| blob | 09d077ade06f91ec354f323fa14639c846bd73c9 |
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 {
912 }
915 }
917 /* Returns nonzero if we can optimize the retrieval of specializations
918 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
919 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
923 {
926 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
927 parameter. */
929 /* The optimized lookup depends on the fact that the
930 template arguments for the member function template apply
931 purely to the containing class, which is not true if the
932 containing class is an explicit or partial
933 specialization. */
937 /* It is possible to have a template that is not a member
938 template and is not a member of a template class:
940 template <typename T>
941 struct S { friend A::f(); };
943 Here, the friend function is a template, but the context does
944 not have template information. The optimized lookup relies
945 on having ARGS be the template arguments for both the class
946 and the function template. */
948 }
950 /* Retrieve the specialization (in the sense of [temp.spec] - a
951 specialization is either an instantiation or an explicit
952 specialization) of TMPL for the given template ARGS. If there is
953 no such specialization, return NULL_TREE. The ARGS are a vector of
954 arguments, or a vector of vectors of arguments, in the case of
955 templates with more than one level of parameters.
957 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
958 then we search for a partial specialization matching ARGS. This
959 parameter is ignored if TMPL is not a class template. */
961 static tree
963 {
969 /* There should be as many levels of arguments as there are
970 levels of parameters. */
975 {
976 tree class_template;
977 tree class_specialization;
979 tree fns;
982 /* The template arguments actually apply to the containing
983 class. Find the class specialization with those
984 arguments. */
986 class_specialization
990 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
991 for the specialization. */
995 /* Iterate through the methods with the indicated name, looking
996 for the one that has an instance of TMPL. */
999 {
1002 /* using-declarations can add base methods to the method vec,
1003 and we don't want those here. */
1006 }
1008 }
1009 else
1010 {
1012 spec_entry elt;
1013 htab_t specializations;
1021 else
1029 }
1032 }
1034 /* Like retrieve_specialization, but for local declarations. */
1036 static tree
1038 {
1039 tree spec;
1047 }
1049 /* Returns nonzero iff DECL is a specialization of TMPL. */
1051 int
1053 {
1054 tree t;
1057 {
1063 }
1064 else
1065 {
1074 }
1077 }
1079 /* Returns nonzero iff DECL is a specialization of friend declaration
1080 FRIEND_DECL according to [temp.friend]. */
1082 bool
1084 {
1091 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1092 of a template class, we want to check if DECL is a specialization
1093 if this. */
1097 {
1098 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1101 }
1106 /* There is nothing to do if this is not a template friend. */
1113 /* [temp.friend/6]
1114 A member of a class template may be declared to be a friend of a
1115 non-template class. In this case, the corresponding member of
1116 every specialization of the class template is a friend of the
1117 class granting friendship.
1119 For example, given a template friend declaration
1121 template <class T> friend void A<T>::f();
1123 the member function below is considered a friend
1125 template <> struct A<int> {
1126 void f();
1127 };
1129 For this type of template friend, TEMPLATE_DEPTH below will be
1130 nonzero. To determine if DECL is a friend of FRIEND, we first
1131 check if the enclosing class is a specialization of another. */
1138 {
1139 /* Next, we check the members themselves. In order to handle
1140 a few tricky cases, such as when FRIEND_DECL's are
1142 template <class T> friend void A<T>::g(T t);
1143 template <class T> template <T t> friend void A<T>::h();
1145 and DECL's are
1147 void A<int>::g(int);
1148 template <int> void A<int>::h();
1150 we need to figure out ARGS, the template arguments from
1151 the context of DECL. This is required for template substitution
1152 of `T' in the function parameter of `g' and template parameter
1153 of `h' in the above examples. Here ARGS corresponds to `int'. */
1160 {
1162 {
1165 else
1167 current_depth++;
1168 }
1170 }
1173 {
1175 tree friend_type;
1176 tree decl_type;
1177 tree friend_args_type;
1178 tree decl_args_type;
1180 /* Make sure that both DECL and FRIEND_DECL are templates or
1181 non-templates. */
1187 {
1188 /* If both are templates, check template parameter list. */
1189 tree friend_parms
1194 friend_parms))
1198 }
1199 else
1207 /* Check if return types match. */
1211 /* Check if function parameter types match, ignoring the
1212 `this' parameter. */
1221 }
1222 else
1223 {
1224 /* DECL is a TYPE_DECL */
1228 /* Make sure that both DECL and FRIEND_DECL are templates or
1229 non-templates. */
1230 is_template
1237 {
1238 tree friend_parms;
1239 /* If both are templates, check the name of the two
1240 TEMPLATE_DECL's first because is_friend didn't. */
1245 /* Now check template parameter list. */
1246 friend_parms
1249 return comp_template_parms
1251 friend_parms);
1252 }
1253 else
1256 }
1257 }
1259 }
1261 /* Register the specialization SPEC as a specialization of TMPL with
1262 the indicated ARGS. IS_FRIEND indicates whether the specialization
1263 is actually just a friend declaration. Returns SPEC, or an
1264 equivalent prior declaration, if available. */
1266 static tree
1268 hashval_t hash)
1269 {
1270 tree fn;
1272 spec_entry elt;
1278 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1279 register it; we want the corresponding TEMPLATE_DECL instead.
1280 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1281 the more obvious `uses_template_parms (spec)' to avoid problems
1282 with default function arguments. In particular, given
1283 something like this:
1285 template <class T> void f(T t1, T t = T())
1287 the default argument expression is not substituted for in an
1288 instantiation unless and until it is actually needed. */
1292 /* We don't put these specializations in the hash table, but we might
1293 want to give an error about a mismatch. */
1295 else
1296 {
1308 else
1310 }
1312 /* We can sometimes try to re-register a specialization that we've
1313 already got. In particular, regenerate_decl_from_template calls
1314 duplicate_decls which will update the specialization list. But,
1315 we'll still get called again here anyhow. It's more convenient
1316 to simply allow this than to try to prevent it. */
1320 {
1322 {
1325 {
1327 fn);
1329 }
1330 else
1331 {
1332 tree clone;
1333 /* This situation should occur only if the first
1334 specialization is an implicit instantiation, the
1335 second is an explicit specialization, and the
1336 implicit instantiation has not yet been used. That
1337 situation can occur if we have implicitly
1338 instantiated a member function and then specialized
1339 it later.
1341 We can also wind up here if a friend declaration that
1342 looked like an instantiation turns out to be a
1343 specialization:
1345 template <class T> void foo(T);
1346 class S { friend void foo<>(int) };
1347 template <> void foo(int);
1349 We transform the existing DECL in place so that any
1350 pointers to it become pointers to the updated
1351 declaration.
1353 If there was a definition for the template, but not
1354 for the specialization, we want this to look as if
1355 there were no definition, and vice versa. */
1358 /* The call to duplicate_decls will have applied
1359 [temp.expl.spec]:
1361 An explicit specialization of a function template
1362 is inline only if it is explicitly declared to be,
1363 and independently of whether its function template
1364 is.
1366 to the primary function; now copy the inline bits to
1367 the various clones. */
1369 {
1374 }
1378 }
1379 }
1381 {
1383 /* Dup decl failed, but this is a new definition. Set the
1384 line number so any errors match this new
1385 definition. */
1389 }
1390 }
1394 /* A specialization must be declared in the same namespace as the
1395 template it is specializing. */
1401 {
1408 /* TMPL is a forward declaration of a template function; keep a list
1409 of all specializations in case we need to reassign them to a friend
1410 template later in tsubst_friend_function. */
1413 }
1416 }
1418 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1419 TMPL and ARGS members, ignores SPEC. */
1421 static int
1423 {
1429 }
1431 /* Returns a hash for a template TMPL and template arguments ARGS. */
1433 static hashval_t
1435 {
1438 }
1440 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1441 ignoring SPEC. */
1443 static hashval_t
1445 {
1448 }
1450 /* Recursively calculate a hash value for a template argument ARG, for use
1451 in the hash tables of template specializations. */
1453 static hashval_t
1455 {
1467 /* We can get one of these when re-hashing a previous entry in the middle
1468 of substituting into a pack expansion. Just look through it. */
1477 {
1485 {
1490 }
1511 {
1514 {
1517 }
1519 }
1534 val = iterative_hash_template_arg
1546 val);
1548 val);
1557 /* layout_type sets structural equality for arrays of
1558 incomplete type, so we can't rely on the canonical type
1559 for hashing. */
1564 /* A lambda can't appear in a template arg, but don't crash on
1565 erroneous input. */
1571 {
1575 val);
1578 /* Otherwise just compare the types during lookup. */
1587 {
1592 }
1593 }
1594 }
1597 }
1599 /* Unregister the specialization SPEC as a specialization of TMPL.
1600 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1601 if the SPEC was listed as a specialization of TMPL.
1603 Note that SPEC has been ggc_freed, so we can't look inside it. */
1605 bool
1607 {
1609 spec_entry elt;
1617 {
1622 }
1625 }
1627 /* Compare an entry in the local specializations hash table P1 (which
1628 is really a pointer to a TREE_LIST) with P2 (which is really a
1629 DECL). */
1631 static int
1633 {
1635 }
1637 /* Hash P1, an entry in the local specializations table. */
1639 static hashval_t
1641 {
1643 }
1645 /* Like register_specialization, but for local declarations. We are
1646 registering SPEC, an instantiation of TMPL. */
1648 static void
1650 {
1656 }
1658 /* TYPE is a class type. Returns true if TYPE is an explicitly
1659 specialized class. */
1661 bool
1663 {
1667 }
1669 /* Print the list of functions at FNS, going through all the overloads
1670 for each element of the list. Alternatively, FNS can not be a
1671 TREE_LIST, in which case it will be printed together with all the
1672 overloads.
1674 MORE and *STR should respectively be FALSE and NULL when the function
1675 is called from the outside. They are used internally on recursive
1676 calls. print_candidates manages the two parameters and leaves NULL
1677 in *STR when it ends. */
1679 static void
1681 {
1687 {
1692 }
1693 else
1694 {
1696 {
1697 /* Pick the prefix string. */
1699 {
1702 }
1706 }
1709 }
1712 {
1715 }
1716 }
1718 /* Print the list of candidate FNS in an error message. */
1720 void
1722 {
1726 }
1728 /* Returns the template (one of the functions given by TEMPLATE_ID)
1729 which can be specialized to match the indicated DECL with the
1730 explicit template args given in TEMPLATE_ID. The DECL may be
1731 NULL_TREE if none is available. In that case, the functions in
1732 TEMPLATE_ID are non-members.
1734 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1735 specialization of a member template.
1737 The TEMPLATE_COUNT is the number of references to qualifying
1738 template classes that appeared in the name of the function. See
1739 check_explicit_specialization for a more accurate description.
1741 TSK indicates what kind of template declaration (if any) is being
1742 declared. TSK_TEMPLATE indicates that the declaration given by
1743 DECL, though a FUNCTION_DECL, has template parameters, and is
1744 therefore a template function.
1746 The template args (those explicitly specified and those deduced)
1747 are output in a newly created vector *TARGS_OUT.
1749 If it is impossible to determine the result, an error message is
1750 issued. The error_mark_node is returned to indicate failure. */
1752 static tree
1754 tree decl,
1758 tmpl_spec_kind tsk)
1759 {
1760 tree fns;
1761 tree targs;
1762 tree explicit_targs;
1764 /* A TREE_LIST of templates of which DECL may be a specialization.
1765 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1766 corresponding TREE_PURPOSE is the set of template arguments that,
1767 when used to instantiate the template, would produce a function
1768 with the signature of DECL. */
1784 /* Check for baselinks. */
1789 {
1792 }
1794 /* Count the number of template headers specified for this
1795 specialization. */
1803 {
1807 {
1808 tree decl_arg_types;
1809 tree fn_arg_types;
1811 /* In case of explicit specialization, we need to check if
1812 the number of template headers appearing in the specialization
1813 is correct. This is usually done in check_explicit_specialization,
1814 but the check done there cannot be exhaustive when specializing
1815 member functions. Consider the following code:
1817 template <> void A<int>::f(int);
1818 template <> template <> void A<int>::f(int);
1820 Assuming that A<int> is not itself an explicit specialization
1821 already, the first line specializes "f" which is a non-template
1822 member function, whilst the second line specializes "f" which
1823 is a template member function. So both lines are syntactically
1824 correct, and check_explicit_specialization does not reject
1825 them.
1827 Here, we can do better, as we are matching the specialization
1828 against the declarations. We count the number of template
1829 headers, and we check if they match TEMPLATE_COUNT + 1
1830 (TEMPLATE_COUNT is the number of qualifying template classes,
1831 plus there must be another header for the member template
1832 itself).
1834 Notice that if header_count is zero, this is not a
1835 specialization but rather a template instantiation, so there
1836 is no check we can perform here. */
1840 /* Check that the number of template arguments at the
1841 innermost level for DECL is the same as for FN. */
1849 /* DECL might be a specialization of FN. */
1853 /* For a non-static member function, we need to make sure
1854 that the const qualification is the same. Since
1855 get_bindings does not try to merge the "this" parameter,
1856 we must do the comparison explicitly. */
1862 /* Skip the "this" parameter and, for constructors of
1863 classes with virtual bases, the VTT parameter. A
1864 full specialization of a constructor will have a VTT
1865 parameter, but a template never will. */
1866 decl_arg_types
1868 fn_arg_types
1871 /* Check that the number of function parameters matches.
1872 For example,
1873 template <class T> void f(int i = 0);
1874 template <> void f<int>();
1875 The specialization f<int> is invalid but is not caught
1876 by get_bindings below. */
1880 /* Function templates cannot be specializations; there are
1881 no partial specializations of functions. Therefore, if
1882 the type of DECL does not match FN, there is no
1883 match. */
1885 {
1889 }
1891 /* See whether this function might be a specialization of this
1892 template. */
1896 /* We cannot deduce template arguments that when used to
1897 specialize TMPL will produce DECL. */
1900 /* Save this template, and the arguments deduced. */
1902 }
1904 /* FN is an ordinary member function, and we need a
1905 specialization of a member template. */
1906 ;
1908 /* We can get IDENTIFIER_NODEs here in certain erroneous
1909 cases. */
1910 ;
1912 /* This is just an ordinary non-member function. Nothing can
1913 be a specialization of that. */
1914 ;
1916 /* Cannot specialize functions that are created implicitly. */
1917 ;
1918 else
1919 {
1920 tree decl_arg_types;
1922 /* This is an ordinary member function. However, since
1923 we're here, we can assume it's enclosing class is a
1924 template class. For example,
1926 template <typename T> struct S { void f(); };
1927 template <> void S<int>::f() {}
1929 Here, S<int>::f is a non-template, but S<int> is a
1930 template class. If FN has the same type as DECL, we
1931 might be in business. */
1934 /* Its enclosing class is an explicit specialization
1935 of a template class. This is not a candidate. */
1940 /* The return types differ. */
1943 /* Adjust the type of DECL in case FN is a static member. */
1950 decl_arg_types))
1951 /* They match! */
1953 }
1954 }
1957 {
1958 /* We have:
1960 [temp.expl.spec]
1962 It is possible for a specialization with a given function
1963 signature to be instantiated from more than one function
1964 template. In such cases, explicit specification of the
1965 template arguments must be used to uniquely identify the
1966 function template specialization being specialized.
1968 Note that here, there's no suggestion that we're supposed to
1969 determine which of the candidate templates is most
1970 specialized. However, we, also have:
1972 [temp.func.order]
1974 Partial ordering of overloaded function template
1975 declarations is used in the following contexts to select
1976 the function template to which a function template
1977 specialization refers:
1979 -- when an explicit specialization refers to a function
1980 template.
1982 So, we do use the partial ordering rules, at least for now.
1983 This extension can only serve to make invalid programs valid,
1984 so it's safe. And, there is strong anecdotal evidence that
1985 the committee intended the partial ordering rules to apply;
1986 the EDG front end has that behavior, and John Spicer claims
1987 that the committee simply forgot to delete the wording in
1988 [temp.expl.spec]. */
1991 {
1994 }
1995 }
1998 {
2006 }
2010 {
2016 }
2018 /* We have one, and exactly one, match. */
2020 {
2023 /* DECL is a re-declaration or partial instantiation of a template
2024 function. */
2027 /* It was a specialization of an ordinary member function in a
2028 template class. */
2030 }
2032 /* It was a specialization of a template. */
2035 {
2040 }
2041 else
2044 }
2046 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2047 but with the default argument values filled in from those in the
2048 TMPL_TYPES. */
2050 static tree
2052 tree tmpl_types)
2053 {
2054 tree new_spec_types;
2062 /* Substitute into the rest of the list. */
2063 new_spec_types =
2067 /* Add the default argument for this parameter. */
2070 new_spec_types);
2071 }
2073 /* DECL is an explicit specialization. Replicate default arguments
2074 from the template it specializes. (That way, code like:
2076 template <class T> void f(T = 3);
2077 template <> void f(double);
2078 void g () { f (); }
2080 works, as required.) An alternative approach would be to look up
2081 the correct default arguments at the call-site, but this approach
2082 is consistent with how implicit instantiations are handled. */
2084 static void
2086 {
2087 tree tmpl;
2088 tree spec_types;
2089 tree tmpl_types;
2090 tree new_spec_types;
2091 tree old_type;
2092 tree new_type;
2093 tree t;
2098 /* See if there's anything we need to do. */
2111 {
2112 /* Remove the this pointer, but remember the object's type for
2113 CV quals. */
2119 {
2120 /* DECL may contain more parameters than TMPL due to the extra
2121 in-charge parameter in constructors and destructors. */
2124 }
2126 {
2129 }
2130 }
2132 /* Compute the merged default arguments. */
2133 new_spec_types =
2136 /* Compute the new FUNCTION_TYPE. */
2138 {
2142 new_spec_types);
2145 /* Put the in-charge parameter back. */
2148 new_spec_types);
2152 new_spec_types);
2153 }
2154 else
2156 new_spec_types);
2162 }
2164 /* Check to see if the function just declared, as indicated in
2165 DECLARATOR, and in DECL, is a specialization of a function
2166 template. We may also discover that the declaration is an explicit
2167 instantiation at this point.
2169 Returns DECL, or an equivalent declaration that should be used
2170 instead if all goes well. Issues an error message if something is
2171 amiss. Returns error_mark_node if the error is not easily
2172 recoverable.
2174 FLAGS is a bitmask consisting of the following flags:
2176 2: The function has a definition.
2177 4: The function is a friend.
2179 The TEMPLATE_COUNT is the number of references to qualifying
2180 template classes that appeared in the name of the function. For
2181 example, in
2183 template <class T> struct S { void f(); };
2184 void S<int>::f();
2186 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2187 classes are not counted in the TEMPLATE_COUNT, so that in
2189 template <class T> struct S {};
2190 template <> struct S<int> { void f(); }
2191 template <> void S<int>::f();
2193 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2194 invalid; there should be no template <>.)
2196 If the function is a specialization, it is marked as such via
2197 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2198 is set up correctly, and it is added to the list of specializations
2199 for that template. */
2201 tree
2203 tree decl,
2206 {
2214 tmpl_spec_kind tsk;
2217 {
2220 else
2222 }
2223 else
2227 {
2230 {
2233 }
2235 {
2237 /* This could be something like:
2239 template <class T> void f(T);
2240 class S { friend void f<>(int); } */
2242 else
2243 {
2244 /* This case handles bogus declarations like template <>
2245 template <class T> void f<int>(); */
2248 declarator);
2250 }
2251 }
2255 /* The error has already been reported in
2256 check_specialization_scope. */
2262 /* Fall through. */
2275 decl);
2278 else
2282 /* Fall through. */
2287 else
2293 {
2294 /* This case handles bogus declarations like template <>
2295 template <class T> void f<int>(); */
2300 else
2302 declarator);
2304 }
2307 /* This is a specialization of a member template, without
2308 specialization the containing class. Something like:
2310 template <class T> struct S {
2311 template <class U> void f (U);
2312 };
2313 template <> template <class U> void S<int>::f(U) {}
2315 That's a specialization -- but of the entire template. */
2321 }
2324 {
2328 {
2332 }
2333 }
2336 {
2340 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2342 {
2343 tree fns;
2348 else
2349 {
2350 /* If there is no class context, the explicit instantiation
2351 must be at namespace scope. */
2354 /* Find the namespace binding, using the declaration
2355 context. */
2359 {
2362 }
2363 else
2364 {
2370 }
2371 }
2374 }
2380 {
2382 /* A specialization in class scope. This is invalid,
2383 but the error will already have been flagged by
2384 check_specialization_scope. */
2386 else
2387 {
2388 /* It's not valid to write an explicit instantiation in
2389 class scope, e.g.:
2391 class C { template void f(); }
2393 This case is caught by the parser. However, on
2394 something like:
2396 template class C { void f(); };
2398 (which is invalid) we can get here. The error will be
2399 issued later. */
2400 ;
2401 }
2404 }
2407 IDENTIFIER_NODE))
2408 {
2409 /* Find the list of functions in ctype that have the same
2410 name as the declared function. */
2416 {
2421 {
2422 /* From [temp.expl.spec]:
2424 If such an explicit specialization for the member
2425 of a class template names an implicitly-declared
2426 special member function (clause _special_), the
2427 program is ill-formed.
2429 Similar language is found in [temp.explicit]. */
2432 }
2435 }
2438 {
2442 }
2443 else
2444 {
2446 tree ovl;
2448 /* For a type-conversion operator, we cannot do a
2449 name-based lookup. We might be looking for `operator
2450 int' which will be a specialization of `operator T'.
2451 So, we find *all* the conversion operators, and then
2452 select from them. */
2460 {
2462 /* There are no more conversion functions. */
2465 /* Glue all these conversion functions together
2466 with those we already have. */
2469 }
2470 }
2473 {
2476 }
2477 else
2479 }
2481 /* Figure out what exactly is being specialized at this point.
2482 Note that for an explicit instantiation, even one for a
2483 member function, we cannot tell apriori whether the
2484 instantiation is for a member template, or just a member
2485 function of a template class. Even if a member template is
2486 being instantiated, the member template arguments may be
2487 elided if they can be deduced from the rest of the
2488 declaration. */
2491 member_specialization,
2492 template_count,
2493 tsk);
2496 /* We couldn't figure out what this declaration was
2497 specializing. */
2499 else
2500 {
2504 {
2505 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2506 is done by do_decl_instantiation later. */
2512 {
2513 /* If TMPL is not the most general template (for
2514 example, if TMPL is a friend template that is
2515 injected into namespace scope), then there will
2516 be too many levels of TARGS. Remove some of them
2517 here. */
2519 tree new_targs;
2526 }
2529 }
2531 /* If we thought that the DECL was a member function, but it
2532 turns out to be specializing a static member function,
2533 make DECL a static member function as well. */
2538 /* If this is a specialization of a member template of a
2539 template class, we want to return the TEMPLATE_DECL, not
2540 the specialization of it. */
2542 {
2547 {
2548 tree parm;
2552 /* We want to use the argument list specified in the
2553 definition, not in the original declaration. */
2558 }
2561 }
2563 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2566 /* Inherit default function arguments from the template
2567 DECL is specializing. */
2570 /* This specialization has the same protection as the
2571 template it specializes. */
2575 /* 7.1.1-1 [dcl.stc]
2577 A storage-class-specifier shall not be specified in an
2578 explicit specialization...
2580 The parser rejects these, so unless action is taken here,
2581 explicit function specializations will always appear with
2582 global linkage.
2584 The action recommended by the C++ CWG in response to C++
2585 defect report 605 is to make the storage class and linkage
2586 of the explicit specialization match the templated function:
2588 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2589 */
2591 {
2595 /* This specialization has the same linkage and visibility as
2596 the function template it specializes. */
2599 {
2602 }
2605 {
2608 }
2609 }
2611 /* If DECL is a friend declaration, declared using an
2612 unqualified name, the namespace associated with DECL may
2613 have been set incorrectly. For example, in:
2615 template <typename T> void f(T);
2616 namespace N {
2617 struct S { friend void f<int>(int); }
2618 }
2620 we will have set the DECL_CONTEXT for the friend
2621 declaration to N, rather than to the global namespace. */
2626 /* This is not really a declaration of a specialization.
2627 It's just the name of an instantiation. But, it's not
2628 a request for an instantiation, either. */
2631 /* This is indeed a specialization. In case of constructors
2632 and destructors, we need in-charge and not-in-charge
2633 versions in V3 ABI. */
2636 /* Register this specialization so that we can find it
2637 again. */
2639 }
2640 }
2643 }
2645 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2646 parameters. These are represented in the same format used for
2647 DECL_TEMPLATE_PARMS. */
2649 int
2651 {
2652 const_tree p1;
2653 const_tree p2;
2661 {
2673 {
2677 /* If either of the template parameters are invalid, assume
2678 they match for the sake of error recovery. */
2691 }
2692 }
2695 /* One set of parameters has more parameters lists than the
2696 other. */
2700 }
2702 /* Determine whether PARM is a parameter pack. */
2704 bool
2706 {
2707 /* Determine if we have a non-type template parameter pack. */
2712 /* If this is a list of template parameters, we could get a
2713 TYPE_DECL or a TEMPLATE_DECL. */
2720 }
2722 /* Determine if T is a function parameter pack. */
2724 bool
2726 {
2730 }
2732 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2733 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2735 tree
2737 {
2744 }
2746 /* Return true iff the function parameter PARAM_DECL was expanded
2747 from the function parameter pack PACK. */
2749 bool
2751 {
2756 /* The parameter pack and its pack arguments have the same
2757 DECL_PARM_INDEX. */
2759 }
2761 /* Determine whether ARGS describes a variadic template args list,
2762 i.e., one that is terminated by a template argument pack. */
2764 static bool
2766 {
2768 tree last_parm;
2782 }
2784 /* Generate a new name for the parameter pack name NAME (an
2785 IDENTIFIER_NODE) that incorporates its */
2787 static tree
2789 {
2790 /* Munge the name to include the parameter index. */
2791 #define NUMBUF_LEN 128
2803 }
2805 /* Return true if T is a primary function
2806 or class template instantiation. */
2808 bool
2810 {
2822 }
2824 /* Return true if PARM is a template template parameter. */
2826 bool
2828 {
2830 }
2832 /* Return the template parameters of T if T is a
2833 primary template instantiation, NULL otherwise. */
2835 tree
2837 {
2842 parms = INNERMOST_TEMPLATE_PARMS
2846 }
2848 /* Return the template parameters of the LEVELth level from the full list
2849 of template parameters PARMS. */
2851 tree
2853 {
2854 tree p;
2865 }
2867 /* Returns the template arguments of T if T is a template instantiation,
2868 NULL otherwise. */
2870 tree
2872 {
2880 }
2882 /* Return the argument pack elements of T if T is a template argument pack,
2883 NULL otherwise. */
2885 tree
2887 {
2893 }
2895 /* Structure used to track the progress of find_parameter_packs_r. */
2896 struct find_parameter_pack_data
2897 {
2898 /* TREE_LIST that will contain all of the parameter packs found by
2899 the traversal. */
2902 /* Set of AST nodes that have been visited by the traversal. */
2904 };
2906 /* Identifies all of the argument packs that occur in a template
2907 argument and appends them to the TREE_LIST inside DATA, which is a
2908 find_parameter_pack_data structure. This is a subroutine of
2909 make_pack_expansion and uses_parameter_packs. */
2910 static tree
2912 {
2918 /* Identify whether this is a parameter pack or not. */
2920 {
2934 {
2935 /* We don't want to walk into the type of a PARM_DECL,
2936 because we don't want to see the type parameter pack. */
2939 }
2943 /* Not a parameter pack. */
2945 }
2948 {
2949 /* Add this parameter pack to the list. */
2951 }
2957 /* This switch statement will return immediately if we don't find a
2958 parameter pack. */
2960 {
2965 /* Check the template itself. */
2968 /* Check the template arguments. */
2984 /* Fall through. */
3025 }
3028 }
3030 /* Determines if the expression or type T uses any parameter packs. */
3031 bool
3033 {
3041 }
3043 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3044 representation a base-class initializer into a parameter pack
3045 expansion. If all goes well, the resulting node will be an
3046 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3047 respectively. */
3048 tree
3050 {
3051 tree result;
3060 {
3061 /* The only time we will see a TREE_LIST here is for a base
3062 class initializer. In this case, the TREE_PURPOSE will be a
3063 _TYPE node (representing the base class expansion we're
3064 initializing) and the TREE_VALUE will be a TREE_LIST
3065 containing the initialization arguments.
