| blob | 3e2927c16139b8118ab10bfa096f8ac50c4f0b5c |
1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
51 /* The type of functions taking a tree, and some additional data, and
52 returning an int. */
55 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
56 instantiations have been deferred, either because their definitions
57 were not yet available, or because we were putting off doing the work. */
61 };
76 /* Live only within one (recursive) call to tsubst_expr. We use
77 this to pass the statement expression node from the STMT_EXPR
78 to the EXPR_STMT that is its result. */
81 /* A map from local variable declarations in the body of the template
82 presently being instantiated to the corresponding instantiated
83 local variables. */
87 {
88 tree tmpl;
89 tree args;
90 tree spec;
94 htab_t decl_specializations;
97 htab_t type_specializations;
99 /* Contains canonical template parameter types. The vector is indexed by
100 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
101 TREE_LIST, whose TREE_VALUEs contain the canonical template
102 parameters of various types and levels. */
105 #define UNIFY_ALLOW_NONE 0
106 #define UNIFY_ALLOW_MORE_CV_QUAL 1
107 #define UNIFY_ALLOW_LESS_CV_QUAL 2
108 #define UNIFY_ALLOW_DERIVED 4
109 #define UNIFY_ALLOW_INTEGER 8
110 #define UNIFY_ALLOW_OUTER_LEVEL 16
111 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
112 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
132 tree);
192 location_t);
197 /* Make the current scope suitable for access checking when we are
198 processing T. T can be FUNCTION_DECL for instantiated function
199 template, or VAR_DECL for static member variable (need by
200 instantiate_decl). */
202 static void
204 {
212 else
216 {
217 saved_access_scope = tree_cons
220 }
221 }
223 /* Restore the scope set up by push_access_scope. T is the node we
224 are processing. */
226 static void
228 {
230 {
233 }
237 else
239 }
241 /* Do any processing required when DECL (a member template
242 declaration) is finished. Returns the TEMPLATE_DECL corresponding
243 to DECL, unless it is a specialization, in which case the DECL
244 itself is returned. */
246 tree
248 {
255 {
256 tree type;
264 {
268 }
270 }
274 {
276 {
279 }
280 else
282 }
283 else
287 }
289 /* Create a template info node. */
291 tree
293 {
298 }
300 /* Return the template info node corresponding to T, whatever T is. */
302 tree
304 {
322 }
324 /* Returns the template nesting level of the indicated class TYPE.
326 For example, in:
327 template <class T>
328 struct A
329 {
330 template <class U>
331 struct B {};
332 };
334 A<T>::B<U> has depth two, while A<T> has depth one.
335 Both A<T>::B<int> and A<int>::B<U> have depth one, if
336 they are instantiations, not specializations.
338 This function is guaranteed to return 0 if passed NULL_TREE so
339 that, for example, `template_class_depth (current_class_type)' is
340 always safe. */
342 int
344 {
351 {
357 }
360 }
362 /* Subroutine of maybe_begin_member_template_processing.
363 Returns true if processing DECL needs us to push template parms. */
365 static bool
367 {
373 }
375 /* Subroutine of maybe_begin_member_template_processing.
376 Push the template parms in PARMS, starting from LEVELS steps into the
377 chain, and ending at the beginning, since template parms are listed
378 innermost first. */
380 static void
382 {
390 current_template_parms
396 NULL);
398 {
407 {
414 {
415 /* Make a CONST_DECL as is done in process_template_parm.
416 It is ugly that we recreate this here; the original
417 version built in process_template_parm is no longer
418 available. */
428 }
433 }
434 }
435 }
437 /* Restore the template parameter context for a member template or
438 a friend template defined in a class definition. */
440 void
442 {
443 tree parms;
447 {
452 {
455 }
458 }
460 /* Remember how many levels of template parameters we pushed so that
461 we can pop them later. */
463 }
465 /* Undo the effects of maybe_begin_member_template_processing. */
467 void
469 {
478 {
482 }
483 }
485 /* Return a new template argument vector which contains all of ARGS,
486 but has as its innermost set of arguments the EXTRA_ARGS. */
488 static tree
490 {
491 tree new_args;
509 }
511 /* Like add_to_template_args, but only the outermost ARGS are added to
512 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
513 (EXTRA_ARGS) levels are added. This function is used to combine
514 the template arguments from a partial instantiation with the
515 template arguments used to attain the full instantiation from the
516 partial instantiation. */
518 static tree
520 {
521 tree new_args;
523 /* If there are more levels of EXTRA_ARGS than there are ARGS,
524 something very fishy is going on. */
527 /* If *all* the new arguments will be the EXTRA_ARGS, just return
528 them. */
532 /* For the moment, we make ARGS look like it contains fewer levels. */
537 /* Now, we restore ARGS to its full dimensions. */
541 }
543 /* Return the N levels of innermost template arguments from the ARGS. */
545 tree
547 {
548 tree new_args;
554 /* If N is 1, just return the innermost set of template arguments. */
558 /* If we're not removing anything, just return the arguments we were
559 given. */
565 /* Make a new set of arguments, not containing the outer arguments. */
572 }
574 /* The inverse of get_innermost_template_args: Return all but the innermost
575 EXTRA_LEVELS levels of template arguments from the ARGS. */
577 static tree
579 {
580 tree new_args;
586 /* If N is 1, just return the outermost set of template arguments. */
590 /* If we're not removing anything, just return the arguments we were
591 given. */
596 /* Make a new set of arguments, not containing the inner arguments. */
603 }
605 /* We've got a template header coming up; push to a new level for storing
606 the parms. */
608 void
610 {
611 /* We use a non-tag-transparent scope here, which causes pushtag to
612 put tags in this scope, rather than in the enclosing class or
613 namespace scope. This is the right thing, since we want
614 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
615 global template class, push_template_decl handles putting the
616 TEMPLATE_DECL into top-level scope. For a nested template class,
617 e.g.:
619 template <class T> struct S1 {
620 template <class T> struct S2 {};
621 };
623 pushtag contains special code to call pushdecl_with_scope on the
624 TEMPLATE_DECL for S2. */
629 }
631 /* This routine is called when a specialization is declared. If it is
632 invalid to declare a specialization here, an error is reported and
633 false is returned, otherwise this routine will return true. */
635 static bool
637 {
640 /* [temp.expl.spec]
642 An explicit specialization shall be declared in the namespace of
643 which the template is a member, or, for member templates, in the
644 namespace of which the enclosing class or enclosing class
645 template is a member. An explicit specialization of a member
646 function, member class or static data member of a class template
647 shall be declared in the namespace of which the class template
648 is a member. */
650 {
653 }
655 /* [temp.expl.spec]
657 In an explicit specialization declaration for a member of a class
658 template or a member template that appears in namespace scope,
659 the member template and some of its enclosing class templates may
660 remain unspecialized, except that the declaration shall not
661 explicitly specialize a class member template if its enclosing
662 class templates are not explicitly specialized as well. */
664 {
667 }
670 }
672 /* We've just seen template <>. */
674 bool
676 {
680 }
682 /* Called at then end of processing a declaration preceded by
683 template<>. */
685 void
687 {
690 }
692 /* Any template <>'s that we have seen thus far are not referring to a
693 function specialization. */
695 void
697 {
700 }
702 /* We've just seen a template header. If SPECIALIZATION is nonzero,
703 it was of the form template <>. */
705 static void
707 {
709 template_header_count++;
710 }
712 /* We're beginning an explicit instantiation. */
714 void
716 {
719 }
722 void
724 {
727 }
729 /* An explicit specialization or partial specialization TMPL is being
730 declared. Check that the namespace in which the specialization is
731 occurring is permissible. Returns false iff it is invalid to
732 specialize TMPL in the current namespace. */
734 static bool
736 {
739 /* [tmpl.expl.spec]
741 An explicit specialization shall be declared in the namespace of
742 which the template is a member, or, for member templates, in the
743 namespace of which the enclosing class or enclosing class
744 template is a member. An explicit specialization of a member
745 function, member class or static data member of a class template
746 shall be declared in the namespace of which the class template is
747 a member. */
750 {
753 }
755 /* Same or super-using namespace. */
757 else
758 {
762 }
763 }
765 /* SPEC is an explicit instantiation. Check that it is valid to
766 perform this explicit instantiation in the current namespace. */
768 static void
770 {
771 tree ns;
773 /* DR 275: An explicit instantiation shall appear in an enclosing
774 namespace of its template. */
780 }
782 /* The TYPE is being declared. If it is a template type, that means it
783 is a partial specialization. Do appropriate error-checking. */
785 tree
787 {
788 tree context;
794 {
798 }
803 {
804 /* This is for ordinary explicit specialization and partial
805 specialization of a template class such as:
807 template <> class C<int>;
809 or:
811 template <class T> class C<T*>;
813 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
817 {
821 {
825 }
826 }
829 }
835 {
836 /* This is for an explicit specialization of member class
837 template according to [temp.expl.spec/18]:
839 template <> template <class U> class C<int>::D;
841 The context `C<int>' must be an implicit instantiation.
842 Otherwise this is just a member class template declared
843 earlier like:
845 template <> class C<int> { template <class U> class D; };
846 template <> template <class U> class C<int>::D;
848 In the first case, `C<int>::D' is a specialization of `C<T>::D'
849 while in the second case, `C<int>::D' is a primary template
850 and `C<T>::D' may not exist. */
854 {
855 tree t;
860 {
863 }
865 /* Check for invalid specialization after instantiation:
867 template <> template <> class C<int>::D<int>;
868 template <> template <class U> class C<int>::D; */
872 {
875 {
876 /* We already have a full specialization of this partial
877 instantiation. Reassign it to the new member
878 specialization template. */
879 spec_entry elt;
895 }
897 /* But if we've had an implicit instantiation, that's a
898 problem ([temp.expl.spec]/6). */
901 }
903 /* Mark TYPE as a specialization. And as a result, we only
904 have one level of template argument for the innermost
905 class template. */
909 }
910 }
912 {
915 }
918 }
920 /* Returns nonzero if we can optimize the retrieval of specializations
921 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
922 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
926 {
929 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
930 parameter. */
932 /* The optimized lookup depends on the fact that the
933 template arguments for the member function template apply
934 purely to the containing class, which is not true if the
935 containing class is an explicit or partial
936 specialization. */
940 /* It is possible to have a template that is not a member
941 template and is not a member of a template class:
943 template <typename T>
944 struct S { friend A::f(); };
946 Here, the friend function is a template, but the context does
947 not have template information. The optimized lookup relies
948 on having ARGS be the template arguments for both the class
949 and the function template. */
951 }
953 /* Retrieve the specialization (in the sense of [temp.spec] - a
954 specialization is either an instantiation or an explicit
955 specialization) of TMPL for the given template ARGS. If there is
956 no such specialization, return NULL_TREE. The ARGS are a vector of
957 arguments, or a vector of vectors of arguments, in the case of
958 templates with more than one level of parameters.
960 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
961 then we search for a partial specialization matching ARGS. This
962 parameter is ignored if TMPL is not a class template. */
964 static tree
966 {
972 /* There should be as many levels of arguments as there are
973 levels of parameters. */
978 {
979 tree class_template;
980 tree class_specialization;
982 tree fns;
985 /* The template arguments actually apply to the containing
986 class. Find the class specialization with those
987 arguments. */
989 class_specialization
993 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
994 for the specialization. */
998 /* Iterate through the methods with the indicated name, looking
999 for the one that has an instance of TMPL. */
1002 {
1005 /* using-declarations can add base methods to the method vec,
1006 and we don't want those here. */
1009 }
1011 }
1012 else
1013 {
1015 spec_entry elt;
1016 htab_t specializations;
1024 else
1032 }
1035 }
1037 /* Like retrieve_specialization, but for local declarations. */
1039 static tree
1041 {
1042 tree spec;
1050 }
1052 /* Returns nonzero iff DECL is a specialization of TMPL. */
1054 int
1056 {
1057 tree t;
1060 {
1066 }
1067 else
1068 {
1077 }
1080 }
1082 /* Returns nonzero iff DECL is a specialization of friend declaration
1083 FRIEND_DECL according to [temp.friend]. */
1085 bool
1087 {
1094 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1095 of a template class, we want to check if DECL is a specialization
1096 if this. */
1100 {
1101 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1104 }
1109 /* There is nothing to do if this is not a template friend. */
1116 /* [temp.friend/6]
1117 A member of a class template may be declared to be a friend of a
1118 non-template class. In this case, the corresponding member of
1119 every specialization of the class template is a friend of the
1120 class granting friendship.
1122 For example, given a template friend declaration
1124 template <class T> friend void A<T>::f();
1126 the member function below is considered a friend
1128 template <> struct A<int> {
1129 void f();
1130 };
1132 For this type of template friend, TEMPLATE_DEPTH below will be
1133 nonzero. To determine if DECL is a friend of FRIEND, we first
1134 check if the enclosing class is a specialization of another. */
1141 {
1142 /* Next, we check the members themselves. In order to handle
1143 a few tricky cases, such as when FRIEND_DECL's are
1145 template <class T> friend void A<T>::g(T t);
1146 template <class T> template <T t> friend void A<T>::h();
1148 and DECL's are
1150 void A<int>::g(int);
1151 template <int> void A<int>::h();
1153 we need to figure out ARGS, the template arguments from
1154 the context of DECL. This is required for template substitution
1155 of `T' in the function parameter of `g' and template parameter
1156 of `h' in the above examples. Here ARGS corresponds to `int'. */
1163 {
1165 {
1168 else
1170 current_depth++;
1171 }
1173 }
1176 {
1178 tree friend_type;
1179 tree decl_type;
1180 tree friend_args_type;
1181 tree decl_args_type;
1183 /* Make sure that both DECL and FRIEND_DECL are templates or
1184 non-templates. */
1190 {
1191 /* If both are templates, check template parameter list. */
1192 tree friend_parms
1197 friend_parms))
1201 }
1202 else
1210 /* Check if return types match. */
1214 /* Check if function parameter types match, ignoring the
1215 `this' parameter. */
1224 }
1225 else
1226 {
1227 /* DECL is a TYPE_DECL */
1231 /* Make sure that both DECL and FRIEND_DECL are templates or
1232 non-templates. */
1233 is_template
1240 {
1241 tree friend_parms;
1242 /* If both are templates, check the name of the two
1243 TEMPLATE_DECL's first because is_friend didn't. */
1248 /* Now check template parameter list. */
1249 friend_parms
1252 return comp_template_parms
1254 friend_parms);
1255 }
1256 else
1259 }
1260 }
1262 }
1264 /* Register the specialization SPEC as a specialization of TMPL with
1265 the indicated ARGS. IS_FRIEND indicates whether the specialization
1266 is actually just a friend declaration. Returns SPEC, or an
1267 equivalent prior declaration, if available. */
1269 static tree
1271 hashval_t hash)
1272 {
1273 tree fn;
1275 spec_entry elt;
1281 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1282 register it; we want the corresponding TEMPLATE_DECL instead.
1283 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1284 the more obvious `uses_template_parms (spec)' to avoid problems
1285 with default function arguments. In particular, given
1286 something like this:
1288 template <class T> void f(T t1, T t = T())
1290 the default argument expression is not substituted for in an
1291 instantiation unless and until it is actually needed. */
1295 /* We don't put these specializations in the hash table, but we might
1296 want to give an error about a mismatch. */
1298 else
1299 {
1311 else
1313 }
1315 /* We can sometimes try to re-register a specialization that we've
1316 already got. In particular, regenerate_decl_from_template calls
1317 duplicate_decls which will update the specialization list. But,
1318 we'll still get called again here anyhow. It's more convenient
1319 to simply allow this than to try to prevent it. */
1323 {
1325 {
1328 {
1330 fn);
1332 }
1333 else
1334 {
1335 tree clone;
1336 /* This situation should occur only if the first
1337 specialization is an implicit instantiation, the
1338 second is an explicit specialization, and the
1339 implicit instantiation has not yet been used. That
1340 situation can occur if we have implicitly
1341 instantiated a member function and then specialized
1342 it later.
1344 We can also wind up here if a friend declaration that
1345 looked like an instantiation turns out to be a
1346 specialization:
1348 template <class T> void foo(T);
1349 class S { friend void foo<>(int) };
1350 template <> void foo(int);
1352 We transform the existing DECL in place so that any
1353 pointers to it become pointers to the updated
1354 declaration.
1356 If there was a definition for the template, but not
1357 for the specialization, we want this to look as if
1358 there were no definition, and vice versa. */
1361 /* The call to duplicate_decls will have applied
1362 [temp.expl.spec]:
1364 An explicit specialization of a function template
1365 is inline only if it is explicitly declared to be,
1366 and independently of whether its function template
1367 is.
1369 to the primary function; now copy the inline bits to
1370 the various clones. */
1372 {
1377 }
1381 }
1382 }
1384 {
1386 /* Dup decl failed, but this is a new definition. Set the
1387 line number so any errors match this new
1388 definition. */
1392 }
1393 }
1397 /* A specialization must be declared in the same namespace as the
1398 template it is specializing. */
1404 {
1411 /* TMPL is a forward declaration of a template function; keep a list
1412 of all specializations in case we need to reassign them to a friend
1413 template later in tsubst_friend_function. */
1416 }
1419 }
1421 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1422 TMPL and ARGS members, ignores SPEC. */
1424 static int
1426 {
1432 }
1434 /* Returns a hash for a template TMPL and template arguments ARGS. */
1436 static hashval_t
1438 {
1441 }
1443 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1444 ignoring SPEC. */
1446 static hashval_t
1448 {
1451 }
1453 /* Recursively calculate a hash value for a template argument ARG, for use
1454 in the hash tables of template specializations. */
1456 static hashval_t
1458 {
1470 /* We can get one of these when re-hashing a previous entry in the middle
1471 of substituting into a pack expansion. Just look through it. */
1480 {
1488 {
1493 }
1514 {
1517 {
1520 }
1522 }
1537 val = iterative_hash_template_arg
1549 val);
1551 val);
1560 /* layout_type sets structural equality for arrays of
1561 incomplete type, so we can't rely on the canonical type
1562 for hashing. */
1568 {
1572 val);
1575 /* Otherwise just compare the types during lookup. */
1584 {
1589 }
1590 }
1591 }
1594 }
1596 /* Unregister the specialization SPEC as a specialization of TMPL.
1597 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1598 if the SPEC was listed as a specialization of TMPL.
1600 Note that SPEC has been ggc_freed, so we can't look inside it. */
1602 bool
1604 {
1606 spec_entry elt;
1614 {
1619 }
1622 }
1624 /* Compare an entry in the local specializations hash table P1 (which
1625 is really a pointer to a TREE_LIST) with P2 (which is really a
1626 DECL). */
1628 static int
1630 {
1632 }
1634 /* Hash P1, an entry in the local specializations table. */
1636 static hashval_t
1638 {
1640 }
1642 /* Like register_specialization, but for local declarations. We are
1643 registering SPEC, an instantiation of TMPL. */
1645 static void
1647 {
1653 }
1655 /* TYPE is a class type. Returns true if TYPE is an explicitly
1656 specialized class. */
1658 bool
1660 {
1664 }
1666 /* Print the list of functions at FNS, going through all the overloads
1667 for each element of the list. Alternatively, FNS can not be a
1668 TREE_LIST, in which case it will be printed together with all the
1669 overloads.
1671 MORE and *STR should respectively be FALSE and NULL when the function
1672 is called from the outside. They are used internally on recursive
1673 calls. print_candidates manages the two parameters and leaves NULL
1674 in *STR when it ends. */
1676 static void
1678 {
1684 {
1689 }
1690 else
1691 {
1693 {
1694 /* Pick the prefix string. */
1696 {
1699 }
1703 }
1706 }
1709 {
1712 }
1713 }
1715 /* Print the list of candidate FNS in an error message. */
1717 void
1719 {
1723 }
1725 /* Returns the template (one of the functions given by TEMPLATE_ID)
1726 which can be specialized to match the indicated DECL with the
1727 explicit template args given in TEMPLATE_ID. The DECL may be
1728 NULL_TREE if none is available. In that case, the functions in
1729 TEMPLATE_ID are non-members.
1731 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1732 specialization of a member template.
1734 The TEMPLATE_COUNT is the number of references to qualifying
1735 template classes that appeared in the name of the function. See
1736 check_explicit_specialization for a more accurate description.
1738 TSK indicates what kind of template declaration (if any) is being
1739 declared. TSK_TEMPLATE indicates that the declaration given by
1740 DECL, though a FUNCTION_DECL, has template parameters, and is
1741 therefore a template function.
1743 The template args (those explicitly specified and those deduced)
1744 are output in a newly created vector *TARGS_OUT.
1746 If it is impossible to determine the result, an error message is
1747 issued. The error_mark_node is returned to indicate failure. */
1749 static tree
1751 tree decl,
1755 tmpl_spec_kind tsk)
1756 {
1757 tree fns;
1758 tree targs;
1759 tree explicit_targs;
1761 /* A TREE_LIST of templates of which DECL may be a specialization.
1762 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1763 corresponding TREE_PURPOSE is the set of template arguments that,
1764 when used to instantiate the template, would produce a function
1765 with the signature of DECL. */
1781 /* Check for baselinks. */
1786 {
1789 }
1791 /* Count the number of template headers specified for this
1792 specialization. */
1800 {
1804 {
1805 tree decl_arg_types;
1806 tree fn_arg_types;
1808 /* In case of explicit specialization, we need to check if
1809 the number of template headers appearing in the specialization
1810 is correct. This is usually done in check_explicit_specialization,
1811 but the check done there cannot be exhaustive when specializing
1812 member functions. Consider the following code:
1814 template <> void A<int>::f(int);
1815 template <> template <> void A<int>::f(int);
1817 Assuming that A<int> is not itself an explicit specialization
1818 already, the first line specializes "f" which is a non-template
1819 member function, whilst the second line specializes "f" which
1820 is a template member function. So both lines are syntactically
1821 correct, and check_explicit_specialization does not reject
1822 them.
1824 Here, we can do better, as we are matching the specialization
1825 against the declarations. We count the number of template
1826 headers, and we check if they match TEMPLATE_COUNT + 1
1827 (TEMPLATE_COUNT is the number of qualifying template classes,
1828 plus there must be another header for the member template
1829 itself).
1831 Notice that if header_count is zero, this is not a
1832 specialization but rather a template instantiation, so there
1833 is no check we can perform here. */
1837 /* Check that the number of template arguments at the
1838 innermost level for DECL is the same as for FN. */
1846 /* DECL might be a specialization of FN. */
1850 /* For a non-static member function, we need to make sure
1851 that the const qualification is the same. Since
1852 get_bindings does not try to merge the "this" parameter,
1853 we must do the comparison explicitly. */
1859 /* Skip the "this" parameter and, for constructors of
1860 classes with virtual bases, the VTT parameter. A
1861 full specialization of a constructor will have a VTT
1862 parameter, but a template never will. */
1863 decl_arg_types
1865 fn_arg_types
1868 /* Check that the number of function parameters matches.
1869 For example,
1870 template <class T> void f(int i = 0);
1871 template <> void f<int>();
1872 The specialization f<int> is invalid but is not caught
1873 by get_bindings below. */
1877 /* Function templates cannot be specializations; there are
1878 no partial specializations of functions. Therefore, if
1879 the type of DECL does not match FN, there is no
1880 match. */
1882 {
1886 }
1888 /* See whether this function might be a specialization of this
1889 template. */
1893 /* We cannot deduce template arguments that when used to
1894 specialize TMPL will produce DECL. */
1897 /* Save this template, and the arguments deduced. */
1899 }
1901 /* FN is an ordinary member function, and we need a
1902 specialization of a member template. */
1903 ;
1905 /* We can get IDENTIFIER_NODEs here in certain erroneous
1906 cases. */
1907 ;
1909 /* This is just an ordinary non-member function. Nothing can
1910 be a specialization of that. */
1911 ;
1913 /* Cannot specialize functions that are created implicitly. */
1914 ;
1915 else
1916 {
1917 tree decl_arg_types;
1919 /* This is an ordinary member function. However, since
1920 we're here, we can assume it's enclosing class is a
1921 template class. For example,
1923 template <typename T> struct S { void f(); };
1924 template <> void S<int>::f() {}
1926 Here, S<int>::f is a non-template, but S<int> is a
1927 template class. If FN has the same type as DECL, we
1928 might be in business. */
1931 /* Its enclosing class is an explicit specialization
1932 of a template class. This is not a candidate. */
1937 /* The return types differ. */
1940 /* Adjust the type of DECL in case FN is a static member. */
1947 decl_arg_types))
1948 /* They match! */
1950 }
1951 }
1954 {
1955 /* We have:
1957 [temp.expl.spec]
1959 It is possible for a specialization with a given function
1960 signature to be instantiated from more than one function
1961 template. In such cases, explicit specification of the
1962 template arguments must be used to uniquely identify the
1963 function template specialization being specialized.
1965 Note that here, there's no suggestion that we're supposed to
1966 determine which of the candidate templates is most
1967 specialized. However, we, also have:
1969 [temp.func.order]
1971 Partial ordering of overloaded function template
1972 declarations is used in the following contexts to select
1973 the function template to which a function template
1974 specialization refers:
1976 -- when an explicit specialization refers to a function
1977 template.
1979 So, we do use the partial ordering rules, at least for now.
1980 This extension can only serve to make invalid programs valid,
1981 so it's safe. And, there is strong anecdotal evidence that
1982 the committee intended the partial ordering rules to apply;
1983 the EDG front end has that behavior, and John Spicer claims
1984 that the committee simply forgot to delete the wording in
1985 [temp.expl.spec]. */
1988 {
1991 }
1992 }
1995 {
2003 }
2007 {
2013 }
2015 /* We have one, and exactly one, match. */
2017 {
2020 /* DECL is a re-declaration or partial instantiation of a template
2021 function. */
2024 /* It was a specialization of an ordinary member function in a
2025 template class. */
2027 }
2029 /* It was a specialization of a template. */
2032 {
2037 }
2038 else
2041 }
2043 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2044 but with the default argument values filled in from those in the
2045 TMPL_TYPES. */
2047 static tree
2049 tree tmpl_types)
2050 {
2051 tree new_spec_types;
2059 /* Substitute into the rest of the list. */
2060 new_spec_types =
2064 /* Add the default argument for this parameter. */
2067 new_spec_types);
2068 }
2070 /* DECL is an explicit specialization. Replicate default arguments
2071 from the template it specializes. (That way, code like:
2073 template <class T> void f(T = 3);
2074 template <> void f(double);
2075 void g () { f (); }
2077 works, as required.) An alternative approach would be to look up
2078 the correct default arguments at the call-site, but this approach
2079 is consistent with how implicit instantiations are handled. */
2081 static void
2083 {
2084 tree tmpl;
2085 tree spec_types;
2086 tree tmpl_types;
2087 tree new_spec_types;
2088 tree old_type;
2089 tree new_type;
2090 tree t;
2095 /* See if there's anything we need to do. */
2108 {
2109 /* Remove the this pointer, but remember the object's type for
2110 CV quals. */
2116 {
2117 /* DECL may contain more parameters than TMPL due to the extra
2118 in-charge parameter in constructors and destructors. */
2121 }
2123 {
2126 }
2127 }
2129 /* Compute the merged default arguments. */
2130 new_spec_types =
2133 /* Compute the new FUNCTION_TYPE. */
2135 {
2139 new_spec_types);
2142 /* Put the in-charge parameter back. */
2145 new_spec_types);
2149 new_spec_types);
2150 }
2151 else
2153 new_spec_types);
2159 }
2161 /* Check to see if the function just declared, as indicated in
2162 DECLARATOR, and in DECL, is a specialization of a function
2163 template. We may also discover that the declaration is an explicit
2164 instantiation at this point.
