| blob | 767c4f6c584255154faaa701f81bf8c6749fc185 |
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, 2011
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". */
49 /* The type of functions taking a tree, and some additional data, and
50 returning an int. */
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
59 };
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
81 local variables. */
85 {
86 tree tmpl;
87 tree args;
88 tree spec;
92 htab_t decl_specializations;
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
130 tree);
190 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 }
1536 {
1539 }
1550 val = iterative_hash_template_arg
1562 val);
1564 val);
1573 /* A lambda can't appear in a template arg, but don't crash on
1574 erroneous input. */
1585 /* Now hash operands as usual. */
1590 }
1593 {
1597 val);
1600 /* Otherwise just compare the types during lookup. */
1609 {
1614 }
1615 }
1618 }
1620 /* Unregister the specialization SPEC as a specialization of TMPL.
1621 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1622 if the SPEC was listed as a specialization of TMPL.
1624 Note that SPEC has been ggc_freed, so we can't look inside it. */
1626 bool
1628 {
1630 spec_entry elt;
1638 {
1643 }
1646 }
1648 /* Compare an entry in the local specializations hash table P1 (which
1649 is really a pointer to a TREE_LIST) with P2 (which is really a
1650 DECL). */
1652 static int
1654 {
1656 }
1658 /* Hash P1, an entry in the local specializations table. */
1660 static hashval_t
1662 {
1664 }
1666 /* Like register_specialization, but for local declarations. We are
1667 registering SPEC, an instantiation of TMPL. */
1669 static void
1671 {
1677 }
1679 /* TYPE is a class type. Returns true if TYPE is an explicitly
1680 specialized class. */
1682 bool
1684 {
1688 }
1690 /* Print the list of functions at FNS, going through all the overloads
1691 for each element of the list. Alternatively, FNS can not be a
1692 TREE_LIST, in which case it will be printed together with all the
1693 overloads.
1695 MORE and *STR should respectively be FALSE and NULL when the function
1696 is called from the outside. They are used internally on recursive
1697 calls. print_candidates manages the two parameters and leaves NULL
1698 in *STR when it ends. */
1700 static void
1702 {
1708 {
1712 }
1713 else
1714 {
1716 {
1717 /* Pick the prefix string. */
1719 {
1722 }
1726 }
1729 }
1732 {
1735 }
1736 }
1738 /* Print the list of candidate FNS in an error message. FNS can also
1739 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1741 void
1743 {
1747 }
1749 /* Returns the template (one of the functions given by TEMPLATE_ID)
1750 which can be specialized to match the indicated DECL with the
1751 explicit template args given in TEMPLATE_ID. The DECL may be
1752 NULL_TREE if none is available. In that case, the functions in
1753 TEMPLATE_ID are non-members.
1755 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1756 specialization of a member template.
1758 The TEMPLATE_COUNT is the number of references to qualifying
1759 template classes that appeared in the name of the function. See
1760 check_explicit_specialization for a more accurate description.
1762 TSK indicates what kind of template declaration (if any) is being
1763 declared. TSK_TEMPLATE indicates that the declaration given by
1764 DECL, though a FUNCTION_DECL, has template parameters, and is
1765 therefore a template function.
1767 The template args (those explicitly specified and those deduced)
1768 are output in a newly created vector *TARGS_OUT.
1770 If it is impossible to determine the result, an error message is
1771 issued. The error_mark_node is returned to indicate failure. */
1773 static tree
1775 tree decl,
1779 tmpl_spec_kind tsk)
1780 {
1781 tree fns;
1782 tree targs;
1783 tree explicit_targs;
1785 /* A TREE_LIST of templates of which DECL may be a specialization.
1786 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1787 corresponding TREE_PURPOSE is the set of template arguments that,
1788 when used to instantiate the template, would produce a function
1789 with the signature of DECL. */
1805 /* Check for baselinks. */
1810 {
1813 }
1815 /* Count the number of template headers specified for this
1816 specialization. */
1824 {
1828 {
1829 tree decl_arg_types;
1830 tree fn_arg_types;
1832 /* In case of explicit specialization, we need to check if
1833 the number of template headers appearing in the specialization
1834 is correct. This is usually done in check_explicit_specialization,
1835 but the check done there cannot be exhaustive when specializing
1836 member functions. Consider the following code:
1838 template <> void A<int>::f(int);
1839 template <> template <> void A<int>::f(int);
1841 Assuming that A<int> is not itself an explicit specialization
1842 already, the first line specializes "f" which is a non-template
1843 member function, whilst the second line specializes "f" which
1844 is a template member function. So both lines are syntactically
1845 correct, and check_explicit_specialization does not reject
1846 them.
1848 Here, we can do better, as we are matching the specialization
1849 against the declarations. We count the number of template
1850 headers, and we check if they match TEMPLATE_COUNT + 1
1851 (TEMPLATE_COUNT is the number of qualifying template classes,
1852 plus there must be another header for the member template
1853 itself).
1855 Notice that if header_count is zero, this is not a
1856 specialization but rather a template instantiation, so there
1857 is no check we can perform here. */
1861 /* Check that the number of template arguments at the
1862 innermost level for DECL is the same as for FN. */
1870 /* DECL might be a specialization of FN. */
1874 /* For a non-static member function, we need to make sure
1875 that the const qualification is the same. Since
1876 get_bindings does not try to merge the "this" parameter,
1877 we must do the comparison explicitly. */
1883 /* Skip the "this" parameter and, for constructors of
1884 classes with virtual bases, the VTT parameter. A
1885 full specialization of a constructor will have a VTT
1886 parameter, but a template never will. */
1887 decl_arg_types
1889 fn_arg_types
1892 /* Check that the number of function parameters matches.
1893 For example,
1894 template <class T> void f(int i = 0);
1895 template <> void f<int>();
1896 The specialization f<int> is invalid but is not caught
1897 by get_bindings below. */
1901 /* Function templates cannot be specializations; there are
1902 no partial specializations of functions. Therefore, if
1903 the type of DECL does not match FN, there is no
1904 match. */
1906 {
1910 }
1912 /* See whether this function might be a specialization of this
1913 template. */
1917 /* We cannot deduce template arguments that when used to
1918 specialize TMPL will produce DECL. */
1921 /* Save this template, and the arguments deduced. */
1923 }
1925 /* FN is an ordinary member function, and we need a
1926 specialization of a member template. */
1927 ;
1929 /* We can get IDENTIFIER_NODEs here in certain erroneous
1930 cases. */
1931 ;
1933 /* This is just an ordinary non-member function. Nothing can
1934 be a specialization of that. */
1935 ;
1937 /* Cannot specialize functions that are created implicitly. */
1938 ;
1939 else
1940 {
1941 tree decl_arg_types;
1943 /* This is an ordinary member function. However, since
1944 we're here, we can assume it's enclosing class is a
1945 template class. For example,
1947 template <typename T> struct S { void f(); };
1948 template <> void S<int>::f() {}
1950 Here, S<int>::f is a non-template, but S<int> is a
1951 template class. If FN has the same type as DECL, we
1952 might be in business. */
1955 /* Its enclosing class is an explicit specialization
1956 of a template class. This is not a candidate. */
1961 /* The return types differ. */
1964 /* Adjust the type of DECL in case FN is a static member. */
1971 decl_arg_types))
1972 /* They match! */
1974 }
1975 }
1978 {
1979 /* We have:
1981 [temp.expl.spec]
1983 It is possible for a specialization with a given function
1984 signature to be instantiated from more than one function
1985 template. In such cases, explicit specification of the
1986 template arguments must be used to uniquely identify the
1987 function template specialization being specialized.
1989 Note that here, there's no suggestion that we're supposed to
1990 determine which of the candidate templates is most
1991 specialized. However, we, also have:
1993 [temp.func.order]
1995 Partial ordering of overloaded function template
1996 declarations is used in the following contexts to select
1997 the function template to which a function template
1998 specialization refers:
2000 -- when an explicit specialization refers to a function
2001 template.
2003 So, we do use the partial ordering rules, at least for now.
2004 This extension can only serve to make invalid programs valid,
2005 so it's safe. And, there is strong anecdotal evidence that
2006 the committee intended the partial ordering rules to apply;
2007 the EDG front end has that behavior, and John Spicer claims
2008 that the committee simply forgot to delete the wording in
2009 [temp.expl.spec]. */
2012 {
2015 }
2016 }
2019 {
2027 }
2031 {
2037 }
2039 /* We have one, and exactly one, match. */
2041 {
2044 /* DECL is a re-declaration or partial instantiation of a template
2045 function. */
2048 /* It was a specialization of an ordinary member function in a
2049 template class. */
2051 }
2053 /* It was a specialization of a template. */
2056 {
2061 }
2062 else
2065 }
2067 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2068 but with the default argument values filled in from those in the
2069 TMPL_TYPES. */
2071 static tree
2073 tree tmpl_types)
2074 {
2075 tree new_spec_types;
2083 /* Substitute into the rest of the list. */
2084 new_spec_types =
2088 /* Add the default argument for this parameter. */
2091 new_spec_types);
2092 }
2094 /* DECL is an explicit specialization. Replicate default arguments
2095 from the template it specializes. (That way, code like:
2097 template <class T> void f(T = 3);
2098 template <> void f(double);
2099 void g () { f (); }
2101 works, as required.) An alternative approach would be to look up
2102 the correct default arguments at the call-site, but this approach
2103 is consistent with how implicit instantiations are handled. */
2105 static void
2107 {
2108 tree tmpl;
2109 tree spec_types;
2110 tree tmpl_types;
2111 tree new_spec_types;
2112 tree old_type;
2113 tree new_type;
2114 tree t;
2119 /* See if there's anything we need to do. */
2132 {
2133 /* Remove the this pointer, but remember the object's type for
2134 CV quals. */
2140 {
2141 /* DECL may contain more parameters than TMPL due to the extra
2142 in-charge parameter in constructors and destructors. */
2145 }
2147 {
2150 }
2151 }
2153 /* Compute the merged default arguments. */
2154 new_spec_types =
2157 /* Compute the new FUNCTION_TYPE. */
2159 {
2163 new_spec_types);
2166 /* Put the in-charge parameter back. */
2169 new_spec_types);
2173 new_spec_types);
2174 }
2175 else
2177 new_spec_types);
2183 }
2185 /* Check to see if the function just declared, as indicated in
2186 DECLARATOR, and in DECL, is a specialization of a function
2187 template. We may also discover that the declaration is an explicit
2188 instantiation at this point.
2190 Returns DECL, or an equivalent declaration that should be used
2191 instead if all goes well. Issues an error message if something is
2192 amiss. Returns error_mark_node if the error is not easily
2193 recoverable.
2195 FLAGS is a bitmask consisting of the following flags:
2197 2: The function has a definition.
2198 4: The function is a friend.
2200 The TEMPLATE_COUNT is the number of references to qualifying
2201 template classes that appeared in the name of the function. For
2202 example, in
2204 template <class T> struct S { void f(); };
2205 void S<int>::f();
2207 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2208 classes are not counted in the TEMPLATE_COUNT, so that in
2210 template <class T> struct S {};
2211 template <> struct S<int> { void f(); }
2212 template <> void S<int>::f();
2214 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2215 invalid; there should be no template <>.)
