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1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992-2013 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
48 /* The type of functions taking a tree, and some additional data, and
49 returning an int. */
52 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
53 instantiations have been deferred, either because their definitions
54 were not yet available, or because we were putting off doing the work. */
58 };
73 /* Live only within one (recursive) call to tsubst_expr. We use
74 this to pass the statement expression node from the STMT_EXPR
75 to the EXPR_STMT that is its result. */
78 /* A map from local variable declarations in the body of the template
79 presently being instantiated to the corresponding instantiated
80 local variables. */
83 /* True if we've recursed into fn_type_unification too many times. */
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
115 tbr_incomplete_type,
116 tbr_ambiguous_baseclass,
117 tbr_success
118 };
141 tree);
204 location_t);
212 /* Make the current scope suitable for access checking when we are
213 processing T. T can be FUNCTION_DECL for instantiated function
214 template, VAR_DECL for static member variable, or TYPE_DECL for
215 alias template (needed by instantiate_decl). */
217 static void
219 {
227 else
231 {
232 saved_access_scope = tree_cons
235 }
236 }
238 /* Restore the scope set up by push_access_scope. T is the node we
239 are processing. */
241 static void
243 {
245 {
248 }
252 else
254 }
256 /* Do any processing required when DECL (a member template
257 declaration) is finished. Returns the TEMPLATE_DECL corresponding
258 to DECL, unless it is a specialization, in which case the DECL
259 itself is returned. */
261 tree
263 {
270 {
271 tree type;
279 {
283 }
285 }
289 {
291 {
294 }
295 else
297 }
298 else
302 }
304 /* Create a template info node. */
306 tree
308 {
313 }
315 /* Return the template info node corresponding to T, whatever T is. */
317 tree
319 {
337 }
339 /* Returns the template nesting level of the indicated class TYPE.
341 For example, in:
342 template <class T>
343 struct A
344 {
345 template <class U>
346 struct B {};
347 };
349 A<T>::B<U> has depth two, while A<T> has depth one.
350 Both A<T>::B<int> and A<int>::B<U> have depth one, if
351 they are instantiations, not specializations.
353 This function is guaranteed to return 0 if passed NULL_TREE so
354 that, for example, `template_class_depth (current_class_type)' is
355 always safe. */
357 int
359 {
366 {
372 }
375 }
377 /* Subroutine of maybe_begin_member_template_processing.
378 Returns true if processing DECL needs us to push template parms. */
380 static bool
382 {
388 }
390 /* Subroutine of maybe_begin_member_template_processing.
391 Push the template parms in PARMS, starting from LEVELS steps into the
392 chain, and ending at the beginning, since template parms are listed
393 innermost first. */
395 static void
397 {
405 current_template_parms
411 NULL);
413 {
422 {
429 {
430 /* Make a CONST_DECL as is done in process_template_parm.
431 It is ugly that we recreate this here; the original
432 version built in process_template_parm is no longer
433 available. */
443 }
448 }
449 }
450 }
452 /* Restore the template parameter context for a member template, a
453 friend template defined in a class definition, or a non-template
454 member of template class. */
456 void
458 {
459 tree parms;
469 {
474 {
477 }
480 }
482 /* Remember how many levels of template parameters we pushed so that
483 we can pop them later. */
485 }
487 /* Undo the effects of maybe_begin_member_template_processing. */
489 void
491 {
500 {
504 }
505 }
507 /* Return a new template argument vector which contains all of ARGS,
508 but has as its innermost set of arguments the EXTRA_ARGS. */
510 static tree
512 {
513 tree new_args;
531 }
533 /* Like add_to_template_args, but only the outermost ARGS are added to
534 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
535 (EXTRA_ARGS) levels are added. This function is used to combine
536 the template arguments from a partial instantiation with the
537 template arguments used to attain the full instantiation from the
538 partial instantiation. */
540 static tree
542 {
543 tree new_args;
545 /* If there are more levels of EXTRA_ARGS than there are ARGS,
546 something very fishy is going on. */
549 /* If *all* the new arguments will be the EXTRA_ARGS, just return
550 them. */
554 /* For the moment, we make ARGS look like it contains fewer levels. */
559 /* Now, we restore ARGS to its full dimensions. */
563 }
565 /* Return the N levels of innermost template arguments from the ARGS. */
567 tree
569 {
570 tree new_args;
576 /* If N is 1, just return the innermost set of template arguments. */
580 /* If we're not removing anything, just return the arguments we were
581 given. */
587 /* Make a new set of arguments, not containing the outer arguments. */
594 }
596 /* The inverse of get_innermost_template_args: Return all but the innermost
597 EXTRA_LEVELS levels of template arguments from the ARGS. */
599 static tree
601 {
602 tree new_args;
608 /* If N is 1, just return the outermost set of template arguments. */
612 /* If we're not removing anything, just return the arguments we were
613 given. */
618 /* Make a new set of arguments, not containing the inner arguments. */
625 }
627 /* We've got a template header coming up; push to a new level for storing
628 the parms. */
630 void
632 {
633 /* We use a non-tag-transparent scope here, which causes pushtag to
634 put tags in this scope, rather than in the enclosing class or
635 namespace scope. This is the right thing, since we want
636 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
637 global template class, push_template_decl handles putting the
638 TEMPLATE_DECL into top-level scope. For a nested template class,
639 e.g.:
641 template <class T> struct S1 {
642 template <class T> struct S2 {};
643 };
645 pushtag contains special code to call pushdecl_with_scope on the
646 TEMPLATE_DECL for S2. */
651 }
653 /* This routine is called when a specialization is declared. If it is
654 invalid to declare a specialization here, an error is reported and
655 false is returned, otherwise this routine will return true. */
657 static bool
659 {
662 /* [temp.expl.spec]
664 An explicit specialization shall be declared in the namespace of
665 which the template is a member, or, for member templates, in the
666 namespace of which the enclosing class or enclosing class
667 template is a member. An explicit specialization of a member
668 function, member class or static data member of a class template
669 shall be declared in the namespace of which the class template
670 is a member. */
672 {
675 }
677 /* [temp.expl.spec]
679 In an explicit specialization declaration for a member of a class
680 template or a member template that appears in namespace scope,
681 the member template and some of its enclosing class templates may
682 remain unspecialized, except that the declaration shall not
683 explicitly specialize a class member template if its enclosing
684 class templates are not explicitly specialized as well. */
686 {
689 }
692 }
694 /* We've just seen template <>. */
696 bool
698 {
702 }
704 /* Called at then end of processing a declaration preceded by
705 template<>. */
707 void
709 {
712 }
714 /* Any template <>'s that we have seen thus far are not referring to a
715 function specialization. */
717 void
719 {
722 }
724 /* We've just seen a template header. If SPECIALIZATION is nonzero,
725 it was of the form template <>. */
727 static void
729 {
731 template_header_count++;
732 }
734 /* We're beginning an explicit instantiation. */
736 void
738 {
741 }
744 void
746 {
749 }
751 /* An explicit specialization or partial specialization of TMPL is being
752 declared. Check that the namespace in which the specialization is
753 occurring is permissible. Returns false iff it is invalid to
754 specialize TMPL in the current namespace. */
756 static bool
758 {
761 /* [tmpl.expl.spec]
763 An explicit specialization shall be declared in the namespace of
764 which the template is a member, or, for member templates, in the
765 namespace of which the enclosing class or enclosing class
766 template is a member. An explicit specialization of a member
767 function, member class or static data member of a class template
768 shall be declared in the namespace of which the class template is
769 a member. */
772 {
775 }
777 /* Same or super-using namespace. */
779 else
780 {
784 }
785 }
787 /* SPEC is an explicit instantiation. Check that it is valid to
788 perform this explicit instantiation in the current namespace. */
790 static void
792 {
793 tree ns;
795 /* DR 275: An explicit instantiation shall appear in an enclosing
796 namespace of its template. */
802 }
804 /* The TYPE is being declared. If it is a template type, that means it
805 is a partial specialization. Do appropriate error-checking. */
807 tree
809 {
810 tree context;
815 /* A lambda that appears in specialization context is not itself a
816 specialization. */
821 {
825 }
830 {
835 else
838 }
840 {
841 /* This is for ordinary explicit specialization and partial
842 specialization of a template class such as:
844 template <> class C<int>;
846 or:
848 template <class T> class C<T*>;
850 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
854 {
859 {
863 }
864 }
870 /* Trying to define a specialization either without a template<> header
871 or in an inappropriate place. We've already given an error, so just
872 bail now so we don't actually define the specialization. */
874 }
880 {
881 /* This is for an explicit specialization of member class
882 template according to [temp.expl.spec/18]:
884 template <> template <class U> class C<int>::D;
886 The context `C<int>' must be an implicit instantiation.
887 Otherwise this is just a member class template declared
888 earlier like:
890 template <> class C<int> { template <class U> class D; };
891 template <> template <class U> class C<int>::D;
893 In the first case, `C<int>::D' is a specialization of `C<T>::D'
894 while in the second case, `C<int>::D' is a primary template
895 and `C<T>::D' may not exist. */
899 {
900 tree t;
905 {
908 }
910 /* Check for invalid specialization after instantiation:
912 template <> template <> class C<int>::D<int>;
913 template <> template <class U> class C<int>::D; */
917 {
920 {
921 /* We already have a full specialization of this partial
922 instantiation. Reassign it to the new member
923 specialization template. */
924 spec_entry elt;
941 }
943 /* But if we've had an implicit instantiation, that's a
944 problem ([temp.expl.spec]/6). */
947 }
949 /* Mark TYPE as a specialization. And as a result, we only
950 have one level of template argument for the innermost
951 class template. */
956 }
957 }
959 {
960 /* Someday C++0x may allow for enum template specialization. */
965 else
966 {
969 }
970 }
973 }
975 /* Returns nonzero if we can optimize the retrieval of specializations
976 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
977 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
981 {
984 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
985 parameter. */
987 /* The optimized lookup depends on the fact that the
988 template arguments for the member function template apply
989 purely to the containing class, which is not true if the
990 containing class is an explicit or partial
991 specialization. */
995 /* It is possible to have a template that is not a member
996 template and is not a member of a template class:
998 template <typename T>
999 struct S { friend A::f(); };
1001 Here, the friend function is a template, but the context does
1002 not have template information. The optimized lookup relies
1003 on having ARGS be the template arguments for both the class
1004 and the function template. */
1006 }
1008 /* Retrieve the specialization (in the sense of [temp.spec] - a
1009 specialization is either an instantiation or an explicit
1010 specialization) of TMPL for the given template ARGS. If there is
1011 no such specialization, return NULL_TREE. The ARGS are a vector of
1012 arguments, or a vector of vectors of arguments, in the case of
1013 templates with more than one level of parameters.
1015 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1016 then we search for a partial specialization matching ARGS. This
1017 parameter is ignored if TMPL is not a class template.
1019 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1020 result is a NONTYPE_ARGUMENT_PACK. */
1022 static tree
1024 {
1034 /* There should be as many levels of arguments as there are
1035 levels of parameters. */
1042 {
1043 tree class_template;
1044 tree class_specialization;
1046 tree fns;
1049 /* The template arguments actually apply to the containing
1050 class. Find the class specialization with those
1051 arguments. */
1053 class_specialization
1057 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1058 for the specialization. */
1062 /* Iterate through the methods with the indicated name, looking
1063 for the one that has an instance of TMPL. */
1066 {
1069 /* using-declarations can add base methods to the method vec,
1070 and we don't want those here. */
1073 }
1075 }
1076 else
1077 {
1079 spec_entry elt;
1080 htab_t specializations;
1088 else
1096 }
1099 }
1101 /* Like retrieve_specialization, but for local declarations. */
1103 static tree
1105 {
1113 }
1115 /* Returns nonzero iff DECL is a specialization of TMPL. */
1117 int
1119 {
1120 tree t;
1123 {
1129 }
1130 else
1131 {
1140 }
1143 }
1145 /* Returns nonzero iff DECL is a specialization of friend declaration
1146 FRIEND_DECL according to [temp.friend]. */
1148 bool
1150 {
1157 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1158 of a template class, we want to check if DECL is a specialization
1159 if this. */
1163 {
1164 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1167 }
1172 /* There is nothing to do if this is not a template friend. */
1179 /* [temp.friend/6]
1180 A member of a class template may be declared to be a friend of a
1181 non-template class. In this case, the corresponding member of
1182 every specialization of the class template is a friend of the
1183 class granting friendship.
1185 For example, given a template friend declaration
1187 template <class T> friend void A<T>::f();
1189 the member function below is considered a friend
1191 template <> struct A<int> {
1192 void f();
1193 };
1195 For this type of template friend, TEMPLATE_DEPTH below will be
1196 nonzero. To determine if DECL is a friend of FRIEND, we first
1197 check if the enclosing class is a specialization of another. */
1204 {
1205 /* Next, we check the members themselves. In order to handle
1206 a few tricky cases, such as when FRIEND_DECL's are
1208 template <class T> friend void A<T>::g(T t);
1209 template <class T> template <T t> friend void A<T>::h();
1211 and DECL's are
1213 void A<int>::g(int);
1214 template <int> void A<int>::h();
1216 we need to figure out ARGS, the template arguments from
1217 the context of DECL. This is required for template substitution
1218 of `T' in the function parameter of `g' and template parameter
1219 of `h' in the above examples. Here ARGS corresponds to `int'. */
1226 {
1228 {
1231 else
1233 current_depth++;
1234 }
1236 }
1239 {
1241 tree friend_type;
1242 tree decl_type;
1243 tree friend_args_type;
1244 tree decl_args_type;
1246 /* Make sure that both DECL and FRIEND_DECL are templates or
1247 non-templates. */
1253 {
1254 /* If both are templates, check template parameter list. */
1255 tree friend_parms
1260 friend_parms))
1264 }
1265 else
1273 /* Check if return types match. */
1277 /* Check if function parameter types match, ignoring the
1278 `this' parameter. */
1287 }
1288 else
1289 {
1290 /* DECL is a TYPE_DECL */
1294 /* Make sure that both DECL and FRIEND_DECL are templates or
1295 non-templates. */
1296 is_template
1303 {
1304 tree friend_parms;
1305 /* If both are templates, check the name of the two
1306 TEMPLATE_DECL's first because is_friend didn't. */
1311 /* Now check template parameter list. */
1312 friend_parms
1315 return comp_template_parms
1317 friend_parms);
1318 }
1319 else
1322 }
1323 }
1325 }
1327 /* Register the specialization SPEC as a specialization of TMPL with
1328 the indicated ARGS. IS_FRIEND indicates whether the specialization
1329 is actually just a friend declaration. Returns SPEC, or an
1330 equivalent prior declaration, if available.
1332 We also store instantiations of field packs in the hash table, even
1333 though they are not themselves templates, to make lookup easier. */
1335 static tree
1337 hashval_t hash)
1338 {
1339 tree fn;
1341 spec_entry elt;
1349 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1350 register it; we want the corresponding TEMPLATE_DECL instead.
1351 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1352 the more obvious `uses_template_parms (spec)' to avoid problems
1353 with default function arguments. In particular, given
1354 something like this:
1356 template <class T> void f(T t1, T t = T())
1358 the default argument expression is not substituted for in an
1359 instantiation unless and until it is actually needed. */
1363 /* We don't put these specializations in the hash table, but we might
1364 want to give an error about a mismatch. */
1366 else
1367 {
1375 slot =
1379 else
1381 }
1383 /* We can sometimes try to re-register a specialization that we've
1384 already got. In particular, regenerate_decl_from_template calls
1385 duplicate_decls which will update the specialization list. But,
1386 we'll still get called again here anyhow. It's more convenient
1387 to simply allow this than to try to prevent it. */
1391 {
1393 {
1396 {
1398 fn);
1400 }
1401 else
1402 {
1403 tree clone;
1404 /* This situation should occur only if the first
1405 specialization is an implicit instantiation, the
1406 second is an explicit specialization, and the
1407 implicit instantiation has not yet been used. That
1408 situation can occur if we have implicitly
1409 instantiated a member function and then specialized
1410 it later.
1412 We can also wind up here if a friend declaration that
1413 looked like an instantiation turns out to be a
1414 specialization:
1416 template <class T> void foo(T);
1417 class S { friend void foo<>(int) };
1418 template <> void foo(int);
1420 We transform the existing DECL in place so that any
1421 pointers to it become pointers to the updated
1422 declaration.
1424 If there was a definition for the template, but not
1425 for the specialization, we want this to look as if
1426 there were no definition, and vice versa. */
1429 /* The call to duplicate_decls will have applied
1430 [temp.expl.spec]:
1432 An explicit specialization of a function template
1433 is inline only if it is explicitly declared to be,
1434 and independently of whether its function template
1435 is.
1437 to the primary function; now copy the inline bits to
1438 the various clones. */
1440 {
1445 }
1449 }
1450 }
1452 {
1454 /* Dup decl failed, but this is a new definition. Set the
1455 line number so any errors match this new
1456 definition. */
1460 }
1461 }
1465 /* A specialization must be declared in the same namespace as the
1466 template it is specializing. */
1472 {
1480 /* TMPL is a forward declaration of a template function; keep a list
1481 of all specializations in case we need to reassign them to a friend
1482 template later in tsubst_friend_function. */
1485 }
1488 }
1490 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1491 TMPL and ARGS members, ignores SPEC. */
1495 static int
1497 {
1508 }
1510 /* Returns a hash for a template TMPL and template arguments ARGS. */
1512 static hashval_t
1514 {
1517 }
1519 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1520 ignoring SPEC. */
1522 static hashval_t
1524 {
1527 }
1529 /* Recursively calculate a hash value for a template argument ARG, for use
1530 in the hash tables of template specializations. */
1532 hashval_t
1534 {
1546 /* We can get one of these when re-hashing a previous entry in the middle
1547 of substituting into a pack expansion. Just look through it. */
1556 {
1564 {
1569 }
1591 {
1594 {
1597 }
1599 }
1603 {
1606 }
1617 val = iterative_hash_template_arg
1629 val);
1631 val);
1640 /* A lambda can't appear in a template arg, but don't crash on
1641 erroneous input. */
1653 /* Now hash operands as usual. */
1658 }
1661 {
1665 val);
1668 /* Otherwise just compare the types during lookup. */
1677 {
1682 }
1683 }
1686 }
1688 /* Unregister the specialization SPEC as a specialization of TMPL.
1689 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1690 if the SPEC was listed as a specialization of TMPL.
1692 Note that SPEC has been ggc_freed, so we can't look inside it. */
1694 bool
1696 {
1698 spec_entry elt;
1706 {
1711 }
1714 }
1716 /* Like register_specialization, but for local declarations. We are
1717 registering SPEC, an instantiation of TMPL. */
1719 static void
1721 {
1726 }
1728 /* TYPE is a class type. Returns true if TYPE is an explicitly
1729 specialized class. */
1731 bool
1733 {
1737 }
1739 /* Print the list of functions at FNS, going through all the overloads
1740 for each element of the list. Alternatively, FNS can not be a
1741 TREE_LIST, in which case it will be printed together with all the
1742 overloads.
1744 MORE and *STR should respectively be FALSE and NULL when the function
1745 is called from the outside. They are used internally on recursive
1746 calls. print_candidates manages the two parameters and leaves NULL
1747 in *STR when it ends. */
1749 static void
1751 {
1757 {
1761 }
1762 else
1763 {
1766 {
1767 /* Pick the prefix string. */
1769 {
1773 }
1777 }
1780 }
1783 {
1786 }
1787 }
1789 /* Print the list of candidate FNS in an error message. FNS can also
1790 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1792 void
1794 {
1798 }
1800 /* Returns the template (one of the functions given by TEMPLATE_ID)
1801 which can be specialized to match the indicated DECL with the
1802 explicit template args given in TEMPLATE_ID. The DECL may be
1803 NULL_TREE if none is available. In that case, the functions in
1804 TEMPLATE_ID are non-members.
1806 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1807 specialization of a member template.
1809 The TEMPLATE_COUNT is the number of references to qualifying
1810 template classes that appeared in the name of the function. See
1811 check_explicit_specialization for a more accurate description.
1813 TSK indicates what kind of template declaration (if any) is being
1814 declared. TSK_TEMPLATE indicates that the declaration given by
1815 DECL, though a FUNCTION_DECL, has template parameters, and is
1816 therefore a template function.
1818 The template args (those explicitly specified and those deduced)
1819 are output in a newly created vector *TARGS_OUT.
1821 If it is impossible to determine the result, an error message is
1822 issued. The error_mark_node is returned to indicate failure. */
1824 static tree
1826 tree decl,
1830 tmpl_spec_kind tsk)
1831 {
1832 tree fns;
1833 tree targs;
1834 tree explicit_targs;
1836 /* A TREE_LIST of templates of which DECL may be a specialization.
1837 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1838 corresponding TREE_PURPOSE is the set of template arguments that,
1839 when used to instantiate the template, would produce a function
1840 with the signature of DECL. */
1850 /* We shouldn't be specializing a member template of an
1851 unspecialized class template; we already gave an error in
1852 check_specialization_scope, now avoid crashing. */
1855 {
1858 }
1866 /* Check for baselinks. */
1871 {
1874 }
1876 /* Count the number of template headers specified for this
1877 specialization. */
1885 {
1889 {
1890 tree decl_arg_types;
1891 tree fn_arg_types;
1892 tree insttype;
1894 /* In case of explicit specialization, we need to check if
1895 the number of template headers appearing in the specialization
1896 is correct. This is usually done in check_explicit_specialization,
1897 but the check done there cannot be exhaustive when specializing
1898 member functions. Consider the following code:
1900 template <> void A<int>::f(int);
1901 template <> template <> void A<int>::f(int);
1903 Assuming that A<int> is not itself an explicit specialization
1904 already, the first line specializes "f" which is a non-template
1905 member function, whilst the second line specializes "f" which
1906 is a template member function. So both lines are syntactically
1907 correct, and check_explicit_specialization does not reject
1908 them.
1910 Here, we can do better, as we are matching the specialization
1911 against the declarations. We count the number of template
1912 headers, and we check if they match TEMPLATE_COUNT + 1
1913 (TEMPLATE_COUNT is the number of qualifying template classes,
1914 plus there must be another header for the member template
1915 itself).
1917 Notice that if header_count is zero, this is not a
1918 specialization but rather a template instantiation, so there
1919 is no check we can perform here. */
1923 /* Check that the number of template arguments at the
1924 innermost level for DECL is the same as for FN. */
1932 /* DECL might be a specialization of FN. */
1936 /* For a non-static member function, we need to make sure
1937 that the const qualification is the same. Since
1938 get_bindings does not try to merge the "this" parameter,
1939 we must do the comparison explicitly. */
1945 /* Skip the "this" parameter and, for constructors of
1946 classes with virtual bases, the VTT parameter. A
1947 full specialization of a constructor will have a VTT
1948 parameter, but a template never will. */
1949 decl_arg_types
1951 fn_arg_types
1954 /* Function templates cannot be specializations; there are
1955 no partial specializations of functions. Therefore, if
1956 the type of DECL does not match FN, there is no
1957 match. */
1959 {
1963 }
1965 /* See whether this function might be a specialization of this
1966 template. Suppress access control because we might be trying
1967 to make this specialization a friend, and we have already done
1968 access control for the declaration of the specialization. */
1974 /* We cannot deduce template arguments that when used to
1975 specialize TMPL will produce DECL. */
1978 /* Make sure that the deduced arguments actually work. */
1982 fn_arg_types
1987 /* Save this template, and the arguments deduced. */
1989 }
1991 /* FN is an ordinary member function, and we need a
1992 specialization of a member template. */
1993 ;
1995 /* We can get IDENTIFIER_NODEs here in certain erroneous
1996 cases. */
1997 ;
1999 /* This is just an ordinary non-member function. Nothing can
2000 be a specialization of that. */
2001 ;
2003 /* Cannot specialize functions that are created implicitly. */
2004 ;
2005 else
2006 {
2007 tree decl_arg_types;
2009 /* This is an ordinary member function. However, since
2010 we're here, we can assume its enclosing class is a
2011 template class. For example,
2013 template <typename T> struct S { void f(); };
2014 template <> void S<int>::f() {}
2016 Here, S<int>::f is a non-template, but S<int> is a
2017 template class. If FN has the same type as DECL, we
2018 might be in business. */
2021 /* Its enclosing class is an explicit specialization
2022 of a template class. This is not a candidate. */
2027 /* The return types differ. */
2030 /* Adjust the type of DECL in case FN is a static member. */
2037 decl_arg_types))
2038 /* They match! */
2040 }
2041 }
2044 {
2045 /* We have:
2047 [temp.expl.spec]
2049 It is possible for a specialization with a given function
2050 signature to be instantiated from more than one function
2051 template. In such cases, explicit specification of the
2052 template arguments must be used to uniquely identify the
2053 function template specialization being specialized.
2055 Note that here, there's no suggestion that we're supposed to
2056 determine which of the candidate templates is most
2057 specialized. However, we, also have:
2059 [temp.func.order]
2061 Partial ordering of overloaded function template
2062 declarations is used in the following contexts to select
2063 the function template to which a function template
2064 specialization refers:
2066 -- when an explicit specialization refers to a function
2067 template.
2069 So, we do use the partial ordering rules, at least for now.
2070 This extension can only serve to make invalid programs valid,
2071 so it's safe. And, there is strong anecdotal evidence that
2072 the committee intended the partial ordering rules to apply;
2073 the EDG front end has that behavior, and John Spicer claims
2074 that the committee simply forgot to delete the wording in
2075 [temp.expl.spec]. */
2078 {
2081 }
2082 }
2085 {
2093 }
2097 {
2103 }
2105 /* We have one, and exactly one, match. */
2107 {
2110 /* DECL is a re-declaration or partial instantiation of a template
2111 function. */
2114 /* It was a specialization of an ordinary member function in a
2115 template class. */
2117 }
2119 /* It was a specialization of a template. */
2122 {
2127 }
2128 else
2131 }
2133 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2134 but with the default argument values filled in from those in the
2135 TMPL_TYPES. */
2137 static tree
2139 tree tmpl_types)
2140 {
2141 tree new_spec_types;
2149 /* Substitute into the rest of the list. */
2150 new_spec_types =
2154 /* Add the default argument for this parameter. */
2157 new_spec_types);
2158 }
2160 /* DECL is an explicit specialization. Replicate default arguments
2161 from the template it specializes. (That way, code like:
2163 template <class T> void f(T = 3);
2164 template <> void f(double);
2165 void g () { f (); }
2167 works, as required.) An alternative approach would be to look up
2168 the correct default arguments at the call-site, but this approach
2169 is consistent with how implicit instantiations are handled. */
2171 static void
2173 {
2174 tree tmpl;
2175 tree spec_types;
2176 tree tmpl_types;
2177 tree new_spec_types;
2178 tree old_type;
2179 tree new_type;
2180 tree t;
2185 /* See if there's anything we need to do. */
2198 {
2199 /* Remove the this pointer, but remember the object's type for
2200 CV quals. */
2206 {
2207 /* DECL may contain more parameters than TMPL due to the extra
2208 in-charge parameter in constructors and destructors. */
2211 }
2213 {
2216 }
2217 }
2219 /* Compute the merged default arguments. */
2220 new_spec_types =
2223 /* Compute the new FUNCTION_TYPE. */
2225 {
2229 new_spec_types);
2232 /* Put the in-charge parameter back. */
2235 new_spec_types);
2239 new_spec_types);
2240 }
2241 else
2243 new_spec_types);
2249 }
2251 /* Return the number of template headers we expect to see for a definition
2252 or specialization of CTYPE or one of its non-template members. */
2254 int
2256 {
2260 {
2261 /* You're supposed to have one `template <...>' for every
2262 template class, but you don't need one for a full
2263 specialization. For example:
2265 template <class T> struct S{};
2266 template <> struct S<int> { void f(); };
2267 void S<int>::f () {}
2269 is correct; there shouldn't be a `template <>' for the
2270 definition of `S<int>::f'. */
2272 /* If CTYPE does not have template information of any
2273 kind, then it is not a template, nor is it nested
2274 within a template. */
2282 }
2285 }
2287 /* Do a simple sanity check on the template headers that precede the
2288 variable declaration DECL. */
2290 void
2292 {
2299 {
2305 "members of an explicitly specialized class are defined "
2307 }
2308 }
2310 /* Check to see if the function just declared, as indicated in
2311 DECLARATOR, and in DECL, is a specialization of a function
2312 template. We may also discover that the declaration is an explicit
2313 instantiation at this point.
2315 Returns DECL, or an equivalent declaration that should be used
2316 instead if all goes well. Issues an error message if something is
2317 amiss. Returns error_mark_node if the error is not easily
2318 recoverable.
2320 FLAGS is a bitmask consisting of the following flags:
2322 2: The function has a definition.
2323 4: The function is a friend.
2325 The TEMPLATE_COUNT is the number of references to qualifying
2326 template classes that appeared in the name of the function. For
2327 example, in
2329 template <class T> struct S { void f(); };
2330 void S<int>::f();
2332 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2333 classes are not counted in the TEMPLATE_COUNT, so that in
2335 template <class T> struct S {};
2336 template <> struct S<int> { void f(); }
2337 template <> void S<int>::f();
2339 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2340 invalid; there should be no template <>.)
2342 If the function is a specialization, it is marked as such via
2343 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2344 is set up correctly, and it is added to the list of specializations
2345 for that template. */
2347 tree
2349 tree decl,
2352 {
2360 tmpl_spec_kind tsk;
2363 {
2366 else
2368 }
2369 else
2373 {
2376 {
2379 }
2381 {
2383 /* This could be something like:
2385 template <class T> void f(T);
2386 class S { friend void f<>(int); } */
2388 else
2389 {
2390 /* This case handles bogus declarations like template <>
2391 template <class T> void f<int>(); */
2394 declarator);
2396 }
2397 }
2401 /* The error has already been reported in
2402 check_specialization_scope. */
2408 /* Fall through. */
2421 decl);
2424 else
2428 /* Fall through. */
2433 else
2439 {
2440 /* This case handles bogus declarations like template <>
2441 template <class T> void f<int>(); */
2446 else
2448 declarator);
2450 }
2453 /* This is a specialization of a member template, without
2454 specialization the containing class. Something like:
2456 template <class T> struct S {
2457 template <class U> void f (U);
2458 };
2459 template <> template <class U> void S<int>::f(U) {}
2461 That's a specialization -- but of the entire template. */
2467 }
2470 {
2474 {
2478 }
2479 }
2482 {
2486 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2488 {
2489 tree fns;
2494 else
2495 {
2496 /* If there is no class context, the explicit instantiation
2497 must be at namespace scope. */
2500 /* Find the namespace binding, using the declaration
2501 context. */
2505 {
2508 }
2509 else
2510 {
2516 }
2517 }
2520 }
2526 {
2528 /* A specialization in class scope. This is invalid,
2529 but the error will already have been flagged by
2530 check_specialization_scope. */
2532 else
2533 {
2534 /* It's not valid to write an explicit instantiation in
2535 class scope, e.g.:
2537 class C { template void f(); }
2539 This case is caught by the parser. However, on
2540 something like:
2542 template class C { void f(); };
2544 (which is invalid) we can get here. The error will be
2545 issued later. */
2546 ;
2547 }
2550 }
2553 {
2554 /* Find the list of functions in ctype that have the same
2555 name as the declared function. */
2561 {
2566 {
2567 /* From [temp.expl.spec]:
2569 If such an explicit specialization for the member
2570 of a class template names an implicitly-declared
2571 special member function (clause _special_), the
2572 program is ill-formed.
2574 Similar language is found in [temp.explicit]. */
2577 }
2580 }
2583 {
2587 }
2588 else
2589 {
2591 tree ovl;
2593 /* For a type-conversion operator, we cannot do a
2594 name-based lookup. We might be looking for `operator
2595 int' which will be a specialization of `operator T'.
