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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, 2010
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". */
48 /* The type of functions taking a tree, and some additional data, and
49 returning an int. */
52 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
53 instantiations have been deferred, either because their definitions
54 were not yet available, or because we were putting off doing the work. */
58 };
73 /* Live only within one (recursive) call to tsubst_expr. We use
74 this to pass the statement expression node from the STMT_EXPR
75 to the EXPR_STMT that is its result. */
78 /* A map from local variable declarations in the body of the template
79 presently being instantiated to the corresponding instantiated
80 local variables. */
84 {
85 tree tmpl;
86 tree args;
87 tree spec;
91 htab_t decl_specializations;
94 htab_t type_specializations;
96 /* Contains canonical template parameter types. The vector is indexed by
97 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
98 TREE_LIST, whose TREE_VALUEs contain the canonical template
99 parameters of various types and levels. */
102 #define UNIFY_ALLOW_NONE 0
103 #define UNIFY_ALLOW_MORE_CV_QUAL 1
104 #define UNIFY_ALLOW_LESS_CV_QUAL 2
105 #define UNIFY_ALLOW_DERIVED 4
106 #define UNIFY_ALLOW_INTEGER 8
107 #define UNIFY_ALLOW_OUTER_LEVEL 16
108 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
109 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
129 tree);
189 location_t);
194 /* Make the current scope suitable for access checking when we are
195 processing T. T can be FUNCTION_DECL for instantiated function
196 template, or VAR_DECL for static member variable (need by
197 instantiate_decl). */
199 static void
201 {
209 else
213 {
214 saved_access_scope = tree_cons
217 }
218 }
220 /* Restore the scope set up by push_access_scope. T is the node we
221 are processing. */
223 static void
225 {
227 {
230 }
234 else
236 }
238 /* Do any processing required when DECL (a member template
239 declaration) is finished. Returns the TEMPLATE_DECL corresponding
240 to DECL, unless it is a specialization, in which case the DECL
241 itself is returned. */
243 tree
245 {
252 {
253 tree type;
261 {
265 }
267 }
271 {
273 {
276 }
277 else
279 }
280 else
284 }
286 /* Create a template info node. */
288 tree
290 {
295 }
297 /* Return the template info node corresponding to T, whatever T is. */
299 tree
301 {
319 }
321 /* Returns the template nesting level of the indicated class TYPE.
323 For example, in:
324 template <class T>
325 struct A
326 {
327 template <class U>
328 struct B {};
329 };
331 A<T>::B<U> has depth two, while A<T> has depth one.
332 Both A<T>::B<int> and A<int>::B<U> have depth one, if
333 they are instantiations, not specializations.
335 This function is guaranteed to return 0 if passed NULL_TREE so
336 that, for example, `template_class_depth (current_class_type)' is
337 always safe. */
339 int
341 {
348 {
354 }
357 }
359 /* Subroutine of maybe_begin_member_template_processing.
360 Returns true if processing DECL needs us to push template parms. */
362 static bool
364 {
370 }
372 /* Subroutine of maybe_begin_member_template_processing.
373 Push the template parms in PARMS, starting from LEVELS steps into the
374 chain, and ending at the beginning, since template parms are listed
375 innermost first. */
377 static void
379 {
387 current_template_parms
393 NULL);
395 {
404 {
411 {
412 /* Make a CONST_DECL as is done in process_template_parm.
413 It is ugly that we recreate this here; the original
414 version built in process_template_parm is no longer
415 available. */
425 }
430 }
431 }
432 }
434 /* Restore the template parameter context for a member template or
435 a friend template defined in a class definition. */
437 void
439 {
440 tree parms;
444 {
449 {
452 }
455 }
457 /* Remember how many levels of template parameters we pushed so that
458 we can pop them later. */
460 }
462 /* Undo the effects of maybe_begin_member_template_processing. */
464 void
466 {
475 {
479 }
480 }
482 /* Return a new template argument vector which contains all of ARGS,
483 but has as its innermost set of arguments the EXTRA_ARGS. */
485 static tree
487 {
488 tree new_args;
506 }
508 /* Like add_to_template_args, but only the outermost ARGS are added to
509 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
510 (EXTRA_ARGS) levels are added. This function is used to combine
511 the template arguments from a partial instantiation with the
512 template arguments used to attain the full instantiation from the
513 partial instantiation. */
515 static tree
517 {
518 tree new_args;
520 /* If there are more levels of EXTRA_ARGS than there are ARGS,
521 something very fishy is going on. */
524 /* If *all* the new arguments will be the EXTRA_ARGS, just return
525 them. */
529 /* For the moment, we make ARGS look like it contains fewer levels. */
534 /* Now, we restore ARGS to its full dimensions. */
538 }
540 /* Return the N levels of innermost template arguments from the ARGS. */
542 tree
544 {
545 tree new_args;
551 /* If N is 1, just return the innermost set of template arguments. */
555 /* If we're not removing anything, just return the arguments we were
556 given. */
562 /* Make a new set of arguments, not containing the outer arguments. */
569 }
571 /* The inverse of get_innermost_template_args: Return all but the innermost
572 EXTRA_LEVELS levels of template arguments from the ARGS. */
574 static tree
576 {
577 tree new_args;
583 /* If N is 1, just return the outermost set of template arguments. */
587 /* If we're not removing anything, just return the arguments we were
588 given. */
593 /* Make a new set of arguments, not containing the inner arguments. */
600 }
602 /* We've got a template header coming up; push to a new level for storing
603 the parms. */
605 void
607 {
608 /* We use a non-tag-transparent scope here, which causes pushtag to
609 put tags in this scope, rather than in the enclosing class or
610 namespace scope. This is the right thing, since we want
611 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
612 global template class, push_template_decl handles putting the
613 TEMPLATE_DECL into top-level scope. For a nested template class,
614 e.g.:
616 template <class T> struct S1 {
617 template <class T> struct S2 {};
618 };
620 pushtag contains special code to call pushdecl_with_scope on the
621 TEMPLATE_DECL for S2. */
626 }
628 /* This routine is called when a specialization is declared. If it is
629 invalid to declare a specialization here, an error is reported and
630 false is returned, otherwise this routine will return true. */
632 static bool
634 {
637 /* [temp.expl.spec]
639 An explicit specialization shall be declared in the namespace of
640 which the template is a member, or, for member templates, in the
641 namespace of which the enclosing class or enclosing class
642 template is a member. An explicit specialization of a member
643 function, member class or static data member of a class template
644 shall be declared in the namespace of which the class template
645 is a member. */
647 {
650 }
652 /* [temp.expl.spec]
654 In an explicit specialization declaration for a member of a class
655 template or a member template that appears in namespace scope,
656 the member template and some of its enclosing class templates may
657 remain unspecialized, except that the declaration shall not
658 explicitly specialize a class member template if its enclosing
659 class templates are not explicitly specialized as well. */
661 {
664 }
667 }
669 /* We've just seen template <>. */
671 bool
673 {
677 }
679 /* Called at then end of processing a declaration preceded by
680 template<>. */
682 void
684 {
687 }
689 /* Any template <>'s that we have seen thus far are not referring to a
690 function specialization. */
692 void
694 {
697 }
699 /* We've just seen a template header. If SPECIALIZATION is nonzero,
700 it was of the form template <>. */
702 static void
704 {
706 template_header_count++;
707 }
709 /* We're beginning an explicit instantiation. */
711 void
713 {
716 }
719 void
721 {
724 }
726 /* An explicit specialization or partial specialization TMPL is being
727 declared. Check that the namespace in which the specialization is
728 occurring is permissible. Returns false iff it is invalid to
729 specialize TMPL in the current namespace. */
731 static bool
733 {
736 /* [tmpl.expl.spec]
738 An explicit specialization shall be declared in the namespace of
739 which the template is a member, or, for member templates, in the
740 namespace of which the enclosing class or enclosing class
741 template is a member. An explicit specialization of a member
742 function, member class or static data member of a class template
743 shall be declared in the namespace of which the class template is
744 a member. */
747 {
750 }
752 /* Same or super-using namespace. */
754 else
755 {
759 }
760 }
762 /* SPEC is an explicit instantiation. Check that it is valid to
763 perform this explicit instantiation in the current namespace. */
765 static void
767 {
768 tree ns;
770 /* DR 275: An explicit instantiation shall appear in an enclosing
771 namespace of its template. */
777 }
779 /* The TYPE is being declared. If it is a template type, that means it
780 is a partial specialization. Do appropriate error-checking. */
782 tree
784 {
785 tree context;
791 {
795 }
800 {
801 /* This is for ordinary explicit specialization and partial
802 specialization of a template class such as:
804 template <> class C<int>;
806 or:
808 template <class T> class C<T*>;
810 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
814 {
818 {
822 }
823 }
826 }
832 {
833 /* This is for an explicit specialization of member class
834 template according to [temp.expl.spec/18]:
836 template <> template <class U> class C<int>::D;
838 The context `C<int>' must be an implicit instantiation.
839 Otherwise this is just a member class template declared
840 earlier like:
842 template <> class C<int> { template <class U> class D; };
843 template <> template <class U> class C<int>::D;
845 In the first case, `C<int>::D' is a specialization of `C<T>::D'
846 while in the second case, `C<int>::D' is a primary template
847 and `C<T>::D' may not exist. */
851 {
852 tree t;
857 {
860 }
862 /* Check for invalid specialization after instantiation:
864 template <> template <> class C<int>::D<int>;
865 template <> template <class U> class C<int>::D; */
869 {
872 {
873 /* We already have a full specialization of this partial
874 instantiation. Reassign it to the new member
875 specialization template. */
876 spec_entry elt;
892 }
894 /* But if we've had an implicit instantiation, that's a
895 problem ([temp.expl.spec]/6). */
898 }
900 /* Mark TYPE as a specialization. And as a result, we only
901 have one level of template argument for the innermost
902 class template. */
906 }
907 }
909 {
910 /* Someday C++0x may allow for enum template specialization. */
915 else
916 {
919 }
920 }
923 }
925 /* Returns nonzero if we can optimize the retrieval of specializations
926 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
927 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
931 {
934 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
935 parameter. */
937 /* The optimized lookup depends on the fact that the
938 template arguments for the member function template apply
939 purely to the containing class, which is not true if the
940 containing class is an explicit or partial
941 specialization. */
945 /* It is possible to have a template that is not a member
946 template and is not a member of a template class:
948 template <typename T>
949 struct S { friend A::f(); };
951 Here, the friend function is a template, but the context does
952 not have template information. The optimized lookup relies
953 on having ARGS be the template arguments for both the class
954 and the function template. */
956 }
958 /* Retrieve the specialization (in the sense of [temp.spec] - a
959 specialization is either an instantiation or an explicit
960 specialization) of TMPL for the given template ARGS. If there is
961 no such specialization, return NULL_TREE. The ARGS are a vector of
962 arguments, or a vector of vectors of arguments, in the case of
963 templates with more than one level of parameters.
965 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
966 then we search for a partial specialization matching ARGS. This
967 parameter is ignored if TMPL is not a class template. */
969 static tree
971 {
977 /* There should be as many levels of arguments as there are
978 levels of parameters. */
983 {
984 tree class_template;
985 tree class_specialization;
987 tree fns;
990 /* The template arguments actually apply to the containing
991 class. Find the class specialization with those
992 arguments. */
994 class_specialization
998 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
999 for the specialization. */
1003 /* Iterate through the methods with the indicated name, looking
1004 for the one that has an instance of TMPL. */
1007 {
1010 /* using-declarations can add base methods to the method vec,
1011 and we don't want those here. */
1014 }
1016 }
1017 else
1018 {
1020 spec_entry elt;
1021 htab_t specializations;
1029 else
1037 }
1040 }
1042 /* Like retrieve_specialization, but for local declarations. */
1044 static tree
1046 {
1047 tree spec;
1055 }
1057 /* Returns nonzero iff DECL is a specialization of TMPL. */
1059 int
1061 {
1062 tree t;
1065 {
1071 }
1072 else
1073 {
1082 }
1085 }
1087 /* Returns nonzero iff DECL is a specialization of friend declaration
1088 FRIEND_DECL according to [temp.friend]. */
1090 bool
1092 {
1099 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1100 of a template class, we want to check if DECL is a specialization
1101 if this. */
1105 {
1106 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1109 }
1114 /* There is nothing to do if this is not a template friend. */
1121 /* [temp.friend/6]
1122 A member of a class template may be declared to be a friend of a
1123 non-template class. In this case, the corresponding member of
1124 every specialization of the class template is a friend of the
1125 class granting friendship.
1127 For example, given a template friend declaration
1129 template <class T> friend void A<T>::f();
1131 the member function below is considered a friend
1133 template <> struct A<int> {
1134 void f();
1135 };
1137 For this type of template friend, TEMPLATE_DEPTH below will be
1138 nonzero. To determine if DECL is a friend of FRIEND, we first
1139 check if the enclosing class is a specialization of another. */
1146 {
1147 /* Next, we check the members themselves. In order to handle
1148 a few tricky cases, such as when FRIEND_DECL's are
1150 template <class T> friend void A<T>::g(T t);
1151 template <class T> template <T t> friend void A<T>::h();
1153 and DECL's are
1155 void A<int>::g(int);
1156 template <int> void A<int>::h();
1158 we need to figure out ARGS, the template arguments from
1159 the context of DECL. This is required for template substitution
1160 of `T' in the function parameter of `g' and template parameter
1161 of `h' in the above examples. Here ARGS corresponds to `int'. */
1168 {
1170 {
1173 else
1175 current_depth++;
1176 }
1178 }
1181 {
1183 tree friend_type;
1184 tree decl_type;
1185 tree friend_args_type;
1186 tree decl_args_type;
1188 /* Make sure that both DECL and FRIEND_DECL are templates or
1189 non-templates. */
1195 {
1196 /* If both are templates, check template parameter list. */
1197 tree friend_parms
1202 friend_parms))
1206 }
1207 else
1215 /* Check if return types match. */
1219 /* Check if function parameter types match, ignoring the
1220 `this' parameter. */
1229 }
1230 else
1231 {
1232 /* DECL is a TYPE_DECL */
1236 /* Make sure that both DECL and FRIEND_DECL are templates or
1237 non-templates. */
1238 is_template
1245 {
1246 tree friend_parms;
1247 /* If both are templates, check the name of the two
1248 TEMPLATE_DECL's first because is_friend didn't. */
1253 /* Now check template parameter list. */
1254 friend_parms
1257 return comp_template_parms
1259 friend_parms);
1260 }
1261 else
1264 }
1265 }
1267 }
1269 /* Register the specialization SPEC as a specialization of TMPL with
1270 the indicated ARGS. IS_FRIEND indicates whether the specialization
1271 is actually just a friend declaration. Returns SPEC, or an
1272 equivalent prior declaration, if available. */
1274 static tree
1276 hashval_t hash)
1277 {
1278 tree fn;
1280 spec_entry elt;
1286 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1287 register it; we want the corresponding TEMPLATE_DECL instead.
1288 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1289 the more obvious `uses_template_parms (spec)' to avoid problems
1290 with default function arguments. In particular, given
1291 something like this:
1293 template <class T> void f(T t1, T t = T())
1295 the default argument expression is not substituted for in an
1296 instantiation unless and until it is actually needed. */
1300 /* We don't put these specializations in the hash table, but we might
1301 want to give an error about a mismatch. */
1303 else
1304 {
1316 else
1318 }
1320 /* We can sometimes try to re-register a specialization that we've
1321 already got. In particular, regenerate_decl_from_template calls
1322 duplicate_decls which will update the specialization list. But,
1323 we'll still get called again here anyhow. It's more convenient
1324 to simply allow this than to try to prevent it. */
1328 {
1330 {
1333 {
1335 fn);
1337 }
1338 else
1339 {
1340 tree clone;
1341 /* This situation should occur only if the first
1342 specialization is an implicit instantiation, the
1343 second is an explicit specialization, and the
1344 implicit instantiation has not yet been used. That
1345 situation can occur if we have implicitly
1346 instantiated a member function and then specialized
1347 it later.
1349 We can also wind up here if a friend declaration that
1350 looked like an instantiation turns out to be a
1351 specialization:
1353 template <class T> void foo(T);
1354 class S { friend void foo<>(int) };
1355 template <> void foo(int);
1357 We transform the existing DECL in place so that any
1358 pointers to it become pointers to the updated
1359 declaration.
1361 If there was a definition for the template, but not
1362 for the specialization, we want this to look as if
1363 there were no definition, and vice versa. */
1366 /* The call to duplicate_decls will have applied
1367 [temp.expl.spec]:
1369 An explicit specialization of a function template
1370 is inline only if it is explicitly declared to be,
1371 and independently of whether its function template
1372 is.
1374 to the primary function; now copy the inline bits to
1375 the various clones. */
1377 {
1382 }
1386 }
1387 }
1389 {
1391 /* Dup decl failed, but this is a new definition. Set the
1392 line number so any errors match this new
1393 definition. */
1397 }
1398 }
1402 /* A specialization must be declared in the same namespace as the
1403 template it is specializing. */
1409 {
1416 /* TMPL is a forward declaration of a template function; keep a list
1417 of all specializations in case we need to reassign them to a friend
1418 template later in tsubst_friend_function. */
1421 }
1424 }
1426 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1427 TMPL and ARGS members, ignores SPEC. */
1429 static int
1431 {
1437 }
1439 /* Returns a hash for a template TMPL and template arguments ARGS. */
1441 static hashval_t
1443 {
1446 }
1448 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1449 ignoring SPEC. */
1451 static hashval_t
1453 {
1456 }
1458 /* Recursively calculate a hash value for a template argument ARG, for use
1459 in the hash tables of template specializations. */
1461 static hashval_t
1463 {
1475 /* We can get one of these when re-hashing a previous entry in the middle
1476 of substituting into a pack expansion. Just look through it. */
1485 {
1493 {
1498 }
1519 {
1522 {
1525 }
1527 }
1542 val = iterative_hash_template_arg
1554 val);
1556 val);
1565 /* layout_type sets structural equality for arrays of
1566 incomplete type, so we can't rely on the canonical type
1567 for hashing. */
1572 /* A lambda can't appear in a template arg, but don't crash on
1573 erroneous input. */
1584 /* Now hash operands as usual. */
1589 }
1592 {
1596 val);
1599 /* Otherwise just compare the types during lookup. */
1608 {
1613 }
1614 }
1617 }
1619 /* Unregister the specialization SPEC as a specialization of TMPL.
1620 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1621 if the SPEC was listed as a specialization of TMPL.
1623 Note that SPEC has been ggc_freed, so we can't look inside it. */
1625 bool
1627 {
1629 spec_entry elt;
1637 {
1642 }
1645 }
1647 /* Compare an entry in the local specializations hash table P1 (which
1648 is really a pointer to a TREE_LIST) with P2 (which is really a
1649 DECL). */
1651 static int
1653 {
1655 }
1657 /* Hash P1, an entry in the local specializations table. */
1659 static hashval_t
1661 {
1663 }
1665 /* Like register_specialization, but for local declarations. We are
1666 registering SPEC, an instantiation of TMPL. */
1668 static void
1670 {
1676 }
1678 /* TYPE is a class type. Returns true if TYPE is an explicitly
1679 specialized class. */
1681 bool
1683 {
1687 }
1689 /* Print the list of functions at FNS, going through all the overloads
1690 for each element of the list. Alternatively, FNS can not be a
1691 TREE_LIST, in which case it will be printed together with all the
1692 overloads.
1694 MORE and *STR should respectively be FALSE and NULL when the function
1695 is called from the outside. They are used internally on recursive
1696 calls. print_candidates manages the two parameters and leaves NULL
1697 in *STR when it ends. */
1699 static void
1701 {
1707 {
1712 }
1713 else
1714 {
1716 {
1717 /* Pick the prefix string. */
1719 {
1722 }
1726 }
1729 }
1732 {
1735 }
1736 }
1738 /* Print the list of candidate FNS in an error message. */
1740 void
1742 {
1746 }
1748 /* Returns the template (one of the functions given by TEMPLATE_ID)
1749 which can be specialized to match the indicated DECL with the
1750 explicit template args given in TEMPLATE_ID. The DECL may be
1751 NULL_TREE if none is available. In that case, the functions in
1752 TEMPLATE_ID are non-members.
1754 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1755 specialization of a member template.
1757 The TEMPLATE_COUNT is the number of references to qualifying
1758 template classes that appeared in the name of the function. See
1759 check_explicit_specialization for a more accurate description.
1761 TSK indicates what kind of template declaration (if any) is being
1762 declared. TSK_TEMPLATE indicates that the declaration given by
1763 DECL, though a FUNCTION_DECL, has template parameters, and is
1764 therefore a template function.
1766 The template args (those explicitly specified and those deduced)
1767 are output in a newly created vector *TARGS_OUT.
1769 If it is impossible to determine the result, an error message is
1770 issued. The error_mark_node is returned to indicate failure. */
1772 static tree
1774 tree decl,
1778 tmpl_spec_kind tsk)
1779 {
1780 tree fns;
1781 tree targs;
1782 tree explicit_targs;
1784 /* A TREE_LIST of templates of which DECL may be a specialization.
1785 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1786 corresponding TREE_PURPOSE is the set of template arguments that,
1787 when used to instantiate the template, would produce a function
1788 with the signature of DECL. */
1804 /* Check for baselinks. */
1809 {
1812 }
1814 /* Count the number of template headers specified for this
1815 specialization. */
1823 {
1827 {
1828 tree decl_arg_types;
1829 tree fn_arg_types;
1831 /* In case of explicit specialization, we need to check if
1832 the number of template headers appearing in the specialization
1833 is correct. This is usually done in check_explicit_specialization,
1834 but the check done there cannot be exhaustive when specializing
1835 member functions. Consider the following code:
1837 template <> void A<int>::f(int);
1838 template <> template <> void A<int>::f(int);
1840 Assuming that A<int> is not itself an explicit specialization
1841 already, the first line specializes "f" which is a non-template
1842 member function, whilst the second line specializes "f" which
1843 is a template member function. So both lines are syntactically
1844 correct, and check_explicit_specialization does not reject
1845 them.
1847 Here, we can do better, as we are matching the specialization
1848 against the declarations. We count the number of template
1849 headers, and we check if they match TEMPLATE_COUNT + 1
1850 (TEMPLATE_COUNT is the number of qualifying template classes,
1851 plus there must be another header for the member template
1852 itself).
1854 Notice that if header_count is zero, this is not a
1855 specialization but rather a template instantiation, so there
1856 is no check we can perform here. */
1860 /* Check that the number of template arguments at the
1861 innermost level for DECL is the same as for FN. */
1869 /* DECL might be a specialization of FN. */
1873 /* For a non-static member function, we need to make sure
1874 that the const qualification is the same. Since
1875 get_bindings does not try to merge the "this" parameter,
1876 we must do the comparison explicitly. */
1882 /* Skip the "this" parameter and, for constructors of
1883 classes with virtual bases, the VTT parameter. A
1884 full specialization of a constructor will have a VTT
1885 parameter, but a template never will. */
1886 decl_arg_types
1888 fn_arg_types
1891 /* Check that the number of function parameters matches.
1892 For example,
1893 template <class T> void f(int i = 0);
1894 template <> void f<int>();
1895 The specialization f<int> is invalid but is not caught
1896 by get_bindings below. */
1900 /* Function templates cannot be specializations; there are
1901 no partial specializations of functions. Therefore, if
1902 the type of DECL does not match FN, there is no
1903 match. */
1905 {
1909 }
1911 /* See whether this function might be a specialization of this
1912 template. */
1916 /* We cannot deduce template arguments that when used to
1917 specialize TMPL will produce DECL. */
1920 /* Save this template, and the arguments deduced. */
1922 }
1924 /* FN is an ordinary member function, and we need a
1925 specialization of a member template. */
1926 ;
1928 /* We can get IDENTIFIER_NODEs here in certain erroneous
1929 cases. */
1930 ;
1932 /* This is just an ordinary non-member function. Nothing can
1933 be a specialization of that. */
1934 ;
1936 /* Cannot specialize functions that are created implicitly. */
1937 ;
1938 else
1939 {
1940 tree decl_arg_types;
1942 /* This is an ordinary member function. However, since
1943 we're here, we can assume it's enclosing class is a
1944 template class. For example,
1946 template <typename T> struct S { void f(); };
1947 template <> void S<int>::f() {}
1949 Here, S<int>::f is a non-template, but S<int> is a
1950 template class. If FN has the same type as DECL, we
1951 might be in business. */
1954 /* Its enclosing class is an explicit specialization
1955 of a template class. This is not a candidate. */
1960 /* The return types differ. */
1963 /* Adjust the type of DECL in case FN is a static member. */
1970 decl_arg_types))
1971 /* They match! */
1973 }
1974 }
1977 {
1978 /* We have:
1980 [temp.expl.spec]
1982 It is possible for a specialization with a given function
1983 signature to be instantiated from more than one function
1984 template. In such cases, explicit specification of the
1985 template arguments must be used to uniquely identify the
1986 function template specialization being specialized.
1988 Note that here, there's no suggestion that we're supposed to
1989 determine which of the candidate templates is most
1990 specialized. However, we, also have:
1992 [temp.func.order]
1994 Partial ordering of overloaded function template
1995 declarations is used in the following contexts to select
1996 the function template to which a function template
1997 specialization refers:
1999 -- when an explicit specialization refers to a function
2000 template.
2002 So, we do use the partial ordering rules, at least for now.
2003 This extension can only serve to make invalid programs valid,
2004 so it's safe. And, there is strong anecdotal evidence that
2005 the committee intended the partial ordering rules to apply;
2006 the EDG front end has that behavior, and John Spicer claims
2007 that the committee simply forgot to delete the wording in
2008 [temp.expl.spec]. */
2011 {
2014 }
2015 }
2018 {
2026 }
2030 {
2036 }
2038 /* We have one, and exactly one, match. */
2040 {
2043 /* DECL is a re-declaration or partial instantiation of a template
2044 function. */
2047 /* It was a specialization of an ordinary member function in a
2048 template class. */
2050 }
2052 /* It was a specialization of a template. */
2055 {
2060 }
2061 else
2064 }
2066 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2067 but with the default argument values filled in from those in the
2068 TMPL_TYPES. */
2070 static tree
2072 tree tmpl_types)
2073 {
2074 tree new_spec_types;
2082 /* Substitute into the rest of the list. */
2083 new_spec_types =
2087 /* Add the default argument for this parameter. */
2090 new_spec_types);
2091 }
2093 /* DECL is an explicit specialization. Replicate default arguments
2094 from the template it specializes. (That way, code like:
2096 template <class T> void f(T = 3);
2097 template <> void f(double);
2098 void g () { f (); }
2100 works, as required.) An alternative approach would be to look up
2101 the correct default arguments at the call-site, but this approach
2102 is consistent with how implicit instantiations are handled. */
2104 static void
2106 {
2107 tree tmpl;
2108 tree spec_types;
2109 tree tmpl_types;
2110 tree new_spec_types;
2111 tree old_type;
2112 tree new_type;
2113 tree t;
2118 /* See if there's anything we need to do. */
2131 {
2132 /* Remove the this pointer, but remember the object's type for
2133 CV quals. */
2139 {
2140 /* DECL may contain more parameters than TMPL due to the extra
2141 in-charge parameter in constructors and destructors. */
2144 }
2146 {
2149 }
2150 }
2152 /* Compute the merged default arguments. */
2153 new_spec_types =
2156 /* Compute the new FUNCTION_TYPE. */
2158 {
2162 new_spec_types);
2165 /* Put the in-charge parameter back. */
2168 new_spec_types);
2172 new_spec_types);
2173 }
2174 else
2176 new_spec_types);
2182 }
2184 /* Check to see if the function just declared, as indicated in
2185 DECLARATOR, and in DECL, is a specialization of a function
2186 template. We may also discover that the declaration is an explicit
2187 instantiation at this point.
2189 Returns DECL, or an equivalent declaration that should be used
2190 instead if all goes well. Issues an error message if something is
2191 amiss. Returns error_mark_node if the error is not easily
2192 recoverable.
