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1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
48 /* The type of functions taking a tree, and some additional data, and
49 returning an int. */
52 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
53 instantiations have been deferred, either because their definitions
54 were not yet available, or because we were putting off doing the work. */
58 };
73 /* Live only within one (recursive) call to tsubst_expr. We use
74 this to pass the statement expression node from the STMT_EXPR
75 to the EXPR_STMT that is its result. */
78 /* A map from local variable declarations in the body of the template
79 presently being instantiated to the corresponding instantiated
80 local variables. */
84 {
85 tree tmpl;
86 tree args;
87 tree spec;
91 htab_t decl_specializations;
94 htab_t type_specializations;
96 /* Contains canonical template parameter types. The vector is indexed by
97 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
98 TREE_LIST, whose TREE_VALUEs contain the canonical template
99 parameters of various types and levels. */
102 #define UNIFY_ALLOW_NONE 0
103 #define UNIFY_ALLOW_MORE_CV_QUAL 1
104 #define UNIFY_ALLOW_LESS_CV_QUAL 2
105 #define UNIFY_ALLOW_DERIVED 4
106 #define UNIFY_ALLOW_INTEGER 8
107 #define UNIFY_ALLOW_OUTER_LEVEL 16
108 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
109 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
129 tree);
189 location_t);
199 /* Make the current scope suitable for access checking when we are
200 processing T. T can be FUNCTION_DECL for instantiated function
201 template, or VAR_DECL for static member variable (need by
202 instantiate_decl). */
204 static void
206 {
214 else
218 {
219 saved_access_scope = tree_cons
222 }
223 }
225 /* Restore the scope set up by push_access_scope. T is the node we
226 are processing. */
228 static void
230 {
232 {
235 }
239 else
241 }
243 /* Do any processing required when DECL (a member template
244 declaration) is finished. Returns the TEMPLATE_DECL corresponding
245 to DECL, unless it is a specialization, in which case the DECL
246 itself is returned. */
248 tree
250 {
257 {
258 tree type;
266 {
270 }
272 }
276 {
278 {
281 }
282 else
284 }
285 else
289 }
291 /* Create a template info node. */
293 tree
295 {
300 }
302 /* Return the template info node corresponding to T, whatever T is. */
304 tree
306 {
324 }
326 /* Returns the template nesting level of the indicated class TYPE.
328 For example, in:
329 template <class T>
330 struct A
331 {
332 template <class U>
333 struct B {};
334 };
336 A<T>::B<U> has depth two, while A<T> has depth one.
337 Both A<T>::B<int> and A<int>::B<U> have depth one, if
338 they are instantiations, not specializations.
340 This function is guaranteed to return 0 if passed NULL_TREE so
341 that, for example, `template_class_depth (current_class_type)' is
342 always safe. */
344 int
346 {
353 {
359 }
362 }
364 /* Subroutine of maybe_begin_member_template_processing.
365 Returns true if processing DECL needs us to push template parms. */
367 static bool
369 {
375 }
377 /* Subroutine of maybe_begin_member_template_processing.
378 Push the template parms in PARMS, starting from LEVELS steps into the
379 chain, and ending at the beginning, since template parms are listed
380 innermost first. */
382 static void
384 {
392 current_template_parms
398 NULL);
400 {
409 {
416 {
417 /* Make a CONST_DECL as is done in process_template_parm.
418 It is ugly that we recreate this here; the original
419 version built in process_template_parm is no longer
420 available. */
430 }
435 }
436 }
437 }
439 /* Restore the template parameter context for a member template or
440 a friend template defined in a class definition. */
442 void
444 {
445 tree parms;
449 {
454 {
457 }
460 }
462 /* Remember how many levels of template parameters we pushed so that
463 we can pop them later. */
465 }
467 /* Undo the effects of maybe_begin_member_template_processing. */
469 void
471 {
480 {
484 }
485 }
487 /* Return a new template argument vector which contains all of ARGS,
488 but has as its innermost set of arguments the EXTRA_ARGS. */
490 static tree
492 {
493 tree new_args;
511 }
513 /* Like add_to_template_args, but only the outermost ARGS are added to
514 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
515 (EXTRA_ARGS) levels are added. This function is used to combine
516 the template arguments from a partial instantiation with the
517 template arguments used to attain the full instantiation from the
518 partial instantiation. */
520 static tree
522 {
523 tree new_args;
525 /* If there are more levels of EXTRA_ARGS than there are ARGS,
526 something very fishy is going on. */
529 /* If *all* the new arguments will be the EXTRA_ARGS, just return
530 them. */
534 /* For the moment, we make ARGS look like it contains fewer levels. */
539 /* Now, we restore ARGS to its full dimensions. */
543 }
545 /* Return the N levels of innermost template arguments from the ARGS. */
547 tree
549 {
550 tree new_args;
556 /* If N is 1, just return the innermost set of template arguments. */
560 /* If we're not removing anything, just return the arguments we were
561 given. */
567 /* Make a new set of arguments, not containing the outer arguments. */
574 }
576 /* The inverse of get_innermost_template_args: Return all but the innermost
577 EXTRA_LEVELS levels of template arguments from the ARGS. */
579 static tree
581 {
582 tree new_args;
588 /* If N is 1, just return the outermost set of template arguments. */
592 /* If we're not removing anything, just return the arguments we were
593 given. */
598 /* Make a new set of arguments, not containing the inner arguments. */
605 }
607 /* We've got a template header coming up; push to a new level for storing
608 the parms. */
610 void
612 {
613 /* We use a non-tag-transparent scope here, which causes pushtag to
614 put tags in this scope, rather than in the enclosing class or
615 namespace scope. This is the right thing, since we want
616 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
617 global template class, push_template_decl handles putting the
618 TEMPLATE_DECL into top-level scope. For a nested template class,
619 e.g.:
621 template <class T> struct S1 {
622 template <class T> struct S2 {};
623 };
625 pushtag contains special code to call pushdecl_with_scope on the
626 TEMPLATE_DECL for S2. */
631 }
633 /* This routine is called when a specialization is declared. If it is
634 invalid to declare a specialization here, an error is reported and
635 false is returned, otherwise this routine will return true. */
637 static bool
639 {
642 /* [temp.expl.spec]
644 An explicit specialization shall be declared in the namespace of
645 which the template is a member, or, for member templates, in the
646 namespace of which the enclosing class or enclosing class
647 template is a member. An explicit specialization of a member
648 function, member class or static data member of a class template
649 shall be declared in the namespace of which the class template
650 is a member. */
652 {
655 }
657 /* [temp.expl.spec]
659 In an explicit specialization declaration for a member of a class
660 template or a member template that appears in namespace scope,
661 the member template and some of its enclosing class templates may
662 remain unspecialized, except that the declaration shall not
663 explicitly specialize a class member template if its enclosing
664 class templates are not explicitly specialized as well. */
666 {
669 }
672 }
674 /* We've just seen template <>. */
676 bool
678 {
682 }
684 /* Called at then end of processing a declaration preceded by
685 template<>. */
687 void
689 {
692 }
694 /* Any template <>'s that we have seen thus far are not referring to a
695 function specialization. */
697 void
699 {
702 }
704 /* We've just seen a template header. If SPECIALIZATION is nonzero,
705 it was of the form template <>. */
707 static void
709 {
711 template_header_count++;
712 }
714 /* We're beginning an explicit instantiation. */
716 void
718 {
721 }
724 void
726 {
729 }
731 /* An explicit specialization or partial specialization TMPL is being
732 declared. Check that the namespace in which the specialization is
733 occurring is permissible. Returns false iff it is invalid to
734 specialize TMPL in the current namespace. */
736 static bool
738 {
741 /* [tmpl.expl.spec]
743 An explicit specialization shall be declared in the namespace of
744 which the template is a member, or, for member templates, in the
745 namespace of which the enclosing class or enclosing class
746 template is a member. An explicit specialization of a member
747 function, member class or static data member of a class template
748 shall be declared in the namespace of which the class template is
749 a member. */
752 {
755 }
757 /* Same or super-using namespace. */
759 else
760 {
764 }
765 }
767 /* SPEC is an explicit instantiation. Check that it is valid to
768 perform this explicit instantiation in the current namespace. */
770 static void
772 {
773 tree ns;
775 /* DR 275: An explicit instantiation shall appear in an enclosing
776 namespace of its template. */
782 }
784 /* The TYPE is being declared. If it is a template type, that means it
785 is a partial specialization. Do appropriate error-checking. */
787 tree
789 {
790 tree context;
796 {
800 }
805 {
806 /* This is for ordinary explicit specialization and partial
807 specialization of a template class such as:
809 template <> class C<int>;
811 or:
813 template <class T> class C<T*>;
815 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
819 {
823 {
827 }
828 }
831 }
837 {
838 /* This is for an explicit specialization of member class
839 template according to [temp.expl.spec/18]:
841 template <> template <class U> class C<int>::D;
843 The context `C<int>' must be an implicit instantiation.
844 Otherwise this is just a member class template declared
845 earlier like:
847 template <> class C<int> { template <class U> class D; };
848 template <> template <class U> class C<int>::D;
850 In the first case, `C<int>::D' is a specialization of `C<T>::D'
851 while in the second case, `C<int>::D' is a primary template
852 and `C<T>::D' may not exist. */
856 {
857 tree t;
862 {
865 }
867 /* Check for invalid specialization after instantiation:
869 template <> template <> class C<int>::D<int>;
870 template <> template <class U> class C<int>::D; */
874 {
877 {
878 /* We already have a full specialization of this partial
879 instantiation. Reassign it to the new member
880 specialization template. */
881 spec_entry elt;
897 }
899 /* But if we've had an implicit instantiation, that's a
900 problem ([temp.expl.spec]/6). */
903 }
905 /* Mark TYPE as a specialization. And as a result, we only
906 have one level of template argument for the innermost
907 class template. */
911 }
912 }
914 {
915 /* Someday C++0x may allow for enum template specialization. */
920 else
921 {
924 }
925 }
928 }
930 /* Returns nonzero if we can optimize the retrieval of specializations
931 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
932 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
936 {
939 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
940 parameter. */
942 /* The optimized lookup depends on the fact that the
943 template arguments for the member function template apply
944 purely to the containing class, which is not true if the
945 containing class is an explicit or partial
946 specialization. */
950 /* It is possible to have a template that is not a member
951 template and is not a member of a template class:
953 template <typename T>
954 struct S { friend A::f(); };
956 Here, the friend function is a template, but the context does
957 not have template information. The optimized lookup relies
958 on having ARGS be the template arguments for both the class
959 and the function template. */
961 }
963 /* Retrieve the specialization (in the sense of [temp.spec] - a
964 specialization is either an instantiation or an explicit
965 specialization) of TMPL for the given template ARGS. If there is
966 no such specialization, return NULL_TREE. The ARGS are a vector of
967 arguments, or a vector of vectors of arguments, in the case of
968 templates with more than one level of parameters.
970 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
971 then we search for a partial specialization matching ARGS. This
972 parameter is ignored if TMPL is not a class template. */
974 static tree
976 {
982 /* There should be as many levels of arguments as there are
983 levels of parameters. */
988 {
989 tree class_template;
990 tree class_specialization;
992 tree fns;
995 /* The template arguments actually apply to the containing
996 class. Find the class specialization with those
997 arguments. */
999 class_specialization
1003 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1004 for the specialization. */
1008 /* Iterate through the methods with the indicated name, looking
1009 for the one that has an instance of TMPL. */
1012 {
1015 /* using-declarations can add base methods to the method vec,
1016 and we don't want those here. */
1019 }
1021 }
1022 else
1023 {
1025 spec_entry elt;
1026 htab_t specializations;
1034 else
1042 }
1045 }
1047 /* Like retrieve_specialization, but for local declarations. */
1049 static tree
1051 {
1052 tree spec;
1060 }
1062 /* Returns nonzero iff DECL is a specialization of TMPL. */
1064 int
1066 {
1067 tree t;
1070 {
1076 }
1077 else
1078 {
1087 }
1090 }
1092 /* Returns nonzero iff DECL is a specialization of friend declaration
1093 FRIEND_DECL according to [temp.friend]. */
1095 bool
1097 {
1104 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1105 of a template class, we want to check if DECL is a specialization
1106 if this. */
1110 {
1111 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1114 }
1119 /* There is nothing to do if this is not a template friend. */
1126 /* [temp.friend/6]
1127 A member of a class template may be declared to be a friend of a
1128 non-template class. In this case, the corresponding member of
1129 every specialization of the class template is a friend of the
1130 class granting friendship.
1132 For example, given a template friend declaration
1134 template <class T> friend void A<T>::f();
1136 the member function below is considered a friend
1138 template <> struct A<int> {
1139 void f();
1140 };
1142 For this type of template friend, TEMPLATE_DEPTH below will be
1143 nonzero. To determine if DECL is a friend of FRIEND, we first
1144 check if the enclosing class is a specialization of another. */
1151 {
1152 /* Next, we check the members themselves. In order to handle
1153 a few tricky cases, such as when FRIEND_DECL's are
1155 template <class T> friend void A<T>::g(T t);
1156 template <class T> template <T t> friend void A<T>::h();
1158 and DECL's are
1160 void A<int>::g(int);
1161 template <int> void A<int>::h();
1163 we need to figure out ARGS, the template arguments from
1164 the context of DECL. This is required for template substitution
1165 of `T' in the function parameter of `g' and template parameter
1166 of `h' in the above examples. Here ARGS corresponds to `int'. */
1173 {
1175 {
1178 else
1180 current_depth++;
1181 }
1183 }
1186 {
1188 tree friend_type;
1189 tree decl_type;
1190 tree friend_args_type;
1191 tree decl_args_type;
1193 /* Make sure that both DECL and FRIEND_DECL are templates or
1194 non-templates. */
1200 {
1201 /* If both are templates, check template parameter list. */
1202 tree friend_parms
1207 friend_parms))
1211 }
1212 else
1220 /* Check if return types match. */
1224 /* Check if function parameter types match, ignoring the
1225 `this' parameter. */
1234 }
1235 else
1236 {
1237 /* DECL is a TYPE_DECL */
1241 /* Make sure that both DECL and FRIEND_DECL are templates or
1242 non-templates. */
1243 is_template
1250 {
1251 tree friend_parms;
1252 /* If both are templates, check the name of the two
1253 TEMPLATE_DECL's first because is_friend didn't. */
1258 /* Now check template parameter list. */
1259 friend_parms
1262 return comp_template_parms
1264 friend_parms);
1265 }
1266 else
1269 }
1270 }
1272 }
1274 /* Register the specialization SPEC as a specialization of TMPL with
1275 the indicated ARGS. IS_FRIEND indicates whether the specialization
1276 is actually just a friend declaration. Returns SPEC, or an
1277 equivalent prior declaration, if available. */
1279 static tree
1281 hashval_t hash)
1282 {
1283 tree fn;
1285 spec_entry elt;
1291 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1292 register it; we want the corresponding TEMPLATE_DECL instead.
1293 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1294 the more obvious `uses_template_parms (spec)' to avoid problems
1295 with default function arguments. In particular, given
1296 something like this:
1298 template <class T> void f(T t1, T t = T())
1300 the default argument expression is not substituted for in an
1301 instantiation unless and until it is actually needed. */
1305 /* We don't put these specializations in the hash table, but we might
1306 want to give an error about a mismatch. */
1308 else
1309 {
1321 else
1323 }
1325 /* We can sometimes try to re-register a specialization that we've
1326 already got. In particular, regenerate_decl_from_template calls
1327 duplicate_decls which will update the specialization list. But,
1328 we'll still get called again here anyhow. It's more convenient
1329 to simply allow this than to try to prevent it. */
1333 {
1335 {
1338 {
1340 fn);
1342 }
1343 else
1344 {
1345 tree clone;
1346 /* This situation should occur only if the first
1347 specialization is an implicit instantiation, the
1348 second is an explicit specialization, and the
1349 implicit instantiation has not yet been used. That
1350 situation can occur if we have implicitly
1351 instantiated a member function and then specialized
1352 it later.
1354 We can also wind up here if a friend declaration that
1355 looked like an instantiation turns out to be a
1356 specialization:
1358 template <class T> void foo(T);
1359 class S { friend void foo<>(int) };
1360 template <> void foo(int);
1362 We transform the existing DECL in place so that any
1363 pointers to it become pointers to the updated
1364 declaration.
1366 If there was a definition for the template, but not
1367 for the specialization, we want this to look as if
1368 there were no definition, and vice versa. */
1371 /* The call to duplicate_decls will have applied
1372 [temp.expl.spec]:
1374 An explicit specialization of a function template
1375 is inline only if it is explicitly declared to be,
1376 and independently of whether its function template
1377 is.
1379 to the primary function; now copy the inline bits to
1380 the various clones. */
1382 {
1387 }
1391 }
1392 }
1394 {
1396 /* Dup decl failed, but this is a new definition. Set the
1397 line number so any errors match this new
1398 definition. */
1402 }
1403 }
1407 /* A specialization must be declared in the same namespace as the
1408 template it is specializing. */
1414 {
1421 /* TMPL is a forward declaration of a template function; keep a list
1422 of all specializations in case we need to reassign them to a friend
1423 template later in tsubst_friend_function. */
1426 }
1429 }
1431 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1432 TMPL and ARGS members, ignores SPEC. */
1434 static int
1436 {
1442 }
1444 /* Returns a hash for a template TMPL and template arguments ARGS. */
1446 static hashval_t
1448 {
1451 }
1453 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1454 ignoring SPEC. */
1456 static hashval_t
1458 {
1461 }
1463 /* Recursively calculate a hash value for a template argument ARG, for use
1464 in the hash tables of template specializations. */
1466 hashval_t
1468 {
1480 /* We can get one of these when re-hashing a previous entry in the middle
1481 of substituting into a pack expansion. Just look through it. */
1490 {
1498 {
1503 }
1524 {
1527 {
1530 }
1532 }
1547 val = iterative_hash_template_arg
1559 val);
1561 val);
1570 /* layout_type sets structural equality for arrays of
1571 incomplete type, so we can't rely on the canonical type
1572 for hashing. */
1577 /* A lambda can't appear in a template arg, but don't crash on
1578 erroneous input. */
1589 /* Now hash operands as usual. */
1594 }
1597 {
1601 val);
1604 /* Otherwise just compare the types during lookup. */
1613 {
1618 }
1619 }
1622 }
1624 /* Unregister the specialization SPEC as a specialization of TMPL.
1625 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1626 if the SPEC was listed as a specialization of TMPL.
1628 Note that SPEC has been ggc_freed, so we can't look inside it. */
1630 bool
1632 {
1634 spec_entry elt;
1642 {
1647 }
1650 }
1652 /* Compare an entry in the local specializations hash table P1 (which
1653 is really a pointer to a TREE_LIST) with P2 (which is really a
1654 DECL). */
1656 static int
1658 {
1660 }
1662 /* Hash P1, an entry in the local specializations table. */
1664 static hashval_t
1666 {
1668 }
1670 /* Like register_specialization, but for local declarations. We are
1671 registering SPEC, an instantiation of TMPL. */
1673 static void
1675 {
1681 }
1683 /* TYPE is a class type. Returns true if TYPE is an explicitly
1684 specialized class. */
1686 bool
1688 {
1692 }
1694 /* Print the list of functions at FNS, going through all the overloads
1695 for each element of the list. Alternatively, FNS can not be a
1696 TREE_LIST, in which case it will be printed together with all the
1697 overloads.
1699 MORE and *STR should respectively be FALSE and NULL when the function
1700 is called from the outside. They are used internally on recursive
1701 calls. print_candidates manages the two parameters and leaves NULL
1702 in *STR when it ends. */
1704 static void
1706 {
1712 {
1717 }
1718 else
1719 {
1721 {
1722 /* Pick the prefix string. */
1724 {
1727 }
1731 }
1734 }
1737 {
1740 }
1741 }
1743 /* Print the list of candidate FNS in an error message. */
1745 void
1747 {
1751 }
1753 /* Returns the template (one of the functions given by TEMPLATE_ID)
1754 which can be specialized to match the indicated DECL with the
1755 explicit template args given in TEMPLATE_ID. The DECL may be
1756 NULL_TREE if none is available. In that case, the functions in
1757 TEMPLATE_ID are non-members.
1759 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1760 specialization of a member template.
1762 The TEMPLATE_COUNT is the number of references to qualifying
1763 template classes that appeared in the name of the function. See
1764 check_explicit_specialization for a more accurate description.
1766 TSK indicates what kind of template declaration (if any) is being
1767 declared. TSK_TEMPLATE indicates that the declaration given by
1768 DECL, though a FUNCTION_DECL, has template parameters, and is
1769 therefore a template function.
1771 The template args (those explicitly specified and those deduced)
1772 are output in a newly created vector *TARGS_OUT.
1774 If it is impossible to determine the result, an error message is
1775 issued. The error_mark_node is returned to indicate failure. */
1777 static tree
1779 tree decl,
1783 tmpl_spec_kind tsk)
1784 {
1785 tree fns;
1786 tree targs;
1787 tree explicit_targs;
1789 /* A TREE_LIST of templates of which DECL may be a specialization.
1790 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1791 corresponding TREE_PURPOSE is the set of template arguments that,
1792 when used to instantiate the template, would produce a function
1793 with the signature of DECL. */
1809 /* Check for baselinks. */
1814 {
1817 }
1819 /* Count the number of template headers specified for this
1820 specialization. */
1828 {
1832 {
1833 tree decl_arg_types;
1834 tree fn_arg_types;
1836 /* In case of explicit specialization, we need to check if
1837 the number of template headers appearing in the specialization
1838 is correct. This is usually done in check_explicit_specialization,
1839 but the check done there cannot be exhaustive when specializing
1840 member functions. Consider the following code:
1842 template <> void A<int>::f(int);
1843 template <> template <> void A<int>::f(int);
1845 Assuming that A<int> is not itself an explicit specialization
1846 already, the first line specializes "f" which is a non-template
1847 member function, whilst the second line specializes "f" which
1848 is a template member function. So both lines are syntactically
1849 correct, and check_explicit_specialization does not reject
1850 them.
1852 Here, we can do better, as we are matching the specialization
1853 against the declarations. We count the number of template
1854 headers, and we check if they match TEMPLATE_COUNT + 1
1855 (TEMPLATE_COUNT is the number of qualifying template classes,
1856 plus there must be another header for the member template
1857 itself).
1859 Notice that if header_count is zero, this is not a
1860 specialization but rather a template instantiation, so there
1861 is no check we can perform here. */
1865 /* Check that the number of template arguments at the
1866 innermost level for DECL is the same as for FN. */
1874 /* DECL might be a specialization of FN. */
1878 /* For a non-static member function, we need to make sure
1879 that the const qualification is the same. Since
1880 get_bindings does not try to merge the "this" parameter,
1881 we must do the comparison explicitly. */
1887 /* Skip the "this" parameter and, for constructors of
1888 classes with virtual bases, the VTT parameter. A
1889 full specialization of a constructor will have a VTT
1890 parameter, but a template never will. */
1891 decl_arg_types
1893 fn_arg_types
1896 /* Check that the number of function parameters matches.
1897 For example,
1898 template <class T> void f(int i = 0);
1899 template <> void f<int>();
1900 The specialization f<int> is invalid but is not caught
1901 by get_bindings below. */
1905 /* Function templates cannot be specializations; there are
1906 no partial specializations of functions. Therefore, if
1907 the type of DECL does not match FN, there is no
1908 match. */
1910 {
1914 }
1916 /* See whether this function might be a specialization of this
1917 template. */
1921 /* We cannot deduce template arguments that when used to
1922 specialize TMPL will produce DECL. */
1925 /* Save this template, and the arguments deduced. */
1927 }
1929 /* FN is an ordinary member function, and we need a
1930 specialization of a member template. */
1931 ;
1933 /* We can get IDENTIFIER_NODEs here in certain erroneous
1934 cases. */
1935 ;
1937 /* This is just an ordinary non-member function. Nothing can
1938 be a specialization of that. */
1939 ;
1941 /* Cannot specialize functions that are created implicitly. */
1942 ;
1943 else
1944 {
1945 tree decl_arg_types;
1947 /* This is an ordinary member function. However, since
1948 we're here, we can assume it's enclosing class is a
1949 template class. For example,
1951 template <typename T> struct S { void f(); };
1952 template <> void S<int>::f() {}
1954 Here, S<int>::f is a non-template, but S<int> is a
1955 template class. If FN has the same type as DECL, we
1956 might be in business. */
1959 /* Its enclosing class is an explicit specialization
1960 of a template class. This is not a candidate. */
1965 /* The return types differ. */
1968 /* Adjust the type of DECL in case FN is a static member. */
1975 decl_arg_types))
1976 /* They match! */
1978 }
1979 }
1982 {
1983 /* We have:
1985 [temp.expl.spec]
1987 It is possible for a specialization with a given function
1988 signature to be instantiated from more than one function
1989 template. In such cases, explicit specification of the
1990 template arguments must be used to uniquely identify the
1991 function template specialization being specialized.
1993 Note that here, there's no suggestion that we're supposed to
1994 determine which of the candidate templates is most
1995 specialized. However, we, also have:
1997 [temp.func.order]
1999 Partial ordering of overloaded function template
2000 declarations is used in the following contexts to select
2001 the function template to which a function template
2002 specialization refers:
2004 -- when an explicit specialization refers to a function
2005 template.
2007 So, we do use the partial ordering rules, at least for now.
2008 This extension can only serve to make invalid programs valid,
2009 so it's safe. And, there is strong anecdotal evidence that
2010 the committee intended the partial ordering rules to apply;
2011 the EDG front end has that behavior, and John Spicer claims
2012 that the committee simply forgot to delete the wording in
2013 [temp.expl.spec]. */
2016 {
2019 }
2020 }
2023 {
2031 }
2035 {
2041 }
2043 /* We have one, and exactly one, match. */
2045 {
2048 /* DECL is a re-declaration or partial instantiation of a template
2049 function. */
2052 /* It was a specialization of an ordinary member function in a
2053 template class. */
2055 }
2057 /* It was a specialization of a template. */
2060 {
2065 }
2066 else
2069 }
2071 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2072 but with the default argument values filled in from those in the
2073 TMPL_TYPES. */
2075 static tree
2077 tree tmpl_types)
2078 {
2079 tree new_spec_types;
2087 /* Substitute into the rest of the list. */
2088 new_spec_types =
2092 /* Add the default argument for this parameter. */
2095 new_spec_types);
2096 }
2098 /* DECL is an explicit specialization. Replicate default arguments
2099 from the template it specializes. (That way, code like:
2101 template <class T> void f(T = 3);
2102 template <> void f(double);
2103 void g () { f (); }
2105 works, as required.) An alternative approach would be to look up
2106 the correct default arguments at the call-site, but this approach
2107 is consistent with how implicit instantiations are handled. */
2109 static void
2111 {
2112 tree tmpl;
2113 tree spec_types;
2114 tree tmpl_types;
2115 tree new_spec_types;
2116 tree old_type;
2117 tree new_type;
2118 tree t;
2123 /* See if there's anything we need to do. */
2136 {
2137 /* Remove the this pointer, but remember the object's type for
2138 CV quals. */
2144 {
2145 /* DECL may contain more parameters than TMPL due to the extra
2146 in-charge parameter in constructors and destructors. */
2149 }
2151 {
2154 }
2155 }
2157 /* Compute the merged default arguments. */
2158 new_spec_types =
2161 /* Compute the new FUNCTION_TYPE. */
2163 {
2167 new_spec_types);
2170 /* Put the in-charge parameter back. */
2173 new_spec_types);
2177 new_spec_types);
2178 }
2179 else
2181 new_spec_types);
2187 }
2189 /* Check to see if the function just declared, as indicated in
2190 DECLARATOR, and in DECL, is a specialization of a function
2191 template. We may also discover that the declaration is an explicit
2192 instantiation at this point.
2194 Returns DECL, or an equivalent declaration that should be used
2195 instead if all goes well. Issues an error message if something is
2196 amiss. Returns error_mark_node if the error is not easily
2197 recoverable.
2199 FLAGS is a bitmask consisting of the following flags:
2201 2: The function has a definition.
2202 4: The function is a friend.
2204 The TEMPLATE_COUNT is the number of references to qualifying
2205 template classes that appeared in the name of the function. For
2206 example, in
2208 template <class T> struct S { void f(); };
2209 void S<int>::f();
2211 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2212 classes are not counted in the TEMPLATE_COUNT, so that in
2214 template <class T> struct S {};
2215 template <> struct S<int> { void f(); }
2216 template <> void S<int>::f();
2218 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2219 invalid; there should be no template <>.)