3067 The resulting expansion looks somewhat different from most
3068 expansions. Rather than returning just one _EXPANSION, we
3069 return a TREE_LIST whose TREE_PURPOSE is a
3070 TYPE_PACK_EXPANSION containing the bases that will be
3071 initialized. The TREE_VALUE will be identical to the
3072 original TREE_VALUE, which is a list of arguments that will
3073 be passed to each base. We do not introduce any new pack
3074 expansion nodes into the TREE_VALUE (although it is possible
3075 that some already exist), because the TREE_PURPOSE and
3076 TREE_VALUE all need to be expanded together with the same
3077 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3078 resulting TREE_PURPOSE will mention the parameter packs in
3079 both the bases and the arguments to the bases. */
3080 tree purpose;
3081 tree value;
3084 /* Determine which parameter packs will be used by the base
3085 class expansion. */
3092 {
3096 }
3099 {
3100 /* Collect the sets of parameter packs used in each of the
3101 initialization arguments. */
3103 {
3104 /* Determine which parameter packs will be expanded in this
3105 argument. */
3108 }
3109 }
3113 /* Create the pack expansion type for the base type. */
3118 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3119 they will rarely be compared to anything. */
3123 }
3128 /* Build the PACK_EXPANSION_* node. */
3129 result = for_types
3134 {
3135 /* Propagate type and const-expression information. */
3138 }
3139 else
3140 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3141 they will rarely be compared to anything. */
3144 /* Determine which parameter packs will be expanded. */
3150 /* Make sure we found some parameter packs. */
3152 {
3155 else
3158 }
3162 }
3164 /* Checks T for any "bare" parameter packs, which have not yet been
3165 expanded, and issues an error if any are found. This operation can
3166 only be done on full expressions or types (e.g., an expression
3167 statement, "if" condition, etc.), because we could have expressions like:
3169 foo(f(g(h(args)))...)
3171 where "args" is a parameter pack. check_for_bare_parameter_packs
3172 should not be called for the subexpressions args, h(args),
3173 g(h(args)), or f(g(h(args))), because we would produce erroneous
3174 error messages.
3176 Returns TRUE and emits an error if there were bare parameter packs,
3177 returns FALSE otherwise. */
3178 bool
3180 {
3196 {
3199 {
3208 else
3213 else
3217 }
3220 }
3223 }
3225 /* Expand any parameter packs that occur in the template arguments in
3226 ARGS. */
3227 tree
3229 {
3235 /* First, determine if we need to expand anything, and the number of
3236 slots we'll need. */
3238 {
3243 {
3247 else
3249 }
3250 else
3251 {
3253 num_result_args++;
3254 }
3255 }
3257 /* If no expansion is necessary, we're done. */
3261 /* Expand arguments. */
3264 non_default_args_count =
3267 {
3270 {
3277 }
3278 else
3279 {
3282 }
3283 }
3287 }
3289 /* Checks if DECL shadows a template parameter.
3291 [temp.local]: A template-parameter shall not be redeclared within its
3292 scope (including nested scopes).
3294 Emits an error and returns TRUE if the DECL shadows a parameter,
3295 returns FALSE otherwise. */
3297 bool
3299 {
3300 tree olddecl;
3302 /* If we're not in a template, we can't possibly shadow a template
3303 parameter. */
3307 /* Figure out what we're shadowing. */
3312 /* If there's no previous binding for this name, we're not shadowing
3313 anything, let alone a template parameter. */
3317 /* If we're not shadowing a template parameter, we're done. Note
3318 that OLDDECL might be an OVERLOAD (or perhaps even an
3319 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3320 node. */
3324 /* We check for decl != olddecl to avoid bogus errors for using a
3325 name inside a class. We check TPFI to avoid duplicate errors for
3326 inline member templates. */
3334 }
3336 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3337 ORIG_LEVEL, DECL, and TYPE. */
3339 static tree
3343 tree decl,
3344 tree type)
3345 {
3356 }
3358 /* Find the canonical type parameter for the given template type
3359 parameter. Returns the canonical type parameter, which may be TYPE
3360 if no such parameter existed. */
3361 static tree
3363 {
3364 tree list;
3378 else
3379 {
3384 }
3385 }
3387 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3388 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3389 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3390 new one is created. */
3392 static tree
3394 tsubst_flags_t complain)
3395 {
3400 {
3419 /* Template template parameters need this. */
3424 }
3427 }
3429 /* Process information from new template parameter PARM and append it to the
3430 LIST being built. This new parameter is a non-type parameter iff
3431 IS_NON_TYPE is true. This new parameter is a parameter
3432 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3433 PARM_LOC. */
3435 tree
3438 {
3440 tree defval;
3441 tree err_parm_list;
3448 {
3452 {
3456 else
3458 }
3461 }
3462 else
3466 {
3472 {
3476 }
3477 else
3478 {
3479 /* [temp.param]
3481 The top-level cv-qualifiers on the template-parameter are
3482 ignored when determining its type. */
3485 {
3489 }
3492 {
3493 /* This template parameter is not a parameter pack, but it
3494 should be. Complain about "bare" parameter packs. */
3497 /* Recover by calling this a parameter pack. */
3499 }
3500 }
3502 /* A template parameter is not modifiable. */
3511 processing_template_decl,
3516 }
3517 else
3518 {
3519 tree t;
3523 {
3525 /* This is for distinguishing between real templates and template
3526 template parameters */
3530 }
3531 else
3532 {
3534 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3537 }
3544 processing_template_decl,
3548 }
3554 }
3556 /* The end of a template parameter list has been reached. Process the
3557 tree list into a parameter vector, converting each parameter into a more
3558 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3559 as PARM_DECLs. */
3561 tree
3563 {
3568 current_template_parms
3573 {
3579 current_template_parms;
3580 }
3585 }
3587 /* end_template_decl is called after a template declaration is seen. */
3589 void
3591 {
3597 /* This matches the pushlevel in begin_template_parm_list. */
3602 }
3604 /* Within the declaration of a template, return all levels of template
3605 parameters that apply. The template parameters are represented as
3606 a TREE_VEC, in the form documented in cp-tree.h for template
3607 arguments. */
3609 static tree
3611 {
3612 tree header;
3617 /* If there is only one level of template parameters, we do not
3618 create a TREE_VEC of TREE_VECs. Instead, we return a single
3619 TREE_VEC containing the arguments. */
3624 {
3630 {
3633 /* T will be a list if we are called from within a
3634 begin/end_template_parm_list pair, but a vector directly
3635 if within a begin/end_member_template_processing pair. */
3637 {
3641 {
3644 {
3648 {
3649 /* Turn this argument into a TYPE_ARGUMENT_PACK
3650 with a single element, which expands T. */
3652 #ifdef ENABLE_CHECKING
3653 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3655 #endif
3660 }
3661 }
3662 else
3663 {
3667 {
3668 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3669 with a single element, which expands T. */
3672 #ifdef ENABLE_CHECKING
3673 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3675 #endif
3681 }
3682 }
3684 }
3685 }
3686 }
3688 #ifdef ENABLE_CHECKING
3690 #endif
3694 else
3696 }
3699 }
3701 /* Update the declared TYPE by doing any lookups which were thought to be
3702 dependent, but are not now that we know the SCOPE of the declarator. */
3704 tree
3706 {
3717 /* Don't bother building up the args in this case. */
3719 {
3720 /* tsubst in the args corresponding to the template parameters,
3721 including auto if present. Most things will be unchanged, but
3722 make_typename_type and tsubst_qualified_id will resolve
3723 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3726 tree pushed;
3728 {
3732 }
3737 }
3743 {
3746 else
3748 }
3750 }
3752 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3753 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3754 a member template. Used by push_template_decl below. */
3756 static tree
3758 {
3765 }
3767 struct template_parm_data
3768 {
3769 /* The level of the template parameters we are currently
3770 processing. */
3773 /* The index of the specialization argument we are currently
3774 processing. */
3777 /* An array whose size is the number of template parameters. The
3778 elements are nonzero if the parameter has been used in any one
3779 of the arguments processed so far. */
3782 /* An array whose size is the number of template arguments. The
3783 elements are nonzero if the argument makes use of template
3784 parameters of this level. */
3786 };
3788 /* Subroutine of push_template_decl used to see if each template
3789 parameter in a partial specialization is used in the explicit
3790 argument list. If T is of the LEVEL given in DATA (which is
3791 treated as a template_parm_data*), then DATA->PARMS is marked
3792 appropriately. */
3794 static int
3796 {
3802 {
3805 }
3806 else
3807 {
3810 }
3813 {
3816 }
3818 /* Return zero so that for_each_template_parm will continue the
3819 traversal of the tree; we want to mark *every* template parm. */
3821 }
3823 /* Process the partial specialization DECL. */
3825 static tree
3827 {
3833 tree inner_parms;
3846 /* We check that each of the template parameters given in the
3847 partial specialization is used in the argument list to the
3848 specialization. For example:
3850 template <class T> struct S;
3851 template <class T> struct S<T*>;
3853 The second declaration is OK because `T*' uses the template
3854 parameter T, whereas
3856 template <class T> struct S<int>;
3858 is no good. Even trickier is:
3860 template <class T>
3861 struct S1
3862 {
3863 template <class U>
3864 struct S2;
3865 template <class U>
3866 struct S2<T>;
3867 };
3869 The S2<T> declaration is actually invalid; it is a
3870 full-specialization. Of course,
3872 template <class U>
3873 struct S2<T (*)(U)>;
3875 or some such would have been OK. */
3883 {
3888 NULL,
3890 }
3893 {
3894 /* One of the template parms was not used in the
3895 specialization. */
3897 {
3900 }
3903 }
3908 /* [temp.class.spec]
3910 The argument list of the specialization shall not be identical to
3911 the implicit argument list of the primary template. */
3918 /* [temp.class.spec]
3920 A partially specialized non-type argument expression shall not
3921 involve template parameters of the partial specialization except
3922 when the argument expression is a simple identifier.
3924 The type of a template parameter corresponding to a specialized
3925 non-type argument shall not be dependent on a parameter of the
3926 specialization.
3928 Also, we verify that pack expansions only occur at the
3929 end of the argument list. */
3933 {
3940 {
3941 /* Extract the arguments from the argument pack. We'll be
3942 iterating over these in the following loop. */
3945 }
3948 {
3950 /* Get the Jth argument in the parameter pack. */
3954 {
3955 /* Pack expansions must come at the end of the
3956 argument list. */
3959 {
3963 else
3966 }
3967 }
3970 /* We only care about the pattern. */
3976 /* This next line is the `argument expression is not just a
3977 simple identifier' condition and also the `specialized
3978 non-type argument' bit. */
3980 {
3984 arg);
3985 else
3986 {
3987 /* Look at the corresponding template parameter,
3988 marking which template parameters its type depends
3989 upon. */
3993 {
3994 /* We haven't yet initialized TPD2. Do so now. */
3996 /* The number of parameters here is the number in the
3997 main template, which, as checked in the assertion
3998 above, is NARGS. */
4002 }
4004 /* Mark the template parameters. But this time, we're
4005 looking for the template parameters of the main
4006 template, not in the specialization. */
4013 NULL,
4017 {
4018 /* The type depended on some template parameters.
4019 If they are fully specialized in the
4020 specialization, that's OK. */
4029 "type %qT of template argument %qE depends "
4031 "type %qT of template argument %qE depends "
4033 type,
4034 arg);
4035 }
4036 }
4037 }
4038 }
4039 }
4041 /* We should only get here once. */
4049 }
4051 /* Check that a template declaration's use of default arguments and
4052 parameter packs is not invalid. Here, PARMS are the template
4053 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4054 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4055 specialization.
4058 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4059 declaration (but not a definition); 1 indicates a declaration, 2
4060 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4061 emitted for extraneous default arguments.
4063 Returns TRUE if there were no errors found, FALSE otherwise. */
4065 bool
4068 {
4071 tree parm_level;
4074 /* [temp.param]
4076 A default template-argument shall not be specified in a
4077 function template declaration or a function template definition, nor
4078 in the template-parameter-list of the definition of a member of a
4079 class template. */
4082 /* You can't have a function template declaration in a local
4083 scope, nor you can you define a member of a class template in a
4084 local scope. */
4091 /* If this is either a friend defined in the scope of the class
4092 or a member function. */
4098 /* And, if it was a member function, it really was defined in
4099 the scope of the class. */
4102 /* We already checked these parameters when the template was
4103 declared, so there's no need to do it again now. This function
4104 was defined in class scope, but we're processing it's body now
4105 that the class is complete. */
4108 /* Core issue 226 (C++0x only): the following only applies to class
4109 templates. */
4111 {
4112 /* [temp.param]
4114 If a template-parameter has a default template-argument, all
4115 subsequent template-parameters shall have a default
4116 template-argument supplied. */
4118 {
4125 {
4135 {
4137 /* For better subsequent error-recovery, we indicate that
4138 there should have been a default argument. */
4141 }
4143 && !is_partial
4144 && !is_friend_decl
4145 /* Don't complain about an enclosing partial
4146 specialization. */
4151 {
4152 /* A primary class template can only have one
4153 parameter pack, at the end of the template
4154 parameter list. */
4159 else
4167 }
4168 }
4169 }
4170 }
4173 || is_partial
4174 || !is_primary
4176 /* For an ordinary class template, default template arguments are
4177 allowed at the innermost level, e.g.:
4178 template <class T = int>
4179 struct S {};
4180 but, in a partial specialization, they're not allowed even
4181 there, as we have in [temp.class.spec]:
4183 The template parameter list of a specialization shall not
4184 contain default template argument values.
4186 So, for a partial specialization, or for a function template
4187 (in C++98/C++03), we look at all of them. */
4188 ;
4189 else
4190 /* But, for a primary class template that is not a partial
4191 specialization we look at all template parameters except the
4192 innermost ones. */
4195 /* Figure out what error message to issue. */
4208 else
4212 /* If we're inside a class definition, there's no need to
4213 examine the parameters to the class itself. On the one
4214 hand, they will be checked when the class is defined, and,
4215 on the other, default arguments are valid in things like:
4216 template <class T = double>
4217 struct S { template <class U> void f(U); };
4218 Here the default argument for `S' has no bearing on the
4219 declaration of `f'. */
4221 else
4222 /* Check everything. */
4228 {
4235 {
4240 {
4242 {
4249 }
4251 /* Clear out the default argument so that we are not
4252 confused later. */
4254 }
4255 }
4257 /* At this point, if we're still interested in issuing messages,
4258 they must apply to classes surrounding the object declared. */
4262 }
4265 }
4267 /* Worker for push_template_decl_real, called via
4268 for_each_template_parm. DATA is really an int, indicating the
4269 level of the parameters we are interested in. If T is a template
4270 parameter of that level, return nonzero. */
4272 static int
4274 {
4280 else
4283 }
4285 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4286 parameters given by current_template_args, or reuses a
4287 previously existing one, if appropriate. Returns the DECL, or an
4288 equivalent one, if it is replaced via a call to duplicate_decls.
4290 If IS_FRIEND is true, DECL is a friend declaration. */
4292 tree
4294 {
4295 tree tmpl;
4296 tree args;
4297 tree info;
4298 tree ctx;
4302 /* True if the template is a member template, in the sense of
4303 [temp.mem]. */
4309 /* See if this is a partial specialization. */
4318 /* For a friend, we want the context of the friend function, not
4319 the type of which it is a friend. */
4323 /* In the case of a virtual function, we want the class in which
4324 it is defined. */
4326 else
4327 /* Otherwise, if we're currently defining some class, the DECL
4328 is assumed to be a member of the class. */
4337 /* See if this is a primary template. */
4339 /* A friend template that specifies a class context, i.e.
4340 template <typename T> friend void A<T>::f();
4341 is not primary. */
4343 else
4347 {
4352 {
4355 }
4357 {
4359 {
4360 /* [temp.mem]
4362 A destructor shall not be a member template. */
4365 }
4372 {
4373 /* [basic.stc.dynamic.allocation]
4375 An allocation function can be a function
4376 template. ... Template allocation functions shall
4377 have two or more parameters. */
4380 }
4381 }
4385 else
4386 {
4389 }
4390 }
4392 /* Check to see that the rules regarding the use of default
4393 arguments are not being violated. */
4397 /* Ensure that there are no parameter packs in the type of this
4398 declaration that have not been expanded. */
4400 {
4401 /* Check each of the arguments individually to see if there are
4402 any bare parameter packs. */
4408 {
4411 {
4412 /* This is a PARM_DECL that contains unexpanded parameter
4413 packs. We have already complained about this in the
4414 check_for_bare_parameter_packs call, so just replace
4415 these types with ERROR_MARK_NODE. */
4418 }
4422 }
4424 /* Check for bare parameter packs in the return type and the
4425 exception specifiers. */
4427 /* Errors were already issued, set return type to int
4428 as the frontend doesn't expect error_mark_node as
4429 the return type. */
4433 }
4435 {
4438 }
4449 {
4454 /* If DECL is a TYPE_DECL for a class-template, then there won't
4455 be DECL_LANG_SPECIFIC. The information equivalent to
4456 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4460 {
4461 /* Since a template declaration already existed for this
4462 class-type, we must be redeclaring it here. Make sure
4463 that the redeclaration is valid. */
4465 current_template_parms);
4466 /* We don't need to create a new TEMPLATE_DECL; just use the
4467 one we already had. */
4469 }
4470 else
4471 {
4473 member_template_p);
4478 {
4479 /* A specialization of a member template of a template
4480 class. */
4484 }
4485 }
4486 }
4487 else
4488 {
4494 {
4497 }
4505 {
4506 tree new_tmpl;
4508 /* The declaration is a specialization of a member
4509 template, declared outside the class. Therefore, the
4510 innermost template arguments will be NULL, so we
4511 replace them with the arguments determined by the
4512 earlier call to check_explicit_specialization. */
4515 new_tmpl
4517 member_template_p);
4527 args,
4530 }
4532 /* Make sure the template headers we got make sense. */
4537 {
4540 }
4541 else
4543 {
4548 {
4552 else
4557 }
4562 /* Can happen in erroneous input. */
4564 else
4568 }
4570 /* Check that the parms are used in the appropriate qualifying scopes
4571 in the declarator. */
4575 {
4581 /* Avoid crash in import_export_decl. */
4584 }
4585 }
4590 /* Push template declarations for global functions and types. Note
4591 that we do not try to push a global template friend declared in a
4592 template class; such a thing may well depend on the template
4593 parameters of the class. */
4596 {
4601 /* Hide template friend classes that haven't been declared yet. */
4603 {
4606 }
4607 }
4610 {
4616 {
4619 /* It is a conversion operator. See if the type converted to
4620 depends on innermost template operands. */
4623 depth))
4625 }
4627 /* Give template template parms a DECL_CONTEXT of the template
4628 for which they are a parameter. */
4631 {
4635 }
4636 }
4638 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4639 back to its most general template. If TMPL is a specialization,
4640 ARGS may only have the innermost set of arguments. Add the missing
4641 argument levels if necessary. */
4653 }
4655 tree
4657 {
4659 }
4661 /* Called when a class template TYPE is redeclared with the indicated
4662 template PARMS, e.g.:
4664 template <class T> struct S;
4665 template <class T> struct S {}; */
4667 bool
4669 {
4670 tree tmpl;
4671 tree tmpl_parms;
4675 {
4678 }
4682 /* The type is nested in some template class. Nothing to worry
4683 about here; there are no new template parameters for the nested
4684 type. */
4688 {
4690 tmpl);
4692 }
4698 {
4708 }
4711 {
4712 tree tmpl_parm;
4713 tree parm;
4714 tree tmpl_default;
4715 tree parm_default;
4729 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4730 TEMPLATE_DECL. */
4740 {
4744 }
4747 {
4748 /* We have in [temp.param]:
4750 A template-parameter may not be given default arguments
4751 by two different declarations in the same scope. */
4756 }
4759 /* Update the previous template parameters (which are the ones
4760 that will really count) with the new default value. */
4763 /* Update the new parameters, too; they'll be used as the
4764 parameters for any members. */
4766 }
4769 }
4771 /* Simplify EXPR if it is a non-dependent expression. Returns the
4772 (possibly simplified) expression. */
4774 tree
4776 {
4780 /* If we're in a template, but EXPR isn't value dependent, simplify
4781 it. We're supposed to treat:
4783 template <typename T> void f(T[1 + 1]);
4784 template <typename T> void f(T[2]);
4786 as two declarations of the same function, for example. */
4790 {
4791 HOST_WIDE_INT saved_processing_template_decl;
4797 tf_error,
4802 }
4804 }
4806 /* EXPR is an expression which is used in a constant-expression context.
4807 For instance, it could be a VAR_DECL with a constant initializer.
4808 Extract the innermost constant expression.
4810 This is basically a more powerful version of
4811 integral_constant_value, which can be used also in templates where
4812 initializers can maintain a syntactic rather than semantic form
4813 (even if they are non-dependent, for access-checking purposes). */
4815 static tree
4817 {
4819 do
4820 {
4823 }
4827 }
4829 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4830 must be a function or a pointer-to-function type, as specified
4831 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4832 and check that the resulting function has external linkage. */
4834 static tree
4836 {
4850 /* [temp.arg.nontype]/1
4852 A template-argument for a non-type, non-template template-parameter
4853 shall be one of:
4854 [...]
4855 -- the address of an object or function with external linkage. */
4857 {
4862 }
4865 }
4867 /* Subroutine of convert_nontype_argument.
4868 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4869 Emit an error otherwise. */
4871 static bool
4873 {
4881 }
4883 /* Returns TRUE iff the address of OP is value-dependent.
4885 14.6.2.4 [temp.dep.temp]:
4886 A non-integral non-type template-argument is dependent if its type is
4887 dependent or it has either of the following forms
4888 qualified-id
4889 & qualified-id
4890 and contains a nested-name-specifier which specifies a class-name that
4891 names a dependent type.
4893 We generalize this to just say that the address of a member of a
4894 dependent class is value-dependent; the above doesn't cover the
4895 address of a static data member named with an unqualified-id. */
4897 static bool
4899 {
4900 /* We could use get_inner_reference here, but there's no need;
4901 this is only relevant for template non-type arguments, which
4902 can only be expressed as &id-expression. */
4904 {
4908 }
4911 }
4913 /* Attempt to convert the non-type template parameter EXPR to the
4914 indicated TYPE. If the conversion is successful, return the
4915 converted value. If the conversion is unsuccessful, return
4916 NULL_TREE if we issued an error message, or error_mark_node if we
4917 did not. We issue error messages for out-and-out bad template
4918 parameters, but not simply because the conversion failed, since we
4919 might be just trying to do argument deduction. Both TYPE and EXPR
4920 must be non-dependent.
4922 The conversion follows the special rules described in
4923 [temp.arg.nontype], and it is much more strict than an implicit
4924 conversion.
4926 This function is called twice for each template argument (see
4927 lookup_template_class for a more accurate description of this
4928 problem). This means that we need to handle expressions which
4929 are not valid in a C++ source, but can be created from the
4930 first call (for instance, casts to perform conversions). These
4931 hacks can go away after we fix the double coercion problem. */
4933 static tree
4935 {
4936 tree expr_type;
4938 /* Detect immediately string literals as invalid non-type argument.
4939 This special-case is not needed for correctness (we would easily
4940 catch this later), but only to provide better diagnostic for this
4941 common user mistake. As suggested by DR 100, we do not mention
4942 linkage issues in the diagnostic as this is not the point. */
4944 {
4949 }
4951 /* Add the ADDR_EXPR now for the benefit of
4952 value_dependent_expression_p. */
4956 /* If we are in a template, EXPR may be non-dependent, but still
4957 have a syntactic, rather than semantic, form. For example, EXPR
4958 might be a SCOPE_REF, rather than the VAR_DECL to which the
4959 SCOPE_REF refers. Preserving the qualifying scope is necessary
4960 so that access checking can be performed when the template is
4961 instantiated -- but here we need the resolved form so that we can
4962 convert the argument. */
4966 else
4973 else
4976 /* HACK: Due to double coercion, we can get a
4977 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4978 which is the tree that we built on the first call (see
4979 below when coercing to reference to object or to reference to
4980 function). We just strip everything and get to the arg.
