */
12610 {
12611 tree spec;
12612 tree clone;
12614 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
12615 DECL_CLONED_FUNCTION. */
12621 /* Look for the clone. */
12625 /* We should always have found the clone by now. */
12628 }
12630 /* Check to see if we already have this specialization. */
12633 /* The TMPL is a partial instantiation. To get a full set of
12634 arguments we must add the arguments used to perform the
12635 partial instantiation. */
12637 targ_ptr);
12639 /* It would be nice to avoid hashing here and then again in tsubst_decl,
12640 but it doesn't seem to be on the hot path. */
12652 complain))
12655 /* We are building a FUNCTION_DECL, during which the access of its
12656 parameters and return types have to be checked. However this
12657 FUNCTION_DECL which is the desired context for access checking
12658 is not built yet. We solve this chicken-and-egg problem by
12659 deferring all checks until we have the FUNCTION_DECL. */
12662 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
12663 (because, for example, we have encountered a non-dependent
12664 function call in the body of a template function and must now
12665 determine which of several overloaded functions will be called),
12666 within the instantiation itself we are not processing a
12667 template. */
12670 /* Substitute template parameters to obtain the specialization. */
12677 /* Now we know the specialization, compute access previously
12678 deferred. */
12681 /* Some typedefs referenced from within the template code need to be access
12682 checked at template instantiation time, i.e now. These types were
12683 added to the template at parsing time. Let's get those and perfom
12684 the acces checks then. */
12690 /* The DECL_TI_TEMPLATE should always be the immediate parent
12691 template, not the most general template. */
12694 /* If we've just instantiated the main entry point for a function,
12695 instantiate all the alternate entry points as well. We do this
12696 by cloning the instantiation of the main entry point, not by
12697 instantiating the template clones. */
12702 }
12704 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
12705 NARGS elements of the arguments that are being used when calling
12706 it. TARGS is a vector into which the deduced template arguments
12707 are placed.
12709 Return zero for success, 2 for an incomplete match that doesn't resolve
12710 all the types, and 1 for complete failure. An error message will be
12711 printed only for an incomplete match.
12713 If FN is a conversion operator, or we are trying to produce a specific
12714 specialization, RETURN_TYPE is the return type desired.
12716 The EXPLICIT_TARGS are explicit template arguments provided via a
12717 template-id.
12719 The parameter STRICT is one of:
12721 DEDUCE_CALL:
12722 We are deducing arguments for a function call, as in
12723 [temp.deduct.call].
12725 DEDUCE_CONV:
12726 We are deducing arguments for a conversion function, as in
12727 [temp.deduct.conv].
12729 DEDUCE_EXACT:
12730 We are deducing arguments when doing an explicit instantiation
12731 as in [temp.explicit], when determining an explicit specialization
12732 as in [temp.expl.spec], or when taking the address of a function
12733 template, as in [temp.deduct.funcaddr]. */
12735 int
12737 tree explicit_targs,
12738 tree targs,
12741 tree return_type,
12742 unification_kind_t strict,
12744 {
12745 tree parms;
12746 tree fntype;
12754 {
12755 /* [temp.deduct]
12757 The specified template arguments must match the template
12758 parameters in kind (i.e., type, nontype, template), and there
12759 must not be more arguments than there are parameters;
12760 otherwise type deduction fails.
12762 Nontype arguments must match the types of the corresponding
12763 nontype template parameters, or must be convertible to the
12764 types of the corresponding nontype parameters as specified in
12765 _temp.arg.nontype_, otherwise type deduction fails.
12767 All references in the function type of the function template
12768 to the corresponding template parameters are replaced by the
12769 specified template argument values. If a substitution in a
12770 template parameter or in the function type of the function
12771 template results in an invalid type, type deduction fails. */
12774 tree converted_args;
12780 converted_args
12787 /* Substitute the explicit args into the function type. This is
12788 necessary so that, for instance, explicitly declared function
12789 arguments can match null pointed constants. If we were given
12790 an incomplete set of explicit args, we must not do semantic
12791 processing during substitution as we could create partial
12792 instantiations. */
12794 {
12798 /* Dig out the actual parm. */
12801 {
12804 }
12806 {
12809 }
12812 {
12814 tree targ;
12817 /* Mark the argument pack as "incomplete". We could
12818 still deduce more arguments during unification. */
12821 {
12825 }
12827 /* We have some incomplete argument packs. */
12829 }
12830 }
12833 /* Any substitution is guaranteed to be incomplete if there
12834 are incomplete argument packs, because we can still deduce
12835 more arguments. */
12837 else
12847 /* Place the explicitly specified arguments in TARGS. */
12850 }
12852 /* Never do unification on the 'this' parameter. */
12856 {
12865 }
12867 /* We allow incomplete unification without an error message here
12868 because the standard doesn't seem to explicitly prohibit it. Our
12869 callers must be ready to deal with unification failures in any
12870 event. */
12876 {
12879 /* Clear the "incomplete" flags on all argument packs. */
12881 {
12884 {
12887 }
12888 }
12889 }
12891 /* Now that we have bindings for all of the template arguments,
12892 ensure that the arguments deduced for the template template
12893 parameters have compatible template parameter lists. We cannot
12894 check this property before we have deduced all template
12895 arguments, because the template parameter types of a template
12896 template parameter might depend on prior template parameters
12897 deduced after the template template parameter. The following
12898 ill-formed example illustrates this issue:
12900 template<typename T, template<T> class C> void f(C<5>, T);
12902 template<int N> struct X {};
12904 void g() {
12905 f(X<5>(), 5l); // error: template argument deduction fails
12906 }
12908 The template parameter list of 'C' depends on the template type
12909 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
12910 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
12911 time that we deduce 'C'. */
12913 && !template_template_parm_bindings_ok_p
12918 /* All is well so far. Now, check:
12920 [temp.deduct]
12922 When all template arguments have been deduced, all uses of
12923 template parameters in nondeduced contexts are replaced with
12924 the corresponding deduced argument values. If the
12925 substitution results in an invalid type, as described above,
12926 type deduction fails. */
12927 {
12932 /* If we're looking for an exact match, check that what we got
12933 is indeed an exact match. It might not be if some template
12934 parameters are used in non-deduced contexts. */
12936 {
12939 tree sarg
12946 }
12947 }
12950 }
12952 /* Adjust types before performing type deduction, as described in
12953 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
12954 sections are symmetric. PARM is the type of a function parameter
12955 or the return type of the conversion function. ARG is the type of
12956 the argument passed to the call, or the type of the value
12957 initialized with the result of the conversion function.
12958 ARG_EXPR is the original argument expression, which may be null. */
12960 static int
12964 tree arg_expr)
12965 {
12969 {
12974 {
12975 /* Swap PARM and ARG throughout the remainder of this
12976 function; the handling is precisely symmetric since PARM
12977 will initialize ARG rather than vice versa. */
12982 }
12985 /* Core issue #873: Do the DR606 thing (see below) for these cases,
12986 too, but here handle it by stripping the reference from PARM
12987 rather than by adding it to ARG. */
12995 /* Nothing else to do in this case. */
13000 }
13003 {
13004 /* [temp.deduct.call]
13006 If P is not a reference type:
13008 --If A is an array type, the pointer type produced by the
13009 array-to-pointer standard conversion (_conv.array_) is
13010 used in place of A for type deduction; otherwise,
13012 --If A is a function type, the pointer type produced by
13013 the function-to-pointer standard conversion
13014 (_conv.func_) is used in place of A for type deduction;
13015 otherwise,
13017 --If A is a cv-qualified type, the top level
13018 cv-qualifiers of A's type are ignored for type
13019 deduction. */
13024 else
13026 }
13028 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13029 of the form T&&, where T is a template parameter, and the argument
13030 is an lvalue, T is deduced as A& */
13038 /* [temp.deduct.call]
13040 If P is a cv-qualified type, the top level cv-qualifiers
13041 of P's type are ignored for type deduction. If P is a
13042 reference type, the type referred to by P is used for
13043 type deduction. */
13046 {
13049 }
13051 /* DR 322. For conversion deduction, remove a reference type on parm
13052 too (which has been swapped into ARG). */
13057 }
13059 /* Most parms like fn_type_unification.
13061 If SUBR is 1, we're being called recursively (to unify the
13062 arguments of a function or method parameter of a function
13063 template). */
13065 static int
13067 tree targs,
13068 tree xparms,
13072 unification_kind_t strict,
13074 {
13080 tree parms;
13090 {
13106 }
13108 again:
13116 {
13129 /* We can't deduce anything from this, but we might get all the
13130 template args from other function args. */
13133 /* Conversions will be performed on a function argument that
13134 corresponds with a function parameter that contains only
13135 non-deducible template parameters and explicitly specified
13136 template parameters. */
13138 {
13139 tree type;
13143 else
13150 flags))
13154 }
13157 {
13160 {
13161 /* [temp.deduct.type]
13163 A template-argument can be deduced from a pointer to
13164 function or pointer to member function argument if
13165 the set of overloaded functions does not contain
13166 function templates and at most one of a set of
13167 overloaded functions provides a unique match. */
13173 }
13178 }
13180 {
13185 arg_expr);
13191 }
13192 }
13198 {
13199 /* Unify the remaining arguments with the pack expansion type. */
13200 tree argvec;
13203 /* Allocate a TREE_VEC and copy in all of the arguments */
13208 /* Copy the parameter into parmvec. */
13214 /* Advance to the end of the list of parameters. */
13216 }
13218 /* Fail if we've reached the end of the parm list, and more args
13219 are present, and the parm list isn't variadic. */
13222 /* Fail if parms are left and they don't have default values. */
13230 {
13231 tree tparm;
13238 /* If this is an undeduced nontype parameter that depends on
13239 a type parameter, try another pass; its type may have been
13240 deduced from a later argument than the one from which
13241 this parameter can be deduced. */
13247 /* Core issue #226 (C++0x) [temp.deduct]:
13249 If a template argument has not been deduced, its
13250 default template argument, if any, is used.