2194 FLAGS is a bitmask consisting of the following flags:
2196 2: The function has a definition.
2197 4: The function is a friend.
2199 The TEMPLATE_COUNT is the number of references to qualifying
2200 template classes that appeared in the name of the function. For
2201 example, in
2203 template <class T> struct S { void f(); };
2204 void S<int>::f();
2206 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2207 classes are not counted in the TEMPLATE_COUNT, so that in
2209 template <class T> struct S {};
2210 template <> struct S<int> { void f(); }
2211 template <> void S<int>::f();
2213 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2214 invalid; there should be no template <>.)
2216 If the function is a specialization, it is marked as such via
2217 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2218 is set up correctly, and it is added to the list of specializations
2219 for that template. */
2221 tree
2223 tree decl,
2226 {
2234 tmpl_spec_kind tsk;
2237 {
2240 else
2242 }
2243 else
2247 {
2250 {
2253 }
2255 {
2257 /* This could be something like:
2259 template <class T> void f(T);
2260 class S { friend void f<>(int); } */
2262 else
2263 {
2264 /* This case handles bogus declarations like template <>
2265 template <class T> void f<int>(); */
2268 declarator);
2270 }
2271 }
2275 /* The error has already been reported in
2276 check_specialization_scope. */
2282 /* Fall through. */
2295 decl);
2298 else
2302 /* Fall through. */
2307 else
2313 {
2314 /* This case handles bogus declarations like template <>
2315 template <class T> void f<int>(); */
2320 else
2322 declarator);
2324 }
2327 /* This is a specialization of a member template, without
2328 specialization the containing class. Something like:
2330 template <class T> struct S {
2331 template <class U> void f (U);
2332 };
2333 template <> template <class U> void S<int>::f(U) {}
2335 That's a specialization -- but of the entire template. */
2341 }
2344 {
2348 {
2352 }
2353 }
2356 {
2360 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2362 {
2363 tree fns;
2368 else
2369 {
2370 /* If there is no class context, the explicit instantiation
2371 must be at namespace scope. */
2374 /* Find the namespace binding, using the declaration
2375 context. */
2379 {
2382 }
2383 else
2384 {
2390 }
2391 }
2394 }
2400 {
2402 /* A specialization in class scope. This is invalid,
2403 but the error will already have been flagged by
2404 check_specialization_scope. */
2406 else
2407 {
2408 /* It's not valid to write an explicit instantiation in
2409 class scope, e.g.:
2411 class C { template void f(); }
2413 This case is caught by the parser. However, on
2414 something like:
2416 template class C { void f(); };
2418 (which is invalid) we can get here. The error will be
2419 issued later. */
2420 ;
2421 }
2424 }
2427 IDENTIFIER_NODE))
2428 {
2429 /* Find the list of functions in ctype that have the same
2430 name as the declared function. */
2436 {
2441 {
2442 /* From [temp.expl.spec]:
2444 If such an explicit specialization for the member
2445 of a class template names an implicitly-declared
2446 special member function (clause _special_), the
2447 program is ill-formed.
2449 Similar language is found in [temp.explicit]. */
2452 }
2455 }
2458 {
2462 }
2463 else
2464 {
2466 tree ovl;
2468 /* For a type-conversion operator, we cannot do a
2469 name-based lookup. We might be looking for `operator
2470 int' which will be a specialization of `operator T'.
2471 So, we find *all* the conversion operators, and then
2472 select from them. */
2480 {
2482 /* There are no more conversion functions. */
2485 /* Glue all these conversion functions together
2486 with those we already have. */
2489 }
2490 }
2493 {
2496 }
2497 else
2499 }
2501 /* Figure out what exactly is being specialized at this point.
2502 Note that for an explicit instantiation, even one for a
2503 member function, we cannot tell apriori whether the
2504 instantiation is for a member template, or just a member
2505 function of a template class. Even if a member template is
2506 being instantiated, the member template arguments may be
2507 elided if they can be deduced from the rest of the
2508 declaration. */
2511 member_specialization,
2512 template_count,
2513 tsk);
2516 /* We couldn't figure out what this declaration was
2517 specializing. */
2519 else
2520 {
2524 {
2525 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2526 is done by do_decl_instantiation later. */
2532 {
2533 /* If TMPL is not the most general template (for
2534 example, if TMPL is a friend template that is
2535 injected into namespace scope), then there will
2536 be too many levels of TARGS. Remove some of them
2537 here. */
2539 tree new_targs;
2546 }
2549 }
2551 /* If we thought that the DECL was a member function, but it
2552 turns out to be specializing a static member function,
2553 make DECL a static member function as well. */
2558 /* If this is a specialization of a member template of a
2559 template class, we want to return the TEMPLATE_DECL, not
2560 the specialization of it. */
2562 {
2567 {
2568 tree parm;
2572 /* We want to use the argument list specified in the
2573 definition, not in the original declaration. */
2578 }
2581 }
2583 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2586 /* Inherit default function arguments from the template
2587 DECL is specializing. */
2590 /* This specialization has the same protection as the
2591 template it specializes. */
2595 /* 7.1.1-1 [dcl.stc]
2597 A storage-class-specifier shall not be specified in an
2598 explicit specialization...
2600 The parser rejects these, so unless action is taken here,
2601 explicit function specializations will always appear with
2602 global linkage.
2604 The action recommended by the C++ CWG in response to C++
2605 defect report 605 is to make the storage class and linkage
2606 of the explicit specialization match the templated function:
2608 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2609 */
2611 {
2615 /* This specialization has the same linkage and visibility as
2616 the function template it specializes. */
2619 {
2622 }
2625 {
2628 }
2629 }
2631 /* If DECL is a friend declaration, declared using an
2632 unqualified name, the namespace associated with DECL may
2633 have been set incorrectly. For example, in:
2635 template <typename T> void f(T);
2636 namespace N {
2637 struct S { friend void f<int>(int); }
2638 }
2640 we will have set the DECL_CONTEXT for the friend
2641 declaration to N, rather than to the global namespace. */
2646 /* This is not really a declaration of a specialization.
2647 It's just the name of an instantiation. But, it's not
2648 a request for an instantiation, either. */
2651 /* This is indeed a specialization. In case of constructors
2652 and destructors, we need in-charge and not-in-charge
2653 versions in V3 ABI. */
2656 /* Register this specialization so that we can find it
2657 again. */
2659 }
2660 }
2663 }
2665 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2666 parameters. These are represented in the same format used for
2667 DECL_TEMPLATE_PARMS. */
2669 int
2671 {
2672 const_tree p1;
2673 const_tree p2;
2681 {
2693 {
2697 /* If either of the template parameters are invalid, assume
2698 they match for the sake of error recovery. */
2711 }
2712 }
2715 /* One set of parameters has more parameters lists than the
2716 other. */
2720 }
2722 /* Determine whether PARM is a parameter pack. */
2724 bool
2726 {
2727 /* Determine if we have a non-type template parameter pack. */
2732 /* If this is a list of template parameters, we could get a
2733 TYPE_DECL or a TEMPLATE_DECL. */
2740 }
2742 /* Determine if T is a function parameter pack. */
2744 bool
2746 {
2750 }
2752 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2753 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2755 tree
2757 {
2764 }
2766 /* Return true iff the function parameter PARAM_DECL was expanded
2767 from the function parameter pack PACK. */
2769 bool
2771 {
2776 /* The parameter pack and its pack arguments have the same
2777 DECL_PARM_INDEX. */
2779 }
2781 /* Determine whether ARGS describes a variadic template args list,
2782 i.e., one that is terminated by a template argument pack. */
2784 static bool
2786 {
2788 tree last_parm;
2802 }
2804 /* Generate a new name for the parameter pack name NAME (an
2805 IDENTIFIER_NODE) that incorporates its */
2807 static tree
2809 {
2810 /* Munge the name to include the parameter index. */
2811 #define NUMBUF_LEN 128
2823 }
2825 /* Return true if T is a primary function
2826 or class template instantiation. */
2828 bool
2830 {
2842 }
2844 /* Return true if PARM is a template template parameter. */
2846 bool
2848 {
2850 }
2852 /* Return the template parameters of T if T is a
2853 primary template instantiation, NULL otherwise. */
2855 tree
2857 {
2862 parms = INNERMOST_TEMPLATE_PARMS
2866 }
2868 /* Return the template parameters of the LEVELth level from the full list
2869 of template parameters PARMS. */
2871 tree
2873 {
2874 tree p;
2885 }
2887 /* Returns the template arguments of T if T is a template instantiation,
2888 NULL otherwise. */
2890 tree
2892 {
2900 }
2902 /* Return the argument pack elements of T if T is a template argument pack,
2903 NULL otherwise. */
2905 tree
2907 {
2913 }
2915 /* Structure used to track the progress of find_parameter_packs_r. */
2916 struct find_parameter_pack_data
2917 {
2918 /* TREE_LIST that will contain all of the parameter packs found by
2919 the traversal. */
2922 /* Set of AST nodes that have been visited by the traversal. */
2924 };
2926 /* Identifies all of the argument packs that occur in a template
2927 argument and appends them to the TREE_LIST inside DATA, which is a
2928 find_parameter_pack_data structure. This is a subroutine of
2929 make_pack_expansion and uses_parameter_packs. */
2930 static tree
2932 {
2938 /* Identify whether this is a parameter pack or not. */
2940 {
2954 {
2955 /* We don't want to walk into the type of a PARM_DECL,
2956 because we don't want to see the type parameter pack. */
2959 }
2963 /* Not a parameter pack. */
2965 }
2968 {
2969 /* Add this parameter pack to the list. */
2971 }
2977 /* This switch statement will return immediately if we don't find a
2978 parameter pack. */
2980 {
2985 /* Check the template itself. */
2988 /* Check the template arguments. */
3004 /* Fall through. */
3045 }
3048 }
3050 /* Determines if the expression or type T uses any parameter packs. */
3051 bool
3053 {
3061 }
3063 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3064 representation a base-class initializer into a parameter pack
3065 expansion. If all goes well, the resulting node will be an
3066 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3067 respectively. */
3068 tree
3070 {
3071 tree result;
3080 {
3081 /* The only time we will see a TREE_LIST here is for a base
3082 class initializer. In this case, the TREE_PURPOSE will be a
3083 _TYPE node (representing the base class expansion we're
3084 initializing) and the TREE_VALUE will be a TREE_LIST
3085 containing the initialization arguments.
3087 The resulting expansion looks somewhat different from most
3088 expansions. Rather than returning just one _EXPANSION, we
3089 return a TREE_LIST whose TREE_PURPOSE is a
3090 TYPE_PACK_EXPANSION containing the bases that will be
3091 initialized. The TREE_VALUE will be identical to the
3092 original TREE_VALUE, which is a list of arguments that will
3093 be passed to each base. We do not introduce any new pack
3094 expansion nodes into the TREE_VALUE (although it is possible
3095 that some already exist), because the TREE_PURPOSE and
3096 TREE_VALUE all need to be expanded together with the same
3097 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3098 resulting TREE_PURPOSE will mention the parameter packs in
3099 both the bases and the arguments to the bases. */
3100 tree purpose;
3101 tree value;
3104 /* Determine which parameter packs will be used by the base
3105 class expansion. */
3112 {
3116 }
3119 {
3120 /* Collect the sets of parameter packs used in each of the
3121 initialization arguments. */
3123 {
3124 /* Determine which parameter packs will be expanded in this
3125 argument. */
3128 }
3129 }
3133 /* Create the pack expansion type for the base type. */
3138 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3139 they will rarely be compared to anything. */
3143 }
3148 /* Build the PACK_EXPANSION_* node. */
3149 result = for_types
3154 {
3155 /* Propagate type and const-expression information. */
3158 }
3159 else
3160 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3161 they will rarely be compared to anything. */
3164 /* Determine which parameter packs will be expanded. */
3170 /* Make sure we found some parameter packs. */
3172 {
3175 else
3178 }
3182 }
3184 /* Checks T for any "bare" parameter packs, which have not yet been
3185 expanded, and issues an error if any are found. This operation can
3186 only be done on full expressions or types (e.g., an expression
3187 statement, "if" condition, etc.), because we could have expressions like:
3189 foo(f(g(h(args)))...)
3191 where "args" is a parameter pack. check_for_bare_parameter_packs
3192 should not be called for the subexpressions args, h(args),
3193 g(h(args)), or f(g(h(args))), because we would produce erroneous
3194 error messages.
3196 Returns TRUE and emits an error if there were bare parameter packs,
3197 returns FALSE otherwise. */
3198 bool
3200 {
3216 {
3219 {
3228 else
3233 else
3237 }
3240 }
3243 }
3245 /* Expand any parameter packs that occur in the template arguments in
3246 ARGS. */
3247 tree
3249 {
3255 /* First, determine if we need to expand anything, and the number of
3256 slots we'll need. */
3258 {
3263 {
3267 else
3269 }
3270 else
3271 {
3273 num_result_args++;
3274 }
3275 }
3277 /* If no expansion is necessary, we're done. */
3281 /* Expand arguments. */
3284 non_default_args_count =
3287 {
3290 {
3297 }
3298 else
3299 {
3302 }
3303 }
3307 }
3309 /* Checks if DECL shadows a template parameter.
3311 [temp.local]: A template-parameter shall not be redeclared within its
3312 scope (including nested scopes).
3314 Emits an error and returns TRUE if the DECL shadows a parameter,
3315 returns FALSE otherwise. */
3317 bool
3319 {
3320 tree olddecl;
3322 /* If we're not in a template, we can't possibly shadow a template
3323 parameter. */
3327 /* Figure out what we're shadowing. */
3332 /* If there's no previous binding for this name, we're not shadowing
3333 anything, let alone a template parameter. */
3337 /* If we're not shadowing a template parameter, we're done. Note
3338 that OLDDECL might be an OVERLOAD (or perhaps even an
3339 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3340 node. */
3344 /* We check for decl != olddecl to avoid bogus errors for using a
3345 name inside a class. We check TPFI to avoid duplicate errors for
3346 inline member templates. */
3354 }
3356 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3357 ORIG_LEVEL, DECL, and TYPE. */
3359 static tree
3363 tree decl,
3364 tree type)
3365 {
3376 }
3378 /* Find the canonical type parameter for the given template type
3379 parameter. Returns the canonical type parameter, which may be TYPE
3380 if no such parameter existed. */
3381 static tree
3383 {
3384 tree list;
3398 else
3399 {
3404 }
3405 }
3407 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3408 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3409 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3410 new one is created. */
3412 static tree
3414 tsubst_flags_t complain)
3415 {
3420 {
3439 /* Template template parameters need this. */
3444 }
3447 }
3449 /* Process information from new template parameter PARM and append it to the
3450 LIST being built. This new parameter is a non-type parameter iff
3451 IS_NON_TYPE is true. This new parameter is a parameter
3452 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3453 PARM_LOC. */
3455 tree
3458 {
3460 tree defval;
3461 tree err_parm_list;
3468 {
3472 {
3476 else
3478 }
3481 }
3482 else
3486 {
3492 {
3496 }
3497 else
3498 {
3499 /* [temp.param]
3501 The top-level cv-qualifiers on the template-parameter are
3502 ignored when determining its type. */
3505 {
3509 }
3512 {
3513 /* This template parameter is not a parameter pack, but it
3514 should be. Complain about "bare" parameter packs. */
3517 /* Recover by calling this a parameter pack. */
3519 }
3520 }
3522 /* A template parameter is not modifiable. */
3531 processing_template_decl,
3536 }
3537 else
3538 {
3539 tree t;
3543 {
3545 /* This is for distinguishing between real templates and template
3546 template parameters */
3550 }
3551 else
3552 {
3554 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3557 }
3564 processing_template_decl,
3568 }
3574 }
3576 /* The end of a template parameter list has been reached. Process the
3577 tree list into a parameter vector, converting each parameter into a more
3578 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3579 as PARM_DECLs. */
3581 tree
3583 {
3588 current_template_parms
3593 {
3599 current_template_parms;
3600 }
3605 }
3607 /* end_template_decl is called after a template declaration is seen. */
3609 void
3611 {
3617 /* This matches the pushlevel in begin_template_parm_list. */
3622 }
3624 /* Within the declaration of a template, return all levels of template
3625 parameters that apply. The template parameters are represented as
3626 a TREE_VEC, in the form documented in cp-tree.h for template
3627 arguments. */
3629 static tree
3631 {
3632 tree header;
3637 /* If there is only one level of template parameters, we do not
3638 create a TREE_VEC of TREE_VECs. Instead, we return a single
3639 TREE_VEC containing the arguments. */
3644 {
3650 {
3653 /* T will be a list if we are called from within a
3654 begin/end_template_parm_list pair, but a vector directly
3655 if within a begin/end_member_template_processing pair. */
3657 {
3661 {
3664 {
3668 {
3669 /* Turn this argument into a TYPE_ARGUMENT_PACK
3670 with a single element, which expands T. */
3672 #ifdef ENABLE_CHECKING
3673 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3675 #endif
3680 }
3681 }
3682 else
3683 {
3687 {
3688 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3689 with a single element, which expands T. */
3692 #ifdef ENABLE_CHECKING
3693 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3695 #endif
3701 }
3702 }
3704 }
3705 }
3706 }
3708 #ifdef ENABLE_CHECKING
3710 #endif
3714 else
3716 }
3719 }
3721 /* Update the declared TYPE by doing any lookups which were thought to be
3722 dependent, but are not now that we know the SCOPE of the declarator. */
3724 tree
3726 {
3737 /* Don't bother building up the args in this case. */
3739 {
3740 /* tsubst in the args corresponding to the template parameters,
3741 including auto if present. Most things will be unchanged, but
3742 make_typename_type and tsubst_qualified_id will resolve
3743 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3746 tree pushed;
3748 {
3752 }
3757 }
3763 {
3766 else
3768 }
3770 }
3772 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3773 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3774 a member template. Used by push_template_decl below. */
3776 static tree
3778 {
3785 }
3787 struct template_parm_data
3788 {
3789 /* The level of the template parameters we are currently
3790 processing. */
3793 /* The index of the specialization argument we are currently
3794 processing. */
3797 /* An array whose size is the number of template parameters. The
3798 elements are nonzero if the parameter has been used in any one
3799 of the arguments processed so far. */
3802 /* An array whose size is the number of template arguments. The
3803 elements are nonzero if the argument makes use of template
3804 parameters of this level. */
3806 };
3808 /* Subroutine of push_template_decl used to see if each template
3809 parameter in a partial specialization is used in the explicit
3810 argument list. If T is of the LEVEL given in DATA (which is
3811 treated as a template_parm_data*), then DATA->PARMS is marked
3812 appropriately. */
3814 static int
3816 {
3822 {
3825 }
3826 else
3827 {
3830 }
3833 {
3836 }
3838 /* Return zero so that for_each_template_parm will continue the
3839 traversal of the tree; we want to mark *every* template parm. */
3841 }
3843 /* Process the partial specialization DECL. */
3845 static tree
3847 {
3853 tree inner_parms;
3854 tree inst;
3867 /* We check that each of the template parameters given in the
3868 partial specialization is used in the argument list to the
3869 specialization. For example:
3871 template <class T> struct S;
3872 template <class T> struct S<T*>;
3874 The second declaration is OK because `T*' uses the template
3875 parameter T, whereas
3877 template <class T> struct S<int>;
3879 is no good. Even trickier is:
3881 template <class T>
3882 struct S1
3883 {
3884 template <class U>
3885 struct S2;
3886 template <class U>
3887 struct S2<T>;
3888 };
3890 The S2<T> declaration is actually invalid; it is a
3891 full-specialization. Of course,
3893 template <class U>
3894 struct S2<T (*)(U)>;
3896 or some such would have been OK. */
3904 {
3909 NULL,
3911 }
3914 {
3915 /* One of the template parms was not used in the
3916 specialization. */
3918 {
3921 }
3924 }
3929 /* [temp.class.spec]
3931 The argument list of the specialization shall not be identical to
3932 the implicit argument list of the primary template. */
3939 /* [temp.class.spec]
3941 A partially specialized non-type argument expression shall not
3942 involve template parameters of the partial specialization except
3943 when the argument expression is a simple identifier.
3945 The type of a template parameter corresponding to a specialized
3946 non-type argument shall not be dependent on a parameter of the
3947 specialization.
3949 Also, we verify that pack expansions only occur at the
3950 end of the argument list. */
3954 {
3961 {
3962 /* Extract the arguments from the argument pack. We'll be
3963 iterating over these in the following loop. */
3966 }
3969 {
3971 /* Get the Jth argument in the parameter pack. */
3975 {
3976 /* Pack expansions must come at the end of the
3977 argument list. */
3980 {
3984 else
3987 }
3988 }
3991 /* We only care about the pattern. */
3997 /* This next line is the `argument expression is not just a
3998 simple identifier' condition and also the `specialized
3999 non-type argument' bit. */
4001 {
4005 arg);
4006 else
4007 {
4008 /* Look at the corresponding template parameter,
4009 marking which template parameters its type depends
4010 upon. */
4014 {
4015 /* We haven't yet initialized TPD2. Do so now. */
4017 /* The number of parameters here is the number in the
4018 main template, which, as checked in the assertion
4019 above, is NARGS. */
4023 }
4025 /* Mark the template parameters. But this time, we're
4026 looking for the template parameters of the main
4027 template, not in the specialization. */
4034 NULL,
4038 {
4039 /* The type depended on some template parameters.
4040 If they are fully specialized in the
4041 specialization, that's OK. */
4050 "type %qT of template argument %qE depends "
4052 "type %qT of template argument %qE depends "
4054 type,
4055 arg);
4056 }
4057 }
4058 }
4059 }
4060 }
4062 /* We should only get here once. */
4072 {
4076 {
4080 "partial specialization of %qT after instantiation "
4082 }
4083 }
4086 }
4088 /* Check that a template declaration's use of default arguments and
4089 parameter packs is not invalid. Here, PARMS are the template
4090 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4091 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4092 specialization.
4095 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4096 declaration (but not a definition); 1 indicates a declaration, 2
4097 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4098 emitted for extraneous default arguments.
4100 Returns TRUE if there were no errors found, FALSE otherwise. */
4102 bool
4105 {
4108 tree parm_level;
4111 /* [temp.param]
4113 A default template-argument shall not be specified in a
4114 function template declaration or a function template definition, nor
4115 in the template-parameter-list of the definition of a member of a
4116 class template. */
4119 /* You can't have a function template declaration in a local
4120 scope, nor you can you define a member of a class template in a
4121 local scope. */
4128 /* If this is either a friend defined in the scope of the class
4129 or a member function. */
4135 /* And, if it was a member function, it really was defined in
4136 the scope of the class. */
4139 /* We already checked these parameters when the template was
4140 declared, so there's no need to do it again now. This function
4141 was defined in class scope, but we're processing it's body now
4142 that the class is complete. */
4145 /* Core issue 226 (C++0x only): the following only applies to class
4146 templates. */
4148 {
4149 /* [temp.param]
4151 If a template-parameter has a default template-argument, all
4152 subsequent template-parameters shall have a default
4153 template-argument supplied. */
4155 {
4162 {
4172 {
4174 /* For better subsequent error-recovery, we indicate that
4175 there should have been a default argument. */
4178 }
4180 && !is_partial
4181 && !is_friend_decl
4182 /* Don't complain about an enclosing partial
4183 specialization. */
4188 {
4189 /* A primary class template can only have one
4190 parameter pack, at the end of the template
4191 parameter list. */
4196 else
4204 }
4205 }
4206 }
4207 }
4210 || is_partial
4211 || !is_primary
4213 /* For an ordinary class template, default template arguments are
4214 allowed at the innermost level, e.g.:
4215 template <class T = int>
4216 struct S {};
4217 but, in a partial specialization, they're not allowed even
4218 there, as we have in [temp.class.spec]:
4220 The template parameter list of a specialization shall not
4221 contain default template argument values.
4223 So, for a partial specialization, or for a function template
4224 (in C++98/C++03), we look at all of them. */
4225 ;
4226 else
4227 /* But, for a primary class template that is not a partial
4228 specialization we look at all template parameters except the
4229 innermost ones. */
4232 /* Figure out what error message to issue. */
4245 else
4249 /* If we're inside a class definition, there's no need to
4250 examine the parameters to the class itself. On the one
4251 hand, they will be checked when the class is defined, and,
4252 on the other, default arguments are valid in things like:
4253 template <class T = double>
4254 struct S { template <class U> void f(U); };
4255 Here the default argument for `S' has no bearing on the
4256 declaration of `f'. */
4258 else
4259 /* Check everything. */
4265 {
4272 {
4277 {
4279 {
4286 }
4288 /* Clear out the default argument so that we are not
4289 confused later. */
4291 }
4292 }
4294 /* At this point, if we're still interested in issuing messages,
4295 they must apply to classes surrounding the object declared. */
4299 }
4302 }
4304 /* Worker for push_template_decl_real, called via
4305 for_each_template_parm. DATA is really an int, indicating the
4306 level of the parameters we are interested in. If T is a template
4307 parameter of that level, return nonzero. */
4309 static int
4311 {
4317 else
4320 }
4322 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4323 parameters given by current_template_args, or reuses a
4324 previously existing one, if appropriate. Returns the DECL, or an
4325 equivalent one, if it is replaced via a call to duplicate_decls.
4327 If IS_FRIEND is true, DECL is a friend declaration. */
4329 tree
4331 {
4332 tree tmpl;
4333 tree args;
4334 tree info;
4335 tree ctx;
4339 /* True if the template is a member template, in the sense of
4340 [temp.mem]. */
4346 /* See if this is a partial specialization. */
4355 /* For a friend, we want the context of the friend function, not
4356 the type of which it is a friend. */
4360 /* In the case of a virtual function, we want the class in which
4361 it is defined. */
4363 else
4364 /* Otherwise, if we're currently defining some class, the DECL
4365 is assumed to be a member of the class. */
4374 /* See if this is a primary template. */
4376 /* A friend template that specifies a class context, i.e.
