| blob | 43cd105474ee98ad5509f01998ae462069a2f476 |
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
134 tree);
194 location_t);
199 /* Make the current scope suitable for access checking when we are
200 processing T. T can be FUNCTION_DECL for instantiated function
201 template, or VAR_DECL for static member variable (need by
202 instantiate_decl). */
204 static void
206 {
214 else
218 {
219 saved_access_scope = tree_cons
222 }
223 }
225 /* Restore the scope set up by push_access_scope. T is the node we
226 are processing. */
228 static void
230 {
232 {
235 }
239 else
241 }
243 /* Do any processing required when DECL (a member template
244 declaration) is finished. Returns the TEMPLATE_DECL corresponding
245 to DECL, unless it is a specialization, in which case the DECL
246 itself is returned. */
248 tree
250 {
257 {
258 tree type;
266 {
270 }
272 }
276 {
278 {
281 }
282 else
284 }
285 else
289 }
291 /* Create a template info node. */
293 tree
295 {
300 }
302 /* Return the template info node corresponding to T, whatever T is. */
304 tree
306 {
324 }
326 /* Returns the template nesting level of the indicated class TYPE.
328 For example, in:
329 template <class T>
330 struct A
331 {
332 template <class U>
333 struct B {};
334 };
336 A<T>::B<U> has depth two, while A<T> has depth one.
337 Both A<T>::B<int> and A<int>::B<U> have depth one, if
338 they are instantiations, not specializations.
340 This function is guaranteed to return 0 if passed NULL_TREE so
341 that, for example, `template_class_depth (current_class_type)' is
342 always safe. */
344 int
346 {
353 {
359 }
362 }
364 /* Subroutine of maybe_begin_member_template_processing.
365 Returns true if processing DECL needs us to push template parms. */
367 static bool
369 {
375 }
377 /* Subroutine of maybe_begin_member_template_processing.
378 Push the template parms in PARMS, starting from LEVELS steps into the
379 chain, and ending at the beginning, since template parms are listed
380 innermost first. */
382 static void
384 {
392 current_template_parms
398 NULL);
400 {
409 {
416 {
417 /* Make a CONST_DECL as is done in process_template_parm.
418 It is ugly that we recreate this here; the original
419 version built in process_template_parm is no longer
420 available. */
430 }
435 }
436 }
437 }
439 /* Restore the template parameter context for a member template or
440 a friend template defined in a class definition. */
442 void
444 {
445 tree parms;
449 {
454 {
457 }
460 }
462 /* Remember how many levels of template parameters we pushed so that
463 we can pop them later. */
465 }
467 /* Undo the effects of maybe_begin_member_template_processing. */
469 void
471 {
480 {
484 }
485 }
487 /* Return a new template argument vector which contains all of ARGS,
488 but has as its innermost set of arguments the EXTRA_ARGS. */
490 static tree
492 {
493 tree new_args;
508 }
510 /* Like add_to_template_args, but only the outermost ARGS are added to
511 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
512 (EXTRA_ARGS) levels are added. This function is used to combine
513 the template arguments from a partial instantiation with the
514 template arguments used to attain the full instantiation from the
515 partial instantiation. */
517 static tree
519 {
520 tree new_args;
522 /* If there are more levels of EXTRA_ARGS than there are ARGS,
523 something very fishy is going on. */
526 /* If *all* the new arguments will be the EXTRA_ARGS, just return
527 them. */
531 /* For the moment, we make ARGS look like it contains fewer levels. */
536 /* Now, we restore ARGS to its full dimensions. */
540 }
542 /* Return the N levels of innermost template arguments from the ARGS. */
544 tree
546 {
547 tree new_args;
553 /* If N is 1, just return the innermost set of template arguments. */
557 /* If we're not removing anything, just return the arguments we were
558 given. */
564 /* Make a new set of arguments, not containing the outer arguments. */
571 }
573 /* The inverse of get_innermost_template_args: Return all but the innermost
574 EXTRA_LEVELS levels of template arguments from the ARGS. */
576 static tree
578 {
579 tree new_args;
585 /* If N is 1, just return the outermost set of template arguments. */
589 /* If we're not removing anything, just return the arguments we were
590 given. */
595 /* Make a new set of arguments, not containing the inner arguments. */
602 }
604 /* We've got a template header coming up; push to a new level for storing
605 the parms. */
607 void
609 {
610 /* We use a non-tag-transparent scope here, which causes pushtag to
611 put tags in this scope, rather than in the enclosing class or
612 namespace scope. This is the right thing, since we want
613 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
614 global template class, push_template_decl handles putting the
615 TEMPLATE_DECL into top-level scope. For a nested template class,
616 e.g.:
618 template <class T> struct S1 {
619 template <class T> struct S2 {};
620 };
622 pushtag contains special code to call pushdecl_with_scope on the
623 TEMPLATE_DECL for S2. */
628 }
630 /* This routine is called when a specialization is declared. If it is
631 invalid to declare a specialization here, an error is reported and
632 false is returned, otherwise this routine will return true. */
634 static bool
636 {
639 /* [temp.expl.spec]
641 An explicit specialization shall be declared in the namespace of
642 which the template is a member, or, for member templates, in the
643 namespace of which the enclosing class or enclosing class
644 template is a member. An explicit specialization of a member
645 function, member class or static data member of a class template
646 shall be declared in the namespace of which the class template
647 is a member. */
649 {
652 }
654 /* [temp.expl.spec]
656 In an explicit specialization declaration for a member of a class
657 template or a member template that appears in namespace scope,
658 the member template and some of its enclosing class templates may
659 remain unspecialized, except that the declaration shall not
660 explicitly specialize a class member template if its enclosing
661 class templates are not explicitly specialized as well. */
663 {
666 }
669 }
671 /* We've just seen template <>. */
673 bool
675 {
679 }
681 /* Called at then end of processing a declaration preceded by
682 template<>. */
684 void
686 {
689 }
691 /* Any template <>'s that we have seen thus far are not referring to a
692 function specialization. */
694 void
696 {
699 }
701 /* We've just seen a template header. If SPECIALIZATION is nonzero,
702 it was of the form template <>. */
704 static void
706 {
708 template_header_count++;
709 }
711 /* We're beginning an explicit instantiation. */
713 void
715 {
718 }
721 void
723 {
726 }
728 /* An explicit specialization or partial specialization TMPL is being
729 declared. Check that the namespace in which the specialization is
730 occurring is permissible. Returns false iff it is invalid to
731 specialize TMPL in the current namespace. */
733 static bool
735 {
738 /* [tmpl.expl.spec]
740 An explicit specialization shall be declared in the namespace of
741 which the template is a member, or, for member templates, in the
742 namespace of which the enclosing class or enclosing class
743 template is a member. An explicit specialization of a member
744 function, member class or static data member of a class template
745 shall be declared in the namespace of which the class template is
746 a member. */
749 {
752 }
754 /* Same or super-using namespace. */
756 else
757 {
761 }
762 }
764 /* SPEC is an explicit instantiation. Check that it is valid to
765 perform this explicit instantiation in the current namespace. */
767 static void
769 {
770 tree ns;
772 /* DR 275: An explicit instantiation shall appear in an enclosing
773 namespace of its template. */
779 }
781 /* The TYPE is being declared. If it is a template type, that means it
782 is a partial specialization. Do appropriate error-checking. */
784 tree
786 {
787 tree context;
793 {
797 }
802 {
803 /* This is for ordinary explicit specialization and partial
804 specialization of a template class such as:
806 template <> class C<int>;
808 or:
810 template <class T> class C<T*>;
812 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
816 {
820 {
824 }
825 }
828 }
834 {
835 /* This is for an explicit specialization of member class
836 template according to [temp.expl.spec/18]:
838 template <> template <class U> class C<int>::D;
840 The context `C<int>' must be an implicit instantiation.
841 Otherwise this is just a member class template declared
842 earlier like:
844 template <> class C<int> { template <class U> class D; };
845 template <> template <class U> class C<int>::D;
847 In the first case, `C<int>::D' is a specialization of `C<T>::D'
848 while in the second case, `C<int>::D' is a primary template
849 and `C<T>::D' may not exist. */
853 {
854 tree t;
859 {
862 }
864 /* Check for invalid specialization after instantiation:
866 template <> template <> class C<int>::D<int>;
867 template <> template <class U> class C<int>::D; */
871 {
874 {
875 /* We already have a full specialization of this partial
876 instantiation. Reassign it to the new member
877 specialization template. */
878 spec_entry elt;
894 }
896 /* But if we've had an implicit instantiation, that's a
897 problem ([temp.expl.spec]/6). */
900 }
902 /* Mark TYPE as a specialization. And as a result, we only
903 have one level of template argument for the innermost
904 class template. */
908 }
909 }
911 {
914 }
917 }
919 /* Returns nonzero if we can optimize the retrieval of specializations
920 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
921 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
925 {
928 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
929 parameter. */
931 /* The optimized lookup depends on the fact that the
932 template arguments for the member function template apply
933 purely to the containing class, which is not true if the
934 containing class is an explicit or partial
935 specialization. */
939 /* It is possible to have a template that is not a member
940 template and is not a member of a template class:
942 template <typename T>
943 struct S { friend A::f(); };
945 Here, the friend function is a template, but the context does
946 not have template information. The optimized lookup relies
947 on having ARGS be the template arguments for both the class
948 and the function template. */
950 }
952 /* Retrieve the specialization (in the sense of [temp.spec] - a
953 specialization is either an instantiation or an explicit
954 specialization) of TMPL for the given template ARGS. If there is
955 no such specialization, return NULL_TREE. The ARGS are a vector of
956 arguments, or a vector of vectors of arguments, in the case of
957 templates with more than one level of parameters.
959 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
960 then we search for a partial specialization matching ARGS. This
961 parameter is ignored if TMPL is not a class template. */
963 static tree
965 {
971 /* There should be as many levels of arguments as there are
972 levels of parameters. */
977 {
978 tree class_template;
979 tree class_specialization;
981 tree fns;
984 /* The template arguments actually apply to the containing
985 class. Find the class specialization with those
986 arguments. */
988 class_specialization
992 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
993 for the specialization. */
997 /* Iterate through the methods with the indicated name, looking
998 for the one that has an instance of TMPL. */
1001 {
1004 /* using-declarations can add base methods to the method vec,
1005 and we don't want those here. */
1008 }
1010 }
1011 else
1012 {
1014 spec_entry elt;
1015 htab_t specializations;
1023 else
1031 }
1034 }
1036 /* Like retrieve_specialization, but for local declarations. */
1038 static tree
1040 {
1041 tree spec;
1049 }
1051 /* Returns nonzero iff DECL is a specialization of TMPL. */
1053 int
1055 {
1056 tree t;
1059 {
1065 }
1066 else
1067 {
1076 }
1079 }
1081 /* Returns nonzero iff DECL is a specialization of friend declaration
1082 FRIEND_DECL according to [temp.friend]. */
1084 bool
1086 {
1093 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1094 of a template class, we want to check if DECL is a specialization
1095 if this. */
1099 {
1100 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1103 }
1108 /* There is nothing to do if this is not a template friend. */
1115 /* [temp.friend/6]
1116 A member of a class template may be declared to be a friend of a
1117 non-template class. In this case, the corresponding member of
1118 every specialization of the class template is a friend of the
1119 class granting friendship.
1121 For example, given a template friend declaration
1123 template <class T> friend void A<T>::f();
1125 the member function below is considered a friend
1127 template <> struct A<int> {
1128 void f();
1129 };
1131 For this type of template friend, TEMPLATE_DEPTH below will be
1132 nonzero. To determine if DECL is a friend of FRIEND, we first
1133 check if the enclosing class is a specialization of another. */
1140 {
1141 /* Next, we check the members themselves. In order to handle
1142 a few tricky cases, such as when FRIEND_DECL's are
1144 template <class T> friend void A<T>::g(T t);
1145 template <class T> template <T t> friend void A<T>::h();
1147 and DECL's are
1149 void A<int>::g(int);
1150 template <int> void A<int>::h();
1152 we need to figure out ARGS, the template arguments from
1153 the context of DECL. This is required for template substitution
1154 of `T' in the function parameter of `g' and template parameter
1155 of `h' in the above examples. Here ARGS corresponds to `int'. */
1162 {
1164 {
1167 else
1169 current_depth++;
1170 }
1172 }
1175 {
1177 tree friend_type;
1178 tree decl_type;
1179 tree friend_args_type;
1180 tree decl_args_type;
1182 /* Make sure that both DECL and FRIEND_DECL are templates or
1183 non-templates. */
1189 {
1190 /* If both are templates, check template parameter list. */
1191 tree friend_parms
1196 friend_parms))
1200 }
1201 else
1209 /* Check if return types match. */
1213 /* Check if function parameter types match, ignoring the
1214 `this' parameter. */
1223 }
1224 else
1225 {
1226 /* DECL is a TYPE_DECL */
1230 /* Make sure that both DECL and FRIEND_DECL are templates or
1231 non-templates. */
1232 is_template
1239 {
1240 tree friend_parms;
1241 /* If both are templates, check the name of the two
1242 TEMPLATE_DECL's first because is_friend didn't. */
1247 /* Now check template parameter list. */
1248 friend_parms
1251 return comp_template_parms
1253 friend_parms);
1254 }
1255 else
1258 }
1259 }
1261 }
1263 /* Register the specialization SPEC as a specialization of TMPL with
1264 the indicated ARGS. IS_FRIEND indicates whether the specialization
1265 is actually just a friend declaration. Returns SPEC, or an
1266 equivalent prior declaration, if available. */
1268 static tree
1270 hashval_t hash)
1271 {
1272 tree fn;
1274 spec_entry elt;
1280 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1281 register it; we want the corresponding TEMPLATE_DECL instead.
1282 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1283 the more obvious `uses_template_parms (spec)' to avoid problems
1284 with default function arguments. In particular, given
1285 something like this:
1287 template <class T> void f(T t1, T t = T())
1289 the default argument expression is not substituted for in an
1290 instantiation unless and until it is actually needed. */
1294 /* We don't put these specializations in the hash table, but we might
1295 want to give an error about a mismatch. */
1297 else
1298 {
1310 else
1312 }
1314 /* We can sometimes try to re-register a specialization that we've
1315 already got. In particular, regenerate_decl_from_template calls
1316 duplicate_decls which will update the specialization list. But,
1317 we'll still get called again here anyhow. It's more convenient
1318 to simply allow this than to try to prevent it. */
1322 {
1324 {
1327 {
1329 fn);
1331 }
1332 else
1333 {
1334 tree clone;
1335 /* This situation should occur only if the first
1336 specialization is an implicit instantiation, the
1337 second is an explicit specialization, and the
1338 implicit instantiation has not yet been used. That
1339 situation can occur if we have implicitly
1340 instantiated a member function and then specialized
1341 it later.
1343 We can also wind up here if a friend declaration that
1344 looked like an instantiation turns out to be a
1345 specialization:
1347 template <class T> void foo(T);
1348 class S { friend void foo<>(int) };
1349 template <> void foo(int);
1351 We transform the existing DECL in place so that any
1352 pointers to it become pointers to the updated
1353 declaration.
1355 If there was a definition for the template, but not
1356 for the specialization, we want this to look as if
1357 there were no definition, and vice versa. */
1360 /* The call to duplicate_decls will have applied
1361 [temp.expl.spec]:
1363 An explicit specialization of a function template
1364 is inline only if it is explicitly declared to be,
1365 and independently of whether its function template
1366 is.
1368 to the primary function; now copy the inline bits to
1369 the various clones. */
1371 {
1376 }
1380 }
1381 }
1383 {
1385 /* Dup decl failed, but this is a new definition. Set the
1386 line number so any errors match this new
1387 definition. */
1391 }
1392 }
1396 /* A specialization must be declared in the same namespace as the
1397 template it is specializing. */
1403 {
1410 /* TMPL is a forward declaration of a template function; keep a list
1411 of all specializations in case we need to reassign them to a friend
1412 template later in tsubst_friend_function. */
1415 }
1418 }
1420 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1421 TMPL and ARGS members, ignores SPEC. */
1423 static int
1425 {
1431 }
1433 /* Returns a hash for a template TMPL and template arguments ARGS. */
1435 static hashval_t
1437 {
1440 }
1442 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1443 ignoring SPEC. */
1445 static hashval_t
1447 {
1450 }
1452 /* Recursively calculate a hash value for a template argument ARG, for use
1453 in the hash tables of template specializations. */
1455 static hashval_t
1457 {
1469 /* We can get one of these when re-hashing a previous entry in the middle
1470 of substituting into a pack expansion. Just look through it. */
1479 {
1487 {
1492 }
1513 {
1516 {
1519 }
1521 }
1536 val = iterative_hash_template_arg
1548 val);
1550 val);
1559 /* layout_type sets structural equality for arrays of
1560 incomplete type, so we can't rely on the canonical type
1561 for hashing. */
1567 {
1571 val);
1574 /* Otherwise just compare the types during lookup. */
1583 {
1588 }
1589 }
1590 }
1593 }
1595 /* Unregister the specialization SPEC as a specialization of TMPL.
1596 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1597 if the SPEC was listed as a specialization of TMPL.
1599 Note that SPEC has been ggc_freed, so we can't look inside it. */
1601 bool
1603 {
1605 spec_entry elt;
1613 {
1618 }
1621 }
1623 /* Compare an entry in the local specializations hash table P1 (which
1624 is really a pointer to a TREE_LIST) with P2 (which is really a
1625 DECL). */
1627 static int
1629 {
1631 }
1633 /* Hash P1, an entry in the local specializations table. */
1635 static hashval_t
1637 {
1639 }
1641 /* Like register_specialization, but for local declarations. We are
1642 registering SPEC, an instantiation of TMPL. */
1644 static void
1646 {
1652 }
1654 /* TYPE is a class type. Returns true if TYPE is an explicitly
1655 specialized class. */
1657 bool
1659 {
1663 }
1665 /* Print the list of functions at FNS, going through all the overloads
1666 for each element of the list. Alternatively, FNS can not be a
1667 TREE_LIST, in which case it will be printed together with all the
1668 overloads.
1670 MORE and *STR should respectively be FALSE and NULL when the function
1671 is called from the outside. They are used internally on recursive
1672 calls. print_candidates manages the two parameters and leaves NULL
1673 in *STR when it ends. */
1675 static void
1677 {
1683 {
1688 }
1689 else
1690 {
1692 {
1693 /* Pick the prefix string. */
1695 {
1698 }
1702 }
1705 }
1708 {
1711 }
1712 }
1714 /* Print the list of candidate FNS in an error message. */
1716 void
1718 {
1722 }
1724 /* Returns the template (one of the functions given by TEMPLATE_ID)
1725 which can be specialized to match the indicated DECL with the
1726 explicit template args given in TEMPLATE_ID. The DECL may be
1727 NULL_TREE if none is available. In that case, the functions in
1728 TEMPLATE_ID are non-members.
1730 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1731 specialization of a member template.
1733 The TEMPLATE_COUNT is the number of references to qualifying
1734 template classes that appeared in the name of the function. See
1735 check_explicit_specialization for a more accurate description.
1737 TSK indicates what kind of template declaration (if any) is being
1738 declared. TSK_TEMPLATE indicates that the declaration given by
1739 DECL, though a FUNCTION_DECL, has template parameters, and is
1740 therefore a template function.
1742 The template args (those explicitly specified and those deduced)
1743 are output in a newly created vector *TARGS_OUT.
1745 If it is impossible to determine the result, an error message is
1746 issued. The error_mark_node is returned to indicate failure. */
1748 static tree
1750 tree decl,
1754 tmpl_spec_kind tsk)
1755 {
1756 tree fns;
1757 tree targs;
1758 tree explicit_targs;
1760 /* A TREE_LIST of templates of which DECL may be a specialization.
1761 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1762 corresponding TREE_PURPOSE is the set of template arguments that,
1763 when used to instantiate the template, would produce a function
1764 with the signature of DECL. */
1780 /* Check for baselinks. */
1785 {
1788 }
1790 /* Count the number of template headers specified for this
1791 specialization. */
1799 {
1803 {
1804 tree decl_arg_types;
1805 tree fn_arg_types;
1807 /* In case of explicit specialization, we need to check if
1808 the number of template headers appearing in the specialization
1809 is correct. This is usually done in check_explicit_specialization,
1810 but the check done there cannot be exhaustive when specializing
1811 member functions. Consider the following code:
1813 template <> void A<int>::f(int);
1814 template <> template <> void A<int>::f(int);
1816 Assuming that A<int> is not itself an explicit specialization
1817 already, the first line specializes "f" which is a non-template
1818 member function, whilst the second line specializes "f" which
1819 is a template member function. So both lines are syntactically
1820 correct, and check_explicit_specialization does not reject
1821 them.
1823 Here, we can do better, as we are matching the specialization
1824 against the declarations. We count the number of template
1825 headers, and we check if they match TEMPLATE_COUNT + 1
1826 (TEMPLATE_COUNT is the number of qualifying template classes,
1827 plus there must be another header for the member template
1828 itself).
1830 Notice that if header_count is zero, this is not a
1831 specialization but rather a template instantiation, so there
1832 is no check we can perform here. */
1836 /* Check that the number of template arguments at the
1837 innermost level for DECL is the same as for FN. */
1845 /* DECL might be a specialization of FN. */
1849 /* For a non-static member function, we need to make sure
1850 that the const qualification is the same. Since
1851 get_bindings does not try to merge the "this" parameter,
1852 we must do the comparison explicitly. */
1858 /* Skip the "this" parameter and, for constructors of
1859 classes with virtual bases, the VTT parameter. A
1860 full specialization of a constructor will have a VTT
1861 parameter, but a template never will. */
1862 decl_arg_types
1864 fn_arg_types
1867 /* Check that the number of function parameters matches.
1868 For example,
1869 template <class T> void f(int i = 0);
1870 template <> void f<int>();
1871 The specialization f<int> is invalid but is not caught
1872 by get_bindings below. */
1876 /* Function templates cannot be specializations; there are
1877 no partial specializations of functions. Therefore, if
1878 the type of DECL does not match FN, there is no
1879 match. */
1881 {
1885 }
1887 /* See whether this function might be a specialization of this
1888 template. */
1892 /* We cannot deduce template arguments that when used to
1893 specialize TMPL will produce DECL. */
1896 /* Save this template, and the arguments deduced. */
1898 }
1900 /* FN is an ordinary member function, and we need a
1901 specialization of a member template. */
1902 ;
1904 /* We can get IDENTIFIER_NODEs here in certain erroneous
1905 cases. */
1906 ;
1908 /* This is just an ordinary non-member function. Nothing can
1909 be a specialization of that. */
1910 ;
1912 /* Cannot specialize functions that are created implicitly. */
1913 ;
1914 else
1915 {
1916 tree decl_arg_types;
1918 /* This is an ordinary member function. However, since
1919 we're here, we can assume it's enclosing class is a
1920 template class. For example,
1922 template <typename T> struct S { void f(); };
1923 template <> void S<int>::f() {}
1925 Here, S<int>::f is a non-template, but S<int> is a
1926 template class. If FN has the same type as DECL, we
1927 might be in business. */
1930 /* Its enclosing class is an explicit specialization
1931 of a template class. This is not a candidate. */
1936 /* The return types differ. */
1939 /* Adjust the type of DECL in case FN is a static member. */
1946 decl_arg_types))
1947 /* They match! */
1949 }
1950 }
1953 {
1954 /* We have:
1956 [temp.expl.spec]
1958 It is possible for a specialization with a given function
1959 signature to be instantiated from more than one function
1960 template. In such cases, explicit specification of the
1961 template arguments must be used to uniquely identify the
1962 function template specialization being specialized.
1964 Note that here, there's no suggestion that we're supposed to
1965 determine which of the candidate templates is most
1966 specialized. However, we, also have:
1968 [temp.func.order]
1970 Partial ordering of overloaded function template
1971 declarations is used in the following contexts to select
1972 the function template to which a function template
1973 specialization refers:
1975 -- when an explicit specialization refers to a function
1976 template.
1978 So, we do use the partial ordering rules, at least for now.
1979 This extension can only serve to make invalid programs valid,
1980 so it's safe. And, there is strong anecdotal evidence that
1981 the committee intended the partial ordering rules to apply;
1982 the EDG front end has that behavior, and John Spicer claims
1983 that the committee simply forgot to delete the wording in
1984 [temp.expl.spec]. */
1987 {
1990 }
1991 }
1994 {
2002 }
2006 {
2012 }
2014 /* We have one, and exactly one, match. */
2016 {
2019 /* DECL is a re-declaration or partial instantiation of a template
2020 function. */
2023 /* It was a specialization of an ordinary member function in a
2024 template class. */
2026 }
2028 /* It was a specialization of a template. */
2031 {
2036 }
2037 else
2040 }
2042 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2043 but with the default argument values filled in from those in the
2044 TMPL_TYPES. */
2046 static tree
2048 tree tmpl_types)
2049 {
2050 tree new_spec_types;
2058 /* Substitute into the rest of the list. */
2059 new_spec_types =
2063 /* Add the default argument for this parameter. */
2066 new_spec_types);
2067 }
2069 /* DECL is an explicit specialization. Replicate default arguments
2070 from the template it specializes. (That way, code like:
2072 template <class T> void f(T = 3);
2073 template <> void f(double);
2074 void g () { f (); }
2076 works, as required.) An alternative approach would be to look up
2077 the correct default arguments at the call-site, but this approach
2078 is consistent with how implicit instantiations are handled. */
2080 static void
2082 {
2083 tree tmpl;
2084 tree spec_types;
2085 tree tmpl_types;
2086 tree new_spec_types;
2087 tree old_type;
2088 tree new_type;
2089 tree t;
2094 /* See if there's anything we need to do. */
2107 {
2108 /* Remove the this pointer, but remember the object's type for
2109 CV quals. */
2115 {
2116 /* DECL may contain more parameters than TMPL due to the extra
2117 in-charge parameter in constructors and destructors. */
2120 }
2122 {
2125 }
2126 }
2128 /* Compute the merged default arguments. */
2129 new_spec_types =
2132 /* Compute the new FUNCTION_TYPE. */
2134 {
2138 new_spec_types);
2141 /* Put the in-charge parameter back. */
2144 new_spec_types);
2148 new_spec_types);
2149 }
2150 else
2152 new_spec_types);
2158 }
2160 /* Check to see if the function just declared, as indicated in
2161 DECLARATOR, and in DECL, is a specialization of a function
2162 template. We may also discover that the declaration is an explicit
2163 instantiation at this point.
2165 Returns DECL, or an equivalent declaration that should be used
2166 instead if all goes well. Issues an error message if something is
2167 amiss. Returns error_mark_node if the error is not easily
2168 recoverable.
2170 FLAGS is a bitmask consisting of the following flags:
2172 2: The function has a definition.
2173 4: The function is a friend.
2175 The TEMPLATE_COUNT is the number of references to qualifying
2176 template classes that appeared in the name of the function. For
2177 example, in
2179 template <class T> struct S { void f(); };
2180 void S<int>::f();
2182 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2183 classes are not counted in the TEMPLATE_COUNT, so that in
2185 template <class T> struct S {};
2186 template <> struct S<int> { void f(); }
2187 template <> void S<int>::f();
2189 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2190 invalid; there should be no template <>.)