13252 When we are in C++98 mode, TREE_PURPOSE will either
13253 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13254 to explicitly check cxx_dialect here. */
13256 {
13264 else
13265 {
13268 }
13269 }
13271 /* If the type parameter is a parameter pack, then it will
13272 be deduced to an empty parameter pack. */
13274 {
13275 tree arg;
13278 {
13282 }
13283 else
13290 }
13293 }
13296 }
13298 /* Subroutine of type_unification_real. Args are like the variables
13299 at the call site. ARG is an overloaded function (or template-id);
13300 we try deducing template args from each of the overloads, and if
13301 only one succeeds, we go with that. Modifies TARGS and returns
13302 true on success. */
13304 static bool
13306 tree targs,
13307 tree parm,
13308 tree arg,
13309 unification_kind_t strict,
13311 {
13318 {
13321 }
13322 else
13326 /* Handle `&x' where `x' is some static or non-static member
13327 function name. */
13333 /* Strip baselink information. */
13338 {
13339 /* If we got some explicit template args, we need to plug them into
13340 the affected templates before we try to unify, in case the
13341 explicit args will completely resolve the templates in question. */
13347 {
13358 {
13363 {
13366 }
13367 }
13369 }
13370 }
13373 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13374 -- but the deduction does not succeed because the expression is
13375 not just the function on its own. */
13377 else
13383 {
13386 }
13388 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13389 to function or pointer to member function argument if the set of
13390 overloaded functions does not contain function templates and at most
13391 one of a set of overloaded functions provides a unique match.
13393 So if we found multiple possibilities, we return success but don't
13394 deduce anything. */
13397 {
13402 }
13407 }
13409 /* Core DR 115: In contexts where deduction is done and fails, or in
13410 contexts where deduction is not done, if a template argument list is
13411 specified and it, along with any default template arguments, identifies
13412 a single function template specialization, then the template-id is an
13413 lvalue for the function template specialization. */
13415 tree
13417 {
13430 {
13433 }
13435 {
13438 }
13440 {
13443 }
13446 {
13450 /* If we got some explicit template args, we need to plug them into
13451 the affected templates before we try to unify, in case the
13452 explicit args will completely resolve the templates in question. */
13460 {
13471 {
13474 {
13477 }
13479 {
13482 }
13483 }
13485 }
13487 {
13499 }
13501 /* There were no good options and at least one bad one, so let the
13502 user know what the problem is. */
13504 }
13506 }
13508 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13509 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13510 different overloads deduce different arguments for a given parm.
13511 ADDR_P is true if the expression for which deduction is being
13512 performed was of the form "& fn" rather than simply "fn".
13514 Returns 1 on success. */
13516 static int
13518 tree orig_targs,
13519 tree targs,
13520 tree parm,
13521 tree arg,
13522 unification_kind_t strict,
13525 {
13527 tree tempargs;
13530 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13531 to function or pointer to member function argument if the set of
13532 overloaded functions does not contain function templates and at most
13533 one of a set of overloaded functions provides a unique match.
13535 So if this is a template, just return success. */
13547 /* We don't copy orig_targs for this because if we have already deduced
13548 some template args from previous args, unify would complain when we
13549 try to deduce a template parameter for the same argument, even though
13550 there isn't really a conflict. */
13557 /* First make sure we didn't deduce anything that conflicts with
13558 explicitly specified args. */
13560 {
13567 /* Since we're unifying against ourselves, we will fill in
13568 template args used in the function parm list with our own
13569 template parms. Discard them. */
13573 }
13576 {
13581 }
13584 }
13586 /* PARM is a template class (perhaps with unbound template
13587 parameters). ARG is a fully instantiated type. If ARG can be
13588 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
13589 TARGS are as for unify. */
13591 static tree
13593 {
13594 tree copy_of_targs;
13601 /* We need to make a new template argument vector for the call to
13602 unify. If we used TARGS, we'd clutter it up with the result of
13603 the attempted unification, even if this class didn't work out.
13604 We also don't want to commit ourselves to all the unifications
13605 we've already done, since unification is supposed to be done on
13606 an argument-by-argument basis. In other words, consider the
13607 following pathological case:
13609 template <int I, int J, int K>
13610 struct S {};
13612 template <int I, int J>
13613 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
13615 template <int I, int J, int K>
13616 void f(S<I, J, K>, S<I, I, I>);
13618 void g() {
13619 S<0, 0, 0> s0;
13620 S<0, 1, 2> s2;
13622 f(s0, s2);
13623 }
13625 Now, by the time we consider the unification involving `s2', we
13626 already know that we must have `f<0, 0, 0>'. But, even though
13627 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
13628 because there are two ways to unify base classes of S<0, 1, 2>
13629 with S<I, I, I>. If we kept the already deduced knowledge, we
13630 would reject the possibility I=1. */
13633 /* If unification failed, we're done. */
13639 }
13641 /* Given a template type PARM and a class type ARG, find the unique
13642 base type in ARG that is an instance of PARM. We do not examine
13643 ARG itself; only its base-classes. If there is not exactly one
13644 appropriate base class, return NULL_TREE. PARM may be the type of
13645 a partial specialization, as well as a plain template type. Used
13646 by unify. */
13648 static tree
13650 {
13652 tree binfo;
13658 /* The type could not be completed. */
13661 /* Walk in inheritance graph order. The search order is not
13662 important, and this avoids multiple walks of virtual bases. */
13664 {
13668 {
13669 /* If there is more than one satisfactory baseclass, then:
13671 [temp.deduct.call]
13673 If they yield more than one possible deduced A, the type
13674 deduction fails.
13676 applies. */
13681 }
13682 }
13685 }
13687 /* Returns the level of DECL, which declares a template parameter. */
13689 static int
13691 {
13693 {
13703 }
13705 }
13707 /* Decide whether ARG can be unified with PARM, considering only the
13708 cv-qualifiers of each type, given STRICT as documented for unify.
13709 Returns nonzero iff the unification is OK on that basis. */
13711 static int
13713 {
13719 {
13720 /* Although a CVR qualifier is ignored when being applied to a
13721 substituted template parameter ([8.3.2]/1 for example), that
13722 does not apply during deduction [14.8.2.4]/1, (even though
13723 that is not explicitly mentioned, [14.8.2.4]/9 indicates
13724 this). Except when we're allowing additional CV qualifiers
13725 at the outer level [14.8.2.1]/3,1st bullet. */
13735 }
13746 }
13748 /* Determines the LEVEL and INDEX for the template parameter PARM. */
13749 void
13751 {
13755 {
13758 }
13759 else
13760 {
13763 }
13764 }
13766 /* Unifies the remaining arguments in PACKED_ARGS with the pack
13767 expansion at the end of PACKED_PARMS. Returns 0 if the type
13768 deduction succeeds, 1 otherwise. STRICT is the same as in
13769 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
13770 call argument list. We'll need to adjust the arguments to make them
13771 types. SUBR tells us if this is from a recursive call to
13772 type_unification_real. */
13773 int
13777 {
13778 tree parm
13785 /* Determine the parameter packs we will be deducing from the
13786 pattern, and record their current deductions. */
13789 {
13793 /* Determine the index and level of this parameter pack. */
13796 /* Keep track of the parameter packs and their corresponding
13797 argument packs. */
13800 }
13802 /* Loop through all of the arguments that have not yet been
13803 unified and unify each with the pattern. */
13805 {
13808 /* For each parameter pack, clear out the deduced value so that
13809 we can deduce it again. */
13811 {
13816 }
13818 /* Unify the pattern with the current argument. */
13819 {
13826 {
13829 /* This mirrors what we do in type_unification_real. */
13831 {
13833 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
13834 | UNIFY_ALLOW_MORE_CV_QUAL
13848 }
13851 {
13854 {
13855 /* [temp.deduct.type] A template-argument can be
13856 deduced from a pointer to function or pointer
13857 to member function argument if the set of
13858 overloaded functions does not contain function
13859 templates and at most one of a set of
13860 overloaded functions provides a unique
13861 match. */
13866 sub_strict)
13870 }
13873 {
13878 }
13879 }
13884 arg_strict |=
13887 }
13890 {
13893 }
13894 }
13896 /* For each parameter pack, collect the deduced value. */
13898 {
13904 }
13905 }
13907 /* Verify that the results of unification with the parameter packs
13908 produce results consistent with what we've seen before, and make
13909 the deduced argument packs available. */
13911 {
13917 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
13918 actually deduce anything. */
13926 {
13927 /* Prepend the explicit arguments onto NEW_ARGS. */
13933 /* Copy the explicit arguments. */
13938 /* Copy the deduced arguments. */
13942 }
13945 {
13946 tree result;
13951 /* Build the deduced *_ARGUMENT_PACK. */
13953 {
13958 }
13959 else
13964 /* Note the deduced argument packs for this parameter
13965 pack. */
13967 }
13971 {
13972 /* We only had the explicitly-provided arguments before, but
13973 now we have a complete set of arguments. */
13978 /* Keep the original deduced argument pack. */
13984 }
13986 new_args))
13987 /* Inconsistent unification of this parameter pack. */
13989 else
13990 {
13995 /* Keep the original deduced argument pack. */
13997 }
13998 }
14001 }
14003 /* Deduce the value of template parameters. TPARMS is the (innermost)
14004 set of template parameters to a template. TARGS is the bindings
14005 for those template parameters, as determined thus far; TARGS may
14006 include template arguments for outer levels of template parameters
14007 as well. PARM is a parameter to a template function, or a
14008 subcomponent of that parameter; ARG is the corresponding argument.