4981 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4982 for examples. */
4984 {
4986 {
4987 /* ??? Maybe we could use convert_from_reference here, but we
4988 would need to relax its constraints because the NOP_EXPR
4989 could actually change the type to something more cv-qualified,
4990 and this is not folded by convert_from_reference. */
5001 }
5003 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5004 parameter is a pointer to object, through decay and
5005 qualification conversion. Let's strip everything. */
5007 {
5011 /* Skip the ADDR_EXPR only if it is part of the decay for
5012 an array. Otherwise, it is part of the original argument
5013 in the source code. */
5017 }
5018 }
5020 /* [temp.arg.nontype]/5, bullet 1
5022 For a non-type template-parameter of integral or enumeration type,
5023 integral promotions (_conv.prom_) and integral conversions
5024 (_conv.integral_) are applied. */
5026 {
5031 /* Notice that there are constant expressions like '4 % 0' which
5032 do not fold into integer constants. */
5034 {
5038 }
5040 /* At this point, an implicit conversion does what we want,
5041 because we already know that the expression is of integral
5042 type. */
5047 /* Conversion was allowed: fold it to a bare integer constant. */
5049 }
5050 /* [temp.arg.nontype]/5, bullet 2
5052 For a non-type template-parameter of type pointer to object,
5053 qualification conversions (_conv.qual_) and the array-to-pointer
5054 conversion (_conv.array_) are applied. */
5056 {
5057 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5059 A template-argument for a non-type, non-template template-parameter
5060 shall be one of: [...]
5062 -- the name of a non-type template-parameter;
5063 -- the address of an object or function with external linkage, [...]
5064 expressed as "& id-expression" where the & is optional if the name
5065 refers to a function or array, or if the corresponding
5066 template-parameter is a reference.
5068 Here, we do not care about functions, as they are invalid anyway
5069 for a parameter of type pointer-to-object. */
5072 /* Non-type template parameters are OK. */
5073 ;
5076 {
5078 {
5080 "because %qD is a variable, not the address of "
5084 }
5085 /* Other values, like integer constants, might be valid
5086 non-type arguments of some other type. */
5088 }
5089 else
5090 {
5091 tree decl;
5096 {
5101 }
5103 {
5108 }
5109 }
5118 }
5119 /* [temp.arg.nontype]/5, bullet 3
5121 For a non-type template-parameter of type reference to object, no
5122 conversions apply. The type referred to by the reference may be more
5123 cv-qualified than the (otherwise identical) type of the
5124 template-argument. The template-parameter is bound directly to the
5125 template-argument, which must be an lvalue. */
5127 {
5129 expr_type))
5133 {
5137 }
5140 {
5144 }
5146 /* [temp.arg.nontype]/1
5148 A template-argument for a non-type, non-template template-parameter
5149 shall be one of: [...]
5151 -- the address of an object or function with external linkage. */
5154 {
5157 {
5159 "because a reference variable does not have a constant "
5162 }
5163 }
5166 {
5171 }
5174 {
5179 }
5182 }
5183 /* [temp.arg.nontype]/5, bullet 4
5185 For a non-type template-parameter of type pointer to function, only
5186 the function-to-pointer conversion (_conv.func_) is applied. If the
5187 template-argument represents a set of overloaded functions (or a
5188 pointer to such), the matching function is selected from the set
5189 (_over.over_). */
5191 {
5192 /* If the argument is a template-id, we might not have enough
5193 context information to decay the pointer. */
5195 {
5199 }
5206 {
5210 }
5211 }
5212 /* [temp.arg.nontype]/5, bullet 5
5214 For a non-type template-parameter of type reference to function, no
5215 conversions apply. If the template-argument represents a set of
5216 overloaded functions, the matching function is selected from the set
5217 (_over.over_). */
5219 {
5221 {
5226 }
5233 }
5234 /* [temp.arg.nontype]/5, bullet 6
5236 For a non-type template-parameter of type pointer to member function,
5237 no conversions apply. If the template-argument represents a set of
5238 overloaded member functions, the matching member function is selected
5239 from the set (_over.over_). */
5241 {
5246 /* [temp.arg.nontype] bullet 1 says the pointer to member
5247 expression must be a pointer-to-member constant. */
5251 /* There is no way to disable standard conversions in
5252 resolve_address_of_overloaded_function (called by
5253 instantiate_type). It is possible that the call succeeded by
5254 converting &B::I to &D::I (where B is a base of D), so we need
5255 to reject this conversion here.
5257 Actually, even if there was a way to disable standard conversions,
5258 it would still be better to reject them here so that we can
5259 provide a superior diagnostic. */
5261 {
5265 /* If we are just one standard conversion off, explain. */
5270 }
5271 }
5272 /* [temp.arg.nontype]/5, bullet 7
5274 For a non-type template-parameter of type pointer to data member,
5275 qualification conversions (_conv.qual_) are applied. */
5277 {
5278 /* [temp.arg.nontype] bullet 1 says the pointer to member
5279 expression must be a pointer-to-member constant. */
5286 }
5287 /* A template non-type parameter must be one of the above. */
5288 else
5291 /* Sanity check: did we actually convert the argument to the
5292 right type? */
5295 }
5297 /* Subroutine of coerce_template_template_parms, which returns 1 if
5298 PARM_PARM and ARG_PARM match using the rule for the template
5299 parameters of template template parameters. Both PARM and ARG are
5300 template parameters; the rest of the arguments are the same as for
5301 coerce_template_template_parms.
5302 */
5303 static int
5305 tree arg,
5306 tsubst_flags_t complain,
5307 tree in_decl,
5308 tree outer_args)
5309 {
5318 {
5320 /* We encounter instantiations of templates like
5321 template <template <template <class> class> class TT>
5322 class C; */
5323 {
5330 }
5331 /* Fall through. */
5336 /* Argument is a parameter pack but parameter is not. */
5341 /* The tsubst call is used to handle cases such as
5343 template <int> class C {};
5344 template <class T, template <T> class TT> class D {};
5345 D<int, C> d;
5347 i.e. the parameter list of TT depends on earlier parameters. */
5349 && !same_type_p
5356 /* Argument is a parameter pack but parameter is not. */
5363 }
5366 }
5369 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5370 template template parameters. Both PARM_PARMS and ARG_PARMS are
5371 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5372 or PARM_DECL.
5374 Consider the example:
5375 template <class T> class A;
5376 template<template <class U> class TT> class B;
5378 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5379 the parameters to A, and OUTER_ARGS contains A. */
5381 static int
5383 tree arg_parms,
5384 tsubst_flags_t complain,
5385 tree in_decl,
5386 tree outer_args)
5387 {
5398 /* Determine whether we have a parameter pack at the end of the
5399 template template parameter's template parameter list. */
5401 {
5408 {
5422 }
5423 }
5429 /* Check all of the template parameters except the parameter pack at
5430 the end (if any). */
5432 {
5441 outer_args))
5444 }
5447 {
5448 /* Check each of the template parameters in the template
5449 argument against the template parameter pack at the end of
5450 the template template parameter. */
5457 {
5464 outer_args))
5466 }
5467 }
5470 }
5472 /* Verifies that the deduced template arguments (in TARGS) for the
5473 template template parameters (in TPARMS) represent valid bindings,
5474 by comparing the template parameter list of each template argument
5475 to the template parameter list of its corresponding template
5476 template parameter, in accordance with DR150. This
5477 routine can only be called after all template arguments have been
5478 deduced. It will return TRUE if all of the template template
5479 parameter bindings are okay, FALSE otherwise. */
5480 bool
5482 {
5486 /* We're dealing with template parms in this process. */
5492 {
5497 {
5502 {
5503 /* Look inside the argument pack. */
5506 }
5509 {
5513 /* Extract the next argument from the argument
5514 pack. */
5518 /* Look at the pattern of the pack expansion. */
5521 /* Extract the template parameters from the template
5522 argument. */
5528 /* Verify that we can coerce the template template
5529 parameters from the template argument to the template
5530 parameter. This requires an exact match. */
5532 && !coerce_template_template_parms
5534 targ_parms,
5535 tf_none,
5536 tparm,
5537 targs))
5538 {
5541 }
5542 }
5543 }
5544 }
5546 out:
5550 }
5552 /* Convert the indicated template ARG as necessary to match the
5553 indicated template PARM. Returns the converted ARG, or
5554 error_mark_node if the conversion was unsuccessful. Error and
5555 warning messages are issued under control of COMPLAIN. This
5556 conversion is for the Ith parameter in the parameter list. ARGS is
5557 the full set of template arguments deduced so far. */
5559 static tree
5561 tree arg,
5562 tree args,
5563 tsubst_flags_t complain,
5565 tree in_decl)
5566 {
5567 tree orig_arg;
5568 tree val;
5573 {
5574 /* The template argument was the name of some
5575 member function. That's usually
5576 invalid, but static members are OK. In any
5577 case, grab the underlying fields/functions
5578 and issue an error later if required. */
5581 }
5589 /* When determining whether an argument pack expansion is a template,
5590 look at the pattern. */
5594 /* Deal with an injected-class-name used as a template template arg. */
5596 {
5599 {
5607 }
5608 }
5610 is_tmpl_type =
5625 {
5631 typename_type,
5635 }
5637 {
5639 {
5641 {
5651 else
5653 }
5654 }
5656 }
5658 {
5660 {
5666 else
5668 }
5670 }
5673 {
5675 {
5677 /* The number of argument required is not known yet.
5678 Just accept it for now. */
5680 else
5681 {
5683 tree argparm;
5689 args))
5690 {
5693 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5694 TEMPLATE_DECL. */
5696 {
5701 }
5702 }
5703 else
5704 {
5706 {
5712 }
5715 }
5716 }
5717 }
5718 else
5720 /* We only form one instance of each template specialization.
5721 Therefore, if we use a non-canonical variant (i.e., a
5722 typedef), any future messages referring to the type will use
5723 the typedef, which is confusing if those future uses do not
5724 themselves also use the typedef. */
5727 }
5728 else
5729 {
5736 {
5739 else
5740 {
5741 /* Not sure if this is reachable, but it doesn't hurt
5742 to be robust. */
5745 }
5746 }
5748 /* We used to call digest_init here. However, digest_init
5749 will report errors, which we don't want when complain
5750 is zero. More importantly, digest_init will try too
5751 hard to convert things: for example, `0' should not be
5752 converted to pointer type at this point according to
5753 the standard. Accepting this is not merely an
5754 extension, since deciding whether or not these
5755 conversions can occur is part of determining which
5756 function template to call, or whether a given explicit
5757 argument specification is valid. */
5759 else
5768 {
5769 /* Strip typedefs from the SCOPE_REF. */
5774 }
5775 }
5778 }
5780 /* Coerces the remaining template arguments in INNER_ARGS (from
5781 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5782 Returns the coerced argument pack. PARM_IDX is the position of this
5783 parameter in the template parameter list. ARGS is the original
5784 template argument list. */
5785 static tree
5788 tree args,
5789 tree inner_args,
5791 tree new_args,
5793 tree in_decl,
5794 tsubst_flags_t complain)
5795 {
5798 tree packed_args;
5799 tree argument_pack;
5809 {
5810 /* When the template parameter is a non-type template
5811 parameter pack whose type uses parameter packs, we need
5812 to look at each of the template arguments
5813 separately. Build a vector of the types for these
5814 non-type template parameters in PACKED_TYPES. */
5815 tree expansion
5823 /* Check that we have the right number of arguments. */
5827 {
5828 int needed_parms
5833 }
5835 /* If we aren't able to check the actual arguments now
5836 (because they haven't been expanded yet), we can at least
5837 verify that all of the types used for the non-type
5838 template parameter pack are, in fact, valid for non-type
5839 template parameters. */
5842 {
5845 {
5849 }
5850 }
5851 }
5853 /* Convert the remaining arguments, which will be a part of the
5854 parameter pack "parm". */
5856 {
5861 {
5862 /* When we have a vector of types (corresponding to the
5863 non-type template parameter pack that uses parameter
5864 packs in its type, as mention above), and the
5865 argument is not an expansion (which expands to a
5866 currently unknown number of arguments), clone the
5867 parm and give it the next type in PACKED_TYPES. */
5871 }
5876 in_decl);
5880 }
5885 else
5886 {
5891 }
5894 #ifdef ENABLE_CHECKING
5897 #endif
5899 }
5901 /* Convert all template arguments to their appropriate types, and
5902 return a vector containing the innermost resulting template
5903 arguments. If any error occurs, return error_mark_node. Error and
5904 warning messages are issued under control of COMPLAIN.
5906 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5907 for arguments not specified in ARGS. Otherwise, if
5908 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5909 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5910 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5911 ARGS. */
5913 static tree
5915 tree args,
5916 tree in_decl,
5917 tsubst_flags_t complain,
5920 {
5922 tree inner_args;
5923 tree new_args;
5924 tree new_inner_args;
5928 /* When used as a boolean value, indicates whether this is a
5929 variadic template parameter list. Since it's an int, we can also
5930 subtract it from nparms to get the number of non-variadic
5931 parameters. */
5936 /* Determine if there are any parameter packs. */
5938 {
5942 }
5945 /* If there are 0 or 1 parameter packs, we need to expand any argument
5946 packs so that we can deduce a parameter pack from some non-packed args
5947 followed by an argument pack, as in variadic85.C. If there are more
5948 than that, we need to leave argument packs intact so the arguments are
5949 assigned to the right parameter packs. This should only happen when
5950 dealing with a nested class inside a partial specialization of a class
5951 template, as in variadic92.C. */
5958 && require_all_args
5959 && (!use_default_args
5962 {
5964 {
5966 {
5970 }
5971 else
5977 }
5980 }
5982 /* We need to evaluate the template arguments, even though this
5983 template-id may be nested within a "sizeof". */
5991 {
5992 tree arg;
5993 tree parm;
5995 /* Get the Ith template parameter. */
5999 {
6002 }
6004 /* Calculate the next argument. */
6007 else
6012 {
6013 /* All remaining arguments will be placed in the
6014 template parameter pack PARM. */
6020 /* Store this argument. */
6022 lost++;
6025 /* We are done with all of the arguments. */
6029 }
6031 {
6033 {
6035 {
6036 /* FIXME this restriction was removed by N2555; see
6037 bug 35722. */
6038 /* If ARG is a pack expansion, but PARM is not a
6039 template parameter pack (if it were, we would have
6040 handled it above), we're trying to expand into a
6041 fixed-length argument list. */
6045 else
6048 }
6050 }
6051 }
6053 {
6054 /* There must be a default arg in this case. */
6057 /* The position of the first default template argument,
6058 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6059 Record that. */
6062 }
6063 else
6067 {
6070 }
6072 /* This only occurs if there was an error in the template
6073 parameter list itself (which we would already have
6074 reported) that we are trying to recover from, e.g., a class
6075 template with a parameter list such as
6076 template<typename..., typename>. */
6078 else
6084 lost++;
6086 }
6093 #ifdef ENABLE_CHECKING
6097 #endif
6100 }
6102 /* Returns 1 if template args OT and NT are equivalent. */
6104 static int
6106 {
6111 /* For member templates */
6118 {
6135 }
6137 {
6138 /* We get here probably because we are in the middle of substituting
6139 into the pattern of a pack expansion. In that case the
6140 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6141 interested in. So we want to use the initial pack argument for
6142 the comparison. */
6147 }
6152 else
6154 }
6156 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6157 of template arguments. Returns 0 otherwise. */
6159 int
6161 {
6168 {
6174 }
6176 }
6178 static void
6180 {
6190 /* We are called both from instantiate_decl, where we've already had a
6191 tinst_level pushed, and instantiate_template, where we haven't.
6192 Compensate. */
6203 else
6212 }
6215 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6216 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6217 documentation for TEMPLATE_ID_EXPR. */
6219 tree
6221 {
6222 tree type;
6232 {
6234 unknown_type_node,
6236 arglist);
6238 }
6245 }
6247 /* Within the scope of a template class S<T>, the name S gets bound
6248 (in build_self_reference) to a TYPE_DECL for the class, not a
6249 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6250 or one of its enclosing classes, and that type is a template,
6251 return the associated TEMPLATE_DECL. Otherwise, the original
6252 DECL is returned.
6254 Also handle the case when DECL is a TREE_LIST of ambiguous
6255 injected-class-names from different bases. */
6257 tree
6259 {
6263 /* DR 176: A lookup that finds an injected-class-name (10.2
6264 [class.member.lookup]) can result in an ambiguity in certain cases
6265 (for example, if it is found in more than one base class). If all of
6266 the injected-class-names that are found refer to specializations of
6267 the same class template, and if the name is followed by a
6268 template-argument-list, the reference refers to the class template
6269 itself and not a specialization thereof, and is not ambiguous. */
6271 {
6274 {
6280 }
6283 else
6285 }
6291 }
6293 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6294 parameters, find the desired type.
6296 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6298 IN_DECL, if non-NULL, is the template declaration we are trying to
6299 instantiate.
6301 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6302 the class we are looking up.
6304 Issue error and warning messages under control of COMPLAIN.
6306 If the template class is really a local class in a template
6307 function, then the FUNCTION_CONTEXT is the function in which it is
6308 being instantiated.
6310 ??? Note that this function is currently called *twice* for each
6311 template-id: the first time from the parser, while creating the
6312 incomplete type (finish_template_type), and the second type during the
6313 real instantiation (instantiate_template_class). This is surely something
6314 that we want to avoid. It also causes some problems with argument
6315 coercion (see convert_nontype_argument for more information on this). */
6317 tree
6319 tree arglist,
6320 tree in_decl,
6321 tree context,
6323 tsubst_flags_t complain)
6324 {
6326 tree t;
6329 spec_entry elt;
6330 hashval_t hash;
6335 {
6339 else
6340 {
6347 }
6350 }
6352 {
6355 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6356 an implicit typename for the second A. Deal with it. */
6361 {
6364 }
6365 }
6368 {
6371 }
6375 {
6379 }
6381 /* Issue an error message if we didn't find a template. */
6383 {
6387 }
6390 /* Make sure it's a user visible template, if it was named by
6391 the user. */
6394 {
6396 {
6400 }
6402 }
6407 {
6408 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6409 template arguments */
6411 tree parm;
6412 tree arglist2;
6413 tree outer;
6417 /* Consider an example where a template template parameter declared as
6419 template <class T, class U = std::allocator<T> > class TT
6421 The template parameter level of T and U are one level larger than
6422 of TT. To proper process the default argument of U, say when an
6423 instantiation `TT<int>' is seen, we need to build the full
6424 arguments containing {int} as the innermost level. Outer levels,
6425 available when not appearing as default template argument, can be
6426 obtained from the arguments of the enclosing template.
6428 Suppose that TT is later substituted with std::vector. The above
6429 instantiation is `TT<int, std::allocator<T> >' with TT at
6430 level 1, and T at level 2, while the template arguments at level 1
6431 becomes {std::vector} and the inner level 2 is {int}. */
6437 /* This is an argument of the current template, so we haven't set
6438 DECL_CONTEXT yet. */
6445 complain,
6455 }
6456 else
6457 {
6459 tree gen_tmpl;
6460 tree type_decl;
6473 {
6474 /* We've been given an incomplete set of template arguments.
6475 For example, given:
6477 template <class T> struct S1 {
6478 template <class U> struct S2 {};
6479 template <class U> struct S2<U*> {};
6480 };
6482 we will be called with an ARGLIST of `U*', but the
6483 TEMPLATE will be `template <class T> template
6484 <class U> struct S1<T>::S2'. We must fill in the missing
6485 arguments. */
6486 arglist
6488 arglist);
6490 }
6492 /* Now we should have enough arguments. */
6495 /* From here on, we're only interested in the most general
6496 template. */
6498 /* Calculate the BOUND_ARGS. These will be the args that are
6499 actually tsubst'd into the definition to create the
6500 instantiation. */
6502 {
6503 /* We have multiple levels of arguments to coerce, at once. */
6513 {
6516 complain,
6520 /* Don't process further if one of the levels fails. */
6522 {
6523 /* Restore the ARGLIST to its full size. */
6526 }
6530 /* We temporarily reduce the length of the ARGLIST so
6531 that coerce_template_parms will see only the arguments
6532 corresponding to the template parameters it is
6533 examining. */
6535 }
6537 /* Restore the ARGLIST to its full size. */
6541 }
6542 else
6543 arglist
6546 gen_tmpl,
6547 complain,
6552 /* We were unable to bind the arguments. */
6555 /* In the scope of a template class, explicit references to the
6556 template class refer to the type of the template, not any
6557 instantiation of it. For example, in:
6559 template <class T> class C { void f(C<T>); }
6561 the `C<T>' is just the same as `C'. Outside of the
6562 class, however, such a reference is an instantiation. */
6566 /* comp_template_args is expensive, check it last. */
6568 arglist))
6571 /* If we already have this specialization, return it. */
6583 /* If the deduced arguments are invalid, then the binding
6584 failed. */
6588 complain))
6595 {
6600 }
6607 /* Create the type. */
6609 {
6611 {
6617 }
6618 else
6619 {
6620 /* We don't want to call start_enum for this type, since
6621 the values for the enumeration constants may involve
6622 template parameters. And, no one should be interested
6623 in the enumeration constants for such a type. */
6626 }
6627 }
6628 else
6629 {
6636 /* A local class. Make sure the decl gets registered properly. */
6641 /* This instantiation is another name for the primary
6642 template type. Set the TYPE_CANONICAL field
6643 appropriately. */
6646 /* Some of the template arguments require structural
6647 equality testing, so this template class requires
6648 structural equality testing. */
6650 }
6652 /* If we called start_enum or pushtag above, this information
6653 will already be set up. */
6655 {
6662 }
6663 else
6671 {
6674 }
6676 /* Let's consider the explicit specialization of a member
6677 of a class template specialization that is implicitely instantiated,
6678 e.g.:
6679 template<class T>
6680 struct S
6681 {
6682 template<class U> struct M {}; //#0
6683 };
6685 template<>
6686 template<>
6687 struct S<int>::M<char> //#1
6688 {
6689 int i;
6690 };
6691 [temp.expl.spec]/4 says this is valid.
6693 In this case, when we write:
6694 S<int>::M<char> m;
6696 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
6697 the one of #0.
6699 When we encounter #1, we want to store the partial instantiation
6700 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
6702 For all cases other than this "explicit specialization of member of a
6703 class template", we just want to store the most general template into
6704 the CLASSTYPE_TI_TEMPLATE of M.
6706 This case of "explicit specialization of member of a class template"
6707 only happens when:
6708 1/ the enclosing class is an instantiation of, and therefore not
6709 the same as, the context of the most general template, and
6710 2/ we aren't looking at the partial instantiation itself, i.e.
6711 the innermost arguments are not the same as the innermost parms of
6712 the most general template.
6714 So it's only when 1/ and 2/ happens that we want to use the partial
6715 instantiation of the member template in lieu of its most general
6716 template. */
6720 /* the enclosing class must be an instantiation... */
6723 {
6724 tree partial_inst_args;
6727 partial_inst_args =
6733 use_partial_inst_tmpl =
6734 /*...and we must not be looking at the partial instantiation
6735 itself. */
6737 partial_inst_args);
6738 }
6741 /* This case is easy; there are no member templates involved. */
6743 else
6744 {
6745 /* This is a full instantiation of a member template. Find
6746 the partial instantiation of which this is an instance. */
6748 /* Temporarily reduce by one the number of levels in the ARGLIST
6749 so as to avoid comparing the last set of arguments. */
6754 }
6764 /* Note this use of the partial instantiation so we can check it
6765 later in maybe_process_partial_specialization. */
6771 /* Now that the type has been registered on the instantiations
6772 list, we set up the enumerators. Because the enumeration
6773 constants may involve the enumeration type itself, we make
6774 sure to register the type first, and then create the
6775 constants. That way, doing tsubst_expr for the enumeration
6776 constants won't result in recursive calls here; we'll find
6777 the instantiation and exit above. */
6781 /* If the type makes use of template parameters, the
6782 code that generates debugging information will crash. */
6785 /* Possibly limit visibility based on template args. */
6790 }
6792 }
6793 \f
6794 struct pair_fn_data
6795 {
6796 tree_fn_t fn;
6798 /* True when we should also visit template parameters that occur in
6799 non-deduced contexts. */
6802 };
6804 /* Called from for_each_template_parm via walk_tree. */
6806 static tree
6808 {
6821 {
6825 /* Fall through. */
6848 /* Since we're not going to walk subtrees, we have to do this
6849 explicitly here. */
6853 /* Fall through. */
6856 /* Check the return type. */
6861 /* Check the parameter types. Since default arguments are not
6862 instantiated until they are needed, the TYPE_ARG_TYPES may
6863 contain expressions that involve template parameters. But,
6864 no-one should be looking at them yet. And, once they're
6865 instantiated, they don't contain template parameters, so
6866 there's no point in looking at them then, either. */
6867 {
6868 tree parm;
6875 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6876 want walk_tree walking into them itself. */
6878 }
6895 /* Fall through. */
6911 /* Record template parameters such as `T' inside `TT<T>'. */
6915 /* Fall through. */
6927 /* A template template parameter is encountered. */
6933 /* Already substituted template template parameter */
6956 /* If there's no type, then this thing must be some expression
6957 involving template parameters. */
6978 }
6980 /* We didn't find any template parameters we liked. */
6982 }
6984 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6985 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6986 call FN with the parameter and the DATA.
6987 If FN returns nonzero, the iteration is terminated, and
6988 for_each_template_parm returns 1. Otherwise, the iteration
6989 continues. If FN never returns a nonzero value, the value
6990 returned by for_each_template_parm is 0. If FN is NULL, it is
6991 considered to be the function which always returns 1.
6993 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6994 parameters that occur in non-deduced contexts. When false, only
6995 visits those template parameters that can be deduced. */
6997 static int
7001 {
7005 /* Set up. */
7010 /* Walk the tree. (Conceptually, we would like to walk without
7011 duplicates, but for_each_template_parm_r recursively calls
7012 for_each_template_parm, so we would need to reorganize a fair
7013 bit to use walk_tree_without_duplicates, so we keep our own
7014 visited list.) */
7017 else
7020 for_each_template_parm_r,
7024 /* Clean up. */
7026 {
7029 }
7032 }
7034 /* Returns true if T depends on any template parameter. */
7036 int
7038 {
7065 else
7066 {
7069 }
7074 }
7076 /* Returns true if T depends on any template parameter with level LEVEL. */
7078 int
7080 {
7083 }
7087 #ifdef GATHER_STATISTICS
7089 #endif
7093 /* We're starting to instantiate D; record the template instantiation context
7094 for diagnostics and to restore it later. */
7096 int
7098 {
7102 {
7103 /* If the instantiation in question still has unbound template parms,
7104 we don't really care if we can't instantiate it, so just return.
7105 This happens with base instantiation for implicit `typename'. */
7117 }
7127 #ifdef GATHER_STATISTICS
7130 #endif
7134 }
7136 /* We're done instantiating this template; return to the instantiation
7137 context. */
7139 void
7141 {
7142 /* Restore the filename and line number stashed away when we started
7143 this instantiation. */
7148 }
7150 /* We're instantiating a deferred template; restore the template
7151 instantiation context in which the instantiation was requested, which
7152 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7154 static tree
7156 {
7166 }
7168 /* Returns the TINST_LEVEL which gives the original instantiation
7169 context. */
7173 {
7179 }
7181 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7183 bool
7185 {
7186 tree parms;
7203 }
7205 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7206 vector of template arguments, as for tsubst.