2596 So, we find *all* the conversion operators, and then
2597 select from them. */
2605 {
2607 /* There are no more conversion functions. */
2610 /* Glue all these conversion functions together
2611 with those we already have. */
2614 }
2615 }
2618 {
2621 }
2622 else
2624 }
2626 /* Figure out what exactly is being specialized at this point.
2627 Note that for an explicit instantiation, even one for a
2628 member function, we cannot tell apriori whether the
2629 instantiation is for a member template, or just a member
2630 function of a template class. Even if a member template is
2631 being instantiated, the member template arguments may be
2632 elided if they can be deduced from the rest of the
2633 declaration. */
2636 member_specialization,
2637 template_count,
2638 tsk);
2641 /* We couldn't figure out what this declaration was
2642 specializing. */
2644 else
2645 {
2649 {
2650 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2651 is done by do_decl_instantiation later. */
2657 {
2658 /* If TMPL is not the most general template (for
2659 example, if TMPL is a friend template that is
2660 injected into namespace scope), then there will
2661 be too many levels of TARGS. Remove some of them
2662 here. */
2664 tree new_targs;
2671 }
2674 }
2676 /* If we thought that the DECL was a member function, but it
2677 turns out to be specializing a static member function,
2678 make DECL a static member function as well. */
2683 /* If this is a specialization of a member template of a
2684 template class, we want to return the TEMPLATE_DECL, not
2685 the specialization of it. */
2687 {
2692 {
2693 tree parm;
2697 /* We want to use the argument list specified in the
2698 definition, not in the original declaration. */
2703 }
2706 }
2708 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2711 /* Inherit default function arguments from the template
2712 DECL is specializing. */
2715 /* This specialization has the same protection as the
2716 template it specializes. */
2720 /* 7.1.1-1 [dcl.stc]
2722 A storage-class-specifier shall not be specified in an
2723 explicit specialization...
2725 The parser rejects these, so unless action is taken here,
2726 explicit function specializations will always appear with
2727 global linkage.
2729 The action recommended by the C++ CWG in response to C++
2730 defect report 605 is to make the storage class and linkage
2731 of the explicit specialization match the templated function:
2733 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2734 */
2736 {
2740 /* This specialization has the same linkage and visibility as
2741 the function template it specializes. */
2744 {
2747 }
2750 {
2753 }
2754 }
2756 /* If DECL is a friend declaration, declared using an
2757 unqualified name, the namespace associated with DECL may
2758 have been set incorrectly. For example, in:
2760 template <typename T> void f(T);
2761 namespace N {
2762 struct S { friend void f<int>(int); }
2763 }
2765 we will have set the DECL_CONTEXT for the friend
2766 declaration to N, rather than to the global namespace. */
2771 /* This is not really a declaration of a specialization.
2772 It's just the name of an instantiation. But, it's not
2773 a request for an instantiation, either. */
2776 /* This is indeed a specialization. In case of constructors
2777 and destructors, we need in-charge and not-in-charge
2778 versions in V3 ABI. */
2781 /* Register this specialization so that we can find it
2782 again. */
2784 }
2785 }
2788 }
2790 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2791 parameters. These are represented in the same format used for
2792 DECL_TEMPLATE_PARMS. */
2794 int
2796 {
2797 const_tree p1;
2798 const_tree p2;
2806 {
2818 {
2822 /* If either of the template parameters are invalid, assume
2823 they match for the sake of error recovery. */
2836 }
2837 }
2840 /* One set of parameters has more parameters lists than the
2841 other. */
2845 }
2847 /* Determine whether PARM is a parameter pack. */
2849 bool
2851 {
2852 /* Determine if we have a non-type template parameter pack. */
2859 /* If this is a list of template parameters, we could get a
2860 TYPE_DECL or a TEMPLATE_DECL. */
2864 /* Otherwise it must be a type template parameter. */
2868 }
2870 /* Determine if T is a function parameter pack. */
2872 bool
2874 {
2878 }
2880 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2881 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2883 tree
2885 {
2892 }
2894 /* Return true iff the function parameter PARAM_DECL was expanded
2895 from the function parameter pack PACK. */
2897 bool
2899 {
2904 /* The parameter pack and its pack arguments have the same
2905 DECL_PARM_INDEX. */
2907 }
2909 /* Determine whether ARGS describes a variadic template args list,
2910 i.e., one that is terminated by a template argument pack. */
2912 static bool
2914 {
2916 tree last_parm;
2930 }
2932 /* Generate a new name for the parameter pack name NAME (an
2933 IDENTIFIER_NODE) that incorporates its */
2935 static tree
2937 {
2938 /* Munge the name to include the parameter index. */
2939 #define NUMBUF_LEN 128
2953 }
2955 /* Return true if T is a primary function, class or alias template
2956 instantiation. */
2958 bool
2960 {
2974 }
2976 /* Return true if PARM is a template template parameter. */
2978 bool
2980 {
2982 }
2984 /* Return true iff PARM is a DECL representing a type template
2985 parameter. */
2987 bool
2989 {
2994 }
2996 /* Return the template parameters of T if T is a
2997 primary template instantiation, NULL otherwise. */
2999 tree
3001 {
3006 parms = INNERMOST_TEMPLATE_PARMS
3010 }
3012 /* Return the template parameters of the LEVELth level from the full list
3013 of template parameters PARMS. */
3015 tree
3017 {
3018 tree p;
3029 }
3031 /* Returns the template arguments of T if T is a template instantiation,
3032 NULL otherwise. */
3034 tree
3036 {
3044 }
3046 /* Return the argument pack elements of T if T is a template argument pack,
3047 NULL otherwise. */
3049 tree
3051 {
3057 }
3059 /* Structure used to track the progress of find_parameter_packs_r. */
3060 struct find_parameter_pack_data
3061 {
3062 /* TREE_LIST that will contain all of the parameter packs found by
3063 the traversal. */
3066 /* Set of AST nodes that have been visited by the traversal. */
3068 };
3070 /* Identifies all of the argument packs that occur in a template
3071 argument and appends them to the TREE_LIST inside DATA, which is a
3072 find_parameter_pack_data structure. This is a subroutine of
3073 make_pack_expansion and uses_parameter_packs. */
3074 static tree
3076 {
3082 /* Handle type aliases/typedefs. */
3084 {
3091 }
3093 /* Identify whether this is a parameter pack or not. */
3095 {
3111 {
3112 /* We don't want to walk into the type of a PARM_DECL,
3113 because we don't want to see the type parameter pack. */
3116 }
3119 /* Look through a lambda capture proxy to the field pack. */
3122 {
3128 }
3135 /* Not a parameter pack. */
3137 }
3140 {
3141 /* Add this parameter pack to the list. */
3143 }
3149 /* This switch statement will return immediately if we don't find a
3150 parameter pack. */
3152 {
3157 /* Check the template itself. */
3160 /* Check the template arguments. */
3176 /* Fall through. */
3218 }
3221 }
3223 /* Determines if the expression or type T uses any parameter packs. */
3224 bool
3226 {
3234 }
3236 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3237 representation a base-class initializer into a parameter pack
3238 expansion. If all goes well, the resulting node will be an
3239 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3240 respectively. */
3241 tree
3243 {
3244 tree result;
3253 {
3254 /* The only time we will see a TREE_LIST here is for a base
3255 class initializer. In this case, the TREE_PURPOSE will be a
3256 _TYPE node (representing the base class expansion we're
3257 initializing) and the TREE_VALUE will be a TREE_LIST
3258 containing the initialization arguments.
3260 The resulting expansion looks somewhat different from most
3261 expansions. Rather than returning just one _EXPANSION, we
3262 return a TREE_LIST whose TREE_PURPOSE is a
3263 TYPE_PACK_EXPANSION containing the bases that will be
3264 initialized. The TREE_VALUE will be identical to the
3265 original TREE_VALUE, which is a list of arguments that will
3266 be passed to each base. We do not introduce any new pack
3267 expansion nodes into the TREE_VALUE (although it is possible
3268 that some already exist), because the TREE_PURPOSE and
3269 TREE_VALUE all need to be expanded together with the same
3270 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3271 resulting TREE_PURPOSE will mention the parameter packs in
3272 both the bases and the arguments to the bases. */
3273 tree purpose;
3274 tree value;
3277 /* Determine which parameter packs will be used by the base
3278 class expansion. */
3285 {
3289 }
3292 {
3293 /* Collect the sets of parameter packs used in each of the
3294 initialization arguments. */
3296 {
3297 /* Determine which parameter packs will be expanded in this
3298 argument. */
3301 }
3302 }
3306 /* Create the pack expansion type for the base type. */
3311 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3312 they will rarely be compared to anything. */
3316 }
3321 /* Build the PACK_EXPANSION_* node. */
3322 result = for_types
3327 {
3328 /* Propagate type and const-expression information. */
3331 }
3332 else
3333 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3334 they will rarely be compared to anything. */
3337 /* Determine which parameter packs will be expanded. */
3343 /* Make sure we found some parameter packs. */
3345 {
3348 else
3351 }
3357 }
3359 /* Checks T for any "bare" parameter packs, which have not yet been
3360 expanded, and issues an error if any are found. This operation can
3361 only be done on full expressions or types (e.g., an expression
3362 statement, "if" condition, etc.), because we could have expressions like:
3364 foo(f(g(h(args)))...)
3366 where "args" is a parameter pack. check_for_bare_parameter_packs
3367 should not be called for the subexpressions args, h(args),
3368 g(h(args)), or f(g(h(args))), because we would produce erroneous
3369 error messages.
3371 Returns TRUE and emits an error if there were bare parameter packs,
3372 returns FALSE otherwise. */
3373 bool
3375 {
3391 {
3394 {
3403 else
3408 else
3412 }
3415 }
3418 }
3420 /* Expand any parameter packs that occur in the template arguments in
3421 ARGS. */
3422 tree
3424 {
3430 /* First, determine if we need to expand anything, and the number of
3431 slots we'll need. */
3433 {
3438 {
3442 else
3444 }
3445 else
3446 {
3448 num_result_args++;
3449 }
3450 }
3452 /* If no expansion is necessary, we're done. */
3456 /* Expand arguments. */
3459 non_default_args_count =
3462 {
3465 {
3472 }
3473 else
3474 {
3477 }
3478 }
3482 }
3484 /* Checks if DECL shadows a template parameter.
3486 [temp.local]: A template-parameter shall not be redeclared within its
3487 scope (including nested scopes).
3489 Emits an error and returns TRUE if the DECL shadows a parameter,
3490 returns FALSE otherwise. */
3492 bool
3494 {
3495 tree olddecl;
3497 /* If we're not in a template, we can't possibly shadow a template
3498 parameter. */
3502 /* Figure out what we're shadowing. */
3507 /* If there's no previous binding for this name, we're not shadowing
3508 anything, let alone a template parameter. */
3512 /* If we're not shadowing a template parameter, we're done. Note
3513 that OLDDECL might be an OVERLOAD (or perhaps even an
3514 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3515 node. */
3519 /* We check for decl != olddecl to avoid bogus errors for using a
3520 name inside a class. We check TPFI to avoid duplicate errors for
3521 inline member templates. */
3530 }
3532 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3533 ORIG_LEVEL, DECL, and TYPE. */
3535 static tree
3539 tree decl,
3540 tree type)
3541 {
3552 }
3554 /* Find the canonical type parameter for the given template type
3555 parameter. Returns the canonical type parameter, which may be TYPE
3556 if no such parameter existed. */
3558 static tree
3560 {
3561 tree list;
3575 else
3576 {
3581 }
3582 }
3584 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3585 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3586 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3587 new one is created. */
3589 static tree
3591 tsubst_flags_t complain)
3592 {
3597 {
3616 /* Template template parameters need this. */
3621 }
3624 }
3626 /* Process information from new template parameter PARM and append it
3627 to the LIST being built. This new parameter is a non-type
3628 parameter iff IS_NON_TYPE is true. This new parameter is a
3629 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3630 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3631 parameter list PARM belongs to. This is used used to create a
3632 proper canonical type for the type of PARM that is to be created,
3633 iff PARM is a type. If the size is not known, this parameter shall
3634 be set to 0. */
3636 tree
3639 {
3641 tree defval;
3642 tree err_parm_list;
3649 {
3653 {
3657 else
3659 }
3662 }
3663 else
3667 {
3673 {
3677 }
3678 else
3679 {
3680 /* [temp.param]
3682 The top-level cv-qualifiers on the template-parameter are
3683 ignored when determining its type. */
3686 {
3690 }
3693 {
3694 /* This template parameter is not a parameter pack, but it
3695 should be. Complain about "bare" parameter packs. */
3698 /* Recover by calling this a parameter pack. */
3700 }
3701 }
3703 /* A template parameter is not modifiable. */
3712 processing_template_decl,
3717 }
3718 else
3719 {
3720 tree t;
3724 {
3726 /* This is for distinguishing between real templates and template
3727 template parameters */
3731 }
3732 else
3733 {
3735 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3738 }
3745 processing_template_decl,
3749 }
3755 }
3757 /* The end of a template parameter list has been reached. Process the
3758 tree list into a parameter vector, converting each parameter into a more
3759 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3760 as PARM_DECLs. */
3762 tree
3764 {
3769 current_template_parms
3774 {
3778 }
3783 }
3785 /* end_template_decl is called after a template declaration is seen. */
3787 void
3789 {
3795 /* This matches the pushlevel in begin_template_parm_list. */
3800 }
3802 /* Takes a TREE_LIST representing a template parameter and convert it
3803 into an argument suitable to be passed to the type substitution
3804 functions. Note that If the TREE_LIST contains an error_mark
3805 node, the returned argument is error_mark_node. */
3807 static tree
3809 {
3822 {
3826 {
3827 /* Turn this argument into a TYPE_ARGUMENT_PACK
3828 with a single element, which expands T. */
3830 #ifdef ENABLE_CHECKING
3831 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3833 #endif
3838 }
3839 }
3840 else
3841 {
3845 {
3846 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3847 with a single element, which expands T. */
3850 #ifdef ENABLE_CHECKING
3851 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3853 #endif
3859 }
3860 }
3862 }
3864 /* Given a set of template parameters, return them as a set of template
3865 arguments. The template parameters are represented as a TREE_VEC, in
3866 the form documented in cp-tree.h for template arguments. */
3868 static tree
3870 {
3871 tree header;
3876 /* If there is only one level of template parameters, we do not
3877 create a TREE_VEC of TREE_VECs. Instead, we return a single
3878 TREE_VEC containing the arguments. */
3883 {
3891 #ifdef ENABLE_CHECKING
3893 #endif
3897 else
3899 }
3902 /* This can happen for template parms of a template template
3903 parameter, e.g:
3905 template<template<class T, class U> class TT> struct S;
3907 Consider the level of the parms of TT; T and U both have
3908 level 2; TT has no template parm of level 1. So in this case
3909 the first element of full_template_args is NULL_TREE. If we
3910 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3911 of 2. This will make tsubst wrongly consider that T and U
3912 have level 1. Instead, let's create a dummy vector as the
3913 first element of full_template_args so that TMPL_ARGS_DEPTH
3914 returns the correct depth for args. */
3917 }
3919 /* Within the declaration of a template, return the currently active
3920 template parameters as an argument TREE_VEC. */
3922 static tree
3924 {
3926 }
3928 /* Update the declared TYPE by doing any lookups which were thought to be
3929 dependent, but are not now that we know the SCOPE of the declarator. */
3931 tree
3933 {
3944 /* Don't bother building up the args in this case. */
3946 {
3947 /* tsubst in the args corresponding to the template parameters,
3948 including auto if present. Most things will be unchanged, but
3949 make_typename_type and tsubst_qualified_id will resolve
3950 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3953 tree pushed;
3955 {
3959 }
3964 }
3970 {
3973 else
3975 }
3977 }
3979 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3980 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3981 a member template. Used by push_template_decl below. */
3983 static tree
3985 {
3993 }
3995 struct template_parm_data
3996 {
3997 /* The level of the template parameters we are currently
3998 processing. */
4001 /* The index of the specialization argument we are currently
4002 processing. */
4005 /* An array whose size is the number of template parameters. The
4006 elements are nonzero if the parameter has been used in any one
4007 of the arguments processed so far. */
4010 /* An array whose size is the number of template arguments. The
4011 elements are nonzero if the argument makes use of template
4012 parameters of this level. */
4014 };
4016 /* Subroutine of push_template_decl used to see if each template
4017 parameter in a partial specialization is used in the explicit
4018 argument list. If T is of the LEVEL given in DATA (which is
4019 treated as a template_parm_data*), then DATA->PARMS is marked
4020 appropriately. */
4022 static int
4024 {
4030 {
4033 }
4034 else
4035 {
4038 }
4041 {
4044 }
4046 /* Return zero so that for_each_template_parm will continue the
4047 traversal of the tree; we want to mark *every* template parm. */
4049 }
4051 /* Process the partial specialization DECL. */
4053 static tree
4055 {
4061 tree inner_parms;
4062 tree inst;
4075 /* We check that each of the template parameters given in the
4076 partial specialization is used in the argument list to the
4077 specialization. For example:
4079 template <class T> struct S;
4080 template <class T> struct S<T*>;
4082 The second declaration is OK because `T*' uses the template
4083 parameter T, whereas
4085 template <class T> struct S<int>;
4087 is no good. Even trickier is:
4089 template <class T>
4090 struct S1
4091 {
4092 template <class U>
4093 struct S2;
4094 template <class U>
4095 struct S2<T>;
4096 };
4098 The S2<T> declaration is actually invalid; it is a
4099 full-specialization. Of course,
4101 template <class U>
4102 struct S2<T (*)(U)>;
4104 or some such would have been OK. */
4112 {
4117 NULL,
4119 }
4122 {
4123 /* One of the template parms was not used in the
4124 specialization. */
4126 {
4129 }
4132 }
4137 /* [temp.class.spec]
4139 The argument list of the specialization shall not be identical to
4140 the implicit argument list of the primary template. */
4147 /* A partial specialization that replaces multiple parameters of the
4148 primary template with a pack expansion is less specialized for those
4149 parameters. */
4151 {
4153 "primary template because it replaces multiple parameters "
4157 }
4159 /* [temp.class.spec]
4161 A partially specialized non-type argument expression shall not
4162 involve template parameters of the partial specialization except
4163 when the argument expression is a simple identifier.
4165 The type of a template parameter corresponding to a specialized
4166 non-type argument shall not be dependent on a parameter of the
4167 specialization.
4169 Also, we verify that pack expansions only occur at the
4170 end of the argument list. */
4174 {
4181 {
4182 /* Extract the arguments from the argument pack. We'll be
4183 iterating over these in the following loop. */
4186 }
4189 {
4191 /* Get the Jth argument in the parameter pack. */
4195 {
4196 /* Pack expansions must come at the end of the
4197 argument list. */
4200 {
4204 else
4207 }
4208 }
4211 /* We only care about the pattern. */
4217 /* This next line is the `argument expression is not just a
4218 simple identifier' condition and also the `specialized
4219 non-type argument' bit. */
4221 {
4225 arg);
4226 else
4227 {
4228 /* Look at the corresponding template parameter,
4229 marking which template parameters its type depends
4230 upon. */
4234 {
4235 /* We haven't yet initialized TPD2. Do so now. */
4237 /* The number of parameters here is the number in the
4238 main template, which, as checked in the assertion
4239 above, is NARGS. */
4243 }
4245 /* Mark the template parameters. But this time, we're
4246 looking for the template parameters of the main
4247 template, not in the specialization. */
4254 NULL,
4258 {
4259 /* The type depended on some template parameters.
4260 If they are fully specialized in the
4261 specialization, that's OK. */
4270 "type %qT of template argument %qE depends "
4272 "type %qT of template argument %qE depends "
4274 type,
4275 arg);
4276 }
4277 }
4278 }
4279 }
4280 }
4282 /* We should only get here once. */
4300 {
4304 {
4308 "partial specialization of %qT after instantiation "
4310 }
4311 }
4314 }
4316 /* Check that a template declaration's use of default arguments and
4317 parameter packs is not invalid. Here, PARMS are the template
4318 parameters. IS_PRIMARY is true if DECL is the thing declared by
4319 a primary template. IS_PARTIAL is true if DECL is a partial
4320 specialization.
4322 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4323 declaration (but not a definition); 1 indicates a declaration, 2
4324 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4325 emitted for extraneous default arguments.
4327 Returns TRUE if there were no errors found, FALSE otherwise. */
4329 bool
4332 {
4335 tree parm_level;
4338 /* [temp.param]
4340 A default template-argument shall not be specified in a
4341 function template declaration or a function template definition, nor
4342 in the template-parameter-list of the definition of a member of a
4343 class template. */
4346 /* You can't have a function template declaration in a local
4347 scope, nor you can you define a member of a class template in a
4348 local scope. */
4354 /* A lambda doesn't have an explicit declaration; don't complain
4355 about the parms of the enclosing class. */
4362 /* If this is either a friend defined in the scope of the class
4363 or a member function. */
4369 /* And, if it was a member function, it really was defined in
4370 the scope of the class. */
4373 /* We already checked these parameters when the template was
4374 declared, so there's no need to do it again now. This function
4375 was defined in class scope, but we're processing its body now
4376 that the class is complete. */
4379 /* Core issue 226 (C++0x only): the following only applies to class
4380 templates. */
4383 {
4384 /* [temp.param]
4386 If a template-parameter has a default template-argument, all
4387 subsequent template-parameters shall have a default
4388 template-argument supplied. */
4390 {
4397 {
4407 {
4409 /* For better subsequent error-recovery, we indicate that
4410 there should have been a default argument. */
4413 }
4415 && !is_friend_decl
4416 /* Don't complain about an enclosing partial
4417 specialization. */
4422 {
4423 /* A primary class template can only have one
4424 parameter pack, at the end of the template
4425 parameter list. */
4430 else
4438 }
4439 }
4440 }
4441 }
4444 || is_partial
4445 || !is_primary
4447 /* For an ordinary class template, default template arguments are
4448 allowed at the innermost level, e.g.:
4449 template <class T = int>
4450 struct S {};
4451 but, in a partial specialization, they're not allowed even
4452 there, as we have in [temp.class.spec]:
4454 The template parameter list of a specialization shall not
4455 contain default template argument values.
4457 So, for a partial specialization, or for a function template
4458 (in C++98/C++03), we look at all of them. */
4459 ;
4460 else
4461 /* But, for a primary class template that is not a partial
4462 specialization we look at all template parameters except the
4463 innermost ones. */
4466 /* Figure out what error message to issue. */
4479 else
4483 /* If we're inside a class definition, there's no need to
4484 examine the parameters to the class itself. On the one
4485 hand, they will be checked when the class is defined, and,
4486 on the other, default arguments are valid in things like:
4487 template <class T = double>
4488 struct S { template <class U> void f(U); };
4489 Here the default argument for `S' has no bearing on the
4490 declaration of `f'. */
4492 else
4493 /* Check everything. */
4499 {
4506 {
4511 {
4513 {
4520 }
4522 /* Clear out the default argument so that we are not
4523 confused later. */
4525 }
4526 }
4528 /* At this point, if we're still interested in issuing messages,
4529 they must apply to classes surrounding the object declared. */
4533 }
4536 }
4538 /* Worker for push_template_decl_real, called via
4539 for_each_template_parm. DATA is really an int, indicating the
4540 level of the parameters we are interested in. If T is a template
4541 parameter of that level, return nonzero. */
4543 static int
4545 {
4551 else
4554 }
4556 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4557 parameters given by current_template_args, or reuses a
4558 previously existing one, if appropriate. Returns the DECL, or an
4559 equivalent one, if it is replaced via a call to duplicate_decls.
4561 If IS_FRIEND is true, DECL is a friend declaration. */
4563 tree
4565 {
4566 tree tmpl;
4567 tree args;
4568 tree info;
4569 tree ctx;
4573 /* True if the template is a member template, in the sense of
4574 [temp.mem]. */
4580 /* See if this is a partial specialization. */
4589 /* For a friend, we want the context of the friend function, not
4590 the type of which it is a friend. */
4594 /* In the case of a virtual function, we want the class in which
4595 it is defined. */
4597 else
4598 /* Otherwise, if we're currently defining some class, the DECL
4599 is assumed to be a member of the class. */
4608 /* See if this is a primary template. */
4610 /* A friend template that specifies a class context, i.e.
4611 template <typename T> friend void A<T>::f();
4612 is not primary. */
4614 else
4618 {
4623 {
4626 }
4628 {
4630 {
4631 /* [temp.mem]
4633 A destructor shall not be a member template. */
4636 }
4643 {
4644 /* [basic.stc.dynamic.allocation]
4646 An allocation function can be a function
4647 template. ... Template allocation functions shall
4648 have two or more parameters. */
4651 }
4652 }
4658 /* alias-declaration */
4660 else
4661 {
4664 }
4665 }
4667 /* Check to see that the rules regarding the use of default
4668 arguments are not being violated. */
4672 /* Ensure that there are no parameter packs in the type of this
4673 declaration that have not been expanded. */
4675 {
4676 /* Check each of the arguments individually to see if there are
4677 any bare parameter packs. */
4683 {
4686 {
4687 /* This is a PARM_DECL that contains unexpanded parameter
4688 packs. We have already complained about this in the
4689 check_for_bare_parameter_packs call, so just replace
4690 these types with ERROR_MARK_NODE. */
4693 }
4697 }
4699 /* Check for bare parameter packs in the return type and the
4700 exception specifiers. */
4702 /* Errors were already issued, set return type to int
4703 as the frontend doesn't expect error_mark_node as
4704 the return type. */
4708 }
4713 {
4716 }
4729 {
4734 /* If DECL is a TYPE_DECL for a class-template, then there won't
4735 be DECL_LANG_SPECIFIC. The information equivalent to
4736 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4740 {
4741 /* Since a template declaration already existed for this
4742 class-type, we must be redeclaring it here. Make sure
4743 that the redeclaration is valid. */
4745 current_template_parms);
4746 /* We don't need to create a new TEMPLATE_DECL; just use the
4747 one we already had. */
4749 }
4750 else
4751 {
4753 member_template_p);
4758 {
4759 /* A specialization of a member template of a template
4760 class. */
4764 }
4765 }
4766 }
4767 else
4768 {
4774 {
4777 }
4785 {
4786 tree new_tmpl;
4788 /* The declaration is a specialization of a member
4789 template, declared outside the class. Therefore, the
4790 innermost template arguments will be NULL, so we
4791 replace them with the arguments determined by the
4792 earlier call to check_explicit_specialization. */
4795 new_tmpl
4797 member_template_p);
4807 args,
4810 }
4812 /* Make sure the template headers we got make sense. */
4817 {
4820 }
4821 else
4823 {
4828 {
4832 else
4836 /* Avoid crash in import_export_decl. */
4839 }
4844 /* Can happen in erroneous input. */
4846 else
4848 }
4850 /* Check that the parms are used in the appropriate qualifying scopes
4851 in the declarator. */
4855 {
4861 /* Avoid crash in import_export_decl. */
4864 }
4865 }
4870 /* Push template declarations for global functions and types. Note
4871 that we do not try to push a global template friend declared in a
4872 template class; such a thing may well depend on the template
4873 parameters of the class. */
4876 {
4881 /* Hide template friend classes that haven't been declared yet. */
4883 {
4886 }
4887 }
4890 {
4896 {
4899 /* It is a conversion operator. See if the type converted to
4900 depends on innermost template operands. */
4903 depth))
4905 }
4907 /* Give template template parms a DECL_CONTEXT of the template
4908 for which they are a parameter. */
4911 {
4915 }
4916 }
4918 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4919 back to its most general template. If TMPL is a specialization,
4920 ARGS may only have the innermost set of arguments. Add the missing
4921 argument levels if necessary. */
4929 else
4930 {
4935 }
4938 }
4940 tree
4942 {
4944 }
4946 /* FN is an inheriting constructor that inherits from the constructor
4947 template INHERITED; turn FN into a constructor template with a matching
4948 template header. */
4950 tree
4952 {
4953 tree inner_parms
4956 tree parms
4967 }
4969 /* Called when a class template TYPE is redeclared with the indicated
4970 template PARMS, e.g.:
4972 template <class T> struct S;
4973 template <class T> struct S {}; */
4975 bool
4977 {
4978 tree tmpl;
4979 tree tmpl_parms;
4983 {
4986 }
4990 /* The type is nested in some template class. Nothing to worry
4991 about here; there are no new template parameters for the nested
4992 type. */
4996 {
4998 tmpl);
5000 }
5006 {
5016 }
5019 {
5020 tree tmpl_parm;
5021 tree parm;
5022 tree tmpl_default;
5023 tree parm_default;
5037 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5038 TEMPLATE_DECL. */
5048 {
5052 }
5055 {
5056 /* We have in [temp.param]:
5058 A template-parameter may not be given default arguments
5059 by two different declarations in the same scope. */
5064 }
5067 /* Update the previous template parameters (which are the ones
5068 that will really count) with the new default value. */
5071 /* Update the new parameters, too; they'll be used as the
5072 parameters for any members. */
5074 }
5077 }
5079 /* Simplify EXPR if it is a non-dependent expression. Returns the
5080 (possibly simplified) expression. */
5082 tree
5084 {
5088 /* If we're in a template, but EXPR isn't value dependent, simplify
5089 it. We're supposed to treat:
5091 template <typename T> void f(T[1 + 1]);
5092 template <typename T> void f(T[2]);
5094 as two declarations of the same function, for example. */
5098 {
5099 HOST_WIDE_INT saved_processing_template_decl;
5105 complain,
5110 }
5112 }
5114 tree
5116 {
5118 }
5120 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5121 template declaration, or a TYPE_DECL for an alias declaration. */
5123 bool
5125 {
5133 }
5135 /* Return TRUE iff is a specialization of an alias template. */
5137 bool
5139 {
5147 }
5149 /* Return either TMPL or another template that it is equivalent to under DR
5150 1286: An alias that just changes the name of a template is equivalent to
5151 the other template. */
5153 static tree
5155 {
5158 {
5161 {
5165 {
5166 /* The alias type is equivalent to the pattern of the
5167 underlying template, so strip the alias. */
5170 }
5171 }
5173 }
5175 }
5177 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5178 must be a function or a pointer-to-function type, as specified
5179 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5180 and check that the resulting function has external linkage. */
5182 static tree
5184 {
5187 linkage_kind linkage;
5199 /* [temp.arg.nontype]/1
5201 A template-argument for a non-type, non-template template-parameter
5202 shall be one of:
5203 [...]
5204 -- the address of an object or function with external [C++11: or
5205 internal] linkage. */
5208 {
5212 else
5215 }
5219 {
5224 else
5229 }
5232 }
5234 /* Subroutine of convert_nontype_argument.
5235 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5236 Emit an error otherwise. */
5238 static bool
5240 tsubst_flags_t complain)
5241 {
5248 {
5252 }
5254 }
5256 /* Returns TRUE iff the address of OP is value-dependent.
5258 14.6.2.4 [temp.dep.temp]:
5259 A non-integral non-type template-argument is dependent if its type is
5260 dependent or it has either of the following forms
5261 qualified-id
5262 & qualified-id
5263 and contains a nested-name-specifier which specifies a class-name that
5264 names a dependent type.