14009 This function attempts to match PARM with ARG in a manner
14010 consistent with the existing assignments in TARGS. If more values
14011 are deduced, then TARGS is updated.
14013 Returns 0 if the type deduction succeeds, 1 otherwise. The
14014 parameter STRICT is a bitwise or of the following flags:
14016 UNIFY_ALLOW_NONE:
14017 Require an exact match between PARM and ARG.
14018 UNIFY_ALLOW_MORE_CV_QUAL:
14019 Allow the deduced ARG to be more cv-qualified (by qualification
14020 conversion) than ARG.
14021 UNIFY_ALLOW_LESS_CV_QUAL:
14022 Allow the deduced ARG to be less cv-qualified than ARG.
14023 UNIFY_ALLOW_DERIVED:
14024 Allow the deduced ARG to be a template base class of ARG,
14025 or a pointer to a template base class of the type pointed to by
14026 ARG.
14027 UNIFY_ALLOW_INTEGER:
14028 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14029 case for more information.
14030 UNIFY_ALLOW_OUTER_LEVEL:
14031 This is the outermost level of a deduction. Used to determine validity
14032 of qualification conversions. A valid qualification conversion must
14033 have const qualified pointers leading up to the inner type which
14034 requires additional CV quals, except at the outer level, where const
14035 is not required [conv.qual]. It would be normal to set this flag in
14036 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14037 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14038 This is the outermost level of a deduction, and PARM can be more CV
14039 qualified at this point.
14040 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14041 This is the outermost level of a deduction, and PARM can be less CV
14042 qualified at this point. */
14044 static int
14046 {
14048 tree targ;
14049 tree tparm;
14052 /* I don't think this will do the right thing with respect to types.
14053 But the only case I've seen it in so far has been array bounds, where
14054 signedness is the only information lost, and I think that will be
14055 okay. */
14063 /* We can't deduce anything from this, but we might get all the
14064 template args from other function args. */
14067 /* If PARM uses template parameters, then we can't bail out here,
14068 even if ARG == PARM, since we won't record unifications for the
14069 template parameters. We might need them if we're trying to
14070 figure out which of two things is more specialized. */
14074 /* Handle init lists early, so the rest of the function can assume
14075 we're dealing with a type. */
14077 {
14082 /* Replace T with std::initializer_list<T> for deduction. */
14088 /* We can only deduce from an initializer list argument if the
14089 parameter is std::initializer_list; otherwise this is a
14090 non-deduced context. */
14096 {
14099 {
14101 /* It should only be possible to get here for a call. */
14103 elt_strict |= maybe_adjust_types_for_deduction
14106 }
14110 }
14112 /* If the std::initializer_list<T> deduction worked, replace the
14113 deduced A with std::initializer_list<A>. */
14115 {
14120 }
14122 }
14124 /* Immediately reject some pairs that won't unify because of
14125 cv-qualification mismatches. */
14128 /* It is the elements of the array which hold the cv quals of an array
14129 type, and the elements might be template type parms. We'll check
14130 when we recurse. */
14132 /* We check the cv-qualifiers when unifying with template type
14133 parameters below. We want to allow ARG `const T' to unify with
14134 PARM `T' for example, when computing which of two templates
14135 is more specialized, for example. */
14149 {
14153 /* In a type which contains a nested-name-specifier, template
14154 argument values cannot be deduced for template parameters used
14155 within the nested-name-specifier. */
14167 /* The PARM is not one we're trying to unify. Just check
14168 to see if it matches ARG. */
14175 /* Check for mixed types and values. */
14183 {
14184 /* ARG must be constructed from a template class or a template
14185 template parameter. */
14190 {
14193 tree parm_parms
14194 = DECL_INNERMOST_TEMPLATE_PARMS
14199 /* The resolution to DR150 makes clear that default
14200 arguments for an N-argument may not be used to bind T
14201 to a template template parameter with fewer than N
14202 parameters. It is not safe to permit the binding of
14203 default arguments as an extension, as that may change
14204 the meaning of a conforming program. Consider:
14206 struct Dense { static const unsigned int dim = 1; };
14208 template <template <typename> class View,
14209 typename Block>
14210 void operator+(float, View<Block> const&);
14212 template <typename Block,
14213 unsigned int Dim = Block::dim>
14214 struct Lvalue_proxy { operator float() const; };
14216 void
14217 test_1d (void) {
14218 Lvalue_proxy<Dense> p;
14219 float b;
14220 b + p;
14221 }
14223 Here, if Lvalue_proxy is permitted to bind to View, then
14224 the global operator+ will be used; if they are not, the
14225 Lvalue_proxy will be converted to float. */
14227 argvec,
14229 tf_none,
14235 /* Deduce arguments T, i from TT<T> or TT<i>.
14236 We check each element of PARMVEC and ARGVEC individually
14237 rather than the whole TREE_VEC since they can have
14238 different number of elements. */
14245 /* Check if the parameters end in a pack, making them
14246 variadic. */
14255 {
14259 UNIFY_ALLOW_NONE))
14261 }
14266 UNIFY_ALLOW_NONE,
14270 }
14273 /* Fall through to deduce template name. */
14274 }
14278 {
14279 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14281 /* Simple cases: Value already set, does match or doesn't. */
14286 }
14287 else
14288 {
14289 /* If PARM is `const T' and ARG is only `int', we don't have
14290 a match unless we are allowing additional qualification.
14291 If ARG is `const int' and PARM is just `T' that's OK;
14292 that binds `const int' to `T'. */
14297 /* Consider the case where ARG is `const volatile int' and
14298 PARM is `const T'. Then, T should be `volatile int'. */
14299 arg = cp_build_qualified_type_real
14304 /* Simple cases: Value already set, does match or doesn't. */
14310 /* Make sure that ARG is not a variable-sized array. (Note
14311 that were talking about variable-sized arrays (like
14312 `int[n]'), rather than arrays of unknown size (like
14313 `int[]').) We'll get very confused by such a type since
14314 the bound of the array will not be computable in an
14315 instantiation. Besides, such types are not allowed in
14316 ISO C++, so we can do as we please here. */
14320 /* Strip typedefs as in convert_template_argument. */
14322 }
14324 /* If ARG is a parameter pack or an expansion, we cannot unify
14325 against it unless PARM is also a parameter pack. */
14330 /* If the argument deduction results is a METHOD_TYPE,
14331 then there is a problem.
14332 METHOD_TYPE doesn't map to any real C++ type the result of
14333 the deduction can not be of that type. */
14347 /* The PARM is not one we're trying to unify. Just check
14348 to see if it matches ARG. */
14358 /* [temp.deduct.type] If, in the declaration of a function template
14359 with a non-type template-parameter, the non-type
14360 template-parameter is used in an expression in the function
14361 parameter-list and, if the corresponding template-argument is
14362 deduced, the template-argument type shall match the type of the
14363 template-parameter exactly, except that a template-argument
14364 deduced from an array bound may be of any integral type.
14365 The non-type parameter might use already deduced type parameters. */
14368 /* Template-parameter dependent expression. Just accept it for now.
14369 It will later be processed in convert_template_argument. */
14370 ;
14376 /* Convert the ARG to the type of PARM; the deduced non-type
14377 template argument must exactly match the types of the
14378 corresponding parameter. */
14381 /* We haven't deduced the type of this parameter yet. Try again
14382 later. */
14384 else
14387 /* If ARG is a parameter pack or an expansion, we cannot unify
14388 against it unless PARM is also a parameter pack. */
14397 {
14398 /* A pointer-to-member constant can be unified only with
14399 another constant. */
14403 /* Just unify the class member. It would be useless (and possibly
14404 wrong, depending on the strict flags) to unify also
14405 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14406 arg refer to the same variable, even if through different
14407 classes. For instance:
14409 struct A { int x; };
14410 struct B : A { };
14412 Unification of &A::x and &B::x must succeed. */
14415 }
14418 {
14422 /* [temp.deduct.call]
14424 A can be another pointer or pointer to member type that can
14425 be converted to the deduced A via a qualification
14426 conversion (_conv.qual_).
14428 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14429 This will allow for additional cv-qualification of the
14430 pointed-to types if appropriate. */
14433 /* The derived-to-base conversion only persists through one
14434 level of pointers. */
14439 }
14454 {
14455 tree parm_max;
14456 tree arg_max;
14460 /* Our representation of array types uses "N - 1" as the
14461 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14462 not an integer constant. We cannot unify arbitrarily
14463 complex expressions, so we eliminate the MINUS_EXPRs
14464 here. */
14468 {
14471 }
14475 {
14476 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14477 trying to unify the type of a variable with the type
14478 of a template parameter. For example:
14480 template <unsigned int N>
14481 void f (char (&) [N]);
14482 int g();
14483 void h(int i) {
14484 char a[g(i)];
14485 f(a);
14486 }
14488 Here, the type of the ARG will be "int [g(i)]", and
14489 may be a SAVE_EXPR, etc. */
14493 }
14495 /* If only one of the bounds used a MINUS_EXPR, compensate
14496 by adding one to the other bound. */
14499 integer_type_node,
14500 parm_max,
14501 integer_one_node);
14504 integer_type_node,
14505 arg_max,
14506 integer_one_node);
14510 }
14524 /* We have already checked cv-qualification at the top of the
14525 function. */
14529 /* As far as unification is concerned, this wins. Later checks
14530 will invalidate it if necessary. */
14533 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14534 /* Type INTEGER_CST can come from ordinary constant template args. */
14544 {
14553 UNIFY_ALLOW_NONE))
14556 }
14564 {
14571 strict);
14572 }
14575 {
14579 {
14580 /* First, we try to unify the PARM and ARG directly. */
14585 {
14586 /* Fallback to the special case allowed in
14587 [temp.deduct.call]:
14589 If P is a class, and P has the form
14590 template-id, then A can be a derived class of
14591 the deduced A. Likewise, if P is a pointer to
14592 a class of the form template-id, A can be a
14593 pointer to a derived class pointed to by the
14594 deduced A. */
14599 }
14600 }
14604 /* Perhaps PARM is something like S<U> and ARG is S<int>.