4377 template <typename T> friend void A<T>::f();
4378 is not primary. */
4380 else
4384 {
4389 {
4392 }
4394 {
4396 {
4397 /* [temp.mem]
4399 A destructor shall not be a member template. */
4402 }
4409 {
4410 /* [basic.stc.dynamic.allocation]
4412 An allocation function can be a function
4413 template. ... Template allocation functions shall
4414 have two or more parameters. */
4417 }
4418 }
4422 else
4423 {
4426 }
4427 }
4429 /* Check to see that the rules regarding the use of default
4430 arguments are not being violated. */
4434 /* Ensure that there are no parameter packs in the type of this
4435 declaration that have not been expanded. */
4437 {
4438 /* Check each of the arguments individually to see if there are
4439 any bare parameter packs. */
4445 {
4448 {
4449 /* This is a PARM_DECL that contains unexpanded parameter
4450 packs. We have already complained about this in the
4451 check_for_bare_parameter_packs call, so just replace
4452 these types with ERROR_MARK_NODE. */
4455 }
4459 }
4461 /* Check for bare parameter packs in the return type and the
4462 exception specifiers. */
4464 /* Errors were already issued, set return type to int
4465 as the frontend doesn't expect error_mark_node as
4466 the return type. */
4470 }
4472 {
4475 }
4486 {
4491 /* If DECL is a TYPE_DECL for a class-template, then there won't
4492 be DECL_LANG_SPECIFIC. The information equivalent to
4493 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4497 {
4498 /* Since a template declaration already existed for this
4499 class-type, we must be redeclaring it here. Make sure
4500 that the redeclaration is valid. */
4502 current_template_parms);
4503 /* We don't need to create a new TEMPLATE_DECL; just use the
4504 one we already had. */
4506 }
4507 else
4508 {
4510 member_template_p);
4515 {
4516 /* A specialization of a member template of a template
4517 class. */
4521 }
4522 }
4523 }
4524 else
4525 {
4531 {
4534 }
4542 {
4543 tree new_tmpl;
4545 /* The declaration is a specialization of a member
4546 template, declared outside the class. Therefore, the
4547 innermost template arguments will be NULL, so we
4548 replace them with the arguments determined by the
4549 earlier call to check_explicit_specialization. */
4552 new_tmpl
4554 member_template_p);
4564 args,
4567 }
4569 /* Make sure the template headers we got make sense. */
4574 {
4577 }
4578 else
4580 {
4585 {
4589 else
4594 }
4599 /* Can happen in erroneous input. */
4601 else
4605 }
4607 /* Check that the parms are used in the appropriate qualifying scopes
4608 in the declarator. */
4612 {
4618 /* Avoid crash in import_export_decl. */
4621 }
4622 }
4627 /* Push template declarations for global functions and types. Note
4628 that we do not try to push a global template friend declared in a
4629 template class; such a thing may well depend on the template
4630 parameters of the class. */
4633 {
4638 /* Hide template friend classes that haven't been declared yet. */
4640 {
4643 }
4644 }
4647 {
4653 {
4656 /* It is a conversion operator. See if the type converted to
4657 depends on innermost template operands. */
4660 depth))
4662 }
4664 /* Give template template parms a DECL_CONTEXT of the template
4665 for which they are a parameter. */
4668 {
4672 }
4673 }
4675 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4676 back to its most general template. If TMPL is a specialization,
4677 ARGS may only have the innermost set of arguments. Add the missing
4678 argument levels if necessary. */
4690 }
4692 tree
4694 {
4696 }
4698 /* Called when a class template TYPE is redeclared with the indicated
4699 template PARMS, e.g.:
4701 template <class T> struct S;
4702 template <class T> struct S {}; */
4704 bool
4706 {
4707 tree tmpl;
4708 tree tmpl_parms;
4712 {
4715 }
4719 /* The type is nested in some template class. Nothing to worry
4720 about here; there are no new template parameters for the nested
4721 type. */
4725 {
4727 tmpl);
4729 }
4735 {
4745 }
4748 {
4749 tree tmpl_parm;
4750 tree parm;
4751 tree tmpl_default;
4752 tree parm_default;
4766 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4767 TEMPLATE_DECL. */
4777 {
4781 }
4784 {
4785 /* We have in [temp.param]:
4787 A template-parameter may not be given default arguments
4788 by two different declarations in the same scope. */
4793 }
4796 /* Update the previous template parameters (which are the ones
4797 that will really count) with the new default value. */
4800 /* Update the new parameters, too; they'll be used as the
4801 parameters for any members. */
4803 }
4806 }
4808 /* Simplify EXPR if it is a non-dependent expression. Returns the
4809 (possibly simplified) expression. */
4811 static tree
4813 {
4817 /* If we're in a template, but EXPR isn't value dependent, simplify
4818 it. We're supposed to treat:
4820 template <typename T> void f(T[1 + 1]);
4821 template <typename T> void f(T[2]);
4823 as two declarations of the same function, for example. */
4827 {
4828 HOST_WIDE_INT saved_processing_template_decl;
4834 complain,
4839 }
4841 }
4843 tree
4845 {
4847 }
4849 /* EXPR is an expression which is used in a constant-expression context.
4850 For instance, it could be a VAR_DECL with a constant initializer.
4851 Extract the innermost constant expression.
4853 This is basically a more powerful version of
4854 integral_constant_value, which can be used also in templates where
4855 initializers can maintain a syntactic rather than semantic form
4856 (even if they are non-dependent, for access-checking purposes). */
4858 static tree
4860 {
4862 do
4863 {
4866 }
4870 }
4872 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4873 must be a function or a pointer-to-function type, as specified
4874 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4875 and check that the resulting function has external linkage. */
4877 static tree
4879 {
4893 /* [temp.arg.nontype]/1
4895 A template-argument for a non-type, non-template template-parameter
4896 shall be one of:
4897 [...]
4898 -- the address of an object or function with external linkage. */
4900 {
4905 }
4908 }
4910 /* Subroutine of convert_nontype_argument.
4911 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4912 Emit an error otherwise. */
4914 static bool
4916 {
4924 }
4926 /* Returns TRUE iff the address of OP is value-dependent.
4928 14.6.2.4 [temp.dep.temp]:
4929 A non-integral non-type template-argument is dependent if its type is
4930 dependent or it has either of the following forms
4931 qualified-id
4932 & qualified-id
4933 and contains a nested-name-specifier which specifies a class-name that
4934 names a dependent type.
4936 We generalize this to just say that the address of a member of a
4937 dependent class is value-dependent; the above doesn't cover the
4938 address of a static data member named with an unqualified-id. */
4940 static bool
4942 {
4943 /* We could use get_inner_reference here, but there's no need;
4944 this is only relevant for template non-type arguments, which
4945 can only be expressed as &id-expression. */
4947 {
4951 }
4954 }
4956 /* Attempt to convert the non-type template parameter EXPR to the
4957 indicated TYPE. If the conversion is successful, return the
4958 converted value. If the conversion is unsuccessful, return
4959 NULL_TREE if we issued an error message, or error_mark_node if we
4960 did not. We issue error messages for out-and-out bad template
4961 parameters, but not simply because the conversion failed, since we
4962 might be just trying to do argument deduction. Both TYPE and EXPR
4963 must be non-dependent.
4965 The conversion follows the special rules described in
4966 [temp.arg.nontype], and it is much more strict than an implicit
4967 conversion.
4969 This function is called twice for each template argument (see
4970 lookup_template_class for a more accurate description of this
4971 problem). This means that we need to handle expressions which
4972 are not valid in a C++ source, but can be created from the
4973 first call (for instance, casts to perform conversions). These
4974 hacks can go away after we fix the double coercion problem. */
4976 static tree
4978 {
4979 tree expr_type;
4981 /* Detect immediately string literals as invalid non-type argument.
4982 This special-case is not needed for correctness (we would easily
4983 catch this later), but only to provide better diagnostic for this
4984 common user mistake. As suggested by DR 100, we do not mention
4985 linkage issues in the diagnostic as this is not the point. */
4986 /* FIXME we're making this OK. */
4988 {
4994 }
4996 /* Add the ADDR_EXPR now for the benefit of
4997 value_dependent_expression_p. */
5001 /* If we are in a template, EXPR may be non-dependent, but still
5002 have a syntactic, rather than semantic, form. For example, EXPR
5003 might be a SCOPE_REF, rather than the VAR_DECL to which the
5004 SCOPE_REF refers. Preserving the qualifying scope is necessary
5005 so that access checking can be performed when the template is
5006 instantiated -- but here we need the resolved form so that we can
5007 convert the argument. */
5018 else
5021 /* HACK: Due to double coercion, we can get a
5022 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5023 which is the tree that we built on the first call (see
5024 below when coercing to reference to object or to reference to
5025 function). We just strip everything and get to the arg.
5026 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5027 for examples. */
5029 {
5031 {
5032 /* ??? Maybe we could use convert_from_reference here, but we
5033 would need to relax its constraints because the NOP_EXPR
5034 could actually change the type to something more cv-qualified,
5035 and this is not folded by convert_from_reference. */
5046 }
5048 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5049 parameter is a pointer to object, through decay and
5050 qualification conversion. Let's strip everything. */
5052 {
5056 /* Skip the ADDR_EXPR only if it is part of the decay for
5057 an array. Otherwise, it is part of the original argument
5058 in the source code. */
5062 }
5063 }
5065 /* [temp.arg.nontype]/5, bullet 1
5067 For a non-type template-parameter of integral or enumeration type,
5068 integral promotions (_conv.prom_) and integral conversions
5069 (_conv.integral_) are applied. */
5071 {
5080 /* Conversion was allowed: fold it to a bare integer constant. */
5083 /* Notice that there are constant expressions like '4 % 0' which
5084 do not fold into integer constants. */
5086 {
5091 }
5092 }
5093 /* [temp.arg.nontype]/5, bullet 2
5095 For a non-type template-parameter of type pointer to object,
5096 qualification conversions (_conv.qual_) and the array-to-pointer
5097 conversion (_conv.array_) are applied. */
5099 {
5100 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5102 A template-argument for a non-type, non-template template-parameter
5103 shall be one of: [...]
5105 -- the name of a non-type template-parameter;
5106 -- the address of an object or function with external linkage, [...]
5107 expressed as "& id-expression" where the & is optional if the name
5108 refers to a function or array, or if the corresponding
5109 template-parameter is a reference.
5111 Here, we do not care about functions, as they are invalid anyway
5112 for a parameter of type pointer-to-object. */
5115 /* Non-type template parameters are OK. */
5116 ;
5119 {
5121 {
5123 "because %qD is a variable, not the address of "
5127 }
5128 /* Other values, like integer constants, might be valid
5129 non-type arguments of some other type. */
5131 }
5132 else
5133 {
5134 tree decl;
5139 {
5144 }
5146 {
5151 }
5152 }
5161 }
5162 /* [temp.arg.nontype]/5, bullet 3
5164 For a non-type template-parameter of type reference to object, no
5165 conversions apply. The type referred to by the reference may be more
5166 cv-qualified than the (otherwise identical) type of the
5167 template-argument. The template-parameter is bound directly to the
5168 template-argument, which must be an lvalue. */
5170 {
5172 expr_type))
5176 {
5180 }
5183 {
5187 }
5189 /* [temp.arg.nontype]/1
5191 A template-argument for a non-type, non-template template-parameter
5192 shall be one of: [...]
5194 -- the address of an object or function with external linkage. */
5197 {
5200 {
5202 "because a reference variable does not have a constant "
5205 }
5206 }
5209 {
5214 }
5217 {
5222 }
5225 }
5226 /* [temp.arg.nontype]/5, bullet 4
5228 For a non-type template-parameter of type pointer to function, only
5229 the function-to-pointer conversion (_conv.func_) is applied. If the
5230 template-argument represents a set of overloaded functions (or a
5231 pointer to such), the matching function is selected from the set
5232 (_over.over_). */
5234 {
5235 /* If the argument is a template-id, we might not have enough
5236 context information to decay the pointer. */
5238 {
5242 }
5249 {
5253 }
5254 }
5255 /* [temp.arg.nontype]/5, bullet 5
5257 For a non-type template-parameter of type reference to function, no
5258 conversions apply. If the template-argument represents a set of
5259 overloaded functions, the matching function is selected from the set
5260 (_over.over_). */
5262 {
5264 {
5269 }
5276 }
5277 /* [temp.arg.nontype]/5, bullet 6
5279 For a non-type template-parameter of type pointer to member function,
5280 no conversions apply. If the template-argument represents a set of
5281 overloaded member functions, the matching member function is selected
5282 from the set (_over.over_). */
5284 {
5289 /* [temp.arg.nontype] bullet 1 says the pointer to member
5290 expression must be a pointer-to-member constant. */
5294 /* There is no way to disable standard conversions in
5295 resolve_address_of_overloaded_function (called by
5296 instantiate_type). It is possible that the call succeeded by
5297 converting &B::I to &D::I (where B is a base of D), so we need
5298 to reject this conversion here.
5300 Actually, even if there was a way to disable standard conversions,
5301 it would still be better to reject them here so that we can
5302 provide a superior diagnostic. */
5304 {
5308 /* If we are just one standard conversion off, explain. */
5313 }
5314 }
5315 /* [temp.arg.nontype]/5, bullet 7
5317 For a non-type template-parameter of type pointer to data member,
5318 qualification conversions (_conv.qual_) are applied. */
5320 {
5321 /* [temp.arg.nontype] bullet 1 says the pointer to member
5322 expression must be a pointer-to-member constant. */
5329 }
5330 /* A template non-type parameter must be one of the above. */
5331 else
5334 /* Sanity check: did we actually convert the argument to the
5335 right type? */
5339 }
5341 /* Subroutine of coerce_template_template_parms, which returns 1 if
5342 PARM_PARM and ARG_PARM match using the rule for the template
5343 parameters of template template parameters. Both PARM and ARG are
5344 template parameters; the rest of the arguments are the same as for
5345 coerce_template_template_parms.
5346 */
5347 static int
5349 tree arg,
5350 tsubst_flags_t complain,
5351 tree in_decl,
5352 tree outer_args)
5353 {
5362 {
5364 /* We encounter instantiations of templates like
5365 template <template <template <class> class> class TT>
5366 class C; */
5367 {
5374 }
5375 /* Fall through. */
5380 /* Argument is a parameter pack but parameter is not. */
5385 /* The tsubst call is used to handle cases such as
5387 template <int> class C {};
5388 template <class T, template <T> class TT> class D {};
5389 D<int, C> d;
5391 i.e. the parameter list of TT depends on earlier parameters. */
5393 && !same_type_p
5400 /* Argument is a parameter pack but parameter is not. */
5407 }
5410 }
5413 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5414 template template parameters. Both PARM_PARMS and ARG_PARMS are
5415 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5416 or PARM_DECL.
5418 Consider the example:
5419 template <class T> class A;
5420 template<template <class U> class TT> class B;
5422 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5423 the parameters to A, and OUTER_ARGS contains A. */
5425 static int
5427 tree arg_parms,
5428 tsubst_flags_t complain,
5429 tree in_decl,
5430 tree outer_args)
5431 {
5442 /* Determine whether we have a parameter pack at the end of the
5443 template template parameter's template parameter list. */
5445 {
5452 {
5466 }
5467 }
5473 /* Check all of the template parameters except the parameter pack at
5474 the end (if any). */
5476 {
5485 outer_args))
5488 }
5491 {
5492 /* Check each of the template parameters in the template
5493 argument against the template parameter pack at the end of
5494 the template template parameter. */
5501 {
5508 outer_args))
5510 }
5511 }
5514 }
5516 /* Verifies that the deduced template arguments (in TARGS) for the
5517 template template parameters (in TPARMS) represent valid bindings,
5518 by comparing the template parameter list of each template argument
5519 to the template parameter list of its corresponding template
5520 template parameter, in accordance with DR150. This
5521 routine can only be called after all template arguments have been
5522 deduced. It will return TRUE if all of the template template
5523 parameter bindings are okay, FALSE otherwise. */
5524 bool
5526 {
5530 /* We're dealing with template parms in this process. */
5536 {
5541 {
5546 {
5547 /* Look inside the argument pack. */
5550 }
5553 {
5557 /* Extract the next argument from the argument
5558 pack. */
5562 /* Look at the pattern of the pack expansion. */
5565 /* Extract the template parameters from the template
5566 argument. */
5572 /* Verify that we can coerce the template template
5573 parameters from the template argument to the template
5574 parameter. This requires an exact match. */
5576 && !coerce_template_template_parms
5578 targ_parms,
5579 tf_none,
5580 tparm,
5581 targs))
5582 {
5585 }
5586 }
5587 }
5588 }
5590 out:
5594 }
5596 /* Convert the indicated template ARG as necessary to match the
5597 indicated template PARM. Returns the converted ARG, or
5598 error_mark_node if the conversion was unsuccessful. Error and
5599 warning messages are issued under control of COMPLAIN. This
5600 conversion is for the Ith parameter in the parameter list. ARGS is
5601 the full set of template arguments deduced so far. */
5603 static tree
5605 tree arg,
5606 tree args,
5607 tsubst_flags_t complain,
5609 tree in_decl)
5610 {
5611 tree orig_arg;
5612 tree val;
5617 {
5618 /* The template argument was the name of some
5619 member function. That's usually
5620 invalid, but static members are OK. In any
5621 case, grab the underlying fields/functions
5622 and issue an error later if required. */
5625 }
5633 /* When determining whether an argument pack expansion is a template,
5634 look at the pattern. */
5638 /* Deal with an injected-class-name used as a template template arg. */
5640 {
5643 {
5651 }
5652 }
5654 is_tmpl_type =
5669 {
5675 typename_type,
5679 }
5681 {
5683 {
5685 {
5695 else
5697 }
5698 }
5700 }
5702 {
5704 {
5710 else
5712 }
5714 }
5717 {
5719 {
5721 /* The number of argument required is not known yet.
5722 Just accept it for now. */
5724 else
5725 {
5727 tree argparm;
5733 args))
5734 {
5737 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5738 TEMPLATE_DECL. */
5740 {
5745 }
5746 }
5747 else
5748 {
5750 {
5756 }
5759 }
5760 }
5761 }
5762 else
5764 /* We only form one instance of each template specialization.
5765 Therefore, if we use a non-canonical variant (i.e., a
5766 typedef), any future messages referring to the type will use
5767 the typedef, which is confusing if those future uses do not
5768 themselves also use the typedef. */
5771 }
5772 else
5773 {
5780 {
5783 else
5784 {
5785 /* Not sure if this is reachable, but it doesn't hurt
5786 to be robust. */
5789 }
5790 }
5792 /* We used to call digest_init here. However, digest_init
5793 will report errors, which we don't want when complain
5794 is zero. More importantly, digest_init will try too
5795 hard to convert things: for example, `0' should not be
5796 converted to pointer type at this point according to
5797 the standard. Accepting this is not merely an
5798 extension, since deciding whether or not these
5799 conversions can occur is part of determining which
5800 function template to call, or whether a given explicit
5801 argument specification is valid. */
5803 else
5812 {
5813 /* Strip typedefs from the SCOPE_REF. */
5818 }
5819 }
5822 }
5824 /* Coerces the remaining template arguments in INNER_ARGS (from
5825 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5826 Returns the coerced argument pack. PARM_IDX is the position of this
5827 parameter in the template parameter list. ARGS is the original
5828 template argument list. */
5829 static tree
5832 tree args,
5833 tree inner_args,
5835 tree new_args,
5837 tree in_decl,
5838 tsubst_flags_t complain)
5839 {
5842 tree packed_args;
5843 tree argument_pack;
5853 {
5854 /* When the template parameter is a non-type template
5855 parameter pack whose type uses parameter packs, we need
5856 to look at each of the template arguments
5857 separately. Build a vector of the types for these
5858 non-type template parameters in PACKED_TYPES. */
5859 tree expansion
5867 /* Check that we have the right number of arguments. */
5871 {
5872 int needed_parms
5877 }
5879 /* If we aren't able to check the actual arguments now
5880 (because they haven't been expanded yet), we can at least
5881 verify that all of the types used for the non-type
5882 template parameter pack are, in fact, valid for non-type
5883 template parameters. */
5886 {
5889 {
5893 }
5894 }
5895 }
5897 /* Convert the remaining arguments, which will be a part of the
5898 parameter pack "parm". */
5900 {
5905 {
5906 /* When we have a vector of types (corresponding to the
5907 non-type template parameter pack that uses parameter
5908 packs in its type, as mention above), and the
5909 argument is not an expansion (which expands to a
5910 currently unknown number of arguments), clone the
5911 parm and give it the next type in PACKED_TYPES. */
5915 }
5920 in_decl);
5924 }
5929 else
5930 {
5935 }
5938 #ifdef ENABLE_CHECKING
5941 #endif
5943 }
5945 /* Convert all template arguments to their appropriate types, and
5946 return a vector containing the innermost resulting template
5947 arguments. If any error occurs, return error_mark_node. Error and
5948 warning messages are issued under control of COMPLAIN.
5950 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5951 for arguments not specified in ARGS. Otherwise, if
5952 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5953 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5954 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5955 ARGS. */
5957 static tree
5959 tree args,
5960 tree in_decl,
5961 tsubst_flags_t complain,
5964 {
5966 tree inner_args;
5967 tree new_args;
5968 tree new_inner_args;
5972 /* When used as a boolean value, indicates whether this is a
5973 variadic template parameter list. Since it's an int, we can also
5974 subtract it from nparms to get the number of non-variadic
5975 parameters. */
5983 /* Determine if there are any parameter packs. */
5985 {
5989 }
5992 /* If there are 0 or 1 parameter packs, we need to expand any argument
5993 packs so that we can deduce a parameter pack from some non-packed args
5994 followed by an argument pack, as in variadic85.C. If there are more
5995 than that, we need to leave argument packs intact so the arguments are
5996 assigned to the right parameter packs. This should only happen when
5997 dealing with a nested class inside a partial specialization of a class
5998 template, as in variadic92.C. */
6005 && require_all_args
6006 && (!use_default_args
6009 {
6011 {
6013 {
6017 }
6018 else
6024 }
6027 }
6029 /* We need to evaluate the template arguments, even though this
6030 template-id may be nested within a "sizeof". */
6038 {
6039 tree arg;
6040 tree parm;
6042 /* Get the Ith template parameter. */
6046 {
6049 }
6051 /* Calculate the next argument. */
6054 else
6059 {
6060 /* All remaining arguments will be placed in the
6061 template parameter pack PARM. */
6067 /* Store this argument. */
6069 lost++;
6072 /* We are done with all of the arguments. */
6076 }
6078 {
6080 {
6082 {
6083 /* FIXME this restriction was removed by N2555; see
6084 bug 35722. */
6085 /* If ARG is a pack expansion, but PARM is not a
6086 template parameter pack (if it were, we would have
6087 handled it above), we're trying to expand into a
6088 fixed-length argument list. */
6092 else
6095 }
6097 }
6098 }
6100 {
6101 /* There must be a default arg in this case. */
6104 /* The position of the first default template argument,
6105 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6106 Record that. */
6109 }
6110 else
6114 {
6117 }
6119 /* This only occurs if there was an error in the template
6120 parameter list itself (which we would already have
6121 reported) that we are trying to recover from, e.g., a class
6122 template with a parameter list such as
6123 template<typename..., typename>. */
6125 else
6131 lost++;
6133 }
6140 #ifdef ENABLE_CHECKING
6144 #endif
6147 }
6149 /* Returns 1 if template args OT and NT are equivalent. */
6151 static int
6153 {
6158 /* For member templates */
6165 {
6182 }
6184 {
6185 /* We get here probably because we are in the middle of substituting
6186 into the pattern of a pack expansion. In that case the
6187 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6188 interested in. So we want to use the initial pack argument for
6189 the comparison. */
6194 }
6199 else
6201 }
6203 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6204 of template arguments. Returns 0 otherwise. */
6206 int
6208 {
6215 {
6221 }
6223 }
6225 static void
6227 {
6237 /* We are called both from instantiate_decl, where we've already had a
6238 tinst_level pushed, and instantiate_template, where we haven't.
6239 Compensate. */
6250 else
6259 }
6262 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6263 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6264 documentation for TEMPLATE_ID_EXPR. */
6266 tree
6268 {
6269 tree type;
6279 {
6281 unknown_type_node,
6283 arglist);
6285 }
6292 }
6294 /* Within the scope of a template class S<T>, the name S gets bound
6295 (in build_self_reference) to a TYPE_DECL for the class, not a
6296 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6297 or one of its enclosing classes, and that type is a template,
6298 return the associated TEMPLATE_DECL. Otherwise, the original
6299 DECL is returned.
6301 Also handle the case when DECL is a TREE_LIST of ambiguous
6302 injected-class-names from different bases. */
6304 tree
6306 {
6310 /* DR 176: A lookup that finds an injected-class-name (10.2
6311 [class.member.lookup]) can result in an ambiguity in certain cases
6312 (for example, if it is found in more than one base class). If all of
6313 the injected-class-names that are found refer to specializations of
6314 the same class template, and if the name is followed by a
6315 template-argument-list, the reference refers to the class template
6316 itself and not a specialization thereof, and is not ambiguous. */
6318 {
6321 {
6327 }
6330 else
6332 }
6338 }
6340 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6341 parameters, find the desired type.
6343 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6345 IN_DECL, if non-NULL, is the template declaration we are trying to
6346 instantiate.
6348 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6349 the class we are looking up.
6351 Issue error and warning messages under control of COMPLAIN.
6353 If the template class is really a local class in a template
6354 function, then the FUNCTION_CONTEXT is the function in which it is
6355 being instantiated.
6357 ??? Note that this function is currently called *twice* for each
6358 template-id: the first time from the parser, while creating the
6359 incomplete type (finish_template_type), and the second type during the
6360 real instantiation (instantiate_template_class). This is surely something
6361 that we want to avoid. It also causes some problems with argument
6362 coercion (see convert_nontype_argument for more information on this). */
6364 tree
6366 tree arglist,
6367 tree in_decl,
6368 tree context,
6370 tsubst_flags_t complain)
6371 {
6373 tree t;
6376 spec_entry elt;
6377 hashval_t hash;
6382 {
6386 else
6387 {
6394 }
6397 }
6399 {
6402 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6403 an implicit typename for the second A. Deal with it. */
6408 {
6411 }
6412 }
6415 {
6418 }
6422 {
6426 }
6428 /* Issue an error message if we didn't find a template. */
6430 {
6434 }
6437 /* Make sure it's a user visible template, if it was named by
6438 the user. */
6441 {
6443 {
6447 }
6449 }
6454 {
6455 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6456 template arguments */
6458 tree parm;
6459 tree arglist2;
6460 tree outer;
6464 /* Consider an example where a template template parameter declared as
6466 template <class T, class U = std::allocator<T> > class TT
6468 The template parameter level of T and U are one level larger than
6469 of TT. To proper process the default argument of U, say when an
6470 instantiation `TT<int>' is seen, we need to build the full
6471 arguments containing {int} as the innermost level. Outer levels,
6472 available when not appearing as default template argument, can be
6473 obtained from the arguments of the enclosing template.
6475 Suppose that TT is later substituted with std::vector. The above
6476 instantiation is `TT<int, std::allocator<T> >' with TT at
6477 level 1, and T at level 2, while the template arguments at level 1
6478 becomes {std::vector} and the inner level 2 is {int}. */
6484 /* This is an argument of the current template, so we haven't set
6485 DECL_CONTEXT yet. */
6492 complain,
6502 }
6503 else
6504 {
6506 tree gen_tmpl;
6507 tree type_decl;
6520 {
6521 /* We've been given an incomplete set of template arguments.
6522 For example, given:
6524 template <class T> struct S1 {
6525 template <class U> struct S2 {};
6526 template <class U> struct S2<U*> {};
6527 };
6529 we will be called with an ARGLIST of `U*', but the
6530 TEMPLATE will be `template <class T> template
6531 <class U> struct S1<T>::S2'. We must fill in the missing
6532 arguments. */
6533 arglist
6535 arglist);
6537 }
6539 /* Now we should have enough arguments. */
6542 /* From here on, we're only interested in the most general
6543 template. */
6545 /* Calculate the BOUND_ARGS. These will be the args that are
6546 actually tsubst'd into the definition to create the
6547 instantiation. */
6549 {
6550 /* We have multiple levels of arguments to coerce, at once. */
6560 {
6561 tree a;
6565 complain,
6568 else
6569 /* Outer levels should have already been coerced. */
6572 /* Don't process further if one of the levels fails. */
6574 {
6575 /* Restore the ARGLIST to its full size. */
6578 }
6582 /* We temporarily reduce the length of the ARGLIST so
6583 that coerce_template_parms will see only the arguments
6584 corresponding to the template parameters it is
6585 examining. */
6587 }
6589 /* Restore the ARGLIST to its full size. */
6593 }
6594 else
6595 arglist
6598 gen_tmpl,
6599 complain,
6604 /* We were unable to bind the arguments. */
6607 /* In the scope of a template class, explicit references to the
6608 template class refer to the type of the template, not any
6609 instantiation of it. For example, in:
6611 template <class T> class C { void f(C<T>); }
6613 the `C<T>' is just the same as `C'. Outside of the
6614 class, however, such a reference is an instantiation. */
6618 /* comp_template_args is expensive, check it last. */
6620 arglist))
6623 /* If we already have this specialization, return it. */
6635 /* If the deduced arguments are invalid, then the binding
6636 failed. */
6640 complain))
6647 {
6652 }
6659 /* Create the type. */
6661 {
6663 {
6669 }
6670 else
6671 {
6672 /* We don't want to call start_enum for this type, since
6673 the values for the enumeration constants may involve
6674 template parameters. And, no one should be interested
6675 in the enumeration constants for such a type. */
6678 }
6680 }
6681 else
6682 {
6689 /* A local class. Make sure the decl gets registered properly. */
6694 /* This instantiation is another name for the primary
6695 template type. Set the TYPE_CANONICAL field
6696 appropriately. */
6699 /* Some of the template arguments require structural
6700 equality testing, so this template class requires
6701 structural equality testing. */
6703 }
6705 /* If we called start_enum or pushtag above, this information
6706 will already be set up. */
6708 {
6715 }
6716 else
6724 {
6727 }
6729 /* Let's consider the explicit specialization of a member
6730 of a class template specialization that is implicitely instantiated,
6731 e.g.:
6732 template<class T>
6733 struct S
6734 {
6735 template<class U> struct M {}; //#0
6736 };
6738 template<>
6739 template<>
6740 struct S<int>::M<char> //#1
6741 {
6742 int i;
6743 };
6744 [temp.expl.spec]/4 says this is valid.