2221 If the function is a specialization, it is marked as such via
2222 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2223 is set up correctly, and it is added to the list of specializations
2224 for that template. */
2226 tree
2228 tree decl,
2231 {
2239 tmpl_spec_kind tsk;
2242 {
2245 else
2247 }
2248 else
2252 {
2255 {
2258 }
2260 {
2262 /* This could be something like:
2264 template <class T> void f(T);
2265 class S { friend void f<>(int); } */
2267 else
2268 {
2269 /* This case handles bogus declarations like template <>
2270 template <class T> void f<int>(); */
2273 declarator);
2275 }
2276 }
2280 /* The error has already been reported in
2281 check_specialization_scope. */
2287 /* Fall through. */
2300 decl);
2303 else
2307 /* Fall through. */
2312 else
2318 {
2319 /* This case handles bogus declarations like template <>
2320 template <class T> void f<int>(); */
2325 else
2327 declarator);
2329 }
2332 /* This is a specialization of a member template, without
2333 specialization the containing class. Something like:
2335 template <class T> struct S {
2336 template <class U> void f (U);
2337 };
2338 template <> template <class U> void S<int>::f(U) {}
2340 That's a specialization -- but of the entire template. */
2346 }
2349 {
2353 {
2357 }
2358 }
2361 {
2365 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2367 {
2368 tree fns;
2373 else
2374 {
2375 /* If there is no class context, the explicit instantiation
2376 must be at namespace scope. */
2379 /* Find the namespace binding, using the declaration
2380 context. */
2384 {
2387 }
2388 else
2389 {
2395 }
2396 }
2399 }
2405 {
2407 /* A specialization in class scope. This is invalid,
2408 but the error will already have been flagged by
2409 check_specialization_scope. */
2411 else
2412 {
2413 /* It's not valid to write an explicit instantiation in
2414 class scope, e.g.:
2416 class C { template void f(); }
2418 This case is caught by the parser. However, on
2419 something like:
2421 template class C { void f(); };
2423 (which is invalid) we can get here. The error will be
2424 issued later. */
2425 ;
2426 }
2429 }
2432 IDENTIFIER_NODE))
2433 {
2434 /* Find the list of functions in ctype that have the same
2435 name as the declared function. */
2441 {
2446 {
2447 /* From [temp.expl.spec]:
2449 If such an explicit specialization for the member
2450 of a class template names an implicitly-declared
2451 special member function (clause _special_), the
2452 program is ill-formed.
2454 Similar language is found in [temp.explicit]. */
2457 }
2460 }
2463 {
2467 }
2468 else
2469 {
2471 tree ovl;
2473 /* For a type-conversion operator, we cannot do a
2474 name-based lookup. We might be looking for `operator
2475 int' which will be a specialization of `operator T'.
2476 So, we find *all* the conversion operators, and then
2477 select from them. */
2485 {
2487 /* There are no more conversion functions. */
2490 /* Glue all these conversion functions together
2491 with those we already have. */
2494 }
2495 }
2498 {
2501 }
2502 else
2504 }
2506 /* Figure out what exactly is being specialized at this point.
2507 Note that for an explicit instantiation, even one for a
2508 member function, we cannot tell apriori whether the
2509 instantiation is for a member template, or just a member
2510 function of a template class. Even if a member template is
2511 being instantiated, the member template arguments may be
2512 elided if they can be deduced from the rest of the
2513 declaration. */
2516 member_specialization,
2517 template_count,
2518 tsk);
2521 /* We couldn't figure out what this declaration was
2522 specializing. */
2524 else
2525 {
2529 {
2530 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2531 is done by do_decl_instantiation later. */
2537 {
2538 /* If TMPL is not the most general template (for
2539 example, if TMPL is a friend template that is
2540 injected into namespace scope), then there will
2541 be too many levels of TARGS. Remove some of them
2542 here. */
2544 tree new_targs;
2551 }
2554 }
2556 /* If we thought that the DECL was a member function, but it
2557 turns out to be specializing a static member function,
2558 make DECL a static member function as well. */
2563 /* If this is a specialization of a member template of a
2564 template class, we want to return the TEMPLATE_DECL, not
2565 the specialization of it. */
2567 {
2572 {
2573 tree parm;
2577 /* We want to use the argument list specified in the
2578 definition, not in the original declaration. */
2583 }
2586 }
2588 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2591 /* Inherit default function arguments from the template
2592 DECL is specializing. */
2595 /* This specialization has the same protection as the
2596 template it specializes. */
2600 /* 7.1.1-1 [dcl.stc]
2602 A storage-class-specifier shall not be specified in an
2603 explicit specialization...
2605 The parser rejects these, so unless action is taken here,
2606 explicit function specializations will always appear with
2607 global linkage.
2609 The action recommended by the C++ CWG in response to C++
2610 defect report 605 is to make the storage class and linkage
2611 of the explicit specialization match the templated function:
2613 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2614 */
2616 {
2620 /* This specialization has the same linkage and visibility as
2621 the function template it specializes. */
2624 {
2627 }
2630 {
2633 }
2634 }
2636 /* If DECL is a friend declaration, declared using an
2637 unqualified name, the namespace associated with DECL may
2638 have been set incorrectly. For example, in:
2640 template <typename T> void f(T);
2641 namespace N {
2642 struct S { friend void f<int>(int); }
2643 }
2645 we will have set the DECL_CONTEXT for the friend
2646 declaration to N, rather than to the global namespace. */
2651 /* This is not really a declaration of a specialization.
2652 It's just the name of an instantiation. But, it's not
2653 a request for an instantiation, either. */
2656 /* This is indeed a specialization. In case of constructors
2657 and destructors, we need in-charge and not-in-charge
2658 versions in V3 ABI. */
2661 /* Register this specialization so that we can find it
2662 again. */
2664 }
2665 }
2668 }
2670 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2671 parameters. These are represented in the same format used for
2672 DECL_TEMPLATE_PARMS. */
2674 int
2676 {
2677 const_tree p1;
2678 const_tree p2;
2686 {
2698 {
2702 /* If either of the template parameters are invalid, assume
2703 they match for the sake of error recovery. */
2716 }
2717 }
2720 /* One set of parameters has more parameters lists than the
2721 other. */
2725 }
2727 /* Determine whether PARM is a parameter pack. */
2729 bool
2731 {
2732 /* Determine if we have a non-type template parameter pack. */
2737 /* If this is a list of template parameters, we could get a
2738 TYPE_DECL or a TEMPLATE_DECL. */
2745 }
2747 /* Determine if T is a function parameter pack. */
2749 bool
2751 {
2755 }
2757 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2758 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2760 tree
2762 {
2769 }
2771 /* Return true iff the function parameter PARAM_DECL was expanded
2772 from the function parameter pack PACK. */
2774 bool
2776 {
2781 /* The parameter pack and its pack arguments have the same
2782 DECL_PARM_INDEX. */
2784 }
2786 /* Determine whether ARGS describes a variadic template args list,
2787 i.e., one that is terminated by a template argument pack. */
2789 static bool
2791 {
2793 tree last_parm;
2807 }
2809 /* Generate a new name for the parameter pack name NAME (an
2810 IDENTIFIER_NODE) that incorporates its */
2812 static tree
2814 {
2815 /* Munge the name to include the parameter index. */
2816 #define NUMBUF_LEN 128
2828 }
2830 /* Return true if T is a primary function
2831 or class template instantiation. */
2833 bool
2835 {
2847 }
2849 /* Return true if PARM is a template template parameter. */
2851 bool
2853 {
2855 }
2857 /* Return the template parameters of T if T is a
2858 primary template instantiation, NULL otherwise. */
2860 tree
2862 {
2867 parms = INNERMOST_TEMPLATE_PARMS
2871 }
2873 /* Return the template parameters of the LEVELth level from the full list
2874 of template parameters PARMS. */
2876 tree
2878 {
2879 tree p;
2890 }
2892 /* Returns the template arguments of T if T is a template instantiation,
2893 NULL otherwise. */
2895 tree
2897 {
2905 }
2907 /* Return the argument pack elements of T if T is a template argument pack,
2908 NULL otherwise. */
2910 tree
2912 {
2918 }
2920 /* Structure used to track the progress of find_parameter_packs_r. */
2921 struct find_parameter_pack_data
2922 {
2923 /* TREE_LIST that will contain all of the parameter packs found by
2924 the traversal. */
2927 /* Set of AST nodes that have been visited by the traversal. */
2929 };
2931 /* Identifies all of the argument packs that occur in a template
2932 argument and appends them to the TREE_LIST inside DATA, which is a
2933 find_parameter_pack_data structure. This is a subroutine of
2934 make_pack_expansion and uses_parameter_packs. */
2935 static tree
2937 {
2943 /* Identify whether this is a parameter pack or not. */
2945 {
2959 {
2960 /* We don't want to walk into the type of a PARM_DECL,
2961 because we don't want to see the type parameter pack. */
2964 }
2968 /* Not a parameter pack. */
2970 }
2973 {
2974 /* Add this parameter pack to the list. */
2976 }
2982 /* This switch statement will return immediately if we don't find a
2983 parameter pack. */
2985 {
2990 /* Check the template itself. */
2993 /* Check the template arguments. */
3009 /* Fall through. */
3050 }
3053 }
3055 /* Determines if the expression or type T uses any parameter packs. */
3056 bool
3058 {
3066 }
3068 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3069 representation a base-class initializer into a parameter pack
3070 expansion. If all goes well, the resulting node will be an
3071 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3072 respectively. */
3073 tree
3075 {
3076 tree result;
3085 {
3086 /* The only time we will see a TREE_LIST here is for a base
3087 class initializer. In this case, the TREE_PURPOSE will be a
3088 _TYPE node (representing the base class expansion we're
3089 initializing) and the TREE_VALUE will be a TREE_LIST
3090 containing the initialization arguments.
3092 The resulting expansion looks somewhat different from most
3093 expansions. Rather than returning just one _EXPANSION, we
3094 return a TREE_LIST whose TREE_PURPOSE is a
3095 TYPE_PACK_EXPANSION containing the bases that will be
3096 initialized. The TREE_VALUE will be identical to the
3097 original TREE_VALUE, which is a list of arguments that will
3098 be passed to each base. We do not introduce any new pack
3099 expansion nodes into the TREE_VALUE (although it is possible
3100 that some already exist), because the TREE_PURPOSE and
3101 TREE_VALUE all need to be expanded together with the same
3102 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3103 resulting TREE_PURPOSE will mention the parameter packs in
3104 both the bases and the arguments to the bases. */
3105 tree purpose;
3106 tree value;
3109 /* Determine which parameter packs will be used by the base
3110 class expansion. */
3117 {
3121 }
3124 {
3125 /* Collect the sets of parameter packs used in each of the
3126 initialization arguments. */
3128 {
3129 /* Determine which parameter packs will be expanded in this
3130 argument. */
3133 }
3134 }
3138 /* Create the pack expansion type for the base type. */
3143 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3144 they will rarely be compared to anything. */
3148 }
3153 /* Build the PACK_EXPANSION_* node. */
3154 result = for_types
3159 {
3160 /* Propagate type and const-expression information. */
3163 }
3164 else
3165 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3166 they will rarely be compared to anything. */
3169 /* Determine which parameter packs will be expanded. */
3175 /* Make sure we found some parameter packs. */
3177 {
3180 else
3183 }
3187 }
3189 /* Checks T for any "bare" parameter packs, which have not yet been
3190 expanded, and issues an error if any are found. This operation can
3191 only be done on full expressions or types (e.g., an expression
3192 statement, "if" condition, etc.), because we could have expressions like:
3194 foo(f(g(h(args)))...)
3196 where "args" is a parameter pack. check_for_bare_parameter_packs
3197 should not be called for the subexpressions args, h(args),
3198 g(h(args)), or f(g(h(args))), because we would produce erroneous
3199 error messages.
3201 Returns TRUE and emits an error if there were bare parameter packs,
3202 returns FALSE otherwise. */
3203 bool
3205 {
3221 {
3224 {
3233 else
3238 else
3242 }
3245 }
3248 }
3250 /* Expand any parameter packs that occur in the template arguments in
3251 ARGS. */
3252 tree
3254 {
3260 /* First, determine if we need to expand anything, and the number of
3261 slots we'll need. */
3263 {
3268 {
3272 else
3274 }
3275 else
3276 {
3278 num_result_args++;
3279 }
3280 }
3282 /* If no expansion is necessary, we're done. */
3286 /* Expand arguments. */
3289 non_default_args_count =
3292 {
3295 {
3302 }
3303 else
3304 {
3307 }
3308 }
3312 }
3314 /* Checks if DECL shadows a template parameter.
3316 [temp.local]: A template-parameter shall not be redeclared within its
3317 scope (including nested scopes).
3319 Emits an error and returns TRUE if the DECL shadows a parameter,
3320 returns FALSE otherwise. */
3322 bool
3324 {
3325 tree olddecl;
3327 /* If we're not in a template, we can't possibly shadow a template
3328 parameter. */
3332 /* Figure out what we're shadowing. */
3337 /* If there's no previous binding for this name, we're not shadowing
3338 anything, let alone a template parameter. */
3342 /* If we're not shadowing a template parameter, we're done. Note
3343 that OLDDECL might be an OVERLOAD (or perhaps even an
3344 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3345 node. */
3349 /* We check for decl != olddecl to avoid bogus errors for using a
3350 name inside a class. We check TPFI to avoid duplicate errors for
3351 inline member templates. */
3359 }
3361 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3362 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3363 template parameters. */
3365 static tree
3370 tree decl,
3371 tree type)
3372 {
3384 }
3386 /* Find the canonical type parameter for the given template type
3387 parameter. Returns the canonical type parameter, which may be TYPE
3388 if no such parameter existed. */
3390 static tree
3392 {
3393 tree list;
3407 else
3408 {
3413 }
3414 }
3416 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3417 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3418 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3419 new one is created. */
3421 static tree
3423 tsubst_flags_t complain)
3424 {
3429 {
3449 /* Template template parameters need this. */
3454 }
3457 }
3459 /* Process information from new template parameter PARM and append it
3460 to the LIST being built. This new parameter is a non-type
3461 parameter iff IS_NON_TYPE is true. This new parameter is a
3462 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3463 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3464 parameter list PARM belongs to. This is used used to create a
3465 proper canonical type for the type of PARM that is to be created,
3466 iff PARM is a type. If the size is not known, this parameter shall
3467 be set to 0. */
3469 tree
3473 {
3475 tree defval;
3476 tree err_parm_list;
3483 {
3487 {
3491 else
3493 }
3496 }
3497 else
3501 {
3507 {
3511 }
3512 else
3513 {
3514 /* [temp.param]
3516 The top-level cv-qualifiers on the template-parameter are
3517 ignored when determining its type. */
3520 {
3524 }
3527 {
3528 /* This template parameter is not a parameter pack, but it
3529 should be. Complain about "bare" parameter packs. */
3532 /* Recover by calling this a parameter pack. */
3534 }
3535 }
3537 /* A template parameter is not modifiable. */
3546 processing_template_decl,
3547 num_template_parms,
3552 }
3553 else
3554 {
3555 tree t;
3559 {
3561 /* This is for distinguishing between real templates and template
3562 template parameters */
3566 }
3567 else
3568 {
3570 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3573 }
3580 processing_template_decl,
3581 num_template_parms,
3585 }
3591 }
3593 /* The end of a template parameter list has been reached. Process the
3594 tree list into a parameter vector, converting each parameter into a more
3595 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3596 as PARM_DECLs. */
3598 tree
3600 {
3605 current_template_parms
3610 {
3614 }
3621 }
3623 /* Create a new type almost identical to TYPE but which has the
3624 following differences:
3626 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3627 template sibling parameters of T.
3629 2/ T has a new canonical type that matches the new number
3630 of sibling parms.
3632 3/ From now on, T is going to be what lookups referring to the
3633 name of TYPE will return. No lookup should return TYPE anymore.
3635 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3637 This is a subroutine of fixup_template_parms. */
3639 static tree
3641 {
3643 tree t;
3644 /* This is the decl which name is inserted into the symbol table for
3645 the template parm type. So whenever we lookup the type name, this
3646 is the DECL we get. */
3647 tree decl;
3649 /* Do not fix up the type twice. */
3664 num_parms,
3675 /* Update the type associated to the type name stored in the symbol
3676 table. Now, whenever the type name is looked up, the resulting
3677 type is properly fixed up. */
3683 }
3685 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3686 identical to I, but that is fixed up as to:
3688 1/ carry the number of sibling parms (NUM_PARMS) of the template
3689 parm represented by I.
3691 2/ replace all references to template parm types declared before I
3692 (in the same template parm list as I) by references to template
3693 parm types contained in ARGS. ARGS should contain the list of
3694 template parms that have been fixed up so far, in a form suitable
3695 to be passed to tsubst.
3697 This is a subroutine of fixup_template_parms. */
3699 static tree
3701 {
3706 /* Do not fix up the index twice. */
3716 num_parms,
3728 }
3730 /*
3731 This is a subroutine of fixup_template_parms.
3733 It computes the canonical type of the type of the template
3734 parameter PARM_DESC and update all references to that type so that
3735 they use the newly computed canonical type. No access check is
3736 performed during the fixup. PARM_DESC is a TREE_LIST which
3737 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3738 default argument of the template parm if any. IDX is the index of
3739 the template parameter, starting at 0. NUM_PARMS is the number of
3740 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3741 TREE_VEC containing the full set of template parameters in a form
3742 suitable to be passed to substs functions as their ARGS
3743 argument. This is what current_template_args returns for a given
3744 template. The innermost vector of args in ARGLIST is the set of
3745 template parms that have been fixed up so far. This function adds
3746 the fixed up parameter into that vector. */
3748 static void
3752 tree arglist)
3753 {
3760 {
3761 /* PARM is a template type parameter. Fix up its type, add
3762 the fixed-up template parm to the vector of fixed-up
3763 template parms so far, and substitute the fixed-up
3764 template parms into the default argument of this
3765 parameter. */
3766 tree t =
3771 }
3773 {
3774 /* PARM is a template template parameter. This is going to
3775 be interesting. */
3779 /* First, fix up the type of the parm. */
3781 tree t =
3788 /* Now we need to substitute the template parm types that
3789 have been fixed up so far into the non-type template
3790 parms of this template template parm. E.g, consider this:
3792 template<class T, template<T u> class TT> class S;
3794 In this case we want to substitute T into the
3795 template parameters of TT.
3797 So let's walk the template parms of PARM here, and
3798 tsubst ARGLIST into into each of the template
3799 parms. */
3801 /* For this substitution we need to build the full set of
3802 template parameters and use that as arguments for the
3803 tsubsting function. */
3806 /* This will contain the innermost parms of PARM into which
3807 we have substituted so far. */
3811 {
3812 tree parameter;
3816 /* INNERMOST_ARGS needs to have at least the same number
3817 of elements as the index PARAMETER, ortherwise
3818 tsubsting into PARAMETER will result in partially
3819 instantiating it, reducing its tempate parm
3820 level. Let's tactically fill INNERMOST_ARGS for that
3821 purpose. */
3827 targs);
3828 }
3829 }
3831 {
3832 /* PARM is a non-type template parameter. We need to:
3834 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3835 proper number of sibling parameters.
3837 * Make lookups of the template parameter return a reference
3838 to the fixed-up index. No lookup should return references
3839 to the former index anymore.
3841 * Substitute the template parms that got fixed up so far
3843 * into the type of PARM. */
3847 /* PUSHED_DECL is the decl added to the symbol table with
3848 the name of the parameter. E,g:
3850 template<class T, T u> //#0
3851 auto my_function(T t) -> decltype(u); //#1
3853 Here, when looking up u at //#1, we get the decl of u
3854 resulting from the declaration in #0. This is what
3855 PUSHED_DECL is. We need to replace the reference to the
3856 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3857 fixed-up TEMPLATE_PARM_INDEX. */
3860 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3861 fixup the type of PUSHED_DECL as well and luckily
3862 fixup_template_parm_index does it for us too. */
3863 tree fixed_up_index =
3868 /* Add this fixed up PARM to the template parms we've fixed
3869 up so far and use that to substitute the fixed-up
3870 template parms into the type of PARM. */
3875 }
3882 }
3884 /* Walk current the template parms and properly compute the canonical
3885 types of the dependent types created during
3886 cp_parser_template_parameter_list. */
3888 static void
3890 {
3891 tree arglist;
3892 tree parameter_vec;
3893 tree fixedup_args;
3902 /* This vector contains the current innermost template parms that
3903 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3904 to be passed to tsubst* functions as their ARGS argument. */
3907 /* This vector contains the full set of template parms in a form
3908 suitable to be passed to substs functions as their ARGS
3909 argument. */
3915 /* Let's do the proper fixup now. */
3919 }
3921 /* end_template_decl is called after a template declaration is seen. */
3923 void
3925 {
3931 /* This matches the pushlevel in begin_template_parm_list. */
3936 }
3938 /* Takes a TREE_LIST representing a template parameter and convert it
3939 into an argument suitable to be passed to the type substitution
3940 functions. Note that If the TREE_LIST contains an error_mark
3941 node, the returned argument is error_mark_node. */
3943 static tree
3945 {
3958 {
3962 {
3963 /* Turn this argument into a TYPE_ARGUMENT_PACK
3964 with a single element, which expands T. */
3966 #ifdef ENABLE_CHECKING
3967 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3969 #endif
3974 }
3975 }
3976 else
3977 {
3981 {
3982 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3983 with a single element, which expands T. */
3986 #ifdef ENABLE_CHECKING
3987 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3989 #endif
3995 }
3996 }
3998 }
4000 /* Within the declaration of a template, return all levels of template
4001 parameters that apply. The template parameters are represented as
4002 a TREE_VEC, in the form documented in cp-tree.h for template
4003 arguments. */
4005 static tree
4007 {
4008 tree header;
4013 /* If there is only one level of template parameters, we do not
4014 create a TREE_VEC of TREE_VECs. Instead, we return a single
4015 TREE_VEC containing the arguments. */
4020 {
4028 #ifdef ENABLE_CHECKING
4030 #endif
4034 else
4036 }
4039 /* This can happen for template parms of a template template
4040 parameter, e.g:
4042 template<template<class T, class U> class TT> struct S;
4044 Consider the level of the parms of TT; T and U both have
4045 level 2; TT has no template parm of level 1. So in this case
4046 the first element of full_template_args is NULL_TREE. If we
4047 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4048 of 2. This will make tsubst wrongly consider that T and U
4049 have level 1. Instead, let's create a dummy vector as the
4050 first element of full_template_args so that TMPL_ARG_DEPTH
4051 returns the correct depth for args. */
4054 }
4056 /* Update the declared TYPE by doing any lookups which were thought to be
4057 dependent, but are not now that we know the SCOPE of the declarator. */
4059 tree
4061 {
4072 /* Don't bother building up the args in this case. */
4074 {
4075 /* tsubst in the args corresponding to the template parameters,
4076 including auto if present. Most things will be unchanged, but
4077 make_typename_type and tsubst_qualified_id will resolve
4078 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4081 tree pushed;
4083 {
4087 }
4092 }
4098 {
4101 else
4103 }
4105 }
4107 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4108 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4109 a member template. Used by push_template_decl below. */
4111 static tree
4113 {
4120 }
4122 struct template_parm_data
4123 {
4124 /* The level of the template parameters we are currently
4125 processing. */
4128 /* The index of the specialization argument we are currently
4129 processing. */
4132 /* An array whose size is the number of template parameters. The
4133 elements are nonzero if the parameter has been used in any one
4134 of the arguments processed so far. */
4137 /* An array whose size is the number of template arguments. The
4138 elements are nonzero if the argument makes use of template
4139 parameters of this level. */
4141 };
4143 /* Subroutine of push_template_decl used to see if each template
4144 parameter in a partial specialization is used in the explicit
4145 argument list. If T is of the LEVEL given in DATA (which is
4146 treated as a template_parm_data*), then DATA->PARMS is marked
4147 appropriately. */
4149 static int
4151 {
4157 {
4160 }
4161 else
4162 {
4165 }
4168 {
4171 }
4173 /* Return zero so that for_each_template_parm will continue the
4174 traversal of the tree; we want to mark *every* template parm. */
4176 }
4178 /* Process the partial specialization DECL. */
4180 static tree
4182 {
4188 tree inner_parms;
4189 tree inst;
4202 /* We check that each of the template parameters given in the
4203 partial specialization is used in the argument list to the
4204 specialization. For example:
4206 template <class T> struct S;
4207 template <class T> struct S<T*>;
4209 The second declaration is OK because `T*' uses the template
4210 parameter T, whereas
4212 template <class T> struct S<int>;
4214 is no good. Even trickier is:
4216 template <class T>
4217 struct S1
4218 {
4219 template <class U>
4220 struct S2;
4221 template <class U>
4222 struct S2<T>;
4223 };
4225 The S2<T> declaration is actually invalid; it is a
4226 full-specialization. Of course,
4228 template <class U>
4229 struct S2<T (*)(U)>;
4231 or some such would have been OK. */
4239 {
4244 NULL,
4246 }
4249 {
4250 /* One of the template parms was not used in the
4251 specialization. */
4253 {
4256 }
4259 }
4264 /* [temp.class.spec]
4266 The argument list of the specialization shall not be identical to
4267 the implicit argument list of the primary template. */
4274 /* [temp.class.spec]
4276 A partially specialized non-type argument expression shall not
4277 involve template parameters of the partial specialization except
4278 when the argument expression is a simple identifier.
4280 The type of a template parameter corresponding to a specialized
4281 non-type argument shall not be dependent on a parameter of the
4282 specialization.
4284 Also, we verify that pack expansions only occur at the
4285 end of the argument list. */
4289 {
4296 {
4297 /* Extract the arguments from the argument pack. We'll be
4298 iterating over these in the following loop. */
4301 }
4304 {
4306 /* Get the Jth argument in the parameter pack. */
4310 {
4311 /* Pack expansions must come at the end of the
4312 argument list. */
4315 {
4319 else
4322 }
4323 }
4326 /* We only care about the pattern. */
4332 /* This next line is the `argument expression is not just a
4333 simple identifier' condition and also the `specialized
4334 non-type argument' bit. */
4336 {
4340 arg);
4341 else
4342 {
4343 /* Look at the corresponding template parameter,
4344 marking which template parameters its type depends
4345 upon. */
4349 {
4350 /* We haven't yet initialized TPD2. Do so now. */
4352 /* The number of parameters here is the number in the
4353 main template, which, as checked in the assertion
4354 above, is NARGS. */
4358 }
4360 /* Mark the template parameters. But this time, we're
4361 looking for the template parameters of the main
4362 template, not in the specialization. */
4369 NULL,
4373 {
4374 /* The type depended on some template parameters.
4375 If they are fully specialized in the
4376 specialization, that's OK. */
4385 "type %qT of template argument %qE depends "
4387 "type %qT of template argument %qE depends "
4389 type,
4390 arg);
4391 }
4392 }
4393 }
4394 }
4395 }
4397 /* We should only get here once. */
4407 {
4411 {
4415 "partial specialization of %qT after instantiation "
4417 }
4418 }
4421 }
4423 /* Check that a template declaration's use of default arguments and
4424 parameter packs is not invalid. Here, PARMS are the template
4425 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4426 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4427 specialization.
4430 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4431 declaration (but not a definition); 1 indicates a declaration, 2
4432 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4433 emitted for extraneous default arguments.
4435 Returns TRUE if there were no errors found, FALSE otherwise. */
4437 bool
4440 {
4443 tree parm_level;
4446 /* [temp.param]
4448 A default template-argument shall not be specified in a
4449 function template declaration or a function template definition, nor
4450 in the template-parameter-list of the definition of a member of a
4451 class template. */
4454 /* You can't have a function template declaration in a local
4455 scope, nor you can you define a member of a class template in a
4456 local scope. */
4463 /* If this is either a friend defined in the scope of the class
4464 or a member function. */
4470 /* And, if it was a member function, it really was defined in
4471 the scope of the class. */
4474 /* We already checked these parameters when the template was
4475 declared, so there's no need to do it again now. This function
4476 was defined in class scope, but we're processing it's body now
4477 that the class is complete. */
4480 /* Core issue 226 (C++0x only): the following only applies to class
4481 templates. */
4483 {
4484 /* [temp.param]
4486 If a template-parameter has a default template-argument, all
4487 subsequent template-parameters shall have a default
4488 template-argument supplied. */
4490 {
4497 {
4507 {
4509 /* For better subsequent error-recovery, we indicate that
4510 there should have been a default argument. */
4513 }
4515 && !is_partial
4516 && !is_friend_decl
4517 /* Don't complain about an enclosing partial
4518 specialization. */
4523 {
4524 /* A primary class template can only have one
4525 parameter pack, at the end of the template
4526 parameter list. */
4531 else
4539 }
4540 }
4541 }
4542 }
4545 || is_partial
4546 || !is_primary
4548 /* For an ordinary class template, default template arguments are
4549 allowed at the innermost level, e.g.:
4550 template <class T = int>
4551 struct S {};
4552 but, in a partial specialization, they're not allowed even
4553 there, as we have in [temp.class.spec]:
4555 The template parameter list of a specialization shall not
4556 contain default template argument values.