2166 Returns DECL, or an equivalent declaration that should be used
2167 instead if all goes well. Issues an error message if something is
2168 amiss. Returns error_mark_node if the error is not easily
2169 recoverable.
2171 FLAGS is a bitmask consisting of the following flags:
2173 2: The function has a definition.
2174 4: The function is a friend.
2176 The TEMPLATE_COUNT is the number of references to qualifying
2177 template classes that appeared in the name of the function. For
2178 example, in
2180 template <class T> struct S { void f(); };
2181 void S<int>::f();
2183 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2184 classes are not counted in the TEMPLATE_COUNT, so that in
2186 template <class T> struct S {};
2187 template <> struct S<int> { void f(); }
2188 template <> void S<int>::f();
2190 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2191 invalid; there should be no template <>.)
2193 If the function is a specialization, it is marked as such via
2194 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2195 is set up correctly, and it is added to the list of specializations
2196 for that template. */
2198 tree
2200 tree decl,
2203 {
2211 tmpl_spec_kind tsk;
2214 {
2217 else
2219 }
2220 else
2224 {
2227 {
2230 }
2232 {
2234 /* This could be something like:
2236 template <class T> void f(T);
2237 class S { friend void f<>(int); } */
2239 else
2240 {
2241 /* This case handles bogus declarations like template <>
2242 template <class T> void f<int>(); */
2245 declarator);
2247 }
2248 }
2252 /* The error has already been reported in
2253 check_specialization_scope. */
2259 /* Fall through. */
2272 decl);
2275 else
2279 /* Fall through. */
2284 else
2290 {
2291 /* This case handles bogus declarations like template <>
2292 template <class T> void f<int>(); */
2297 else
2299 declarator);
2301 }
2304 /* This is a specialization of a member template, without
2305 specialization the containing class. Something like:
2307 template <class T> struct S {
2308 template <class U> void f (U);
2309 };
2310 template <> template <class U> void S<int>::f(U) {}
2312 That's a specialization -- but of the entire template. */
2318 }
2321 {
2325 {
2329 }
2330 }
2333 {
2337 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2339 {
2340 tree fns;
2345 else
2346 {
2347 /* If there is no class context, the explicit instantiation
2348 must be at namespace scope. */
2351 /* Find the namespace binding, using the declaration
2352 context. */
2356 {
2359 }
2360 else
2361 {
2367 }
2368 }
2371 }
2377 {
2379 /* A specialization in class scope. This is invalid,
2380 but the error will already have been flagged by
2381 check_specialization_scope. */
2383 else
2384 {
2385 /* It's not valid to write an explicit instantiation in
2386 class scope, e.g.:
2388 class C { template void f(); }
2390 This case is caught by the parser. However, on
2391 something like:
2393 template class C { void f(); };
2395 (which is invalid) we can get here. The error will be
2396 issued later. */
2397 ;
2398 }
2401 }
2404 IDENTIFIER_NODE))
2405 {
2406 /* Find the list of functions in ctype that have the same
2407 name as the declared function. */
2413 {
2418 {
2419 /* From [temp.expl.spec]:
2421 If such an explicit specialization for the member
2422 of a class template names an implicitly-declared
2423 special member function (clause _special_), the
2424 program is ill-formed.
2426 Similar language is found in [temp.explicit]. */
2429 }
2432 }
2435 {
2439 }
2440 else
2441 {
2443 tree ovl;
2445 /* For a type-conversion operator, we cannot do a
2446 name-based lookup. We might be looking for `operator
2447 int' which will be a specialization of `operator T'.
2448 So, we find *all* the conversion operators, and then
2449 select from them. */
2457 {
2459 /* There are no more conversion functions. */
2462 /* Glue all these conversion functions together
2463 with those we already have. */
2466 }
2467 }
2470 {
2473 }
2474 else
2476 }
2478 /* Figure out what exactly is being specialized at this point.
2479 Note that for an explicit instantiation, even one for a
2480 member function, we cannot tell apriori whether the
2481 instantiation is for a member template, or just a member
2482 function of a template class. Even if a member template is
2483 being instantiated, the member template arguments may be
2484 elided if they can be deduced from the rest of the
2485 declaration. */
2488 member_specialization,
2489 template_count,
2490 tsk);
2493 /* We couldn't figure out what this declaration was
2494 specializing. */
2496 else
2497 {
2501 {
2502 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2503 is done by do_decl_instantiation later. */
2509 {
2510 /* If TMPL is not the most general template (for
2511 example, if TMPL is a friend template that is
2512 injected into namespace scope), then there will
2513 be too many levels of TARGS. Remove some of them
2514 here. */
2516 tree new_targs;
2523 }
2526 }
2528 /* If we thought that the DECL was a member function, but it
2529 turns out to be specializing a static member function,
2530 make DECL a static member function as well. */
2535 /* If this is a specialization of a member template of a
2536 template class, we want to return the TEMPLATE_DECL, not
2537 the specialization of it. */
2539 {
2544 {
2545 tree parm;
2549 /* We want to use the argument list specified in the
2550 definition, not in the original declaration. */
2555 }
2558 }
2560 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2563 /* Inherit default function arguments from the template
2564 DECL is specializing. */
2567 /* This specialization has the same protection as the
2568 template it specializes. */
2572 /* 7.1.1-1 [dcl.stc]
2574 A storage-class-specifier shall not be specified in an
2575 explicit specialization...
2577 The parser rejects these, so unless action is taken here,
2578 explicit function specializations will always appear with
2579 global linkage.
2581 The action recommended by the C++ CWG in response to C++
2582 defect report 605 is to make the storage class and linkage
2583 of the explicit specialization match the templated function:
2585 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2586 */
2588 {
2592 /* This specialization has the same linkage and visibility as
2593 the function template it specializes. */
2596 {
2599 }
2602 {
2605 }
2606 }
2608 /* If DECL is a friend declaration, declared using an
2609 unqualified name, the namespace associated with DECL may
2610 have been set incorrectly. For example, in:
2612 template <typename T> void f(T);
2613 namespace N {
2614 struct S { friend void f<int>(int); }
2615 }
2617 we will have set the DECL_CONTEXT for the friend
2618 declaration to N, rather than to the global namespace. */
2623 /* This is not really a declaration of a specialization.
2624 It's just the name of an instantiation. But, it's not
2625 a request for an instantiation, either. */
2628 /* This is indeed a specialization. In case of constructors
2629 and destructors, we need in-charge and not-in-charge
2630 versions in V3 ABI. */
2633 /* Register this specialization so that we can find it
2634 again. */
2636 }
2637 }
2640 }
2642 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2643 parameters. These are represented in the same format used for
2644 DECL_TEMPLATE_PARMS. */
2646 int
2648 {
2649 const_tree p1;
2650 const_tree p2;
2658 {
2670 {
2674 /* If either of the template parameters are invalid, assume
2675 they match for the sake of error recovery. */
2688 }
2689 }
2692 /* One set of parameters has more parameters lists than the
2693 other. */
2697 }
2699 /* Determine whether PARM is a parameter pack. */
2701 bool
2703 {
2704 /* Determine if we have a non-type template parameter pack. */
2709 /* If this is a list of template parameters, we could get a
2710 TYPE_DECL or a TEMPLATE_DECL. */
2717 }
2719 /* Determine if T is a function parameter pack. */
2721 bool
2723 {
2727 }
2729 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2730 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2732 tree
2734 {
2741 }
2743 /* Return true iff the function parameter PARAM_DECL was expanded
2744 from the function parameter pack PACK. */
2746 bool
2748 {
2753 /* The parameter pack and its pack arguments have the same
2754 DECL_PARM_INDEX. */
2756 }
2758 /* Determine whether ARGS describes a variadic template args list,
2759 i.e., one that is terminated by a template argument pack. */
2761 static bool
2763 {
2765 tree last_parm;
2779 }
2781 /* Generate a new name for the parameter pack name NAME (an
2782 IDENTIFIER_NODE) that incorporates its */
2784 static tree
2786 {
2787 /* Munge the name to include the parameter index. */
2788 #define NUMBUF_LEN 128
2800 }
2802 /* Return true if T is a primary function
2803 or class template instantiation. */
2805 bool
2807 {
2819 }
2821 /* Return true if PARM is a template template parameter. */
2823 bool
2825 {
2827 }
2829 /* Return the template parameters of T if T is a
2830 primary template instantiation, NULL otherwise. */
2832 tree
2834 {
2839 parms = INNERMOST_TEMPLATE_PARMS
2843 }
2845 /* Return the template parameters of the LEVELth level from the full list
2846 of template parameters PARMS. */
2848 tree
2850 {
2851 tree p;
2862 }
2864 /* Returns the template arguments of T if T is a template instantiation,
2865 NULL otherwise. */
2867 tree
2869 {
2877 }
2879 /* Return the argument pack elements of T if T is a template argument pack,
2880 NULL otherwise. */
2882 tree
2884 {
2890 }
2892 /* Structure used to track the progress of find_parameter_packs_r. */
2893 struct find_parameter_pack_data
2894 {
2895 /* TREE_LIST that will contain all of the parameter packs found by
2896 the traversal. */
2899 /* Set of AST nodes that have been visited by the traversal. */
2901 };
2903 /* Identifies all of the argument packs that occur in a template
2904 argument and appends them to the TREE_LIST inside DATA, which is a
2905 find_parameter_pack_data structure. This is a subroutine of
2906 make_pack_expansion and uses_parameter_packs. */
2907 static tree
2909 {
2915 /* Identify whether this is a parameter pack or not. */
2917 {
2931 {
2932 /* We don't want to walk into the type of a PARM_DECL,
2933 because we don't want to see the type parameter pack. */
2936 }
2940 /* Not a parameter pack. */
2942 }
2945 {
2946 /* Add this parameter pack to the list. */
2948 }
2954 /* This switch statement will return immediately if we don't find a
2955 parameter pack. */
2957 {
2962 /* Check the template itself. */
2965 /* Check the template arguments. */
2981 /* Fall through. */
3022 }
3025 }
3027 /* Determines if the expression or type T uses any parameter packs. */
3028 bool
3030 {
3038 }
3040 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3041 representation a base-class initializer into a parameter pack
3042 expansion. If all goes well, the resulting node will be an
3043 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3044 respectively. */
3045 tree
3047 {
3048 tree result;
3057 {
3058 /* The only time we will see a TREE_LIST here is for a base
3059 class initializer. In this case, the TREE_PURPOSE will be a
3060 _TYPE node (representing the base class expansion we're
3061 initializing) and the TREE_VALUE will be a TREE_LIST
3062 containing the initialization arguments.
3064 The resulting expansion looks somewhat different from most
3065 expansions. Rather than returning just one _EXPANSION, we
3066 return a TREE_LIST whose TREE_PURPOSE is a
3067 TYPE_PACK_EXPANSION containing the bases that will be
3068 initialized. The TREE_VALUE will be identical to the
3069 original TREE_VALUE, which is a list of arguments that will
3070 be passed to each base. We do not introduce any new pack
3071 expansion nodes into the TREE_VALUE (although it is possible
3072 that some already exist), because the TREE_PURPOSE and
3073 TREE_VALUE all need to be expanded together with the same
3074 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3075 resulting TREE_PURPOSE will mention the parameter packs in
3076 both the bases and the arguments to the bases. */
3077 tree purpose;
3078 tree value;
3081 /* Determine which parameter packs will be used by the base
3082 class expansion. */
3089 {
3093 }
3096 {
3097 /* Collect the sets of parameter packs used in each of the
3098 initialization arguments. */
3100 {
3101 /* Determine which parameter packs will be expanded in this
3102 argument. */
3105 }
3106 }
3110 /* Create the pack expansion type for the base type. */
3115 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3116 they will rarely be compared to anything. */
3120 }
3125 /* Build the PACK_EXPANSION_* node. */
3126 result = for_types
3131 {
3132 /* Propagate type and const-expression information. */
3135 }
3136 else
3137 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3138 they will rarely be compared to anything. */
3141 /* Determine which parameter packs will be expanded. */
3147 /* Make sure we found some parameter packs. */
3149 {
3152 else
3155 }
3159 }
3161 /* Checks T for any "bare" parameter packs, which have not yet been
3162 expanded, and issues an error if any are found. This operation can
3163 only be done on full expressions or types (e.g., an expression
3164 statement, "if" condition, etc.), because we could have expressions like:
3166 foo(f(g(h(args)))...)
3168 where "args" is a parameter pack. check_for_bare_parameter_packs
3169 should not be called for the subexpressions args, h(args),
3170 g(h(args)), or f(g(h(args))), because we would produce erroneous
3171 error messages.
3173 Returns TRUE and emits an error if there were bare parameter packs,
3174 returns FALSE otherwise. */
3175 bool
3177 {
3193 {
3196 {
3205 else
3210 else
3214 }
3217 }
3220 }
3222 /* Expand any parameter packs that occur in the template arguments in
3223 ARGS. */
3224 tree
3226 {
3232 /* First, determine if we need to expand anything, and the number of
3233 slots we'll need. */
3235 {
3240 {
3244 else
3246 }
3247 else
3248 {
3250 num_result_args++;
3251 }
3252 }
3254 /* If no expansion is necessary, we're done. */
3258 /* Expand arguments. */
3261 non_default_args_count =
3264 {
3267 {
3274 }
3275 else
3276 {
3279 }
3280 }
3284 }
3286 /* Checks if DECL shadows a template parameter.
3288 [temp.local]: A template-parameter shall not be redeclared within its
3289 scope (including nested scopes).
3291 Emits an error and returns TRUE if the DECL shadows a parameter,
3292 returns FALSE otherwise. */
3294 bool
3296 {
3297 tree olddecl;
3299 /* If we're not in a template, we can't possibly shadow a template
3300 parameter. */
3304 /* Figure out what we're shadowing. */
3309 /* If there's no previous binding for this name, we're not shadowing
3310 anything, let alone a template parameter. */
3314 /* If we're not shadowing a template parameter, we're done. Note
3315 that OLDDECL might be an OVERLOAD (or perhaps even an
3316 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3317 node. */
3321 /* We check for decl != olddecl to avoid bogus errors for using a
3322 name inside a class. We check TPFI to avoid duplicate errors for
3323 inline member templates. */
3331 }
3333 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3334 ORIG_LEVEL, DECL, and TYPE. */
3336 static tree
3340 tree decl,
3341 tree type)
3342 {
3353 }
3355 /* Find the canonical type parameter for the given template type
3356 parameter. Returns the canonical type parameter, which may be TYPE
3357 if no such parameter existed. */
3358 static tree
3360 {
3361 tree list;
3375 else
3376 {
3381 }
3382 }
3384 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3385 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3386 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3387 new one is created. */
3389 static tree
3391 tsubst_flags_t complain)
3392 {
3397 {
3416 /* Template template parameters need this. */
3421 }
3424 }
3426 /* Process information from new template parameter PARM and append it to the
3427 LIST being built. This new parameter is a non-type parameter iff
3428 IS_NON_TYPE is true. This new parameter is a parameter
3429 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3430 PARM_LOC. */
3432 tree
3435 {
3437 tree defval;
3438 tree err_parm_list;
3445 {
3449 {
3453 else
3455 }
3458 }
3459 else
3463 {
3469 {
3473 }
3474 else
3475 {
3476 /* [temp.param]
3478 The top-level cv-qualifiers on the template-parameter are
3479 ignored when determining its type. */
3482 {
3486 }
3489 {
3490 /* This template parameter is not a parameter pack, but it
3491 should be. Complain about "bare" parameter packs. */
3494 /* Recover by calling this a parameter pack. */
3496 }
3497 }
3499 /* A template parameter is not modifiable. */
3508 processing_template_decl,
3513 }
3514 else
3515 {
3516 tree t;
3520 {
3522 /* This is for distinguishing between real templates and template
3523 template parameters */
3527 }
3528 else
3529 {
3531 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3534 }
3541 processing_template_decl,
3545 }
3551 }
3553 /* The end of a template parameter list has been reached. Process the
3554 tree list into a parameter vector, converting each parameter into a more
3555 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3556 as PARM_DECLs. */
3558 tree
3560 {
3565 current_template_parms
3570 {
3576 current_template_parms;
3577 }
3582 }
3584 /* end_template_decl is called after a template declaration is seen. */
3586 void
3588 {
3594 /* This matches the pushlevel in begin_template_parm_list. */
3599 }
3601 /* Within the declaration of a template, return all levels of template
3602 parameters that apply. The template parameters are represented as
3603 a TREE_VEC, in the form documented in cp-tree.h for template
3604 arguments. */
3606 static tree
3608 {
3609 tree header;
3614 /* If there is only one level of template parameters, we do not
3615 create a TREE_VEC of TREE_VECs. Instead, we return a single
3616 TREE_VEC containing the arguments. */
3621 {
3627 {
3630 /* T will be a list if we are called from within a
3631 begin/end_template_parm_list pair, but a vector directly
3632 if within a begin/end_member_template_processing pair. */
3634 {
3638 {
3641 {
3645 {
3646 /* Turn this argument into a TYPE_ARGUMENT_PACK
3647 with a single element, which expands T. */
3649 #ifdef ENABLE_CHECKING
3650 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3652 #endif
3657 }
3658 }
3659 else
3660 {
3664 {
3665 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3666 with a single element, which expands T. */
3669 #ifdef ENABLE_CHECKING
3670 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3672 #endif
3678 }
3679 }
3681 }
3682 }
3683 }
3685 #ifdef ENABLE_CHECKING
3687 #endif
3691 else
3693 }
3696 }
3698 /* Update the declared TYPE by doing any lookups which were thought to be
3699 dependent, but are not now that we know the SCOPE of the declarator. */
3701 tree
3703 {
3714 /* Don't bother building up the args in this case. */
3716 {
3717 /* tsubst in the args corresponding to the template parameters,
3718 including auto if present. Most things will be unchanged, but
3719 make_typename_type and tsubst_qualified_id will resolve
3720 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3724 {
3728 }
3732 }
3738 {
3741 else
3743 }
3745 }
3747 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3748 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3749 a member template. Used by push_template_decl below. */
3751 static tree
3753 {
3760 }
3762 struct template_parm_data
3763 {
3764 /* The level of the template parameters we are currently
3765 processing. */
3768 /* The index of the specialization argument we are currently
3769 processing. */
3772 /* An array whose size is the number of template parameters. The
3773 elements are nonzero if the parameter has been used in any one
3774 of the arguments processed so far. */
3777 /* An array whose size is the number of template arguments. The
3778 elements are nonzero if the argument makes use of template
3779 parameters of this level. */
3781 };
3783 /* Subroutine of push_template_decl used to see if each template
3784 parameter in a partial specialization is used in the explicit
3785 argument list. If T is of the LEVEL given in DATA (which is
3786 treated as a template_parm_data*), then DATA->PARMS is marked
3787 appropriately. */
3789 static int
3791 {
3797 {
3800 }
3801 else
3802 {
3805 }
3808 {
3811 }
3813 /* Return zero so that for_each_template_parm will continue the
3814 traversal of the tree; we want to mark *every* template parm. */
3816 }
3818 /* Process the partial specialization DECL. */
3820 static tree
3822 {
3828 tree inner_parms;
3841 /* We check that each of the template parameters given in the
3842 partial specialization is used in the argument list to the
3843 specialization. For example:
3845 template <class T> struct S;
3846 template <class T> struct S<T*>;
3848 The second declaration is OK because `T*' uses the template
3849 parameter T, whereas
3851 template <class T> struct S<int>;
3853 is no good. Even trickier is:
3855 template <class T>
3856 struct S1
3857 {
3858 template <class U>
3859 struct S2;
3860 template <class U>
3861 struct S2<T>;
3862 };
3864 The S2<T> declaration is actually invalid; it is a
3865 full-specialization. Of course,
3867 template <class U>
3868 struct S2<T (*)(U)>;
3870 or some such would have been OK. */
3878 {
3883 NULL,
3885 }
3888 {
3889 /* One of the template parms was not used in the
3890 specialization. */
3892 {
3895 }
3898 }
3900 /* [temp.class.spec]
3902 The argument list of the specialization shall not be identical to
3903 the implicit argument list of the primary template. */
3910 /* [temp.class.spec]
3912 A partially specialized non-type argument expression shall not
3913 involve template parameters of the partial specialization except
3914 when the argument expression is a simple identifier.
3916 The type of a template parameter corresponding to a specialized
3917 non-type argument shall not be dependent on a parameter of the
3918 specialization.
3920 Also, we verify that pack expansions only occur at the
3921 end of the argument list. */
3925 {
3932 {
3933 /* Extract the arguments from the argument pack. We'll be
3934 iterating over these in the following loop. */
3937 }
3940 {
3942 /* Get the Jth argument in the parameter pack. */
3946 {
3947 /* Pack expansions must come at the end of the
3948 argument list. */
3951 {
3955 else
3958 }
3959 }
3962 /* We only care about the pattern. */
3968 /* This next line is the `argument expression is not just a
3969 simple identifier' condition and also the `specialized
3970 non-type argument' bit. */
3972 {
3976 arg);
3977 else
3978 {
3979 /* Look at the corresponding template parameter,
3980 marking which template parameters its type depends
3981 upon. */
3985 {
3986 /* We haven't yet initialized TPD2. Do so now. */
3987 tpd2.arg_uses_template_parms
3989 /* The number of parameters here is the number in the
3990 main template, which, as checked in the assertion
3991 above, is NARGS. */
3995 }
3997 /* Mark the template parameters. But this time, we're
3998 looking for the template parameters of the main
3999 template, not in the specialization. */
4006 NULL,
4010 {
4011 /* The type depended on some template parameters.
4012 If they are fully specialized in the
4013 specialization, that's OK. */
4022 "type %qT of template argument %qE depends "
4024 "type %qT of template argument %qE depends "
4026 type,
4027 arg);
4028 }
4029 }
4030 }
4031 }
4032 }
4034 /* We should only get here once. */
4042 }
4044 /* Check that a template declaration's use of default arguments and
4045 parameter packs is not invalid. Here, PARMS are the template
4046 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4047 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4048 specialization.
4051 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4052 declaration (but not a definition); 1 indicates a declaration, 2
4053 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4054 emitted for extraneous default arguments.
4056 Returns TRUE if there were no errors found, FALSE otherwise. */
4058 bool
4061 {
4064 tree parm_level;
4067 /* [temp.param]
4069 A default template-argument shall not be specified in a
4070 function template declaration or a function template definition, nor
4071 in the template-parameter-list of the definition of a member of a
4072 class template. */
4075 /* You can't have a function template declaration in a local
4076 scope, nor you can you define a member of a class template in a
4077 local scope. */
4084 /* If this is either a friend defined in the scope of the class
4085 or a member function. */
4091 /* And, if it was a member function, it really was defined in
4092 the scope of the class. */
4095 /* We already checked these parameters when the template was
4096 declared, so there's no need to do it again now. This function
4097 was defined in class scope, but we're processing it's body now
4098 that the class is complete. */
4101 /* Core issue 226 (C++0x only): the following only applies to class
4102 templates. */
4104 {
4105 /* [temp.param]
4107 If a template-parameter has a default template-argument, all
4108 subsequent template-parameters shall have a default
4109 template-argument supplied. */
4111 {
4118 {
4128 {
4130 /* For better subsequent error-recovery, we indicate that
4131 there should have been a default argument. */
4134 }
4136 && !is_partial
4137 && !is_friend_decl
4138 /* Don't complain about an enclosing partial
4139 specialization. */
4144 {
4145 /* A primary class template can only have one
4146 parameter pack, at the end of the template
4147 parameter list. */
4152 else
4160 }
4161 }
4162 }
4163 }
4166 || is_partial
4167 || !is_primary
4169 /* For an ordinary class template, default template arguments are
4170 allowed at the innermost level, e.g.:
4171 template <class T = int>
4172 struct S {};
4173 but, in a partial specialization, they're not allowed even
4174 there, as we have in [temp.class.spec]:
4176 The template parameter list of a specialization shall not
4177 contain default template argument values.
4179 So, for a partial specialization, or for a function template
4180 (in C++98/C++03), we look at all of them. */
4181 ;
4182 else
4183 /* But, for a primary class template that is not a partial
4184 specialization we look at all template parameters except the
4185 innermost ones. */
4188 /* Figure out what error message to issue. */
4201 else
4205 /* If we're inside a class definition, there's no need to
4206 examine the parameters to the class itself. On the one
4207 hand, they will be checked when the class is defined, and,
4208 on the other, default arguments are valid in things like:
4209 template <class T = double>
4210 struct S { template <class U> void f(U); };
4211 Here the default argument for `S' has no bearing on the
4212 declaration of `f'. */
4214 else
4215 /* Check everything. */
4221 {
4228 {
4233 {
4235 {
4242 }
4244 /* Clear out the default argument so that we are not
4245 confused later. */
4247 }
4248 }
4250 /* At this point, if we're still interested in issuing messages,
4251 they must apply to classes surrounding the object declared. */
4255 }
4258 }
4260 /* Worker for push_template_decl_real, called via
4261 for_each_template_parm. DATA is really an int, indicating the
4262 level of the parameters we are interested in. If T is a template
4263 parameter of that level, return nonzero. */
4265 static int
4267 {
4273 else
4276 }
4278 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4279 parameters given by current_template_args, or reuses a
4280 previously existing one, if appropriate. Returns the DECL, or an
4281 equivalent one, if it is replaced via a call to duplicate_decls.
4283 If IS_FRIEND is true, DECL is a friend declaration. */
4285 tree
4287 {
4288 tree tmpl;
4289 tree args;
4290 tree info;
4291 tree ctx;
4295 /* True if the template is a member template, in the sense of
4296 [temp.mem]. */
4302 /* See if this is a partial specialization. */
4311 /* For a friend, we want the context of the friend function, not
4312 the type of which it is a friend. */
4316 /* In the case of a virtual function, we want the class in which
4317 it is defined. */
4319 else
4320 /* Otherwise, if we're currently defining some class, the DECL
4321 is assumed to be a member of the class. */
4330 /* See if this is a primary template. */
4332 /* A friend template that specifies a class context, i.e.