14605 Then, we should unify `int' and `U'. */
14607 else
14608 /* There's no chance of unification succeeding. */
14613 }
14620 {
14623 tree a;
14629 /* CV qualifications for methods can never be deduced, they must
14630 match exactly. We need to check them explicitly here,
14631 because type_unification_real treats them as any other
14632 cv-qualified parameter. */
14634 && (!check_cv_quals_for_unify
14654 LOOKUP_NORMAL);
14655 }
14658 /* Unify a pointer to member with a pointer to member function, which
14659 deduces the type of the member as a function type. */
14661 {
14662 tree method_type;
14663 tree fntype;
14664 cp_cv_quals cv_quals;
14666 /* Check top-level cv qualifiers */
14674 /* Determine the type of the function we are unifying against. */
14676 fntype =
14680 /* Extract the cv-qualifiers of the member function from the
14681 implicit object parameter and place them on the function
14682 type to be restored later. */
14683 cv_quals =
14687 }
14695 strict);
14706 /* Matched cases are handled by the ARG == PARM test above. */
14711 {
14719 {
14721 {
14723 /* We can unify against something with a trailing
14724 parameter pack. */
14726 else
14727 /* Since there is something following the pack
14728 expansion, we cannot unify this template argument
14729 list. */
14731 }
14732 }
14735 /* If we don't have enough arguments to satisfy the parameters
14736 (not counting the pack expression at the end), or we have
14737 too many arguments for a parameter list that doesn't end in
14738 a pack expression, we can't unify. */
14743 /* Unify all of the parameters that precede the (optional)
14744 pack expression. */
14746 {
14750 }
14758 }
14764 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
14765 nodes. */
14769 /* Unification fails if we hit an error node. */
14775 /* We must be looking at an expression. This can happen with
14776 something like:
14778 template <int I>
14779 void foo(S<I>, S<I + 2>);
14781 This is a "nondeduced context":
14783 [deduct.type]
14785 The nondeduced contexts are:
14787 --A type that is a template-id in which one or more of
14788 the template-arguments is an expression that references
14789 a template-parameter.
14791 In these cases, we assume deduction succeeded, but don't
14792 actually infer any unifications. */
14797 else
14799 }
14800 }
14801 \f
14802 /* Note that DECL can be defined in this translation unit, if
14803 required. */
14805 static void
14807 {
14808 tree clone;
14812 }
14814 /* Called if RESULT is explicitly instantiated, or is a member of an
14815 explicitly instantiated class. */
14817 void
14819 {
14822 /* If this entity has already been written out, it's too late to
14823 make any modifications. */
14828 /* The TREE_PUBLIC flag for function declarations will have been
14829 set correctly by tsubst. */
14832 /* This might have been set by an earlier implicit instantiation. */
14837 else
14838 {
14840 /* Always make artificials weak. */
14843 /* For WIN32 we also want to put explicit instantiations in
14844 linkonce sections. */
14847 }
14849 /* If EXTERN_P, then this function will not be emitted -- unless
14850 followed by an explicit instantiation, at which point its linkage
14851 will be adjusted. If !EXTERN_P, then this function will be
14852 emitted here. In neither circumstance do we want
14853 import_export_decl to adjust the linkage. */
14855 }
14857 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
14858 important template arguments. If any are missing, we check whether
14859 they're important by using error_mark_node for substituting into any
14860 args that were used for partial ordering (the ones between ARGS and END)
14861 and seeing if it bubbles up. */
14863 static bool
14865 {
14870 {
14873 }
14875 {
14877 {
14881 }
14882 }
14884 }
14886 /* Given two function templates PAT1 and PAT2, return:
14888 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
14889 -1 if PAT2 is more specialized than PAT1.
14890 0 if neither is more specialized.
14892 LEN indicates the number of parameters we should consider
14893 (defaulted parameters should not be considered).
14895 The 1998 std underspecified function template partial ordering, and
14896 DR214 addresses the issue. We take pairs of arguments, one from
14897 each of the templates, and deduce them against each other. One of
14898 the templates will be more specialized if all the *other*
14899 template's arguments deduce against its arguments and at least one
14900 of its arguments *does* *not* deduce against the other template's
14901 corresponding argument. Deduction is done as for class templates.
14902 The arguments used in deduction have reference and top level cv
14903 qualifiers removed. Iff both arguments were originally reference
14904 types *and* deduction succeeds in both directions, the template
14905 with the more cv-qualified argument wins for that pairing (if
14906 neither is more cv-qualified, they both are equal). Unlike regular
14907 deduction, after all the arguments have been deduced in this way,
14908 we do *not* verify the deduced template argument values can be
14909 substituted into non-deduced contexts.
14911 The logic can be a bit confusing here, because we look at deduce1 and
14912 targs1 to see if pat2 is at least as specialized, and vice versa; if we
14913 can find template arguments for pat1 to make arg1 look like arg2, that
14914 means that arg2 is at least as specialized as arg1. */
14916 int
14918 {
14931 /* Remove the this parameter from non-static member functions. If
14932 one is a non-static member function and the other is not a static
14933 member function, remove the first parameter from that function
14934 also. This situation occurs for operator functions where we
14935 locate both a member function (with this pointer) and non-member
14936 operator (with explicit first operand). */
14938 {
14943 }
14945 {
14948 {
14949 len--;
14951 }
14952 }
14954 /* If only one is a conversion operator, they are unordered. */
14958 /* Consider the return type for a conversion function */
14960 {
14963 len++;
14964 }
14966 processing_template_decl++;
14972 /* Stop when an ellipsis is seen. */
14974 {
14983 {
14984 /* When both arguments are pack expansions, we need only
14985 unify the patterns themselves. */
14989 /* This is the last comparison we need to do. */
14991 }
14994 {
14997 }
15000 {
15003 }
15006 {
15007 /* Only of the args is a reference, see if we should apply
15008 array/function pointer decay to it. This is not part of
15009 DR214, but is, IMHO, consistent with the deduction rules
15010 for the function call itself, and with our earlier
15011 implementation of the underspecified partial ordering
15012 rules. (nathan). */
15014 {
15016 {
15019 /* FALLTHROUGH. */
15026 }
15027 }
15028 else
15029 {
15031 {
15034 /* FALLTHROUGH. */
15041 }
15042 }
15043 }
15049 {
15055 /* Setup the parameter vector, which contains only ARG1. */
15058 /* Setup the argument vector, which contains the remaining
15059 arguments. */
15068 /* We cannot deduce in the other direction, because ARG1 is
15069 a pack expansion but ARG2 is not. */
15071 }
15073 {
15079 /* Setup the parameter vector, which contains only ARG1. */
15082 /* Setup the argument vector, which contains the remaining
15083 arguments. */
15092 /* We cannot deduce in the other direction, because ARG2 is
15093 a pack expansion but ARG1 is not.*/
15095 }
15097 else
15098 {
15099 /* The normal case, where neither argument is a pack
15100 expansion. */
15103 }
15105 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15106 arg2, then arg2 is not as specialized as arg1. */
15112 /* "If, for a given type, deduction succeeds in both directions
15113 (i.e., the types are identical after the transformations above)
15114 and if the type from the argument template is more cv-qualified
15115 than the type from the parameter template (as described above)
15116 that type is considered to be more specialized than the other. If
15117 neither type is more cv-qualified than the other then neither type
15118 is more specialized than the other."
15120 We check same_type_p explicitly because deduction can also succeed
15121 in both directions when there is a nondeduced context. */
15125 {
15130 }
15133 /* We've failed to deduce something in either direction.
15134 These must be unordered. */
15139 /* We have already processed all of the arguments in our
15140 handing of the pack expansion type. */
15145 }
15147 /* "In most cases, all template parameters must have values in order for
15148 deduction to succeed, but for partial ordering purposes a template
15149 parameter may remain without a value provided it is not used in the
15150 types being used for partial ordering."
15152 Thus, if we are missing any of the targs1 we need to substitute into
15153 origs1, then pat2 is not as specialized as pat1. This can happen when
15154 there is a nondeduced context. */
15160 processing_template_decl--;
15162 /* All things being equal, if the next argument is a pack expansion
15163 for one function but not for the other, prefer the
15164 non-variadic function. FIXME this is bogus; see c++/41958. */
15168 {
15171 }
15177 else
15179 }
15181 /* Determine which of two partial specializations is more specialized.
15183 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15184 to the first partial specialization. The TREE_VALUE is the
15185 innermost set of template parameters for the partial
15186 specialization. PAT2 is similar, but for the second template.