2192 If the function is a specialization, it is marked as such via
2193 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2194 is set up correctly, and it is added to the list of specializations
2195 for that template. */
2197 tree
2199 tree decl,
2202 {
2210 tmpl_spec_kind tsk;
2213 {
2216 else
2218 }
2219 else
2223 {
2226 {
2229 }
2231 {
2233 /* This could be something like:
2235 template <class T> void f(T);
2236 class S { friend void f<>(int); } */
2238 else
2239 {
2240 /* This case handles bogus declarations like template <>
2241 template <class T> void f<int>(); */
2244 declarator);
2246 }
2247 }
2251 /* The error has already been reported in
2252 check_specialization_scope. */
2258 /* Fall through. */
2271 decl);
2274 else
2278 /* Fall through. */
2283 else
2289 {
2290 /* This case handles bogus declarations like template <>
2291 template <class T> void f<int>(); */
2296 else
2298 declarator);
2300 }
2303 /* This is a specialization of a member template, without
2304 specialization the containing class. Something like:
2306 template <class T> struct S {
2307 template <class U> void f (U);
2308 };
2309 template <> template <class U> void S<int>::f(U) {}
2311 That's a specialization -- but of the entire template. */
2317 }
2320 {
2324 {
2328 }
2329 }
2332 {
2336 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2338 {
2339 tree fns;
2344 else
2345 {
2346 /* If there is no class context, the explicit instantiation
2347 must be at namespace scope. */
2350 /* Find the namespace binding, using the declaration
2351 context. */
2355 {
2358 }
2359 else
2360 {
2366 }
2367 }
2370 }
2376 {
2378 /* A specialization in class scope. This is invalid,
2379 but the error will already have been flagged by
2380 check_specialization_scope. */
2382 else
2383 {
2384 /* It's not valid to write an explicit instantiation in
2385 class scope, e.g.:
2387 class C { template void f(); }
2389 This case is caught by the parser. However, on
2390 something like:
2392 template class C { void f(); };
2394 (which is invalid) we can get here. The error will be
2395 issued later. */
2396 ;
2397 }
2400 }
2403 IDENTIFIER_NODE))
2404 {
2405 /* Find the list of functions in ctype that have the same
2406 name as the declared function. */
2412 {
2417 {
2418 /* From [temp.expl.spec]:
2420 If such an explicit specialization for the member
2421 of a class template names an implicitly-declared
2422 special member function (clause _special_), the
2423 program is ill-formed.
2425 Similar language is found in [temp.explicit]. */
2428 }
2431 }
2434 {
2438 }
2439 else
2440 {
2442 tree ovl;
2444 /* For a type-conversion operator, we cannot do a
2445 name-based lookup. We might be looking for `operator
2446 int' which will be a specialization of `operator T'.
2447 So, we find *all* the conversion operators, and then
2448 select from them. */
2456 {
2458 /* There are no more conversion functions. */
2461 /* Glue all these conversion functions together
2462 with those we already have. */
2465 }
2466 }
2469 {
2472 }
2473 else
2475 }
2477 /* Figure out what exactly is being specialized at this point.
2478 Note that for an explicit instantiation, even one for a
2479 member function, we cannot tell apriori whether the
2480 instantiation is for a member template, or just a member
2481 function of a template class. Even if a member template is
2482 being instantiated, the member template arguments may be
2483 elided if they can be deduced from the rest of the
2484 declaration. */
2487 member_specialization,
2488 template_count,
2489 tsk);
2492 /* We couldn't figure out what this declaration was
2493 specializing. */
2495 else
2496 {
2500 {
2501 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2502 is done by do_decl_instantiation later. */
2508 {
2509 /* If TMPL is not the most general template (for
2510 example, if TMPL is a friend template that is
2511 injected into namespace scope), then there will
2512 be too many levels of TARGS. Remove some of them
2513 here. */
2515 tree new_targs;
2522 }
2525 }
2527 /* If we thought that the DECL was a member function, but it
2528 turns out to be specializing a static member function,
2529 make DECL a static member function as well. */
2534 /* If this is a specialization of a member template of a
2535 template class, we want to return the TEMPLATE_DECL, not
2536 the specialization of it. */
2538 {
2543 {
2544 tree parm;
2548 /* We want to use the argument list specified in the
2549 definition, not in the original declaration. */
2554 }
2557 }
2559 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2562 /* Inherit default function arguments from the template
2563 DECL is specializing. */
2566 /* This specialization has the same protection as the
2567 template it specializes. */
2571 /* 7.1.1-1 [dcl.stc]
2573 A storage-class-specifier shall not be specified in an
2574 explicit specialization...
2576 The parser rejects these, so unless action is taken here,
2577 explicit function specializations will always appear with
2578 global linkage.
2580 The action recommended by the C++ CWG in response to C++
2581 defect report 605 is to make the storage class and linkage
2582 of the explicit specialization match the templated function:
2584 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2585 */
2587 {
2591 /* This specialization has the same linkage and visibility as
2592 the function template it specializes. */
2595 {
2598 }
2601 {
2604 }
2605 }
2607 /* If DECL is a friend declaration, declared using an
2608 unqualified name, the namespace associated with DECL may
2609 have been set incorrectly. For example, in:
2611 template <typename T> void f(T);
2612 namespace N {
2613 struct S { friend void f<int>(int); }
2614 }
2616 we will have set the DECL_CONTEXT for the friend
2617 declaration to N, rather than to the global namespace. */
2622 /* This is not really a declaration of a specialization.
2623 It's just the name of an instantiation. But, it's not
2624 a request for an instantiation, either. */
2627 /* This is indeed a specialization. In case of constructors
2628 and destructors, we need in-charge and not-in-charge
2629 versions in V3 ABI. */
2632 /* Register this specialization so that we can find it
2633 again. */
2635 }
2636 }
2639 }
2641 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2642 parameters. These are represented in the same format used for
2643 DECL_TEMPLATE_PARMS. */
2645 int
2647 {
2648 const_tree p1;
2649 const_tree p2;
2657 {
2669 {
2673 /* If either of the template parameters are invalid, assume
2674 they match for the sake of error recovery. */
2687 }
2688 }
2691 /* One set of parameters has more parameters lists than the
2692 other. */
2696 }
2698 /* Determine whether PARM is a parameter pack. */
2700 bool
2702 {
2703 /* Determine if we have a non-type template parameter pack. */
2708 /* If this is a list of template parameters, we could get a
2709 TYPE_DECL or a TEMPLATE_DECL. */
2716 }
2718 /* Determine if T is a function parameter pack. */
2720 bool
2722 {
2726 }
2728 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2729 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2731 tree
2733 {
2740 }
2742 /* Return true iff the function parameter PARAM_DECL was expanded
2743 from the function parameter pack PACK. */
2745 bool
2747 {
2752 /* The parameter pack and its pack arguments have the same
2753 DECL_PARM_INDEX. */
2755 }
2757 /* Determine whether ARGS describes a variadic template args list,
2758 i.e., one that is terminated by a template argument pack. */
2760 static bool
2762 {
2764 tree last_parm;
2778 }
2780 /* Generate a new name for the parameter pack name NAME (an
2781 IDENTIFIER_NODE) that incorporates its */
2783 static tree
2785 {
2786 /* Munge the name to include the parameter index. */
2787 #define NUMBUF_LEN 128
2799 }
2801 /* Return true if T is a primary function
2802 or class template instantiation. */
2804 bool
2806 {
2818 }
2820 /* Return true if PARM is a template template parameter. */
2822 bool
2824 {
2826 }
2828 /* Return the template parameters of T if T is a
2829 primary template instantiation, NULL otherwise. */
2831 tree
2833 {
2838 parms = INNERMOST_TEMPLATE_PARMS
2842 }
2844 /* Returns the template arguments of T if T is a template instantiation,
2845 NULL otherwise. */
2847 tree
2849 {
2857 }
2859 /* Return the argument pack elements of T if T is a template argument pack,
2860 NULL otherwise. */
2862 tree
2864 {
2870 }
2872 /* Structure used to track the progress of find_parameter_packs_r. */
2873 struct find_parameter_pack_data
2874 {
2875 /* TREE_LIST that will contain all of the parameter packs found by
2876 the traversal. */
2879 /* Set of AST nodes that have been visited by the traversal. */
2881 };
2883 /* Identifies all of the argument packs that occur in a template
2884 argument and appends them to the TREE_LIST inside DATA, which is a
2885 find_parameter_pack_data structure. This is a subroutine of
2886 make_pack_expansion and uses_parameter_packs. */
2887 static tree
2889 {
2895 /* Identify whether this is a parameter pack or not. */
2897 {
2911 {
2912 /* We don't want to walk into the type of a PARM_DECL,
2913 because we don't want to see the type parameter pack. */
2916 }
2920 /* Not a parameter pack. */
2922 }
2925 {
2926 /* Add this parameter pack to the list. */
2928 }
2934 /* This switch statement will return immediately if we don't find a
2935 parameter pack. */
2937 {
2942 /* Check the template itself. */
2945 /* Check the template arguments. */
2961 /* Fall through. */
3002 }
3005 }
3007 /* Determines if the expression or type T uses any parameter packs. */
3008 bool
3010 {
3018 }
3020 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3021 representation a base-class initializer into a parameter pack
3022 expansion. If all goes well, the resulting node will be an
3023 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3024 respectively. */
3025 tree
3027 {
3028 tree result;
3037 {
3038 /* The only time we will see a TREE_LIST here is for a base
3039 class initializer. In this case, the TREE_PURPOSE will be a
3040 _TYPE node (representing the base class expansion we're
3041 initializing) and the TREE_VALUE will be a TREE_LIST
3042 containing the initialization arguments.
3044 The resulting expansion looks somewhat different from most
3045 expansions. Rather than returning just one _EXPANSION, we
3046 return a TREE_LIST whose TREE_PURPOSE is a
3047 TYPE_PACK_EXPANSION containing the bases that will be
3048 initialized. The TREE_VALUE will be identical to the
3049 original TREE_VALUE, which is a list of arguments that will
3050 be passed to each base. We do not introduce any new pack
3051 expansion nodes into the TREE_VALUE (although it is possible
3052 that some already exist), because the TREE_PURPOSE and
3053 TREE_VALUE all need to be expanded together with the same
3054 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3055 resulting TREE_PURPOSE will mention the parameter packs in
3056 both the bases and the arguments to the bases. */
3057 tree purpose;
3058 tree value;
3061 /* Determine which parameter packs will be used by the base
3062 class expansion. */
3069 {
3073 }
3076 {
3077 /* Collect the sets of parameter packs used in each of the
3078 initialization arguments. */
3080 {
3081 /* Determine which parameter packs will be expanded in this
3082 argument. */
3085 }
3086 }
3090 /* Create the pack expansion type for the base type. */
3095 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3096 they will rarely be compared to anything. */
3100 }
3105 /* Build the PACK_EXPANSION_* node. */
3106 result = for_types
3111 {
3112 /* Propagate type and const-expression information. */
3115 }
3116 else
3117 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3118 they will rarely be compared to anything. */
3121 /* Determine which parameter packs will be expanded. */
3127 /* Make sure we found some parameter packs. */
3129 {
3132 else
3135 }
3139 }
3141 /* Checks T for any "bare" parameter packs, which have not yet been
3142 expanded, and issues an error if any are found. This operation can
3143 only be done on full expressions or types (e.g., an expression
3144 statement, "if" condition, etc.), because we could have expressions like:
3146 foo(f(g(h(args)))...)
3148 where "args" is a parameter pack. check_for_bare_parameter_packs
3149 should not be called for the subexpressions args, h(args),
3150 g(h(args)), or f(g(h(args))), because we would produce erroneous
3151 error messages.
3153 Returns TRUE and emits an error if there were bare parameter packs,
3154 returns FALSE otherwise. */
3155 bool
3157 {
3173 {
3176 {
3185 else
3190 else
3194 }
3197 }
3200 }
3202 /* Expand any parameter packs that occur in the template arguments in
3203 ARGS. */
3204 tree
3206 {
3212 /* First, determine if we need to expand anything, and the number of
3213 slots we'll need. */
3215 {
3220 {
3224 else
3226 }
3227 else
3228 {
3230 num_result_args++;
3231 }
3232 }
3234 /* If no expansion is necessary, we're done. */
3238 /* Expand arguments. */
3241 non_default_args_count =
3244 {
3247 {
3254 }
3255 else
3256 {
3259 }
3260 }
3264 }
3266 /* Checks if DECL shadows a template parameter.
3268 [temp.local]: A template-parameter shall not be redeclared within its
3269 scope (including nested scopes).
3271 Emits an error and returns TRUE if the DECL shadows a parameter,
3272 returns FALSE otherwise. */
3274 bool
3276 {
3277 tree olddecl;
3279 /* If we're not in a template, we can't possibly shadow a template
3280 parameter. */
3284 /* Figure out what we're shadowing. */
3289 /* If there's no previous binding for this name, we're not shadowing
3290 anything, let alone a template parameter. */
3294 /* If we're not shadowing a template parameter, we're done. Note
3295 that OLDDECL might be an OVERLOAD (or perhaps even an
3296 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3297 node. */
3301 /* We check for decl != olddecl to avoid bogus errors for using a
3302 name inside a class. We check TPFI to avoid duplicate errors for
3303 inline member templates. */
3311 }
3313 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3314 ORIG_LEVEL, DECL, and TYPE. */
3316 static tree
3320 tree decl,
3321 tree type)
3322 {
3333 }
3335 /* Find the canonical type parameter for the given template type
3336 parameter. Returns the canonical type parameter, which may be TYPE
3337 if no such parameter existed. */
3338 static tree
3340 {
3341 tree list;
3355 else
3356 {
3361 }
3362 }
3364 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3365 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3366 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3367 new one is created. */
3369 static tree
3371 tsubst_flags_t complain)
3372 {
3377 {
3396 /* Template template parameters need this. */
3401 }
3404 }
3406 /* Process information from new template parameter PARM and append it to the
3407 LIST being built. This new parameter is a non-type parameter iff
3408 IS_NON_TYPE is true. This new parameter is a parameter
3409 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3410 PARM_LOC. */
3412 tree
3415 {
3417 tree defval;
3418 tree err_parm_list;
3425 {
3429 {
3433 else
3435 }
3438 }
3439 else
3443 {
3449 {
3453 }
3454 else
3455 {
3456 /* [temp.param]
3458 The top-level cv-qualifiers on the template-parameter are
3459 ignored when determining its type. */
3462 {
3466 }
3469 {
3470 /* This template parameter is not a parameter pack, but it
3471 should be. Complain about "bare" parameter packs. */
3474 /* Recover by calling this a parameter pack. */
3476 }
3477 }
3479 /* A template parameter is not modifiable. */
3488 processing_template_decl,
3493 }
3494 else
3495 {
3496 tree t;
3500 {
3502 /* This is for distinguishing between real templates and template
3503 template parameters */
3507 }
3508 else
3509 {
3511 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3514 }
3521 processing_template_decl,
3525 }
3531 }
3533 /* The end of a template parameter list has been reached. Process the
3534 tree list into a parameter vector, converting each parameter into a more
3535 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3536 as PARM_DECLs. */
3538 tree
3540 {
3545 current_template_parms
3550 {
3554 }
3559 }
3561 /* end_template_decl is called after a template declaration is seen. */
3563 void
3565 {
3571 /* This matches the pushlevel in begin_template_parm_list. */
3576 }
3578 /* Within the declaration of a template, return all levels of template
3579 parameters that apply. The template parameters are represented as
3580 a TREE_VEC, in the form documented in cp-tree.h for template
3581 arguments. */
3583 static tree
3585 {
3586 tree header;
3591 /* If there is only one level of template parameters, we do not
3592 create a TREE_VEC of TREE_VECs. Instead, we return a single
3593 TREE_VEC containing the arguments. */
3598 {
3604 {
3607 /* T will be a list if we are called from within a
3608 begin/end_template_parm_list pair, but a vector directly
3609 if within a begin/end_member_template_processing pair. */
3611 {
3615 {
3618 {
3622 {
3623 /* Turn this argument into a TYPE_ARGUMENT_PACK
3624 with a single element, which expands T. */
3626 #ifdef ENABLE_CHECKING
3627 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3629 #endif
3634 }
3635 }
3636 else
3637 {
3641 {
3642 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3643 with a single element, which expands T. */
3646 #ifdef ENABLE_CHECKING
3647 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3649 #endif
3655 }
3656 }
3658 }
3659 }
3660 }
3662 #ifdef ENABLE_CHECKING
3664 #endif
3668 else
3670 }
3673 }
3675 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3676 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3677 a member template. Used by push_template_decl below. */
3679 static tree
3681 {
3688 }
3690 struct template_parm_data
3691 {
3692 /* The level of the template parameters we are currently
3693 processing. */
3696 /* The index of the specialization argument we are currently
3697 processing. */
3700 /* An array whose size is the number of template parameters. The
3701 elements are nonzero if the parameter has been used in any one
3702 of the arguments processed so far. */
3705 /* An array whose size is the number of template arguments. The
3706 elements are nonzero if the argument makes use of template
3707 parameters of this level. */
3709 };
3711 /* Subroutine of push_template_decl used to see if each template
3712 parameter in a partial specialization is used in the explicit
3713 argument list. If T is of the LEVEL given in DATA (which is
3714 treated as a template_parm_data*), then DATA->PARMS is marked
3715 appropriately. */
3717 static int
3719 {
3725 {
3728 }
3729 else
3730 {
3733 }
3736 {
3739 }
3741 /* Return zero so that for_each_template_parm will continue the
3742 traversal of the tree; we want to mark *every* template parm. */
3744 }
3746 /* Process the partial specialization DECL. */
3748 static tree
3750 {
3756 tree inner_parms;
3769 /* We check that each of the template parameters given in the
3770 partial specialization is used in the argument list to the
3771 specialization. For example:
3773 template <class T> struct S;
3774 template <class T> struct S<T*>;
3776 The second declaration is OK because `T*' uses the template
3777 parameter T, whereas
3779 template <class T> struct S<int>;
3781 is no good. Even trickier is:
3783 template <class T>
3784 struct S1
3785 {
3786 template <class U>
3787 struct S2;
3788 template <class U>
3789 struct S2<T>;
3790 };
3792 The S2<T> declaration is actually invalid; it is a
3793 full-specialization. Of course,
3795 template <class U>
3796 struct S2<T (*)(U)>;
3798 or some such would have been OK. */
3806 {
3811 NULL,
3813 }
3816 {
3817 /* One of the template parms was not used in the
3818 specialization. */
3820 {
3823 }
3826 }
3828 /* [temp.class.spec]
3830 The argument list of the specialization shall not be identical to
3831 the implicit argument list of the primary template. */
3838 /* [temp.class.spec]
3840 A partially specialized non-type argument expression shall not
3841 involve template parameters of the partial specialization except
3842 when the argument expression is a simple identifier.
3844 The type of a template parameter corresponding to a specialized
3845 non-type argument shall not be dependent on a parameter of the
3846 specialization.
3848 Also, we verify that pack expansions only occur at the
3849 end of the argument list. */
3853 {
3860 {
3861 /* Extract the arguments from the argument pack. We'll be
3862 iterating over these in the following loop. */
3865 }
3868 {
3870 /* Get the Jth argument in the parameter pack. */
3874 {
3875 /* Pack expansions must come at the end of the
3876 argument list. */
3879 {
3883 else
3886 }
3887 }
3890 /* We only care about the pattern. */
3896 /* This next line is the `argument expression is not just a
3897 simple identifier' condition and also the `specialized
3898 non-type argument' bit. */
3900 {
3904 arg);
3905 else
3906 {
3907 /* Look at the corresponding template parameter,
3908 marking which template parameters its type depends
3909 upon. */
3913 {
3914 /* We haven't yet initialized TPD2. Do so now. */
3915 tpd2.arg_uses_template_parms
3917 /* The number of parameters here is the number in the
3918 main template, which, as checked in the assertion
3919 above, is NARGS. */
3923 }
3925 /* Mark the template parameters. But this time, we're
3926 looking for the template parameters of the main
3927 template, not in the specialization. */
3934 NULL,
3938 {
3939 /* The type depended on some template parameters.
3940 If they are fully specialized in the
3941 specialization, that's OK. */
3946 {
3949 type,
3950 arg);
3952 }
3953 }
3954 }
3955 }
3956 }
3957 }
3959 /* We should only get here once. */
3967 }
3969 /* Check that a template declaration's use of default arguments and
3970 parameter packs is not invalid. Here, PARMS are the template
3971 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
3972 a primary template. IS_PARTIAL is nonzero if DECL is a partial
3973 specialization.
3976 IS_FRIEND_DECL is nonzero if DECL is a friend function template
3977 declaration (but not a definition); 1 indicates a declaration, 2
3978 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
3979 emitted for extraneous default arguments.
3981 Returns TRUE if there were no errors found, FALSE otherwise. */
3983 bool
3986 {
3989 tree parm_level;
3992 /* [temp.param]
3994 A default template-argument shall not be specified in a
3995 function template declaration or a function template definition, nor
3996 in the template-parameter-list of the definition of a member of a
3997 class template. */
4000 /* You can't have a function template declaration in a local
4001 scope, nor you can you define a member of a class template in a
4002 local scope. */
4009 /* If this is either a friend defined in the scope of the class
4010 or a member function. */
4016 /* And, if it was a member function, it really was defined in
4017 the scope of the class. */
4020 /* We already checked these parameters when the template was
4021 declared, so there's no need to do it again now. This function
4022 was defined in class scope, but we're processing it's body now
4023 that the class is complete. */
4026 /* Core issue 226 (C++0x only): the following only applies to class
4027 templates. */
4029 {
4030 /* [temp.param]
4032 If a template-parameter has a default template-argument, all
4033 subsequent template-parameters shall have a default
4034 template-argument supplied. */
4036 {
4043 {
4053 {
4055 /* For better subsequent error-recovery, we indicate that
4056 there should have been a default argument. */
4059 }
4061 && !is_partial
4062 && !is_friend_decl
4063 /* Don't complain about an enclosing partial
4064 specialization. */
4069 {
4070 /* A primary class template can only have one
4071 parameter pack, at the end of the template
4072 parameter list. */
4077 else
4085 }
4086 }
4087 }
4088 }
4091 || is_partial
4092 || !is_primary
4094 /* For an ordinary class template, default template arguments are
4095 allowed at the innermost level, e.g.:
4096 template <class T = int>
4097 struct S {};
4098 but, in a partial specialization, they're not allowed even
4099 there, as we have in [temp.class.spec]:
4101 The template parameter list of a specialization shall not
4102 contain default template argument values.
4104 So, for a partial specialization, or for a function template
4105 (in C++98/C++03), we look at all of them. */
4106 ;
4107 else
4108 /* But, for a primary class template that is not a partial
4109 specialization we look at all template parameters except the
4110 innermost ones. */
4113 /* Figure out what error message to issue. */
4126 else
4130 /* If we're inside a class definition, there's no need to
4131 examine the parameters to the class itself. On the one
4132 hand, they will be checked when the class is defined, and,
4133 on the other, default arguments are valid in things like:
4134 template <class T = double>
4135 struct S { template <class U> void f(U); };
4136 Here the default argument for `S' has no bearing on the
4137 declaration of `f'. */
4139 else
4140 /* Check everything. */
4146 {
4153 {
4158 {
4160 {
4167 }
4169 /* Clear out the default argument so that we are not
4170 confused later. */
4172 }
4173 }
4175 /* At this point, if we're still interested in issuing messages,
4176 they must apply to classes surrounding the object declared. */
4180 }
4183 }
4185 /* Worker for push_template_decl_real, called via
4186 for_each_template_parm. DATA is really an int, indicating the
4187 level of the parameters we are interested in. If T is a template
4188 parameter of that level, return nonzero. */
4190 static int
4192 {
4198 else
4201 }
4203 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4204 parameters given by current_template_args, or reuses a
4205 previously existing one, if appropriate. Returns the DECL, or an
4206 equivalent one, if it is replaced via a call to duplicate_decls.
4208 If IS_FRIEND is true, DECL is a friend declaration. */
4210 tree
4212 {
4213 tree tmpl;
4214 tree args;
4215 tree info;
4216 tree ctx;
4220 /* True if the template is a member template, in the sense of
4221 [temp.mem]. */
4227 /* See if this is a partial specialization. */
4236 /* For a friend, we want the context of the friend function, not
4237 the type of which it is a friend. */
4241 /* In the case of a virtual function, we want the class in which
4242 it is defined. */
4244 else
4245 /* Otherwise, if we're currently defining some class, the DECL
4246 is assumed to be a member of the class. */
4255 /* See if this is a primary template. */
4257 /* A friend template that specifies a class context, i.e.
4258 template <typename T> friend void A<T>::f();
4259 is not primary. */
4261 else
4265 {
4270 {
4273 }
4275 {
4277 {
4278 /* [temp.mem]
4280 A destructor shall not be a member template. */
4283 }
4290 {
4291 /* [basic.stc.dynamic.allocation]
4293 An allocation function can be a function
4294 template. ... Template allocation functions shall
4295 have two or more parameters. */
4298 }
4299 }
4303 else
4304 {
4307 }
4308 }
4310 /* Check to see that the rules regarding the use of default
4311 arguments are not being violated. */
4315 /* Ensure that there are no parameter packs in the type of this
4316 declaration that have not been expanded. */
4318 {
4319 /* Check each of the arguments individually to see if there are
4320 any bare parameter packs. */
4326 {
4329 {
4330 /* This is a PARM_DECL that contains unexpanded parameter
4331 packs. We have already complained about this in the
4332 check_for_bare_parameter_packs call, so just replace
4333 these types with ERROR_MARK_NODE. */
4336 }
4340 }
4342 /* Check for bare parameter packs in the return type and the
4343 exception specifiers. */
4345 /* Errors were already issued, set return type to int
4346 as the frontend doesn't expect error_mark_node as
4347 the return type. */
4351 }
4353 {
4356 }
4367 {
4372 /* If DECL is a TYPE_DECL for a class-template, then there won't
4373 be DECL_LANG_SPECIFIC. The information equivalent to
4374 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4378 {
4379 /* Since a template declaration already existed for this
4380 class-type, we must be redeclaring it here. Make sure
4381 that the redeclaration is valid. */
4383 current_template_parms);
4384 /* We don't need to create a new TEMPLATE_DECL; just use the
4385 one we already had. */
4387 }
4388 else
4389 {
4391 member_template_p);
4396 {
4397 /* A specialization of a member template of a template
4398 class. */
4402 }
4403 }
4404 }
4405 else
4406 {
4412 {
4415 }
4423 {
4424 tree new_tmpl;
4426 /* The declaration is a specialization of a member
4427 template, declared outside the class. Therefore, the
4428 innermost template arguments will be NULL, so we
4429 replace them with the arguments determined by the
4430 earlier call to check_explicit_specialization. */
4433 new_tmpl
4435 member_template_p);
4445 args,
4448 }
4450 /* Make sure the template headers we got make sense. */
4455 {
4458 }
4459 else
4461 {
4466 {
4470 else
4475 }
4479 else
4483 }
4485 /* Check that the parms are used in the appropriate qualifying scopes
4486 in the declarator. */
4490 {
4496 /* Avoid crash in import_export_decl. */
4499 }
4500 }
4505 /* Push template declarations for global functions and types. Note
4506 that we do not try to push a global template friend declared in a
4507 template class; such a thing may well depend on the template
4508 parameters of the class. */
4511 {
4516 /* Hide template friend classes that haven't been declared yet. */
4518 {
4521 }
4522 }
4525 {
4531 {
4534 /* It is a conversion operator. See if the type converted to
4535 depends on innermost template operands. */
4538 depth))
4540 }
4542 /* Give template template parms a DECL_CONTEXT of the template
4543 for which they are a parameter. */
4546 {
4553 }
4554 }
4556 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4557 back to its most general template. If TMPL is a specialization,
4558 ARGS may only have the innermost set of arguments. Add the missing
4559 argument levels if necessary. */
4571 }
4573 tree
4575 {
4577 }
4579 /* Called when a class template TYPE is redeclared with the indicated
4580 template PARMS, e.g.:
4582 template <class T> struct S;
4583 template <class T> struct S {}; */
4585 bool
4587 {
4588 tree tmpl;
4589 tree tmpl_parms;
4593 {
4596 }
4600 /* The type is nested in some template class. Nothing to worry
4601 about here; there are no new template parameters for the nested
4602 type. */
4606 {
4608 tmpl);
4610 }
4616 {
4622 }
4625 {
4626 tree tmpl_parm;
4627 tree parm;
4628 tree tmpl_default;
4629 tree parm_default;
4640 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4641 TEMPLATE_DECL. */
4652 {
4656 }
4659 {
4660 /* We have in [temp.param]:
4662 A template-parameter may not be given default arguments
4663 by two different declarations in the same scope. */
4668 }
4671 /* Update the previous template parameters (which are the ones
4672 that will really count) with the new default value. */
4675 /* Update the new parameters, too; they'll be used as the
4676 parameters for any members. */
4678 }
4681 }
4683 /* Simplify EXPR if it is a non-dependent expression. Returns the
4684 (possibly simplified) expression. */
4686 tree
4688 {
4692 /* If we're in a template, but EXPR isn't value dependent, simplify
4693 it. We're supposed to treat:
4695 template <typename T> void f(T[1 + 1]);
4696 template <typename T> void f(T[2]);
4698 as two declarations of the same function, for example. */
4702 {
4703 HOST_WIDE_INT saved_processing_template_decl;
4709 tf_error,
4714 }
4716 }
4718 /* EXPR is an expression which is used in a constant-expression context.