2217 If the function is a specialization, it is marked as such via
2218 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2219 is set up correctly, and it is added to the list of specializations
2220 for that template. */
2222 tree
2224 tree decl,
2227 {
2235 tmpl_spec_kind tsk;
2238 {
2241 else
2243 }
2244 else
2248 {
2251 {
2254 }
2256 {
2258 /* This could be something like:
2260 template <class T> void f(T);
2261 class S { friend void f<>(int); } */
2263 else
2264 {
2265 /* This case handles bogus declarations like template <>
2266 template <class T> void f<int>(); */
2269 declarator);
2271 }
2272 }
2276 /* The error has already been reported in
2277 check_specialization_scope. */
2283 /* Fall through. */
2296 decl);
2299 else
2303 /* Fall through. */
2308 else
2314 {
2315 /* This case handles bogus declarations like template <>
2316 template <class T> void f<int>(); */
2321 else
2323 declarator);
2325 }
2328 /* This is a specialization of a member template, without
2329 specialization the containing class. Something like:
2331 template <class T> struct S {
2332 template <class U> void f (U);
2333 };
2334 template <> template <class U> void S<int>::f(U) {}
2336 That's a specialization -- but of the entire template. */
2342 }
2345 {
2349 {
2353 }
2354 }
2357 {
2361 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2363 {
2364 tree fns;
2369 else
2370 {
2371 /* If there is no class context, the explicit instantiation
2372 must be at namespace scope. */
2375 /* Find the namespace binding, using the declaration
2376 context. */
2380 {
2383 }
2384 else
2385 {
2391 }
2392 }
2395 }
2401 {
2403 /* A specialization in class scope. This is invalid,
2404 but the error will already have been flagged by
2405 check_specialization_scope. */
2407 else
2408 {
2409 /* It's not valid to write an explicit instantiation in
2410 class scope, e.g.:
2412 class C { template void f(); }
2414 This case is caught by the parser. However, on
2415 something like:
2417 template class C { void f(); };
2419 (which is invalid) we can get here. The error will be
2420 issued later. */
2421 ;
2422 }
2425 }
2428 IDENTIFIER_NODE))
2429 {
2430 /* Find the list of functions in ctype that have the same
2431 name as the declared function. */
2437 {
2442 {
2443 /* From [temp.expl.spec]:
2445 If such an explicit specialization for the member
2446 of a class template names an implicitly-declared
2447 special member function (clause _special_), the
2448 program is ill-formed.
2450 Similar language is found in [temp.explicit]. */
2453 }
2456 }
2459 {
2463 }
2464 else
2465 {
2467 tree ovl;
2469 /* For a type-conversion operator, we cannot do a
2470 name-based lookup. We might be looking for `operator
2471 int' which will be a specialization of `operator T'.
2472 So, we find *all* the conversion operators, and then
2473 select from them. */
2481 {
2483 /* There are no more conversion functions. */
2486 /* Glue all these conversion functions together
2487 with those we already have. */
2490 }
2491 }
2494 {
2497 }
2498 else
2500 }
2502 /* Figure out what exactly is being specialized at this point.
2503 Note that for an explicit instantiation, even one for a
2504 member function, we cannot tell apriori whether the
2505 instantiation is for a member template, or just a member
2506 function of a template class. Even if a member template is
2507 being instantiated, the member template arguments may be
2508 elided if they can be deduced from the rest of the
2509 declaration. */
2512 member_specialization,
2513 template_count,
2514 tsk);
2517 /* We couldn't figure out what this declaration was
2518 specializing. */
2520 else
2521 {
2525 {
2526 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2527 is done by do_decl_instantiation later. */
2533 {
2534 /* If TMPL is not the most general template (for
2535 example, if TMPL is a friend template that is
2536 injected into namespace scope), then there will
2537 be too many levels of TARGS. Remove some of them
2538 here. */
2540 tree new_targs;
2547 }
2550 }
2552 /* If we thought that the DECL was a member function, but it
2553 turns out to be specializing a static member function,
2554 make DECL a static member function as well. */
2559 /* If this is a specialization of a member template of a
2560 template class, we want to return the TEMPLATE_DECL, not
2561 the specialization of it. */
2563 {
2568 {
2569 tree parm;
2573 /* We want to use the argument list specified in the
2574 definition, not in the original declaration. */
2579 }
2582 }
2584 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2587 /* Inherit default function arguments from the template
2588 DECL is specializing. */
2591 /* This specialization has the same protection as the
2592 template it specializes. */
2596 /* 7.1.1-1 [dcl.stc]
2598 A storage-class-specifier shall not be specified in an
2599 explicit specialization...
2601 The parser rejects these, so unless action is taken here,
2602 explicit function specializations will always appear with
2603 global linkage.
2605 The action recommended by the C++ CWG in response to C++
2606 defect report 605 is to make the storage class and linkage
2607 of the explicit specialization match the templated function:
2609 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2610 */
2612 {
2616 /* This specialization has the same linkage and visibility as
2617 the function template it specializes. */
2620 {
2623 }
2626 {
2629 }
2630 }
2632 /* If DECL is a friend declaration, declared using an
2633 unqualified name, the namespace associated with DECL may
2634 have been set incorrectly. For example, in:
2636 template <typename T> void f(T);
2637 namespace N {
2638 struct S { friend void f<int>(int); }
2639 }
2641 we will have set the DECL_CONTEXT for the friend
2642 declaration to N, rather than to the global namespace. */
2647 /* This is not really a declaration of a specialization.
2648 It's just the name of an instantiation. But, it's not
2649 a request for an instantiation, either. */
2652 /* This is indeed a specialization. In case of constructors
2653 and destructors, we need in-charge and not-in-charge
2654 versions in V3 ABI. */
2657 /* Register this specialization so that we can find it
2658 again. */
2660 }
2661 }
2664 }
2666 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2667 parameters. These are represented in the same format used for
2668 DECL_TEMPLATE_PARMS. */
2670 int
2672 {
2673 const_tree p1;
2674 const_tree p2;
2682 {
2694 {
2698 /* If either of the template parameters are invalid, assume
2699 they match for the sake of error recovery. */
2712 }
2713 }
2716 /* One set of parameters has more parameters lists than the
2717 other. */
2721 }
2723 /* Determine whether PARM is a parameter pack. */
2725 bool
2727 {
2728 /* Determine if we have a non-type template parameter pack. */
2733 /* If this is a list of template parameters, we could get a
2734 TYPE_DECL or a TEMPLATE_DECL. */
2741 }
2743 /* Determine if T is a function parameter pack. */
2745 bool
2747 {
2751 }
2753 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2754 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2756 tree
2758 {
2765 }
2767 /* Return true iff the function parameter PARAM_DECL was expanded
2768 from the function parameter pack PACK. */
2770 bool
2772 {
2777 /* The parameter pack and its pack arguments have the same
2778 DECL_PARM_INDEX. */
2780 }
2782 /* Determine whether ARGS describes a variadic template args list,
2783 i.e., one that is terminated by a template argument pack. */
2785 static bool
2787 {
2789 tree last_parm;
2803 }
2805 /* Generate a new name for the parameter pack name NAME (an
2806 IDENTIFIER_NODE) that incorporates its */
2808 static tree
2810 {
2811 /* Munge the name to include the parameter index. */
2812 #define NUMBUF_LEN 128
2824 }
2826 /* Return true if T is a primary function
2827 or class template instantiation. */
2829 bool
2831 {
2843 }
2845 /* Return true if PARM is a template template parameter. */
2847 bool
2849 {
2851 }
2853 /* Return the template parameters of T if T is a
2854 primary template instantiation, NULL otherwise. */
2856 tree
2858 {
2863 parms = INNERMOST_TEMPLATE_PARMS
2867 }
2869 /* Return the template parameters of the LEVELth level from the full list
2870 of template parameters PARMS. */
2872 tree
2874 {
2875 tree p;
2886 }
2888 /* Returns the template arguments of T if T is a template instantiation,
2889 NULL otherwise. */
2891 tree
2893 {
2901 }
2903 /* Return the argument pack elements of T if T is a template argument pack,
2904 NULL otherwise. */
2906 tree
2908 {
2914 }
2916 /* Structure used to track the progress of find_parameter_packs_r. */
2917 struct find_parameter_pack_data
2918 {
2919 /* TREE_LIST that will contain all of the parameter packs found by
2920 the traversal. */
2923 /* Set of AST nodes that have been visited by the traversal. */
2925 };
2927 /* Identifies all of the argument packs that occur in a template
2928 argument and appends them to the TREE_LIST inside DATA, which is a
2929 find_parameter_pack_data structure. This is a subroutine of
2930 make_pack_expansion and uses_parameter_packs. */
2931 static tree
2933 {
2939 /* Identify whether this is a parameter pack or not. */
2941 {
2955 {
2956 /* We don't want to walk into the type of a PARM_DECL,
2957 because we don't want to see the type parameter pack. */
2960 }
2964 /* Not a parameter pack. */
2966 }
2969 {
2970 /* Add this parameter pack to the list. */
2972 }
2978 /* This switch statement will return immediately if we don't find a
2979 parameter pack. */
2981 {
2986 /* Check the template itself. */
2989 /* Check the template arguments. */
3005 /* Fall through. */
3046 }
3049 }
3051 /* Determines if the expression or type T uses any parameter packs. */
3052 bool
3054 {
3062 }
3064 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3065 representation a base-class initializer into a parameter pack
3066 expansion. If all goes well, the resulting node will be an
3067 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3068 respectively. */
3069 tree
3071 {
3072 tree result;
3081 {
3082 /* The only time we will see a TREE_LIST here is for a base
3083 class initializer. In this case, the TREE_PURPOSE will be a
3084 _TYPE node (representing the base class expansion we're
3085 initializing) and the TREE_VALUE will be a TREE_LIST
3086 containing the initialization arguments.
3088 The resulting expansion looks somewhat different from most
3089 expansions. Rather than returning just one _EXPANSION, we
3090 return a TREE_LIST whose TREE_PURPOSE is a
3091 TYPE_PACK_EXPANSION containing the bases that will be
3092 initialized. The TREE_VALUE will be identical to the
3093 original TREE_VALUE, which is a list of arguments that will
3094 be passed to each base. We do not introduce any new pack
3095 expansion nodes into the TREE_VALUE (although it is possible
3096 that some already exist), because the TREE_PURPOSE and
3097 TREE_VALUE all need to be expanded together with the same
3098 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3099 resulting TREE_PURPOSE will mention the parameter packs in
3100 both the bases and the arguments to the bases. */
3101 tree purpose;
3102 tree value;
3105 /* Determine which parameter packs will be used by the base
3106 class expansion. */
3113 {
3117 }
3120 {
3121 /* Collect the sets of parameter packs used in each of the
3122 initialization arguments. */
3124 {
3125 /* Determine which parameter packs will be expanded in this
3126 argument. */
3129 }
3130 }
3134 /* Create the pack expansion type for the base type. */
3139 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3140 they will rarely be compared to anything. */
3144 }
3149 /* Build the PACK_EXPANSION_* node. */
3150 result = for_types
3155 {
3156 /* Propagate type and const-expression information. */
3159 }
3160 else
3161 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3162 they will rarely be compared to anything. */
3165 /* Determine which parameter packs will be expanded. */
3171 /* Make sure we found some parameter packs. */
3173 {
3176 else
3179 }
3183 }
3185 /* Checks T for any "bare" parameter packs, which have not yet been
3186 expanded, and issues an error if any are found. This operation can
3187 only be done on full expressions or types (e.g., an expression
3188 statement, "if" condition, etc.), because we could have expressions like:
3190 foo(f(g(h(args)))...)