4558 So, for a partial specialization, or for a function template
4559 (in C++98/C++03), we look at all of them. */
4560 ;
4561 else
4562 /* But, for a primary class template that is not a partial
4563 specialization we look at all template parameters except the
4564 innermost ones. */
4567 /* Figure out what error message to issue. */
4580 else
4584 /* If we're inside a class definition, there's no need to
4585 examine the parameters to the class itself. On the one
4586 hand, they will be checked when the class is defined, and,
4587 on the other, default arguments are valid in things like:
4588 template <class T = double>
4589 struct S { template <class U> void f(U); };
4590 Here the default argument for `S' has no bearing on the
4591 declaration of `f'. */
4593 else
4594 /* Check everything. */
4600 {
4607 {
4612 {
4614 {
4621 }
4623 /* Clear out the default argument so that we are not
4624 confused later. */
4626 }
4627 }
4629 /* At this point, if we're still interested in issuing messages,
4630 they must apply to classes surrounding the object declared. */
4634 }
4637 }
4639 /* Worker for push_template_decl_real, called via
4640 for_each_template_parm. DATA is really an int, indicating the
4641 level of the parameters we are interested in. If T is a template
4642 parameter of that level, return nonzero. */
4644 static int
4646 {
4652 else
4655 }
4657 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4658 parameters given by current_template_args, or reuses a
4659 previously existing one, if appropriate. Returns the DECL, or an
4660 equivalent one, if it is replaced via a call to duplicate_decls.
4662 If IS_FRIEND is true, DECL is a friend declaration. */
4664 tree
4666 {
4667 tree tmpl;
4668 tree args;
4669 tree info;
4670 tree ctx;
4674 /* True if the template is a member template, in the sense of
4675 [temp.mem]. */
4681 /* See if this is a partial specialization. */
4690 /* For a friend, we want the context of the friend function, not
4691 the type of which it is a friend. */
4695 /* In the case of a virtual function, we want the class in which
4696 it is defined. */
4698 else
4699 /* Otherwise, if we're currently defining some class, the DECL
4700 is assumed to be a member of the class. */
4709 /* See if this is a primary template. */
4711 /* A friend template that specifies a class context, i.e.
4712 template <typename T> friend void A<T>::f();
4713 is not primary. */
4715 else
4719 {
4724 {
4727 }
4729 {
4731 {
4732 /* [temp.mem]
4734 A destructor shall not be a member template. */
4737 }
4744 {
4745 /* [basic.stc.dynamic.allocation]
4747 An allocation function can be a function
4748 template. ... Template allocation functions shall
4749 have two or more parameters. */
4752 }
4753 }
4757 else
4758 {
4761 }
4762 }
4764 /* Check to see that the rules regarding the use of default
4765 arguments are not being violated. */
4769 /* Ensure that there are no parameter packs in the type of this
4770 declaration that have not been expanded. */
4772 {
4773 /* Check each of the arguments individually to see if there are
4774 any bare parameter packs. */
4780 {
4783 {
4784 /* This is a PARM_DECL that contains unexpanded parameter
4785 packs. We have already complained about this in the
4786 check_for_bare_parameter_packs call, so just replace
4787 these types with ERROR_MARK_NODE. */
4790 }
4794 }
4796 /* Check for bare parameter packs in the return type and the
4797 exception specifiers. */
4799 /* Errors were already issued, set return type to int
4800 as the frontend doesn't expect error_mark_node as
4801 the return type. */
4805 }
4807 {
4810 }
4821 {
4826 /* If DECL is a TYPE_DECL for a class-template, then there won't
4827 be DECL_LANG_SPECIFIC. The information equivalent to
4828 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4832 {
4833 /* Since a template declaration already existed for this
4834 class-type, we must be redeclaring it here. Make sure
4835 that the redeclaration is valid. */
4837 current_template_parms);
4838 /* We don't need to create a new TEMPLATE_DECL; just use the
4839 one we already had. */
4841 }
4842 else
4843 {
4845 member_template_p);
4850 {
4851 /* A specialization of a member template of a template
4852 class. */
4856 }
4857 }
4858 }
4859 else
4860 {
4866 {
4869 }
4877 {
4878 tree new_tmpl;
4880 /* The declaration is a specialization of a member
4881 template, declared outside the class. Therefore, the
4882 innermost template arguments will be NULL, so we
4883 replace them with the arguments determined by the
4884 earlier call to check_explicit_specialization. */
4887 new_tmpl
4889 member_template_p);
4899 args,
4902 }
4904 /* Make sure the template headers we got make sense. */
4909 {
4912 }
4913 else
4915 {
4920 {
4924 else
4929 }
4934 /* Can happen in erroneous input. */
4936 else
4940 }
4942 /* Check that the parms are used in the appropriate qualifying scopes
4943 in the declarator. */
4947 {
4953 /* Avoid crash in import_export_decl. */
4956 }
4957 }
4962 /* Push template declarations for global functions and types. Note
4963 that we do not try to push a global template friend declared in a
4964 template class; such a thing may well depend on the template
4965 parameters of the class. */
4968 {
4973 /* Hide template friend classes that haven't been declared yet. */
4975 {
4978 }
4979 }
4982 {
4988 {
4991 /* It is a conversion operator. See if the type converted to
4992 depends on innermost template operands. */
4995 depth))
4997 }
4999 /* Give template template parms a DECL_CONTEXT of the template
5000 for which they are a parameter. */
5003 {
5007 }
5008 }
5010 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5011 back to its most general template. If TMPL is a specialization,
5012 ARGS may only have the innermost set of arguments. Add the missing
5013 argument levels if necessary. */
5025 }
5027 tree
5029 {
5031 }
5033 /* Called when a class template TYPE is redeclared with the indicated
5034 template PARMS, e.g.:
5036 template <class T> struct S;
5037 template <class T> struct S {}; */
5039 bool
5041 {
5042 tree tmpl;
5043 tree tmpl_parms;
5047 {
5050 }
5054 /* The type is nested in some template class. Nothing to worry
5055 about here; there are no new template parameters for the nested
5056 type. */
5060 {
5062 tmpl);
5064 }
5070 {
5080 }
5083 {
5084 tree tmpl_parm;
5085 tree parm;
5086 tree tmpl_default;
5087 tree parm_default;
5101 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5102 TEMPLATE_DECL. */
5112 {
5116 }
5119 {
5120 /* We have in [temp.param]:
5122 A template-parameter may not be given default arguments
5123 by two different declarations in the same scope. */
5128 }
5131 /* Update the previous template parameters (which are the ones
5132 that will really count) with the new default value. */
5135 /* Update the new parameters, too; they'll be used as the
5136 parameters for any members. */
5138 }
5141 }
5143 /* Simplify EXPR if it is a non-dependent expression. Returns the
5144 (possibly simplified) expression. */
5146 static tree
5148 {
5152 /* If we're in a template, but EXPR isn't value dependent, simplify
5153 it. We're supposed to treat:
5155 template <typename T> void f(T[1 + 1]);
5156 template <typename T> void f(T[2]);
5158 as two declarations of the same function, for example. */
5162 {
5163 HOST_WIDE_INT saved_processing_template_decl;
5169 complain,
5174 }
5176 }
5178 tree
5180 {
5182 }
5184 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5185 must be a function or a pointer-to-function type, as specified
5186 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5187 and check that the resulting function has external linkage. */
5189 static tree
5191 {
5205 /* [temp.arg.nontype]/1
5207 A template-argument for a non-type, non-template template-parameter
5208 shall be one of:
5209 [...]
5210 -- the address of an object or function with external linkage. */
5212 {
5217 }
5220 }
5222 /* Subroutine of convert_nontype_argument.
5223 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5224 Emit an error otherwise. */
5226 static bool
5228 tsubst_flags_t complain)
5229 {
5234 {
5238 }
5240 }
5242 /* Returns TRUE iff the address of OP is value-dependent.
5244 14.6.2.4 [temp.dep.temp]:
5245 A non-integral non-type template-argument is dependent if its type is
5246 dependent or it has either of the following forms
5247 qualified-id
5248 & qualified-id
5249 and contains a nested-name-specifier which specifies a class-name that
5250 names a dependent type.
5252 We generalize this to just say that the address of a member of a
5253 dependent class is value-dependent; the above doesn't cover the
5254 address of a static data member named with an unqualified-id. */
5256 static bool
5258 {
5259 /* We could use get_inner_reference here, but there's no need;
5260 this is only relevant for template non-type arguments, which
5261 can only be expressed as &id-expression. */
5263 {
5267 }
5270 }
5272 /* Attempt to convert the non-type template parameter EXPR to the
5273 indicated TYPE. If the conversion is successful, return the
5274 converted value. If the conversion is unsuccessful, return
5275 NULL_TREE if we issued an error message, or error_mark_node if we
5276 did not. We issue error messages for out-and-out bad template
5277 parameters, but not simply because the conversion failed, since we
5278 might be just trying to do argument deduction. Both TYPE and EXPR
5279 must be non-dependent.
5281 The conversion follows the special rules described in
5282 [temp.arg.nontype], and it is much more strict than an implicit
5283 conversion.
5285 This function is called twice for each template argument (see
5286 lookup_template_class for a more accurate description of this
5287 problem). This means that we need to handle expressions which
5288 are not valid in a C++ source, but can be created from the
5289 first call (for instance, casts to perform conversions). These
5290 hacks can go away after we fix the double coercion problem. */
5292 static tree
5294 {
5295 tree expr_type;
5297 /* Detect immediately string literals as invalid non-type argument.
5298 This special-case is not needed for correctness (we would easily
5299 catch this later), but only to provide better diagnostic for this
5300 common user mistake. As suggested by DR 100, we do not mention
5301 linkage issues in the diagnostic as this is not the point. */
5302 /* FIXME we're making this OK. */
5304 {
5310 }
5312 /* Add the ADDR_EXPR now for the benefit of
5313 value_dependent_expression_p. */
5317 /* If we are in a template, EXPR may be non-dependent, but still
5318 have a syntactic, rather than semantic, form. For example, EXPR
5319 might be a SCOPE_REF, rather than the VAR_DECL to which the
5320 SCOPE_REF refers. Preserving the qualifying scope is necessary
5321 so that access checking can be performed when the template is
5322 instantiated -- but here we need the resolved form so that we can
5323 convert the argument. */
5334 else
5337 /* HACK: Due to double coercion, we can get a
5338 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5339 which is the tree that we built on the first call (see
5340 below when coercing to reference to object or to reference to
5341 function). We just strip everything and get to the arg.
5342 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5343 for examples. */
5345 {
5347 {
5348 /* ??? Maybe we could use convert_from_reference here, but we
5349 would need to relax its constraints because the NOP_EXPR
5350 could actually change the type to something more cv-qualified,
5351 and this is not folded by convert_from_reference. */
5362 }
5364 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5365 parameter is a pointer to object, through decay and
5366 qualification conversion. Let's strip everything. */
5368 {
5372 /* Skip the ADDR_EXPR only if it is part of the decay for
5373 an array. Otherwise, it is part of the original argument
5374 in the source code. */
5378 }
5379 }
5381 /* [temp.arg.nontype]/5, bullet 1
5383 For a non-type template-parameter of integral or enumeration type,
5384 integral promotions (_conv.prom_) and integral conversions
5385 (_conv.integral_) are applied. */
5387 {
5396 /* Notice that there are constant expressions like '4 % 0' which
5397 do not fold into integer constants. */
5399 {
5401 {
5405 }
5407 }
5408 }
5409 /* [temp.arg.nontype]/5, bullet 2
5411 For a non-type template-parameter of type pointer to object,
5412 qualification conversions (_conv.qual_) and the array-to-pointer
5413 conversion (_conv.array_) are applied. */
5415 {
5416 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5418 A template-argument for a non-type, non-template template-parameter
5419 shall be one of: [...]
5421 -- the name of a non-type template-parameter;
5422 -- the address of an object or function with external linkage, [...]
5423 expressed as "& id-expression" where the & is optional if the name
5424 refers to a function or array, or if the corresponding
5425 template-parameter is a reference.
5427 Here, we do not care about functions, as they are invalid anyway
5428 for a parameter of type pointer-to-object. */
5431 /* Non-type template parameters are OK. */
5432 ;
5435 {
5437 {
5439 "because %qD is a variable, not the address of "
5443 }
5444 /* Other values, like integer constants, might be valid
5445 non-type arguments of some other type. */
5447 }
5448 else
5449 {
5450 tree decl;
5455 {
5460 }
5462 {
5467 }
5468 }
5477 }
5478 /* [temp.arg.nontype]/5, bullet 3
5480 For a non-type template-parameter of type reference to object, no
5481 conversions apply. The type referred to by the reference may be more
5482 cv-qualified than the (otherwise identical) type of the
5483 template-argument. The template-parameter is bound directly to the
5484 template-argument, which must be an lvalue. */
5486 {
5488 expr_type))
5492 {
5496 }
5499 {
5503 }
5505 /* [temp.arg.nontype]/1
5507 A template-argument for a non-type, non-template template-parameter
5508 shall be one of: [...]
5510 -- the address of an object or function with external linkage. */
5513 {
5516 {
5518 "because a reference variable does not have a constant "
5521 }
5522 }
5525 {
5530 }
5533 {
5538 }
5541 }
5542 /* [temp.arg.nontype]/5, bullet 4
5544 For a non-type template-parameter of type pointer to function, only
5545 the function-to-pointer conversion (_conv.func_) is applied. If the
5546 template-argument represents a set of overloaded functions (or a
5547 pointer to such), the matching function is selected from the set
5548 (_over.over_). */
5550 {
5551 /* If the argument is a template-id, we might not have enough
5552 context information to decay the pointer. */
5554 {
5558 }
5565 {
5569 }
5570 }
5571 /* [temp.arg.nontype]/5, bullet 5
5573 For a non-type template-parameter of type reference to function, no
5574 conversions apply. If the template-argument represents a set of
5575 overloaded functions, the matching function is selected from the set
5576 (_over.over_). */
5578 {
5580 {
5585 }
5592 }
5593 /* [temp.arg.nontype]/5, bullet 6
5595 For a non-type template-parameter of type pointer to member function,
5596 no conversions apply. If the template-argument represents a set of
5597 overloaded member functions, the matching member function is selected
5598 from the set (_over.over_). */
5600 {
5605 /* [temp.arg.nontype] bullet 1 says the pointer to member
5606 expression must be a pointer-to-member constant. */
5610 /* There is no way to disable standard conversions in
5611 resolve_address_of_overloaded_function (called by
5612 instantiate_type). It is possible that the call succeeded by
5613 converting &B::I to &D::I (where B is a base of D), so we need
5614 to reject this conversion here.
5616 Actually, even if there was a way to disable standard conversions,
5617 it would still be better to reject them here so that we can
5618 provide a superior diagnostic. */
5620 {
5624 /* If we are just one standard conversion off, explain. */
5629 }
5630 }
5631 /* [temp.arg.nontype]/5, bullet 7
5633 For a non-type template-parameter of type pointer to data member,
5634 qualification conversions (_conv.qual_) are applied. */
5636 {
5637 /* [temp.arg.nontype] bullet 1 says the pointer to member
5638 expression must be a pointer-to-member constant. */
5645 }
5646 /* A template non-type parameter must be one of the above. */
5647 else
5650 /* Sanity check: did we actually convert the argument to the
5651 right type? */
5655 }
5657 /* Subroutine of coerce_template_template_parms, which returns 1 if
5658 PARM_PARM and ARG_PARM match using the rule for the template
5659 parameters of template template parameters. Both PARM and ARG are
5660 template parameters; the rest of the arguments are the same as for
5661 coerce_template_template_parms.
5662 */
5663 static int
5665 tree arg,
5666 tsubst_flags_t complain,
5667 tree in_decl,
5668 tree outer_args)
5669 {
5678 {
5680 /* We encounter instantiations of templates like
5681 template <template <template <class> class> class TT>
5682 class C; */
5683 {
5690 }
5691 /* Fall through. */
5696 /* Argument is a parameter pack but parameter is not. */
5701 /* The tsubst call is used to handle cases such as
5703 template <int> class C {};
5704 template <class T, template <T> class TT> class D {};
5705 D<int, C> d;
5707 i.e. the parameter list of TT depends on earlier parameters. */
5709 && !same_type_p
5716 /* Argument is a parameter pack but parameter is not. */
5723 }
5726 }
5729 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5730 template template parameters. Both PARM_PARMS and ARG_PARMS are
5731 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5732 or PARM_DECL.
5734 Consider the example:
5735 template <class T> class A;
5736 template<template <class U> class TT> class B;
5738 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5739 the parameters to A, and OUTER_ARGS contains A. */
5741 static int
5743 tree arg_parms,
5744 tsubst_flags_t complain,
5745 tree in_decl,
5746 tree outer_args)
5747 {
5758 /* Determine whether we have a parameter pack at the end of the
5759 template template parameter's template parameter list. */
5761 {
5768 {
5782 }
5783 }
5789 /* Check all of the template parameters except the parameter pack at
5790 the end (if any). */
5792 {
5801 outer_args))
5804 }
5807 {
5808 /* Check each of the template parameters in the template
5809 argument against the template parameter pack at the end of
5810 the template template parameter. */
5817 {
5824 outer_args))
5826 }
5827 }
5830 }
5832 /* Verifies that the deduced template arguments (in TARGS) for the
5833 template template parameters (in TPARMS) represent valid bindings,
5834 by comparing the template parameter list of each template argument
5835 to the template parameter list of its corresponding template
5836 template parameter, in accordance with DR150. This
5837 routine can only be called after all template arguments have been
5838 deduced. It will return TRUE if all of the template template
5839 parameter bindings are okay, FALSE otherwise. */
5840 bool
5842 {
5846 /* We're dealing with template parms in this process. */
5852 {
5857 {
5862 {
5863 /* Look inside the argument pack. */
5866 }
5869 {
5873 /* Extract the next argument from the argument
5874 pack. */
5878 /* Look at the pattern of the pack expansion. */
5881 /* Extract the template parameters from the template
5882 argument. */
5888 /* Verify that we can coerce the template template
5889 parameters from the template argument to the template
5890 parameter. This requires an exact match. */
5892 && !coerce_template_template_parms
5894 targ_parms,
5895 tf_none,
5896 tparm,
5897 targs))
5898 {
5901 }
5902 }
5903 }
5904 }
5906 out:
5910 }
5912 /* Convert the indicated template ARG as necessary to match the
5913 indicated template PARM. Returns the converted ARG, or
5914 error_mark_node if the conversion was unsuccessful. Error and
5915 warning messages are issued under control of COMPLAIN. This
5916 conversion is for the Ith parameter in the parameter list. ARGS is
5917 the full set of template arguments deduced so far. */
5919 static tree
5921 tree arg,
5922 tree args,
5923 tsubst_flags_t complain,
5925 tree in_decl)
5926 {
5927 tree orig_arg;
5928 tree val;
5933 {
5934 /* The template argument was the name of some
5935 member function. That's usually
5936 invalid, but static members are OK. In any
5937 case, grab the underlying fields/functions
5938 and issue an error later if required. */
5941 }
5949 /* When determining whether an argument pack expansion is a template,
5950 look at the pattern. */
5954 /* Deal with an injected-class-name used as a template template arg. */
5956 {
5959 {
5967 }
5968 }
5970 is_tmpl_type =
5985 {
5991 typename_type,
5995 }
5997 {
5999 {
6001 {
6011 else
6013 }
6014 }
6016 }
6018 {
6020 {
6026 else
6028 }
6030 }
6033 {
6035 {
6037 /* The number of argument required is not known yet.
6038 Just accept it for now. */
6040 else
6041 {
6043 tree argparm;
6049 args))
6050 {
6053 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6054 TEMPLATE_DECL. */
6056 {
6061 }
6062 }
6063 else
6064 {
6066 {
6072 }
6075 }
6076 }
6077 }
6078 else
6080 /* We only form one instance of each template specialization.
6081 Therefore, if we use a non-canonical variant (i.e., a
6082 typedef), any future messages referring to the type will use
6083 the typedef, which is confusing if those future uses do not
6084 themselves also use the typedef. */
6087 }
6088 else
6089 {
6096 {
6099 else
6100 {
6101 /* Not sure if this is reachable, but it doesn't hurt
6102 to be robust. */
6105 }
6106 }
6108 /* We used to call digest_init here. However, digest_init
6109 will report errors, which we don't want when complain
6110 is zero. More importantly, digest_init will try too
6111 hard to convert things: for example, `0' should not be
6112 converted to pointer type at this point according to
6113 the standard. Accepting this is not merely an
6114 extension, since deciding whether or not these
6115 conversions can occur is part of determining which
6116 function template to call, or whether a given explicit
6117 argument specification is valid. */
6119 else
6128 {
6129 /* Strip typedefs from the SCOPE_REF. */
6134 }
6135 }
6138 }
6140 /* Coerces the remaining template arguments in INNER_ARGS (from
6141 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6142 Returns the coerced argument pack. PARM_IDX is the position of this
6143 parameter in the template parameter list. ARGS is the original
6144 template argument list. */
6145 static tree
6148 tree args,
6149 tree inner_args,
6151 tree new_args,
6153 tree in_decl,
6154 tsubst_flags_t complain)
6155 {
6158 tree packed_args;
6159 tree argument_pack;
6169 {
6170 /* When the template parameter is a non-type template
6171 parameter pack whose type uses parameter packs, we need
6172 to look at each of the template arguments
6173 separately. Build a vector of the types for these
6174 non-type template parameters in PACKED_TYPES. */
6175 tree expansion
6183 /* Check that we have the right number of arguments. */
6187 {
6188 int needed_parms
6193 }
6195 /* If we aren't able to check the actual arguments now
6196 (because they haven't been expanded yet), we can at least
6197 verify that all of the types used for the non-type
6198 template parameter pack are, in fact, valid for non-type
6199 template parameters. */
6202 {
6205 {
6209 }
6210 }
6211 }
6213 /* Convert the remaining arguments, which will be a part of the
6214 parameter pack "parm". */
6216 {
6221 {
6222 /* When we have a vector of types (corresponding to the
6223 non-type template parameter pack that uses parameter
6224 packs in its type, as mention above), and the
6225 argument is not an expansion (which expands to a
6226 currently unknown number of arguments), clone the
6227 parm and give it the next type in PACKED_TYPES. */
6231 }
6236 in_decl);
6240 }
6245 else
6246 {
6251 }
6254 #ifdef ENABLE_CHECKING
6257 #endif
6259 }
6261 /* Convert all template arguments to their appropriate types, and
6262 return a vector containing the innermost resulting template
6263 arguments. If any error occurs, return error_mark_node. Error and
6264 warning messages are issued under control of COMPLAIN.
6266 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6267 for arguments not specified in ARGS. Otherwise, if
6268 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6269 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6270 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6271 ARGS. */
6273 static tree
6275 tree args,
6276 tree in_decl,
6277 tsubst_flags_t complain,
6280 {
6282 tree inner_args;
6283 tree new_args;
6284 tree new_inner_args;
6288 /* When used as a boolean value, indicates whether this is a
6289 variadic template parameter list. Since it's an int, we can also
6290 subtract it from nparms to get the number of non-variadic
6291 parameters. */
6299 /* Determine if there are any parameter packs. */
6301 {
6305 }
6308 /* If there are 0 or 1 parameter packs, we need to expand any argument
6309 packs so that we can deduce a parameter pack from some non-packed args
6310 followed by an argument pack, as in variadic85.C. If there are more
6311 than that, we need to leave argument packs intact so the arguments are
6312 assigned to the right parameter packs. This should only happen when
6313 dealing with a nested class inside a partial specialization of a class
6314 template, as in variadic92.C. */
6321 && require_all_args
6322 && (!use_default_args
6325 {
6327 {
6329 {
6333 }
6334 else
6340 }
6343 }
6345 /* We need to evaluate the template arguments, even though this
6346 template-id may be nested within a "sizeof". */
6354 {
6355 tree arg;
6356 tree parm;
6358 /* Get the Ith template parameter. */
6362 {
6365 }
6367 /* Calculate the next argument. */
6370 else
6375 {
6376 /* All remaining arguments will be placed in the
6377 template parameter pack PARM. */
6383 /* Store this argument. */
6385 lost++;
6388 /* We are done with all of the arguments. */
6392 }
6394 {
6396 {
6398 {
6399 /* FIXME this restriction was removed by N2555; see
6400 bug 35722. */
6401 /* If ARG is a pack expansion, but PARM is not a
6402 template parameter pack (if it were, we would have
6403 handled it above), we're trying to expand into a
6404 fixed-length argument list. */
6408 else
6411 }
6413 }
6414 }
6416 {
6417 /* There must be a default arg in this case. */
6420 /* The position of the first default template argument,
6421 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6422 Record that. */
6425 }
6426 else
6430 {
6433 }
6435 /* This only occurs if there was an error in the template
6436 parameter list itself (which we would already have
6437 reported) that we are trying to recover from, e.g., a class
6438 template with a parameter list such as
6439 template<typename..., typename>. */
6441 else
6447 lost++;
6449 }
6456 #ifdef ENABLE_CHECKING
6460 #endif
6463 }
6465 /* Returns 1 if template args OT and NT are equivalent. */
6467 static int
6469 {
6474 /* For member templates */
6481 {
6498 }
6500 {
6501 /* We get here probably because we are in the middle of substituting
6502 into the pattern of a pack expansion. In that case the
6503 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6504 interested in. So we want to use the initial pack argument for
6505 the comparison. */
6510 }
6515 else
6517 }
6519 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6520 of template arguments. Returns 0 otherwise. */
6522 int
6524 {
6531 {
6537 }
6539 }
6541 static void
6543 {
6553 /* We are called both from instantiate_decl, where we've already had a
6554 tinst_level pushed, and instantiate_template, where we haven't.
6555 Compensate. */
6566 else
6575 }
6578 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6579 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6580 documentation for TEMPLATE_ID_EXPR. */
6582 tree
6584 {
6585 tree type;
6595 {
6597 unknown_type_node,
6599 arglist);
6601 }
6608 }
6610 /* Within the scope of a template class S<T>, the name S gets bound
6611 (in build_self_reference) to a TYPE_DECL for the class, not a
6612 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6613 or one of its enclosing classes, and that type is a template,
6614 return the associated TEMPLATE_DECL. Otherwise, the original
6615 DECL is returned.
6617 Also handle the case when DECL is a TREE_LIST of ambiguous
6618 injected-class-names from different bases. */
6620 tree
6622 {
6626 /* DR 176: A lookup that finds an injected-class-name (10.2
6627 [class.member.lookup]) can result in an ambiguity in certain cases
6628 (for example, if it is found in more than one base class). If all of
6629 the injected-class-names that are found refer to specializations of
6630 the same class template, and if the name is followed by a
6631 template-argument-list, the reference refers to the class template
6632 itself and not a specialization thereof, and is not ambiguous. */
6634 {
6637 {
6643 }
6646 else
6648 }
6654 }
6656 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6657 parameters, find the desired type.
6659 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6661 IN_DECL, if non-NULL, is the template declaration we are trying to
6662 instantiate.
6664 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6665 the class we are looking up.
6667 Issue error and warning messages under control of COMPLAIN.
6669 If the template class is really a local class in a template
6670 function, then the FUNCTION_CONTEXT is the function in which it is
6671 being instantiated.
6673 ??? Note that this function is currently called *twice* for each
6674 template-id: the first time from the parser, while creating the
6675 incomplete type (finish_template_type), and the second type during the
6676 real instantiation (instantiate_template_class). This is surely something
6677 that we want to avoid. It also causes some problems with argument
6678 coercion (see convert_nontype_argument for more information on this). */
6680 tree
6682 tree arglist,
6683 tree in_decl,
6684 tree context,
6686 tsubst_flags_t complain)
6687 {
6689 tree t;
6692 spec_entry elt;
6693 hashval_t hash;
6698 {
6702 else
6703 {
6710 }
6713 }
6715 {
6718 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6719 an implicit typename for the second A. Deal with it. */
6724 {
6727 }
6728 }
6731 {
6734 }
6738 {
6742 }
6744 /* Issue an error message if we didn't find a template. */
6746 {
6750 }
6753 /* Make sure it's a user visible template, if it was named by
6754 the user. */
6757 {
6759 {
6763 }
6765 }
6770 {
6771 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6772 template arguments */
6774 tree parm;
6775 tree arglist2;
6776 tree outer;
6780 /* Consider an example where a template template parameter declared as
6782 template <class T, class U = std::allocator<T> > class TT
6784 The template parameter level of T and U are one level larger than
6785 of TT. To proper process the default argument of U, say when an
6786 instantiation `TT<int>' is seen, we need to build the full
6787 arguments containing {int} as the innermost level. Outer levels,
6788 available when not appearing as default template argument, can be
6789 obtained from the arguments of the enclosing template.