4719 For instance, it could be a VAR_DECL with a constant initializer.
4720 Extract the innermost constant expression.
4722 This is basically a more powerful version of
4723 integral_constant_value, which can be used also in templates where
4724 initializers can maintain a syntactic rather than semantic form
4725 (even if they are non-dependent, for access-checking purposes). */
4727 static tree
4729 {
4731 do
4732 {
4735 }
4739 }
4741 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4742 must be a function or a pointer-to-function type, as specified
4743 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4744 and check that the resulting function has external linkage. */
4746 static tree
4748 {
4762 /* [temp.arg.nontype]/1
4764 A template-argument for a non-type, non-template template-parameter
4765 shall be one of:
4766 [...]
4767 -- the address of an object or function with external linkage. */
4769 {
4774 }
4777 }
4779 /* Subroutine of convert_nontype_argument.
4780 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4781 Emit an error otherwise. */
4783 static bool
4785 {
4793 }
4795 /* Attempt to convert the non-type template parameter EXPR to the
4796 indicated TYPE. If the conversion is successful, return the
4797 converted value. If the conversion is unsuccessful, return
4798 NULL_TREE if we issued an error message, or error_mark_node if we
4799 did not. We issue error messages for out-and-out bad template
4800 parameters, but not simply because the conversion failed, since we
4801 might be just trying to do argument deduction. Both TYPE and EXPR
4802 must be non-dependent.
4804 The conversion follows the special rules described in
4805 [temp.arg.nontype], and it is much more strict than an implicit
4806 conversion.
4808 This function is called twice for each template argument (see
4809 lookup_template_class for a more accurate description of this
4810 problem). This means that we need to handle expressions which
4811 are not valid in a C++ source, but can be created from the
4812 first call (for instance, casts to perform conversions). These
4813 hacks can go away after we fix the double coercion problem. */
4815 static tree
4817 {
4818 tree expr_type;
4820 /* Detect immediately string literals as invalid non-type argument.
4821 This special-case is not needed for correctness (we would easily
4822 catch this later), but only to provide better diagnostic for this
4823 common user mistake. As suggested by DR 100, we do not mention
4824 linkage issues in the diagnostic as this is not the point. */
4826 {
4831 }
4833 /* If we are in a template, EXPR may be non-dependent, but still
4834 have a syntactic, rather than semantic, form. For example, EXPR
4835 might be a SCOPE_REF, rather than the VAR_DECL to which the
4836 SCOPE_REF refers. Preserving the qualifying scope is necessary
4837 so that access checking can be performed when the template is
4838 instantiated -- but here we need the resolved form so that we can
4839 convert the argument. */
4845 /* HACK: Due to double coercion, we can get a
4846 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4847 which is the tree that we built on the first call (see
4848 below when coercing to reference to object or to reference to
4849 function). We just strip everything and get to the arg.
4850 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4851 for examples. */
4853 {
4855 {
4856 /* ??? Maybe we could use convert_from_reference here, but we
4857 would need to relax its constraints because the NOP_EXPR
4858 could actually change the type to something more cv-qualified,
4859 and this is not folded by convert_from_reference. */
4870 }
4872 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4873 parameter is a pointer to object, through decay and
4874 qualification conversion. Let's strip everything. */
4876 {
4880 /* Skip the ADDR_EXPR only if it is part of the decay for
4881 an array. Otherwise, it is part of the original argument
4882 in the source code. */
4886 }
4887 }
4889 /* [temp.arg.nontype]/5, bullet 1
4891 For a non-type template-parameter of integral or enumeration type,
4892 integral promotions (_conv.prom_) and integral conversions
4893 (_conv.integral_) are applied. */
4895 {
4900 /* Notice that there are constant expressions like '4 % 0' which
4901 do not fold into integer constants. */
4903 {
4907 }
4909 /* At this point, an implicit conversion does what we want,
4910 because we already know that the expression is of integral
4911 type. */
4916 /* Conversion was allowed: fold it to a bare integer constant. */
4918 }
4919 /* [temp.arg.nontype]/5, bullet 2
4921 For a non-type template-parameter of type pointer to object,
4922 qualification conversions (_conv.qual_) and the array-to-pointer
4923 conversion (_conv.array_) are applied. */
4925 {
4926 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
4928 A template-argument for a non-type, non-template template-parameter
4929 shall be one of: [...]
4931 -- the name of a non-type template-parameter;
4932 -- the address of an object or function with external linkage, [...]
4933 expressed as "& id-expression" where the & is optional if the name
4934 refers to a function or array, or if the corresponding
4935 template-parameter is a reference.
4937 Here, we do not care about functions, as they are invalid anyway
4938 for a parameter of type pointer-to-object. */
4941 /* Non-type template parameters are OK. */
4942 ;
4945 {
4947 {
4949 "because %qD is a variable, not the address of "
4953 }
4954 /* Other values, like integer constants, might be valid
4955 non-type arguments of some other type. */
4957 }
4958 else
4959 {
4960 tree decl;
4965 {
4970 }
4972 {
4977 }
4978 }
4987 }
4988 /* [temp.arg.nontype]/5, bullet 3
4990 For a non-type template-parameter of type reference to object, no
4991 conversions apply. The type referred to by the reference may be more
4992 cv-qualified than the (otherwise identical) type of the
4993 template-argument. The template-parameter is bound directly to the
4994 template-argument, which must be an lvalue. */
4996 {
4998 expr_type))
5002 {
5006 }
5009 {
5013 }
5015 /* [temp.arg.nontype]/1
5017 A template-argument for a non-type, non-template template-parameter
5018 shall be one of: [...]
5020 -- the address of an object or function with external linkage. */
5023 {
5026 {
5028 "because a reference variable does not have a constant "
5031 }
5032 }
5035 {
5040 }
5043 {
5048 }
5051 }
5052 /* [temp.arg.nontype]/5, bullet 4
5054 For a non-type template-parameter of type pointer to function, only
5055 the function-to-pointer conversion (_conv.func_) is applied. If the
5056 template-argument represents a set of overloaded functions (or a
5057 pointer to such), the matching function is selected from the set
5058 (_over.over_). */
5060 {
5061 /* If the argument is a template-id, we might not have enough
5062 context information to decay the pointer. */
5064 {
5068 }
5075 {
5079 }
5080 }
5081 /* [temp.arg.nontype]/5, bullet 5
5083 For a non-type template-parameter of type reference to function, no
5084 conversions apply. If the template-argument represents a set of
5085 overloaded functions, the matching function is selected from the set
5086 (_over.over_). */
5088 {
5090 {
5095 }
5102 }
5103 /* [temp.arg.nontype]/5, bullet 6
5105 For a non-type template-parameter of type pointer to member function,
5106 no conversions apply. If the template-argument represents a set of
5107 overloaded member functions, the matching member function is selected
5108 from the set (_over.over_). */
5110 {
5115 /* [temp.arg.nontype] bullet 1 says the pointer to member
5116 expression must be a pointer-to-member constant. */
5120 /* There is no way to disable standard conversions in
5121 resolve_address_of_overloaded_function (called by
5122 instantiate_type). It is possible that the call succeeded by
5123 converting &B::I to &D::I (where B is a base of D), so we need
5124 to reject this conversion here.
5126 Actually, even if there was a way to disable standard conversions,
5127 it would still be better to reject them here so that we can
5128 provide a superior diagnostic. */
5130 {
5131 /* Make sure we are just one standard conversion off. */
5138 }
5139 }
5140 /* [temp.arg.nontype]/5, bullet 7
5142 For a non-type template-parameter of type pointer to data member,
5143 qualification conversions (_conv.qual_) are applied. */
5145 {
5146 /* [temp.arg.nontype] bullet 1 says the pointer to member
5147 expression must be a pointer-to-member constant. */
5154 }
5155 /* A template non-type parameter must be one of the above. */
5156 else
5159 /* Sanity check: did we actually convert the argument to the
5160 right type? */
5163 }
5165 /* Subroutine of coerce_template_template_parms, which returns 1 if
5166 PARM_PARM and ARG_PARM match using the rule for the template
5167 parameters of template template parameters. Both PARM and ARG are
5168 template parameters; the rest of the arguments are the same as for
5169 coerce_template_template_parms.
5170 */
5171 static int
5173 tree arg,
5174 tsubst_flags_t complain,
5175 tree in_decl,
5176 tree outer_args)
5177 {
5186 {
5188 /* We encounter instantiations of templates like
5189 template <template <template <class> class> class TT>
5190 class C; */
5191 {
5198 }
5199 /* Fall through. */
5204 /* Argument is a parameter pack but parameter is not. */
5209 /* The tsubst call is used to handle cases such as
5211 template <int> class C {};
5212 template <class T, template <T> class TT> class D {};
5213 D<int, C> d;
5215 i.e. the parameter list of TT depends on earlier parameters. */
5217 && !same_type_p
5224 /* Argument is a parameter pack but parameter is not. */
5231 }
5234 }
5237 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5238 template template parameters. Both PARM_PARMS and ARG_PARMS are
5239 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5240 or PARM_DECL.
5242 Consider the example:
5243 template <class T> class A;
5244 template<template <class U> class TT> class B;
5246 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5247 the parameters to A, and OUTER_ARGS contains A. */
5249 static int
5251 tree arg_parms,
5252 tsubst_flags_t complain,
5253 tree in_decl,
5254 tree outer_args)
5255 {
5266 /* Determine whether we have a parameter pack at the end of the
5267 template template parameter's template parameter list. */
5269 {
5276 {
5290 }
5291 }
5297 /* Check all of the template parameters except the parameter pack at
5298 the end (if any). */
5300 {
5309 outer_args))
5312 }
5315 {
5316 /* Check each of the template parameters in the template
5317 argument against the template parameter pack at the end of
5318 the template template parameter. */
5325 {
5332 outer_args))
5334 }
5335 }
5338 }
5340 /* Verifies that the deduced template arguments (in TARGS) for the
5341 template template parameters (in TPARMS) represent valid bindings,
5342 by comparing the template parameter list of each template argument
5343 to the template parameter list of its corresponding template
5344 template parameter, in accordance with DR150. This
5345 routine can only be called after all template arguments have been
5346 deduced. It will return TRUE if all of the template template
5347 parameter bindings are okay, FALSE otherwise. */
5348 bool
5350 {
5354 /* We're dealing with template parms in this process. */
5360 {
5365 {
5370 {
5371 /* Look inside the argument pack. */
5374 }
5377 {
5381 /* Extract the next argument from the argument
5382 pack. */
5386 /* Look at the pattern of the pack expansion. */
5389 /* Extract the template parameters from the template
5390 argument. */
5396 /* Verify that we can coerce the template template
5397 parameters from the template argument to the template
5398 parameter. This requires an exact match. */
5400 && !coerce_template_template_parms
5402 targ_parms,
5403 tf_none,
5404 tparm,
5405 targs))
5406 {
5409 }
5410 }
5411 }
5412 }
5414 out:
5418 }
5420 /* Convert the indicated template ARG as necessary to match the
5421 indicated template PARM. Returns the converted ARG, or
5422 error_mark_node if the conversion was unsuccessful. Error and
5423 warning messages are issued under control of COMPLAIN. This
5424 conversion is for the Ith parameter in the parameter list. ARGS is
5425 the full set of template arguments deduced so far. */
5427 static tree
5429 tree arg,
5430 tree args,
5431 tsubst_flags_t complain,
5433 tree in_decl)
5434 {
5435 tree orig_arg;
5436 tree val;
5441 {
5442 /* The template argument was the name of some
5443 member function. That's usually
5444 invalid, but static members are OK. In any
5445 case, grab the underlying fields/functions
5446 and issue an error later if required. */
5449 }
5457 /* When determining whether an argument pack expansion is a template,
5458 look at the pattern. */
5462 /* Deal with an injected-class-name used as a template template arg. */
5464 {
5467 {
5475 }
5476 }
5478 is_tmpl_type =
5493 {
5499 typename_type,
5503 }
5505 {
5507 {
5509 {
5519 else
5521 }
5522 }
5524 }
5526 {
5528 {
5534 else
5536 }
5538 }
5541 {
5543 {
5545 /* The number of argument required is not known yet.
5546 Just accept it for now. */
5548 else
5549 {
5551 tree argparm;
5557 args))
5558 {
5561 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5562 TEMPLATE_DECL. */
5564 {
5569 }
5570 }
5571 else
5572 {
5574 {
5580 }
5583 }
5584 }
5585 }
5586 else
5588 /* We only form one instance of each template specialization.
5589 Therefore, if we use a non-canonical variant (i.e., a
5590 typedef), any future messages referring to the type will use
5591 the typedef, which is confusing if those future uses do not
5592 themselves also use the typedef. */
5595 }
5596 else
5597 {
5604 {
5607 else
5608 {
5609 /* Not sure if this is reachable, but it doesn't hurt
5610 to be robust. */
5613 }
5614 }
5616 /* We used to call digest_init here. However, digest_init
5617 will report errors, which we don't want when complain
5618 is zero. More importantly, digest_init will try too
5619 hard to convert things: for example, `0' should not be
5620 converted to pointer type at this point according to
5621 the standard. Accepting this is not merely an
5622 extension, since deciding whether or not these
5623 conversions can occur is part of determining which
5624 function template to call, or whether a given explicit
5625 argument specification is valid. */
5627 else
5636 {
5637 /* Strip typedefs from the SCOPE_REF. */
5642 }
5643 }
5646 }
5648 /* Coerces the remaining template arguments in INNER_ARGS (from
5649 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5650 Returns the coerced argument pack. PARM_IDX is the position of this
5651 parameter in the template parameter list. ARGS is the original
5652 template argument list. */
5653 static tree
5656 tree args,
5657 tree inner_args,
5659 tree new_args,
5661 tree in_decl,
5662 tsubst_flags_t complain)
5663 {
5666 tree packed_args;
5667 tree argument_pack;
5677 {
5678 /* When the template parameter is a non-type template
5679 parameter pack whose type uses parameter packs, we need
5680 to look at each of the template arguments
5681 separately. Build a vector of the types for these
5682 non-type template parameters in PACKED_TYPES. */
5683 tree expansion
5691 /* Check that we have the right number of arguments. */
5695 {
5696 int needed_parms
5701 }
5703 /* If we aren't able to check the actual arguments now
5704 (because they haven't been expanded yet), we can at least
5705 verify that all of the types used for the non-type
5706 template parameter pack are, in fact, valid for non-type
5707 template parameters. */
5710 {
5713 {
5717 }
5718 }
5719 }
5721 /* Convert the remaining arguments, which will be a part of the
5722 parameter pack "parm". */
5724 {
5729 {
5730 /* When we have a vector of types (corresponding to the
5731 non-type template parameter pack that uses parameter
5732 packs in its type, as mention above), and the
5733 argument is not an expansion (which expands to a
5734 currently unknown number of arguments), clone the
5735 parm and give it the next type in PACKED_TYPES. */
5739 }
5744 in_decl);
5748 }
5753 else
5754 {
5759 }
5762 #ifdef ENABLE_CHECKING
5765 #endif
5767 }
5769 /* Convert all template arguments to their appropriate types, and
5770 return a vector containing the innermost resulting template
5771 arguments. If any error occurs, return error_mark_node. Error and
5772 warning messages are issued under control of COMPLAIN.
5774 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5775 for arguments not specified in ARGS. Otherwise, if
5776 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5777 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5778 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5779 ARGS. */
5781 static tree
5783 tree args,
5784 tree in_decl,
5785 tsubst_flags_t complain,
5788 {
5790 tree inner_args;
5791 tree new_args;
5792 tree new_inner_args;
5796 /* When used as a boolean value, indicates whether this is a
5797 variadic template parameter list. Since it's an int, we can also
5798 subtract it from nparms to get the number of non-variadic
5799 parameters. */
5804 /* Determine if there are any parameter packs. */
5806 {
5810 }
5813 /* If there are 0 or 1 parameter packs, we need to expand any argument
5814 packs so that we can deduce a parameter pack from some non-packed args
5815 followed by an argument pack, as in variadic85.C. If there are more
5816 than that, we need to leave argument packs intact so the arguments are
5817 assigned to the right parameter packs. This should only happen when
5818 dealing with a nested class inside a partial specialization of a class
5819 template, as in variadic92.C. */
5826 && require_all_args
5827 && (!use_default_args
5830 {
5832 {
5835 {
5838 }
5845 }
5848 }
5850 /* We need to evaluate the template arguments, even though this
5851 template-id may be nested within a "sizeof". */
5859 {
5860 tree arg;
5861 tree parm;
5863 /* Get the Ith template parameter. */
5867 {
5870 }
5872 /* Calculate the next argument. */
5875 else
5880 {
5881 /* All remaining arguments will be placed in the
5882 template parameter pack PARM. */
5888 /* Store this argument. */
5890 lost++;
5893 /* We are done with all of the arguments. */
5897 }
5899 {
5901 {
5903 {
5904 /* FIXME this restriction was removed by N2555; see
5905 bug 35722. */
5906 /* If ARG is a pack expansion, but PARM is not a
5907 template parameter pack (if it were, we would have
5908 handled it above), we're trying to expand into a
5909 fixed-length argument list. */
5913 else
5916 }
5918 }
5919 }
5921 {
5922 /* There must be a default arg in this case. */
5925 /* The position of the first default template argument,
5926 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
5927 Record that. */
5930 }
5931 else
5935 {
5938 }
5940 /* This only occurs if there was an error in the template
5941 parameter list itself (which we would already have
5942 reported) that we are trying to recover from, e.g., a class
5943 template with a parameter list such as
5944 template<typename..., typename>. */
5946 else
5952 lost++;
5954 }
5961 #ifdef ENABLE_CHECKING
5965 #endif
5968 }
5970 /* Returns 1 if template args OT and NT are equivalent. */
5972 static int
5974 {
5979 /* For member templates */
5986 {
6003 }
6005 {
6006 /* We get here probably because we are in the middle of substituting
6007 into the pattern of a pack expansion. In that case the
6008 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6009 interested in. So we want to use the initial pack argument for
6010 the comparison. */
6015 }
6020 else
6022 }
6024 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6025 of template arguments. Returns 0 otherwise. */
6027 int
6029 {
6036 {
6042 }
6044 }
6046 static void
6048 {
6058 /* We are called both from instantiate_decl, where we've already had a
6059 tinst_level pushed, and instantiate_template, where we haven't.
6060 Compensate. */
6071 else
6080 }
6083 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6084 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6085 documentation for TEMPLATE_ID_EXPR. */
6087 tree
6089 {
6090 tree type;
6100 {
6102 unknown_type_node,
6104 arglist);
6106 }
6113 }
6115 /* Within the scope of a template class S<T>, the name S gets bound
6116 (in build_self_reference) to a TYPE_DECL for the class, not a
6117 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6118 or one of its enclosing classes, and that type is a template,
6119 return the associated TEMPLATE_DECL. Otherwise, the original
6120 DECL is returned.
6122 Also handle the case when DECL is a TREE_LIST of ambiguous
6123 injected-class-names from different bases. */
6125 tree
6127 {
6131 /* DR 176: A lookup that finds an injected-class-name (10.2
6132 [class.member.lookup]) can result in an ambiguity in certain cases
6133 (for example, if it is found in more than one base class). If all of
6134 the injected-class-names that are found refer to specializations of
6135 the same class template, and if the name is followed by a
6136 template-argument-list, the reference refers to the class template
6137 itself and not a specialization thereof, and is not ambiguous. */
6139 {
6142 {
6148 }
6151 else
6153 }
6159 }
6161 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6162 parameters, find the desired type.
6164 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6166 IN_DECL, if non-NULL, is the template declaration we are trying to
6167 instantiate.
6169 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6170 the class we are looking up.
6172 Issue error and warning messages under control of COMPLAIN.
6174 If the template class is really a local class in a template
6175 function, then the FUNCTION_CONTEXT is the function in which it is
6176 being instantiated.
6178 ??? Note that this function is currently called *twice* for each
6179 template-id: the first time from the parser, while creating the
6180 incomplete type (finish_template_type), and the second type during the
6181 real instantiation (instantiate_template_class). This is surely something
6182 that we want to avoid. It also causes some problems with argument
6183 coercion (see convert_nontype_argument for more information on this). */
6185 tree
6187 tree arglist,
6188 tree in_decl,
6189 tree context,
6191 tsubst_flags_t complain)
6192 {
6194 tree t;
6197 spec_entry elt;
6198 hashval_t hash;
6203 {
6207 else
6208 {
6215 }
6218 }
6220 {
6223 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6224 an implicit typename for the second A. Deal with it. */
6229 {
6232 }
6233 }
6236 {
6239 }
6243 {
6247 }
6249 /* Issue an error message if we didn't find a template. */
6251 {
6255 }
6258 /* Make sure it's a user visible template, if it was named by
6259 the user. */
6262 {
6264 {
6268 }
6270 }
6275 {
6276 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6277 template arguments */
6279 tree parm;
6280 tree arglist2;
6281 tree outer;
6285 /* Consider an example where a template template parameter declared as
6287 template <class T, class U = std::allocator<T> > class TT
6289 The template parameter level of T and U are one level larger than
6290 of TT. To proper process the default argument of U, say when an
6291 instantiation `TT<int>' is seen, we need to build the full
6292 arguments containing {int} as the innermost level. Outer levels,
6293 available when not appearing as default template argument, can be
6294 obtained from the arguments of the enclosing template.
6296 Suppose that TT is later substituted with std::vector. The above
6297 instantiation is `TT<int, std::allocator<T> >' with TT at
6298 level 1, and T at level 2, while the template arguments at level 1
6299 becomes {std::vector} and the inner level 2 is {int}. */
6305 /* This is an argument of the current template, so we haven't set
6306 DECL_CONTEXT yet. */
6313 complain,
6323 }
6324 else
6325 {
6327 tree gen_tmpl;
6328 tree type_decl;
6340 {
6341 /* We've been given an incomplete set of template arguments.
6342 For example, given:
6344 template <class T> struct S1 {
6345 template <class U> struct S2 {};
6346 template <class U> struct S2<U*> {};
6347 };
6349 we will be called with an ARGLIST of `U*', but the
6350 TEMPLATE will be `template <class T> template
6351 <class U> struct S1<T>::S2'. We must fill in the missing
6352 arguments. */
6353 arglist
6355 arglist);
6357 }
6359 /* Now we should have enough arguments. */
6362 /* From here on, we're only interested in the most general
6363 template. */
6365 /* Calculate the BOUND_ARGS. These will be the args that are
6366 actually tsubst'd into the definition to create the
6367 instantiation. */
6369 {
6370 /* We have multiple levels of arguments to coerce, at once. */
6380 {
6383 complain,
6387 /* Don't process further if one of the levels fails. */
6389 {
6390 /* Restore the ARGLIST to its full size. */
6393 }
6397 /* We temporarily reduce the length of the ARGLIST so
6398 that coerce_template_parms will see only the arguments
6399 corresponding to the template parameters it is
6400 examining. */
6402 }
6404 /* Restore the ARGLIST to its full size. */
6408 }
6409 else
6410 arglist
6413 gen_tmpl,
6414 complain,
6419 /* We were unable to bind the arguments. */
6422 /* In the scope of a template class, explicit references to the
6423 template class refer to the type of the template, not any
6424 instantiation of it. For example, in:
6426 template <class T> class C { void f(C<T>); }
6428 the `C<T>' is just the same as `C'. Outside of the
6429 class, however, such a reference is an instantiation. */
6433 /* comp_template_args is expensive, check it last. */
6435 arglist))
6438 /* If we already have this specialization, return it. */
6448 /* This type is a "partial instantiation" if any of the template
6449 arguments still involve template parameters. Note that we set
6450 IS_PARTIAL_INSTANTIATION for partial specializations as
6451 well. */
6454 /* If the deduced arguments are invalid, then the binding
6455 failed. */
6459 complain))
6466 {
6471 }
6478 /* Create the type. */
6480 {
6482 {
6488 }
6489 else
6490 {
6491 /* We don't want to call start_enum for this type, since
6492 the values for the enumeration constants may involve
6493 template parameters. And, no one should be interested
6494 in the enumeration constants for such a type. */
6497 }
6498 }
6499 else
6500 {
6507 /* A local class. Make sure the decl gets registered properly. */
6512 /* This instantiation is another name for the primary
6513 template type. Set the TYPE_CANONICAL field
6514 appropriately. */
6517 /* Some of the template arguments require structural
6518 equality testing, so this template class requires
6519 structural equality testing. */
6521 }
6523 /* If we called start_enum or pushtag above, this information
6524 will already be set up. */
6526 {
6533 }
6534 else
6542 {
6545 }
6547 /* Set up the template information. We have to figure out which
6548 template is the immediate parent if this is a full
6549 instantiation. */
6552 /* This case is easy; there are no member templates involved. */
6554 else
6555 {
6556 /* This is a full instantiation of a member template. Find
6557 the partial instantiation of which this is an instance. */
6559 /* Temporarily reduce by one the number of levels in the ARGLIST
6560 so as to avoid comparing the last set of arguments. */
6565 }
6575 /* Note this use of the partial instantiation so we can check it
6576 later in maybe_process_partial_specialization. */
6583 /* Now that the type has been registered on the instantiations
6584 list, we set up the enumerators. Because the enumeration
6585 constants may involve the enumeration type itself, we make
6586 sure to register the type first, and then create the
6587 constants. That way, doing tsubst_expr for the enumeration
6588 constants won't result in recursive calls here; we'll find
6589 the instantiation and exit above. */
6593 /* If the type makes use of template parameters, the
6594 code that generates debugging information will crash. */
6597 /* Possibly limit visibility based on template args. */
6602 }
6604 }
6605 \f
6606 struct pair_fn_data
6607 {
6608 tree_fn_t fn;
6610 /* True when we should also visit template parameters that occur in
6611 non-deduced contexts. */
6614 };
6616 /* Called from for_each_template_parm via walk_tree. */
6618 static tree
6620 {
6633 {
6637 /* Fall through. */
6660 /* Since we're not going to walk subtrees, we have to do this
6661 explicitly here. */
6665 /* Fall through. */
6668 /* Check the return type. */
6673 /* Check the parameter types. Since default arguments are not
6674 instantiated until they are needed, the TYPE_ARG_TYPES may
6675 contain expressions that involve template parameters. But,
6676 no-one should be looking at them yet. And, once they're
6677 instantiated, they don't contain template parameters, so
6678 there's no point in looking at them then, either. */
6679 {
6680 tree parm;
6687 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6688 want walk_tree walking into them itself. */
6690 }
6707 /* Fall through. */
6723 /* Record template parameters such as `T' inside `TT<T>'. */
6727 /* Fall through. */
6739 /* A template template parameter is encountered. */
6745 /* Already substituted template template parameter */
6768 /* If there's no type, then this thing must be some expression
6769 involving template parameters. */
6790 }
6792 /* We didn't find any template parameters we liked. */
6794 }
6796 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6797 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6798 call FN with the parameter and the DATA.