7208 Returns an appropriate tsubst'd friend declaration. */
7210 static tree
7212 {
7213 tree new_friend;
7218 /* This was a friend declared with an explicit template
7219 argument list, e.g.:
7221 friend void f<>(T);
7223 to indicate that f was a template instantiation, not a new
7224 function declaration. Now, we have to figure out what
7225 instantiation of what template. */
7226 {
7228 tree new_args;
7229 tree tmpl;
7232 /* Friend functions are looked up in the containing namespace scope.
7233 We must enter that scope, to avoid finding member functions of the
7234 current class with same name. */
7249 tsk_none);
7251 }
7255 /* The NEW_FRIEND will look like an instantiation, to the
7256 compiler, but is not an instantiation from the point of view of
7257 the language. For example, we might have had:
7259 template <class T> struct S {
7260 template <class U> friend void f(T, U);
7261 };
7263 Then, in S<int>, template <class U> void f(int, U) is not an
7264 instantiation of anything. */
7270 {
7274 }
7276 /* The mangled name for the NEW_FRIEND is incorrect. The function
7277 is not a template instantiation and should not be mangled like
7278 one. Therefore, we forget the mangling here; we'll recompute it
7279 later if we need it. */
7281 {
7284 }
7287 {
7288 tree old_decl;
7289 tree new_friend_template_info;
7290 tree new_friend_result_template_info;
7291 tree ns;
7294 /* We must save some information from NEW_FRIEND before calling
7295 duplicate decls since that function will free NEW_FRIEND if
7296 possible. */
7298 new_friend_is_defn =
7303 {
7304 /* This declaration is a `primary' template. */
7307 new_friend_result_template_info
7309 }
7310 else
7313 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7317 /* Inside pushdecl_namespace_level, we will push into the
7318 current namespace. However, the friend function should go
7319 into the namespace of the template. */
7329 {
7330 /* This new friend declaration matched an existing
7331 declaration. For example, given:
7333 template <class T> void f(T);
7334 template <class U> class C {
7335 template <class T> friend void f(T) {}
7336 };
7338 the friend declaration actually provides the definition
7339 of `f', once C has been instantiated for some type. So,
7340 old_decl will be the out-of-class template declaration,
7341 while new_friend is the in-class definition.
7343 But, if `f' was called before this point, the
7344 instantiation of `f' will have DECL_TI_ARGS corresponding
7345 to `T' but not to `U', references to which might appear
7346 in the definition of `f'. Previously, the most general
7347 template for an instantiation of `f' was the out-of-class
7348 version; now it is the in-class version. Therefore, we
7349 run through all specialization of `f', adding to their
7350 DECL_TI_ARGS appropriately. In particular, they need a
7351 new set of outer arguments, corresponding to the
7352 arguments for this class instantiation.
7354 The same situation can arise with something like this:
7356 friend void f(int);
7357 template <class T> class C {
7358 friend void f(T) {}
7359 };
7361 when `C<int>' is instantiated. Now, `f(int)' is defined
7362 in the class. */
7365 /* On the other hand, if the in-class declaration does
7366 *not* provide a definition, then we don't want to alter
7367 existing definitions. We can just leave everything
7368 alone. */
7369 ;
7370 else
7371 {
7375 /* Overwrite whatever template info was there before, if
7376 any, with the new template information pertaining to
7377 the declaration. */
7381 {
7382 /* We should have called reregister_specialization in
7383 duplicate_decls. */
7388 /* Instantiate it if the global has already been used. */
7392 }
7393 else
7394 {
7395 tree t;
7397 /* Indicate that the old function template is a partial
7398 instantiation. */
7406 /* Reassign any specializations already in the hash table
7407 to the new more general template, and add the
7408 additional template args. */
7412 {
7414 spec_entry elt;
7426 register_specialization
7429 }
7431 }
7432 }
7434 /* The information from NEW_FRIEND has been merged into OLD_DECL
7435 by duplicate_decls. */
7437 }
7438 }
7439 else
7440 {
7444 /* In the code
7445 template <class T> class C {
7446 template <class U> friend void C1<U>::f (); // case 1
7447 friend void C2<T>::f (); // case 2
7448 };
7449 we only need to make sure CONTEXT is a complete type for
7450 case 2. To distinguish between the two cases, we note that
7451 CONTEXT of case 1 remains dependent type after tsubst while
7452 this isn't true for case 2. */
7462 {
7463 /* Check to see that the declaration is really present, and,
7464 possibly obtain an improved declaration. */
7470 }
7471 }
7474 }
7476 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7477 template arguments, as for tsubst.
7479 Returns an appropriate tsubst'd friend type or error_mark_node on
7480 failure. */
7482 static tree
7484 {
7485 tree friend_type;
7486 tree tmpl;
7487 tree context;
7492 {
7495 else
7497 }
7499 /* Look for a class template declaration. We look for hidden names
7500 because two friend declarations of the same template are the
7501 same. For example, in:
7503 struct A {
7504 template <typename> friend class F;
7505 };
7506 template <typename> struct B {
7507 template <typename> friend class F;
7508 };
7510 both F templates are the same. */
7515 /* But, if we don't find one, it might be because we're in a
7516 situation like this:
7518 template <class T>
7519 struct S {
7520 template <class U>
7521 friend struct S;
7522 };
7524 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7525 for `S<int>', not the TEMPLATE_DECL. */
7527 {
7530 }
7533 {
7534 /* The friend template has already been declared. Just
7535 check to see that the declarations match, and install any new
7536 default parameters. We must tsubst the default parameters,
7537 of course. We only need the innermost template parameters
7538 because that is all that redeclare_class_template will look
7539 at. */
7542 {
7543 tree parms;
7544 location_t saved_input_location;
7553 }
7556 }
7557 else
7558 {
7559 /* The friend template has not already been declared. In this
7560 case, the instantiation of the template class will cause the
7561 injection of this template into the global scope. */
7566 /* The new TMPL is not an instantiation of anything, so we
7567 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7568 the new type because that is supposed to be the corresponding
7569 template decl, i.e., TMPL. */
7576 /* Inject this template into the global scope. */
7578 }
7581 {
7584 else
7586 }
7589 }
7591 /* Returns zero if TYPE cannot be completed later due to circularity.
7592 Otherwise returns one. */
7594 static int
7596 {
7606 else
7608 }
7610 /* Apply any attributes which had to be deferred until instantiation
7611 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7612 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7614 static void
7617 {
7619 tree t;
7624 {
7628 }
7631 {
7635 }
7636 else
7640 {
7645 {
7648 {
7651 /* If the first attribute argument is an identifier, don't
7652 pass it through tsubst. Attributes like mode, format,
7653 cleanup and several target specific attributes expect it
7654 unmodified. */
7660 {
7661 tree chain
7663 in_decl,
7668 chain);
7669 }
7670 else
7676 }
7677 else
7679 }
7682 }
7683 }
7685 /* Perform (or defer) access check for typedefs that were referenced
7686 from within the template TMPL code.
7687 This is a subroutine of instantiate_template and instantiate_class_template.
7688 TMPL is the template to consider and TARGS is the list of arguments of
7689 that template. */
7691 static void
7693 {
7694 location_t saved_location;
7709 {
7721 /* Make access check error messages point to the location
7722 of the use of the typedef. */
7726 }
7728 }
7730 tree
7732 {
7734 tree typedecl;
7735 tree pbinfo;
7736 tree base_list;
7746 /* Figure out which template is being instantiated. */
7750 /* Determine what specialization of the original template to
7751 instantiate. */
7754 {
7757 }
7759 {
7760 /* This TYPE is actually an instantiation of a partial
7761 specialization. We replace the innermost set of ARGS with
7762 the arguments appropriate for substitution. For example,
7763 given:
7765 template <class T> struct S {};
7766 template <class T> struct S<T*> {};
7768 and supposing that we are instantiating S<int*>, ARGS will
7769 presently be {int*} -- but we need {int}. */
7772 }
7773 else
7774 {
7777 }
7779 /* If the template we're instantiating is incomplete, then clearly
7780 there's nothing we can do. */
7784 /* If we've recursively instantiated too many templates, stop. */
7788 /* Now we're really doing the instantiation. Mark the type as in
7789 the process of being defined. */
7792 /* We may be in the middle of deferred access check. Disable
7793 it now. */
7797 /* Use #pragma pack from the template context. */
7803 /* Set the input location to the most specialized template definition.
7804 This is needed if tsubsting causes an error. */
7825 {
7828 }
7832 /* We should never instantiate a nested class before its enclosing
7833 class; we need to look up the nested class by name before we can
7834 instantiate it, and that lookup should instantiate the enclosing
7835 class. */
7841 {
7842 tree pbase_binfo;
7844 tree pushed_scope;
7847 /* We must enter the scope containing the type, as that is where
7848 the accessibility of types named in dependent bases are
7849 looked up from. */
7852 /* Substitute into each of the bases to determine the actual
7853 basetypes. */
7855 {
7856 tree base;
7862 {
7863 expanded_bases =
7870 }
7873 {
7875 /* Extract the already-expanded base class. */
7877 else
7878 /* Substitute to figure out the base class. */
7880 NULL_TREE);
7888 }
7889 }
7891 /* The list is now in reverse order; correct that. */
7896 }
7897 /* Now call xref_basetypes to set up all the base-class
7898 information. */
7905 /* Now that our base classes are set up, enter the scope of the
7906 class, so that name lookups into base classes, etc. will work
7907 correctly. This is precisely analogous to what we do in
7908 begin_class_definition when defining an ordinary non-template
7909 class, except we also need to push the enclosing classes. */
7912 /* Now members are processed in the order of declaration. */
7915 {
7919 {
7921 {
7922 /* Build new CLASSTYPE_NESTED_UTDS. */
7924 tree newtag;
7930 /* If the member is a class template, then -- even after
7931 substitution -- there may be dependent types in the
7932 template argument list for the class. We increment
7933 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7934 that function will assume that no types are dependent
7935 when outside of a template. */
7945 {
7949 /* Unfortunately, lookup_template_class sets
7950 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7951 instantiation (i.e., for the type of a member
7952 template class nested within a template class.)
7953 This behavior is required for
7954 maybe_process_partial_specialization to work
7955 correctly, but is not accurate in this case;
7956 the TAG is not an instantiation of anything.
7957 (The corresponding TEMPLATE_DECL is an
7958 instantiation, but the TYPE is not.) */
7961 /* Now, we call pushtag to put this NEWTAG into the scope of
7962 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7963 pushtag calling push_template_decl. We don't have to do
7964 this for enums because it will already have been done in
7965 tsubst_enum. */
7969 }
7970 }
7973 {
7974 /* Build new TYPE_METHODS. */
7975 tree r;
7984 }
7985 else
7986 {
7987 /* Build new TYPE_FIELDS. */
7989 {
7990 tree condition =
7998 }
8000 {
8001 tree r;
8003 /* The file and line for this declaration, to
8004 assist in error message reporting. Since we
8005 called push_tinst_level above, we don't need to
8006 restore these. */
8015 {
8016 /* In [temp.inst]:
8018 [t]he initialization (and any associated
8019 side-effects) of a static data member does
8020 not occur unless the static data member is
8021 itself used in a way that requires the
8022 definition of the static data member to
8023 exist.
8025 Therefore, we do not substitute into the
8026 initialized for the static data member here. */
8027 finish_static_data_member_decl
8035 }
8037 {
8038 /* Determine whether R has a valid type and can be
8039 completed later. If R is invalid, then it is
8040 replaced by error_mark_node so that it will not be
8041 added to TYPE_FIELDS. */
8047 {
8050 }
8051 }
8053 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8054 such a thing will already have been added to the field
8055 list by tsubst_enum in finish_member_declaration in the
8056 CLASSTYPE_NESTED_UTDS case above. */
8060 {
8063 }
8064 }
8065 }
8066 }
8067 else
8068 {
8070 {
8071 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8077 {
8078 /* template <class T> friend class C; */
8081 }
8083 {
8084 /* template <class T> friend class C::D; */
8090 }
8092 {
8093 /* This could be either
8095 friend class T::C;
8097 when dependent_type_p is false or
8099 template <class U> friend class T::C;
8101 otherwise. */
8104 /* Bump processing_template_decl for correct
8105 dependent_type_p calculation. */
8110 }
8113 {
8114 /* friend class C;
8116 where C hasn't been declared yet. Let's lookup name
8117 from namespace scope directly, bypassing any name that
8118 come from dependent base class. */
8121 /* The call to xref_tag_from_type does injection for friend
8122 classes. */
8124 friend_type =
8128 }
8130 /* friend class C<T>; */
8133 /* Otherwise it's
8135 friend class C;
8137 where C is already declared or
8139 friend class C<int>;
8141 We don't have to do anything in these cases. */
8144 /* Trick make_friend_class into realizing that the friend
8145 we're adding is a template, not an ordinary class. It's
8146 important that we use make_friend_class since it will
8147 perform some error-checking and output cross-reference
8148 information. */
8156 }
8157 else
8158 {
8159 /* Build new DECL_FRIENDLIST. */
8160 tree r;
8162 /* The file and line for this declaration, to
8163 assist in error message reporting. Since we
8164 called push_tinst_level above, we don't need to
8165 restore these. */
8169 {
8172 }
8177 {
8180 }
8181 }
8182 }
8183 }
8185 /* Set the file and line number information to whatever is given for
8186 the class itself. This puts error messages involving generated
8187 implicit functions at a predictable point, and the same point
8188 that would be used for non-template classes. */
8195 /* Now that the class is complete, instantiate default arguments for
8196 any member functions. We don't do this earlier because the
8197 default arguments may reference members of the class. */
8201 /* Implicitly generated member functions will not have template
8202 information; they are not instantiations, but instead are
8203 created "fresh" for each instantiation. */
8207 /* Some typedefs referenced from within the template code need to be access
8208 checked at template instantiation time, i.e now. These types were
8209 added to the template at parsing time. Let's get those and perform
8210 the access checks then. */
8219 /* The vtable for a template class can be emitted in any translation
8220 unit in which the class is instantiated. When there is no key
8221 method, however, finish_struct_1 will already have added TYPE to
8222 the keyed_classes list. */
8227 }
8229 static tree
8231 {
8232 tree r;
8238 else
8239 {
8243 }
8245 }
8247 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8248 NONTYPE_ARGUMENT_PACK. */
8250 static tree
8252 {
8253 /* Collect all of the extra "packed" parameters into an
8254 argument pack. */
8255 tree parmvec;
8256 tree parmtypevec;
8261 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8265 {
8268 }
8270 /* Build the argument packs. */
8276 }
8278 /* Substitute ARGS into T, which is an pack expansion
8279 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8280 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8281 (if only a partial substitution could be performed) or
8282 ERROR_MARK_NODE if there was an error. */
8283 tree
8285 tree in_decl)
8286 {
8287 tree pattern;
8290 tree result;
8297 /* Determine the argument packs that will instantiate the parameter
8298 packs used in the expansion expression. While we're at it,
8299 compute the number of arguments to be expanded and make sure it
8300 is consistent. */
8303 {
8309 {
8312 else
8313 {
8314 /* We can't rely on local_specializations for a parameter
8315 name used later in a function declaration (such as in a
8316 late-specified return type). Even if it exists, it might
8317 have the wrong value for a recursive call. Just make a
8318 dummy decl, since it's only used for its type. */
8321 }
8322 }
8323 else
8324 {
8331 }
8338 /* This can only happen if we forget to expand an argument
8339 pack somewhere else. Just return an error, silently. */
8340 {
8344 }
8349 {
8354 /* The argument pack that the parameter maps to is just an
8355 expansion of the parameter itself, such as one would
8356 find in the implicit typedef of a class inside the
8357 class itself. Consider this parameter "unsubstituted",
8358 so that we will maintain the outer pack expansion. */
8360 }
8363 {
8367 /* It's all-or-nothing with incomplete argument packs. */
8377 {
8379 /* We got explicit args for some packs but not others;
8380 do nothing now and try again after deduction. */
8385 pattern);
8386 else
8389 pattern);
8391 }
8393 /* Keep track of the parameter packs and their corresponding
8394 argument packs. */
8397 }
8398 else
8399 /* We can't substitute for this parameter pack. */
8402 unsubstituted_packs);
8403 }
8405 /* We cannot expand this expansion expression, because we don't have
8406 all of the argument packs we need. Substitute into the pattern
8407 and return a PACK_EXPANSION_*. The caller will need to deal with
8408 that. */
8410 {
8411 tree new_pat;
8415 else
8418 }
8420 /* We could not find any argument packs that work. */
8425 {
8426 /* We're in a late-specified return type, so create our own local
8427 specializations table; the current table is either NULL or (in the
8428 case of recursive unification) might have bindings that we don't
8429 want to use or alter. */
8432 hash_local_specialization,
8433 eq_local_specializations,
8434 NULL);
8435 }
8437 /* For each argument in each argument pack, substitute into the
8438 pattern. */
8441 {
8442 /* For parameter pack, change the substitution of the parameter
8443 pack to the ith argument in its argument pack, then expand
8444 the pattern. */
8446 {
8450 {
8451 /* Select the Ith argument from the pack. */
8457 }
8458 else
8459 {
8465 {
8466 /* Select the Ith argument from the pack. */
8470 }
8472 /* Update the corresponding argument. */
8474 }
8475 }
8477 /* Substitute into the PATTERN with the altered arguments. */
8482 else
8486 /* When we have incomplete argument packs, the last "expanded"
8487 result is itself a pack expansion, which allows us
8488 to deduce more arguments. */
8493 {
8496 }
8497 }
8499 /* Update ARGS to restore the substitution from parameter packs to
8500 their argument packs. */
8502 {
8507 else
8508 {
8512 /* Update the corresponding argument. */
8516 else
8518 }
8519 }
8522 {
8525 }
8528 }
8530 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8531 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8532 parameter packs; all parms generated from a function parameter pack will
8533 have the same DECL_PARM_INDEX. */
8535 tree
8537 {
8539 tree patparm;
8542 {
8548 }
8549 else
8550 {
8555 }
8558 }
8560 /* Substitute ARGS into the vector or list of template arguments T. */
8562 static tree
8564 {
8571 {
8573 tree new_arg;
8578 {
8579 /* Substitute into an expansion expression. */
8583 /* Add to the expanded length adjustment the number of
8584 expanded arguments. We subtract one from this
8585 measurement, because the argument pack expression
8586 itself is already counted as 1 in
8587 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8588 the argument pack is empty. */
8590 }
8592 {
8593 /* Substitute into each of the arguments. */
8599 new_arg,
8613 }
8614 }
8615 else
8624 }
8629 /* Make space for the expanded arguments coming from template
8630 argument packs. */
8632 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8633 arguments for a member template.
8634 In that case each TREE_VEC in ORIG_T represents a level of template
8635 arguments, and ORIG_T won't carry any non defaulted argument count.
8636 It will rather be the nested TREE_VECs that will carry one.
8637 In other words, ORIG_T carries a non defaulted argument count only
8638 if it doesn't contain any nested TREE_VEC. */
8640 {
8644 }
8646 {
8650 {
8653 /* Now expand the template argument pack "in place". */
8656 }
8657 else
8658 {
8660 out++;
8661 }
8662 }
8665 }
8667 /* Return the result of substituting ARGS into the template parameters
8668 given by PARMS. If there are m levels of ARGS and m + n levels of
8669 PARMS, then the result will contain n levels of PARMS. For
8670 example, if PARMS is `template <class T> template <class U>
8671 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8672 result will be `template <int*, double, class V>'. */
8674 static tree
8676 {
8680 /* When substituting into a template, we must set
8681 PROCESSING_TEMPLATE_DECL as the template parameters may be
8682 dependent if they are based on one-another, and the dependency
8683 predicates are short-circuit outside of templates. */
8690 {
8691 tree new_vec =
8696 {
8697 tree tuple;
8698 tree default_value;
8699 tree parm_decl;
8721 }
8727 }
8732 }
8734 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8735 type T. If T is not an aggregate or enumeration type, it is
8736 handled as if by tsubst. IN_DECL is as for tsubst. If
8737 ENTERING_SCOPE is nonzero, T is the context for a template which
8738 we are presently tsubst'ing. Return the substituted value. */
8740 static tree
8742 tree args,
8743 tsubst_flags_t complain,
8744 tree in_decl,
8746 {
8751 {
8756 /* Else fall through. */
8760 {
8761 tree argvec;
8762 tree context;
8763 tree r;
8767 /* In "sizeof(X<I>)" we need to evaluate "I". */
8773 /* First, determine the context for the type we are looking
8774 up. */
8777 {
8780 /* If context is a nested class inside a class template,
8781 it may still need to be instantiated (c++/33959). */
8784 }
8786 /* Then, figure out what arguments are appropriate for the
8787 type we are trying to find. For example, given:
8789 template <class T> struct S;
8790 template <class T, class U> void f(T, U) { S<U> su; }
8792 and supposing that we are instantiating f<int, double>,
8793 then our ARGS will be {int, double}, but, when looking up
8794 S we only want {double}. */
8799 else
8800 {
8804 }
8810 }
8811 else
8812 /* This is not a template type, so there's nothing to do. */
8817 }
8818 }
8820 /* Substitute into the default argument ARG (a default argument for
8821 FN), which has the indicated TYPE. */
8823 tree
8825 {
8829 /* This default argument came from a template. Instantiate the
8830 default argument here, not in tsubst. In the case of
8831 something like:
8833 template <class T>
8834 struct S {
8835 static T t();
8836 void f(T = t());
8837 };
8839 we must be careful to do name lookup in the scope of S<T>,
8840 rather than in the current class. */
8842 /* The "this" pointer is not valid in a default argument. */
8844 {
8849 }
8852 /* The default argument expression may cause implicitly defined
8853 member functions to be synthesized, which will result in garbage
8854 collection. We must treat this situation as if we were within
8855 the body of function so as to avoid collecting live data on the
8856 stack. */
8864 /* Restore the "this" pointer. */
8866 {
8869 }
8871 /* Make sure the default argument is reasonable. */
8877 }
8879 /* Substitute into all the default arguments for FN. */
8881 static void
8883 {
8884 tree arg;
8885 tree tmpl_args;
8889 /* If this function is not yet instantiated, we certainly don't need
8890 its default arguments. */
8895 arg;
8901 }
8903 /* Substitute the ARGS into the T, which is a _DECL. Return the
8904 result of the substitution. Issue error and warning messages under
8905 control of COMPLAIN. */
8907 static tree
8909 {
8910 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8911 location_t saved_loc;
8916 /* Set the filename and linenumber to improve error-reporting. */
8921 {
8923 {
8924 /* We can get here when processing a member function template,
8925 member class template, or template template parameter. */
8927 tree spec;
8928 tree tmpl_args;
8929 tree full_args;
8932 {
8933 /* Template template parameter is treated here. */
8946 complain);
8949 }
8951 /* We might already have an instance of this template.
8952 The ARGS are for the surrounding class type, so the
8953 full args contain the tsubst'd args for the context,
8954 plus the innermost args from the template decl. */
8958 /* Because this is a template, the arguments will still be
8959 dependent, even after substitution. If
8960 PROCESSING_TEMPLATE_DECL is not set, the dependency
8961 predicates will short-circuit. */
8969 /* If this is a default template template argument,
8970 tsubst might not have changed anything. */
8977 {
8980 }
8982 /* Make a new template decl. It will be similar to the
8983 original, but will record the current template arguments.
8984 We also create a new function declaration, which is just
8985 like the old one, but points to this new template, rather
8986 than the old one. */
8994 {
8995 tree new_type;
9007 }
9008 else
9009 {
9010 tree new_decl;
9022 }
9028 /* The template parameters for this new template are all the
9029 template parameters for the old template, except the
9030 outermost level of parameters. */
9033 complain);
9039 /* Record this non-type partial instantiation. */
9043 }
9047 {
9048 tree ctx;
9051 tree gen_tmpl;
9052 tree type;
9057 /* Nobody should be tsubst'ing into non-template functions. */
9061 {
9062 tree spec;
9065 /* If T is not dependent, just return it. We have to
9066 increment PROCESSING_TEMPLATE_DECL because
9067 value_dependent_expression_p assumes that nothing is
9068 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9075 /* Calculate the most general template of which R is a
9076 specialization, and the complete set of arguments used to
9077 specialize R. */
9080 (DECL_TEMPLATE_RESULT
9084 /* Check to see if we already have this specialization. */
9089 {
9092 }
9094 /* We can see more levels of arguments than parameters if
9095 there was a specialization of a member template, like
9096 this:
9098 template <class T> struct S { template <class U> void f(); }
9099 template <> template <class U> void S<int>::f(U);
9101 Here, we'll be substituting into the specialization,
9102 because that's where we can find the code we actually
9103 want to generate, but we'll have enough arguments for
9104 the most general template.
9106 We also deal with the peculiar case:
9108 template <class T> struct S {
9109 template <class U> friend void f();
9110 };
9111 template <class U> void f() {}
9112 template S<int>;
9113 template void f<double>();
9115 Here, the ARGS for the instantiation of will be {int,
9116 double}. But, we only need as many ARGS as there are
9117 levels of template parameters in CODE_PATTERN. We are
9118 careful not to get fooled into reducing the ARGS in
9119 situations like:
9121 template <class T> struct S { template <class U> void f(U); }
9122 template <class T> template <> void S<T>::f(int) {}
9124 which we can spot because the pattern will be a
9125 specialization in this case. */
9127 parms_depth =
9132 }
9133 else
9134 {
9135 /* This special case arises when we have something like this:
9137 template <class T> struct S {
9138 friend void f<int>(int, double);
9139 };
9141 Here, the DECL_TI_TEMPLATE for the friend declaration
9142 will be an IDENTIFIER_NODE. We are being called from
9143 tsubst_friend_function, and we want only to create a
9144 new decl (R) with appropriate types so that we can call
9145 determine_specialization. */
9147 }
9150 {
9153 else
9157 }
9158 else
9159 {
9162 }
9167 /* We do NOT check for matching decls pushed separately at this
9168 point, as they may not represent instantiations of this
9169 template, and in any case are considered separate under the
9170 discrete model. */
9174 /* Clear out the mangled name and RTL for the instantiation. */
9177 /* Leave DECL_INITIAL set on deleted instantiations. */
9183 /* Type-conversion operator. Reconstruct the name, in
9184 case it's the name of one of the template's parameters. */
9194 /* If this is an instantiation of a function with internal
9195 linkage, we already know what object file linkage will be
9196 assigned to the instantiation. */
9205 /* We'll re-clone as appropriate in instantiate_template. */
9208 /* If we aren't complaining now, return on error before we register
9209 the specialization so that we'll complain eventually. */
9215 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9216 this in the special friend case mentioned above where
9217 GEN_TMPL is NULL. */
9219 {
9225 /* We're not supposed to instantiate default arguments
9226 until they are called, for a template. But, for a
9227 declaration like:
9229 template <class T> void f ()
9230 { extern void g(int i = T()); }
9232 we should do the substitution when the template is
9233 instantiated. We handle the member function case in
9234 instantiate_class_template since the default arguments
9235 might refer to other members of the class. */
9240 }
9241 else
9244 /* Copy the list of befriending classes. */
9248 {
9252 in_decl);
9253 }
9256 {
9260 /* If this is an instantiation of a member template, clone it.