6791 Suppose that TT is later substituted with std::vector. The above
6792 instantiation is `TT<int, std::allocator<T> >' with TT at
6793 level 1, and T at level 2, while the template arguments at level 1
6794 becomes {std::vector} and the inner level 2 is {int}. */
6800 /* This is an argument of the current template, so we haven't set
6801 DECL_CONTEXT yet. */
6808 complain,
6818 }
6819 else
6820 {
6822 tree gen_tmpl;
6823 tree type_decl;
6836 {
6837 /* We've been given an incomplete set of template arguments.
6838 For example, given:
6840 template <class T> struct S1 {
6841 template <class U> struct S2 {};
6842 template <class U> struct S2<U*> {};
6843 };
6845 we will be called with an ARGLIST of `U*', but the
6846 TEMPLATE will be `template <class T> template
6847 <class U> struct S1<T>::S2'. We must fill in the missing
6848 arguments. */
6849 arglist
6851 arglist);
6853 }
6855 /* Now we should have enough arguments. */
6858 /* From here on, we're only interested in the most general
6859 template. */
6861 /* Calculate the BOUND_ARGS. These will be the args that are
6862 actually tsubst'd into the definition to create the
6863 instantiation. */
6865 {
6866 /* We have multiple levels of arguments to coerce, at once. */
6876 {
6877 tree a;
6881 complain,
6884 else
6885 /* Outer levels should have already been coerced. */
6888 /* Don't process further if one of the levels fails. */
6890 {
6891 /* Restore the ARGLIST to its full size. */
6894 }
6898 /* We temporarily reduce the length of the ARGLIST so
6899 that coerce_template_parms will see only the arguments
6900 corresponding to the template parameters it is
6901 examining. */
6903 }
6905 /* Restore the ARGLIST to its full size. */
6909 }
6910 else
6911 arglist
6914 gen_tmpl,
6915 complain,
6920 /* We were unable to bind the arguments. */
6923 /* In the scope of a template class, explicit references to the
6924 template class refer to the type of the template, not any
6925 instantiation of it. For example, in:
6927 template <class T> class C { void f(C<T>); }
6929 the `C<T>' is just the same as `C'. Outside of the
6930 class, however, such a reference is an instantiation. */
6934 /* comp_template_args is expensive, check it last. */
6936 arglist))
6939 /* If we already have this specialization, return it. */
6951 /* If the deduced arguments are invalid, then the binding
6952 failed. */
6956 complain))
6963 {
6968 }
6975 /* Create the type. */
6977 {
6979 {
6985 }
6986 else
6987 {
6988 /* We don't want to call start_enum for this type, since
6989 the values for the enumeration constants may involve
6990 template parameters. And, no one should be interested
6991 in the enumeration constants for such a type. */
6994 }
6996 }
6997 else
6998 {
7005 /* A local class. Make sure the decl gets registered properly. */
7010 /* This instantiation is another name for the primary
7011 template type. Set the TYPE_CANONICAL field
7012 appropriately. */
7015 /* Some of the template arguments require structural
7016 equality testing, so this template class requires
7017 structural equality testing. */
7019 }
7021 /* If we called start_enum or pushtag above, this information
7022 will already be set up. */
7024 {
7031 }
7032 else
7040 {
7043 }
7045 /* Let's consider the explicit specialization of a member
7046 of a class template specialization that is implicitely instantiated,
7047 e.g.:
7048 template<class T>
7049 struct S
7050 {
7051 template<class U> struct M {}; //#0
7052 };
7054 template<>
7055 template<>
7056 struct S<int>::M<char> //#1
7057 {
7058 int i;
7059 };
7060 [temp.expl.spec]/4 says this is valid.
7062 In this case, when we write:
7063 S<int>::M<char> m;
7065 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7066 the one of #0.
7068 When we encounter #1, we want to store the partial instantiation
7069 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7071 For all cases other than this "explicit specialization of member of a
7072 class template", we just want to store the most general template into
7073 the CLASSTYPE_TI_TEMPLATE of M.
7075 This case of "explicit specialization of member of a class template"
7076 only happens when:
7077 1/ the enclosing class is an instantiation of, and therefore not
7078 the same as, the context of the most general template, and
7079 2/ we aren't looking at the partial instantiation itself, i.e.
7080 the innermost arguments are not the same as the innermost parms of
7081 the most general template.
7083 So it's only when 1/ and 2/ happens that we want to use the partial
7084 instantiation of the member template in lieu of its most general
7085 template. */
7089 /* the enclosing class must be an instantiation... */
7092 {
7093 tree partial_inst_args;
7096 partial_inst_args =
7102 use_partial_inst_tmpl =
7103 /*...and we must not be looking at the partial instantiation
7104 itself. */
7106 partial_inst_args);
7107 }
7110 /* This case is easy; there are no member templates involved. */
7112 else
7113 {
7114 /* This is a full instantiation of a member template. Find
7115 the partial instantiation of which this is an instance. */
7117 /* Temporarily reduce by one the number of levels in the ARGLIST
7118 so as to avoid comparing the last set of arguments. */
7123 }
7133 /* Note this use of the partial instantiation so we can check it
7134 later in maybe_process_partial_specialization. */
7140 /* Now that the type has been registered on the instantiations
7141 list, we set up the enumerators. Because the enumeration
7142 constants may involve the enumeration type itself, we make
7143 sure to register the type first, and then create the
7144 constants. That way, doing tsubst_expr for the enumeration
7145 constants won't result in recursive calls here; we'll find
7146 the instantiation and exit above. */
7150 /* If the type makes use of template parameters, the
7151 code that generates debugging information will crash. */
7154 /* Possibly limit visibility based on template args. */
7159 }
7161 }
7162 \f
7163 struct pair_fn_data
7164 {
7165 tree_fn_t fn;
7167 /* True when we should also visit template parameters that occur in
7168 non-deduced contexts. */
7171 };
7173 /* Called from for_each_template_parm via walk_tree. */
7175 static tree
7177 {
7190 {
7194 /* Fall through. */
7217 /* Since we're not going to walk subtrees, we have to do this
7218 explicitly here. */
7222 /* Fall through. */
7225 /* Check the return type. */
7230 /* Check the parameter types. Since default arguments are not
7231 instantiated until they are needed, the TYPE_ARG_TYPES may
7232 contain expressions that involve template parameters. But,
7233 no-one should be looking at them yet. And, once they're
7234 instantiated, they don't contain template parameters, so
7235 there's no point in looking at them then, either. */
7236 {
7237 tree parm;
7244 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7245 want walk_tree walking into them itself. */
7247 }
7264 /* Fall through. */
7280 /* Record template parameters such as `T' inside `TT<T>'. */
7284 /* Fall through. */
7296 /* A template template parameter is encountered. */
7302 /* Already substituted template template parameter */
7325 /* If there's no type, then this thing must be some expression
7326 involving template parameters. */
7347 }
7349 /* We didn't find any template parameters we liked. */
7351 }
7353 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7354 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7355 call FN with the parameter and the DATA.
7356 If FN returns nonzero, the iteration is terminated, and
7357 for_each_template_parm returns 1. Otherwise, the iteration
7358 continues. If FN never returns a nonzero value, the value
7359 returned by for_each_template_parm is 0. If FN is NULL, it is
7360 considered to be the function which always returns 1.
7362 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7363 parameters that occur in non-deduced contexts. When false, only
7364 visits those template parameters that can be deduced. */
7366 static int
7370 {
7374 /* Set up. */
7379 /* Walk the tree. (Conceptually, we would like to walk without
7380 duplicates, but for_each_template_parm_r recursively calls
7381 for_each_template_parm, so we would need to reorganize a fair
7382 bit to use walk_tree_without_duplicates, so we keep our own
7383 visited list.) */
7386 else
7389 for_each_template_parm_r,
7393 /* Clean up. */
7395 {
7398 }
7401 }
7403 /* Returns true if T depends on any template parameter. */
7405 int
7407 {
7434 else
7435 {
7438 }
7443 }
7445 /* Returns true if T depends on any template parameter with level LEVEL. */
7447 int
7449 {
7452 }
7456 #ifdef GATHER_STATISTICS
7458 #endif
7462 /* We're starting to instantiate D; record the template instantiation context
7463 for diagnostics and to restore it later. */
7465 int
7467 {
7471 {
7472 /* If the instantiation in question still has unbound template parms,
7473 we don't really care if we can't instantiate it, so just return.
7474 This happens with base instantiation for implicit `typename'. */
7486 }
7496 #ifdef GATHER_STATISTICS
7499 #endif
7503 }
7505 /* We're done instantiating this template; return to the instantiation
7506 context. */
7508 void
7510 {
7511 /* Restore the filename and line number stashed away when we started
7512 this instantiation. */
7517 }
7519 /* We're instantiating a deferred template; restore the template
7520 instantiation context in which the instantiation was requested, which
7521 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7523 static tree
7525 {
7535 }
7537 /* Returns the TINST_LEVEL which gives the original instantiation
7538 context. */
7542 {
7548 }
7550 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7552 bool
7554 {
7555 tree parms;
7572 }
7574 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7575 vector of template arguments, as for tsubst.
7577 Returns an appropriate tsubst'd friend declaration. */
7579 static tree
7581 {
7582 tree new_friend;
7587 /* This was a friend declared with an explicit template
7588 argument list, e.g.:
7590 friend void f<>(T);
7592 to indicate that f was a template instantiation, not a new
7593 function declaration. Now, we have to figure out what
7594 instantiation of what template. */
7595 {
7597 tree new_args;
7598 tree tmpl;
7601 /* Friend functions are looked up in the containing namespace scope.
7602 We must enter that scope, to avoid finding member functions of the
7603 current class with same name. */
7618 tsk_none);
7620 }
7624 /* The NEW_FRIEND will look like an instantiation, to the
7625 compiler, but is not an instantiation from the point of view of
7626 the language. For example, we might have had:
7628 template <class T> struct S {
7629 template <class U> friend void f(T, U);
7630 };
7632 Then, in S<int>, template <class U> void f(int, U) is not an
7633 instantiation of anything. */
7639 {
7643 }
7645 /* The mangled name for the NEW_FRIEND is incorrect. The function
7646 is not a template instantiation and should not be mangled like
7647 one. Therefore, we forget the mangling here; we'll recompute it
7648 later if we need it. */
7650 {
7653 }
7656 {
7657 tree old_decl;
7658 tree new_friend_template_info;
7659 tree new_friend_result_template_info;
7660 tree ns;
7663 /* We must save some information from NEW_FRIEND before calling
7664 duplicate decls since that function will free NEW_FRIEND if
7665 possible. */
7667 new_friend_is_defn =
7672 {
7673 /* This declaration is a `primary' template. */
7676 new_friend_result_template_info
7678 }
7679 else
7682 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7686 /* Inside pushdecl_namespace_level, we will push into the
7687 current namespace. However, the friend function should go
7688 into the namespace of the template. */
7698 {
7699 /* This new friend declaration matched an existing
7700 declaration. For example, given:
7702 template <class T> void f(T);
7703 template <class U> class C {
7704 template <class T> friend void f(T) {}
7705 };
7707 the friend declaration actually provides the definition
7708 of `f', once C has been instantiated for some type. So,
7709 old_decl will be the out-of-class template declaration,
7710 while new_friend is the in-class definition.
7712 But, if `f' was called before this point, the
7713 instantiation of `f' will have DECL_TI_ARGS corresponding
7714 to `T' but not to `U', references to which might appear
7715 in the definition of `f'. Previously, the most general
7716 template for an instantiation of `f' was the out-of-class
7717 version; now it is the in-class version. Therefore, we
7718 run through all specialization of `f', adding to their
7719 DECL_TI_ARGS appropriately. In particular, they need a
7720 new set of outer arguments, corresponding to the
7721 arguments for this class instantiation.
7723 The same situation can arise with something like this:
7725 friend void f(int);
7726 template <class T> class C {
7727 friend void f(T) {}
7728 };
7730 when `C<int>' is instantiated. Now, `f(int)' is defined
7731 in the class. */
7734 /* On the other hand, if the in-class declaration does
7735 *not* provide a definition, then we don't want to alter
7736 existing definitions. We can just leave everything
7737 alone. */
7738 ;
7739 else
7740 {
7744 /* Overwrite whatever template info was there before, if
7745 any, with the new template information pertaining to
7746 the declaration. */
7750 {
7751 /* We should have called reregister_specialization in
7752 duplicate_decls. */
7757 /* Instantiate it if the global has already been used. */
7761 }
7762 else
7763 {
7764 tree t;
7766 /* Indicate that the old function template is a partial
7767 instantiation. */
7775 /* Reassign any specializations already in the hash table
7776 to the new more general template, and add the
7777 additional template args. */
7781 {
7783 spec_entry elt;
7795 register_specialization
7798 }
7800 }
7801 }
7803 /* The information from NEW_FRIEND has been merged into OLD_DECL
7804 by duplicate_decls. */
7806 }
7807 }
7808 else
7809 {
7813 /* In the code
7814 template <class T> class C {
7815 template <class U> friend void C1<U>::f (); // case 1
7816 friend void C2<T>::f (); // case 2
7817 };
7818 we only need to make sure CONTEXT is a complete type for
7819 case 2. To distinguish between the two cases, we note that
7820 CONTEXT of case 1 remains dependent type after tsubst while
7821 this isn't true for case 2. */
7831 {
7832 /* Check to see that the declaration is really present, and,
7833 possibly obtain an improved declaration. */
7839 }
7840 }
7843 }
7845 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7846 template arguments, as for tsubst.
7848 Returns an appropriate tsubst'd friend type or error_mark_node on
7849 failure. */
7851 static tree
7853 {
7854 tree friend_type;
7855 tree tmpl;
7856 tree context;
7861 {
7864 else
7866 }
7868 /* Look for a class template declaration. We look for hidden names
7869 because two friend declarations of the same template are the
7870 same. For example, in:
7872 struct A {
7873 template <typename> friend class F;
7874 };
7875 template <typename> struct B {
7876 template <typename> friend class F;
7877 };
7879 both F templates are the same. */
7884 /* But, if we don't find one, it might be because we're in a
7885 situation like this:
7887 template <class T>
7888 struct S {
7889 template <class U>
7890 friend struct S;
7891 };
7893 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7894 for `S<int>', not the TEMPLATE_DECL. */
7896 {
7899 }
7902 {
7903 /* The friend template has already been declared. Just
7904 check to see that the declarations match, and install any new
7905 default parameters. We must tsubst the default parameters,
7906 of course. We only need the innermost template parameters
7907 because that is all that redeclare_class_template will look
7908 at. */
7911 {
7912 tree parms;
7913 location_t saved_input_location;
7922 }
7925 }
7926 else
7927 {
7928 /* The friend template has not already been declared. In this
7929 case, the instantiation of the template class will cause the
7930 injection of this template into the global scope. */
7935 /* The new TMPL is not an instantiation of anything, so we
7936 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7937 the new type because that is supposed to be the corresponding
7938 template decl, i.e., TMPL. */
7945 /* Inject this template into the global scope. */
7947 }
7950 {
7953 else
7955 }
7958 }
7960 /* Returns zero if TYPE cannot be completed later due to circularity.
7961 Otherwise returns one. */
7963 static int
7965 {
7975 else
7977 }
7979 /* Apply any attributes which had to be deferred until instantiation
7980 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7981 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7983 static void
7986 {
7988 tree t;
7993 {
7997 }
8000 {
8004 }
8005 else
8009 {
8014 {
8017 {
8020 /* If the first attribute argument is an identifier, don't
8021 pass it through tsubst. Attributes like mode, format,
8022 cleanup and several target specific attributes expect it
8023 unmodified. */
8029 {
8030 tree chain
8032 in_decl,
8037 chain);
8038 }
8039 else
8045 }
8046 else
8048 }
8051 }
8052 }
8054 /* Perform (or defer) access check for typedefs that were referenced
8055 from within the template TMPL code.
8056 This is a subroutine of instantiate_template and instantiate_class_template.
8057 TMPL is the template to consider and TARGS is the list of arguments of
8058 that template. */
8060 static void
8062 {
8063 location_t saved_location;
8076 {
8088 /* Make access check error messages point to the location
8089 of the use of the typedef. */
8093 }
8095 }
8097 tree
8099 {
8101 tree typedecl;
8102 tree pbinfo;
8103 tree base_list;
8113 /* Figure out which template is being instantiated. */
8117 /* Determine what specialization of the original template to
8118 instantiate. */
8121 {
8124 }
8126 {
8127 /* This TYPE is actually an instantiation of a partial
8128 specialization. We replace the innermost set of ARGS with
8129 the arguments appropriate for substitution. For example,
8130 given:
8132 template <class T> struct S {};
8133 template <class T> struct S<T*> {};
8135 and supposing that we are instantiating S<int*>, ARGS will
8136 presently be {int*} -- but we need {int}. */
8139 }
8140 else
8141 {
8144 }
8146 /* If the template we're instantiating is incomplete, then clearly
8147 there's nothing we can do. */
8151 /* If we've recursively instantiated too many templates, stop. */
8155 /* Now we're really doing the instantiation. Mark the type as in
8156 the process of being defined. */
8159 /* We may be in the middle of deferred access check. Disable
8160 it now. */
8164 /* Use #pragma pack from the template context. */
8170 /* Set the input location to the most specialized template definition.
8171 This is needed if tsubsting causes an error. */
8193 {
8196 }
8200 /* We should never instantiate a nested class before its enclosing
8201 class; we need to look up the nested class by name before we can
8202 instantiate it, and that lookup should instantiate the enclosing
8203 class. */
8209 {
8210 tree pbase_binfo;
8211 tree pushed_scope;
8214 /* We must enter the scope containing the type, as that is where
8215 the accessibility of types named in dependent bases are
8216 looked up from. */
8219 /* Substitute into each of the bases to determine the actual
8220 basetypes. */
8222 {
8223 tree base;
8229 {
8230 expanded_bases =
8237 }
8240 {
8242 /* Extract the already-expanded base class. */
8244 else
8245 /* Substitute to figure out the base class. */
8247 NULL_TREE);
8255 }
8256 }
8258 /* The list is now in reverse order; correct that. */
8263 }
8264 /* Now call xref_basetypes to set up all the base-class
8265 information. */
8273 /* Now that our base classes are set up, enter the scope of the
8274 class, so that name lookups into base classes, etc. will work
8275 correctly. This is precisely analogous to what we do in
8276 begin_class_definition when defining an ordinary non-template
8277 class, except we also need to push the enclosing classes. */
8280 /* Now members are processed in the order of declaration. */
8283 {
8287 {
8289 {
8290 /* Build new CLASSTYPE_NESTED_UTDS. */
8292 tree newtag;
8298 /* If the member is a class template, then -- even after
8299 substitution -- there may be dependent types in the
8300 template argument list for the class. We increment
8301 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8302 that function will assume that no types are dependent
8303 when outside of a template. */
8313 {
8317 /* Unfortunately, lookup_template_class sets
8318 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8319 instantiation (i.e., for the type of a member
8320 template class nested within a template class.)
8321 This behavior is required for
8322 maybe_process_partial_specialization to work
8323 correctly, but is not accurate in this case;
8324 the TAG is not an instantiation of anything.
8325 (The corresponding TEMPLATE_DECL is an
8326 instantiation, but the TYPE is not.) */
8329 /* Now, we call pushtag to put this NEWTAG into the scope of
8330 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8331 pushtag calling push_template_decl. We don't have to do
8332 this for enums because it will already have been done in
8333 tsubst_enum. */
8337 }
8338 }
8341 {
8342 /* Build new TYPE_METHODS. */
8343 tree r;
8352 }
8353 else
8354 {
8355 /* Build new TYPE_FIELDS. */
8357 {
8358 tree condition =
8366 }
8368 {
8369 tree r;
8371 /* The file and line for this declaration, to
8372 assist in error message reporting. Since we
8373 called push_tinst_level above, we don't need to
8374 restore these. */
8383 {
8384 /* In [temp.inst]:
8386 [t]he initialization (and any associated
8387 side-effects) of a static data member does
8388 not occur unless the static data member is
8389 itself used in a way that requires the
8390 definition of the static data member to
8391 exist.
8393 Therefore, we do not substitute into the
8394 initialized for the static data member here. */
8395 finish_static_data_member_decl
8403 }
8405 {
8406 /* Determine whether R has a valid type and can be
8407 completed later. If R is invalid, then it is
8408 replaced by error_mark_node so that it will not be
8409 added to TYPE_FIELDS. */
8415 {
8418 }
8419 }
8421 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8422 such a thing will already have been added to the field
8423 list by tsubst_enum in finish_member_declaration in the
8424 CLASSTYPE_NESTED_UTDS case above. */
8428 {
8431 }
8432 }
8433 }
8434 }
8435 else
8436 {
8438 {
8439 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8445 {
8446 /* template <class T> friend class C; */
8449 }
8451 {
8452 /* template <class T> friend class C::D; */
8458 }
8460 {
8461 /* This could be either
8463 friend class T::C;
8465 when dependent_type_p is false or
8467 template <class U> friend class T::C;
8469 otherwise. */
8472 /* Bump processing_template_decl for correct
8473 dependent_type_p calculation. */
8478 }
8481 {
8482 /* friend class C;
8484 where C hasn't been declared yet. Let's lookup name
8485 from namespace scope directly, bypassing any name that
8486 come from dependent base class. */
8489 /* The call to xref_tag_from_type does injection for friend
8490 classes. */
8492 friend_type =
8496 }
8498 /* friend class C<T>; */
8501 /* Otherwise it's
8503 friend class C;
8505 where C is already declared or
8507 friend class C<int>;
8509 We don't have to do anything in these cases. */
8512 /* Trick make_friend_class into realizing that the friend
8513 we're adding is a template, not an ordinary class. It's
8514 important that we use make_friend_class since it will
8515 perform some error-checking and output cross-reference
8516 information. */
8524 }
8525 else
8526 {
8527 /* Build new DECL_FRIENDLIST. */
8528 tree r;
8530 /* The file and line for this declaration, to
8531 assist in error message reporting. Since we
8532 called push_tinst_level above, we don't need to
8533 restore these. */
8537 {
8540 }
8545 {
8548 }
8549 }
8550 }
8551 }
8553 /* Set the file and line number information to whatever is given for
8554 the class itself. This puts error messages involving generated
8555 implicit functions at a predictable point, and the same point
8556 that would be used for non-template classes. */
8563 /* We don't instantiate default arguments for member functions. 14.7.1:
8565 The implicit instantiation of a class template specialization causes
8566 the implicit instantiation of the declarations, but not of the
8567 definitions or default arguments, of the class member functions,
8568 member classes, static data members and member templates.... */
8570 /* Some typedefs referenced from within the template code need to be access
8571 checked at template instantiation time, i.e now. These types were
8572 added to the template at parsing time. Let's get those and perform
8573 the access checks then. */
8582 /* The vtable for a template class can be emitted in any translation
8583 unit in which the class is instantiated. When there is no key
8584 method, however, finish_struct_1 will already have added TYPE to
8585 the keyed_classes list. */
8590 }
8592 static tree
8594 {
8595 tree r;
8601 else
8602 {
8609 }
8611 }
8613 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8614 NONTYPE_ARGUMENT_PACK. */
8616 static tree
8618 {
8619 /* Collect all of the extra "packed" parameters into an
8620 argument pack. */
8621 tree parmvec;
8622 tree parmtypevec;
8627 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8631 {
8634 }
8636 /* Build the argument packs. */
8642 }
8644 /* Substitute ARGS into T, which is an pack expansion
8645 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8646 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8647 (if only a partial substitution could be performed) or
8648 ERROR_MARK_NODE if there was an error. */
8649 tree
8651 tree in_decl)
8652 {
8653 tree pattern;
8656 tree result;
8663 /* Determine the argument packs that will instantiate the parameter
8664 packs used in the expansion expression. While we're at it,
8665 compute the number of arguments to be expanded and make sure it
8666 is consistent. */
8669 {
8675 {
8678 else
8679 {
8680 /* We can't rely on local_specializations for a parameter
8681 name used later in a function declaration (such as in a
8682 late-specified return type). Even if it exists, it might
8683 have the wrong value for a recursive call. Just make a
8684 dummy decl, since it's only used for its type. */
8687 }
8688 }
8689 else
8690 {
8697 }
8704 /* This can only happen if we forget to expand an argument
8705 pack somewhere else. Just return an error, silently. */
8706 {
8710 }
8715 {
8720 /* The argument pack that the parameter maps to is just an
8721 expansion of the parameter itself, such as one would
8722 find in the implicit typedef of a class inside the
8723 class itself. Consider this parameter "unsubstituted",
8724 so that we will maintain the outer pack expansion. */
8726 }
8729 {
8733 /* It's all-or-nothing with incomplete argument packs. */
8743 {
8745 /* We got explicit args for some packs but not others;
8746 do nothing now and try again after deduction. */
8751 pattern);
8752 else
8755 pattern);
8757 }
8759 /* Keep track of the parameter packs and their corresponding
8760 argument packs. */
8763 }
8764 else
8765 /* We can't substitute for this parameter pack. */
8768 unsubstituted_packs);
8769 }
8771 /* We cannot expand this expansion expression, because we don't have
8772 all of the argument packs we need. Substitute into the pattern
8773 and return a PACK_EXPANSION_*. The caller will need to deal with
8774 that. */
8776 {
8777 tree new_pat;
8781 else
8784 }
8786 /* We could not find any argument packs that work. */
8791 {
8792 /* We're in a late-specified return type, so create our own local
8793 specializations table; the current table is either NULL or (in the
8794 case of recursive unification) might have bindings that we don't
8795 want to use or alter. */
8798 hash_local_specialization,
8799 eq_local_specializations,
8800 NULL);
8801 }
8803 /* For each argument in each argument pack, substitute into the
8804 pattern. */
8807 {
8808 /* For parameter pack, change the substitution of the parameter
8809 pack to the ith argument in its argument pack, then expand
8810 the pattern. */
8812 {
8816 {
8817 /* Select the Ith argument from the pack. */
8823 }
8824 else
8825 {
8831 {
8832 /* Select the Ith argument from the pack. */
8836 }
8838 /* Update the corresponding argument. */
8840 }
8841 }
8843 /* Substitute into the PATTERN with the altered arguments. */
8848 else
8852 /* When we have incomplete argument packs, the last "expanded"
8853 result is itself a pack expansion, which allows us
8854 to deduce more arguments. */
8859 {
8862 }
8863 }
8865 /* Update ARGS to restore the substitution from parameter packs to
8866 their argument packs. */
8868 {
8873 else
8874 {
8878 /* Update the corresponding argument. */
8882 else
8884 }
8885 }
8888 {
8891 }
8894 }
8896 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8897 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8898 parameter packs; all parms generated from a function parameter pack will
8899 have the same DECL_PARM_INDEX. */
8901 tree
8903 {
8905 tree patparm;
8908 {
8914 }
8915 else
8916 {
8921 }
8924 }
8926 /* Substitute ARGS into the vector or list of template arguments T. */
8928 static tree
8930 {
8937 {
8939 tree new_arg;
8944 {
8945 /* Substitute into an expansion expression. */
8949 /* Add to the expanded length adjustment the number of
8950 expanded arguments. We subtract one from this
8951 measurement, because the argument pack expression
8952 itself is already counted as 1 in
8953 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8954 the argument pack is empty. */
8956 }
8958 {
8959 /* Substitute into each of the arguments. */
8965 new_arg,
8979 }
8980 }
8981 else
8990 }
8995 /* Make space for the expanded arguments coming from template
8996 argument packs. */
8998 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8999 arguments for a member template.
9000 In that case each TREE_VEC in ORIG_T represents a level of template
9001 arguments, and ORIG_T won't carry any non defaulted argument count.