6746 In this case, when we write:
6747 S<int>::M<char> m;
6749 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
6750 the one of #0.
6752 When we encounter #1, we want to store the partial instantiation
6753 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
6755 For all cases other than this "explicit specialization of member of a
6756 class template", we just want to store the most general template into
6757 the CLASSTYPE_TI_TEMPLATE of M.
6759 This case of "explicit specialization of member of a class template"
6760 only happens when:
6761 1/ the enclosing class is an instantiation of, and therefore not
6762 the same as, the context of the most general template, and
6763 2/ we aren't looking at the partial instantiation itself, i.e.
6764 the innermost arguments are not the same as the innermost parms of
6765 the most general template.
6767 So it's only when 1/ and 2/ happens that we want to use the partial
6768 instantiation of the member template in lieu of its most general
6769 template. */
6773 /* the enclosing class must be an instantiation... */
6776 {
6777 tree partial_inst_args;
6780 partial_inst_args =
6786 use_partial_inst_tmpl =
6787 /*...and we must not be looking at the partial instantiation
6788 itself. */
6790 partial_inst_args);
6791 }
6794 /* This case is easy; there are no member templates involved. */
6796 else
6797 {
6798 /* This is a full instantiation of a member template. Find
6799 the partial instantiation of which this is an instance. */
6801 /* Temporarily reduce by one the number of levels in the ARGLIST
6802 so as to avoid comparing the last set of arguments. */
6807 }
6817 /* Note this use of the partial instantiation so we can check it
6818 later in maybe_process_partial_specialization. */
6824 /* Now that the type has been registered on the instantiations
6825 list, we set up the enumerators. Because the enumeration
6826 constants may involve the enumeration type itself, we make
6827 sure to register the type first, and then create the
6828 constants. That way, doing tsubst_expr for the enumeration
6829 constants won't result in recursive calls here; we'll find
6830 the instantiation and exit above. */
6834 /* If the type makes use of template parameters, the
6835 code that generates debugging information will crash. */
6838 /* Possibly limit visibility based on template args. */
6843 }
6845 }
6846 \f
6847 struct pair_fn_data
6848 {
6849 tree_fn_t fn;
6851 /* True when we should also visit template parameters that occur in
6852 non-deduced contexts. */
6855 };
6857 /* Called from for_each_template_parm via walk_tree. */
6859 static tree
6861 {
6874 {
6878 /* Fall through. */
6901 /* Since we're not going to walk subtrees, we have to do this
6902 explicitly here. */
6906 /* Fall through. */
6909 /* Check the return type. */
6914 /* Check the parameter types. Since default arguments are not
6915 instantiated until they are needed, the TYPE_ARG_TYPES may
6916 contain expressions that involve template parameters. But,
6917 no-one should be looking at them yet. And, once they're
6918 instantiated, they don't contain template parameters, so
6919 there's no point in looking at them then, either. */
6920 {
6921 tree parm;
6928 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6929 want walk_tree walking into them itself. */
6931 }
6948 /* Fall through. */
6964 /* Record template parameters such as `T' inside `TT<T>'. */
6968 /* Fall through. */
6980 /* A template template parameter is encountered. */
6986 /* Already substituted template template parameter */
7009 /* If there's no type, then this thing must be some expression
7010 involving template parameters. */
7031 }
7033 /* We didn't find any template parameters we liked. */
7035 }
7037 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7038 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7039 call FN with the parameter and the DATA.
7040 If FN returns nonzero, the iteration is terminated, and
7041 for_each_template_parm returns 1. Otherwise, the iteration
7042 continues. If FN never returns a nonzero value, the value
7043 returned by for_each_template_parm is 0. If FN is NULL, it is
7044 considered to be the function which always returns 1.
7046 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7047 parameters that occur in non-deduced contexts. When false, only
7048 visits those template parameters that can be deduced. */
7050 static int
7054 {
7058 /* Set up. */
7063 /* Walk the tree. (Conceptually, we would like to walk without
7064 duplicates, but for_each_template_parm_r recursively calls
7065 for_each_template_parm, so we would need to reorganize a fair
7066 bit to use walk_tree_without_duplicates, so we keep our own
7067 visited list.) */
7070 else
7073 for_each_template_parm_r,
7077 /* Clean up. */
7079 {
7082 }
7085 }
7087 /* Returns true if T depends on any template parameter. */
7089 int
7091 {
7118 else
7119 {
7122 }
7127 }
7129 /* Returns true if T depends on any template parameter with level LEVEL. */
7131 int
7133 {
7136 }
7140 #ifdef GATHER_STATISTICS
7142 #endif
7146 /* We're starting to instantiate D; record the template instantiation context
7147 for diagnostics and to restore it later. */
7149 int
7151 {
7155 {
7156 /* If the instantiation in question still has unbound template parms,
7157 we don't really care if we can't instantiate it, so just return.
7158 This happens with base instantiation for implicit `typename'. */
7170 }
7180 #ifdef GATHER_STATISTICS
7183 #endif
7187 }
7189 /* We're done instantiating this template; return to the instantiation
7190 context. */
7192 void
7194 {
7195 /* Restore the filename and line number stashed away when we started
7196 this instantiation. */
7201 }
7203 /* We're instantiating a deferred template; restore the template
7204 instantiation context in which the instantiation was requested, which
7205 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7207 static tree
7209 {
7219 }
7221 /* Returns the TINST_LEVEL which gives the original instantiation
7222 context. */
7226 {
7232 }
7234 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7236 bool
7238 {
7239 tree parms;
7256 }
7258 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7259 vector of template arguments, as for tsubst.
7261 Returns an appropriate tsubst'd friend declaration. */
7263 static tree
7265 {
7266 tree new_friend;
7271 /* This was a friend declared with an explicit template
7272 argument list, e.g.:
7274 friend void f<>(T);
7276 to indicate that f was a template instantiation, not a new
7277 function declaration. Now, we have to figure out what
7278 instantiation of what template. */
7279 {
7281 tree new_args;
7282 tree tmpl;
7285 /* Friend functions are looked up in the containing namespace scope.
7286 We must enter that scope, to avoid finding member functions of the
7287 current class with same name. */
7302 tsk_none);
7304 }
7308 /* The NEW_FRIEND will look like an instantiation, to the
7309 compiler, but is not an instantiation from the point of view of
7310 the language. For example, we might have had:
7312 template <class T> struct S {
7313 template <class U> friend void f(T, U);
7314 };
7316 Then, in S<int>, template <class U> void f(int, U) is not an
7317 instantiation of anything. */
7323 {
7327 }
7329 /* The mangled name for the NEW_FRIEND is incorrect. The function
7330 is not a template instantiation and should not be mangled like
7331 one. Therefore, we forget the mangling here; we'll recompute it
7332 later if we need it. */
7334 {
7337 }
7340 {
7341 tree old_decl;
7342 tree new_friend_template_info;
7343 tree new_friend_result_template_info;
7344 tree ns;
7347 /* We must save some information from NEW_FRIEND before calling
7348 duplicate decls since that function will free NEW_FRIEND if
7349 possible. */
7351 new_friend_is_defn =
7356 {
7357 /* This declaration is a `primary' template. */
7360 new_friend_result_template_info
7362 }
7363 else
7366 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7370 /* Inside pushdecl_namespace_level, we will push into the
7371 current namespace. However, the friend function should go
7372 into the namespace of the template. */
7382 {
7383 /* This new friend declaration matched an existing
7384 declaration. For example, given:
7386 template <class T> void f(T);
7387 template <class U> class C {
7388 template <class T> friend void f(T) {}
7389 };
7391 the friend declaration actually provides the definition
7392 of `f', once C has been instantiated for some type. So,
7393 old_decl will be the out-of-class template declaration,
7394 while new_friend is the in-class definition.
7396 But, if `f' was called before this point, the
7397 instantiation of `f' will have DECL_TI_ARGS corresponding
7398 to `T' but not to `U', references to which might appear
7399 in the definition of `f'. Previously, the most general
7400 template for an instantiation of `f' was the out-of-class
7401 version; now it is the in-class version. Therefore, we
7402 run through all specialization of `f', adding to their
7403 DECL_TI_ARGS appropriately. In particular, they need a
7404 new set of outer arguments, corresponding to the
7405 arguments for this class instantiation.
7407 The same situation can arise with something like this:
7409 friend void f(int);
7410 template <class T> class C {
7411 friend void f(T) {}
7412 };
7414 when `C<int>' is instantiated. Now, `f(int)' is defined
7415 in the class. */
7418 /* On the other hand, if the in-class declaration does
7419 *not* provide a definition, then we don't want to alter
7420 existing definitions. We can just leave everything
7421 alone. */
7422 ;
7423 else
7424 {
7428 /* Overwrite whatever template info was there before, if
7429 any, with the new template information pertaining to
7430 the declaration. */
7434 {
7435 /* We should have called reregister_specialization in
7436 duplicate_decls. */
7441 /* Instantiate it if the global has already been used. */
7445 }
7446 else
7447 {
7448 tree t;
7450 /* Indicate that the old function template is a partial
7451 instantiation. */
7459 /* Reassign any specializations already in the hash table
7460 to the new more general template, and add the
7461 additional template args. */
7465 {
7467 spec_entry elt;
7479 register_specialization
7482 }
7484 }
7485 }
7487 /* The information from NEW_FRIEND has been merged into OLD_DECL
7488 by duplicate_decls. */
7490 }
7491 }
7492 else
7493 {
7497 /* In the code
7498 template <class T> class C {
7499 template <class U> friend void C1<U>::f (); // case 1
7500 friend void C2<T>::f (); // case 2
7501 };
7502 we only need to make sure CONTEXT is a complete type for
7503 case 2. To distinguish between the two cases, we note that
7504 CONTEXT of case 1 remains dependent type after tsubst while
7505 this isn't true for case 2. */
7515 {
7516 /* Check to see that the declaration is really present, and,
7517 possibly obtain an improved declaration. */
7523 }
7524 }
7527 }
7529 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7530 template arguments, as for tsubst.
7532 Returns an appropriate tsubst'd friend type or error_mark_node on
7533 failure. */
7535 static tree
7537 {
7538 tree friend_type;
7539 tree tmpl;
7540 tree context;
7545 {
7548 else
7550 }
7552 /* Look for a class template declaration. We look for hidden names
7553 because two friend declarations of the same template are the
7554 same. For example, in:
7556 struct A {
7557 template <typename> friend class F;
7558 };
7559 template <typename> struct B {
7560 template <typename> friend class F;
7561 };
7563 both F templates are the same. */
7568 /* But, if we don't find one, it might be because we're in a
7569 situation like this:
7571 template <class T>
7572 struct S {
7573 template <class U>
7574 friend struct S;
7575 };
7577 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7578 for `S<int>', not the TEMPLATE_DECL. */
7580 {
7583 }
7586 {
7587 /* The friend template has already been declared. Just
7588 check to see that the declarations match, and install any new
7589 default parameters. We must tsubst the default parameters,
7590 of course. We only need the innermost template parameters
7591 because that is all that redeclare_class_template will look
7592 at. */
7595 {
7596 tree parms;
7597 location_t saved_input_location;
7606 }
7609 }
7610 else
7611 {
7612 /* The friend template has not already been declared. In this
7613 case, the instantiation of the template class will cause the
7614 injection of this template into the global scope. */
7619 /* The new TMPL is not an instantiation of anything, so we
7620 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7621 the new type because that is supposed to be the corresponding
7622 template decl, i.e., TMPL. */
7629 /* Inject this template into the global scope. */
7631 }
7634 {
7637 else
7639 }
7642 }
7644 /* Returns zero if TYPE cannot be completed later due to circularity.
7645 Otherwise returns one. */
7647 static int
7649 {
7659 else
7661 }
7663 /* Apply any attributes which had to be deferred until instantiation
7664 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7665 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7667 static void
7670 {
7672 tree t;
7677 {
7681 }
7684 {
7688 }
7689 else
7693 {
7698 {
7701 {
7704 /* If the first attribute argument is an identifier, don't
7705 pass it through tsubst. Attributes like mode, format,
7706 cleanup and several target specific attributes expect it
7707 unmodified. */
7713 {
7714 tree chain
7716 in_decl,
7721 chain);
7722 }
7723 else
7729 }
7730 else
7732 }
7735 }
7736 }
7738 /* Perform (or defer) access check for typedefs that were referenced
7739 from within the template TMPL code.
7740 This is a subroutine of instantiate_template and instantiate_class_template.
7741 TMPL is the template to consider and TARGS is the list of arguments of
7742 that template. */
7744 static void
7746 {
7747 location_t saved_location;
7760 {
7772 /* Make access check error messages point to the location
7773 of the use of the typedef. */
7777 }
7779 }
7781 tree
7783 {
7785 tree typedecl;
7786 tree pbinfo;
7787 tree base_list;
7797 /* Figure out which template is being instantiated. */
7801 /* Determine what specialization of the original template to
7802 instantiate. */
7805 {
7808 }
7810 {
7811 /* This TYPE is actually an instantiation of a partial
7812 specialization. We replace the innermost set of ARGS with
7813 the arguments appropriate for substitution. For example,
7814 given:
7816 template <class T> struct S {};
7817 template <class T> struct S<T*> {};
7819 and supposing that we are instantiating S<int*>, ARGS will
7820 presently be {int*} -- but we need {int}. */
7823 }
7824 else
7825 {
7828 }
7830 /* If the template we're instantiating is incomplete, then clearly
7831 there's nothing we can do. */
7835 /* If we've recursively instantiated too many templates, stop. */
7839 /* Now we're really doing the instantiation. Mark the type as in
7840 the process of being defined. */
7843 /* We may be in the middle of deferred access check. Disable
7844 it now. */
7848 /* Use #pragma pack from the template context. */
7854 /* Set the input location to the most specialized template definition.
7855 This is needed if tsubsting causes an error. */
7877 {
7880 }
7884 /* We should never instantiate a nested class before its enclosing
7885 class; we need to look up the nested class by name before we can
7886 instantiate it, and that lookup should instantiate the enclosing
7887 class. */
7893 {
7894 tree pbase_binfo;
7895 tree pushed_scope;
7898 /* We must enter the scope containing the type, as that is where
7899 the accessibility of types named in dependent bases are
7900 looked up from. */
7903 /* Substitute into each of the bases to determine the actual
7904 basetypes. */
7906 {
7907 tree base;
7913 {
7914 expanded_bases =
7921 }
7924 {
7926 /* Extract the already-expanded base class. */
7928 else
7929 /* Substitute to figure out the base class. */
7931 NULL_TREE);
7939 }
7940 }
7942 /* The list is now in reverse order; correct that. */
7947 }
7948 /* Now call xref_basetypes to set up all the base-class
7949 information. */
7957 /* Now that our base classes are set up, enter the scope of the
7958 class, so that name lookups into base classes, etc. will work
7959 correctly. This is precisely analogous to what we do in
7960 begin_class_definition when defining an ordinary non-template
7961 class, except we also need to push the enclosing classes. */
7964 /* Now members are processed in the order of declaration. */
7967 {
7971 {
7973 {
7974 /* Build new CLASSTYPE_NESTED_UTDS. */
7976 tree newtag;
7982 /* If the member is a class template, then -- even after
7983 substitution -- there may be dependent types in the
7984 template argument list for the class. We increment
7985 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7986 that function will assume that no types are dependent
7987 when outside of a template. */
7997 {
8001 /* Unfortunately, lookup_template_class sets
8002 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8003 instantiation (i.e., for the type of a member
8004 template class nested within a template class.)
8005 This behavior is required for
8006 maybe_process_partial_specialization to work
8007 correctly, but is not accurate in this case;
8008 the TAG is not an instantiation of anything.
8009 (The corresponding TEMPLATE_DECL is an
8010 instantiation, but the TYPE is not.) */
8013 /* Now, we call pushtag to put this NEWTAG into the scope of
8014 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8015 pushtag calling push_template_decl. We don't have to do
8016 this for enums because it will already have been done in
8017 tsubst_enum. */
8021 }
8022 }
8025 {
8026 /* Build new TYPE_METHODS. */
8027 tree r;
8036 }
8037 else
8038 {
8039 /* Build new TYPE_FIELDS. */
8041 {
8042 tree condition =
8050 }
8052 {
8053 tree r;
8055 /* The file and line for this declaration, to
8056 assist in error message reporting. Since we
8057 called push_tinst_level above, we don't need to
8058 restore these. */
8067 {
8068 /* In [temp.inst]:
8070 [t]he initialization (and any associated
8071 side-effects) of a static data member does
8072 not occur unless the static data member is
8073 itself used in a way that requires the
8074 definition of the static data member to
8075 exist.
8077 Therefore, we do not substitute into the
8078 initialized for the static data member here. */
8079 finish_static_data_member_decl
8087 }
8089 {
8090 /* Determine whether R has a valid type and can be
8091 completed later. If R is invalid, then it is
8092 replaced by error_mark_node so that it will not be
8093 added to TYPE_FIELDS. */
8099 {
8102 }
8103 }
8105 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8106 such a thing will already have been added to the field
8107 list by tsubst_enum in finish_member_declaration in the
8108 CLASSTYPE_NESTED_UTDS case above. */
8112 {
8115 }
8116 }
8117 }
8118 }
8119 else
8120 {
8122 {
8123 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8129 {
8130 /* template <class T> friend class C; */
8133 }
8135 {
8136 /* template <class T> friend class C::D; */
8142 }
8144 {
8145 /* This could be either
8147 friend class T::C;
8149 when dependent_type_p is false or
8151 template <class U> friend class T::C;
8153 otherwise. */
8156 /* Bump processing_template_decl for correct
8157 dependent_type_p calculation. */
8162 }
8165 {
8166 /* friend class C;
8168 where C hasn't been declared yet. Let's lookup name
8169 from namespace scope directly, bypassing any name that
8170 come from dependent base class. */
8173 /* The call to xref_tag_from_type does injection for friend
8174 classes. */
8176 friend_type =
8180 }
8182 /* friend class C<T>; */
8185 /* Otherwise it's
8187 friend class C;
8189 where C is already declared or
8191 friend class C<int>;
8193 We don't have to do anything in these cases. */
8196 /* Trick make_friend_class into realizing that the friend
8197 we're adding is a template, not an ordinary class. It's
8198 important that we use make_friend_class since it will
8199 perform some error-checking and output cross-reference
8200 information. */
8208 }
8209 else
8210 {
8211 /* Build new DECL_FRIENDLIST. */
8212 tree r;
8214 /* The file and line for this declaration, to
8215 assist in error message reporting. Since we
8216 called push_tinst_level above, we don't need to
8217 restore these. */
8221 {
8224 }
8229 {
8232 }
8233 }
8234 }
8235 }
8237 /* Set the file and line number information to whatever is given for
8238 the class itself. This puts error messages involving generated
8239 implicit functions at a predictable point, and the same point
8240 that would be used for non-template classes. */
8247 /* We don't instantiate default arguments for member functions. 14.7.1:
8249 The implicit instantiation of a class template specialization causes
8250 the implicit instantiation of the declarations, but not of the
8251 definitions or default arguments, of the class member functions,
8252 member classes, static data members and member templates.... */
8254 /* Some typedefs referenced from within the template code need to be access
8255 checked at template instantiation time, i.e now. These types were
8256 added to the template at parsing time. Let's get those and perform
8257 the access checks then. */
8266 /* The vtable for a template class can be emitted in any translation
8267 unit in which the class is instantiated. When there is no key
8268 method, however, finish_struct_1 will already have added TYPE to
8269 the keyed_classes list. */
8274 }
8276 static tree
8278 {
8279 tree r;
8285 else
8286 {
8293 }
8295 }
8297 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8298 NONTYPE_ARGUMENT_PACK. */
8300 static tree
8302 {
8303 /* Collect all of the extra "packed" parameters into an
8304 argument pack. */
8305 tree parmvec;
8306 tree parmtypevec;
8311 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8315 {
8318 }
8320 /* Build the argument packs. */
8326 }
8328 /* Substitute ARGS into T, which is an pack expansion
8329 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8330 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8331 (if only a partial substitution could be performed) or
8332 ERROR_MARK_NODE if there was an error. */
8333 tree
8335 tree in_decl)
8336 {
8337 tree pattern;
8340 tree result;
8347 /* Determine the argument packs that will instantiate the parameter
8348 packs used in the expansion expression. While we're at it,
8349 compute the number of arguments to be expanded and make sure it
8350 is consistent. */
8353 {
8359 {
8362 else
8363 {
8364 /* We can't rely on local_specializations for a parameter
8365 name used later in a function declaration (such as in a
8366 late-specified return type). Even if it exists, it might
8367 have the wrong value for a recursive call. Just make a
8368 dummy decl, since it's only used for its type. */
8371 }
8372 }
8373 else
8374 {
8381 }
8388 /* This can only happen if we forget to expand an argument
8389 pack somewhere else. Just return an error, silently. */
8390 {
8394 }
8399 {
8404 /* The argument pack that the parameter maps to is just an
8405 expansion of the parameter itself, such as one would
8406 find in the implicit typedef of a class inside the
8407 class itself. Consider this parameter "unsubstituted",
8408 so that we will maintain the outer pack expansion. */
8410 }
8413 {
8417 /* It's all-or-nothing with incomplete argument packs. */
8427 {
8429 /* We got explicit args for some packs but not others;
8430 do nothing now and try again after deduction. */
8435 pattern);
8436 else
8439 pattern);
8441 }
8443 /* Keep track of the parameter packs and their corresponding
8444 argument packs. */
8447 }
8448 else
8449 /* We can't substitute for this parameter pack. */
8452 unsubstituted_packs);
8453 }
8455 /* We cannot expand this expansion expression, because we don't have
8456 all of the argument packs we need. Substitute into the pattern
8457 and return a PACK_EXPANSION_*. The caller will need to deal with
8458 that. */
8460 {
8461 tree new_pat;
8465 else
8468 }
8470 /* We could not find any argument packs that work. */
8475 {
8476 /* We're in a late-specified return type, so create our own local
8477 specializations table; the current table is either NULL or (in the
8478 case of recursive unification) might have bindings that we don't
8479 want to use or alter. */
8482 hash_local_specialization,
8483 eq_local_specializations,
8484 NULL);
8485 }
8487 /* For each argument in each argument pack, substitute into the
8488 pattern. */
8491 {
8492 /* For parameter pack, change the substitution of the parameter
8493 pack to the ith argument in its argument pack, then expand
8494 the pattern. */
8496 {
8500 {
8501 /* Select the Ith argument from the pack. */
8507 }
8508 else
8509 {
8515 {
8516 /* Select the Ith argument from the pack. */
8520 }
8522 /* Update the corresponding argument. */
8524 }
8525 }
8527 /* Substitute into the PATTERN with the altered arguments. */
8532 else
8536 /* When we have incomplete argument packs, the last "expanded"
8537 result is itself a pack expansion, which allows us
8538 to deduce more arguments. */
8543 {
8546 }
8547 }
8549 /* Update ARGS to restore the substitution from parameter packs to
8550 their argument packs. */
8552 {
8557 else
8558 {
8562 /* Update the corresponding argument. */
8566 else
8568 }
8569 }
8572 {
8575 }
8578 }
8580 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8581 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8582 parameter packs; all parms generated from a function parameter pack will
8583 have the same DECL_PARM_INDEX. */
8585 tree
8587 {
8589 tree patparm;
8592 {
8598 }
8599 else
8600 {
8605 }
8608 }
8610 /* Substitute ARGS into the vector or list of template arguments T. */
8612 static tree
8614 {
8621 {
8623 tree new_arg;
8628 {
8629 /* Substitute into an expansion expression. */
8633 /* Add to the expanded length adjustment the number of
8634 expanded arguments. We subtract one from this
8635 measurement, because the argument pack expression
8636 itself is already counted as 1 in
8637 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8638 the argument pack is empty. */
8640 }
8642 {
8643 /* Substitute into each of the arguments. */
8649 new_arg,
8663 }
8664 }
8665 else
8674 }
8679 /* Make space for the expanded arguments coming from template
8680 argument packs. */
8682 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8683 arguments for a member template.
8684 In that case each TREE_VEC in ORIG_T represents a level of template
8685 arguments, and ORIG_T won't carry any non defaulted argument count.
8686 It will rather be the nested TREE_VECs that will carry one.
8687 In other words, ORIG_T carries a non defaulted argument count only
8688 if it doesn't contain any nested TREE_VEC. */
8690 {
8694 }
8696 {
8700 {
8703 /* Now expand the template argument pack "in place". */
8706 }
8707 else
8708 {
8710 out++;
8711 }
8712 }
8715 }
8717 /* Return the result of substituting ARGS into the template parameters
8718 given by PARMS. If there are m levels of ARGS and m + n levels of
8719 PARMS, then the result will contain n levels of PARMS. For
8720 example, if PARMS is `template <class T> template <class U>
8721 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8722 result will be `template <int*, double, class V>'. */
8724 static tree
8726 {
8730 /* When substituting into a template, we must set
8731 PROCESSING_TEMPLATE_DECL as the template parameters may be
8732 dependent if they are based on one-another, and the dependency
8733 predicates are short-circuit outside of templates. */
8740 {
8741 tree new_vec =
8746 {
8747 tree tuple;
8748 tree default_value;
8749 tree parm_decl;
8771 }
8777 }
8782 }
8784 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8785 type T. If T is not an aggregate or enumeration type, it is
8786 handled as if by tsubst. IN_DECL is as for tsubst. If
8787 ENTERING_SCOPE is nonzero, T is the context for a template which
8788 we are presently tsubst'ing. Return the substituted value. */
8790 static tree
8792 tree args,
8793 tsubst_flags_t complain,
8794 tree in_decl,
8796 {
8801 {
8806 /* Else fall through. */
8810 {
8811 tree argvec;
8812 tree context;
8813 tree r;
8817 /* In "sizeof(X<I>)" we need to evaluate "I". */
8823 /* First, determine the context for the type we are looking
8824 up. */
8827 {
8830 /* If context is a nested class inside a class template,
8831 it may still need to be instantiated (c++/33959). */
8834 }
8836 /* Then, figure out what arguments are appropriate for the
8837 type we are trying to find. For example, given:
8839 template <class T> struct S;
8840 template <class T, class U> void f(T, U) { S<U> su; }
8842 and supposing that we are instantiating f<int, double>,
8843 then our ARGS will be {int, double}, but, when looking up
8844 S we only want {double}. */
8849 else
8850 {
8854 }
8860 }
8861 else
8862 /* This is not a template type, so there's nothing to do. */
8867 }
8868 }
8870 /* Substitute into the default argument ARG (a default argument for
8871 FN), which has the indicated TYPE. */
8873 tree
8875 {
8879 /* This can happen in invalid code. */
8883 /* This default argument came from a template. Instantiate the
8884 default argument here, not in tsubst. In the case of
8885 something like:
8887 template <class T>
8888 struct S {
8889 static T t();
8890 void f(T = t());
8891 };
8893 we must be careful to do name lookup in the scope of S<T>,
8894 rather than in the current class. */
8896 /* The "this" pointer is not valid in a default argument. */
8898 {
8903 }
8906 /* The default argument expression may cause implicitly defined
8907 member functions to be synthesized, which will result in garbage
8908 collection. We must treat this situation as if we were within
8909 the body of function so as to avoid collecting live data on the
8910 stack. */
8918 /* Restore the "this" pointer. */
8920 {
8923 }
8925 /* Make sure the default argument is reasonable. */
8931 }
8933 /* Substitute into all the default arguments for FN. */
8935 static void
8937 {
8938 tree arg;
8939 tree tmpl_args;
8943 /* If this function is not yet instantiated, we certainly don't need
8944 its default arguments. */
8947 /* Don't do this again for clones. */
8952 arg;
8958 }
8960 /* Substitute the ARGS into the T, which is a _DECL. Return the
8961 result of the substitution. Issue error and warning messages under
8962 control of COMPLAIN. */
8964 static tree
8966 {
8967 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8968 location_t saved_loc;
8973 /* Set the filename and linenumber to improve error-reporting. */
8978 {
8980 {
8981 /* We can get here when processing a member function template,
8982 member class template, or template template parameter. */
8984 tree spec;
8985 tree tmpl_args;
8986 tree full_args;
8989 {
8990 /* Template template parameter is treated here. */
9003 complain);
9006 }
9008 /* We might already have an instance of this template.