9261 If it isn't, that'll be handled by
9262 clone_constructors_and_destructors. */
9265 }
9276 /* Possibly limit visibility based on template args. */
9279 {
9283 }
9291 }
9295 {
9303 {
9304 /* If there is a local specialization that isn't a
9305 parameter pack, it means that we're doing a "simple"
9306 substitution from inside tsubst_pack_expansion. Just
9307 return the local specialization (which will be a single
9308 parm). */
9315 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9316 the parameters in this function parameter pack. */
9320 {
9323 /* Zero-length parameter packs are boring. Just substitute
9324 into the chain. */
9328 }
9329 else
9330 {
9331 /* All we did was update the type. Make a note of that. */
9334 }
9335 }
9337 /* Loop through all of the parameter's we'll build. When T is
9338 a function parameter pack, LEN is the number of expanded
9339 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9342 {
9348 /* An argument of a function parameter pack is not a parameter
9349 pack. */
9353 /* We're on the Ith parameter of the function parameter
9354 pack. */
9355 {
9356 /* Get the Ith type. */
9360 /* Rename the parameter to include the index. */
9363 }
9365 /* We're dealing with a normal parameter. */
9373 {
9376 else
9379 }
9389 /* Keep track of the first new parameter we
9390 generate. That's what will be returned to the
9391 caller. */
9395 /* Build a proper chain of parameters when substituting
9396 into a function parameter pack. */
9399 }
9405 /* FIRST_R contains the start of the chain we've built. */
9407 }
9411 {
9412 tree type;
9421 /* DECL_INITIAL gives the number of bits in a bit-field. */
9426 /* We don't have to set DECL_CONTEXT here; it is set by
9427 finish_member_declaration. */
9434 }
9438 /* We reach here only for member using decls. */
9440 {
9441 r = do_class_using_decl
9446 else
9447 {
9450 }
9451 }
9452 else
9453 {
9456 }
9461 {
9464 tree spec;
9466 tree ctx;
9472 {
9473 /* If this is the canonical decl, we don't have to
9474 mess with instantiations, and often we can't (for
9475 typename, template type parms and such). Note that
9476 TYPE_NAME is not correct for the above test if
9477 we've copied the type for a typedef. */
9483 }
9485 /* Check to see if we already have the specialization we
9486 need. */
9489 {
9490 /* T is a static data member or namespace-scope entity.
9491 We have to substitute into namespace-scope variables
9492 (even though such entities are never templates) because
9493 of cases like:
9495 template <class T> void f() { extern T t; }
9497 where the entity referenced is not known until
9498 instantiation time. */
9502 {
9504 complain,
9506 /* If CTX is unchanged, then T is in fact the
9507 specialization we want. That situation occurs when
9508 referencing a static data member within in its own
9509 class. We can use pointer equality, rather than
9510 same_type_p, because DECL_CONTEXT is always
9511 canonical. */
9514 }
9517 {
9523 }
9524 }
9525 else
9526 {
9527 /* A local variable. */
9529 /* Subsequent calls to pushdecl will fill this in. */
9532 }
9533 /* If we already have the specialization we need, there is
9534 nothing more to do. */
9536 {
9539 }
9541 /* Create a new node for the specialization we need. */
9544 {
9547 else
9552 }
9554 {
9555 /* Even if the original location is out of scope, the
9556 newly substituted one is not. */
9563 {
9564 /* It may seem that this case cannot occur, since:
9566 typedef void f();
9567 void g() { f x; }
9569 declares a function, not a variable. However:
9571 typedef void f();
9572 template <typename T> void g() { T t; }
9573 template void g<f>();
9575 is an attempt to declare a variable with function
9576 type. */
9578 /* R is not yet sufficiently initialized, so we
9579 just use its name. */
9582 }
9589 {
9594 }
9595 }
9601 /* Clear out the mangled name and RTL for the instantiation. */
9605 /* The initializer must not be expanded until it is required;
9606 see [temp.inst]. */
9612 {
9613 /* Possibly limit visibility based on template args. */
9616 {
9620 }
9622 }
9625 {
9626 /* A static data member declaration is always marked
9627 external when it is declared in-class, even if an
9628 initializer is present. We mimic the non-template
9629 processing here. */
9635 }
9637 {
9638 /* We're substituting this var in a decltype outside of its
9639 scope, such as for a lambda return type. Don't add it to
9640 local_specializations, do perform auto deduction. */
9642 tree init
9647 {
9650 }
9651 }
9652 else
9661 /* Preserve a typedef that names a type. */
9663 {
9666 }
9669 }
9674 }
9675 #undef RETURN
9677 out:
9678 /* Restore the file and line information. */
9682 }
9684 /* Substitute into the ARG_TYPES of a function type. */
9686 static tree
9688 tree args,
9689 tsubst_flags_t complain,
9690 tree in_decl)
9691 {
9692 tree remaining_arg_types;
9696 tree default_arg;
9707 {
9708 /* For a pack expansion, perform substitution on the
9709 entire expression. Later on, we'll handle the arguments
9710 one-by-one. */
9715 /* So that we'll spin through the parameters, one by one. */
9717 else
9718 {
9719 /* We only partially substituted into the parameter
9720 pack. Our type is TYPE_PACK_EXPANSION. */
9723 }
9724 }
9737 {
9739 {
9743 }
9745 }
9747 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9748 top-level qualifiers as required. */
9751 /* We do not substitute into default arguments here. The standard
9752 mandates that they be instantiated only when needed, which is
9753 done in build_over_call. */
9757 {
9758 /* We've instantiated a template before its default arguments
9759 have been parsed. This can happen for a nested template
9760 class, and is not an error unless we require the default
9761 argument in a call of this function. */
9762 remaining_arg_types =
9765 remaining_arg_types);
9766 }
9767 else
9768 remaining_arg_types =
9770 }
9773 }
9775 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9776 *not* handle the exception-specification for FNTYPE, because the
9777 initial substitution of explicitly provided template parameters
9778 during argument deduction forbids substitution into the
9779 exception-specification:
9781 [temp.deduct]
9783 All references in the function type of the function template to the
9784 corresponding template parameters are replaced by the specified tem-
9785 plate argument values. If a substitution in a template parameter or
9786 in the function type of the function template results in an invalid
9787 type, type deduction fails. [Note: The equivalent substitution in
9788 exception specifications is done only when the function is instanti-
9789 ated, at which point a program is ill-formed if the substitution
9790 results in an invalid type.] */
9792 static tree
9794 tree args,
9795 tsubst_flags_t complain,
9796 tree in_decl)
9797 {
9798 tree return_type;
9799 tree arg_types;
9800 tree fntype;
9802 /* The TYPE_CONTEXT is not used for function/method types. */
9805 /* Substitute the return type. */
9809 /* The standard does not presently indicate that creation of a
9810 function type with an invalid return type is a deduction failure.
9811 However, that is clearly analogous to creating an array of "void"
9812 or a reference to a reference. This is core issue #486. */
9815 {
9817 {
9820 else
9822 }
9824 }
9826 /* Substitute the argument types. */
9832 /* Construct a new type node and return it. */
9834 {
9837 }
9838 else
9839 {
9842 {
9843 /* [temp.deduct]
9845 Type deduction may fail for any of the following
9846 reasons:
9848 -- Attempting to create "pointer to member of T" when T
9849 is not a class type. */
9852 r);
9854 }
9858 }
9862 }
9864 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9865 ARGS into that specification, and return the substituted
9866 specification. If there is no specification, return NULL_TREE. */
9868 static tree
9870 tree args,
9871 tsubst_flags_t complain,
9872 tree in_decl)
9873 {
9874 tree specs;
9875 tree new_specs;
9880 {
9881 /* A noexcept-specifier. */
9882 new_specs = tsubst_copy_and_build
9886 }
9888 {
9891 else
9893 {
9894 tree spec;
9899 {
9900 /* Expand the pack expansion type. */
9903 in_decl);
9909 else
9910 {
9911 /* We're substituting into a member template, so
9912 we got a TYPE_PACK_EXPANSION back. Add that
9913 expansion and move on. */
9917 expanded_specs,
9918 complain);
9921 }
9922 }
9925 {
9928 else
9933 complain);
9934 }
9937 }
9938 }
9940 }
9942 /* Take the tree structure T and replace template parameters used
9943 therein with the argument vector ARGS. IN_DECL is an associated
9944 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9945 Issue error and warning messages under control of COMPLAIN. Note
9946 that we must be relatively non-tolerant of extensions here, in
9947 order to preserve conformance; if we allow substitutions that
9948 should not be allowed, we may allow argument deductions that should
9949 not succeed, and therefore report ambiguous overload situations
9950 where there are none. In theory, we could allow the substitution,
9951 but indicate that it should have failed, and allow our caller to
9952 make sure that the right thing happens, but we don't try to do this
9953 yet.
9955 This function is used for dealing with types, decls and the like;
9956 for expressions, use tsubst_expr or tsubst_copy. */
9958 tree
9960 {
9979 else
9984 /* Reuse typedefs. We need to do this to handle dependent attributes,
9985 such as attribute aligned. */
9989 {
9995 {
9999 }
10004 else
10005 /* The typedef is from a non-template context. */
10009 {
10011 r = cp_build_qualified_type_real
10015 }
10016 /* Else we must be instantiating the typedef, so fall through. */
10017 }
10030 {
10057 {
10063 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10064 needed. */
10072 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10073 with TREE_SIDE_EFFECTS that indicates this is not an integral
10074 constant expression. */
10077 {
10080 }
10086 {
10090 }
10092 /* [temp.deduct]
10094 Type deduction may fail for any of the following
10095 reasons:
10097 Attempting to create an array with a size that is
10098 zero or negative. */
10100 /* We must fail if performing argument deduction (as
10101 indicated by the state of complain), so that
10102 another substitution can be found. */
10106 {
10111 }
10114 }
10120 {
10133 {
10137 /* See through ARGUMENT_PACK_SELECT arguments. */
10139 }
10144 {
10146 /* If ARG is an argument pack, we don't actually want to
10147 perform a substitution here, because substitutions
10148 for argument packs are only done
10149 element-by-element. We can get to this point when
10150 substituting the type of a non-type template
10151 parameter pack, when that type actually contains
10152 template parameter packs from an outer template, e.g.,
10154 template<typename... Types> struct A {
10155 template<Types... Values> struct B { };
10156 }; */
10160 {
10166 return cp_build_qualified_type_real
10168 }
10170 {
10171 /* We are processing a type constructed from a
10172 template template parameter. */
10178 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10179 are resolving nested-types in the signature of a
10180 member function templates. Otherwise ARG is a
10181 TEMPLATE_DECL and is the real template to be
10182 instantiated. */
10190 complain);
10191 return cp_build_qualified_type_real
10193 }
10194 else
10195 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10197 }
10200 /* This can happen during the attempted tsubst'ing in
10201 unify. This means that we don't yet have any information
10202 about the template parameter in question. */
10205 /* If we get here, we must have been looking at a parm for a
10206 more deeply nested template. Make a new version of this
10207 template parameter, but with a lower level. */
10209 {
10214 {
10216 r = cp_build_qualified_type_real
10220 }
10221 else
10222 {
10233 /* We have reduced the level of the template
10234 template parameter, but not the levels of its
10235 template parameters, so canonical_type_parameter
10236 will not be able to find the canonical template
10237 template parameter for this level. Thus, we
10238 require structural equality checking to compare
10239 TEMPLATE_TEMPLATE_PARMs. */
10243 else
10247 {
10255 }
10256 }
10265 }
10268 }
10271 {
10279 {
10283 }
10286 {
10290 }
10293 {
10297 }
10303 }
10306 /* We should never be tsubsting a binfo. */
10310 /* A vector of template arguments. */
10316 {
10325 /* [temp.deduct]
10327 Type deduction may fail for any of the following
10328 reasons:
10330 -- Attempting to create a pointer to reference type.
10331 -- Attempting to create a reference to a reference type or
10332 a reference to void.
10334 Core issue 106 says that creating a reference to a reference
10335 during instantiation is no longer a cause for failure. We
10336 only enforce this check in strict C++98 mode. */
10340 {
10343 /* We keep track of the last time we issued this error
10344 message to avoid spewing a ton of messages during a
10345 single bad template instantiation. */
10348 {
10353 else
10356 }
10359 }
10361 {
10365 }
10367 /* In C++0x, during template argument substitution, when there is an
10368 attempt to create a reference to a reference type, reference
10369 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10371 "If a template-argument for a template-parameter T names a type
10372 that is a reference to a type A, an attempt to create the type
10373 'lvalue reference to cv T' creates the type 'lvalue reference to
10374 A,' while an attempt to create the type type rvalue reference to
10375 cv T' creates the type T"
10376 */
10377 r = cp_build_reference_type
10380 else
10385 /* Will this ever be needed for TYPE_..._TO values? */
10389 }
10391 {
10394 {
10395 /* [temp.deduct]
10397 Type deduction may fail for any of the following
10398 reasons:
10400 -- Attempting to create "pointer to member of T" when T
10401 is not a class type. */
10405 }
10407 {
10411 }
10413 {
10417 }
10420 {
10421 /* The type of the implicit object parameter gets its
10422 cv-qualifiers from the FUNCTION_TYPE. */
10423 tree memptr;
10427 complain);
10428 }
10429 else
10432 complain);
10433 }
10436 {
10437 tree fntype;
10438 tree specs;
10443 /* Substitute the exception specification. */
10445 in_decl);
10451 }
10453 {
10458 /* As an optimization, we avoid regenerating the array type if
10459 it will obviously be the same as T. */
10463 /* These checks should match the ones in grokdeclarator.
10465 [temp.deduct]
10467 The deduction may fail for any of the following reasons:
10469 -- Attempting to create an array with an element type that
10470 is void, a function type, or a reference type, or [DR337]
10471 an abstract class type. */
10475 {
10479 }
10481 {
10484 type);
10486 }
10491 {
10494 }
10497 }
10501 {
10510 }
10514 {
10520 }
10523 {
10533 {
10537 }
10539 {
10540 /* Normally, make_typename_type does not require that the CTX
10541 have complete type in order to allow things like:
10543 template <class T> struct S { typename S<T>::X Y; };
10545 But, such constructs have already been resolved by this
10546 point, so here CTX really should have complete type, unless
10547 it's a partial instantiation. */
10551 {
10555 }
10556 }
10563 {
10566 }
10569 {
10576 }
10578 return cp_build_qualified_type_real
10580 }
10583 {
10595 }
10603 {
10611 }
10614 {
10622 }
10625 {
10626 tree type;
10642 complain);
10643 }
10646 {
10647 tree type;
10663 else
10664 type = finish_decltype_type
10669 complain);
10670 }
10674 {
10678 tree packed_out =
10680 args,
10681 complain,
10682 in_decl);
10685 /* For template nontype argument packs, also substitute into
10686 the type. */
10691 }
10698 }
10699 }
10701 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10702 type of the expression on the left-hand side of the "." or "->"
10703 operator. */
10705 static tree
10708 {
10709 tree name;
10710 tree qualifying_scope;
10711 tree fns;
10712 tree optype;
10716 /* A baselink indicates a function from a base class. Both the
10717 BASELINK_ACCESS_BINFO and the base class referenced may
10718 indicate bases of the template class, rather than the
10719 instantiated class. In addition, lookups that were not
10720 ambiguous before may be ambiguous now. Therefore, we perform
10721 the lookup again. */
10728 {
10735 }
10741 /* If lookup found a single function, mark it as used at this
10742 point. (If it lookup found multiple functions the one selected
10743 later by overload resolution will be marked as used at that
10744 point.) */
10750 /* Add back the template arguments, if present. */
10755 template_args);
10756 /* Update the conversion operator type. */
10762 qualifying_scope,
10763 object_type);
10764 }
10766 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10767 true if the qualified-id will be a postfix-expression in-and-of
10768 itself; false if more of the postfix-expression follows the
10769 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10770 of "&". */
10772 static tree
10776 {
10777 tree expr;
10778 tree scope;
10779 tree name;
10781 tree template_args;
10785 /* Figure out what name to look up. */
10788 {
10795 }
10796 else
10797 {
10800 }
10802 /* Substitute into the qualifying scope. When there are no ARGS, we
10803 are just trying to simplify a non-dependent expression. In that
10804 case the qualifying scope may be dependent, and, in any case,
10805 substituting will not help. */
10808 {
10811 }
10812 else
10820 {
10822 {
10823 /* A BIT_NOT_EXPR is used to represent a destructor. */
10825 {
10829 }
10830 else
10833 }
10834 else
10838 {
10840 {
10844 }
10846 }
10847 }
10850 {
10852 scope);
10853 /* Remember that there was a reference to this entity. */
10855 }
10858 {
10864 }
10873 {
10874 expr = (adjust_result_of_qualified_name_lookup
10876 expr = (finish_qualified_id_expr
10880 }
10882 /* Expressions do not generally have reference type. */
10884 /* However, if we're about to form a pointer-to-member, we just
10885 want the referenced member referenced. */
10890 }
10892 /* Like tsubst, but deals with expressions. This function just replaces
10893 template parms; to finish processing the resultant expression, use
10894 tsubst_expr. */
10896 static tree
10898 {
10900 tree r;
10908 {
10913 {
10914 tree c;
10915 /* This can happen for a parameter name used later in a function
10916 declaration (such as in a late-specified return type). Just
10917 make a dummy decl, since it's only used for its type. */
10919 /* We copy T because want to tsubst the PARM_DECL only,
10920 not the following PARM_DECLs that are chained to T. */
10923 /* Give it the template pattern as its context; its true context
10924 hasn't been instantiated yet and this is good enough for
10925 mangling. */
10927 }
10935 {
10936 tree enum_type;
10937 tree v;
10941 /* There is no need to substitute into namespace-scope
10942 enumerators. */
10945 /* If ARGS is NULL, then T is known to be non-dependent. */
10949 /* Unfortunately, we cannot just call lookup_name here.
10950 Consider:
10952 template <int I> int f() {
10953 enum E { a = I };
10954 struct S { void g() { E e = a; } };
10955 };
10957 When we instantiate f<7>::S::g(), say, lookup_name is not
10958 clever enough to find f<7>::a. */
10959 enum_type
10969 /* We didn't find the name. That should never happen; if
10970 name-lookup found it during preliminary parsing, we
10971 should find it again here during instantiation. */
10973 }
10978 {
10979 tree ctx;
10984 {
10987 {
10991 }
10993 }
10994 }
11017 {
11018 /* Template template argument like the following example need
11019 special treatment:
11021 template <template <class> class TT> struct C {};
11022 template <class T> struct D {
11023 template <class U> struct E {};
11024 C<E> c; // #1
11025 };
11026 D<int> d; // #2
11028 We are processing the template argument `E' in #1 for
11029 the template instantiation #2. Originally, `E' is a
11030 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11031 have to substitute this with one having context `D<int>'. */
11035 }
11036 else
11037 /* Ordinary template template argument. */
11046 return build1
11052 {
11053 /* We only want to compute the number of arguments. */
11067 {
11074 else
11077 }
11078 else
11080 }
11081 /* Fall through */
11095 return build1
11100 {
11101 tree object;
11102 tree name;
11107 {
11111 }
11114 {
11124 }
11129 in_decl);
11130 else
11133 }
11171 return build_nt
11184 return build_nt
11191 {
11199 }
11204 {
11205 r = build_nt
11211 }
11214 {
11215 r = build_nt
11221 }
11224 {
11225 r = build_nt
11231 }
11234 {
11235 /* Substituted template arguments */
11244 }
11247 {
11267 }
11292 {
11295 }
11296 else
11300 /* This is handled by tsubst_copy_and_build. */
11305 in_decl),
11309 /* We shouldn't have built any of these during initial template
11310 generation. Instead, they should be built during instantiation
11311 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11328 }
11329 }
11331 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11333 static tree
11335 tree in_decl)
11336 {
11340 {
11346 {
11349 {
11355 }
11356 /* FALLTHRU */
11378 }
11379 }
11382 }
11384 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11386 static tree
11388 tree in_decl)
11389 {
11390 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11415 #undef RECUR
11416 }
11418 /* Substitute one OMP_FOR iterator. */
11420 static void
11425 {
11426 #define RECUR(NODE) \
11427 tsubst_expr ((NODE), args, complain, in_decl, \
11428 integral_constant_expression_p)
11437 {
11444 }
11448 {
11454 complain);
11455 else
11462 }
11465 {
11466 tree c;
11468 {
11479 }
11481 {
11486 {
11489 }
11490 }
11491 }
11497 else
11501 {
11512 {
11519 }
11520 else
11526 {
11532 }
11536 {
11543 }
11544 else
11550 }
11556 #undef RECUR
11557 }
11559 /* Like tsubst_copy for expressions, etc. but also does semantic
11560 processing. */
11562 static tree
11565 {
11566 #define RECUR(NODE) \
11567 tsubst_expr ((NODE), args, complain, in_decl, \
11568 integral_constant_expression_p)
11581 {
11583 {
11584 tree_stmt_iterator i;
11588 }
11603 else
11612 {
11613 tree decl;
11614 tree init;
11620 {
11623 tree decl;
11631 else
11633 }
11634 else
11635 {
11639 {
11640 /* By marking the declaration as instantiated, we avoid
11641 trying to instantiate it. Since instantiate_decl can't
11642 handle local variables, and since we've already done
11643 all that needs to be done, that's the right thing to
11644 do. */
11649 /* Anonymous aggregates are a special case. */
11651 else
11652 {
11656 {
11657 /* For __PRETTY_FUNCTION__ we have to adjust the
11658 initializer. */
11662 }
11663 else
11664 {
11668 /* If we had an initializer but it
11669 instantiated to nothing,
11670 value-initialize the object. This will
11671 only occur when the initializer was a
11672 pack expansion where the parameter packs
11673 used in that expansion were of length
11674 zero. */
11676 else
11678 }
11681 }
11682 }
11683 }
11685 /* A DECL_EXPR can also be used as an expression, in the condition
11686 clause of an if/for/while construct. */
11688 }
11726 {
11730 }
11738 else
11746 else
11773 {
11775 tree label;
11780 }
11786 /* Computed goto's must be tsubst'd into. On the other hand,
11787 non-computed gotos must not be; the identifier in question
11788 will have no binding. */
11790 else
11796 tmp = finish_asm_stmt
11803 {
11808 }
11813 {
11818 }
11819 else
11820 {
11825 else
11832 else
11838 else
11840 }
11844 {
11848 {
11850 /* Prevent instantiate_decl from trying to instantiate
11851 this variable. We've already done all that needs to be
11852 done. */
11855 }
11860 }
11868 {
11869 tree condition =
11871 args,
11878 }
11899 {
11914 integral_constant_expression_p);
11923 {
11927 }
11928 else
11929 {
11937 }
11951 }
11982 {
11987 }
12003 integral_constant_expression_p);
12004 }
12007 #undef RECUR
12008 }
12010 /* T is a postfix-expression that is not being used in a function
12011 call. Return the substituted version of T. */
12013 static tree
12015 tsubst_flags_t complain,
12016 tree in_decl)
12017 {
12021 else
12027 }
12029 /* Like tsubst but deals with expressions and performs semantic
12030 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12032 tree
12034 tree args,
12035 tsubst_flags_t complain,
12036 tree in_decl,
12039 {
12040 #define RECUR(NODE) \
12041 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12043 integral_constant_expression_p)
12045 tree op1;
12051 {
12054 /* Fall through. */
12056 {
12057 tree decl;
12058 cp_id_kind idk;
12063 {
12066 }
12068 /* Look up the name. */
12071 /* By convention, expressions use ERROR_MARK_NODE to indicate
12072 failure, not NULL_TREE. */
12078 integral_constant_expression_p,
12086 input_location);
12092 }
12095 {
12096 tree object;
12104 {
12107 }
12108 else
12115 else
12117 }
12120 {
12124 {
12125 /* A type conversion to reference type will be enclosed in
12126 such an indirect ref, but the substitution of the cast
12127 will have also added such an indirect ref. */
12130 }
12131 else
12134 }
12137 return build_nop
12146 {
12147 tree type;
12148 tree op;
12153 {
12158 }
12163 {
12176 }
12177 }
12195 complain);
12202 else
12204 in_decl);
12241 return build_x_binary_op
12245 ? ERROR_MARK
12249 ? ERROR_MARK
12252 complain);
12265 /* Fall through */
12270 {
12271 /* When there are no ARGS, we are trying to evaluate a
12272 non-dependent expression from the parser. Trying to do
12273 the substitutions may not work. */
12276 }
12277 else
12278 {
12286 }
12290 else
12306 {
12307 tree r = build_x_modify_expr
12311 complain);
12312 /* TREE_NO_WARNING must be set if either the expression was
12313 parenthesized or it uses an operator such as >>= rather
12314 than plain assignment. In the former case, it was already
12315 set and must be copied. In the latter case,
12316 build_x_modify_expr sets it and it must not be reset
12317 here. */
12321 }
12326 /* Remember that there was a reference to this entity. */
12332 {
12337 tree ret;
12341 else
12342 {
12346 }
12348 /* If there was an initializer in the original tree, but it
12349 instantiated to an empty list, then we should pass a
12350 non-NULL empty vector to tell build_new that it was an
12351 empty initializer() rather than no initializer. This can
12352 only happen when the initializer is a pack expansion whose
12353 parameter packs are of length zero. */
12356 else
12357 {
12361 else
12362 {
12365 }
12366 }
12373 complain);
12381 }
12384 return delete_sanity
12393 complain);
12396 {
12397 tree function;
12402 tree ret;
12405 /* When we parsed the expression, we determined whether or
12406 not Koenig lookup should be performed. */
12409 {
12414 }
12415 else
12416 {
12418 {
12424 }
12425 else
12429 in_decl,
12431 integral_constant_expression_p);
12435 }
12440 {
12446 else
12447 {
12448 /* Expand the pack expansion and push each entry onto
12449 CALL_ARGS. */
12452 {
12457 {
12462 }
12463 }
12464 else
12465 {
12466 /* A partial substitution. Add one entry. */
12468 }
12469 }
12470 }
12472 /* We do not perform argument-dependent lookup if normal
12473 lookup finds a non-function, in accordance with the
12474 expected resolution of DR 218. */
12477 /* If lookup found a member function, the Koenig lookup is
12478 not appropriate, even if an unqualified-name was used
12479 to denote the function. */
12482 /* Only do this when substitution turns a dependent call
12483 into a non-dependent call. */
12489 {
12493 }
12495 /* Remember that there was a reference to this entity. */
12502 {
12507 complain);
12508 else
12509 ret = (build_new_method_call
12515 complain));
12516 }
12517 else
12520 koenig_p,
12521 complain);
12526 }
12529 return build_x_conditional_expr
12533 complain);
12536 return finish_pseudo_destructor_expr
12542 {
12550 {
12551 /* We have pack expansions, so expand those and
12552 create a new list out of it. */
12555 tree chain;
12558 /* Expand the argument expressions. */
12566 /* Build the rest of the list. */
12571 /* Determine the number of arguments. */
12573 {
12576 }
12579 else
12580 {
12581 /* Since we only performed a partial substitution into
12582 the argument pack, we only return a single list
12583 node. */
12590 }
12592 /* Convert the argument vectors into a TREE_LIST */
12595 {
12596 /* Grab the Ith values. */
12597 i--;
12600 value
12604 /* Build the list (backwards). */
12606 }
12609 }
12625 }
12628 {
12629 tree object;
12630 tree object_type;
12631 tree member;
12635 /* Remember that there was a reference to this entity. */
12645 else
12651 {
12653 {
12658 {
12661 }
12663 {
12667 }
12668 }
12669 }
12672 {
12673 tree tmpl;
12674 tree args;
12676 /* Lookup the template functions now that we know what the
12677 scope is. */
12684 {
12687 args);
12688 member = (adjust_result_of_qualified_name_lookup
12690 object_type));
12691 }
12692 else
12693 {
12695 input_location);
12697 }
12698 }
12702 {
12704 {
12708 else
12711 }
12713 }
12719 complain);
12720 }
12723 return build_throw
12727 {
12735 tree r;
12740 /* digest_init will do the wrong thing if we let it. */
12744 /* We do not want to process the index of aggregate
12745 initializers as they are identifier nodes which will be
12746 looked up by digest_init. */
12752 {
12757 {
12758 /* Substitute into the pack expansion. */
12760 in_decl);
12763 ;
12765 /* Just move the argument into place. */
12767 else
12768 {
12769 /* Update the length of the final CONSTRUCTOR
12770 arguments vector, and note that we will need to
12771 copy.*/
12774 }
12775 }
12776 else
12778 }
12781 {
12786 idx++)
12787 {
12789 {
12794 }
12795 else
12797 }
12798 }
12807 }
12810 {
12815 }
12820 /* Fall through */
12823 {
12827 /* If the original type was a reference, we'll be wrapped in
12828 the appropriate INDIRECT_REF. */
12831 }
12836 in_decl));
12842 {
12851 }
12854 {
12860 integral_constant_expression_p);
12864 /* If the resulting list of expression statement is empty,
12865 fold it further into void_zero_node. */
12870 }
12874 /* As in finish_id_expression, we resolve enumeration constants
12875 to their underlying values. */
12877 {
12880 }
12884 {
12905 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12907 /* Now that we know visibility, instantiate the type so we have a
12908 declaration of the op() for later calls to lambda_function. */
12916 }
12919 /* Handle Objective-C++ constructs, if appropriate. */
12920 {
12921 tree subst
12926 }
12928 }
12930 #undef RECUR
12931 }
12933 /* Verify that the instantiated ARGS are valid. For type arguments,
12934 make sure that the type's linkage is ok. For non-type arguments,
12935 make sure they are constants if they are integral or enumerations.