5266 We generalize this to just say that the address of a member of a
5267 dependent class is value-dependent; the above doesn't cover the
5268 address of a static data member named with an unqualified-id. */
5270 static bool
5272 {
5273 /* We could use get_inner_reference here, but there's no need;
5274 this is only relevant for template non-type arguments, which
5275 can only be expressed as &id-expression. */
5277 {
5281 }
5284 }
5286 /* The next set of functions are used for providing helpful explanatory
5287 diagnostics for failed overload resolution. Their messages should be
5288 indented by two spaces for consistency with the messages in
5289 call.c */
5291 static int
5293 {
5295 }
5297 static int
5299 {
5304 }
5306 static int
5308 {
5310 }
5312 static int
5314 {
5320 }
5322 static int
5324 {
5328 }
5330 static int
5332 {
5335 " template parameter %qD is not a parameter pack, but "
5339 }
5341 static int
5343 {
5346 " template argument %qE does not match "
5350 }
5352 static int
5354 {
5358 }
5360 static int
5362 {
5368 }
5370 static int
5372 {
5374 {
5379 else
5381 " deduced conflicting values for non-type parameter "
5383 }
5385 }
5387 static int
5389 {
5392 " variable-sized array type %qT is not "
5394 arg);
5396 }
5398 static int
5400 {
5404 arg);
5406 }
5408 static int
5410 {
5417 }
5419 static int
5421 {
5423 }
5425 static int
5427 {
5429 }
5431 static int
5434 {
5440 }
5442 static int
5445 {
5448 {
5456 }
5458 }
5460 static int
5462 {
5465 " template parameters of a template template argument are "
5468 }
5470 static int
5472 {
5478 }
5480 static int
5482 {
5487 }
5489 static int
5491 {
5495 arg);
5497 }
5499 /* Attempt to convert the non-type template parameter EXPR to the
5500 indicated TYPE. If the conversion is successful, return the
5501 converted value. If the conversion is unsuccessful, return
5502 NULL_TREE if we issued an error message, or error_mark_node if we
5503 did not. We issue error messages for out-and-out bad template
5504 parameters, but not simply because the conversion failed, since we
5505 might be just trying to do argument deduction. Both TYPE and EXPR
5506 must be non-dependent.
5508 The conversion follows the special rules described in
5509 [temp.arg.nontype], and it is much more strict than an implicit
5510 conversion.
5512 This function is called twice for each template argument (see
5513 lookup_template_class for a more accurate description of this
5514 problem). This means that we need to handle expressions which
5515 are not valid in a C++ source, but can be created from the
5516 first call (for instance, casts to perform conversions). These
5517 hacks can go away after we fix the double coercion problem. */
5519 static tree
5521 {
5522 tree expr_type;
5524 /* Detect immediately string literals as invalid non-type argument.
5525 This special-case is not needed for correctness (we would easily
5526 catch this later), but only to provide better diagnostic for this
5527 common user mistake. As suggested by DR 100, we do not mention
5528 linkage issues in the diagnostic as this is not the point. */
5529 /* FIXME we're making this OK. */
5531 {
5537 }
5539 /* Add the ADDR_EXPR now for the benefit of
5540 value_dependent_expression_p. */
5543 {
5547 }
5549 /* If we are in a template, EXPR may be non-dependent, but still
5550 have a syntactic, rather than semantic, form. For example, EXPR
5551 might be a SCOPE_REF, rather than the VAR_DECL to which the
5552 SCOPE_REF refers. Preserving the qualifying scope is necessary
5553 so that access checking can be performed when the template is
5554 instantiated -- but here we need the resolved form so that we can
5555 convert the argument. */
5566 else
5569 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5570 to a non-type argument of "nullptr". */
5574 /* In C++11, integral or enumeration non-type template arguments can be
5575 arbitrary constant expressions. Pointer and pointer to
5576 member arguments can be general constant expressions that evaluate
5577 to a null value, but otherwise still need to be of a specific form. */
5579 {
5581 /* A PTRMEM_CST is already constant, and a valid template
5582 argument for a parameter of pointer to member type, we just want
5583 to leave it in that form rather than lower it to a
5588 {
5593 }
5594 }
5596 /* HACK: Due to double coercion, we can get a
5597 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5598 which is the tree that we built on the first call (see
5599 below when coercing to reference to object or to reference to
5600 function). We just strip everything and get to the arg.
5601 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5602 for examples. */
5604 {
5610 {
5611 /* ??? Maybe we could use convert_from_reference here, but we
5612 would need to relax its constraints because the NOP_EXPR
5613 could actually change the type to something more cv-qualified,
5614 and this is not folded by convert_from_reference. */
5619 && (same_type_ignoring_top_level_qualifiers_p
5622 {
5625 }
5626 }
5627 }
5629 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5630 parameter is a pointer to object, through decay and
5631 qualification conversion. Let's strip everything. */
5633 {
5638 {
5639 /* Skip the ADDR_EXPR only if it is part of the decay for
5640 an array. Otherwise, it is part of the original argument
5641 in the source code. */
5646 }
5647 }
5649 /* [temp.arg.nontype]/5, bullet 1
5651 For a non-type template-parameter of integral or enumeration type,
5652 integral promotions (_conv.prom_) and integral conversions
5653 (_conv.integral_) are applied. */
5655 {
5664 /* Notice that there are constant expressions like '4 % 0' which
5665 do not fold into integer constants. */
5667 {
5669 {
5680 /* else cxx_constant_value complained but gave us
5681 a real constant, so go ahead. */
5683 }
5684 else
5686 }
5688 /* Avoid typedef problems. */
5691 }
5692 /* [temp.arg.nontype]/5, bullet 2
5694 For a non-type template-parameter of type pointer to object,
5695 qualification conversions (_conv.qual_) and the array-to-pointer
5696 conversion (_conv.array_) are applied. */
5698 {
5699 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5701 A template-argument for a non-type, non-template template-parameter
5702 shall be one of: [...]
5704 -- the name of a non-type template-parameter;
5705 -- the address of an object or function with external linkage, [...]
5706 expressed as "& id-expression" where the & is optional if the name
5707 refers to a function or array, or if the corresponding
5708 template-parameter is a reference.
5710 Here, we do not care about functions, as they are invalid anyway
5711 for a parameter of type pointer-to-object. */
5714 /* Non-type template parameters are OK. */
5715 ;
5720 {
5722 {
5724 "because %qD is a variable, not the address of "
5728 }
5730 {
5735 }
5736 /* Other values, like integer constants, might be valid
5737 non-type arguments of some other type. */
5739 }
5740 else
5741 {
5742 tree decl;
5747 {
5752 }
5754 {
5759 }
5761 {
5766 }
5767 }
5776 }
5777 /* [temp.arg.nontype]/5, bullet 3
5779 For a non-type template-parameter of type reference to object, no
5780 conversions apply. The type referred to by the reference may be more
5781 cv-qualified than the (otherwise identical) type of the
5782 template-argument. The template-parameter is bound directly to the
5783 template-argument, which must be an lvalue. */
5785 {
5787 expr_type))
5791 {
5795 }
5798 {
5802 }
5804 /* [temp.arg.nontype]/1
5806 A template-argument for a non-type, non-template template-parameter
5807 shall be one of: [...]
5809 -- the address of an object or function with external linkage. */
5812 {
5815 {
5817 "because a reference variable does not have a constant "
5820 }
5821 }
5824 {
5829 }
5832 {
5837 }
5840 }
5841 /* [temp.arg.nontype]/5, bullet 4
5843 For a non-type template-parameter of type pointer to function, only
5844 the function-to-pointer conversion (_conv.func_) is applied. If the
5845 template-argument represents a set of overloaded functions (or a
5846 pointer to such), the matching function is selected from the set
5847 (_over.over_). */
5849 {
5850 /* If the argument is a template-id, we might not have enough
5851 context information to decay the pointer. */
5853 {
5857 }
5860 /* Null pointer values are OK in C++11. */
5866 }
5867 /* [temp.arg.nontype]/5, bullet 5
5869 For a non-type template-parameter of type reference to function, no
5870 conversions apply. If the template-argument represents a set of
5871 overloaded functions, the matching function is selected from the set
5872 (_over.over_). */
5874 {
5876 {
5881 }
5888 }
5889 /* [temp.arg.nontype]/5, bullet 6
5891 For a non-type template-parameter of type pointer to member function,
5892 no conversions apply. If the template-argument represents a set of
5893 overloaded member functions, the matching member function is selected
5894 from the set (_over.over_). */
5896 {
5901 /* [temp.arg.nontype] bullet 1 says the pointer to member
5902 expression must be a pointer-to-member constant. */
5906 /* There is no way to disable standard conversions in
5907 resolve_address_of_overloaded_function (called by
5908 instantiate_type). It is possible that the call succeeded by
5909 converting &B::I to &D::I (where B is a base of D), so we need
5910 to reject this conversion here.
5912 Actually, even if there was a way to disable standard conversions,
5913 it would still be better to reject them here so that we can
5914 provide a superior diagnostic. */
5916 {
5920 /* If we are just one standard conversion off, explain. */
5925 }
5926 }
5927 /* [temp.arg.nontype]/5, bullet 7
5929 For a non-type template-parameter of type pointer to data member,
5930 qualification conversions (_conv.qual_) are applied. */
5932 {
5933 /* [temp.arg.nontype] bullet 1 says the pointer to member
5934 expression must be a pointer-to-member constant. */
5941 }
5943 {
5945 {
5949 }
5951 }
5952 /* A template non-type parameter must be one of the above. */
5953 else
5956 /* Sanity check: did we actually convert the argument to the
5957 right type? */
5961 }
5963 /* Subroutine of coerce_template_template_parms, which returns 1 if
5964 PARM_PARM and ARG_PARM match using the rule for the template
5965 parameters of template template parameters. Both PARM and ARG are
5966 template parameters; the rest of the arguments are the same as for
5967 coerce_template_template_parms.
5968 */
5969 static int
5971 tree arg,
5972 tsubst_flags_t complain,
5973 tree in_decl,
5974 tree outer_args)
5975 {
5984 {
5986 /* We encounter instantiations of templates like
5987 template <template <template <class> class> class TT>
5988 class C; */
5989 {
5996 }
5997 /* Fall through. */
6002 /* Argument is a parameter pack but parameter is not. */
6007 /* The tsubst call is used to handle cases such as
6009 template <int> class C {};
6010 template <class T, template <T> class TT> class D {};
6011 D<int, C> d;
6013 i.e. the parameter list of TT depends on earlier parameters. */
6015 && !same_type_p
6022 /* Argument is a parameter pack but parameter is not. */
6029 }
6032 }
6035 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6036 template template parameters. Both PARM_PARMS and ARG_PARMS are
6037 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6038 or PARM_DECL.
6040 Consider the example:
6041 template <class T> class A;
6042 template<template <class U> class TT> class B;
6044 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6045 the parameters to A, and OUTER_ARGS contains A. */
6047 static int
6049 tree arg_parms,
6050 tsubst_flags_t complain,
6051 tree in_decl,
6052 tree outer_args)
6053 {
6064 /* Determine whether we have a parameter pack at the end of the
6065 template template parameter's template parameter list. */
6067 {
6074 {
6088 }
6089 }
6095 /* Check all of the template parameters except the parameter pack at
6096 the end (if any). */
6098 {
6107 outer_args))
6110 }
6113 {
6114 /* Check each of the template parameters in the template
6115 argument against the template parameter pack at the end of
6116 the template template parameter. */
6123 {
6130 outer_args))
6132 }
6133 }
6136 }
6138 /* Verifies that the deduced template arguments (in TARGS) for the
6139 template template parameters (in TPARMS) represent valid bindings,
6140 by comparing the template parameter list of each template argument
6141 to the template parameter list of its corresponding template
6142 template parameter, in accordance with DR150. This
6143 routine can only be called after all template arguments have been
6144 deduced. It will return TRUE if all of the template template
6145 parameter bindings are okay, FALSE otherwise. */
6146 bool
6148 {
6152 /* We're dealing with template parms in this process. */
6158 {
6163 {
6168 {
6169 /* Look inside the argument pack. */
6172 }
6175 {
6179 /* Extract the next argument from the argument
6180 pack. */
6184 /* Look at the pattern of the pack expansion. */
6187 /* Extract the template parameters from the template
6188 argument. */
6194 /* Verify that we can coerce the template template
6195 parameters from the template argument to the template
6196 parameter. This requires an exact match. */
6198 && !coerce_template_template_parms
6200 targ_parms,
6201 tf_none,
6202 tparm,
6203 targs))
6204 {
6207 }
6208 }
6209 }
6210 }
6212 out:
6216 }
6218 /* Since type attributes aren't mangled, we need to strip them from
6219 template type arguments. */
6221 static tree
6223 {
6224 tree mv;
6231 {
6236 }
6238 }
6240 /* Convert the indicated template ARG as necessary to match the
6241 indicated template PARM. Returns the converted ARG, or
6242 error_mark_node if the conversion was unsuccessful. Error and
6243 warning messages are issued under control of COMPLAIN. This
6244 conversion is for the Ith parameter in the parameter list. ARGS is
6245 the full set of template arguments deduced so far. */
6247 static tree
6249 tree arg,
6250 tree args,
6251 tsubst_flags_t complain,
6253 tree in_decl)
6254 {
6255 tree orig_arg;
6256 tree val;
6261 {
6262 /* The template argument was the name of some
6263 member function. That's usually
6264 invalid, but static members are OK. In any
6265 case, grab the underlying fields/functions
6266 and issue an error later if required. */
6269 }
6277 /* When determining whether an argument pack expansion is a template,
6278 look at the pattern. */
6282 /* Deal with an injected-class-name used as a template template arg. */
6284 {
6287 {
6297 }
6298 }
6300 is_tmpl_type =
6316 {
6318 {
6322 }
6325 "to refer to a type member of a template parameter, "
6330 typename_type,
6331 complain);
6334 }
6336 {
6338 {
6340 {
6350 else
6352 }
6353 }
6355 }
6357 {
6359 {
6365 else
6367 }
6369 }
6372 {
6374 {
6378 /* The number of argument required is not known yet.
6379 Just accept it for now. */
6381 else
6382 {
6384 tree argparm;
6386 /* Strip alias templates that are equivalent to another
6387 template. */
6393 args))
6394 {
6397 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6398 TEMPLATE_DECL. */
6400 {
6405 }
6406 }
6407 else
6408 {
6410 {
6416 }
6419 }
6420 }
6421 }
6422 else
6424 /* We only form one instance of each template specialization.
6425 Therefore, if we use a non-canonical variant (i.e., a
6426 typedef), any future messages referring to the type will use
6427 the typedef, which is confusing if those future uses do not
6428 themselves also use the typedef. */
6431 }
6432 else
6433 {
6440 {
6443 else
6444 {
6445 /* Not sure if this is reachable, but it doesn't hurt
6446 to be robust. */
6449 }
6450 }
6453 /* We used to call digest_init here. However, digest_init
6454 will report errors, which we don't want when complain
6455 is zero. More importantly, digest_init will try too
6456 hard to convert things: for example, `0' should not be
6457 converted to pointer type at this point according to
6458 the standard. Accepting this is not merely an
6459 extension, since deciding whether or not these
6460 conversions can occur is part of determining which
6461 function template to call, or whether a given explicit
6462 argument specification is valid. */
6464 else
6473 {
6474 /* Strip typedefs from the SCOPE_REF. */
6477 complain);
6480 }
6481 }
6484 }
6486 /* Coerces the remaining template arguments in INNER_ARGS (from
6487 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6488 Returns the coerced argument pack. PARM_IDX is the position of this
6489 parameter in the template parameter list. ARGS is the original
6490 template argument list. */
6491 static tree
6494 tree args,
6495 tree inner_args,
6497 tree new_args,
6499 tree in_decl,
6500 tsubst_flags_t complain)
6501 {
6504 tree packed_args;
6505 tree argument_pack;
6515 {
6516 /* When the template parameter is a non-type template
6517 parameter pack whose type uses parameter packs, we need
6518 to look at each of the template arguments
6519 separately. Build a vector of the types for these
6520 non-type template parameters in PACKED_TYPES. */
6521 tree expansion
6529 /* Check that we have the right number of arguments. */
6533 {
6534 int needed_parms
6539 }
6541 /* If we aren't able to check the actual arguments now
6542 (because they haven't been expanded yet), we can at least
6543 verify that all of the types used for the non-type
6544 template parameter pack are, in fact, valid for non-type
6545 template parameters. */
6548 {
6551 {
6555 }
6556 }
6557 }
6559 /* Convert the remaining arguments, which will be a part of the
6560 parameter pack "parm". */
6562 {
6567 {
6568 /* When we have a vector of types (corresponding to the
6569 non-type template parameter pack that uses parameter
6570 packs in its type, as mention above), and the
6571 argument is not an expansion (which expands to a
6572 currently unknown number of arguments), clone the
6573 parm and give it the next type in PACKED_TYPES. */
6577 }
6580 {
6583 }
6584 else
6587 in_decl);
6591 }
6596 else
6597 {
6602 }
6605 #ifdef ENABLE_CHECKING
6608 #endif
6610 }
6612 /* Returns the number of pack expansions in the template argument vector
6613 ARGS. */
6615 static int
6617 {
6622 {
6626 }
6628 }
6630 /* Convert all template arguments to their appropriate types, and
6631 return a vector containing the innermost resulting template
6632 arguments. If any error occurs, return error_mark_node. Error and
6633 warning messages are issued under control of COMPLAIN.
6635 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6636 for arguments not specified in ARGS. Otherwise, if
6637 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6638 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6639 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6640 ARGS. */
6642 static tree
6644 tree args,
6645 tree in_decl,
6646 tsubst_flags_t complain,
6649 {
6651 tree inner_args;
6652 tree new_args;
6653 tree new_inner_args;
6657 /* When used as a boolean value, indicates whether this is a
6658 variadic template parameter list. Since it's an int, we can also
6659 subtract it from nparms to get the number of non-variadic
6660 parameters. */
6670 /* Determine if there are any parameter packs. */
6672 {
6678 }
6681 /* If there are no parameters that follow a parameter pack, we need to
6682 expand any argument packs so that we can deduce a parameter pack from
6683 some non-packed args followed by an argument pack, as in variadic85.C.
6684 If there are such parameters, we need to leave argument packs intact
6685 so the arguments are assigned properly. This can happen when dealing
6686 with a nested class inside a partial specialization of a class
6687 template, as in variadic92.C, or when deducing a template parameter pack
6688 from a sub-declarator, as in variadic114.C. */
6692 /* Count any pack expansion args. */
6698 && require_all_args
6699 && !variadic_args_p
6700 && (!use_default_args
6703 {
6705 {
6707 {
6711 }
6712 else
6718 }
6721 }
6722 /* We can't pass a pack expansion to a non-pack parameter of an alias
6723 template (DR 1430). */
6725 && variadic_args_p
6727 {
6729 {
6731 {
6737 {
6742 }
6743 }
6745 found:;
6746 }
6748 }
6750 /* We need to evaluate the template arguments, even though this
6751 template-id may be nested within a "sizeof". */
6759 {
6760 tree arg;
6761 tree parm;
6763 /* Get the Ith template parameter. */
6767 {
6770 }
6772 /* Calculate the next argument. */
6775 else
6780 {
6781 /* All remaining arguments will be placed in the
6782 template parameter pack PARM. */
6788 /* Store this argument. */
6790 lost++;
6793 /* We are done with all of the arguments. */
6797 }
6799 {
6801 {
6802 /* We don't know how many args we have yet, just
6803 use the unconverted ones for now. */
6806 }
6807 }
6809 {
6810 /* There must be a default arg in this case. */
6813 /* The position of the first default template argument,
6814 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6815 Record that. */
6818 }
6819 else
6823 {
6826 }
6828 /* This only occurs if there was an error in the template
6829 parameter list itself (which we would already have
6830 reported) that we are trying to recover from, e.g., a class
6831 template with a parameter list such as
6832 template<typename..., typename>. */
6834 else
6840 lost++;
6842 }
6849 #ifdef ENABLE_CHECKING
6853 #endif
6856 }
6858 /* Like coerce_template_parms. If PARMS represents all template
6859 parameters levels, this function returns a vector of vectors
6860 representing all the resulting argument levels. Note that in this
6861 case, only the innermost arguments are coerced because the
6862 outermost ones are supposed to have been coerced already.
6864 Otherwise, if PARMS represents only (the innermost) vector of
6865 parameters, this function returns a vector containing just the
6866 innermost resulting arguments. */
6868 static tree
6870 tree args,
6871 tree in_decl,
6872 tsubst_flags_t complain,
6875 {
6878 tree coerced_args;
6881 {
6883 tree level;
6889 {
6890 tree l;
6894 require_all_args,
6895 use_default_args);
6896 else
6903 }
6904 }
6905 else
6908 require_all_args,
6909 use_default_args);
6911 }
6913 /* Returns 1 if template args OT and NT are equivalent. */
6915 static int
6917 {
6924 /* For member templates */
6933 {
6950 }
6952 {
6953 /* We get here probably because we are in the middle of substituting
6954 into the pattern of a pack expansion. In that case the
6955 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6956 interested in. So we want to use the initial pack argument for
6957 the comparison. */
6962 }
6967 else
6969 }
6971 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6972 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6973 NEWARG_PTR with the offending arguments if they are non-NULL. */
6975 static int
6978 {
6991 {
6996 {
7002 }
7003 }
7005 }
7007 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7008 of template arguments. Returns 0 otherwise. */
7010 int
7012 {
7014 }
7016 static void
7018 {
7028 /* We are called both from instantiate_decl, where we've already had a
7029 tinst_level pushed, and instantiate_template, where we haven't.
7030 Compensate. */
7041 else
7050 }
7053 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7054 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7055 documentation for TEMPLATE_ID_EXPR. */
7057 tree
7059 {
7060 tree type;
7068 {
7071 }
7074 {
7076 unknown_type_node,
7078 arglist);
7080 }
7087 }
7089 /* Within the scope of a template class S<T>, the name S gets bound
7090 (in build_self_reference) to a TYPE_DECL for the class, not a
7091 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7092 or one of its enclosing classes, and that type is a template,
7093 return the associated TEMPLATE_DECL. Otherwise, the original
7094 DECL is returned.
7096 Also handle the case when DECL is a TREE_LIST of ambiguous
7097 injected-class-names from different bases. */
7099 tree
7101 {
7105 /* DR 176: A lookup that finds an injected-class-name (10.2
7106 [class.member.lookup]) can result in an ambiguity in certain cases
7107 (for example, if it is found in more than one base class). If all of
7108 the injected-class-names that are found refer to specializations of
7109 the same class template, and if the name is followed by a
7110 template-argument-list, the reference refers to the class template
7111 itself and not a specialization thereof, and is not ambiguous. */
7113 {
7116 {
7122 }
7125 else
7127 }
7133 }
7135 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7136 parameters, find the desired type.
7138 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7140 IN_DECL, if non-NULL, is the template declaration we are trying to
7141 instantiate.
7143 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7144 the class we are looking up.
7146 Issue error and warning messages under control of COMPLAIN.
7148 If the template class is really a local class in a template
7149 function, then the FUNCTION_CONTEXT is the function in which it is
7150 being instantiated.
7152 ??? Note that this function is currently called *twice* for each
7153 template-id: the first time from the parser, while creating the
7154 incomplete type (finish_template_type), and the second type during the
7155 real instantiation (instantiate_template_class). This is surely something
7156 that we want to avoid. It also causes some problems with argument
7157 coercion (see convert_nontype_argument for more information on this). */
7159 static tree
7162 {
7164 tree t;
7167 spec_entry elt;
7168 hashval_t hash;
7171 {
7175 else
7176 {
7183 }
7186 }
7188 {
7191 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7192 an implicit typename for the second A. Deal with it. */
7197 {
7200 }
7201 }
7204 {
7207 }
7211 {
7215 }
7217 {
7220 }
7222 /* Issue an error message if we didn't find a template. */
7224 {
7228 }
7231 /* Make sure it's a user visible template, if it was named by
7232 the user. */
7235 {
7237 {
7241 }
7243 }
7247 /* An alias that just changes the name of a template is equivalent to the
7248 other template, so if any of the arguments are pack expansions, strip
7249 the alias to avoid problems with a pack expansion passed to a non-pack
7250 alias template parameter (DR 1430). */
7255 {
7256 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7257 template arguments */
7259 tree parm;
7260 tree arglist2;
7261 tree outer;
7265 /* Consider an example where a template template parameter declared as
7267 template <class T, class U = std::allocator<T> > class TT
7269 The template parameter level of T and U are one level larger than
7270 of TT. To proper process the default argument of U, say when an
7271 instantiation `TT<int>' is seen, we need to build the full
7272 arguments containing {int} as the innermost level. Outer levels,
7273 available when not appearing as default template argument, can be
7274 obtained from the arguments of the enclosing template.
7276 Suppose that TT is later substituted with std::vector. The above
7277 instantiation is `TT<int, std::allocator<T> >' with TT at
7278 level 1, and T at level 2, while the template arguments at level 1
7279 becomes {std::vector} and the inner level 2 is {int}. */
7285 /* This is an argument of the current template, so we haven't set
7286 DECL_CONTEXT yet. */
7293 complain,
7303 }
7304 else
7305 {
7307 tree gen_tmpl;
7308 tree type_decl;
7316 /* An error occurred while building the template TEMPL, and a
7317 diagnostic has most certainly been emitted for that
7318 already. Let's propagate that error. */
7327 {
7328 /* We've been given an incomplete set of template arguments.
7329 For example, given:
7331 template <class T> struct S1 {
7332 template <class U> struct S2 {};
7333 template <class U> struct S2<U*> {};
7334 };
7336 we will be called with an ARGLIST of `U*', but the
7337 TEMPLATE will be `template <class T> template
7338 <class U> struct S1<T>::S2'. We must fill in the missing
7339 arguments. */
7340 arglist
7342 arglist);
7344 }
7346 /* Now we should have enough arguments. */
7349 /* From here on, we're only interested in the most general
7350 template. */
7352 /* Calculate the BOUND_ARGS. These will be the args that are
7353 actually tsubst'd into the definition to create the
7354 instantiation. */
7356 {
7357 /* We have multiple levels of arguments to coerce, at once. */
7367 {
7368 tree a;
7372 complain,
7375 else
7376 /* Outer levels should have already been coerced. */
7379 /* Don't process further if one of the levels fails. */
7381 {
7382 /* Restore the ARGLIST to its full size. */
7385 }
7389 /* We temporarily reduce the length of the ARGLIST so
7390 that coerce_template_parms will see only the arguments
7391 corresponding to the template parameters it is
7392 examining. */
7394 }
7396 /* Restore the ARGLIST to its full size. */
7400 }
7401 else
7402 arglist
7405 gen_tmpl,
7406 complain,
7411 /* We were unable to bind the arguments. */
7414 /* In the scope of a template class, explicit references to the
7415 template class refer to the type of the template, not any
7416 instantiation of it. For example, in:
7418 template <class T> class C { void f(C<T>); }
7420 the `C<T>' is just the same as `C'. Outside of the
7421 class, however, such a reference is an instantiation. */
7425 /* comp_template_args is expensive, check it last. */
7427 arglist))
7430 /* If we already have this specialization, return it. */
7442 /* If the deduced arguments are invalid, then the binding
7443 failed. */
7447 complain))
7454 {
7459 }
7469 /* Create the type. */
7471 {
7472 /* The user referred to a specialization of an alias
7473 template represented by GEN_TMPL.
7475 [temp.alias]/2 says:
7477 When a template-id refers to the specialization of an
7478 alias template, it is equivalent to the associated
7479 type obtained by substitution of its
7480 template-arguments for the template-parameters in the
7481 type-id of the alias template. */
7484 /* Note that the call above (by indirectly calling
7485 register_specialization in tsubst_decl) registers the
7486 TYPE_DECL representing the specialization of the alias
7487 template. So next time someone substitutes ARGLIST for
7488 the template parms into the alias template (GEN_TMPL),
7489 she'll get that TYPE_DECL back. */
7493 }
7495 {
7497 {
7503 }
7504 else
7505 {
7506 /* We don't want to call start_enum for this type, since
7507 the values for the enumeration constants may involve
7508 template parameters. And, no one should be interested
7509 in the enumeration constants for such a type. */
7512 }
7516 }
7518 {
7525 /* A local class. Make sure the decl gets registered properly. */
7530 /* This instantiation is another name for the primary
7531 template type. Set the TYPE_CANONICAL field
7532 appropriately. */
7535 /* Some of the template arguments require structural
7536 equality testing, so this template class requires
7537 structural equality testing. */
7539 }
7540 else
7543 /* If we called start_enum or pushtag above, this information
7544 will already be set up. */
7546 {
7553 }
7554 else
7558 {
7564 {
7567 }
7568 }
7570 /* Let's consider the explicit specialization of a member
7571 of a class template specialization that is implicitely instantiated,
7572 e.g.:
7573 template<class T>
7574 struct S
7575 {
7576 template<class U> struct M {}; //#0
7577 };
7579 template<>
7580 template<>
7581 struct S<int>::M<char> //#1
7582 {
7583 int i;
7584 };
7585 [temp.expl.spec]/4 says this is valid.
7587 In this case, when we write:
7588 S<int>::M<char> m;
7590 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7591 the one of #0.
7593 When we encounter #1, we want to store the partial instantiation
7594 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7596 For all cases other than this "explicit specialization of member of a
7597 class template", we just want to store the most general template into
7598 the CLASSTYPE_TI_TEMPLATE of M.
7600 This case of "explicit specialization of member of a class template"
7601 only happens when:
7602 1/ the enclosing class is an instantiation of, and therefore not
7603 the same as, the context of the most general template, and
7604 2/ we aren't looking at the partial instantiation itself, i.e.
7605 the innermost arguments are not the same as the innermost parms of
7606 the most general template.
7608 So it's only when 1/ and 2/ happens that we want to use the partial
7609 instantiation of the member template in lieu of its most general
7610 template. */
7614 /* the enclosing class must be an instantiation... */
7617 {
7618 tree partial_inst_args;
7621 partial_inst_args =
7627 use_partial_inst_tmpl =
7628 /*...and we must not be looking at the partial instantiation
7629 itself. */
7631 partial_inst_args);
7632 }
7635 /* This case is easy; there are no member templates involved. */
7637 else
7638 {
7639 /* This is a full instantiation of a member template. Find
7640 the partial instantiation of which this is an instance. */
7642 /* Temporarily reduce by one the number of levels in the ARGLIST
7643 so as to avoid comparing the last set of arguments. */
7647 /* FOUND is either a proper class type, or an alias
7648 template specialization. In the later case, it's a
7649 TYPE_DECL, resulting from the substituting of arguments
7650 for parameters in the TYPE_DECL of the alias template
7651 done earlier. So be careful while getting the template
7652 of FOUND. */
7656 }
7667 /* Note this use of the partial instantiation so we can check it
7668 later in maybe_process_partial_specialization. */
7675 /* Now that the type has been registered on the instantiations
7676 list, we set up the enumerators. Because the enumeration
7677 constants may involve the enumeration type itself, we make
7678 sure to register the type first, and then create the
7679 constants. That way, doing tsubst_expr for the enumeration
7680 constants won't result in recursive calls here; we'll find
7681 the instantiation and exit above. */
7685 /* If the type makes use of template parameters, the
7686 code that generates debugging information will crash. */
7689 /* Possibly limit visibility based on template args. */
7694 }
7695 }
7697 /* Wrapper for lookup_template_class_1. */
7699 tree
7702 {
7703 tree ret;
7709 }
7710 \f
7711 struct pair_fn_data
7712 {
7713 tree_fn_t fn;
7715 /* True when we should also visit template parameters that occur in
7716 non-deduced contexts. */
7719 };
7721 /* Called from for_each_template_parm via walk_tree. */
7723 static tree
7725 {
7738 {
7742 /* Fall through. */
7765 /* Since we're not going to walk subtrees, we have to do this
7766 explicitly here. */
7770 /* Fall through. */
7773 /* Check the return type. */
7778 /* Check the parameter types. Since default arguments are not
7779 instantiated until they are needed, the TYPE_ARG_TYPES may
7780 contain expressions that involve template parameters. But,
7781 no-one should be looking at them yet. And, once they're
7782 instantiated, they don't contain template parameters, so
7783 there's no point in looking at them then, either. */
7784 {
7785 tree parm;
7792 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7793 want walk_tree walking into them itself. */
7795 }
7813 /* Fall through. */
7829 /* Record template parameters such as `T' inside `TT<T>'. */
7833 /* Fall through. */
7845 /* A template template parameter is encountered. */
7851 /* Already substituted template template parameter */
7874 /* If there's no type, then this thing must be some expression
7875 involving template parameters. */
7897 }
7899 /* We didn't find any template parameters we liked. */
7901 }
7903 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7904 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7905 call FN with the parameter and the DATA.