9009 The ARGS are for the surrounding class type, so the
9010 full args contain the tsubst'd args for the context,
9011 plus the innermost args from the template decl. */
9015 /* Because this is a template, the arguments will still be
9016 dependent, even after substitution. If
9017 PROCESSING_TEMPLATE_DECL is not set, the dependency
9018 predicates will short-circuit. */
9026 /* If this is a default template template argument,
9027 tsubst might not have changed anything. */
9034 {
9037 }
9039 /* Make a new template decl. It will be similar to the
9040 original, but will record the current template arguments.
9041 We also create a new function declaration, which is just
9042 like the old one, but points to this new template, rather
9043 than the old one. */
9051 {
9052 tree new_type;
9064 }
9065 else
9066 {
9067 tree new_decl;
9079 }
9085 /* The template parameters for this new template are all the
9086 template parameters for the old template, except the
9087 outermost level of parameters. */
9090 complain);
9096 /* Record this non-type partial instantiation. */
9100 }
9104 {
9105 tree ctx;
9108 tree gen_tmpl;
9109 tree type;
9114 /* Nobody should be tsubst'ing into non-template functions. */
9118 {
9119 tree spec;
9122 /* If T is not dependent, just return it. We have to
9123 increment PROCESSING_TEMPLATE_DECL because
9124 value_dependent_expression_p assumes that nothing is
9125 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9132 /* Calculate the most general template of which R is a
9133 specialization, and the complete set of arguments used to
9134 specialize R. */
9137 (DECL_TEMPLATE_RESULT
9141 /* Check to see if we already have this specialization. */
9146 {
9149 }
9151 /* We can see more levels of arguments than parameters if
9152 there was a specialization of a member template, like
9153 this:
9155 template <class T> struct S { template <class U> void f(); }
9156 template <> template <class U> void S<int>::f(U);
9158 Here, we'll be substituting into the specialization,
9159 because that's where we can find the code we actually
9160 want to generate, but we'll have enough arguments for
9161 the most general template.
9163 We also deal with the peculiar case:
9165 template <class T> struct S {
9166 template <class U> friend void f();
9167 };
9168 template <class U> void f() {}
9169 template S<int>;
9170 template void f<double>();
9172 Here, the ARGS for the instantiation of will be {int,
9173 double}. But, we only need as many ARGS as there are
9174 levels of template parameters in CODE_PATTERN. We are
9175 careful not to get fooled into reducing the ARGS in
9176 situations like:
9178 template <class T> struct S { template <class U> void f(U); }
9179 template <class T> template <> void S<T>::f(int) {}
9181 which we can spot because the pattern will be a
9182 specialization in this case. */
9184 parms_depth =
9189 }
9190 else
9191 {
9192 /* This special case arises when we have something like this:
9194 template <class T> struct S {
9195 friend void f<int>(int, double);
9196 };
9198 Here, the DECL_TI_TEMPLATE for the friend declaration
9199 will be an IDENTIFIER_NODE. We are being called from
9200 tsubst_friend_function, and we want only to create a
9201 new decl (R) with appropriate types so that we can call
9202 determine_specialization. */
9204 }
9207 {
9210 else
9214 }
9215 else
9216 {
9219 }
9224 /* We do NOT check for matching decls pushed separately at this
9225 point, as they may not represent instantiations of this
9226 template, and in any case are considered separate under the
9227 discrete model. */
9231 /* Clear out the mangled name and RTL for the instantiation. */
9234 /* Leave DECL_INITIAL set on deleted instantiations. */
9240 /* Type-conversion operator. Reconstruct the name, in
9241 case it's the name of one of the template's parameters. */
9251 /* If this is an instantiation of a function with internal
9252 linkage, we already know what object file linkage will be
9253 assigned to the instantiation. */
9262 /* We'll re-clone as appropriate in instantiate_template. */
9265 /* If we aren't complaining now, return on error before we register
9266 the specialization so that we'll complain eventually. */
9272 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9273 this in the special friend case mentioned above where
9274 GEN_TMPL is NULL. */
9276 {
9282 /* We're not supposed to instantiate default arguments
9283 until they are called, for a template. But, for a
9284 declaration like:
9286 template <class T> void f ()
9287 { extern void g(int i = T()); }
9289 we should do the substitution when the template is
9290 instantiated. We handle the member function case in
9291 instantiate_class_template since the default arguments
9292 might refer to other members of the class. */
9297 }
9298 else
9301 /* Copy the list of befriending classes. */
9305 {
9309 in_decl);
9310 }
9313 {
9317 /* If this is an instantiation of a member template, clone it.
9318 If it isn't, that'll be handled by
9319 clone_constructors_and_destructors. */
9322 }
9333 /* Possibly limit visibility based on template args. */
9336 {
9340 }
9348 }
9352 {
9360 {
9361 /* If there is a local specialization that isn't a
9362 parameter pack, it means that we're doing a "simple"
9363 substitution from inside tsubst_pack_expansion. Just
9364 return the local specialization (which will be a single
9365 parm). */
9372 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9373 the parameters in this function parameter pack. */
9377 {
9380 /* Zero-length parameter packs are boring. Just substitute
9381 into the chain. */
9385 }
9386 else
9387 {
9388 /* All we did was update the type. Make a note of that. */
9391 }
9392 }
9394 /* Loop through all of the parameter's we'll build. When T is
9395 a function parameter pack, LEN is the number of expanded
9396 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9399 {
9405 /* An argument of a function parameter pack is not a parameter
9406 pack. */
9410 /* We're on the Ith parameter of the function parameter
9411 pack. */
9412 {
9413 /* Get the Ith type. */
9417 /* Rename the parameter to include the index. */
9420 }
9422 /* We're dealing with a normal parameter. */
9430 {
9433 else
9436 }
9446 /* Keep track of the first new parameter we
9447 generate. That's what will be returned to the
9448 caller. */
9452 /* Build a proper chain of parameters when substituting
9453 into a function parameter pack. */
9456 }
9462 /* FIRST_R contains the start of the chain we've built. */
9464 }
9468 {
9469 tree type;
9478 /* DECL_INITIAL gives the number of bits in a bit-field. */
9483 /* We don't have to set DECL_CONTEXT here; it is set by
9484 finish_member_declaration. */
9491 }
9495 /* We reach here only for member using decls. */
9497 {
9498 r = do_class_using_decl
9503 else
9504 {
9507 }
9508 }
9509 else
9510 {
9513 }
9518 {
9521 tree spec;
9523 tree ctx;
9529 {
9530 /* If this is the canonical decl, we don't have to
9531 mess with instantiations, and often we can't (for
9532 typename, template type parms and such). Note that
9533 TYPE_NAME is not correct for the above test if
9534 we've copied the type for a typedef. */
9540 }
9542 /* Check to see if we already have the specialization we
9543 need. */
9546 {
9547 /* T is a static data member or namespace-scope entity.
9548 We have to substitute into namespace-scope variables
9549 (even though such entities are never templates) because
9550 of cases like:
9552 template <class T> void f() { extern T t; }
9554 where the entity referenced is not known until
9555 instantiation time. */
9559 {
9561 complain,
9563 /* If CTX is unchanged, then T is in fact the
9564 specialization we want. That situation occurs when
9565 referencing a static data member within in its own
9566 class. We can use pointer equality, rather than
9567 same_type_p, because DECL_CONTEXT is always
9568 canonical. */
9571 }
9574 {
9580 }
9581 }
9582 else
9583 {
9584 /* A local variable. */
9586 /* Subsequent calls to pushdecl will fill this in. */
9589 }
9590 /* If we already have the specialization we need, there is
9591 nothing more to do. */
9593 {
9596 }
9598 /* Create a new node for the specialization we need. */
9601 {
9604 else
9609 }
9611 {
9612 /* Even if the original location is out of scope, the
9613 newly substituted one is not. */
9620 {
9621 /* It may seem that this case cannot occur, since:
9623 typedef void f();
9624 void g() { f x; }
9626 declares a function, not a variable. However:
9628 typedef void f();
9629 template <typename T> void g() { T t; }
9630 template void g<f>();
9632 is an attempt to declare a variable with function
9633 type. */
9635 /* R is not yet sufficiently initialized, so we
9636 just use its name. */
9639 }
9646 {
9651 }
9652 }
9658 /* Clear out the mangled name and RTL for the instantiation. */
9662 /* The initializer must not be expanded until it is required;
9663 see [temp.inst]. */
9669 {
9670 /* Possibly limit visibility based on template args. */
9673 {
9677 }
9679 }
9682 {
9683 /* A static data member declaration is always marked
9684 external when it is declared in-class, even if an
9685 initializer is present. We mimic the non-template
9686 processing here. */
9692 }
9694 {
9695 /* We're substituting this var in a decltype outside of its
9696 scope, such as for a lambda return type. Don't add it to
9697 local_specializations, do perform auto deduction. */
9699 tree init
9704 {
9707 }
9708 }
9709 else
9718 /* Preserve a typedef that names a type. */
9720 {
9723 }
9726 }
9731 }
9732 #undef RETURN
9734 out:
9735 /* Restore the file and line information. */
9739 }
9741 /* Substitute into the ARG_TYPES of a function type. */
9743 static tree
9745 tree args,
9746 tsubst_flags_t complain,
9747 tree in_decl)
9748 {
9749 tree remaining_arg_types;
9753 tree default_arg;
9764 {
9765 /* For a pack expansion, perform substitution on the
9766 entire expression. Later on, we'll handle the arguments
9767 one-by-one. */
9772 /* So that we'll spin through the parameters, one by one. */
9774 else
9775 {
9776 /* We only partially substituted into the parameter
9777 pack. Our type is TYPE_PACK_EXPANSION. */
9780 }
9781 }
9794 {
9796 {
9800 }
9802 }
9804 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9805 top-level qualifiers as required. */
9808 /* We do not substitute into default arguments here. The standard
9809 mandates that they be instantiated only when needed, which is
9810 done in build_over_call. */
9814 {
9815 /* We've instantiated a template before its default arguments
9816 have been parsed. This can happen for a nested template
9817 class, and is not an error unless we require the default
9818 argument in a call of this function. */
9819 remaining_arg_types =
9822 remaining_arg_types);
9823 }
9824 else
9825 remaining_arg_types =
9827 }
9830 }
9832 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9833 *not* handle the exception-specification for FNTYPE, because the
9834 initial substitution of explicitly provided template parameters
9835 during argument deduction forbids substitution into the
9836 exception-specification:
9838 [temp.deduct]
9840 All references in the function type of the function template to the
9841 corresponding template parameters are replaced by the specified tem-
9842 plate argument values. If a substitution in a template parameter or
9843 in the function type of the function template results in an invalid
9844 type, type deduction fails. [Note: The equivalent substitution in
9845 exception specifications is done only when the function is instanti-
9846 ated, at which point a program is ill-formed if the substitution
9847 results in an invalid type.] */
9849 static tree
9851 tree args,
9852 tsubst_flags_t complain,
9853 tree in_decl)
9854 {
9855 tree return_type;
9856 tree arg_types;
9857 tree fntype;
9859 /* The TYPE_CONTEXT is not used for function/method types. */
9862 /* Substitute the return type. */
9866 /* The standard does not presently indicate that creation of a
9867 function type with an invalid return type is a deduction failure.
9868 However, that is clearly analogous to creating an array of "void"
9869 or a reference to a reference. This is core issue #486. */
9872 {
9874 {
9877 else
9879 }
9881 }
9883 /* Substitute the argument types. */
9889 /* Construct a new type node and return it. */
9891 {
9894 }
9895 else
9896 {
9899 {
9900 /* [temp.deduct]
9902 Type deduction may fail for any of the following
9903 reasons:
9905 -- Attempting to create "pointer to member of T" when T
9906 is not a class type. */
9909 r);
9911 }
9915 }
9919 }
9921 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9922 ARGS into that specification, and return the substituted
9923 specification. If there is no specification, return NULL_TREE. */
9925 static tree
9927 tree args,
9928 tsubst_flags_t complain,
9929 tree in_decl)
9930 {
9931 tree specs;
9932 tree new_specs;
9937 {
9938 /* A noexcept-specifier. */
9939 new_specs = tsubst_copy_and_build
9943 }
9945 {
9948 else
9950 {
9951 tree spec;
9956 {
9957 /* Expand the pack expansion type. */
9960 in_decl);
9966 else
9967 {
9968 /* We're substituting into a member template, so
9969 we got a TYPE_PACK_EXPANSION back. Add that
9970 expansion and move on. */
9974 expanded_specs,
9975 complain);
9978 }
9979 }
9982 {
9985 else
9990 complain);
9991 }
9994 }
9995 }
9997 }
9999 /* Take the tree structure T and replace template parameters used
10000 therein with the argument vector ARGS. IN_DECL is an associated
10001 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10002 Issue error and warning messages under control of COMPLAIN. Note
10003 that we must be relatively non-tolerant of extensions here, in
10004 order to preserve conformance; if we allow substitutions that
10005 should not be allowed, we may allow argument deductions that should
10006 not succeed, and therefore report ambiguous overload situations
10007 where there are none. In theory, we could allow the substitution,
10008 but indicate that it should have failed, and allow our caller to
10009 make sure that the right thing happens, but we don't try to do this
10010 yet.
10012 This function is used for dealing with types, decls and the like;
10013 for expressions, use tsubst_expr or tsubst_copy. */
10015 tree
10017 {
10040 else
10045 /* Reuse typedefs. We need to do this to handle dependent attributes,
10046 such as attribute aligned. */
10049 {
10055 {
10059 }
10064 else
10065 /* The typedef is from a non-template context. */
10069 {
10071 r = cp_build_qualified_type_real
10075 }
10076 /* Else we must be instantiating the typedef, so fall through. */
10077 }
10090 {
10116 {
10122 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10123 needed. */
10132 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10133 with TREE_SIDE_EFFECTS that indicates this is not an integral
10134 constant expression. */
10137 {
10140 }
10146 {
10150 }
10152 /* [temp.deduct]
10154 Type deduction may fail for any of the following
10155 reasons:
10157 Attempting to create an array with a size that is
10158 zero or negative. */
10160 /* We must fail if performing argument deduction (as
10161 indicated by the state of complain), so that
10162 another substitution can be found. */
10166 {
10171 }
10174 }
10180 {
10193 {
10197 /* See through ARGUMENT_PACK_SELECT arguments. */
10199 }
10204 {
10206 /* If ARG is an argument pack, we don't actually want to
10207 perform a substitution here, because substitutions
10208 for argument packs are only done
10209 element-by-element. We can get to this point when
10210 substituting the type of a non-type template
10211 parameter pack, when that type actually contains
10212 template parameter packs from an outer template, e.g.,
10214 template<typename... Types> struct A {
10215 template<Types... Values> struct B { };
10216 }; */
10220 {
10226 return cp_build_qualified_type_real
10228 }
10230 {
10231 /* We are processing a type constructed from a
10232 template template parameter. */
10238 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10239 are resolving nested-types in the signature of a
10240 member function templates. Otherwise ARG is a
10241 TEMPLATE_DECL and is the real template to be
10242 instantiated. */
10250 complain);
10251 return cp_build_qualified_type_real
10253 }
10254 else
10255 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10257 }
10260 /* This can happen during the attempted tsubst'ing in
10261 unify. This means that we don't yet have any information
10262 about the template parameter in question. */
10265 /* If we get here, we must have been looking at a parm for a
10266 more deeply nested template. Make a new version of this
10267 template parameter, but with a lower level. */
10269 {
10274 {
10276 r = cp_build_qualified_type_real
10280 }
10281 else
10282 {
10293 /* We have reduced the level of the template
10294 template parameter, but not the levels of its
10295 template parameters, so canonical_type_parameter
10296 will not be able to find the canonical template
10297 template parameter for this level. Thus, we
10298 require structural equality checking to compare
10299 TEMPLATE_TEMPLATE_PARMs. */
10303 else
10307 {
10315 }
10316 }
10325 }
10328 }
10331 {
10339 {
10343 }
10346 {
10350 }
10353 {
10357 }
10363 }
10366 /* We should never be tsubsting a binfo. */
10370 /* A vector of template arguments. */
10376 {
10380 /* [temp.deduct]
10382 Type deduction may fail for any of the following
10383 reasons:
10385 -- Attempting to create a pointer to reference type.
10386 -- Attempting to create a reference to a reference type or
10387 a reference to void.
10389 Core issue 106 says that creating a reference to a reference
10390 during instantiation is no longer a cause for failure. We
10391 only enforce this check in strict C++98 mode. */
10395 {
10398 /* We keep track of the last time we issued this error
10399 message to avoid spewing a ton of messages during a
10400 single bad template instantiation. */
10403 {
10408 else
10411 }
10414 }
10416 {
10420 }
10422 /* In C++0x, during template argument substitution, when there is an
10423 attempt to create a reference to a reference type, reference
10424 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10426 "If a template-argument for a template-parameter T names a type
10427 that is a reference to a type A, an attempt to create the type
10428 'lvalue reference to cv T' creates the type 'lvalue reference to
10429 A,' while an attempt to create the type type rvalue reference to
10430 cv T' creates the type T"
10431 */
10432 r = cp_build_reference_type
10435 else
10440 /* Will this ever be needed for TYPE_..._TO values? */
10444 }
10446 {
10449 {
10450 /* [temp.deduct]
10452 Type deduction may fail for any of the following
10453 reasons:
10455 -- Attempting to create "pointer to member of T" when T
10456 is not a class type. */
10460 }
10462 {
10466 }
10468 {
10472 }
10475 {
10476 /* The type of the implicit object parameter gets its
10477 cv-qualifiers from the FUNCTION_TYPE. */
10478 tree memptr;
10482 complain);
10483 }
10484 else
10487 complain);
10488 }
10491 {
10492 tree fntype;
10493 tree specs;
10498 /* Substitute the exception specification. */
10500 in_decl);
10506 }
10508 {
10513 /* As an optimization, we avoid regenerating the array type if
10514 it will obviously be the same as T. */
10518 /* These checks should match the ones in grokdeclarator.
10520 [temp.deduct]
10522 The deduction may fail for any of the following reasons:
10524 -- Attempting to create an array with an element type that
10525 is void, a function type, or a reference type, or [DR337]
10526 an abstract class type. */
10530 {
10534 }
10536 {
10539 type);
10541 }
10546 {
10549 }
10552 }
10555 {
10565 {
10569 }
10571 {
10572 /* Normally, make_typename_type does not require that the CTX
10573 have complete type in order to allow things like:
10575 template <class T> struct S { typename S<T>::X Y; };
10577 But, such constructs have already been resolved by this
10578 point, so here CTX really should have complete type, unless
10579 it's a partial instantiation. */
10583 {
10587 }
10588 }
10595 {
10598 }
10601 {
10608 }
10610 return cp_build_qualified_type_real
10612 }
10615 {
10627 }
10630 {
10631 tree type;
10647 complain);
10648 }
10651 {
10652 tree type;
10668 else
10669 type = finish_decltype_type
10674 complain);
10675 }
10679 {
10681 tree packed_out =
10683 args,
10684 complain,
10685 in_decl);
10688 /* For template nontype argument packs, also substitute into
10689 the type. */
10694 }
10709 /* We should use one of the expression tsubsts for these codes. */
10715 }
10716 }
10718 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10719 type of the expression on the left-hand side of the "." or "->"
10720 operator. */
10722 static tree
10725 {
10726 tree name;
10727 tree qualifying_scope;
10728 tree fns;
10729 tree optype;
10733 /* A baselink indicates a function from a base class. Both the
10734 BASELINK_ACCESS_BINFO and the base class referenced may
10735 indicate bases of the template class, rather than the
10736 instantiated class. In addition, lookups that were not
10737 ambiguous before may be ambiguous now. Therefore, we perform
10738 the lookup again. */
10745 {
10752 }
10760 /* If lookup found a single function, mark it as used at this
10761 point. (If it lookup found multiple functions the one selected
10762 later by overload resolution will be marked as used at that
10763 point.) */
10769 /* Add back the template arguments, if present. */
10774 template_args);
10775 /* Update the conversion operator type. */
10781 qualifying_scope,
10782 object_type);
10783 }
10785 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10786 true if the qualified-id will be a postfix-expression in-and-of
10787 itself; false if more of the postfix-expression follows the
10788 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10789 of "&". */
10791 static tree
10795 {
10796 tree expr;
10797 tree scope;
10798 tree name;
10800 tree template_args;
10804 /* Figure out what name to look up. */
10807 {
10814 }
10815 else
10816 {
10819 }
10821 /* Substitute into the qualifying scope. When there are no ARGS, we
10822 are just trying to simplify a non-dependent expression. In that
10823 case the qualifying scope may be dependent, and, in any case,
10824 substituting will not help. */
10827 {
10830 }
10831 else
10839 {
10841 {
10842 /* A BIT_NOT_EXPR is used to represent a destructor. */
10844 {
10848 }
10849 else
10852 }
10853 else
10857 {
10859 {
10863 }
10865 }
10866 }
10869 {
10871 scope);
10872 /* Remember that there was a reference to this entity. */
10874 }
10877 {
10883 }
10892 {
10893 expr = (adjust_result_of_qualified_name_lookup
10895 expr = (finish_qualified_id_expr
10899 }
10901 /* Expressions do not generally have reference type. */
10903 /* However, if we're about to form a pointer-to-member, we just
10904 want the referenced member referenced. */
10909 }
10911 /* Like tsubst, but deals with expressions. This function just replaces
10912 template parms; to finish processing the resultant expression, use
10913 tsubst_expr. */
10915 static tree
10917 {
10919 tree r;
10927 {
10932 {
10933 tree c;
10934 /* This can happen for a parameter name used later in a function
10935 declaration (such as in a late-specified return type). Just
10936 make a dummy decl, since it's only used for its type. */
10938 /* We copy T because want to tsubst the PARM_DECL only,
10939 not the following PARM_DECLs that are chained to T. */
10942 /* Give it the template pattern as its context; its true context
10943 hasn't been instantiated yet and this is good enough for
10944 mangling. */
10946 }
10954 {
10955 tree enum_type;
10956 tree v;
10960 /* There is no need to substitute into namespace-scope
10961 enumerators. */
10964 /* If ARGS is NULL, then T is known to be non-dependent. */
10968 /* Unfortunately, we cannot just call lookup_name here.