12936 Emit an error under control of COMPLAIN, and return TRUE on error. */
12938 static bool
12940 {
12942 {
12952 }
12954 {
12955 /* [basic.link]: A name with no linkage (notably, the name
12956 of a class or enumeration declared in a local scope)
12957 shall not be used to declare an entity with linkage.
12958 This implies that names with no linkage cannot be used as
12959 template arguments
12961 DR 757 relaxes this restriction for C++0x. */
12966 {
12967 /* DR 488 makes use of a type with no linkage cause
12968 type deduction to fail. */
12970 {
12973 else
12976 }
12978 }
12979 /* In order to avoid all sorts of complications, we do not
12980 allow variably-modified types as template arguments. */
12982 {
12986 }
12987 }
12988 /* A non-type argument of integral or enumerated type must be a
12989 constant. */
12993 {
12997 }
12999 }
13001 static bool
13003 {
13008 {
13011 }
13015 }
13017 /* Instantiate the indicated variable or function template TMPL with
13018 the template arguments in TARG_PTR. */
13020 tree
13022 {
13024 tree fndecl;
13025 tree gen_tmpl;
13026 tree spec;
13027 HOST_WIDE_INT saved_processing_template_decl;
13034 /* If this function is a clone, handle it specially. */
13036 {
13037 tree spec;
13038 tree clone;
13040 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13041 DECL_CLONED_FUNCTION. */
13047 /* Look for the clone. */
13051 /* We should always have found the clone by now. */
13054 }
13056 /* Check to see if we already have this specialization. */
13059 /* The TMPL is a partial instantiation. To get a full set of
13060 arguments we must add the arguments used to perform the
13061 partial instantiation. */
13063 targ_ptr);
13065 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13066 but it doesn't seem to be on the hot path. */
13078 complain))
13081 /* We are building a FUNCTION_DECL, during which the access of its
13082 parameters and return types have to be checked. However this
13083 FUNCTION_DECL which is the desired context for access checking
13084 is not built yet. We solve this chicken-and-egg problem by
13085 deferring all checks until we have the FUNCTION_DECL. */
13088 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13089 (because, for example, we have encountered a non-dependent
13090 function call in the body of a template function and must now
13091 determine which of several overloaded functions will be called),
13092 within the instantiation itself we are not processing a
13093 template. */
13096 /* Substitute template parameters to obtain the specialization. */
13103 /* Now we know the specialization, compute access previously
13104 deferred. */
13107 /* Some typedefs referenced from within the template code need to be access
13108 checked at template instantiation time, i.e now. These types were
13109 added to the template at parsing time. Let's get those and perfom
13110 the acces checks then. */
13116 /* The DECL_TI_TEMPLATE should always be the immediate parent
13117 template, not the most general template. */
13120 /* If we've just instantiated the main entry point for a function,
13121 instantiate all the alternate entry points as well. We do this
13122 by cloning the instantiation of the main entry point, not by
13123 instantiating the template clones. */
13128 }
13130 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13131 NARGS elements of the arguments that are being used when calling
13132 it. TARGS is a vector into which the deduced template arguments
13133 are placed.
13135 Return zero for success, 2 for an incomplete match that doesn't resolve
13136 all the types, and 1 for complete failure. An error message will be
13137 printed only for an incomplete match.
13139 If FN is a conversion operator, or we are trying to produce a specific
13140 specialization, RETURN_TYPE is the return type desired.
13142 The EXPLICIT_TARGS are explicit template arguments provided via a
13143 template-id.
13145 The parameter STRICT is one of:
13147 DEDUCE_CALL:
13148 We are deducing arguments for a function call, as in
13149 [temp.deduct.call].
13151 DEDUCE_CONV:
13152 We are deducing arguments for a conversion function, as in
13153 [temp.deduct.conv].
13155 DEDUCE_EXACT:
13156 We are deducing arguments when doing an explicit instantiation
13157 as in [temp.explicit], when determining an explicit specialization
13158 as in [temp.expl.spec], or when taking the address of a function
13159 template, as in [temp.deduct.funcaddr]. */
13161 int
13163 tree explicit_targs,
13164 tree targs,
13167 tree return_type,
13168 unification_kind_t strict,
13170 {
13171 tree parms;
13172 tree fntype;
13180 {
13181 /* [temp.deduct]
13183 The specified template arguments must match the template
13184 parameters in kind (i.e., type, nontype, template), and there
13185 must not be more arguments than there are parameters;
13186 otherwise type deduction fails.
13188 Nontype arguments must match the types of the corresponding
13189 nontype template parameters, or must be convertible to the
13190 types of the corresponding nontype parameters as specified in
13191 _temp.arg.nontype_, otherwise type deduction fails.
13193 All references in the function type of the function template
13194 to the corresponding template parameters are replaced by the
13195 specified template argument values. If a substitution in a
13196 template parameter or in the function type of the function
13197 template results in an invalid type, type deduction fails. */
13200 tree converted_args;
13206 converted_args
13213 /* Substitute the explicit args into the function type. This is
13214 necessary so that, for instance, explicitly declared function
13215 arguments can match null pointed constants. If we were given
13216 an incomplete set of explicit args, we must not do semantic
13217 processing during substitution as we could create partial
13218 instantiations. */
13220 {
13224 /* Dig out the actual parm. */
13227 {
13230 }
13232 {
13235 }
13238 {
13240 tree targ;
13243 /* Mark the argument pack as "incomplete". We could
13244 still deduce more arguments during unification. */
13247 {
13251 }
13253 /* We have some incomplete argument packs. */
13255 }
13256 }
13259 /* Any substitution is guaranteed to be incomplete if there
13260 are incomplete argument packs, because we can still deduce
13261 more arguments. */
13263 else
13273 /* Place the explicitly specified arguments in TARGS. */
13276 }
13278 /* Never do unification on the 'this' parameter. */
13282 {
13291 }
13293 /* We allow incomplete unification without an error message here
13294 because the standard doesn't seem to explicitly prohibit it. Our
13295 callers must be ready to deal with unification failures in any
13296 event. */
13302 {
13305 /* Clear the "incomplete" flags on all argument packs. */
13307 {
13310 {
13313 }
13314 }
13315 }
13317 /* Now that we have bindings for all of the template arguments,
13318 ensure that the arguments deduced for the template template
13319 parameters have compatible template parameter lists. We cannot
13320 check this property before we have deduced all template
13321 arguments, because the template parameter types of a template
13322 template parameter might depend on prior template parameters
13323 deduced after the template template parameter. The following
13324 ill-formed example illustrates this issue:
13326 template<typename T, template<T> class C> void f(C<5>, T);
13328 template<int N> struct X {};
13330 void g() {
13331 f(X<5>(), 5l); // error: template argument deduction fails
13332 }
13334 The template parameter list of 'C' depends on the template type
13335 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13336 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13337 time that we deduce 'C'. */
13339 && !template_template_parm_bindings_ok_p
13344 /* All is well so far. Now, check:
13346 [temp.deduct]
13348 When all template arguments have been deduced, all uses of
13349 template parameters in nondeduced contexts are replaced with
13350 the corresponding deduced argument values. If the
13351 substitution results in an invalid type, as described above,
13352 type deduction fails. */
13353 {
13358 /* If we're looking for an exact match, check that what we got
13359 is indeed an exact match. It might not be if some template
13360 parameters are used in non-deduced contexts. */
13362 {
13365 tree sarg
13372 }
13373 }
13376 }
13378 /* Adjust types before performing type deduction, as described in
13379 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13380 sections are symmetric. PARM is the type of a function parameter
13381 or the return type of the conversion function. ARG is the type of
13382 the argument passed to the call, or the type of the value
13383 initialized with the result of the conversion function.
13384 ARG_EXPR is the original argument expression, which may be null. */
13386 static int
13390 tree arg_expr)
13391 {
13395 {
13400 {
13401 /* Swap PARM and ARG throughout the remainder of this
13402 function; the handling is precisely symmetric since PARM
13403 will initialize ARG rather than vice versa. */
13408 }
13411 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13412 too, but here handle it by stripping the reference from PARM
13413 rather than by adding it to ARG. */
13421 /* Nothing else to do in this case. */
13426 }
13429 {
13430 /* [temp.deduct.call]
13432 If P is not a reference type:
13434 --If A is an array type, the pointer type produced by the
13435 array-to-pointer standard conversion (_conv.array_) is
13436 used in place of A for type deduction; otherwise,
13438 --If A is a function type, the pointer type produced by
13439 the function-to-pointer standard conversion
13440 (_conv.func_) is used in place of A for type deduction;
13441 otherwise,
13443 --If A is a cv-qualified type, the top level
13444 cv-qualifiers of A's type are ignored for type
13445 deduction. */
13450 else
13452 }
13454 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13455 of the form T&&, where T is a template parameter, and the argument
13456 is an lvalue, T is deduced as A& */
13464 /* [temp.deduct.call]
13466 If P is a cv-qualified type, the top level cv-qualifiers
13467 of P's type are ignored for type deduction. If P is a
13468 reference type, the type referred to by P is used for
13469 type deduction. */
13472 {
13475 }
13477 /* DR 322. For conversion deduction, remove a reference type on parm
13478 too (which has been swapped into ARG). */
13483 }
13485 /* Most parms like fn_type_unification.
13487 If SUBR is 1, we're being called recursively (to unify the
13488 arguments of a function or method parameter of a function
13489 template). */
13491 static int
13493 tree targs,
13494 tree xparms,
13498 unification_kind_t strict,
13500 {
13506 tree parms;
13515 /* Reset the number of non-defaulted template arguments contained
13516 in in TARGS. */
13520 {
13536 }
13538 again:
13546 {
13559 /* We can't deduce anything from this, but we might get all the
13560 template args from other function args. */
13563 /* Conversions will be performed on a function argument that
13564 corresponds with a function parameter that contains only
13565 non-deducible template parameters and explicitly specified
13566 template parameters. */
13568 {
13569 tree type;
13573 else
13580 flags))
13584 }
13587 {
13590 {
13591 /* [temp.deduct.type]
13593 A template-argument can be deduced from a pointer to
13594 function or pointer to member function argument if
13595 the set of overloaded functions does not contain
13596 function templates and at most one of a set of
13597 overloaded functions provides a unique match. */
13603 }
13608 }
13610 {
13615 arg_expr);
13621 }
13622 }
13628 {
13629 /* Unify the remaining arguments with the pack expansion type. */
13630 tree argvec;
13633 /* Allocate a TREE_VEC and copy in all of the arguments */
13638 /* Copy the parameter into parmvec. */
13644 /* Advance to the end of the list of parameters. */
13646 }
13648 /* Fail if we've reached the end of the parm list, and more args
13649 are present, and the parm list isn't variadic. */
13652 /* Fail if parms are left and they don't have default values. */
13660 {
13661 tree tparm;
13668 /* If this is an undeduced nontype parameter that depends on
13669 a type parameter, try another pass; its type may have been
13670 deduced from a later argument than the one from which
13671 this parameter can be deduced. */
13677 /* Core issue #226 (C++0x) [temp.deduct]:
13679 If a template argument has not been deduced, its
13680 default template argument, if any, is used.
13682 When we are in C++98 mode, TREE_PURPOSE will either
13683 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13684 to explicitly check cxx_dialect here. */
13686 {
13694 else
13695 {
13697 /* The position of the first default template argument,
13698 is also the number of non-defaulted arguments in TARGS.
13699 Record that. */
13703 }
13704 }
13706 /* If the type parameter is a parameter pack, then it will
13707 be deduced to an empty parameter pack. */
13709 {
13710 tree arg;
13713 {
13717 }
13718 else
13725 }
13728 }
13729 #ifdef ENABLE_CHECKING
13732 #endif
13735 }
13737 /* Subroutine of type_unification_real. Args are like the variables
13738 at the call site. ARG is an overloaded function (or template-id);
13739 we try deducing template args from each of the overloads, and if
13740 only one succeeds, we go with that. Modifies TARGS and returns
13741 true on success. */
13743 static bool
13745 tree targs,
13746 tree parm,
13747 tree arg,
13748 unification_kind_t strict,
13750 {
13757 {
13760 }
13761 else
13765 /* Handle `&x' where `x' is some static or non-static member
13766 function name. */
13772 /* Strip baselink information. */
13777 {
13778 /* If we got some explicit template args, we need to plug them into
13779 the affected templates before we try to unify, in case the
13780 explicit args will completely resolve the templates in question. */
13786 {
13797 {
13802 {
13805 }
13806 }
13808 }
13809 }
13812 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13813 -- but the deduction does not succeed because the expression is
13814 not just the function on its own. */
13816 else
13822 {
13825 }
13827 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13828 to function or pointer to member function argument if the set of
13829 overloaded functions does not contain function templates and at most
13830 one of a set of overloaded functions provides a unique match.
13832 So if we found multiple possibilities, we return success but don't
13833 deduce anything. */
13836 {
13841 }
13846 }
13848 /* Core DR 115: In contexts where deduction is done and fails, or in
13849 contexts where deduction is not done, if a template argument list is
13850 specified and it, along with any default template arguments, identifies
13851 a single function template specialization, then the template-id is an
13852 lvalue for the function template specialization. */
13854 tree
13856 {
13869 {
13872 }
13874 {
13877 }
13879 {
13882 }
13885 {
13889 /* If we got some explicit template args, we need to plug them into
13890 the affected templates before we try to unify, in case the
13891 explicit args will completely resolve the templates in question. */
13899 {
13910 {
13913 {
13916 }
13918 {
13921 }
13922 }
13924 }
13926 {
13938 }
13940 /* There were no good options and at least one bad one, so let the
13941 user know what the problem is. */
13943 }
13945 }
13947 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13948 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13949 different overloads deduce different arguments for a given parm.
13950 ADDR_P is true if the expression for which deduction is being
13951 performed was of the form "& fn" rather than simply "fn".
13953 Returns 1 on success. */
13955 static int
13957 tree orig_targs,
13958 tree targs,
13959 tree parm,
13960 tree arg,
13961 unification_kind_t strict,
13964 {
13966 tree tempargs;
13969 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13970 to function or pointer to member function argument if the set of
13971 overloaded functions does not contain function templates and at most
13972 one of a set of overloaded functions provides a unique match.
13974 So if this is a template, just return success. */
13986 /* We don't copy orig_targs for this because if we have already deduced
13987 some template args from previous args, unify would complain when we
13988 try to deduce a template parameter for the same argument, even though
13989 there isn't really a conflict. */
13996 /* First make sure we didn't deduce anything that conflicts with
13997 explicitly specified args. */
13999 {
14006 /* Since we're unifying against ourselves, we will fill in
14007 template args used in the function parm list with our own
14008 template parms. Discard them. */
14012 }
14015 {
14020 }
14023 }
14025 /* PARM is a template class (perhaps with unbound template
14026 parameters). ARG is a fully instantiated type. If ARG can be
14027 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14028 TARGS are as for unify. */
14030 static tree
14032 {
14033 tree copy_of_targs;
14040 /* We need to make a new template argument vector for the call to
14041 unify. If we used TARGS, we'd clutter it up with the result of
14042 the attempted unification, even if this class didn't work out.
14043 We also don't want to commit ourselves to all the unifications
14044 we've already done, since unification is supposed to be done on
14045 an argument-by-argument basis. In other words, consider the
14046 following pathological case:
14048 template <int I, int J, int K>
14049 struct S {};
14051 template <int I, int J>
14052 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14054 template <int I, int J, int K>
14055 void f(S<I, J, K>, S<I, I, I>);
14057 void g() {
14058 S<0, 0, 0> s0;
14059 S<0, 1, 2> s2;
14061 f(s0, s2);
14062 }
14064 Now, by the time we consider the unification involving `s2', we
14065 already know that we must have `f<0, 0, 0>'. But, even though
14066 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14067 because there are two ways to unify base classes of S<0, 1, 2>
14068 with S<I, I, I>. If we kept the already deduced knowledge, we
14069 would reject the possibility I=1. */
14072 /* If unification failed, we're done. */
14078 }
14080 /* Given a template type PARM and a class type ARG, find the unique
14081 base type in ARG that is an instance of PARM. We do not examine
14082 ARG itself; only its base-classes. If there is not exactly one
14083 appropriate base class, return NULL_TREE. PARM may be the type of
14084 a partial specialization, as well as a plain template type. Used
14085 by unify. */
14087 static tree
14089 {
14091 tree binfo;
14097 /* The type could not be completed. */
14100 /* Walk in inheritance graph order. The search order is not
14101 important, and this avoids multiple walks of virtual bases. */
14103 {
14107 {
14108 /* If there is more than one satisfactory baseclass, then:
14110 [temp.deduct.call]
14112 If they yield more than one possible deduced A, the type
14113 deduction fails.
14115 applies. */
14120 }
14121 }
14124 }
14126 /* Returns the level of DECL, which declares a template parameter. */
14128 static int
14130 {
14132 {
14142 }
14144 }
14146 /* Decide whether ARG can be unified with PARM, considering only the
14147 cv-qualifiers of each type, given STRICT as documented for unify.
14148 Returns nonzero iff the unification is OK on that basis. */
14150 static int
14152 {
14158 {
14159 /* Although a CVR qualifier is ignored when being applied to a
14160 substituted template parameter ([8.3.2]/1 for example), that
14161 does not allow us to unify "const T" with "int&" because both
14162 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14163 It is ok when we're allowing additional CV qualifiers
14164 at the outer level [14.8.2.1]/3,1st bullet. */
14174 }
14185 }
14187 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14188 void
14190 {
14194 {
14197 }
14198 else
14199 {
14202 }
14203 }
14205 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14206 expansion at the end of PACKED_PARMS. Returns 0 if the type
14207 deduction succeeds, 1 otherwise. STRICT is the same as in
14208 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14209 call argument list. We'll need to adjust the arguments to make them
14210 types. SUBR tells us if this is from a recursive call to
14211 type_unification_real. */
14212 int
14216 {
14217 tree parm
14224 /* Determine the parameter packs we will be deducing from the
14225 pattern, and record their current deductions. */
14228 {
14232 /* Determine the index and level of this parameter pack. */
14235 /* Keep track of the parameter packs and their corresponding
14236 argument packs. */
14239 }
14241 /* Loop through all of the arguments that have not yet been
14242 unified and unify each with the pattern. */
14244 {
14247 /* For each parameter pack, clear out the deduced value so that
14248 we can deduce it again. */
14250 {
14255 }
14257 /* Unify the pattern with the current argument. */
14258 {
14265 {
14268 /* This mirrors what we do in type_unification_real. */
14270 {
14272 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14273 | UNIFY_ALLOW_MORE_CV_QUAL
14287 }
14290 {
14293 {
14294 /* [temp.deduct.type] A template-argument can be
14295 deduced from a pointer to function or pointer
14296 to member function argument if the set of
14297 overloaded functions does not contain function
14298 templates and at most one of a set of
14299 overloaded functions provides a unique
14300 match. */
14305 sub_strict)
14309 }
14312 {
14317 }
14318 }
14323 arg_strict |=
14326 }
14329 {
14330 /* For deduction from an init-list we need the actual list. */
14335 }
14336 }
14338 /* For each parameter pack, collect the deduced value. */
14340 {
14346 }
14347 }
14349 /* Verify that the results of unification with the parameter packs
14350 produce results consistent with what we've seen before, and make
14351 the deduced argument packs available. */
14353 {
14360 /* By default keep the original deduced argument pack.
14361 If necessary, more specific code is going to update the
14362 resulting deduced argument later down in this function. */
14366 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14367 actually deduce anything. */
14375 {
14376 /* Prepend the explicit arguments onto NEW_ARGS. */
14382 /* Copy the explicit arguments. */
14387 /* Copy the deduced arguments. */
14391 }
14394 {
14395 tree result;
14396 /* Build the deduced *_ARGUMENT_PACK. */
14398 {
14403 }
14404 else
14409 /* Note the deduced argument packs for this parameter
14410 pack. */
14412 }
14416 {
14417 /* We only had the explicitly-provided arguments before, but
14418 now we have a complete set of arguments. */
14424 }
14426 new_args))
14427 /* Inconsistent unification of this parameter pack. */
14429 }
14432 }
14434 /* Deduce the value of template parameters. TPARMS is the (innermost)
14435 set of template parameters to a template. TARGS is the bindings
14436 for those template parameters, as determined thus far; TARGS may
14437 include template arguments for outer levels of template parameters
14438 as well. PARM is a parameter to a template function, or a
14439 subcomponent of that parameter; ARG is the corresponding argument.
14440 This function attempts to match PARM with ARG in a manner
14441 consistent with the existing assignments in TARGS. If more values
14442 are deduced, then TARGS is updated.
14444 Returns 0 if the type deduction succeeds, 1 otherwise. The
14445 parameter STRICT is a bitwise or of the following flags:
14447 UNIFY_ALLOW_NONE:
14448 Require an exact match between PARM and ARG.
14449 UNIFY_ALLOW_MORE_CV_QUAL:
14450 Allow the deduced ARG to be more cv-qualified (by qualification
14451 conversion) than ARG.
14452 UNIFY_ALLOW_LESS_CV_QUAL:
14453 Allow the deduced ARG to be less cv-qualified than ARG.
14454 UNIFY_ALLOW_DERIVED:
14455 Allow the deduced ARG to be a template base class of ARG,
14456 or a pointer to a template base class of the type pointed to by
14457 ARG.
14458 UNIFY_ALLOW_INTEGER:
14459 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14460 case for more information.
14461 UNIFY_ALLOW_OUTER_LEVEL:
14462 This is the outermost level of a deduction. Used to determine validity
14463 of qualification conversions. A valid qualification conversion must
14464 have const qualified pointers leading up to the inner type which
14465 requires additional CV quals, except at the outer level, where const
14466 is not required [conv.qual]. It would be normal to set this flag in
14467 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14468 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14469 This is the outermost level of a deduction, and PARM can be more CV
14470 qualified at this point.
14471 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14472 This is the outermost level of a deduction, and PARM can be less CV
14473 qualified at this point. */
14475 static int
14477 {
14479 tree targ;
14480 tree tparm;
14483 /* I don't think this will do the right thing with respect to types.