15188 Return 1 if the first partial specialization is more specialized;
15189 -1 if the second is more specialized; 0 if neither is more
15190 specialized.
15192 See [temp.class.order] for information about determining which of
15193 two templates is more specialized. */
15195 static int
15197 {
15198 tree targs;
15206 /* Just like what happens for functions, if we are ordering between
15207 different class template specializations, we may encounter dependent
15208 types in the arguments, and we need our dependency check functions
15209 to behave correctly. */
15215 {
15218 }
15224 {
15227 }
15230 /* In the case of a tie where at least one of the class templates
15231 has a parameter pack at the end, the template with the most
15232 non-packed parameters wins. */
15234 && any_deductions
15237 {
15243 /* We don't count the pack expansion at the end. */
15253 }
15256 }
15258 /* Return the template arguments that will produce the function signature
15259 DECL from the function template FN, with the explicit template
15260 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15261 also match. Return NULL_TREE if no satisfactory arguments could be
15262 found. */
15264 static tree
15266 {
15269 tree decl_type;
15270 tree decl_arg_types;
15273 tree arg;
15275 /* Substitute the explicit template arguments into the type of DECL.
15276 The call to fn_type_unification will handle substitution into the
15277 FN. */
15280 {
15281 tree tmpl;
15282 tree converted_args;
15286 else
15287 /* We can get here for some invalid specializations. */
15290 converted_args
15293 tf_none,
15302 }
15304 /* Never do unification on the 'this' parameter. */
15323 }
15325 /* Return the innermost template arguments that, when applied to a
15326 template specialization whose innermost template parameters are
15327 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15328 ARGS.
15330 For example, suppose we have:
15332 template <class T, class U> struct S {};
15333 template <class T> struct S<T*, int> {};
15335 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15336 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15337 int}. The resulting vector will be {double}, indicating that `T'
15338 is bound to `double'. */
15340 static tree
15342 {
15344 tree deduced_args;
15345 tree innermost_deduced_args;
15349 {
15353 innermost_deduced_args);
15354 }
15355 else
15361 UNIFY_ALLOW_NONE))
15368 /* Verify that nondeduced template arguments agree with the type
15369 obtained from argument deduction.
15371 For example:
15373 struct A { typedef int X; };
15374 template <class T, class U> struct C {};
15375 template <class T> struct C<T, typename T::X> {};
15377 Then with the instantiation `C<A, int>', we can deduce that
15378 `T' is `A' but unify () does not check whether `typename T::X'
15379 is `int'. */
15382 /* We only need to check the innermost arguments; the other
15383 arguments will always agree. */
15388 /* Now that we have bindings for all of the template arguments,
15389 ensure that the arguments deduced for the template template
15390 parameters have compatible template parameter lists. See the use
15391 of template_template_parm_bindings_ok_p in fn_type_unification
15392 for more information. */
15397 }
15399 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15400 Return the TREE_LIST node with the most specialized template, if
15401 any. If there is no most specialized template, the error_mark_node
15402 is returned.
15404 Note that this function does not look at, or modify, the
15405 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15406 returned is one of the elements of INSTANTIATIONS, callers may
15407 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15408 and retrieve it from the value returned. */
15410 tree
15412 {
15419 {
15425 fate--;
15430 fate++;
15435 {
15436 /* Equally specialized, move to next function. If there
15437 is no next function, nothing's most specialized. */
15442 }
15443 }
15446 /* Now verify that champ is better than everything earlier in the
15447 instantiation list. */
15455 {
15458 }
15460 processing_template_decl--;
15466 }
15468 /* If DECL is a specialization of some template, return the most
15469 general such template. Otherwise, returns NULL_TREE.
15471 For example, given:
15473 template <class T> struct S { template <class U> void f(U); };
15475 if TMPL is `template <class U> void S<int>::f(U)' this will return
15476 the full template. This function will not trace past partial
15477 specializations, however. For example, given in addition:
15479 template <class T> struct S<T*> { template <class U> void f(U); };
15481 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15482 `template <class T> template <class U> S<T*>::f(U)'. */
15484 tree
15486 {
15487 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15488 an immediate specialization. */
15490 {
15494 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15495 template friend. */
15500 }
15502 /* Look for more and more general templates. */
15504 {
15505 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15506 (See cp-tree.h for details.) */
15514 /* Stop if we run into an explicitly specialized class template. */
15521 }
15524 }
15526 /* Return the most specialized of the class template partial
15527 specializations of TMPL which can produce TYPE, a specialization of
15528 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15529 a _TYPE node corresponding to the partial specialization, while the
15530 TREE_PURPOSE is the set of template arguments that must be
15531 substituted into the TREE_TYPE in order to generate TYPE.
15533 If the choice of partial specialization is ambiguous, a diagnostic
15534 is issued, and the error_mark_node is returned. If there are no
15535 partial specializations of TMPL matching TYPE, then NULL_TREE is
15536 returned. */
15538 static tree
15540 {
15542 tree t;
15543 tree champ;
15546 tree args;
15552 /* For determining which partial specialization to use, only the
15553 innermost args are interesting. */
15555 {
15558 }
15561 {
15562 tree partial_spec_args;
15563 tree spec_args;
15568 {
15573 /* Discard the outer levels of args, and then substitute in the
15574 template args from the enclosing class. */
15576 partial_spec_args = tsubst_template_args
15579 /* PARMS already refers to just the innermost parms, but the
15580 template parms in partial_spec_args had their levels lowered
15581 by tsubst, so we need to do the same for the parm list. We
15582 can't just tsubst the TREE_VEC itself, as tsubst wants to
15583 treat a TREE_VEC as an argument vector. */
15590 }
15592 partial_spec_args,
15593 args);
15595 {
15600 }
15601 }
15611 {
15614 ;
15615 else
15616 {
15618 {
15621 {
15624 }
15625 }
15627 }
15628 }
15632 {
15635 {
15638 }
15639 }
15642 {
15646 {
15649 }
15651 }
15654 }
15656 /* Explicitly instantiate DECL. */
15658 void
15660 {
15665 /* An error occurred, for which grokdeclarator has already issued
15666 an appropriate message. */
15669 {
15672 }
15674 {
15675 /* There is an asymmetry here in the way VAR_DECLs and
15676 FUNCTION_DECLs are handled by grokdeclarator. In the case of
15677 the latter, the DECL we get back will be marked as a
15678 template instantiation, and the appropriate
15679 DECL_TEMPLATE_INFO will be set up. This does not happen for
15680 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
15681 should handle VAR_DECLs as it currently handles
15682 FUNCTION_DECLs. */
15684 {
15687 }
15690 {
15693 }
15695 {
15700 }
15701 }
15703 {
15706 }
15707 else
15710 /* Check for various error cases. Note that if the explicit
15711 instantiation is valid the RESULT will currently be marked as an
15712 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
15713 until we get here. */
15716 {
15717 /* DR 259 [temp.spec].
15719 Both an explicit instantiation and a declaration of an explicit
15720 specialization shall not appear in a program unless the explicit
15721 instantiation follows a declaration of the explicit specialization.
15723 For a given set of template parameters, if an explicit
15724 instantiation of a template appears after a declaration of an
15725 explicit specialization for that template, the explicit
15726 instantiation has no effect. */
15728 }
15730 {
15731 /* [temp.spec]
15733 No program shall explicitly instantiate any template more
15734 than once.
15736 We check DECL_NOT_REALLY_EXTERN so as not to complain when
15737 the first instantiation was `extern' and the second is not,
15738 and EXTERN_P for the opposite case. */
15741 /* If an "extern" explicit instantiation follows an ordinary
15742 explicit instantiation, the template is instantiated. */
15745 }
15747 {
15750 }
15752 {
15755 }
15758 ;
15760 {
15763 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
15766 }
15767 else
15775 }
15777 static void
15779 {
15785 {
15788 }
15789 }
15791 /* Called from do_type_instantiation through binding_table_foreach to
15792 do recursive instantiation for the type bound in ENTRY. */
15793 static void
15795 {
15801 }
15803 /* Called from do_type_instantiation to instantiate a member
15804 (a member function or a static member variable) of an
15805 explicitly instantiated class template. */
15806 static void
15808 {
15813 }
15815 /* Perform an explicit instantiation of template class T. STORAGE, if
15816 non-null, is the RID for extern, inline or static. COMPLAIN is
15817 nonzero if this is called from the parser, zero if called recursively,
15818 since the standard is unclear (as detailed below). */
15820 void
15822 {
15832 {
15835 }
15840 {
15843 t);
15845 }
15848 {
15850 {
15852 {
15855 "ISO C++ 1998 forbids the use of %<extern%> on "
15857 }
15858 else
15860 "ISO C++ forbids the use of %qE"
15862 }
15870 else
15871 {
15873 storage);
15875 }
15876 }
15879 {
15880 /* DR 259 [temp.spec].
15882 Both an explicit instantiation and a declaration of an explicit
15883 specialization shall not appear in a program unless the explicit
15884 instantiation follows a declaration of the explicit specialization.
15886 For a given set of template parameters, if an explicit
15887 instantiation of a template appears after a declaration of an
15888 explicit specialization for that template, the explicit
15889 instantiation has no effect. */
15891 }
15893 {
15894 /* [temp.spec]
15896 No program shall explicitly instantiate any template more
15897 than once.
15899 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
15900 instantiation was `extern'. If EXTERN_P then the second is.