4333 template <typename T> friend void A<T>::f();
4334 is not primary. */
4336 else
4340 {
4345 {
4348 }
4350 {
4352 {
4353 /* [temp.mem]
4355 A destructor shall not be a member template. */
4358 }
4365 {
4366 /* [basic.stc.dynamic.allocation]
4368 An allocation function can be a function
4369 template. ... Template allocation functions shall
4370 have two or more parameters. */
4373 }
4374 }
4378 else
4379 {
4382 }
4383 }
4385 /* Check to see that the rules regarding the use of default
4386 arguments are not being violated. */
4390 /* Ensure that there are no parameter packs in the type of this
4391 declaration that have not been expanded. */
4393 {
4394 /* Check each of the arguments individually to see if there are
4395 any bare parameter packs. */
4401 {
4404 {
4405 /* This is a PARM_DECL that contains unexpanded parameter
4406 packs. We have already complained about this in the
4407 check_for_bare_parameter_packs call, so just replace
4408 these types with ERROR_MARK_NODE. */
4411 }
4415 }
4417 /* Check for bare parameter packs in the return type and the
4418 exception specifiers. */
4420 /* Errors were already issued, set return type to int
4421 as the frontend doesn't expect error_mark_node as
4422 the return type. */
4426 }
4428 {
4431 }
4442 {
4447 /* If DECL is a TYPE_DECL for a class-template, then there won't
4448 be DECL_LANG_SPECIFIC. The information equivalent to
4449 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4453 {
4454 /* Since a template declaration already existed for this
4455 class-type, we must be redeclaring it here. Make sure
4456 that the redeclaration is valid. */
4458 current_template_parms);
4459 /* We don't need to create a new TEMPLATE_DECL; just use the
4460 one we already had. */
4462 }
4463 else
4464 {
4466 member_template_p);
4471 {
4472 /* A specialization of a member template of a template
4473 class. */
4477 }
4478 }
4479 }
4480 else
4481 {
4487 {
4490 }
4498 {
4499 tree new_tmpl;
4501 /* The declaration is a specialization of a member
4502 template, declared outside the class. Therefore, the
4503 innermost template arguments will be NULL, so we
4504 replace them with the arguments determined by the
4505 earlier call to check_explicit_specialization. */
4508 new_tmpl
4510 member_template_p);
4520 args,
4523 }
4525 /* Make sure the template headers we got make sense. */
4530 {
4533 }
4534 else
4536 {
4541 {
4545 else
4550 }
4555 /* Can happen in erroneous input. */
4557 else
4561 }
4563 /* Check that the parms are used in the appropriate qualifying scopes
4564 in the declarator. */
4568 {
4574 /* Avoid crash in import_export_decl. */
4577 }
4578 }
4583 /* Push template declarations for global functions and types. Note
4584 that we do not try to push a global template friend declared in a
4585 template class; such a thing may well depend on the template
4586 parameters of the class. */
4589 {
4594 /* Hide template friend classes that haven't been declared yet. */
4596 {
4599 }
4600 }
4603 {
4609 {
4612 /* It is a conversion operator. See if the type converted to
4613 depends on innermost template operands. */
4616 depth))
4618 }
4620 /* Give template template parms a DECL_CONTEXT of the template
4621 for which they are a parameter. */
4624 {
4628 }
4629 }
4631 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4632 back to its most general template. If TMPL is a specialization,
4633 ARGS may only have the innermost set of arguments. Add the missing
4634 argument levels if necessary. */
4646 }
4648 tree
4650 {
4652 }
4654 /* Called when a class template TYPE is redeclared with the indicated
4655 template PARMS, e.g.:
4657 template <class T> struct S;
4658 template <class T> struct S {}; */
4660 bool
4662 {
4663 tree tmpl;
4664 tree tmpl_parms;
4668 {
4671 }
4675 /* The type is nested in some template class. Nothing to worry
4676 about here; there are no new template parameters for the nested
4677 type. */
4681 {
4683 tmpl);
4685 }
4691 {
4701 }
4704 {
4705 tree tmpl_parm;
4706 tree parm;
4707 tree tmpl_default;
4708 tree parm_default;
4722 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4723 TEMPLATE_DECL. */
4733 {
4737 }
4740 {
4741 /* We have in [temp.param]:
4743 A template-parameter may not be given default arguments
4744 by two different declarations in the same scope. */
4749 }
4752 /* Update the previous template parameters (which are the ones
4753 that will really count) with the new default value. */
4756 /* Update the new parameters, too; they'll be used as the
4757 parameters for any members. */
4759 }
4762 }
4764 /* Simplify EXPR if it is a non-dependent expression. Returns the
4765 (possibly simplified) expression. */
4767 tree
4769 {
4773 /* If we're in a template, but EXPR isn't value dependent, simplify
4774 it. We're supposed to treat:
4776 template <typename T> void f(T[1 + 1]);
4777 template <typename T> void f(T[2]);
4779 as two declarations of the same function, for example. */
4783 {
4784 HOST_WIDE_INT saved_processing_template_decl;
4790 tf_error,
4795 }
4797 }
4799 /* EXPR is an expression which is used in a constant-expression context.
4800 For instance, it could be a VAR_DECL with a constant initializer.
4801 Extract the innermost constant expression.
4803 This is basically a more powerful version of
4804 integral_constant_value, which can be used also in templates where
4805 initializers can maintain a syntactic rather than semantic form
4806 (even if they are non-dependent, for access-checking purposes). */
4808 static tree
4810 {
4812 do
4813 {
4816 }
4820 }
4822 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4823 must be a function or a pointer-to-function type, as specified
4824 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4825 and check that the resulting function has external linkage. */
4827 static tree
4829 {
4843 /* [temp.arg.nontype]/1
4845 A template-argument for a non-type, non-template template-parameter
4846 shall be one of:
4847 [...]
4848 -- the address of an object or function with external linkage. */
4850 {
4855 }
4858 }
4860 /* Subroutine of convert_nontype_argument.
4861 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4862 Emit an error otherwise. */
4864 static bool
4866 {
4874 }
4876 /* Attempt to convert the non-type template parameter EXPR to the
4877 indicated TYPE. If the conversion is successful, return the
4878 converted value. If the conversion is unsuccessful, return
4879 NULL_TREE if we issued an error message, or error_mark_node if we
4880 did not. We issue error messages for out-and-out bad template
4881 parameters, but not simply because the conversion failed, since we
4882 might be just trying to do argument deduction. Both TYPE and EXPR
4883 must be non-dependent.
4885 The conversion follows the special rules described in
4886 [temp.arg.nontype], and it is much more strict than an implicit
4887 conversion.
4889 This function is called twice for each template argument (see
4890 lookup_template_class for a more accurate description of this
4891 problem). This means that we need to handle expressions which
4892 are not valid in a C++ source, but can be created from the
4893 first call (for instance, casts to perform conversions). These
4894 hacks can go away after we fix the double coercion problem. */
4896 static tree
4898 {
4899 tree expr_type;
4901 /* Detect immediately string literals as invalid non-type argument.
4902 This special-case is not needed for correctness (we would easily
4903 catch this later), but only to provide better diagnostic for this
4904 common user mistake. As suggested by DR 100, we do not mention
4905 linkage issues in the diagnostic as this is not the point. */
4907 {
4912 }
4914 /* If we are in a template, EXPR may be non-dependent, but still
4915 have a syntactic, rather than semantic, form. For example, EXPR
4916 might be a SCOPE_REF, rather than the VAR_DECL to which the
4917 SCOPE_REF refers. Preserving the qualifying scope is necessary
4918 so that access checking can be performed when the template is
4919 instantiated -- but here we need the resolved form so that we can
4920 convert the argument. */
4926 /* HACK: Due to double coercion, we can get a
4927 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4928 which is the tree that we built on the first call (see
4929 below when coercing to reference to object or to reference to
4930 function). We just strip everything and get to the arg.
4931 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4932 for examples. */
4934 {
4936 {
4937 /* ??? Maybe we could use convert_from_reference here, but we
4938 would need to relax its constraints because the NOP_EXPR
4939 could actually change the type to something more cv-qualified,
4940 and this is not folded by convert_from_reference. */
4951 }
4953 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4954 parameter is a pointer to object, through decay and
4955 qualification conversion. Let's strip everything. */
4957 {
4961 /* Skip the ADDR_EXPR only if it is part of the decay for
4962 an array. Otherwise, it is part of the original argument
4963 in the source code. */
4967 }
4968 }
4970 /* [temp.arg.nontype]/5, bullet 1
4972 For a non-type template-parameter of integral or enumeration type,
4973 integral promotions (_conv.prom_) and integral conversions
4974 (_conv.integral_) are applied. */
4976 {
4981 /* Notice that there are constant expressions like '4 % 0' which
4982 do not fold into integer constants. */
4984 {
4988 }
4990 /* At this point, an implicit conversion does what we want,
4991 because we already know that the expression is of integral
4992 type. */
4997 /* Conversion was allowed: fold it to a bare integer constant. */
4999 }
5000 /* [temp.arg.nontype]/5, bullet 2
5002 For a non-type template-parameter of type pointer to object,
5003 qualification conversions (_conv.qual_) and the array-to-pointer
5004 conversion (_conv.array_) are applied. */
5006 {
5007 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5009 A template-argument for a non-type, non-template template-parameter
5010 shall be one of: [...]
5012 -- the name of a non-type template-parameter;
5013 -- the address of an object or function with external linkage, [...]
5014 expressed as "& id-expression" where the & is optional if the name
5015 refers to a function or array, or if the corresponding
5016 template-parameter is a reference.
5018 Here, we do not care about functions, as they are invalid anyway
5019 for a parameter of type pointer-to-object. */
5022 /* Non-type template parameters are OK. */
5023 ;
5026 {
5028 {
5030 "because %qD is a variable, not the address of "
5034 }
5035 /* Other values, like integer constants, might be valid
5036 non-type arguments of some other type. */
5038 }
5039 else
5040 {
5041 tree decl;
5046 {
5051 }
5053 {
5058 }
5059 }
5068 }
5069 /* [temp.arg.nontype]/5, bullet 3
5071 For a non-type template-parameter of type reference to object, no
5072 conversions apply. The type referred to by the reference may be more
5073 cv-qualified than the (otherwise identical) type of the
5074 template-argument. The template-parameter is bound directly to the
5075 template-argument, which must be an lvalue. */
5077 {
5079 expr_type))
5083 {
5087 }
5090 {
5094 }
5096 /* [temp.arg.nontype]/1
5098 A template-argument for a non-type, non-template template-parameter
5099 shall be one of: [...]
5101 -- the address of an object or function with external linkage. */
5104 {
5107 {
5109 "because a reference variable does not have a constant "
5112 }
5113 }
5116 {
5121 }
5124 {
5129 }
5132 }
5133 /* [temp.arg.nontype]/5, bullet 4
5135 For a non-type template-parameter of type pointer to function, only
5136 the function-to-pointer conversion (_conv.func_) is applied. If the
5137 template-argument represents a set of overloaded functions (or a
5138 pointer to such), the matching function is selected from the set
5139 (_over.over_). */
5141 {
5142 /* If the argument is a template-id, we might not have enough
5143 context information to decay the pointer. */
5145 {
5149 }
5156 {
5160 }
5161 }
5162 /* [temp.arg.nontype]/5, bullet 5
5164 For a non-type template-parameter of type reference to function, no
5165 conversions apply. If the template-argument represents a set of
5166 overloaded functions, the matching function is selected from the set
5167 (_over.over_). */
5169 {
5171 {
5176 }
5183 }
5184 /* [temp.arg.nontype]/5, bullet 6
5186 For a non-type template-parameter of type pointer to member function,
5187 no conversions apply. If the template-argument represents a set of
5188 overloaded member functions, the matching member function is selected
5189 from the set (_over.over_). */
5191 {
5196 /* [temp.arg.nontype] bullet 1 says the pointer to member
5197 expression must be a pointer-to-member constant. */
5201 /* There is no way to disable standard conversions in
5202 resolve_address_of_overloaded_function (called by
5203 instantiate_type). It is possible that the call succeeded by
5204 converting &B::I to &D::I (where B is a base of D), so we need
5205 to reject this conversion here.
5207 Actually, even if there was a way to disable standard conversions,
5208 it would still be better to reject them here so that we can
5209 provide a superior diagnostic. */
5211 {
5215 /* If we are just one standard conversion off, explain. */
5220 }
5221 }
5222 /* [temp.arg.nontype]/5, bullet 7
5224 For a non-type template-parameter of type pointer to data member,
5225 qualification conversions (_conv.qual_) are applied. */
5227 {
5228 /* [temp.arg.nontype] bullet 1 says the pointer to member
5229 expression must be a pointer-to-member constant. */
5236 }
5237 /* A template non-type parameter must be one of the above. */
5238 else
5241 /* Sanity check: did we actually convert the argument to the
5242 right type? */
5245 }
5247 /* Subroutine of coerce_template_template_parms, which returns 1 if
5248 PARM_PARM and ARG_PARM match using the rule for the template
5249 parameters of template template parameters. Both PARM and ARG are
5250 template parameters; the rest of the arguments are the same as for
5251 coerce_template_template_parms.
5252 */
5253 static int
5255 tree arg,
5256 tsubst_flags_t complain,
5257 tree in_decl,
5258 tree outer_args)
5259 {
5268 {
5270 /* We encounter instantiations of templates like
5271 template <template <template <class> class> class TT>
5272 class C; */
5273 {
5280 }
5281 /* Fall through. */
5286 /* Argument is a parameter pack but parameter is not. */
5291 /* The tsubst call is used to handle cases such as
5293 template <int> class C {};
5294 template <class T, template <T> class TT> class D {};
5295 D<int, C> d;
5297 i.e. the parameter list of TT depends on earlier parameters. */
5299 && !same_type_p
5306 /* Argument is a parameter pack but parameter is not. */
5313 }
5316 }
5319 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5320 template template parameters. Both PARM_PARMS and ARG_PARMS are
5321 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5322 or PARM_DECL.
5324 Consider the example:
5325 template <class T> class A;
5326 template<template <class U> class TT> class B;
5328 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5329 the parameters to A, and OUTER_ARGS contains A. */
5331 static int
5333 tree arg_parms,
5334 tsubst_flags_t complain,
5335 tree in_decl,
5336 tree outer_args)
5337 {
5348 /* Determine whether we have a parameter pack at the end of the
5349 template template parameter's template parameter list. */
5351 {
5358 {
5372 }
5373 }
5379 /* Check all of the template parameters except the parameter pack at
5380 the end (if any). */
5382 {
5391 outer_args))
5394 }
5397 {
5398 /* Check each of the template parameters in the template
5399 argument against the template parameter pack at the end of
5400 the template template parameter. */
5407 {
5414 outer_args))
5416 }
5417 }
5420 }
5422 /* Verifies that the deduced template arguments (in TARGS) for the
5423 template template parameters (in TPARMS) represent valid bindings,
5424 by comparing the template parameter list of each template argument
5425 to the template parameter list of its corresponding template
5426 template parameter, in accordance with DR150. This
5427 routine can only be called after all template arguments have been
5428 deduced. It will return TRUE if all of the template template
5429 parameter bindings are okay, FALSE otherwise. */
5430 bool
5432 {
5436 /* We're dealing with template parms in this process. */
5442 {
5447 {
5452 {
5453 /* Look inside the argument pack. */
5456 }
5459 {
5463 /* Extract the next argument from the argument
5464 pack. */
5468 /* Look at the pattern of the pack expansion. */
5471 /* Extract the template parameters from the template
5472 argument. */
5478 /* Verify that we can coerce the template template
5479 parameters from the template argument to the template
5480 parameter. This requires an exact match. */
5482 && !coerce_template_template_parms
5484 targ_parms,
5485 tf_none,
5486 tparm,
5487 targs))
5488 {
5491 }
5492 }
5493 }
5494 }
5496 out:
5500 }
5502 /* Convert the indicated template ARG as necessary to match the
5503 indicated template PARM. Returns the converted ARG, or
5504 error_mark_node if the conversion was unsuccessful. Error and
5505 warning messages are issued under control of COMPLAIN. This
5506 conversion is for the Ith parameter in the parameter list. ARGS is
5507 the full set of template arguments deduced so far. */
5509 static tree
5511 tree arg,
5512 tree args,
5513 tsubst_flags_t complain,
5515 tree in_decl)
5516 {
5517 tree orig_arg;
5518 tree val;
5523 {
5524 /* The template argument was the name of some
5525 member function. That's usually
5526 invalid, but static members are OK. In any
5527 case, grab the underlying fields/functions
5528 and issue an error later if required. */
5531 }
5539 /* When determining whether an argument pack expansion is a template,
5540 look at the pattern. */
5544 /* Deal with an injected-class-name used as a template template arg. */
5546 {
5549 {
5557 }
5558 }
5560 is_tmpl_type =
5575 {
5581 typename_type,
5585 }
5587 {
5589 {
5591 {
5601 else
5603 }
5604 }
5606 }
5608 {
5610 {
5616 else
5618 }
5620 }
5623 {
5625 {
5627 /* The number of argument required is not known yet.
5628 Just accept it for now. */
5630 else
5631 {
5633 tree argparm;
5639 args))
5640 {
5643 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5644 TEMPLATE_DECL. */
5646 {
5651 }
5652 }
5653 else
5654 {
5656 {
5662 }
5665 }
5666 }
5667 }
5668 else
5670 /* We only form one instance of each template specialization.
5671 Therefore, if we use a non-canonical variant (i.e., a
5672 typedef), any future messages referring to the type will use
5673 the typedef, which is confusing if those future uses do not
5674 themselves also use the typedef. */
5677 }
5678 else
5679 {
5686 {
5689 else
5690 {
5691 /* Not sure if this is reachable, but it doesn't hurt
5692 to be robust. */
5695 }
5696 }
5698 /* We used to call digest_init here. However, digest_init
5699 will report errors, which we don't want when complain
5700 is zero. More importantly, digest_init will try too
5701 hard to convert things: for example, `0' should not be
5702 converted to pointer type at this point according to
5703 the standard. Accepting this is not merely an
5704 extension, since deciding whether or not these
5705 conversions can occur is part of determining which
5706 function template to call, or whether a given explicit
5707 argument specification is valid. */
5709 else
5718 {
5719 /* Strip typedefs from the SCOPE_REF. */
5724 }
5725 }
5728 }
5730 /* Coerces the remaining template arguments in INNER_ARGS (from
5731 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5732 Returns the coerced argument pack. PARM_IDX is the position of this
5733 parameter in the template parameter list. ARGS is the original
5734 template argument list. */
5735 static tree
5738 tree args,
5739 tree inner_args,
5741 tree new_args,
5743 tree in_decl,
5744 tsubst_flags_t complain)
5745 {
5748 tree packed_args;
5749 tree argument_pack;
5759 {
5760 /* When the template parameter is a non-type template
5761 parameter pack whose type uses parameter packs, we need
5762 to look at each of the template arguments
5763 separately. Build a vector of the types for these
5764 non-type template parameters in PACKED_TYPES. */
5765 tree expansion
5773 /* Check that we have the right number of arguments. */
5777 {
5778 int needed_parms
5783 }
5785 /* If we aren't able to check the actual arguments now
5786 (because they haven't been expanded yet), we can at least
5787 verify that all of the types used for the non-type
5788 template parameter pack are, in fact, valid for non-type
5789 template parameters. */
5792 {
5795 {
5799 }
5800 }
5801 }
5803 /* Convert the remaining arguments, which will be a part of the
5804 parameter pack "parm". */
5806 {
5811 {
5812 /* When we have a vector of types (corresponding to the
5813 non-type template parameter pack that uses parameter
5814 packs in its type, as mention above), and the
5815 argument is not an expansion (which expands to a
5816 currently unknown number of arguments), clone the
5817 parm and give it the next type in PACKED_TYPES. */
5821 }
5826 in_decl);
5830 }
5835 else
5836 {
5841 }
5844 #ifdef ENABLE_CHECKING
5847 #endif
5849 }
5851 /* Convert all template arguments to their appropriate types, and
5852 return a vector containing the innermost resulting template
5853 arguments. If any error occurs, return error_mark_node. Error and
5854 warning messages are issued under control of COMPLAIN.
5856 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5857 for arguments not specified in ARGS. Otherwise, if
5858 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5859 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5860 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5861 ARGS. */
5863 static tree
5865 tree args,
5866 tree in_decl,
5867 tsubst_flags_t complain,
5870 {
5872 tree inner_args;
5873 tree new_args;
5874 tree new_inner_args;
5878 /* When used as a boolean value, indicates whether this is a
5879 variadic template parameter list. Since it's an int, we can also
5880 subtract it from nparms to get the number of non-variadic
5881 parameters. */
5886 /* Determine if there are any parameter packs. */
5888 {
5892 }
5895 /* If there are 0 or 1 parameter packs, we need to expand any argument
5896 packs so that we can deduce a parameter pack from some non-packed args
5897 followed by an argument pack, as in variadic85.C. If there are more
5898 than that, we need to leave argument packs intact so the arguments are
5899 assigned to the right parameter packs. This should only happen when
5900 dealing with a nested class inside a partial specialization of a class
5901 template, as in variadic92.C. */
5908 && require_all_args
5909 && (!use_default_args
5912 {
5914 {
5917 {
5920 }
5927 }
5930 }
5932 /* We need to evaluate the template arguments, even though this
5933 template-id may be nested within a "sizeof". */
5941 {
5942 tree arg;
5943 tree parm;
5945 /* Get the Ith template parameter. */
5949 {
5952 }
5954 /* Calculate the next argument. */
5957 else
5962 {
5963 /* All remaining arguments will be placed in the
5964 template parameter pack PARM. */
5970 /* Store this argument. */
5972 lost++;
5975 /* We are done with all of the arguments. */
5979 }
5981 {
5983 {
5985 {
5986 /* FIXME this restriction was removed by N2555; see
5987 bug 35722. */
5988 /* If ARG is a pack expansion, but PARM is not a
5989 template parameter pack (if it were, we would have
5990 handled it above), we're trying to expand into a
5991 fixed-length argument list. */
5995 else
5998 }
6000 }
6001 }
6003 {
6004 /* There must be a default arg in this case. */
6007 /* The position of the first default template argument,
6008 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6009 Record that. */
6012 }
6013 else
6017 {
6020 }
6022 /* This only occurs if there was an error in the template
6023 parameter list itself (which we would already have
6024 reported) that we are trying to recover from, e.g., a class
6025 template with a parameter list such as
6026 template<typename..., typename>. */
6028 else
6034 lost++;
6036 }
6043 #ifdef ENABLE_CHECKING
6047 #endif
6050 }
6052 /* Returns 1 if template args OT and NT are equivalent. */
6054 static int
6056 {
6061 /* For member templates */
6068 {
6085 }
6087 {
6088 /* We get here probably because we are in the middle of substituting
6089 into the pattern of a pack expansion. In that case the
6090 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6091 interested in. So we want to use the initial pack argument for
6092 the comparison. */
6097 }
6102 else
6104 }
6106 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6107 of template arguments. Returns 0 otherwise. */
6109 int
6111 {
6118 {
6124 }
6126 }
6128 static void
6130 {
6140 /* We are called both from instantiate_decl, where we've already had a
6141 tinst_level pushed, and instantiate_template, where we haven't.
6142 Compensate. */
6153 else
6162 }
6165 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6166 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6167 documentation for TEMPLATE_ID_EXPR. */
6169 tree
6171 {
6172 tree type;
6182 {
6184 unknown_type_node,
6186 arglist);
6188 }
6195 }
6197 /* Within the scope of a template class S<T>, the name S gets bound
6198 (in build_self_reference) to a TYPE_DECL for the class, not a
6199 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6200 or one of its enclosing classes, and that type is a template,
6201 return the associated TEMPLATE_DECL. Otherwise, the original
6202 DECL is returned.
6204 Also handle the case when DECL is a TREE_LIST of ambiguous
6205 injected-class-names from different bases. */
6207 tree
6209 {
6213 /* DR 176: A lookup that finds an injected-class-name (10.2
6214 [class.member.lookup]) can result in an ambiguity in certain cases
6215 (for example, if it is found in more than one base class). If all of
6216 the injected-class-names that are found refer to specializations of
6217 the same class template, and if the name is followed by a
6218 template-argument-list, the reference refers to the class template
6219 itself and not a specialization thereof, and is not ambiguous. */
6221 {
6224 {
6230 }
6233 else
6235 }
6241 }
6243 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6244 parameters, find the desired type.
6246 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6248 IN_DECL, if non-NULL, is the template declaration we are trying to
6249 instantiate.
6251 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6252 the class we are looking up.
6254 Issue error and warning messages under control of COMPLAIN.
6256 If the template class is really a local class in a template
6257 function, then the FUNCTION_CONTEXT is the function in which it is
6258 being instantiated.
6260 ??? Note that this function is currently called *twice* for each
6261 template-id: the first time from the parser, while creating the
6262 incomplete type (finish_template_type), and the second type during the
6263 real instantiation (instantiate_template_class). This is surely something
6264 that we want to avoid. It also causes some problems with argument
6265 coercion (see convert_nontype_argument for more information on this). */
6267 tree
6269 tree arglist,
6270 tree in_decl,
6271 tree context,
6273 tsubst_flags_t complain)
6274 {
6276 tree t;
6279 spec_entry elt;
6280 hashval_t hash;
6285 {
6289 else
6290 {
6297 }
6300 }
6302 {
6305 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6306 an implicit typename for the second A. Deal with it. */
6311 {
6314 }
6315 }
6318 {
6321 }
6325 {
6329 }
6331 /* Issue an error message if we didn't find a template. */
6333 {
6337 }
6340 /* Make sure it's a user visible template, if it was named by
6341 the user. */
6344 {
6346 {
6350 }
6352 }
6357 {
6358 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6359 template arguments */
6361 tree parm;
6362 tree arglist2;
6363 tree outer;
6367 /* Consider an example where a template template parameter declared as
6369 template <class T, class U = std::allocator<T> > class TT
6371 The template parameter level of T and U are one level larger than
6372 of TT. To proper process the default argument of U, say when an
6373 instantiation `TT<int>' is seen, we need to build the full
6374 arguments containing {int} as the innermost level. Outer levels,
6375 available when not appearing as default template argument, can be
6376 obtained from the arguments of the enclosing template.
6378 Suppose that TT is later substituted with std::vector. The above
6379 instantiation is `TT<int, std::allocator<T> >' with TT at
6380 level 1, and T at level 2, while the template arguments at level 1
6381 becomes {std::vector} and the inner level 2 is {int}. */
6387 /* This is an argument of the current template, so we haven't set
6388 DECL_CONTEXT yet. */
6395 complain,
6405 }
6406 else
6407 {
6409 tree gen_tmpl;
6410 tree type_decl;
6423 {
6424 /* We've been given an incomplete set of template arguments.
6425 For example, given:
6427 template <class T> struct S1 {
6428 template <class U> struct S2 {};
6429 template <class U> struct S2<U*> {};
6430 };
6432 we will be called with an ARGLIST of `U*', but the
6433 TEMPLATE will be `template <class T> template
6434 <class U> struct S1<T>::S2'. We must fill in the missing
6435 arguments. */
6436 arglist
6438 arglist);
6440 }
6442 /* Now we should have enough arguments. */
6445 /* From here on, we're only interested in the most general
6446 template. */
6448 /* Calculate the BOUND_ARGS. These will be the args that are
6449 actually tsubst'd into the definition to create the
6450 instantiation. */
6452 {
6453 /* We have multiple levels of arguments to coerce, at once. */
6463 {
6466 complain,
6470 /* Don't process further if one of the levels fails. */
6472 {
6473 /* Restore the ARGLIST to its full size. */
6476 }
6480 /* We temporarily reduce the length of the ARGLIST so
6481 that coerce_template_parms will see only the arguments
6482 corresponding to the template parameters it is
6483 examining. */
6485 }
6487 /* Restore the ARGLIST to its full size. */
6491 }
6492 else
6493 arglist
6496 gen_tmpl,
6497 complain,
6502 /* We were unable to bind the arguments. */
6505 /* In the scope of a template class, explicit references to the
6506 template class refer to the type of the template, not any
6507 instantiation of it. For example, in:
6509 template <class T> class C { void f(C<T>); }
6511 the `C<T>' is just the same as `C'. Outside of the
6512 class, however, such a reference is an instantiation. */
6516 /* comp_template_args is expensive, check it last. */
6518 arglist))
6521 /* If we already have this specialization, return it. */
6533 /* If the deduced arguments are invalid, then the binding
6534 failed. */
6538 complain))
6545 {
6550 }
6557 /* Create the type. */
6559 {
6561 {
6567 }
6568 else
6569 {
6570 /* We don't want to call start_enum for this type, since
6571 the values for the enumeration constants may involve
6572 template parameters. And, no one should be interested
6573 in the enumeration constants for such a type. */
6576 }
6577 }
6578 else
6579 {
6586 /* A local class. Make sure the decl gets registered properly. */
6591 /* This instantiation is another name for the primary
6592 template type. Set the TYPE_CANONICAL field
6593 appropriately. */
6596 /* Some of the template arguments require structural
6597 equality testing, so this template class requires
6598 structural equality testing. */
6600 }
6602 /* If we called start_enum or pushtag above, this information
6603 will already be set up. */
6605 {
6612 }
6613 else
6621 {
6624 }
6626 /* Let's consider the explicit specialization of a member
6627 of a class template specialization that is implicitely instantiated,
6628 e.g.:
6629 template<class T>
6630 struct S
6631 {
6632 template<class U> struct M {}; //#0
6633 };
6635 template<>
6636 template<>
6637 struct S<int>::M<char> //#1
6638 {
6639 int i;
6640 };
6641 [temp.expl.spec]/4 says this is valid.