6799 If FN returns nonzero, the iteration is terminated, and
6800 for_each_template_parm returns 1. Otherwise, the iteration
6801 continues. If FN never returns a nonzero value, the value
6802 returned by for_each_template_parm is 0. If FN is NULL, it is
6803 considered to be the function which always returns 1.
6805 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6806 parameters that occur in non-deduced contexts. When false, only
6807 visits those template parameters that can be deduced. */
6809 static int
6813 {
6817 /* Set up. */
6822 /* Walk the tree. (Conceptually, we would like to walk without
6823 duplicates, but for_each_template_parm_r recursively calls
6824 for_each_template_parm, so we would need to reorganize a fair
6825 bit to use walk_tree_without_duplicates, so we keep our own
6826 visited list.) */
6829 else
6832 for_each_template_parm_r,
6836 /* Clean up. */
6838 {
6841 }
6844 }
6846 /* Returns true if T depends on any template parameter. */
6848 int
6850 {
6877 else
6878 {
6881 }
6886 }
6888 /* Returns true if T depends on any template parameter with level LEVEL. */
6890 int
6892 {
6895 }
6899 #ifdef GATHER_STATISTICS
6901 #endif
6905 /* We're starting to instantiate D; record the template instantiation context
6906 for diagnostics and to restore it later. */
6908 static int
6910 {
6914 {
6915 /* If the instantiation in question still has unbound template parms,
6916 we don't really care if we can't instantiate it, so just return.
6917 This happens with base instantiation for implicit `typename'. */
6929 }
6939 #ifdef GATHER_STATISTICS
6942 #endif
6946 }
6948 /* We're done instantiating this template; return to the instantiation
6949 context. */
6951 static void
6953 {
6954 /* Restore the filename and line number stashed away when we started
6955 this instantiation. */
6960 }
6962 /* We're instantiating a deferred template; restore the template
6963 instantiation context in which the instantiation was requested, which
6964 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
6966 static tree
6968 {
6978 }
6980 /* Returns the TINST_LEVEL which gives the original instantiation
6981 context. */
6985 {
6991 }
6993 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
6995 bool
6997 {
6998 tree parms;
7015 }
7017 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7018 vector of template arguments, as for tsubst.
7020 Returns an appropriate tsubst'd friend declaration. */
7022 static tree
7024 {
7025 tree new_friend;
7030 /* This was a friend declared with an explicit template
7031 argument list, e.g.:
7033 friend void f<>(T);
7035 to indicate that f was a template instantiation, not a new
7036 function declaration. Now, we have to figure out what
7037 instantiation of what template. */
7038 {
7040 tree new_args;
7041 tree tmpl;
7044 /* Friend functions are looked up in the containing namespace scope.
7045 We must enter that scope, to avoid finding member functions of the
7046 current class with same name. */
7061 tsk_none);
7063 }
7067 /* The NEW_FRIEND will look like an instantiation, to the
7068 compiler, but is not an instantiation from the point of view of
7069 the language. For example, we might have had:
7071 template <class T> struct S {
7072 template <class U> friend void f(T, U);
7073 };
7075 Then, in S<int>, template <class U> void f(int, U) is not an
7076 instantiation of anything. */
7082 {
7086 }
7088 /* The mangled name for the NEW_FRIEND is incorrect. The function
7089 is not a template instantiation and should not be mangled like
7090 one. Therefore, we forget the mangling here; we'll recompute it
7091 later if we need it. */
7093 {
7096 }
7099 {
7100 tree old_decl;
7101 tree new_friend_template_info;
7102 tree new_friend_result_template_info;
7103 tree ns;
7106 /* We must save some information from NEW_FRIEND before calling
7107 duplicate decls since that function will free NEW_FRIEND if
7108 possible. */
7110 new_friend_is_defn =
7115 {
7116 /* This declaration is a `primary' template. */
7119 new_friend_result_template_info
7121 }
7122 else
7125 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7129 /* Inside pushdecl_namespace_level, we will push into the
7130 current namespace. However, the friend function should go
7131 into the namespace of the template. */
7141 {
7142 /* This new friend declaration matched an existing
7143 declaration. For example, given:
7145 template <class T> void f(T);
7146 template <class U> class C {
7147 template <class T> friend void f(T) {}
7148 };
7150 the friend declaration actually provides the definition
7151 of `f', once C has been instantiated for some type. So,
7152 old_decl will be the out-of-class template declaration,
7153 while new_friend is the in-class definition.
7155 But, if `f' was called before this point, the
7156 instantiation of `f' will have DECL_TI_ARGS corresponding
7157 to `T' but not to `U', references to which might appear
7158 in the definition of `f'. Previously, the most general
7159 template for an instantiation of `f' was the out-of-class
7160 version; now it is the in-class version. Therefore, we
7161 run through all specialization of `f', adding to their
7162 DECL_TI_ARGS appropriately. In particular, they need a
7163 new set of outer arguments, corresponding to the
7164 arguments for this class instantiation.
7166 The same situation can arise with something like this:
7168 friend void f(int);
7169 template <class T> class C {
7170 friend void f(T) {}
7171 };
7173 when `C<int>' is instantiated. Now, `f(int)' is defined
7174 in the class. */
7177 /* On the other hand, if the in-class declaration does
7178 *not* provide a definition, then we don't want to alter
7179 existing definitions. We can just leave everything
7180 alone. */
7181 ;
7182 else
7183 {
7187 /* Overwrite whatever template info was there before, if
7188 any, with the new template information pertaining to
7189 the declaration. */
7193 /* We should have called reregister_specialization in
7194 duplicate_decls. */
7198 else
7199 {
7200 tree t;
7202 /* Indicate that the old function template is a partial
7203 instantiation. */
7211 /* Reassign any specializations already in the hash table
7212 to the new more general template, and add the
7213 additional template args. */
7217 {
7219 spec_entry elt;
7231 register_specialization
7234 }
7236 }
7237 }
7239 /* The information from NEW_FRIEND has been merged into OLD_DECL
7240 by duplicate_decls. */
7242 }
7243 }
7244 else
7245 {
7249 /* In the code
7250 template <class T> class C {
7251 template <class U> friend void C1<U>::f (); // case 1
7252 friend void C2<T>::f (); // case 2
7253 };
7254 we only need to make sure CONTEXT is a complete type for
7255 case 2. To distinguish between the two cases, we note that
7256 CONTEXT of case 1 remains dependent type after tsubst while
7257 this isn't true for case 2. */
7267 {
7268 /* Check to see that the declaration is really present, and,
7269 possibly obtain an improved declaration. */
7275 }
7276 }
7279 }
7281 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7282 template arguments, as for tsubst.
7284 Returns an appropriate tsubst'd friend type or error_mark_node on
7285 failure. */
7287 static tree
7289 {
7290 tree friend_type;
7291 tree tmpl;
7292 tree context;
7297 {
7300 else
7302 }
7304 /* Look for a class template declaration. We look for hidden names
7305 because two friend declarations of the same template are the
7306 same. For example, in:
7308 struct A {
7309 template <typename> friend class F;
7310 };
7311 template <typename> struct B {
7312 template <typename> friend class F;
7313 };
7315 both F templates are the same. */
7320 /* But, if we don't find one, it might be because we're in a
7321 situation like this:
7323 template <class T>
7324 struct S {
7325 template <class U>
7326 friend struct S;
7327 };
7329 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7330 for `S<int>', not the TEMPLATE_DECL. */
7332 {
7335 }
7338 {
7339 /* The friend template has already been declared. Just
7340 check to see that the declarations match, and install any new
7341 default parameters. We must tsubst the default parameters,
7342 of course. We only need the innermost template parameters
7343 because that is all that redeclare_class_template will look
7344 at. */
7347 {
7348 tree parms;
7349 location_t saved_input_location;
7358 }
7361 }
7362 else
7363 {
7364 /* The friend template has not already been declared. In this
7365 case, the instantiation of the template class will cause the
7366 injection of this template into the global scope. */
7371 /* The new TMPL is not an instantiation of anything, so we
7372 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7373 the new type because that is supposed to be the corresponding
7374 template decl, i.e., TMPL. */
7381 /* Inject this template into the global scope. */
7383 }
7386 {
7389 else
7391 }
7394 }
7396 /* Returns zero if TYPE cannot be completed later due to circularity.
7397 Otherwise returns one. */
7399 static int
7401 {
7411 else
7413 }
7415 /* Apply any attributes which had to be deferred until instantiation
7416 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7417 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7419 static void
7422 {
7424 tree t;
7429 {
7433 }
7436 {
7440 }
7441 else
7445 {
7450 {
7453 {
7456 /* If the first attribute argument is an identifier, don't
7457 pass it through tsubst. Attributes like mode, format,
7458 cleanup and several target specific attributes expect it
7459 unmodified. */
7465 {
7466 tree chain
7468 in_decl,
7473 chain);
7474 }
7475 else
7481 }
7482 else
7484 }
7487 }
7488 }
7490 /* Perform (or defer) access check for typedefs that were referenced
7491 from within the template TMPL code.
7492 This is a subroutine of instantiate_template and instantiate_class_template.
7493 TMPL is the template to consider and TARGS is the list of arguments of
7494 that template. */
7496 static void
7498 {
7499 location_t saved_location;
7514 {
7526 /* Make access check error messages point to the location
7527 of the use of the typedef. */
7531 }
7533 }
7535 tree
7537 {
7539 tree typedecl;
7540 tree pbinfo;
7541 tree base_list;
7552 /* Figure out which template is being instantiated. */
7556 /* Determine what specialization of the original template to
7557 instantiate. */
7560 {
7563 }
7565 {
7566 /* This TYPE is actually an instantiation of a partial
7567 specialization. We replace the innermost set of ARGS with
7568 the arguments appropriate for substitution. For example,
7569 given:
7571 template <class T> struct S {};
7572 template <class T> struct S<T*> {};
7574 and supposing that we are instantiating S<int*>, ARGS will
7575 presently be {int*} -- but we need {int}. */
7578 }
7579 else
7580 {
7583 }
7585 /* If the template we're instantiating is incomplete, then clearly
7586 there's nothing we can do. */
7590 /* If we've recursively instantiated too many templates, stop. */
7594 /* Now we're really doing the instantiation. Mark the type as in
7595 the process of being defined. */
7598 /* We may be in the middle of deferred access check. Disable
7599 it now. */
7603 /* Use #pragma pack from the template context. */
7609 /* Set the input location to the most specialized template definition.
7610 This is needed if tsubsting causes an error. */
7631 {
7634 }
7638 /* We should never instantiate a nested class before its enclosing
7639 class; we need to look up the nested class by name before we can
7640 instantiate it, and that lookup should instantiate the enclosing
7641 class. */
7648 {
7649 tree pbase_binfo;
7651 tree pushed_scope;
7654 /* We must enter the scope containing the type, as that is where
7655 the accessibility of types named in dependent bases are
7656 looked up from. */
7659 /* Substitute into each of the bases to determine the actual
7660 basetypes. */
7662 {
7663 tree base;
7669 {
7670 expanded_bases =
7677 }
7680 {
7682 /* Extract the already-expanded base class. */
7684 else
7685 /* Substitute to figure out the base class. */
7687 NULL_TREE);
7695 }
7696 }
7698 /* The list is now in reverse order; correct that. */
7703 }
7704 /* Now call xref_basetypes to set up all the base-class
7705 information. */
7712 /* Now that our base classes are set up, enter the scope of the
7713 class, so that name lookups into base classes, etc. will work
7714 correctly. This is precisely analogous to what we do in
7715 begin_class_definition when defining an ordinary non-template
7716 class, except we also need to push the enclosing classes. */
7719 /* Now members are processed in the order of declaration. */
7722 {
7726 {
7728 {
7729 /* Build new CLASSTYPE_NESTED_UTDS. */
7731 tree newtag;
7737 /* If the member is a class template, then -- even after
7738 substitution -- there may be dependent types in the
7739 template argument list for the class. We increment
7740 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7741 that function will assume that no types are dependent
7742 when outside of a template. */
7752 {
7756 /* Unfortunately, lookup_template_class sets
7757 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7758 instantiation (i.e., for the type of a member
7759 template class nested within a template class.)
7760 This behavior is required for
7761 maybe_process_partial_specialization to work
7762 correctly, but is not accurate in this case;
7763 the TAG is not an instantiation of anything.
7764 (The corresponding TEMPLATE_DECL is an
7765 instantiation, but the TYPE is not.) */
7768 /* Now, we call pushtag to put this NEWTAG into the scope of
7769 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7770 pushtag calling push_template_decl. We don't have to do
7771 this for enums because it will already have been done in
7772 tsubst_enum. */
7776 }
7777 }
7780 {
7781 /* Build new TYPE_METHODS. */
7782 tree r;
7791 }
7792 else
7793 {
7794 /* Build new TYPE_FIELDS. */
7796 {
7797 tree condition =
7805 }
7807 {
7808 tree r;
7810 /* The file and line for this declaration, to
7811 assist in error message reporting. Since we
7812 called push_tinst_level above, we don't need to
7813 restore these. */
7822 {
7823 /* In [temp.inst]:
7825 [t]he initialization (and any associated
7826 side-effects) of a static data member does
7827 not occur unless the static data member is
7828 itself used in a way that requires the
7829 definition of the static data member to
7830 exist.
7832 Therefore, we do not substitute into the
7833 initialized for the static data member here. */
7834 finish_static_data_member_decl
7842 }
7844 {
7845 /* Determine whether R has a valid type and can be
7846 completed later. If R is invalid, then it is
7847 replaced by error_mark_node so that it will not be
7848 added to TYPE_FIELDS. */
7854 {
7857 }
7858 }
7860 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
7861 such a thing will already have been added to the field
7862 list by tsubst_enum in finish_member_declaration in the
7863 CLASSTYPE_NESTED_UTDS case above. */
7867 {
7870 }
7871 }
7872 }
7873 }
7874 else
7875 {
7877 {
7878 /* Build new CLASSTYPE_FRIEND_CLASSES. */
7884 {
7885 /* template <class T> friend class C; */
7888 }
7890 {
7891 /* template <class T> friend class C::D; */
7897 }
7899 {
7900 /* This could be either
7902 friend class T::C;
7904 when dependent_type_p is false or
7906 template <class U> friend class T::C;
7908 otherwise. */
7911 /* Bump processing_template_decl for correct
7912 dependent_type_p calculation. */
7917 }
7920 {
7921 /* friend class C;
7923 where C hasn't been declared yet. Let's lookup name
7924 from namespace scope directly, bypassing any name that
7925 come from dependent base class. */
7928 /* The call to xref_tag_from_type does injection for friend
7929 classes. */
7931 friend_type =
7935 }
7937 /* friend class C<T>; */
7940 /* Otherwise it's
7942 friend class C;
7944 where C is already declared or
7946 friend class C<int>;
7948 We don't have to do anything in these cases. */
7951 /* Trick make_friend_class into realizing that the friend
7952 we're adding is a template, not an ordinary class. It's
7953 important that we use make_friend_class since it will
7954 perform some error-checking and output cross-reference
7955 information. */
7963 }
7964 else
7965 {
7966 /* Build new DECL_FRIENDLIST. */
7967 tree r;
7969 /* The file and line for this declaration, to
7970 assist in error message reporting. Since we
7971 called push_tinst_level above, we don't need to
7972 restore these. */
7976 {
7979 }
7984 {
7987 }
7988 }
7989 }
7990 }
7992 /* Set the file and line number information to whatever is given for
7993 the class itself. This puts error messages involving generated
7994 implicit functions at a predictable point, and the same point
7995 that would be used for non-template classes. */
8002 /* Now that the class is complete, instantiate default arguments for
8003 any member functions. We don't do this earlier because the
8004 default arguments may reference members of the class. */
8008 /* Implicitly generated member functions will not have template
8009 information; they are not instantiations, but instead are
8010 created "fresh" for each instantiation. */
8014 /* Some typedefs referenced from within the template code need to be access
8015 checked at template instantiation time, i.e now. These types were
8016 added to the template at parsing time. Let's get those and perform
8017 the access checks then. */
8026 /* The vtable for a template class can be emitted in any translation
8027 unit in which the class is instantiated. When there is no key
8028 method, however, finish_struct_1 will already have added TYPE to
8029 the keyed_classes list. */
8034 }
8036 static tree
8038 {
8039 tree r;
8045 else
8046 {
8050 }
8052 }
8054 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8055 NONTYPE_ARGUMENT_PACK. */
8057 static tree
8059 {
8060 /* Collect all of the extra "packed" parameters into an
8061 argument pack. */
8062 tree parmvec;
8063 tree parmtypevec;
8068 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8072 {
8075 }
8077 /* Build the argument packs. */
8083 }
8085 /* Substitute ARGS into T, which is an pack expansion
8086 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8087 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8088 (if only a partial substitution could be performed) or
8089 ERROR_MARK_NODE if there was an error. */
8090 tree
8092 tree in_decl)
8093 {
8094 tree pattern;
8097 tree result;
8104 /* Determine the argument packs that will instantiate the parameter
8105 packs used in the expansion expression. While we're at it,
8106 compute the number of arguments to be expanded and make sure it
8107 is consistent. */
8110 {
8116 {
8119 {
8120 /* This can happen for a parameter name used later in a function
8121 declaration (such as in a late-specified return type). Just
8122 make a dummy decl, since it's only used for its type. */
8126 }
8127 }
8128 else
8129 {
8136 }
8143 /* This can only happen if we forget to expand an argument
8144 pack somewhere else. Just return an error, silently. */
8145 {
8149 }
8154 {
8159 /* The argument pack that the parameter maps to is just an
8160 expansion of the parameter itself, such as one would
8161 find in the implicit typedef of a class inside the
8162 class itself. Consider this parameter "unsubstituted",
8163 so that we will maintain the outer pack expansion. */
8165 }
8168 {
8172 /* It's all-or-nothing with incomplete argument packs. */
8182 {
8184 /* We got explicit args for some packs but not others;
8185 do nothing now and try again after deduction. */
8190 pattern);
8191 else
8194 pattern);
8196 }
8198 /* Keep track of the parameter packs and their corresponding
8199 argument packs. */
8202 }
8203 else
8204 /* We can't substitute for this parameter pack. */
8207 unsubstituted_packs);
8208 }
8210 /* We cannot expand this expansion expression, because we don't have
8211 all of the argument packs we need. Substitute into the pattern
8212 and return a PACK_EXPANSION_*. The caller will need to deal with
8213 that. */
8215 {
8216 tree new_pat;
8220 else
8223 }
8225 /* We could not find any argument packs that work. */
8230 {
8231 /* We're in a late-specified return type, so we don't have a local
8232 specializations table. Create one for doing this expansion. */
8235 hash_local_specialization,
8236 eq_local_specializations,
8237 NULL);
8238 }
8240 /* For each argument in each argument pack, substitute into the
8241 pattern. */
8244 {
8245 /* For parameter pack, change the substitution of the parameter
8246 pack to the ith argument in its argument pack, then expand
8247 the pattern. */
8249 {
8253 {
8254 /* Select the Ith argument from the pack. */
8260 }
8261 else
8262 {
8268 {
8269 /* Select the Ith argument from the pack. */
8273 }
8275 /* Update the corresponding argument. */
8277 }
8278 }
8280 /* Substitute into the PATTERN with the altered arguments. */
8285 else
8289 /* When we have incomplete argument packs, the last "expanded"
8290 result is itself a pack expansion, which allows us
8291 to deduce more arguments. */
8296 {
8299 }
8300 }
8302 /* Update ARGS to restore the substitution from parameter packs to
8303 their argument packs. */
8305 {
8310 else
8311 {
8315 /* Update the corresponding argument. */
8319 else
8321 }
8322 }
8325 {
8328 }
8331 }
8333 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8334 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8335 parameter packs; all parms generated from a function parameter pack will
8336 have the same DECL_PARM_INDEX. */
8338 tree
8340 {
8342 tree patparm;
8345 {
8351 }
8352 else
8353 {
8358 }
8361 }
8363 /* Substitute ARGS into the vector or list of template arguments T. */
8365 static tree
8367 {
8374 {
8376 tree new_arg;
8381 {
8382 /* Substitute into an expansion expression. */
8386 /* Add to the expanded length adjustment the number of
8387 expanded arguments. We subtract one from this
8388 measurement, because the argument pack expression
8389 itself is already counted as 1 in
8390 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8391 the argument pack is empty. */
8393 }
8395 {
8396 /* Substitute into each of the arguments. */
8402 new_arg,
8416 }
8417 }
8418 else
8427 }
8432 /* Make space for the expanded arguments coming from template
8433 argument packs. */
8435 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8436 arguments for a member template.
8437 In that case each TREE_VEC in ORIG_T represents a level of template
8438 arguments, and ORIG_T won't carry any non defaulted argument count.
8439 It will rather be the nested TREE_VECs that will carry one.
8440 In other words, ORIG_T carries a non defaulted argument count only
8441 if it doesn't contain any nested TREE_VEC. */
8443 {
8447 }
8449 {
8453 {
8456 /* Now expand the template argument pack "in place". */
8459 }
8460 else
8461 {
8463 out++;
8464 }
8465 }
8468 }
8470 /* Return the result of substituting ARGS into the template parameters
8471 given by PARMS. If there are m levels of ARGS and m + n levels of
8472 PARMS, then the result will contain n levels of PARMS. For
8473 example, if PARMS is `template <class T> template <class U>
8474 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8475 result will be `template <int*, double, class V>'. */
8477 static tree
8479 {
8483 /* When substituting into a template, we must set
8484 PROCESSING_TEMPLATE_DECL as the template parameters may be
8485 dependent if they are based on one-another, and the dependency
8486 predicates are short-circuit outside of templates. */
8493 {
8494 tree new_vec =
8499 {
8500 tree tuple;
8501 tree default_value;
8502 tree parm_decl;
8524 }
8530 }
8535 }
8537 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8538 type T. If T is not an aggregate or enumeration type, it is
8539 handled as if by tsubst. IN_DECL is as for tsubst. If
8540 ENTERING_SCOPE is nonzero, T is the context for a template which
8541 we are presently tsubst'ing. Return the substituted value. */
8543 static tree
8545 tree args,
8546 tsubst_flags_t complain,
8547 tree in_decl,
8549 {
8554 {
8559 /* Else fall through. */
8563 {
8564 tree argvec;
8565 tree context;
8566 tree r;
8570 /* In "sizeof(X<I>)" we need to evaluate "I". */
8576 /* First, determine the context for the type we are looking
8577 up. */
8580 {
8583 /* If context is a nested class inside a class template,
8584 it may still need to be instantiated (c++/33959). */
8587 }
8589 /* Then, figure out what arguments are appropriate for the
8590 type we are trying to find. For example, given:
8592 template <class T> struct S;
8593 template <class T, class U> void f(T, U) { S<U> su; }
8595 and supposing that we are instantiating f<int, double>,
8596 then our ARGS will be {int, double}, but, when looking up
8597 S we only want {double}. */
8602 else
8603 {
8607 }
8613 }
8614 else
8615 /* This is not a template type, so there's nothing to do. */
8620 }
8621 }
8623 /* Substitute into the default argument ARG (a default argument for
8624 FN), which has the indicated TYPE. */
8626 tree
8628 {
8632 /* This default argument came from a template. Instantiate the
8633 default argument here, not in tsubst. In the case of
8634 something like:
8636 template <class T>
8637 struct S {
8638 static T t();
8639 void f(T = t());
8640 };
8642 we must be careful to do name lookup in the scope of S<T>,
8643 rather than in the current class. */
8645 /* The "this" pointer is not valid in a default argument. */
8647 {
8652 }
8655 /* The default argument expression may cause implicitly defined
8656 member functions to be synthesized, which will result in garbage
8657 collection. We must treat this situation as if we were within
8658 the body of function so as to avoid collecting live data on the
8659 stack. */
8667 /* Restore the "this" pointer. */
8669 {
8672 }
8674 /* Make sure the default argument is reasonable. */
8680 }
8682 /* Substitute into all the default arguments for FN. */
8684 static void
8686 {
8687 tree arg;
8688 tree tmpl_args;
8692 /* If this function is not yet instantiated, we certainly don't need
8693 its default arguments. */
8698 arg;
8704 }
8706 /* Substitute the ARGS into the T, which is a _DECL. Return the
8707 result of the substitution. Issue error and warning messages under
8708 control of COMPLAIN. */
8710 static tree
8712 {
8713 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8714 location_t saved_loc;
8719 /* Set the filename and linenumber to improve error-reporting. */
8724 {
8726 {
8727 /* We can get here when processing a member function template,
8728 member class template, or template template parameter. */
8730 tree spec;
8731 tree tmpl_args;
8732 tree full_args;
8735 {
8736 /* Template template parameter is treated here. */
8749 complain);
8752 }
8754 /* We might already have an instance of this template.
8755 The ARGS are for the surrounding class type, so the
8756 full args contain the tsubst'd args for the context,
8757 plus the innermost args from the template decl. */
8761 /* Because this is a template, the arguments will still be
8762 dependent, even after substitution. If
8763 PROCESSING_TEMPLATE_DECL is not set, the dependency
8764 predicates will short-circuit. */
8772 /* If this is a default template template argument,
8773 tsubst might not have changed anything. */
8780 {
8783 }
8785 /* Make a new template decl. It will be similar to the
8786 original, but will record the current template arguments.