9002 It will rather be the nested TREE_VECs that will carry one.
9003 In other words, ORIG_T carries a non defaulted argument count only
9004 if it doesn't contain any nested TREE_VEC. */
9006 {
9010 }
9012 {
9016 {
9019 /* Now expand the template argument pack "in place". */
9022 }
9023 else
9024 {
9026 out++;
9027 }
9028 }
9031 }
9033 /* Return the result of substituting ARGS into the template parameters
9034 given by PARMS. If there are m levels of ARGS and m + n levels of
9035 PARMS, then the result will contain n levels of PARMS. For
9036 example, if PARMS is `template <class T> template <class U>
9037 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9038 result will be `template <int*, double, class V>'. */
9040 static tree
9042 {
9046 /* When substituting into a template, we must set
9047 PROCESSING_TEMPLATE_DECL as the template parameters may be
9048 dependent if they are based on one-another, and the dependency
9049 predicates are short-circuit outside of templates. */
9056 {
9057 tree new_vec =
9062 {
9063 tree tuple;
9075 }
9081 }
9086 }
9088 /* Return the result of substituting ARGS into one template parameter
9089 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9090 parameter and which TREE_PURPOSE is the default argument of the
9091 template parameter. */
9093 static tree
9095 {
9116 }
9118 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9119 type T. If T is not an aggregate or enumeration type, it is
9120 handled as if by tsubst. IN_DECL is as for tsubst. If
9121 ENTERING_SCOPE is nonzero, T is the context for a template which
9122 we are presently tsubst'ing. Return the substituted value. */
9124 static tree
9126 tree args,
9127 tsubst_flags_t complain,
9128 tree in_decl,
9130 {
9135 {
9140 /* Else fall through. */
9144 {
9145 tree argvec;
9146 tree context;
9147 tree r;
9151 /* In "sizeof(X<I>)" we need to evaluate "I". */
9157 /* First, determine the context for the type we are looking
9158 up. */
9161 {
9164 /* If context is a nested class inside a class template,
9165 it may still need to be instantiated (c++/33959). */
9168 }
9170 /* Then, figure out what arguments are appropriate for the
9171 type we are trying to find. For example, given:
9173 template <class T> struct S;
9174 template <class T, class U> void f(T, U) { S<U> su; }
9176 and supposing that we are instantiating f<int, double>,
9177 then our ARGS will be {int, double}, but, when looking up
9178 S we only want {double}. */
9183 else
9184 {
9188 }
9194 }
9195 else
9196 /* This is not a template type, so there's nothing to do. */
9201 }
9202 }
9204 /* Substitute into the default argument ARG (a default argument for
9205 FN), which has the indicated TYPE. */
9207 tree
9209 {
9213 /* This can happen in invalid code. */
9217 /* This default argument came from a template. Instantiate the
9218 default argument here, not in tsubst. In the case of
9219 something like:
9221 template <class T>
9222 struct S {
9223 static T t();
9224 void f(T = t());
9225 };
9227 we must be careful to do name lookup in the scope of S<T>,
9228 rather than in the current class. */
9230 /* The "this" pointer is not valid in a default argument. */
9232 {
9237 }
9240 /* The default argument expression may cause implicitly defined
9241 member functions to be synthesized, which will result in garbage
9242 collection. We must treat this situation as if we were within
9243 the body of function so as to avoid collecting live data on the
9244 stack. */
9252 /* Restore the "this" pointer. */
9254 {
9257 }
9259 /* Make sure the default argument is reasonable. */
9265 }
9267 /* Substitute into all the default arguments for FN. */
9269 static void
9271 {
9272 tree arg;
9273 tree tmpl_args;
9277 /* If this function is not yet instantiated, we certainly don't need
9278 its default arguments. */
9281 /* Don't do this again for clones. */
9286 arg;
9292 }
9294 /* Substitute the ARGS into the T, which is a _DECL. Return the
9295 result of the substitution. Issue error and warning messages under
9296 control of COMPLAIN. */
9298 static tree
9300 {
9301 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9302 location_t saved_loc;
9307 /* Set the filename and linenumber to improve error-reporting. */
9312 {
9314 {
9315 /* We can get here when processing a member function template,
9316 member class template, or template template parameter. */
9318 tree spec;
9319 tree tmpl_args;
9320 tree full_args;
9323 {
9324 /* Template template parameter is treated here. */
9337 complain);
9340 }
9342 /* We might already have an instance of this template.
9343 The ARGS are for the surrounding class type, so the
9344 full args contain the tsubst'd args for the context,
9345 plus the innermost args from the template decl. */
9349 /* Because this is a template, the arguments will still be
9350 dependent, even after substitution. If
9351 PROCESSING_TEMPLATE_DECL is not set, the dependency
9352 predicates will short-circuit. */
9360 /* If this is a default template template argument,
9361 tsubst might not have changed anything. */
9368 {
9371 }
9373 /* Make a new template decl. It will be similar to the
9374 original, but will record the current template arguments.
9375 We also create a new function declaration, which is just
9376 like the old one, but points to this new template, rather
9377 than the old one. */
9385 {
9386 tree new_type;
9398 }
9399 else
9400 {
9401 tree new_decl;
9413 }
9419 /* The template parameters for this new template are all the
9420 template parameters for the old template, except the
9421 outermost level of parameters. */
9424 complain);
9430 /* Record this non-type partial instantiation. */
9434 }
9438 {
9439 tree ctx;
9442 tree gen_tmpl;
9443 tree type;
9448 /* Nobody should be tsubst'ing into non-template functions. */
9452 {
9453 tree spec;
9456 /* If T is not dependent, just return it. We have to
9457 increment PROCESSING_TEMPLATE_DECL because
9458 value_dependent_expression_p assumes that nothing is
9459 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9466 /* Calculate the most general template of which R is a
9467 specialization, and the complete set of arguments used to
9468 specialize R. */
9471 (DECL_TEMPLATE_RESULT
9475 /* Check to see if we already have this specialization. */
9480 {
9483 }
9485 /* We can see more levels of arguments than parameters if
9486 there was a specialization of a member template, like
9487 this:
9489 template <class T> struct S { template <class U> void f(); }
9490 template <> template <class U> void S<int>::f(U);
9492 Here, we'll be substituting into the specialization,
9493 because that's where we can find the code we actually
9494 want to generate, but we'll have enough arguments for
9495 the most general template.
9497 We also deal with the peculiar case:
9499 template <class T> struct S {
9500 template <class U> friend void f();
9501 };
9502 template <class U> void f() {}
9503 template S<int>;
9504 template void f<double>();
9506 Here, the ARGS for the instantiation of will be {int,
9507 double}. But, we only need as many ARGS as there are
9508 levels of template parameters in CODE_PATTERN. We are
9509 careful not to get fooled into reducing the ARGS in
9510 situations like:
9512 template <class T> struct S { template <class U> void f(U); }
9513 template <class T> template <> void S<T>::f(int) {}
9515 which we can spot because the pattern will be a
9516 specialization in this case. */
9518 parms_depth =
9523 }
9524 else
9525 {
9526 /* This special case arises when we have something like this:
9528 template <class T> struct S {
9529 friend void f<int>(int, double);
9530 };
9532 Here, the DECL_TI_TEMPLATE for the friend declaration
9533 will be an IDENTIFIER_NODE. We are being called from
9534 tsubst_friend_function, and we want only to create a
9535 new decl (R) with appropriate types so that we can call
9536 determine_specialization. */
9538 }
9541 {
9544 else
9548 }
9549 else
9550 {
9553 }
9558 /* We do NOT check for matching decls pushed separately at this
9559 point, as they may not represent instantiations of this
9560 template, and in any case are considered separate under the
9561 discrete model. */
9565 /* Clear out the mangled name and RTL for the instantiation. */
9568 /* Leave DECL_INITIAL set on deleted instantiations. */
9574 /* Type-conversion operator. Reconstruct the name, in
9575 case it's the name of one of the template's parameters. */
9585 /* If this is an instantiation of a function with internal
9586 linkage, we already know what object file linkage will be
9587 assigned to the instantiation. */
9596 /* We'll re-clone as appropriate in instantiate_template. */
9599 /* If we aren't complaining now, return on error before we register
9600 the specialization so that we'll complain eventually. */
9606 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9607 this in the special friend case mentioned above where
9608 GEN_TMPL is NULL. */
9610 {
9616 /* We're not supposed to instantiate default arguments
9617 until they are called, for a template. But, for a
9618 declaration like:
9620 template <class T> void f ()
9621 { extern void g(int i = T()); }
9623 we should do the substitution when the template is
9624 instantiated. We handle the member function case in
9625 instantiate_class_template since the default arguments
9626 might refer to other members of the class. */
9631 }
9632 else
9635 /* Copy the list of befriending classes. */
9639 {
9643 in_decl);
9644 }
9647 {
9651 /* If this is an instantiation of a member template, clone it.
9652 If it isn't, that'll be handled by
9653 clone_constructors_and_destructors. */
9656 }
9667 /* Possibly limit visibility based on template args. */
9670 {
9674 }
9682 }
9686 {
9694 {
9695 /* If there is a local specialization that isn't a
9696 parameter pack, it means that we're doing a "simple"
9697 substitution from inside tsubst_pack_expansion. Just
9698 return the local specialization (which will be a single
9699 parm). */
9706 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9707 the parameters in this function parameter pack. */
9711 {
9714 /* Zero-length parameter packs are boring. Just substitute
9715 into the chain. */
9719 }
9720 else
9721 {
9722 /* All we did was update the type. Make a note of that. */
9725 }
9726 }
9728 /* Loop through all of the parameter's we'll build. When T is
9729 a function parameter pack, LEN is the number of expanded
9730 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9733 {
9739 /* An argument of a function parameter pack is not a parameter
9740 pack. */
9744 /* We're on the Ith parameter of the function parameter
9745 pack. */
9746 {
9747 /* Get the Ith type. */
9751 /* Rename the parameter to include the index. */
9754 }
9756 /* We're dealing with a normal parameter. */
9764 {
9767 else
9770 }
9780 /* Keep track of the first new parameter we
9781 generate. That's what will be returned to the
9782 caller. */
9786 /* Build a proper chain of parameters when substituting
9787 into a function parameter pack. */
9790 }
9796 /* FIRST_R contains the start of the chain we've built. */
9798 }
9802 {
9803 tree type;
9812 /* DECL_INITIAL gives the number of bits in a bit-field. */
9817 /* We don't have to set DECL_CONTEXT here; it is set by
9818 finish_member_declaration. */
9825 }
9829 /* We reach here only for member using decls. */
9831 {
9832 r = do_class_using_decl
9837 else
9838 {
9841 }
9842 }
9843 else
9844 {
9847 }
9852 {
9855 tree spec;
9857 tree ctx;
9863 {
9864 /* If this is the canonical decl, we don't have to
9865 mess with instantiations, and often we can't (for
9866 typename, template type parms and such). Note that
9867 TYPE_NAME is not correct for the above test if
9868 we've copied the type for a typedef. */
9874 }
9876 /* Check to see if we already have the specialization we
9877 need. */
9880 {
9881 /* T is a static data member or namespace-scope entity.
9882 We have to substitute into namespace-scope variables
9883 (even though such entities are never templates) because
9884 of cases like:
9886 template <class T> void f() { extern T t; }
9888 where the entity referenced is not known until
9889 instantiation time. */
9893 {
9895 complain,
9897 /* If CTX is unchanged, then T is in fact the
9898 specialization we want. That situation occurs when
9899 referencing a static data member within in its own
9900 class. We can use pointer equality, rather than
9901 same_type_p, because DECL_CONTEXT is always
9902 canonical. */
9905 }
9908 {
9914 }
9915 }
9916 else
9917 {
9918 /* A local variable. */
9920 /* Subsequent calls to pushdecl will fill this in. */
9923 }
9924 /* If we already have the specialization we need, there is
9925 nothing more to do. */
9927 {
9930 }
9932 /* Create a new node for the specialization we need. */
9935 {
9938 else
9943 }
9945 {
9946 /* Even if the original location is out of scope, the
9947 newly substituted one is not. */
9954 {
9955 /* It may seem that this case cannot occur, since:
9957 typedef void f();
9958 void g() { f x; }
9960 declares a function, not a variable. However:
9962 typedef void f();
9963 template <typename T> void g() { T t; }
9964 template void g<f>();
9966 is an attempt to declare a variable with function
9967 type. */
9969 /* R is not yet sufficiently initialized, so we
9970 just use its name. */
9973 }
9975 /* Wait until cp_finish_decl to set this again, to handle
9976 circular dependency (template/instantiate6.C). */
9981 {
9986 }
9987 }
9993 /* Clear out the mangled name and RTL for the instantiation. */
9997 /* The initializer must not be expanded until it is required;
9998 see [temp.inst]. */
10004 {
10005 /* Possibly limit visibility based on template args. */
10008 {
10012 }
10014 }
10017 {
10018 /* A static data member declaration is always marked
10019 external when it is declared in-class, even if an
10020 initializer is present. We mimic the non-template
10021 processing here. */
10027 }
10029 {
10030 /* We're substituting this var in a decltype outside of its
10031 scope, such as for a lambda return type. Don't add it to
10032 local_specializations, do perform auto deduction. */
10034 tree init
10039 {
10042 {
10045 }
10046 }
10047 }
10048 else
10057 /* Preserve a typedef that names a type. */
10059 {
10062 }
10065 }
10070 }
10071 #undef RETURN
10073 out:
10074 /* Restore the file and line information. */
10078 }
10080 /* Substitute into the ARG_TYPES of a function type. */
10082 static tree
10084 tree args,
10085 tsubst_flags_t complain,
10086 tree in_decl)
10087 {
10088 tree remaining_arg_types;
10092 tree default_arg;
10103 {
10104 /* For a pack expansion, perform substitution on the
10105 entire expression. Later on, we'll handle the arguments
10106 one-by-one. */
10111 /* So that we'll spin through the parameters, one by one. */
10113 else
10114 {
10115 /* We only partially substituted into the parameter
10116 pack. Our type is TYPE_PACK_EXPANSION. */
10119 }
10120 }
10133 {
10135 {
10139 }
10141 }
10143 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10144 top-level qualifiers as required. */
10147 /* We do not substitute into default arguments here. The standard
10148 mandates that they be instantiated only when needed, which is
10149 done in build_over_call. */
10153 {
10154 /* We've instantiated a template before its default arguments
10155 have been parsed. This can happen for a nested template
10156 class, and is not an error unless we require the default
10157 argument in a call of this function. */
10158 remaining_arg_types =
10161 remaining_arg_types);
10162 }
10163 else
10164 remaining_arg_types =
10166 }
10169 }
10171 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10172 *not* handle the exception-specification for FNTYPE, because the
10173 initial substitution of explicitly provided template parameters
10174 during argument deduction forbids substitution into the
10175 exception-specification:
10177 [temp.deduct]
10179 All references in the function type of the function template to the
10180 corresponding template parameters are replaced by the specified tem-
10181 plate argument values. If a substitution in a template parameter or
10182 in the function type of the function template results in an invalid
10183 type, type deduction fails. [Note: The equivalent substitution in
10184 exception specifications is done only when the function is instanti-
10185 ated, at which point a program is ill-formed if the substitution
10186 results in an invalid type.] */
10188 static tree
10190 tree args,
10191 tsubst_flags_t complain,
10192 tree in_decl)
10193 {
10194 tree return_type;
10195 tree arg_types;
10196 tree fntype;
10198 /* The TYPE_CONTEXT is not used for function/method types. */
10201 /* Substitute the return type. */
10205 /* The standard does not presently indicate that creation of a
10206 function type with an invalid return type is a deduction failure.
10207 However, that is clearly analogous to creating an array of "void"
10208 or a reference to a reference. This is core issue #486. */
10211 {
10213 {
10216 else
10218 }
10220 }
10222 /* Substitute the argument types. */
10228 /* Construct a new type node and return it. */
10230 {
10233 }
10234 else
10235 {
10238 {
10239 /* [temp.deduct]
10241 Type deduction may fail for any of the following
10242 reasons:
10244 -- Attempting to create "pointer to member of T" when T
10245 is not a class type. */
10248 r);
10250 }
10254 }
10258 }
10260 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10261 ARGS into that specification, and return the substituted
10262 specification. If there is no specification, return NULL_TREE. */
10264 static tree
10266 tree args,
10267 tsubst_flags_t complain,
10268 tree in_decl)
10269 {
10270 tree specs;
10271 tree new_specs;
10276 {
10277 /* A noexcept-specifier. */
10278 new_specs = tsubst_copy_and_build
10282 }
10284 {
10287 else
10289 {
10290 tree spec;
10295 {
10296 /* Expand the pack expansion type. */
10299 in_decl);
10305 else
10306 {
10307 /* We're substituting into a member template, so
10308 we got a TYPE_PACK_EXPANSION back. Add that
10309 expansion and move on. */
10313 expanded_specs,
10314 complain);
10317 }
10318 }
10321 {
10324 else
10329 complain);
10330 }
10333 }
10334 }
10336 }
10338 /* Take the tree structure T and replace template parameters used
10339 therein with the argument vector ARGS. IN_DECL is an associated
10340 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10341 Issue error and warning messages under control of COMPLAIN. Note
10342 that we must be relatively non-tolerant of extensions here, in
10343 order to preserve conformance; if we allow substitutions that
10344 should not be allowed, we may allow argument deductions that should
10345 not succeed, and therefore report ambiguous overload situations
10346 where there are none. In theory, we could allow the substitution,
10347 but indicate that it should have failed, and allow our caller to
10348 make sure that the right thing happens, but we don't try to do this
10349 yet.
10351 This function is used for dealing with types, decls and the like;
10352 for expressions, use tsubst_expr or tsubst_copy. */
10354 tree
10356 {
10379 else
10384 /* Reuse typedefs. We need to do this to handle dependent attributes,
10385 such as attribute aligned. */
10388 {
10394 {
10398 }
10403 else
10404 /* The typedef is from a non-template context. */
10408 {
10410 r = cp_build_qualified_type_real
10414 }
10415 /* Else we must be instantiating the typedef, so fall through. */
10416 }
10429 {
10455 {
10461 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10462 needed. */
10468 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10469 with TREE_SIDE_EFFECTS that indicates this is not an integral
10470 constant expression. */
10473 {
10476 }
10479 }
10485 {
10498 {
10502 /* See through ARGUMENT_PACK_SELECT arguments. */
10504 }
10509 {
10511 /* If ARG is an argument pack, we don't actually want to
10512 perform a substitution here, because substitutions
10513 for argument packs are only done
10514 element-by-element. We can get to this point when
10515 substituting the type of a non-type template
10516 parameter pack, when that type actually contains
10517 template parameter packs from an outer template, e.g.,
10519 template<typename... Types> struct A {
10520 template<Types... Values> struct B { };
10521 }; */
10525 {
10531 return cp_build_qualified_type_real
10533 }
10535 {
10536 /* We are processing a type constructed from a
10537 template template parameter. */
10543 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10544 are resolving nested-types in the signature of a
10545 member function templates. Otherwise ARG is a
10546 TEMPLATE_DECL and is the real template to be
10547 instantiated. */
10555 complain);
10556 return cp_build_qualified_type_real
10558 }
10559 else
10560 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10562 }
10565 /* This can happen during the attempted tsubst'ing in
10566 unify. This means that we don't yet have any information
10567 about the template parameter in question. */
10570 /* If we get here, we must have been looking at a parm for a
10571 more deeply nested template. Make a new version of this
10572 template parameter, but with a lower level. */
10574 {
10579 {
10581 r = cp_build_qualified_type_real
10585 }
10586 else
10587 {
10598 /* We have reduced the level of the template
10599 template parameter, but not the levels of its
10600 template parameters, so canonical_type_parameter
10601 will not be able to find the canonical template
10602 template parameter for this level. Thus, we
10603 require structural equality checking to compare
10604 TEMPLATE_TEMPLATE_PARMs. */
10608 else
10612 {
10620 }
10621 }
10630 }
10633 }
10636 {
10644 {
10648 }
10651 {
10655 }
10658 {
10662 }
10668 }
10671 /* We should never be tsubsting a binfo. */
10675 /* A vector of template arguments. */
10681 {
10685 /* [temp.deduct]
10687 Type deduction may fail for any of the following
10688 reasons:
10690 -- Attempting to create a pointer to reference type.
10691 -- Attempting to create a reference to a reference type or
10692 a reference to void.
10694 Core issue 106 says that creating a reference to a reference
10695 during instantiation is no longer a cause for failure. We
10696 only enforce this check in strict C++98 mode. */
10700 {
10703 /* We keep track of the last time we issued this error
10704 message to avoid spewing a ton of messages during a
10705 single bad template instantiation. */
10708 {
10713 else
10716 }
10719 }
10721 {
10725 }
10727 /* In C++0x, during template argument substitution, when there is an
10728 attempt to create a reference to a reference type, reference
10729 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10731 "If a template-argument for a template-parameter T names a type
10732 that is a reference to a type A, an attempt to create the type
10733 'lvalue reference to cv T' creates the type 'lvalue reference to
10734 A,' while an attempt to create the type type rvalue reference to
10735 cv T' creates the type T"
10736 */
10737 r = cp_build_reference_type
10740 else
10745 /* Will this ever be needed for TYPE_..._TO values? */
10749 }
10751 {
10754 {
10755 /* [temp.deduct]
10757 Type deduction may fail for any of the following
10758 reasons:
10760 -- Attempting to create "pointer to member of T" when T
10761 is not a class type. */
10765 }
10767 {
10771 }
10773 {
10777 }
10780 {
10781 /* The type of the implicit object parameter gets its
10782 cv-qualifiers from the FUNCTION_TYPE. */
10783 tree memptr;
10787 complain);
10788 }
10789 else
10792 complain);
10793 }
10796 {
10797 tree fntype;
10798 tree specs;
10803 /* Substitute the exception specification. */
10805 in_decl);
10811 }
10813 {
10818 /* As an optimization, we avoid regenerating the array type if
10819 it will obviously be the same as T. */
10823 /* These checks should match the ones in grokdeclarator.
10825 [temp.deduct]
10827 The deduction may fail for any of the following reasons:
10829 -- Attempting to create an array with an element type that
10830 is void, a function type, or a reference type, or [DR337]
10831 an abstract class type. */
10835 {
10839 }
10841 {
10844 type);
10846 }
10851 {
10854 }
10857 }
10860 {
10870 {
10874 }
10876 {
10877 /* Normally, make_typename_type does not require that the CTX
10878 have complete type in order to allow things like:
10880 template <class T> struct S { typename S<T>::X Y; };
10882 But, such constructs have already been resolved by this
10883 point, so here CTX really should have complete type, unless
10884 it's a partial instantiation. */
10887 {
10891 }
10892 }
10899 {
10902 }
10905 {
10912 }
10914 return cp_build_qualified_type_real
10916 }
10919 {
10931 }
10934 {
10935 tree type;
10951 complain);
10952 }
10955 {
10956 tree type;
10972 else
10973 type = finish_decltype_type
10978 complain);
10979 }
10983 {
10985 tree packed_out =
10987 args,
10988 complain,
10989 in_decl);
10992 /* For template nontype argument packs, also substitute into
10993 the type. */
10998 }
11013 /* We should use one of the expression tsubsts for these codes. */
11019 }
11020 }
11022 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11023 type of the expression on the left-hand side of the "." or "->"
11024 operator. */
11026 static tree
11029 {
11030 tree name;
11031 tree qualifying_scope;
11032 tree fns;
11033 tree optype;
11037 /* A baselink indicates a function from a base class. Both the
11038 BASELINK_ACCESS_BINFO and the base class referenced may
11039 indicate bases of the template class, rather than the
11040 instantiated class. In addition, lookups that were not
11041 ambiguous before may be ambiguous now. Therefore, we perform
11042 the lookup again. */
11049 {
11056 }
11064 /* If lookup found a single function, mark it as used at this
11065 point. (If it lookup found multiple functions the one selected
11066 later by overload resolution will be marked as used at that
11067 point.) */
11073 /* Add back the template arguments, if present. */
11078 template_args);
11079 /* Update the conversion operator type. */
11085 qualifying_scope,
11086 object_type);
11087 }
11089 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11090 true if the qualified-id will be a postfix-expression in-and-of
11091 itself; false if more of the postfix-expression follows the
11092 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11093 of "&". */
11095 static tree
11099 {
11100 tree expr;
11101 tree scope;
11102 tree name;
11104 tree template_args;
11108 /* Figure out what name to look up. */
11111 {
11118 }
11119 else
11120 {
11123 }
11125 /* Substitute into the qualifying scope. When there are no ARGS, we
11126 are just trying to simplify a non-dependent expression. In that
11127 case the qualifying scope may be dependent, and, in any case,
11128 substituting will not help. */
11131 {
11134 }
11135 else
11143 {
11145 {
11146 /* A BIT_NOT_EXPR is used to represent a destructor. */
11148 {
11152 }
11153 else
11156 }
11157 else
11161 {
11163 {
11167 }
11169 }
11170 }
11173 {
11175 scope);
11176 /* Remember that there was a reference to this entity. */
11178 }
11181 {
11187 }
11196 {
11197 expr = (adjust_result_of_qualified_name_lookup
11199 expr = (finish_qualified_id_expr
11203 }
11205 /* Expressions do not generally have reference type. */
11207 /* However, if we're about to form a pointer-to-member, we just
11208 want the referenced member referenced. */
11213 }
11215 /* Like tsubst, but deals with expressions. This function just replaces
11216 template parms; to finish processing the resultant expression, use
11217 tsubst_expr. */
11219 static tree
11221 {
11223 tree r;
11231 {
11236 {
11237 tree c;
11238 /* This can happen for a parameter name used later in a function
11239 declaration (such as in a late-specified return type). Just
11240 make a dummy decl, since it's only used for its type. */
11242 /* We copy T because want to tsubst the PARM_DECL only,
11243 not the following PARM_DECLs that are chained to T. */
11246 /* Give it the template pattern as its context; its true context
11247 hasn't been instantiated yet and this is good enough for
11248 mangling. */
11250 }
11258 {
11259 tree enum_type;
11260 tree v;
11264 /* There is no need to substitute into namespace-scope
11265 enumerators. */
11268 /* If ARGS is NULL, then T is known to be non-dependent. */
11272 /* Unfortunately, we cannot just call lookup_name here.