15901 These cases are OK. */
15908 /* If we've already instantiated the template, just return now. */
15911 }
15919 {
15920 tree tmp;
15922 /* In contrast to implicit instantiation, where only the
15923 declarations, and not the definitions, of members are
15924 instantiated, we have here:
15926 [temp.explicit]
15928 The explicit instantiation of a class template specialization
15929 implies the instantiation of all of its members not
15930 previously explicitly specialized in the translation unit
15931 containing the explicit instantiation.
15933 Of course, we can't instantiate member template classes, since
15934 we don't have any arguments for them. Note that the standard
15935 is unclear on whether the instantiation of the members are
15936 *explicit* instantiations or not. However, the most natural
15937 interpretation is that it should be an explicit instantiation. */
15952 }
15953 }
15955 /* Given a function DECL, which is a specialization of TMPL, modify
15956 DECL to be a re-instantiation of TMPL with the same template
15957 arguments. TMPL should be the template into which tsubst'ing
15958 should occur for DECL, not the most general template.
15960 One reason for doing this is a scenario like this:
15962 template <class T>
15963 void f(const T&, int i);
15965 void g() { f(3, 7); }
15967 template <class T>
15968 void f(const T& t, const int i) { }
15970 Note that when the template is first instantiated, with
15971 instantiate_template, the resulting DECL will have no name for the
15972 first parameter, and the wrong type for the second. So, when we go
15973 to instantiate the DECL, we regenerate it. */
15975 static void
15977 {
15978 /* The arguments used to instantiate DECL, from the most general
15979 template. */
15980 tree args;
15981 tree code_pattern;
15986 /* Make sure that we can see identifiers, and compute access
15987 correctly. */
15991 {
15992 tree decl_parm;
15993 tree pattern_parm;
15994 tree specs;
16007 specs);
16009 /* Merge parameter declarations. */
16012 pattern_parm
16016 {
16017 tree parm_type;
16018 tree attributes;
16023 NULL_TREE);
16029 {
16032 }
16035 }
16036 /* Merge any parameters that match with the function parameter
16037 pack. */
16039 {
16041 tree expanded_types;
16042 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16043 the parameters in this function parameter pack. */
16048 {
16049 tree parm_type;
16050 tree attributes;
16053 /* Rename the parameter to include the index. */
16062 {
16065 }
16067 }
16068 }
16069 /* Merge additional specifiers from the CODE_PATTERN. */
16073 }
16079 else
16083 }
16085 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16086 substituted to get DECL. */
16088 tree
16090 {
16093 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16094 for the instantiation. This is not always the most general
16095 template. Consider, for example:
16097 template <class T>
16098 struct S { template <class U> void f();
16099 template <> void f<int>(); };
16101 and an instantiation of S<double>::f<int>. We want TD to be the
16102 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16104 more general template. */
16106 /* We must also deal with friend templates. Given:
16108 template <class T> struct S {
16109 template <class U> friend void f() {};
16110 };
16112 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16113 so far as the language is concerned, but that's still
16114 where we get the pattern for the instantiation from. On
16115 other hand, if the definition comes outside the class, say:
16117 template <class T> struct S {
16118 template <class U> friend void f();
16119 };
16120 template <class U> friend void f() {}
16122 we don't need to look any further. That's what the check for
16123 DECL_INITIAL is for. */
16127 {
16128 /* The present template, TD, should not be a definition. If it
16129 were a definition, we should be using it! Note that we
16130 cannot restructure the loop to just keep going until we find
16131 a template with a definition, since that might go too far if
16132 a specialization was declared, but not defined. */
16136 /* Fetch the more general template. */
16138 }
16141 }
16143 /* Returns true if we need to instantiate this template instance even if we
16144 know we aren't going to emit it.. */
16146 bool
16148 {
16149 /* We always instantiate inline functions so that we can inline them. An
16150 explicit instantiation declaration prohibits implicit instantiation of
16151 non-inline functions. With high levels of optimization, we would
16152 normally inline non-inline functions -- but we're not allowed to do
16153 that for "extern template" functions. Therefore, we check
16154 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16157 /* And we need to instantiate static data members so that
16158 their initializers are available in integral constant
16159 expressions. */
16162 }
16164 /* Produce the definition of D, a _DECL generated from a template. If
16165 DEFER_OK is nonzero, then we don't have to actually do the
16166 instantiation now; we just have to do it sometime. Normally it is
16167 an error if this is an explicit instantiation but D is undefined.
16168 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16169 explicitly instantiated class template. */
16171 tree
16174 {
16176 tree gen_args;
16177 tree args;
16178 tree td;
16179 tree code_pattern;
16180 tree spec;
16181 tree gen_tmpl;
16187 /* This function should only be used to instantiate templates for
16188 functions and static member variables. */
16192 /* Variables are never deferred; if instantiation is required, they
16193 are instantiated right away. That allows for better code in the
16194 case that an expression refers to the value of the variable --
16195 if the variable has a constant value the referring expression can
16196 take advantage of that fact. */
16200 /* Don't instantiate cloned functions. Instead, instantiate the
16201 functions they cloned. */
16207 /* D has already been instantiated or explicitly specialized, so
16208 there's nothing for us to do here.
16210 It might seem reasonable to check whether or not D is an explicit
16211 instantiation, and, if so, stop here. But when an explicit
16212 instantiation is deferred until the end of the compilation,
16213 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16214 the instantiation. */
16217 /* Check to see whether we know that this template will be
16218 instantiated in some other file, as with "extern template"
16219 extension. */
16222 /* In general, we do not instantiate such templates. */
16230 /* We should already have the extra args. */
16233 /* And what's in the hash table should match D. */
16237 /* This needs to happen before any tsubsting. */
16243 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16244 for the instantiation. */
16248 /* We should never be trying to instantiate a member of a class
16249 template or partial specialization. */
16254 /* In the case of a friend template whose definition is provided
16255 outside the class, we may have too many arguments. Drop the
16256 ones we don't need. The same is true for specializations. */
16257 args = get_innermost_template_args
16259 else
16264 else
16267 /* We may be in the middle of deferred access check. Disable it now. */
16270 /* Unless an explicit instantiation directive has already determined
16271 the linkage of D, remember that a definition is available for
16272 this entity. */
16280 /* If D is a member of an explicitly instantiated class template,
16281 and no definition is available, treat it like an implicit
16282 instantiation. */
16285 {
16289 }
16291 /* Recheck the substitutions to obtain any warning messages
16292 about ignoring cv qualifiers. Don't do this for artificial decls,
16293 as it breaks the context-sensitive substitution for lambda op(). */
16295 {
16299 /* Make sure that we can see identifiers, and compute access
16300 correctly. D is already the target FUNCTION_DECL with the
16301 right context. */
16305 {
16308 d);
16309 /* Don't simply tsubst the function type, as that will give
16310 duplicate warnings about poor parameter qualifications.
16311 The function arguments are the same as the decl_arguments
16312 without the top level cv qualifiers. */
16314 }
16318 }
16320 /* Defer all other templates, unless we have been explicitly
16321 forbidden from doing so. */
16323 template. */
16324 ! pattern_defined
16325 /* If it's OK to postpone instantiation, do so. */
16326 || defer_ok
16327 /* If this is a static data member that will be defined
16328 elsewhere, we don't want to instantiate the entire data
16329 member, but we do want to instantiate the initializer so that
16330 we can substitute that elsewhere. */
16332 {
16333 /* The definition of the static data member is now required so
16334 we must substitute the initializer. */
16338 {
16339 tree ns;
16340 tree init;
16346 args,
16351 LOOKUP_ONLYCONVERTING);
16354 }
16356 /* We restore the source position here because it's used by
16357 add_pending_template. */
16363 /* [temp.explicit]
16365 The definition of a non-exported function template, a
16366 non-exported member function template, or a non-exported
16367 member function or static data member of a class template
16368 shall be present in every translation unit in which it is
16369 explicitly instantiated. */
16373 /* ??? Historically, we have instantiated inline functions, even
16374 when marked as "extern template". */
16378 }
16379 /* Tell the repository that D is available in this translation unit
16380 -- and see if it is supposed to be instantiated here. */
16382 {
16383 /* In a PCH file, despite the fact that the repository hasn't
16384 requested instantiation in the PCH it is still possible that
16385 an instantiation will be required in a file that includes the
16386 PCH. */
16389 /* Instantiate inline functions so that the inliner can do its
16390 job, even though we'll not be emitting a copy of this
16391 function. */
16394 }
16400 /* Mark D as instantiated so that recursive calls to
16401 instantiate_decl do not try to instantiate it again. */
16404 /* Regenerate the declaration in case the template has been modified
16405 by a subsequent redeclaration. */
16408 /* We already set the file and line above. Reset them now in case
16409 they changed as a result of calling regenerate_decl_from_template. */
16413 {
16414 tree init;
16416 /* Clear out DECL_RTL; whatever was there before may not be right
16417 since we've reset the type of the declaration. */
16421 /* The initializer is placed in DECL_INITIAL by
16422 regenerate_decl_from_template. Pull it out so that
16423 cp_finish_decl can process it. */