8787 We also create a new function declaration, which is just
8788 like the old one, but points to this new template, rather
8789 than the old one. */
8797 {
8798 tree new_type;
8810 }
8811 else
8812 {
8813 tree new_decl;
8825 }
8831 /* The template parameters for this new template are all the
8832 template parameters for the old template, except the
8833 outermost level of parameters. */
8836 complain);
8842 /* Record this non-type partial instantiation. */
8846 }
8850 {
8851 tree ctx;
8854 tree gen_tmpl;
8855 tree type;
8860 /* Nobody should be tsubst'ing into non-template functions. */
8864 {
8865 tree spec;
8868 /* If T is not dependent, just return it. We have to
8869 increment PROCESSING_TEMPLATE_DECL because
8870 value_dependent_expression_p assumes that nothing is
8871 dependent when PROCESSING_TEMPLATE_DECL is zero. */
8878 /* Calculate the most general template of which R is a
8879 specialization, and the complete set of arguments used to
8880 specialize R. */
8886 /* Check to see if we already have this specialization. */
8891 {
8894 }
8896 /* We can see more levels of arguments than parameters if
8897 there was a specialization of a member template, like
8898 this:
8900 template <class T> struct S { template <class U> void f(); }
8901 template <> template <class U> void S<int>::f(U);
8903 Here, we'll be substituting into the specialization,
8904 because that's where we can find the code we actually
8905 want to generate, but we'll have enough arguments for
8906 the most general template.
8908 We also deal with the peculiar case:
8910 template <class T> struct S {
8911 template <class U> friend void f();
8912 };
8913 template <class U> void f() {}
8914 template S<int>;
8915 template void f<double>();
8917 Here, the ARGS for the instantiation of will be {int,
8918 double}. But, we only need as many ARGS as there are
8919 levels of template parameters in CODE_PATTERN. We are
8920 careful not to get fooled into reducing the ARGS in
8921 situations like:
8923 template <class T> struct S { template <class U> void f(U); }
8924 template <class T> template <> void S<T>::f(int) {}
8926 which we can spot because the pattern will be a
8927 specialization in this case. */
8929 parms_depth =
8934 }
8935 else
8936 {
8937 /* This special case arises when we have something like this:
8939 template <class T> struct S {
8940 friend void f<int>(int, double);
8941 };
8943 Here, the DECL_TI_TEMPLATE for the friend declaration
8944 will be an IDENTIFIER_NODE. We are being called from
8945 tsubst_friend_function, and we want only to create a
8946 new decl (R) with appropriate types so that we can call
8947 determine_specialization. */
8949 }
8952 {
8955 else
8959 }
8960 else
8961 {
8964 }
8969 /* We do NOT check for matching decls pushed separately at this
8970 point, as they may not represent instantiations of this
8971 template, and in any case are considered separate under the
8972 discrete model. */
8976 /* Clear out the mangled name and RTL for the instantiation. */
8979 /* Leave DECL_INITIAL set on deleted instantiations. */
8985 /* Type-conversion operator. Reconstruct the name, in
8986 case it's the name of one of the template's parameters. */
8996 /* If this is an instantiation of a function with internal
8997 linkage, we already know what object file linkage will be
8998 assigned to the instantiation. */
9007 /* We'll re-clone as appropriate in instantiate_template. */
9010 /* If we aren't complaining now, return on error before we register
9011 the specialization so that we'll complain eventually. */
9017 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9018 this in the special friend case mentioned above where
9019 GEN_TMPL is NULL. */
9021 {
9027 /* We're not supposed to instantiate default arguments
9028 until they are called, for a template. But, for a
9029 declaration like:
9031 template <class T> void f ()
9032 { extern void g(int i = T()); }
9034 we should do the substitution when the template is
9035 instantiated. We handle the member function case in
9036 instantiate_class_template since the default arguments
9037 might refer to other members of the class. */
9042 }
9043 else
9046 /* Copy the list of befriending classes. */
9050 {
9054 in_decl);
9055 }
9058 {
9062 /* If this is an instantiation of a member template, clone it.
9063 If it isn't, that'll be handled by
9064 clone_constructors_and_destructors. */
9067 }
9078 /* Possibly limit visibility based on template args. */
9081 {
9085 }
9093 }
9097 {
9105 {
9106 /* If there is a local specialization that isn't a
9107 parameter pack, it means that we're doing a "simple"
9108 substitution from inside tsubst_pack_expansion. Just
9109 return the local specialization (which will be a single
9110 parm). */
9117 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9118 the parameters in this function parameter pack. */
9122 {
9125 /* Zero-length parameter packs are boring. Just substitute
9126 into the chain. */
9130 }
9131 else
9132 {
9133 /* All we did was update the type. Make a note of that. */
9136 }
9137 }
9139 /* Loop through all of the parameter's we'll build. When T is
9140 a function parameter pack, LEN is the number of expanded
9141 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9144 {
9150 /* An argument of a function parameter pack is not a parameter
9151 pack. */
9155 /* We're on the Ith parameter of the function parameter
9156 pack. */
9157 {
9158 /* Get the Ith type. */
9162 /* Rename the parameter to include the index. */
9165 }
9167 /* We're dealing with a normal parameter. */
9175 {
9178 else
9181 }
9191 /* Keep track of the first new parameter we
9192 generate. That's what will be returned to the
9193 caller. */
9197 /* Build a proper chain of parameters when substituting
9198 into a function parameter pack. */
9201 }
9207 /* FIRST_R contains the start of the chain we've built. */
9209 }
9213 {
9214 tree type;
9223 /* DECL_INITIAL gives the number of bits in a bit-field. */
9228 /* We don't have to set DECL_CONTEXT here; it is set by
9229 finish_member_declaration. */
9236 }
9240 /* We reach here only for member using decls. */
9242 {
9243 r = do_class_using_decl
9248 else
9249 {
9252 }
9253 }
9254 else
9255 {
9258 }
9263 {
9266 tree spec;
9268 tree ctx;
9274 {
9275 /* If this is the canonical decl, we don't have to
9276 mess with instantiations, and often we can't (for
9277 typename, template type parms and such). Note that
9278 TYPE_NAME is not correct for the above test if
9279 we've copied the type for a typedef. */
9285 }
9287 /* Check to see if we already have the specialization we
9288 need. */
9291 {
9292 /* T is a static data member or namespace-scope entity.
9293 We have to substitute into namespace-scope variables
9294 (even though such entities are never templates) because
9295 of cases like:
9297 template <class T> void f() { extern T t; }
9299 where the entity referenced is not known until
9300 instantiation time. */
9304 {
9306 complain,
9308 /* If CTX is unchanged, then T is in fact the
9309 specialization we want. That situation occurs when
9310 referencing a static data member within in its own
9311 class. We can use pointer equality, rather than
9312 same_type_p, because DECL_CONTEXT is always
9313 canonical. */
9316 }
9319 {
9325 }
9326 }
9327 else
9328 {
9329 /* A local variable. */
9331 /* Subsequent calls to pushdecl will fill this in. */
9334 }
9335 /* If we already have the specialization we need, there is
9336 nothing more to do. */
9338 {
9341 }
9343 /* Create a new node for the specialization we need. */
9346 {
9349 else
9352 }
9354 {
9355 /* Even if the original location is out of scope, the
9356 newly substituted one is not. */
9363 {
9364 /* It may seem that this case cannot occur, since:
9366 typedef void f();
9367 void g() { f x; }
9369 declares a function, not a variable. However:
9371 typedef void f();
9372 template <typename T> void g() { T t; }
9373 template void g<f>();
9375 is an attempt to declare a variable with function
9376 type. */
9378 /* R is not yet sufficiently initialized, so we
9379 just use its name. */
9382 }
9389 {
9394 }
9395 }
9401 /* Clear out the mangled name and RTL for the instantiation. */
9405 /* The initializer must not be expanded until it is required;
9406 see [temp.inst]. */
9412 {
9413 /* Possibly limit visibility based on template args. */
9416 {
9420 }
9422 }
9425 {
9426 /* A static data member declaration is always marked
9427 external when it is declared in-class, even if an
9428 initializer is present. We mimic the non-template
9429 processing here. */
9435 }
9437 {
9438 /* We're substituting this var in a decltype outside of its
9439 scope, such as for a lambda return type. Don't add it to
9440 local_specializations, do perform auto deduction. */
9442 tree init
9447 {
9450 }
9451 }
9452 else
9461 /* Preserve a typedef that names a type. */
9463 {
9466 }
9469 }
9474 }
9475 #undef RETURN
9477 out:
9478 /* Restore the file and line information. */
9482 }
9484 /* Substitute into the ARG_TYPES of a function type. */
9486 static tree
9488 tree args,
9489 tsubst_flags_t complain,
9490 tree in_decl)
9491 {
9492 tree remaining_arg_types;
9496 tree default_arg;
9507 {
9508 /* For a pack expansion, perform substitution on the
9509 entire expression. Later on, we'll handle the arguments
9510 one-by-one. */
9515 /* So that we'll spin through the parameters, one by one. */
9517 else
9518 {
9519 /* We only partially substituted into the parameter
9520 pack. Our type is TYPE_PACK_EXPANSION. */
9523 }
9524 }
9537 {
9539 {
9543 }
9545 }
9547 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9548 top-level qualifiers as required. */
9551 /* We do not substitute into default arguments here. The standard
9552 mandates that they be instantiated only when needed, which is
9553 done in build_over_call. */
9557 {
9558 /* We've instantiated a template before its default arguments
9559 have been parsed. This can happen for a nested template
9560 class, and is not an error unless we require the default
9561 argument in a call of this function. */
9562 remaining_arg_types =
9565 remaining_arg_types);
9566 }
9567 else
9568 remaining_arg_types =
9570 }
9573 }
9575 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9576 *not* handle the exception-specification for FNTYPE, because the
9577 initial substitution of explicitly provided template parameters
9578 during argument deduction forbids substitution into the
9579 exception-specification:
9581 [temp.deduct]
9583 All references in the function type of the function template to the
9584 corresponding template parameters are replaced by the specified tem-
9585 plate argument values. If a substitution in a template parameter or
9586 in the function type of the function template results in an invalid
9587 type, type deduction fails. [Note: The equivalent substitution in
9588 exception specifications is done only when the function is instanti-
9589 ated, at which point a program is ill-formed if the substitution
9590 results in an invalid type.] */
9592 static tree
9594 tree args,
9595 tsubst_flags_t complain,
9596 tree in_decl)
9597 {
9598 tree return_type;
9599 tree arg_types;
9600 tree fntype;
9602 /* The TYPE_CONTEXT is not used for function/method types. */
9605 /* Substitute the return type. */
9609 /* The standard does not presently indicate that creation of a
9610 function type with an invalid return type is a deduction failure.
9611 However, that is clearly analogous to creating an array of "void"
9612 or a reference to a reference. This is core issue #486. */
9615 {
9617 {
9620 else
9622 }
9624 }
9626 /* Substitute the argument types. */
9632 /* Construct a new type node and return it. */
9635 else
9636 {
9639 {
9640 /* [temp.deduct]
9642 Type deduction may fail for any of the following
9643 reasons:
9645 -- Attempting to create "pointer to member of T" when T
9646 is not a class type. */
9649 r);
9651 }
9655 }
9660 }
9662 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9663 ARGS into that specification, and return the substituted
9664 specification. If there is no specification, return NULL_TREE. */
9666 static tree
9668 tree args,
9669 tsubst_flags_t complain,
9670 tree in_decl)
9671 {
9672 tree specs;
9673 tree new_specs;
9678 {
9681 else
9683 {
9684 tree spec;
9689 {
9690 /* Expand the pack expansion type. */
9693 in_decl);
9699 else
9700 {
9701 /* We're substituting into a member template, so
9702 we got a TYPE_PACK_EXPANSION back. Add that
9703 expansion and move on. */
9707 expanded_specs,
9708 complain);
9711 }
9712 }
9715 {
9718 else
9723 complain);
9724 }
9727 }
9728 }
9730 }
9732 /* Take the tree structure T and replace template parameters used
9733 therein with the argument vector ARGS. IN_DECL is an associated
9734 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9735 Issue error and warning messages under control of COMPLAIN. Note
9736 that we must be relatively non-tolerant of extensions here, in
9737 order to preserve conformance; if we allow substitutions that
9738 should not be allowed, we may allow argument deductions that should
9739 not succeed, and therefore report ambiguous overload situations
9740 where there are none. In theory, we could allow the substitution,
9741 but indicate that it should have failed, and allow our caller to
9742 make sure that the right thing happens, but we don't try to do this
9743 yet.
9745 This function is used for dealing with types, decls and the like;
9746 for expressions, use tsubst_expr or tsubst_copy. */
9748 tree
9750 {
9769 else
9774 /* Reuse typedefs. We need to do this to handle dependent attributes,
9775 such as attribute aligned. */
9779 {
9785 {
9789 }
9794 else
9795 /* The typedef is from a non-template context. */
9799 {
9801 r = cp_build_qualified_type_real
9805 }
9806 /* Else we must be instantiating the typedef, so fall through. */
9807 }
9819 {
9846 {
9852 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
9853 needed. */
9861 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
9862 with TREE_SIDE_EFFECTS that indicates this is not an integral
9863 constant expression. */
9866 {
9869 }
9875 {
9879 }
9881 /* [temp.deduct]
9883 Type deduction may fail for any of the following
9884 reasons:
9886 Attempting to create an array with a size that is
9887 zero or negative. */
9889 /* We must fail if performing argument deduction (as
9890 indicated by the state of complain), so that
9891 another substitution can be found. */
9895 {
9900 }
9903 }
9909 {
9922 {
9926 /* See through ARGUMENT_PACK_SELECT arguments. */
9928 }
9933 {
9935 /* If ARG is an argument pack, we don't actually want to
9936 perform a substitution here, because substitutions
9937 for argument packs are only done
9938 element-by-element. We can get to this point when
9939 substituting the type of a non-type template
9940 parameter pack, when that type actually contains
9941 template parameter packs from an outer template, e.g.,
9943 template<typename... Types> struct A {
9944 template<Types... Values> struct B { };
9945 }; */
9949 {
9953 /* cv-quals from the template are discarded when
9954 substituting in a function or reference type. */
9959 else
9962 return cp_build_qualified_type_real
9964 }
9966 {
9967 /* We are processing a type constructed from a
9968 template template parameter. */
9974 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
9975 are resolving nested-types in the signature of a
9976 member function templates. Otherwise ARG is a
9977 TEMPLATE_DECL and is the real template to be
9978 instantiated. */
9986 complain);
9987 return cp_build_qualified_type_real
9989 }
9990 else
9991 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
9993 }
9996 /* This can happen during the attempted tsubst'ing in
9997 unify. This means that we don't yet have any information
9998 about the template parameter in question. */
10001 /* If we get here, we must have been looking at a parm for a
10002 more deeply nested template. Make a new version of this
10003 template parameter, but with a lower level. */
10005 {
10010 {
10012 r = cp_build_qualified_type_real
10016 }
10017 else
10018 {
10029 /* We have reduced the level of the template
10030 template parameter, but not the levels of its
10031 template parameters, so canonical_type_parameter
10032 will not be able to find the canonical template
10033 template parameter for this level. Thus, we
10034 require structural equality checking to compare
10035 TEMPLATE_TEMPLATE_PARMs. */
10039 else
10043 {
10051 }
10052 }
10061 }
10064 }
10067 {
10075 {
10079 }
10082 {
10086 }
10089 {
10093 }
10099 }
10102 /* We should never be tsubsting a binfo. */
10106 /* A vector of template arguments. */
10112 {
10121 /* [temp.deduct]
10123 Type deduction may fail for any of the following
10124 reasons:
10126 -- Attempting to create a pointer to reference type.
10127 -- Attempting to create a reference to a reference type or
10128 a reference to void.
10130 Core issue 106 says that creating a reference to a reference
10131 during instantiation is no longer a cause for failure. We
10132 only enforce this check in strict C++98 mode. */
10136 {
10139 /* We keep track of the last time we issued this error
10140 message to avoid spewing a ton of messages during a
10141 single bad template instantiation. */
10144 {
10149 else
10152 }
10155 }
10157 {
10161 }
10163 /* In C++0x, during template argument substitution, when there is an
10164 attempt to create a reference to a reference type, reference
10165 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10167 "If a template-argument for a template-parameter T names a type
10168 that is a reference to a type A, an attempt to create the type
10169 'lvalue reference to cv T' creates the type 'lvalue reference to
10170 A,' while an attempt to create the type type rvalue reference to
10171 cv T' creates the type T"
10172 */
10173 r = cp_build_reference_type
10176 else
10181 /* Will this ever be needed for TYPE_..._TO values? */
10185 }
10187 {
10190 {
10191 /* [temp.deduct]
10193 Type deduction may fail for any of the following
10194 reasons:
10196 -- Attempting to create "pointer to member of T" when T
10197 is not a class type. */
10201 }
10203 {
10207 }
10209 {
10213 }
10216 {
10217 /* The type of the implicit object parameter gets its
10218 cv-qualifiers from the FUNCTION_TYPE. */
10219 tree memptr;
10223 complain);
10224 }
10225 else
10228 complain);
10229 }
10232 {
10233 tree fntype;
10234 tree specs;
10239 /* Substitute the exception specification. */
10241 in_decl);
10247 }
10249 {
10254 /* As an optimization, we avoid regenerating the array type if
10255 it will obviously be the same as T. */
10259 /* These checks should match the ones in grokdeclarator.
10261 [temp.deduct]
10263 The deduction may fail for any of the following reasons:
10265 -- Attempting to create an array with an element type that
10266 is void, a function type, or a reference type, or [DR337]
10267 an abstract class type. */
10271 {
10275 }
10277 {
10280 type);
10282 }
10287 {
10290 }
10293 }
10297 {
10306 }
10310 {
10316 }
10319 {
10329 {
10333 }
10335 {
10336 /* Normally, make_typename_type does not require that the CTX
10337 have complete type in order to allow things like:
10339 template <class T> struct S { typename S<T>::X Y; };
10341 But, such constructs have already been resolved by this
10342 point, so here CTX really should have complete type, unless
10343 it's a partial instantiation. */
10347 {
10351 }
10352 }
10359 {
10362 }
10365 {
10372 }
10374 return cp_build_qualified_type_real
10376 }
10379 {
10391 }
10399 {
10407 }
10410 {
10418 }
10421 {
10422 tree type;
10438 complain);
10439 }
10442 {
10443 tree type;
10459 else
10460 type = finish_decltype_type
10465 complain);
10466 }
10470 {
10474 tree packed_out =
10476 args,
10477 complain,
10478 in_decl);
10481 /* For template nontype argument packs, also substitute into
10482 the type. */
10487 }
10494 }
10495 }
10497 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10498 type of the expression on the left-hand side of the "." or "->"
10499 operator. */
10501 static tree
10504 {
10505 tree name;
10506 tree qualifying_scope;
10507 tree fns;
10508 tree optype;
10512 /* A baselink indicates a function from a base class. Both the
10513 BASELINK_ACCESS_BINFO and the base class referenced may
10514 indicate bases of the template class, rather than the
10515 instantiated class. In addition, lookups that were not
10516 ambiguous before may be ambiguous now. Therefore, we perform
10517 the lookup again. */
10524 {
10531 }
10537 /* If lookup found a single function, mark it as used at this
10538 point. (If it lookup found multiple functions the one selected
10539 later by overload resolution will be marked as used at that
10540 point.) */
10546 /* Add back the template arguments, if present. */
10551 template_args);
10552 /* Update the conversion operator type. */
10558 qualifying_scope,
10559 object_type);
10560 }
10562 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10563 true if the qualified-id will be a postfix-expression in-and-of
10564 itself; false if more of the postfix-expression follows the
10565 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10566 of "&". */
10568 static tree
10572 {
10573 tree expr;
10574 tree scope;
10575 tree name;
10577 tree template_args;
10581 /* Figure out what name to look up. */
10584 {
10591 }
10592 else
10593 {
10596 }
10598 /* Substitute into the qualifying scope. When there are no ARGS, we
10599 are just trying to simplify a non-dependent expression. In that
10600 case the qualifying scope may be dependent, and, in any case,
10601 substituting will not help. */
10604 {
10607 }
10608 else
10612 {
10618 }
10621 {
10623 {
10624 /* A BIT_NOT_EXPR is used to represent a destructor. */
10626 {
10630 }
10631 else
10634 }
10635 else
10639 {
10641 {
10645 }
10647 }
10648 }
10651 {
10653 scope);
10654 /* Remember that there was a reference to this entity. */
10656 }
10659 {
10665 }
10674 {
10675 expr = (adjust_result_of_qualified_name_lookup
10677 expr = (finish_qualified_id_expr
10681 }
10683 /* Expressions do not generally have reference type. */
10685 /* However, if we're about to form a pointer-to-member, we just
10686 want the referenced member referenced. */
10691 }
10693 /* Like tsubst, but deals with expressions. This function just replaces
10694 template parms; to finish processing the resultant expression, use
10695 tsubst_expr. */
10697 static tree
10699 {
10701 tree r;
10709 {
10714 {
10715 tree c;
10716 /* This can happen for a parameter name used later in a function
10717 declaration (such as in a late-specified return type). Just
10718 make a dummy decl, since it's only used for its type. */
10720 /* We copy T because want to tsubst the PARM_DECL only,
10721 not the following PARM_DECLs that are chained to T. */
10724 /* Give it the template pattern as its context; its true context
10725 hasn't been instantiated yet and this is good enough for
10726 mangling. */
10728 }
10736 {
10737 tree enum_type;
10738 tree v;
10742 /* There is no need to substitute into namespace-scope
10743 enumerators. */
10746 /* If ARGS is NULL, then T is known to be non-dependent. */
10750 /* Unfortunately, we cannot just call lookup_name here.
10751 Consider:
10753 template <int I> int f() {
10754 enum E { a = I };
10755 struct S { void g() { E e = a; } };
10756 };
10758 When we instantiate f<7>::S::g(), say, lookup_name is not
10759 clever enough to find f<7>::a. */
10760 enum_type
10770 /* We didn't find the name. That should never happen; if
10771 name-lookup found it during preliminary parsing, we
10772 should find it again here during instantiation. */
10774 }
10779 {
10780 tree ctx;
10785 {
10788 {
10792 }
10794 }
10795 }
10818 {
10819 /* Template template argument like the following example need
10820 special treatment:
10822 template <template <class> class TT> struct C {};
10823 template <class T> struct D {
10824 template <class U> struct E {};
10825 C<E> c; // #1
10826 };
10827 D<int> d; // #2
10829 We are processing the template argument `E' in #1 for
10830 the template instantiation #2. Originally, `E' is a
10831 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10832 have to substitute this with one having context `D<int>'. */
10836 }
10837 else
10838 /* Ordinary template template argument. */
10847 return build1
10853 {
10854 /* We only want to compute the number of arguments. */
10868 {
10875 else
10878 }
10879 else
10881 }
10882 /* Fall through */
10896 return build1
10901 {
10902 tree object;
10903 tree name;
10908 {
10912 }
10915 {
10925 }
10930 in_decl);
10931 else
10934 }
10972 return build_nt
10985 return build_nt
10992 {
11000 }
11005 {
11006 r = build_nt
11012 }
11015 {
11016 r = build_nt
11022 }
11025 {
11026 r = build_nt
11032 }
11035 {
11036 /* Substituted template arguments */
11045 }
11048 {
11068 }
11093 {
11096 }
11097 else
11101 /* This is handled by tsubst_copy_and_build. */
11106 in_decl),
11110 /* We shouldn't have built any of these during initial template
11111 generation. Instead, they should be built during instantiation
11112 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11129 }
11130 }
11132 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11134 static tree
11136 tree in_decl)
11137 {
11141 {
11147 {
11150 {
11156 }
11157 /* FALLTHRU */
11179 }
11180 }
11183 }
11185 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11187 static tree
11189 tree in_decl)
11190 {
11191 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11216 #undef RECUR
11217 }
11219 /* Substitute one OMP_FOR iterator. */
11221 static void
11226 {
11227 #define RECUR(NODE) \
11228 tsubst_expr ((NODE), args, complain, in_decl, \
11229 integral_constant_expression_p)
11238 {
11245 }
11249 {
11255 complain);
11256 else
11263 }
11266 {
11267 tree c;
11269 {
11280 }
11282 {
11287 {
11290 }
11291 }
11292 }
11298 else
11302 {
11313 {
11320 }
11321 else
11327 {
11333 }
11337 {
11344 }
11345 else
11351 }
11357 #undef RECUR
11358 }
11360 /* Like tsubst_copy for expressions, etc. but also does semantic
11361 processing. */
11363 static tree
11366 {
11367 #define RECUR(NODE) \
11368 tsubst_expr ((NODE), args, complain, in_decl, \
11369 integral_constant_expression_p)
11382 {
11384 {
11385 tree_stmt_iterator i;
11389 }
11404 else
11413 {
11414 tree decl;
11415 tree init;
11421 {
11424 tree decl;
11432 else
11434 }
11435 else
11436 {
11440 {
11441 /* By marking the declaration as instantiated, we avoid
11442 trying to instantiate it. Since instantiate_decl can't
11443 handle local variables, and since we've already done
11444 all that needs to be done, that's the right thing to
11445 do. */
11450 /* Anonymous aggregates are a special case. */
11452 else
11453 {
11457 {
11458 /* For __PRETTY_FUNCTION__ we have to adjust the
11459 initializer. */
11463 }
11464 else
11465 {
11469 /* If we had an initializer but it
11470 instantiated to nothing,
11471 value-initialize the object. This will
11472 only occur when the initializer was a
11473 pack expansion where the parameter packs
11474 used in that expansion were of length
11475 zero. */
11477 else
11479 }
11482 }
11483 }
11484 }
11486 /* A DECL_EXPR can also be used as an expression, in the condition
11487 clause of an if/for/while construct. */
11489 }
11527 {
11531 }
11539 else
11547 else
11574 {
11576 tree label;
11581 }
11587 /* Computed goto's must be tsubst'd into. On the other hand,
11588 non-computed gotos must not be; the identifier in question
11589 will have no binding. */
11591 else
11597 tmp = finish_asm_stmt
11604 {
11609 }
11614 {
11619 }
11620 else
11621 {
11626 else
11633 else
11639 else
11641 }
11645 {
11649 {
11651 /* Prevent instantiate_decl from trying to instantiate
11652 this variable. We've already done all that needs to be
11653 done. */
11656 }
11661 }
11669 {
11670 tree condition =
11672 args,
11679 }
11700 {
11715 integral_constant_expression_p);
11724 {
11728 }
11729 else
11730 {
11738 }
11752 }
11783 {
11788 }
11804 integral_constant_expression_p);
11805 }
11808 #undef RECUR
11809 }
11811 /* T is a postfix-expression that is not being used in a function
11812 call. Return the substituted version of T. */
11814 static tree
11816 tsubst_flags_t complain,
11817 tree in_decl)
11818 {
11822 else
11828 }
11830 /* Like tsubst but deals with expressions and performs semantic
11831 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11833 tree
11835 tree args,
11836 tsubst_flags_t complain,
11837 tree in_decl,
11840 {
11841 #define RECUR(NODE) \
11842 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11844 integral_constant_expression_p)
11846 tree op1;
11852 {
11855 /* Fall through. */
11857 {
11858 tree decl;
11859 cp_id_kind idk;
11864 {
11867 }
11869 /* Look up the name. */
11872 /* By convention, expressions use ERROR_MARK_NODE to indicate
11873 failure, not NULL_TREE. */
11879 integral_constant_expression_p,
11887 input_location);
11893 }
11896 {
11897 tree object;
11905 {
11908 }
11909 else
11916 else
11918 }
11921 {
11925 {
11926 /* A type conversion to reference type will be enclosed in
11927 such an indirect ref, but the substitution of the cast
11928 will have also added such an indirect ref. */
11931 }
11932 else
11935 }
11938 return build_nop
11947 {
11948 tree type;
11949 tree op;
11954 {
11959 }
11964 {
11977 }
11978 }
11996 complain);
12003 else
12005 in_decl);
12042 return build_x_binary_op
12046 ? ERROR_MARK
12050 ? ERROR_MARK
12053 complain);
12066 /* Fall through */
12071 {
12072 /* When there are no ARGS, we are trying to evaluate a
12073 non-dependent expression from the parser. Trying to do
12074 the substitutions may not work. */
12077 }
12078 else
12079 {
12087 }
12091 else
12096 {
12097 tree r = build_x_modify_expr
12101 complain);
12102 /* TREE_NO_WARNING must be set if either the expression was
12103 parenthesized or it uses an operator such as >>= rather
12104 than plain assignment. In the former case, it was already
12105 set and must be copied. In the latter case,
12106 build_x_modify_expr sets it and it must not be reset
12107 here. */
12111 }
12116 /* Remember that there was a reference to this entity. */
12122 {
12127 tree ret;
12131 else
12132 {
12136 }
12138 /* If there was an initializer in the original tree, but it
12139 instantiated to an empty list, then we should pass a
12140 non-NULL empty vector to tell build_new that it was an
12141 empty initializer() rather than no initializer. This can
12142 only happen when the initializer is a pack expansion whose
12143 parameter packs are of length zero. */
12146 else
12147 {
12151 else
12152 {
12155 }
12156 }
12163 complain);
12171 }
12174 return delete_sanity
12183 complain);
12186 {
12187 tree function;
12192 tree ret;
12195 /* When we parsed the expression, we determined whether or
12196 not Koenig lookup should be performed. */
12199 {
12204 }
12205 else
12206 {
12208 {
12214 }
12215 else
12219 in_decl,
12221 integral_constant_expression_p);
12225 }
12230 {
12236 else
12237 {
12238 /* Expand the pack expansion and push each entry onto
12239 CALL_ARGS. */
12242 {
12247 {
12252 }
12253 }
12254 else
12255 {
12256 /* A partial substitution. Add one entry. */
12258 }
12259 }
12260 }
12262 /* We do not perform argument-dependent lookup if normal
12263 lookup finds a non-function, in accordance with the
12264 expected resolution of DR 218. */
12267 /* If lookup found a member function, the Koenig lookup is
12268 not appropriate, even if an unqualified-name was used
12269 to denote the function. */
12272 /* Only do this when substitution turns a dependent call
12273 into a non-dependent call. */
12279 {
12283 }
12285 /* Remember that there was a reference to this entity. */
12292 {
12297 complain);
12298 else
12299 ret = (build_new_method_call
12305 complain));
12306 }
12307 else
12310 koenig_p,
12311 complain);
12316 }
12319 return build_x_conditional_expr
12323 complain);
12326 return finish_pseudo_destructor_expr
12332 {
12340 {
12341 /* We have pack expansions, so expand those and
12342 create a new list out of it. */
12345 tree chain;
12348 /* Expand the argument expressions. */
12356 /* Build the rest of the list. */
12361 /* Determine the number of arguments. */
12363 {
12366 }
12369 else
12370 {
12371 /* Since we only performed a partial substitution into
12372 the argument pack, we only return a single list
12373 node. */
12380 }
12382 /* Convert the argument vectors into a TREE_LIST */
12385 {
12386 /* Grab the Ith values. */
12387 i--;
12390 value
12394 /* Build the list (backwards). */
12396 }
12399 }
12415 }
12418 {
12419 tree object;
12420 tree object_type;
12421 tree member;
12425 /* Remember that there was a reference to this entity. */
12435 else
12441 {
12443 {
12448 {
12451 }
12453 {
12457 }
12458 }
12459 }
12462 {
12463 tree tmpl;
12464 tree args;
12466 /* Lookup the template functions now that we know what the
12467 scope is. */
12474 {
12477 args);
12478 member = (adjust_result_of_qualified_name_lookup
12480 object_type));
12481 }
12482 else
12483 {
12485 input_location);
12487 }
12488 }
12492 {
12494 {
12498 else
12501 }
12503 }
12509 complain);
12510 }
12513 return build_throw
12517 {
12525 tree r;
12530 /* digest_init will do the wrong thing if we let it. */
12534 /* We do not want to process the index of aggregate
12535 initializers as they are identifier nodes which will be
12536 looked up by digest_init. */
12542 {
12547 {
12548 /* Substitute into the pack expansion. */
12550 in_decl);
12553 ;
12555 /* Just move the argument into place. */
12557 else
12558 {
12559 /* Update the length of the final CONSTRUCTOR
12560 arguments vector, and note that we will need to
12561 copy.*/
12564 }
12565 }
12566 else
12568 }
12571 {
12576 idx++)
12577 {
12579 {
12584 }
12585 else
12587 }
12588 }
12597 }
12600 {
12605 }
12610 /* Fall through */
12613 {
12617 /* If the original type was a reference, we'll be wrapped in
12618 the appropriate INDIRECT_REF. */
12621 }
12626 in_decl));
12632 {
12641 }
12644 {
12650 integral_constant_expression_p);
12654 /* If the resulting list of expression statement is empty,
12655 fold it further into void_zero_node. */
12660 }
12664 /* As in finish_id_expression, we resolve enumeration constants
12665 to their underlying values. */
12667 {
12670 }
12674 {
12695 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12697 /* Now that we know visibility, instantiate the type so we have a
12698 declaration of the op() for later calls to lambda_function. */
12706 }
12709 /* Handle Objective-C++ constructs, if appropriate. */
12710 {
12711 tree subst
12716 }
12718 }
12720 #undef RECUR
12721 }
12723 /* Verify that the instantiated ARGS are valid. For type arguments,
12724 make sure that the type's linkage is ok. For non-type arguments,
12725 make sure they are constants if they are integral or enumerations.