3192 where "args" is a parameter pack. check_for_bare_parameter_packs
3193 should not be called for the subexpressions args, h(args),
3194 g(h(args)), or f(g(h(args))), because we would produce erroneous
3195 error messages.
3197 Returns TRUE and emits an error if there were bare parameter packs,
3198 returns FALSE otherwise. */
3199 bool
3201 {
3217 {
3220 {
3229 else
3234 else
3238 }
3241 }
3244 }
3246 /* Expand any parameter packs that occur in the template arguments in
3247 ARGS. */
3248 tree
3250 {
3256 /* First, determine if we need to expand anything, and the number of
3257 slots we'll need. */
3259 {
3264 {
3268 else
3270 }
3271 else
3272 {
3274 num_result_args++;
3275 }
3276 }
3278 /* If no expansion is necessary, we're done. */
3282 /* Expand arguments. */
3285 non_default_args_count =
3288 {
3291 {
3298 }
3299 else
3300 {
3303 }
3304 }
3308 }
3310 /* Checks if DECL shadows a template parameter.
3312 [temp.local]: A template-parameter shall not be redeclared within its
3313 scope (including nested scopes).
3315 Emits an error and returns TRUE if the DECL shadows a parameter,
3316 returns FALSE otherwise. */
3318 bool
3320 {
3321 tree olddecl;
3323 /* If we're not in a template, we can't possibly shadow a template
3324 parameter. */
3328 /* Figure out what we're shadowing. */
3333 /* If there's no previous binding for this name, we're not shadowing
3334 anything, let alone a template parameter. */
3338 /* If we're not shadowing a template parameter, we're done. Note
3339 that OLDDECL might be an OVERLOAD (or perhaps even an
3340 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3341 node. */
3345 /* We check for decl != olddecl to avoid bogus errors for using a
3346 name inside a class. We check TPFI to avoid duplicate errors for
3347 inline member templates. */
3355 }
3357 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3358 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3359 template parameters. */
3361 static tree
3366 tree decl,
3367 tree type)
3368 {
3380 }
3382 /* Find the canonical type parameter for the given template type
3383 parameter. Returns the canonical type parameter, which may be TYPE
3384 if no such parameter existed. */
3386 static tree
3388 {
3389 tree list;
3403 else
3404 {
3409 }
3410 }
3412 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3413 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3414 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3415 new one is created. */
3417 static tree
3419 tsubst_flags_t complain)
3420 {
3425 {
3445 /* Template template parameters need this. */
3450 }
3453 }
3455 /* Process information from new template parameter PARM and append it
3456 to the LIST being built. This new parameter is a non-type
3457 parameter iff IS_NON_TYPE is true. This new parameter is a
3458 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3459 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3460 parameter list PARM belongs to. This is used used to create a
3461 proper canonical type for the type of PARM that is to be created,
3462 iff PARM is a type. If the size is not known, this parameter shall
3463 be set to 0. */
3465 tree
3469 {
3471 tree defval;
3472 tree err_parm_list;
3479 {
3483 {
3487 else
3489 }
3492 }
3493 else
3497 {
3503 {
3507 }
3508 else
3509 {
3510 /* [temp.param]
3512 The top-level cv-qualifiers on the template-parameter are
3513 ignored when determining its type. */
3516 {
3520 }
3523 {
3524 /* This template parameter is not a parameter pack, but it
3525 should be. Complain about "bare" parameter packs. */
3528 /* Recover by calling this a parameter pack. */
3530 }
3531 }
3533 /* A template parameter is not modifiable. */
3542 processing_template_decl,
3543 num_template_parms,
3548 }
3549 else
3550 {
3551 tree t;
3555 {
3557 /* This is for distinguishing between real templates and template
3558 template parameters */
3562 }
3563 else
3564 {
3566 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3569 }
3576 processing_template_decl,
3577 num_template_parms,
3581 }
3587 }
3589 /* The end of a template parameter list has been reached. Process the
3590 tree list into a parameter vector, converting each parameter into a more
3591 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3592 as PARM_DECLs. */
3594 tree
3596 {
3601 current_template_parms
3606 {
3610 }
3615 }
3617 /* Create a new type almost identical to TYPE but which has the
3618 following differences:
3620 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3621 template sibling parameters of T.
3623 2/ T has a new canonical type that matches the new number
3624 of sibling parms.
3626 3/ From now on, T is going to be what lookups referring to the
3627 name of TYPE will return. No lookup should return TYPE anymore.
3629 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3631 This is a subroutine of fixup_template_parms. */
3633 static tree
3635 {
3637 tree t;
3638 /* This is the decl which name is inserted into the symbol table for
3639 the template parm type. So whenever we lookup the type name, this
3640 is the DECL we get. */
3641 tree decl;
3643 /* Do not fix up the type twice. */
3658 num_parms,
3669 /* Update the type associated to the type name stored in the symbol
3670 table. Now, whenever the type name is looked up, the resulting
3671 type is properly fixed up. */
3677 }
3679 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3680 identical to I, but that is fixed up as to:
3682 1/ carry the number of sibling parms (NUM_PARMS) of the template
3683 parm represented by I.
3685 2/ replace all references to template parm types declared before I
3686 (in the same template parm list as I) by references to template
3687 parm types contained in ARGS. ARGS should contain the list of
3688 template parms that have been fixed up so far, in a form suitable
3689 to be passed to tsubst.
3691 This is a subroutine of fixup_template_parms. */
3693 static tree
3695 {
3700 /* Do not fix up the index twice. */
3710 num_parms,
3722 }
3724 /*
3725 This is a subroutine of fixup_template_parms.
3727 It computes the canonical type of the type of the template
3728 parameter PARM_DESC and update all references to that type so that
3729 they use the newly computed canonical type. No access check is
3730 performed during the fixup. PARM_DESC is a TREE_LIST which
3731 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3732 default argument of the template parm if any. IDX is the index of
3733 the template parameter, starting at 0. NUM_PARMS is the number of
3734 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3735 TREE_VEC containing the full set of template parameters in a form
3736 suitable to be passed to substs functions as their ARGS
3737 argument. This is what current_template_args returns for a given
3738 template. The innermost vector of args in ARGLIST is the set of
3739 template parms that have been fixed up so far. This function adds
3740 the fixed up parameter into that vector. */
3742 static void
3746 tree arglist)
3747 {
3754 {
3755 /* PARM is a template type parameter. Fix up its type, add
3756 the fixed-up template parm to the vector of fixed-up
3757 template parms so far, and substitute the fixed-up
3758 template parms into the default argument of this
3759 parameter. */
3760 tree t =
3765 }
3767 {
3768 /* PARM is a template template parameter. This is going to
3769 be interesting. */
3773 /* First, fix up the parms of the template template parm
3774 because the parms are involved in defining the new canonical
3775 type of the template template parm. */
3777 /* So we need to substitute the template parm types that have
3778 been fixed up so far into the template parms of this template
3779 template parm. E.g, consider this:
3781 template<class T, template<T u> class TT> class S;
3783 In this case we want to substitute T into the
3784 template parameters of TT.
3786 So let's walk the template parms of PARM here, and
3787 tsubst ARGLIST into into each of the template
3788 parms. */
3790 /* For this substitution we need to build the full set of
3791 template parameters and use that as arguments for the
3792 tsubsting function. */
3795 /* This will contain the innermost parms of PARM into which
3796 we have substituted so far. */
3800 {
3801 tree parameter;
3805 /* INNERMOST_ARGS needs to have at least the same number
3806 of elements as the index PARAMETER, ortherwise
3807 tsubsting into PARAMETER will result in partially
3808 instantiating it, reducing its tempate parm
3809 level. Let's tactically fill INNERMOST_ARGS for that
3810 purpose. */
3816 targs);
3817 }
3819 /* Now fix up the type of the template template parm. */
3826 }
3828 {
3829 /* PARM is a non-type template parameter. We need to:
3831 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3832 proper number of sibling parameters.
3834 * Make lookups of the template parameter return a reference
3835 to the fixed-up index. No lookup should return references
3836 to the former index anymore.
3838 * Substitute the template parms that got fixed up so far
3840 * into the type of PARM. */
3844 /* PUSHED_DECL is the decl added to the symbol table with
3845 the name of the parameter. E,g:
3847 template<class T, T u> //#0
3848 auto my_function(T t) -> decltype(u); //#1
3850 Here, when looking up u at //#1, we get the decl of u
3851 resulting from the declaration in #0. This is what
3852 PUSHED_DECL is. We need to replace the reference to the
3853 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3854 fixed-up TEMPLATE_PARM_INDEX. */
3857 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3858 fixup the type of PUSHED_DECL as well and luckily
3859 fixup_template_parm_index does it for us too. */
3860 tree fixed_up_index =
3865 /* Add this fixed up PARM to the template parms we've fixed
3866 up so far and use that to substitute the fixed-up
3867 template parms into the type of PARM. */
3872 }
3879 }
3881 /* Walk the current template parms and properly compute the canonical
3882 types of the dependent types created during
3883 cp_parser_template_parameter_list. */
3885 void
3887 {
3888 tree arglist;
3889 tree parameter_vec;
3890 tree fixedup_args;
3899 /* This vector contains the current innermost template parms that
3900 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3901 to be passed to tsubst* functions as their ARGS argument. */
3904 /* This vector contains the full set of template parms in a form
3905 suitable to be passed to substs functions as their ARGS
3906 argument. */
3910 /* Let's do the proper fixup now. */
3914 }
3916 /* end_template_decl is called after a template declaration is seen. */
3918 void
3920 {
3926 /* This matches the pushlevel in begin_template_parm_list. */
3931 }
3933 /* Takes a TREE_LIST representing a template parameter and convert it
3934 into an argument suitable to be passed to the type substitution
3935 functions. Note that If the TREE_LIST contains an error_mark
3936 node, the returned argument is error_mark_node. */
3938 static tree
3940 {
3953 {
3957 {
3958 /* Turn this argument into a TYPE_ARGUMENT_PACK
3959 with a single element, which expands T. */
3961 #ifdef ENABLE_CHECKING
3962 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3964 #endif
3969 }
3970 }
3971 else
3972 {
3976 {
3977 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3978 with a single element, which expands T. */
3981 #ifdef ENABLE_CHECKING
3982 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3984 #endif
3990 }
3991 }
3993 }
3995 /* Within the declaration of a template, return all levels of template
3996 parameters that apply. The template parameters are represented as
3997 a TREE_VEC, in the form documented in cp-tree.h for template
3998 arguments. */
4000 static tree
4002 {
4003 tree header;
4008 /* If there is only one level of template parameters, we do not
4009 create a TREE_VEC of TREE_VECs. Instead, we return a single
4010 TREE_VEC containing the arguments. */
4015 {
4023 #ifdef ENABLE_CHECKING
4025 #endif
4029 else
4031 }
4034 /* This can happen for template parms of a template template
4035 parameter, e.g:
4037 template<template<class T, class U> class TT> struct S;
4039 Consider the level of the parms of TT; T and U both have
4040 level 2; TT has no template parm of level 1. So in this case
4041 the first element of full_template_args is NULL_TREE. If we
4042 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4043 of 2. This will make tsubst wrongly consider that T and U
4044 have level 1. Instead, let's create a dummy vector as the
4045 first element of full_template_args so that TMPL_ARG_DEPTH
4046 returns the correct depth for args. */
4049 }
4051 /* Update the declared TYPE by doing any lookups which were thought to be
4052 dependent, but are not now that we know the SCOPE of the declarator. */
4054 tree
4056 {
4067 /* Don't bother building up the args in this case. */
4069 {
4070 /* tsubst in the args corresponding to the template parameters,
4071 including auto if present. Most things will be unchanged, but
4072 make_typename_type and tsubst_qualified_id will resolve
4073 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4076 tree pushed;
4078 {
4082 }
4087 }
4093 {
4096 else
4098 }
4100 }
4102 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4103 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4104 a member template. Used by push_template_decl below. */
4106 static tree
4108 {
4115 }
4117 struct template_parm_data
4118 {
4119 /* The level of the template parameters we are currently
4120 processing. */
4123 /* The index of the specialization argument we are currently
4124 processing. */
4127 /* An array whose size is the number of template parameters. The
4128 elements are nonzero if the parameter has been used in any one
4129 of the arguments processed so far. */
4132 /* An array whose size is the number of template arguments. The
4133 elements are nonzero if the argument makes use of template
4134 parameters of this level. */
4136 };
4138 /* Subroutine of push_template_decl used to see if each template
4139 parameter in a partial specialization is used in the explicit
4140 argument list. If T is of the LEVEL given in DATA (which is
4141 treated as a template_parm_data*), then DATA->PARMS is marked
4142 appropriately. */
4144 static int
4146 {
4152 {
4155 }
4156 else
4157 {
4160 }
4163 {
4166 }
4168 /* Return zero so that for_each_template_parm will continue the
4169 traversal of the tree; we want to mark *every* template parm. */
4171 }
4173 /* Process the partial specialization DECL. */
4175 static tree
4177 {
4183 tree inner_parms;
4184 tree inst;
4197 /* We check that each of the template parameters given in the
4198 partial specialization is used in the argument list to the
4199 specialization. For example:
4201 template <class T> struct S;
4202 template <class T> struct S<T*>;
4204 The second declaration is OK because `T*' uses the template
4205 parameter T, whereas
4207 template <class T> struct S<int>;
4209 is no good. Even trickier is:
4211 template <class T>
4212 struct S1
4213 {
4214 template <class U>
4215 struct S2;
4216 template <class U>
4217 struct S2<T>;
4218 };
4220 The S2<T> declaration is actually invalid; it is a
4221 full-specialization. Of course,
4223 template <class U>
4224 struct S2<T (*)(U)>;
4226 or some such would have been OK. */
4234 {
4239 NULL,
4241 }
4244 {
4245 /* One of the template parms was not used in the
4246 specialization. */
4248 {
4251 }
4254 }
4259 /* [temp.class.spec]
4261 The argument list of the specialization shall not be identical to
4262 the implicit argument list of the primary template. */
4269 /* [temp.class.spec]
4271 A partially specialized non-type argument expression shall not
4272 involve template parameters of the partial specialization except
4273 when the argument expression is a simple identifier.