7906 If FN returns nonzero, the iteration is terminated, and
7907 for_each_template_parm returns 1. Otherwise, the iteration
7908 continues. If FN never returns a nonzero value, the value
7909 returned by for_each_template_parm is 0. If FN is NULL, it is
7910 considered to be the function which always returns 1.
7912 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7913 parameters that occur in non-deduced contexts. When false, only
7914 visits those template parameters that can be deduced. */
7916 static int
7920 {
7924 /* Set up. */
7929 /* Walk the tree. (Conceptually, we would like to walk without
7930 duplicates, but for_each_template_parm_r recursively calls
7931 for_each_template_parm, so we would need to reorganize a fair
7932 bit to use walk_tree_without_duplicates, so we keep our own
7933 visited list.) */
7936 else
7939 for_each_template_parm_r,
7943 /* Clean up. */
7945 {
7948 }
7951 }
7953 /* Returns true if T depends on any template parameter. */
7955 int
7957 {
7984 else
7985 {
7988 }
7993 }
7995 /* Returns true iff current_function_decl is an incompletely instantiated
7996 template. Useful instead of processing_template_decl because the latter
7997 is set to 0 during fold_non_dependent_expr. */
7999 bool
8001 {
8010 }
8012 /* Returns true if T depends on any template parameter with level LEVEL. */
8014 int
8016 {
8019 }
8021 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8022 ill-formed translation unit, i.e. a variable or function that isn't
8023 usable in a constant expression. */
8027 {
8031 }
8033 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8034 neglectable and instantiated from within an erroneous instantiation. */
8036 static bool
8038 {
8049 }
8057 /* We're starting to instantiate D; record the template instantiation context
8058 for diagnostics and to restore it later. */
8060 int
8062 {
8066 {
8072 else
8080 }
8082 /* If the current instantiation caused problems, don't let it instantiate
8083 anything else. Do allow deduction substitution and decls usable in
8084 constant expressions. */
8101 }
8103 /* We're done instantiating this template; return to the instantiation
8104 context. */
8106 void
8108 {
8109 /* Restore the filename and line number stashed away when we started
8110 this instantiation. */
8114 }
8116 /* We're instantiating a deferred template; restore the template
8117 instantiation context in which the instantiation was requested, which
8118 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8120 static tree
8122 {
8134 }
8136 /* Returns the TINST_LEVEL which gives the original instantiation
8137 context. */
8141 {
8147 }
8149 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8150 vector of template arguments, as for tsubst.
8152 Returns an appropriate tsubst'd friend declaration. */
8154 static tree
8156 {
8157 tree new_friend;
8162 /* This was a friend declared with an explicit template
8163 argument list, e.g.:
8165 friend void f<>(T);
8167 to indicate that f was a template instantiation, not a new
8168 function declaration. Now, we have to figure out what
8169 instantiation of what template. */
8170 {
8172 tree new_args;
8173 tree tmpl;
8176 /* Friend functions are looked up in the containing namespace scope.
8177 We must enter that scope, to avoid finding member functions of the
8178 current class with same name. */
8193 tsk_none);
8195 }
8199 /* The NEW_FRIEND will look like an instantiation, to the
8200 compiler, but is not an instantiation from the point of view of
8201 the language. For example, we might have had:
8203 template <class T> struct S {
8204 template <class U> friend void f(T, U);
8205 };
8207 Then, in S<int>, template <class U> void f(int, U) is not an
8208 instantiation of anything. */
8214 {
8218 }
8220 /* The mangled name for the NEW_FRIEND is incorrect. The function
8221 is not a template instantiation and should not be mangled like
8222 one. Therefore, we forget the mangling here; we'll recompute it
8223 later if we need it. */
8225 {
8228 }
8231 {
8232 tree old_decl;
8233 tree new_friend_template_info;
8234 tree new_friend_result_template_info;
8235 tree ns;
8238 /* We must save some information from NEW_FRIEND before calling
8239 duplicate decls since that function will free NEW_FRIEND if
8240 possible. */
8242 new_friend_is_defn =
8247 {
8248 /* This declaration is a `primary' template. */
8251 new_friend_result_template_info
8253 }
8254 else
8257 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8261 /* Inside pushdecl_namespace_level, we will push into the
8262 current namespace. However, the friend function should go
8263 into the namespace of the template. */
8273 {
8274 /* This new friend declaration matched an existing
8275 declaration. For example, given:
8277 template <class T> void f(T);
8278 template <class U> class C {
8279 template <class T> friend void f(T) {}
8280 };
8282 the friend declaration actually provides the definition
8283 of `f', once C has been instantiated for some type. So,
8284 old_decl will be the out-of-class template declaration,
8285 while new_friend is the in-class definition.
8287 But, if `f' was called before this point, the
8288 instantiation of `f' will have DECL_TI_ARGS corresponding
8289 to `T' but not to `U', references to which might appear
8290 in the definition of `f'. Previously, the most general
8291 template for an instantiation of `f' was the out-of-class
8292 version; now it is the in-class version. Therefore, we
8293 run through all specialization of `f', adding to their
8294 DECL_TI_ARGS appropriately. In particular, they need a
8295 new set of outer arguments, corresponding to the
8296 arguments for this class instantiation.
8298 The same situation can arise with something like this:
8300 friend void f(int);
8301 template <class T> class C {
8302 friend void f(T) {}
8303 };
8305 when `C<int>' is instantiated. Now, `f(int)' is defined
8306 in the class. */
8309 /* On the other hand, if the in-class declaration does
8310 *not* provide a definition, then we don't want to alter
8311 existing definitions. We can just leave everything
8312 alone. */
8313 ;
8314 else
8315 {
8319 /* Overwrite whatever template info was there before, if
8320 any, with the new template information pertaining to
8321 the declaration. */
8325 {
8326 /* We should have called reregister_specialization in
8327 duplicate_decls. */
8332 /* Instantiate it if the global has already been used. */
8336 }
8337 else
8338 {
8339 tree t;
8341 /* Indicate that the old function template is a partial
8342 instantiation. */
8350 /* Reassign any specializations already in the hash table
8351 to the new more general template, and add the
8352 additional template args. */
8356 {
8358 spec_entry elt;
8370 register_specialization
8373 }
8375 }
8376 }
8378 /* The information from NEW_FRIEND has been merged into OLD_DECL
8379 by duplicate_decls. */
8381 }
8382 }
8383 else
8384 {
8388 /* In the code
8389 template <class T> class C {
8390 template <class U> friend void C1<U>::f (); // case 1
8391 friend void C2<T>::f (); // case 2
8392 };
8393 we only need to make sure CONTEXT is a complete type for
8394 case 2. To distinguish between the two cases, we note that
8395 CONTEXT of case 1 remains dependent type after tsubst while
8396 this isn't true for case 2. */
8406 {
8407 /* Check to see that the declaration is really present, and,
8408 possibly obtain an improved declaration. */
8414 }
8415 }
8418 }
8420 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8421 template arguments, as for tsubst.
8423 Returns an appropriate tsubst'd friend type or error_mark_node on
8424 failure. */
8426 static tree
8428 {
8429 tree friend_type;
8430 tree tmpl;
8431 tree context;
8434 {
8437 }
8442 {
8445 else
8447 }
8449 /* Look for a class template declaration. We look for hidden names
8450 because two friend declarations of the same template are the
8451 same. For example, in:
8453 struct A {
8454 template <typename> friend class F;
8455 };
8456 template <typename> struct B {
8457 template <typename> friend class F;
8458 };
8460 both F templates are the same. */
8464 /* But, if we don't find one, it might be because we're in a
8465 situation like this:
8467 template <class T>
8468 struct S {
8469 template <class U>
8470 friend struct S;
8471 };
8473 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8474 for `S<int>', not the TEMPLATE_DECL. */
8476 {
8479 }
8482 {
8483 /* The friend template has already been declared. Just
8484 check to see that the declarations match, and install any new
8485 default parameters. We must tsubst the default parameters,
8486 of course. We only need the innermost template parameters
8487 because that is all that redeclare_class_template will look
8488 at. */
8491 {
8492 tree parms;
8493 location_t saved_input_location;
8502 }
8505 }
8506 else
8507 {
8508 /* The friend template has not already been declared. In this
8509 case, the instantiation of the template class will cause the
8510 injection of this template into the global scope. */
8515 /* The new TMPL is not an instantiation of anything, so we
8516 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8517 the new type because that is supposed to be the corresponding
8518 template decl, i.e., TMPL. */
8525 /* Inject this template into the global scope. */
8527 }
8530 {
8533 else
8535 }
8538 }
8540 /* Returns zero if TYPE cannot be completed later due to circularity.
8541 Otherwise returns one. */
8543 static int
8545 {
8555 else
8557 }
8561 /* Apply any attributes which had to be deferred until instantiation
8562 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8563 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8565 static void
8568 {
8570 tree t;
8575 {
8579 }
8582 {
8586 }
8587 else
8591 {
8596 {
8599 {
8606 {
8613 clauses
8617 else
8619 }
8620 /* If the first attribute argument is an identifier, don't
8621 pass it through tsubst. Attributes like mode, format,
8622 cleanup and several target specific attributes expect it
8623 unmodified. */
8625 {
8626 tree chain
8628 in_decl,
8633 chain);
8634 }
8635 else
8641 }
8642 else
8644 }
8647 }
8648 }
8650 /* Perform (or defer) access check for typedefs that were referenced
8651 from within the template TMPL code.
8652 This is a subroutine of instantiate_decl and instantiate_class_template.
8653 TMPL is the template to consider and TARGS is the list of arguments of
8654 that template. */
8656 static void
8658 {
8659 location_t saved_location;
8670 {
8682 /* Make access check error messages point to the location
8683 of the use of the typedef. */
8687 tf_warning_or_error);
8688 }
8690 }
8692 static tree
8694 {
8696 tree typedecl;
8697 tree pbinfo;
8698 tree base_list;
8700 tree fn_context;
8709 /* Figure out which template is being instantiated. */
8713 /* Determine what specialization of the original template to
8714 instantiate. */
8717 {
8720 }
8722 {
8723 /* This TYPE is actually an instantiation of a partial
8724 specialization. We replace the innermost set of ARGS with
8725 the arguments appropriate for substitution. For example,
8726 given:
8728 template <class T> struct S {};
8729 template <class T> struct S<T*> {};
8731 and supposing that we are instantiating S<int*>, ARGS will
8732 presently be {int*} -- but we need {int}. */
8735 }
8736 else
8737 {
8740 }
8742 /* If the template we're instantiating is incomplete, then clearly
8743 there's nothing we can do. */
8747 /* If we've recursively instantiated too many templates, stop. */
8751 /* Now we're really doing the instantiation. Mark the type as in
8752 the process of being defined. */
8755 /* We may be in the middle of deferred access check. Disable
8756 it now. */
8762 /* Use #pragma pack from the template context. */
8768 /* Set the input location to the most specialized template definition.
8769 This is needed if tsubsting causes an error. */
8781 {
8784 /* Adjust visibility for template arguments. */
8786 }
8792 /* We should never instantiate a nested class before its enclosing
8793 class; we need to look up the nested class by name before we can
8794 instantiate it, and that lookup should instantiate the enclosing
8795 class. */
8801 {
8802 tree pbase_binfo;
8803 tree pushed_scope;
8806 /* We must enter the scope containing the type, as that is where
8807 the accessibility of types named in dependent bases are
8808 looked up from. */
8811 /* Substitute into each of the bases to determine the actual
8812 basetypes. */
8814 {
8815 tree base;
8821 {
8822 expanded_bases =
8829 }
8832 {
8834 /* Extract the already-expanded base class. */
8836 else
8837 /* Substitute to figure out the base class. */
8839 NULL_TREE);
8847 }
8848 }
8850 /* The list is now in reverse order; correct that. */
8855 }
8856 /* Now call xref_basetypes to set up all the base-class
8857 information. */
8865 /* Now that our base classes are set up, enter the scope of the
8866 class, so that name lookups into base classes, etc. will work
8867 correctly. This is precisely analogous to what we do in
8868 begin_class_definition when defining an ordinary non-template
8869 class, except we also need to push the enclosing classes. */
8872 /* Now members are processed in the order of declaration. */
8875 {
8879 {
8881 {
8882 /* Build new CLASSTYPE_NESTED_UTDS. */
8884 tree newtag;
8890 /* If the member is a class template, then -- even after
8891 substitution -- there may be dependent types in the
8892 template argument list for the class. We increment
8893 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8894 that function will assume that no types are dependent
8895 when outside of a template. */
8905 {
8909 /* Unfortunately, lookup_template_class sets
8910 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8911 instantiation (i.e., for the type of a member
8912 template class nested within a template class.)
8913 This behavior is required for
8914 maybe_process_partial_specialization to work
8915 correctly, but is not accurate in this case;
8916 the TAG is not an instantiation of anything.
8917 (The corresponding TEMPLATE_DECL is an
8918 instantiation, but the TYPE is not.) */
8921 /* Now, we call pushtag to put this NEWTAG into the scope of
8922 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8923 pushtag calling push_template_decl. We don't have to do
8924 this for enums because it will already have been done in
8925 tsubst_enum. */
8929 }
8930 }
8932 {
8933 /* Build new TYPE_METHODS. */
8934 tree r;
8943 /* Instantiate members marked with attribute used. */
8949 }
8950 else
8951 {
8952 /* Build new TYPE_FIELDS. */
8954 {
8955 tree condition;
8958 condition =
8968 }
8970 {
8971 tree r;
8975 /* The file and line for this declaration, to
8976 assist in error message reporting. Since we
8977 called push_tinst_level above, we don't need to
8978 restore these. */
8988 {
8989 /* A capture pack became multiple fields. */
8992 }
8995 {
8999 {
9000 /* In [temp.inst]:
9002 [t]he initialization (and any associated
9003 side-effects) of a static data member does
9004 not occur unless the static data member is
9005 itself used in a way that requires the
9006 definition of the static data member to
9007 exist.
9009 Therefore, we do not substitute into the
9010 initialized for the static data member here. */
9011 finish_static_data_member_decl
9017 /* Instantiate members marked with attribute used. */
9020 }
9022 {
9023 /* Determine whether R has a valid type and can be
9024 completed later. If R is invalid, then its type
9025 is replaced by error_mark_node. */
9031 {
9034 }
9035 }
9037 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9038 such a thing will already have been added to the field
9039 list by tsubst_enum in finish_member_declaration in the
9040 CLASSTYPE_NESTED_UTDS case above. */
9044 {
9047 }
9048 }
9049 }
9050 }
9051 }
9052 else
9053 {
9056 {
9057 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9063 {
9064 /* template <class T> friend class C; */
9067 }
9069 {
9070 /* template <class T> friend class C::D; */
9076 }
9079 {
9080 /* This could be either
9082 friend class T::C;
9084 when dependent_type_p is false or
9086 template <class U> friend class T::C;
9088 otherwise. */
9091 /* Bump processing_template_decl for correct
9092 dependent_type_p calculation. */
9097 }
9100 {
9101 /* friend class C;
9103 where C hasn't been declared yet. Let's lookup name
9104 from namespace scope directly, bypassing any name that
9105 come from dependent base class. */
9108 /* The call to xref_tag_from_type does injection for friend
9109 classes. */
9111 friend_type =
9115 }
9117 /* friend class C<T>; */
9120 /* Otherwise it's
9122 friend class C;
9124 where C is already declared or
9126 friend class C<int>;
9128 We don't have to do anything in these cases. */
9131 /* Trick make_friend_class into realizing that the friend
9132 we're adding is a template, not an ordinary class. It's
9133 important that we use make_friend_class since it will
9134 perform some error-checking and output cross-reference
9135 information. */
9143 }
9144 else
9145 {
9146 /* Build new DECL_FRIENDLIST. */
9147 tree r;
9149 /* The file and line for this declaration, to
9150 assist in error message reporting. Since we
9151 called push_tinst_level above, we don't need to
9152 restore these. */
9156 {
9159 }
9164 {
9167 }
9168 }
9169 }
9170 }
9173 {
9176 {
9181 /* We need to instantiate the capture list from the template
9182 after we've instantiated the closure members, but before we
9183 consider adding the conversion op. Also keep any captures
9184 that may have been added during instantiation of the op(). */
9186 tree tmpl_cap
9195 }
9196 else
9198 }
9200 /* Set the file and line number information to whatever is given for
9201 the class itself. This puts error messages involving generated
9202 implicit functions at a predictable point, and the same point
9203 that would be used for non-template classes. */
9210 /* We don't instantiate default arguments for member functions. 14.7.1:
9212 The implicit instantiation of a class template specialization causes
9213 the implicit instantiation of the declarations, but not of the
9214 definitions or default arguments, of the class member functions,
9215 member classes, static data members and member templates.... */
9217 /* Some typedefs referenced from within the template code need to be access
9218 checked at template instantiation time, i.e now. These types were
9219 added to the template at parsing time. Let's get those and perform
9220 the access checks then. */
9230 /* The vtable for a template class can be emitted in any translation
9231 unit in which the class is instantiated. When there is no key
9232 method, however, finish_struct_1 will already have added TYPE to
9233 the keyed_classes list. */
9238 }
9240 /* Wrapper for instantiate_class_template_1. */
9242 tree
9244 {
9245 tree ret;
9250 }
9252 static tree
9254 {
9255 tree r;
9261 else
9262 {
9269 /* Preserve the raw-reference nature of T. */
9273 }
9275 }
9277 /* Given a function parameter pack TMPL_PARM and some function parameters
9278 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9279 and set *SPEC_P to point at the next point in the list. */
9281 static tree
9283 {
9284 /* Collect all of the extra "packed" parameters into an
9285 argument pack. */
9286 tree parmvec;
9287 tree parmtypevec;
9298 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9303 {
9306 }
9308 /* Build the argument packs. */
9315 }
9317 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9318 NONTYPE_ARGUMENT_PACK. */
9320 static tree
9322 {
9324 }
9326 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9327 pack expansion. */
9329 static bool
9331 {
9336 }
9339 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9341 static tree
9343 {
9350 }
9352 /* This is a subroutine of tsubst_pack_expansion.
9354 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9355 mechanism to store the (non complete list of) arguments of the
9356 substitution and return a non substituted pack expansion, in order
9357 to wait for when we have enough arguments to really perform the
9358 substitution. */
9360 static bool
9364 {
9365 /* If one pack has an expansion and another pack has a normal
9366 argument or if one pack has an empty argument and an another
9367 one hasn't then tsubst_pack_expansion cannot perform the
9368 substitution and need to fall back on the
9369 PACK_EXPANSION_EXTRA mechanism. */
9377 {
9380 parm_pack;
9382 {
9387 else
9389 }
9393 }
9395 }
9397 /* [temp.variadic]/6 says that:
9399 The instantiation of a pack expansion [...]
9400 produces a list E1,E2, ..., En, where N is the number of elements
9401 in the pack expansion parameters.
9403 This subroutine of tsubst_pack_expansion produces one of these Ei.
9405 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9406 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9407 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9408 INDEX is the index 'i' of the element Ei to produce. ARGS,
9409 COMPLAIN, and IN_DECL are the same parameters as for the
9410 tsubst_pack_expansion function.
9412 The function returns the resulting Ei upon successful completion,
9413 or error_mark_node.
9415 Note that this function possibly modifies the ARGS parameter, so
9416 it's the responsibility of the caller to restore it. */
9418 static tree
9420 tree parm_packs,
9422 tree args /* This parm gets
9424 tsubst_flags_t complain,
9425 tree in_decl)
9426 {
9427 tree t;
9430 /* For each parameter pack, change the substitution of the parameter
9431 pack to the ith argument in its argument pack, then expand the
9432 pattern. */
9434 {
9439 ith_elem_is_expansion |=
9442 /* Select the Ith argument from the pack. */
9445 {
9447 {
9451 }
9452 else
9454 }
9455 else
9456 {
9461 {
9463 /* Update the corresponding argument. */
9465 }
9466 else
9467 /* Re-use the ARGUMENT_PACK_SELECT. */
9469 }
9471 }
9473 /* Substitute into the PATTERN with the (possibly altered)
9474 arguments. */
9478 else
9481 /* If the Ith argument pack element is a pack expansion, then
9482 the Ith element resulting from the substituting is going to
9483 be a pack expansion as well. */
9488 }
9490 /* Substitute ARGS into T, which is an pack expansion
9491 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9492 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9493 (if only a partial substitution could be performed) or
9494 ERROR_MARK_NODE if there was an error. */
9495 tree
9497 tree in_decl)
9498 {
9499 tree pattern;
9503 tree result;
9511 /* Add in any args remembered from an earlier partial instantiation. */
9516 /* Determine the argument packs that will instantiate the parameter
9517 packs used in the expansion expression. While we're at it,
9518 compute the number of arguments to be expanded and make sure it
9519 is consistent. */
9522 {
9529 {
9533 else
9536 }
9538 {
9541 else
9542 {
9543 /* We can't rely on local_specializations for a parameter
9544 name used later in a function declaration (such as in a
9545 late-specified return type). Even if it exists, it might
9546 have the wrong value for a recursive call. Just make a
9547 dummy decl, since it's only used for its type. */
9550 /* Partial instantiation of the parm_pack, we can't build
9551 up an argument pack yet. */
9553 else
9556 }
9557 }
9560 else
9561 {
9567 }
9574 /* This can only happen if we forget to expand an argument
9575 pack somewhere else. Just return an error, silently. */
9576 {
9580 }
9583 {
9587 /* Don't bother trying to do a partial substitution with
9588 incomplete packs; we'll try again after deduction. */
9595 {
9601 pattern);
9602 else
9605 pattern);
9607 }
9609 /* Keep track of the parameter packs and their corresponding
9610 argument packs. */
9613 }
9614 else
9615 {
9616 /* We can't substitute for this parameter pack. We use a flag as
9617 well as the missing_level counter because function parameter
9618 packs don't have a level. */
9620 }
9621 }
9623 /* We cannot expand this expansion expression, because we don't have
9624 all of the argument packs we need. */
9626 {
9627 /* We got some full packs, but we can't substitute them in until we
9628 have values for all the packs. So remember these until then. */
9633 }
9635 {
9636 /* There were no real arguments, we're just replacing a parameter
9637 pack with another version of itself. Substitute into the
9638 pattern and return a PACK_EXPANSION_*. The caller will need to
9639 deal with that. */
9643 else
9647 }
9652 {
9653 /* We're in a late-specified return type, so create our own local
9654 specializations map; the current map is either NULL or (in the
9655 case of recursive unification) might have bindings that we don't
9656 want to use or alter. */
9659 }
9661 /* For each argument in each argument pack, substitute into the
9662 pattern. */
9665 {
9667 i,
9669 in_decl);
9672 {
9675 }
9676 }
9678 /* Update ARGS to restore the substitution from parameter packs to
9679 their argument packs. */
9681 {
9687 else
9688 {
9696 /* Update the corresponding argument. */
9700 else
9702 }
9703 }
9706 {
9709 }
9712 }
9714 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9715 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9716 parameter packs; all parms generated from a function parameter pack will
9717 have the same DECL_PARM_INDEX. */
9719 tree
9721 {
9723 tree patparm;
9726 {
9732 }
9733 else
9734 {
9739 }
9742 }
9744 /* Substitute ARGS into the vector or list of template arguments T. */
9746 static tree
9748 {
9760 {
9762 tree new_arg;
9767 {
9768 /* Substitute into an expansion expression. */
9772 /* Add to the expanded length adjustment the number of
9773 expanded arguments. We subtract one from this
9774 measurement, because the argument pack expression
9775 itself is already counted as 1 in
9776 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9777 the argument pack is empty. */
9779 }
9781 {
9782 /* Substitute into each of the arguments. */
9788 new_arg,
9802 }
9803 }
9804 else
9813 }
9818 /* Make space for the expanded arguments coming from template
9819 argument packs. */
9821 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9822 arguments for a member template.
9823 In that case each TREE_VEC in ORIG_T represents a level of template
9824 arguments, and ORIG_T won't carry any non defaulted argument count.
9825 It will rather be the nested TREE_VECs that will carry one.
9826 In other words, ORIG_T carries a non defaulted argument count only
9827 if it doesn't contain any nested TREE_VEC. */
9829 {
9833 }
9835 {
9839 {
9842 /* Now expand the template argument pack "in place". */
9845 }
9846 else
9847 {
9849 out++;
9850 }
9851 }
9854 }
9856 /* Return the result of substituting ARGS into the template parameters
9857 given by PARMS. If there are m levels of ARGS and m + n levels of
9858 PARMS, then the result will contain n levels of PARMS. For
9859 example, if PARMS is `template <class T> template <class U>
9860 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9861 result will be `template <int*, double, class V>'. */
9863 static tree
9865 {
9869 /* When substituting into a template, we must set
9870 PROCESSING_TEMPLATE_DECL as the template parameters may be
9871 dependent if they are based on one-another, and the dependency
9872 predicates are short-circuit outside of templates. */
9879 {
9880 tree new_vec =
9885 {
9886 tree tuple;
9898 }
9904 }
9909 }
9911 /* Return the result of substituting ARGS into one template parameter
9912 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9913 parameter and which TREE_PURPOSE is the default argument of the
9914 template parameter. */
9916 static tree
9918 {
9939 }
9941 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9942 type T. If T is not an aggregate or enumeration type, it is
9943 handled as if by tsubst. IN_DECL is as for tsubst. If
9944 ENTERING_SCOPE is nonzero, T is the context for a template which
9945 we are presently tsubst'ing. Return the substituted value. */
9947 static tree
9949 tree args,
9950 tsubst_flags_t complain,
9951 tree in_decl,
9953 {
9958 {
9963 /* Else fall through. */
9967 {
9968 tree argvec;
9969 tree context;
9970 tree r;
9974 /* In "sizeof(X<I>)" we need to evaluate "I". */
9980 /* First, determine the context for the type we are looking
9981 up. */
9984 {
9987 /* If context is a nested class inside a class template,
9988 it may still need to be instantiated (c++/33959). */
9990 }
9992 /* Then, figure out what arguments are appropriate for the
9993 type we are trying to find. For example, given:
9995 template <class T> struct S;
9996 template <class T, class U> void f(T, U) { S<U> su; }
9998 and supposing that we are instantiating f<int, double>,
9999 then our ARGS will be {int, double}, but, when looking up
10000 S we only want {double}. */
10005 else
10006 {
10010 }
10016 }
10017 else
10018 /* This is not a template type, so there's nothing to do. */
10023 }
10024 }
10026 /* Substitute into the default argument ARG (a default argument for
10027 FN), which has the indicated TYPE. */
10029 tree
10031 {
10036 /* This can happen in invalid code. */
10040 /* This default argument came from a template. Instantiate the
10041 default argument here, not in tsubst. In the case of
10042 something like:
10044 template <class T>
10045 struct S {
10046 static T t();
10047 void f(T = t());
10048 };
10050 we must be careful to do name lookup in the scope of S<T>,
10051 rather than in the current class. */
10053 /* The "this" pointer is not valid in a default argument. */
10055 {
10060 }
10063 /* The default argument expression may cause implicitly defined
10064 member functions to be synthesized, which will result in garbage
10065 collection. We must treat this situation as if we were within
10066 the body of function so as to avoid collecting live data on the
10067 stack. */
10075 /* Restore the "this" pointer. */
10077 {
10080 }
10087 /* Make sure the default argument is reasonable. */
10093 }
10095 /* Substitute into all the default arguments for FN. */
10097 static void
10099 {
10100 tree arg;
10101 tree tmpl_args;
10105 /* If this function is not yet instantiated, we certainly don't need
10106 its default arguments. */
10109 /* Don't do this again for clones. */
10114 arg;
10120 complain);
10121 }
10123 /* Substitute the ARGS into the T, which is a _DECL. Return the
10124 result of the substitution. Issue error and warning messages under
10125 control of COMPLAIN. */
10127 static tree
10129 {
10130 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10131 location_t saved_loc;
10136 /* Set the filename and linenumber to improve error-reporting. */
10141 {
10143 {
10144 /* We can get here when processing a member function template,
10145 member class template, or template template parameter. */
10147 tree spec;
10148 tree tmpl_args;
10149 tree full_args;
10152 {
10153 /* Template template parameter is treated here. */
10157 /* If we get a real template back, return it. This can happen in
10158 the context of most_specialized_class. */
10170 complain);
10173 }
10175 /* We might already have an instance of this template.
10176 The ARGS are for the surrounding class type, so the
10177 full args contain the tsubst'd args for the context,
10178 plus the innermost args from the template decl. */
10182 /* Because this is a template, the arguments will still be
10183 dependent, even after substitution. If
10184 PROCESSING_TEMPLATE_DECL is not set, the dependency
10185 predicates will short-circuit. */
10193 /* If this is a default template template argument,
10194 tsubst might not have changed anything. */
10201 {
10204 }
10206 /* Make a new template decl. It will be similar to the
10207 original, but will record the current template arguments.
10208 We also create a new function declaration, which is just
10209 like the old one, but points to this new template, rather
10210 than the old one. */
10219 {
10220 tree new_type;
10228 /* For a partial specialization, we need to keep pointing to
10229 the primary template. */
10235 }
10236 else
10237 {
10238 tree new_decl;
10250 }
10256 /* The template parameters for this new template are all the
10257 template parameters for the old template, except the
10258 outermost level of parameters. */
10261 complain);
10267 /* Record this non-type partial instantiation. */
10271 }
10275 {
10276 tree ctx;
10279 tree gen_tmpl;
10280 tree type;
10285 /* Nobody should be tsubst'ing into non-template functions. */
10289 {
10290 tree spec;
10293 /* If T is not dependent, just return it. We have to
10294 increment PROCESSING_TEMPLATE_DECL because
10295 value_dependent_expression_p assumes that nothing is
10296 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10303 /* Calculate the most general template of which R is a
10304 specialization, and the complete set of arguments used to
10305 specialize R. */
10308 (DECL_TEMPLATE_RESULT
10314 /* Check to see if we already have this specialization. */
10319 {
10322 }
10324 /* We can see more levels of arguments than parameters if
10325 there was a specialization of a member template, like
10326 this:
10328 template <class T> struct S { template <class U> void f(); }
10329 template <> template <class U> void S<int>::f(U);
10331 Here, we'll be substituting into the specialization,
10332 because that's where we can find the code we actually
10333 want to generate, but we'll have enough arguments for
10334 the most general template.