12726 Emit an error under control of COMPLAIN, and return TRUE on error. */
12728 static bool
12730 {
12732 {
12742 }
12744 {
12745 /* [basic.link]: A name with no linkage (notably, the name
12746 of a class or enumeration declared in a local scope)
12747 shall not be used to declare an entity with linkage.
12748 This implies that names with no linkage cannot be used as
12749 template arguments
12751 DR 757 relaxes this restriction for C++0x. */
12756 {
12757 /* DR 488 makes use of a type with no linkage cause
12758 type deduction to fail. */
12760 {
12763 else
12766 }
12768 }
12769 /* In order to avoid all sorts of complications, we do not
12770 allow variably-modified types as template arguments. */
12772 {
12776 }
12777 }
12778 /* A non-type argument of integral or enumerated type must be a
12779 constant. */
12783 {
12787 }
12789 }
12791 static bool
12793 {
12798 {
12801 }
12805 }
12807 /* Instantiate the indicated variable or function template TMPL with
12808 the template arguments in TARG_PTR. */
12810 tree
12812 {
12814 tree fndecl;
12815 tree gen_tmpl;
12816 tree spec;
12817 HOST_WIDE_INT saved_processing_template_decl;
12824 /* If this function is a clone, handle it specially. */
12826 {
12827 tree spec;
12828 tree clone;
12830 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
12831 DECL_CLONED_FUNCTION. */
12837 /* Look for the clone. */
12841 /* We should always have found the clone by now. */
12844 }
12846 /* Check to see if we already have this specialization. */
12849 /* The TMPL is a partial instantiation. To get a full set of
12850 arguments we must add the arguments used to perform the
12851 partial instantiation. */
12853 targ_ptr);
12855 /* It would be nice to avoid hashing here and then again in tsubst_decl,
12856 but it doesn't seem to be on the hot path. */
12868 complain))
12871 /* We are building a FUNCTION_DECL, during which the access of its
12872 parameters and return types have to be checked. However this
12873 FUNCTION_DECL which is the desired context for access checking
12874 is not built yet. We solve this chicken-and-egg problem by
12875 deferring all checks until we have the FUNCTION_DECL. */
12878 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
12879 (because, for example, we have encountered a non-dependent
12880 function call in the body of a template function and must now
12881 determine which of several overloaded functions will be called),
12882 within the instantiation itself we are not processing a
12883 template. */
12886 /* Substitute template parameters to obtain the specialization. */
12893 /* Now we know the specialization, compute access previously
12894 deferred. */
12897 /* Some typedefs referenced from within the template code need to be access
12898 checked at template instantiation time, i.e now. These types were
12899 added to the template at parsing time. Let's get those and perfom
12900 the acces checks then. */
12906 /* The DECL_TI_TEMPLATE should always be the immediate parent
12907 template, not the most general template. */
12910 /* If we've just instantiated the main entry point for a function,
12911 instantiate all the alternate entry points as well. We do this
12912 by cloning the instantiation of the main entry point, not by
12913 instantiating the template clones. */
12918 }
12920 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
12921 NARGS elements of the arguments that are being used when calling
12922 it. TARGS is a vector into which the deduced template arguments
12923 are placed.
12925 Return zero for success, 2 for an incomplete match that doesn't resolve
12926 all the types, and 1 for complete failure. An error message will be
12927 printed only for an incomplete match.
12929 If FN is a conversion operator, or we are trying to produce a specific
12930 specialization, RETURN_TYPE is the return type desired.
12932 The EXPLICIT_TARGS are explicit template arguments provided via a
12933 template-id.
12935 The parameter STRICT is one of:
12937 DEDUCE_CALL:
12938 We are deducing arguments for a function call, as in
12939 [temp.deduct.call].
12941 DEDUCE_CONV:
12942 We are deducing arguments for a conversion function, as in
12943 [temp.deduct.conv].
12945 DEDUCE_EXACT:
12946 We are deducing arguments when doing an explicit instantiation
12947 as in [temp.explicit], when determining an explicit specialization
12948 as in [temp.expl.spec], or when taking the address of a function
12949 template, as in [temp.deduct.funcaddr]. */
12951 int
12953 tree explicit_targs,
12954 tree targs,
12957 tree return_type,
12958 unification_kind_t strict,
12960 {
12961 tree parms;
12962 tree fntype;
12970 {
12971 /* [temp.deduct]
12973 The specified template arguments must match the template
12974 parameters in kind (i.e., type, nontype, template), and there
12975 must not be more arguments than there are parameters;
12976 otherwise type deduction fails.
12978 Nontype arguments must match the types of the corresponding
12979 nontype template parameters, or must be convertible to the
12980 types of the corresponding nontype parameters as specified in
12981 _temp.arg.nontype_, otherwise type deduction fails.
12983 All references in the function type of the function template
12984 to the corresponding template parameters are replaced by the
12985 specified template argument values. If a substitution in a
12986 template parameter or in the function type of the function
12987 template results in an invalid type, type deduction fails. */
12990 tree converted_args;
12996 converted_args
13003 /* Substitute the explicit args into the function type. This is
13004 necessary so that, for instance, explicitly declared function
13005 arguments can match null pointed constants. If we were given
13006 an incomplete set of explicit args, we must not do semantic
13007 processing during substitution as we could create partial
13008 instantiations. */
13010 {
13014 /* Dig out the actual parm. */
13017 {
13020 }
13022 {
13025 }
13028 {
13030 tree targ;
13033 /* Mark the argument pack as "incomplete". We could
13034 still deduce more arguments during unification. */
13037 {
13041 }
13043 /* We have some incomplete argument packs. */
13045 }
13046 }
13049 /* Any substitution is guaranteed to be incomplete if there
13050 are incomplete argument packs, because we can still deduce
13051 more arguments. */
13053 else
13063 /* Place the explicitly specified arguments in TARGS. */
13066 }
13068 /* Never do unification on the 'this' parameter. */
13072 {
13081 }
13083 /* We allow incomplete unification without an error message here
13084 because the standard doesn't seem to explicitly prohibit it. Our
13085 callers must be ready to deal with unification failures in any
13086 event. */
13092 {
13095 /* Clear the "incomplete" flags on all argument packs. */
13097 {
13100 {
13103 }
13104 }
13105 }
13107 /* Now that we have bindings for all of the template arguments,
13108 ensure that the arguments deduced for the template template
13109 parameters have compatible template parameter lists. We cannot
13110 check this property before we have deduced all template
13111 arguments, because the template parameter types of a template
13112 template parameter might depend on prior template parameters
13113 deduced after the template template parameter. The following
13114 ill-formed example illustrates this issue:
13116 template<typename T, template<T> class C> void f(C<5>, T);
13118 template<int N> struct X {};
13120 void g() {
13121 f(X<5>(), 5l); // error: template argument deduction fails
13122 }
13124 The template parameter list of 'C' depends on the template type
13125 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13126 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13127 time that we deduce 'C'. */
13129 && !template_template_parm_bindings_ok_p
13134 /* All is well so far. Now, check:
13136 [temp.deduct]
13138 When all template arguments have been deduced, all uses of
13139 template parameters in nondeduced contexts are replaced with
13140 the corresponding deduced argument values. If the
13141 substitution results in an invalid type, as described above,
13142 type deduction fails. */
13143 {
13148 /* If we're looking for an exact match, check that what we got
13149 is indeed an exact match. It might not be if some template
13150 parameters are used in non-deduced contexts. */
13152 {
13155 tree sarg
13162 }
13163 }
13166 }
13168 /* Adjust types before performing type deduction, as described in
13169 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13170 sections are symmetric. PARM is the type of a function parameter
13171 or the return type of the conversion function. ARG is the type of
13172 the argument passed to the call, or the type of the value
13173 initialized with the result of the conversion function.
13174 ARG_EXPR is the original argument expression, which may be null. */
13176 static int
13180 tree arg_expr)
13181 {
13185 {
13190 {
13191 /* Swap PARM and ARG throughout the remainder of this
13192 function; the handling is precisely symmetric since PARM
13193 will initialize ARG rather than vice versa. */
13198 }
13201 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13202 too, but here handle it by stripping the reference from PARM
13203 rather than by adding it to ARG. */
13211 /* Nothing else to do in this case. */
13216 }
13219 {
13220 /* [temp.deduct.call]
13222 If P is not a reference type:
13224 --If A is an array type, the pointer type produced by the
13225 array-to-pointer standard conversion (_conv.array_) is
13226 used in place of A for type deduction; otherwise,
13228 --If A is a function type, the pointer type produced by
13229 the function-to-pointer standard conversion
13230 (_conv.func_) is used in place of A for type deduction;
13231 otherwise,
13233 --If A is a cv-qualified type, the top level
13234 cv-qualifiers of A's type are ignored for type
13235 deduction. */
13240 else
13242 }
13244 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13245 of the form T&&, where T is a template parameter, and the argument
13246 is an lvalue, T is deduced as A& */
13254 /* [temp.deduct.call]
13256 If P is a cv-qualified type, the top level cv-qualifiers
13257 of P's type are ignored for type deduction. If P is a
13258 reference type, the type referred to by P is used for
13259 type deduction. */
13262 {
13265 }
13267 /* DR 322. For conversion deduction, remove a reference type on parm
13268 too (which has been swapped into ARG). */
13273 }
13275 /* Most parms like fn_type_unification.
13277 If SUBR is 1, we're being called recursively (to unify the
13278 arguments of a function or method parameter of a function
13279 template). */
13281 static int
13283 tree targs,
13284 tree xparms,
13288 unification_kind_t strict,
13290 {
13296 tree parms;
13305 /* Reset the number of non-defaulted template arguments contained
13306 in in TARGS. */
13310 {
13326 }
13328 again:
13336 {
13349 /* We can't deduce anything from this, but we might get all the
13350 template args from other function args. */
13353 /* Conversions will be performed on a function argument that
13354 corresponds with a function parameter that contains only
13355 non-deducible template parameters and explicitly specified
13356 template parameters. */
13358 {
13359 tree type;
13363 else
13370 flags))
13374 }
13377 {
13380 {
13381 /* [temp.deduct.type]
13383 A template-argument can be deduced from a pointer to
13384 function or pointer to member function argument if
13385 the set of overloaded functions does not contain
13386 function templates and at most one of a set of
13387 overloaded functions provides a unique match. */
13393 }
13398 }
13400 {
13405 arg_expr);
13411 }
13412 }
13418 {
13419 /* Unify the remaining arguments with the pack expansion type. */
13420 tree argvec;
13423 /* Allocate a TREE_VEC and copy in all of the arguments */
13428 /* Copy the parameter into parmvec. */
13434 /* Advance to the end of the list of parameters. */
13436 }
13438 /* Fail if we've reached the end of the parm list, and more args
13439 are present, and the parm list isn't variadic. */
13442 /* Fail if parms are left and they don't have default values. */
13450 {
13451 tree tparm;
13458 /* If this is an undeduced nontype parameter that depends on
13459 a type parameter, try another pass; its type may have been
13460 deduced from a later argument than the one from which
13461 this parameter can be deduced. */
13467 /* Core issue #226 (C++0x) [temp.deduct]:
13469 If a template argument has not been deduced, its
13470 default template argument, if any, is used.
13472 When we are in C++98 mode, TREE_PURPOSE will either
13473 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13474 to explicitly check cxx_dialect here. */
13476 {
13484 else
13485 {
13487 /* The position of the first default template argument,
13488 is also the number of non-defaulted arguments in TARGS.
13489 Record that. */
13493 }
13494 }
13496 /* If the type parameter is a parameter pack, then it will
13497 be deduced to an empty parameter pack. */
13499 {
13500 tree arg;
13503 {
13507 }
13508 else
13515 }
13518 }
13519 #ifdef ENABLE_CHECKING
13522 #endif
13525 }
13527 /* Subroutine of type_unification_real. Args are like the variables
13528 at the call site. ARG is an overloaded function (or template-id);
13529 we try deducing template args from each of the overloads, and if
13530 only one succeeds, we go with that. Modifies TARGS and returns
13531 true on success. */
13533 static bool
13535 tree targs,
13536 tree parm,
13537 tree arg,
13538 unification_kind_t strict,
13540 {
13547 {
13550 }
13551 else
13555 /* Handle `&x' where `x' is some static or non-static member
13556 function name. */
13562 /* Strip baselink information. */
13567 {
13568 /* If we got some explicit template args, we need to plug them into
13569 the affected templates before we try to unify, in case the
13570 explicit args will completely resolve the templates in question. */
13576 {
13587 {
13592 {
13595 }
13596 }
13598 }
13599 }
13602 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13603 -- but the deduction does not succeed because the expression is
13604 not just the function on its own. */
13606 else
13612 {
13615 }
13617 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13618 to function or pointer to member function argument if the set of
13619 overloaded functions does not contain function templates and at most
13620 one of a set of overloaded functions provides a unique match.
13622 So if we found multiple possibilities, we return success but don't
13623 deduce anything. */
13626 {
13631 }
13636 }
13638 /* Core DR 115: In contexts where deduction is done and fails, or in
13639 contexts where deduction is not done, if a template argument list is
13640 specified and it, along with any default template arguments, identifies
13641 a single function template specialization, then the template-id is an
13642 lvalue for the function template specialization. */
13644 tree
13646 {
13659 {
13662 }
13664 {
13667 }
13669 {
13672 }
13675 {
13679 /* If we got some explicit template args, we need to plug them into
13680 the affected templates before we try to unify, in case the
13681 explicit args will completely resolve the templates in question. */
13689 {
13700 {
13703 {
13706 }
13708 {
13711 }
13712 }
13714 }
13716 {
13728 }
13730 /* There were no good options and at least one bad one, so let the
13731 user know what the problem is. */
13733 }
13735 }
13737 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13738 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13739 different overloads deduce different arguments for a given parm.
13740 ADDR_P is true if the expression for which deduction is being
13741 performed was of the form "& fn" rather than simply "fn".
13743 Returns 1 on success. */
13745 static int
13747 tree orig_targs,
13748 tree targs,
13749 tree parm,
13750 tree arg,
13751 unification_kind_t strict,
13754 {
13756 tree tempargs;
13759 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13760 to function or pointer to member function argument if the set of
13761 overloaded functions does not contain function templates and at most
13762 one of a set of overloaded functions provides a unique match.
13764 So if this is a template, just return success. */
13776 /* We don't copy orig_targs for this because if we have already deduced
13777 some template args from previous args, unify would complain when we
13778 try to deduce a template parameter for the same argument, even though
13779 there isn't really a conflict. */
13786 /* First make sure we didn't deduce anything that conflicts with
13787 explicitly specified args. */
13789 {
13796 /* Since we're unifying against ourselves, we will fill in
13797 template args used in the function parm list with our own
13798 template parms. Discard them. */
13802 }
13805 {
13810 }
13813 }
13815 /* PARM is a template class (perhaps with unbound template
13816 parameters). ARG is a fully instantiated type. If ARG can be
13817 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
13818 TARGS are as for unify. */
13820 static tree
13822 {
13823 tree copy_of_targs;
13830 /* We need to make a new template argument vector for the call to
13831 unify. If we used TARGS, we'd clutter it up with the result of
13832 the attempted unification, even if this class didn't work out.
13833 We also don't want to commit ourselves to all the unifications
13834 we've already done, since unification is supposed to be done on
13835 an argument-by-argument basis. In other words, consider the
13836 following pathological case:
13838 template <int I, int J, int K>
13839 struct S {};
13841 template <int I, int J>
13842 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
13844 template <int I, int J, int K>
13845 void f(S<I, J, K>, S<I, I, I>);
13847 void g() {
13848 S<0, 0, 0> s0;
13849 S<0, 1, 2> s2;
13851 f(s0, s2);
13852 }
13854 Now, by the time we consider the unification involving `s2', we
13855 already know that we must have `f<0, 0, 0>'. But, even though
13856 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
13857 because there are two ways to unify base classes of S<0, 1, 2>
13858 with S<I, I, I>. If we kept the already deduced knowledge, we
13859 would reject the possibility I=1. */
13862 /* If unification failed, we're done. */
13868 }
13870 /* Given a template type PARM and a class type ARG, find the unique
13871 base type in ARG that is an instance of PARM. We do not examine
13872 ARG itself; only its base-classes. If there is not exactly one
13873 appropriate base class, return NULL_TREE. PARM may be the type of
13874 a partial specialization, as well as a plain template type. Used
13875 by unify. */
13877 static tree
13879 {
13881 tree binfo;
13887 /* The type could not be completed. */
13890 /* Walk in inheritance graph order. The search order is not
13891 important, and this avoids multiple walks of virtual bases. */
13893 {
13897 {
13898 /* If there is more than one satisfactory baseclass, then:
13900 [temp.deduct.call]
13902 If they yield more than one possible deduced A, the type
13903 deduction fails.
13905 applies. */
13910 }
13911 }
13914 }
13916 /* Returns the level of DECL, which declares a template parameter. */
13918 static int
13920 {
13922 {
13932 }
13934 }
13936 /* Decide whether ARG can be unified with PARM, considering only the
13937 cv-qualifiers of each type, given STRICT as documented for unify.
13938 Returns nonzero iff the unification is OK on that basis. */
13940 static int
13942 {
13948 {
13949 /* Although a CVR qualifier is ignored when being applied to a
13950 substituted template parameter ([8.3.2]/1 for example), that
13951 does not apply during deduction [14.8.2.4]/1, (even though
13952 that is not explicitly mentioned, [14.8.2.4]/9 indicates
13953 this). Except when we're allowing additional CV qualifiers
13954 at the outer level [14.8.2.1]/3,1st bullet. */
13964 }
13975 }
13977 /* Determines the LEVEL and INDEX for the template parameter PARM. */
13978 void
13980 {
13984 {
13987 }
13988 else
13989 {
13992 }
13993 }
13995 /* Unifies the remaining arguments in PACKED_ARGS with the pack
13996 expansion at the end of PACKED_PARMS. Returns 0 if the type
13997 deduction succeeds, 1 otherwise. STRICT is the same as in
13998 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
13999 call argument list. We'll need to adjust the arguments to make them
14000 types. SUBR tells us if this is from a recursive call to
14001 type_unification_real. */
14002 int
14006 {
14007 tree parm
14014 /* Determine the parameter packs we will be deducing from the
14015 pattern, and record their current deductions. */
14018 {
14022 /* Determine the index and level of this parameter pack. */
14025 /* Keep track of the parameter packs and their corresponding
14026 argument packs. */
14029 }
14031 /* Loop through all of the arguments that have not yet been
14032 unified and unify each with the pattern. */
14034 {
14037 /* For each parameter pack, clear out the deduced value so that
14038 we can deduce it again. */
14040 {
14045 }
14047 /* Unify the pattern with the current argument. */
14048 {
14055 {
14058 /* This mirrors what we do in type_unification_real. */
14060 {
14062 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14063 | UNIFY_ALLOW_MORE_CV_QUAL
14077 }
14080 {
14083 {
14084 /* [temp.deduct.type] A template-argument can be
14085 deduced from a pointer to function or pointer
14086 to member function argument if the set of
14087 overloaded functions does not contain function
14088 templates and at most one of a set of
14089 overloaded functions provides a unique
14090 match. */
14095 sub_strict)
14099 }
14102 {
14107 }
14108 }
14113 arg_strict |=
14116 }
14119 {
14120 /* For deduction from an init-list we need the actual list. */
14125 }
14126 }
14128 /* For each parameter pack, collect the deduced value. */
14130 {
14136 }
14137 }
14139 /* Verify that the results of unification with the parameter packs
14140 produce results consistent with what we've seen before, and make
14141 the deduced argument packs available. */
14143 {
14150 /* By default keep the original deduced argument pack.
14151 If necessary, more specific code is going to update the
14152 resulting deduced argument later down in this function. */
14156 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14157 actually deduce anything. */
14165 {
14166 /* Prepend the explicit arguments onto NEW_ARGS. */
14172 /* Copy the explicit arguments. */
14177 /* Copy the deduced arguments. */
14181 }
14184 {
14185 tree result;
14186 /* Build the deduced *_ARGUMENT_PACK. */
14188 {
14193 }
14194 else
14199 /* Note the deduced argument packs for this parameter
14200 pack. */
14202 }
14206 {
14207 /* We only had the explicitly-provided arguments before, but
14208 now we have a complete set of arguments. */
14214 }
14216 new_args))
14217 /* Inconsistent unification of this parameter pack. */
14219 }
14222 }
14224 /* Deduce the value of template parameters. TPARMS is the (innermost)
14225 set of template parameters to a template. TARGS is the bindings
14226 for those template parameters, as determined thus far; TARGS may
14227 include template arguments for outer levels of template parameters
14228 as well. PARM is a parameter to a template function, or a
14229 subcomponent of that parameter; ARG is the corresponding argument.
14230 This function attempts to match PARM with ARG in a manner
14231 consistent with the existing assignments in TARGS. If more values
14232 are deduced, then TARGS is updated.
14234 Returns 0 if the type deduction succeeds, 1 otherwise. The
14235 parameter STRICT is a bitwise or of the following flags:
14237 UNIFY_ALLOW_NONE:
14238 Require an exact match between PARM and ARG.
14239 UNIFY_ALLOW_MORE_CV_QUAL:
14240 Allow the deduced ARG to be more cv-qualified (by qualification
14241 conversion) than ARG.
14242 UNIFY_ALLOW_LESS_CV_QUAL:
14243 Allow the deduced ARG to be less cv-qualified than ARG.
14244 UNIFY_ALLOW_DERIVED:
14245 Allow the deduced ARG to be a template base class of ARG,
14246 or a pointer to a template base class of the type pointed to by
14247 ARG.
14248 UNIFY_ALLOW_INTEGER:
14249 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14250 case for more information.