4275 The type of a template parameter corresponding to a specialized
4276 non-type argument shall not be dependent on a parameter of the
4277 specialization.
4279 Also, we verify that pack expansions only occur at the
4280 end of the argument list. */
4284 {
4291 {
4292 /* Extract the arguments from the argument pack. We'll be
4293 iterating over these in the following loop. */
4296 }
4299 {
4301 /* Get the Jth argument in the parameter pack. */
4305 {
4306 /* Pack expansions must come at the end of the
4307 argument list. */
4310 {
4314 else
4317 }
4318 }
4321 /* We only care about the pattern. */
4327 /* This next line is the `argument expression is not just a
4328 simple identifier' condition and also the `specialized
4329 non-type argument' bit. */
4331 {
4335 arg);
4336 else
4337 {
4338 /* Look at the corresponding template parameter,
4339 marking which template parameters its type depends
4340 upon. */
4344 {
4345 /* We haven't yet initialized TPD2. Do so now. */
4347 /* The number of parameters here is the number in the
4348 main template, which, as checked in the assertion
4349 above, is NARGS. */
4353 }
4355 /* Mark the template parameters. But this time, we're
4356 looking for the template parameters of the main
4357 template, not in the specialization. */
4364 NULL,
4368 {
4369 /* The type depended on some template parameters.
4370 If they are fully specialized in the
4371 specialization, that's OK. */
4380 "type %qT of template argument %qE depends "
4382 "type %qT of template argument %qE depends "
4384 type,
4385 arg);
4386 }
4387 }
4388 }
4389 }
4390 }
4392 /* We should only get here once. */
4402 {
4406 {
4410 "partial specialization of %qT after instantiation "
4412 }
4413 }
4416 }
4418 /* Check that a template declaration's use of default arguments and
4419 parameter packs is not invalid. Here, PARMS are the template
4420 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4421 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4422 specialization.
4425 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4426 declaration (but not a definition); 1 indicates a declaration, 2
4427 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4428 emitted for extraneous default arguments.
4430 Returns TRUE if there were no errors found, FALSE otherwise. */
4432 bool
4435 {
4438 tree parm_level;
4441 /* [temp.param]
4443 A default template-argument shall not be specified in a
4444 function template declaration or a function template definition, nor
4445 in the template-parameter-list of the definition of a member of a
4446 class template. */
4449 /* You can't have a function template declaration in a local
4450 scope, nor you can you define a member of a class template in a
4451 local scope. */
4458 /* If this is either a friend defined in the scope of the class
4459 or a member function. */
4465 /* And, if it was a member function, it really was defined in
4466 the scope of the class. */
4469 /* We already checked these parameters when the template was
4470 declared, so there's no need to do it again now. This function
4471 was defined in class scope, but we're processing it's body now
4472 that the class is complete. */
4475 /* Core issue 226 (C++0x only): the following only applies to class
4476 templates. */
4478 {
4479 /* [temp.param]
4481 If a template-parameter has a default template-argument, all
4482 subsequent template-parameters shall have a default
4483 template-argument supplied. */
4485 {
4492 {
4502 {
4504 /* For better subsequent error-recovery, we indicate that
4505 there should have been a default argument. */
4508 }
4510 && !is_partial
4511 && !is_friend_decl
4512 /* Don't complain about an enclosing partial
4513 specialization. */
4518 {
4519 /* A primary class template can only have one
4520 parameter pack, at the end of the template
4521 parameter list. */
4526 else
4534 }
4535 }
4536 }
4537 }
4540 || is_partial
4541 || !is_primary
4543 /* For an ordinary class template, default template arguments are
4544 allowed at the innermost level, e.g.:
4545 template <class T = int>
4546 struct S {};
4547 but, in a partial specialization, they're not allowed even
4548 there, as we have in [temp.class.spec]:
4550 The template parameter list of a specialization shall not
4551 contain default template argument values.
4553 So, for a partial specialization, or for a function template
4554 (in C++98/C++03), we look at all of them. */
4555 ;
4556 else
4557 /* But, for a primary class template that is not a partial
4558 specialization we look at all template parameters except the
4559 innermost ones. */
4562 /* Figure out what error message to issue. */
4575 else
4579 /* If we're inside a class definition, there's no need to
4580 examine the parameters to the class itself. On the one
4581 hand, they will be checked when the class is defined, and,
4582 on the other, default arguments are valid in things like:
4583 template <class T = double>
4584 struct S { template <class U> void f(U); };
4585 Here the default argument for `S' has no bearing on the
4586 declaration of `f'. */
4588 else
4589 /* Check everything. */
4595 {
4602 {
4607 {
4609 {
4616 }
4618 /* Clear out the default argument so that we are not
4619 confused later. */
4621 }
4622 }
4624 /* At this point, if we're still interested in issuing messages,
4625 they must apply to classes surrounding the object declared. */
4629 }
4632 }
4634 /* Worker for push_template_decl_real, called via
4635 for_each_template_parm. DATA is really an int, indicating the
4636 level of the parameters we are interested in. If T is a template
4637 parameter of that level, return nonzero. */
4639 static int
4641 {
4647 else
4650 }
4652 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4653 parameters given by current_template_args, or reuses a
4654 previously existing one, if appropriate. Returns the DECL, or an
4655 equivalent one, if it is replaced via a call to duplicate_decls.
4657 If IS_FRIEND is true, DECL is a friend declaration. */
4659 tree
4661 {
4662 tree tmpl;
4663 tree args;
4664 tree info;
4665 tree ctx;
4669 /* True if the template is a member template, in the sense of
4670 [temp.mem]. */
4676 /* See if this is a partial specialization. */
4685 /* For a friend, we want the context of the friend function, not
4686 the type of which it is a friend. */
4690 /* In the case of a virtual function, we want the class in which
4691 it is defined. */
4693 else
4694 /* Otherwise, if we're currently defining some class, the DECL
4695 is assumed to be a member of the class. */
4704 /* See if this is a primary template. */
4706 /* A friend template that specifies a class context, i.e.