10336 We also deal with the peculiar case:
10338 template <class T> struct S {
10339 template <class U> friend void f();
10340 };
10341 template <class U> void f() {}
10342 template S<int>;
10343 template void f<double>();
10345 Here, the ARGS for the instantiation of will be {int,
10346 double}. But, we only need as many ARGS as there are
10347 levels of template parameters in CODE_PATTERN. We are
10348 careful not to get fooled into reducing the ARGS in
10349 situations like:
10351 template <class T> struct S { template <class U> void f(U); }
10352 template <class T> template <> void S<T>::f(int) {}
10354 which we can spot because the pattern will be a
10355 specialization in this case. */
10357 parms_depth =
10362 }
10363 else
10364 {
10365 /* This special case arises when we have something like this:
10367 template <class T> struct S {
10368 friend void f<int>(int, double);
10369 };
10371 Here, the DECL_TI_TEMPLATE for the friend declaration
10372 will be an IDENTIFIER_NODE. We are being called from
10373 tsubst_friend_function, and we want only to create a
10374 new decl (R) with appropriate types so that we can call
10375 determine_specialization. */
10377 }
10380 {
10383 else
10387 }
10388 else
10389 {
10392 }
10397 /* If we hit excessive deduction depth, the type is bogus even if
10398 it isn't error_mark_node, so don't build a decl. */
10402 /* We do NOT check for matching decls pushed separately at this
10403 point, as they may not represent instantiations of this
10404 template, and in any case are considered separate under the
10405 discrete model. */
10409 /* Clear out the mangled name and RTL for the instantiation. */
10412 /* Leave DECL_INITIAL set on deleted instantiations. */
10417 /* OpenMP UDRs have the only argument a reference to the declared
10418 type. We want to diagnose if the declared type is a reference,
10419 which is invalid, but as references to references are usually
10420 quietly merged, diagnose it here. */
10422 {
10423 tree argtype
10428 "reference type %qT in "
10432 argtype);
10433 }
10436 /* Type-conversion operator. Reconstruct the name, in
10437 case it's the name of one of the template's parameters. */
10447 /* If this is an instantiation of a function with internal
10448 linkage, we already know what object file linkage will be
10449 assigned to the instantiation. */
10458 /* We'll re-clone as appropriate in instantiate_template. */
10461 /* If we aren't complaining now, return on error before we register
10462 the specialization so that we'll complain eventually. */
10468 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10469 this in the special friend case mentioned above where
10470 GEN_TMPL is NULL. */
10472 {
10477 tree new_r
10480 /* We instantiated this while substituting into
10481 the type earlier (template/friend54.C). */
10484 /* We're not supposed to instantiate default arguments
10485 until they are called, for a template. But, for a
10486 declaration like:
10488 template <class T> void f ()
10489 { extern void g(int i = T()); }
10491 we should do the substitution when the template is
10492 instantiated. We handle the member function case in
10493 instantiate_class_template since the default arguments
10494 might refer to other members of the class. */
10499 }
10500 else
10503 /* Copy the list of befriending classes. */
10507 {
10511 in_decl);
10512 }
10515 {
10521 /* If this is an instantiation of a member template, clone it.
10522 If it isn't, that'll be handled by
10523 clone_constructors_and_destructors. */
10526 }
10537 /* Possibly limit visibility based on template args. */
10540 {
10544 }
10552 }
10556 {
10564 {
10565 /* If there is a local specialization that isn't a
10566 parameter pack, it means that we're doing a "simple"
10567 substitution from inside tsubst_pack_expansion. Just
10568 return the local specialization (which will be a single
10569 parm). */
10576 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10577 the parameters in this function parameter pack. */
10581 {
10584 /* Zero-length parameter packs are boring. Just substitute
10585 into the chain. */
10589 }
10590 else
10591 {
10592 /* All we did was update the type. Make a note of that. */
10595 }
10596 }
10598 /* Loop through all of the parameters we'll build. When T is
10599 a function parameter pack, LEN is the number of expanded
10600 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10603 {
10610 /* We're on the Ith parameter of the function parameter
10611 pack. */
10612 {
10613 /* Get the Ith type. */
10616 /* Rename the parameter to include the index. */
10619 }
10621 /* We're dealing with a normal parameter. */
10629 {
10632 else
10635 }
10645 /* Keep track of the first new parameter we
10646 generate. That's what will be returned to the
10647 caller. */
10651 /* Build a proper chain of parameters when substituting
10652 into a function parameter pack. */
10655 }
10657 /* If cp_unevaluated_operand is set, we're just looking for a
10658 single dummy parameter, so don't keep going. */
10663 /* FIRST_R contains the start of the chain we've built. */
10665 }
10669 {
10676 {
10677 /* This field is a lambda capture pack. Return a TREE_VEC of
10678 the expanded fields to instantiate_class_template_1 and
10679 store them in the specializations hash table as a
10680 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10684 {
10687 }
10688 else
10689 {
10690 /* All we did was update the type. Make a note of that. */
10693 }
10694 }
10697 {
10700 {
10704 }
10714 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10715 non-bit-fields DECL_INITIAL is a non-static data member
10716 initializer, which gets deferred instantiation. */
10722 {
10723 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10724 NSDMI in perform_member_init. Still set DECL_INITIAL
10725 so that we know there is one. */
10730 }
10731 /* We don't have to set DECL_CONTEXT here; it is set by
10732 finish_member_declaration. */
10740 }
10743 {
10751 }
10752 }
10756 /* We reach here only for member using decls. We also need to check
10757 uses_template_parms because DECL_DEPENDENT_P is not set for a
10758 using-declaration that designates a member of the current
10759 instantiation (c++/53549). */
10762 {
10769 else
10770 {
10773 }
10774 }
10775 else
10776 {
10779 }
10784 {
10787 tree spec;
10789 tree ctx;
10795 {
10796 /* If this is the canonical decl, we don't have to
10797 mess with instantiations, and often we can't (for
10798 typename, template type parms and such). Note that
10799 TYPE_NAME is not correct for the above test if
10800 we've copied the type for a typedef. */
10806 }
10808 /* Check to see if we already have the specialization we
10809 need. */
10812 {
10813 /* T is a static data member or namespace-scope entity.
10814 We have to substitute into namespace-scope variables
10815 (even though such entities are never templates) because
10816 of cases like:
10818 template <class T> void f() { extern T t; }
10820 where the entity referenced is not known until
10821 instantiation time. */
10825 {
10827 complain,
10829 /* If CTX is unchanged, then T is in fact the
10830 specialization we want. That situation occurs when
10831 referencing a static data member within in its own
10832 class. We can use pointer equality, rather than
10833 same_type_p, because DECL_CONTEXT is always
10834 canonical... */
10837 /* ... unless T is a member template; in which
10838 case our caller can be willing to create a
10839 specialization of that template represented
10840 by T. */
10844 }
10847 {
10855 }
10856 }
10857 else
10858 {
10859 /* A local variable. */
10861 /* Subsequent calls to pushdecl will fill this in. */
10864 }
10865 /* If we already have the specialization we need, there is
10866 nothing more to do. */
10868 {
10871 }
10873 /* Create a new node for the specialization we need. */
10876 {
10879 else
10886 }
10888 {
10889 /* Even if the original location is out of scope, the
10890 newly substituted one is not. */
10897 {
10898 /* It may seem that this case cannot occur, since:
10900 typedef void f();
10901 void g() { f x; }
10903 declares a function, not a variable. However:
10905 typedef void f();
10906 template <typename T> void g() { T t; }
10907 template void g<f>();
10909 is an attempt to declare a variable with function
10910 type. */
10912 /* R is not yet sufficiently initialized, so we
10913 just use its name. */
10916 }
10918 /* Wait until cp_finish_decl to set this again, to handle
10919 circular dependency (template/instantiate6.C). */
10924 {
10929 {
10932 }
10934 }
10935 }
10941 /* Clear out the mangled name and RTL for the instantiation. */
10945 /* The initializer must not be expanded until it is required;
10946 see [temp.inst]. */
10952 {
10953 /* Possibly limit visibility based on template args. */
10956 {
10960 }
10962 }
10965 {
10966 /* A static data member declaration is always marked
10967 external when it is declared in-class, even if an
10968 initializer is present. We mimic the non-template
10969 processing here. */
10975 }
10978 else
10987 /* Preserve a typedef that names a type. */
10989 {
10992 }
10995 }
11000 }
11001 #undef RETURN
11003 out:
11004 /* Restore the file and line information. */
11008 }
11010 /* Substitute into the ARG_TYPES of a function type.
11011 If END is a TREE_CHAIN, leave it and any following types
11012 un-substituted. */
11014 static tree
11016 tree args,
11017 tree end,
11018 tsubst_flags_t complain,
11019 tree in_decl)
11020 {
11021 tree remaining_arg_types;
11025 tree default_arg;
11036 {
11037 /* For a pack expansion, perform substitution on the
11038 entire expression. Later on, we'll handle the arguments
11039 one-by-one. */
11044 /* So that we'll spin through the parameters, one by one. */
11046 else
11047 {
11048 /* We only partially substituted into the parameter
11049 pack. Our type is TYPE_PACK_EXPANSION. */
11052 }
11053 }
11066 {
11068 {
11072 }
11074 }
11075 /* DR 657. */
11079 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11080 top-level qualifiers as required. */
11083 /* We do not substitute into default arguments here. The standard
11084 mandates that they be instantiated only when needed, which is
11085 done in build_over_call. */
11089 {
11090 /* We've instantiated a template before its default arguments
11091 have been parsed. This can happen for a nested template
11092 class, and is not an error unless we require the default
11093 argument in a call of this function. */
11094 remaining_arg_types =
11097 }
11098 else
11099 remaining_arg_types =
11101 }
11104 }
11106 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11107 *not* handle the exception-specification for FNTYPE, because the
11108 initial substitution of explicitly provided template parameters
11109 during argument deduction forbids substitution into the
11110 exception-specification:
11112 [temp.deduct]
11114 All references in the function type of the function template to the
11115 corresponding template parameters are replaced by the specified tem-
11116 plate argument values. If a substitution in a template parameter or
11117 in the function type of the function template results in an invalid
11118 type, type deduction fails. [Note: The equivalent substitution in
11119 exception specifications is done only when the function is instanti-
11120 ated, at which point a program is ill-formed if the substitution
11121 results in an invalid type.] */
11123 static tree
11125 tree args,
11126 tsubst_flags_t complain,
11127 tree in_decl)
11128 {
11129 tree return_type;
11130 tree arg_types;
11131 tree fntype;
11133 /* The TYPE_CONTEXT is not used for function/method types. */
11136 /* Substitute the return type. */
11140 /* DR 486 clarifies that creation of a function type with an
11141 invalid return type is a deduction failure. */
11144 {
11146 {
11149 else
11151 }
11153 }
11154 /* And DR 657. */
11158 /* Substitute the argument types. */
11164 /* Construct a new type node and return it. */
11166 {
11171 }
11172 else
11173 {
11176 {
11177 /* [temp.deduct]
11179 Type deduction may fail for any of the following
11180 reasons:
11182 -- Attempting to create "pointer to member of T" when T
11183 is not a class type. */
11186 r);
11188 }
11193 }
11197 }
11199 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11200 ARGS into that specification, and return the substituted
11201 specification. If there is no specification, return NULL_TREE. */
11203 static tree
11205 tree args,
11206 tsubst_flags_t complain,
11207 tree in_decl,
11209 {
11210 tree specs;
11211 tree new_specs;
11216 {
11217 /* A noexcept-specifier. */
11222 {
11223 /* Defer instantiation of noexcept-specifiers to avoid
11224 excessive instantiations (c++/49107). */
11227 {
11228 /* We already partially instantiated this member template,
11229 so combine the new args with the old. */
11234 }
11235 else
11236 {
11239 }
11240 }
11241 else
11242 new_specs = tsubst_copy_and_build
11246 }
11248 {
11251 else
11253 {
11254 tree spec;
11259 {
11260 /* Expand the pack expansion type. */
11263 in_decl);
11269 else
11270 {
11271 /* We're substituting into a member template, so
11272 we got a TYPE_PACK_EXPANSION back. Add that
11273 expansion and move on. */
11277 expanded_specs,
11278 complain);
11281 }
11282 }
11285 {
11288 else
11293 complain);
11294 }
11297 }
11298 }
11300 }
11302 /* Take the tree structure T and replace template parameters used
11303 therein with the argument vector ARGS. IN_DECL is an associated
11304 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11305 Issue error and warning messages under control of COMPLAIN. Note
11306 that we must be relatively non-tolerant of extensions here, in
11307 order to preserve conformance; if we allow substitutions that
11308 should not be allowed, we may allow argument deductions that should
11309 not succeed, and therefore report ambiguous overload situations
11310 where there are none. In theory, we could allow the substitution,
11311 but indicate that it should have failed, and allow our caller to
11312 make sure that the right thing happens, but we don't try to do this
11313 yet.
11315 This function is used for dealing with types, decls and the like;
11316 for expressions, use tsubst_expr or tsubst_copy. */
11318 tree
11320 {
11343 else
11348 /* Reuse typedefs. We need to do this to handle dependent attributes,
11349 such as attribute aligned. */
11352 {
11356 {
11357 /* DECL represents an alias template and we want to
11358 instantiate it. */
11362 }
11366 {
11370 }
11375 else
11376 /* The typedef is from a non-template context. */
11380 {
11382 r = cp_build_qualified_type_real
11386 }
11387 else
11388 {
11389 /* We don't have an instantiation yet, so drop the typedef. */
11394 }
11395 }
11408 {
11434 {
11440 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11441 needed. */
11447 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11448 with TREE_SIDE_EFFECTS that indicates this is not an integral
11449 constant expression. */
11452 {
11455 }
11458 }
11464 {
11477 {
11481 {
11482 /* See through ARGUMENT_PACK_SELECT arguments. */
11484 /* If the selected argument is an expansion E, that most
11485 likely means we were called from
11486 gen_elem_of_pack_expansion_instantiation during the
11487 substituting of pack an argument pack (which Ith
11488 element is a pack expansion, where I is
11489 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11490 In this case, the Ith element resulting from this
11491 substituting is going to be a pack expansion, which
11492 pattern is the pattern of E. Let's return the
11493 pattern of E, and
11494 gen_elem_of_pack_expansion_instantiation will
11495 build the resulting pack expansion from it. */
11498 }
11499 }
11504 {
11506 /* If ARG is an argument pack, we don't actually want to
11507 perform a substitution here, because substitutions
11508 for argument packs are only done
11509 element-by-element. We can get to this point when
11510 substituting the type of a non-type template
11511 parameter pack, when that type actually contains
11512 template parameter packs from an outer template, e.g.,
11514 template<typename... Types> struct A {
11515 template<Types... Values> struct B { };
11516 }; */
11520 {
11526 return cp_build_qualified_type_real
11528 }
11530 {
11531 /* We are processing a type constructed from a
11532 template template parameter. */
11543 /* Consider this code:
11545 template <template <class> class Template>
11546 struct Internal {
11547 template <class Arg> using Bind = Template<Arg>;
11548 };
11550 template <template <class> class Template, class Arg>
11551 using Instantiate = Template<Arg>; //#0
11553 template <template <class> class Template,
11554 class Argument>
11555 using Bind =
11556 Instantiate<Internal<Template>::template Bind,
11557 Argument>; //#1
11559 When #1 is parsed, the
11560 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11561 parameter `Template' in #0 matches the
11562 UNBOUND_CLASS_TEMPLATE representing the argument
11563 `Internal<Template>::template Bind'; We then want
11564 to assemble the type `Bind<Argument>' that can't
11565 be fully created right now, because
11566 `Internal<Template>' not being complete, the Bind
11567 template cannot be looked up in that context. So
11568 we need to "store" `Bind<Argument>' for later
11569 when the context of Bind becomes complete. Let's
11570 store that in a TYPENAME_TYPE. */
11574 argvec),
11575 typename_type,
11576 complain);
11578 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11579 are resolving nested-types in the signature of a
11580 member function templates. Otherwise ARG is a
11581 TEMPLATE_DECL and is the real template to be
11582 instantiated. */
11590 complain);
11591 return cp_build_qualified_type_real
11593 }
11594 else
11595 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11597 }
11600 /* This can happen during the attempted tsubst'ing in
11601 unify. This means that we don't yet have any information
11602 about the template parameter in question. */
11605 /* Early in template argument deduction substitution, we don't
11606 want to reduce the level of 'auto', or it will be confused
11607 with a normal template parm in subsequent deduction. */
11611 /* If we get here, we must have been looking at a parm for a
11612 more deeply nested template. Make a new version of this
11613 template parameter, but with a lower level. */
11615 {
11620 {
11622 r = cp_build_qualified_type_real
11626 }
11627 else
11628 {
11639 /* We have reduced the level of the template
11640 template parameter, but not the levels of its
11641 template parameters, so canonical_type_parameter
11642 will not be able to find the canonical template
11643 template parameter for this level. Thus, we
11644 require structural equality checking to compare
11645 TEMPLATE_TEMPLATE_PARMs. */
11649 else
11653 {
11661 }
11662 }
11671 }
11674 }
11677 {
11685 {
11689 }
11692 {
11696 }
11699 {
11703 }
11709 }
11712 /* We should never be tsubsting a binfo. */
11716 /* A vector of template arguments. */
11722 {
11726 /* [temp.deduct]
11728 Type deduction may fail for any of the following
11729 reasons:
11731 -- Attempting to create a pointer to reference type.
11732 -- Attempting to create a reference to a reference type or
11733 a reference to void.
11735 Core issue 106 says that creating a reference to a reference
11736 during instantiation is no longer a cause for failure. We
11737 only enforce this check in strict C++98 mode. */
11741 {
11744 /* We keep track of the last time we issued this error
11745 message to avoid spewing a ton of messages during a
11746 single bad template instantiation. */
11749 {
11754 else
11757 }
11760 }
11764 {
11766 {
11769 type);
11770 else
11772 type);
11773 }
11775 }
11777 {
11781 }
11783 /* In C++0x, during template argument substitution, when there is an
11784 attempt to create a reference to a reference type, reference
11785 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11787 "If a template-argument for a template-parameter T names a type
11788 that is a reference to a type A, an attempt to create the type
11789 'lvalue reference to cv T' creates the type 'lvalue reference to
11790 A,' while an attempt to create the type type rvalue reference to
11791 cv T' creates the type T"
11792 */
11793 r = cp_build_reference_type
11796 else
11803 {
11805 pedwarn
11807 code == REFERENCE_TYPE
11810 else
11812 }
11815 /* Will this ever be needed for TYPE_..._TO values? */
11819 }
11821 {
11824 {
11825 /* [temp.deduct]
11827 Type deduction may fail for any of the following
11828 reasons:
11830 -- Attempting to create "pointer to member of T" when T
11831 is not a class type. */
11835 }
11837 {
11841 }
11843 {
11847 }
11850 {
11851 /* The type of the implicit object parameter gets its
11852 cv-qualifiers from the FUNCTION_TYPE. */
11853 tree memptr;
11854 tree method_type
11859 complain);
11860 }
11861 else
11864 complain);
11865 }
11868 {
11869 tree fntype;
11870 tree specs;
11875 /* Substitute the exception specification. */
11883 }
11885 {
11890 /* As an optimization, we avoid regenerating the array type if
11891 it will obviously be the same as T. */
11895 /* These checks should match the ones in grokdeclarator.
11897 [temp.deduct]
11899 The deduction may fail for any of the following reasons:
11901 -- Attempting to create an array with an element type that
11902 is void, a function type, or a reference type, or [DR337]
11903 an abstract class type. */
11907 {
11911 }
11919 {
11922 }
11925 }
11928 {
11938 {
11942 }
11944 {
11945 /* Normally, make_typename_type does not require that the CTX
11946 have complete type in order to allow things like:
11948 template <class T> struct S { typename S<T>::X Y; };
11950 But, such constructs have already been resolved by this
11951 point, so here CTX really should have complete type, unless
11952 it's a partial instantiation. */
11955 {
11959 }
11960 }
11967 {
11970 }
11973 {
11975 {
11979 else
11981 }
11983 {
11987 else
11989 }
11990 }
11992 return cp_build_qualified_type_real
11994 }
11997 {
12009 }
12012 {
12013 tree type;
12029 complain);
12030 }
12033 {
12034 tree type;
12052 else
12053 {
12057 /* In a template ~id could be either a complement expression
12058 or an unqualified-id naming a destructor; if instantiating
12059 it produces an expression, it's not an id-expression or
12060 member access. */
12063 }
12067 complain);
12068 }
12071 {
12075 }
12079 {
12081 tree packed_out =
12083 args,
12084 complain,
12085 in_decl);
12088 /* For template nontype argument packs, also substitute into
12089 the type. */
12094 }
12109 /* We should use one of the expression tsubsts for these codes. */
12115 }
12116 }
12118 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12119 type of the expression on the left-hand side of the "." or "->"
12120 operator. */
12122 static tree
12125 {
12126 tree name;
12127 tree qualifying_scope;
12128 tree fns;
12129 tree optype;
12134 /* A baselink indicates a function from a base class. Both the
12135 BASELINK_ACCESS_BINFO and the base class referenced may
12136 indicate bases of the template class, rather than the
12137 instantiated class. In addition, lookups that were not
12138 ambiguous before may be ambiguous now. Therefore, we perform
12139 the lookup again. */
12146 {
12153 }
12161 /* If lookup found a single function, mark it as used at this
12162 point. (If it lookup found multiple functions the one selected
12163 later by overload resolution will be marked as used at that
12164 point.) */
12170 /* Add back the template arguments, if present. */
12175 template_args);
12176 /* Update the conversion operator type. */
12184 qualifying_scope,
12185 object_type);
12187 }
12189 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12190 true if the qualified-id will be a postfix-expression in-and-of
12191 itself; false if more of the postfix-expression follows the
12192 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12193 of "&". */
12195 static tree
12199 {
12200 tree expr;
12201 tree scope;
12202 tree name;
12204 tree template_args;
12209 /* Figure out what name to look up. */
12212 {
12220 }
12221 else
12222 {
12225 }
12227 /* Substitute into the qualifying scope. When there are no ARGS, we
12228 are just trying to simplify a non-dependent expression. In that
12229 case the qualifying scope may be dependent, and, in any case,
12230 substituting will not help. */
12233 {
12236 }
12237 else
12241 {
12246 }
12249 {
12251 {
12252 /* A BIT_NOT_EXPR is used to represent a destructor. */
12254 {
12258 }
12259 else
12262 }
12263 else
12267 {
12269 {
12273 }
12275 }
12276 }
12279 {
12281 scope);
12282 /* Remember that there was a reference to this entity. */
12284 }
12287 {
12293 }
12302 {
12303 expr = (adjust_result_of_qualified_name_lookup
12305 expr = (finish_qualified_id_expr
12309 }
12311 /* Expressions do not generally have reference type. */
12313 /* However, if we're about to form a pointer-to-member, we just
12314 want the referenced member referenced. */
12319 }
12321 /* Like tsubst, but deals with expressions. This function just replaces
12322 template parms; to finish processing the resultant expression, use
12323 tsubst_copy_and_build or tsubst_expr. */
12325 static tree
12327 {
12329 tree r;
12337 {
12342 {
12343 /* We get here for a use of 'this' in an NSDMI. */
12349 /* This can happen for a parameter name used later in a function
12350 declaration (such as in a late-specified return type). Just
12351 make a dummy decl, since it's only used for its type. */
12354 /* Give it the template pattern as its context; its true context
12355 hasn't been instantiated yet and this is good enough for
12356 mangling. */
12358 }
12366 {
12367 tree enum_type;
12368 tree v;
12372 /* There is no need to substitute into namespace-scope
12373 enumerators. */
12376 /* If ARGS is NULL, then T is known to be non-dependent. */
12380 /* Unfortunately, we cannot just call lookup_name here.
12381 Consider:
12383 template <int I> int f() {
12384 enum E { a = I };
12385 struct S { void g() { E e = a; } };
12386 };
12388 When we instantiate f<7>::S::g(), say, lookup_name is not
12389 clever enough to find f<7>::a. */
12390 enum_type
12400 /* We didn't find the name. That should never happen; if
12401 name-lookup found it during preliminary parsing, we
12402 should find it again here during instantiation. */
12404 }
12409 {
12410 /* Check for a local specialization set up by
12411 tsubst_pack_expansion. */
12414 {
12418 }
12420 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12421 tsubst_decl put in the hash table. */
12423 }
12426 {
12427 tree ctx;
12432 {
12435 {
12439 }
12441 }
12442 }
12451 {
12454 {
12456 {
12457 /* Just use name lookup to find a member alias for an
12458 anonymous union, but then add it to the hash table. */
12462 }
12463 else
12464 {
12467 }
12468 }
12469 }
12470 else
12479 /* An OVERLOAD will always be a non-dependent overload set; an
12480 overload set from function scope will just be represented with an
12481 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12497 {
12498 /* Template template argument like the following example need
12499 special treatment:
12501 template <template <class> class TT> struct C {};
12502 template <class T> struct D {
12503 template <class U> struct E {};
12504 C<E> c; // #1
12505 };
12506 D<int> d; // #2
12508 We are processing the template argument `E' in #1 for
12509 the template instantiation #2. Originally, `E' is a
12510 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12511 have to substitute this with one having context `D<int>'. */
12515 }
12516 else
12517 /* Ordinary template template argument. */
12528 return build1
12534 {
12544 /* We only want to compute the number of arguments. */
12558 {
12565 else
12568 }
12569 else
12571 }
12573 {
12581 }
12582 /* Fall through */
12598 return build1
12603 {
12604 tree object;
12605 tree name;
12610 {
12614 }
12617 {
12627 }
12632 in_decl);
12633 else
12636 }
12674 return build_nt
12687 return build_nt
12694 {
12702 }
12708 {
12709 r = build_nt
12715 }
12718 {
12719 r = build_nt
12725 }
12728 {
12729 r = build_nt
12735 }
12738 {
12739 /* Substituted template arguments */
12748 }
12751 {
12771 }
12796 /* Fall through. */
12799 {
12802 }
12803 else
12807 /* This is handled by tsubst_copy_and_build. */
12813 in_decl),
12817 /* We shouldn't have built any of these during initial template
12818 generation. Instead, they should be built during instantiation
12819 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12823 r = build2
12843 {
12844 /* Instantiate any typedefs in the type. */
12849 }
12852 /* These can sometimes show up in a partial instantiation, but never
12853 involve template parms. */
12858 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12861 }
12862 }
12864 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12866 static tree
12869 {
12873 {
12879 {
12882 {
12888 }
12889 /* FALLTHRU */
12917 {
12920 {
12927 }
12928 else
12930 }
12960 }
12961 }
12967 }
12969 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12971 static tree
12973 tree in_decl)
12974 {
12975 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12995 {
12998 else
12999 {
13003 }
13004 }
13009 #undef RECUR
13010 }
13012 /* Substitute one OMP_FOR iterator. */
13014 static void
13019 {
13020 #define RECUR(NODE) \
13021 tsubst_expr ((NODE), args, complain, in_decl, \
13022 integral_constant_expression_p)
13030 /* Do this before substituting into decl to handle 'auto'. */
13035 {
13039 }
13044 {
13051 complain);
13052 else
13059 }
13062 {
13063 tree c;
13065 {
13076 }
13078 {
13083 {
13086 }
13087 }
13088 }
13094 else
13098 {
13109 {
13116 }
13117 else
13123 {
13129 }
13133 {
13140 }
13141 else
13147 }
13153 #undef RECUR
13154 }
13156 /* Like tsubst_copy for expressions, etc. but also does semantic
13157 processing. */
13159 static tree
13162 {
13163 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13164 #define RECUR(NODE) \
13165 tsubst_expr ((NODE), args, complain, in_decl, \
13166 integral_constant_expression_p)
13169 tree r;
13170 location_t loc;
13182 {
13184 {
13185 tree_stmt_iterator i;
13189 }
13204 else
13213 {
13215 tree init;
13221 {
13224 tree decl;
13232 else
13234 }
13236 {
13237 /* Don't build up decls for a variadic capture proxy, we'll
13238 instantiate the elements directly as needed. */
13240 }
13241 else
13242 {
13246 {
13247 /* By marking the declaration as instantiated, we avoid
13248 trying to instantiate it. Since instantiate_decl can't
13249 handle local variables, and since we've already done
13250 all that needs to be done, that's the right thing to
13251 do. */
13256 /* Anonymous aggregates are a special case. */
13259 {
13262 {
13266 }
13268 }
13274 {
13279 }
13280 else
13281 {
13286 {
13287 /* For __PRETTY_FUNCTION__ we have to adjust the
13288 initializer. */
13292 }
13293 else
13294 {
13298 {
13299 /* If we had an initializer but it
13300 instantiated to nothing,
13301 value-initialize the object. This will
13302 only occur when the initializer was a
13303 pack expansion where the parameter packs
13304 used in that expansion were of length
13305 zero. */
13307 complain);
13310 }
13311 else
13313 }
13316 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13319 }
13320 }
13321 }
13324 }
13339 {
13349 }
13376 {
13380 }
13388 else
13396 else
13423 {
13425 tree label;
13430 }
13436 /* Computed goto's must be tsubst'd into. On the other hand,
13437 non-computed gotos must not be; the identifier in question
13438 will have no binding. */
13440 else
13446 tmp = finish_asm_stmt
13453 {
13458 }
13463 {
13468 }
13469 else
13470 {
13475 else
13482 else
13488 else
13490 }
13494 {
13498 {
13500 /* Prevent instantiate_decl from trying to instantiate
13501 this variable. We've already done all that needs to be
13502 done. */
13505 }
13510 }
13516 {
13517 /* Local classes are not independent templates; they are
13518 instantiated along with their containing function. And this
13519 way we don't have to deal with pushing out of one local class
13520 to instantiate a member of another local class. */
13521 tree fn;
13522 /* Closures are handled by the LAMBDA_EXPR. */
13528 }
13532 {
13533 tree condition;
13536 condition =
13538 args,
13547 }
13571 {
13580 {
13585 }
13597 integral_constant_expression_p);
13606 else
13607 {
13615 }
13618 }
13663 {
13668 {
13671 }
13677 }
13678 else
13679 {
13686 {
13689 }
13692 {
13697 {
13700 }
13706 }
13707 else
13708 {
13712 }
13715 }
13719 {
13725 {
13729 {
13734 }
13738 }
13739 else
13740 {
13745 }
13746 }
13764 /* If the first operand was a statement, we're done with it. */
13768 complain));
13775 integral_constant_expression_p));
13776 }
13779 out:
13782 #undef RECUR
13783 #undef RETURN
13784 }
13786 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
13787 function. For description of the body see comment above
13788 cp_parser_omp_declare_reduction_exprs. */
13790 static void
13792 {
13798 tree_stmt_iterator tsi;
13809 {
13828 }
13830 {
13850 }
13851 }
13853 /* T is a postfix-expression that is not being used in a function
13854 call. Return the substituted version of T. */
13856 static tree
13858 tsubst_flags_t complain,
13859 tree in_decl)
13860 {
13864 else
13870 }
13872 /* Like tsubst but deals with expressions and performs semantic
13873 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13875 tree
13877 tree args,
13878 tsubst_flags_t complain,
13879 tree in_decl,
13882 {
13883 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
13884 #define RECUR(NODE) \
13885 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13887 integral_constant_expression_p)
13890 location_t loc;
13899 /* N3276 decltype magic only applies to calls at the top level or on the
13900 right side of a comma. */
13905 {
13908 /* Fall through. */
13910 {
13911 tree decl;
13912 cp_id_kind idk;
13917 {
13920 }
13922 /* Look up the name. */
13925 /* By convention, expressions use ERROR_MARK_NODE to indicate
13926 failure, not NULL_TREE. */
13932 integral_constant_expression_p,
13940 input_location);
13944 {
13948 }
13950 }
13953 {
13954 tree object;
13962 {
13965 }
13966 else
13973 else
13975 }
13978 {
13982 {
13983 /* A type conversion to reference type will be enclosed in
13984 such an indirect ref, but the substitution of the cast
13985 will have also added such an indirect ref. */
13988 }
13989 else
13993 }
14001 {
14008 flags));
14009 }
14022 {
14023 tree type;
14029 {
14034 }
14040 {
14058 }
14062 }
14096 else
14098 in_decl);
14133 {
14134 tree r;
14138 r = build_x_binary_op
14142 ? ERROR_MARK
14146 ? ERROR_MARK
14156 }
14169 {
14178 }
14182 /* Fall through */
14185 {
14186 tree r;
14192 {
14193 /* When there are no ARGS, we are trying to evaluate a
14194 non-dependent expression from the parser. Trying to do
14195 the substitutions may not work. */
14198 }
14199 else
14200 {
14205 else
14208 /*integral_constant_expression_p=*/
14212 }
14216 else
14220 {
14222 {
14224 {
14228 }
14229 else
14233 }
14235 }
14237 }
14240 {
14250 }
14264 {
14265 tree r;
14269 r = build_x_modify_expr
14275 /* TREE_NO_WARNING must be set if either the expression was
14276 parenthesized or it uses an operator such as >>= rather
14277 than plain assignment. In the former case, it was already
14278 set and must be copied. In the latter case,
14279 build_x_modify_expr sets it and it must not be reset
14280 here. */
14287 }
14292 /* Remember that there was a reference to this entity. */
14298 {
14303 tree ret;
14307 else
14308 {
14312 }
14314 /* If there was an initializer in the original tree, but it
14315 instantiated to an empty list, then we should pass a
14316 non-NULL empty vector to tell build_new that it was an
14317 empty initializer() rather than no initializer. This can
14318 only happen when the initializer is a pack expansion whose
14319 parameter packs are of length zero. */
14322 else
14323 {
14327 else
14328 {
14331 }
14332 }
14339 complain);
14347 }
14355 complain));
14358 {
14362 integral_constant_expression_p);
14364 op0,
14367 }
14370 {
14371 tree function;
14376 tree ret;
14379 /* When we parsed the expression, we determined whether or
14380 not Koenig lookup should be performed. */
14383 {
14388 }
14390 {
14391 /* Do nothing; calling tsubst_copy_and_build on an identifier
14392 would incorrectly perform unqualified lookup again.