16428 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16429 initializer. That function will defer actual emission until
16430 we have a chance to determine linkage. */
16433 /* Enter the scope of D so that access-checking works correctly. */
16437 }
16439 {
16440 htab_t saved_local_specializations;
16441 tree subst_decl;
16442 tree tmpl_parm;
16443 tree spec_parm;
16445 /* Save away the current list, in case we are instantiating one
16446 template from within the body of another. */
16449 /* Set up the list of local specializations. */
16451 hash_local_specialization,
16452 eq_local_specializations,
16453 NULL);
16455 /* Set up context. */
16458 /* Create substitution entries for the parameters. */
16463 {
16467 }
16469 {
16473 }
16475 {
16476 /* Register the (value) argument pack as a specialization of
16477 TMPL_PARM, then move on. */
16482 }
16485 /* Substitute into the body of the function. */
16490 /* Set the current input_location to the end of the function
16491 so that finish_function knows where we are. */
16494 /* We don't need the local specializations any more. */
16498 /* Finish the function. */
16501 }
16503 /* We're not deferring instantiation any more. */
16509 out:
16517 }
16519 /* Run through the list of templates that we wish we could
16520 instantiate, and instantiate any we can. RETRIES is the
16521 number of times we retry pending template instantiation. */
16523 void
16525 {
16529 /* Instantiating templates may trigger vtable generation. This in turn
16530 may require further template instantiations. We place a limit here
16531 to avoid infinite loop. */
16533 {
16537 " instantiating %q+D, possibly from virtual table generation"
16541 /* Pretend that we defined it. */
16544 }
16546 do
16547 {
16552 {
16557 {
16558 tree fn;
16561 {
16565 fn;
16573 }
16576 }
16577 else
16578 {
16581 {
16582 instantiation
16588 }
16592 }
16595 /* If INSTANTIATION has been instantiated, then we don't
16596 need to consider it again in the future. */
16598 else
16599 {
16602 }
16605 }
16607 }
16611 }
16613 /* Substitute ARGVEC into T, which is a list of initializers for
16614 either base class or a non-static data member. The TREE_PURPOSEs
16615 are DECLs, and the TREE_VALUEs are the initializer values. Used by
16616 instantiate_decl. */
16618 static tree
16620 {
16624 {
16625 tree decl;
16626 tree init;
16632 {
16633 tree expr;
16634 tree arg;
16636 /* Expand the base class expansion type into separate base
16637 classes. */
16639 tf_warning_or_error,
16640 NULL_TREE);
16644 /* We'll be building separate TREE_LISTs of arguments for
16645 each base. */
16651 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
16652 expand each argument in the TREE_VALUE of t. */
16658 /* VOID_TYPE_NODE is used to indicate
16659 value-initialization. */
16660 {
16663 }
16664 else
16665 {
16666 /* Substitute parameter packs into each argument in the
16667 TREE_LIST. */
16670 {
16671 tree expanded_exprs;
16673 /* Expand the argument. */
16675 expanded_exprs
16677 tf_warning_or_error,
16678 NULL_TREE);
16682 /* Prepend each of the expanded expressions to the
16683 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
16685 {
16690 }
16691 }
16694 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
16695 since we built them backwards. */
16697 {
16700 }
16701 }
16702 }
16705 {
16707 {
16711 }
16712 else
16713 {
16725 }
16728 {
16732 }
16733 }
16734 }
16736 }
16738 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
16740 static void
16742 {
16747 else
16749 }
16751 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
16752 is the instantiation (which should have been created with
16753 start_enum) and ARGS are the template arguments to use. */
16755 static void
16757 {
16758 tree e;
16761 {
16762 tree value;
16763 tree decl;
16766 /* Note that in a template enum, the TREE_VALUE is the
16767 CONST_DECL, not the corresponding INTEGER_CST. */
16772 /* Give this enumeration constant the correct access. */
16775 /* Actually build the enumerator itself. */
16777 }
16782 }
16784 /* DECL is a FUNCTION_DECL that is a template specialization. Return
16785 its type -- but without substituting the innermost set of template
16786 arguments. So, innermost set of template parameters will appear in
16787 the type. */
16789 tree
16791 {
16792 tree fn_type;
16793 tree tmpl;
16794 tree targs;
16795 tree tparms;
16803 /* There should be as many levels of arguments as there are levels
16804 of parameters. */
16810 /* No substitution is necessary. */
16811 ;
16812 else
16813 {
16815 tree partial_args;
16817 /* Replace the innermost level of the TARGS with NULL_TREEs to
16818 let tsubst know not to substitute for those parameters. */
16827 /* Disable access control as this function is used only during
16828 name-mangling. */
16833 /* Now, do the (partial) substitution to figure out the
16834 appropriate function type. */
16838 /* Substitute into the template parameters to obtain the real
16839 innermost set of parameters. This step is important if the
16840 innermost set of template parameters contains value
16841 parameters whose types depend on outer template parameters. */
16846 }
16849 }
16851 /* Return truthvalue if we're processing a template different from
16852 the last one involved in diagnostics. */
16853 int
16855 {
16857 }
16859 /* Remember current template involved in diagnostics. */
16860 void
16862 {
16864 }
16868 {
16870 }
16872 /* [temp.param] Check that template non-type parm TYPE is of an allowable
16873 type. Return zero for ok, nonzero for disallowed. Issue error and
16874 warning messages under control of COMPLAIN. */
16876 static int
16878 {
16893 }
16895 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
16896 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
16898 static bool
16900 {
16901 tree scope;
16903 /* [temp.dep.type]
16905 A type is dependent if it is:
16907 -- a template parameter. Template template parameters are types
16908 for us (since TYPE_P holds true for them) so we handle
16909 them here. */
16913 /* -- a qualified-id with a nested-name-specifier which contains a
16914 class-name that names a dependent type or whose unqualified-id
16915 names a dependent type. */
16918 /* -- a cv-qualified type where the cv-unqualified type is
16919 dependent. */
16921 /* -- a compound type constructed from any dependent type. */
16931 {
16932 tree arg_type;
16937 arg_type;
16942 }
16943 /* -- an array type constructed from any dependent type or whose
16944 size is specified by a constant expression that is
16945 value-dependent. */
16947 {
16952 }
16955 {
16956 /* If this is the TYPE_DOMAIN of an array type, consider it
16957 dependent. We already checked for value-dependence in
16958 compute_array_index_type. */
16960 }
16962 /* -- a template-id in which either the template name is a template
16963 parameter ... */
16966 /* ... or any of the template arguments is a dependent type or
16967 an expression that is type-dependent or value-dependent. */
16969 && (any_dependent_template_arguments_p
16973 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
16974 argument of the `typeof' expression is not type-dependent, then
16975 it should already been have resolved. */
16980 /* A template argument pack is dependent if any of its packed
16981 arguments are. */
16983 {
16989 }
16991 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
16992 be template parameters. */
16996 /* The standard does not specifically mention types that are local
16997 to template functions or local classes, but they should be
16998 considered dependent too. For example:
17000 template <int I> void f() {
17001 enum E { a = I };
17002 S<sizeof (E)> s;
17003 }
17005 The size of `E' cannot be known until the value of `I' has been
17006 determined. Therefore, `E' must be considered dependent. */
17013 /* Other types are non-dependent. */
17015 }
17017 /* Returns TRUE if TYPE is dependent, in the sense of
17018 [temp.dep.type]. */
17020 bool
17022 {
17023 /* If there are no template parameters in scope, then there can't be
17024 any dependent types. */
17026 {
17027 /* If we are not processing a template, then nobody should be
17028 providing us with a dependent type. */
17032 }
17034 /* If the type is NULL, we have not computed a type for the entity
17035 in question; in that case, the type is dependent. */
17039 /* Erroneous types can be considered non-dependent. */
17043 /* If we have not already computed the appropriate value for TYPE,
17044 do so now. */
17046 {
17049 }
17052 }
17054 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17055 lookup. In other words, a dependent type that is not the current
17056 instantiation. */
17058 bool
17060 {
17063 }
17065 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
17067 static bool
17069 {
17070 tree scope;
17071 tree name;
17081 /* [temp.dep.expr]
17083 An id-expression is type-dependent if it contains a
17084 nested-name-specifier that contains a class-name that names a
17085 dependent type. */
17086 /* The suggested resolution to Core Issue 224 implies that if the
17087 qualifying type is the current class, then we must peek
17088 inside it. */
17097 }
17099 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17100 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17101 expression. */
17103 bool
17105 {
17109 /* A name declared with a dependent type. */
17114 {
17116 /* A name that has not been looked up -- must be dependent. */
17120 /* A non-type template parm. */
17124 /* A non-type template parm. */
17130 /* A constant with integral or enumeration type and is initialized
17131 with an expression that is value-dependent. */
17143 /* These expressions are value-dependent if the type to which
17144 the cast occurs is dependent or the expression being casted
17145 is value-dependent. */
17146 {
17152 /* A functional cast has a list of operands. */
17155 {
17156 /* If there are no operands, it must be an expression such
17157 as "int()". This should not happen for aggregate types
17158 because it would form non-constant expressions. */
17162 }
17168 }
17172 /* A `sizeof' expression is value-dependent if the operand is
17173 type-dependent or is a pack expansion. */
17189 /* A CALL_EXPR may appear in a constant expression if it is a
17190 call to a builtin function, e.g., __builtin_constant_p. All
17191 such calls are value-dependent. */
17195 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17196 is value-dependent. */
17197 {
17206 }
17209 {
17213 }
17220 /* A constant expression is value-dependent if any subexpression is
17221 value-dependent. */
17223 {
17233 || (value_dependent_expression_p
17238 {
17241 /* In some cases, some of the operands may be missing.