4707 template <typename T> friend void A<T>::f();
4708 is not primary. */
4710 else
4714 {
4719 {
4722 }
4724 {
4726 {
4727 /* [temp.mem]
4729 A destructor shall not be a member template. */
4732 }
4739 {
4740 /* [basic.stc.dynamic.allocation]
4742 An allocation function can be a function
4743 template. ... Template allocation functions shall
4744 have two or more parameters. */
4747 }
4748 }
4752 else
4753 {
4756 }
4757 }
4759 /* Check to see that the rules regarding the use of default
4760 arguments are not being violated. */
4764 /* Ensure that there are no parameter packs in the type of this
4765 declaration that have not been expanded. */
4767 {
4768 /* Check each of the arguments individually to see if there are
4769 any bare parameter packs. */
4775 {
4778 {
4779 /* This is a PARM_DECL that contains unexpanded parameter
4780 packs. We have already complained about this in the
4781 check_for_bare_parameter_packs call, so just replace
4782 these types with ERROR_MARK_NODE. */
4785 }
4789 }
4791 /* Check for bare parameter packs in the return type and the
4792 exception specifiers. */
4794 /* Errors were already issued, set return type to int
4795 as the frontend doesn't expect error_mark_node as
4796 the return type. */
4800 }
4802 {
4805 }
4816 {
4821 /* If DECL is a TYPE_DECL for a class-template, then there won't
4822 be DECL_LANG_SPECIFIC. The information equivalent to
4823 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4827 {
4828 /* Since a template declaration already existed for this
4829 class-type, we must be redeclaring it here. Make sure
4830 that the redeclaration is valid. */
4832 current_template_parms);
4833 /* We don't need to create a new TEMPLATE_DECL; just use the
4834 one we already had. */
4836 }
4837 else
4838 {
4840 member_template_p);
4845 {
4846 /* A specialization of a member template of a template
4847 class. */
4851 }
4852 }
4853 }
4854 else
4855 {
4861 {
4864 }
4872 {
4873 tree new_tmpl;
4875 /* The declaration is a specialization of a member
4876 template, declared outside the class. Therefore, the
4877 innermost template arguments will be NULL, so we
4878 replace them with the arguments determined by the
4879 earlier call to check_explicit_specialization. */
4882 new_tmpl
4884 member_template_p);
4894 args,
4897 }
4899 /* Make sure the template headers we got make sense. */
4904 {
4907 }
4908 else
4910 {
4915 {
4919 else
4924 }
4929 /* Can happen in erroneous input. */
4931 else
4935 }
4937 /* Check that the parms are used in the appropriate qualifying scopes
4938 in the declarator. */
4942 {
4948 /* Avoid crash in import_export_decl. */
4951 }
4952 }
4957 /* Push template declarations for global functions and types. Note
4958 that we do not try to push a global template friend declared in a
4959 template class; such a thing may well depend on the template
4960 parameters of the class. */
4963 {
4968 /* Hide template friend classes that haven't been declared yet. */
4970 {
4973 }
4974 }
4977 {
4983 {
4986 /* It is a conversion operator. See if the type converted to
4987 depends on innermost template operands. */
4990 depth))
4992 }
4994 /* Give template template parms a DECL_CONTEXT of the template
4995 for which they are a parameter. */
4998 {
5002 }
5003 }
5005 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5006 back to its most general template. If TMPL is a specialization,
5007 ARGS may only have the innermost set of arguments. Add the missing
5008 argument levels if necessary. */
5020 }
5022 tree
5024 {
5026 }
5028 /* Called when a class template TYPE is redeclared with the indicated
5029 template PARMS, e.g.:
5031 template <class T> struct S;
5032 template <class T> struct S {}; */
5034 bool
5036 {
5037 tree tmpl;
5038 tree tmpl_parms;
5042 {
5045 }
5049 /* The type is nested in some template class. Nothing to worry
5050 about here; there are no new template parameters for the nested
5051 type. */
5055 {
5057 tmpl);
5059 }
5065 {
5075 }
5078 {
5079 tree tmpl_parm;
5080 tree parm;
5081 tree tmpl_default;
5082 tree parm_default;
5096 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5097 TEMPLATE_DECL. */
5107 {
5111 }
5114 {
5115 /* We have in [temp.param]:
5117 A template-parameter may not be given default arguments
5118 by two different declarations in the same scope. */
5123 }
5126 /* Update the previous template parameters (which are the ones
5127 that will really count) with the new default value. */
5130 /* Update the new parameters, too; they'll be used as the
5131 parameters for any members. */
5133 }
5136 }
5138 /* Simplify EXPR if it is a non-dependent expression. Returns the
5139 (possibly simplified) expression. */
5141 static tree
5143 {
5147 /* If we're in a template, but EXPR isn't value dependent, simplify
5148 it. We're supposed to treat:
5150 template <typename T> void f(T[1 + 1]);
5151 template <typename T> void f(T[2]);
5153 as two declarations of the same function, for example. */
5158 {
5159 HOST_WIDE_INT saved_processing_template_decl;
5165 complain,
5170 }
5172 }
5174 tree
5176 {
5178 }
5180 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5181 must be a function or a pointer-to-function type, as specified
5182 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5183 and check that the resulting function has external linkage. */
5185 static tree
5187 {
5201 /* [temp.arg.nontype]/1
5203 A template-argument for a non-type, non-template template-parameter
5204 shall be one of:
5205 [...]
5206 -- the address of an object or function with external linkage. */
5208 {
5213 }
5216 }
5218 /* Subroutine of convert_nontype_argument.
5219 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5220 Emit an error otherwise. */
5222 static bool
5224 tsubst_flags_t complain)
5225 {
5230 {
5234 }
5236 }
5238 /* Returns TRUE iff the address of OP is value-dependent.
5240 14.6.2.4 [temp.dep.temp]:
5241 A non-integral non-type template-argument is dependent if its type is
5242 dependent or it has either of the following forms
5243 qualified-id
5244 & qualified-id
5245 and contains a nested-name-specifier which specifies a class-name that
5246 names a dependent type.
5248 We generalize this to just say that the address of a member of a
5249 dependent class is value-dependent; the above doesn't cover the
5250 address of a static data member named with an unqualified-id. */
5252 static bool
5254 {
5255 /* We could use get_inner_reference here, but there's no need;
5256 this is only relevant for template non-type arguments, which
5257 can only be expressed as &id-expression. */
5259 {
5263 }
5266 }
5268 /* Attempt to convert the non-type template parameter EXPR to the
5269 indicated TYPE. If the conversion is successful, return the
5270 converted value. If the conversion is unsuccessful, return
5271 NULL_TREE if we issued an error message, or error_mark_node if we
5272 did not. We issue error messages for out-and-out bad template
5273 parameters, but not simply because the conversion failed, since we
5274 might be just trying to do argument deduction. Both TYPE and EXPR
5275 must be non-dependent.
5277 The conversion follows the special rules described in
5278 [temp.arg.nontype], and it is much more strict than an implicit
5279 conversion.
5281 This function is called twice for each template argument (see
5282 lookup_template_class for a more accurate description of this
5283 problem). This means that we need to handle expressions which
5284 are not valid in a C++ source, but can be created from the
5285 first call (for instance, casts to perform conversions). These
5286 hacks can go away after we fix the double coercion problem. */
5288 static tree
5290 {
5291 tree expr_type;
5293 /* Detect immediately string literals as invalid non-type argument.
5294 This special-case is not needed for correctness (we would easily
5295 catch this later), but only to provide better diagnostic for this
5296 common user mistake. As suggested by DR 100, we do not mention
5297 linkage issues in the diagnostic as this is not the point. */
5298 /* FIXME we're making this OK. */
5300 {
5306 }
5308 /* Add the ADDR_EXPR now for the benefit of
5309 value_dependent_expression_p. */
5314 /* If we are in a template, EXPR may be non-dependent, but still
5315 have a syntactic, rather than semantic, form. For example, EXPR
5316 might be a SCOPE_REF, rather than the VAR_DECL to which the
5317 SCOPE_REF refers. Preserving the qualifying scope is necessary
5318 so that access checking can be performed when the template is
5319 instantiated -- but here we need the resolved form so that we can
5320 convert the argument. */
5331 else
5334 /* HACK: Due to double coercion, we can get a
5335 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5336 which is the tree that we built on the first call (see
5337 below when coercing to reference to object or to reference to
5338 function). We just strip everything and get to the arg.
5339 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5340 for examples. */
5342 {
5344 {
5345 /* ??? Maybe we could use convert_from_reference here, but we
5346 would need to relax its constraints because the NOP_EXPR
5347 could actually change the type to something more cv-qualified,
5348 and this is not folded by convert_from_reference. */
5359 }
5361 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5362 parameter is a pointer to object, through decay and
5363 qualification conversion. Let's strip everything. */
5365 {
5369 /* Skip the ADDR_EXPR only if it is part of the decay for
5370 an array. Otherwise, it is part of the original argument
5371 in the source code. */
5375 }
5376 }
5378 /* [temp.arg.nontype]/5, bullet 1
5380 For a non-type template-parameter of integral or enumeration type,
5381 integral promotions (_conv.prom_) and integral conversions
5382 (_conv.integral_) are applied. */
5384 {
5393 /* Notice that there are constant expressions like '4 % 0' which
5394 do not fold into integer constants. */
5396 {
5398 {
5406 /* else cxx_constant_value complained but gave us
5407 a real constant, so go ahead. */
5409 }
5410 else
5412 }
5413 }
5414 /* [temp.arg.nontype]/5, bullet 2
5416 For a non-type template-parameter of type pointer to object,
5417 qualification conversions (_conv.qual_) and the array-to-pointer
5418 conversion (_conv.array_) are applied. */
5420 {
5421 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5423 A template-argument for a non-type, non-template template-parameter
5424 shall be one of: [...]
5426 -- the name of a non-type template-parameter;
5427 -- the address of an object or function with external linkage, [...]
5428 expressed as "& id-expression" where the & is optional if the name
5429 refers to a function or array, or if the corresponding
5430 template-parameter is a reference.
5432 Here, we do not care about functions, as they are invalid anyway
5433 for a parameter of type pointer-to-object. */
5436 /* Non-type template parameters are OK. */
5437 ;
5440 {
5442 {
5444 "because %qD is a variable, not the address of "
5448 }
5449 /* Other values, like integer constants, might be valid
5450 non-type arguments of some other type. */
5452 }
5453 else
5454 {
5455 tree decl;
5460 {
5465 }
5467 {
5472 }
5473 }
5482 }
5483 /* [temp.arg.nontype]/5, bullet 3
5485 For a non-type template-parameter of type reference to object, no
5486 conversions apply. The type referred to by the reference may be more
5487 cv-qualified than the (otherwise identical) type of the
5488 template-argument. The template-parameter is bound directly to the
5489 template-argument, which must be an lvalue. */
5491 {
5493 expr_type))
5497 {
5501 }
5504 {
5508 }
5510 /* [temp.arg.nontype]/1
5512 A template-argument for a non-type, non-template template-parameter
5513 shall be one of: [...]
5515 -- the address of an object or function with external linkage. */
5518 {
5521 {
5523 "because a reference variable does not have a constant "
5526 }
5527 }
5530 {
5535 }
5538 {
5543 }
5546 }
5547 /* [temp.arg.nontype]/5, bullet 4
5549 For a non-type template-parameter of type pointer to function, only
5550 the function-to-pointer conversion (_conv.func_) is applied. If the
5551 template-argument represents a set of overloaded functions (or a
5552 pointer to such), the matching function is selected from the set
5553 (_over.over_). */
5555 {
5556 /* If the argument is a template-id, we might not have enough
5557 context information to decay the pointer. */
5559 {
5563 }
5570 {
5574 }
5575 }
5576 /* [temp.arg.nontype]/5, bullet 5
5578 For a non-type template-parameter of type reference to function, no
5579 conversions apply. If the template-argument represents a set of
5580 overloaded functions, the matching function is selected from the set
5581 (_over.over_). */
5583 {
5585 {
5590 }
5597 }
5598 /* [temp.arg.nontype]/5, bullet 6
5600 For a non-type template-parameter of type pointer to member function,
5601 no conversions apply. If the template-argument represents a set of
5602 overloaded member functions, the matching member function is selected
5603 from the set (_over.over_). */
5605 {
5610 /* [temp.arg.nontype] bullet 1 says the pointer to member
5611 expression must be a pointer-to-member constant. */
5615 /* There is no way to disable standard conversions in
5616 resolve_address_of_overloaded_function (called by
5617 instantiate_type). It is possible that the call succeeded by
5618 converting &B::I to &D::I (where B is a base of D), so we need
5619 to reject this conversion here.
5621 Actually, even if there was a way to disable standard conversions,
5622 it would still be better to reject them here so that we can
5623 provide a superior diagnostic. */
5625 {
5629 /* If we are just one standard conversion off, explain. */
5634 }
5635 }
5636 /* [temp.arg.nontype]/5, bullet 7
5638 For a non-type template-parameter of type pointer to data member,
5639 qualification conversions (_conv.qual_) are applied. */
5641 {
5642 /* [temp.arg.nontype] bullet 1 says the pointer to member
5643 expression must be a pointer-to-member constant. */
5650 }
5651 /* A template non-type parameter must be one of the above. */
5652 else
5655 /* Sanity check: did we actually convert the argument to the
5656 right type? */
5660 }
5662 /* Subroutine of coerce_template_template_parms, which returns 1 if
5663 PARM_PARM and ARG_PARM match using the rule for the template
5664 parameters of template template parameters. Both PARM and ARG are
5665 template parameters; the rest of the arguments are the same as for
5666 coerce_template_template_parms.