14394 Note that we can also have an IDENTIFIER_NODE if the earlier
14395 unqualified lookup found a member function; in that case
14396 koenig_p will be false and we do want to do the lookup
14397 again to find the instantiated member function.
14399 FIXME but doing that causes c++/15272, so we need to stop
14400 using IDENTIFIER_NODE in that situation. */
14402 }
14403 else
14404 {
14406 {
14412 }
14413 else
14418 /* Avoid error about taking the address of a constructor. */
14422 in_decl,
14424 integral_constant_expression_p);
14428 }
14433 {
14438 else
14439 {
14440 /* Expand the pack expansion and push each entry onto
14441 CALL_ARGS. */
14444 {
14449 {
14454 }
14455 }
14456 else
14457 {
14458 /* A partial substitution. Add one entry. */
14460 }
14461 }
14462 }
14464 /* We do not perform argument-dependent lookup if normal
14465 lookup finds a non-function, in accordance with the
14466 expected resolution of DR 218. */
14469 /* If lookup found a member function, the Koenig lookup is
14470 not appropriate, even if an unqualified-name was used
14471 to denote the function. */
14474 /* Only do this when substitution turns a dependent call
14475 into a non-dependent call. */
14479 tf_none);
14483 {
14485 {
14486 /* For backwards compatibility and good diagnostics, try
14487 the unqualified lookup again if we aren't in SFINAE
14488 context. */
14489 tree unq = (tsubst_copy_and_build
14491 integral_constant_expression_p));
14496 {
14505 "%qD was not declared in this scope, "
14506 "and no declarations were found by "
14507 "argument-dependent lookup at the point "
14509 {
14513 {
14515 "declarations in dependent base %qT are "
14521 else
14525 }
14526 else
14529 }
14531 }
14532 }
14534 {
14539 }
14540 }
14542 /* Remember that there was a reference to this entity. */
14546 /* Put back tf_decltype for the actual call. */
14551 complain);
14553 {
14568 complain);
14569 else
14570 ret = (build_new_method_call
14575 complain));
14576 }
14577 else
14580 koenig_p,
14581 complain);
14586 }
14589 {
14594 {
14596 {
14601 }
14602 else
14603 {
14608 }
14609 }
14610 else
14611 {
14614 }
14618 }
14625 input_location));
14628 {
14636 {
14637 /* We have pack expansions, so expand those and
14638 create a new list out of it. */
14641 tree chain;
14644 /* Expand the argument expressions. */
14652 /* Build the rest of the list. */
14657 /* Determine the number of arguments. */
14659 {
14662 }
14665 else
14666 {
14667 /* Since we only performed a partial substitution into
14668 the argument pack, we only RETURN (a single list
14669 node. */
14676 }
14678 /* Convert the argument vectors into a TREE_LIST */
14681 {
14682 /* Grab the Ith values. */
14683 i--;
14686 value
14690 /* Build the list (backwards). */
14692 }
14695 }
14711 }
14714 {
14715 tree object;
14716 tree object_type;
14717 tree member;
14721 /* Remember that there was a reference to this entity. */
14731 else
14739 {
14741 {
14746 {
14749 }
14751 {
14756 }
14757 }
14758 }
14761 {
14762 /* Lookup the template functions now that we know what the
14763 scope is. */
14771 {
14774 args);
14775 member = (adjust_result_of_qualified_name_lookup
14777 object_type));
14778 }
14779 else
14780 {
14782 input_location);
14784 }
14785 }
14789 {
14791 {
14795 else
14798 }
14800 }
14806 complain));
14807 }
14814 {
14822 tree r;
14827 /* digest_init will do the wrong thing if we let it. */
14831 /* We do not want to process the index of aggregate
14832 initializers as they are identifier nodes which will be
14833 looked up by digest_init. */
14839 {
14841 /* An identifier index is looked up in the type
14842 being initialized, not the current scope. */
14847 {
14848 /* Substitute into the pack expansion. */
14850 in_decl);
14854 ;
14856 /* Just move the argument into place. */
14858 else
14859 {
14860 /* Update the length of the final CONSTRUCTOR
14861 arguments vector, and note that we will need to
14862 copy.*/
14865 }
14866 }
14867 else
14869 }
14872 {
14877 {
14879 {
14884 }
14885 else
14887 }
14888 }
14898 }
14901 {
14904 {
14907 }
14908 else
14909 {
14912 }
14913 }
14919 {
14920 /* We don't build decls for an instantiation of a
14921 variadic capture proxy, we instantiate the elements
14922 when needed. */
14925 }
14926 /* Fall through */
14929 {
14933 /* If the original type was a reference, we'll be wrapped in
14934 the appropriate INDIRECT_REF. */
14937 }
14948 {
14957 }
14960 {
14966 integral_constant_expression_p);
14970 /* If the resulting list of expression statement is empty,
14971 fold it further into void_zero_node. */
14976 }
14979 {
14993 /* For a function scope, we want to use tsubst so that we don't
14994 complain about referring to an auto function before its return
14995 type has been deduced. Otherwise, we want to use tsubst_copy so
14996 that we look up the existing field/parameter/variable rather
14997 than build a new one. */
15002 {
15003 /* Look up the parameter we want directly, as tsubst_copy
15004 doesn't do what we need. */
15010 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15013 }
15014 else
15023 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15025 /* Now that we know visibility, instantiate the type so we have a
15026 declaration of the op() for later calls to lambda_function. */
15032 }
15035 /* We can get here for a constant initializer of non-dependent type.
15036 FIXME stop folding in cp_parser_initializer_clause. */
15037 {
15039 complain);
15041 }
15045 integral_constant_expression_p));
15055 complain));
15058 /* Handle Objective-C++ constructs, if appropriate. */
15059 {
15060 tree subst
15065 }
15067 }
15069 #undef RECUR
15070 #undef RETURN
15071 out:
15074 }
15076 /* Verify that the instantiated ARGS are valid. For type arguments,
15077 make sure that the type's linkage is ok. For non-type arguments,
15078 make sure they are constants if they are integral or enumerations.
15079 Emit an error under control of COMPLAIN, and return TRUE on error. */
15081 static bool
15083 {
15087 {
15097 }
15099 {
15100 /* [basic.link]: A name with no linkage (notably, the name
15101 of a class or enumeration declared in a local scope)
15102 shall not be used to declare an entity with linkage.
15103 This implies that names with no linkage cannot be used as
15104 template arguments
15106 DR 757 relaxes this restriction for C++0x. */
15111 {
15112 /* DR 488 makes use of a type with no linkage cause
15113 type deduction to fail. */
15115 {
15118 else
15121 }
15123 }
15124 /* In order to avoid all sorts of complications, we do not
15125 allow variably-modified types as template arguments. */
15127 {
15131 }
15132 }
15133 /* Class template and alias template arguments should be OK. */
15135 ;
15136 /* A non-type argument of integral or enumerated type must be a
15137 constant. */
15141 {
15145 }
15147 }
15149 static bool
15151 {
15156 {
15159 }
15163 }
15165 /* We're out of SFINAE context now, so generate diagnostics for the access
15166 errors we saw earlier when instantiating D from TMPL and ARGS. */
15168 static void
15170 {
15182 }
15184 /* Instantiate the indicated variable, function, or alias template TMPL with
15185 the template arguments in TARG_PTR. */
15187 static tree
15189 {
15191 tree fndecl;
15192 tree gen_tmpl;
15193 tree spec;
15201 /* If this function is a clone, handle it specially. */
15203 {
15204 tree spec;
15205 tree clone;
15207 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15208 DECL_CLONED_FUNCTION. */
15214 /* Look for the clone. */
15218 /* We should always have found the clone by now. */
15221 }
15223 /* Check to see if we already have this specialization. */
15226 /* The TMPL is a partial instantiation. To get a full set of
15227 arguments we must add the arguments used to perform the
15228 partial instantiation. */
15230 targ_ptr);
15232 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15233 but it doesn't seem to be on the hot path. */
15242 {
15244 {
15248 }
15250 }
15253 complain))
15256 /* We are building a FUNCTION_DECL, during which the access of its
15257 parameters and return types have to be checked. However this
15258 FUNCTION_DECL which is the desired context for access checking
15259 is not built yet. We solve this chicken-and-egg problem by
15260 deferring all checks until we have the FUNCTION_DECL. */
15263 /* Instantiation of the function happens in the context of the function
15264 template, not the context of the overload resolution we're doing. */
15266 /* If there are dependent arguments, e.g. because we're doing partial
15267 ordering, make sure processing_template_decl stays set. */
15271 {
15275 }
15276 /* Substitute template parameters to obtain the specialization. */
15284 {
15287 }
15289 /* The DECL_TI_TEMPLATE should always be the immediate parent
15290 template, not the most general template. */
15293 /* Now we know the specialization, compute access previously
15294 deferred. */
15301 /* If we've just instantiated the main entry point for a function,
15302 instantiate all the alternate entry points as well. We do this
15303 by cloning the instantiation of the main entry point, not by
15304 instantiating the template clones. */
15309 {
15311 {
15312 /* Remember to reinstantiate when we're out of SFINAE so the user
15313 can see the errors. */
15315 }
15317 }
15319 }
15321 /* Wrapper for instantiate_template_1. */
15323 tree
15325 {
15326 tree ret;
15331 }
15333 /* Instantiate the alias template TMPL with ARGS. Also push a template
15334 instantiation level, which instantiate_template doesn't do because
15335 functions and variables have sufficient context established by the
15336 callers. */
15338 static tree
15340 {
15347 {
15350 }
15352 args =
15360 /* We can't free this if a pending_template entry or last_error_tinst_level
15361 is pointing at it. */
15367 }
15369 /* PARM is a template parameter pack for FN. Returns true iff
15370 PARM is used in a deducible way in the argument list of FN. */
15372 static bool
15374 {
15377 {
15379 tree packs;
15385 {
15386 /* The template parameter pack is used in a function parameter
15387 pack. If this is the end of the parameter list, the
15388 template parameter pack is deducible. */
15391 else
15392 /* Otherwise, not. Well, it could be deduced from
15393 a non-pack parameter, but doing so would end up with
15394 a deduction mismatch, so don't bother. */
15396 }
15397 }
15398 /* The template parameter pack isn't used in any function parameter
15399 packs, but it might be used deeper, e.g. tuple<Args...>. */
15401 }
15403 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15404 NARGS elements of the arguments that are being used when calling
15405 it. TARGS is a vector into which the deduced template arguments
15406 are placed.
15408 Return zero for success, 2 for an incomplete match that doesn't resolve
15409 all the types, and 1 for complete failure. An error message will be
15410 printed only for an incomplete match.
15412 If FN is a conversion operator, or we are trying to produce a specific
15413 specialization, RETURN_TYPE is the return type desired.
15415 The EXPLICIT_TARGS are explicit template arguments provided via a
15416 template-id.
15418 The parameter STRICT is one of:
15420 DEDUCE_CALL:
15421 We are deducing arguments for a function call, as in
15422 [temp.deduct.call].
15424 DEDUCE_CONV:
15425 We are deducing arguments for a conversion function, as in
15426 [temp.deduct.conv].
15428 DEDUCE_EXACT:
15429 We are deducing arguments when doing an explicit instantiation
15430 as in [temp.explicit], when determining an explicit specialization
15431 as in [temp.expl.spec], or when taking the address of a function
15432 template, as in [temp.deduct.funcaddr]. */
15434 tree
15436 tree explicit_targs,
15437 tree targs,
15440 tree return_type,
15441 unification_kind_t strict,
15445 {
15446 tree parms;
15447 tree fntype;
15455 tree tinst;
15461 /* In C++0x, it's possible to have a function template whose type depends
15462 on itself recursively. This is most obvious with decltype, but can also
15463 occur with enumeration scope (c++/48969). So we need to catch infinite
15464 recursion and reject the substitution at deduction time; this function
15465 will return error_mark_node for any repeated substitution.
15467 This also catches excessive recursion such as when f<N> depends on
15468 f<N-1> across all integers, and returns error_mark_node for all the
15469 substitutions back up to the initial one.
15471 This is, of course, not reentrant. */
15481 {
15482 /* [temp.deduct]
15484 The specified template arguments must match the template
15485 parameters in kind (i.e., type, nontype, template), and there
15486 must not be more arguments than there are parameters;
15487 otherwise type deduction fails.
15489 Nontype arguments must match the types of the corresponding
15490 nontype template parameters, or must be convertible to the
15491 types of the corresponding nontype parameters as specified in
15492 _temp.arg.nontype_, otherwise type deduction fails.
15494 All references in the function type of the function template
15495 to the corresponding template parameters are replaced by the
15496 specified template argument values. If a substitution in a
15497 template parameter or in the function type of the function
15498 template results in an invalid type, type deduction fails. */
15503 /* Adjust any explicit template arguments before entering the
15504 substitution context. */
15505 explicit_targs
15507 complain,
15513 /* Substitute the explicit args into the function type. This is
15514 necessary so that, for instance, explicitly declared function
15515 arguments can match null pointed constants. If we were given
15516 an incomplete set of explicit args, we must not do semantic
15517 processing during substitution as we could create partial
15518 instantiations. */
15520 {
15525 /* Dig out the actual parm. */
15528 {
15531 }
15533 {
15536 }
15539 /* No explicit argument for this template parameter. */
15543 {
15544 /* Mark the argument pack as "incomplete". We could
15545 still deduce more arguments during unification.
15546 We remove this mark in type_unification_real. */
15548 {
15552 }
15554 /* We have some incomplete argument packs. */
15556 }
15557 }
15561 {
15564 }
15567 /* Ignore any access checks; we'll see them again in
15568 instantiate_template and they might have the wrong
15569 access path at this point. */
15581 /* Place the explicitly specified arguments in TARGS. */
15584 }
15586 /* Never do unification on the 'this' parameter. */
15590 {
15599 }
15601 /* We allow incomplete unification without an error message here
15602 because the standard doesn't seem to explicitly prohibit it. Our
15603 callers must be ready to deal with unification failures in any
15604 event. */
15607 /* If we aren't explaining yet, push tinst context so we can see where
15608 any errors (e.g. from class instantiations triggered by instantiation
15609 of default template arguments) come from. If we are explaining, this
15610 context is redundant. */
15612 {
15615 }
15617 /* type_unification_real will pass back any access checks from default
15618 template argument substitution. */
15630 /* Now that we have bindings for all of the template arguments,
15631 ensure that the arguments deduced for the template template
15632 parameters have compatible template parameter lists. We cannot
15633 check this property before we have deduced all template
15634 arguments, because the template parameter types of a template
15635 template parameter might depend on prior template parameters
15636 deduced after the template template parameter. The following
15637 ill-formed example illustrates this issue:
15639 template<typename T, template<T> class C> void f(C<5>, T);
15641 template<int N> struct X {};
15643 void g() {
15644 f(X<5>(), 5l); // error: template argument deduction fails
15645 }
15647 The template parameter list of 'C' depends on the template type
15648 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15649 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15650 time that we deduce 'C'. */
15653 {
15656 }
15658 /* All is well so far. Now, check:
15660 [temp.deduct]
15662 When all template arguments have been deduced, all uses of
15663 template parameters in nondeduced contexts are replaced with
15664 the corresponding deduced argument values. If the
15665 substitution results in an invalid type, as described above,
15666 type deduction fails. */
15669 {
15672 }
15674 /* Also collect access checks from the instantiation. */
15687 /* Now perform any access checks encountered during substitution. */
15694 /* If we're looking for an exact match, check that what we got
15695 is indeed an exact match. It might not be if some template
15696 parameters are used in non-deduced contexts. */
15698 {
15702 tree sarg
15708 {
15712 }
15713 }
15717 fail:
15720 {
15722 /* Reset once we're all the way out. */
15724 }
15726 /* We can't free this if a pending_template entry or last_error_tinst_level
15727 is pointing at it. */
15733 }
15735 /* Adjust types before performing type deduction, as described in
15736 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15737 sections are symmetric. PARM is the type of a function parameter
15738 or the return type of the conversion function. ARG is the type of
15739 the argument passed to the call, or the type of the value
15740 initialized with the result of the conversion function.
15741 ARG_EXPR is the original argument expression, which may be null. */
15743 static int
15747 tree arg_expr)
15748 {
15752 {
15757 {
15758 /* Swap PARM and ARG throughout the remainder of this
15759 function; the handling is precisely symmetric since PARM
15760 will initialize ARG rather than vice versa. */
15765 }
15768 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15769 too, but here handle it by stripping the reference from PARM
15770 rather than by adding it to ARG. */
15778 /* Nothing else to do in this case. */
15783 }
15786 {
15787 /* [temp.deduct.call]
15789 If P is not a reference type:
15791 --If A is an array type, the pointer type produced by the
15792 array-to-pointer standard conversion (_conv.array_) is
15793 used in place of A for type deduction; otherwise,
15795 --If A is a function type, the pointer type produced by
15796 the function-to-pointer standard conversion
15797 (_conv.func_) is used in place of A for type deduction;
15798 otherwise,
15800 --If A is a cv-qualified type, the top level
15801 cv-qualifiers of A's type are ignored for type
15802 deduction. */
15807 else
15809 }
15811 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15812 of the form T&&, where T is a template parameter, and the argument
15813 is an lvalue, T is deduced as A& */
15819 /* try_one_overload doesn't provide an arg_expr, but
15820 functions are always lvalues. */
15824 /* [temp.deduct.call]
15826 If P is a cv-qualified type, the top level cv-qualifiers
15827 of P's type are ignored for type deduction. If P is a
15828 reference type, the type referred to by P is used for
15829 type deduction. */
15832 {
15835 }
15837 /* DR 322. For conversion deduction, remove a reference type on parm
15838 too (which has been swapped into ARG). */
15843 }
15845 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15846 template which does contain any deducible template parameters; check if
15847 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15848 unify_one_argument. */
15850 static int
15853 {
15854 tree type;
15858 else
15865 {
15869 }
15871 {
15876 }
15880 else
15882 }
15886 /* Returns true iff the expression EXPR is one from which a template
15887 argument can be deduced. In other words, if it's an undecorated
15888 use of a template non-type parameter. */
15890 static bool
15892 {
15894 }
15896 /* Returns true iff the array domain DOMAIN uses a template parameter in a
15897 deducible way; that is, if it has a max value of <PARM> - 1. */
15899 static bool
15901 {
15910 }
15912 /* Returns true iff the template arguments ARGS use a template parameter
15913 in a deducible way. */
15915 static bool
15917 {
15919 {
15924 else
15925 {
15932 else
15934 }
15937 }
15939 }
15941 /* Returns true iff TYPE contains any deducible references to template
15942 parameters, as per 14.8.2.5. */
15944 static bool
15946 {
15950 /* T
15951 cv-list T
15952 TT<T>
15953 TT<i>
15954 TT<> */
15959 /* T*
15960 T&
15961 T&& */
15965 /* T[integer-constant ]
15966 type [i] */
15971 /* T type ::*
15972 type T::*
15973 T T::*
15974 T (type ::*)()
15975 type (T::*)()
15976 type (type ::*)(T)
15977 type (T::*)(T)
15978 T (type ::*)(T)
15979 T (T::*)()
15980 T (T::*)(T) */
15983 || (uses_deducible_template_parms
15986 /* template-name <T> (where template-name refers to a class template)
15987 template-name <i> (where template-name refers to a class template) */
15994 /* type (T)
15995 T()
15996 T(T) */
15999 {
16008 }
16011 }
16013 /* Subroutine of type_unification_real and unify_pack_expansion to
16014 handle unification of a single P/A pair. Parameters are as
16015 for those functions. */
16017 static int
16021 {
16028 /* We can't deduce anything from this, but we might get all the
16029 template args from other function args. */
16032 /* Implicit conversions (Clause 4) will be performed on a function
16033 argument to convert it to the type of the corresponding function
16034 parameter if the parameter type contains no template-parameters that
16035 participate in template argument deduction. */
16037 /* For function parameters that contain no template-parameters at all,
16038 we have historically checked for convertibility in order to shortcut
16039 consideration of this candidate. */
16041 explain_p);
16044 /* For function parameters with only non-deducible template parameters,
16045 just return. */
16049 {
16051 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16052 | UNIFY_ALLOW_MORE_CV_QUAL
16066 }
16068 /* We only do these transformations if this is the top-level
16069 parameter_type_list in a call or declaration matching; in other
16070 situations (nested function declarators, template argument lists) we
16071 won't be comparing a type to an expression, and we don't do any type
16072 adjustments. */
16074 {
16076 {
16079 {
16080 /* [temp.deduct.type] A template-argument can be
16081 deduced from a pointer to function or pointer
16082 to member function argument if the set of
16083 overloaded functions does not contain function
16084 templates and at most one of a set of
16085 overloaded functions provides a unique
16086 match. */
16093 }
16099 }
16101 arg_strict |=
16103 }
16104 else
16108 /* For deduction from an init-list we need the actual list. */
16112 }
16114 /* Most parms like fn_type_unification.
16116 If SUBR is 1, we're being called recursively (to unify the
16117 arguments of a function or method parameter of a function
16118 template).
16120 CHECKS is a pointer to a vector of access checks encountered while
16121 substituting default template arguments. */
16123 static int
16125 tree targs,
16126 tree xparms,
16130 unification_kind_t strict,
16134 {
16139 tree parms;
16148 /* Reset the number of non-defaulted template arguments contained
16149 in TARGS. */
16152 again:
16160 {
16165 /* For a function parameter pack that occurs at the end of the
16166 parameter-declaration-list, the type A of each remaining
16167 argument of the call is compared with the type P of the
16168 declarator-id of the function parameter pack. */
16174 /* For a function parameter pack that does not occur at the
16175 end of the parameter-declaration-list, the type of the
16176 parameter pack is a non-deduced context. */
16185 }
16190 {
16191 /* Unify the remaining arguments with the pack expansion type. */
16192 tree argvec;
16195 /* Allocate a TREE_VEC and copy in all of the arguments */
16200 /* Copy the parameter into parmvec. */
16206 /* Advance to the end of the list of parameters. */
16208 }
16210 /* Fail if we've reached the end of the parm list, and more args
16211 are present, and the parm list isn't variadic. */
16214 /* Fail if parms are left and they don't have default values. */
16217 {
16221 {
16222 count++;
16224 }
16226 }
16229 {
16230 tsubst_flags_t complain = (explain_p
16231 ? tf_warning_or_error
16235 {
16239 /* Clear the "incomplete" flags on all argument packs now so that
16240 substituting them into later default arguments works. */
16242 {
16245 }
16251 /* If this is an undeduced nontype parameter that depends on
16252 a type parameter, try another pass; its type may have been
16253 deduced from a later argument than the one from which
16254 this parameter can be deduced. */
16260 /* Core issue #226 (C++0x) [temp.deduct]:
16262 If a template argument has not been deduced, its
16263 default template argument, if any, is used.
16265 When we are in C++98 mode, TREE_PURPOSE will either
16266 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16267 to explicitly check cxx_dialect here. */
16269 {
16284 else
16285 {
16287 /* The position of the first default template argument,
16288 is also the number of non-defaulted arguments in TARGS.
16289 Record that. */
16293 }
16294 }
16296 /* If the type parameter is a parameter pack, then it will
16297 be deduced to an empty parameter pack. */
16299 {
16300 tree arg;
16303 {
16307 }
16308 else
16315 }
16318 }
16319 }
16320 #ifdef ENABLE_CHECKING
16323 #endif
16326 }
16328 /* Subroutine of type_unification_real. Args are like the variables
16329 at the call site. ARG is an overloaded function (or template-id);
16330 we try deducing template args from each of the overloads, and if
16331 only one succeeds, we go with that. Modifies TARGS and returns
16332 true on success. */
16334 static bool
16336 tree targs,
16337 tree parm,
16338 tree arg,
16339 unification_kind_t strict,
16342 {
16349 {
16352 }
16353 else
16357 /* Handle `&x' where `x' is some static or non-static member
16358 function name. */
16364 /* Strip baselink information. */
16369 {
16370 /* If we got some explicit template args, we need to plug them into
16371 the affected templates before we try to unify, in case the
16372 explicit args will completely resolve the templates in question. */
16379 {
16392 {
16397 {
16400 }
16401 }
16404 }
16405 /* If no templates (or more than one) are fully resolved by the
16406 explicit arguments, this template-id is a non-deduced context; it
16407 could still be OK if we deduce all template arguments for the
16408 enclosing call through other arguments. */
16411 }
16414 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16415 -- but the deduction does not succeed because the expression is
16416 not just the function on its own. */
16418 else
16424 {
16427 }
16429 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16430 to function or pointer to member function argument if the set of
16431 overloaded functions does not contain function templates and at most
16432 one of a set of overloaded functions provides a unique match.
16434 So if we found multiple possibilities, we return success but don't
16435 deduce anything. */
16438 {
16443 }
16448 }
16450 /* Core DR 115: In contexts where deduction is done and fails, or in
16451 contexts where deduction is not done, if a template argument list is
16452 specified and it, along with any default template arguments, identifies
16453 a single function template specialization, then the template-id is an
16454 lvalue for the function template specialization. */
16456 tree
16458 {
16471 {
16474 }
16476 {
16479 }
16481 {
16484 }
16487 {
16491 /* If we got some explicit template args, we need to plug them into
16492 the affected templates before we try to unify, in case the
16493 explicit args will completely resolve the templates in question. */
16501 {
16514 {
16517 {
16520 }
16522 {
16525 }
16526 }
16527 }
16529 {
16537 {
16538 tree base
16541 }
16545 }
16547 /* There were no good options and at least one bad one, so let the
16548 user know what the problem is. */
16550 }
16552 }
16554 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16555 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16556 different overloads deduce different arguments for a given parm.
16557 ADDR_P is true if the expression for which deduction is being
16558 performed was of the form "& fn" rather than simply "fn".
16560 Returns 1 on success. */
16562 static int
16564 tree orig_targs,
16565 tree targs,
16566 tree parm,
16567 tree arg,
16568 unification_kind_t strict,
16572 {
16574 tree tempargs;
16580 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16581 to function or pointer to member function argument if the set of
16582 overloaded functions does not contain function templates and at most
16583 one of a set of overloaded functions provides a unique match.
16585 So if this is a template, just return success. */
16597 /* We don't copy orig_targs for this because if we have already deduced
16598 some template args from previous args, unify would complain when we
16599 try to deduce a template parameter for the same argument, even though
16600 there isn't really a conflict. */
16607 /* First make sure we didn't deduce anything that conflicts with
16608 explicitly specified args. */
16610 {
16617 /* Since we're unifying against ourselves, we will fill in
16618 template args used in the function parm list with our own
16619 template parms. Discard them. */
16623 }
16626 {
16631 }
16634 }
16636 /* PARM is a template class (perhaps with unbound template
16637 parameters). ARG is a fully instantiated type. If ARG can be
16638 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16639 TARGS are as for unify. */
16641 static tree
16644 {
16645 tree copy_of_targs;
16652 /* We need to make a new template argument vector for the call to
16653 unify. If we used TARGS, we'd clutter it up with the result of
16654 the attempted unification, even if this class didn't work out.
16655 We also don't want to commit ourselves to all the unifications
16656 we've already done, since unification is supposed to be done on
16657 an argument-by-argument basis. In other words, consider the
16658 following pathological case:
16660 template <int I, int J, int K>
16661 struct S {};
16663 template <int I, int J>
16664 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16666 template <int I, int J, int K>
16667 void f(S<I, J, K>, S<I, I, I>);
16669 void g() {
16670 S<0, 0, 0> s0;
16671 S<0, 1, 2> s2;
16673 f(s0, s2);
16674 }
16676 Now, by the time we consider the unification involving `s2', we
16677 already know that we must have `f<0, 0, 0>'. But, even though
16678 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
16679 because there are two ways to unify base classes of S<0, 1, 2>
16680 with S<I, I, I>. If we kept the already deduced knowledge, we
16681 would reject the possibility I=1. */
16684 /* If unification failed, we're done. */
16690 }
16692 /* Given a template type PARM and a class type ARG, find the unique
16693 base type in ARG that is an instance of PARM. We do not examine
16694 ARG itself; only its base-classes. If there is not exactly one
16695 appropriate base class, return NULL_TREE. PARM may be the type of
16696 a partial specialization, as well as a plain template type. Used
16697 by unify. */
16699 static enum template_base_result
16702 {
16704 tree binfo;
16710 {
16711 /* The type could not be completed. */
16714 }
16716 /* Walk in inheritance graph order. The search order is not
16717 important, and this avoids multiple walks of virtual bases. */
16719 {
16724 {
16725 /* If there is more than one satisfactory baseclass, then:
16727 [temp.deduct.call]
16729 If they yield more than one possible deduced A, the type
16730 deduction fails.
16732 applies. */
16734 {
16737 }
16740 }
16741 }
16745 }
16747 /* Returns the level of DECL, which declares a template parameter. */
16749 static int
16751 {
16753 {
16763 }
16765 }
16767 /* Decide whether ARG can be unified with PARM, considering only the
16768 cv-qualifiers of each type, given STRICT as documented for unify.