10969 Consider:
10971 template <int I> int f() {
10972 enum E { a = I };
10973 struct S { void g() { E e = a; } };
10974 };
10976 When we instantiate f<7>::S::g(), say, lookup_name is not
10977 clever enough to find f<7>::a. */
10978 enum_type
10988 /* We didn't find the name. That should never happen; if
10989 name-lookup found it during preliminary parsing, we
10990 should find it again here during instantiation. */
10992 }
10997 {
10998 tree ctx;
11003 {
11006 {
11010 }
11012 }
11013 }
11026 /* An OVERLOAD will always be a non-dependent overload set; an
11027 overload set from function scope will just be represented with an
11028 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11043 {
11044 /* Template template argument like the following example need
11045 special treatment:
11047 template <template <class> class TT> struct C {};
11048 template <class T> struct D {
11049 template <class U> struct E {};
11050 C<E> c; // #1
11051 };
11052 D<int> d; // #2
11054 We are processing the template argument `E' in #1 for
11055 the template instantiation #2. Originally, `E' is a
11056 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11057 have to substitute this with one having context `D<int>'. */
11061 }
11062 else
11063 /* Ordinary template template argument. */
11072 return build1
11078 {
11079 /* We only want to compute the number of arguments. */
11093 {
11100 else
11103 }
11104 else
11106 }
11107 /* Fall through */
11122 return build1
11127 {
11128 tree object;
11129 tree name;
11134 {
11138 }
11141 {
11151 }
11156 in_decl);
11157 else
11160 }
11198 return build_nt
11211 return build_nt
11218 {
11226 }
11231 {
11232 r = build_nt
11238 }
11241 {
11242 r = build_nt
11248 }
11251 {
11252 r = build_nt
11258 }
11261 {
11262 /* Substituted template arguments */
11271 }
11274 {
11294 }
11319 {
11322 }
11323 else
11327 /* This is handled by tsubst_copy_and_build. */
11332 in_decl),
11336 /* We shouldn't have built any of these during initial template
11337 generation. Instead, they should be built during instantiation
11338 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11342 r = build2
11361 {
11362 /* Instantiate any typedefs in the type. */
11367 }
11370 /* These can sometimes show up in a partial instantiation, but never
11371 involve template parms. */
11377 }
11378 }
11380 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11382 static tree
11384 tree in_decl)
11385 {
11389 {
11395 {
11398 {
11404 }
11405 /* FALLTHRU */
11427 }
11428 }
11431 }
11433 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11435 static tree
11437 tree in_decl)
11438 {
11439 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11464 #undef RECUR
11465 }
11467 /* Substitute one OMP_FOR iterator. */
11469 static void
11474 {
11475 #define RECUR(NODE) \
11476 tsubst_expr ((NODE), args, complain, in_decl, \
11477 integral_constant_expression_p)
11486 {
11493 }
11497 {
11503 complain);
11504 else
11511 }
11514 {
11515 tree c;
11517 {
11528 }
11530 {
11535 {
11538 }
11539 }
11540 }
11546 else
11550 {
11561 {
11568 }
11569 else
11575 {
11581 }
11585 {
11592 }
11593 else
11599 }
11605 #undef RECUR
11606 }
11608 /* Like tsubst_copy for expressions, etc. but also does semantic
11609 processing. */
11611 static tree
11614 {
11615 #define RECUR(NODE) \
11616 tsubst_expr ((NODE), args, complain, in_decl, \
11617 integral_constant_expression_p)
11630 {
11632 {
11633 tree_stmt_iterator i;
11637 }
11652 else
11661 {
11662 tree decl;
11663 tree init;
11669 {
11672 tree decl;
11680 else
11682 }
11683 else
11684 {
11688 {
11689 /* By marking the declaration as instantiated, we avoid
11690 trying to instantiate it. Since instantiate_decl can't
11691 handle local variables, and since we've already done
11692 all that needs to be done, that's the right thing to
11693 do. */
11698 /* Anonymous aggregates are a special case. */
11700 else
11701 {
11705 {
11706 /* For __PRETTY_FUNCTION__ we have to adjust the
11707 initializer. */
11711 }
11712 else
11713 {
11717 {
11718 /* If we had an initializer but it
11719 instantiated to nothing,
11720 value-initialize the object. This will
11721 only occur when the initializer was a
11722 pack expansion where the parameter packs
11723 used in that expansion were of length
11724 zero. */
11726 complain);
11729 }
11730 else
11732 }
11735 }
11736 }
11737 }
11739 /* A DECL_EXPR can also be used as an expression, in the condition
11740 clause of an if/for/while construct. */
11742 }
11757 {
11767 }
11794 {
11798 }
11806 else
11814 else
11841 {
11843 tree label;
11848 }
11854 /* Computed goto's must be tsubst'd into. On the other hand,
11855 non-computed gotos must not be; the identifier in question
11856 will have no binding. */
11858 else
11864 tmp = finish_asm_stmt
11871 {
11876 }
11881 {
11886 }
11887 else
11888 {
11893 else
11900 else
11906 else
11908 }
11912 {
11916 {
11918 /* Prevent instantiate_decl from trying to instantiate
11919 this variable. We've already done all that needs to be
11920 done. */
11923 }
11928 }
11936 {
11937 tree condition =
11939 args,
11946 }
11967 {
11982 integral_constant_expression_p);
11991 {
11995 }
11996 else
11997 {
12005 }
12019 }
12050 {
12055 }
12071 integral_constant_expression_p);
12072 }
12075 #undef RECUR
12076 }
12078 /* T is a postfix-expression that is not being used in a function
12079 call. Return the substituted version of T. */
12081 static tree
12083 tsubst_flags_t complain,
12084 tree in_decl)
12085 {
12089 else
12095 }
12097 /* Like tsubst but deals with expressions and performs semantic
12098 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12100 tree
12102 tree args,
12103 tsubst_flags_t complain,
12104 tree in_decl,
12107 {
12108 #define RECUR(NODE) \
12109 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12111 integral_constant_expression_p)
12113 tree op1;
12119 {
12122 /* Fall through. */
12124 {
12125 tree decl;
12126 cp_id_kind idk;
12131 {
12134 }
12136 /* Look up the name. */
12139 /* By convention, expressions use ERROR_MARK_NODE to indicate
12140 failure, not NULL_TREE. */
12146 integral_constant_expression_p,
12154 input_location);
12160 }
12163 {
12164 tree object;
12172 {
12175 }
12176 else
12183 else
12185 }
12188 {
12192 {
12193 /* A type conversion to reference type will be enclosed in
12194 such an indirect ref, but the substitution of the cast
12195 will have also added such an indirect ref. */
12198 }
12199 else
12202 }
12205 return build_nop
12214 {
12215 tree type;
12216 tree op;
12221 {
12226 }
12231 {
12244 }
12245 }
12263 complain);
12273 else
12275 in_decl);
12309 return build_x_binary_op
12313 ? ERROR_MARK
12317 ? ERROR_MARK
12320 complain);
12333 /* Fall through */
12338 {
12339 /* When there are no ARGS, we are trying to evaluate a
12340 non-dependent expression from the parser. Trying to do
12341 the substitutions may not work. */
12344 }
12345 else
12346 {
12354 }
12358 else
12363 {
12373 }
12387 {
12388 tree r = build_x_modify_expr
12392 complain);
12393 /* TREE_NO_WARNING must be set if either the expression was
12394 parenthesized or it uses an operator such as >>= rather
12395 than plain assignment. In the former case, it was already
12396 set and must be copied. In the latter case,
12397 build_x_modify_expr sets it and it must not be reset
12398 here. */
12402 }
12407 /* Remember that there was a reference to this entity. */
12413 {
12418 tree ret;
12422 else
12423 {
12427 }
12429 /* If there was an initializer in the original tree, but it
12430 instantiated to an empty list, then we should pass a
12431 non-NULL empty vector to tell build_new that it was an
12432 empty initializer() rather than no initializer. This can
12433 only happen when the initializer is a pack expansion whose
12434 parameter packs are of length zero. */
12437 else
12438 {
12442 else
12443 {
12446 }
12447 }
12454 complain);
12462 }
12465 return delete_sanity
12474 complain);
12477 {
12478 tree function;
12483 tree ret;
12486 /* When we parsed the expression, we determined whether or
12487 not Koenig lookup should be performed. */
12490 {
12495 }
12496 else
12497 {
12499 {
12505 }
12506 else
12510 in_decl,
12512 integral_constant_expression_p);
12516 }
12521 {
12527 else
12528 {
12529 /* Expand the pack expansion and push each entry onto
12530 CALL_ARGS. */
12533 {
12538 {
12543 }
12544 }
12545 else
12546 {
12547 /* A partial substitution. Add one entry. */
12549 }
12550 }
12551 }
12553 /* We do not perform argument-dependent lookup if normal
12554 lookup finds a non-function, in accordance with the
12555 expected resolution of DR 218. */
12558 /* If lookup found a member function, the Koenig lookup is
12559 not appropriate, even if an unqualified-name was used
12560 to denote the function. */
12563 /* Only do this when substitution turns a dependent call
12564 into a non-dependent call. */
12570 {
12574 }
12576 /* Remember that there was a reference to this entity. */
12583 {
12598 complain);
12599 else
12600 ret = (build_new_method_call
12605 complain));
12606 }
12607 else
12610 koenig_p,
12611 complain);
12616 }
12619 return build_x_conditional_expr
12623 complain);
12626 return finish_pseudo_destructor_expr
12632 {
12640 {
12641 /* We have pack expansions, so expand those and
12642 create a new list out of it. */
12645 tree chain;
12648 /* Expand the argument expressions. */
12656 /* Build the rest of the list. */
12661 /* Determine the number of arguments. */
12663 {
12666 }
12669 else
12670 {
12671 /* Since we only performed a partial substitution into
12672 the argument pack, we only return a single list
12673 node. */
12680 }
12682 /* Convert the argument vectors into a TREE_LIST */
12685 {
12686 /* Grab the Ith values. */
12687 i--;
12690 value
12694 /* Build the list (backwards). */
12696 }
12699 }
12715 }
12718 {
12719 tree object;
12720 tree object_type;
12721 tree member;
12725 /* Remember that there was a reference to this entity. */
12735 else
12741 {
12743 {
12748 {
12751 }
12753 {
12757 }
12758 }
12759 }
12762 {
12763 tree tmpl;
12764 tree args;
12766 /* Lookup the template functions now that we know what the
12767 scope is. */
12774 {
12777 args);
12778 member = (adjust_result_of_qualified_name_lookup
12780 object_type));
12781 }
12782 else
12783 {
12785 input_location);
12787 }
12788 }
12792 {
12794 {
12798 else
12801 }
12803 }
12809 complain);
12810 }
12813 return build_throw
12817 {
12825 tree r;
12830 /* digest_init will do the wrong thing if we let it. */
12834 /* We do not want to process the index of aggregate
12835 initializers as they are identifier nodes which will be
12836 looked up by digest_init. */
12842 {
12847 {
12848 /* Substitute into the pack expansion. */
12850 in_decl);
12853 ;
12855 /* Just move the argument into place. */
12857 else
12858 {
12859 /* Update the length of the final CONSTRUCTOR
12860 arguments vector, and note that we will need to
12861 copy.*/
12864 }
12865 }
12866 else
12868 }
12871 {
12876 {
12878 {
12883 }
12884 else
12886 }
12887 }
12896 }
12899 {
12902 {
12905 }
12906 else
12907 {
12910 }
12911 }
12916 /* Fall through */
12919 {
12923 /* If the original type was a reference, we'll be wrapped in
12924 the appropriate INDIRECT_REF. */
12927 }
12932 in_decl));
12938 {
12947 }
12950 {
12956 integral_constant_expression_p);
12960 /* If the resulting list of expression statement is empty,
12961 fold it further into void_zero_node. */
12966 }
12970 /* As in finish_id_expression, we resolve enumeration constants
12971 to their underlying values. */
12973 {
12976 }
12980 {
13001 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
13003 /* Now that we know visibility, instantiate the type so we have a
13004 declaration of the op() for later calls to lambda_function. */
13012 }
13015 /* Handle Objective-C++ constructs, if appropriate. */
13016 {
13017 tree subst
13022 }
13024 }
13026 #undef RECUR
13027 }
13029 /* Verify that the instantiated ARGS are valid. For type arguments,
13030 make sure that the type's linkage is ok. For non-type arguments,
13031 make sure they are constants if they are integral or enumerations.
13032 Emit an error under control of COMPLAIN, and return TRUE on error. */
13034 static bool
13036 {
13038 {
13048 }
13050 {
13051 /* [basic.link]: A name with no linkage (notably, the name
13052 of a class or enumeration declared in a local scope)
13053 shall not be used to declare an entity with linkage.
13054 This implies that names with no linkage cannot be used as
13055 template arguments
13057 DR 757 relaxes this restriction for C++0x. */
13062 {
13063 /* DR 488 makes use of a type with no linkage cause
13064 type deduction to fail. */
13066 {
13069 else
13072 }
13074 }
13075 /* In order to avoid all sorts of complications, we do not
13076 allow variably-modified types as template arguments. */
13078 {
13082 }
13083 }
13084 /* A non-type argument of integral or enumerated type must be a
13085 constant. */
13089 {
13093 }
13095 }
13097 static bool
13099 {
13104 {
13107 }
13111 }
13113 /* Instantiate the indicated variable or function template TMPL with
13114 the template arguments in TARG_PTR. */
13116 tree
13118 {
13120 tree fndecl;
13121 tree gen_tmpl;
13122 tree spec;
13123 HOST_WIDE_INT saved_processing_template_decl;
13130 /* If this function is a clone, handle it specially. */
13132 {
13133 tree spec;
13134 tree clone;
13136 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13137 DECL_CLONED_FUNCTION. */
13143 /* Look for the clone. */
13147 /* We should always have found the clone by now. */
13150 }
13152 /* Check to see if we already have this specialization. */
13155 /* The TMPL is a partial instantiation. To get a full set of
13156 arguments we must add the arguments used to perform the
13157 partial instantiation. */
13159 targ_ptr);
13161 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13162 but it doesn't seem to be on the hot path. */
13174 complain))
13177 /* We are building a FUNCTION_DECL, during which the access of its
13178 parameters and return types have to be checked. However this
13179 FUNCTION_DECL which is the desired context for access checking
13180 is not built yet. We solve this chicken-and-egg problem by
13181 deferring all checks until we have the FUNCTION_DECL. */
13184 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13185 (because, for example, we have encountered a non-dependent
13186 function call in the body of a template function and must now
13187 determine which of several overloaded functions will be called),
13188 within the instantiation itself we are not processing a
13189 template. */
13192 /* Substitute template parameters to obtain the specialization. */
13199 /* Now we know the specialization, compute access previously
13200 deferred. */
13203 /* Some typedefs referenced from within the template code need to be access
13204 checked at template instantiation time, i.e now. These types were
13205 added to the template at parsing time. Let's get those and perfom
13206 the acces checks then. */
13212 /* The DECL_TI_TEMPLATE should always be the immediate parent
13213 template, not the most general template. */
13216 /* If we've just instantiated the main entry point for a function,
13217 instantiate all the alternate entry points as well. We do this
13218 by cloning the instantiation of the main entry point, not by
13219 instantiating the template clones. */
13224 }
13226 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13227 NARGS elements of the arguments that are being used when calling
13228 it. TARGS is a vector into which the deduced template arguments
13229 are placed.
13231 Return zero for success, 2 for an incomplete match that doesn't resolve
13232 all the types, and 1 for complete failure. An error message will be
13233 printed only for an incomplete match.
13235 If FN is a conversion operator, or we are trying to produce a specific
13236 specialization, RETURN_TYPE is the return type desired.
13238 The EXPLICIT_TARGS are explicit template arguments provided via a
13239 template-id.
13241 The parameter STRICT is one of:
13243 DEDUCE_CALL:
13244 We are deducing arguments for a function call, as in
13245 [temp.deduct.call].
13247 DEDUCE_CONV:
13248 We are deducing arguments for a conversion function, as in
13249 [temp.deduct.conv].
13251 DEDUCE_EXACT:
13252 We are deducing arguments when doing an explicit instantiation
13253 as in [temp.explicit], when determining an explicit specialization
13254 as in [temp.expl.spec], or when taking the address of a function
13255 template, as in [temp.deduct.funcaddr]. */
13257 int
13259 tree explicit_targs,
13260 tree targs,
13263 tree return_type,
13264 unification_kind_t strict,
13266 {
13267 tree parms;
13268 tree fntype;
13276 {
13277 /* [temp.deduct]
13279 The specified template arguments must match the template
13280 parameters in kind (i.e., type, nontype, template), and there
13281 must not be more arguments than there are parameters;
13282 otherwise type deduction fails.
13284 Nontype arguments must match the types of the corresponding
13285 nontype template parameters, or must be convertible to the
13286 types of the corresponding nontype parameters as specified in
13287 _temp.arg.nontype_, otherwise type deduction fails.
13289 All references in the function type of the function template
13290 to the corresponding template parameters are replaced by the
13291 specified template argument values. If a substitution in a
13292 template parameter or in the function type of the function
13293 template results in an invalid type, type deduction fails. */
13296 tree converted_args;
13302 converted_args
13309 /* Substitute the explicit args into the function type. This is
13310 necessary so that, for instance, explicitly declared function
13311 arguments can match null pointed constants. If we were given
13312 an incomplete set of explicit args, we must not do semantic
13313 processing during substitution as we could create partial
13314 instantiations. */
13316 {
13320 /* Dig out the actual parm. */
13323 {
13326 }
13328 {
13331 }
13334 {
13336 tree targ;
13339 /* Mark the argument pack as "incomplete". We could
13340 still deduce more arguments during unification. */
13343 {
13347 }
13349 /* We have some incomplete argument packs. */
13351 }
13352 }
13355 /* Any substitution is guaranteed to be incomplete if there
13356 are incomplete argument packs, because we can still deduce
13357 more arguments. */
13359 else
13369 /* Place the explicitly specified arguments in TARGS. */
13372 }
13374 /* Never do unification on the 'this' parameter. */
13378 {
13387 }
13389 /* We allow incomplete unification without an error message here
13390 because the standard doesn't seem to explicitly prohibit it. Our
13391 callers must be ready to deal with unification failures in any
13392 event. */
13398 {
13401 /* Clear the "incomplete" flags on all argument packs. */
13403 {
13406 {
13409 }
13410 }
13411 }
13413 /* Now that we have bindings for all of the template arguments,
13414 ensure that the arguments deduced for the template template
13415 parameters have compatible template parameter lists. We cannot
13416 check this property before we have deduced all template
13417 arguments, because the template parameter types of a template
13418 template parameter might depend on prior template parameters
13419 deduced after the template template parameter. The following
13420 ill-formed example illustrates this issue:
13422 template<typename T, template<T> class C> void f(C<5>, T);
13424 template<int N> struct X {};
13426 void g() {
13427 f(X<5>(), 5l); // error: template argument deduction fails
13428 }
13430 The template parameter list of 'C' depends on the template type
13431 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13432 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13433 time that we deduce 'C'. */
13435 && !template_template_parm_bindings_ok_p
13440 /* All is well so far. Now, check:
13442 [temp.deduct]
13444 When all template arguments have been deduced, all uses of
13445 template parameters in nondeduced contexts are replaced with
13446 the corresponding deduced argument values. If the
13447 substitution results in an invalid type, as described above,
13448 type deduction fails. */
13449 {
13454 /* If we're looking for an exact match, check that what we got
13455 is indeed an exact match. It might not be if some template
13456 parameters are used in non-deduced contexts. */
13458 {
13461 tree sarg
13468 }
13469 }
13472 }
13474 /* Adjust types before performing type deduction, as described in
13475 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13476 sections are symmetric. PARM is the type of a function parameter
13477 or the return type of the conversion function. ARG is the type of
13478 the argument passed to the call, or the type of the value
13479 initialized with the result of the conversion function.
13480 ARG_EXPR is the original argument expression, which may be null. */
13482 static int
13486 tree arg_expr)
13487 {
13491 {
13496 {
13497 /* Swap PARM and ARG throughout the remainder of this
13498 function; the handling is precisely symmetric since PARM
13499 will initialize ARG rather than vice versa. */
13504 }
13507 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13508 too, but here handle it by stripping the reference from PARM
13509 rather than by adding it to ARG. */
13517 /* Nothing else to do in this case. */
13522 }
13525 {
13526 /* [temp.deduct.call]
13528 If P is not a reference type:
13530 --If A is an array type, the pointer type produced by the
13531 array-to-pointer standard conversion (_conv.array_) is
13532 used in place of A for type deduction; otherwise,
13534 --If A is a function type, the pointer type produced by
13535 the function-to-pointer standard conversion
13536 (_conv.func_) is used in place of A for type deduction;
13537 otherwise,
13539 --If A is a cv-qualified type, the top level
13540 cv-qualifiers of A's type are ignored for type
13541 deduction. */
13546 else
13548 }
13550 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13551 of the form T&&, where T is a template parameter, and the argument
13552 is an lvalue, T is deduced as A& */
13560 /* [temp.deduct.call]
13562 If P is a cv-qualified type, the top level cv-qualifiers
13563 of P's type are ignored for type deduction. If P is a
13564 reference type, the type referred to by P is used for
13565 type deduction. */
13568 {
13571 }
13573 /* DR 322. For conversion deduction, remove a reference type on parm
13574 too (which has been swapped into ARG). */
13579 }
13581 /* Most parms like fn_type_unification.
13583 If SUBR is 1, we're being called recursively (to unify the
13584 arguments of a function or method parameter of a function
13585 template). */
13587 static int
13589 tree targs,
13590 tree xparms,
13594 unification_kind_t strict,
13596 {
13602 tree parms;
13611 /* Reset the number of non-defaulted template arguments contained
13612 in in TARGS. */
13616 {
13632 }
13634 again:
13642 {
13655 /* We can't deduce anything from this, but we might get all the
13656 template args from other function args. */
13659 /* Conversions will be performed on a function argument that
13660 corresponds with a function parameter that contains only
13661 non-deducible template parameters and explicitly specified
13662 template parameters. */
13664 {
13665 tree type;
13669 else
13676 flags))
13680 }
13683 {
13686 {
13687 /* [temp.deduct.type]
13689 A template-argument can be deduced from a pointer to
13690 function or pointer to member function argument if
13691 the set of overloaded functions does not contain
13692 function templates and at most one of a set of
13693 overloaded functions provides a unique match. */
13699 }
13704 }
13706 {
13711 arg_expr);
13717 }
13718 }
13724 {
13725 /* Unify the remaining arguments with the pack expansion type. */
13726 tree argvec;
13729 /* Allocate a TREE_VEC and copy in all of the arguments */
13734 /* Copy the parameter into parmvec. */
13740 /* Advance to the end of the list of parameters. */
13742 }
13744 /* Fail if we've reached the end of the parm list, and more args
13745 are present, and the parm list isn't variadic. */
13748 /* Fail if parms are left and they don't have default values. */
13756 {
13757 tree tparm;
13764 /* If this is an undeduced nontype parameter that depends on
13765 a type parameter, try another pass; its type may have been
13766 deduced from a later argument than the one from which
13767 this parameter can be deduced. */
13773 /* Core issue #226 (C++0x) [temp.deduct]:
13775 If a template argument has not been deduced, its
13776 default template argument, if any, is used.
13778 When we are in C++98 mode, TREE_PURPOSE will either
13779 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13780 to explicitly check cxx_dialect here. */
13782 {
13790 else
13791 {
13793 /* The position of the first default template argument,
13794 is also the number of non-defaulted arguments in TARGS.
13795 Record that. */
13799 }
13800 }
13802 /* If the type parameter is a parameter pack, then it will
13803 be deduced to an empty parameter pack. */
13805 {
13806 tree arg;
13809 {
13813 }
13814 else
13821 }
13824 }
13825 #ifdef ENABLE_CHECKING
13828 #endif
13831 }
13833 /* Subroutine of type_unification_real. Args are like the variables
13834 at the call site. ARG is an overloaded function (or template-id);
13835 we try deducing template args from each of the overloads, and if
13836 only one succeeds, we go with that. Modifies TARGS and returns
13837 true on success. */
13839 static bool
13841 tree targs,
13842 tree parm,
13843 tree arg,
13844 unification_kind_t strict,
13846 {
13853 {
13856 }
13857 else
13861 /* Handle `&x' where `x' is some static or non-static member
13862 function name. */
13868 /* Strip baselink information. */
13873 {
13874 /* If we got some explicit template args, we need to plug them into
13875 the affected templates before we try to unify, in case the
13876 explicit args will completely resolve the templates in question. */
13882 {
13893 {
13898 {
13901 }
13902 }
13904 }
13905 }
13908 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13909 -- but the deduction does not succeed because the expression is
13910 not just the function on its own. */
13912 else
13918 {
13921 }
13923 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13924 to function or pointer to member function argument if the set of
13925 overloaded functions does not contain function templates and at most
13926 one of a set of overloaded functions provides a unique match.
13928 So if we found multiple possibilities, we return success but don't
13929 deduce anything. */
13932 {
13937 }
13942 }
13944 /* Core DR 115: In contexts where deduction is done and fails, or in
13945 contexts where deduction is not done, if a template argument list is
13946 specified and it, along with any default template arguments, identifies
13947 a single function template specialization, then the template-id is an
13948 lvalue for the function template specialization. */
13950 tree
13952 {
13965 {
13968 }
13970 {
13973 }
13975 {
13978 }
13981 {
13985 /* If we got some explicit template args, we need to plug them into
13986 the affected templates before we try to unify, in case the
13987 explicit args will completely resolve the templates in question. */
13995 {
14006 {
14009 {
14012 }
14014 {
14017 }
14018 }
14020 }
14022 {
14034 }
14036 /* There were no good options and at least one bad one, so let the
14037 user know what the problem is. */
14039 }
14041 }
14043 /* Subroutine of resolve_overloaded_unification; does deduction for a single
14044 overload. Fills TARGS with any deduced arguments, or error_mark_node if
14045 different overloads deduce different arguments for a given parm.
14046 ADDR_P is true if the expression for which deduction is being
14047 performed was of the form "& fn" rather than simply "fn".
14049 Returns 1 on success. */
14051 static int
14053 tree orig_targs,
14054 tree targs,
14055 tree parm,
14056 tree arg,
14057 unification_kind_t strict,
14060 {
14062 tree tempargs;
14065 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14066 to function or pointer to member function argument if the set of
14067 overloaded functions does not contain function templates and at most
14068 one of a set of overloaded functions provides a unique match.
14070 So if this is a template, just return success. */
14082 /* We don't copy orig_targs for this because if we have already deduced
14083 some template args from previous args, unify would complain when we
14084 try to deduce a template parameter for the same argument, even though
14085 there isn't really a conflict. */
14092 /* First make sure we didn't deduce anything that conflicts with
14093 explicitly specified args. */
14095 {
14102 /* Since we're unifying against ourselves, we will fill in
14103 template args used in the function parm list with our own
14104 template parms. Discard them. */
14108 }
14111 {
14116 }
14119 }
14121 /* PARM is a template class (perhaps with unbound template
14122 parameters). ARG is a fully instantiated type. If ARG can be
14123 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14124 TARGS are as for unify. */
14126 static tree
14128 {
14129 tree copy_of_targs;
14136 /* We need to make a new template argument vector for the call to
14137 unify. If we used TARGS, we'd clutter it up with the result of
14138 the attempted unification, even if this class didn't work out.
14139 We also don't want to commit ourselves to all the unifications
14140 we've already done, since unification is supposed to be done on
14141 an argument-by-argument basis. In other words, consider the
14142 following pathological case:
14144 template <int I, int J, int K>
14145 struct S {};
14147 template <int I, int J>
14148 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14150 template <int I, int J, int K>
14151 void f(S<I, J, K>, S<I, I, I>);
14153 void g() {
14154 S<0, 0, 0> s0;
14155 S<0, 1, 2> s2;
14157 f(s0, s2);
14158 }
14160 Now, by the time we consider the unification involving `s2', we
14161 already know that we must have `f<0, 0, 0>'. But, even though
14162 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14163 because there are two ways to unify base classes of S<0, 1, 2>
14164 with S<I, I, I>. If we kept the already deduced knowledge, we
14165 would reject the possibility I=1. */
14168 /* If unification failed, we're done. */
14174 }
14176 /* Given a template type PARM and a class type ARG, find the unique
14177 base type in ARG that is an instance of PARM. We do not examine
14178 ARG itself; only its base-classes. If there is not exactly one
14179 appropriate base class, return NULL_TREE. PARM may be the type of
14180 a partial specialization, as well as a plain template type. Used
14181 by unify. */
14183 static tree
14185 {
14187 tree binfo;
14193 /* The type could not be completed. */
14196 /* Walk in inheritance graph order. The search order is not
14197 important, and this avoids multiple walks of virtual bases. */
14199 {
14203 {
14204 /* If there is more than one satisfactory baseclass, then:
14206 [temp.deduct.call]
14208 If they yield more than one possible deduced A, the type
14209 deduction fails.
14211 applies. */
14216 }
14217 }
14220 }
14222 /* Returns the level of DECL, which declares a template parameter. */
14224 static int
14226 {
14228 {
14238 }
14240 }
14242 /* Decide whether ARG can be unified with PARM, considering only the
14243 cv-qualifiers of each type, given STRICT as documented for unify.
14244 Returns nonzero iff the unification is OK on that basis. */
14246 static int
14248 {
14254 {
14255 /* Although a CVR qualifier is ignored when being applied to a
14256 substituted template parameter ([8.3.2]/1 for example), that
14257 does not allow us to unify "const T" with "int&" because both
14258 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14259 It is ok when we're allowing additional CV qualifiers
14260 at the outer level [14.8.2.1]/3,1st bullet. */
14270 }
14281 }
14283 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14284 void
14286 {
14290 {
14293 }
14294 else
14295 {
14298 }
14299 }
14301 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14302 expansion at the end of PACKED_PARMS. Returns 0 if the type
14303 deduction succeeds, 1 otherwise. STRICT is the same as in
14304 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14305 call argument list. We'll need to adjust the arguments to make them
14306 types. SUBR tells us if this is from a recursive call to
14307 type_unification_real. */
14308 int
14312 {
14313 tree parm
14320 /* Determine the parameter packs we will be deducing from the
14321 pattern, and record their current deductions. */
14324 {
14328 /* Determine the index and level of this parameter pack. */
14331 /* Keep track of the parameter packs and their corresponding
14332 argument packs. */
14335 }
14337 /* Loop through all of the arguments that have not yet been
14338 unified and unify each with the pattern. */
14340 {
14343 /* For each parameter pack, clear out the deduced value so that
14344 we can deduce it again. */
14346 {
14351 }
14353 /* Unify the pattern with the current argument. */
14354 {
14361 {
14364 /* This mirrors what we do in type_unification_real. */
14366 {
14368 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14369 | UNIFY_ALLOW_MORE_CV_QUAL
14383 }
14386 {
14389 {
14390 /* [temp.deduct.type] A template-argument can be
14391 deduced from a pointer to function or pointer
14392 to member function argument if the set of
14393 overloaded functions does not contain function
14394 templates and at most one of a set of
14395 overloaded functions provides a unique
14396 match. */
14401 sub_strict)
14405 }
14408 {
14413 }
14414 }
14419 arg_strict |=
14422 }
14425 {
14426 /* For deduction from an init-list we need the actual list. */
14431 }
14432 }
14434 /* For each parameter pack, collect the deduced value. */
14436 {
14442 }
14443 }
14445 /* Verify that the results of unification with the parameter packs
14446 produce results consistent with what we've seen before, and make
14447 the deduced argument packs available. */
14449 {
14456 /* By default keep the original deduced argument pack.
14457 If necessary, more specific code is going to update the
14458 resulting deduced argument later down in this function. */
14462 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14463 actually deduce anything. */
14471 {
14472 /* Prepend the explicit arguments onto NEW_ARGS. */
14478 /* Copy the explicit arguments. */
14483 /* Copy the deduced arguments. */
14487 }
14490 {
14491 tree result;
14492 /* Build the deduced *_ARGUMENT_PACK. */
14494 {
14499 }
14500 else
14505 /* Note the deduced argument packs for this parameter
14506 pack. */
14508 }
14512 {
14513 /* We only had the explicitly-provided arguments before, but
14514 now we have a complete set of arguments. */
14520 }
14522 new_args))
14523 /* Inconsistent unification of this parameter pack. */
14525 }
14528 }
14530 /* Deduce the value of template parameters. TPARMS is the (innermost)
14531 set of template parameters to a template. TARGS is the bindings
14532 for those template parameters, as determined thus far; TARGS may
14533 include template arguments for outer levels of template parameters
14534 as well. PARM is a parameter to a template function, or a
14535 subcomponent of that parameter; ARG is the corresponding argument.