5667 */
5668 static int
5670 tree arg,
5671 tsubst_flags_t complain,
5672 tree in_decl,
5673 tree outer_args)
5674 {
5683 {
5685 /* We encounter instantiations of templates like
5686 template <template <template <class> class> class TT>
5687 class C; */
5688 {
5695 }
5696 /* Fall through. */
5701 /* Argument is a parameter pack but parameter is not. */
5706 /* The tsubst call is used to handle cases such as
5708 template <int> class C {};
5709 template <class T, template <T> class TT> class D {};
5710 D<int, C> d;
5712 i.e. the parameter list of TT depends on earlier parameters. */
5714 && !same_type_p
5721 /* Argument is a parameter pack but parameter is not. */
5728 }
5731 }
5734 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5735 template template parameters. Both PARM_PARMS and ARG_PARMS are
5736 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5737 or PARM_DECL.
5739 Consider the example:
5740 template <class T> class A;
5741 template<template <class U> class TT> class B;
5743 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5744 the parameters to A, and OUTER_ARGS contains A. */
5746 static int
5748 tree arg_parms,
5749 tsubst_flags_t complain,
5750 tree in_decl,
5751 tree outer_args)
5752 {
5763 /* Determine whether we have a parameter pack at the end of the
5764 template template parameter's template parameter list. */
5766 {
5773 {
5787 }
5788 }
5794 /* Check all of the template parameters except the parameter pack at
5795 the end (if any). */
5797 {
5806 outer_args))
5809 }
5812 {
5813 /* Check each of the template parameters in the template
5814 argument against the template parameter pack at the end of
5815 the template template parameter. */
5822 {
5829 outer_args))
5831 }
5832 }
5835 }
5837 /* Verifies that the deduced template arguments (in TARGS) for the
5838 template template parameters (in TPARMS) represent valid bindings,
5839 by comparing the template parameter list of each template argument
5840 to the template parameter list of its corresponding template
5841 template parameter, in accordance with DR150. This
5842 routine can only be called after all template arguments have been
5843 deduced. It will return TRUE if all of the template template
5844 parameter bindings are okay, FALSE otherwise. */
5845 bool
5847 {
5851 /* We're dealing with template parms in this process. */
5857 {
5862 {
5867 {
5868 /* Look inside the argument pack. */
5871 }
5874 {
5878 /* Extract the next argument from the argument
5879 pack. */
5883 /* Look at the pattern of the pack expansion. */
5886 /* Extract the template parameters from the template
5887 argument. */
5893 /* Verify that we can coerce the template template
5894 parameters from the template argument to the template
5895 parameter. This requires an exact match. */
5897 && !coerce_template_template_parms
5899 targ_parms,
5900 tf_none,
5901 tparm,
5902 targs))
5903 {
5906 }
5907 }
5908 }
5909 }
5911 out:
5915 }
5917 /* Convert the indicated template ARG as necessary to match the
5918 indicated template PARM. Returns the converted ARG, or
5919 error_mark_node if the conversion was unsuccessful. Error and
5920 warning messages are issued under control of COMPLAIN. This
5921 conversion is for the Ith parameter in the parameter list. ARGS is
5922 the full set of template arguments deduced so far. */
5924 static tree
5926 tree arg,
5927 tree args,
5928 tsubst_flags_t complain,
5930 tree in_decl)
5931 {
5932 tree orig_arg;
5933 tree val;
5938 {
5939 /* The template argument was the name of some
5940 member function. That's usually
5941 invalid, but static members are OK. In any
5942 case, grab the underlying fields/functions
5943 and issue an error later if required. */
5946 }
5954 /* When determining whether an argument pack expansion is a template,
5955 look at the pattern. */
5959 /* Deal with an injected-class-name used as a template template arg. */
5961 {
5964 {
5974 }
5975 }
5977 is_tmpl_type =
5992 {
5998 typename_type,
6002 }
6004 {
6006 {
6008 {
6018 else
6020 }
6021 }
6023 }
6025 {
6027 {
6033 else
6035 }
6037 }
6040 {
6042 {
6044 /* The number of argument required is not known yet.
6045 Just accept it for now. */
6047 else
6048 {
6050 tree argparm;
6056 args))
6057 {
6060 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6061 TEMPLATE_DECL. */
6063 {
6068 }
6069 }
6070 else
6071 {
6073 {
6079 }
6082 }
6083 }
6084 }
6085 else
6087 /* We only form one instance of each template specialization.
6088 Therefore, if we use a non-canonical variant (i.e., a
6089 typedef), any future messages referring to the type will use
6090 the typedef, which is confusing if those future uses do not
6091 themselves also use the typedef. */
6094 }
6095 else
6096 {
6103 {
6106 else
6107 {
6108 /* Not sure if this is reachable, but it doesn't hurt
6109 to be robust. */
6112 }
6113 }
6115 /* We used to call digest_init here. However, digest_init
6116 will report errors, which we don't want when complain
6117 is zero. More importantly, digest_init will try too
6118 hard to convert things: for example, `0' should not be
6119 converted to pointer type at this point according to
6120 the standard. Accepting this is not merely an
6121 extension, since deciding whether or not these
6122 conversions can occur is part of determining which
6123 function template to call, or whether a given explicit
6124 argument specification is valid. */
6126 else
6135 {
6136 /* Strip typedefs from the SCOPE_REF. */
6141 }
6142 }
6145 }
6147 /* Coerces the remaining template arguments in INNER_ARGS (from
6148 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6149 Returns the coerced argument pack. PARM_IDX is the position of this
6150 parameter in the template parameter list. ARGS is the original
6151 template argument list. */
6152 static tree
6155 tree args,
6156 tree inner_args,
6158 tree new_args,
6160 tree in_decl,
6161 tsubst_flags_t complain)
6162 {
6165 tree packed_args;
6166 tree argument_pack;
6176 {
6177 /* When the template parameter is a non-type template
6178 parameter pack whose type uses parameter packs, we need
6179 to look at each of the template arguments
6180 separately. Build a vector of the types for these
6181 non-type template parameters in PACKED_TYPES. */
6182 tree expansion
6190 /* Check that we have the right number of arguments. */
6194 {
6195 int needed_parms
6200 }
6202 /* If we aren't able to check the actual arguments now
6203 (because they haven't been expanded yet), we can at least
6204 verify that all of the types used for the non-type
6205 template parameter pack are, in fact, valid for non-type
6206 template parameters. */
6209 {
6212 {
6216 }
6217 }
6218 }
6220 /* Convert the remaining arguments, which will be a part of the
6221 parameter pack "parm". */
6223 {
6228 {
6229 /* When we have a vector of types (corresponding to the
6230 non-type template parameter pack that uses parameter
6231 packs in its type, as mention above), and the
6232 argument is not an expansion (which expands to a
6233 currently unknown number of arguments), clone the
6234 parm and give it the next type in PACKED_TYPES. */
6238 }
6243 in_decl);
6247 }
6252 else
6253 {
6258 }
6261 #ifdef ENABLE_CHECKING
6264 #endif
6266 }
6268 /* Convert all template arguments to their appropriate types, and
6269 return a vector containing the innermost resulting template
6270 arguments. If any error occurs, return error_mark_node. Error and
6271 warning messages are issued under control of COMPLAIN.
6273 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6274 for arguments not specified in ARGS. Otherwise, if
6275 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6276 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6277 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6278 ARGS. */
6280 static tree
6282 tree args,
6283 tree in_decl,
6284 tsubst_flags_t complain,
6287 {
6289 tree inner_args;
6290 tree new_args;
6291 tree new_inner_args;
6295 /* When used as a boolean value, indicates whether this is a
6296 variadic template parameter list. Since it's an int, we can also
6297 subtract it from nparms to get the number of non-variadic
6298 parameters. */
6306 /* Determine if there are any parameter packs. */
6308 {
6312 }
6315 /* If there are 0 or 1 parameter packs, we need to expand any argument
6316 packs so that we can deduce a parameter pack from some non-packed args
6317 followed by an argument pack, as in variadic85.C. If there are more
6318 than that, we need to leave argument packs intact so the arguments are
6319 assigned to the right parameter packs. This should only happen when
6320 dealing with a nested class inside a partial specialization of a class
6321 template, as in variadic92.C. */
6328 && require_all_args
6329 && (!use_default_args
6332 {
6334 {
6336 {
6340 }
6341 else
6347 }
6350 }
6352 /* We need to evaluate the template arguments, even though this
6353 template-id may be nested within a "sizeof". */
6361 {
6362 tree arg;
6363 tree parm;
6365 /* Get the Ith template parameter. */
6369 {
6372 }
6374 /* Calculate the next argument. */
6377 else
6382 {
6383 /* All remaining arguments will be placed in the
6384 template parameter pack PARM. */
6390 /* Store this argument. */
6392 lost++;
6395 /* We are done with all of the arguments. */
6399 }
6401 {
6403 {
6405 {
6406 /* FIXME this restriction was removed by N2555; see
6407 bug 35722. */
6408 /* If ARG is a pack expansion, but PARM is not a
6409 template parameter pack (if it were, we would have
6410 handled it above), we're trying to expand into a
6411 fixed-length argument list. */
6415 else
6418 }
6420 }
6421 }
6423 {
6424 /* There must be a default arg in this case. */
6427 /* The position of the first default template argument,
6428 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6429 Record that. */
6432 }
6433 else
6437 {
6440 }
6442 /* This only occurs if there was an error in the template
6443 parameter list itself (which we would already have
6444 reported) that we are trying to recover from, e.g., a class
6445 template with a parameter list such as
6446 template<typename..., typename>. */
6448 else
6454 lost++;
6456 }
6463 #ifdef ENABLE_CHECKING
6467 #endif
6470 }
6472 /* Returns 1 if template args OT and NT are equivalent. */
6474 static int
6476 {
6481 /* For member templates */
6488 {
6505 }
6507 {
6508 /* We get here probably because we are in the middle of substituting
6509 into the pattern of a pack expansion. In that case the
6510 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6511 interested in. So we want to use the initial pack argument for
6512 the comparison. */
6517 }
6522 else
6524 }
6526 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6527 of template arguments. Returns 0 otherwise. */
6529 int
6531 {
6538 {
6544 }
6546 }
6548 static void
6550 {
6560 /* We are called both from instantiate_decl, where we've already had a
6561 tinst_level pushed, and instantiate_template, where we haven't.
6562 Compensate. */
6573 else
6582 }
6585 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6586 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6587 documentation for TEMPLATE_ID_EXPR. */
6589 tree
6591 {
6592 tree type;
6602 {
6604 unknown_type_node,
6606 arglist);
6608 }
6615 }
6617 /* Within the scope of a template class S<T>, the name S gets bound
6618 (in build_self_reference) to a TYPE_DECL for the class, not a
6619 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6620 or one of its enclosing classes, and that type is a template,
6621 return the associated TEMPLATE_DECL. Otherwise, the original
6622 DECL is returned.
6624 Also handle the case when DECL is a TREE_LIST of ambiguous
6625 injected-class-names from different bases. */
6627 tree
6629 {
6633 /* DR 176: A lookup that finds an injected-class-name (10.2
6634 [class.member.lookup]) can result in an ambiguity in certain cases
6635 (for example, if it is found in more than one base class). If all of
6636 the injected-class-names that are found refer to specializations of
6637 the same class template, and if the name is followed by a
6638 template-argument-list, the reference refers to the class template
6639 itself and not a specialization thereof, and is not ambiguous. */
6641 {
6644 {
6650 }
6653 else
6655 }
6661 }
6663 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6664 parameters, find the desired type.