14251 UNIFY_ALLOW_OUTER_LEVEL:
14252 This is the outermost level of a deduction. Used to determine validity
14253 of qualification conversions. A valid qualification conversion must
14254 have const qualified pointers leading up to the inner type which
14255 requires additional CV quals, except at the outer level, where const
14256 is not required [conv.qual]. It would be normal to set this flag in
14257 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14258 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14259 This is the outermost level of a deduction, and PARM can be more CV
14260 qualified at this point.
14261 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14262 This is the outermost level of a deduction, and PARM can be less CV
14263 qualified at this point. */
14265 static int
14267 {
14269 tree targ;
14270 tree tparm;
14273 /* I don't think this will do the right thing with respect to types.
14274 But the only case I've seen it in so far has been array bounds, where
14275 signedness is the only information lost, and I think that will be
14276 okay. */
14284 /* We can't deduce anything from this, but we might get all the
14285 template args from other function args. */
14288 /* If PARM uses template parameters, then we can't bail out here,
14289 even if ARG == PARM, since we won't record unifications for the
14290 template parameters. We might need them if we're trying to
14291 figure out which of two things is more specialized. */
14295 /* Handle init lists early, so the rest of the function can assume
14296 we're dealing with a type. */
14298 {
14303 /* Replace T with std::initializer_list<T> for deduction. */
14309 /* We can only deduce from an initializer list argument if the
14310 parameter is std::initializer_list; otherwise this is a
14311 non-deduced context. */
14317 {
14320 {
14322 /* It should only be possible to get here for a call. */
14324 elt_strict |= maybe_adjust_types_for_deduction
14327 }
14331 }
14333 /* If the std::initializer_list<T> deduction worked, replace the
14334 deduced A with std::initializer_list<A>. */
14336 {
14341 }
14343 }
14345 /* Immediately reject some pairs that won't unify because of
14346 cv-qualification mismatches. */
14349 /* It is the elements of the array which hold the cv quals of an array
14350 type, and the elements might be template type parms. We'll check
14351 when we recurse. */
14353 /* We check the cv-qualifiers when unifying with template type
14354 parameters below. We want to allow ARG `const T' to unify with
14355 PARM `T' for example, when computing which of two templates
14356 is more specialized, for example. */
14370 {
14374 /* In a type which contains a nested-name-specifier, template
14375 argument values cannot be deduced for template parameters used
14376 within the nested-name-specifier. */
14388 /* The PARM is not one we're trying to unify. Just check
14389 to see if it matches ARG. */
14396 /* Check for mixed types and values. */
14404 {
14405 /* ARG must be constructed from a template class or a template
14406 template parameter. */
14411 {
14414 tree parm_parms
14415 = DECL_INNERMOST_TEMPLATE_PARMS
14420 /* The resolution to DR150 makes clear that default
14421 arguments for an N-argument may not be used to bind T
14422 to a template template parameter with fewer than N
14423 parameters. It is not safe to permit the binding of
14424 default arguments as an extension, as that may change
14425 the meaning of a conforming program. Consider:
14427 struct Dense { static const unsigned int dim = 1; };
14429 template <template <typename> class View,
14430 typename Block>
14431 void operator+(float, View<Block> const&);
14433 template <typename Block,
14434 unsigned int Dim = Block::dim>
14435 struct Lvalue_proxy { operator float() const; };
14437 void
14438 test_1d (void) {
14439 Lvalue_proxy<Dense> p;
14440 float b;
14441 b + p;
14442 }
14444 Here, if Lvalue_proxy is permitted to bind to View, then
14445 the global operator+ will be used; if they are not, the
14446 Lvalue_proxy will be converted to float. */
14448 argvec,
14450 tf_none,
14456 /* Deduce arguments T, i from TT<T> or TT<i>.
14457 We check each element of PARMVEC and ARGVEC individually
14458 rather than the whole TREE_VEC since they can have
14459 different number of elements. */
14466 /* Check if the parameters end in a pack, making them
14467 variadic. */
14476 {
14480 UNIFY_ALLOW_NONE))
14482 }
14487 UNIFY_ALLOW_NONE,
14491 }
14494 /* Fall through to deduce template name. */
14495 }
14499 {
14500 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14502 /* Simple cases: Value already set, does match or doesn't. */
14507 }
14508 else
14509 {
14510 /* If PARM is `const T' and ARG is only `int', we don't have
14511 a match unless we are allowing additional qualification.
14512 If ARG is `const int' and PARM is just `T' that's OK;
14513 that binds `const int' to `T'. */
14518 /* Consider the case where ARG is `const volatile int' and
14519 PARM is `const T'. Then, T should be `volatile int'. */
14520 arg = cp_build_qualified_type_real
14525 /* Simple cases: Value already set, does match or doesn't. */
14531 /* Make sure that ARG is not a variable-sized array. (Note
14532 that were talking about variable-sized arrays (like
14533 `int[n]'), rather than arrays of unknown size (like
14534 `int[]').) We'll get very confused by such a type since
14535 the bound of the array will not be computable in an
14536 instantiation. Besides, such types are not allowed in
14537 ISO C++, so we can do as we please here. */
14541 /* Strip typedefs as in convert_template_argument. */
14543 }
14545 /* If ARG is a parameter pack or an expansion, we cannot unify
14546 against it unless PARM is also a parameter pack. */
14551 /* If the argument deduction results is a METHOD_TYPE,
14552 then there is a problem.
14553 METHOD_TYPE doesn't map to any real C++ type the result of
14554 the deduction can not be of that type. */
14568 /* The PARM is not one we're trying to unify. Just check
14569 to see if it matches ARG. */
14579 /* [temp.deduct.type] If, in the declaration of a function template
14580 with a non-type template-parameter, the non-type
14581 template-parameter is used in an expression in the function
14582 parameter-list and, if the corresponding template-argument is
14583 deduced, the template-argument type shall match the type of the
14584 template-parameter exactly, except that a template-argument
14585 deduced from an array bound may be of any integral type.
14586 The non-type parameter might use already deduced type parameters. */
14589 /* Template-parameter dependent expression. Just accept it for now.
14590 It will later be processed in convert_template_argument. */
14591 ;
14597 /* Convert the ARG to the type of PARM; the deduced non-type
14598 template argument must exactly match the types of the
14599 corresponding parameter. */
14602 /* We haven't deduced the type of this parameter yet. Try again
14603 later. */
14605 else
14608 /* If ARG is a parameter pack or an expansion, we cannot unify
14609 against it unless PARM is also a parameter pack. */
14618 {
14619 /* A pointer-to-member constant can be unified only with
14620 another constant. */
14624 /* Just unify the class member. It would be useless (and possibly
14625 wrong, depending on the strict flags) to unify also
14626 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14627 arg refer to the same variable, even if through different
14628 classes. For instance:
14630 struct A { int x; };
14631 struct B : A { };
14633 Unification of &A::x and &B::x must succeed. */
14636 }
14639 {
14643 /* [temp.deduct.call]
14645 A can be another pointer or pointer to member type that can
14646 be converted to the deduced A via a qualification
14647 conversion (_conv.qual_).
14649 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14650 This will allow for additional cv-qualification of the
14651 pointed-to types if appropriate. */
14654 /* The derived-to-base conversion only persists through one
14655 level of pointers. */
14660 }
14675 {
14676 tree parm_max;
14677 tree arg_max;
14681 /* Our representation of array types uses "N - 1" as the
14682 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14683 not an integer constant. We cannot unify arbitrarily
14684 complex expressions, so we eliminate the MINUS_EXPRs
14685 here. */
14689 {
14692 }
14696 {
14697 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14698 trying to unify the type of a variable with the type
14699 of a template parameter. For example:
14701 template <unsigned int N>
14702 void f (char (&) [N]);
14703 int g();
14704 void h(int i) {
14705 char a[g(i)];
14706 f(a);
14707 }
14709 Here, the type of the ARG will be "int [g(i)]", and
14710 may be a SAVE_EXPR, etc. */
14714 }
14716 /* If only one of the bounds used a MINUS_EXPR, compensate
14717 by adding one to the other bound. */
14720 integer_type_node,
14721 parm_max,
14722 integer_one_node);
14725 integer_type_node,
14726 arg_max,
14727 integer_one_node);
14731 }
14745 /* We have already checked cv-qualification at the top of the
14746 function. */
14750 /* As far as unification is concerned, this wins. Later checks
14751 will invalidate it if necessary. */
14754 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14755 /* Type INTEGER_CST can come from ordinary constant template args. */
14765 {
14774 UNIFY_ALLOW_NONE))
14777 }
14785 {
14792 strict);
14793 }
14796 {
14800 {
14801 /* First, we try to unify the PARM and ARG directly. */
14806 {
14807 /* Fallback to the special case allowed in
14808 [temp.deduct.call]:
14810 If P is a class, and P has the form
14811 template-id, then A can be a derived class of
14812 the deduced A. Likewise, if P is a pointer to
14813 a class of the form template-id, A can be a
14814 pointer to a derived class pointed to by the
14815 deduced A. */
14820 }
14821 }
14825 /* Perhaps PARM is something like S<U> and ARG is S<int>.
14826 Then, we should unify `int' and `U'. */
14828 else
14829 /* There's no chance of unification succeeding. */
14834 }
14841 {
14844 tree a;
14850 /* CV qualifications for methods can never be deduced, they must
14851 match exactly. We need to check them explicitly here,
14852 because type_unification_real treats them as any other
14853 cv-qualified parameter. */
14855 && (!check_cv_quals_for_unify
14875 LOOKUP_NORMAL);
14876 }
14879 /* Unify a pointer to member with a pointer to member function, which
14880 deduces the type of the member as a function type. */
14882 {
14883 tree method_type;
14884 tree fntype;
14885 cp_cv_quals cv_quals;
14887 /* Check top-level cv qualifiers */
14895 /* Determine the type of the function we are unifying against. */
14897 fntype =
14901 /* Extract the cv-qualifiers of the member function from the
14902 implicit object parameter and place them on the function
14903 type to be restored later. */
14904 cv_quals =
14908 }
14916 strict);
14927 /* Matched cases are handled by the ARG == PARM test above. */
14932 {
14940 {
14942 {
14944 /* We can unify against something with a trailing
14945 parameter pack. */
14947 else
14948 /* Since there is something following the pack
14949 expansion, we cannot unify this template argument
14950 list. */
14952 }
14953 }
14956 /* If we don't have enough arguments to satisfy the parameters
14957 (not counting the pack expression at the end), or we have
14958 too many arguments for a parameter list that doesn't end in
14959 a pack expression, we can't unify. */
14964 /* Unify all of the parameters that precede the (optional)
14965 pack expression. */
14967 {
14971 }
14979 }
14985 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
14986 nodes. */
14990 /* Unification fails if we hit an error node. */
14996 /* We must be looking at an expression. This can happen with
14997 something like:
14999 template <int I>
15000 void foo(S<I>, S<I + 2>);
15002 This is a "nondeduced context":
15004 [deduct.type]
15006 The nondeduced contexts are:
15008 --A type that is a template-id in which one or more of
15009 the template-arguments is an expression that references
15010 a template-parameter.
15012 In these cases, we assume deduction succeeded, but don't
15013 actually infer any unifications. */
15018 else
15020 }
15021 }
15022 \f
15023 /* Note that DECL can be defined in this translation unit, if
15024 required. */
15026 static void
15028 {
15029 tree clone;
15033 }
15035 /* Called if RESULT is explicitly instantiated, or is a member of an
15036 explicitly instantiated class. */
15038 void
15040 {
15043 /* If this entity has already been written out, it's too late to
15044 make any modifications. */
15049 /* The TREE_PUBLIC flag for function declarations will have been
15050 set correctly by tsubst. */
15053 /* This might have been set by an earlier implicit instantiation. */
15058 else
15059 {
15061 /* Always make artificials weak. */
15064 /* For WIN32 we also want to put explicit instantiations in
15065 linkonce sections. */
15068 }
15070 /* If EXTERN_P, then this function will not be emitted -- unless
15071 followed by an explicit instantiation, at which point its linkage
15072 will be adjusted. If !EXTERN_P, then this function will be
15073 emitted here. In neither circumstance do we want
15074 import_export_decl to adjust the linkage. */
15076 }
15078 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15079 important template arguments. If any are missing, we check whether
15080 they're important by using error_mark_node for substituting into any
15081 args that were used for partial ordering (the ones between ARGS and END)
15082 and seeing if it bubbles up. */
15084 static bool
15086 {
15091 {
15094 }
15096 {
15098 {
15102 }
15103 }
15105 }
15107 /* Given two function templates PAT1 and PAT2, return:
15109 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15110 -1 if PAT2 is more specialized than PAT1.
15111 0 if neither is more specialized.
15113 LEN indicates the number of parameters we should consider
15114 (defaulted parameters should not be considered).
15116 The 1998 std underspecified function template partial ordering, and
15117 DR214 addresses the issue. We take pairs of arguments, one from
15118 each of the templates, and deduce them against each other. One of
15119 the templates will be more specialized if all the *other*
15120 template's arguments deduce against its arguments and at least one
15121 of its arguments *does* *not* deduce against the other template's
15122 corresponding argument. Deduction is done as for class templates.
15123 The arguments used in deduction have reference and top level cv
15124 qualifiers removed. Iff both arguments were originally reference
15125 types *and* deduction succeeds in both directions, the template
15126 with the more cv-qualified argument wins for that pairing (if
15127 neither is more cv-qualified, they both are equal). Unlike regular
15128 deduction, after all the arguments have been deduced in this way,
15129 we do *not* verify the deduced template argument values can be
15130 substituted into non-deduced contexts.
15132 The logic can be a bit confusing here, because we look at deduce1 and
15133 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15134 can find template arguments for pat1 to make arg1 look like arg2, that
15135 means that arg2 is at least as specialized as arg1. */
15137 int
15139 {
15152 /* Remove the this parameter from non-static member functions. If
15153 one is a non-static member function and the other is not a static
15154 member function, remove the first parameter from that function
15155 also. This situation occurs for operator functions where we
15156 locate both a member function (with this pointer) and non-member
15157 operator (with explicit first operand). */
15159 {
15164 }
15166 {
15169 {
15170 len--;
15172 }
15173 }
15175 /* If only one is a conversion operator, they are unordered. */
15179 /* Consider the return type for a conversion function */
15181 {
15184 len++;
15185 }
15187 processing_template_decl++;
15193 /* Stop when an ellipsis is seen. */
15195 {
15204 {
15205 /* When both arguments are pack expansions, we need only
15206 unify the patterns themselves. */
15210 /* This is the last comparison we need to do. */
15212 }
15215 {
15218 }
15221 {
15224 }
15227 {
15228 /* Only of the args is a reference, see if we should apply
15229 array/function pointer decay to it. This is not part of
15230 DR214, but is, IMHO, consistent with the deduction rules
15231 for the function call itself, and with our earlier
15232 implementation of the underspecified partial ordering
15233 rules. (nathan). */
15235 {
15237 {
15240 /* FALLTHROUGH. */
15247 }
15248 }
15249 else
15250 {
15252 {
15255 /* FALLTHROUGH. */
15262 }
15263 }
15264 }
15270 {
15276 /* Setup the parameter vector, which contains only ARG1. */
15279 /* Setup the argument vector, which contains the remaining
15280 arguments. */
15289 /* We cannot deduce in the other direction, because ARG1 is
15290 a pack expansion but ARG2 is not. */
15292 }
15294 {
15300 /* Setup the parameter vector, which contains only ARG1. */
15303 /* Setup the argument vector, which contains the remaining
15304 arguments. */
15313 /* We cannot deduce in the other direction, because ARG2 is
15314 a pack expansion but ARG1 is not.*/
15316 }
15318 else
15319 {
15320 /* The normal case, where neither argument is a pack
15321 expansion. */
15324 }
15326 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15327 arg2, then arg2 is not as specialized as arg1. */
15333 /* "If, for a given type, deduction succeeds in both directions
15334 (i.e., the types are identical after the transformations above)
15335 and if the type from the argument template is more cv-qualified
15336 than the type from the parameter template (as described above)
15337 that type is considered to be more specialized than the other. If
15338 neither type is more cv-qualified than the other then neither type
15339 is more specialized than the other."
15341 We check same_type_p explicitly because deduction can also succeed
15342 in both directions when there is a nondeduced context. */
15346 {
15351 }
15354 /* We've failed to deduce something in either direction.
15355 These must be unordered. */
15360 /* We have already processed all of the arguments in our
15361 handing of the pack expansion type. */
15366 }
15368 /* "In most cases, all template parameters must have values in order for
15369 deduction to succeed, but for partial ordering purposes a template
15370 parameter may remain without a value provided it is not used in the
15371 types being used for partial ordering."
15373 Thus, if we are missing any of the targs1 we need to substitute into
15374 origs1, then pat2 is not as specialized as pat1. This can happen when
15375 there is a nondeduced context. */
15381 processing_template_decl--;
15383 /* All things being equal, if the next argument is a pack expansion
15384 for one function but not for the other, prefer the
15385 non-variadic function. FIXME this is bogus; see c++/41958. */
15389 {
15392 }
15398 else
15400 }
15402 /* Determine which of two partial specializations is more specialized.
15404 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15405 to the first partial specialization. The TREE_VALUE is the
15406 innermost set of template parameters for the partial
15407 specialization. PAT2 is similar, but for the second template.
15409 Return 1 if the first partial specialization is more specialized;
15410 -1 if the second is more specialized; 0 if neither is more
15411 specialized.
15413 See [temp.class.order] for information about determining which of
15414 two templates is more specialized. */
15416 static int
15418 {
15419 tree targs;
15427 /* Just like what happens for functions, if we are ordering between
15428 different class template specializations, we may encounter dependent
15429 types in the arguments, and we need our dependency check functions
15430 to behave correctly. */
15436 {
15439 }
15445 {
15448 }
15451 /* In the case of a tie where at least one of the class templates
15452 has a parameter pack at the end, the template with the most
15453 non-packed parameters wins. */
15455 && any_deductions
15458 {
15464 /* We don't count the pack expansion at the end. */
15474 }
15477 }
15479 /* Return the template arguments that will produce the function signature
15480 DECL from the function template FN, with the explicit template
15481 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15482 also match. Return NULL_TREE if no satisfactory arguments could be
15483 found. */
15485 static tree
15487 {
15490 tree decl_type;
15491 tree decl_arg_types;
15494 tree arg;
15496 /* Substitute the explicit template arguments into the type of DECL.
15497 The call to fn_type_unification will handle substitution into the
15498 FN. */
15501 {
15502 tree tmpl;
15503 tree converted_args;
15507 else
15508 /* We can get here for some invalid specializations. */
15511 converted_args
15514 tf_none,
15523 }
15525 /* Never do unification on the 'this' parameter. */
15544 }
15546 /* Return the innermost template arguments that, when applied to a
15547 template specialization whose innermost template parameters are
15548 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15549 ARGS.
15551 For example, suppose we have:
15553 template <class T, class U> struct S {};
15554 template <class T> struct S<T*, int> {};
15556 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15557 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15558 int}. The resulting vector will be {double}, indicating that `T'
15559 is bound to `double'. */
15561 static tree
15563 {
15565 tree deduced_args;
15566 tree innermost_deduced_args;
15570 {
15574 innermost_deduced_args);
15575 }
15576 else
15582 UNIFY_ALLOW_NONE))
15589 /* Verify that nondeduced template arguments agree with the type
15590 obtained from argument deduction.
15592 For example:
15594 struct A { typedef int X; };
15595 template <class T, class U> struct C {};
15596 template <class T> struct C<T, typename T::X> {};
15598 Then with the instantiation `C<A, int>', we can deduce that
15599 `T' is `A' but unify () does not check whether `typename T::X'
15600 is `int'. */
15603 /* We only need to check the innermost arguments; the other
15604 arguments will always agree. */
15609 /* Now that we have bindings for all of the template arguments,
15610 ensure that the arguments deduced for the template template
15611 parameters have compatible template parameter lists. See the use
15612 of template_template_parm_bindings_ok_p in fn_type_unification
15613 for more information. */
15618 }
15620 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15621 Return the TREE_LIST node with the most specialized template, if
15622 any. If there is no most specialized template, the error_mark_node
15623 is returned.
15625 Note that this function does not look at, or modify, the
15626 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15627 returned is one of the elements of INSTANTIATIONS, callers may
15628 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15629 and retrieve it from the value returned. */
15631 tree
15633 {
15640 {
15646 fate--;
15651 fate++;
15656 {
15657 /* Equally specialized, move to next function. If there
15658 is no next function, nothing's most specialized. */
15663 }
15664 }
15667 /* Now verify that champ is better than everything earlier in the
15668 instantiation list. */
15676 {
15679 }
15681 processing_template_decl--;
15687 }
15689 /* If DECL is a specialization of some template, return the most
15690 general such template. Otherwise, returns NULL_TREE.
15692 For example, given:
15694 template <class T> struct S { template <class U> void f(U); };
15696 if TMPL is `template <class U> void S<int>::f(U)' this will return
15697 the full template. This function will not trace past partial
15698 specializations, however. For example, given in addition:
15700 template <class T> struct S<T*> { template <class U> void f(U); };
15702 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15703 `template <class T> template <class U> S<T*>::f(U)'. */
15705 tree
15707 {
15708 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15709 an immediate specialization. */
15711 {
15715 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15716 template friend. */
15721 }
15723 /* Look for more and more general templates. */
15725 {
15726 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15727 (See cp-tree.h for details.) */
15735 /* Stop if we run into an explicitly specialized class template. */
15742 }
15745 }
15747 /* Return the most specialized of the class template partial
15748 specializations of TMPL which can produce TYPE, a specialization of
15749 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15750 a _TYPE node corresponding to the partial specialization, while the
15751 TREE_PURPOSE is the set of template arguments that must be
15752 substituted into the TREE_TYPE in order to generate TYPE.
15754 If the choice of partial specialization is ambiguous, a diagnostic
15755 is issued, and the error_mark_node is returned. If there are no
15756 partial specializations of TMPL matching TYPE, then NULL_TREE is
15757 returned. */
15759 static tree
15761 {
15763 tree t;
15764 tree champ;
15767 tree args;
15773 /* For determining which partial specialization to use, only the
15774 innermost args are interesting. */
15776 {
15779 }
15782 {
15783 tree partial_spec_args;
15784 tree spec_args;
15789 {
15794 /* Discard the outer levels of args, and then substitute in the
15795 template args from the enclosing class. */
15797 partial_spec_args = tsubst_template_args
15800 /* PARMS already refers to just the innermost parms, but the
15801 template parms in partial_spec_args had their levels lowered
15802 by tsubst, so we need to do the same for the parm list. We
15803 can't just tsubst the TREE_VEC itself, as tsubst wants to
15804 treat a TREE_VEC as an argument vector. */
15811 }
15813 partial_spec_args,
15814 args);
15816 {
15821 }
15822 }
15832 {
15835 ;
15836 else
15837 {
15839 {
15842 {
15845 }
15846 }
15848 }
15849 }
15853 {
15856 {
15859 }
15860 }
15863 {
15869 {
15872 }
15875 }
15878 }
15880 /* Explicitly instantiate DECL. */
15882 void
15884 {
15889 /* An error occurred, for which grokdeclarator has already issued
15890 an appropriate message. */
15893 {
15896 }
15898 {
15899 /* There is an asymmetry here in the way VAR_DECLs and
15900 FUNCTION_DECLs are handled by grokdeclarator. In the case of
15901 the latter, the DECL we get back will be marked as a
15902 template instantiation, and the appropriate
15903 DECL_TEMPLATE_INFO will be set up. This does not happen for
15904 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
15905 should handle VAR_DECLs as it currently handles
15906 FUNCTION_DECLs. */
15908 {
15911 }
15914 {
15917 }
15919 {
15924 }
15925 }
15927 {
15930 }
15931 else
15934 /* Check for various error cases. Note that if the explicit
15935 instantiation is valid the RESULT will currently be marked as an
15936 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
15937 until we get here. */
15940 {
15941 /* DR 259 [temp.spec].
15943 Both an explicit instantiation and a declaration of an explicit
15944 specialization shall not appear in a program unless the explicit
15945 instantiation follows a declaration of the explicit specialization.
15947 For a given set of template parameters, if an explicit
15948 instantiation of a template appears after a declaration of an
15949 explicit specialization for that template, the explicit
15950 instantiation has no effect. */
15952 }
15954 {
15955 /* [temp.spec]
15957 No program shall explicitly instantiate any template more
15958 than once.
15960 We check DECL_NOT_REALLY_EXTERN so as not to complain when
15961 the first instantiation was `extern' and the second is not,
15962 and EXTERN_P for the opposite case. */
15965 /* If an "extern" explicit instantiation follows an ordinary
15966 explicit instantiation, the template is instantiated. */
15969 }
15971 {
15974 }
15976 {
15979 }
15982 ;
15984 {
15987 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
15990 }
15991 else
15999 }
16001 static void
16003 {
16009 {
16012 }
16013 }
16015 /* Called from do_type_instantiation through binding_table_foreach to
16016 do recursive instantiation for the type bound in ENTRY. */
16017 static void
16019 {
16025 }
16027 /* Called from do_type_instantiation to instantiate a member
16028 (a member function or a static member variable) of an
16029 explicitly instantiated class template. */
16030 static void
16032 {
16037 }
16039 /* Perform an explicit instantiation of template class T. STORAGE, if
16040 non-null, is the RID for extern, inline or static. COMPLAIN is
16041 nonzero if this is called from the parser, zero if called recursively,
16042 since the standard is unclear (as detailed below). */
16044 void
16046 {
16056 {
16059 }
16064 {
16067 t);
16069 }
16072 {
16074 {
16076 {
16079 "ISO C++ 1998 forbids the use of %<extern%> on "
16081 }
16082 else
16084 "ISO C++ forbids the use of %qE"
16086 }
16094 else
16095 {
16097 storage);
16099 }
16100 }
16103 {
16104 /* DR 259 [temp.spec].
16106 Both an explicit instantiation and a declaration of an explicit
16107 specialization shall not appear in a program unless the explicit
16108 instantiation follows a declaration of the explicit specialization.
16110 For a given set of template parameters, if an explicit
16111 instantiation of a template appears after a declaration of an
16112 explicit specialization for that template, the explicit
16113 instantiation has no effect. */
16115 }
16117 {
16118 /* [temp.spec]
16120 No program shall explicitly instantiate any template more
16121 than once.
16123 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16124 instantiation was `extern'. If EXTERN_P then the second is.
16125 These cases are OK. */
16132 /* If we've already instantiated the template, just return now. */
16135 }
16143 {
16144 tree tmp;
16146 /* In contrast to implicit instantiation, where only the
16147 declarations, and not the definitions, of members are
16148 instantiated, we have here:
16150 [temp.explicit]
16152 The explicit instantiation of a class template specialization
16153 implies the instantiation of all of its members not
16154 previously explicitly specialized in the translation unit
16155 containing the explicit instantiation.
16157 Of course, we can't instantiate member template classes, since
16158 we don't have any arguments for them. Note that the standard
16159 is unclear on whether the instantiation of the members are
16160 *explicit* instantiations or not. However, the most natural
16161 interpretation is that it should be an explicit instantiation. */
16176 }
16177 }
16179 /* Given a function DECL, which is a specialization of TMPL, modify
16180 DECL to be a re-instantiation of TMPL with the same template
16181 arguments. TMPL should be the template into which tsubst'ing
16182 should occur for DECL, not the most general template.