16769 Returns nonzero iff the unification is OK on that basis. */
16771 static int
16773 {
16779 {
16780 /* Although a CVR qualifier is ignored when being applied to a
16781 substituted template parameter ([8.3.2]/1 for example), that
16782 does not allow us to unify "const T" with "int&" because both
16783 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
16784 It is ok when we're allowing additional CV qualifiers
16785 at the outer level [14.8.2.1]/3,1st bullet. */
16795 }
16806 }
16808 /* Determines the LEVEL and INDEX for the template parameter PARM. */
16809 void
16811 {
16815 {
16818 }
16819 else
16820 {
16823 }
16824 }
16826 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
16827 do { \
16828 if (unify (TP, TA, P, A, S, EP)) \
16829 return 1; \
16830 } while (0);
16832 /* Unifies the remaining arguments in PACKED_ARGS with the pack
16833 expansion at the end of PACKED_PARMS. Returns 0 if the type
16834 deduction succeeds, 1 otherwise. STRICT is the same as in
16835 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
16836 call argument list. We'll need to adjust the arguments to make them
16837 types. SUBR tells us if this is from a recursive call to
16838 type_unification_real, or for comparing two template argument
16839 lists. */
16841 static int
16845 {
16846 tree parm
16853 /* Determine the parameter packs we will be deducing from the
16854 pattern, and record their current deductions. */
16857 {
16861 /* Determine the index and level of this parameter pack. */
16864 /* Keep track of the parameter packs and their corresponding
16865 argument packs. */
16868 }
16870 /* Loop through all of the arguments that have not yet been
16871 unified and unify each with the pattern. */
16873 {
16874 tree parm;
16878 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
16879 or the element of its argument pack at the current index if
16880 this argument was explicitly specified. */
16882 {
16891 {
16894 }
16896 }
16898 /* If we had explicit template arguments, substitute them into the
16899 pattern before deduction. */
16901 {
16902 /* Some arguments might still be unspecified or dependent. */
16910 NULL_TREE);
16915 }
16916 else
16919 /* Unify the pattern with the current argument. */
16924 /* For each parameter pack, collect the deduced value. */
16926 {
16932 }
16933 }
16935 /* Verify that the results of unification with the parameter packs
16936 produce results consistent with what we've seen before, and make
16937 the deduced argument packs available. */
16939 {
16946 /* By default keep the original deduced argument pack.
16947 If necessary, more specific code is going to update the
16948 resulting deduced argument later down in this function. */
16952 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16953 actually deduce anything. */
16961 {
16962 /* If we had fewer function args than explicit template args,
16963 just use the explicits. */
16968 }
16971 {
16972 tree result;
16973 /* Build the deduced *_ARGUMENT_PACK. */
16975 {
16980 }
16981 else
16986 /* Note the deduced argument packs for this parameter
16987 pack. */
16989 }
16993 {
16994 /* We only had the explicitly-provided arguments before, but
16995 now we have a complete set of arguments. */
17001 }
17002 else
17003 {
17009 /* Inconsistent unification of this parameter pack. */
17011 bad_old_arg,
17012 bad_new_arg);
17013 }
17014 }
17017 }
17019 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17020 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17021 parameters and return value are as for unify. */
17023 static int
17027 {
17028 tree parm_max;
17029 tree arg_max;
17033 /* Our representation of array types uses "N - 1" as the
17034 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17035 not an integer constant. We cannot unify arbitrarily
17036 complex expressions, so we eliminate the MINUS_EXPRs
17037 here. */
17041 {
17044 }
17048 {
17049 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17050 trying to unify the type of a variable with the type
17051 of a template parameter. For example:
17053 template <unsigned int N>
17054 void f (char (&) [N]);
17055 int g();
17056 void h(int i) {
17057 char a[g(i)];
17058 f(a);
17059 }
17061 Here, the type of the ARG will be "int [g(i)]", and
17062 may be a SAVE_EXPR, etc. */
17066 }
17068 /* If only one of the bounds used a MINUS_EXPR, compensate
17069 by adding one to the other bound. */
17072 integer_type_node,
17073 parm_max,
17074 integer_one_node);
17077 integer_type_node,
17078 arg_max,
17079 integer_one_node);
17083 }
17085 /* Deduce the value of template parameters. TPARMS is the (innermost)
17086 set of template parameters to a template. TARGS is the bindings
17087 for those template parameters, as determined thus far; TARGS may
17088 include template arguments for outer levels of template parameters
17089 as well. PARM is a parameter to a template function, or a
17090 subcomponent of that parameter; ARG is the corresponding argument.
17091 This function attempts to match PARM with ARG in a manner
17092 consistent with the existing assignments in TARGS. If more values
17093 are deduced, then TARGS is updated.
17095 Returns 0 if the type deduction succeeds, 1 otherwise. The
17096 parameter STRICT is a bitwise or of the following flags:
17098 UNIFY_ALLOW_NONE:
17099 Require an exact match between PARM and ARG.
17100 UNIFY_ALLOW_MORE_CV_QUAL:
17101 Allow the deduced ARG to be more cv-qualified (by qualification
17102 conversion) than ARG.
17103 UNIFY_ALLOW_LESS_CV_QUAL:
17104 Allow the deduced ARG to be less cv-qualified than ARG.
17105 UNIFY_ALLOW_DERIVED:
17106 Allow the deduced ARG to be a template base class of ARG,
17107 or a pointer to a template base class of the type pointed to by
17108 ARG.
17109 UNIFY_ALLOW_INTEGER:
17110 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17111 case for more information.
17112 UNIFY_ALLOW_OUTER_LEVEL:
17113 This is the outermost level of a deduction. Used to determine validity
17114 of qualification conversions. A valid qualification conversion must
17115 have const qualified pointers leading up to the inner type which
17116 requires additional CV quals, except at the outer level, where const
17117 is not required [conv.qual]. It would be normal to set this flag in
17118 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17119 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17120 This is the outermost level of a deduction, and PARM can be more CV
17121 qualified at this point.
17122 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17123 This is the outermost level of a deduction, and PARM can be less CV
17124 qualified at this point. */
17126 static int
17129 {
17131 tree targ;
17132 tree tparm;
17135 /* I don't think this will do the right thing with respect to types.
17136 But the only case I've seen it in so far has been array bounds, where
17137 signedness is the only information lost, and I think that will be
17138 okay. */
17146 /* We can't deduce anything from this, but we might get all the
17147 template args from other function args. */
17150 /* If PARM uses template parameters, then we can't bail out here,
17151 even if ARG == PARM, since we won't record unifications for the
17152 template parameters. We might need them if we're trying to
17153 figure out which of two things is more specialized. */
17157 /* Handle init lists early, so the rest of the function can assume
17158 we're dealing with a type. */
17160 {
17165 /* Replace T with std::initializer_list<T> for deduction. */
17172 /* We can only deduce from an initializer list argument if the
17173 parameter is std::initializer_list or an array; otherwise this
17174 is a non-deduced context. */
17179 else
17183 {
17190 {
17192 /* It should only be possible to get here for a call. */
17194 elt_strict |= maybe_adjust_types_for_deduction
17197 }
17200 explain_p);
17201 }
17204 {
17205 /* Also deduce from the length of the initializer list. */
17210 }
17212 /* If the std::initializer_list<T> deduction worked, replace the
17213 deduced A with std::initializer_list<A>. */
17215 {
17220 }
17222 }
17224 /* Immediately reject some pairs that won't unify because of
17225 cv-qualification mismatches. */
17228 /* It is the elements of the array which hold the cv quals of an array
17229 type, and the elements might be template type parms. We'll check
17230 when we recurse. */
17232 /* We check the cv-qualifiers when unifying with template type
17233 parameters below. We want to allow ARG `const T' to unify with
17234 PARM `T' for example, when computing which of two templates
17235 is more specialized, for example. */
17249 {
17253 /* In a type which contains a nested-name-specifier, template
17254 argument values cannot be deduced for template parameters used
17255 within the nested-name-specifier. */
17267 /* The PARM is not one we're trying to unify. Just check
17268 to see if it matches ARG. */
17269 {
17274 else
17276 }
17283 /* Check for mixed types and values. */
17291 {
17292 /* ARG must be constructed from a template class or a template
17293 template parameter. */
17298 {
17302 tree parm_parms
17303 = DECL_INNERMOST_TEMPLATE_PARMS
17308 /* The resolution to DR150 makes clear that default
17309 arguments for an N-argument may not be used to bind T
17310 to a template template parameter with fewer than N
17311 parameters. It is not safe to permit the binding of
17312 default arguments as an extension, as that may change
17313 the meaning of a conforming program. Consider:
17315 struct Dense { static const unsigned int dim = 1; };
17317 template <template <typename> class View,
17318 typename Block>
17319 void operator+(float, View<Block> const&);
17321 template <typename Block,
17322 unsigned int Dim = Block::dim>
17323 struct Lvalue_proxy { operator float() const; };
17325 void
17326 test_1d (void) {
17327 Lvalue_proxy<Dense> p;
17328 float b;
17329 b + p;
17330 }
17332 Here, if Lvalue_proxy is permitted to bind to View, then
17333 the global operator+ will be used; if they are not, the
17334 Lvalue_proxy will be converted to float. */
17336 full_argvec,
17338 (explain_p
17339 ? tf_warning_or_error
17346 /* Deduce arguments T, i from TT<T> or TT<i>.
17347 We check each element of PARMVEC and ARGVEC individually
17348 rather than the whole TREE_VEC since they can have
17349 different number of elements. */
17356 /* Check if the parameters end in a pack, making them
17357 variadic. */
17363 /* If the template argument list of P contains a pack
17364 expansion that is not the last template argument, the
17365 entire template argument list is a non-deduced
17366 context. */
17375 {
17380 }
17385 DEDUCE_EXACT,
17388 }
17391 /* Fall through to deduce template name. */
17392 }
17396 {
17397 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17399 /* Simple cases: Value already set, does match or doesn't. */
17404 }
17405 else
17406 {
17407 /* If PARM is `const T' and ARG is only `int', we don't have
17408 a match unless we are allowing additional qualification.
17409 If ARG is `const int' and PARM is just `T' that's OK;
17410 that binds `const int' to `T'. */
17415 /* Consider the case where ARG is `const volatile int' and
17416 PARM is `const T'. Then, T should be `volatile int'. */
17417 arg = cp_build_qualified_type_real
17422 /* Simple cases: Value already set, does match or doesn't. */
17428 /* Make sure that ARG is not a variable-sized array. (Note
17429 that were talking about variable-sized arrays (like
17430 `int[n]'), rather than arrays of unknown size (like
17431 `int[]').) We'll get very confused by such a type since
17432 the bound of the array is not constant, and therefore
17433 not mangleable. Besides, such types are not allowed in
17434 ISO C++, so we can do as we please here. We do allow
17435 them for 'auto' deduction, since that isn't ABI-exposed. */
17439 /* Strip typedefs as in convert_template_argument. */
17441 }
17443 /* If ARG is a parameter pack or an expansion, we cannot unify
17444 against it unless PARM is also a parameter pack. */
17449 /* If the argument deduction results is a METHOD_TYPE,
17450 then there is a problem.
17451 METHOD_TYPE doesn't map to any real C++ type the result of
17452 the deduction can not be of that type. */
17466 {
17467 /* The PARM is not one we're trying to unify. Just check
17468 to see if it matches ARG. */
17474 }
17480 {
17485 }
17487 /* [temp.deduct.type] If, in the declaration of a function template
17488 with a non-type template-parameter, the non-type
17489 template-parameter is used in an expression in the function
17490 parameter-list and, if the corresponding template-argument is
17491 deduced, the template-argument type shall match the type of the
17492 template-parameter exactly, except that a template-argument
17493 deduced from an array bound may be of any integral type.
17494 The non-type parameter might use already deduced type parameters. */
17497 /* Template-parameter dependent expression. Just accept it for now.
17498 It will later be processed in convert_template_argument. */
17499 ;
17504 /* Convert the ARG to the type of PARM; the deduced non-type
17505 template argument must exactly match the types of the
17506 corresponding parameter. */
17509 /* We haven't deduced the type of this parameter yet. Try again
17510 later. */
17512 else
17515 /* If ARG is a parameter pack or an expansion, we cannot unify
17516 against it unless PARM is also a parameter pack. */
17526 {
17527 /* A pointer-to-member constant can be unified only with
17528 another constant. */
17532 /* Just unify the class member. It would be useless (and possibly
17533 wrong, depending on the strict flags) to unify also
17534 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17535 arg refer to the same variable, even if through different
17536 classes. For instance:
17538 struct A { int x; };
17539 struct B : A { };
17541 Unification of &A::x and &B::x must succeed. */
17544 }
17547 {
17551 /* [temp.deduct.call]
17553 A can be another pointer or pointer to member type that can
17554 be converted to the deduced A via a qualification
17555 conversion (_conv.qual_).
17557 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17558 This will allow for additional cv-qualification of the
17559 pointed-to types if appropriate. */
17562 /* The derived-to-base conversion only persists through one
17563 level of pointers. */
17568 }
17600 /* We have already checked cv-qualification at the top of the
17601 function. */
17605 /* As far as unification is concerned, this wins. Later checks
17606 will invalidate it if necessary. */
17609 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17610 /* Type INTEGER_CST can come from ordinary constant template args. */
17622 {
17632 /* Check for pack expansions in the parameters. */
17634 {
17636 {
17638 /* We can unify against something with a trailing
17639 parameter pack. */
17641 else
17642 /* [temp.deduct.type]/9: If the template argument list of
17643 P contains a pack expansion that is not the last
17644 template argument, the entire template argument list
17645 is a non-deduced context. */
17647 }
17648 }
17650 /* If we don't have enough arguments to satisfy the parameters
17651 (not counting the pack expression at the end), or we have
17652 too many arguments for a parameter list that doesn't end in
17653 a pack expression, we can't unify. */
17659 /* Unify all of the parameters that precede the (optional)
17660 pack expression. */
17662 {
17667 }
17670 DEDUCE_EXACT,
17673 }
17681 {
17689 }
17692 {
17696 {
17697 /* First, we try to unify the PARM and ARG directly. */
17702 {
17703 /* Fallback to the special case allowed in
17704 [temp.deduct.call]:
17706 If P is a class, and P has the form
17707 template-id, then A can be a derived class of
17708 the deduced A. Likewise, if P is a pointer to
17709 a class of the form template-id, A can be a
17710 pointer to a derived class pointed to by the
17711 deduced A. */
17718 }
17719 }
17723 /* Perhaps PARM is something like S<U> and ARG is S<int>.
17724 Then, we should unify `int' and `U'. */
17726 else
17727 /* There's no chance of unification succeeding. */
17732 }
17739 {
17742 tree a;
17748 /* CV qualifications for methods can never be deduced, they must
17749 match exactly. We need to check them explicitly here,
17750 because type_unification_real treats them as any other
17751 cv-qualified parameter. */
17753 && (!check_cv_quals_for_unify
17773 }
17776 /* Unify a pointer to member with a pointer to member function, which
17777 deduces the type of the member as a function type. */
17779 {
17780 /* Check top-level cv qualifiers */
17788 /* Determine the type of the function we are unifying against. */
17792 }
17811 /* Matched cases are handled by the ARG == PARM test above. */
17815 /* A non-type template parameter that is a variable should be a
17816 an integral constant, in which case, it whould have been
17817 folded into its (constant) value. So we should not be getting
17818 a variable here. */
17829 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
17830 or UNDERLYING_TYPE nodes. */
17834 /* Unification fails if we hit an error node. */
17838 /* An unresolved overload is a nondeduced context. */
17843 /* We must be looking at an expression. This can happen with
17844 something like:
17846 template <int I>
17847 void foo(S<I>, S<I + 2>);
17849 This is a "nondeduced context":
17851 [deduct.type]
17853 The nondeduced contexts are:
17855 --A type that is a template-id in which one or more of
17856 the template-arguments is an expression that references
17857 a template-parameter.
17859 In these cases, we assume deduction succeeded, but don't
17860 actually infer any unifications. */
17865 else
17867 }
17868 }
17869 #undef RECUR_AND_CHECK_FAILURE
17870 \f
17871 /* Note that DECL can be defined in this translation unit, if
17872 required. */
17874 static void
17876 {
17877 tree clone;
17881 }
17883 /* Called if RESULT is explicitly instantiated, or is a member of an
17884 explicitly instantiated class. */
17886 void
17888 {
17891 /* If this entity has already been written out, it's too late to
17892 make any modifications. */
17896 /* For anonymous namespace we don't need to do anything. */
17898 {
17901 }
17904 /* The TREE_PUBLIC flag for function declarations will have been
17905 set correctly by tsubst. */
17908 /* This might have been set by an earlier implicit instantiation. */
17913 else
17914 {
17916 /* Always make artificials weak. */
17919 /* For WIN32 we also want to put explicit instantiations in
17920 linkonce sections. */
17923 }
17925 /* If EXTERN_P, then this function will not be emitted -- unless
17926 followed by an explicit instantiation, at which point its linkage
17927 will be adjusted. If !EXTERN_P, then this function will be
17928 emitted here. In neither circumstance do we want
17929 import_export_decl to adjust the linkage. */
17931 }
17933 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17934 important template arguments. If any are missing, we check whether
17935 they're important by using error_mark_node for substituting into any
17936 args that were used for partial ordering (the ones between ARGS and END)
17937 and seeing if it bubbles up. */
17939 static bool
17941 {
17946 {
17949 }
17951 {
17955 }
17957 }
17959 /* Given two function templates PAT1 and PAT2, return:
17961 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17962 -1 if PAT2 is more specialized than PAT1.
17963 0 if neither is more specialized.
17965 LEN indicates the number of parameters we should consider
17966 (defaulted parameters should not be considered).
17968 The 1998 std underspecified function template partial ordering, and
17969 DR214 addresses the issue. We take pairs of arguments, one from
17970 each of the templates, and deduce them against each other. One of
17971 the templates will be more specialized if all the *other*
17972 template's arguments deduce against its arguments and at least one
17973 of its arguments *does* *not* deduce against the other template's
17974 corresponding argument. Deduction is done as for class templates.
17975 The arguments used in deduction have reference and top level cv
17976 qualifiers removed. Iff both arguments were originally reference
17977 types *and* deduction succeeds in both directions, an lvalue reference
17978 wins against an rvalue reference and otherwise the template
17979 with the more cv-qualified argument wins for that pairing (if
17980 neither is more cv-qualified, they both are equal). Unlike regular
17981 deduction, after all the arguments have been deduced in this way,
17982 we do *not* verify the deduced template argument values can be
17983 substituted into non-deduced contexts.
17985 The logic can be a bit confusing here, because we look at deduce1 and
17986 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17987 can find template arguments for pat1 to make arg1 look like arg2, that
17988 means that arg2 is at least as specialized as arg1. */
17990 int
17992 {
18005 /* Remove the this parameter from non-static member functions. If
18006 one is a non-static member function and the other is not a static
18007 member function, remove the first parameter from that function
18008 also. This situation occurs for operator functions where we
18009 locate both a member function (with this pointer) and non-member
18010 operator (with explicit first operand). */
18012 {
18017 }
18019 {
18022 {
18023 len--;
18025 }
18026 }
18028 /* If only one is a conversion operator, they are unordered. */
18032 /* Consider the return type for a conversion function */
18034 {
18037 len++;
18038 }
18040 processing_template_decl++;
18046 /* Stop when an ellipsis is seen. */
18048 {
18059 {
18060 /* When both arguments are pack expansions, we need only
18061 unify the patterns themselves. */
18065 /* This is the last comparison we need to do. */
18067 }
18070 {
18074 }
18077 {
18081 }
18087 {
18093 /* Setup the parameter vector, which contains only ARG1. */
18096 /* Setup the argument vector, which contains the remaining
18097 arguments. */
18106 /* We cannot deduce in the other direction, because ARG1 is
18107 a pack expansion but ARG2 is not. */
18109 }
18111 {
18117 /* Setup the parameter vector, which contains only ARG1. */
18120 /* Setup the argument vector, which contains the remaining
18121 arguments. */
18130 /* We cannot deduce in the other direction, because ARG2 is
18131 a pack expansion but ARG1 is not.*/
18133 }
18135 else
18136 {
18137 /* The normal case, where neither argument is a pack
18138 expansion. */
18145 }
18147 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18148 arg2, then arg2 is not as specialized as arg1. */
18154 /* "If, for a given type, deduction succeeds in both directions
18155 (i.e., the types are identical after the transformations above)
18156 and both P and A were reference types (before being replaced with
18157 the type referred to above):
18158 - if the type from the argument template was an lvalue reference and
18159 the type from the parameter template was not, the argument type is
18160 considered to be more specialized than the other; otherwise,
18161 - if the type from the argument template is more cv-qualified
18162 than the type from the parameter template (as described above),
18163 the argument type is considered to be more specialized than the other;
18164 otherwise,
18165 - neither type is more specialized than the other." */
18168 {
18170 {
18173 else
18175 }
18177 {
18182 }
18183 }
18186 /* We've failed to deduce something in either direction.
18187 These must be unordered. */
18192 /* We have already processed all of the arguments in our
18193 handing of the pack expansion type. */
18198 }
18200 /* "In most cases, all template parameters must have values in order for
18201 deduction to succeed, but for partial ordering purposes a template
18202 parameter may remain without a value provided it is not used in the
18203 types being used for partial ordering."
18205 Thus, if we are missing any of the targs1 we need to substitute into
18206 origs1, then pat2 is not as specialized as pat1. This can happen when
18207 there is a nondeduced context. */
18213 processing_template_decl--;
18215 /* All things being equal, if the next argument is a pack expansion
18216 for one function but not for the other, prefer the
18217 non-variadic function. FIXME this is bogus; see c++/41958. */
18221 {
18224 }
18230 else
18232 }
18234 /* Determine which of two partial specializations of MAIN_TMPL is more
18235 specialized.
18237 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18238 to the first partial specialization. The TREE_VALUE is the
18239 innermost set of template parameters for the partial
18240 specialization. PAT2 is similar, but for the second template.
18242 Return 1 if the first partial specialization is more specialized;
18243 -1 if the second is more specialized; 0 if neither is more
18244 specialized.
18246 See [temp.class.order] for information about determining which of
18247 two templates is more specialized. */
18249 static int
18251 {
18252 tree targs;
18260 /* Just like what happens for functions, if we are ordering between
18261 different class template specializations, we may encounter dependent
18262 types in the arguments, and we need our dependency check functions
18263 to behave correctly. */
18269 {
18272 }
18278 {
18281 }
18284 /* In the case of a tie where at least one of the class templates
18285 has a parameter pack at the end, the template with the most
18286 non-packed parameters wins. */
18288 && any_deductions
18291 {
18297 /* We don't count the pack expansion at the end. */
18307 }
18310 }
18312 /* Return the template arguments that will produce the function signature
18313 DECL from the function template FN, with the explicit template
18314 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18315 also match. Return NULL_TREE if no satisfactory arguments could be
18316 found. */
18318 static tree
18320 {
18324 tree decl_arg_types;
18327 tree arg;
18331 /* Never do unification on the 'this' parameter. */
18352 }
18354 /* Return the innermost template arguments that, when applied to a partial
18355 specialization of MAIN_TMPL whose innermost template parameters are
18356 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18357 ARGS.
18359 For example, suppose we have:
18361 template <class T, class U> struct S {};
18362 template <class T> struct S<T*, int> {};
18364 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18365 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18366 int}. The resulting vector will be {double}, indicating that `T'
18367 is bound to `double'. */
18369 static tree
18371 {
18373 tree deduced_args;
18374 tree innermost_deduced_args;
18378 {
18382 innermost_deduced_args);
18383 }
18384 else
18397 /* Verify that nondeduced template arguments agree with the type
18398 obtained from argument deduction.
18400 For example:
18402 struct A { typedef int X; };
18403 template <class T, class U> struct C {};
18404 template <class T> struct C<T, typename T::X> {};
18406 Then with the instantiation `C<A, int>', we can deduce that
18407 `T' is `A' but unify () does not check whether `typename T::X'
18408 is `int'. */
18414 /* We only need to check the innermost arguments; the other
18415 arguments will always agree. */
18420 /* Now that we have bindings for all of the template arguments,
18421 ensure that the arguments deduced for the template template
18422 parameters have compatible template parameter lists. See the use
18423 of template_template_parm_bindings_ok_p in fn_type_unification
18424 for more information. */
18429 }
18431 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18432 Return the TREE_LIST node with the most specialized template, if
18433 any. If there is no most specialized template, the error_mark_node
18434 is returned.
18436 Note that this function does not look at, or modify, the
18437 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18438 returned is one of the elements of INSTANTIATIONS, callers may
18439 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18440 and retrieve it from the value returned. */
18442 tree
18444 {
18451 {
18457 fate--;
18462 fate++;
18467 {
18468 /* Equally specialized, move to next function. If there
18469 is no next function, nothing's most specialized. */
18474 }
18475 }
18478 /* Now verify that champ is better than everything earlier in the
18479 instantiation list. */
18487 {
18490 }
18492 processing_template_decl--;
18498 }
18500 /* If DECL is a specialization of some template, return the most
18501 general such template. Otherwise, returns NULL_TREE.
18503 For example, given:
18505 template <class T> struct S { template <class U> void f(U); };
18507 if TMPL is `template <class U> void S<int>::f(U)' this will return
18508 the full template. This function will not trace past partial
18509 specializations, however. For example, given in addition:
18511 template <class T> struct S<T*> { template <class U> void f(U); };
18513 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18514 `template <class T> template <class U> S<T*>::f(U)'. */
18516 tree
18518 {
18519 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
18520 an immediate specialization. */
18522 {
18526 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
18527 template friend. */
18532 }
18534 /* Look for more and more general templates. */
18536 {
18537 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18538 (See cp-tree.h for details.) */
18546 /* Stop if we run into an explicitly specialized class template. */
18553 }
18556 }
18558 /* Return the most specialized of the class template partial
18559 specializations of TMPL which can produce TYPE, a specialization of
18560 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
18561 a _TYPE node corresponding to the partial specialization, while the
18562 TREE_PURPOSE is the set of template arguments that must be
18563 substituted into the TREE_TYPE in order to generate TYPE.
18565 If the choice of partial specialization is ambiguous, a diagnostic
18566 is issued, and the error_mark_node is returned. If there are no
18567 partial specializations of TMPL matching TYPE, then NULL_TREE is
18568 returned. */
18570 static tree
18572 {
18574 tree t;
18575 tree champ;
18578 tree args;
18584 /* For determining which partial specialization to use, only the
18585 innermost args are interesting. */
18587 {
18590 }
18593 {
18594 tree partial_spec_args;
18595 tree spec_args;
18604 {
18605 /* Discard the outer levels of args, and then substitute in the
18606 template args from the enclosing class. */
18608 partial_spec_args = tsubst_template_args
18611 /* And the same for the partial specialization TEMPLATE_DECL. */
18613 }
18615 partial_spec_args =
18618 partial_spec_args),
18632 partial_spec_args,
18633 args);
18635 {
18640 }
18641 }
18651 {
18654 ;
18655 else
18656 {
18658 {
18661 {
18664 }
18665 }
18667 }
18668 }
18672 {
18675 {
18678 }
18679 }
18682 {
18690 {
18693 }
18696 }
18699 }
18701 /* Explicitly instantiate DECL. */
18703 void
18705 {
18710 /* An error occurred, for which grokdeclarator has already issued
18711 an appropriate message. */
18714 {
18717 }
18719 {
18720 /* There is an asymmetry here in the way VAR_DECLs and
18721 FUNCTION_DECLs are handled by grokdeclarator. In the case of
18722 the latter, the DECL we get back will be marked as a
18723 template instantiation, and the appropriate
18724 DECL_TEMPLATE_INFO will be set up. This does not happen for
18725 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
18726 should handle VAR_DECLs as it currently handles
18727 FUNCTION_DECLs. */
18729 {
18732 }
18735 {
18738 }
18740 {
18745 }
18746 }
18748 {
18751 }
18752 else
18755 /* Check for various error cases. Note that if the explicit
18756 instantiation is valid the RESULT will currently be marked as an
18757 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
18758 until we get here. */
18761 {
18762 /* DR 259 [temp.spec].
18764 Both an explicit instantiation and a declaration of an explicit
18765 specialization shall not appear in a program unless the explicit
18766 instantiation follows a declaration of the explicit specialization.
18768 For a given set of template parameters, if an explicit
18769 instantiation of a template appears after a declaration of an
18770 explicit specialization for that template, the explicit
18771 instantiation has no effect. */
18773 }
18775 {
18776 /* [temp.spec]
18778 No program shall explicitly instantiate any template more
18779 than once.
18781 We check DECL_NOT_REALLY_EXTERN so as not to complain when
18782 the first instantiation was `extern' and the second is not,
18783 and EXTERN_P for the opposite case. */
18786 /* If an "extern" explicit instantiation follows an ordinary
18787 explicit instantiation, the template is instantiated. */
18790 }
18792 {
18795 }
18797 {
18800 }
18803 ;
18805 {
18808 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
18811 }
18812 else
18820 }
18822 static void
18824 {
18830 {
18833 }
18834 }
18836 /* Called from do_type_instantiation through binding_table_foreach to
18837 do recursive instantiation for the type bound in ENTRY. */
18838 static void
18840 {
18846 }
18848 /* Called from do_type_instantiation to instantiate a member
18849 (a member function or a static member variable) of an
18850 explicitly instantiated class template. */
18851 static void
18853 {
18858 }
18860 /* Perform an explicit instantiation of template class T. STORAGE, if
18861 non-null, is the RID for extern, inline or static. COMPLAIN is
18862 nonzero if this is called from the parser, zero if called recursively,
18863 since the standard is unclear (as detailed below). */
18865 void
18867 {
18877 {
18878 tree tmpl =
18882 else
18885 }
18890 {
18893 t);
18895 }
18898 {
18900 {
18902 {
18905 "ISO C++ 1998 forbids the use of %<extern%> on "
18907 }
18908 else
18910 "ISO C++ forbids the use of %qE"
18912 }
18920 else
18921 {
18923 storage);
18925 }
18926 }
18929 {
18930 /* DR 259 [temp.spec].
18932 Both an explicit instantiation and a declaration of an explicit
18933 specialization shall not appear in a program unless the explicit
18934 instantiation follows a declaration of the explicit specialization.
18936 For a given set of template parameters, if an explicit
18937 instantiation of a template appears after a declaration of an
18938 explicit specialization for that template, the explicit
18939 instantiation has no effect. */
18941 }
18943 {
18944 /* [temp.spec]
18946 No program shall explicitly instantiate any template more
18947 than once.
18949 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18950 instantiation was `extern'. If EXTERN_P then the second is.
18951 These cases are OK. */
18958 /* If we've already instantiated the template, just return now. */
18961 }
18969 {
18970 tree tmp;
18972 /* In contrast to implicit instantiation, where only the
18973 declarations, and not the definitions, of members are
18974 instantiated, we have here:
18976 [temp.explicit]
18978 The explicit instantiation of a class template specialization
18979 implies the instantiation of all of its members not
18980 previously explicitly specialized in the translation unit
18981 containing the explicit instantiation.
18983 Of course, we can't instantiate member template classes, since
18984 we don't have any arguments for them. Note that the standard
18985 is unclear on whether the instantiation of the members are
18986 *explicit* instantiations or not. However, the most natural
18987 interpretation is that it should be an explicit instantiation. */
19002 }
19003 }
19005 /* Given a function DECL, which is a specialization of TMPL, modify
19006 DECL to be a re-instantiation of TMPL with the same template
19007 arguments. TMPL should be the template into which tsubst'ing
19008 should occur for DECL, not the most general template.