6643 In this case, when we write:
6644 S<int>::M<char> m;
6646 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
6647 the one of #0.
6649 When we encounter #1, we want to store the partial instantiation
6650 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
6652 For all cases other than this "explicit specialization of member of a
6653 class template", we just want to store the most general template into
6654 the CLASSTYPE_TI_TEMPLATE of M.
6656 This case of "explicit specialization of member of a class template"
6657 only happens when:
6658 1/ the enclosing class is an instantiation of, and therefore not
6659 the same as, the context of the most general template, and
6660 2/ we aren't looking at the partial instantiation itself, i.e.
6661 the innermost arguments are not the same as the innermost parms of
6662 the most general template.
6664 So it's only when 1/ and 2/ happens that we want to use the partial
6665 instantiation of the member template in lieu of its most general
6666 template. */
6670 /* the enclosing class must be an instantiation... */
6673 {
6674 tree partial_inst_args;
6677 partial_inst_args =
6683 use_partial_inst_tmpl =
6684 /*...and we must not be looking at the partial instantiation
6685 itself. */
6687 partial_inst_args);
6688 }
6691 /* This case is easy; there are no member templates involved. */
6693 else
6694 {
6695 /* This is a full instantiation of a member template. Find
6696 the partial instantiation of which this is an instance. */
6698 /* Temporarily reduce by one the number of levels in the ARGLIST
6699 so as to avoid comparing the last set of arguments. */
6704 }
6714 /* Note this use of the partial instantiation so we can check it
6715 later in maybe_process_partial_specialization. */
6721 /* Now that the type has been registered on the instantiations
6722 list, we set up the enumerators. Because the enumeration
6723 constants may involve the enumeration type itself, we make
6724 sure to register the type first, and then create the
6725 constants. That way, doing tsubst_expr for the enumeration
6726 constants won't result in recursive calls here; we'll find
6727 the instantiation and exit above. */
6731 /* If the type makes use of template parameters, the
6732 code that generates debugging information will crash. */
6735 /* Possibly limit visibility based on template args. */
6740 }
6742 }
6743 \f
6744 struct pair_fn_data
6745 {
6746 tree_fn_t fn;
6748 /* True when we should also visit template parameters that occur in
6749 non-deduced contexts. */
6752 };
6754 /* Called from for_each_template_parm via walk_tree. */
6756 static tree
6758 {
6771 {
6775 /* Fall through. */
6798 /* Since we're not going to walk subtrees, we have to do this
6799 explicitly here. */
6803 /* Fall through. */
6806 /* Check the return type. */
6811 /* Check the parameter types. Since default arguments are not
6812 instantiated until they are needed, the TYPE_ARG_TYPES may
6813 contain expressions that involve template parameters. But,
6814 no-one should be looking at them yet. And, once they're
6815 instantiated, they don't contain template parameters, so
6816 there's no point in looking at them then, either. */
6817 {
6818 tree parm;
6825 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6826 want walk_tree walking into them itself. */
6828 }
6845 /* Fall through. */
6861 /* Record template parameters such as `T' inside `TT<T>'. */
6865 /* Fall through. */
6877 /* A template template parameter is encountered. */
6883 /* Already substituted template template parameter */
6906 /* If there's no type, then this thing must be some expression
6907 involving template parameters. */
6928 }
6930 /* We didn't find any template parameters we liked. */
6932 }
6934 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6935 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6936 call FN with the parameter and the DATA.
6937 If FN returns nonzero, the iteration is terminated, and
6938 for_each_template_parm returns 1. Otherwise, the iteration
6939 continues. If FN never returns a nonzero value, the value
6940 returned by for_each_template_parm is 0. If FN is NULL, it is
6941 considered to be the function which always returns 1.
6943 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6944 parameters that occur in non-deduced contexts. When false, only
6945 visits those template parameters that can be deduced. */
6947 static int
6951 {
6955 /* Set up. */
6960 /* Walk the tree. (Conceptually, we would like to walk without
6961 duplicates, but for_each_template_parm_r recursively calls
6962 for_each_template_parm, so we would need to reorganize a fair
6963 bit to use walk_tree_without_duplicates, so we keep our own
6964 visited list.) */
6967 else
6970 for_each_template_parm_r,
6974 /* Clean up. */
6976 {
6979 }
6982 }
6984 /* Returns true if T depends on any template parameter. */
6986 int
6988 {
7015 else
7016 {
7019 }
7024 }
7026 /* Returns true if T depends on any template parameter with level LEVEL. */
7028 int
7030 {
7033 }
7037 #ifdef GATHER_STATISTICS
7039 #endif
7043 /* We're starting to instantiate D; record the template instantiation context
7044 for diagnostics and to restore it later. */
7046 int
7048 {
7052 {
7053 /* If the instantiation in question still has unbound template parms,
7054 we don't really care if we can't instantiate it, so just return.
7055 This happens with base instantiation for implicit `typename'. */
7067 }
7077 #ifdef GATHER_STATISTICS
7080 #endif
7084 }
7086 /* We're done instantiating this template; return to the instantiation
7087 context. */
7089 void
7091 {
7092 /* Restore the filename and line number stashed away when we started
7093 this instantiation. */
7098 }
7100 /* We're instantiating a deferred template; restore the template
7101 instantiation context in which the instantiation was requested, which
7102 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7104 static tree
7106 {
7116 }
7118 /* Returns the TINST_LEVEL which gives the original instantiation
7119 context. */
7123 {
7129 }
7131 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7133 bool
7135 {
7136 tree parms;
7153 }
7155 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7156 vector of template arguments, as for tsubst.
7158 Returns an appropriate tsubst'd friend declaration. */
7160 static tree
7162 {
7163 tree new_friend;
7168 /* This was a friend declared with an explicit template
7169 argument list, e.g.:
7171 friend void f<>(T);
7173 to indicate that f was a template instantiation, not a new
7174 function declaration. Now, we have to figure out what
7175 instantiation of what template. */
7176 {
7178 tree new_args;
7179 tree tmpl;
7182 /* Friend functions are looked up in the containing namespace scope.
7183 We must enter that scope, to avoid finding member functions of the
7184 current class with same name. */
7199 tsk_none);
7201 }
7205 /* The NEW_FRIEND will look like an instantiation, to the
7206 compiler, but is not an instantiation from the point of view of
7207 the language. For example, we might have had:
7209 template <class T> struct S {
7210 template <class U> friend void f(T, U);
7211 };
7213 Then, in S<int>, template <class U> void f(int, U) is not an
7214 instantiation of anything. */
7220 {
7224 }
7226 /* The mangled name for the NEW_FRIEND is incorrect. The function
7227 is not a template instantiation and should not be mangled like
7228 one. Therefore, we forget the mangling here; we'll recompute it
7229 later if we need it. */
7231 {
7234 }
7237 {
7238 tree old_decl;
7239 tree new_friend_template_info;
7240 tree new_friend_result_template_info;
7241 tree ns;
7244 /* We must save some information from NEW_FRIEND before calling
7245 duplicate decls since that function will free NEW_FRIEND if
7246 possible. */
7248 new_friend_is_defn =
7253 {
7254 /* This declaration is a `primary' template. */
7257 new_friend_result_template_info
7259 }
7260 else
7263 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7267 /* Inside pushdecl_namespace_level, we will push into the
7268 current namespace. However, the friend function should go
7269 into the namespace of the template. */
7279 {
7280 /* This new friend declaration matched an existing
7281 declaration. For example, given:
7283 template <class T> void f(T);
7284 template <class U> class C {
7285 template <class T> friend void f(T) {}
7286 };
7288 the friend declaration actually provides the definition
7289 of `f', once C has been instantiated for some type. So,
7290 old_decl will be the out-of-class template declaration,
7291 while new_friend is the in-class definition.
7293 But, if `f' was called before this point, the
7294 instantiation of `f' will have DECL_TI_ARGS corresponding
7295 to `T' but not to `U', references to which might appear
7296 in the definition of `f'. Previously, the most general
7297 template for an instantiation of `f' was the out-of-class
7298 version; now it is the in-class version. Therefore, we
7299 run through all specialization of `f', adding to their
7300 DECL_TI_ARGS appropriately. In particular, they need a
7301 new set of outer arguments, corresponding to the
7302 arguments for this class instantiation.
7304 The same situation can arise with something like this:
7306 friend void f(int);
7307 template <class T> class C {
7308 friend void f(T) {}
7309 };
7311 when `C<int>' is instantiated. Now, `f(int)' is defined
7312 in the class. */
7315 /* On the other hand, if the in-class declaration does
7316 *not* provide a definition, then we don't want to alter
7317 existing definitions. We can just leave everything
7318 alone. */
7319 ;
7320 else
7321 {
7325 /* Overwrite whatever template info was there before, if
7326 any, with the new template information pertaining to
7327 the declaration. */
7331 /* We should have called reregister_specialization in
7332 duplicate_decls. */
7336 else
7337 {
7338 tree t;
7340 /* Indicate that the old function template is a partial
7341 instantiation. */
7349 /* Reassign any specializations already in the hash table
7350 to the new more general template, and add the
7351 additional template args. */
7355 {
7357 spec_entry elt;
7369 register_specialization
7372 }
7374 }
7375 }
7377 /* The information from NEW_FRIEND has been merged into OLD_DECL
7378 by duplicate_decls. */
7380 }
7381 }
7382 else
7383 {
7387 /* In the code
7388 template <class T> class C {
7389 template <class U> friend void C1<U>::f (); // case 1
7390 friend void C2<T>::f (); // case 2
7391 };
7392 we only need to make sure CONTEXT is a complete type for
7393 case 2. To distinguish between the two cases, we note that
7394 CONTEXT of case 1 remains dependent type after tsubst while
7395 this isn't true for case 2. */
7405 {
7406 /* Check to see that the declaration is really present, and,
7407 possibly obtain an improved declaration. */
7413 }
7414 }
7417 }
7419 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7420 template arguments, as for tsubst.
7422 Returns an appropriate tsubst'd friend type or error_mark_node on
7423 failure. */
7425 static tree
7427 {
7428 tree friend_type;
7429 tree tmpl;
7430 tree context;
7435 {
7438 else
7440 }
7442 /* Look for a class template declaration. We look for hidden names
7443 because two friend declarations of the same template are the
7444 same. For example, in:
7446 struct A {
7447 template <typename> friend class F;
7448 };
7449 template <typename> struct B {
7450 template <typename> friend class F;
7451 };
7453 both F templates are the same. */
7458 /* But, if we don't find one, it might be because we're in a
7459 situation like this:
7461 template <class T>
7462 struct S {
7463 template <class U>
7464 friend struct S;
7465 };
7467 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7468 for `S<int>', not the TEMPLATE_DECL. */
7470 {
7473 }
7476 {
7477 /* The friend template has already been declared. Just
7478 check to see that the declarations match, and install any new
7479 default parameters. We must tsubst the default parameters,
7480 of course. We only need the innermost template parameters
7481 because that is all that redeclare_class_template will look
7482 at. */
7485 {
7486 tree parms;
7487 location_t saved_input_location;
7496 }
7499 }
7500 else
7501 {
7502 /* The friend template has not already been declared. In this
7503 case, the instantiation of the template class will cause the
7504 injection of this template into the global scope. */
7509 /* The new TMPL is not an instantiation of anything, so we
7510 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7511 the new type because that is supposed to be the corresponding
7512 template decl, i.e., TMPL. */
7519 /* Inject this template into the global scope. */
7521 }
7524 {
7527 else
7529 }
7532 }
7534 /* Returns zero if TYPE cannot be completed later due to circularity.
7535 Otherwise returns one. */
7537 static int
7539 {
7549 else
7551 }
7553 /* Apply any attributes which had to be deferred until instantiation
7554 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7555 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7557 static void
7560 {
7562 tree t;
7567 {
7571 }
7574 {
7578 }
7579 else
7583 {
7588 {
7591 {
7594 /* If the first attribute argument is an identifier, don't
7595 pass it through tsubst. Attributes like mode, format,
7596 cleanup and several target specific attributes expect it
7597 unmodified. */
7603 {
7604 tree chain
7606 in_decl,
7611 chain);
7612 }
7613 else
7619 }
7620 else
7622 }
7625 }
7626 }
7628 /* Perform (or defer) access check for typedefs that were referenced
7629 from within the template TMPL code.
7630 This is a subroutine of instantiate_template and instantiate_class_template.
7631 TMPL is the template to consider and TARGS is the list of arguments of
7632 that template. */
7634 static void
7636 {
7637 location_t saved_location;
7652 {
7664 /* Make access check error messages point to the location
7665 of the use of the typedef. */
7669 }
7671 }
7673 tree
7675 {
7677 tree typedecl;
7678 tree pbinfo;
7679 tree base_list;
7690 /* Figure out which template is being instantiated. */
7694 /* Determine what specialization of the original template to
7695 instantiate. */
7698 {
7701 }
7703 {
7704 /* This TYPE is actually an instantiation of a partial
7705 specialization. We replace the innermost set of ARGS with
7706 the arguments appropriate for substitution. For example,
7707 given:
7709 template <class T> struct S {};
7710 template <class T> struct S<T*> {};
7712 and supposing that we are instantiating S<int*>, ARGS will
7713 presently be {int*} -- but we need {int}. */
7716 }
7717 else
7718 {
7721 }
7723 /* If the template we're instantiating is incomplete, then clearly
7724 there's nothing we can do. */
7728 /* If we've recursively instantiated too many templates, stop. */
7732 /* Now we're really doing the instantiation. Mark the type as in
7733 the process of being defined. */
7736 /* We may be in the middle of deferred access check. Disable
7737 it now. */
7741 /* Use #pragma pack from the template context. */
7747 /* Set the input location to the most specialized template definition.
7748 This is needed if tsubsting causes an error. */
7769 {
7772 }
7776 /* We should never instantiate a nested class before its enclosing
7777 class; we need to look up the nested class by name before we can
7778 instantiate it, and that lookup should instantiate the enclosing
7779 class. */
7786 {
7787 tree pbase_binfo;
7789 tree pushed_scope;
7792 /* We must enter the scope containing the type, as that is where
7793 the accessibility of types named in dependent bases are
7794 looked up from. */
7797 /* Substitute into each of the bases to determine the actual
7798 basetypes. */
7800 {
7801 tree base;
7807 {
7808 expanded_bases =
7815 }
7818 {
7820 /* Extract the already-expanded base class. */
7822 else
7823 /* Substitute to figure out the base class. */
7825 NULL_TREE);
7833 }
7834 }
7836 /* The list is now in reverse order; correct that. */
7841 }
7842 /* Now call xref_basetypes to set up all the base-class
7843 information. */
7850 /* Now that our base classes are set up, enter the scope of the
7851 class, so that name lookups into base classes, etc. will work
7852 correctly. This is precisely analogous to what we do in
7853 begin_class_definition when defining an ordinary non-template
7854 class, except we also need to push the enclosing classes. */
7857 /* Now members are processed in the order of declaration. */
7860 {
7864 {
7866 {
7867 /* Build new CLASSTYPE_NESTED_UTDS. */
7869 tree newtag;
7875 /* If the member is a class template, then -- even after
7876 substitution -- there may be dependent types in the
7877 template argument list for the class. We increment
7878 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7879 that function will assume that no types are dependent
7880 when outside of a template. */
7890 {
7894 /* Unfortunately, lookup_template_class sets
7895 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7896 instantiation (i.e., for the type of a member
7897 template class nested within a template class.)
7898 This behavior is required for
7899 maybe_process_partial_specialization to work
7900 correctly, but is not accurate in this case;
7901 the TAG is not an instantiation of anything.
7902 (The corresponding TEMPLATE_DECL is an
7903 instantiation, but the TYPE is not.) */
7906 /* Now, we call pushtag to put this NEWTAG into the scope of
7907 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7908 pushtag calling push_template_decl. We don't have to do
7909 this for enums because it will already have been done in
7910 tsubst_enum. */
7914 }
7915 }
7918 {
7919 /* Build new TYPE_METHODS. */
7920 tree r;
7929 }
7930 else
7931 {
7932 /* Build new TYPE_FIELDS. */
7934 {
7935 tree condition =
7943 }
7945 {
7946 tree r;
7948 /* The file and line for this declaration, to
7949 assist in error message reporting. Since we
7950 called push_tinst_level above, we don't need to
7951 restore these. */
7960 {
7961 /* In [temp.inst]:
7963 [t]he initialization (and any associated
7964 side-effects) of a static data member does
7965 not occur unless the static data member is
7966 itself used in a way that requires the
7967 definition of the static data member to
7968 exist.
7970 Therefore, we do not substitute into the
7971 initialized for the static data member here. */
7972 finish_static_data_member_decl
7980 }
7982 {
7983 /* Determine whether R has a valid type and can be
7984 completed later. If R is invalid, then it is
7985 replaced by error_mark_node so that it will not be
7986 added to TYPE_FIELDS. */
7992 {
7995 }
7996 }
7998 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
7999 such a thing will already have been added to the field
8000 list by tsubst_enum in finish_member_declaration in the
8001 CLASSTYPE_NESTED_UTDS case above. */
8005 {
8008 }
8009 }
8010 }
8011 }
8012 else
8013 {
8015 {
8016 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8022 {
8023 /* template <class T> friend class C; */
8026 }
8028 {
8029 /* template <class T> friend class C::D; */
8035 }
8037 {
8038 /* This could be either
8040 friend class T::C;
8042 when dependent_type_p is false or
8044 template <class U> friend class T::C;
8046 otherwise. */
8049 /* Bump processing_template_decl for correct
8050 dependent_type_p calculation. */
8055 }
8058 {
8059 /* friend class C;
8061 where C hasn't been declared yet. Let's lookup name
8062 from namespace scope directly, bypassing any name that
8063 come from dependent base class. */
8066 /* The call to xref_tag_from_type does injection for friend
8067 classes. */
8069 friend_type =
8073 }
8075 /* friend class C<T>; */
8078 /* Otherwise it's
8080 friend class C;
8082 where C is already declared or
8084 friend class C<int>;
8086 We don't have to do anything in these cases. */
8089 /* Trick make_friend_class into realizing that the friend
8090 we're adding is a template, not an ordinary class. It's
8091 important that we use make_friend_class since it will
8092 perform some error-checking and output cross-reference
8093 information. */
8101 }
8102 else
8103 {
8104 /* Build new DECL_FRIENDLIST. */
8105 tree r;
8107 /* The file and line for this declaration, to
8108 assist in error message reporting. Since we
8109 called push_tinst_level above, we don't need to
8110 restore these. */
8114 {
8117 }
8122 {
8125 }
8126 }
8127 }
8128 }
8130 /* Set the file and line number information to whatever is given for
8131 the class itself. This puts error messages involving generated
8132 implicit functions at a predictable point, and the same point
8133 that would be used for non-template classes. */
8140 /* Now that the class is complete, instantiate default arguments for
8141 any member functions. We don't do this earlier because the
8142 default arguments may reference members of the class. */
8146 /* Implicitly generated member functions will not have template
8147 information; they are not instantiations, but instead are
8148 created "fresh" for each instantiation. */
8152 /* Some typedefs referenced from within the template code need to be access
8153 checked at template instantiation time, i.e now. These types were
8154 added to the template at parsing time. Let's get those and perform
8155 the access checks then. */
8164 /* The vtable for a template class can be emitted in any translation
8165 unit in which the class is instantiated. When there is no key
8166 method, however, finish_struct_1 will already have added TYPE to
8167 the keyed_classes list. */
8172 }
8174 static tree
8176 {
8177 tree r;
8183 else
8184 {
8188 }
8190 }
8192 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8193 NONTYPE_ARGUMENT_PACK. */
8195 static tree
8197 {
8198 /* Collect all of the extra "packed" parameters into an
8199 argument pack. */
8200 tree parmvec;
8201 tree parmtypevec;
8206 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8210 {
8213 }
8215 /* Build the argument packs. */
8221 }
8223 /* Substitute ARGS into T, which is an pack expansion
8224 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8225 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8226 (if only a partial substitution could be performed) or
8227 ERROR_MARK_NODE if there was an error. */
8228 tree
8230 tree in_decl)
8231 {
8232 tree pattern;
8235 tree result;
8242 /* Determine the argument packs that will instantiate the parameter
8243 packs used in the expansion expression. While we're at it,
8244 compute the number of arguments to be expanded and make sure it
8245 is consistent. */
8248 {
8254 {
8257 {
8258 /* This can happen for a parameter name used later in a function
8259 declaration (such as in a late-specified return type). Just
8260 make a dummy decl, since it's only used for its type. */
8264 }
8265 }
8266 else
8267 {
8274 }
8281 /* This can only happen if we forget to expand an argument
8282 pack somewhere else. Just return an error, silently. */
8283 {
8287 }
8292 {
8297 /* The argument pack that the parameter maps to is just an
8298 expansion of the parameter itself, such as one would
8299 find in the implicit typedef of a class inside the
8300 class itself. Consider this parameter "unsubstituted",
8301 so that we will maintain the outer pack expansion. */
8303 }
8306 {
8310 /* It's all-or-nothing with incomplete argument packs. */
8320 {
8322 /* We got explicit args for some packs but not others;
8323 do nothing now and try again after deduction. */
8328 pattern);
8329 else
8332 pattern);
8334 }
8336 /* Keep track of the parameter packs and their corresponding
8337 argument packs. */
8340 }
8341 else
8342 /* We can't substitute for this parameter pack. */
8345 unsubstituted_packs);
8346 }
8348 /* We cannot expand this expansion expression, because we don't have
8349 all of the argument packs we need. Substitute into the pattern
8350 and return a PACK_EXPANSION_*. The caller will need to deal with
8351 that. */
8353 {
8354 tree new_pat;
8358 else
8361 }
8363 /* We could not find any argument packs that work. */
8368 {
8369 /* We're in a late-specified return type, so we don't have a local
8370 specializations table. Create one for doing this expansion. */
8373 hash_local_specialization,
8374 eq_local_specializations,
8375 NULL);
8376 }
8378 /* For each argument in each argument pack, substitute into the
8379 pattern. */
8382 {
8383 /* For parameter pack, change the substitution of the parameter
8384 pack to the ith argument in its argument pack, then expand
8385 the pattern. */
8387 {
8391 {
8392 /* Select the Ith argument from the pack. */
8398 }
8399 else
8400 {
8406 {
8407 /* Select the Ith argument from the pack. */
8411 }
8413 /* Update the corresponding argument. */
8415 }
8416 }
8418 /* Substitute into the PATTERN with the altered arguments. */
8423 else
8427 /* When we have incomplete argument packs, the last "expanded"
8428 result is itself a pack expansion, which allows us
8429 to deduce more arguments. */
8434 {
8437 }
8438 }
8440 /* Update ARGS to restore the substitution from parameter packs to
8441 their argument packs. */
8443 {
8448 else
8449 {
8453 /* Update the corresponding argument. */
8457 else
8459 }
8460 }
8463 {
8466 }
8469 }
8471 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8472 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8473 parameter packs; all parms generated from a function parameter pack will
8474 have the same DECL_PARM_INDEX. */
8476 tree
8478 {
8480 tree patparm;
8483 {
8489 }
8490 else
8491 {
8496 }
8499 }
8501 /* Substitute ARGS into the vector or list of template arguments T. */
8503 static tree
8505 {
8512 {
8514 tree new_arg;
8519 {
8520 /* Substitute into an expansion expression. */
8524 /* Add to the expanded length adjustment the number of
8525 expanded arguments. We subtract one from this
8526 measurement, because the argument pack expression
8527 itself is already counted as 1 in
8528 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8529 the argument pack is empty. */
8531 }
8533 {
8534 /* Substitute into each of the arguments. */
8540 new_arg,
8554 }
8555 }
8556 else
8565 }
8570 /* Make space for the expanded arguments coming from template
8571 argument packs. */
8573 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8574 arguments for a member template.
8575 In that case each TREE_VEC in ORIG_T represents a level of template
8576 arguments, and ORIG_T won't carry any non defaulted argument count.
8577 It will rather be the nested TREE_VECs that will carry one.
8578 In other words, ORIG_T carries a non defaulted argument count only
8579 if it doesn't contain any nested TREE_VEC. */
8581 {
8585 }
8587 {
8591 {
8594 /* Now expand the template argument pack "in place". */
8597 }
8598 else
8599 {
8601 out++;
8602 }
8603 }
8606 }
8608 /* Return the result of substituting ARGS into the template parameters
8609 given by PARMS. If there are m levels of ARGS and m + n levels of
8610 PARMS, then the result will contain n levels of PARMS. For
8611 example, if PARMS is `template <class T> template <class U>
8612 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8613 result will be `template <int*, double, class V>'. */
8615 static tree
8617 {
8621 /* When substituting into a template, we must set
8622 PROCESSING_TEMPLATE_DECL as the template parameters may be
8623 dependent if they are based on one-another, and the dependency
8624 predicates are short-circuit outside of templates. */
8631 {
8632 tree new_vec =
8637 {
8638 tree tuple;
8639 tree default_value;
8640 tree parm_decl;
8662 }
8668 }
8673 }
8675 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8676 type T. If T is not an aggregate or enumeration type, it is
8677 handled as if by tsubst. IN_DECL is as for tsubst. If
8678 ENTERING_SCOPE is nonzero, T is the context for a template which
8679 we are presently tsubst'ing. Return the substituted value. */
8681 static tree
8683 tree args,
8684 tsubst_flags_t complain,
8685 tree in_decl,
8687 {
8692 {
8697 /* Else fall through. */
8701 {
8702 tree argvec;
8703 tree context;
8704 tree r;
8708 /* In "sizeof(X<I>)" we need to evaluate "I". */
8714 /* First, determine the context for the type we are looking
8715 up. */
8718 {
8721 /* If context is a nested class inside a class template,
8722 it may still need to be instantiated (c++/33959). */
8725 }
8727 /* Then, figure out what arguments are appropriate for the
8728 type we are trying to find. For example, given:
8730 template <class T> struct S;
8731 template <class T, class U> void f(T, U) { S<U> su; }
8733 and supposing that we are instantiating f<int, double>,
8734 then our ARGS will be {int, double}, but, when looking up
8735 S we only want {double}. */
8740 else
8741 {
8745 }
8751 }
8752 else
8753 /* This is not a template type, so there's nothing to do. */
8758 }
8759 }
8761 /* Substitute into the default argument ARG (a default argument for
8762 FN), which has the indicated TYPE. */
8764 tree
8766 {
8770 /* This default argument came from a template. Instantiate the
8771 default argument here, not in tsubst. In the case of
8772 something like:
8774 template <class T>
8775 struct S {
8776 static T t();
8777 void f(T = t());
8778 };
8780 we must be careful to do name lookup in the scope of S<T>,
8781 rather than in the current class. */
8783 /* The "this" pointer is not valid in a default argument. */
8785 {
8790 }
8793 /* The default argument expression may cause implicitly defined
8794 member functions to be synthesized, which will result in garbage
8795 collection. We must treat this situation as if we were within
8796 the body of function so as to avoid collecting live data on the
8797 stack. */
8805 /* Restore the "this" pointer. */
8807 {
8810 }
8812 /* Make sure the default argument is reasonable. */
8818 }
8820 /* Substitute into all the default arguments for FN. */
8822 static void
8824 {
8825 tree arg;
8826 tree tmpl_args;
8830 /* If this function is not yet instantiated, we certainly don't need
8831 its default arguments. */
8836 arg;
8842 }
8844 /* Substitute the ARGS into the T, which is a _DECL. Return the
8845 result of the substitution. Issue error and warning messages under
8846 control of COMPLAIN. */
8848 static tree
8850 {
8851 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8852 location_t saved_loc;
8857 /* Set the filename and linenumber to improve error-reporting. */
8862 {
8864 {
8865 /* We can get here when processing a member function template,
8866 member class template, or template template parameter. */
8868 tree spec;
8869 tree tmpl_args;
8870 tree full_args;
8873 {
8874 /* Template template parameter is treated here. */
8887 complain);
8890 }
8892 /* We might already have an instance of this template.