14484 But the only case I've seen it in so far has been array bounds, where
14485 signedness is the only information lost, and I think that will be
14486 okay. */
14494 /* We can't deduce anything from this, but we might get all the
14495 template args from other function args. */
14498 /* If PARM uses template parameters, then we can't bail out here,
14499 even if ARG == PARM, since we won't record unifications for the
14500 template parameters. We might need them if we're trying to
14501 figure out which of two things is more specialized. */
14505 /* Handle init lists early, so the rest of the function can assume
14506 we're dealing with a type. */
14508 {
14513 /* Replace T with std::initializer_list<T> for deduction. */
14519 /* We can only deduce from an initializer list argument if the
14520 parameter is std::initializer_list; otherwise this is a
14521 non-deduced context. */
14527 {
14534 {
14536 /* It should only be possible to get here for a call. */
14538 elt_strict |= maybe_adjust_types_for_deduction
14541 }
14545 }
14547 /* If the std::initializer_list<T> deduction worked, replace the
14548 deduced A with std::initializer_list<A>. */
14550 {
14555 }
14557 }
14559 /* Immediately reject some pairs that won't unify because of
14560 cv-qualification mismatches. */
14563 /* It is the elements of the array which hold the cv quals of an array
14564 type, and the elements might be template type parms. We'll check
14565 when we recurse. */
14567 /* We check the cv-qualifiers when unifying with template type
14568 parameters below. We want to allow ARG `const T' to unify with
14569 PARM `T' for example, when computing which of two templates
14570 is more specialized, for example. */
14584 {
14588 /* In a type which contains a nested-name-specifier, template
14589 argument values cannot be deduced for template parameters used
14590 within the nested-name-specifier. */
14602 /* The PARM is not one we're trying to unify. Just check
14603 to see if it matches ARG. */
14610 /* Check for mixed types and values. */
14618 {
14619 /* ARG must be constructed from a template class or a template
14620 template parameter. */
14625 {
14628 tree parm_parms
14629 = DECL_INNERMOST_TEMPLATE_PARMS
14634 /* The resolution to DR150 makes clear that default
14635 arguments for an N-argument may not be used to bind T
14636 to a template template parameter with fewer than N
14637 parameters. It is not safe to permit the binding of
14638 default arguments as an extension, as that may change
14639 the meaning of a conforming program. Consider:
14641 struct Dense { static const unsigned int dim = 1; };
14643 template <template <typename> class View,
14644 typename Block>
14645 void operator+(float, View<Block> const&);
14647 template <typename Block,
14648 unsigned int Dim = Block::dim>
14649 struct Lvalue_proxy { operator float() const; };
14651 void
14652 test_1d (void) {
14653 Lvalue_proxy<Dense> p;
14654 float b;
14655 b + p;
14656 }
14658 Here, if Lvalue_proxy is permitted to bind to View, then
14659 the global operator+ will be used; if they are not, the
14660 Lvalue_proxy will be converted to float. */
14662 argvec,
14664 tf_none,
14670 /* Deduce arguments T, i from TT<T> or TT<i>.
14671 We check each element of PARMVEC and ARGVEC individually
14672 rather than the whole TREE_VEC since they can have
14673 different number of elements. */
14680 /* Check if the parameters end in a pack, making them
14681 variadic. */
14690 {
14694 UNIFY_ALLOW_NONE))
14696 }
14701 UNIFY_ALLOW_NONE,
14705 }
14708 /* Fall through to deduce template name. */
14709 }
14713 {
14714 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14716 /* Simple cases: Value already set, does match or doesn't. */
14721 }
14722 else
14723 {
14724 /* If PARM is `const T' and ARG is only `int', we don't have
14725 a match unless we are allowing additional qualification.
14726 If ARG is `const int' and PARM is just `T' that's OK;
14727 that binds `const int' to `T'. */
14732 /* Consider the case where ARG is `const volatile int' and
14733 PARM is `const T'. Then, T should be `volatile int'. */
14734 arg = cp_build_qualified_type_real
14739 /* Simple cases: Value already set, does match or doesn't. */
14745 /* Make sure that ARG is not a variable-sized array. (Note
14746 that were talking about variable-sized arrays (like
14747 `int[n]'), rather than arrays of unknown size (like
14748 `int[]').) We'll get very confused by such a type since
14749 the bound of the array will not be computable in an
14750 instantiation. Besides, such types are not allowed in
14751 ISO C++, so we can do as we please here. */
14755 /* Strip typedefs as in convert_template_argument. */
14757 }
14759 /* If ARG is a parameter pack or an expansion, we cannot unify
14760 against it unless PARM is also a parameter pack. */
14765 /* If the argument deduction results is a METHOD_TYPE,
14766 then there is a problem.
14767 METHOD_TYPE doesn't map to any real C++ type the result of
14768 the deduction can not be of that type. */
14782 /* The PARM is not one we're trying to unify. Just check
14783 to see if it matches ARG. */
14793 /* [temp.deduct.type] If, in the declaration of a function template
14794 with a non-type template-parameter, the non-type
14795 template-parameter is used in an expression in the function
14796 parameter-list and, if the corresponding template-argument is
14797 deduced, the template-argument type shall match the type of the
14798 template-parameter exactly, except that a template-argument
14799 deduced from an array bound may be of any integral type.
14800 The non-type parameter might use already deduced type parameters. */
14803 /* Template-parameter dependent expression. Just accept it for now.
14804 It will later be processed in convert_template_argument. */
14805 ;
14811 /* Convert the ARG to the type of PARM; the deduced non-type
14812 template argument must exactly match the types of the
14813 corresponding parameter. */
14816 /* We haven't deduced the type of this parameter yet. Try again
14817 later. */
14819 else
14822 /* If ARG is a parameter pack or an expansion, we cannot unify
14823 against it unless PARM is also a parameter pack. */
14832 {
14833 /* A pointer-to-member constant can be unified only with
14834 another constant. */
14838 /* Just unify the class member. It would be useless (and possibly
14839 wrong, depending on the strict flags) to unify also
14840 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14841 arg refer to the same variable, even if through different
14842 classes. For instance:
14844 struct A { int x; };
14845 struct B : A { };
14847 Unification of &A::x and &B::x must succeed. */
14850 }
14853 {
14857 /* [temp.deduct.call]
14859 A can be another pointer or pointer to member type that can
14860 be converted to the deduced A via a qualification
14861 conversion (_conv.qual_).
14863 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14864 This will allow for additional cv-qualification of the
14865 pointed-to types if appropriate. */
14868 /* The derived-to-base conversion only persists through one
14869 level of pointers. */
14874 }
14889 {
14890 tree parm_max;
14891 tree arg_max;
14895 /* Our representation of array types uses "N - 1" as the
14896 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14897 not an integer constant. We cannot unify arbitrarily
14898 complex expressions, so we eliminate the MINUS_EXPRs
14899 here. */
14903 {
14906 }
14910 {
14911 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14912 trying to unify the type of a variable with the type
14913 of a template parameter. For example:
14915 template <unsigned int N>
14916 void f (char (&) [N]);
14917 int g();
14918 void h(int i) {
14919 char a[g(i)];
14920 f(a);
14921 }
14923 Here, the type of the ARG will be "int [g(i)]", and
14924 may be a SAVE_EXPR, etc. */
14928 }
14930 /* If only one of the bounds used a MINUS_EXPR, compensate
14931 by adding one to the other bound. */
14934 integer_type_node,
14935 parm_max,
14936 integer_one_node);
14939 integer_type_node,
14940 arg_max,
14941 integer_one_node);
14945 }
14959 /* We have already checked cv-qualification at the top of the
14960 function. */
14964 /* As far as unification is concerned, this wins. Later checks
14965 will invalidate it if necessary. */
14968 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14969 /* Type INTEGER_CST can come from ordinary constant template args. */
14979 {
14988 UNIFY_ALLOW_NONE))
14991 }
14999 {
15006 strict);
15007 }
15010 {
15014 {
15015 /* First, we try to unify the PARM and ARG directly. */
15020 {
15021 /* Fallback to the special case allowed in
15022 [temp.deduct.call]:
15024 If P is a class, and P has the form
15025 template-id, then A can be a derived class of
15026 the deduced A. Likewise, if P is a pointer to
15027 a class of the form template-id, A can be a
15028 pointer to a derived class pointed to by the
15029 deduced A. */
15034 }
15035 }
15039 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15040 Then, we should unify `int' and `U'. */
15042 else
15043 /* There's no chance of unification succeeding. */
15048 }
15055 {
15058 tree a;
15064 /* CV qualifications for methods can never be deduced, they must
15065 match exactly. We need to check them explicitly here,
15066 because type_unification_real treats them as any other
15067 cv-qualified parameter. */
15069 && (!check_cv_quals_for_unify
15089 LOOKUP_NORMAL);
15090 }
15093 /* Unify a pointer to member with a pointer to member function, which
15094 deduces the type of the member as a function type. */
15096 {
15097 tree method_type;
15098 tree fntype;
15100 /* Check top-level cv qualifiers */
15108 /* Determine the type of the function we are unifying against. */
15110 fntype =
15114 /* Extract the cv-qualifiers of the member function from the
15115 implicit object parameter and place them on the function
15116 type to be restored later. */
15119 }
15127 strict);
15138 /* Matched cases are handled by the ARG == PARM test above. */
15142 /* A non-type template parameter that is a variable should be a
15143 an integral constant, in which case, it whould have been
15144 folded into its (constant) value. So we should not be getting
15145 a variable here. */
15150 {
15158 {
15160 {
15162 /* We can unify against something with a trailing
15163 parameter pack. */
15165 else
15166 /* Since there is something following the pack
15167 expansion, we cannot unify this template argument
15168 list. */
15170 }
15171 }
15174 /* If we don't have enough arguments to satisfy the parameters
15175 (not counting the pack expression at the end), or we have
15176 too many arguments for a parameter list that doesn't end in
15177 a pack expression, we can't unify. */
15182 /* Unify all of the parameters that precede the (optional)
15183 pack expression. */
15185 {
15189 }
15197 }
15203 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15204 nodes. */
15208 /* Unification fails if we hit an error node. */
15214 /* We must be looking at an expression. This can happen with
15215 something like:
15217 template <int I>
15218 void foo(S<I>, S<I + 2>);
15220 This is a "nondeduced context":
15222 [deduct.type]
15224 The nondeduced contexts are:
15226 --A type that is a template-id in which one or more of
15227 the template-arguments is an expression that references
15228 a template-parameter.
15230 In these cases, we assume deduction succeeded, but don't
15231 actually infer any unifications. */
15236 else
15238 }
15239 }
15240 \f
15241 /* Note that DECL can be defined in this translation unit, if
15242 required. */
15244 static void
15246 {
15247 tree clone;
15251 }
15253 /* Called if RESULT is explicitly instantiated, or is a member of an
15254 explicitly instantiated class. */
15256 void
15258 {
15261 /* If this entity has already been written out, it's too late to
15262 make any modifications. */
15267 /* The TREE_PUBLIC flag for function declarations will have been
15268 set correctly by tsubst. */
15271 /* This might have been set by an earlier implicit instantiation. */
15276 else
15277 {
15279 /* Always make artificials weak. */
15282 /* For WIN32 we also want to put explicit instantiations in
15283 linkonce sections. */
15286 }
15288 /* If EXTERN_P, then this function will not be emitted -- unless
15289 followed by an explicit instantiation, at which point its linkage
15290 will be adjusted. If !EXTERN_P, then this function will be
15291 emitted here. In neither circumstance do we want
15292 import_export_decl to adjust the linkage. */
15294 }
15296 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15297 important template arguments. If any are missing, we check whether
15298 they're important by using error_mark_node for substituting into any
15299 args that were used for partial ordering (the ones between ARGS and END)
15300 and seeing if it bubbles up. */
15302 static bool
15304 {
15309 {
15312 }
15314 {
15316 {
15320 }
15321 }
15323 }
15325 /* Given two function templates PAT1 and PAT2, return:
15327 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15328 -1 if PAT2 is more specialized than PAT1.
15329 0 if neither is more specialized.
15331 LEN indicates the number of parameters we should consider
15332 (defaulted parameters should not be considered).
15334 The 1998 std underspecified function template partial ordering, and
15335 DR214 addresses the issue. We take pairs of arguments, one from
15336 each of the templates, and deduce them against each other. One of
15337 the templates will be more specialized if all the *other*
15338 template's arguments deduce against its arguments and at least one
15339 of its arguments *does* *not* deduce against the other template's
15340 corresponding argument. Deduction is done as for class templates.
15341 The arguments used in deduction have reference and top level cv
15342 qualifiers removed. Iff both arguments were originally reference
15343 types *and* deduction succeeds in both directions, the template
15344 with the more cv-qualified argument wins for that pairing (if
15345 neither is more cv-qualified, they both are equal). Unlike regular
15346 deduction, after all the arguments have been deduced in this way,
15347 we do *not* verify the deduced template argument values can be
15348 substituted into non-deduced contexts.
15350 The logic can be a bit confusing here, because we look at deduce1 and
15351 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15352 can find template arguments for pat1 to make arg1 look like arg2, that
15353 means that arg2 is at least as specialized as arg1. */
15355 int
15357 {
15370 /* Remove the this parameter from non-static member functions. If
15371 one is a non-static member function and the other is not a static
15372 member function, remove the first parameter from that function
15373 also. This situation occurs for operator functions where we
15374 locate both a member function (with this pointer) and non-member
15375 operator (with explicit first operand). */
15377 {
15382 }
15384 {
15387 {
15388 len--;
15390 }
15391 }
15393 /* If only one is a conversion operator, they are unordered. */
15397 /* Consider the return type for a conversion function */
15399 {
15402 len++;
15403 }
15405 processing_template_decl++;
15411 /* Stop when an ellipsis is seen. */
15413 {
15422 {
15423 /* When both arguments are pack expansions, we need only
15424 unify the patterns themselves. */
15428 /* This is the last comparison we need to do. */
15430 }
15433 {
15436 }
15439 {
15442 }
15445 {
15446 /* Only of the args is a reference, see if we should apply
15447 array/function pointer decay to it. This is not part of
15448 DR214, but is, IMHO, consistent with the deduction rules
15449 for the function call itself, and with our earlier
15450 implementation of the underspecified partial ordering
15451 rules. (nathan). */
15453 {
15455 {
15458 /* FALLTHROUGH. */
15465 }
15466 }
15467 else
15468 {
15470 {
15473 /* FALLTHROUGH. */
15480 }
15481 }
15482 }
15488 {
15494 /* Setup the parameter vector, which contains only ARG1. */
15497 /* Setup the argument vector, which contains the remaining
15498 arguments. */
15507 /* We cannot deduce in the other direction, because ARG1 is
15508 a pack expansion but ARG2 is not. */
15510 }
15512 {
15518 /* Setup the parameter vector, which contains only ARG1. */
15521 /* Setup the argument vector, which contains the remaining
15522 arguments. */
15531 /* We cannot deduce in the other direction, because ARG2 is
15532 a pack expansion but ARG1 is not.*/
15534 }
15536 else
15537 {
15538 /* The normal case, where neither argument is a pack
15539 expansion. */
15542 }
15544 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15545 arg2, then arg2 is not as specialized as arg1. */
15551 /* "If, for a given type, deduction succeeds in both directions
15552 (i.e., the types are identical after the transformations above)
15553 and if the type from the argument template is more cv-qualified
15554 than the type from the parameter template (as described above)
15555 that type is considered to be more specialized than the other. If
15556 neither type is more cv-qualified than the other then neither type
15557 is more specialized than the other." */
15561 {
15566 }
15569 /* We've failed to deduce something in either direction.
15570 These must be unordered. */
15575 /* We have already processed all of the arguments in our
15576 handing of the pack expansion type. */
15581 }
15583 /* "In most cases, all template parameters must have values in order for
15584 deduction to succeed, but for partial ordering purposes a template
15585 parameter may remain without a value provided it is not used in the
15586 types being used for partial ordering."
15588 Thus, if we are missing any of the targs1 we need to substitute into
15589 origs1, then pat2 is not as specialized as pat1. This can happen when
15590 there is a nondeduced context. */
15596 processing_template_decl--;
15598 /* All things being equal, if the next argument is a pack expansion
15599 for one function but not for the other, prefer the
15600 non-variadic function. FIXME this is bogus; see c++/41958. */
15604 {
15607 }
15613 else
15615 }
15617 /* Determine which of two partial specializations is more specialized.
15619 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15620 to the first partial specialization. The TREE_VALUE is the
15621 innermost set of template parameters for the partial
15622 specialization. PAT2 is similar, but for the second template.
15624 Return 1 if the first partial specialization is more specialized;
15625 -1 if the second is more specialized; 0 if neither is more
15626 specialized.
15628 See [temp.class.order] for information about determining which of
15629 two templates is more specialized. */
15631 static int
15633 {
15634 tree targs;
15642 /* Just like what happens for functions, if we are ordering between
15643 different class template specializations, we may encounter dependent
15644 types in the arguments, and we need our dependency check functions
15645 to behave correctly. */
15651 {
15654 }
15660 {
15663 }
15666 /* In the case of a tie where at least one of the class templates
15667 has a parameter pack at the end, the template with the most
15668 non-packed parameters wins. */
15670 && any_deductions
15673 {
15679 /* We don't count the pack expansion at the end. */
15689 }
15692 }
15694 /* Return the template arguments that will produce the function signature
15695 DECL from the function template FN, with the explicit template
15696 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15697 also match. Return NULL_TREE if no satisfactory arguments could be
15698 found. */
15700 static tree
15702 {
15705 tree decl_type;
15706 tree decl_arg_types;
15709 tree arg;
15711 /* Substitute the explicit template arguments into the type of DECL.
15712 The call to fn_type_unification will handle substitution into the
15713 FN. */
15716 {
15717 tree tmpl;
15718 tree converted_args;
15722 else
15723 /* We can get here for some invalid specializations. */
15726 converted_args
15729 tf_none,
15738 }
15740 /* Never do unification on the 'this' parameter. */
15759 }
15761 /* Return the innermost template arguments that, when applied to a
15762 template specialization whose innermost template parameters are
15763 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15764 ARGS.
15766 For example, suppose we have:
15768 template <class T, class U> struct S {};
15769 template <class T> struct S<T*, int> {};
15771 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15772 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15773 int}. The resulting vector will be {double}, indicating that `T'
15774 is bound to `double'. */
15776 static tree
15778 {
15780 tree deduced_args;
15781 tree innermost_deduced_args;
15785 {
15789 innermost_deduced_args);
15790 }
15791 else
15797 UNIFY_ALLOW_NONE))
15804 /* Verify that nondeduced template arguments agree with the type
15805 obtained from argument deduction.
15807 For example:
15809 struct A { typedef int X; };
15810 template <class T, class U> struct C {};
15811 template <class T> struct C<T, typename T::X> {};
15813 Then with the instantiation `C<A, int>', we can deduce that
15814 `T' is `A' but unify () does not check whether `typename T::X'
15815 is `int'. */
15818 /* We only need to check the innermost arguments; the other
15819 arguments will always agree. */
15824 /* Now that we have bindings for all of the template arguments,
15825 ensure that the arguments deduced for the template template
15826 parameters have compatible template parameter lists. See the use
15827 of template_template_parm_bindings_ok_p in fn_type_unification
15828 for more information. */
15833 }
15835 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15836 Return the TREE_LIST node with the most specialized template, if
15837 any. If there is no most specialized template, the error_mark_node
15838 is returned.
15840 Note that this function does not look at, or modify, the
15841 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15842 returned is one of the elements of INSTANTIATIONS, callers may
15843 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15844 and retrieve it from the value returned. */
15846 tree
15848 {
15855 {
15861 fate--;
15866 fate++;
15871 {
15872 /* Equally specialized, move to next function. If there
15873 is no next function, nothing's most specialized. */
15878 }
15879 }
15882 /* Now verify that champ is better than everything earlier in the
15883 instantiation list. */
15891 {
15894 }
15896 processing_template_decl--;
15902 }
15904 /* If DECL is a specialization of some template, return the most
15905 general such template. Otherwise, returns NULL_TREE.
15907 For example, given:
15909 template <class T> struct S { template <class U> void f(U); };
15911 if TMPL is `template <class U> void S<int>::f(U)' this will return
15912 the full template. This function will not trace past partial
15913 specializations, however. For example, given in addition:
15915 template <class T> struct S<T*> { template <class U> void f(U); };
15917 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15918 `template <class T> template <class U> S<T*>::f(U)'. */
15920 tree
15922 {
15923 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15924 an immediate specialization. */
15926 {
15930 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15931 template friend. */
15936 }
15938 /* Look for more and more general templates. */
15940 {
15941 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15942 (See cp-tree.h for details.) */
15950 /* Stop if we run into an explicitly specialized class template. */
15957 }
15960 }
15962 /* Return the most specialized of the class template partial
15963 specializations of TMPL which can produce TYPE, a specialization of
15964 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15965 a _TYPE node corresponding to the partial specialization, while the
15966 TREE_PURPOSE is the set of template arguments that must be
15967 substituted into the TREE_TYPE in order to generate TYPE.
15969 If the choice of partial specialization is ambiguous, a diagnostic
15970 is issued, and the error_mark_node is returned. If there are no
15971 partial specializations of TMPL matching TYPE, then NULL_TREE is
15972 returned. */
15974 static tree
15976 {
15978 tree t;
15979 tree champ;
15982 tree args;
15988 /* For determining which partial specialization to use, only the
15989 innermost args are interesting. */
15991 {
15994 }
15997 {
15998 tree partial_spec_args;
15999 tree spec_args;
16007 {
16010 /* Discard the outer levels of args, and then substitute in the
16011 template args from the enclosing class. */
16013 partial_spec_args = tsubst_template_args
16016 /* PARMS already refers to just the innermost parms, but the
16017 template parms in partial_spec_args had their levels lowered
16018 by tsubst, so we need to do the same for the parm list. We
16019 can't just tsubst the TREE_VEC itself, as tsubst wants to
16020 treat a TREE_VEC as an argument vector. */
16026 }
16028 partial_spec_args =
16031 partial_spec_args),
16042 partial_spec_args,
16043 args);
16045 {
16050 }
16051 }
16061 {
16064 ;
16065 else
16066 {
16068 {
16071 {
16074 }
16075 }
16077 }
16078 }
16082 {
16085 {
16088 }
16089 }
16092 {
16098 {
16101 }
16104 }
16107 }
16109 /* Explicitly instantiate DECL. */
16111 void
16113 {
16118 /* An error occurred, for which grokdeclarator has already issued
16119 an appropriate message. */
16122 {
16125 }
16127 {
16128 /* There is an asymmetry here in the way VAR_DECLs and
16129 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16130 the latter, the DECL we get back will be marked as a
16131 template instantiation, and the appropriate
16132 DECL_TEMPLATE_INFO will be set up. This does not happen for
16133 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16134 should handle VAR_DECLs as it currently handles
16135 FUNCTION_DECLs. */
16137 {
16140 }
16143 {
16146 }
16148 {
16153 }
16154 }
16156 {
16159 }
16160 else
16163 /* Check for various error cases. Note that if the explicit
16164 instantiation is valid the RESULT will currently be marked as an
16165 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16166 until we get here. */
16169 {
16170 /* DR 259 [temp.spec].
16172 Both an explicit instantiation and a declaration of an explicit
16173 specialization shall not appear in a program unless the explicit
16174 instantiation follows a declaration of the explicit specialization.
16176 For a given set of template parameters, if an explicit
16177 instantiation of a template appears after a declaration of an
16178 explicit specialization for that template, the explicit
16179 instantiation has no effect. */
16181 }
16183 {
16184 /* [temp.spec]
16186 No program shall explicitly instantiate any template more
16187 than once.
16189 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16190 the first instantiation was `extern' and the second is not,
16191 and EXTERN_P for the opposite case. */
16194 /* If an "extern" explicit instantiation follows an ordinary
16195 explicit instantiation, the template is instantiated. */
16198 }
16200 {
16203 }
16205 {
16208 }
16211 ;
16213 {
16216 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16219 }
16220 else
16228 }
16230 static void
16232 {
16238 {
16241 }
16242 }
16244 /* Called from do_type_instantiation through binding_table_foreach to
16245 do recursive instantiation for the type bound in ENTRY. */
16246 static void
16248 {
16254 }
16256 /* Called from do_type_instantiation to instantiate a member
16257 (a member function or a static member variable) of an
16258 explicitly instantiated class template. */
16259 static void
16261 {
16266 }
16268 /* Perform an explicit instantiation of template class T. STORAGE, if
16269 non-null, is the RID for extern, inline or static. COMPLAIN is
16270 nonzero if this is called from the parser, zero if called recursively,
16271 since the standard is unclear (as detailed below). */
16273 void
16275 {
16285 {
16288 }
16293 {
16296 t);
16298 }
16301 {
16303 {
16305 {
16308 "ISO C++ 1998 forbids the use of %<extern%> on "
16310 }
16311 else
16313 "ISO C++ forbids the use of %qE"
16315 }
16323 else
16324 {
16326 storage);
16328 }
16329 }
16332 {
16333 /* DR 259 [temp.spec].
16335 Both an explicit instantiation and a declaration of an explicit
16336 specialization shall not appear in a program unless the explicit
16337 instantiation follows a declaration of the explicit specialization.
16339 For a given set of template parameters, if an explicit
16340 instantiation of a template appears after a declaration of an
16341 explicit specialization for that template, the explicit
16342 instantiation has no effect. */
16344 }
16346 {
16347 /* [temp.spec]
16349 No program shall explicitly instantiate any template more
16350 than once.
16352 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16353 instantiation was `extern'. If EXTERN_P then the second is.
16354 These cases are OK. */
16361 /* If we've already instantiated the template, just return now. */
16364 }
16372 {
16373 tree tmp;
16375 /* In contrast to implicit instantiation, where only the
16376 declarations, and not the definitions, of members are
16377 instantiated, we have here:
16379 [temp.explicit]
16381 The explicit instantiation of a class template specialization
16382 implies the instantiation of all of its members not
16383 previously explicitly specialized in the translation unit
16384 containing the explicit instantiation.
16386 Of course, we can't instantiate member template classes, since
16387 we don't have any arguments for them. Note that the standard
16388 is unclear on whether the instantiation of the members are
16389 *explicit* instantiations or not. However, the most natural
16390 interpretation is that it should be an explicit instantiation. */
16405 }
16406 }
16408 /* Given a function DECL, which is a specialization of TMPL, modify
16409 DECL to be a re-instantiation of TMPL with the same template
16410 arguments. TMPL should be the template into which tsubst'ing
16411 should occur for DECL, not the most general template.