14536 This function attempts to match PARM with ARG in a manner
14537 consistent with the existing assignments in TARGS. If more values
14538 are deduced, then TARGS is updated.
14540 Returns 0 if the type deduction succeeds, 1 otherwise. The
14541 parameter STRICT is a bitwise or of the following flags:
14543 UNIFY_ALLOW_NONE:
14544 Require an exact match between PARM and ARG.
14545 UNIFY_ALLOW_MORE_CV_QUAL:
14546 Allow the deduced ARG to be more cv-qualified (by qualification
14547 conversion) than ARG.
14548 UNIFY_ALLOW_LESS_CV_QUAL:
14549 Allow the deduced ARG to be less cv-qualified than ARG.
14550 UNIFY_ALLOW_DERIVED:
14551 Allow the deduced ARG to be a template base class of ARG,
14552 or a pointer to a template base class of the type pointed to by
14553 ARG.
14554 UNIFY_ALLOW_INTEGER:
14555 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14556 case for more information.
14557 UNIFY_ALLOW_OUTER_LEVEL:
14558 This is the outermost level of a deduction. Used to determine validity
14559 of qualification conversions. A valid qualification conversion must
14560 have const qualified pointers leading up to the inner type which
14561 requires additional CV quals, except at the outer level, where const
14562 is not required [conv.qual]. It would be normal to set this flag in
14563 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14564 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14565 This is the outermost level of a deduction, and PARM can be more CV
14566 qualified at this point.
14567 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14568 This is the outermost level of a deduction, and PARM can be less CV
14569 qualified at this point. */
14571 static int
14573 {
14575 tree targ;
14576 tree tparm;
14579 /* I don't think this will do the right thing with respect to types.
14580 But the only case I've seen it in so far has been array bounds, where
14581 signedness is the only information lost, and I think that will be
14582 okay. */
14590 /* We can't deduce anything from this, but we might get all the
14591 template args from other function args. */
14594 /* If PARM uses template parameters, then we can't bail out here,
14595 even if ARG == PARM, since we won't record unifications for the
14596 template parameters. We might need them if we're trying to
14597 figure out which of two things is more specialized. */
14601 /* Handle init lists early, so the rest of the function can assume
14602 we're dealing with a type. */
14604 {
14609 /* Replace T with std::initializer_list<T> for deduction. */
14615 /* We can only deduce from an initializer list argument if the
14616 parameter is std::initializer_list; otherwise this is a
14617 non-deduced context. */
14623 {
14630 {
14632 /* It should only be possible to get here for a call. */
14634 elt_strict |= maybe_adjust_types_for_deduction
14637 }
14641 }
14643 /* If the std::initializer_list<T> deduction worked, replace the
14644 deduced A with std::initializer_list<A>. */
14646 {
14651 }
14653 }
14655 /* Immediately reject some pairs that won't unify because of
14656 cv-qualification mismatches. */
14659 /* It is the elements of the array which hold the cv quals of an array
14660 type, and the elements might be template type parms. We'll check
14661 when we recurse. */
14663 /* We check the cv-qualifiers when unifying with template type
14664 parameters below. We want to allow ARG `const T' to unify with
14665 PARM `T' for example, when computing which of two templates
14666 is more specialized, for example. */
14680 {
14684 /* In a type which contains a nested-name-specifier, template
14685 argument values cannot be deduced for template parameters used
14686 within the nested-name-specifier. */
14698 /* The PARM is not one we're trying to unify. Just check
14699 to see if it matches ARG. */
14706 /* Check for mixed types and values. */
14714 {
14715 /* ARG must be constructed from a template class or a template
14716 template parameter. */
14721 {
14724 tree parm_parms
14725 = DECL_INNERMOST_TEMPLATE_PARMS
14730 /* The resolution to DR150 makes clear that default
14731 arguments for an N-argument may not be used to bind T
14732 to a template template parameter with fewer than N
14733 parameters. It is not safe to permit the binding of
14734 default arguments as an extension, as that may change
14735 the meaning of a conforming program. Consider:
14737 struct Dense { static const unsigned int dim = 1; };
14739 template <template <typename> class View,
14740 typename Block>
14741 void operator+(float, View<Block> const&);
14743 template <typename Block,
14744 unsigned int Dim = Block::dim>
14745 struct Lvalue_proxy { operator float() const; };
14747 void
14748 test_1d (void) {
14749 Lvalue_proxy<Dense> p;
14750 float b;
14751 b + p;
14752 }
14754 Here, if Lvalue_proxy is permitted to bind to View, then
14755 the global operator+ will be used; if they are not, the
14756 Lvalue_proxy will be converted to float. */
14758 argvec,
14760 tf_none,
14766 /* Deduce arguments T, i from TT<T> or TT<i>.
14767 We check each element of PARMVEC and ARGVEC individually
14768 rather than the whole TREE_VEC since they can have
14769 different number of elements. */
14776 /* Check if the parameters end in a pack, making them
14777 variadic. */
14786 {
14790 UNIFY_ALLOW_NONE))
14792 }
14797 UNIFY_ALLOW_NONE,
14801 }
14804 /* Fall through to deduce template name. */
14805 }
14809 {
14810 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14812 /* Simple cases: Value already set, does match or doesn't. */
14817 }
14818 else
14819 {
14820 /* If PARM is `const T' and ARG is only `int', we don't have
14821 a match unless we are allowing additional qualification.
14822 If ARG is `const int' and PARM is just `T' that's OK;
14823 that binds `const int' to `T'. */
14828 /* Consider the case where ARG is `const volatile int' and
14829 PARM is `const T'. Then, T should be `volatile int'. */
14830 arg = cp_build_qualified_type_real
14835 /* Simple cases: Value already set, does match or doesn't. */
14841 /* Make sure that ARG is not a variable-sized array. (Note
14842 that were talking about variable-sized arrays (like
14843 `int[n]'), rather than arrays of unknown size (like
14844 `int[]').) We'll get very confused by such a type since
14845 the bound of the array will not be computable in an
14846 instantiation. Besides, such types are not allowed in
14847 ISO C++, so we can do as we please here. */
14851 /* Strip typedefs as in convert_template_argument. */
14853 }
14855 /* If ARG is a parameter pack or an expansion, we cannot unify
14856 against it unless PARM is also a parameter pack. */
14861 /* If the argument deduction results is a METHOD_TYPE,
14862 then there is a problem.
14863 METHOD_TYPE doesn't map to any real C++ type the result of
14864 the deduction can not be of that type. */
14878 /* The PARM is not one we're trying to unify. Just check
14879 to see if it matches ARG. */
14889 /* [temp.deduct.type] If, in the declaration of a function template
14890 with a non-type template-parameter, the non-type
14891 template-parameter is used in an expression in the function
14892 parameter-list and, if the corresponding template-argument is
14893 deduced, the template-argument type shall match the type of the
14894 template-parameter exactly, except that a template-argument
14895 deduced from an array bound may be of any integral type.
14896 The non-type parameter might use already deduced type parameters. */
14899 /* Template-parameter dependent expression. Just accept it for now.
14900 It will later be processed in convert_template_argument. */
14901 ;
14907 /* Convert the ARG to the type of PARM; the deduced non-type
14908 template argument must exactly match the types of the
14909 corresponding parameter. */
14912 /* We haven't deduced the type of this parameter yet. Try again
14913 later. */
14915 else
14918 /* If ARG is a parameter pack or an expansion, we cannot unify
14919 against it unless PARM is also a parameter pack. */
14928 {
14929 /* A pointer-to-member constant can be unified only with
14930 another constant. */
14934 /* Just unify the class member. It would be useless (and possibly
14935 wrong, depending on the strict flags) to unify also
14936 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14937 arg refer to the same variable, even if through different
14938 classes. For instance:
14940 struct A { int x; };
14941 struct B : A { };
14943 Unification of &A::x and &B::x must succeed. */
14946 }
14949 {
14953 /* [temp.deduct.call]
14955 A can be another pointer or pointer to member type that can
14956 be converted to the deduced A via a qualification
14957 conversion (_conv.qual_).
14959 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14960 This will allow for additional cv-qualification of the
14961 pointed-to types if appropriate. */
14964 /* The derived-to-base conversion only persists through one
14965 level of pointers. */
14970 }
14985 {
14986 tree parm_max;
14987 tree arg_max;
14991 /* Our representation of array types uses "N - 1" as the
14992 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14993 not an integer constant. We cannot unify arbitrarily
14994 complex expressions, so we eliminate the MINUS_EXPRs
14995 here. */
14999 {
15002 }
15006 {
15007 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
15008 trying to unify the type of a variable with the type
15009 of a template parameter. For example:
15011 template <unsigned int N>
15012 void f (char (&) [N]);
15013 int g();
15014 void h(int i) {
15015 char a[g(i)];
15016 f(a);
15017 }
15019 Here, the type of the ARG will be "int [g(i)]", and
15020 may be a SAVE_EXPR, etc. */
15024 }
15026 /* If only one of the bounds used a MINUS_EXPR, compensate
15027 by adding one to the other bound. */
15030 integer_type_node,
15031 parm_max,
15032 integer_one_node);
15035 integer_type_node,
15036 arg_max,
15037 integer_one_node);
15041 }
15055 /* We have already checked cv-qualification at the top of the
15056 function. */
15060 /* As far as unification is concerned, this wins. Later checks
15061 will invalidate it if necessary. */
15064 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
15065 /* Type INTEGER_CST can come from ordinary constant template args. */
15075 {
15084 UNIFY_ALLOW_NONE))
15087 }
15095 {
15102 strict);
15103 }
15106 {
15110 {
15111 /* First, we try to unify the PARM and ARG directly. */
15116 {
15117 /* Fallback to the special case allowed in
15118 [temp.deduct.call]:
15120 If P is a class, and P has the form
15121 template-id, then A can be a derived class of
15122 the deduced A. Likewise, if P is a pointer to
15123 a class of the form template-id, A can be a
15124 pointer to a derived class pointed to by the
15125 deduced A. */
15130 }
15131 }
15135 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15136 Then, we should unify `int' and `U'. */
15138 else
15139 /* There's no chance of unification succeeding. */
15144 }
15151 {
15154 tree a;
15160 /* CV qualifications for methods can never be deduced, they must
15161 match exactly. We need to check them explicitly here,
15162 because type_unification_real treats them as any other
15163 cv-qualified parameter. */
15165 && (!check_cv_quals_for_unify
15185 LOOKUP_NORMAL);
15186 }
15189 /* Unify a pointer to member with a pointer to member function, which
15190 deduces the type of the member as a function type. */
15192 {
15193 tree method_type;
15194 tree fntype;
15196 /* Check top-level cv qualifiers */
15204 /* Determine the type of the function we are unifying against. */
15206 fntype =
15210 /* Extract the cv-qualifiers of the member function from the
15211 implicit object parameter and place them on the function
15212 type to be restored later. */
15215 }
15223 strict);
15234 /* Matched cases are handled by the ARG == PARM test above. */
15238 /* A non-type template parameter that is a variable should be a
15239 an integral constant, in which case, it whould have been
15240 folded into its (constant) value. So we should not be getting
15241 a variable here. */
15246 {
15254 {
15256 {
15258 /* We can unify against something with a trailing
15259 parameter pack. */
15261 else
15262 /* Since there is something following the pack
15263 expansion, we cannot unify this template argument
15264 list. */
15266 }
15267 }
15270 /* If we don't have enough arguments to satisfy the parameters
15271 (not counting the pack expression at the end), or we have
15272 too many arguments for a parameter list that doesn't end in
15273 a pack expression, we can't unify. */
15278 /* Unify all of the parameters that precede the (optional)
15279 pack expression. */
15281 {
15285 }
15293 }
15299 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15300 nodes. */
15304 /* Unification fails if we hit an error node. */
15310 /* We must be looking at an expression. This can happen with
15311 something like:
15313 template <int I>
15314 void foo(S<I>, S<I + 2>);
15316 This is a "nondeduced context":
15318 [deduct.type]
15320 The nondeduced contexts are:
15322 --A type that is a template-id in which one or more of
15323 the template-arguments is an expression that references
15324 a template-parameter.
15326 In these cases, we assume deduction succeeded, but don't
15327 actually infer any unifications. */
15332 else
15334 }
15335 }
15336 \f
15337 /* Note that DECL can be defined in this translation unit, if
15338 required. */
15340 static void
15342 {
15343 tree clone;
15347 }
15349 /* Called if RESULT is explicitly instantiated, or is a member of an
15350 explicitly instantiated class. */
15352 void
15354 {
15357 /* If this entity has already been written out, it's too late to
15358 make any modifications. */
15363 /* The TREE_PUBLIC flag for function declarations will have been
15364 set correctly by tsubst. */
15367 /* This might have been set by an earlier implicit instantiation. */
15372 else
15373 {
15375 /* Always make artificials weak. */
15378 /* For WIN32 we also want to put explicit instantiations in
15379 linkonce sections. */
15382 }
15384 /* If EXTERN_P, then this function will not be emitted -- unless
15385 followed by an explicit instantiation, at which point its linkage
15386 will be adjusted. If !EXTERN_P, then this function will be
15387 emitted here. In neither circumstance do we want
15388 import_export_decl to adjust the linkage. */
15390 }
15392 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15393 important template arguments. If any are missing, we check whether
15394 they're important by using error_mark_node for substituting into any
15395 args that were used for partial ordering (the ones between ARGS and END)
15396 and seeing if it bubbles up. */
15398 static bool
15400 {
15405 {
15408 }
15410 {
15412 {
15416 }
15417 }
15419 }
15421 /* Given two function templates PAT1 and PAT2, return:
15423 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15424 -1 if PAT2 is more specialized than PAT1.
15425 0 if neither is more specialized.
15427 LEN indicates the number of parameters we should consider
15428 (defaulted parameters should not be considered).
15430 The 1998 std underspecified function template partial ordering, and
15431 DR214 addresses the issue. We take pairs of arguments, one from
15432 each of the templates, and deduce them against each other. One of
15433 the templates will be more specialized if all the *other*
15434 template's arguments deduce against its arguments and at least one
15435 of its arguments *does* *not* deduce against the other template's
15436 corresponding argument. Deduction is done as for class templates.
15437 The arguments used in deduction have reference and top level cv
15438 qualifiers removed. Iff both arguments were originally reference
15439 types *and* deduction succeeds in both directions, the template
15440 with the more cv-qualified argument wins for that pairing (if
15441 neither is more cv-qualified, they both are equal). Unlike regular
15442 deduction, after all the arguments have been deduced in this way,
15443 we do *not* verify the deduced template argument values can be
15444 substituted into non-deduced contexts.
15446 The logic can be a bit confusing here, because we look at deduce1 and
15447 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15448 can find template arguments for pat1 to make arg1 look like arg2, that
15449 means that arg2 is at least as specialized as arg1. */
15451 int
15453 {
15466 /* Remove the this parameter from non-static member functions. If
15467 one is a non-static member function and the other is not a static
15468 member function, remove the first parameter from that function
15469 also. This situation occurs for operator functions where we
15470 locate both a member function (with this pointer) and non-member
15471 operator (with explicit first operand). */
15473 {
15478 }
15480 {
15483 {
15484 len--;
15486 }
15487 }
15489 /* If only one is a conversion operator, they are unordered. */
15493 /* Consider the return type for a conversion function */
15495 {
15498 len++;
15499 }
15501 processing_template_decl++;
15507 /* Stop when an ellipsis is seen. */
15509 {
15518 {
15519 /* When both arguments are pack expansions, we need only
15520 unify the patterns themselves. */
15524 /* This is the last comparison we need to do. */
15526 }
15529 {
15532 }
15535 {
15538 }
15541 {
15542 /* Only of the args is a reference, see if we should apply
15543 array/function pointer decay to it. This is not part of
15544 DR214, but is, IMHO, consistent with the deduction rules
15545 for the function call itself, and with our earlier
15546 implementation of the underspecified partial ordering
15547 rules. (nathan). */
15549 {
15551 {
15554 /* FALLTHROUGH. */
15561 }
15562 }
15563 else
15564 {
15566 {
15569 /* FALLTHROUGH. */
15576 }
15577 }
15578 }
15584 {
15590 /* Setup the parameter vector, which contains only ARG1. */
15593 /* Setup the argument vector, which contains the remaining
15594 arguments. */
15603 /* We cannot deduce in the other direction, because ARG1 is
15604 a pack expansion but ARG2 is not. */
15606 }
15608 {
15614 /* Setup the parameter vector, which contains only ARG1. */
15617 /* Setup the argument vector, which contains the remaining
15618 arguments. */
15627 /* We cannot deduce in the other direction, because ARG2 is
15628 a pack expansion but ARG1 is not.*/
15630 }
15632 else
15633 {
15634 /* The normal case, where neither argument is a pack
15635 expansion. */
15638 }
15640 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15641 arg2, then arg2 is not as specialized as arg1. */
15647 /* "If, for a given type, deduction succeeds in both directions
15648 (i.e., the types are identical after the transformations above)
15649 and if the type from the argument template is more cv-qualified
15650 than the type from the parameter template (as described above)
15651 that type is considered to be more specialized than the other. If
15652 neither type is more cv-qualified than the other then neither type
15653 is more specialized than the other." */
15657 {
15662 }
15665 /* We've failed to deduce something in either direction.
15666 These must be unordered. */
15671 /* We have already processed all of the arguments in our
15672 handing of the pack expansion type. */
15677 }
15679 /* "In most cases, all template parameters must have values in order for
15680 deduction to succeed, but for partial ordering purposes a template
15681 parameter may remain without a value provided it is not used in the
15682 types being used for partial ordering."
15684 Thus, if we are missing any of the targs1 we need to substitute into
15685 origs1, then pat2 is not as specialized as pat1. This can happen when
15686 there is a nondeduced context. */
15692 processing_template_decl--;
15694 /* All things being equal, if the next argument is a pack expansion
15695 for one function but not for the other, prefer the
15696 non-variadic function. FIXME this is bogus; see c++/41958. */
15700 {
15703 }
15709 else
15711 }
15713 /* Determine which of two partial specializations is more specialized.
15715 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15716 to the first partial specialization. The TREE_VALUE is the
15717 innermost set of template parameters for the partial
15718 specialization. PAT2 is similar, but for the second template.
15720 Return 1 if the first partial specialization is more specialized;
15721 -1 if the second is more specialized; 0 if neither is more
15722 specialized.
15724 See [temp.class.order] for information about determining which of
15725 two templates is more specialized. */
15727 static int
15729 {
15730 tree targs;
15738 /* Just like what happens for functions, if we are ordering between
15739 different class template specializations, we may encounter dependent
15740 types in the arguments, and we need our dependency check functions
15741 to behave correctly. */
15747 {
15750 }
15756 {
15759 }
15762 /* In the case of a tie where at least one of the class templates
15763 has a parameter pack at the end, the template with the most
15764 non-packed parameters wins. */
15766 && any_deductions
15769 {
15775 /* We don't count the pack expansion at the end. */
15785 }
15788 }
15790 /* Return the template arguments that will produce the function signature
15791 DECL from the function template FN, with the explicit template
15792 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15793 also match. Return NULL_TREE if no satisfactory arguments could be
15794 found. */
15796 static tree
15798 {
15801 tree decl_type;
15802 tree decl_arg_types;
15805 tree arg;
15807 /* Substitute the explicit template arguments into the type of DECL.
15808 The call to fn_type_unification will handle substitution into the
15809 FN. */
15812 {
15813 tree tmpl;
15814 tree converted_args;
15818 else
15819 /* We can get here for some invalid specializations. */
15822 converted_args
15825 tf_none,
15834 }
15836 /* Never do unification on the 'this' parameter. */
15855 }
15857 /* Return the innermost template arguments that, when applied to a
15858 template specialization whose innermost template parameters are
15859 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15860 ARGS.
15862 For example, suppose we have:
15864 template <class T, class U> struct S {};
15865 template <class T> struct S<T*, int> {};
15867 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15868 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15869 int}. The resulting vector will be {double}, indicating that `T'
15870 is bound to `double'. */
15872 static tree
15874 {
15876 tree deduced_args;
15877 tree innermost_deduced_args;
15881 {
15885 innermost_deduced_args);
15886 }
15887 else
15893 UNIFY_ALLOW_NONE))
15900 /* Verify that nondeduced template arguments agree with the type
15901 obtained from argument deduction.
15903 For example:
15905 struct A { typedef int X; };
15906 template <class T, class U> struct C {};
15907 template <class T> struct C<T, typename T::X> {};
15909 Then with the instantiation `C<A, int>', we can deduce that
15910 `T' is `A' but unify () does not check whether `typename T::X'
15911 is `int'. */
15914 /* We only need to check the innermost arguments; the other
15915 arguments will always agree. */
15920 /* Now that we have bindings for all of the template arguments,
15921 ensure that the arguments deduced for the template template
15922 parameters have compatible template parameter lists. See the use
15923 of template_template_parm_bindings_ok_p in fn_type_unification
15924 for more information. */
15929 }
15931 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15932 Return the TREE_LIST node with the most specialized template, if
15933 any. If there is no most specialized template, the error_mark_node
15934 is returned.
15936 Note that this function does not look at, or modify, the
15937 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15938 returned is one of the elements of INSTANTIATIONS, callers may
15939 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15940 and retrieve it from the value returned. */
15942 tree
15944 {
15951 {
15957 fate--;
15962 fate++;
15967 {
15968 /* Equally specialized, move to next function. If there
15969 is no next function, nothing's most specialized. */
15974 }
15975 }
15978 /* Now verify that champ is better than everything earlier in the
15979 instantiation list. */
15987 {
15990 }
15992 processing_template_decl--;
15998 }
16000 /* If DECL is a specialization of some template, return the most
16001 general such template. Otherwise, returns NULL_TREE.
16003 For example, given:
16005 template <class T> struct S { template <class U> void f(U); };
16007 if TMPL is `template <class U> void S<int>::f(U)' this will return
16008 the full template. This function will not trace past partial
16009 specializations, however. For example, given in addition:
16011 template <class T> struct S<T*> { template <class U> void f(U); };
16013 if TMPL is `template <class U> void S<int*>::f(U)' this will return
16014 `template <class T> template <class U> S<T*>::f(U)'. */
16016 tree
16018 {
16019 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
16020 an immediate specialization. */
16022 {
16026 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
16027 template friend. */
16032 }
16034 /* Look for more and more general templates. */
16036 {
16037 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
16038 (See cp-tree.h for details.) */
16046 /* Stop if we run into an explicitly specialized class template. */
16053 }
16056 }
16058 /* Return the most specialized of the class template partial
16059 specializations of TMPL which can produce TYPE, a specialization of
16060 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
16061 a _TYPE node corresponding to the partial specialization, while the
16062 TREE_PURPOSE is the set of template arguments that must be
16063 substituted into the TREE_TYPE in order to generate TYPE.
16065 If the choice of partial specialization is ambiguous, a diagnostic
16066 is issued, and the error_mark_node is returned. If there are no
16067 partial specializations of TMPL matching TYPE, then NULL_TREE is
16068 returned. */
16070 static tree
16072 {
16074 tree t;
16075 tree champ;
16078 tree args;
16084 /* For determining which partial specialization to use, only the
16085 innermost args are interesting. */
16087 {
16090 }
16093 {
16094 tree partial_spec_args;
16095 tree spec_args;
16103 {
16106 /* Discard the outer levels of args, and then substitute in the
16107 template args from the enclosing class. */
16109 partial_spec_args = tsubst_template_args
16112 /* PARMS already refers to just the innermost parms, but the
16113 template parms in partial_spec_args had their levels lowered
16114 by tsubst, so we need to do the same for the parm list. We
16115 can't just tsubst the TREE_VEC itself, as tsubst wants to
16116 treat a TREE_VEC as an argument vector. */
16122 }
16124 partial_spec_args =
16127 partial_spec_args),
16138 partial_spec_args,
16139 args);
16141 {
16146 }
16147 }
16157 {
16160 ;
16161 else
16162 {
16164 {
16167 {
16170 }
16171 }
16173 }
16174 }
16178 {
16181 {
16184 }
16185 }
16188 {
16196 {
16199 }
16202 }
16205 }
16207 /* Explicitly instantiate DECL. */
16209 void
16211 {
16216 /* An error occurred, for which grokdeclarator has already issued
16217 an appropriate message. */
16220 {
16223 }
16225 {
16226 /* There is an asymmetry here in the way VAR_DECLs and
16227 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16228 the latter, the DECL we get back will be marked as a
16229 template instantiation, and the appropriate
16230 DECL_TEMPLATE_INFO will be set up. This does not happen for
16231 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16232 should handle VAR_DECLs as it currently handles
16233 FUNCTION_DECLs. */
16235 {
16238 }
16241 {
16244 }
16246 {
16251 }
16252 }
16254 {
16257 }
16258 else
16261 /* Check for various error cases. Note that if the explicit
16262 instantiation is valid the RESULT will currently be marked as an
16263 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16264 until we get here. */
16267 {
16268 /* DR 259 [temp.spec].
16270 Both an explicit instantiation and a declaration of an explicit
16271 specialization shall not appear in a program unless the explicit
16272 instantiation follows a declaration of the explicit specialization.
16274 For a given set of template parameters, if an explicit
16275 instantiation of a template appears after a declaration of an
16276 explicit specialization for that template, the explicit
16277 instantiation has no effect. */
16279 }
16281 {
16282 /* [temp.spec]
16284 No program shall explicitly instantiate any template more
16285 than once.
16287 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16288 the first instantiation was `extern' and the second is not,
16289 and EXTERN_P for the opposite case. */
16292 /* If an "extern" explicit instantiation follows an ordinary
16293 explicit instantiation, the template is instantiated. */
16296 }
16298 {
16301 }
16303 {
16306 }
16309 ;
16311 {
16314 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16317 }
16318 else
16326 }
16328 static void
16330 {
16336 {
16339 }
16340 }
16342 /* Called from do_type_instantiation through binding_table_foreach to
16343 do recursive instantiation for the type bound in ENTRY. */
16344 static void
16346 {
16352 }
16354 /* Called from do_type_instantiation to instantiate a member
16355 (a member function or a static member variable) of an
16356 explicitly instantiated class template. */
16357 static void
16359 {
16364 }
16366 /* Perform an explicit instantiation of template class T. STORAGE, if
16367 non-null, is the RID for extern, inline or static. COMPLAIN is
16368 nonzero if this is called from the parser, zero if called recursively,
16369 since the standard is unclear (as detailed below). */
16371 void
16373 {
16383 {
16386 }
16391 {
16394 t);
16396 }
16399 {
16401 {
16403 {
16406 "ISO C++ 1998 forbids the use of %<extern%> on "
16408 }
16409 else
16411 "ISO C++ forbids the use of %qE"
16413 }
16421 else
16422 {
16424 storage);
16426 }
16427 }
16430 {
16431 /* DR 259 [temp.spec].
16433 Both an explicit instantiation and a declaration of an explicit
16434 specialization shall not appear in a program unless the explicit
16435 instantiation follows a declaration of the explicit specialization.
16437 For a given set of template parameters, if an explicit
16438 instantiation of a template appears after a declaration of an
16439 explicit specialization for that template, the explicit
16440 instantiation has no effect. */
16442 }
16444 {
16445 /* [temp.spec]
16447 No program shall explicitly instantiate any template more
16448 than once.
16450 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16451 instantiation was `extern'. If EXTERN_P then the second is.
16452 These cases are OK. */
16459 /* If we've already instantiated the template, just return now. */
16462 }
16470 {
16471 tree tmp;
16473 /* In contrast to implicit instantiation, where only the
16474 declarations, and not the definitions, of members are
16475 instantiated, we have here:
16477 [temp.explicit]
16479 The explicit instantiation of a class template specialization
16480 implies the instantiation of all of its members not
16481 previously explicitly specialized in the translation unit
16482 containing the explicit instantiation.
16484 Of course, we can't instantiate member template classes, since
16485 we don't have any arguments for them. Note that the standard
16486 is unclear on whether the instantiation of the members are
16487 *explicit* instantiations or not. However, the most natural
16488 interpretation is that it should be an explicit instantiation. */
16503 }
16504 }
16506 /* Given a function DECL, which is a specialization of TMPL, modify
16507 DECL to be a re-instantiation of TMPL with the same template
16508 arguments. TMPL should be the template into which tsubst'ing
16509 should occur for DECL, not the most general template.