11273 Consider:
11275 template <int I> int f() {
11276 enum E { a = I };
11277 struct S { void g() { E e = a; } };
11278 };
11280 When we instantiate f<7>::S::g(), say, lookup_name is not
11281 clever enough to find f<7>::a. */
11282 enum_type
11292 /* We didn't find the name. That should never happen; if
11293 name-lookup found it during preliminary parsing, we
11294 should find it again here during instantiation. */
11296 }
11301 {
11302 tree ctx;
11307 {
11310 {
11314 }
11316 }
11317 }
11330 /* An OVERLOAD will always be a non-dependent overload set; an
11331 overload set from function scope will just be represented with an
11332 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11347 {
11348 /* Template template argument like the following example need
11349 special treatment:
11351 template <template <class> class TT> struct C {};
11352 template <class T> struct D {
11353 template <class U> struct E {};
11354 C<E> c; // #1
11355 };
11356 D<int> d; // #2
11358 We are processing the template argument `E' in #1 for
11359 the template instantiation #2. Originally, `E' is a
11360 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11361 have to substitute this with one having context `D<int>'. */
11365 }
11366 else
11367 /* Ordinary template template argument. */
11376 return build1
11382 {
11383 /* We only want to compute the number of arguments. */
11397 {
11404 else
11407 }
11408 else
11410 }
11411 /* Fall through */
11426 return build1
11431 {
11432 tree object;
11433 tree name;
11438 {
11442 }
11445 {
11455 }
11460 in_decl);
11461 else
11464 }
11502 return build_nt
11515 return build_nt
11522 {
11530 }
11535 {
11536 r = build_nt
11542 }
11545 {
11546 r = build_nt
11552 }
11555 {
11556 r = build_nt
11562 }
11565 {
11566 /* Substituted template arguments */
11575 }
11578 {
11598 }
11623 {
11626 }
11627 else
11631 /* This is handled by tsubst_copy_and_build. */
11636 in_decl),
11640 /* We shouldn't have built any of these during initial template
11641 generation. Instead, they should be built during instantiation
11642 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11646 r = build2
11666 {
11667 /* Instantiate any typedefs in the type. */
11672 }
11675 /* These can sometimes show up in a partial instantiation, but never
11676 involve template parms. */
11682 }
11683 }
11685 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11687 static tree
11689 tree in_decl)
11690 {
11694 {
11700 {
11703 {
11709 }
11710 /* FALLTHRU */
11732 }
11733 }
11736 }
11738 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11740 static tree
11742 tree in_decl)
11743 {
11744 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11769 #undef RECUR
11770 }
11772 /* Substitute one OMP_FOR iterator. */
11774 static void
11779 {
11780 #define RECUR(NODE) \
11781 tsubst_expr ((NODE), args, complain, in_decl, \
11782 integral_constant_expression_p)
11791 {
11798 }
11802 {
11808 complain);
11809 else
11816 }
11819 {
11820 tree c;
11822 {
11833 }
11835 {
11840 {
11843 }
11844 }
11845 }
11851 else
11855 {
11866 {
11873 }
11874 else
11880 {
11886 }
11890 {
11897 }
11898 else
11904 }
11910 #undef RECUR
11911 }
11913 /* Like tsubst_copy for expressions, etc. but also does semantic
11914 processing. */
11916 static tree
11919 {
11920 #define RECUR(NODE) \
11921 tsubst_expr ((NODE), args, complain, in_decl, \
11922 integral_constant_expression_p)
11935 {
11937 {
11938 tree_stmt_iterator i;
11942 }
11957 else
11966 {
11968 tree init;
11974 {
11977 tree decl;
11985 else
11987 }
11988 else
11989 {
11993 {
11994 /* By marking the declaration as instantiated, we avoid
11995 trying to instantiate it. Since instantiate_decl can't
11996 handle local variables, and since we've already done
11997 all that needs to be done, that's the right thing to
11998 do. */
12003 /* Anonymous aggregates are a special case. */
12005 else
12006 {
12011 {
12012 /* For __PRETTY_FUNCTION__ we have to adjust the
12013 initializer. */
12017 }
12018 else
12019 {
12023 {
12024 /* If we had an initializer but it
12025 instantiated to nothing,
12026 value-initialize the object. This will
12027 only occur when the initializer was a
12028 pack expansion where the parameter packs
12029 used in that expansion were of length
12030 zero. */
12032 complain);
12035 }
12036 else
12038 }
12041 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12044 }
12045 }
12046 }
12048 /* A DECL_EXPR can also be used as an expression, in the condition
12049 clause of an if/for/while construct. */
12051 }
12066 {
12076 }
12103 {
12107 }
12115 else
12123 else
12150 {
12152 tree label;
12157 }
12163 /* Computed goto's must be tsubst'd into. On the other hand,
12164 non-computed gotos must not be; the identifier in question
12165 will have no binding. */
12167 else
12173 tmp = finish_asm_stmt
12180 {
12185 }
12190 {
12195 }
12196 else
12197 {
12202 else
12209 else
12215 else
12217 }
12221 {
12225 {
12227 /* Prevent instantiate_decl from trying to instantiate
12228 this variable. We've already done all that needs to be
12229 done. */
12232 }
12237 }
12245 {
12246 tree condition =
12248 args,
12255 }
12276 {
12291 integral_constant_expression_p);
12300 {
12304 }
12305 else
12306 {
12314 }
12328 }
12359 {
12364 }
12380 integral_constant_expression_p);
12381 }
12384 #undef RECUR
12385 }
12387 /* T is a postfix-expression that is not being used in a function
12388 call. Return the substituted version of T. */
12390 static tree
12392 tsubst_flags_t complain,
12393 tree in_decl)
12394 {
12398 else
12404 }
12406 /* Like tsubst but deals with expressions and performs semantic
12407 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12409 tree
12411 tree args,
12412 tsubst_flags_t complain,
12413 tree in_decl,
12416 {
12417 #define RECUR(NODE) \
12418 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12420 integral_constant_expression_p)
12422 tree op1;
12428 {
12431 /* Fall through. */
12433 {
12434 tree decl;
12435 cp_id_kind idk;
12440 {
12443 }
12445 /* Look up the name. */
12448 /* By convention, expressions use ERROR_MARK_NODE to indicate
12449 failure, not NULL_TREE. */
12455 integral_constant_expression_p,
12463 input_location);
12469 }
12472 {
12473 tree object;
12481 {
12484 }
12485 else
12492 else
12494 }
12497 {
12501 {
12502 /* A type conversion to reference type will be enclosed in
12503 such an indirect ref, but the substitution of the cast
12504 will have also added such an indirect ref. */
12507 }
12508 else
12511 }
12514 return build_nop
12523 {
12524 tree type;
12525 tree op;
12530 {
12535 }
12540 {
12553 }
12554 }
12572 complain);
12582 else
12584 in_decl);
12618 return build_x_binary_op
12622 ? ERROR_MARK
12626 ? ERROR_MARK
12629 complain);
12642 /* Fall through */
12647 {
12648 /* When there are no ARGS, we are trying to evaluate a
12649 non-dependent expression from the parser. Trying to do
12650 the substitutions may not work. */
12653 }
12654 else
12655 {
12663 }
12667 else
12672 {
12682 }
12696 {
12697 tree r = build_x_modify_expr
12701 complain);
12702 /* TREE_NO_WARNING must be set if either the expression was
12703 parenthesized or it uses an operator such as >>= rather
12704 than plain assignment. In the former case, it was already
12705 set and must be copied. In the latter case,
12706 build_x_modify_expr sets it and it must not be reset
12707 here. */
12711 }
12716 /* Remember that there was a reference to this entity. */
12722 {
12727 tree ret;
12731 else
12732 {
12736 }
12738 /* If there was an initializer in the original tree, but it
12739 instantiated to an empty list, then we should pass a
12740 non-NULL empty vector to tell build_new that it was an
12741 empty initializer() rather than no initializer. This can
12742 only happen when the initializer is a pack expansion whose
12743 parameter packs are of length zero. */
12746 else
12747 {
12751 else
12752 {
12755 }
12756 }
12763 complain);
12771 }
12774 return delete_sanity
12783 complain);
12786 {
12787 tree function;
12792 tree ret;
12795 /* When we parsed the expression, we determined whether or
12796 not Koenig lookup should be performed. */
12799 {
12804 }
12805 else
12806 {
12808 {
12814 }
12815 else
12819 in_decl,
12821 integral_constant_expression_p);
12825 }
12830 {
12836 else
12837 {
12838 /* Expand the pack expansion and push each entry onto
12839 CALL_ARGS. */
12842 {
12847 {
12852 }
12853 }
12854 else
12855 {
12856 /* A partial substitution. Add one entry. */
12858 }
12859 }
12860 }
12862 /* We do not perform argument-dependent lookup if normal
12863 lookup finds a non-function, in accordance with the
12864 expected resolution of DR 218. */
12867 /* If lookup found a member function, the Koenig lookup is
12868 not appropriate, even if an unqualified-name was used
12869 to denote the function. */
12872 /* Only do this when substitution turns a dependent call
12873 into a non-dependent call. */
12879 {
12883 }
12885 /* Remember that there was a reference to this entity. */
12892 {
12907 complain);
12908 else
12909 ret = (build_new_method_call
12914 complain));
12915 }
12916 else
12919 koenig_p,
12920 complain);
12925 }
12928 return build_x_conditional_expr
12932 complain);
12935 return finish_pseudo_destructor_expr
12941 {
12949 {
12950 /* We have pack expansions, so expand those and
12951 create a new list out of it. */
12954 tree chain;
12957 /* Expand the argument expressions. */
12965 /* Build the rest of the list. */
12970 /* Determine the number of arguments. */
12972 {
12975 }
12978 else
12979 {
12980 /* Since we only performed a partial substitution into
12981 the argument pack, we only return a single list
12982 node. */
12989 }
12991 /* Convert the argument vectors into a TREE_LIST */
12994 {
12995 /* Grab the Ith values. */
12996 i--;
12999 value
13003 /* Build the list (backwards). */
13005 }
13008 }
13024 }
13027 {
13028 tree object;
13029 tree object_type;
13030 tree member;
13034 /* Remember that there was a reference to this entity. */
13044 else
13050 {
13052 {
13057 {
13060 }
13062 {
13066 }
13067 }
13068 }
13071 {
13072 tree tmpl;
13073 tree args;
13075 /* Lookup the template functions now that we know what the
13076 scope is. */
13083 {
13086 args);
13087 member = (adjust_result_of_qualified_name_lookup
13089 object_type));
13090 }
13091 else
13092 {
13094 input_location);
13096 }
13097 }
13101 {
13103 {
13107 else
13110 }
13112 }
13118 complain);
13119 }
13122 return build_throw
13126 {
13134 tree r;
13139 /* digest_init will do the wrong thing if we let it. */
13143 /* We do not want to process the index of aggregate
13144 initializers as they are identifier nodes which will be
13145 looked up by digest_init. */
13151 {
13156 {
13157 /* Substitute into the pack expansion. */
13159 in_decl);
13162 ;
13164 /* Just move the argument into place. */
13166 else
13167 {
13168 /* Update the length of the final CONSTRUCTOR
13169 arguments vector, and note that we will need to
13170 copy.*/
13173 }
13174 }
13175 else
13177 }
13180 {
13185 {
13187 {
13192 }
13193 else
13195 }
13196 }
13206 }
13209 {
13212 {
13215 }
13216 else
13217 {
13220 }
13221 }
13226 /* Fall through */
13229 {
13233 /* If the original type was a reference, we'll be wrapped in
13234 the appropriate INDIRECT_REF. */
13237 }
13242 in_decl));
13248 {
13257 }
13260 {
13266 integral_constant_expression_p);
13270 /* If the resulting list of expression statement is empty,
13271 fold it further into void_zero_node. */
13276 }
13280 /* As in finish_id_expression, we resolve enumeration constants
13281 to their underlying values. */
13283 {
13286 }
13290 {
13311 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
13313 /* Now that we know visibility, instantiate the type so we have a
13314 declaration of the op() for later calls to lambda_function. */
13322 }
13325 /* We can get here for a constant initializer of non-dependent type.
13326 FIXME stop folding in cp_parser_initializer_clause. */
13331 /* Handle Objective-C++ constructs, if appropriate. */
13332 {
13333 tree subst
13338 }
13340 }
13342 #undef RECUR
13343 }
13345 /* Verify that the instantiated ARGS are valid. For type arguments,
13346 make sure that the type's linkage is ok. For non-type arguments,
13347 make sure they are constants if they are integral or enumerations.
13348 Emit an error under control of COMPLAIN, and return TRUE on error. */
13350 static bool
13352 {
13354 {
13364 }
13366 {
13367 /* [basic.link]: A name with no linkage (notably, the name
13368 of a class or enumeration declared in a local scope)
13369 shall not be used to declare an entity with linkage.
13370 This implies that names with no linkage cannot be used as
13371 template arguments
13373 DR 757 relaxes this restriction for C++0x. */
13378 {
13379 /* DR 488 makes use of a type with no linkage cause
13380 type deduction to fail. */
13382 {
13385 else
13388 }
13390 }
13391 /* In order to avoid all sorts of complications, we do not
13392 allow variably-modified types as template arguments. */
13394 {
13398 }
13399 }
13400 /* A non-type argument of integral or enumerated type must be a
13401 constant. */
13405 {
13409 }
13411 }
13413 static bool
13415 {
13420 {
13423 }
13427 }
13429 /* Instantiate the indicated variable or function template TMPL with
13430 the template arguments in TARG_PTR. */
13432 tree
13434 {
13436 tree fndecl;
13437 tree gen_tmpl;
13438 tree spec;
13439 HOST_WIDE_INT saved_processing_template_decl;
13446 /* If this function is a clone, handle it specially. */
13448 {
13449 tree spec;
13450 tree clone;
13452 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13453 DECL_CLONED_FUNCTION. */
13459 /* Look for the clone. */
13463 /* We should always have found the clone by now. */
13466 }
13468 /* Check to see if we already have this specialization. */
13471 /* The TMPL is a partial instantiation. To get a full set of
13472 arguments we must add the arguments used to perform the
13473 partial instantiation. */
13475 targ_ptr);
13477 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13478 but it doesn't seem to be on the hot path. */
13490 complain))
13493 /* We are building a FUNCTION_DECL, during which the access of its
13494 parameters and return types have to be checked. However this
13495 FUNCTION_DECL which is the desired context for access checking
13496 is not built yet. We solve this chicken-and-egg problem by
13497 deferring all checks until we have the FUNCTION_DECL. */
13500 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13501 (because, for example, we have encountered a non-dependent
13502 function call in the body of a template function and must now
13503 determine which of several overloaded functions will be called),
13504 within the instantiation itself we are not processing a
13505 template. */
13508 /* Substitute template parameters to obtain the specialization. */
13515 /* Now we know the specialization, compute access previously
13516 deferred. */
13519 /* Some typedefs referenced from within the template code need to be access
13520 checked at template instantiation time, i.e now. These types were
13521 added to the template at parsing time. Let's get those and perfom
13522 the acces checks then. */
13528 /* The DECL_TI_TEMPLATE should always be the immediate parent
13529 template, not the most general template. */
13532 /* If we've just instantiated the main entry point for a function,
13533 instantiate all the alternate entry points as well. We do this
13534 by cloning the instantiation of the main entry point, not by
13535 instantiating the template clones. */
13540 }
13542 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13543 NARGS elements of the arguments that are being used when calling
13544 it. TARGS is a vector into which the deduced template arguments
13545 are placed.
13547 Return zero for success, 2 for an incomplete match that doesn't resolve
13548 all the types, and 1 for complete failure. An error message will be
13549 printed only for an incomplete match.
13551 If FN is a conversion operator, or we are trying to produce a specific
13552 specialization, RETURN_TYPE is the return type desired.
13554 The EXPLICIT_TARGS are explicit template arguments provided via a
13555 template-id.
13557 The parameter STRICT is one of:
13559 DEDUCE_CALL:
13560 We are deducing arguments for a function call, as in
13561 [temp.deduct.call].
13563 DEDUCE_CONV:
13564 We are deducing arguments for a conversion function, as in
13565 [temp.deduct.conv].
13567 DEDUCE_EXACT:
13568 We are deducing arguments when doing an explicit instantiation
13569 as in [temp.explicit], when determining an explicit specialization
13570 as in [temp.expl.spec], or when taking the address of a function
13571 template, as in [temp.deduct.funcaddr]. */
13573 int
13575 tree explicit_targs,
13576 tree targs,
13579 tree return_type,
13580 unification_kind_t strict,
13582 {
13583 tree parms;
13584 tree fntype;
13592 {
13593 /* [temp.deduct]
13595 The specified template arguments must match the template
13596 parameters in kind (i.e., type, nontype, template), and there
13597 must not be more arguments than there are parameters;
13598 otherwise type deduction fails.
13600 Nontype arguments must match the types of the corresponding
13601 nontype template parameters, or must be convertible to the
13602 types of the corresponding nontype parameters as specified in
13603 _temp.arg.nontype_, otherwise type deduction fails.
13605 All references in the function type of the function template
13606 to the corresponding template parameters are replaced by the
13607 specified template argument values. If a substitution in a
13608 template parameter or in the function type of the function
13609 template results in an invalid type, type deduction fails. */
13612 tree converted_args;
13618 converted_args
13625 /* Substitute the explicit args into the function type. This is
13626 necessary so that, for instance, explicitly declared function
13627 arguments can match null pointed constants. If we were given
13628 an incomplete set of explicit args, we must not do semantic
13629 processing during substitution as we could create partial
13630 instantiations. */
13632 {
13636 /* Dig out the actual parm. */
13639 {
13642 }
13644 {
13647 }
13650 {
13652 tree targ;
13655 /* Mark the argument pack as "incomplete". We could
13656 still deduce more arguments during unification. */
13659 {
13663 }
13665 /* We have some incomplete argument packs. */
13667 }
13668 }
13671 /* Any substitution is guaranteed to be incomplete if there
13672 are incomplete argument packs, because we can still deduce
13673 more arguments. */
13675 else
13685 /* Place the explicitly specified arguments in TARGS. */
13688 }
13690 /* Never do unification on the 'this' parameter. */
13694 {
13703 }
13705 /* We allow incomplete unification without an error message here
13706 because the standard doesn't seem to explicitly prohibit it. Our
13707 callers must be ready to deal with unification failures in any
13708 event. */
13714 {
13717 /* Clear the "incomplete" flags on all argument packs. */
13719 {
13722 {
13725 }
13726 }
13727 }
13729 /* Now that we have bindings for all of the template arguments,
13730 ensure that the arguments deduced for the template template
13731 parameters have compatible template parameter lists. We cannot
13732 check this property before we have deduced all template
13733 arguments, because the template parameter types of a template
13734 template parameter might depend on prior template parameters
13735 deduced after the template template parameter. The following
13736 ill-formed example illustrates this issue:
13738 template<typename T, template<T> class C> void f(C<5>, T);
13740 template<int N> struct X {};
13742 void g() {
13743 f(X<5>(), 5l); // error: template argument deduction fails
13744 }
13746 The template parameter list of 'C' depends on the template type
13747 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13748 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13749 time that we deduce 'C'. */
13751 && !template_template_parm_bindings_ok_p
13756 /* All is well so far. Now, check:
13758 [temp.deduct]
13760 When all template arguments have been deduced, all uses of
13761 template parameters in nondeduced contexts are replaced with
13762 the corresponding deduced argument values. If the
13763 substitution results in an invalid type, as described above,
13764 type deduction fails. */
13765 {
13770 /* If we're looking for an exact match, check that what we got
13771 is indeed an exact match. It might not be if some template
13772 parameters are used in non-deduced contexts. */
13774 {
13777 tree sarg
13784 }
13785 }
13788 }
13790 /* Adjust types before performing type deduction, as described in
13791 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13792 sections are symmetric. PARM is the type of a function parameter
13793 or the return type of the conversion function. ARG is the type of
13794 the argument passed to the call, or the type of the value
13795 initialized with the result of the conversion function.
13796 ARG_EXPR is the original argument expression, which may be null. */
13798 static int
13802 tree arg_expr)
13803 {
13807 {
13812 {
13813 /* Swap PARM and ARG throughout the remainder of this
13814 function; the handling is precisely symmetric since PARM
13815 will initialize ARG rather than vice versa. */
13820 }
13823 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13824 too, but here handle it by stripping the reference from PARM
13825 rather than by adding it to ARG. */
13833 /* Nothing else to do in this case. */
13838 }
13841 {
13842 /* [temp.deduct.call]
13844 If P is not a reference type:
13846 --If A is an array type, the pointer type produced by the
13847 array-to-pointer standard conversion (_conv.array_) is
13848 used in place of A for type deduction; otherwise,
13850 --If A is a function type, the pointer type produced by
13851 the function-to-pointer standard conversion
13852 (_conv.func_) is used in place of A for type deduction;
13853 otherwise,
13855 --If A is a cv-qualified type, the top level
13856 cv-qualifiers of A's type are ignored for type
13857 deduction. */
13862 else
13864 }
13866 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13867 of the form T&&, where T is a template parameter, and the argument
13868 is an lvalue, T is deduced as A& */
13876 /* [temp.deduct.call]
13878 If P is a cv-qualified type, the top level cv-qualifiers
13879 of P's type are ignored for type deduction. If P is a
13880 reference type, the type referred to by P is used for
13881 type deduction. */
13884 {
13887 }
13889 /* DR 322. For conversion deduction, remove a reference type on parm
13890 too (which has been swapped into ARG). */
13895 }
13897 /* Most parms like fn_type_unification.
13899 If SUBR is 1, we're being called recursively (to unify the
13900 arguments of a function or method parameter of a function
13901 template). */
13903 static int
13905 tree targs,
13906 tree xparms,
13910 unification_kind_t strict,
13912 {
13918 tree parms;
13927 /* Reset the number of non-defaulted template arguments contained
13928 in in TARGS. */
13932 {
13948 }
13950 again:
13958 {
13971 /* We can't deduce anything from this, but we might get all the
13972 template args from other function args. */
13975 /* Conversions will be performed on a function argument that
13976 corresponds with a function parameter that contains only
13977 non-deducible template parameters and explicitly specified
13978 template parameters. */
13980 {
13981 tree type;
13985 else
13992 flags))
13996 }
13999 {
14002 {
14003 /* [temp.deduct.type]
14005 A template-argument can be deduced from a pointer to
14006 function or pointer to member function argument if
14007 the set of overloaded functions does not contain
14008 function templates and at most one of a set of
14009 overloaded functions provides a unique match. */
14015 }
14020 }
14022 {
14027 arg_expr);
14033 }
14034 }
14040 {
14041 /* Unify the remaining arguments with the pack expansion type. */
14042 tree argvec;
14045 /* Allocate a TREE_VEC and copy in all of the arguments */
14050 /* Copy the parameter into parmvec. */
14056 /* Advance to the end of the list of parameters. */
14058 }
14060 /* Fail if we've reached the end of the parm list, and more args
14061 are present, and the parm list isn't variadic. */
14064 /* Fail if parms are left and they don't have default values. */
14072 {
14073 tree tparm;
14080 /* If this is an undeduced nontype parameter that depends on
14081 a type parameter, try another pass; its type may have been
14082 deduced from a later argument than the one from which
14083 this parameter can be deduced. */
14089 /* Core issue #226 (C++0x) [temp.deduct]:
14091 If a template argument has not been deduced, its
14092 default template argument, if any, is used.
14094 When we are in C++98 mode, TREE_PURPOSE will either
14095 be NULL_TREE or ERROR_MARK_NODE, so we do not need
14096 to explicitly check cxx_dialect here. */
14098 {
14106 else
14107 {
14109 /* The position of the first default template argument,
14110 is also the number of non-defaulted arguments in TARGS.
14111 Record that. */
14115 }
14116 }
14118 /* If the type parameter is a parameter pack, then it will
14119 be deduced to an empty parameter pack. */
14121 {
14122 tree arg;
14125 {
14129 }
14130 else
14137 }
14140 }
14141 #ifdef ENABLE_CHECKING
14144 #endif
14147 }
14149 /* Subroutine of type_unification_real. Args are like the variables
14150 at the call site. ARG is an overloaded function (or template-id);
14151 we try deducing template args from each of the overloads, and if
14152 only one succeeds, we go with that. Modifies TARGS and returns
14153 true on success. */
14155 static bool
14157 tree targs,
14158 tree parm,
14159 tree arg,
14160 unification_kind_t strict,
14162 {
14169 {
14172 }
14173 else
14177 /* Handle `&x' where `x' is some static or non-static member
14178 function name. */
14184 /* Strip baselink information. */
14189 {
14190 /* If we got some explicit template args, we need to plug them into
14191 the affected templates before we try to unify, in case the
14192 explicit args will completely resolve the templates in question. */
14198 {
14209 {
14214 {
14217 }
14218 }
14220 }
14221 }
14224 /* If ARG is, for example, "(0, &f)" then its type will be unknown
14225 -- but the deduction does not succeed because the expression is
14226 not just the function on its own. */
14228 else
14234 {
14237 }
14239 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14240 to function or pointer to member function argument if the set of
14241 overloaded functions does not contain function templates and at most
14242 one of a set of overloaded functions provides a unique match.
14244 So if we found multiple possibilities, we return success but don't
14245 deduce anything. */
14248 {
14253 }
14258 }
14260 /* Core DR 115: In contexts where deduction is done and fails, or in
14261 contexts where deduction is not done, if a template argument list is
14262 specified and it, along with any default template arguments, identifies
14263 a single function template specialization, then the template-id is an
14264 lvalue for the function template specialization. */
14266 tree
14268 {
14281 {
14284 }
14286 {
14289 }
14291 {
14294 }
14297 {
14301 /* If we got some explicit template args, we need to plug them into
14302 the affected templates before we try to unify, in case the
14303 explicit args will completely resolve the templates in question. */
14311 {
14322 {
14325 {
14328 }
14330 {
14333 }
14334 }
14336 }
14338 {
14345 {
14346 tree base
14349 }
14353 }
14355 /* There were no good options and at least one bad one, so let the
14356 user know what the problem is. */
14358 }
14360 }
14362 /* Subroutine of resolve_overloaded_unification; does deduction for a single
14363 overload. Fills TARGS with any deduced arguments, or error_mark_node if
14364 different overloads deduce different arguments for a given parm.
14365 ADDR_P is true if the expression for which deduction is being
14366 performed was of the form "& fn" rather than simply "fn".
14368 Returns 1 on success. */
14370 static int
14372 tree orig_targs,
14373 tree targs,
14374 tree parm,
14375 tree arg,
14376 unification_kind_t strict,
14379 {
14381 tree tempargs;
14384 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14385 to function or pointer to member function argument if the set of
14386 overloaded functions does not contain function templates and at most
14387 one of a set of overloaded functions provides a unique match.
14389 So if this is a template, just return success. */
14401 /* We don't copy orig_targs for this because if we have already deduced
14402 some template args from previous args, unify would complain when we
14403 try to deduce a template parameter for the same argument, even though
14404 there isn't really a conflict. */
14411 /* First make sure we didn't deduce anything that conflicts with
14412 explicitly specified args. */
14414 {
14421 /* Since we're unifying against ourselves, we will fill in
14422 template args used in the function parm list with our own
14423 template parms. Discard them. */
14427 }
14430 {
14435 }
14438 }
14440 /* PARM is a template class (perhaps with unbound template
14441 parameters). ARG is a fully instantiated type. If ARG can be
14442 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14443 TARGS are as for unify. */
14445 static tree
14447 {
14448 tree copy_of_targs;
14455 /* We need to make a new template argument vector for the call to
14456 unify. If we used TARGS, we'd clutter it up with the result of
14457 the attempted unification, even if this class didn't work out.
14458 We also don't want to commit ourselves to all the unifications
14459 we've already done, since unification is supposed to be done on
14460 an argument-by-argument basis. In other words, consider the
14461 following pathological case:
14463 template <int I, int J, int K>
14464 struct S {};
14466 template <int I, int J>
14467 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14469 template <int I, int J, int K>
14470 void f(S<I, J, K>, S<I, I, I>);
14472 void g() {
14473 S<0, 0, 0> s0;
14474 S<0, 1, 2> s2;
14476 f(s0, s2);
14477 }
14479 Now, by the time we consider the unification involving `s2', we
14480 already know that we must have `f<0, 0, 0>'. But, even though
14481 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14482 because there are two ways to unify base classes of S<0, 1, 2>
14483 with S<I, I, I>. If we kept the already deduced knowledge, we
14484 would reject the possibility I=1. */
14487 /* If unification failed, we're done. */
14493 }
14495 /* Given a template type PARM and a class type ARG, find the unique
14496 base type in ARG that is an instance of PARM. We do not examine
14497 ARG itself; only its base-classes. If there is not exactly one
14498 appropriate base class, return NULL_TREE. PARM may be the type of
14499 a partial specialization, as well as a plain template type. Used
14500 by unify. */
14502 static tree
14504 {
14506 tree binfo;
14512 /* The type could not be completed. */
14515 /* Walk in inheritance graph order. The search order is not
14516 important, and this avoids multiple walks of virtual bases. */
14518 {
14522 {
14523 /* If there is more than one satisfactory baseclass, then:
14525 [temp.deduct.call]
14527 If they yield more than one possible deduced A, the type
14528 deduction fails.
14530 applies. */
14535 }
14536 }
14539 }
14541 /* Returns the level of DECL, which declares a template parameter. */
14543 static int
14545 {
14547 {
14557 }
14559 }
14561 /* Decide whether ARG can be unified with PARM, considering only the
14562 cv-qualifiers of each type, given STRICT as documented for unify.
14563 Returns nonzero iff the unification is OK on that basis. */
14565 static int
14567 {
14573 {
14574 /* Although a CVR qualifier is ignored when being applied to a
14575 substituted template parameter ([8.3.2]/1 for example), that
14576 does not allow us to unify "const T" with "int&" because both
14577 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14578 It is ok when we're allowing additional CV qualifiers
14579 at the outer level [14.8.2.1]/3,1st bullet. */
14589 }
14600 }
14602 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14603 void
14605 {
14609 {
14612 }
14613 else
14614 {
14617 }
14618 }
14620 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14621 expansion at the end of PACKED_PARMS. Returns 0 if the type
14622 deduction succeeds, 1 otherwise. STRICT is the same as in
14623 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14624 call argument list. We'll need to adjust the arguments to make them
14625 types. SUBR tells us if this is from a recursive call to
14626 type_unification_real. */
14627 int
14631 {
14632 tree parm
14639 /* Determine the parameter packs we will be deducing from the
14640 pattern, and record their current deductions. */
14643 {
14647 /* Determine the index and level of this parameter pack. */
14650 /* Keep track of the parameter packs and their corresponding
14651 argument packs. */
14654 }
14656 /* Loop through all of the arguments that have not yet been
14657 unified and unify each with the pattern. */
14659 {
14662 /* For each parameter pack, clear out the deduced value so that
14663 we can deduce it again. */
14665 {
14670 }
14672 /* Unify the pattern with the current argument. */
14673 {
14680 {
14683 /* This mirrors what we do in type_unification_real. */
14685 {
14687 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14688 | UNIFY_ALLOW_MORE_CV_QUAL
14702 }
14705 {
14708 {
14709 /* [temp.deduct.type] A template-argument can be
14710 deduced from a pointer to function or pointer
14711 to member function argument if the set of
14712 overloaded functions does not contain function
14713 templates and at most one of a set of
14714 overloaded functions provides a unique
14715 match. */
14720 sub_strict)
14724 }
14727 {
14732 }
14733 }
14738 arg_strict |=
14741 }
14744 {
14745 /* For deduction from an init-list we need the actual list. */
14750 }
14751 }
14753 /* For each parameter pack, collect the deduced value. */
14755 {
14761 }
14762 }
14764 /* Verify that the results of unification with the parameter packs
14765 produce results consistent with what we've seen before, and make
14766 the deduced argument packs available. */
14768 {
14775 /* By default keep the original deduced argument pack.
14776 If necessary, more specific code is going to update the
14777 resulting deduced argument later down in this function. */
14781 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14782 actually deduce anything. */
14790 {
14791 /* Prepend the explicit arguments onto NEW_ARGS. */
14797 /* Copy the explicit arguments. */
14802 /* Copy the deduced arguments. */
14806 }
14809 {
14810 tree result;
14811 /* Build the deduced *_ARGUMENT_PACK. */
14813 {
14818 }
14819 else
14824 /* Note the deduced argument packs for this parameter
14825 pack. */
14827 }
14831 {
14832 /* We only had the explicitly-provided arguments before, but
14833 now we have a complete set of arguments. */
14839 }
14841 new_args))
14842 /* Inconsistent unification of this parameter pack. */
14844 }
14847 }
14849 /* Deduce the value of template parameters. TPARMS is the (innermost)
14850 set of template parameters to a template. TARGS is the bindings
14851 for those template parameters, as determined thus far; TARGS may
14852 include template arguments for outer levels of template parameters
14853 as well. PARM is a parameter to a template function, or a
14854 subcomponent of that parameter; ARG is the corresponding argument.