8893 The ARGS are for the surrounding class type, so the
8894 full args contain the tsubst'd args for the context,
8895 plus the innermost args from the template decl. */
8899 /* Because this is a template, the arguments will still be
8900 dependent, even after substitution. If
8901 PROCESSING_TEMPLATE_DECL is not set, the dependency
8902 predicates will short-circuit. */
8910 /* If this is a default template template argument,
8911 tsubst might not have changed anything. */
8918 {
8921 }
8923 /* Make a new template decl. It will be similar to the
8924 original, but will record the current template arguments.
8925 We also create a new function declaration, which is just
8926 like the old one, but points to this new template, rather
8927 than the old one. */
8935 {
8936 tree new_type;
8948 }
8949 else
8950 {
8951 tree new_decl;
8963 }
8969 /* The template parameters for this new template are all the
8970 template parameters for the old template, except the
8971 outermost level of parameters. */
8974 complain);
8980 /* Record this non-type partial instantiation. */
8984 }
8988 {
8989 tree ctx;
8992 tree gen_tmpl;
8993 tree type;
8998 /* Nobody should be tsubst'ing into non-template functions. */
9002 {
9003 tree spec;
9006 /* If T is not dependent, just return it. We have to
9007 increment PROCESSING_TEMPLATE_DECL because
9008 value_dependent_expression_p assumes that nothing is
9009 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9016 /* Calculate the most general template of which R is a
9017 specialization, and the complete set of arguments used to
9018 specialize R. */
9024 /* Check to see if we already have this specialization. */
9029 {
9032 }
9034 /* We can see more levels of arguments than parameters if
9035 there was a specialization of a member template, like
9036 this:
9038 template <class T> struct S { template <class U> void f(); }
9039 template <> template <class U> void S<int>::f(U);
9041 Here, we'll be substituting into the specialization,
9042 because that's where we can find the code we actually
9043 want to generate, but we'll have enough arguments for
9044 the most general template.
9046 We also deal with the peculiar case:
9048 template <class T> struct S {
9049 template <class U> friend void f();
9050 };
9051 template <class U> void f() {}
9052 template S<int>;
9053 template void f<double>();
9055 Here, the ARGS for the instantiation of will be {int,
9056 double}. But, we only need as many ARGS as there are
9057 levels of template parameters in CODE_PATTERN. We are
9058 careful not to get fooled into reducing the ARGS in
9059 situations like:
9061 template <class T> struct S { template <class U> void f(U); }
9062 template <class T> template <> void S<T>::f(int) {}
9064 which we can spot because the pattern will be a
9065 specialization in this case. */
9067 parms_depth =
9072 }
9073 else
9074 {
9075 /* This special case arises when we have something like this:
9077 template <class T> struct S {
9078 friend void f<int>(int, double);
9079 };
9081 Here, the DECL_TI_TEMPLATE for the friend declaration
9082 will be an IDENTIFIER_NODE. We are being called from
9083 tsubst_friend_function, and we want only to create a
9084 new decl (R) with appropriate types so that we can call
9085 determine_specialization. */
9087 }
9090 {
9093 else
9097 }
9098 else
9099 {
9102 }
9107 /* We do NOT check for matching decls pushed separately at this
9108 point, as they may not represent instantiations of this
9109 template, and in any case are considered separate under the
9110 discrete model. */
9114 /* Clear out the mangled name and RTL for the instantiation. */
9117 /* Leave DECL_INITIAL set on deleted instantiations. */
9123 /* Type-conversion operator. Reconstruct the name, in
9124 case it's the name of one of the template's parameters. */
9134 /* If this is an instantiation of a function with internal
9135 linkage, we already know what object file linkage will be
9136 assigned to the instantiation. */
9145 /* We'll re-clone as appropriate in instantiate_template. */
9148 /* If we aren't complaining now, return on error before we register
9149 the specialization so that we'll complain eventually. */
9155 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9156 this in the special friend case mentioned above where
9157 GEN_TMPL is NULL. */
9159 {
9165 /* We're not supposed to instantiate default arguments
9166 until they are called, for a template. But, for a
9167 declaration like:
9169 template <class T> void f ()
9170 { extern void g(int i = T()); }
9172 we should do the substitution when the template is
9173 instantiated. We handle the member function case in
9174 instantiate_class_template since the default arguments
9175 might refer to other members of the class. */
9180 }
9181 else
9184 /* Copy the list of befriending classes. */
9188 {
9192 in_decl);
9193 }
9196 {
9200 /* If this is an instantiation of a member template, clone it.
9201 If it isn't, that'll be handled by
9202 clone_constructors_and_destructors. */
9205 }
9216 /* Possibly limit visibility based on template args. */
9219 {
9223 }
9231 }
9235 {
9243 {
9244 /* If there is a local specialization that isn't a
9245 parameter pack, it means that we're doing a "simple"
9246 substitution from inside tsubst_pack_expansion. Just
9247 return the local specialization (which will be a single
9248 parm). */
9255 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9256 the parameters in this function parameter pack. */
9260 {
9263 /* Zero-length parameter packs are boring. Just substitute
9264 into the chain. */
9268 }
9269 else
9270 {
9271 /* All we did was update the type. Make a note of that. */
9274 }
9275 }
9277 /* Loop through all of the parameter's we'll build. When T is
9278 a function parameter pack, LEN is the number of expanded
9279 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9282 {
9288 /* An argument of a function parameter pack is not a parameter
9289 pack. */
9293 /* We're on the Ith parameter of the function parameter
9294 pack. */
9295 {
9296 /* Get the Ith type. */
9300 /* Rename the parameter to include the index. */
9303 }
9305 /* We're dealing with a normal parameter. */
9313 {
9316 else
9319 }
9329 /* Keep track of the first new parameter we
9330 generate. That's what will be returned to the
9331 caller. */
9335 /* Build a proper chain of parameters when substituting
9336 into a function parameter pack. */
9339 }
9345 /* FIRST_R contains the start of the chain we've built. */
9347 }
9351 {
9352 tree type;
9361 /* DECL_INITIAL gives the number of bits in a bit-field. */
9366 /* We don't have to set DECL_CONTEXT here; it is set by
9367 finish_member_declaration. */
9374 }
9378 /* We reach here only for member using decls. */
9380 {
9381 r = do_class_using_decl
9386 else
9387 {
9390 }
9391 }
9392 else
9393 {
9396 }
9401 {
9404 tree spec;
9406 tree ctx;
9412 {
9413 /* If this is the canonical decl, we don't have to
9414 mess with instantiations, and often we can't (for
9415 typename, template type parms and such). Note that
9416 TYPE_NAME is not correct for the above test if
9417 we've copied the type for a typedef. */
9423 }
9425 /* Check to see if we already have the specialization we
9426 need. */
9429 {
9430 /* T is a static data member or namespace-scope entity.
9431 We have to substitute into namespace-scope variables
9432 (even though such entities are never templates) because
9433 of cases like:
9435 template <class T> void f() { extern T t; }
9437 where the entity referenced is not known until
9438 instantiation time. */
9442 {
9444 complain,
9446 /* If CTX is unchanged, then T is in fact the
9447 specialization we want. That situation occurs when
9448 referencing a static data member within in its own
9449 class. We can use pointer equality, rather than
9450 same_type_p, because DECL_CONTEXT is always
9451 canonical. */
9454 }
9457 {
9463 }
9464 }
9465 else
9466 {
9467 /* A local variable. */
9469 /* Subsequent calls to pushdecl will fill this in. */
9472 }
9473 /* If we already have the specialization we need, there is
9474 nothing more to do. */
9476 {
9479 }
9481 /* Create a new node for the specialization we need. */
9484 {
9487 else
9490 }
9492 {
9493 /* Even if the original location is out of scope, the
9494 newly substituted one is not. */
9501 {
9502 /* It may seem that this case cannot occur, since:
9504 typedef void f();
9505 void g() { f x; }
9507 declares a function, not a variable. However:
9509 typedef void f();
9510 template <typename T> void g() { T t; }
9511 template void g<f>();
9513 is an attempt to declare a variable with function
9514 type. */
9516 /* R is not yet sufficiently initialized, so we
9517 just use its name. */
9520 }
9527 {
9532 }
9533 }
9539 /* Clear out the mangled name and RTL for the instantiation. */
9543 /* The initializer must not be expanded until it is required;
9544 see [temp.inst]. */
9550 {
9551 /* Possibly limit visibility based on template args. */
9554 {
9558 }
9560 }
9563 {
9564 /* A static data member declaration is always marked
9565 external when it is declared in-class, even if an
9566 initializer is present. We mimic the non-template
9567 processing here. */
9573 }
9575 {
9576 /* We're substituting this var in a decltype outside of its
9577 scope, such as for a lambda return type. Don't add it to
9578 local_specializations, do perform auto deduction. */
9580 tree init
9585 {
9588 }
9589 }
9590 else
9599 /* Preserve a typedef that names a type. */
9601 {
9604 }
9607 }
9612 }
9613 #undef RETURN
9615 out:
9616 /* Restore the file and line information. */
9620 }
9622 /* Substitute into the ARG_TYPES of a function type. */
9624 static tree
9626 tree args,
9627 tsubst_flags_t complain,
9628 tree in_decl)
9629 {
9630 tree remaining_arg_types;
9634 tree default_arg;
9645 {
9646 /* For a pack expansion, perform substitution on the
9647 entire expression. Later on, we'll handle the arguments
9648 one-by-one. */
9653 /* So that we'll spin through the parameters, one by one. */
9655 else
9656 {
9657 /* We only partially substituted into the parameter
9658 pack. Our type is TYPE_PACK_EXPANSION. */
9661 }
9662 }
9675 {
9677 {
9681 }
9683 }
9685 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9686 top-level qualifiers as required. */
9689 /* We do not substitute into default arguments here. The standard
9690 mandates that they be instantiated only when needed, which is
9691 done in build_over_call. */
9695 {
9696 /* We've instantiated a template before its default arguments
9697 have been parsed. This can happen for a nested template
9698 class, and is not an error unless we require the default
9699 argument in a call of this function. */
9700 remaining_arg_types =
9703 remaining_arg_types);
9704 }
9705 else
9706 remaining_arg_types =
9708 }
9711 }
9713 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9714 *not* handle the exception-specification for FNTYPE, because the
9715 initial substitution of explicitly provided template parameters
9716 during argument deduction forbids substitution into the
9717 exception-specification:
9719 [temp.deduct]
9721 All references in the function type of the function template to the
9722 corresponding template parameters are replaced by the specified tem-
9723 plate argument values. If a substitution in a template parameter or
9724 in the function type of the function template results in an invalid
9725 type, type deduction fails. [Note: The equivalent substitution in
9726 exception specifications is done only when the function is instanti-
9727 ated, at which point a program is ill-formed if the substitution
9728 results in an invalid type.] */
9730 static tree
9732 tree args,
9733 tsubst_flags_t complain,
9734 tree in_decl)
9735 {
9736 tree return_type;
9737 tree arg_types;
9738 tree fntype;
9740 /* The TYPE_CONTEXT is not used for function/method types. */
9743 /* Substitute the return type. */
9747 /* The standard does not presently indicate that creation of a
9748 function type with an invalid return type is a deduction failure.
9749 However, that is clearly analogous to creating an array of "void"
9750 or a reference to a reference. This is core issue #486. */
9753 {
9755 {
9758 else
9760 }
9762 }
9764 /* Substitute the argument types. */
9770 /* Construct a new type node and return it. */
9773 else
9774 {
9777 {
9778 /* [temp.deduct]
9780 Type deduction may fail for any of the following
9781 reasons:
9783 -- Attempting to create "pointer to member of T" when T
9784 is not a class type. */
9787 r);
9789 }
9793 }
9798 }
9800 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9801 ARGS into that specification, and return the substituted
9802 specification. If there is no specification, return NULL_TREE. */
9804 static tree
9806 tree args,
9807 tsubst_flags_t complain,
9808 tree in_decl)
9809 {
9810 tree specs;
9811 tree new_specs;
9816 {
9819 else
9821 {
9822 tree spec;
9827 {
9828 /* Expand the pack expansion type. */
9831 in_decl);
9837 else
9838 {
9839 /* We're substituting into a member template, so
9840 we got a TYPE_PACK_EXPANSION back. Add that
9841 expansion and move on. */
9845 expanded_specs,
9846 complain);
9849 }
9850 }
9853 {
9856 else
9861 complain);
9862 }
9865 }
9866 }
9868 }
9870 /* Take the tree structure T and replace template parameters used
9871 therein with the argument vector ARGS. IN_DECL is an associated
9872 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9873 Issue error and warning messages under control of COMPLAIN. Note
9874 that we must be relatively non-tolerant of extensions here, in
9875 order to preserve conformance; if we allow substitutions that
9876 should not be allowed, we may allow argument deductions that should
9877 not succeed, and therefore report ambiguous overload situations
9878 where there are none. In theory, we could allow the substitution,
9879 but indicate that it should have failed, and allow our caller to
9880 make sure that the right thing happens, but we don't try to do this
9881 yet.
9883 This function is used for dealing with types, decls and the like;
9884 for expressions, use tsubst_expr or tsubst_copy. */
9886 tree
9888 {
9907 else
9912 /* Reuse typedefs. We need to do this to handle dependent attributes,
9913 such as attribute aligned. */
9917 {
9923 {
9927 }
9932 else
9933 /* The typedef is from a non-template context. */
9937 {
9939 r = cp_build_qualified_type_real
9943 }
9944 /* Else we must be instantiating the typedef, so fall through. */
9945 }
9958 {
9985 {
9991 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
9992 needed. */
10000 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10001 with TREE_SIDE_EFFECTS that indicates this is not an integral
10002 constant expression. */
10005 {
10008 }
10014 {
10018 }
10020 /* [temp.deduct]
10022 Type deduction may fail for any of the following
10023 reasons:
10025 Attempting to create an array with a size that is
10026 zero or negative. */
10028 /* We must fail if performing argument deduction (as
10029 indicated by the state of complain), so that
10030 another substitution can be found. */
10034 {
10039 }
10042 }
10048 {
10061 {
10065 /* See through ARGUMENT_PACK_SELECT arguments. */
10067 }
10072 {
10074 /* If ARG is an argument pack, we don't actually want to
10075 perform a substitution here, because substitutions
10076 for argument packs are only done
10077 element-by-element. We can get to this point when
10078 substituting the type of a non-type template
10079 parameter pack, when that type actually contains
10080 template parameter packs from an outer template, e.g.,
10082 template<typename... Types> struct A {
10083 template<Types... Values> struct B { };
10084 }; */
10088 {
10092 /* cv-quals from the template are discarded when
10093 substituting in a function or reference type. */
10098 else
10101 return cp_build_qualified_type_real
10103 }
10105 {
10106 /* We are processing a type constructed from a
10107 template template parameter. */
10113 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10114 are resolving nested-types in the signature of a
10115 member function templates. Otherwise ARG is a
10116 TEMPLATE_DECL and is the real template to be
10117 instantiated. */
10125 complain);
10126 return cp_build_qualified_type_real
10128 }
10129 else
10130 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10132 }
10135 /* This can happen during the attempted tsubst'ing in
10136 unify. This means that we don't yet have any information
10137 about the template parameter in question. */
10140 /* If we get here, we must have been looking at a parm for a
10141 more deeply nested template. Make a new version of this
10142 template parameter, but with a lower level. */
10144 {
10149 {
10151 r = cp_build_qualified_type_real
10155 }
10156 else
10157 {
10168 /* We have reduced the level of the template
10169 template parameter, but not the levels of its
10170 template parameters, so canonical_type_parameter
10171 will not be able to find the canonical template
10172 template parameter for this level. Thus, we
10173 require structural equality checking to compare
10174 TEMPLATE_TEMPLATE_PARMs. */
10178 else
10182 {
10190 }
10191 }
10200 }
10203 }
10206 {
10214 {
10218 }
10221 {
10225 }
10228 {
10232 }
10238 }
10241 /* We should never be tsubsting a binfo. */
10245 /* A vector of template arguments. */
10251 {
10260 /* [temp.deduct]
10262 Type deduction may fail for any of the following
10263 reasons:
10265 -- Attempting to create a pointer to reference type.
10266 -- Attempting to create a reference to a reference type or
10267 a reference to void.
10269 Core issue 106 says that creating a reference to a reference
10270 during instantiation is no longer a cause for failure. We
10271 only enforce this check in strict C++98 mode. */
10275 {
10278 /* We keep track of the last time we issued this error
10279 message to avoid spewing a ton of messages during a
10280 single bad template instantiation. */
10283 {
10288 else
10291 }
10294 }
10296 {
10300 }
10302 /* In C++0x, during template argument substitution, when there is an
10303 attempt to create a reference to a reference type, reference
10304 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10306 "If a template-argument for a template-parameter T names a type
10307 that is a reference to a type A, an attempt to create the type
10308 'lvalue reference to cv T' creates the type 'lvalue reference to
10309 A,' while an attempt to create the type type rvalue reference to
10310 cv T' creates the type T"
10311 */
10312 r = cp_build_reference_type
10315 else
10320 /* Will this ever be needed for TYPE_..._TO values? */
10324 }
10326 {
10329 {
10330 /* [temp.deduct]
10332 Type deduction may fail for any of the following
10333 reasons:
10335 -- Attempting to create "pointer to member of T" when T
10336 is not a class type. */
10340 }
10342 {
10346 }
10348 {
10352 }
10355 {
10356 /* The type of the implicit object parameter gets its
10357 cv-qualifiers from the FUNCTION_TYPE. */
10358 tree memptr;
10362 complain);
10363 }
10364 else
10367 complain);
10368 }
10371 {
10372 tree fntype;
10373 tree specs;
10378 /* Substitute the exception specification. */
10380 in_decl);
10386 }
10388 {
10393 /* As an optimization, we avoid regenerating the array type if
10394 it will obviously be the same as T. */
10398 /* These checks should match the ones in grokdeclarator.
10400 [temp.deduct]
10402 The deduction may fail for any of the following reasons:
10404 -- Attempting to create an array with an element type that
10405 is void, a function type, or a reference type, or [DR337]
10406 an abstract class type. */
10410 {
10414 }
10416 {
10419 type);
10421 }
10426 {
10429 }
10432 }
10436 {
10445 }
10449 {
10455 }
10458 {
10468 {
10472 }
10474 {
10475 /* Normally, make_typename_type does not require that the CTX
10476 have complete type in order to allow things like:
10478 template <class T> struct S { typename S<T>::X Y; };
10480 But, such constructs have already been resolved by this
10481 point, so here CTX really should have complete type, unless
10482 it's a partial instantiation. */
10486 {
10490 }
10491 }
10498 {
10501 }
10504 {
10511 }
10513 return cp_build_qualified_type_real
10515 }
10518 {
10530 }
10538 {
10546 }
10549 {
10557 }
10560 {
10561 tree type;
10577 complain);
10578 }
10581 {
10582 tree type;
10598 else
10599 type = finish_decltype_type
10604 complain);
10605 }
10609 {
10613 tree packed_out =
10615 args,
10616 complain,
10617 in_decl);
10620 /* For template nontype argument packs, also substitute into
10621 the type. */
10626 }
10633 }
10634 }
10636 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10637 type of the expression on the left-hand side of the "." or "->"
10638 operator. */
10640 static tree
10643 {
10644 tree name;
10645 tree qualifying_scope;
10646 tree fns;
10647 tree optype;
10651 /* A baselink indicates a function from a base class. Both the
10652 BASELINK_ACCESS_BINFO and the base class referenced may
10653 indicate bases of the template class, rather than the
10654 instantiated class. In addition, lookups that were not
10655 ambiguous before may be ambiguous now. Therefore, we perform
10656 the lookup again. */
10663 {
10670 }
10676 /* If lookup found a single function, mark it as used at this
10677 point. (If it lookup found multiple functions the one selected
10678 later by overload resolution will be marked as used at that
10679 point.) */
10685 /* Add back the template arguments, if present. */
10690 template_args);
10691 /* Update the conversion operator type. */
10697 qualifying_scope,
10698 object_type);
10699 }
10701 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10702 true if the qualified-id will be a postfix-expression in-and-of
10703 itself; false if more of the postfix-expression follows the
10704 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10705 of "&". */
10707 static tree
10711 {
10712 tree expr;
10713 tree scope;
10714 tree name;
10716 tree template_args;
10720 /* Figure out what name to look up. */
10723 {
10730 }
10731 else
10732 {
10735 }
10737 /* Substitute into the qualifying scope. When there are no ARGS, we
10738 are just trying to simplify a non-dependent expression. In that
10739 case the qualifying scope may be dependent, and, in any case,
10740 substituting will not help. */
10743 {
10746 }
10747 else
10755 {
10757 {
10758 /* A BIT_NOT_EXPR is used to represent a destructor. */
10760 {
10764 }
10765 else
10768 }
10769 else
10773 {
10775 {
10779 }
10781 }
10782 }
10785 {
10787 scope);
10788 /* Remember that there was a reference to this entity. */
10790 }
10793 {
10799 }
10808 {
10809 expr = (adjust_result_of_qualified_name_lookup
10811 expr = (finish_qualified_id_expr
10815 }
10817 /* Expressions do not generally have reference type. */
10819 /* However, if we're about to form a pointer-to-member, we just
10820 want the referenced member referenced. */
10825 }
10827 /* Like tsubst, but deals with expressions. This function just replaces
10828 template parms; to finish processing the resultant expression, use
10829 tsubst_expr. */
10831 static tree
10833 {
10835 tree r;
10843 {
10848 {
10849 tree c;
10850 /* This can happen for a parameter name used later in a function
10851 declaration (such as in a late-specified return type). Just
10852 make a dummy decl, since it's only used for its type. */
10854 /* We copy T because want to tsubst the PARM_DECL only,
10855 not the following PARM_DECLs that are chained to T. */
10858 /* Give it the template pattern as its context; its true context
10859 hasn't been instantiated yet and this is good enough for
10860 mangling. */
10862 }
10870 {
10871 tree enum_type;
10872 tree v;
10876 /* There is no need to substitute into namespace-scope
10877 enumerators. */
10880 /* If ARGS is NULL, then T is known to be non-dependent. */
10884 /* Unfortunately, we cannot just call lookup_name here.