6666 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6668 IN_DECL, if non-NULL, is the template declaration we are trying to
6669 instantiate.
6671 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6672 the class we are looking up.
6674 Issue error and warning messages under control of COMPLAIN.
6676 If the template class is really a local class in a template
6677 function, then the FUNCTION_CONTEXT is the function in which it is
6678 being instantiated.
6680 ??? Note that this function is currently called *twice* for each
6681 template-id: the first time from the parser, while creating the
6682 incomplete type (finish_template_type), and the second type during the
6683 real instantiation (instantiate_template_class). This is surely something
6684 that we want to avoid. It also causes some problems with argument
6685 coercion (see convert_nontype_argument for more information on this). */
6687 static tree
6690 {
6692 tree t;
6695 spec_entry elt;
6696 hashval_t hash;
6699 {
6703 else
6704 {
6711 }
6714 }
6716 {
6719 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6720 an implicit typename for the second A. Deal with it. */
6725 {
6728 }
6729 }
6732 {
6735 }
6739 {
6743 }
6745 /* Issue an error message if we didn't find a template. */
6747 {
6751 }
6754 /* Make sure it's a user visible template, if it was named by
6755 the user. */
6758 {
6760 {
6764 }
6766 }
6771 {
6772 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6773 template arguments */
6775 tree parm;
6776 tree arglist2;
6777 tree outer;
6781 /* Consider an example where a template template parameter declared as
6783 template <class T, class U = std::allocator<T> > class TT
6785 The template parameter level of T and U are one level larger than
6786 of TT. To proper process the default argument of U, say when an
6787 instantiation `TT<int>' is seen, we need to build the full
6788 arguments containing {int} as the innermost level. Outer levels,
6789 available when not appearing as default template argument, can be
6790 obtained from the arguments of the enclosing template.
6792 Suppose that TT is later substituted with std::vector. The above
6793 instantiation is `TT<int, std::allocator<T> >' with TT at
6794 level 1, and T at level 2, while the template arguments at level 1
6795 becomes {std::vector} and the inner level 2 is {int}. */
6801 /* This is an argument of the current template, so we haven't set
6802 DECL_CONTEXT yet. */
6809 complain,
6819 }
6820 else
6821 {
6823 tree gen_tmpl;
6824 tree type_decl;
6837 {
6838 /* We've been given an incomplete set of template arguments.
6839 For example, given:
6841 template <class T> struct S1 {
6842 template <class U> struct S2 {};
6843 template <class U> struct S2<U*> {};
6844 };
6846 we will be called with an ARGLIST of `U*', but the
6847 TEMPLATE will be `template <class T> template
6848 <class U> struct S1<T>::S2'. We must fill in the missing
6849 arguments. */
6850 arglist
6852 arglist);
6854 }
6856 /* Now we should have enough arguments. */
6859 /* From here on, we're only interested in the most general
6860 template. */
6862 /* Calculate the BOUND_ARGS. These will be the args that are
6863 actually tsubst'd into the definition to create the
6864 instantiation. */
6866 {
6867 /* We have multiple levels of arguments to coerce, at once. */
6877 {
6878 tree a;
6882 complain,
6885 else
6886 /* Outer levels should have already been coerced. */
6889 /* Don't process further if one of the levels fails. */
6891 {
6892 /* Restore the ARGLIST to its full size. */
6895 }
6899 /* We temporarily reduce the length of the ARGLIST so
6900 that coerce_template_parms will see only the arguments
6901 corresponding to the template parameters it is
6902 examining. */
6904 }
6906 /* Restore the ARGLIST to its full size. */
6910 }
6911 else
6912 arglist
6915 gen_tmpl,
6916 complain,
6921 /* We were unable to bind the arguments. */
6924 /* In the scope of a template class, explicit references to the
6925 template class refer to the type of the template, not any
6926 instantiation of it. For example, in:
6928 template <class T> class C { void f(C<T>); }
6930 the `C<T>' is just the same as `C'. Outside of the
6931 class, however, such a reference is an instantiation. */
6935 /* comp_template_args is expensive, check it last. */
6937 arglist))
6940 /* If we already have this specialization, return it. */
6952 /* If the deduced arguments are invalid, then the binding
6953 failed. */
6957 complain))
6964 {
6969 }
6976 /* Create the type. */
6978 {
6980 {
6986 }
6987 else
6988 {
6989 /* We don't want to call start_enum for this type, since
6990 the values for the enumeration constants may involve
6991 template parameters. And, no one should be interested
6992 in the enumeration constants for such a type. */
6995 }
6999 }
7000 else
7001 {
7008 /* A local class. Make sure the decl gets registered properly. */
7013 /* This instantiation is another name for the primary
7014 template type. Set the TYPE_CANONICAL field
7015 appropriately. */
7018 /* Some of the template arguments require structural
7019 equality testing, so this template class requires
7020 structural equality testing. */
7022 }
7024 /* If we called start_enum or pushtag above, this information
7025 will already be set up. */
7027 {
7034 }
7035 else
7043 {
7046 }
7048 /* Let's consider the explicit specialization of a member
7049 of a class template specialization that is implicitely instantiated,
7050 e.g.:
7051 template<class T>
7052 struct S
7053 {
7054 template<class U> struct M {}; //#0
7055 };
7057 template<>
7058 template<>
7059 struct S<int>::M<char> //#1
7060 {
7061 int i;
7062 };
7063 [temp.expl.spec]/4 says this is valid.
7065 In this case, when we write:
7066 S<int>::M<char> m;
7068 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7069 the one of #0.
7071 When we encounter #1, we want to store the partial instantiation
7072 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7074 For all cases other than this "explicit specialization of member of a
7075 class template", we just want to store the most general template into
7076 the CLASSTYPE_TI_TEMPLATE of M.
7078 This case of "explicit specialization of member of a class template"
7079 only happens when:
7080 1/ the enclosing class is an instantiation of, and therefore not
7081 the same as, the context of the most general template, and
7082 2/ we aren't looking at the partial instantiation itself, i.e.
7083 the innermost arguments are not the same as the innermost parms of
7084 the most general template.
7086 So it's only when 1/ and 2/ happens that we want to use the partial
7087 instantiation of the member template in lieu of its most general
7088 template. */
7092 /* the enclosing class must be an instantiation... */
7095 {
7096 tree partial_inst_args;
7099 partial_inst_args =
7105 use_partial_inst_tmpl =
7106 /*...and we must not be looking at the partial instantiation
7107 itself. */
7109 partial_inst_args);
7110 }
7113 /* This case is easy; there are no member templates involved. */
7115 else
7116 {
7117 /* This is a full instantiation of a member template. Find
7118 the partial instantiation of which this is an instance. */
7120 /* Temporarily reduce by one the number of levels in the ARGLIST
7121 so as to avoid comparing the last set of arguments. */
7126 }
7136 /* Note this use of the partial instantiation so we can check it
7137 later in maybe_process_partial_specialization. */
7143 /* Now that the type has been registered on the instantiations
7144 list, we set up the enumerators. Because the enumeration
7145 constants may involve the enumeration type itself, we make
7146 sure to register the type first, and then create the
7147 constants. That way, doing tsubst_expr for the enumeration
7148 constants won't result in recursive calls here; we'll find
7149 the instantiation and exit above. */
7153 /* If the type makes use of template parameters, the
7154 code that generates debugging information will crash. */
7157 /* Possibly limit visibility based on template args. */
7162 }
7163 }
7165 /* Wrapper for lookup_template_class_1. */
7167 tree
7170 {
7171 tree ret;
7177 }
7178 \f
7179 struct pair_fn_data
7180 {
7181 tree_fn_t fn;
7183 /* True when we should also visit template parameters that occur in
7184 non-deduced contexts. */
7187 };
7189 /* Called from for_each_template_parm via walk_tree. */
7191 static tree
7193 {
7206 {
7210 /* Fall through. */
7233 /* Since we're not going to walk subtrees, we have to do this
7234 explicitly here. */
7238 /* Fall through. */
7241 /* Check the return type. */
7246 /* Check the parameter types. Since default arguments are not
7247 instantiated until they are needed, the TYPE_ARG_TYPES may
7248 contain expressions that involve template parameters. But,
7249 no-one should be looking at them yet. And, once they're
7250 instantiated, they don't contain template parameters, so
7251 there's no point in looking at them then, either. */
7252 {
7253 tree parm;
7260 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7261 want walk_tree walking into them itself. */
7263 }
7281 /* Fall through. */
7297 /* Record template parameters such as `T' inside `TT<T>'. */
7301 /* Fall through. */
7313 /* A template template parameter is encountered. */
7319 /* Already substituted template template parameter */
7342 /* If there's no type, then this thing must be some expression
7343 involving template parameters. */
7364 }
7366 /* We didn't find any template parameters we liked. */
7368 }
7370 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7371 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7372 call FN with the parameter and the DATA.
7373 If FN returns nonzero, the iteration is terminated, and
7374 for_each_template_parm returns 1. Otherwise, the iteration
7375 continues. If FN never returns a nonzero value, the value
7376 returned by for_each_template_parm is 0. If FN is NULL, it is
7377 considered to be the function which always returns 1.
7379 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7380 parameters that occur in non-deduced contexts. When false, only
7381 visits those template parameters that can be deduced. */
7383 static int
7387 {
7391 /* Set up. */
7396 /* Walk the tree. (Conceptually, we would like to walk without
7397 duplicates, but for_each_template_parm_r recursively calls
7398 for_each_template_parm, so we would need to reorganize a fair
7399 bit to use walk_tree_without_duplicates, so we keep our own
7400 visited list.) */
7403 else
7406 for_each_template_parm_r,
7410 /* Clean up. */
7412 {
7415 }
7418 }
7420 /* Returns true if T depends on any template parameter. */
7422 int
7424 {
7451 else
7452 {
7455 }
7460 }
7462 /* Returns true if T depends on any template parameter with level LEVEL. */
7464 int
7466 {
7469 }
7473 #ifdef GATHER_STATISTICS
7475 #endif
7479 /* We're starting to instantiate D; record the template instantiation context
7480 for diagnostics and to restore it later. */
7482 int
7484 {
7488 {
7489 /* If the instantiation in question still has unbound template parms,
7490 we don't really care if we can't instantiate it, so just return.
7491 This happens with base instantiation for implicit `typename'. */
7503 }
7513 #ifdef GATHER_STATISTICS
7516 #endif
7520 }
7522 /* We're done instantiating this template; return to the instantiation
7523 context. */
7525 void
7527 {
7528 /* Restore the filename and line number stashed away when we started
7529 this instantiation. */
7534 }
7536 /* We're instantiating a deferred template; restore the template
7537 instantiation context in which the instantiation was requested, which
7538 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7540 static tree
7542 {
7552 }
7554 /* Returns the TINST_LEVEL which gives the original instantiation
7555 context. */
7559 {
7565 }
7567 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7569 bool
7571 {
7572 tree parms;
7589 }
7591 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7592 vector of template arguments, as for tsubst.
7594 Returns an appropriate tsubst'd friend declaration. */
7596 static tree
7598 {
7599 tree new_friend;
7604 /* This was a friend declared with an explicit template
7605 argument list, e.g.:
7607 friend void f<>(T);
7609 to indicate that f was a template instantiation, not a new
7610 function declaration. Now, we have to figure out what
7611 instantiation of what template. */
7612 {
7614 tree new_args;
7615 tree tmpl;
7618 /* Friend functions are looked up in the containing namespace scope.