16184 One reason for doing this is a scenario like this:
16186 template <class T>
16187 void f(const T&, int i);
16189 void g() { f(3, 7); }
16191 template <class T>
16192 void f(const T& t, const int i) { }
16194 Note that when the template is first instantiated, with
16195 instantiate_template, the resulting DECL will have no name for the
16196 first parameter, and the wrong type for the second. So, when we go
16197 to instantiate the DECL, we regenerate it. */
16199 static void
16201 {
16202 /* The arguments used to instantiate DECL, from the most general
16203 template. */
16204 tree args;
16205 tree code_pattern;
16210 /* Make sure that we can see identifiers, and compute access
16211 correctly. */
16215 {
16216 tree decl_parm;
16217 tree pattern_parm;
16218 tree specs;
16231 specs);
16233 /* Merge parameter declarations. */
16236 pattern_parm
16240 {
16241 tree parm_type;
16242 tree attributes;
16247 NULL_TREE);
16253 {
16256 }
16259 }
16260 /* Merge any parameters that match with the function parameter
16261 pack. */
16263 {
16265 tree expanded_types;
16266 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16267 the parameters in this function parameter pack. */
16272 {
16273 tree parm_type;
16274 tree attributes;
16277 /* Rename the parameter to include the index. */
16286 {
16289 }
16291 }
16292 }
16293 /* Merge additional specifiers from the CODE_PATTERN. */
16297 }
16303 else
16307 }
16309 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16310 substituted to get DECL. */
16312 tree
16314 {
16317 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16318 for the instantiation. This is not always the most general
16319 template. Consider, for example:
16321 template <class T>
16322 struct S { template <class U> void f();
16323 template <> void f<int>(); };
16325 and an instantiation of S<double>::f<int>. We want TD to be the
16326 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16328 more general template. */
16330 /* We must also deal with friend templates. Given:
16332 template <class T> struct S {
16333 template <class U> friend void f() {};
16334 };
16336 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16337 so far as the language is concerned, but that's still
16338 where we get the pattern for the instantiation from. On
16339 other hand, if the definition comes outside the class, say:
16341 template <class T> struct S {
16342 template <class U> friend void f();
16343 };
16344 template <class U> friend void f() {}
16346 we don't need to look any further. That's what the check for
16347 DECL_INITIAL is for. */
16351 {
16352 /* The present template, TD, should not be a definition. If it
16353 were a definition, we should be using it! Note that we
16354 cannot restructure the loop to just keep going until we find
16355 a template with a definition, since that might go too far if
16356 a specialization was declared, but not defined. */
16360 /* Fetch the more general template. */
16362 }
16365 }
16367 /* Returns true if we need to instantiate this template instance even if we
16368 know we aren't going to emit it.. */
16370 bool
16372 {
16373 /* We always instantiate inline functions so that we can inline them. An
16374 explicit instantiation declaration prohibits implicit instantiation of
16375 non-inline functions. With high levels of optimization, we would
16376 normally inline non-inline functions -- but we're not allowed to do
16377 that for "extern template" functions. Therefore, we check
16378 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16381 /* And we need to instantiate static data members so that
16382 their initializers are available in integral constant
16383 expressions. */
16386 }
16388 /* Produce the definition of D, a _DECL generated from a template. If
16389 DEFER_OK is nonzero, then we don't have to actually do the
16390 instantiation now; we just have to do it sometime. Normally it is
16391 an error if this is an explicit instantiation but D is undefined.
16392 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16393 explicitly instantiated class template. */
16395 tree
16398 {
16400 tree gen_args;
16401 tree args;
16402 tree td;
16403 tree code_pattern;
16404 tree spec;
16405 tree gen_tmpl;
16411 /* This function should only be used to instantiate templates for
16412 functions and static member variables. */
16416 /* Variables are never deferred; if instantiation is required, they
16417 are instantiated right away. That allows for better code in the
16418 case that an expression refers to the value of the variable --
16419 if the variable has a constant value the referring expression can
16420 take advantage of that fact. */
16424 /* Don't instantiate cloned functions. Instead, instantiate the
16425 functions they cloned. */
16431 /* D has already been instantiated or explicitly specialized, so
16432 there's nothing for us to do here.
16434 It might seem reasonable to check whether or not D is an explicit
16435 instantiation, and, if so, stop here. But when an explicit
16436 instantiation is deferred until the end of the compilation,
16437 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16438 the instantiation. */
16441 /* Check to see whether we know that this template will be
16442 instantiated in some other file, as with "extern template"
16443 extension. */
16446 /* In general, we do not instantiate such templates. */
16454 /* We should already have the extra args. */
16457 /* And what's in the hash table should match D. */
16461 /* This needs to happen before any tsubsting. */
16467 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16468 for the instantiation. */
16472 /* We should never be trying to instantiate a member of a class
16473 template or partial specialization. */
16478 /* In the case of a friend template whose definition is provided
16479 outside the class, we may have too many arguments. Drop the
16480 ones we don't need. The same is true for specializations. */
16481 args = get_innermost_template_args
16483 else
16488 else
16491 /* We may be in the middle of deferred access check. Disable it now. */
16494 /* Unless an explicit instantiation directive has already determined
16495 the linkage of D, remember that a definition is available for
16496 this entity. */
16504 /* If D is a member of an explicitly instantiated class template,
16505 and no definition is available, treat it like an implicit
16506 instantiation. */
16509 {
16513 }
16515 /* Recheck the substitutions to obtain any warning messages
16516 about ignoring cv qualifiers. Don't do this for artificial decls,
16517 as it breaks the context-sensitive substitution for lambda op(). */
16519 {
16523 /* Make sure that we can see identifiers, and compute access
16524 correctly. D is already the target FUNCTION_DECL with the
16525 right context. */
16529 {
16532 d);
16533 /* Don't simply tsubst the function type, as that will give
16534 duplicate warnings about poor parameter qualifications.
16535 The function arguments are the same as the decl_arguments
16536 without the top level cv qualifiers. */
16538 }
16542 }
16544 /* Defer all other templates, unless we have been explicitly
16545 forbidden from doing so. */
16547 template. */
16548 ! pattern_defined
16549 /* If it's OK to postpone instantiation, do so. */
16550 || defer_ok
16551 /* If this is a static data member that will be defined
16552 elsewhere, we don't want to instantiate the entire data
16553 member, but we do want to instantiate the initializer so that
16554 we can substitute that elsewhere. */
16556 {
16557 /* The definition of the static data member is now required so
16558 we must substitute the initializer. */
16562 {
16563 tree ns;
16564 tree init;
16570 args,
16575 LOOKUP_ONLYCONVERTING);
16578 }
16580 /* We restore the source position here because it's used by
16581 add_pending_template. */
16587 /* [temp.explicit]
16589 The definition of a non-exported function template, a
16590 non-exported member function template, or a non-exported
16591 member function or static data member of a class template
16592 shall be present in every translation unit in which it is
16593 explicitly instantiated. */
16597 /* ??? Historically, we have instantiated inline functions, even
16598 when marked as "extern template". */
16602 }
16603 /* Tell the repository that D is available in this translation unit
16604 -- and see if it is supposed to be instantiated here. */
16606 {
16607 /* In a PCH file, despite the fact that the repository hasn't
16608 requested instantiation in the PCH it is still possible that
16609 an instantiation will be required in a file that includes the
16610 PCH. */
16613 /* Instantiate inline functions so that the inliner can do its
16614 job, even though we'll not be emitting a copy of this
16615 function. */
16618 }
16624 /* Mark D as instantiated so that recursive calls to
16625 instantiate_decl do not try to instantiate it again. */
16628 /* Regenerate the declaration in case the template has been modified
16629 by a subsequent redeclaration. */
16632 /* We already set the file and line above. Reset them now in case
16633 they changed as a result of calling regenerate_decl_from_template. */
16637 {
16638 tree init;
16640 /* Clear out DECL_RTL; whatever was there before may not be right
16641 since we've reset the type of the declaration. */
16645 /* The initializer is placed in DECL_INITIAL by
16646 regenerate_decl_from_template. Pull it out so that
16647 cp_finish_decl can process it. */
16652 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16653 initializer. That function will defer actual emission until
16654 we have a chance to determine linkage. */
16657 /* Enter the scope of D so that access-checking works correctly. */
16661 }
16663 {
16664 htab_t saved_local_specializations;
16665 tree subst_decl;
16666 tree tmpl_parm;
16667 tree spec_parm;
16669 /* Save away the current list, in case we are instantiating one
16670 template from within the body of another. */
16673 /* Set up the list of local specializations. */
16675 hash_local_specialization,
16676 eq_local_specializations,
16677 NULL);
16679 /* Set up context. */
16682 /* Create substitution entries for the parameters. */
16687 {
16691 }
16693 {
16697 }
16699 {
16700 /* Register the (value) argument pack as a specialization of
16701 TMPL_PARM, then move on. */
16706 }
16709 /* Substitute into the body of the function. */
16714 /* Set the current input_location to the end of the function
16715 so that finish_function knows where we are. */
16718 /* We don't need the local specializations any more. */
16722 /* Finish the function. */
16725 }
16727 /* We're not deferring instantiation any more. */
16733 out:
16741 }
16743 /* Run through the list of templates that we wish we could
16744 instantiate, and instantiate any we can. RETRIES is the
16745 number of times we retry pending template instantiation. */
16747 void
16749 {
16753 /* Instantiating templates may trigger vtable generation. This in turn
16754 may require further template instantiations. We place a limit here
16755 to avoid infinite loop. */
16757 {
16761 " instantiating %q+D, possibly from virtual table generation"
16765 /* Pretend that we defined it. */
16768 }
16770 do
16771 {
16776 {
16781 {
16782 tree fn;
16785 {
16789 fn;
16797 }
16800 }
16801 else
16802 {
16805 {
16806 instantiation
16812 }
16816 }
16819 /* If INSTANTIATION has been instantiated, then we don't
16820 need to consider it again in the future. */
16822 else
16823 {
16826 }
16829 }
16831 }
16835 }
16837 /* Substitute ARGVEC into T, which is a list of initializers for
16838 either base class or a non-static data member. The TREE_PURPOSEs
16839 are DECLs, and the TREE_VALUEs are the initializer values. Used by
16840 instantiate_decl. */
16842 static tree
16844 {
16848 {
16849 tree decl;
16850 tree init;
16856 {
16857 tree expr;
16858 tree arg;
16860 /* Expand the base class expansion type into separate base
16861 classes. */
16863 tf_warning_or_error,
16864 NULL_TREE);
16868 /* We'll be building separate TREE_LISTs of arguments for
16869 each base. */
16875 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
16876 expand each argument in the TREE_VALUE of t. */
16882 /* VOID_TYPE_NODE is used to indicate
16883 value-initialization. */
16884 {
16887 }
16888 else
16889 {
16890 /* Substitute parameter packs into each argument in the
16891 TREE_LIST. */
16894 {
16895 tree expanded_exprs;
16897 /* Expand the argument. */
16899 expanded_exprs
16901 tf_warning_or_error,
16902 NULL_TREE);
16906 /* Prepend each of the expanded expressions to the
16907 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
16909 {
16914 }
16915 }
16918 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
16919 since we built them backwards. */
16921 {
16924 }
16925 }
16926 }
16929 {
16931 {
16935 }
16936 else
16937 {
16949 }
16952 {
16956 }
16957 }
16958 }
16960 }
16962 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
16964 static void
16966 {
16971 else
16973 }
16975 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
16976 is the instantiation (which should have been created with
16977 start_enum) and ARGS are the template arguments to use. */
16979 static void
16981 {
16982 tree e;
16985 {
16986 tree value;
16987 tree decl;
16990 /* Note that in a template enum, the TREE_VALUE is the
16991 CONST_DECL, not the corresponding INTEGER_CST. */
16996 /* Give this enumeration constant the correct access. */
16999 /* Actually build the enumerator itself. */
17001 }
17006 }
17008 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17009 its type -- but without substituting the innermost set of template
17010 arguments. So, innermost set of template parameters will appear in
17011 the type. */
17013 tree
17015 {
17016 tree fn_type;
17017 tree tmpl;
17018 tree targs;
17019 tree tparms;
17027 /* There should be as many levels of arguments as there are levels
17028 of parameters. */
17034 /* No substitution is necessary. */
17035 ;
17036 else
17037 {
17039 tree partial_args;
17041 /* Replace the innermost level of the TARGS with NULL_TREEs to
17042 let tsubst know not to substitute for those parameters. */
17051 /* Disable access control as this function is used only during
17052 name-mangling. */
17057 /* Now, do the (partial) substitution to figure out the
17058 appropriate function type. */
17062 /* Substitute into the template parameters to obtain the real
17063 innermost set of parameters. This step is important if the
17064 innermost set of template parameters contains value
17065 parameters whose types depend on outer template parameters. */
17070 }
17073 }
17075 /* Return truthvalue if we're processing a template different from
17076 the last one involved in diagnostics. */
17077 int
17079 {
17081 }
17083 /* Remember current template involved in diagnostics. */
17084 void
17086 {
17088 }
17092 {
17094 }
17096 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17097 type. Return zero for ok, nonzero for disallowed. Issue error and
17098 warning messages under control of COMPLAIN. */
17100 static int
17102 {
17117 }
17119 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17120 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17122 static bool
17124 {
17125 tree scope;
17127 /* [temp.dep.type]
17129 A type is dependent if it is:
17131 -- a template parameter. Template template parameters are types
17132 for us (since TYPE_P holds true for them) so we handle
17133 them here. */
17137 /* -- a qualified-id with a nested-name-specifier which contains a
17138 class-name that names a dependent type or whose unqualified-id
17139 names a dependent type. */
17142 /* -- a cv-qualified type where the cv-unqualified type is
17143 dependent. */
17145 /* -- a compound type constructed from any dependent type. */
17155 {
17156 tree arg_type;
17161 arg_type;
17166 }
17167 /* -- an array type constructed from any dependent type or whose
17168 size is specified by a constant expression that is
17169 value-dependent. */
17171 {
17176 }
17179 {
17180 /* If this is the TYPE_DOMAIN of an array type, consider it
17181 dependent. We already checked for value-dependence in
17182 compute_array_index_type. */
17184 }
17186 /* -- a template-id in which either the template name is a template
17187 parameter ... */
17190 /* ... or any of the template arguments is a dependent type or
17191 an expression that is type-dependent or value-dependent. */
17193 && (any_dependent_template_arguments_p
17197 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17198 argument of the `typeof' expression is not type-dependent, then
17199 it should already been have resolved. */
17204 /* A template argument pack is dependent if any of its packed
17205 arguments are. */
17207 {
17213 }
17215 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17216 be template parameters. */
17220 /* The standard does not specifically mention types that are local
17221 to template functions or local classes, but they should be
17222 considered dependent too. For example:
17224 template <int I> void f() {
17225 enum E { a = I };
17226 S<sizeof (E)> s;
17227 }
17229 The size of `E' cannot be known until the value of `I' has been
17230 determined. Therefore, `E' must be considered dependent. */
17237 /* Other types are non-dependent. */
17239 }
17241 /* Returns TRUE if TYPE is dependent, in the sense of
17242 [temp.dep.type]. */
17244 bool
17246 {
17247 /* If there are no template parameters in scope, then there can't be
17248 any dependent types. */
17250 {
17251 /* If we are not processing a template, then nobody should be
17252 providing us with a dependent type. */
17256 }
17258 /* If the type is NULL, we have not computed a type for the entity
17259 in question; in that case, the type is dependent. */
17263 /* Erroneous types can be considered non-dependent. */
17267 /* If we have not already computed the appropriate value for TYPE,
17268 do so now. */
17270 {
17273 }
17276 }
17278 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17279 lookup. In other words, a dependent type that is not the current
17280 instantiation. */
17282 bool
17284 {
17287 }
17289 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
17291 static bool
17293 {
17294 tree scope;
17295 tree name;
17305 /* [temp.dep.expr]
17307 An id-expression is type-dependent if it contains a
17308 nested-name-specifier that contains a class-name that names a
17309 dependent type. */
17310 /* The suggested resolution to Core Issue 224 implies that if the
17311 qualifying type is the current class, then we must peek
17312 inside it. */
17321 }
17323 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17324 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17325 expression. */
17327 bool
17329 {
17333 /* A name declared with a dependent type. */
17338 {
17340 /* A name that has not been looked up -- must be dependent. */
17344 /* A non-type template parm. */
17348 /* A non-type template parm. */
17354 /* A constant with integral or enumeration type and is initialized
17355 with an expression that is value-dependent. */
17367 /* These expressions are value-dependent if the type to which
17368 the cast occurs is dependent or the expression being casted
17369 is value-dependent. */
17370 {
17376 /* A functional cast has a list of operands. */
17379 {
17380 /* If there are no operands, it must be an expression such
17381 as "int()". This should not happen for aggregate types
17382 because it would form non-constant expressions. */
17386 }
17392 }
17396 /* A `sizeof' expression is value-dependent if the operand is
17397 type-dependent or is a pack expansion. */
17413 /* A CALL_EXPR may appear in a constant expression if it is a
17414 call to a builtin function, e.g., __builtin_constant_p. All
17415 such calls are value-dependent. */
17419 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17420 is value-dependent. */
17421 {
17430 }
17433 {
17437 }
17444 /* A constant expression is value-dependent if any subexpression is
17445 value-dependent. */
17447 {
17457 || (value_dependent_expression_p
17462 {
17465 /* In some cases, some of the operands may be missing.
17466 (For example, in the case of PREDECREMENT_EXPR, the
17467 amount to increment by may be missing.) That doesn't
17468 make the expression dependent. */
17470 && (value_dependent_expression_p
17474 }
17478 }
17479 }
17481 /* The expression is not value-dependent. */
17483 }
17485 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17486 [temp.dep.expr]. */
17488 bool
17490 {
17497 /* An unresolved name is always dependent. */
17502 /* Some expression forms are never type-dependent. */
17513 /* The types of these expressions depends only on the type to which
17514 the cast occurs. */
17522 /* The types of these expressions depends only on the type created
17523 by the expression. */
17526 {
17527 /* For NEW_EXPR tree nodes created inside a template, either
17528 the object type itself or a TREE_LIST may appear as the
17529 operand 1. */
17532 /* This is an array type. We need to check array dimensions
17533 as well. */
17535 || value_dependent_expression_p
17537 else
17539 }
17543 type_dependent_expression_p))
17549 && (any_dependent_template_arguments_p
17561 {
17562 tree elt;
17566 {
17569 }
17571 }
17574 {
17579 {
17585 }
17586 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17594 {
17599 }
17604 {
17608 }
17610 }
17615 }
17617 /* Like type_dependent_expression_p, but it also works while not processing
17618 a template definition, i.e. during substitution or mangling. */
17620 bool
17622 {
17628 }
17630 /* Returns TRUE if ARGS contains a type-dependent expression. */
17632 bool
17634 {
17636 tree arg;
17639 {
17642 }
17644 }
17646 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17647 expressions) contains any value-dependent expressions. */
17649 bool
17651 {
17657 }
17659 /* Returns TRUE if the ARG (a template argument) is dependent. */
17661 bool
17663 {
17671 {
17675 {
17678 }
17681 }
17684 else
17687 }
17689 /* Returns true if ARGS (a collection of template arguments) contains
17690 any types that require structural equality testing. */
17692 bool
17694 {
17704 {
17707 {
17713 {
17714 /* Look inside the argument pack. */
17717 }
17720 {
17734 }
17735 }
17736 }
17739 }
17741 /* Returns true if ARGS (a collection of template arguments) contains
17742 any dependent arguments. */
17744 bool
17746 {
17756 {
17761 }
17764 }
17766 /* Returns TRUE if the template TMPL is dependent. */
17768 bool
17770 {
17772 {
17774 {
17778 }
17780 }
17782 /* Template template parameters are dependent. */
17786 /* So are names that have not been looked up. */
17790 /* So are member templates of dependent classes. */
17794 }
17796 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
17798 bool
17800 {
17803 }
17805 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
17806 is dependent. */
17808 bool
17810 {
17817 {
17838 {
17842 }
17846 {
17850 {
17855 }
17856 }
17857 }
17860 }
17862 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
17863 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
17864 no such TYPE can be found. Note that this function peers inside
17865 uninstantiated templates and therefore should be used only in
17866 extremely limited situations. ONLY_CURRENT_P restricts this
17867 peering to the currently open classes hierarchy (which is required
17868 when comparing types). */
17870 tree
17872 {
17873 tree scope;
17874 tree name;
17875 tree decl;
17877 tree pushed_scope;
17878 tree result;
17883 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
17884 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
17885 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
17886 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
17887 identifier of the TYPENAME_TYPE anymore.
17888 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
17889 TYPENAME_TYPE instead, we avoid messing up with a possible
17890 typedef variant case. */
17893 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
17894 it first before we can figure out what NAME refers to. */
17897 /* If we don't know what SCOPE refers to, then we cannot resolve the
17898 TYPENAME_TYPE. */
17901 /* If the SCOPE is a template type parameter, we have no way of
17902 resolving the name. */
17905 /* If the SCOPE is not the current instantiation, there's no reason
17906 to look inside it. */
17909 /* If this is a typedef, we don't want to look inside (c++/11987). */
17912 /* If SCOPE isn't the template itself, it will not have a valid
17913 TYPE_FIELDS list. */
17915 /* scope is either the template itself or a compatible instantiation
17916 like X<T>, so look up the name in the original template. */
17918 else
17919 /* scope is a partial instantiation, so we can't do the lookup or we
17920 will lose the template arguments. */
17922 /* Enter the SCOPE so that name lookup will be resolved as if we
17923 were in the class definition. In particular, SCOPE will no
17924 longer be considered a dependent type. */
17926 /* Look up the declaration. */
17931 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
17932 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
17937 {
17941 }
17944 {
17945 tree tmpl;
17946 tree args;
17947 /* Obtain the template and the arguments. */
17950 /* Instantiate the template. */
17956 }
17958 /* Leave the SCOPE. */
17962 /* If we failed to resolve it, return the original typename. */
17966 /* If lookup found a typename type, resolve that too. */
17968 {
17969 /* Ill-formed programs can cause infinite recursion here, so we
17970 must catch that. */
17974 }
17976 /* Qualify the resulting type. */
17982 }
17984 /* EXPR is an expression which is not type-dependent. Return a proxy
17985 for EXPR that can be used to compute the types of larger
17986 expressions containing EXPR. */
17988 tree
17990 {
17991 tree inner_expr;
17993 /* Preserve null pointer constants so that the type of things like
17994 "p == 0" where "p" is a pointer can be determined. */
17997 /* Preserve OVERLOADs; the functions must be available to resolve
17998 types. */
18009 /* There is no need to return a proxy for a variable. */
18012 /* Preserve string constants; conversions from string constants to
18013 "char *" are allowed, even though normally a "const char *"
18014 cannot be used to initialize a "char *". */
18017 /* Preserve arithmetic constants, as an optimization -- there is no
18018 reason to create a new node. */
18021 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18022 There is at least one place where we want to know that a
18023 particular expression is a throw-expression: when checking a ?:
18024 expression, there are special rules if the second or third
18025 argument is a throw-expression. */
18044 /* If the type is unknown, it can't really be non-dependent */
18047 /* Otherwise, build a NON_DEPENDENT_EXPR.
18049 REFERENCE_TYPEs are not stripped for expressions in templates
18050 because doing so would play havoc with mangling. Consider, for
18051 example:
18053 template <typename T> void f<T& g>() { g(); }
18055 In the body of "f", the expression for "g" will have
18056 REFERENCE_TYPE, even though the standard says that it should
18057 not. The reason is that we must preserve the syntactic form of
18058 the expression so that mangling (say) "f<g>" inside the body of
18059 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18060 stripped here. */
18062 }
18064 /* ARGS is a vector of expressions as arguments to a function call.
18065 Replace the arguments with equivalent non-dependent expressions.
18066 This modifies ARGS in place. */
18068 void
18070 {
18072 tree arg;
18075 {
18079 }
18080 }
18082 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18083 with a level one deeper than the actual template parms. */
18085 tree
18087 {
18100 }
18102 /* Given type ARG, return std::initializer_list<ARG>. */
18104 static tree
18106 {
18107 tree std_init_list = namespace_binding
18109 tree argvec;
18111 {
18115 }
18120 }
18122 /* Replace auto in TYPE with std::initializer_list<auto>. */
18124 static tree
18126 {
18133 }
18135 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18136 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18138 tree
18140 {
18145 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18146 with either a new invented type template parameter U or, if the
18147 initializer is a braced-init-list (8.5.4), with
18148 std::initializer_list<U>. */
18161 {
18164 }
18166 /* If the list of declarators contains more than one declarator, the type
18167 of each declared variable is determined as described above. If the
18168 type deduced for the template parameter U is not the same in each
18169 deduction, the program is ill-formed. */
18172 {
18176 }
18182 }
18184 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18185 result. */
18187 tree
18189 {
18190 tree argvec;
18199 }
18201 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18203 bool
18205 {
18209 else
18211 }
18213 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18214 appear as a type-specifier for the declaration in question, we don't
18215 have to look through the whole type. */
18217 tree
18219 {
18236 }
18238 /* For a given template T, return the vector of typedefs referenced
18239 in T for which access check is needed at T instantiation time.
18240 T is either a FUNCTION_DECL or a RECORD_TYPE.
18241 Those typedefs were added to T by the function
18242 append_type_to_template_for_access_check. */
18246 {
18247 tree ti;
18258 {
18263 }
18266 }
18268 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18269 tied to T. That list of typedefs will be access checked at
18270 T instantiation time.
18271 T is either a FUNCTION_DECL or a RECORD_TYPE.
18272 TYPE_DECL is a TYPE_DECL node representing a typedef.
18273 SCOPE is the scope through which TYPE_DECL is accessed.
18274 LOCATION is the location of the usage point of TYPE_DECL.
18276 This function is a subroutine of
18277 append_type_to_template_for_access_check. */
18279 static void
18281 tree type_decl,
18282 tree scope,
18283 location_t location)
18284 {
18285 qualified_typedef_usage_t typedef_usage;
18286 tree ti;
18293 && type_decl
18309 }
18311 /* Append TYPE_DECL to the template TEMPL.
18312 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18313 At TEMPL instanciation time, TYPE_DECL will be checked to see
18314 if it can be accessed through SCOPE.
18315 LOCATION is the location of the usage point of TYPE_DECL.
18317 e.g. consider the following code snippet:
18319 class C
18320 {
18321 typedef int myint;
18322 };
18324 template<class U> struct S
18325 {
18326 C::myint mi; // <-- usage point of the typedef C::myint
18327 };
18329 S<char> s;
18331 At S<char> instantiation time, we need to check the access of C::myint
18332 In other words, we need to check the access of the myint typedef through
18333 the C scope. For that purpose, this function will add the myint typedef
18334 and the scope C through which its being accessed to a list of typedefs
18335 tied to the template S. That list will be walked at template instantiation
18336 time and access check performed on each typedefs it contains.
18337 Note that this particular code snippet should yield an error because
18338 myint is private to C. */
18340 void
18342 tree type_decl,
18343 tree scope,
18344 location_t location)
18345 {
18351 /* Make sure we don't append the type to the template twice. */
18362 }
18364 /* Set up the hash tables for template instantiations. */
18366 void
18368 {
18370 hash_specialization,
18371 eq_specializations,
18372 ggc_free);
18374 hash_specialization,
18375 eq_specializations,
18376 ggc_free);
18377 }