16511 One reason for doing this is a scenario like this:
16513 template <class T>
16514 void f(const T&, int i);
16516 void g() { f(3, 7); }
16518 template <class T>
16519 void f(const T& t, const int i) { }
16521 Note that when the template is first instantiated, with
16522 instantiate_template, the resulting DECL will have no name for the
16523 first parameter, and the wrong type for the second. So, when we go
16524 to instantiate the DECL, we regenerate it. */
16526 static void
16528 {
16529 /* The arguments used to instantiate DECL, from the most general
16530 template. */
16531 tree args;
16532 tree code_pattern;
16537 /* Make sure that we can see identifiers, and compute access
16538 correctly. */
16542 {
16543 tree decl_parm;
16544 tree pattern_parm;
16545 tree specs;
16558 specs);
16560 /* Merge parameter declarations. */
16563 pattern_parm
16567 {
16568 tree parm_type;
16569 tree attributes;
16574 NULL_TREE);
16580 {
16583 }
16586 }
16587 /* Merge any parameters that match with the function parameter
16588 pack. */
16590 {
16592 tree expanded_types;
16593 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16594 the parameters in this function parameter pack. */
16599 {
16600 tree parm_type;
16601 tree attributes;
16604 /* Rename the parameter to include the index. */
16613 {
16616 }
16618 }
16619 }
16620 /* Merge additional specifiers from the CODE_PATTERN. */
16624 }
16626 {
16634 }
16635 else
16639 }
16641 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16642 substituted to get DECL. */
16644 tree
16646 {
16649 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16650 for the instantiation. This is not always the most general
16651 template. Consider, for example:
16653 template <class T>
16654 struct S { template <class U> void f();
16655 template <> void f<int>(); };
16657 and an instantiation of S<double>::f<int>. We want TD to be the
16658 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16660 more general template. */
16662 /* We must also deal with friend templates. Given:
16664 template <class T> struct S {
16665 template <class U> friend void f() {};
16666 };
16668 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16669 so far as the language is concerned, but that's still
16670 where we get the pattern for the instantiation from. On
16671 other hand, if the definition comes outside the class, say:
16673 template <class T> struct S {
16674 template <class U> friend void f();
16675 };
16676 template <class U> friend void f() {}
16678 we don't need to look any further. That's what the check for
16679 DECL_INITIAL is for. */
16683 {
16684 /* The present template, TD, should not be a definition. If it
16685 were a definition, we should be using it! Note that we
16686 cannot restructure the loop to just keep going until we find
16687 a template with a definition, since that might go too far if
16688 a specialization was declared, but not defined. */
16692 /* Fetch the more general template. */
16694 }
16697 }
16699 /* Returns true if we need to instantiate this template instance even if we
16700 know we aren't going to emit it.. */
16702 bool
16704 {
16705 /* We always instantiate inline functions so that we can inline them. An
16706 explicit instantiation declaration prohibits implicit instantiation of
16707 non-inline functions. With high levels of optimization, we would
16708 normally inline non-inline functions -- but we're not allowed to do
16709 that for "extern template" functions. Therefore, we check
16710 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16713 /* And we need to instantiate static data members so that
16714 their initializers are available in integral constant
16715 expressions. */
16718 }
16720 /* Produce the definition of D, a _DECL generated from a template. If
16721 DEFER_OK is nonzero, then we don't have to actually do the
16722 instantiation now; we just have to do it sometime. Normally it is
16723 an error if this is an explicit instantiation but D is undefined.
16724 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16725 explicitly instantiated class template. */
16727 tree
16730 {
16732 tree gen_args;
16733 tree args;
16734 tree td;
16735 tree code_pattern;
16736 tree spec;
16737 tree gen_tmpl;
16743 /* This function should only be used to instantiate templates for
16744 functions and static member variables. */
16748 /* Variables are never deferred; if instantiation is required, they
16749 are instantiated right away. That allows for better code in the
16750 case that an expression refers to the value of the variable --
16751 if the variable has a constant value the referring expression can
16752 take advantage of that fact. */
16756 /* Don't instantiate cloned functions. Instead, instantiate the
16757 functions they cloned. */
16763 /* D has already been instantiated or explicitly specialized, so
16764 there's nothing for us to do here.
16766 It might seem reasonable to check whether or not D is an explicit
16767 instantiation, and, if so, stop here. But when an explicit
16768 instantiation is deferred until the end of the compilation,
16769 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16770 the instantiation. */
16773 /* Check to see whether we know that this template will be
16774 instantiated in some other file, as with "extern template"
16775 extension. */
16778 /* In general, we do not instantiate such templates. */
16786 /* We should already have the extra args. */
16789 /* And what's in the hash table should match D. */
16793 /* This needs to happen before any tsubsting. */
16799 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16800 for the instantiation. */
16804 /* We should never be trying to instantiate a member of a class
16805 template or partial specialization. */
16810 /* In the case of a friend template whose definition is provided
16811 outside the class, we may have too many arguments. Drop the
16812 ones we don't need. The same is true for specializations. */
16813 args = get_innermost_template_args
16815 else
16820 else
16823 /* We may be in the middle of deferred access check. Disable it now. */
16826 /* Unless an explicit instantiation directive has already determined
16827 the linkage of D, remember that a definition is available for
16828 this entity. */
16836 /* If D is a member of an explicitly instantiated class template,
16837 and no definition is available, treat it like an implicit
16838 instantiation. */
16841 {
16845 }
16847 /* Recheck the substitutions to obtain any warning messages
16848 about ignoring cv qualifiers. Don't do this for artificial decls,
16849 as it breaks the context-sensitive substitution for lambda op(). */
16851 {
16855 /* Make sure that we can see identifiers, and compute access
16856 correctly. D is already the target FUNCTION_DECL with the
16857 right context. */
16861 {
16864 d);
16865 /* Don't simply tsubst the function type, as that will give
16866 duplicate warnings about poor parameter qualifications.
16867 The function arguments are the same as the decl_arguments
16868 without the top level cv qualifiers. */
16870 }
16874 }
16876 /* Defer all other templates, unless we have been explicitly
16877 forbidden from doing so. */
16879 template. */
16880 ! pattern_defined
16881 /* If it's OK to postpone instantiation, do so. */
16882 || defer_ok
16883 /* If this is a static data member that will be defined
16884 elsewhere, we don't want to instantiate the entire data
16885 member, but we do want to instantiate the initializer so that
16886 we can substitute that elsewhere. */
16888 {
16889 /* The definition of the static data member is now required so
16890 we must substitute the initializer. */
16894 {
16895 tree ns;
16896 tree init;
16902 args,
16907 LOOKUP_ONLYCONVERTING);
16910 }
16912 /* We restore the source position here because it's used by
16913 add_pending_template. */
16919 /* [temp.explicit]
16921 The definition of a non-exported function template, a
16922 non-exported member function template, or a non-exported
16923 member function or static data member of a class template
16924 shall be present in every translation unit in which it is
16925 explicitly instantiated. */
16929 /* ??? Historically, we have instantiated inline functions, even
16930 when marked as "extern template". */
16934 }
16935 /* Tell the repository that D is available in this translation unit
16936 -- and see if it is supposed to be instantiated here. */
16938 {
16939 /* In a PCH file, despite the fact that the repository hasn't
16940 requested instantiation in the PCH it is still possible that
16941 an instantiation will be required in a file that includes the
16942 PCH. */
16945 /* Instantiate inline functions so that the inliner can do its
16946 job, even though we'll not be emitting a copy of this
16947 function. */
16950 }
16956 /* Mark D as instantiated so that recursive calls to
16957 instantiate_decl do not try to instantiate it again. */
16960 /* Regenerate the declaration in case the template has been modified
16961 by a subsequent redeclaration. */
16964 /* We already set the file and line above. Reset them now in case
16965 they changed as a result of calling regenerate_decl_from_template. */
16969 {
16970 tree init;
16972 /* Clear out DECL_RTL; whatever was there before may not be right
16973 since we've reset the type of the declaration. */
16977 /* The initializer is placed in DECL_INITIAL by
16978 regenerate_decl_from_template. Pull it out so that
16979 cp_finish_decl can process it. */
16984 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16985 initializer. That function will defer actual emission until
16986 we have a chance to determine linkage. */
16989 /* Enter the scope of D so that access-checking works correctly. */
16993 }
16995 {
16996 htab_t saved_local_specializations;
16997 tree subst_decl;
16998 tree tmpl_parm;
16999 tree spec_parm;
17001 /* Save away the current list, in case we are instantiating one
17002 template from within the body of another. */
17005 /* Set up the list of local specializations. */
17007 hash_local_specialization,
17008 eq_local_specializations,
17009 NULL);
17011 /* Set up context. */
17014 /* Create substitution entries for the parameters. */
17019 {
17023 }
17025 {
17029 }
17031 {
17032 /* Register the (value) argument pack as a specialization of
17033 TMPL_PARM, then move on. */
17038 }
17041 /* Substitute into the body of the function. */
17046 /* Set the current input_location to the end of the function
17047 so that finish_function knows where we are. */
17050 /* We don't need the local specializations any more. */
17054 /* Finish the function. */
17057 }
17059 /* We're not deferring instantiation any more. */
17065 out:
17073 }
17075 /* Run through the list of templates that we wish we could
17076 instantiate, and instantiate any we can. RETRIES is the
17077 number of times we retry pending template instantiation. */
17079 void
17081 {
17085 /* Instantiating templates may trigger vtable generation. This in turn
17086 may require further template instantiations. We place a limit here
17087 to avoid infinite loop. */
17089 {
17093 " instantiating %q+D, possibly from virtual table generation"
17097 /* Pretend that we defined it. */
17100 }
17102 do
17103 {
17108 {
17113 {
17114 tree fn;
17117 {
17121 fn;
17129 }
17132 }
17133 else
17134 {
17137 {
17138 instantiation
17144 }
17148 }
17151 /* If INSTANTIATION has been instantiated, then we don't
17152 need to consider it again in the future. */
17154 else
17155 {
17158 }
17161 }
17163 }
17167 }
17169 /* Substitute ARGVEC into T, which is a list of initializers for
17170 either base class or a non-static data member. The TREE_PURPOSEs
17171 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17172 instantiate_decl. */
17174 static tree
17176 {
17180 {
17181 tree decl;
17182 tree init;
17188 {
17189 tree expr;
17190 tree arg;
17192 /* Expand the base class expansion type into separate base
17193 classes. */
17195 tf_warning_or_error,
17196 NULL_TREE);
17200 /* We'll be building separate TREE_LISTs of arguments for
17201 each base. */
17207 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17208 expand each argument in the TREE_VALUE of t. */
17214 /* VOID_TYPE_NODE is used to indicate
17215 value-initialization. */
17216 {
17219 }
17220 else
17221 {
17222 /* Substitute parameter packs into each argument in the
17223 TREE_LIST. */
17226 {
17227 tree expanded_exprs;
17229 /* Expand the argument. */
17231 expanded_exprs
17233 tf_warning_or_error,
17234 NULL_TREE);
17238 /* Prepend each of the expanded expressions to the
17239 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17241 {
17246 }
17247 }
17250 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17251 since we built them backwards. */
17253 {
17256 }
17257 }
17258 }
17261 {
17263 {
17267 }
17268 else
17269 {
17283 }
17286 {
17290 }
17291 }
17292 }
17294 }
17296 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17298 static void
17300 {
17305 else
17307 }
17309 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17310 is the instantiation (which should have been created with
17311 start_enum) and ARGS are the template arguments to use. */
17313 static void
17315 {
17316 tree e;
17322 {
17323 tree value;
17324 tree decl;
17327 /* Note that in a template enum, the TREE_VALUE is the
17328 CONST_DECL, not the corresponding INTEGER_CST. */
17333 /* Give this enumeration constant the correct access. */
17336 /* Actually build the enumerator itself. */
17337 build_enumerator
17339 }
17349 }
17351 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17352 its type -- but without substituting the innermost set of template
17353 arguments. So, innermost set of template parameters will appear in
17354 the type. */
17356 tree
17358 {
17359 tree fn_type;
17360 tree tmpl;
17361 tree targs;
17362 tree tparms;
17370 /* There should be as many levels of arguments as there are levels
17371 of parameters. */
17377 /* No substitution is necessary. */
17378 ;
17379 else
17380 {
17382 tree partial_args;
17384 /* Replace the innermost level of the TARGS with NULL_TREEs to
17385 let tsubst know not to substitute for those parameters. */
17394 /* Disable access control as this function is used only during
17395 name-mangling. */
17400 /* Now, do the (partial) substitution to figure out the
17401 appropriate function type. */
17405 /* Substitute into the template parameters to obtain the real
17406 innermost set of parameters. This step is important if the
17407 innermost set of template parameters contains value
17408 parameters whose types depend on outer template parameters. */
17413 }
17416 }
17418 /* Return truthvalue if we're processing a template different from
17419 the last one involved in diagnostics. */
17420 int
17422 {
17424 }
17426 /* Remember current template involved in diagnostics. */
17427 void
17429 {
17431 }
17435 {
17437 }
17439 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17440 type. Return zero for ok, nonzero for disallowed. Issue error and
17441 warning messages under control of COMPLAIN. */
17443 static int
17445 {
17460 }
17462 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17463 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17465 static bool
17467 {
17468 tree scope;
17470 /* [temp.dep.type]
17472 A type is dependent if it is:
17474 -- a template parameter. Template template parameters are types
17475 for us (since TYPE_P holds true for them) so we handle
17476 them here. */
17480 /* -- a qualified-id with a nested-name-specifier which contains a
17481 class-name that names a dependent type or whose unqualified-id
17482 names a dependent type. */
17485 /* -- a cv-qualified type where the cv-unqualified type is
17486 dependent. */
17488 /* -- a compound type constructed from any dependent type. */
17498 {
17499 tree arg_type;
17504 arg_type;
17509 }
17510 /* -- an array type constructed from any dependent type or whose
17511 size is specified by a constant expression that is
17512 value-dependent.
17514 We checked for type- and value-dependence of the bounds in
17515 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
17517 {
17522 }
17524 /* -- a template-id in which either the template name is a template
17525 parameter ... */
17528 /* ... or any of the template arguments is a dependent type or
17529 an expression that is type-dependent or value-dependent. */
17531 && (any_dependent_template_arguments_p
17535 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17536 argument of the `typeof' expression is not type-dependent, then
17537 it should already been have resolved. */
17542 /* A template argument pack is dependent if any of its packed
17543 arguments are. */
17545 {
17551 }
17553 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17554 be template parameters. */
17558 /* The standard does not specifically mention types that are local
17559 to template functions or local classes, but they should be
17560 considered dependent too. For example:
17562 template <int I> void f() {
17563 enum E { a = I };
17564 S<sizeof (E)> s;
17565 }
17567 The size of `E' cannot be known until the value of `I' has been
17568 determined. Therefore, `E' must be considered dependent. */
17575 /* Other types are non-dependent. */
17577 }
17579 /* Returns TRUE if TYPE is dependent, in the sense of
17580 [temp.dep.type]. */
17582 bool
17584 {
17585 /* If there are no template parameters in scope, then there can't be
17586 any dependent types. */
17588 {
17589 /* If we are not processing a template, then nobody should be
17590 providing us with a dependent type. */
17594 }
17596 /* If the type is NULL, we have not computed a type for the entity
17597 in question; in that case, the type is dependent. */
17601 /* Erroneous types can be considered non-dependent. */
17605 /* If we have not already computed the appropriate value for TYPE,
17606 do so now. */
17608 {
17611 }
17614 }
17616 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17617 lookup. In other words, a dependent type that is not the current
17618 instantiation. */
17620 bool
17622 {
17625 }
17627 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17628 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17629 expression. */
17631 bool
17633 {
17637 /* A name declared with a dependent type. */
17642 {
17644 /* A name that has not been looked up -- must be dependent. */
17648 /* A non-type template parm. */
17652 /* A non-type template parm. */
17658 /* A constant with integral or enumeration type and is initialized
17659 with an expression that is value-dependent. */
17671 /* These expressions are value-dependent if the type to which
17672 the cast occurs is dependent or the expression being casted
17673 is value-dependent. */
17674 {
17680 /* A functional cast has a list of operands. */
17683 {
17684 /* If there are no operands, it must be an expression such
17685 as "int()". This should not happen for aggregate types
17686 because it would form non-constant expressions. */
17690 }
17696 }
17700 /* A `sizeof' expression is value-dependent if the operand is
17701 type-dependent or is a pack expansion. */
17710 /* An 'encode' expression is value-dependent if the operand is
17711 type-dependent. */
17717 /* FIXME why check value-dependency? */
17722 {
17725 }
17732 /* A CALL_EXPR may appear in a constant expression if it is a
17733 call to a builtin function, e.g., __builtin_constant_p. All
17734 such calls are value-dependent. */
17738 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17739 is value-dependent. */
17740 {
17749 }
17752 {
17756 }
17763 {
17767 }
17770 /* A constant expression is value-dependent if any subexpression is
17771 value-dependent. */
17773 {
17783 || (value_dependent_expression_p
17788 {
17791 /* In some cases, some of the operands may be missing.
17792 (For example, in the case of PREDECREMENT_EXPR, the
17793 amount to increment by may be missing.) That doesn't
17794 make the expression dependent. */
17796 && (value_dependent_expression_p
17800 }
17804 }
17805 }
17807 /* The expression is not value-dependent. */
17809 }
17811 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17812 [temp.dep.expr]. */
17814 bool
17816 {
17823 /* An unresolved name is always dependent. */
17828 /* Some expression forms are never type-dependent. */
17841 /* The types of these expressions depends only on the type to which
17842 the cast occurs. */
17850 /* The types of these expressions depends only on the type created
17851 by the expression. */
17854 {
17855 /* For NEW_EXPR tree nodes created inside a template, either
17856 the object type itself or a TREE_LIST may appear as the
17857 operand 1. */
17860 /* This is an array type. We need to check array dimensions
17861 as well. */
17863 || value_dependent_expression_p
17865 else
17867 }
17870 {
17874 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
17875 contains an identifier associated by name lookup with one or more
17876 declarations declared with a dependent type, or...a
17877 nested-name-specifier or qualified-id that names a member of an
17878 unknown specialization. */
17881 }
17886 && (any_dependent_template_arguments_p
17898 {
17899 tree elt;
17903 {
17906 }
17908 }
17910 /* A static data member of the current instantiation with incomplete
17911 array type is type-dependent, as the definition and specializations
17912 can have different bounds. */
17920 {
17925 {
17931 }
17932 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17940 {
17945 }
17950 {
17954 }
17956 }
17961 }
17963 /* Like type_dependent_expression_p, but it also works while not processing
17964 a template definition, i.e. during substitution or mangling. */
17966 bool
17968 {
17974 }
17976 /* Returns TRUE if ARGS contains a type-dependent expression. */
17978 bool
17980 {
17982 tree arg;
17985 {
17988 }
17990 }
17992 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17993 expressions) contains any value-dependent expressions. */
17995 bool
17997 {
18003 }
18005 /* Returns TRUE if the ARG (a template argument) is dependent. */
18007 bool
18009 {
18017 {
18021 {
18024 }
18027 }
18030 else
18033 }
18035 /* Returns true if ARGS (a collection of template arguments) contains
18036 any types that require structural equality testing. */
18038 bool
18040 {
18050 {
18053 {
18059 {
18060 /* Look inside the argument pack. */
18063 }
18066 {
18080 }
18081 }
18082 }
18085 }
18087 /* Returns true if ARGS (a collection of template arguments) contains
18088 any dependent arguments. */
18090 bool
18092 {
18102 {
18107 }
18110 }
18112 /* Returns TRUE if the template TMPL is dependent. */
18114 bool
18116 {
18118 {
18120 {
18124 }
18126 }
18128 /* Template template parameters are dependent. */
18132 /* So are names that have not been looked up. */
18136 /* So are member templates of dependent classes. */
18140 }
18142 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18144 bool
18146 {
18149 }
18151 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18152 is dependent. */
18154 bool
18156 {
18163 {
18184 {
18188 }
18192 {
18196 {
18201 }
18202 }
18203 }
18206 }
18208 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18209 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18210 no such TYPE can be found. Note that this function peers inside
18211 uninstantiated templates and therefore should be used only in
18212 extremely limited situations. ONLY_CURRENT_P restricts this
18213 peering to the currently open classes hierarchy (which is required
18214 when comparing types). */
18216 tree
18218 {
18219 tree scope;
18220 tree name;
18221 tree decl;
18223 tree pushed_scope;
18224 tree result;
18229 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18230 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18231 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18232 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18233 identifier of the TYPENAME_TYPE anymore.
18234 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18235 TYPENAME_TYPE instead, we avoid messing up with a possible
18236 typedef variant case. */
18239 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18240 it first before we can figure out what NAME refers to. */
18243 /* If we don't know what SCOPE refers to, then we cannot resolve the
18244 TYPENAME_TYPE. */
18247 /* If the SCOPE is a template type parameter, we have no way of
18248 resolving the name. */
18251 /* If the SCOPE is not the current instantiation, there's no reason
18252 to look inside it. */
18255 /* If this is a typedef, we don't want to look inside (c++/11987). */
18258 /* If SCOPE isn't the template itself, it will not have a valid
18259 TYPE_FIELDS list. */
18261 /* scope is either the template itself or a compatible instantiation
18262 like X<T>, so look up the name in the original template. */
18264 else
18265 /* scope is a partial instantiation, so we can't do the lookup or we
18266 will lose the template arguments. */
18268 /* Enter the SCOPE so that name lookup will be resolved as if we
18269 were in the class definition. In particular, SCOPE will no
18270 longer be considered a dependent type. */
18272 /* Look up the declaration. */
18277 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18278 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18283 {
18287 }
18290 {
18291 tree tmpl;
18292 tree args;
18293 /* Obtain the template and the arguments. */
18296 /* Instantiate the template. */
18302 }
18304 /* Leave the SCOPE. */
18308 /* If we failed to resolve it, return the original typename. */
18312 /* If lookup found a typename type, resolve that too. */
18314 {
18315 /* Ill-formed programs can cause infinite recursion here, so we
18316 must catch that. */
18320 }
18322 /* Qualify the resulting type. */
18328 }
18330 /* EXPR is an expression which is not type-dependent. Return a proxy
18331 for EXPR that can be used to compute the types of larger
18332 expressions containing EXPR. */
18334 tree
18336 {
18337 tree inner_expr;
18339 /* Preserve null pointer constants so that the type of things like
18340 "p == 0" where "p" is a pointer can be determined. */
18343 /* Preserve OVERLOADs; the functions must be available to resolve
18344 types. */
18355 /* There is no need to return a proxy for a variable. */
18358 /* Preserve string constants; conversions from string constants to
18359 "char *" are allowed, even though normally a "const char *"
18360 cannot be used to initialize a "char *". */
18363 /* Preserve arithmetic constants, as an optimization -- there is no
18364 reason to create a new node. */
18367 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18368 There is at least one place where we want to know that a
18369 particular expression is a throw-expression: when checking a ?:
18370 expression, there are special rules if the second or third
18371 argument is a throw-expression. */
18390 /* If the type is unknown, it can't really be non-dependent */
18393 /* Otherwise, build a NON_DEPENDENT_EXPR.
18395 REFERENCE_TYPEs are not stripped for expressions in templates
18396 because doing so would play havoc with mangling. Consider, for
18397 example:
18399 template <typename T> void f<T& g>() { g(); }
18401 In the body of "f", the expression for "g" will have
18402 REFERENCE_TYPE, even though the standard says that it should
18403 not. The reason is that we must preserve the syntactic form of
18404 the expression so that mangling (say) "f<g>" inside the body of
18405 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18406 stripped here. */
18408 }
18410 /* ARGS is a vector of expressions as arguments to a function call.
18411 Replace the arguments with equivalent non-dependent expressions.
18412 This modifies ARGS in place. */
18414 void
18416 {
18418 tree arg;
18421 {
18425 }
18426 }
18428 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18429 with a level one deeper than the actual template parms. */
18431 tree
18433 {
18446 }
18448 /* Given type ARG, return std::initializer_list<ARG>. */
18450 static tree
18452 {
18453 tree std_init_list = namespace_binding
18455 tree argvec;
18457 {
18461 }
18466 }
18468 /* Replace auto in TYPE with std::initializer_list<auto>. */
18470 static tree
18472 {
18479 }
18481 /* walk_tree helper for do_auto_deduction. */
18483 static tree
18486 {
18487 /* Is this a variable with the type we're looking for? */
18491 else
18493 }
18495 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18496 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18498 tree
18500 {
18503 tree decl;
18506 /* The name of the object being declared shall not appear in the
18507 initializer expression. */
18510 {
18514 }
18516 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18517 with either a new invented type template parameter U or, if the
18518 initializer is a braced-init-list (8.5.4), with
18519 std::initializer_list<U>. */
18532 {
18535 }
18537 /* If the list of declarators contains more than one declarator, the type
18538 of each declared variable is determined as described above. If the
18539 type deduced for the template parameter U is not the same in each
18540 deduction, the program is ill-formed. */
18543 {
18547 }
18553 }
18555 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18556 result. */
18558 tree
18560 {
18561 tree argvec;
18570 }
18572 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18574 bool
18576 {
18580 else
18582 }
18584 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18585 appear as a type-specifier for the declaration in question, we don't
18586 have to look through the whole type. */
18588 tree
18590 {
18607 }
18609 /* For a given template T, return the vector of typedefs referenced
18610 in T for which access check is needed at T instantiation time.
18611 T is either a FUNCTION_DECL or a RECORD_TYPE.
18612 Those typedefs were added to T by the function
18613 append_type_to_template_for_access_check. */
18617 {
18618 tree ti;
18629 {
18634 }
18637 }
18639 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18640 tied to T. That list of typedefs will be access checked at
18641 T instantiation time.
18642 T is either a FUNCTION_DECL or a RECORD_TYPE.
18643 TYPE_DECL is a TYPE_DECL node representing a typedef.
18644 SCOPE is the scope through which TYPE_DECL is accessed.
18645 LOCATION is the location of the usage point of TYPE_DECL.
18647 This function is a subroutine of
18648 append_type_to_template_for_access_check. */
18650 static void
18652 tree type_decl,
18653 tree scope,
18654 location_t location)
18655 {
18656 qualified_typedef_usage_t typedef_usage;
18657 tree ti;
18664 && type_decl
18680 }
18682 /* Append TYPE_DECL to the template TEMPL.
18683 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18684 At TEMPL instanciation time, TYPE_DECL will be checked to see
18685 if it can be accessed through SCOPE.
18686 LOCATION is the location of the usage point of TYPE_DECL.
18688 e.g. consider the following code snippet:
18690 class C
18691 {
18692 typedef int myint;
18693 };
18695 template<class U> struct S
18696 {
18697 C::myint mi; // <-- usage point of the typedef C::myint
18698 };
18700 S<char> s;
18702 At S<char> instantiation time, we need to check the access of C::myint
18703 In other words, we need to check the access of the myint typedef through
18704 the C scope. For that purpose, this function will add the myint typedef
18705 and the scope C through which its being accessed to a list of typedefs
18706 tied to the template S. That list will be walked at template instantiation
18707 time and access check performed on each typedefs it contains.
18708 Note that this particular code snippet should yield an error because
18709 myint is private to C. */
18711 void
18713 tree type_decl,
18714 tree scope,
18715 location_t location)
18716 {
18722 /* Make sure we don't append the type to the template twice. */
18731 }
18733 /* Set up the hash tables for template instantiations. */
18735 void
18737 {
18739 hash_specialization,
18740 eq_specializations,
18741 ggc_free);
18743 hash_specialization,
18744 eq_specializations,
18745 ggc_free);
18746 }
18748 /* Print stats about the template hash tables for -fstats. */
18750 void
18752 {
18761 }