10885 Consider:
10887 template <int I> int f() {
10888 enum E { a = I };
10889 struct S { void g() { E e = a; } };
10890 };
10892 When we instantiate f<7>::S::g(), say, lookup_name is not
10893 clever enough to find f<7>::a. */
10894 enum_type
10904 /* We didn't find the name. That should never happen; if
10905 name-lookup found it during preliminary parsing, we
10906 should find it again here during instantiation. */
10908 }
10913 {
10914 tree ctx;
10919 {
10922 {
10926 }
10928 }
10929 }
10952 {
10953 /* Template template argument like the following example need
10954 special treatment:
10956 template <template <class> class TT> struct C {};
10957 template <class T> struct D {
10958 template <class U> struct E {};
10959 C<E> c; // #1
10960 };
10961 D<int> d; // #2
10963 We are processing the template argument `E' in #1 for
10964 the template instantiation #2. Originally, `E' is a
10965 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10966 have to substitute this with one having context `D<int>'. */
10970 }
10971 else
10972 /* Ordinary template template argument. */
10981 return build1
10987 {
10988 /* We only want to compute the number of arguments. */
11002 {
11009 else
11012 }
11013 else
11015 }
11016 /* Fall through */
11030 return build1
11035 {
11036 tree object;
11037 tree name;
11042 {
11046 }
11049 {
11059 }
11064 in_decl);
11065 else
11068 }
11106 return build_nt
11119 return build_nt
11126 {
11134 }
11139 {
11140 r = build_nt
11146 }
11149 {
11150 r = build_nt
11156 }
11159 {
11160 r = build_nt
11166 }
11169 {
11170 /* Substituted template arguments */
11179 }
11182 {
11202 }
11227 {
11230 }
11231 else
11235 /* This is handled by tsubst_copy_and_build. */
11240 in_decl),
11244 /* We shouldn't have built any of these during initial template
11245 generation. Instead, they should be built during instantiation
11246 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11263 }
11264 }
11266 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11268 static tree
11270 tree in_decl)
11271 {
11275 {
11281 {
11284 {
11290 }
11291 /* FALLTHRU */
11313 }
11314 }
11317 }
11319 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11321 static tree
11323 tree in_decl)
11324 {
11325 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11350 #undef RECUR
11351 }
11353 /* Substitute one OMP_FOR iterator. */
11355 static void
11360 {
11361 #define RECUR(NODE) \
11362 tsubst_expr ((NODE), args, complain, in_decl, \
11363 integral_constant_expression_p)
11372 {
11379 }
11383 {
11389 complain);
11390 else
11397 }
11400 {
11401 tree c;
11403 {
11414 }
11416 {
11421 {
11424 }
11425 }
11426 }
11432 else
11436 {
11447 {
11454 }
11455 else
11461 {
11467 }
11471 {
11478 }
11479 else
11485 }
11491 #undef RECUR
11492 }
11494 /* Like tsubst_copy for expressions, etc. but also does semantic
11495 processing. */
11497 static tree
11500 {
11501 #define RECUR(NODE) \
11502 tsubst_expr ((NODE), args, complain, in_decl, \
11503 integral_constant_expression_p)
11516 {
11518 {
11519 tree_stmt_iterator i;
11523 }
11538 else
11547 {
11548 tree decl;
11549 tree init;
11555 {
11558 tree decl;
11566 else
11568 }
11569 else
11570 {
11574 {
11575 /* By marking the declaration as instantiated, we avoid
11576 trying to instantiate it. Since instantiate_decl can't
11577 handle local variables, and since we've already done
11578 all that needs to be done, that's the right thing to
11579 do. */
11584 /* Anonymous aggregates are a special case. */
11586 else
11587 {
11591 {
11592 /* For __PRETTY_FUNCTION__ we have to adjust the
11593 initializer. */
11597 }
11598 else
11599 {
11603 /* If we had an initializer but it
11604 instantiated to nothing,
11605 value-initialize the object. This will
11606 only occur when the initializer was a
11607 pack expansion where the parameter packs
11608 used in that expansion were of length
11609 zero. */
11611 else
11613 }
11616 }
11617 }
11618 }
11620 /* A DECL_EXPR can also be used as an expression, in the condition
11621 clause of an if/for/while construct. */
11623 }
11661 {
11665 }
11673 else
11681 else
11708 {
11710 tree label;
11715 }
11721 /* Computed goto's must be tsubst'd into. On the other hand,
11722 non-computed gotos must not be; the identifier in question
11723 will have no binding. */
11725 else
11731 tmp = finish_asm_stmt
11738 {
11743 }
11748 {
11753 }
11754 else
11755 {
11760 else
11767 else
11773 else
11775 }
11779 {
11783 {
11785 /* Prevent instantiate_decl from trying to instantiate
11786 this variable. We've already done all that needs to be
11787 done. */
11790 }
11795 }
11803 {
11804 tree condition =
11806 args,
11813 }
11834 {
11849 integral_constant_expression_p);
11858 {
11862 }
11863 else
11864 {
11872 }
11886 }
11917 {
11922 }
11938 integral_constant_expression_p);
11939 }
11942 #undef RECUR
11943 }
11945 /* T is a postfix-expression that is not being used in a function
11946 call. Return the substituted version of T. */
11948 static tree
11950 tsubst_flags_t complain,
11951 tree in_decl)
11952 {
11956 else
11962 }
11964 /* Like tsubst but deals with expressions and performs semantic
11965 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11967 tree
11969 tree args,
11970 tsubst_flags_t complain,
11971 tree in_decl,
11974 {
11975 #define RECUR(NODE) \
11976 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11978 integral_constant_expression_p)
11980 tree op1;
11986 {
11989 /* Fall through. */
11991 {
11992 tree decl;
11993 cp_id_kind idk;
11998 {
12001 }
12003 /* Look up the name. */
12006 /* By convention, expressions use ERROR_MARK_NODE to indicate
12007 failure, not NULL_TREE. */
12013 integral_constant_expression_p,
12021 input_location);
12027 }
12030 {
12031 tree object;
12039 {
12042 }
12043 else
12050 else
12052 }
12055 {
12059 {
12060 /* A type conversion to reference type will be enclosed in
12061 such an indirect ref, but the substitution of the cast
12062 will have also added such an indirect ref. */
12065 }
12066 else
12069 }
12072 return build_nop
12081 {
12082 tree type;
12083 tree op;
12088 {
12093 }
12098 {
12111 }
12112 }
12130 complain);
12137 else
12139 in_decl);
12176 return build_x_binary_op
12180 ? ERROR_MARK
12184 ? ERROR_MARK
12187 complain);
12200 /* Fall through */
12205 {
12206 /* When there are no ARGS, we are trying to evaluate a
12207 non-dependent expression from the parser. Trying to do
12208 the substitutions may not work. */
12211 }
12212 else
12213 {
12221 }
12225 else
12230 {
12231 tree r = build_x_modify_expr
12235 complain);
12236 /* TREE_NO_WARNING must be set if either the expression was
12237 parenthesized or it uses an operator such as >>= rather
12238 than plain assignment. In the former case, it was already
12239 set and must be copied. In the latter case,
12240 build_x_modify_expr sets it and it must not be reset
12241 here. */
12245 }
12250 /* Remember that there was a reference to this entity. */
12256 {
12261 tree ret;
12265 else
12266 {
12270 }
12272 /* If there was an initializer in the original tree, but it
12273 instantiated to an empty list, then we should pass a
12274 non-NULL empty vector to tell build_new that it was an
12275 empty initializer() rather than no initializer. This can
12276 only happen when the initializer is a pack expansion whose
12277 parameter packs are of length zero. */
12280 else
12281 {
12285 else
12286 {
12289 }
12290 }
12297 complain);
12305 }
12308 return delete_sanity
12317 complain);
12320 {
12321 tree function;
12326 tree ret;
12329 /* When we parsed the expression, we determined whether or
12330 not Koenig lookup should be performed. */
12333 {
12338 }
12339 else
12340 {
12342 {
12348 }
12349 else
12353 in_decl,
12355 integral_constant_expression_p);
12359 }
12364 {
12370 else
12371 {
12372 /* Expand the pack expansion and push each entry onto
12373 CALL_ARGS. */
12376 {
12381 {
12386 }
12387 }
12388 else
12389 {
12390 /* A partial substitution. Add one entry. */
12392 }
12393 }
12394 }
12396 /* We do not perform argument-dependent lookup if normal
12397 lookup finds a non-function, in accordance with the
12398 expected resolution of DR 218. */
12401 /* If lookup found a member function, the Koenig lookup is
12402 not appropriate, even if an unqualified-name was used
12403 to denote the function. */
12406 /* Only do this when substitution turns a dependent call
12407 into a non-dependent call. */
12413 {
12417 }
12419 /* Remember that there was a reference to this entity. */
12426 {
12431 complain);
12432 else
12433 ret = (build_new_method_call
12439 complain));
12440 }
12441 else
12444 koenig_p,
12445 complain);
12450 }
12453 return build_x_conditional_expr
12457 complain);
12460 return finish_pseudo_destructor_expr
12466 {
12474 {
12475 /* We have pack expansions, so expand those and
12476 create a new list out of it. */
12479 tree chain;
12482 /* Expand the argument expressions. */
12490 /* Build the rest of the list. */
12495 /* Determine the number of arguments. */
12497 {
12500 }
12503 else
12504 {
12505 /* Since we only performed a partial substitution into
12506 the argument pack, we only return a single list
12507 node. */
12514 }
12516 /* Convert the argument vectors into a TREE_LIST */
12519 {
12520 /* Grab the Ith values. */
12521 i--;
12524 value
12528 /* Build the list (backwards). */
12530 }
12533 }
12549 }
12552 {
12553 tree object;
12554 tree object_type;
12555 tree member;
12559 /* Remember that there was a reference to this entity. */
12569 else
12575 {
12577 {
12582 {
12585 }
12587 {
12591 }
12592 }
12593 }
12596 {
12597 tree tmpl;
12598 tree args;
12600 /* Lookup the template functions now that we know what the
12601 scope is. */
12608 {
12611 args);
12612 member = (adjust_result_of_qualified_name_lookup
12614 object_type));
12615 }
12616 else
12617 {
12619 input_location);
12621 }
12622 }
12626 {
12628 {
12632 else
12635 }
12637 }
12643 complain);
12644 }
12647 return build_throw
12651 {
12659 tree r;
12664 /* digest_init will do the wrong thing if we let it. */
12668 /* We do not want to process the index of aggregate
12669 initializers as they are identifier nodes which will be
12670 looked up by digest_init. */
12676 {
12681 {
12682 /* Substitute into the pack expansion. */
12684 in_decl);
12687 ;
12689 /* Just move the argument into place. */
12691 else
12692 {
12693 /* Update the length of the final CONSTRUCTOR
12694 arguments vector, and note that we will need to
12695 copy.*/
12698 }
12699 }
12700 else
12702 }
12705 {
12710 idx++)
12711 {
12713 {
12718 }
12719 else
12721 }
12722 }
12731 }
12734 {
12739 }
12744 /* Fall through */
12747 {
12751 /* If the original type was a reference, we'll be wrapped in
12752 the appropriate INDIRECT_REF. */
12755 }
12760 in_decl));
12766 {
12775 }
12778 {
12784 integral_constant_expression_p);
12788 /* If the resulting list of expression statement is empty,
12789 fold it further into void_zero_node. */
12794 }
12798 /* As in finish_id_expression, we resolve enumeration constants
12799 to their underlying values. */
12801 {
12804 }
12808 {
12829 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12831 /* Now that we know visibility, instantiate the type so we have a
12832 declaration of the op() for later calls to lambda_function. */
12840 }
12843 /* Handle Objective-C++ constructs, if appropriate. */
12844 {
12845 tree subst
12850 }
12852 }
12854 #undef RECUR
12855 }
12857 /* Verify that the instantiated ARGS are valid. For type arguments,
12858 make sure that the type's linkage is ok. For non-type arguments,
12859 make sure they are constants if they are integral or enumerations.
12860 Emit an error under control of COMPLAIN, and return TRUE on error. */
12862 static bool
12864 {
12866 {
12876 }
12878 {
12879 /* [basic.link]: A name with no linkage (notably, the name
12880 of a class or enumeration declared in a local scope)
12881 shall not be used to declare an entity with linkage.
12882 This implies that names with no linkage cannot be used as
12883 template arguments
12885 DR 757 relaxes this restriction for C++0x. */
12890 {
12891 /* DR 488 makes use of a type with no linkage cause
12892 type deduction to fail. */
12894 {
12897 else
12900 }
12902 }
12903 /* In order to avoid all sorts of complications, we do not
12904 allow variably-modified types as template arguments. */
12906 {
12910 }
12911 }
12912 /* A non-type argument of integral or enumerated type must be a
12913 constant. */
12917 {
12921 }
12923 }
12925 static bool
12927 {
12932 {
12935 }
12939 }
12941 /* Instantiate the indicated variable or function template TMPL with
12942 the template arguments in TARG_PTR. */
12944 tree
12946 {
12948 tree fndecl;
12949 tree gen_tmpl;
12950 tree spec;
12951 HOST_WIDE_INT saved_processing_template_decl;
12958 /* If this function is a clone, handle it specially. */
12960 {
12961 tree spec;
12962 tree clone;
12964 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
12965 DECL_CLONED_FUNCTION. */
12971 /* Look for the clone. */
12975 /* We should always have found the clone by now. */
12978 }
12980 /* Check to see if we already have this specialization. */
12983 /* The TMPL is a partial instantiation. To get a full set of
12984 arguments we must add the arguments used to perform the
12985 partial instantiation. */
12987 targ_ptr);
12989 /* It would be nice to avoid hashing here and then again in tsubst_decl,
12990 but it doesn't seem to be on the hot path. */
13002 complain))
13005 /* We are building a FUNCTION_DECL, during which the access of its
13006 parameters and return types have to be checked. However this
13007 FUNCTION_DECL which is the desired context for access checking
13008 is not built yet. We solve this chicken-and-egg problem by
13009 deferring all checks until we have the FUNCTION_DECL. */
13012 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13013 (because, for example, we have encountered a non-dependent
13014 function call in the body of a template function and must now
13015 determine which of several overloaded functions will be called),
13016 within the instantiation itself we are not processing a
13017 template. */
13020 /* Substitute template parameters to obtain the specialization. */
13027 /* Now we know the specialization, compute access previously
13028 deferred. */
13031 /* Some typedefs referenced from within the template code need to be access
13032 checked at template instantiation time, i.e now. These types were
13033 added to the template at parsing time. Let's get those and perfom
13034 the acces checks then. */
13040 /* The DECL_TI_TEMPLATE should always be the immediate parent
13041 template, not the most general template. */
13044 /* If we've just instantiated the main entry point for a function,
13045 instantiate all the alternate entry points as well. We do this
13046 by cloning the instantiation of the main entry point, not by
13047 instantiating the template clones. */
13052 }
13054 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13055 NARGS elements of the arguments that are being used when calling
13056 it. TARGS is a vector into which the deduced template arguments
13057 are placed.
13059 Return zero for success, 2 for an incomplete match that doesn't resolve
13060 all the types, and 1 for complete failure. An error message will be
13061 printed only for an incomplete match.
13063 If FN is a conversion operator, or we are trying to produce a specific
13064 specialization, RETURN_TYPE is the return type desired.
13066 The EXPLICIT_TARGS are explicit template arguments provided via a
13067 template-id.
13069 The parameter STRICT is one of:
13071 DEDUCE_CALL:
13072 We are deducing arguments for a function call, as in
13073 [temp.deduct.call].
13075 DEDUCE_CONV:
13076 We are deducing arguments for a conversion function, as in
13077 [temp.deduct.conv].
13079 DEDUCE_EXACT:
13080 We are deducing arguments when doing an explicit instantiation
13081 as in [temp.explicit], when determining an explicit specialization
13082 as in [temp.expl.spec], or when taking the address of a function
13083 template, as in [temp.deduct.funcaddr]. */
13085 int
13087 tree explicit_targs,
13088 tree targs,
13091 tree return_type,
13092 unification_kind_t strict,
13094 {
13095 tree parms;
13096 tree fntype;
13104 {
13105 /* [temp.deduct]
13107 The specified template arguments must match the template
13108 parameters in kind (i.e., type, nontype, template), and there
13109 must not be more arguments than there are parameters;
13110 otherwise type deduction fails.
13112 Nontype arguments must match the types of the corresponding
13113 nontype template parameters, or must be convertible to the
13114 types of the corresponding nontype parameters as specified in
13115 _temp.arg.nontype_, otherwise type deduction fails.
13117 All references in the function type of the function template
13118 to the corresponding template parameters are replaced by the
13119 specified template argument values. If a substitution in a
13120 template parameter or in the function type of the function
13121 template results in an invalid type, type deduction fails. */
13124 tree converted_args;
13130 converted_args
13137 /* Substitute the explicit args into the function type. This is
13138 necessary so that, for instance, explicitly declared function
13139 arguments can match null pointed constants. If we were given
13140 an incomplete set of explicit args, we must not do semantic
13141 processing during substitution as we could create partial
13142 instantiations. */
13144 {
13148 /* Dig out the actual parm. */
13151 {
13154 }
13156 {
13159 }
13162 {
13164 tree targ;
13167 /* Mark the argument pack as "incomplete". We could
13168 still deduce more arguments during unification. */
13171 {
13175 }
13177 /* We have some incomplete argument packs. */
13179 }
13180 }
13183 /* Any substitution is guaranteed to be incomplete if there
13184 are incomplete argument packs, because we can still deduce
13185 more arguments. */
13187 else
13197 /* Place the explicitly specified arguments in TARGS. */
13200 }
13202 /* Never do unification on the 'this' parameter. */
13206 {
13215 }
13217 /* We allow incomplete unification without an error message here
13218 because the standard doesn't seem to explicitly prohibit it. Our
13219 callers must be ready to deal with unification failures in any
13220 event. */
13226 {
13229 /* Clear the "incomplete" flags on all argument packs. */
13231 {
13234 {
13237 }
13238 }
13239 }
13241 /* Now that we have bindings for all of the template arguments,
13242 ensure that the arguments deduced for the template template
13243 parameters have compatible template parameter lists. We cannot
13244 check this property before we have deduced all template
13245 arguments, because the template parameter types of a template
13246 template parameter might depend on prior template parameters
13247 deduced after the template template parameter. The following
13248 ill-formed example illustrates this issue:
13250 template<typename T, template<T> class C> void f(C<5>, T);
13252 template<int N> struct X {};
13254 void g() {
13255 f(X<5>(), 5l); // error: template argument deduction fails
13256 }
13258 The template parameter list of 'C' depends on the template type
13259 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13260 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13261 time that we deduce 'C'. */
13263 && !template_template_parm_bindings_ok_p
13268 /* All is well so far. Now, check:
13270 [temp.deduct]
13272 When all template arguments have been deduced, all uses of
13273 template parameters in nondeduced contexts are replaced with
13274 the corresponding deduced argument values. If the
13275 substitution results in an invalid type, as described above,
13276 type deduction fails. */
13277 {
13282 /* If we're looking for an exact match, check that what we got
13283 is indeed an exact match. It might not be if some template
13284 parameters are used in non-deduced contexts. */
13286 {
13289 tree sarg
13296 }
13297 }
13300 }
13302 /* Adjust types before performing type deduction, as described in
13303 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13304 sections are symmetric. PARM is the type of a function parameter
13305 or the return type of the conversion function. ARG is the type of
13306 the argument passed to the call, or the type of the value
13307 initialized with the result of the conversion function.
13308 ARG_EXPR is the original argument expression, which may be null. */
13310 static int
13314 tree arg_expr)
13315 {
13319 {
13324 {
13325 /* Swap PARM and ARG throughout the remainder of this
13326 function; the handling is precisely symmetric since PARM
13327 will initialize ARG rather than vice versa. */
13332 }
13335 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13336 too, but here handle it by stripping the reference from PARM
13337 rather than by adding it to ARG. */
13345 /* Nothing else to do in this case. */
13350 }
13353 {
13354 /* [temp.deduct.call]
13356 If P is not a reference type:
13358 --If A is an array type, the pointer type produced by the
13359 array-to-pointer standard conversion (_conv.array_) is
13360 used in place of A for type deduction; otherwise,
13362 --If A is a function type, the pointer type produced by
13363 the function-to-pointer standard conversion
13364 (_conv.func_) is used in place of A for type deduction;
13365 otherwise,
13367 --If A is a cv-qualified type, the top level
13368 cv-qualifiers of A's type are ignored for type
13369 deduction. */
13374 else
13376 }
13378 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13379 of the form T&&, where T is a template parameter, and the argument
13380 is an lvalue, T is deduced as A& */
13388 /* [temp.deduct.call]
13390 If P is a cv-qualified type, the top level cv-qualifiers
13391 of P's type are ignored for type deduction. If P is a
13392 reference type, the type referred to by P is used for
13393 type deduction. */
13396 {
13399 }
13401 /* DR 322. For conversion deduction, remove a reference type on parm
13402 too (which has been swapped into ARG). */
13407 }
13409 /* Most parms like fn_type_unification.
13411 If SUBR is 1, we're being called recursively (to unify the
13412 arguments of a function or method parameter of a function
13413 template). */
13415 static int
13417 tree targs,
13418 tree xparms,
13422 unification_kind_t strict,
13424 {
13430 tree parms;
13439 /* Reset the number of non-defaulted template arguments contained
13440 in in TARGS. */
13444 {
13460 }
13462 again:
13470 {
13483 /* We can't deduce anything from this, but we might get all the
13484 template args from other function args. */
13487 /* Conversions will be performed on a function argument that
13488 corresponds with a function parameter that contains only
13489 non-deducible template parameters and explicitly specified
13490 template parameters. */
13492 {
13493 tree type;
13497 else
13504 flags))
13508 }
13511 {
13514 {
13515 /* [temp.deduct.type]
13517 A template-argument can be deduced from a pointer to
13518 function or pointer to member function argument if
13519 the set of overloaded functions does not contain
13520 function templates and at most one of a set of
13521 overloaded functions provides a unique match. */
13527 }
13532 }
13534 {
13539 arg_expr);
13545 }
13546 }
13552 {
13553 /* Unify the remaining arguments with the pack expansion type. */
13554 tree argvec;
13557 /* Allocate a TREE_VEC and copy in all of the arguments */
13562 /* Copy the parameter into parmvec. */
13568 /* Advance to the end of the list of parameters. */
13570 }
13572 /* Fail if we've reached the end of the parm list, and more args
13573 are present, and the parm list isn't variadic. */
13576 /* Fail if parms are left and they don't have default values. */
13584 {
13585 tree tparm;
13592 /* If this is an undeduced nontype parameter that depends on
13593 a type parameter, try another pass; its type may have been
13594 deduced from a later argument than the one from which
13595 this parameter can be deduced. */
13601 /* Core issue #226 (C++0x) [temp.deduct]:
13603 If a template argument has not been deduced, its
13604 default template argument, if any, is used.
13606 When we are in C++98 mode, TREE_PURPOSE will either
13607 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13608 to explicitly check cxx_dialect here. */
13610 {
13618 else
13619 {
13621 /* The position of the first default template argument,
13622 is also the number of non-defaulted arguments in TARGS.
13623 Record that. */
13627 }
13628 }
13630 /* If the type parameter is a parameter pack, then it will
13631 be deduced to an empty parameter pack. */
13633 {
13634 tree arg;
13637 {
13641 }
13642 else
13649 }
13652 }
13653 #ifdef ENABLE_CHECKING
13656 #endif
13659 }
13661 /* Subroutine of type_unification_real. Args are like the variables
13662 at the call site. ARG is an overloaded function (or template-id);
13663 we try deducing template args from each of the overloads, and if
13664 only one succeeds, we go with that. Modifies TARGS and returns
13665 true on success. */
13667 static bool
13669 tree targs,
13670 tree parm,
13671 tree arg,
13672 unification_kind_t strict,
13674 {
13681 {
13684 }
13685 else
13689 /* Handle `&x' where `x' is some static or non-static member
13690 function name. */
13696 /* Strip baselink information. */
13701 {
13702 /* If we got some explicit template args, we need to plug them into
13703 the affected templates before we try to unify, in case the
13704 explicit args will completely resolve the templates in question. */
13710 {
13721 {
13726 {
13729 }
13730 }
13732 }
13733 }
13736 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13737 -- but the deduction does not succeed because the expression is
13738 not just the function on its own. */
13740 else
13746 {
13749 }
13751 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13752 to function or pointer to member function argument if the set of
13753 overloaded functions does not contain function templates and at most
13754 one of a set of overloaded functions provides a unique match.
13756 So if we found multiple possibilities, we return success but don't
13757 deduce anything. */
13760 {
13765 }
13770 }
13772 /* Core DR 115: In contexts where deduction is done and fails, or in
13773 contexts where deduction is not done, if a template argument list is
13774 specified and it, along with any default template arguments, identifies
13775 a single function template specialization, then the template-id is an
13776 lvalue for the function template specialization. */
13778 tree
13780 {
13793 {
13796 }
13798 {
13801 }
13803 {
13806 }
13809 {
13813 /* If we got some explicit template args, we need to plug them into
13814 the affected templates before we try to unify, in case the
13815 explicit args will completely resolve the templates in question. */
13823 {
13834 {
13837 {
13840 }
13842 {
13845 }
13846 }
13848 }
13850 {
13862 }
13864 /* There were no good options and at least one bad one, so let the
13865 user know what the problem is. */
13867 }
13869 }
13871 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13872 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13873 different overloads deduce different arguments for a given parm.
13874 ADDR_P is true if the expression for which deduction is being
13875 performed was of the form "& fn" rather than simply "fn".
13877 Returns 1 on success. */
13879 static int
13881 tree orig_targs,
13882 tree targs,
13883 tree parm,
13884 tree arg,
13885 unification_kind_t strict,
13888 {
13890 tree tempargs;
13893 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13894 to function or pointer to member function argument if the set of
13895 overloaded functions does not contain function templates and at most
13896 one of a set of overloaded functions provides a unique match.
13898 So if this is a template, just return success. */
13910 /* We don't copy orig_targs for this because if we have already deduced
13911 some template args from previous args, unify would complain when we
13912 try to deduce a template parameter for the same argument, even though
13913 there isn't really a conflict. */
13920 /* First make sure we didn't deduce anything that conflicts with
13921 explicitly specified args. */
13923 {
13930 /* Since we're unifying against ourselves, we will fill in
13931 template args used in the function parm list with our own
13932 template parms. Discard them. */
13936 }
13939 {
13944 }
13947 }
13949 /* PARM is a template class (perhaps with unbound template
13950 parameters). ARG is a fully instantiated type. If ARG can be
13951 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
13952 TARGS are as for unify. */
13954 static tree
13956 {
13957 tree copy_of_targs;
13964 /* We need to make a new template argument vector for the call to
13965 unify. If we used TARGS, we'd clutter it up with the result of
13966 the attempted unification, even if this class didn't work out.
13967 We also don't want to commit ourselves to all the unifications
13968 we've already done, since unification is supposed to be done on
13969 an argument-by-argument basis. In other words, consider the
13970 following pathological case:
13972 template <int I, int J, int K>
13973 struct S {};
13975 template <int I, int J>
13976 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
13978 template <int I, int J, int K>
13979 void f(S<I, J, K>, S<I, I, I>);
13981 void g() {
13982 S<0, 0, 0> s0;
13983 S<0, 1, 2> s2;
13985 f(s0, s2);
13986 }
13988 Now, by the time we consider the unification involving `s2', we
13989 already know that we must have `f<0, 0, 0>'. But, even though
13990 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
13991 because there are two ways to unify base classes of S<0, 1, 2>
13992 with S<I, I, I>. If we kept the already deduced knowledge, we
13993 would reject the possibility I=1. */
13996 /* If unification failed, we're done. */
14002 }
14004 /* Given a template type PARM and a class type ARG, find the unique
14005 base type in ARG that is an instance of PARM. We do not examine
14006 ARG itself; only its base-classes. If there is not exactly one
14007 appropriate base class, return NULL_TREE. PARM may be the type of
14008 a partial specialization, as well as a plain template type. Used
14009 by unify. */
14011 static tree
14013 {
14015 tree binfo;
14021 /* The type could not be completed. */
14024 /* Walk in inheritance graph order. The search order is not
14025 important, and this avoids multiple walks of virtual bases. */
14027 {
14031 {
14032 /* If there is more than one satisfactory baseclass, then:
14034 [temp.deduct.call]
14036 If they yield more than one possible deduced A, the type
14037 deduction fails.
14039 applies. */
14044 }
14045 }
14048 }
14050 /* Returns the level of DECL, which declares a template parameter. */
14052 static int
14054 {
14056 {
14066 }
14068 }
14070 /* Decide whether ARG can be unified with PARM, considering only the
14071 cv-qualifiers of each type, given STRICT as documented for unify.
14072 Returns nonzero iff the unification is OK on that basis. */
14074 static int
14076 {
14082 {
14083 /* Although a CVR qualifier is ignored when being applied to a
14084 substituted template parameter ([8.3.2]/1 for example), that
14085 does not apply during deduction [14.8.2.4]/1, (even though
14086 that is not explicitly mentioned, [14.8.2.4]/9 indicates
14087 this). Except when we're allowing additional CV qualifiers
14088 at the outer level [14.8.2.1]/3,1st bullet. */
14098 }
14109 }
14111 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14112 void
14114 {
14118 {
14121 }
14122 else
14123 {
14126 }
14127 }
14129 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14130 expansion at the end of PACKED_PARMS. Returns 0 if the type
14131 deduction succeeds, 1 otherwise. STRICT is the same as in
14132 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14133 call argument list. We'll need to adjust the arguments to make them
14134 types. SUBR tells us if this is from a recursive call to
14135 type_unification_real. */
14136 int
14140 {
14141 tree parm
14148 /* Determine the parameter packs we will be deducing from the
14149 pattern, and record their current deductions. */
14152 {
14156 /* Determine the index and level of this parameter pack. */
14159 /* Keep track of the parameter packs and their corresponding
14160 argument packs. */
14163 }
14165 /* Loop through all of the arguments that have not yet been
14166 unified and unify each with the pattern. */
14168 {
14171 /* For each parameter pack, clear out the deduced value so that
14172 we can deduce it again. */
14174 {
14179 }
14181 /* Unify the pattern with the current argument. */
14182 {
14189 {
14192 /* This mirrors what we do in type_unification_real. */
14194 {
14196 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14197 | UNIFY_ALLOW_MORE_CV_QUAL
14211 }
14214 {
14217 {
14218 /* [temp.deduct.type] A template-argument can be
14219 deduced from a pointer to function or pointer
14220 to member function argument if the set of
14221 overloaded functions does not contain function
14222 templates and at most one of a set of
14223 overloaded functions provides a unique
14224 match. */
14229 sub_strict)
14233 }
14236 {
14241 }
14242 }
14247 arg_strict |=
14250 }
14253 {
14254 /* For deduction from an init-list we need the actual list. */
14259 }
14260 }
14262 /* For each parameter pack, collect the deduced value. */
14264 {
14270 }
14271 }
14273 /* Verify that the results of unification with the parameter packs
14274 produce results consistent with what we've seen before, and make
14275 the deduced argument packs available. */
14277 {
14284 /* By default keep the original deduced argument pack.
14285 If necessary, more specific code is going to update the
14286 resulting deduced argument later down in this function. */
14290 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14291 actually deduce anything. */
14299 {
14300 /* Prepend the explicit arguments onto NEW_ARGS. */
14306 /* Copy the explicit arguments. */
14311 /* Copy the deduced arguments. */
14315 }
14318 {
14319 tree result;
14320 /* Build the deduced *_ARGUMENT_PACK. */
14322 {
14327 }
14328 else
14333 /* Note the deduced argument packs for this parameter
14334 pack. */
14336 }
14340 {
14341 /* We only had the explicitly-provided arguments before, but
14342 now we have a complete set of arguments. */
14348 }
14350 new_args))
14351 /* Inconsistent unification of this parameter pack. */
14353 }
14356 }
14358 /* Deduce the value of template parameters. TPARMS is the (innermost)
14359 set of template parameters to a template. TARGS is the bindings
14360 for those template parameters, as determined thus far; TARGS may
14361 include template arguments for outer levels of template parameters
14362 as well. PARM is a parameter to a template function, or a
14363 subcomponent of that parameter; ARG is the corresponding argument.
14364 This function attempts to match PARM with ARG in a manner
14365 consistent with the existing assignments in TARGS. If more values
14366 are deduced, then TARGS is updated.
14368 Returns 0 if the type deduction succeeds, 1 otherwise. The
14369 parameter STRICT is a bitwise or of the following flags:
14371 UNIFY_ALLOW_NONE:
14372 Require an exact match between PARM and ARG.
14373 UNIFY_ALLOW_MORE_CV_QUAL:
14374 Allow the deduced ARG to be more cv-qualified (by qualification
14375 conversion) than ARG.