19010 One reason for doing this is a scenario like this:
19012 template <class T>
19013 void f(const T&, int i);
19015 void g() { f(3, 7); }
19017 template <class T>
19018 void f(const T& t, const int i) { }
19020 Note that when the template is first instantiated, with
19021 instantiate_template, the resulting DECL will have no name for the
19022 first parameter, and the wrong type for the second. So, when we go
19023 to instantiate the DECL, we regenerate it. */
19025 static void
19027 {
19028 /* The arguments used to instantiate DECL, from the most general
19029 template. */
19030 tree args;
19031 tree code_pattern;
19036 /* Make sure that we can see identifiers, and compute access
19037 correctly. */
19041 {
19042 tree decl_parm;
19043 tree pattern_parm;
19044 tree specs;
19058 specs);
19060 /* Merge parameter declarations. */
19063 pattern_parm
19067 {
19068 tree parm_type;
19069 tree attributes;
19074 NULL_TREE);
19080 {
19083 }
19086 }
19087 /* Merge any parameters that match with the function parameter
19088 pack. */
19090 {
19092 tree expanded_types;
19093 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19094 the parameters in this function parameter pack. */
19099 {
19100 tree parm_type;
19101 tree attributes;
19104 /* Rename the parameter to include the index. */
19113 {
19116 }
19118 }
19119 }
19120 /* Merge additional specifiers from the CODE_PATTERN. */
19124 }
19126 {
19134 }
19135 else
19139 }
19141 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19142 substituted to get DECL. */
19144 tree
19146 {
19149 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19150 for the instantiation. This is not always the most general
19151 template. Consider, for example:
19153 template <class T>
19154 struct S { template <class U> void f();
19155 template <> void f<int>(); };
19157 and an instantiation of S<double>::f<int>. We want TD to be the
19158 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19160 more general template. */
19162 /* We must also deal with friend templates. Given:
19164 template <class T> struct S {
19165 template <class U> friend void f() {};
19166 };
19168 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19169 so far as the language is concerned, but that's still
19170 where we get the pattern for the instantiation from. On
19171 other hand, if the definition comes outside the class, say:
19173 template <class T> struct S {
19174 template <class U> friend void f();
19175 };
19176 template <class U> friend void f() {}
19178 we don't need to look any further. That's what the check for
19179 DECL_INITIAL is for. */
19183 {
19184 /* The present template, TD, should not be a definition. If it
19185 were a definition, we should be using it! Note that we
19186 cannot restructure the loop to just keep going until we find
19187 a template with a definition, since that might go too far if
19188 a specialization was declared, but not defined. */
19192 /* Fetch the more general template. */
19194 }
19197 }
19199 /* Returns true if we need to instantiate this template instance even if we
19200 know we aren't going to emit it.. */
19202 bool
19204 {
19205 /* We always instantiate inline functions so that we can inline them. An
19206 explicit instantiation declaration prohibits implicit instantiation of
19207 non-inline functions. With high levels of optimization, we would
19208 normally inline non-inline functions -- but we're not allowed to do
19209 that for "extern template" functions. Therefore, we check
19210 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19214 /* And we need to instantiate static data members so that
19215 their initializers are available in integral constant
19216 expressions. */
19219 }
19221 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19222 instantiate it now, modifying TREE_TYPE (fn). */
19224 void
19226 {
19240 {
19242 {
19257 }
19258 else
19260 }
19261 else
19262 {
19263 /* This is an implicitly declared function, so NOEX is a list of
19264 other functions to evaluate and merge. */
19265 tree elt;
19268 {
19270 tree subspec;
19274 }
19275 }
19280 {
19283 else
19285 }
19286 }
19288 /* Produce the definition of D, a _DECL generated from a template. If
19289 DEFER_OK is nonzero, then we don't have to actually do the
19290 instantiation now; we just have to do it sometime. Normally it is
19291 an error if this is an explicit instantiation but D is undefined.
19292 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19293 explicitly instantiated class template. */
19295 tree
19298 {
19300 tree gen_args;
19301 tree args;
19302 tree td;
19303 tree code_pattern;
19304 tree spec;
19305 tree gen_tmpl;
19311 tree fn_context;
19314 /* This function should only be used to instantiate templates for
19315 functions and static member variables. */
19318 /* Variables are never deferred; if instantiation is required, they
19319 are instantiated right away. That allows for better code in the
19320 case that an expression refers to the value of the variable --
19321 if the variable has a constant value the referring expression can
19322 take advantage of that fact. */
19327 /* Don't instantiate cloned functions. Instead, instantiate the
19328 functions they cloned. */
19336 /* D has already been instantiated or explicitly specialized, so
19337 there's nothing for us to do here.
19339 It might seem reasonable to check whether or not D is an explicit
19340 instantiation, and, if so, stop here. But when an explicit
19341 instantiation is deferred until the end of the compilation,
19342 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19343 the instantiation. */
19346 /* Check to see whether we know that this template will be
19347 instantiated in some other file, as with "extern template"
19348 extension. */
19351 /* In general, we do not instantiate such templates. */
19359 /* We should already have the extra args. */
19362 /* And what's in the hash table should match D. */
19366 /* This needs to happen before any tsubsting. */
19372 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19373 for the instantiation. */
19377 /* We should never be trying to instantiate a member of a class
19378 template or partial specialization. */
19383 /* In the case of a friend template whose definition is provided
19384 outside the class, we may have too many arguments. Drop the
19385 ones we don't need. The same is true for specializations. */
19386 args = get_innermost_template_args
19388 else
19394 else
19397 /* We may be in the middle of deferred access check. Disable it now. */
19400 /* Unless an explicit instantiation directive has already determined
19401 the linkage of D, remember that a definition is available for
19402 this entity. */
19412 /* If D is a member of an explicitly instantiated class template,
19413 and no definition is available, treat it like an implicit
19414 instantiation. */
19417 {
19418 /* Leave linkage flags alone on instantiations with anonymous
19419 visibility. */
19421 {
19424 }
19426 }
19431 /* Defer all other templates, unless we have been explicitly
19432 forbidden from doing so. */
19434 template. */
19435 ! pattern_defined
19436 /* If it's OK to postpone instantiation, do so. */
19437 || defer_ok
19438 /* If this is a static data member that will be defined
19439 elsewhere, we don't want to instantiate the entire data
19440 member, but we do want to instantiate the initializer so that
19441 we can substitute that elsewhere. */
19443 {
19444 /* The definition of the static data member is now required so
19445 we must substitute the initializer. */
19449 {
19450 tree ns;
19451 tree init;
19458 args,
19461 /* Make sure the initializer is still constant, in case of
19462 circular dependency (template/instantiate6.C). */
19463 const_init
19467 LOOKUP_ONLYCONVERTING);
19470 }
19472 /* We restore the source position here because it's used by
19473 add_pending_template. */
19479 /* [temp.explicit]
19481 The definition of a non-exported function template, a
19482 non-exported member function template, or a non-exported
19483 member function or static data member of a class template
19484 shall be present in every translation unit in which it is
19485 explicitly instantiated. */
19489 /* If we're in unevaluated context, we just wanted to get the
19490 constant value; this isn't an odr use, so don't queue
19491 a full instantiation. */
19494 /* ??? Historically, we have instantiated inline functions, even
19495 when marked as "extern template". */
19499 }
19500 /* Tell the repository that D is available in this translation unit
19501 -- and see if it is supposed to be instantiated here. */
19503 {
19504 /* In a PCH file, despite the fact that the repository hasn't
19505 requested instantiation in the PCH it is still possible that
19506 an instantiation will be required in a file that includes the
19507 PCH. */
19510 /* Instantiate inline functions so that the inliner can do its
19511 job, even though we'll not be emitting a copy of this
19512 function. */
19515 }
19521 else
19522 {
19527 }
19529 /* Mark D as instantiated so that recursive calls to
19530 instantiate_decl do not try to instantiate it again. */
19533 /* Regenerate the declaration in case the template has been modified
19534 by a subsequent redeclaration. */
19537 /* We already set the file and line above. Reset them now in case
19538 they changed as a result of calling regenerate_decl_from_template. */
19542 {
19543 tree init;
19546 /* Clear out DECL_RTL; whatever was there before may not be right
19547 since we've reset the type of the declaration. */
19551 /* The initializer is placed in DECL_INITIAL by
19552 regenerate_decl_from_template so we don't need to
19553 push/pop_access_scope again here. Pull it out so that
19554 cp_finish_decl can process it. */
19559 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19560 initializer. That function will defer actual emission until
19561 we have a chance to determine linkage. */
19564 /* Enter the scope of D so that access-checking works correctly. */
19569 }
19573 {
19575 tree subst_decl;
19576 tree tmpl_parm;
19577 tree spec_parm;
19580 /* Save away the current list, in case we are instantiating one
19581 template from within the body of another. */
19584 /* Set up the list of local specializations. */
19587 /* Set up context. */
19591 else
19594 /* Some typedefs referenced from within the template code need to be
19595 access checked at template instantiation time, i.e now. These
19596 types were added to the template at parsing time. Let's get those
19597 and perform the access checks then. */
19599 gen_args);
19601 /* Create substitution entries for the parameters. */
19606 {
19610 }
19612 {
19614 {
19617 }
19618 else
19619 {
19620 /* Register the (value) argument pack as a specialization of
19621 TMPL_PARM, then move on. */
19624 }
19625 }
19628 /* Substitute into the body of the function. */
19632 else
19633 {
19638 /* Set the current input_location to the end of the function
19639 so that finish_function knows where we are. */
19640 input_location
19642 }
19644 /* We don't need the local specializations any more. */
19648 /* Finish the function. */
19652 else
19653 {
19656 }
19660 }
19662 /* We're not deferring instantiation any more. */
19670 out:
19680 }
19682 /* Run through the list of templates that we wish we could
19683 instantiate, and instantiate any we can. RETRIES is the
19684 number of times we retry pending template instantiation. */
19686 void
19688 {
19692 /* Instantiating templates may trigger vtable generation. This in turn
19693 may require further template instantiations. We place a limit here
19694 to avoid infinite loop. */
19696 {
19700 " instantiating %q+D, possibly from virtual table generation"
19704 /* Pretend that we defined it. */
19707 }
19709 do
19710 {
19715 {
19720 {
19721 tree fn;
19724 {
19728 fn;
19736 }
19739 }
19740 else
19741 {
19744 {
19745 instantiation
19751 }
19755 }
19758 /* If INSTANTIATION has been instantiated, then we don't
19759 need to consider it again in the future. */
19761 else
19762 {
19765 }
19768 }
19770 }
19774 }
19776 /* Substitute ARGVEC into T, which is a list of initializers for
19777 either base class or a non-static data member. The TREE_PURPOSEs
19778 are DECLs, and the TREE_VALUEs are the initializer values. Used by
19779 instantiate_decl. */
19781 static tree
19783 {
19787 {
19788 tree decl;
19789 tree init;
19795 {
19796 tree expr;
19797 tree arg;
19799 /* Expand the base class expansion type into separate base
19800 classes. */
19802 tf_warning_or_error,
19803 NULL_TREE);
19807 /* We'll be building separate TREE_LISTs of arguments for
19808 each base. */
19814 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
19815 expand each argument in the TREE_VALUE of t. */
19822 /* VOID_TYPE_NODE is used to indicate
19823 value-initialization. */
19824 {
19827 }
19828 else
19829 {
19830 /* Substitute parameter packs into each argument in the
19831 TREE_LIST. */
19834 {
19835 tree expanded_exprs;
19837 /* Expand the argument. */
19839 expanded_exprs
19841 tf_warning_or_error,
19842 NULL_TREE);
19846 /* Prepend each of the expanded expressions to the
19847 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
19849 {
19854 }
19855 }
19858 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
19859 since we built them backwards. */
19861 {
19864 }
19865 }
19866 }
19869 {
19871 {
19875 }
19876 else
19877 {
19878 tree tmp;
19893 /* If we had an initializer but it instantiated to nothing,
19894 value-initialize the object. This will only occur when
19895 the initializer was a pack expansion where the parameter
19896 packs used in that expansion were of length zero. */
19899 }
19902 {
19906 }
19907 }
19908 }
19910 }
19912 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19914 static void
19916 {
19921 else
19923 }
19925 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19926 is the instantiation (which should have been created with
19927 start_enum) and ARGS are the template arguments to use. */
19929 static void
19931 {
19932 tree e;
19938 {
19939 tree value;
19940 tree decl;
19943 /* Note that in a template enum, the TREE_VALUE is the
19944 CONST_DECL, not the corresponding INTEGER_CST. */
19949 /* Give this enumeration constant the correct access. */
19952 /* Actually build the enumerator itself. */
19953 build_enumerator
19955 }
19965 }
19967 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19968 its type -- but without substituting the innermost set of template
19969 arguments. So, innermost set of template parameters will appear in
19970 the type. */
19972 tree
19974 {
19975 tree fn_type;
19976 tree tmpl;
19977 tree targs;
19978 tree tparms;
19986 /* There should be as many levels of arguments as there are levels
19987 of parameters. */
19993 /* No substitution is necessary. */
19994 ;
19995 else
19996 {
19998 tree partial_args;
20000 /* Replace the innermost level of the TARGS with NULL_TREEs to
20001 let tsubst know not to substitute for those parameters. */
20010 /* Make sure that we can see identifiers, and compute access
20011 correctly. */
20015 /* Now, do the (partial) substitution to figure out the
20016 appropriate function type. */
20020 /* Substitute into the template parameters to obtain the real
20021 innermost set of parameters. This step is important if the
20022 innermost set of template parameters contains value
20023 parameters whose types depend on outer template parameters. */
20028 }
20031 }
20033 /* Return truthvalue if we're processing a template different from
20034 the last one involved in diagnostics. */
20035 int
20037 {
20039 }
20041 /* Remember current template involved in diagnostics. */
20042 void
20044 {
20046 }
20050 {
20052 }
20054 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20055 type. Return zero for ok, nonzero for disallowed. Issue error and
20056 warning messages under control of COMPLAIN. */
20058 static int
20060 {
20077 {
20080 else
20082 type);
20083 }
20085 }
20087 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20088 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20090 static bool
20092 {
20093 tree scope;
20095 /* [temp.dep.type]
20097 A type is dependent if it is:
20099 -- a template parameter. Template template parameters are types
20100 for us (since TYPE_P holds true for them) so we handle
20101 them here. */
20105 /* -- a qualified-id with a nested-name-specifier which contains a
20106 class-name that names a dependent type or whose unqualified-id
20107 names a dependent type. */
20110 /* -- a cv-qualified type where the cv-unqualified type is
20111 dependent. */
20113 /* -- a compound type constructed from any dependent type. */
20123 {
20124 tree arg_type;
20129 arg_type;
20134 }
20135 /* -- an array type constructed from any dependent type or whose
20136 size is specified by a constant expression that is
20137 value-dependent.
20139 We checked for type- and value-dependence of the bounds in
20140 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20142 {
20147 }
20149 /* -- a template-id in which either the template name is a template
20150 parameter ... */
20153 /* ... or any of the template arguments is a dependent type or
20154 an expression that is type-dependent or value-dependent. */
20156 && (any_dependent_template_arguments_p
20160 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20161 dependent; if the argument of the `typeof' expression is not
20162 type-dependent, then it should already been have resolved. */
20168 /* A template argument pack is dependent if any of its packed
20169 arguments are. */
20171 {
20177 }
20179 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20180 be template parameters. */
20184 /* The standard does not specifically mention types that are local
20185 to template functions or local classes, but they should be
20186 considered dependent too. For example:
20188 template <int I> void f() {
20189 enum E { a = I };
20190 S<sizeof (E)> s;
20191 }
20193 The size of `E' cannot be known until the value of `I' has been
20194 determined. Therefore, `E' must be considered dependent. */
20198 /* Don't use type_dependent_expression_p here, as it can lead
20199 to infinite recursion trying to determine whether a lambda
20200 nested in a lambda is dependent (c++/47687). */
20204 && (any_dependent_template_arguments_p
20208 /* Other types are non-dependent. */
20210 }
20212 /* Returns TRUE if TYPE is dependent, in the sense of
20213 [temp.dep.type]. Note that a NULL type is considered dependent. */
20215 bool
20217 {
20218 /* If there are no template parameters in scope, then there can't be
20219 any dependent types. */
20221 {
20222 /* If we are not processing a template, then nobody should be
20223 providing us with a dependent type. */
20227 }
20229 /* If the type is NULL, we have not computed a type for the entity
20230 in question; in that case, the type is dependent. */
20234 /* Erroneous types can be considered non-dependent. */
20238 /* If we have not already computed the appropriate value for TYPE,
20239 do so now. */
20241 {
20244 }
20247 }
20249 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20250 lookup. In other words, a dependent type that is not the current
20251 instantiation. */
20253 bool
20255 {
20258 }
20260 /* T is a SCOPE_REF; return whether we need to consider it
20261 instantiation-dependent so that we can check access at instantiation
20262 time even though we know which member it resolves to. */
20264 static bool
20266 {
20272 else
20274 }
20276 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20277 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20278 expression. */
20280 /* Note that this predicate is not appropriate for general expressions;
20281 only constant expressions (that satisfy potential_constant_expression)
20282 can be tested for value dependence. */
20284 bool
20286 {
20290 /* A name declared with a dependent type. */
20295 {
20297 /* A name that has not been looked up -- must be dependent. */
20301 /* A non-type template parm. */
20305 /* A non-type template parm. */
20311 /* A constant with literal type and is initialized
20312 with an expression that is value-dependent.
20314 Note that a non-dependent parenthesized initializer will have
20315 already been replaced with its constant value, so if we see
20316 a TREE_LIST it must be dependent. */
20329 /* These expressions are value-dependent if the type to which
20330 the cast occurs is dependent or the expression being casted
20331 is value-dependent. */
20332 {
20338 /* A functional cast has a list of operands. */
20341 {
20342 /* If there are no operands, it must be an expression such
20343 as "int()". This should not happen for aggregate types
20344 because it would form non-constant expressions. */
20349 }
20355 }
20360 /* FALLTHRU */
20363 /* A `sizeof' expression is value-dependent if the operand is
20364 type-dependent or is a pack expansion. */
20373 /* An 'encode' expression is value-dependent if the operand is
20374 type-dependent. */
20383 /* All instantiation-dependent expressions should also be considered
20384 value-dependent. */
20392 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20393 is value-dependent. */
20394 {
20403 }
20406 {
20410 }
20421 {
20425 }
20428 {
20435 {
20437 /* In a call to a constexpr member function, look through the
20438 implicit ADDR_EXPR on the object argument so that it doesn't
20439 cause the call to be considered value-dependent. We also
20440 look through it in potential_constant_expression. */
20447 }
20449 }
20452 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20453 type-dependent. */
20457 {
20459 tree val;
20464 }
20467 /* Treat a GNU statement expression as dependent to avoid crashing
20468 under fold_non_dependent_expr; it can't be constant. */
20472 /* A constant expression is value-dependent if any subexpression is
20473 value-dependent. */
20475 {
20482 {
20486 {
20489 /* In some cases, some of the operands may be missing.l
20490 (For example, in the case of PREDECREMENT_EXPR, the
20491 amount to increment by may be missing.) That doesn't
20492 make the expression dependent. */
20495 }
20496 }
20500 }
20502 }
20504 /* The expression is not value-dependent. */
20506 }
20508 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20509 [temp.dep.expr]. Note that an expression with no type is
20510 considered dependent. Other parts of the compiler arrange for an
20511 expression with type-dependent subexpressions to have no type, so
20512 this function doesn't have to be fully recursive. */
20514 bool
20516 {
20523 /* An unresolved name is always dependent. */
20527 /* Some expression forms are never type-dependent. */
20540 /* The types of these expressions depends only on the type to which
20541 the cast occurs. */
20550 /* The types of these expressions depends only on the type created
20551 by the expression. */
20554 {
20555 /* For NEW_EXPR tree nodes created inside a template, either
20556 the object type itself or a TREE_LIST may appear as the
20557 operand 1. */
20560 /* This is an array type. We need to check array dimensions
20561 as well. */
20563 || value_dependent_expression_p
20565 else
20567 }
20570 {
20574 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20575 contains an identifier associated by name lookup with one or more
20576 declarations declared with a dependent type, or...a
20577 nested-name-specifier or qualified-id that names a member of an
20578 unknown specialization. */
20581 }
20586 && (any_dependent_template_arguments_p
20598 {
20599 tree elt;
20603 {
20606 }
20608 }
20610 /* A static data member of the current instantiation with incomplete
20611 array type is type-dependent, as the definition and specializations
20612 can have different bounds. */
20619 /* An array of unknown bound depending on a variadic parameter, eg:
20621 template<typename... Args>
20622 void foo (Args... args)
20623 {
20624 int arr[] = { args... };
20625 }
20627 template<int... vals>
20628 void bar ()
20629 {
20630 int arr[] = { vals... };
20631 }
20633 If the array has no length and has an initializer, it must be that
20634 we couldn't determine its length in cp_complete_array_type because
20635 it is dependent. */
20643 {
20648 {
20654 }
20655 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
20659 /* Always dependent, on the number of arguments if nothing else. */
20667 {
20672 }
20677 {
20681 }
20683 }
20688 }
20690 /* walk_tree callback function for instantiation_dependent_expression_p,
20691 below. Returns non-zero if a dependent subexpression is found. */
20693 static tree
20696 {
20698 {
20699 /* We don't have to worry about decltype currently because decltype
20700 of an instantiation-dependent expr is a dependent type. This
20701 might change depending on the resolution of DR 1172. */
20704 }
20707 {
20708 /* Don't treat an argument list as dependent just because it has no
20709 TREE_TYPE. */
20716 /* A constant with a dependent initializer is dependent. */
20724 /* Handle expressions with type operands. */
20729 {
20734 {
20737 else
20738 {
20741 }
20742 }
20744 }
20756 /* In a template, finish_class_member_access_expr creates a
20757 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
20758 type-dependent, so that we can check access control at
20759 instantiation time (PR 42277). See also Core issue 1273. */
20766 else
20769 /* Treat statement-expressions as dependent. */
20775 }
20779 else
20781 }
20783 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
20784 sense defined by the ABI:
20786 "An expression is instantiation-dependent if it is type-dependent
20787 or value-dependent, or it has a subexpression that is type-dependent
20788 or value-dependent." */
20790 bool
20792 {
20793 tree result;
20804 }
20806 /* Like type_dependent_expression_p, but it also works while not processing
20807 a template definition, i.e. during substitution or mangling. */
20809 bool
20811 {
20817 }
20819 /* Returns TRUE if ARGS contains a type-dependent expression. */
20821 bool
20823 {
20825 tree arg;
20828 {
20831 }
20833 }
20835 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20836 expressions) contains any type-dependent expressions. */
20838 bool
20840 {
20846 }
20848 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20849 expressions) contains any value-dependent expressions. */
20851 bool
20853 {
20859 }
20861 /* Returns TRUE if the ARG (a template argument) is dependent. */
20863 bool
20865 {
20869 /* Assume a template argument that was wrongly written by the user
20870 is dependent. This is consistent with what
20871 any_dependent_template_arguments_p [that calls this function]
20872 does. */
20883 {
20887 {
20890 }
20893 }
20896 else
20899 }
20901 /* Returns true if ARGS (a collection of template arguments) contains
20902 any types that require structural equality testing. */
20904 bool
20906 {
20916 {
20919 {
20925 {
20926 /* Look inside the argument pack. */
20929 }
20932 {
20945 }
20946 }
20947 }
20950 }
20952 /* Returns true if ARGS (a collection of template arguments) contains
20953 any dependent arguments. */
20955 bool
20957 {
20967 {
20972 }
20975 }
20977 /* Returns TRUE if the template TMPL is dependent. */
20979 bool
20981 {
20983 {
20985 {
20989 }
20991 }
20993 /* Template template parameters are dependent. */
20997 /* So are names that have not been looked up. */
21000 /* So are member templates of dependent classes. */
21004 }
21006 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21008 bool
21010 {
21013 }
21015 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21016 is dependent. */
21018 bool
21020 {
21027 {
21048 {
21052 }
21056 {
21060 {
21065 }
21066 }
21067 }
21070 }
21072 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21073 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21074 no such TYPE can be found. Note that this function peers inside
21075 uninstantiated templates and therefore should be used only in
21076 extremely limited situations. ONLY_CURRENT_P restricts this
21077 peering to the currently open classes hierarchy (which is required
21078 when comparing types). */
21080 tree
21082 {
21083 tree scope;
21084 tree name;
21085 tree decl;
21087 tree pushed_scope;
21088 tree result;
21093 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21094 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21095 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21096 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21097 identifier of the TYPENAME_TYPE anymore.
21098 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21099 TYPENAME_TYPE instead, we avoid messing up with a possible
21100 typedef variant case. */
21103 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21104 it first before we can figure out what NAME refers to. */
21106 {
21108 /* Given a class template A with a dependent base with nested type C,
21109 typedef typename A::C::C C will land us here, as trying to resolve
21110 the initial A::C leads to the local C typedef, which leads back to
21111 A::C::C. So we break the recursion now. */
21113 else
21115 }
21116 /* If we don't know what SCOPE refers to, then we cannot resolve the
21117 TYPENAME_TYPE. */
21120 /* If the SCOPE is a template type parameter, we have no way of
21121 resolving the name. */
21124 /* If the SCOPE is not the current instantiation, there's no reason
21125 to look inside it. */
21128 /* If this is a typedef, we don't want to look inside (c++/11987). */
21131 /* If SCOPE isn't the template itself, it will not have a valid
21132 TYPE_FIELDS list. */
21134 /* scope is either the template itself or a compatible instantiation
21135 like X<T>, so look up the name in the original template. */
21137 else
21138 /* scope is a partial instantiation, so we can't do the lookup or we
21139 will lose the template arguments. */
21141 /* Enter the SCOPE so that name lookup will be resolved as if we
21142 were in the class definition. In particular, SCOPE will no
21143 longer be considered a dependent type. */
21145 /* Look up the declaration. */
21147 tf_warning_or_error);
21151 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21152 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21157 {
21161 }
21164 {
21165 tree tmpl;
21166 tree args;
21167 /* Obtain the template and the arguments. */
21170 /* Instantiate the template. */
21176 }
21178 /* Leave the SCOPE. */
21182 /* If we failed to resolve it, return the original typename. */
21186 /* If lookup found a typename type, resolve that too. */
21188 {
21189 /* Ill-formed programs can cause infinite recursion here, so we
21190 must catch that. */
21194 }
21196 /* Qualify the resulting type. */
21202 }
21204 /* EXPR is an expression which is not type-dependent. Return a proxy
21205 for EXPR that can be used to compute the types of larger
21206 expressions containing EXPR. */
21208 tree
21210 {
21211 tree inner_expr;
21213 #ifdef ENABLE_CHECKING
21214 /* Try to get a constant value for all non-dependent expressions in
21215 order to expose bugs in *_dependent_expression_p and constexpr. */
21218 #endif
21220 /* Preserve OVERLOADs; the functions must be available to resolve
21221 types. */
21232 /* There is no need to return a proxy for a variable. */
21235 /* Preserve string constants; conversions from string constants to
21236 "char *" are allowed, even though normally a "const char *"
21237 cannot be used to initialize a "char *". */
21240 /* Preserve arithmetic constants, as an optimization -- there is no
21241 reason to create a new node. */
21244 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21245 There is at least one place where we want to know that a
21246 particular expression is a throw-expression: when checking a ?:
21247 expression, there are special rules if the second or third
21248 argument is a throw-expression. */
21252 /* Don't wrap an initializer list, we need to be able to look inside. */
21256 /* Don't wrap a dummy object, we need to be able to test for it. */
21275 /* If the type is unknown, it can't really be non-dependent */
21278 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21280 }
21282 /* ARGS is a vector of expressions as arguments to a function call.
21283 Replace the arguments with equivalent non-dependent expressions.
21284 This modifies ARGS in place. */
21286 void
21288 {
21290 tree arg;
21293 {
21297 }
21298 }
21300 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21301 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21302 parms. */
21304 static tree
21306 {
21319 }
21321 tree
21323 {
21325 }
21327 tree
21329 {
21331 }
21333 /* Given type ARG, return std::initializer_list<ARG>. */
21335 static tree
21337 {
21338 tree std_init_list = namespace_binding
21340 tree argvec;
21342 {
21346 }
21351 }
21353 /* Replace auto in TYPE with std::initializer_list<auto>. */
21355 static tree
21357 {
21364 }
21366 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21367 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21369 tree
21371 {
21372 tree targs;
21378 /* Defining a subset of type-dependent expressions that we can deduce
21379 from ahead of time isn't worth the trouble. */
21382 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21383 with either a new invented type template parameter U or, if the
21384 initializer is a braced-init-list (8.5.4), with
21385 std::initializer_list<U>. */
21393 {
21398 {
21401 }
21402 }
21403 else
21404 {
21415 {
21417 /* Try again at instantiation time. */
21420 /* If type is error_mark_node a diagnostic must have been
21421 emitted by now. Also, having a mention to '<type error>'
21422 in the diagnostic is not really useful to the user. */
21423 {
21427 else
21429 }
21431 }
21432 }
21434 /* If the list of declarators contains more than one declarator, the type
21435 of each declared variable is determined as described above. If the
21436 type deduced for the template parameter U is not the same in each
21437 deduction, the program is ill-formed. */
21440 {
21446 else
21450 }
21456 }
21458 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21459 result. */
21461 tree
21463 {
21464 tree argvec;
21471 /* For a late-specified return type in a template type-parameter, we
21472 need to add a dummy argument level for its parmlist. */
21473 argvec = add_to_template_args
21478 }
21480 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21481 'decltype(auto)'. */
21483 bool
21485 {
21490 else
21492 }
21494 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21495 a use of `auto'. Returns NULL_TREE otherwise. */
21497 tree
21499 {
21501 }
21503 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21504 'decltype(auto)' or a concept. */
21506 bool
21508 {
21510 }
21512 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21513 a concept identifier) iff TYPE contains a use of a generic type. Returns
21514 NULL_TREE otherwise. */
21516 tree
21518 {
21520 }
21523 /* For a given template T, return the vector of typedefs referenced
21524 in T for which access check is needed at T instantiation time.
21525 T is either a FUNCTION_DECL or a RECORD_TYPE.
21526 Those typedefs were added to T by the function
21527 append_type_to_template_for_access_check. */
21531 {
21532 tree ti;
21543 {
21548 }
21551 }
21553 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21554 tied to T. That list of typedefs will be access checked at
21555 T instantiation time.
21556 T is either a FUNCTION_DECL or a RECORD_TYPE.
21557 TYPE_DECL is a TYPE_DECL node representing a typedef.
21558 SCOPE is the scope through which TYPE_DECL is accessed.
21559 LOCATION is the location of the usage point of TYPE_DECL.
21561 This function is a subroutine of
21562 append_type_to_template_for_access_check. */
21564 static void
21566 tree type_decl,
21567 tree scope,
21568 location_t location)
21569 {
21570 qualified_typedef_usage_t typedef_usage;
21571 tree ti;
21578 && type_decl
21592 }
21594 /* Append TYPE_DECL to the template TEMPL.
21595 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21596 At TEMPL instanciation time, TYPE_DECL will be checked to see
21597 if it can be accessed through SCOPE.
21598 LOCATION is the location of the usage point of TYPE_DECL.
21600 e.g. consider the following code snippet:
21602 class C
21603 {
21604 typedef int myint;
21605 };
21607 template<class U> struct S
21608 {
21609 C::myint mi; // <-- usage point of the typedef C::myint
21610 };
21612 S<char> s;
21614 At S<char> instantiation time, we need to check the access of C::myint
21615 In other words, we need to check the access of the myint typedef through
21616 the C scope. For that purpose, this function will add the myint typedef
21617 and the scope C through which its being accessed to a list of typedefs
21618 tied to the template S. That list will be walked at template instantiation
21619 time and access check performed on each typedefs it contains.
21620 Note that this particular code snippet should yield an error because
21621 myint is private to C. */
21623 void
21625 tree type_decl,
21626 tree scope,
21627 location_t location)
21628 {
21634 /* Make sure we don't append the type to the template twice. */
21641 }
21643 /* Convert the generic type parameters in PARM that match the types given in the
21644 range [START_IDX, END_IDX) from the current_template_parms into generic type
21645 packs. */
21647 tree
21649 {
21660 {
21661 /* Create a distinct parameter pack type from the current parm and add it
21662 to the replacement args to tsubst below into the generic function
21663 parameter. */
21678 }
21684 /* If there are more levels then build up the replacement with the outer
21685 template parms. */
21689 replacement);
21692 }
21695 /* Set up the hash tables for template instantiations. */
21697 void
21699 {
21701 hash_specialization,
21702 eq_specializations,
21703 ggc_free);
21705 hash_specialization,
21706 eq_specializations,
21707 ggc_free);
21708 }
21710 /* Print stats about the template hash tables for -fstats. */
21712 void
21714 {
21723 }