17242 (For example, in the case of PREDECREMENT_EXPR, the
17243 amount to increment by may be missing.) That doesn't
17244 make the expression dependent. */
17246 && (value_dependent_expression_p
17250 }
17254 }
17255 }
17257 /* The expression is not value-dependent. */
17259 }
17261 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17262 [temp.dep.expr]. */
17264 bool
17266 {
17273 /* An unresolved name is always dependent. */
17278 /* Some expression forms are never type-dependent. */
17289 /* The types of these expressions depends only on the type to which
17290 the cast occurs. */
17298 /* The types of these expressions depends only on the type created
17299 by the expression. */
17302 {
17303 /* For NEW_EXPR tree nodes created inside a template, either
17304 the object type itself or a TREE_LIST may appear as the
17305 operand 1. */
17308 /* This is an array type. We need to check array dimensions
17309 as well. */
17311 || value_dependent_expression_p
17313 else
17315 }
17319 type_dependent_expression_p))
17325 && (any_dependent_template_arguments_p
17337 {
17338 tree elt;
17342 {
17345 }
17347 }
17350 {
17355 {
17361 }
17362 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17370 {
17375 }
17380 {
17384 }
17386 }
17391 }
17393 /* Like type_dependent_expression_p, but it also works while not processing
17394 a template definition, i.e. during substitution or mangling. */
17396 bool
17398 {
17404 }
17406 /* Returns TRUE if ARGS contains a type-dependent expression. */
17408 bool
17410 {
17412 tree arg;
17415 {
17418 }
17420 }
17422 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17423 expressions) contains any value-dependent expressions. */
17425 bool
17427 {
17433 }
17435 /* Returns TRUE if the ARG (a template argument) is dependent. */
17437 bool
17439 {
17447 {
17451 {
17454 }
17457 }
17460 else
17463 }
17465 /* Returns true if ARGS (a collection of template arguments) contains
17466 any types that require structural equality testing. */
17468 bool
17470 {
17480 {
17483 {
17489 {
17490 /* Look inside the argument pack. */
17493 }
17496 {
17510 }
17511 }
17512 }
17515 }
17517 /* Returns true if ARGS (a collection of template arguments) contains
17518 any dependent arguments. */
17520 bool
17522 {
17532 {
17537 }
17540 }
17542 /* Returns TRUE if the template TMPL is dependent. */
17544 bool
17546 {
17548 {
17550 {
17554 }
17556 }
17558 /* Template template parameters are dependent. */
17562 /* So are names that have not been looked up. */
17566 /* So are member templates of dependent classes. */
17570 }
17572 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
17574 bool
17576 {
17579 }
17581 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
17582 is dependent. */
17584 bool
17586 {
17593 {
17614 {
17618 }
17622 {
17626 {
17631 }
17632 }
17633 }
17636 }
17638 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
17639 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
17640 no such TYPE can be found. Note that this function peers inside
17641 uninstantiated templates and therefore should be used only in
17642 extremely limited situations. ONLY_CURRENT_P restricts this
17643 peering to the currently open classes hierarchy (which is required
17644 when comparing types). */
17646 tree
17648 {
17649 tree scope;
17650 tree name;
17651 tree decl;
17653 tree pushed_scope;
17654 tree result;
17659 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
17660 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
17661 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
17662 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
17663 identifier of the TYPENAME_TYPE anymore.
17664 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
17665 TYPENAME_TYPE instead, we avoid messing up with a possible
17666 typedef variant case. */
17669 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
17670 it first before we can figure out what NAME refers to. */
17673 /* If we don't know what SCOPE refers to, then we cannot resolve the
17674 TYPENAME_TYPE. */
17677 /* If the SCOPE is a template type parameter, we have no way of
17678 resolving the name. */
17681 /* If the SCOPE is not the current instantiation, there's no reason
17682 to look inside it. */
17685 /* If SCOPE isn't the template itself, it will not have a valid
17686 TYPE_FIELDS list. */
17688 /* scope is either the template itself or a compatible instantiation
17689 like X<T>, so look up the name in the original template. */
17691 else
17692 /* scope is a partial instantiation, so we can't do the lookup or we
17693 will lose the template arguments. */
17695 /* Enter the SCOPE so that name lookup will be resolved as if we
17696 were in the class definition. In particular, SCOPE will no
17697 longer be considered a dependent type. */
17699 /* Look up the declaration. */
17704 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
17705 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
17710 {
17714 }
17717 {
17718 tree tmpl;
17719 tree args;
17720 /* Obtain the template and the arguments. */
17723 /* Instantiate the template. */
17729 }
17731 /* Leave the SCOPE. */
17735 /* If we failed to resolve it, return the original typename. */
17739 /* If lookup found a typename type, resolve that too. */
17741 {
17742 /* Ill-formed programs can cause infinite recursion here, so we
17743 must catch that. */
17747 }
17749 /* Qualify the resulting type. */
17755 }
17757 /* EXPR is an expression which is not type-dependent. Return a proxy
17758 for EXPR that can be used to compute the types of larger
17759 expressions containing EXPR. */
17761 tree
17763 {
17764 tree inner_expr;
17766 /* Preserve null pointer constants so that the type of things like
17767 "p == 0" where "p" is a pointer can be determined. */
17770 /* Preserve OVERLOADs; the functions must be available to resolve
17771 types. */
17782 /* There is no need to return a proxy for a variable. */
17785 /* Preserve string constants; conversions from string constants to
17786 "char *" are allowed, even though normally a "const char *"
17787 cannot be used to initialize a "char *". */
17790 /* Preserve arithmetic constants, as an optimization -- there is no
17791 reason to create a new node. */
17794 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
17795 There is at least one place where we want to know that a
17796 particular expression is a throw-expression: when checking a ?:
17797 expression, there are special rules if the second or third
17798 argument is a throw-expression. */
17817 /* If the type is unknown, it can't really be non-dependent */
17820 /* Otherwise, build a NON_DEPENDENT_EXPR.
17822 REFERENCE_TYPEs are not stripped for expressions in templates
17823 because doing so would play havoc with mangling. Consider, for
17824 example:
17826 template <typename T> void f<T& g>() { g(); }
17828 In the body of "f", the expression for "g" will have
17829 REFERENCE_TYPE, even though the standard says that it should
17830 not. The reason is that we must preserve the syntactic form of
17831 the expression so that mangling (say) "f<g>" inside the body of
17832 "f" works out correctly. Therefore, the REFERENCE_TYPE is
17833 stripped here. */
17835 }
17837 /* ARGS is a vector of expressions as arguments to a function call.
17838 Replace the arguments with equivalent non-dependent expressions.
17839 This modifies ARGS in place. */
17841 void
17843 {
17845 tree arg;
17848 {
17852 }
17853 }
17855 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
17856 with a level one deeper than the actual template parms. */
17858 tree
17860 {
17873 }
17875 /* Given type ARG, return std::initializer_list<ARG>. */
17877 static tree
17879 {
17880 tree std_init_list = namespace_binding
17882 tree argvec;
17884 {
17888 }
17893 }
17895 /* Replace auto in TYPE with std::initializer_list<auto>. */
17897 static tree
17899 {
17906 }
17908 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
17909 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
17911 tree
17913 {
17918 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
17919 with either a new invented type template parameter U or, if the
17920 initializer is a braced-init-list (8.5.4), with
17921 std::initializer_list<U>. */
17934 {
17937 }
17939 /* If the list of declarators contains more than one declarator, the type
17940 of each declared variable is determined as described above. If the
17941 type deduced for the template parameter U is not the same in each
17942 deduction, the program is ill-formed. */
17945 {
17949 }
17955 }
17957 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
17958 result. */
17960 tree
17962 {
17963 tree argvec;
17972 }
17974 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
17976 bool
17978 {
17982 else
17984 }
17986 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
17987 appear as a type-specifier for the declaration in question, we don't
17988 have to look through the whole type. */
17990 tree
17992 {
18009 }
18011 /* For a given template T, return the list of typedefs referenced
18012 in T for which access check is needed at T instantiation time.
18013 T is either a FUNCTION_DECL or a RECORD_TYPE.
18014 Those typedefs were added to T by the function
18015 append_type_to_template_for_access_check. */
18017 tree
18019 {
18030 {
18035 }
18038 }
18040 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18041 tied to T. That list of typedefs will be access checked at
18042 T instantiation time.
18043 T is either a FUNCTION_DECL or a RECORD_TYPE.
18044 TYPE_DECL is a TYPE_DECL node representing a typedef.
18045 SCOPE is the scope through which TYPE_DECL is accessed.
18047 This function is a subroutine of
18048 append_type_to_template_for_access_check. */
18050 static void
18052 tree type_decl,
18053 tree scope)
18054 {
18055 tree ti;
18062 && type_decl
18073 }
18075 /* Append TYPE_DECL to the template TEMPL.
18076 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18077 At TEMPL instanciation time, TYPE_DECL will be checked to see
18078 if it can be accessed through SCOPE.
18080 e.g. consider the following code snippet:
18082 class C
18083 {
18084 typedef int myint;
18085 };
18087 template<class U> struct S
18088 {
18089 C::myint mi;
18090 };
18092 S<char> s;
18094 At S<char> instantiation time, we need to check the access of C::myint
18095 In other words, we need to check the access of the myint typedef through
18096 the C scope. For that purpose, this function will add the myint typedef
18097 and the scope C through which its being accessed to a list of typedefs
18098 tied to the template S. That list will be walked at template instantiation
18099 time and access check performed on each typedefs it contains.
18100 Note that this particular code snippet should yield an error because
18101 myint is private to C. */
18103 void
18105 tree type_decl,
18106 tree scope)
18107 {
18108 tree node;
18112 /* Make sure we don't append the type to the template twice. */
18114 node;
18116 {
18122 }
18125 }
18127 /* Set up the hash tables for template instantiations. */
18129 void
18131 {
18133 hash_specialization,
18134 eq_specializations,
18135 ggc_free);
18137 hash_specialization,
18138 eq_specializations,
18139 ggc_free);
18140 }