14376 UNIFY_ALLOW_LESS_CV_QUAL:
14377 Allow the deduced ARG to be less cv-qualified than ARG.
14378 UNIFY_ALLOW_DERIVED:
14379 Allow the deduced ARG to be a template base class of ARG,
14380 or a pointer to a template base class of the type pointed to by
14381 ARG.
14382 UNIFY_ALLOW_INTEGER:
14383 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14384 case for more information.
14385 UNIFY_ALLOW_OUTER_LEVEL:
14386 This is the outermost level of a deduction. Used to determine validity
14387 of qualification conversions. A valid qualification conversion must
14388 have const qualified pointers leading up to the inner type which
14389 requires additional CV quals, except at the outer level, where const
14390 is not required [conv.qual]. It would be normal to set this flag in
14391 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14392 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14393 This is the outermost level of a deduction, and PARM can be more CV
14394 qualified at this point.
14395 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14396 This is the outermost level of a deduction, and PARM can be less CV
14397 qualified at this point. */
14399 static int
14401 {
14403 tree targ;
14404 tree tparm;
14407 /* I don't think this will do the right thing with respect to types.
14408 But the only case I've seen it in so far has been array bounds, where
14409 signedness is the only information lost, and I think that will be
14410 okay. */
14418 /* We can't deduce anything from this, but we might get all the
14419 template args from other function args. */
14422 /* If PARM uses template parameters, then we can't bail out here,
14423 even if ARG == PARM, since we won't record unifications for the
14424 template parameters. We might need them if we're trying to
14425 figure out which of two things is more specialized. */
14429 /* Handle init lists early, so the rest of the function can assume
14430 we're dealing with a type. */
14432 {
14437 /* Replace T with std::initializer_list<T> for deduction. */
14443 /* We can only deduce from an initializer list argument if the
14444 parameter is std::initializer_list; otherwise this is a
14445 non-deduced context. */
14451 {
14454 {
14456 /* It should only be possible to get here for a call. */
14458 elt_strict |= maybe_adjust_types_for_deduction
14461 }
14465 }
14467 /* If the std::initializer_list<T> deduction worked, replace the
14468 deduced A with std::initializer_list<A>. */
14470 {
14475 }
14477 }
14479 /* Immediately reject some pairs that won't unify because of
14480 cv-qualification mismatches. */
14483 /* It is the elements of the array which hold the cv quals of an array
14484 type, and the elements might be template type parms. We'll check
14485 when we recurse. */
14487 /* We check the cv-qualifiers when unifying with template type
14488 parameters below. We want to allow ARG `const T' to unify with
14489 PARM `T' for example, when computing which of two templates
14490 is more specialized, for example. */
14504 {
14508 /* In a type which contains a nested-name-specifier, template
14509 argument values cannot be deduced for template parameters used
14510 within the nested-name-specifier. */
14522 /* The PARM is not one we're trying to unify. Just check
14523 to see if it matches ARG. */
14530 /* Check for mixed types and values. */
14538 {
14539 /* ARG must be constructed from a template class or a template
14540 template parameter. */
14545 {
14548 tree parm_parms
14549 = DECL_INNERMOST_TEMPLATE_PARMS
14554 /* The resolution to DR150 makes clear that default
14555 arguments for an N-argument may not be used to bind T
14556 to a template template parameter with fewer than N
14557 parameters. It is not safe to permit the binding of
14558 default arguments as an extension, as that may change
14559 the meaning of a conforming program. Consider:
14561 struct Dense { static const unsigned int dim = 1; };
14563 template <template <typename> class View,
14564 typename Block>
14565 void operator+(float, View<Block> const&);
14567 template <typename Block,
14568 unsigned int Dim = Block::dim>
14569 struct Lvalue_proxy { operator float() const; };
14571 void
14572 test_1d (void) {
14573 Lvalue_proxy<Dense> p;
14574 float b;
14575 b + p;
14576 }
14578 Here, if Lvalue_proxy is permitted to bind to View, then
14579 the global operator+ will be used; if they are not, the
14580 Lvalue_proxy will be converted to float. */
14582 argvec,
14584 tf_none,
14590 /* Deduce arguments T, i from TT<T> or TT<i>.
14591 We check each element of PARMVEC and ARGVEC individually
14592 rather than the whole TREE_VEC since they can have
14593 different number of elements. */
14600 /* Check if the parameters end in a pack, making them
14601 variadic. */
14610 {
14614 UNIFY_ALLOW_NONE))
14616 }
14621 UNIFY_ALLOW_NONE,
14625 }
14628 /* Fall through to deduce template name. */
14629 }
14633 {
14634 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14636 /* Simple cases: Value already set, does match or doesn't. */
14641 }
14642 else
14643 {
14644 /* If PARM is `const T' and ARG is only `int', we don't have
14645 a match unless we are allowing additional qualification.
14646 If ARG is `const int' and PARM is just `T' that's OK;
14647 that binds `const int' to `T'. */
14652 /* Consider the case where ARG is `const volatile int' and
14653 PARM is `const T'. Then, T should be `volatile int'. */
14654 arg = cp_build_qualified_type_real
14659 /* Simple cases: Value already set, does match or doesn't. */
14665 /* Make sure that ARG is not a variable-sized array. (Note
14666 that were talking about variable-sized arrays (like
14667 `int[n]'), rather than arrays of unknown size (like
14668 `int[]').) We'll get very confused by such a type since
14669 the bound of the array will not be computable in an
14670 instantiation. Besides, such types are not allowed in
14671 ISO C++, so we can do as we please here. */
14675 /* Strip typedefs as in convert_template_argument. */
14677 }
14679 /* If ARG is a parameter pack or an expansion, we cannot unify
14680 against it unless PARM is also a parameter pack. */
14685 /* If the argument deduction results is a METHOD_TYPE,
14686 then there is a problem.
14687 METHOD_TYPE doesn't map to any real C++ type the result of
14688 the deduction can not be of that type. */
14702 /* The PARM is not one we're trying to unify. Just check
14703 to see if it matches ARG. */
14713 /* [temp.deduct.type] If, in the declaration of a function template
14714 with a non-type template-parameter, the non-type
14715 template-parameter is used in an expression in the function
14716 parameter-list and, if the corresponding template-argument is
14717 deduced, the template-argument type shall match the type of the
14718 template-parameter exactly, except that a template-argument
14719 deduced from an array bound may be of any integral type.
14720 The non-type parameter might use already deduced type parameters. */
14723 /* Template-parameter dependent expression. Just accept it for now.
14724 It will later be processed in convert_template_argument. */
14725 ;
14731 /* Convert the ARG to the type of PARM; the deduced non-type
14732 template argument must exactly match the types of the
14733 corresponding parameter. */
14736 /* We haven't deduced the type of this parameter yet. Try again
14737 later. */
14739 else
14742 /* If ARG is a parameter pack or an expansion, we cannot unify
14743 against it unless PARM is also a parameter pack. */
14752 {
14753 /* A pointer-to-member constant can be unified only with
14754 another constant. */
14758 /* Just unify the class member. It would be useless (and possibly
14759 wrong, depending on the strict flags) to unify also
14760 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14761 arg refer to the same variable, even if through different
14762 classes. For instance:
14764 struct A { int x; };
14765 struct B : A { };
14767 Unification of &A::x and &B::x must succeed. */
14770 }
14773 {
14777 /* [temp.deduct.call]
14779 A can be another pointer or pointer to member type that can
14780 be converted to the deduced A via a qualification
14781 conversion (_conv.qual_).
14783 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14784 This will allow for additional cv-qualification of the
14785 pointed-to types if appropriate. */
14788 /* The derived-to-base conversion only persists through one
14789 level of pointers. */
14794 }
14809 {
14810 tree parm_max;
14811 tree arg_max;
14815 /* Our representation of array types uses "N - 1" as the
14816 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14817 not an integer constant. We cannot unify arbitrarily
14818 complex expressions, so we eliminate the MINUS_EXPRs
14819 here. */
14823 {
14826 }
14830 {
14831 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14832 trying to unify the type of a variable with the type
14833 of a template parameter. For example:
14835 template <unsigned int N>
14836 void f (char (&) [N]);
14837 int g();
14838 void h(int i) {
14839 char a[g(i)];
14840 f(a);
14841 }
14843 Here, the type of the ARG will be "int [g(i)]", and
14844 may be a SAVE_EXPR, etc. */
14848 }
14850 /* If only one of the bounds used a MINUS_EXPR, compensate
14851 by adding one to the other bound. */
14854 integer_type_node,
14855 parm_max,
14856 integer_one_node);
14859 integer_type_node,
14860 arg_max,
14861 integer_one_node);
14865 }
14879 /* We have already checked cv-qualification at the top of the
14880 function. */
14884 /* As far as unification is concerned, this wins. Later checks
14885 will invalidate it if necessary. */
14888 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14889 /* Type INTEGER_CST can come from ordinary constant template args. */
14899 {
14908 UNIFY_ALLOW_NONE))
14911 }
14919 {
14926 strict);
14927 }
14930 {
14934 {
14935 /* First, we try to unify the PARM and ARG directly. */
14940 {
14941 /* Fallback to the special case allowed in
14942 [temp.deduct.call]:
14944 If P is a class, and P has the form
14945 template-id, then A can be a derived class of
14946 the deduced A. Likewise, if P is a pointer to
14947 a class of the form template-id, A can be a
14948 pointer to a derived class pointed to by the
14949 deduced A. */
14954 }
14955 }
14959 /* Perhaps PARM is something like S<U> and ARG is S<int>.
14960 Then, we should unify `int' and `U'. */
14962 else
14963 /* There's no chance of unification succeeding. */
14968 }
14975 {
14978 tree a;
14984 /* CV qualifications for methods can never be deduced, they must
14985 match exactly. We need to check them explicitly here,
14986 because type_unification_real treats them as any other
14987 cv-qualified parameter. */
14989 && (!check_cv_quals_for_unify
15009 LOOKUP_NORMAL);
15010 }
15013 /* Unify a pointer to member with a pointer to member function, which
15014 deduces the type of the member as a function type. */
15016 {
15017 tree method_type;
15018 tree fntype;
15019 cp_cv_quals cv_quals;
15021 /* Check top-level cv qualifiers */
15029 /* Determine the type of the function we are unifying against. */
15031 fntype =
15035 /* Extract the cv-qualifiers of the member function from the
15036 implicit object parameter and place them on the function
15037 type to be restored later. */
15038 cv_quals =
15042 }
15050 strict);
15061 /* Matched cases are handled by the ARG == PARM test above. */
15065 /* A non-type template parameter that is a variable should be a
15066 an integral constant, in which case, it whould have been
15067 folded into its (constant) value. So we should not be getting
15068 a variable here. */
15073 {
15081 {
15083 {
15085 /* We can unify against something with a trailing
15086 parameter pack. */
15088 else
15089 /* Since there is something following the pack
15090 expansion, we cannot unify this template argument
15091 list. */
15093 }
15094 }
15097 /* If we don't have enough arguments to satisfy the parameters
15098 (not counting the pack expression at the end), or we have
15099 too many arguments for a parameter list that doesn't end in
15100 a pack expression, we can't unify. */
15105 /* Unify all of the parameters that precede the (optional)
15106 pack expression. */
15108 {
15112 }
15120 }
15126 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15127 nodes. */
15131 /* Unification fails if we hit an error node. */
15137 /* We must be looking at an expression. This can happen with
15138 something like:
15140 template <int I>
15141 void foo(S<I>, S<I + 2>);
15143 This is a "nondeduced context":
15145 [deduct.type]
15147 The nondeduced contexts are:
15149 --A type that is a template-id in which one or more of
15150 the template-arguments is an expression that references
15151 a template-parameter.
15153 In these cases, we assume deduction succeeded, but don't
15154 actually infer any unifications. */
15159 else
15161 }
15162 }
15163 \f
15164 /* Note that DECL can be defined in this translation unit, if
15165 required. */
15167 static void
15169 {
15170 tree clone;
15174 }
15176 /* Called if RESULT is explicitly instantiated, or is a member of an
15177 explicitly instantiated class. */
15179 void
15181 {
15184 /* If this entity has already been written out, it's too late to
15185 make any modifications. */
15190 /* The TREE_PUBLIC flag for function declarations will have been
15191 set correctly by tsubst. */
15194 /* This might have been set by an earlier implicit instantiation. */
15199 else
15200 {
15202 /* Always make artificials weak. */
15205 /* For WIN32 we also want to put explicit instantiations in
15206 linkonce sections. */
15209 }
15211 /* If EXTERN_P, then this function will not be emitted -- unless
15212 followed by an explicit instantiation, at which point its linkage
15213 will be adjusted. If !EXTERN_P, then this function will be
15214 emitted here. In neither circumstance do we want
15215 import_export_decl to adjust the linkage. */
15217 }
15219 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15220 important template arguments. If any are missing, we check whether
15221 they're important by using error_mark_node for substituting into any
15222 args that were used for partial ordering (the ones between ARGS and END)
15223 and seeing if it bubbles up. */
15225 static bool
15227 {
15232 {
15235 }
15237 {
15239 {
15243 }
15244 }
15246 }
15248 /* Given two function templates PAT1 and PAT2, return:
15250 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15251 -1 if PAT2 is more specialized than PAT1.
15252 0 if neither is more specialized.
15254 LEN indicates the number of parameters we should consider
15255 (defaulted parameters should not be considered).
15257 The 1998 std underspecified function template partial ordering, and
15258 DR214 addresses the issue. We take pairs of arguments, one from
15259 each of the templates, and deduce them against each other. One of
15260 the templates will be more specialized if all the *other*
15261 template's arguments deduce against its arguments and at least one
15262 of its arguments *does* *not* deduce against the other template's
15263 corresponding argument. Deduction is done as for class templates.
15264 The arguments used in deduction have reference and top level cv
15265 qualifiers removed. Iff both arguments were originally reference
15266 types *and* deduction succeeds in both directions, the template
15267 with the more cv-qualified argument wins for that pairing (if
15268 neither is more cv-qualified, they both are equal). Unlike regular
15269 deduction, after all the arguments have been deduced in this way,
15270 we do *not* verify the deduced template argument values can be
15271 substituted into non-deduced contexts.
15273 The logic can be a bit confusing here, because we look at deduce1 and
15274 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15275 can find template arguments for pat1 to make arg1 look like arg2, that
15276 means that arg2 is at least as specialized as arg1. */
15278 int
15280 {
15293 /* Remove the this parameter from non-static member functions. If
15294 one is a non-static member function and the other is not a static
15295 member function, remove the first parameter from that function
15296 also. This situation occurs for operator functions where we
15297 locate both a member function (with this pointer) and non-member
15298 operator (with explicit first operand). */
15300 {
15305 }
15307 {
15310 {
15311 len--;
15313 }
15314 }
15316 /* If only one is a conversion operator, they are unordered. */
15320 /* Consider the return type for a conversion function */
15322 {
15325 len++;
15326 }
15328 processing_template_decl++;
15334 /* Stop when an ellipsis is seen. */
15336 {
15345 {
15346 /* When both arguments are pack expansions, we need only
15347 unify the patterns themselves. */
15351 /* This is the last comparison we need to do. */
15353 }
15356 {
15359 }
15362 {
15365 }
15368 {
15369 /* Only of the args is a reference, see if we should apply
15370 array/function pointer decay to it. This is not part of
15371 DR214, but is, IMHO, consistent with the deduction rules
15372 for the function call itself, and with our earlier
15373 implementation of the underspecified partial ordering
15374 rules. (nathan). */
15376 {
15378 {
15381 /* FALLTHROUGH. */
15388 }
15389 }
15390 else
15391 {
15393 {
15396 /* FALLTHROUGH. */
15403 }
15404 }
15405 }
15411 {
15417 /* Setup the parameter vector, which contains only ARG1. */
15420 /* Setup the argument vector, which contains the remaining
15421 arguments. */
15430 /* We cannot deduce in the other direction, because ARG1 is
15431 a pack expansion but ARG2 is not. */
15433 }
15435 {
15441 /* Setup the parameter vector, which contains only ARG1. */
15444 /* Setup the argument vector, which contains the remaining
15445 arguments. */
15454 /* We cannot deduce in the other direction, because ARG2 is
15455 a pack expansion but ARG1 is not.*/
15457 }
15459 else
15460 {
15461 /* The normal case, where neither argument is a pack
15462 expansion. */
15465 }
15467 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15468 arg2, then arg2 is not as specialized as arg1. */
15474 /* "If, for a given type, deduction succeeds in both directions
15475 (i.e., the types are identical after the transformations above)
15476 and if the type from the argument template is more cv-qualified
15477 than the type from the parameter template (as described above)
15478 that type is considered to be more specialized than the other. If
15479 neither type is more cv-qualified than the other then neither type
15480 is more specialized than the other." */
15484 {
15489 }
15492 /* We've failed to deduce something in either direction.
15493 These must be unordered. */
15498 /* We have already processed all of the arguments in our
15499 handing of the pack expansion type. */
15504 }
15506 /* "In most cases, all template parameters must have values in order for
15507 deduction to succeed, but for partial ordering purposes a template
15508 parameter may remain without a value provided it is not used in the
15509 types being used for partial ordering."
15511 Thus, if we are missing any of the targs1 we need to substitute into
15512 origs1, then pat2 is not as specialized as pat1. This can happen when
15513 there is a nondeduced context. */
15519 processing_template_decl--;
15521 /* All things being equal, if the next argument is a pack expansion
15522 for one function but not for the other, prefer the
15523 non-variadic function. FIXME this is bogus; see c++/41958. */
15527 {
15530 }
15536 else
15538 }
15540 /* Determine which of two partial specializations is more specialized.
15542 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15543 to the first partial specialization. The TREE_VALUE is the
15544 innermost set of template parameters for the partial
15545 specialization. PAT2 is similar, but for the second template.
15547 Return 1 if the first partial specialization is more specialized;
15548 -1 if the second is more specialized; 0 if neither is more
15549 specialized.
15551 See [temp.class.order] for information about determining which of
15552 two templates is more specialized. */
15554 static int
15556 {
15557 tree targs;
15565 /* Just like what happens for functions, if we are ordering between
15566 different class template specializations, we may encounter dependent
15567 types in the arguments, and we need our dependency check functions
15568 to behave correctly. */
15574 {
15577 }
15583 {
15586 }
15589 /* In the case of a tie where at least one of the class templates
15590 has a parameter pack at the end, the template with the most
15591 non-packed parameters wins. */
15593 && any_deductions
15596 {
15602 /* We don't count the pack expansion at the end. */
15612 }
15615 }
15617 /* Return the template arguments that will produce the function signature
15618 DECL from the function template FN, with the explicit template
15619 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15620 also match. Return NULL_TREE if no satisfactory arguments could be
15621 found. */
15623 static tree
15625 {
15628 tree decl_type;
15629 tree decl_arg_types;
15632 tree arg;
15634 /* Substitute the explicit template arguments into the type of DECL.
15635 The call to fn_type_unification will handle substitution into the
15636 FN. */
15639 {
15640 tree tmpl;
15641 tree converted_args;
15645 else
15646 /* We can get here for some invalid specializations. */
15649 converted_args
15652 tf_none,
15661 }
15663 /* Never do unification on the 'this' parameter. */
15682 }
15684 /* Return the innermost template arguments that, when applied to a
15685 template specialization whose innermost template parameters are
15686 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15687 ARGS.
15689 For example, suppose we have:
15691 template <class T, class U> struct S {};
15692 template <class T> struct S<T*, int> {};
15694 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15695 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15696 int}. The resulting vector will be {double}, indicating that `T'
15697 is bound to `double'. */
15699 static tree
15701 {
15703 tree deduced_args;
15704 tree innermost_deduced_args;
15708 {
15712 innermost_deduced_args);
15713 }
15714 else
15720 UNIFY_ALLOW_NONE))
15727 /* Verify that nondeduced template arguments agree with the type
15728 obtained from argument deduction.
15730 For example:
15732 struct A { typedef int X; };
15733 template <class T, class U> struct C {};
15734 template <class T> struct C<T, typename T::X> {};
15736 Then with the instantiation `C<A, int>', we can deduce that
15737 `T' is `A' but unify () does not check whether `typename T::X'
15738 is `int'. */
15741 /* We only need to check the innermost arguments; the other
15742 arguments will always agree. */
15747 /* Now that we have bindings for all of the template arguments,
15748 ensure that the arguments deduced for the template template
15749 parameters have compatible template parameter lists. See the use
15750 of template_template_parm_bindings_ok_p in fn_type_unification
15751 for more information. */
15756 }
15758 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15759 Return the TREE_LIST node with the most specialized template, if
15760 any. If there is no most specialized template, the error_mark_node
15761 is returned.
15763 Note that this function does not look at, or modify, the
15764 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15765 returned is one of the elements of INSTANTIATIONS, callers may
15766 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15767 and retrieve it from the value returned. */
15769 tree
15771 {
15778 {
15784 fate--;
15789 fate++;
15794 {
15795 /* Equally specialized, move to next function. If there
15796 is no next function, nothing's most specialized. */
15801 }
15802 }
15805 /* Now verify that champ is better than everything earlier in the
15806 instantiation list. */
15814 {
15817 }
15819 processing_template_decl--;
15825 }
15827 /* If DECL is a specialization of some template, return the most
15828 general such template. Otherwise, returns NULL_TREE.
15830 For example, given:
15832 template <class T> struct S { template <class U> void f(U); };
15834 if TMPL is `template <class U> void S<int>::f(U)' this will return
15835 the full template. This function will not trace past partial
15836 specializations, however. For example, given in addition:
15838 template <class T> struct S<T*> { template <class U> void f(U); };
15840 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15841 `template <class T> template <class U> S<T*>::f(U)'. */
15843 tree
15845 {
15846 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15847 an immediate specialization. */
15849 {
15853 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15854 template friend. */
15859 }
15861 /* Look for more and more general templates. */
15863 {
15864 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15865 (See cp-tree.h for details.) */
15873 /* Stop if we run into an explicitly specialized class template. */
15880 }
15883 }
15885 /* Return the most specialized of the class template partial
15886 specializations of TMPL which can produce TYPE, a specialization of
15887 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15888 a _TYPE node corresponding to the partial specialization, while the
15889 TREE_PURPOSE is the set of template arguments that must be
15890 substituted into the TREE_TYPE in order to generate TYPE.
15892 If the choice of partial specialization is ambiguous, a diagnostic
15893 is issued, and the error_mark_node is returned. If there are no
15894 partial specializations of TMPL matching TYPE, then NULL_TREE is
15895 returned. */
15897 static tree
15899 {
15901 tree t;
15902 tree champ;
15905 tree args;
15911 /* For determining which partial specialization to use, only the
15912 innermost args are interesting. */
15914 {
15917 }
15920 {
15921 tree partial_spec_args;
15922 tree spec_args;
15927 {
15932 /* Discard the outer levels of args, and then substitute in the
15933 template args from the enclosing class. */
15935 partial_spec_args = tsubst_template_args
15938 /* PARMS already refers to just the innermost parms, but the
15939 template parms in partial_spec_args had their levels lowered
15940 by tsubst, so we need to do the same for the parm list. We
15941 can't just tsubst the TREE_VEC itself, as tsubst wants to
15942 treat a TREE_VEC as an argument vector. */
15949 }
15951 partial_spec_args =
15954 partial_spec_args),
15963 partial_spec_args,
15964 args);
15966 {
15971 }
15972 }
15982 {
15985 ;
15986 else
15987 {
15989 {
15992 {
15995 }
15996 }
15998 }
15999 }
16003 {
16006 {
16009 }
16010 }
16013 {
16019 {
16022 }
16025 }
16028 }
16030 /* Explicitly instantiate DECL. */
16032 void
16034 {
16039 /* An error occurred, for which grokdeclarator has already issued
16040 an appropriate message. */
16043 {
16046 }
16048 {
16049 /* There is an asymmetry here in the way VAR_DECLs and
16050 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16051 the latter, the DECL we get back will be marked as a
16052 template instantiation, and the appropriate
16053 DECL_TEMPLATE_INFO will be set up. This does not happen for
16054 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16055 should handle VAR_DECLs as it currently handles
16056 FUNCTION_DECLs. */
16058 {
16061 }
16064 {
16067 }
16069 {
16074 }
16075 }
16077 {
16080 }
16081 else
16084 /* Check for various error cases. Note that if the explicit
16085 instantiation is valid the RESULT will currently be marked as an
16086 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16087 until we get here. */
16090 {
16091 /* DR 259 [temp.spec].
16093 Both an explicit instantiation and a declaration of an explicit
16094 specialization shall not appear in a program unless the explicit
16095 instantiation follows a declaration of the explicit specialization.
16097 For a given set of template parameters, if an explicit
16098 instantiation of a template appears after a declaration of an
16099 explicit specialization for that template, the explicit
16100 instantiation has no effect. */
16102 }
16104 {
16105 /* [temp.spec]
16107 No program shall explicitly instantiate any template more
16108 than once.
16110 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16111 the first instantiation was `extern' and the second is not,
16112 and EXTERN_P for the opposite case. */
16115 /* If an "extern" explicit instantiation follows an ordinary
16116 explicit instantiation, the template is instantiated. */
16119 }
16121 {
16124 }
16126 {
16129 }
16132 ;
16134 {
16137 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16140 }
16141 else
16149 }
16151 static void
16153 {
16159 {
16162 }
16163 }
16165 /* Called from do_type_instantiation through binding_table_foreach to
16166 do recursive instantiation for the type bound in ENTRY. */
16167 static void
16169 {
16175 }
16177 /* Called from do_type_instantiation to instantiate a member
16178 (a member function or a static member variable) of an
16179 explicitly instantiated class template. */
16180 static void
16182 {
16187 }
16189 /* Perform an explicit instantiation of template class T. STORAGE, if
16190 non-null, is the RID for extern, inline or static. COMPLAIN is
16191 nonzero if this is called from the parser, zero if called recursively,
16192 since the standard is unclear (as detailed below). */
16194 void
16196 {
16206 {
16209 }
16214 {
16217 t);
16219 }
16222 {
16224 {
16226 {
16229 "ISO C++ 1998 forbids the use of %<extern%> on "
16231 }
16232 else
16234 "ISO C++ forbids the use of %qE"
16236 }
16244 else
16245 {
16247 storage);
16249 }
16250 }
16253 {
16254 /* DR 259 [temp.spec].
16256 Both an explicit instantiation and a declaration of an explicit
16257 specialization shall not appear in a program unless the explicit
16258 instantiation follows a declaration of the explicit specialization.
16260 For a given set of template parameters, if an explicit
16261 instantiation of a template appears after a declaration of an
16262 explicit specialization for that template, the explicit
16263 instantiation has no effect. */
16265 }
16267 {
16268 /* [temp.spec]
16270 No program shall explicitly instantiate any template more
16271 than once.
16273 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16274 instantiation was `extern'. If EXTERN_P then the second is.
16275 These cases are OK. */
16282 /* If we've already instantiated the template, just return now. */
16285 }
16293 {
16294 tree tmp;
16296 /* In contrast to implicit instantiation, where only the
16297 declarations, and not the definitions, of members are
16298 instantiated, we have here:
16300 [temp.explicit]
16302 The explicit instantiation of a class template specialization
16303 implies the instantiation of all of its members not
16304 previously explicitly specialized in the translation unit
16305 containing the explicit instantiation.
16307 Of course, we can't instantiate member template classes, since
16308 we don't have any arguments for them. Note that the standard
16309 is unclear on whether the instantiation of the members are
16310 *explicit* instantiations or not. However, the most natural
16311 interpretation is that it should be an explicit instantiation. */
16326 }
16327 }
16329 /* Given a function DECL, which is a specialization of TMPL, modify
16330 DECL to be a re-instantiation of TMPL with the same template
16331 arguments. TMPL should be the template into which tsubst'ing
16332 should occur for DECL, not the most general template.