14855 This function attempts to match PARM with ARG in a manner
14856 consistent with the existing assignments in TARGS. If more values
14857 are deduced, then TARGS is updated.
14859 Returns 0 if the type deduction succeeds, 1 otherwise. The
14860 parameter STRICT is a bitwise or of the following flags:
14862 UNIFY_ALLOW_NONE:
14863 Require an exact match between PARM and ARG.
14864 UNIFY_ALLOW_MORE_CV_QUAL:
14865 Allow the deduced ARG to be more cv-qualified (by qualification
14866 conversion) than ARG.
14867 UNIFY_ALLOW_LESS_CV_QUAL:
14868 Allow the deduced ARG to be less cv-qualified than ARG.
14869 UNIFY_ALLOW_DERIVED:
14870 Allow the deduced ARG to be a template base class of ARG,
14871 or a pointer to a template base class of the type pointed to by
14872 ARG.
14873 UNIFY_ALLOW_INTEGER:
14874 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14875 case for more information.
14876 UNIFY_ALLOW_OUTER_LEVEL:
14877 This is the outermost level of a deduction. Used to determine validity
14878 of qualification conversions. A valid qualification conversion must
14879 have const qualified pointers leading up to the inner type which
14880 requires additional CV quals, except at the outer level, where const
14881 is not required [conv.qual]. It would be normal to set this flag in
14882 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14883 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14884 This is the outermost level of a deduction, and PARM can be more CV
14885 qualified at this point.
14886 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14887 This is the outermost level of a deduction, and PARM can be less CV
14888 qualified at this point. */
14890 static int
14892 {
14894 tree targ;
14895 tree tparm;
14898 /* I don't think this will do the right thing with respect to types.
14899 But the only case I've seen it in so far has been array bounds, where
14900 signedness is the only information lost, and I think that will be
14901 okay. */
14909 /* We can't deduce anything from this, but we might get all the
14910 template args from other function args. */
14913 /* If PARM uses template parameters, then we can't bail out here,
14914 even if ARG == PARM, since we won't record unifications for the
14915 template parameters. We might need them if we're trying to
14916 figure out which of two things is more specialized. */
14920 /* Handle init lists early, so the rest of the function can assume
14921 we're dealing with a type. */
14923 {
14928 /* Replace T with std::initializer_list<T> for deduction. */
14934 /* We can only deduce from an initializer list argument if the
14935 parameter is std::initializer_list; otherwise this is a
14936 non-deduced context. */
14942 {
14949 {
14951 /* It should only be possible to get here for a call. */
14953 elt_strict |= maybe_adjust_types_for_deduction
14956 }
14960 }
14962 /* If the std::initializer_list<T> deduction worked, replace the
14963 deduced A with std::initializer_list<A>. */
14965 {
14970 }
14972 }
14974 /* Immediately reject some pairs that won't unify because of
14975 cv-qualification mismatches. */
14978 /* It is the elements of the array which hold the cv quals of an array
14979 type, and the elements might be template type parms. We'll check
14980 when we recurse. */
14982 /* We check the cv-qualifiers when unifying with template type
14983 parameters below. We want to allow ARG `const T' to unify with
14984 PARM `T' for example, when computing which of two templates
14985 is more specialized, for example. */
14999 {
15003 /* In a type which contains a nested-name-specifier, template
15004 argument values cannot be deduced for template parameters used
15005 within the nested-name-specifier. */
15017 /* The PARM is not one we're trying to unify. Just check
15018 to see if it matches ARG. */
15025 /* Check for mixed types and values. */
15033 {
15034 /* ARG must be constructed from a template class or a template
15035 template parameter. */
15040 {
15044 tree parm_parms
15045 = DECL_INNERMOST_TEMPLATE_PARMS
15050 /* The resolution to DR150 makes clear that default
15051 arguments for an N-argument may not be used to bind T
15052 to a template template parameter with fewer than N
15053 parameters. It is not safe to permit the binding of
15054 default arguments as an extension, as that may change
15055 the meaning of a conforming program. Consider:
15057 struct Dense { static const unsigned int dim = 1; };
15059 template <template <typename> class View,
15060 typename Block>
15061 void operator+(float, View<Block> const&);
15063 template <typename Block,
15064 unsigned int Dim = Block::dim>
15065 struct Lvalue_proxy { operator float() const; };
15067 void
15068 test_1d (void) {
15069 Lvalue_proxy<Dense> p;
15070 float b;
15071 b + p;
15072 }
15074 Here, if Lvalue_proxy is permitted to bind to View, then
15075 the global operator+ will be used; if they are not, the
15076 Lvalue_proxy will be converted to float. */
15078 full_argvec,
15080 tf_none,
15086 /* Deduce arguments T, i from TT<T> or TT<i>.
15087 We check each element of PARMVEC and ARGVEC individually
15088 rather than the whole TREE_VEC since they can have
15089 different number of elements. */
15096 /* Check if the parameters end in a pack, making them
15097 variadic. */
15106 {
15110 UNIFY_ALLOW_NONE))
15112 }
15117 UNIFY_ALLOW_NONE,
15121 }
15124 /* Fall through to deduce template name. */
15125 }
15129 {
15130 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
15132 /* Simple cases: Value already set, does match or doesn't. */
15137 }
15138 else
15139 {
15140 /* If PARM is `const T' and ARG is only `int', we don't have
15141 a match unless we are allowing additional qualification.
15142 If ARG is `const int' and PARM is just `T' that's OK;
15143 that binds `const int' to `T'. */
15148 /* Consider the case where ARG is `const volatile int' and
15149 PARM is `const T'. Then, T should be `volatile int'. */
15150 arg = cp_build_qualified_type_real
15155 /* Simple cases: Value already set, does match or doesn't. */
15161 /* Make sure that ARG is not a variable-sized array. (Note
15162 that were talking about variable-sized arrays (like
15163 `int[n]'), rather than arrays of unknown size (like
15164 `int[]').) We'll get very confused by such a type since
15165 the bound of the array will not be computable in an
15166 instantiation. Besides, such types are not allowed in
15167 ISO C++, so we can do as we please here. */
15171 /* Strip typedefs as in convert_template_argument. */
15173 }
15175 /* If ARG is a parameter pack or an expansion, we cannot unify
15176 against it unless PARM is also a parameter pack. */
15181 /* If the argument deduction results is a METHOD_TYPE,
15182 then there is a problem.
15183 METHOD_TYPE doesn't map to any real C++ type the result of
15184 the deduction can not be of that type. */
15198 /* The PARM is not one we're trying to unify. Just check
15199 to see if it matches ARG. */
15209 /* [temp.deduct.type] If, in the declaration of a function template
15210 with a non-type template-parameter, the non-type
15211 template-parameter is used in an expression in the function
15212 parameter-list and, if the corresponding template-argument is
15213 deduced, the template-argument type shall match the type of the
15214 template-parameter exactly, except that a template-argument
15215 deduced from an array bound may be of any integral type.
15216 The non-type parameter might use already deduced type parameters. */
15219 /* Template-parameter dependent expression. Just accept it for now.
15220 It will later be processed in convert_template_argument. */
15221 ;
15227 /* Convert the ARG to the type of PARM; the deduced non-type
15228 template argument must exactly match the types of the
15229 corresponding parameter. */
15232 /* We haven't deduced the type of this parameter yet. Try again
15233 later. */
15235 else
15238 /* If ARG is a parameter pack or an expansion, we cannot unify
15239 against it unless PARM is also a parameter pack. */
15248 {
15249 /* A pointer-to-member constant can be unified only with
15250 another constant. */
15254 /* Just unify the class member. It would be useless (and possibly
15255 wrong, depending on the strict flags) to unify also
15256 PTRMEM_CST_CLASS, because we want to be sure that both parm and
15257 arg refer to the same variable, even if through different
15258 classes. For instance:
15260 struct A { int x; };
15261 struct B : A { };
15263 Unification of &A::x and &B::x must succeed. */
15266 }
15269 {
15273 /* [temp.deduct.call]
15275 A can be another pointer or pointer to member type that can
15276 be converted to the deduced A via a qualification
15277 conversion (_conv.qual_).
15279 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
15280 This will allow for additional cv-qualification of the
15281 pointed-to types if appropriate. */
15284 /* The derived-to-base conversion only persists through one
15285 level of pointers. */
15290 }
15305 {
15306 tree parm_max;
15307 tree arg_max;
15311 /* Our representation of array types uses "N - 1" as the
15312 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
15313 not an integer constant. We cannot unify arbitrarily
15314 complex expressions, so we eliminate the MINUS_EXPRs
15315 here. */
15319 {
15322 }
15326 {
15327 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
15328 trying to unify the type of a variable with the type
15329 of a template parameter. For example:
15331 template <unsigned int N>
15332 void f (char (&) [N]);
15333 int g();
15334 void h(int i) {
15335 char a[g(i)];
15336 f(a);
15337 }
15339 Here, the type of the ARG will be "int [g(i)]", and
15340 may be a SAVE_EXPR, etc. */
15344 }
15346 /* If only one of the bounds used a MINUS_EXPR, compensate
15347 by adding one to the other bound. */
15350 integer_type_node,
15351 parm_max,
15352 integer_one_node);
15355 integer_type_node,
15356 arg_max,
15357 integer_one_node);
15361 }
15375 /* We have already checked cv-qualification at the top of the
15376 function. */
15380 /* As far as unification is concerned, this wins. Later checks
15381 will invalidate it if necessary. */
15384 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
15385 /* Type INTEGER_CST can come from ordinary constant template args. */
15395 {
15404 UNIFY_ALLOW_NONE))
15407 }
15415 {
15422 strict);
15423 }
15426 {
15430 {
15431 /* First, we try to unify the PARM and ARG directly. */
15436 {
15437 /* Fallback to the special case allowed in
15438 [temp.deduct.call]:
15440 If P is a class, and P has the form
15441 template-id, then A can be a derived class of
15442 the deduced A. Likewise, if P is a pointer to
15443 a class of the form template-id, A can be a
15444 pointer to a derived class pointed to by the
15445 deduced A. */
15450 }
15451 }
15455 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15456 Then, we should unify `int' and `U'. */
15458 else
15459 /* There's no chance of unification succeeding. */
15464 }
15471 {
15474 tree a;
15480 /* CV qualifications for methods can never be deduced, they must
15481 match exactly. We need to check them explicitly here,
15482 because type_unification_real treats them as any other
15483 cv-qualified parameter. */
15485 && (!check_cv_quals_for_unify
15505 LOOKUP_NORMAL);
15506 }
15509 /* Unify a pointer to member with a pointer to member function, which
15510 deduces the type of the member as a function type. */
15512 {
15513 tree method_type;
15514 tree fntype;
15516 /* Check top-level cv qualifiers */
15524 /* Determine the type of the function we are unifying against. */
15526 fntype =
15530 /* Extract the cv-qualifiers of the member function from the
15531 implicit object parameter and place them on the function
15532 type to be restored later. */
15535 }
15543 strict);
15554 /* Matched cases are handled by the ARG == PARM test above. */
15558 /* A non-type template parameter that is a variable should be a
15559 an integral constant, in which case, it whould have been
15560 folded into its (constant) value. So we should not be getting
15561 a variable here. */
15566 {
15574 {
15576 {
15578 /* We can unify against something with a trailing
15579 parameter pack. */
15581 else
15582 /* Since there is something following the pack
15583 expansion, we cannot unify this template argument
15584 list. */
15586 }
15587 }
15590 /* If we don't have enough arguments to satisfy the parameters
15591 (not counting the pack expression at the end), or we have
15592 too many arguments for a parameter list that doesn't end in
15593 a pack expression, we can't unify. */
15598 /* Unify all of the parameters that precede the (optional)
15599 pack expression. */
15601 {
15605 }
15613 }
15619 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15620 nodes. */
15624 /* Unification fails if we hit an error node. */
15630 /* We must be looking at an expression. This can happen with
15631 something like:
15633 template <int I>
15634 void foo(S<I>, S<I + 2>);
15636 This is a "nondeduced context":
15638 [deduct.type]
15640 The nondeduced contexts are:
15642 --A type that is a template-id in which one or more of
15643 the template-arguments is an expression that references
15644 a template-parameter.
15646 In these cases, we assume deduction succeeded, but don't
15647 actually infer any unifications. */
15652 else
15654 }
15655 }
15656 \f
15657 /* Note that DECL can be defined in this translation unit, if
15658 required. */
15660 static void
15662 {
15663 tree clone;
15667 }
15669 /* Called if RESULT is explicitly instantiated, or is a member of an
15670 explicitly instantiated class. */
15672 void
15674 {
15677 /* If this entity has already been written out, it's too late to
15678 make any modifications. */
15683 /* The TREE_PUBLIC flag for function declarations will have been
15684 set correctly by tsubst. */
15687 /* This might have been set by an earlier implicit instantiation. */
15692 else
15693 {
15695 /* Always make artificials weak. */
15698 /* For WIN32 we also want to put explicit instantiations in
15699 linkonce sections. */
15702 }
15704 /* If EXTERN_P, then this function will not be emitted -- unless
15705 followed by an explicit instantiation, at which point its linkage
15706 will be adjusted. If !EXTERN_P, then this function will be
15707 emitted here. In neither circumstance do we want
15708 import_export_decl to adjust the linkage. */
15710 }
15712 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15713 important template arguments. If any are missing, we check whether
15714 they're important by using error_mark_node for substituting into any
15715 args that were used for partial ordering (the ones between ARGS and END)
15716 and seeing if it bubbles up. */
15718 static bool
15720 {
15725 {
15728 }
15730 {
15732 {
15736 }
15737 }
15739 }
15741 /* Given two function templates PAT1 and PAT2, return:
15743 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15744 -1 if PAT2 is more specialized than PAT1.
15745 0 if neither is more specialized.
15747 LEN indicates the number of parameters we should consider
15748 (defaulted parameters should not be considered).
15750 The 1998 std underspecified function template partial ordering, and
15751 DR214 addresses the issue. We take pairs of arguments, one from
15752 each of the templates, and deduce them against each other. One of
15753 the templates will be more specialized if all the *other*
15754 template's arguments deduce against its arguments and at least one
15755 of its arguments *does* *not* deduce against the other template's
15756 corresponding argument. Deduction is done as for class templates.
15757 The arguments used in deduction have reference and top level cv
15758 qualifiers removed. Iff both arguments were originally reference
15759 types *and* deduction succeeds in both directions, the template
15760 with the more cv-qualified argument wins for that pairing (if
15761 neither is more cv-qualified, they both are equal). Unlike regular
15762 deduction, after all the arguments have been deduced in this way,
15763 we do *not* verify the deduced template argument values can be
15764 substituted into non-deduced contexts.
15766 The logic can be a bit confusing here, because we look at deduce1 and
15767 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15768 can find template arguments for pat1 to make arg1 look like arg2, that
15769 means that arg2 is at least as specialized as arg1. */
15771 int
15773 {
15786 /* Remove the this parameter from non-static member functions. If
15787 one is a non-static member function and the other is not a static
15788 member function, remove the first parameter from that function
15789 also. This situation occurs for operator functions where we
15790 locate both a member function (with this pointer) and non-member
15791 operator (with explicit first operand). */
15793 {
15798 }
15800 {
15803 {
15804 len--;
15806 }
15807 }
15809 /* If only one is a conversion operator, they are unordered. */
15813 /* Consider the return type for a conversion function */
15815 {
15818 len++;
15819 }
15821 processing_template_decl++;
15827 /* Stop when an ellipsis is seen. */
15829 {
15838 {
15839 /* When both arguments are pack expansions, we need only
15840 unify the patterns themselves. */
15844 /* This is the last comparison we need to do. */
15846 }
15849 {
15852 }
15855 {
15858 }
15861 {
15862 /* Only of the args is a reference, see if we should apply
15863 array/function pointer decay to it. This is not part of
15864 DR214, but is, IMHO, consistent with the deduction rules
15865 for the function call itself, and with our earlier
15866 implementation of the underspecified partial ordering
15867 rules. (nathan). */
15869 {
15871 {
15874 /* FALLTHROUGH. */
15881 }
15882 }
15883 else
15884 {
15886 {
15889 /* FALLTHROUGH. */
15896 }
15897 }
15898 }
15904 {
15910 /* Setup the parameter vector, which contains only ARG1. */
15913 /* Setup the argument vector, which contains the remaining
15914 arguments. */
15923 /* We cannot deduce in the other direction, because ARG1 is
15924 a pack expansion but ARG2 is not. */
15926 }
15928 {
15934 /* Setup the parameter vector, which contains only ARG1. */
15937 /* Setup the argument vector, which contains the remaining
15938 arguments. */
15947 /* We cannot deduce in the other direction, because ARG2 is
15948 a pack expansion but ARG1 is not.*/
15950 }
15952 else
15953 {
15954 /* The normal case, where neither argument is a pack
15955 expansion. */
15958 }
15960 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15961 arg2, then arg2 is not as specialized as arg1. */
15967 /* "If, for a given type, deduction succeeds in both directions
15968 (i.e., the types are identical after the transformations above)
15969 and if the type from the argument template is more cv-qualified
15970 than the type from the parameter template (as described above)
15971 that type is considered to be more specialized than the other. If
15972 neither type is more cv-qualified than the other then neither type
15973 is more specialized than the other." */
15977 {
15982 }
15985 /* We've failed to deduce something in either direction.
15986 These must be unordered. */
15991 /* We have already processed all of the arguments in our
15992 handing of the pack expansion type. */
15997 }
15999 /* "In most cases, all template parameters must have values in order for
16000 deduction to succeed, but for partial ordering purposes a template
16001 parameter may remain without a value provided it is not used in the
16002 types being used for partial ordering."
16004 Thus, if we are missing any of the targs1 we need to substitute into
16005 origs1, then pat2 is not as specialized as pat1. This can happen when
16006 there is a nondeduced context. */
16012 processing_template_decl--;
16014 /* All things being equal, if the next argument is a pack expansion
16015 for one function but not for the other, prefer the
16016 non-variadic function. FIXME this is bogus; see c++/41958. */
16020 {
16023 }
16029 else
16031 }
16033 /* Determine which of two partial specializations is more specialized.
16035 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
16036 to the first partial specialization. The TREE_VALUE is the
16037 innermost set of template parameters for the partial
16038 specialization. PAT2 is similar, but for the second template.
16040 Return 1 if the first partial specialization is more specialized;
16041 -1 if the second is more specialized; 0 if neither is more
16042 specialized.
16044 See [temp.class.order] for information about determining which of
16045 two templates is more specialized. */
16047 static int
16049 {
16050 tree targs;
16058 /* Just like what happens for functions, if we are ordering between
16059 different class template specializations, we may encounter dependent
16060 types in the arguments, and we need our dependency check functions
16061 to behave correctly. */
16067 {
16070 }
16076 {
16079 }
16082 /* In the case of a tie where at least one of the class templates
16083 has a parameter pack at the end, the template with the most
16084 non-packed parameters wins. */
16086 && any_deductions
16089 {
16095 /* We don't count the pack expansion at the end. */
16105 }
16108 }
16110 /* Return the template arguments that will produce the function signature
16111 DECL from the function template FN, with the explicit template
16112 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
16113 also match. Return NULL_TREE if no satisfactory arguments could be
16114 found. */
16116 static tree
16118 {
16121 tree decl_type;
16122 tree decl_arg_types;
16125 tree arg;
16127 /* Substitute the explicit template arguments into the type of DECL.
16128 The call to fn_type_unification will handle substitution into the
16129 FN. */
16132 {
16133 tree tmpl;
16134 tree converted_args;
16138 else
16139 /* We can get here for some invalid specializations. */
16142 converted_args
16145 tf_none,
16154 }
16156 /* Never do unification on the 'this' parameter. */
16175 }
16177 /* Return the innermost template arguments that, when applied to a
16178 template specialization whose innermost template parameters are
16179 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
16180 ARGS.
16182 For example, suppose we have:
16184 template <class T, class U> struct S {};
16185 template <class T> struct S<T*, int> {};
16187 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
16188 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
16189 int}. The resulting vector will be {double}, indicating that `T'
16190 is bound to `double'. */
16192 static tree
16194 {
16196 tree deduced_args;
16197 tree innermost_deduced_args;
16201 {
16205 innermost_deduced_args);
16206 }
16207 else
16213 UNIFY_ALLOW_NONE))
16220 /* Verify that nondeduced template arguments agree with the type
16221 obtained from argument deduction.
16223 For example:
16225 struct A { typedef int X; };
16226 template <class T, class U> struct C {};
16227 template <class T> struct C<T, typename T::X> {};
16229 Then with the instantiation `C<A, int>', we can deduce that
16230 `T' is `A' but unify () does not check whether `typename T::X'
16231 is `int'. */
16234 /* We only need to check the innermost arguments; the other
16235 arguments will always agree. */
16240 /* Now that we have bindings for all of the template arguments,
16241 ensure that the arguments deduced for the template template
16242 parameters have compatible template parameter lists. See the use
16243 of template_template_parm_bindings_ok_p in fn_type_unification
16244 for more information. */
16249 }
16251 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
16252 Return the TREE_LIST node with the most specialized template, if
16253 any. If there is no most specialized template, the error_mark_node
16254 is returned.
16256 Note that this function does not look at, or modify, the
16257 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
16258 returned is one of the elements of INSTANTIATIONS, callers may
16259 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
16260 and retrieve it from the value returned. */
16262 tree
16264 {
16271 {
16277 fate--;
16282 fate++;
16287 {
16288 /* Equally specialized, move to next function. If there
16289 is no next function, nothing's most specialized. */
16294 }
16295 }
16298 /* Now verify that champ is better than everything earlier in the
16299 instantiation list. */
16307 {
16310 }
16312 processing_template_decl--;
16318 }
16320 /* If DECL is a specialization of some template, return the most
16321 general such template. Otherwise, returns NULL_TREE.
16323 For example, given:
16325 template <class T> struct S { template <class U> void f(U); };
16327 if TMPL is `template <class U> void S<int>::f(U)' this will return
16328 the full template. This function will not trace past partial
16329 specializations, however. For example, given in addition:
16331 template <class T> struct S<T*> { template <class U> void f(U); };
16333 if TMPL is `template <class U> void S<int*>::f(U)' this will return
16334 `template <class T> template <class U> S<T*>::f(U)'. */
16336 tree
16338 {
16339 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
16340 an immediate specialization. */
16342 {
16346 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
16347 template friend. */
16352 }
16354 /* Look for more and more general templates. */
16356 {
16357 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
16358 (See cp-tree.h for details.) */
16366 /* Stop if we run into an explicitly specialized class template. */
16373 }
16376 }
16378 /* Return the most specialized of the class template partial
16379 specializations of TMPL which can produce TYPE, a specialization of
16380 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
16381 a _TYPE node corresponding to the partial specialization, while the
16382 TREE_PURPOSE is the set of template arguments that must be
16383 substituted into the TREE_TYPE in order to generate TYPE.
16385 If the choice of partial specialization is ambiguous, a diagnostic
16386 is issued, and the error_mark_node is returned. If there are no
16387 partial specializations of TMPL matching TYPE, then NULL_TREE is
16388 returned. */
16390 static tree
16392 {
16394 tree t;
16395 tree champ;
16398 tree args;
16404 /* For determining which partial specialization to use, only the
16405 innermost args are interesting. */
16407 {
16410 }
16413 {
16414 tree partial_spec_args;
16415 tree spec_args;
16423 {
16426 /* Discard the outer levels of args, and then substitute in the
16427 template args from the enclosing class. */
16429 partial_spec_args = tsubst_template_args
16432 /* PARMS already refers to just the innermost parms, but the
16433 template parms in partial_spec_args had their levels lowered
16434 by tsubst, so we need to do the same for the parm list. We
16435 can't just tsubst the TREE_VEC itself, as tsubst wants to
16436 treat a TREE_VEC as an argument vector. */
16442 }
16444 partial_spec_args =
16447 partial_spec_args),
16458 partial_spec_args,
16459 args);
16461 {
16466 }
16467 }
16477 {
16480 ;
16481 else
16482 {
16484 {
16487 {
16490 }
16491 }
16493 }
16494 }
16498 {
16501 {
16504 }
16505 }
16508 {
16516 {
16519 }
16522 }
16525 }
16527 /* Explicitly instantiate DECL. */
16529 void
16531 {
16536 /* An error occurred, for which grokdeclarator has already issued
16537 an appropriate message. */
16540 {
16543 }
16545 {
16546 /* There is an asymmetry here in the way VAR_DECLs and
16547 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16548 the latter, the DECL we get back will be marked as a
16549 template instantiation, and the appropriate
16550 DECL_TEMPLATE_INFO will be set up. This does not happen for
16551 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16552 should handle VAR_DECLs as it currently handles
16553 FUNCTION_DECLs. */
16555 {
16558 }
16561 {
16564 }
16566 {
16571 }
16572 }
16574 {
16577 }
16578 else
16581 /* Check for various error cases. Note that if the explicit
16582 instantiation is valid the RESULT will currently be marked as an
16583 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16584 until we get here. */
16587 {
16588 /* DR 259 [temp.spec].
16590 Both an explicit instantiation and a declaration of an explicit
16591 specialization shall not appear in a program unless the explicit
16592 instantiation follows a declaration of the explicit specialization.
16594 For a given set of template parameters, if an explicit
16595 instantiation of a template appears after a declaration of an
16596 explicit specialization for that template, the explicit
16597 instantiation has no effect. */
16599 }
16601 {
16602 /* [temp.spec]
16604 No program shall explicitly instantiate any template more
16605 than once.
16607 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16608 the first instantiation was `extern' and the second is not,
16609 and EXTERN_P for the opposite case. */
16612 /* If an "extern" explicit instantiation follows an ordinary
16613 explicit instantiation, the template is instantiated. */
16616 }
16618 {
16621 }
16623 {
16626 }
16629 ;
16631 {
16634 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16637 }
16638 else
16646 }
16648 static void
16650 {
16656 {
16659 }
16660 }
16662 /* Called from do_type_instantiation through binding_table_foreach to
16663 do recursive instantiation for the type bound in ENTRY. */
16664 static void
16666 {
16672 }
16674 /* Called from do_type_instantiation to instantiate a member
16675 (a member function or a static member variable) of an
16676 explicitly instantiated class template. */
16677 static void
16679 {
16684 }
16686 /* Perform an explicit instantiation of template class T. STORAGE, if
16687 non-null, is the RID for extern, inline or static. COMPLAIN is
16688 nonzero if this is called from the parser, zero if called recursively,
16689 since the standard is unclear (as detailed below). */
16691 void
16693 {
16703 {
16706 }
16711 {
16714 t);
16716 }
16719 {
16721 {
16723 {
16726 "ISO C++ 1998 forbids the use of %<extern%> on "
16728 }
16729 else
16731 "ISO C++ forbids the use of %qE"
16733 }
16741 else
16742 {
16744 storage);
16746 }
16747 }
16750 {
16751 /* DR 259 [temp.spec].
16753 Both an explicit instantiation and a declaration of an explicit
16754 specialization shall not appear in a program unless the explicit
16755 instantiation follows a declaration of the explicit specialization.
16757 For a given set of template parameters, if an explicit
16758 instantiation of a template appears after a declaration of an
16759 explicit specialization for that template, the explicit
16760 instantiation has no effect. */
16762 }
16764 {
16765 /* [temp.spec]
16767 No program shall explicitly instantiate any template more
16768 than once.
16770 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16771 instantiation was `extern'. If EXTERN_P then the second is.
16772 These cases are OK. */
16779 /* If we've already instantiated the template, just return now. */
16782 }
16790 {
16791 tree tmp;
16793 /* In contrast to implicit instantiation, where only the
16794 declarations, and not the definitions, of members are
16795 instantiated, we have here:
16797 [temp.explicit]
16799 The explicit instantiation of a class template specialization
16800 implies the instantiation of all of its members not
16801 previously explicitly specialized in the translation unit
16802 containing the explicit instantiation.
16804 Of course, we can't instantiate member template classes, since
16805 we don't have any arguments for them. Note that the standard
16806 is unclear on whether the instantiation of the members are
16807 *explicit* instantiations or not. However, the most natural
16808 interpretation is that it should be an explicit instantiation. */
16823 }
16824 }
16826 /* Given a function DECL, which is a specialization of TMPL, modify
16827 DECL to be a re-instantiation of TMPL with the same template
16828 arguments. TMPL should be the template into which tsubst'ing
16829 should occur for DECL, not the most general template.