16413 One reason for doing this is a scenario like this:
16415 template <class T>
16416 void f(const T&, int i);
16418 void g() { f(3, 7); }
16420 template <class T>
16421 void f(const T& t, const int i) { }
16423 Note that when the template is first instantiated, with
16424 instantiate_template, the resulting DECL will have no name for the
16425 first parameter, and the wrong type for the second. So, when we go
16426 to instantiate the DECL, we regenerate it. */
16428 static void
16430 {
16431 /* The arguments used to instantiate DECL, from the most general
16432 template. */
16433 tree args;
16434 tree code_pattern;
16439 /* Make sure that we can see identifiers, and compute access
16440 correctly. */
16444 {
16445 tree decl_parm;
16446 tree pattern_parm;
16447 tree specs;
16460 specs);
16462 /* Merge parameter declarations. */
16465 pattern_parm
16469 {
16470 tree parm_type;
16471 tree attributes;
16476 NULL_TREE);
16482 {
16485 }
16488 }
16489 /* Merge any parameters that match with the function parameter
16490 pack. */
16492 {
16494 tree expanded_types;
16495 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16496 the parameters in this function parameter pack. */
16501 {
16502 tree parm_type;
16503 tree attributes;
16506 /* Rename the parameter to include the index. */
16515 {
16518 }
16520 }
16521 }
16522 /* Merge additional specifiers from the CODE_PATTERN. */
16526 }
16528 {
16536 }
16537 else
16541 }
16543 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16544 substituted to get DECL. */
16546 tree
16548 {
16551 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16552 for the instantiation. This is not always the most general
16553 template. Consider, for example:
16555 template <class T>
16556 struct S { template <class U> void f();
16557 template <> void f<int>(); };
16559 and an instantiation of S<double>::f<int>. We want TD to be the
16560 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16562 more general template. */
16564 /* We must also deal with friend templates. Given:
16566 template <class T> struct S {
16567 template <class U> friend void f() {};
16568 };
16570 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16571 so far as the language is concerned, but that's still
16572 where we get the pattern for the instantiation from. On
16573 other hand, if the definition comes outside the class, say:
16575 template <class T> struct S {
16576 template <class U> friend void f();
16577 };
16578 template <class U> friend void f() {}
16580 we don't need to look any further. That's what the check for
16581 DECL_INITIAL is for. */
16585 {
16586 /* The present template, TD, should not be a definition. If it
16587 were a definition, we should be using it! Note that we
16588 cannot restructure the loop to just keep going until we find
16589 a template with a definition, since that might go too far if
16590 a specialization was declared, but not defined. */
16594 /* Fetch the more general template. */
16596 }
16599 }
16601 /* Returns true if we need to instantiate this template instance even if we
16602 know we aren't going to emit it.. */
16604 bool
16606 {
16607 /* We always instantiate inline functions so that we can inline them. An
16608 explicit instantiation declaration prohibits implicit instantiation of
16609 non-inline functions. With high levels of optimization, we would
16610 normally inline non-inline functions -- but we're not allowed to do
16611 that for "extern template" functions. Therefore, we check
16612 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16615 /* And we need to instantiate static data members so that
16616 their initializers are available in integral constant
16617 expressions. */
16620 }
16622 /* Produce the definition of D, a _DECL generated from a template. If
16623 DEFER_OK is nonzero, then we don't have to actually do the
16624 instantiation now; we just have to do it sometime. Normally it is
16625 an error if this is an explicit instantiation but D is undefined.
16626 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16627 explicitly instantiated class template. */
16629 tree
16632 {
16634 tree gen_args;
16635 tree args;
16636 tree td;
16637 tree code_pattern;
16638 tree spec;
16639 tree gen_tmpl;
16645 /* This function should only be used to instantiate templates for
16646 functions and static member variables. */
16650 /* Variables are never deferred; if instantiation is required, they
16651 are instantiated right away. That allows for better code in the
16652 case that an expression refers to the value of the variable --
16653 if the variable has a constant value the referring expression can
16654 take advantage of that fact. */
16658 /* Don't instantiate cloned functions. Instead, instantiate the
16659 functions they cloned. */
16665 /* D has already been instantiated or explicitly specialized, so
16666 there's nothing for us to do here.
16668 It might seem reasonable to check whether or not D is an explicit
16669 instantiation, and, if so, stop here. But when an explicit
16670 instantiation is deferred until the end of the compilation,
16671 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16672 the instantiation. */
16675 /* Check to see whether we know that this template will be
16676 instantiated in some other file, as with "extern template"
16677 extension. */
16680 /* In general, we do not instantiate such templates. */
16688 /* We should already have the extra args. */
16691 /* And what's in the hash table should match D. */
16695 /* This needs to happen before any tsubsting. */
16701 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16702 for the instantiation. */
16706 /* We should never be trying to instantiate a member of a class
16707 template or partial specialization. */
16712 /* In the case of a friend template whose definition is provided
16713 outside the class, we may have too many arguments. Drop the
16714 ones we don't need. The same is true for specializations. */
16715 args = get_innermost_template_args
16717 else
16722 else
16725 /* We may be in the middle of deferred access check. Disable it now. */
16728 /* Unless an explicit instantiation directive has already determined
16729 the linkage of D, remember that a definition is available for
16730 this entity. */
16738 /* If D is a member of an explicitly instantiated class template,
16739 and no definition is available, treat it like an implicit
16740 instantiation. */
16743 {
16747 }
16749 /* Recheck the substitutions to obtain any warning messages
16750 about ignoring cv qualifiers. Don't do this for artificial decls,
16751 as it breaks the context-sensitive substitution for lambda op(). */
16753 {
16757 /* Make sure that we can see identifiers, and compute access
16758 correctly. D is already the target FUNCTION_DECL with the
16759 right context. */
16763 {
16766 d);
16767 /* Don't simply tsubst the function type, as that will give
16768 duplicate warnings about poor parameter qualifications.
16769 The function arguments are the same as the decl_arguments
16770 without the top level cv qualifiers. */
16772 }
16776 }
16778 /* Defer all other templates, unless we have been explicitly
16779 forbidden from doing so. */
16781 template. */
16782 ! pattern_defined
16783 /* If it's OK to postpone instantiation, do so. */
16784 || defer_ok
16785 /* If this is a static data member that will be defined
16786 elsewhere, we don't want to instantiate the entire data
16787 member, but we do want to instantiate the initializer so that
16788 we can substitute that elsewhere. */
16790 {
16791 /* The definition of the static data member is now required so
16792 we must substitute the initializer. */
16796 {
16797 tree ns;
16798 tree init;
16804 args,
16809 LOOKUP_ONLYCONVERTING);
16812 }
16814 /* We restore the source position here because it's used by
16815 add_pending_template. */
16821 /* [temp.explicit]
16823 The definition of a non-exported function template, a
16824 non-exported member function template, or a non-exported
16825 member function or static data member of a class template
16826 shall be present in every translation unit in which it is
16827 explicitly instantiated. */
16831 /* ??? Historically, we have instantiated inline functions, even
16832 when marked as "extern template". */
16836 }
16837 /* Tell the repository that D is available in this translation unit
16838 -- and see if it is supposed to be instantiated here. */
16840 {
16841 /* In a PCH file, despite the fact that the repository hasn't
16842 requested instantiation in the PCH it is still possible that
16843 an instantiation will be required in a file that includes the
16844 PCH. */
16847 /* Instantiate inline functions so that the inliner can do its
16848 job, even though we'll not be emitting a copy of this
16849 function. */
16852 }
16858 /* Mark D as instantiated so that recursive calls to
16859 instantiate_decl do not try to instantiate it again. */
16862 /* Regenerate the declaration in case the template has been modified
16863 by a subsequent redeclaration. */
16866 /* We already set the file and line above. Reset them now in case
16867 they changed as a result of calling regenerate_decl_from_template. */
16871 {
16872 tree init;
16874 /* Clear out DECL_RTL; whatever was there before may not be right
16875 since we've reset the type of the declaration. */
16879 /* The initializer is placed in DECL_INITIAL by
16880 regenerate_decl_from_template. Pull it out so that
16881 cp_finish_decl can process it. */
16886 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16887 initializer. That function will defer actual emission until
16888 we have a chance to determine linkage. */
16891 /* Enter the scope of D so that access-checking works correctly. */
16895 }
16897 {
16898 htab_t saved_local_specializations;
16899 tree subst_decl;
16900 tree tmpl_parm;
16901 tree spec_parm;
16903 /* Save away the current list, in case we are instantiating one
16904 template from within the body of another. */
16907 /* Set up the list of local specializations. */
16909 hash_local_specialization,
16910 eq_local_specializations,
16911 NULL);
16913 /* Set up context. */
16916 /* Create substitution entries for the parameters. */
16921 {
16925 }
16927 {
16931 }
16933 {
16934 /* Register the (value) argument pack as a specialization of
16935 TMPL_PARM, then move on. */
16940 }
16943 /* Substitute into the body of the function. */
16948 /* Set the current input_location to the end of the function
16949 so that finish_function knows where we are. */
16952 /* We don't need the local specializations any more. */
16956 /* Finish the function. */
16959 }
16961 /* We're not deferring instantiation any more. */
16967 out:
16975 }
16977 /* Run through the list of templates that we wish we could
16978 instantiate, and instantiate any we can. RETRIES is the
16979 number of times we retry pending template instantiation. */
16981 void
16983 {
16987 /* Instantiating templates may trigger vtable generation. This in turn
16988 may require further template instantiations. We place a limit here
16989 to avoid infinite loop. */
16991 {
16995 " instantiating %q+D, possibly from virtual table generation"
16999 /* Pretend that we defined it. */
17002 }
17004 do
17005 {
17010 {
17015 {
17016 tree fn;
17019 {
17023 fn;
17031 }
17034 }
17035 else
17036 {
17039 {
17040 instantiation
17046 }
17050 }
17053 /* If INSTANTIATION has been instantiated, then we don't
17054 need to consider it again in the future. */
17056 else
17057 {
17060 }
17063 }
17065 }
17069 }
17071 /* Substitute ARGVEC into T, which is a list of initializers for
17072 either base class or a non-static data member. The TREE_PURPOSEs
17073 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17074 instantiate_decl. */
17076 static tree
17078 {
17082 {
17083 tree decl;
17084 tree init;
17090 {
17091 tree expr;
17092 tree arg;
17094 /* Expand the base class expansion type into separate base
17095 classes. */
17097 tf_warning_or_error,
17098 NULL_TREE);
17102 /* We'll be building separate TREE_LISTs of arguments for
17103 each base. */
17109 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17110 expand each argument in the TREE_VALUE of t. */
17116 /* VOID_TYPE_NODE is used to indicate
17117 value-initialization. */
17118 {
17121 }
17122 else
17123 {
17124 /* Substitute parameter packs into each argument in the
17125 TREE_LIST. */
17128 {
17129 tree expanded_exprs;
17131 /* Expand the argument. */
17133 expanded_exprs
17135 tf_warning_or_error,
17136 NULL_TREE);
17140 /* Prepend each of the expanded expressions to the
17141 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17143 {
17148 }
17149 }
17152 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17153 since we built them backwards. */
17155 {
17158 }
17159 }
17160 }
17163 {
17165 {
17169 }
17170 else
17171 {
17183 }
17186 {
17190 }
17191 }
17192 }
17194 }
17196 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17198 static void
17200 {
17205 else
17207 }
17209 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17210 is the instantiation (which should have been created with
17211 start_enum) and ARGS are the template arguments to use. */
17213 static void
17215 {
17216 tree e;
17219 {
17220 tree value;
17221 tree decl;
17224 /* Note that in a template enum, the TREE_VALUE is the
17225 CONST_DECL, not the corresponding INTEGER_CST. */
17230 /* Give this enumeration constant the correct access. */
17233 /* Actually build the enumerator itself. */
17235 }
17240 }
17242 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17243 its type -- but without substituting the innermost set of template
17244 arguments. So, innermost set of template parameters will appear in
17245 the type. */
17247 tree
17249 {
17250 tree fn_type;
17251 tree tmpl;
17252 tree targs;
17253 tree tparms;
17261 /* There should be as many levels of arguments as there are levels
17262 of parameters. */
17268 /* No substitution is necessary. */
17269 ;
17270 else
17271 {
17273 tree partial_args;
17275 /* Replace the innermost level of the TARGS with NULL_TREEs to
17276 let tsubst know not to substitute for those parameters. */
17285 /* Disable access control as this function is used only during
17286 name-mangling. */
17291 /* Now, do the (partial) substitution to figure out the
17292 appropriate function type. */
17296 /* Substitute into the template parameters to obtain the real
17297 innermost set of parameters. This step is important if the
17298 innermost set of template parameters contains value
17299 parameters whose types depend on outer template parameters. */
17304 }
17307 }
17309 /* Return truthvalue if we're processing a template different from
17310 the last one involved in diagnostics. */
17311 int
17313 {
17315 }
17317 /* Remember current template involved in diagnostics. */
17318 void
17320 {
17322 }
17326 {
17328 }
17330 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17331 type. Return zero for ok, nonzero for disallowed. Issue error and
17332 warning messages under control of COMPLAIN. */
17334 static int
17336 {
17351 }
17353 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17354 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17356 static bool
17358 {
17359 tree scope;
17361 /* [temp.dep.type]
17363 A type is dependent if it is:
17365 -- a template parameter. Template template parameters are types
17366 for us (since TYPE_P holds true for them) so we handle
17367 them here. */
17371 /* -- a qualified-id with a nested-name-specifier which contains a
17372 class-name that names a dependent type or whose unqualified-id
17373 names a dependent type. */
17376 /* -- a cv-qualified type where the cv-unqualified type is
17377 dependent. */
17379 /* -- a compound type constructed from any dependent type. */
17389 {
17390 tree arg_type;
17395 arg_type;
17400 }
17401 /* -- an array type constructed from any dependent type or whose
17402 size is specified by a constant expression that is
17403 value-dependent. */
17405 {
17410 }
17413 {
17414 /* If this is the TYPE_DOMAIN of an array type, consider it
17415 dependent. We already checked for value-dependence in
17416 compute_array_index_type. */
17418 }
17420 /* -- a template-id in which either the template name is a template
17421 parameter ... */
17424 /* ... or any of the template arguments is a dependent type or
17425 an expression that is type-dependent or value-dependent. */
17427 && (any_dependent_template_arguments_p
17431 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17432 argument of the `typeof' expression is not type-dependent, then
17433 it should already been have resolved. */
17438 /* A template argument pack is dependent if any of its packed
17439 arguments are. */
17441 {
17447 }
17449 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17450 be template parameters. */
17454 /* The standard does not specifically mention types that are local
17455 to template functions or local classes, but they should be
17456 considered dependent too. For example:
17458 template <int I> void f() {
17459 enum E { a = I };
17460 S<sizeof (E)> s;
17461 }
17463 The size of `E' cannot be known until the value of `I' has been
17464 determined. Therefore, `E' must be considered dependent. */
17471 /* Other types are non-dependent. */
17473 }
17475 /* Returns TRUE if TYPE is dependent, in the sense of
17476 [temp.dep.type]. */
17478 bool
17480 {
17481 /* If there are no template parameters in scope, then there can't be
17482 any dependent types. */
17484 {
17485 /* If we are not processing a template, then nobody should be
17486 providing us with a dependent type. */
17490 }
17492 /* If the type is NULL, we have not computed a type for the entity
17493 in question; in that case, the type is dependent. */
17497 /* Erroneous types can be considered non-dependent. */
17501 /* If we have not already computed the appropriate value for TYPE,
17502 do so now. */
17504 {
17507 }
17510 }
17512 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17513 lookup. In other words, a dependent type that is not the current
17514 instantiation. */
17516 bool
17518 {
17521 }
17523 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17524 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17525 expression. */
17527 bool
17529 {
17533 /* A name declared with a dependent type. */
17538 {
17540 /* A name that has not been looked up -- must be dependent. */
17544 /* A non-type template parm. */
17548 /* A non-type template parm. */
17554 /* A constant with integral or enumeration type and is initialized
17555 with an expression that is value-dependent. */
17567 /* These expressions are value-dependent if the type to which
17568 the cast occurs is dependent or the expression being casted
17569 is value-dependent. */
17570 {
17576 /* A functional cast has a list of operands. */
17579 {
17580 /* If there are no operands, it must be an expression such
17581 as "int()". This should not happen for aggregate types
17582 because it would form non-constant expressions. */
17586 }
17592 }
17596 /* A `sizeof' expression is value-dependent if the operand is
17597 type-dependent or is a pack expansion. */
17607 /* FIXME why check value-dependency? */
17612 {
17615 }
17622 /* A CALL_EXPR may appear in a constant expression if it is a
17623 call to a builtin function, e.g., __builtin_constant_p. All
17624 such calls are value-dependent. */
17628 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17629 is value-dependent. */
17630 {
17639 }
17642 {
17646 }
17653 {
17657 }
17660 /* A constant expression is value-dependent if any subexpression is
17661 value-dependent. */
17663 {
17673 || (value_dependent_expression_p
17678 {
17681 /* In some cases, some of the operands may be missing.
17682 (For example, in the case of PREDECREMENT_EXPR, the
17683 amount to increment by may be missing.) That doesn't
17684 make the expression dependent. */
17686 && (value_dependent_expression_p
17690 }
17694 }
17695 }
17697 /* The expression is not value-dependent. */
17699 }
17701 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17702 [temp.dep.expr]. */
17704 bool
17706 {
17713 /* An unresolved name is always dependent. */
17718 /* Some expression forms are never type-dependent. */
17730 /* The types of these expressions depends only on the type to which
17731 the cast occurs. */
17739 /* The types of these expressions depends only on the type created
17740 by the expression. */
17743 {
17744 /* For NEW_EXPR tree nodes created inside a template, either
17745 the object type itself or a TREE_LIST may appear as the
17746 operand 1. */
17749 /* This is an array type. We need to check array dimensions
17750 as well. */
17752 || value_dependent_expression_p
17754 else
17756 }
17759 {
17763 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
17764 contains an identifier associated by name lookup with one or more
17765 declarations declared with a dependent type, or...a
17766 nested-name-specifier or qualified-id that names a member of an
17767 unknown specialization. */
17770 }
17775 && (any_dependent_template_arguments_p
17787 {
17788 tree elt;
17792 {
17795 }
17797 }
17799 /* A static data member of the current instantiation with incomplete
17800 array type is type-dependent, as the definition and specializations
17801 can have different bounds. */
17809 {
17814 {
17820 }
17821 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17829 {
17834 }
17839 {
17843 }
17845 }
17850 }
17852 /* Like type_dependent_expression_p, but it also works while not processing
17853 a template definition, i.e. during substitution or mangling. */
17855 bool
17857 {
17863 }
17865 /* Returns TRUE if ARGS contains a type-dependent expression. */
17867 bool
17869 {
17871 tree arg;
17874 {
17877 }
17879 }
17881 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17882 expressions) contains any value-dependent expressions. */
17884 bool
17886 {
17892 }
17894 /* Returns TRUE if the ARG (a template argument) is dependent. */
17896 bool
17898 {
17906 {
17910 {
17913 }
17916 }
17919 else
17922 }
17924 /* Returns true if ARGS (a collection of template arguments) contains
17925 any types that require structural equality testing. */
17927 bool
17929 {
17939 {
17942 {
17948 {
17949 /* Look inside the argument pack. */
17952 }
17955 {
17969 }
17970 }
17971 }
17974 }
17976 /* Returns true if ARGS (a collection of template arguments) contains
17977 any dependent arguments. */
17979 bool
17981 {
17991 {
17996 }
17999 }
18001 /* Returns TRUE if the template TMPL is dependent. */
18003 bool
18005 {
18007 {
18009 {
18013 }
18015 }
18017 /* Template template parameters are dependent. */
18021 /* So are names that have not been looked up. */
18025 /* So are member templates of dependent classes. */
18029 }
18031 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18033 bool
18035 {
18038 }
18040 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18041 is dependent. */
18043 bool
18045 {
18052 {
18073 {
18077 }
18081 {
18085 {
18090 }
18091 }
18092 }
18095 }
18097 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18098 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18099 no such TYPE can be found. Note that this function peers inside
18100 uninstantiated templates and therefore should be used only in
18101 extremely limited situations. ONLY_CURRENT_P restricts this
18102 peering to the currently open classes hierarchy (which is required
18103 when comparing types). */
18105 tree
18107 {
18108 tree scope;
18109 tree name;
18110 tree decl;
18112 tree pushed_scope;
18113 tree result;
18118 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18119 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18120 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18121 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18122 identifier of the TYPENAME_TYPE anymore.
18123 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18124 TYPENAME_TYPE instead, we avoid messing up with a possible
18125 typedef variant case. */
18128 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18129 it first before we can figure out what NAME refers to. */
18132 /* If we don't know what SCOPE refers to, then we cannot resolve the
18133 TYPENAME_TYPE. */
18136 /* If the SCOPE is a template type parameter, we have no way of
18137 resolving the name. */
18140 /* If the SCOPE is not the current instantiation, there's no reason
18141 to look inside it. */
18144 /* If this is a typedef, we don't want to look inside (c++/11987). */
18147 /* If SCOPE isn't the template itself, it will not have a valid
18148 TYPE_FIELDS list. */
18150 /* scope is either the template itself or a compatible instantiation
18151 like X<T>, so look up the name in the original template. */
18153 else
18154 /* scope is a partial instantiation, so we can't do the lookup or we
18155 will lose the template arguments. */
18157 /* Enter the SCOPE so that name lookup will be resolved as if we
18158 were in the class definition. In particular, SCOPE will no
18159 longer be considered a dependent type. */
18161 /* Look up the declaration. */
18166 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18167 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18172 {
18176 }
18179 {
18180 tree tmpl;
18181 tree args;
18182 /* Obtain the template and the arguments. */
18185 /* Instantiate the template. */
18191 }
18193 /* Leave the SCOPE. */
18197 /* If we failed to resolve it, return the original typename. */
18201 /* If lookup found a typename type, resolve that too. */
18203 {
18204 /* Ill-formed programs can cause infinite recursion here, so we
18205 must catch that. */
18209 }
18211 /* Qualify the resulting type. */
18217 }
18219 /* EXPR is an expression which is not type-dependent. Return a proxy
18220 for EXPR that can be used to compute the types of larger
18221 expressions containing EXPR. */
18223 tree
18225 {
18226 tree inner_expr;
18228 /* Preserve null pointer constants so that the type of things like
18229 "p == 0" where "p" is a pointer can be determined. */
18232 /* Preserve OVERLOADs; the functions must be available to resolve
18233 types. */
18244 /* There is no need to return a proxy for a variable. */
18247 /* Preserve string constants; conversions from string constants to
18248 "char *" are allowed, even though normally a "const char *"
18249 cannot be used to initialize a "char *". */
18252 /* Preserve arithmetic constants, as an optimization -- there is no
18253 reason to create a new node. */
18256 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18257 There is at least one place where we want to know that a
18258 particular expression is a throw-expression: when checking a ?:
18259 expression, there are special rules if the second or third
18260 argument is a throw-expression. */
18279 /* If the type is unknown, it can't really be non-dependent */
18282 /* Otherwise, build a NON_DEPENDENT_EXPR.
18284 REFERENCE_TYPEs are not stripped for expressions in templates
18285 because doing so would play havoc with mangling. Consider, for
18286 example:
18288 template <typename T> void f<T& g>() { g(); }
18290 In the body of "f", the expression for "g" will have
18291 REFERENCE_TYPE, even though the standard says that it should
18292 not. The reason is that we must preserve the syntactic form of
18293 the expression so that mangling (say) "f<g>" inside the body of
18294 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18295 stripped here. */
18297 }
18299 /* ARGS is a vector of expressions as arguments to a function call.
18300 Replace the arguments with equivalent non-dependent expressions.
18301 This modifies ARGS in place. */
18303 void
18305 {
18307 tree arg;
18310 {
18314 }
18315 }
18317 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18318 with a level one deeper than the actual template parms. */
18320 tree
18322 {
18335 }
18337 /* Given type ARG, return std::initializer_list<ARG>. */
18339 static tree
18341 {
18342 tree std_init_list = namespace_binding
18344 tree argvec;
18346 {
18350 }
18355 }
18357 /* Replace auto in TYPE with std::initializer_list<auto>. */
18359 static tree
18361 {
18368 }
18370 /* walk_tree helper for do_auto_deduction. */
18372 static tree
18375 {
18376 /* Is this a variable with the type we're looking for? */
18380 else
18382 }
18384 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18385 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18387 tree
18389 {
18392 tree decl;
18395 /* The name of the object being declared shall not appear in the
18396 initializer expression. */
18399 {
18403 }
18405 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18406 with either a new invented type template parameter U or, if the
18407 initializer is a braced-init-list (8.5.4), with
18408 std::initializer_list<U>. */
18421 {
18424 }
18426 /* If the list of declarators contains more than one declarator, the type
18427 of each declared variable is determined as described above. If the
18428 type deduced for the template parameter U is not the same in each
18429 deduction, the program is ill-formed. */
18432 {
18436 }
18442 }
18444 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18445 result. */
18447 tree
18449 {
18450 tree argvec;
18459 }
18461 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18463 bool
18465 {
18469 else
18471 }
18473 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18474 appear as a type-specifier for the declaration in question, we don't
18475 have to look through the whole type. */
18477 tree
18479 {
18496 }
18498 /* For a given template T, return the vector of typedefs referenced
18499 in T for which access check is needed at T instantiation time.
18500 T is either a FUNCTION_DECL or a RECORD_TYPE.
18501 Those typedefs were added to T by the function
18502 append_type_to_template_for_access_check. */
18506 {
18507 tree ti;
18518 {
18523 }
18526 }
18528 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18529 tied to T. That list of typedefs will be access checked at
18530 T instantiation time.
18531 T is either a FUNCTION_DECL or a RECORD_TYPE.
18532 TYPE_DECL is a TYPE_DECL node representing a typedef.
18533 SCOPE is the scope through which TYPE_DECL is accessed.
18534 LOCATION is the location of the usage point of TYPE_DECL.
18536 This function is a subroutine of
18537 append_type_to_template_for_access_check. */
18539 static void
18541 tree type_decl,
18542 tree scope,
18543 location_t location)
18544 {
18545 qualified_typedef_usage_t typedef_usage;
18546 tree ti;
18553 && type_decl
18569 }
18571 /* Append TYPE_DECL to the template TEMPL.
18572 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18573 At TEMPL instanciation time, TYPE_DECL will be checked to see
18574 if it can be accessed through SCOPE.
18575 LOCATION is the location of the usage point of TYPE_DECL.
18577 e.g. consider the following code snippet:
18579 class C
18580 {
18581 typedef int myint;
18582 };
18584 template<class U> struct S
18585 {
18586 C::myint mi; // <-- usage point of the typedef C::myint
18587 };
18589 S<char> s;
18591 At S<char> instantiation time, we need to check the access of C::myint
18592 In other words, we need to check the access of the myint typedef through
18593 the C scope. For that purpose, this function will add the myint typedef
18594 and the scope C through which its being accessed to a list of typedefs
18595 tied to the template S. That list will be walked at template instantiation
18596 time and access check performed on each typedefs it contains.
18597 Note that this particular code snippet should yield an error because
18598 myint is private to C. */
18600 void
18602 tree type_decl,
18603 tree scope,
18604 location_t location)
18605 {
18611 /* Make sure we don't append the type to the template twice. */
18622 }
18624 /* Set up the hash tables for template instantiations. */
18626 void
18628 {
18630 hash_specialization,
18631 eq_specializations,
18632 ggc_free);
18634 hash_specialization,
18635 eq_specializations,
18636 ggc_free);
18637 }
18639 /* Print stats about the template hash tables for -fstats. */
18641 void
18643 {
18652 }