16334 One reason for doing this is a scenario like this:
16336 template <class T>
16337 void f(const T&, int i);
16339 void g() { f(3, 7); }
16341 template <class T>
16342 void f(const T& t, const int i) { }
16344 Note that when the template is first instantiated, with
16345 instantiate_template, the resulting DECL will have no name for the
16346 first parameter, and the wrong type for the second. So, when we go
16347 to instantiate the DECL, we regenerate it. */
16349 static void
16351 {
16352 /* The arguments used to instantiate DECL, from the most general
16353 template. */
16354 tree args;
16355 tree code_pattern;
16360 /* Make sure that we can see identifiers, and compute access
16361 correctly. */
16365 {
16366 tree decl_parm;
16367 tree pattern_parm;
16368 tree specs;
16381 specs);
16383 /* Merge parameter declarations. */
16386 pattern_parm
16390 {
16391 tree parm_type;
16392 tree attributes;
16397 NULL_TREE);
16403 {
16406 }
16409 }
16410 /* Merge any parameters that match with the function parameter
16411 pack. */
16413 {
16415 tree expanded_types;
16416 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16417 the parameters in this function parameter pack. */
16422 {
16423 tree parm_type;
16424 tree attributes;
16427 /* Rename the parameter to include the index. */
16436 {
16439 }
16441 }
16442 }
16443 /* Merge additional specifiers from the CODE_PATTERN. */
16447 }
16453 else
16457 }
16459 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16460 substituted to get DECL. */
16462 tree
16464 {
16467 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16468 for the instantiation. This is not always the most general
16469 template. Consider, for example:
16471 template <class T>
16472 struct S { template <class U> void f();
16473 template <> void f<int>(); };
16475 and an instantiation of S<double>::f<int>. We want TD to be the
16476 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16478 more general template. */
16480 /* We must also deal with friend templates. Given:
16482 template <class T> struct S {
16483 template <class U> friend void f() {};
16484 };
16486 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16487 so far as the language is concerned, but that's still
16488 where we get the pattern for the instantiation from. On
16489 other hand, if the definition comes outside the class, say:
16491 template <class T> struct S {
16492 template <class U> friend void f();
16493 };
16494 template <class U> friend void f() {}
16496 we don't need to look any further. That's what the check for
16497 DECL_INITIAL is for. */
16501 {
16502 /* The present template, TD, should not be a definition. If it
16503 were a definition, we should be using it! Note that we
16504 cannot restructure the loop to just keep going until we find
16505 a template with a definition, since that might go too far if
16506 a specialization was declared, but not defined. */
16510 /* Fetch the more general template. */
16512 }
16515 }
16517 /* Returns true if we need to instantiate this template instance even if we
16518 know we aren't going to emit it.. */
16520 bool
16522 {
16523 /* We always instantiate inline functions so that we can inline them. An
16524 explicit instantiation declaration prohibits implicit instantiation of
16525 non-inline functions. With high levels of optimization, we would
16526 normally inline non-inline functions -- but we're not allowed to do
16527 that for "extern template" functions. Therefore, we check
16528 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16531 /* And we need to instantiate static data members so that
16532 their initializers are available in integral constant
16533 expressions. */
16536 }
16538 /* Produce the definition of D, a _DECL generated from a template. If
16539 DEFER_OK is nonzero, then we don't have to actually do the
16540 instantiation now; we just have to do it sometime. Normally it is
16541 an error if this is an explicit instantiation but D is undefined.
16542 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16543 explicitly instantiated class template. */
16545 tree
16548 {
16550 tree gen_args;
16551 tree args;
16552 tree td;
16553 tree code_pattern;
16554 tree spec;
16555 tree gen_tmpl;
16561 /* This function should only be used to instantiate templates for
16562 functions and static member variables. */
16566 /* Variables are never deferred; if instantiation is required, they
16567 are instantiated right away. That allows for better code in the
16568 case that an expression refers to the value of the variable --
16569 if the variable has a constant value the referring expression can
16570 take advantage of that fact. */
16574 /* Don't instantiate cloned functions. Instead, instantiate the
16575 functions they cloned. */
16581 /* D has already been instantiated or explicitly specialized, so
16582 there's nothing for us to do here.
16584 It might seem reasonable to check whether or not D is an explicit
16585 instantiation, and, if so, stop here. But when an explicit
16586 instantiation is deferred until the end of the compilation,
16587 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16588 the instantiation. */
16591 /* Check to see whether we know that this template will be
16592 instantiated in some other file, as with "extern template"
16593 extension. */
16596 /* In general, we do not instantiate such templates. */
16604 /* We should already have the extra args. */
16607 /* And what's in the hash table should match D. */
16611 /* This needs to happen before any tsubsting. */
16617 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16618 for the instantiation. */
16622 /* We should never be trying to instantiate a member of a class
16623 template or partial specialization. */
16628 /* In the case of a friend template whose definition is provided
16629 outside the class, we may have too many arguments. Drop the
16630 ones we don't need. The same is true for specializations. */
16631 args = get_innermost_template_args
16633 else
16638 else
16641 /* We may be in the middle of deferred access check. Disable it now. */
16644 /* Unless an explicit instantiation directive has already determined
16645 the linkage of D, remember that a definition is available for
16646 this entity. */
16654 /* If D is a member of an explicitly instantiated class template,
16655 and no definition is available, treat it like an implicit
16656 instantiation. */
16659 {
16663 }
16665 /* Recheck the substitutions to obtain any warning messages
16666 about ignoring cv qualifiers. Don't do this for artificial decls,
16667 as it breaks the context-sensitive substitution for lambda op(). */
16669 {
16673 /* Make sure that we can see identifiers, and compute access
16674 correctly. D is already the target FUNCTION_DECL with the
16675 right context. */
16679 {
16682 d);
16683 /* Don't simply tsubst the function type, as that will give
16684 duplicate warnings about poor parameter qualifications.
16685 The function arguments are the same as the decl_arguments
16686 without the top level cv qualifiers. */
16688 }
16692 }
16694 /* Defer all other templates, unless we have been explicitly
16695 forbidden from doing so. */
16697 template. */
16698 ! pattern_defined
16699 /* If it's OK to postpone instantiation, do so. */
16700 || defer_ok
16701 /* If this is a static data member that will be defined
16702 elsewhere, we don't want to instantiate the entire data
16703 member, but we do want to instantiate the initializer so that
16704 we can substitute that elsewhere. */
16706 {
16707 /* The definition of the static data member is now required so
16708 we must substitute the initializer. */
16712 {
16713 tree ns;
16714 tree init;
16720 args,
16725 LOOKUP_ONLYCONVERTING);
16728 }
16730 /* We restore the source position here because it's used by
16731 add_pending_template. */
16737 /* [temp.explicit]
16739 The definition of a non-exported function template, a
16740 non-exported member function template, or a non-exported
16741 member function or static data member of a class template
16742 shall be present in every translation unit in which it is
16743 explicitly instantiated. */
16747 /* ??? Historically, we have instantiated inline functions, even
16748 when marked as "extern template". */
16752 }
16753 /* Tell the repository that D is available in this translation unit
16754 -- and see if it is supposed to be instantiated here. */
16756 {
16757 /* In a PCH file, despite the fact that the repository hasn't
16758 requested instantiation in the PCH it is still possible that
16759 an instantiation will be required in a file that includes the
16760 PCH. */
16763 /* Instantiate inline functions so that the inliner can do its
16764 job, even though we'll not be emitting a copy of this
16765 function. */
16768 }
16774 /* Mark D as instantiated so that recursive calls to
16775 instantiate_decl do not try to instantiate it again. */
16778 /* Regenerate the declaration in case the template has been modified
16779 by a subsequent redeclaration. */
16782 /* We already set the file and line above. Reset them now in case
16783 they changed as a result of calling regenerate_decl_from_template. */
16787 {
16788 tree init;
16790 /* Clear out DECL_RTL; whatever was there before may not be right
16791 since we've reset the type of the declaration. */
16795 /* The initializer is placed in DECL_INITIAL by
16796 regenerate_decl_from_template. Pull it out so that
16797 cp_finish_decl can process it. */
16802 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16803 initializer. That function will defer actual emission until
16804 we have a chance to determine linkage. */
16807 /* Enter the scope of D so that access-checking works correctly. */
16811 }
16813 {
16814 htab_t saved_local_specializations;
16815 tree subst_decl;
16816 tree tmpl_parm;
16817 tree spec_parm;
16819 /* Save away the current list, in case we are instantiating one
16820 template from within the body of another. */
16823 /* Set up the list of local specializations. */
16825 hash_local_specialization,
16826 eq_local_specializations,
16827 NULL);
16829 /* Set up context. */
16832 /* Create substitution entries for the parameters. */
16837 {
16841 }
16843 {
16847 }
16849 {
16850 /* Register the (value) argument pack as a specialization of
16851 TMPL_PARM, then move on. */
16856 }
16859 /* Substitute into the body of the function. */
16864 /* Set the current input_location to the end of the function
16865 so that finish_function knows where we are. */
16868 /* We don't need the local specializations any more. */
16872 /* Finish the function. */
16875 }
16877 /* We're not deferring instantiation any more. */
16883 out:
16891 }
16893 /* Run through the list of templates that we wish we could
16894 instantiate, and instantiate any we can. RETRIES is the
16895 number of times we retry pending template instantiation. */
16897 void
16899 {
16903 /* Instantiating templates may trigger vtable generation. This in turn
16904 may require further template instantiations. We place a limit here
16905 to avoid infinite loop. */
16907 {
16911 " instantiating %q+D, possibly from virtual table generation"
16915 /* Pretend that we defined it. */
16918 }
16920 do
16921 {
16926 {
16931 {
16932 tree fn;
16935 {
16939 fn;
16947 }
16950 }
16951 else
16952 {
16955 {
16956 instantiation
16962 }
16966 }
16969 /* If INSTANTIATION has been instantiated, then we don't
16970 need to consider it again in the future. */
16972 else
16973 {
16976 }
16979 }
16981 }
16985 }
16987 /* Substitute ARGVEC into T, which is a list of initializers for
16988 either base class or a non-static data member. The TREE_PURPOSEs
16989 are DECLs, and the TREE_VALUEs are the initializer values. Used by
16990 instantiate_decl. */
16992 static tree
16994 {
16998 {
16999 tree decl;
17000 tree init;
17006 {
17007 tree expr;
17008 tree arg;
17010 /* Expand the base class expansion type into separate base
17011 classes. */
17013 tf_warning_or_error,
17014 NULL_TREE);
17018 /* We'll be building separate TREE_LISTs of arguments for
17019 each base. */
17025 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17026 expand each argument in the TREE_VALUE of t. */
17032 /* VOID_TYPE_NODE is used to indicate
17033 value-initialization. */
17034 {
17037 }
17038 else
17039 {
17040 /* Substitute parameter packs into each argument in the
17041 TREE_LIST. */
17044 {
17045 tree expanded_exprs;
17047 /* Expand the argument. */
17049 expanded_exprs
17051 tf_warning_or_error,
17052 NULL_TREE);
17056 /* Prepend each of the expanded expressions to the
17057 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17059 {
17064 }
17065 }
17068 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17069 since we built them backwards. */
17071 {
17074 }
17075 }
17076 }
17079 {
17081 {
17085 }
17086 else
17087 {
17099 }
17102 {
17106 }
17107 }
17108 }
17110 }
17112 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17114 static void
17116 {
17121 else
17123 }
17125 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17126 is the instantiation (which should have been created with
17127 start_enum) and ARGS are the template arguments to use. */
17129 static void
17131 {
17132 tree e;
17135 {
17136 tree value;
17137 tree decl;
17140 /* Note that in a template enum, the TREE_VALUE is the
17141 CONST_DECL, not the corresponding INTEGER_CST. */
17146 /* Give this enumeration constant the correct access. */
17149 /* Actually build the enumerator itself. */
17151 }
17156 }
17158 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17159 its type -- but without substituting the innermost set of template
17160 arguments. So, innermost set of template parameters will appear in
17161 the type. */
17163 tree
17165 {
17166 tree fn_type;
17167 tree tmpl;
17168 tree targs;
17169 tree tparms;
17177 /* There should be as many levels of arguments as there are levels
17178 of parameters. */
17184 /* No substitution is necessary. */
17185 ;
17186 else
17187 {
17189 tree partial_args;
17191 /* Replace the innermost level of the TARGS with NULL_TREEs to
17192 let tsubst know not to substitute for those parameters. */
17201 /* Disable access control as this function is used only during
17202 name-mangling. */
17207 /* Now, do the (partial) substitution to figure out the
17208 appropriate function type. */
17212 /* Substitute into the template parameters to obtain the real
17213 innermost set of parameters. This step is important if the
17214 innermost set of template parameters contains value
17215 parameters whose types depend on outer template parameters. */
17220 }
17223 }
17225 /* Return truthvalue if we're processing a template different from
17226 the last one involved in diagnostics. */
17227 int
17229 {
17231 }
17233 /* Remember current template involved in diagnostics. */
17234 void
17236 {
17238 }
17242 {
17244 }
17246 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17247 type. Return zero for ok, nonzero for disallowed. Issue error and
17248 warning messages under control of COMPLAIN. */
17250 static int
17252 {
17267 }
17269 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17270 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17272 static bool
17274 {
17275 tree scope;
17277 /* [temp.dep.type]
17279 A type is dependent if it is:
17281 -- a template parameter. Template template parameters are types
17282 for us (since TYPE_P holds true for them) so we handle
17283 them here. */
17287 /* -- a qualified-id with a nested-name-specifier which contains a
17288 class-name that names a dependent type or whose unqualified-id
17289 names a dependent type. */
17292 /* -- a cv-qualified type where the cv-unqualified type is
17293 dependent. */
17295 /* -- a compound type constructed from any dependent type. */
17305 {
17306 tree arg_type;
17311 arg_type;
17316 }
17317 /* -- an array type constructed from any dependent type or whose
17318 size is specified by a constant expression that is
17319 value-dependent. */
17321 {
17326 }
17329 {
17330 /* If this is the TYPE_DOMAIN of an array type, consider it
17331 dependent. We already checked for value-dependence in
17332 compute_array_index_type. */
17334 }
17336 /* -- a template-id in which either the template name is a template
17337 parameter ... */
17340 /* ... or any of the template arguments is a dependent type or
17341 an expression that is type-dependent or value-dependent. */
17343 && (any_dependent_template_arguments_p
17347 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17348 argument of the `typeof' expression is not type-dependent, then
17349 it should already been have resolved. */
17354 /* A template argument pack is dependent if any of its packed
17355 arguments are. */
17357 {
17363 }
17365 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17366 be template parameters. */
17370 /* The standard does not specifically mention types that are local
17371 to template functions or local classes, but they should be
17372 considered dependent too. For example:
17374 template <int I> void f() {
17375 enum E { a = I };
17376 S<sizeof (E)> s;
17377 }
17379 The size of `E' cannot be known until the value of `I' has been
17380 determined. Therefore, `E' must be considered dependent. */
17387 /* Other types are non-dependent. */
17389 }
17391 /* Returns TRUE if TYPE is dependent, in the sense of
17392 [temp.dep.type]. */
17394 bool
17396 {
17397 /* If there are no template parameters in scope, then there can't be
17398 any dependent types. */
17400 {
17401 /* If we are not processing a template, then nobody should be
17402 providing us with a dependent type. */
17406 }
17408 /* If the type is NULL, we have not computed a type for the entity
17409 in question; in that case, the type is dependent. */
17413 /* Erroneous types can be considered non-dependent. */
17417 /* If we have not already computed the appropriate value for TYPE,
17418 do so now. */
17420 {
17423 }
17426 }
17428 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17429 lookup. In other words, a dependent type that is not the current
17430 instantiation. */
17432 bool
17434 {
17437 }
17439 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
17441 static bool
17443 {
17444 tree scope;
17445 tree name;
17455 /* [temp.dep.expr]
17457 An id-expression is type-dependent if it contains a
17458 nested-name-specifier that contains a class-name that names a
17459 dependent type. */
17460 /* The suggested resolution to Core Issue 224 implies that if the
17461 qualifying type is the current class, then we must peek
17462 inside it. */
17471 }
17473 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17474 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17475 expression. */
17477 bool
17479 {
17483 /* A name declared with a dependent type. */
17488 {
17490 /* A name that has not been looked up -- must be dependent. */
17494 /* A non-type template parm. */
17498 /* A non-type template parm. */
17504 /* A constant with integral or enumeration type and is initialized
17505 with an expression that is value-dependent. */
17517 /* These expressions are value-dependent if the type to which
17518 the cast occurs is dependent or the expression being casted
17519 is value-dependent. */
17520 {
17526 /* A functional cast has a list of operands. */
17529 {
17530 /* If there are no operands, it must be an expression such
17531 as "int()". This should not happen for aggregate types
17532 because it would form non-constant expressions. */
17536 }
17542 }
17546 /* A `sizeof' expression is value-dependent if the operand is
17547 type-dependent or is a pack expansion. */
17563 /* A CALL_EXPR may appear in a constant expression if it is a
17564 call to a builtin function, e.g., __builtin_constant_p. All
17565 such calls are value-dependent. */
17569 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17570 is value-dependent. */
17571 {
17580 }
17583 {
17587 }
17594 /* A constant expression is value-dependent if any subexpression is
17595 value-dependent. */
17597 {
17607 || (value_dependent_expression_p
17612 {
17615 /* In some cases, some of the operands may be missing.
17616 (For example, in the case of PREDECREMENT_EXPR, the
17617 amount to increment by may be missing.) That doesn't
17618 make the expression dependent. */
17620 && (value_dependent_expression_p
17624 }
17628 }
17629 }
17631 /* The expression is not value-dependent. */
17633 }
17635 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17636 [temp.dep.expr]. */
17638 bool
17640 {
17647 /* An unresolved name is always dependent. */
17652 /* Some expression forms are never type-dependent. */
17663 /* The types of these expressions depends only on the type to which
17664 the cast occurs. */
17672 /* The types of these expressions depends only on the type created
17673 by the expression. */
17676 {
17677 /* For NEW_EXPR tree nodes created inside a template, either
17678 the object type itself or a TREE_LIST may appear as the
17679 operand 1. */
17682 /* This is an array type. We need to check array dimensions
17683 as well. */
17685 || value_dependent_expression_p
17687 else
17689 }
17693 type_dependent_expression_p))
17699 && (any_dependent_template_arguments_p
17711 {
17712 tree elt;
17716 {
17719 }
17721 }
17724 {
17729 {
17735 }
17736 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17744 {
17749 }
17754 {
17758 }
17760 }
17765 }
17767 /* Like type_dependent_expression_p, but it also works while not processing
17768 a template definition, i.e. during substitution or mangling. */
17770 bool
17772 {
17778 }
17780 /* Returns TRUE if ARGS contains a type-dependent expression. */
17782 bool
17784 {
17786 tree arg;
17789 {
17792 }
17794 }
17796 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17797 expressions) contains any value-dependent expressions. */
17799 bool
17801 {
17807 }
17809 /* Returns TRUE if the ARG (a template argument) is dependent. */
17811 bool
17813 {
17821 {
17825 {
17828 }
17831 }
17834 else
17837 }
17839 /* Returns true if ARGS (a collection of template arguments) contains
17840 any types that require structural equality testing. */
17842 bool
17844 {
17854 {
17857 {
17863 {
17864 /* Look inside the argument pack. */
17867 }
17870 {
17884 }
17885 }
17886 }
17889 }
17891 /* Returns true if ARGS (a collection of template arguments) contains
17892 any dependent arguments. */
17894 bool
17896 {
17906 {
17911 }
17914 }
17916 /* Returns TRUE if the template TMPL is dependent. */
17918 bool
17920 {
17922 {
17924 {
17928 }
17930 }
17932 /* Template template parameters are dependent. */
17936 /* So are names that have not been looked up. */
17940 /* So are member templates of dependent classes. */
17944 }
17946 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
17948 bool
17950 {
17953 }
17955 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
17956 is dependent. */
17958 bool
17960 {
17967 {
17988 {
17992 }
17996 {
18000 {
18005 }
18006 }
18007 }
18010 }
18012 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18013 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18014 no such TYPE can be found. Note that this function peers inside
18015 uninstantiated templates and therefore should be used only in
18016 extremely limited situations. ONLY_CURRENT_P restricts this
18017 peering to the currently open classes hierarchy (which is required
18018 when comparing types). */
18020 tree
18022 {
18023 tree scope;
18024 tree name;
18025 tree decl;
18027 tree pushed_scope;
18028 tree result;
18033 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18034 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18035 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18036 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18037 identifier of the TYPENAME_TYPE anymore.
18038 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18039 TYPENAME_TYPE instead, we avoid messing up with a possible
18040 typedef variant case. */
18043 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18044 it first before we can figure out what NAME refers to. */
18047 /* If we don't know what SCOPE refers to, then we cannot resolve the
18048 TYPENAME_TYPE. */
18051 /* If the SCOPE is a template type parameter, we have no way of
18052 resolving the name. */
18055 /* If the SCOPE is not the current instantiation, there's no reason
18056 to look inside it. */
18059 /* If this is a typedef, we don't want to look inside (c++/11987). */
18062 /* If SCOPE isn't the template itself, it will not have a valid
18063 TYPE_FIELDS list. */
18065 /* scope is either the template itself or a compatible instantiation
18066 like X<T>, so look up the name in the original template. */
18068 else
18069 /* scope is a partial instantiation, so we can't do the lookup or we
18070 will lose the template arguments. */
18072 /* Enter the SCOPE so that name lookup will be resolved as if we
18073 were in the class definition. In particular, SCOPE will no
18074 longer be considered a dependent type. */
18076 /* Look up the declaration. */
18081 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18082 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18087 {
18091 }
18094 {
18095 tree tmpl;
18096 tree args;
18097 /* Obtain the template and the arguments. */
18100 /* Instantiate the template. */
18106 }
18108 /* Leave the SCOPE. */
18112 /* If we failed to resolve it, return the original typename. */
18116 /* If lookup found a typename type, resolve that too. */
18118 {
18119 /* Ill-formed programs can cause infinite recursion here, so we
18120 must catch that. */
18124 }
18126 /* Qualify the resulting type. */
18132 }
18134 /* EXPR is an expression which is not type-dependent. Return a proxy
18135 for EXPR that can be used to compute the types of larger
18136 expressions containing EXPR. */
18138 tree
18140 {
18141 tree inner_expr;
18143 /* Preserve null pointer constants so that the type of things like
18144 "p == 0" where "p" is a pointer can be determined. */
18147 /* Preserve OVERLOADs; the functions must be available to resolve
18148 types. */
18159 /* There is no need to return a proxy for a variable. */
18162 /* Preserve string constants; conversions from string constants to
18163 "char *" are allowed, even though normally a "const char *"
18164 cannot be used to initialize a "char *". */
18167 /* Preserve arithmetic constants, as an optimization -- there is no
18168 reason to create a new node. */
18171 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18172 There is at least one place where we want to know that a
18173 particular expression is a throw-expression: when checking a ?:
18174 expression, there are special rules if the second or third
18175 argument is a throw-expression. */
18194 /* If the type is unknown, it can't really be non-dependent */
18197 /* Otherwise, build a NON_DEPENDENT_EXPR.
18199 REFERENCE_TYPEs are not stripped for expressions in templates
18200 because doing so would play havoc with mangling. Consider, for
18201 example:
18203 template <typename T> void f<T& g>() { g(); }
18205 In the body of "f", the expression for "g" will have
18206 REFERENCE_TYPE, even though the standard says that it should
18207 not. The reason is that we must preserve the syntactic form of
18208 the expression so that mangling (say) "f<g>" inside the body of
18209 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18210 stripped here. */
18212 }
18214 /* ARGS is a vector of expressions as arguments to a function call.
18215 Replace the arguments with equivalent non-dependent expressions.
18216 This modifies ARGS in place. */
18218 void
18220 {
18222 tree arg;
18225 {
18229 }
18230 }
18232 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18233 with a level one deeper than the actual template parms. */
18235 tree
18237 {
18250 }
18252 /* Given type ARG, return std::initializer_list<ARG>. */
18254 static tree
18256 {
18257 tree std_init_list = namespace_binding
18259 tree argvec;
18261 {
18265 }
18270 }
18272 /* Replace auto in TYPE with std::initializer_list<auto>. */
18274 static tree
18276 {
18283 }
18285 /* walk_tree helper for do_auto_deduction. */
18287 static tree
18290 {
18291 /* Is this a variable with the type we're looking for? */
18295 else
18297 }
18299 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18300 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18302 tree
18304 {
18307 tree decl;
18310 /* The name of the object being declared shall not appear in the
18311 initializer expression. */
18314 {
18318 }
18320 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18321 with either a new invented type template parameter U or, if the
18322 initializer is a braced-init-list (8.5.4), with
18323 std::initializer_list<U>. */
18336 {
18339 }
18341 /* If the list of declarators contains more than one declarator, the type
18342 of each declared variable is determined as described above. If the
18343 type deduced for the template parameter U is not the same in each
18344 deduction, the program is ill-formed. */
18347 {
18351 }
18357 }
18359 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18360 result. */
18362 tree
18364 {
18365 tree argvec;
18374 }
18376 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18378 bool
18380 {
18384 else
18386 }
18388 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18389 appear as a type-specifier for the declaration in question, we don't
18390 have to look through the whole type. */
18392 tree
18394 {
18411 }
18413 /* For a given template T, return the vector of typedefs referenced
18414 in T for which access check is needed at T instantiation time.
18415 T is either a FUNCTION_DECL or a RECORD_TYPE.
18416 Those typedefs were added to T by the function
18417 append_type_to_template_for_access_check. */
18421 {
18422 tree ti;
18433 {
18438 }
18441 }
18443 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18444 tied to T. That list of typedefs will be access checked at
18445 T instantiation time.
18446 T is either a FUNCTION_DECL or a RECORD_TYPE.
18447 TYPE_DECL is a TYPE_DECL node representing a typedef.
18448 SCOPE is the scope through which TYPE_DECL is accessed.
18449 LOCATION is the location of the usage point of TYPE_DECL.
18451 This function is a subroutine of
18452 append_type_to_template_for_access_check. */
18454 static void
18456 tree type_decl,
18457 tree scope,
18458 location_t location)
18459 {
18460 qualified_typedef_usage_t typedef_usage;
18461 tree ti;
18468 && type_decl
18484 }
18486 /* Append TYPE_DECL to the template TEMPL.
18487 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18488 At TEMPL instanciation time, TYPE_DECL will be checked to see
18489 if it can be accessed through SCOPE.
18490 LOCATION is the location of the usage point of TYPE_DECL.
18492 e.g. consider the following code snippet:
18494 class C
18495 {
18496 typedef int myint;
18497 };
18499 template<class U> struct S
18500 {
18501 C::myint mi; // <-- usage point of the typedef C::myint
18502 };
18504 S<char> s;
18506 At S<char> instantiation time, we need to check the access of C::myint
18507 In other words, we need to check the access of the myint typedef through
18508 the C scope. For that purpose, this function will add the myint typedef
18509 and the scope C through which its being accessed to a list of typedefs
18510 tied to the template S. That list will be walked at template instantiation
18511 time and access check performed on each typedefs it contains.
18512 Note that this particular code snippet should yield an error because
18513 myint is private to C. */
18515 void
18517 tree type_decl,
18518 tree scope,
18519 location_t location)
18520 {
18526 /* Make sure we don't append the type to the template twice. */
18537 }
18539 /* Set up the hash tables for template instantiations. */
18541 void
18543 {
18545 hash_specialization,
18546 eq_specializations,
18547 ggc_free);
18549 hash_specialization,
18550 eq_specializations,
18551 ggc_free);
18552 }