16831 One reason for doing this is a scenario like this:
16833 template <class T>
16834 void f(const T&, int i);
16836 void g() { f(3, 7); }
16838 template <class T>
16839 void f(const T& t, const int i) { }
16841 Note that when the template is first instantiated, with
16842 instantiate_template, the resulting DECL will have no name for the
16843 first parameter, and the wrong type for the second. So, when we go
16844 to instantiate the DECL, we regenerate it. */
16846 static void
16848 {
16849 /* The arguments used to instantiate DECL, from the most general
16850 template. */
16851 tree args;
16852 tree code_pattern;
16857 /* Make sure that we can see identifiers, and compute access
16858 correctly. */
16862 {
16863 tree decl_parm;
16864 tree pattern_parm;
16865 tree specs;
16878 specs);
16880 /* Merge parameter declarations. */
16883 pattern_parm
16887 {
16888 tree parm_type;
16889 tree attributes;
16894 NULL_TREE);
16900 {
16903 }
16906 }
16907 /* Merge any parameters that match with the function parameter
16908 pack. */
16910 {
16912 tree expanded_types;
16913 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16914 the parameters in this function parameter pack. */
16919 {
16920 tree parm_type;
16921 tree attributes;
16924 /* Rename the parameter to include the index. */
16933 {
16936 }
16938 }
16939 }
16940 /* Merge additional specifiers from the CODE_PATTERN. */
16944 }
16946 {
16954 }
16955 else
16959 }
16961 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16962 substituted to get DECL. */
16964 tree
16966 {
16969 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16970 for the instantiation. This is not always the most general
16971 template. Consider, for example:
16973 template <class T>
16974 struct S { template <class U> void f();
16975 template <> void f<int>(); };
16977 and an instantiation of S<double>::f<int>. We want TD to be the
16978 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16980 more general template. */
16982 /* We must also deal with friend templates. Given:
16984 template <class T> struct S {
16985 template <class U> friend void f() {};
16986 };
16988 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16989 so far as the language is concerned, but that's still
16990 where we get the pattern for the instantiation from. On
16991 other hand, if the definition comes outside the class, say:
16993 template <class T> struct S {
16994 template <class U> friend void f();
16995 };
16996 template <class U> friend void f() {}
16998 we don't need to look any further. That's what the check for
16999 DECL_INITIAL is for. */
17003 {
17004 /* The present template, TD, should not be a definition. If it
17005 were a definition, we should be using it! Note that we
17006 cannot restructure the loop to just keep going until we find
17007 a template with a definition, since that might go too far if
17008 a specialization was declared, but not defined. */
17012 /* Fetch the more general template. */
17014 }
17017 }
17019 /* Returns true if we need to instantiate this template instance even if we
17020 know we aren't going to emit it.. */
17022 bool
17024 {
17025 /* We always instantiate inline functions so that we can inline them. An
17026 explicit instantiation declaration prohibits implicit instantiation of
17027 non-inline functions. With high levels of optimization, we would
17028 normally inline non-inline functions -- but we're not allowed to do
17029 that for "extern template" functions. Therefore, we check
17030 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
17033 /* And we need to instantiate static data members so that
17034 their initializers are available in integral constant
17035 expressions. */
17038 }
17040 /* Produce the definition of D, a _DECL generated from a template. If
17041 DEFER_OK is nonzero, then we don't have to actually do the
17042 instantiation now; we just have to do it sometime. Normally it is
17043 an error if this is an explicit instantiation but D is undefined.
17044 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
17045 explicitly instantiated class template. */
17047 tree
17050 {
17052 tree gen_args;
17053 tree args;
17054 tree td;
17055 tree code_pattern;
17056 tree spec;
17057 tree gen_tmpl;
17063 /* This function should only be used to instantiate templates for
17064 functions and static member variables. */
17068 /* Variables are never deferred; if instantiation is required, they
17069 are instantiated right away. That allows for better code in the
17070 case that an expression refers to the value of the variable --
17071 if the variable has a constant value the referring expression can
17072 take advantage of that fact. */
17077 /* Don't instantiate cloned functions. Instead, instantiate the
17078 functions they cloned. */
17084 /* D has already been instantiated or explicitly specialized, so
17085 there's nothing for us to do here.
17087 It might seem reasonable to check whether or not D is an explicit
17088 instantiation, and, if so, stop here. But when an explicit
17089 instantiation is deferred until the end of the compilation,
17090 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
17091 the instantiation. */
17094 /* Check to see whether we know that this template will be
17095 instantiated in some other file, as with "extern template"
17096 extension. */
17099 /* In general, we do not instantiate such templates. */
17107 /* We should already have the extra args. */
17110 /* And what's in the hash table should match D. */
17114 /* This needs to happen before any tsubsting. */
17120 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
17121 for the instantiation. */
17125 /* We should never be trying to instantiate a member of a class
17126 template or partial specialization. */
17131 /* In the case of a friend template whose definition is provided
17132 outside the class, we may have too many arguments. Drop the
17133 ones we don't need. The same is true for specializations. */
17134 args = get_innermost_template_args
17136 else
17141 else
17144 /* We may be in the middle of deferred access check. Disable it now. */
17147 /* Unless an explicit instantiation directive has already determined
17148 the linkage of D, remember that a definition is available for
17149 this entity. */
17159 /* If D is a member of an explicitly instantiated class template,
17160 and no definition is available, treat it like an implicit
17161 instantiation. */
17164 {
17168 }
17170 /* Recheck the substitutions to obtain any warning messages
17171 about ignoring cv qualifiers. Don't do this for artificial decls,
17172 as it breaks the context-sensitive substitution for lambda op(). */
17174 {
17178 /* Make sure that we can see identifiers, and compute access
17179 correctly. D is already the target FUNCTION_DECL with the
17180 right context. */
17184 {
17187 d);
17188 /* Don't simply tsubst the function type, as that will give
17189 duplicate warnings about poor parameter qualifications.
17190 The function arguments are the same as the decl_arguments
17191 without the top level cv qualifiers. */
17193 }
17197 }
17199 /* Defer all other templates, unless we have been explicitly
17200 forbidden from doing so. */
17202 template. */
17203 ! pattern_defined
17204 /* If it's OK to postpone instantiation, do so. */
17205 || defer_ok
17206 /* If this is a static data member that will be defined
17207 elsewhere, we don't want to instantiate the entire data
17208 member, but we do want to instantiate the initializer so that
17209 we can substitute that elsewhere. */
17211 {
17212 /* The definition of the static data member is now required so
17213 we must substitute the initializer. */
17217 {
17218 tree ns;
17219 tree init;
17226 args,
17229 /* Make sure the initializer is still constant, in case of
17230 circular dependency (template/instantiate6.C). */
17231 const_init
17235 LOOKUP_ONLYCONVERTING);
17238 }
17240 /* We restore the source position here because it's used by
17241 add_pending_template. */
17247 /* [temp.explicit]
17249 The definition of a non-exported function template, a
17250 non-exported member function template, or a non-exported
17251 member function or static data member of a class template
17252 shall be present in every translation unit in which it is
17253 explicitly instantiated. */
17257 /* If we're in unevaluated context, we just wanted to get the
17258 constant value; this isn't an odr use, so don't queue
17259 a full instantiation. */
17262 /* ??? Historically, we have instantiated inline functions, even
17263 when marked as "extern template". */
17267 }
17268 /* Tell the repository that D is available in this translation unit
17269 -- and see if it is supposed to be instantiated here. */
17271 {
17272 /* In a PCH file, despite the fact that the repository hasn't
17273 requested instantiation in the PCH it is still possible that
17274 an instantiation will be required in a file that includes the
17275 PCH. */
17278 /* Instantiate inline functions so that the inliner can do its
17279 job, even though we'll not be emitting a copy of this
17280 function. */
17283 }
17289 /* Mark D as instantiated so that recursive calls to
17290 instantiate_decl do not try to instantiate it again. */
17293 /* Regenerate the declaration in case the template has been modified
17294 by a subsequent redeclaration. */
17297 /* We already set the file and line above. Reset them now in case
17298 they changed as a result of calling regenerate_decl_from_template. */
17302 {
17303 tree init;
17306 /* Clear out DECL_RTL; whatever was there before may not be right
17307 since we've reset the type of the declaration. */
17311 /* The initializer is placed in DECL_INITIAL by
17312 regenerate_decl_from_template so we don't need to
17313 push/pop_access_scope again here. Pull it out so that
17314 cp_finish_decl can process it. */
17319 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
17320 initializer. That function will defer actual emission until
17321 we have a chance to determine linkage. */
17324 /* Enter the scope of D so that access-checking works correctly. */
17329 }
17331 {
17332 htab_t saved_local_specializations;
17333 tree subst_decl;
17334 tree tmpl_parm;
17335 tree spec_parm;
17337 /* Save away the current list, in case we are instantiating one
17338 template from within the body of another. */
17341 /* Set up the list of local specializations. */
17343 hash_local_specialization,
17344 eq_local_specializations,
17345 NULL);
17347 /* Set up context. */
17350 /* Create substitution entries for the parameters. */
17355 {
17359 }
17361 {
17365 }
17367 {
17368 /* Register the (value) argument pack as a specialization of
17369 TMPL_PARM, then move on. */
17374 }
17377 /* Substitute into the body of the function. */
17382 /* Set the current input_location to the end of the function
17383 so that finish_function knows where we are. */
17386 /* We don't need the local specializations any more. */
17390 /* Finish the function. */
17393 }
17395 /* We're not deferring instantiation any more. */
17401 out:
17409 }
17411 /* Run through the list of templates that we wish we could
17412 instantiate, and instantiate any we can. RETRIES is the
17413 number of times we retry pending template instantiation. */
17415 void
17417 {
17421 /* Instantiating templates may trigger vtable generation. This in turn
17422 may require further template instantiations. We place a limit here
17423 to avoid infinite loop. */
17425 {
17429 " instantiating %q+D, possibly from virtual table generation"
17433 /* Pretend that we defined it. */
17436 }
17438 do
17439 {
17444 {
17449 {
17450 tree fn;
17453 {
17457 fn;
17465 }
17468 }
17469 else
17470 {
17473 {
17474 instantiation
17480 }
17484 }
17487 /* If INSTANTIATION has been instantiated, then we don't
17488 need to consider it again in the future. */
17490 else
17491 {
17494 }
17497 }
17499 }
17503 }
17505 /* Substitute ARGVEC into T, which is a list of initializers for
17506 either base class or a non-static data member. The TREE_PURPOSEs
17507 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17508 instantiate_decl. */
17510 static tree
17512 {
17516 {
17517 tree decl;
17518 tree init;
17524 {
17525 tree expr;
17526 tree arg;
17528 /* Expand the base class expansion type into separate base
17529 classes. */
17531 tf_warning_or_error,
17532 NULL_TREE);
17536 /* We'll be building separate TREE_LISTs of arguments for
17537 each base. */
17543 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17544 expand each argument in the TREE_VALUE of t. */
17550 /* VOID_TYPE_NODE is used to indicate
17551 value-initialization. */
17552 {
17555 }
17556 else
17557 {
17558 /* Substitute parameter packs into each argument in the
17559 TREE_LIST. */
17562 {
17563 tree expanded_exprs;
17565 /* Expand the argument. */
17567 expanded_exprs
17569 tf_warning_or_error,
17570 NULL_TREE);
17574 /* Prepend each of the expanded expressions to the
17575 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17577 {
17582 }
17583 }
17586 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17587 since we built them backwards. */
17589 {
17592 }
17593 }
17594 }
17597 {
17599 {
17603 }
17604 else
17605 {
17619 }
17622 {
17626 }
17627 }
17628 }
17630 }
17632 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17634 static void
17636 {
17641 else
17643 }
17645 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17646 is the instantiation (which should have been created with
17647 start_enum) and ARGS are the template arguments to use. */
17649 static void
17651 {
17652 tree e;
17658 {
17659 tree value;
17660 tree decl;
17663 /* Note that in a template enum, the TREE_VALUE is the
17664 CONST_DECL, not the corresponding INTEGER_CST. */
17669 /* Give this enumeration constant the correct access. */
17672 /* Actually build the enumerator itself. */
17673 build_enumerator
17675 }
17685 }
17687 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17688 its type -- but without substituting the innermost set of template
17689 arguments. So, innermost set of template parameters will appear in
17690 the type. */
17692 tree
17694 {
17695 tree fn_type;
17696 tree tmpl;
17697 tree targs;
17698 tree tparms;
17706 /* There should be as many levels of arguments as there are levels
17707 of parameters. */
17713 /* No substitution is necessary. */
17714 ;
17715 else
17716 {
17718 tree partial_args;
17720 /* Replace the innermost level of the TARGS with NULL_TREEs to
17721 let tsubst know not to substitute for those parameters. */
17730 /* Disable access control as this function is used only during
17731 name-mangling. */
17736 /* Now, do the (partial) substitution to figure out the
17737 appropriate function type. */
17741 /* Substitute into the template parameters to obtain the real
17742 innermost set of parameters. This step is important if the
17743 innermost set of template parameters contains value
17744 parameters whose types depend on outer template parameters. */
17749 }
17752 }
17754 /* Return truthvalue if we're processing a template different from
17755 the last one involved in diagnostics. */
17756 int
17758 {
17760 }
17762 /* Remember current template involved in diagnostics. */
17763 void
17765 {
17767 }
17771 {
17773 }
17775 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17776 type. Return zero for ok, nonzero for disallowed. Issue error and
17777 warning messages under control of COMPLAIN. */
17779 static int
17781 {
17796 }
17798 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17799 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17801 static bool
17803 {
17804 tree scope;
17806 /* [temp.dep.type]
17808 A type is dependent if it is:
17810 -- a template parameter. Template template parameters are types
17811 for us (since TYPE_P holds true for them) so we handle
17812 them here. */
17816 /* -- a qualified-id with a nested-name-specifier which contains a
17817 class-name that names a dependent type or whose unqualified-id
17818 names a dependent type. */
17821 /* -- a cv-qualified type where the cv-unqualified type is
17822 dependent. */
17824 /* -- a compound type constructed from any dependent type. */
17834 {
17835 tree arg_type;
17840 arg_type;
17845 }
17846 /* -- an array type constructed from any dependent type or whose
17847 size is specified by a constant expression that is
17848 value-dependent.
17850 We checked for type- and value-dependence of the bounds in
17851 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
17853 {
17858 }
17860 /* -- a template-id in which either the template name is a template
17861 parameter ... */
17864 /* ... or any of the template arguments is a dependent type or
17865 an expression that is type-dependent or value-dependent. */
17867 && (any_dependent_template_arguments_p
17871 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17872 argument of the `typeof' expression is not type-dependent, then
17873 it should already been have resolved. */
17878 /* A template argument pack is dependent if any of its packed
17879 arguments are. */
17881 {
17887 }
17889 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17890 be template parameters. */
17894 /* The standard does not specifically mention types that are local
17895 to template functions or local classes, but they should be
17896 considered dependent too. For example:
17898 template <int I> void f() {
17899 enum E { a = I };
17900 S<sizeof (E)> s;
17901 }
17903 The size of `E' cannot be known until the value of `I' has been
17904 determined. Therefore, `E' must be considered dependent. */
17911 /* Other types are non-dependent. */
17913 }
17915 /* Returns TRUE if TYPE is dependent, in the sense of
17916 [temp.dep.type]. */
17918 bool
17920 {
17921 /* If there are no template parameters in scope, then there can't be
17922 any dependent types. */
17924 {
17925 /* If we are not processing a template, then nobody should be
17926 providing us with a dependent type. */
17930 }
17932 /* If the type is NULL, we have not computed a type for the entity
17933 in question; in that case, the type is dependent. */
17937 /* Erroneous types can be considered non-dependent. */
17941 /* If we have not already computed the appropriate value for TYPE,
17942 do so now. */
17944 {
17947 }
17950 }
17952 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17953 lookup. In other words, a dependent type that is not the current
17954 instantiation. */
17956 bool
17958 {
17961 }
17963 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17964 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17965 expression. */
17967 /* FIXME this predicate is not appropriate for general expressions; the
17968 predicates we want instead are "valid constant expression, value
17969 dependent or not?", "really constant expression, not value dependent?"
17970 and "instantiation-dependent?". Try to integrate with
17971 potential_constant_expression?
17973 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
17974 (what about instantiation-dependent constant-expressions?)
17975 is_late_template_attribute: defer if instantiation-dependent.
17976 compute_array_index_type: proceed if constant and not t- or v-dependent
17977 if instantiation-dependent, need to remember full expression
17978 uses_template_parms: FIXME - need to audit callers
17979 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
17980 dependent_type_p [array_type]: dependent if index type is dependent
17981 (or non-constant?)
17982 static_assert - instantiation-dependent */
17984 bool
17986 {
17990 /* A name declared with a dependent type. */
17995 {
17997 /* A name that has not been looked up -- must be dependent. */
18001 /* A non-type template parm. */
18005 /* A non-type template parm. */
18011 /* A constant with integral or enumeration type and is initialized
18012 with an expression that is value-dependent. */
18024 /* These expressions are value-dependent if the type to which
18025 the cast occurs is dependent or the expression being casted
18026 is value-dependent. */
18027 {
18033 /* A functional cast has a list of operands. */
18036 {
18037 /* If there are no operands, it must be an expression such
18038 as "int()". This should not happen for aggregate types
18039 because it would form non-constant expressions. */
18044 }
18050 }
18054 /* A `sizeof' expression is value-dependent if the operand is
18055 type-dependent or is a pack expansion. */
18064 /* An 'encode' expression is value-dependent if the operand is
18065 type-dependent. */
18071 /* FIXME why check value-dependency? */
18076 {
18079 }
18086 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
18087 is value-dependent. */
18088 {
18097 }
18100 {
18104 }
18111 {
18115 }
18118 {
18125 {
18127 /* In a call to a constexpr member function, look through the
18128 implicit ADDR_EXPR on the object argument so that it doesn't
18129 cause the call to be considered value-dependent. We also
18130 look through it in potential_constant_expression. */
18137 }
18139 }
18142 /* A constant expression is value-dependent if any subexpression is
18143 value-dependent. */
18145 {
18155 || (value_dependent_expression_p
18160 {
18163 /* In some cases, some of the operands may be missing.
18164 (For example, in the case of PREDECREMENT_EXPR, the
18165 amount to increment by may be missing.) That doesn't
18166 make the expression dependent. */
18168 && (value_dependent_expression_p
18172 }
18176 }
18177 }
18179 /* The expression is not value-dependent. */
18181 }
18183 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
18184 [temp.dep.expr]. */
18186 bool
18188 {
18195 /* An unresolved name is always dependent. */
18200 /* Some expression forms are never type-dependent. */
18213 /* The types of these expressions depends only on the type to which
18214 the cast occurs. */
18222 /* The types of these expressions depends only on the type created
18223 by the expression. */
18226 {
18227 /* For NEW_EXPR tree nodes created inside a template, either
18228 the object type itself or a TREE_LIST may appear as the
18229 operand 1. */
18232 /* This is an array type. We need to check array dimensions
18233 as well. */
18235 || value_dependent_expression_p
18237 else
18239 }
18242 {
18246 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
18247 contains an identifier associated by name lookup with one or more
18248 declarations declared with a dependent type, or...a
18249 nested-name-specifier or qualified-id that names a member of an
18250 unknown specialization. */
18253 }
18258 && (any_dependent_template_arguments_p
18270 {
18271 tree elt;
18275 {
18278 }
18280 }
18282 /* A static data member of the current instantiation with incomplete
18283 array type is type-dependent, as the definition and specializations
18284 can have different bounds. */
18292 {
18297 {
18303 }
18304 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
18312 {
18317 }
18322 {
18326 }
18328 }
18333 }
18335 /* Like type_dependent_expression_p, but it also works while not processing
18336 a template definition, i.e. during substitution or mangling. */
18338 bool
18340 {
18346 }
18348 /* Returns TRUE if ARGS contains a type-dependent expression. */
18350 bool
18352 {
18354 tree arg;
18357 {
18360 }
18362 }
18364 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
18365 expressions) contains any value-dependent expressions. */
18367 bool
18369 {
18375 }
18377 /* Returns TRUE if the ARG (a template argument) is dependent. */
18379 bool
18381 {
18385 /* Assume a template argument that was wrongly written by the user
18386 is dependent. This is consistent with what
18387 any_dependent_template_arguments_p [that calls this function]
18388 does. */
18396 {
18400 {
18403 }
18406 }
18409 else
18412 }
18414 /* Returns true if ARGS (a collection of template arguments) contains
18415 any types that require structural equality testing. */
18417 bool
18419 {
18429 {
18432 {
18438 {
18439 /* Look inside the argument pack. */
18442 }
18445 {
18459 }
18460 }
18461 }
18464 }
18466 /* Returns true if ARGS (a collection of template arguments) contains
18467 any dependent arguments. */
18469 bool
18471 {
18481 {
18486 }
18489 }
18491 /* Returns TRUE if the template TMPL is dependent. */
18493 bool
18495 {
18497 {
18499 {
18503 }
18505 }
18507 /* Template template parameters are dependent. */
18511 /* So are names that have not been looked up. */
18515 /* So are member templates of dependent classes. */
18519 }
18521 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18523 bool
18525 {
18528 }
18530 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18531 is dependent. */
18533 bool
18535 {
18542 {
18563 {
18567 }
18571 {
18575 {
18580 }
18581 }
18582 }
18585 }
18587 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18588 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18589 no such TYPE can be found. Note that this function peers inside
18590 uninstantiated templates and therefore should be used only in
18591 extremely limited situations. ONLY_CURRENT_P restricts this
18592 peering to the currently open classes hierarchy (which is required
18593 when comparing types). */
18595 tree
18597 {
18598 tree scope;
18599 tree name;
18600 tree decl;
18602 tree pushed_scope;
18603 tree result;
18608 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18609 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18610 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18611 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18612 identifier of the TYPENAME_TYPE anymore.
18613 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18614 TYPENAME_TYPE instead, we avoid messing up with a possible
18615 typedef variant case. */
18618 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18619 it first before we can figure out what NAME refers to. */
18622 /* If we don't know what SCOPE refers to, then we cannot resolve the
18623 TYPENAME_TYPE. */
18626 /* If the SCOPE is a template type parameter, we have no way of
18627 resolving the name. */
18630 /* If the SCOPE is not the current instantiation, there's no reason
18631 to look inside it. */
18634 /* If this is a typedef, we don't want to look inside (c++/11987). */
18637 /* If SCOPE isn't the template itself, it will not have a valid
18638 TYPE_FIELDS list. */
18640 /* scope is either the template itself or a compatible instantiation
18641 like X<T>, so look up the name in the original template. */
18643 else
18644 /* scope is a partial instantiation, so we can't do the lookup or we
18645 will lose the template arguments. */
18647 /* Enter the SCOPE so that name lookup will be resolved as if we
18648 were in the class definition. In particular, SCOPE will no
18649 longer be considered a dependent type. */
18651 /* Look up the declaration. */
18656 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18657 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18662 {
18666 }
18669 {
18670 tree tmpl;
18671 tree args;
18672 /* Obtain the template and the arguments. */
18675 /* Instantiate the template. */
18681 }
18683 /* Leave the SCOPE. */
18687 /* If we failed to resolve it, return the original typename. */
18691 /* If lookup found a typename type, resolve that too. */
18693 {
18694 /* Ill-formed programs can cause infinite recursion here, so we
18695 must catch that. */
18699 }
18701 /* Qualify the resulting type. */
18707 }
18709 /* EXPR is an expression which is not type-dependent. Return a proxy
18710 for EXPR that can be used to compute the types of larger
18711 expressions containing EXPR. */
18713 tree
18715 {
18716 tree inner_expr;
18718 /* Preserve null pointer constants so that the type of things like
18719 "p == 0" where "p" is a pointer can be determined. */
18722 /* Preserve OVERLOADs; the functions must be available to resolve
18723 types. */
18734 /* There is no need to return a proxy for a variable. */
18737 /* Preserve string constants; conversions from string constants to
18738 "char *" are allowed, even though normally a "const char *"
18739 cannot be used to initialize a "char *". */
18742 /* Preserve arithmetic constants, as an optimization -- there is no
18743 reason to create a new node. */
18746 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18747 There is at least one place where we want to know that a
18748 particular expression is a throw-expression: when checking a ?:
18749 expression, there are special rules if the second or third
18750 argument is a throw-expression. */
18769 /* If the type is unknown, it can't really be non-dependent */
18772 /* Otherwise, build a NON_DEPENDENT_EXPR.
18774 REFERENCE_TYPEs are not stripped for expressions in templates
18775 because doing so would play havoc with mangling. Consider, for
18776 example:
18778 template <typename T> void f<T& g>() { g(); }
18780 In the body of "f", the expression for "g" will have
18781 REFERENCE_TYPE, even though the standard says that it should
18782 not. The reason is that we must preserve the syntactic form of
18783 the expression so that mangling (say) "f<g>" inside the body of
18784 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18785 stripped here. */
18787 }
18789 /* ARGS is a vector of expressions as arguments to a function call.
18790 Replace the arguments with equivalent non-dependent expressions.
18791 This modifies ARGS in place. */
18793 void
18795 {
18797 tree arg;
18800 {
18804 }
18805 }
18807 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18808 with a level one deeper than the actual template parms. */
18810 tree
18812 {
18825 }
18827 /* Given type ARG, return std::initializer_list<ARG>. */
18829 static tree
18831 {
18832 tree std_init_list = namespace_binding
18834 tree argvec;
18836 {
18840 }
18845 }
18847 /* Replace auto in TYPE with std::initializer_list<auto>. */
18849 static tree
18851 {
18858 }
18860 /* walk_tree helper for do_auto_deduction. */
18862 static tree
18865 {
18866 /* Is this a variable with the type we're looking for? */
18870 else
18872 }
18874 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18875 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18877 tree
18879 {
18882 tree decl;
18885 /* The name of the object being declared shall not appear in the
18886 initializer expression. */
18889 {
18893 }
18895 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18896 with either a new invented type template parameter U or, if the
18897 initializer is a braced-init-list (8.5.4), with
18898 std::initializer_list<U>. */
18913 {
18916 }
18918 /* If the list of declarators contains more than one declarator, the type
18919 of each declared variable is determined as described above. If the
18920 type deduced for the template parameter U is not the same in each
18921 deduction, the program is ill-formed. */
18924 {
18928 }
18934 }
18936 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18937 result. */
18939 tree
18941 {
18942 tree argvec;
18951 }
18953 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18955 bool
18957 {
18961 else
18963 }
18965 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18966 appear as a type-specifier for the declaration in question, we don't
18967 have to look through the whole type. */
18969 tree
18971 {
18988 }
18990 /* For a given template T, return the vector of typedefs referenced
18991 in T for which access check is needed at T instantiation time.
18992 T is either a FUNCTION_DECL or a RECORD_TYPE.
18993 Those typedefs were added to T by the function
18994 append_type_to_template_for_access_check. */
18998 {
18999 tree ti;
19010 {
19015 }
19018 }
19020 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
19021 tied to T. That list of typedefs will be access checked at
19022 T instantiation time.
19023 T is either a FUNCTION_DECL or a RECORD_TYPE.
19024 TYPE_DECL is a TYPE_DECL node representing a typedef.
19025 SCOPE is the scope through which TYPE_DECL is accessed.
19026 LOCATION is the location of the usage point of TYPE_DECL.
19028 This function is a subroutine of
19029 append_type_to_template_for_access_check. */
19031 static void
19033 tree type_decl,
19034 tree scope,
19035 location_t location)
19036 {
19037 qualified_typedef_usage_t typedef_usage;
19038 tree ti;
19045 && type_decl
19061 }
19063 /* Append TYPE_DECL to the template TEMPL.
19064 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
19065 At TEMPL instanciation time, TYPE_DECL will be checked to see
19066 if it can be accessed through SCOPE.
19067 LOCATION is the location of the usage point of TYPE_DECL.
19069 e.g. consider the following code snippet:
19071 class C
19072 {
19073 typedef int myint;
19074 };
19076 template<class U> struct S
19077 {
19078 C::myint mi; // <-- usage point of the typedef C::myint
19079 };
19081 S<char> s;
19083 At S<char> instantiation time, we need to check the access of C::myint
19084 In other words, we need to check the access of the myint typedef through
19085 the C scope. For that purpose, this function will add the myint typedef
19086 and the scope C through which its being accessed to a list of typedefs
19087 tied to the template S. That list will be walked at template instantiation
19088 time and access check performed on each typedefs it contains.
19089 Note that this particular code snippet should yield an error because
19090 myint is private to C. */
19092 void
19094 tree type_decl,
19095 tree scope,
19096 location_t location)
19097 {
19103 /* Make sure we don't append the type to the template twice. */
19112 }
19114 /* Set up the hash tables for template instantiations. */
19116 void
19118 {
19120 hash_specialization,
19121 eq_specializations,
19122 ggc_free);
19124 hash_specialization,
19125 eq_specializations,
19126 ggc_free);
19127 }
19129 /* Print stats about the template hash tables for -fstats. */
19131 void
19133 {
19142 }