7619 We must enter that scope, to avoid finding member functions of the
7620 current class with same name. */
7635 tsk_none);
7637 }
7641 /* The NEW_FRIEND will look like an instantiation, to the
7642 compiler, but is not an instantiation from the point of view of
7643 the language. For example, we might have had:
7645 template <class T> struct S {
7646 template <class U> friend void f(T, U);
7647 };
7649 Then, in S<int>, template <class U> void f(int, U) is not an
7650 instantiation of anything. */
7656 {
7660 }
7662 /* The mangled name for the NEW_FRIEND is incorrect. The function
7663 is not a template instantiation and should not be mangled like
7664 one. Therefore, we forget the mangling here; we'll recompute it
7665 later if we need it. */
7667 {
7670 }
7673 {
7674 tree old_decl;
7675 tree new_friend_template_info;
7676 tree new_friend_result_template_info;
7677 tree ns;
7680 /* We must save some information from NEW_FRIEND before calling
7681 duplicate decls since that function will free NEW_FRIEND if
7682 possible. */
7684 new_friend_is_defn =
7689 {
7690 /* This declaration is a `primary' template. */
7693 new_friend_result_template_info
7695 }
7696 else
7699 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7703 /* Inside pushdecl_namespace_level, we will push into the
7704 current namespace. However, the friend function should go
7705 into the namespace of the template. */
7715 {
7716 /* This new friend declaration matched an existing
7717 declaration. For example, given:
7719 template <class T> void f(T);
7720 template <class U> class C {
7721 template <class T> friend void f(T) {}
7722 };
7724 the friend declaration actually provides the definition
7725 of `f', once C has been instantiated for some type. So,
7726 old_decl will be the out-of-class template declaration,
7727 while new_friend is the in-class definition.
7729 But, if `f' was called before this point, the
7730 instantiation of `f' will have DECL_TI_ARGS corresponding
7731 to `T' but not to `U', references to which might appear
7732 in the definition of `f'. Previously, the most general
7733 template for an instantiation of `f' was the out-of-class
7734 version; now it is the in-class version. Therefore, we
7735 run through all specialization of `f', adding to their
7736 DECL_TI_ARGS appropriately. In particular, they need a
7737 new set of outer arguments, corresponding to the
7738 arguments for this class instantiation.
7740 The same situation can arise with something like this:
7742 friend void f(int);
7743 template <class T> class C {
7744 friend void f(T) {}
7745 };
7747 when `C<int>' is instantiated. Now, `f(int)' is defined
7748 in the class. */
7751 /* On the other hand, if the in-class declaration does
7752 *not* provide a definition, then we don't want to alter
7753 existing definitions. We can just leave everything
7754 alone. */
7755 ;
7756 else
7757 {
7761 /* Overwrite whatever template info was there before, if
7762 any, with the new template information pertaining to
7763 the declaration. */
7767 {
7768 /* We should have called reregister_specialization in
7769 duplicate_decls. */
7774 /* Instantiate it if the global has already been used. */
7778 }
7779 else
7780 {
7781 tree t;
7783 /* Indicate that the old function template is a partial
7784 instantiation. */
7792 /* Reassign any specializations already in the hash table
7793 to the new more general template, and add the
7794 additional template args. */
7798 {
7800 spec_entry elt;
7812 register_specialization
7815 }
7817 }
7818 }
7820 /* The information from NEW_FRIEND has been merged into OLD_DECL
7821 by duplicate_decls. */
7823 }
7824 }
7825 else
7826 {
7830 /* In the code
7831 template <class T> class C {
7832 template <class U> friend void C1<U>::f (); // case 1
7833 friend void C2<T>::f (); // case 2
7834 };
7835 we only need to make sure CONTEXT is a complete type for
7836 case 2. To distinguish between the two cases, we note that
7837 CONTEXT of case 1 remains dependent type after tsubst while
7838 this isn't true for case 2. */
7848 {
7849 /* Check to see that the declaration is really present, and,
7850 possibly obtain an improved declaration. */
7856 }
7857 }
7860 }
7862 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7863 template arguments, as for tsubst.
7865 Returns an appropriate tsubst'd friend type or error_mark_node on
7866 failure. */
7868 static tree
7870 {
7871 tree friend_type;
7872 tree tmpl;
7873 tree context;
7878 {
7881 else
7883 }
7885 /* Look for a class template declaration. We look for hidden names
7886 because two friend declarations of the same template are the
7887 same. For example, in:
7889 struct A {
7890 template <typename> friend class F;
7891 };
7892 template <typename> struct B {
7893 template <typename> friend class F;
7894 };
7896 both F templates are the same. */
7901 /* But, if we don't find one, it might be because we're in a
7902 situation like this:
7904 template <class T>
7905 struct S {
7906 template <class U>
7907 friend struct S;
7908 };
7910 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7911 for `S<int>', not the TEMPLATE_DECL. */
7913 {
7916 }
7919 {
7920 /* The friend template has already been declared. Just
7921 check to see that the declarations match, and install any new
7922 default parameters. We must tsubst the default parameters,
7923 of course. We only need the innermost template parameters
7924 because that is all that redeclare_class_template will look
7925 at. */
7928 {
7929 tree parms;
7930 location_t saved_input_location;
7939 }
7942 }
7943 else
7944 {
7945 /* The friend template has not already been declared. In this
7946 case, the instantiation of the template class will cause the
7947 injection of this template into the global scope. */
7952 /* The new TMPL is not an instantiation of anything, so we
7953 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7954 the new type because that is supposed to be the corresponding
7955 template decl, i.e., TMPL. */
7962 /* Inject this template into the global scope. */
7964 }
7967 {
7970 else
7972 }
7975 }
7977 /* Returns zero if TYPE cannot be completed later due to circularity.
7978 Otherwise returns one. */
7980 static int
7982 {
7992 else
7994 }
7996 /* Apply any attributes which had to be deferred until instantiation
7997 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7998 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8000 static void
8003 {
8005 tree t;
8010 {
8014 }
8017 {
8021 }
8022 else
8026 {
8031 {
8034 {
8037 /* If the first attribute argument is an identifier, don't
8038 pass it through tsubst. Attributes like mode, format,
8039 cleanup and several target specific attributes expect it
8040 unmodified. */
8046 {
8047 tree chain
8049 in_decl,
8054 chain);
8055 }
8056 else
8062 }
8063 else
8065 }
8068 }
8069 }
8071 /* Perform (or defer) access check for typedefs that were referenced
8072 from within the template TMPL code.
8073 This is a subroutine of instantiate_template and instantiate_class_template.
8074 TMPL is the template to consider and TARGS is the list of arguments of
8075 that template. */
8077 static void
8079 {
8080 location_t saved_location;
8093 {
8105 /* Make access check error messages point to the location
8106 of the use of the typedef. */
8110 }
8112 }
8114 static tree
8116 {
8118 tree typedecl;
8119 tree pbinfo;
8120 tree base_list;
8130 /* Figure out which template is being instantiated. */
8134 /* Determine what specialization of the original template to
8135 instantiate. */
8138 {
8141 }
8143 {
8144 /* This TYPE is actually an instantiation of a partial
8145 specialization. We replace the innermost set of ARGS with
8146 the arguments appropriate for substitution. For example,
8147 given:
8149 template <class T> struct S {};
8150 template <class T> struct S<T*> {};
8152 and supposing that we are instantiating S<int*>, ARGS will
8153 presently be {int*} -- but we need {int}. */
8156 }
8157 else
8158 {
8161 }
8163 /* If the template we're instantiating is incomplete, then clearly
8164 there's nothing we can do. */
8168 /* If we've recursively instantiated too many templates, stop. */
8172 /* Now we're really doing the instantiation. Mark the type as in
8173 the process of being defined. */
8176 /* We may be in the middle of deferred access check. Disable
8177 it now. */
8181 /* Use #pragma pack from the template context. */
8187 /* Set the input location to the most specialized template definition.
8188 This is needed if tsubsting causes an error. */
8210 {
8213 }
8218 /* We should never instantiate a nested class before its enclosing
8219 class; we need to look up the nested class by name before we can
8220 instantiate it, and that lookup should instantiate the enclosing
8221 class. */
8227 {
8228 tree pbase_binfo;
8229 tree pushed_scope;
8232 /* We must enter the scope containing the type, as that is where
8233 the accessibility of types named in dependent bases are
8234 looked up from. */
8237 /* Substitute into each of the bases to determine the actual
8238 basetypes. */
8240 {
8241 tree base;
8247 {
8248 expanded_bases =
8255 }
8258 {
8260 /* Extract the already-expanded base class. */
8262 else
8263 /* Substitute to figure out the base class. */
8265 NULL_TREE);
8273 }
8274 }
8276 /* The list is now in reverse order; correct that. */
8281 }
8282 /* Now call xref_basetypes to set up all the base-class
8283 information. */
8291 /* Now that our base classes are set up, enter the scope of the
8292 class, so that name lookups into base classes, etc. will work
8293 correctly. This is precisely analogous to what we do in
8294 begin_class_definition when defining an ordinary non-template
8295 class, except we also need to push the enclosing classes. */
8298 /* Now members are processed in the order of declaration. */
8301 {
8305 {
8307 {
8308 /* Build new CLASSTYPE_NESTED_UTDS. */
8310 tree newtag;
8316 /* If the member is a class template, then -- even after
8317 substitution -- there may be dependent types in the
8318 template argument list for the class. We increment
8319 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8320 that function will assume that no types are dependent
8321 when outside of a template. */
8331 {
8335 /* Unfortunately, lookup_template_class sets
8336 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8337 instantiation (i.e., for the type of a member
8338 template class nested within a template class.)
8339 This behavior is required for
8340 maybe_process_partial_specialization to work
8341 correctly, but is not accurate in this case;
8342 the TAG is not an instantiation of anything.
8343 (The corresponding TEMPLATE_DECL is an
8344 instantiation, but the TYPE is not.) */
8347 /* Now, we call pushtag to put this NEWTAG into the scope of
8348 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8349 pushtag calling push_template_decl. We don't have to do
8350 this for enums because it will already have been done in
8351 tsubst_enum. */
8355 }
8356 }
8359 {
8360 /* Build new TYPE_METHODS. */
8361 tree r;
8370 }
8371 else
8372 {
8373 /* Build new TYPE_FIELDS. */
8375 {
8376 tree condition =
8384 }
8386 {
8387 tree r;
8389 /* The file and line for this declaration, to
8390 assist in error message reporting. Since we
8391 called push_tinst_level above, we don't need to
8392 restore these. */
8401 {
8402 /* In [temp.inst]:
8404 [t]he initialization (and any associated
8405 side-effects) of a static data member does
8406 not occur unless the static data member is
8407 itself used in a way that requires the
8408 definition of the static data member to
8409 exist.
8411 Therefore, we do not substitute into the
8412 initialized for the static data member here. */
8413 finish_static_data_member_decl
8419 }
8421 {
8422 /* Determine whether R has a valid type and can be
8423 completed later. If R is invalid, then it is
8424 replaced by error_mark_node so that it will not be
8425 added to TYPE_FIELDS. */
8431 {
8434 }
8435 }
8437 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8438 such a thing will already have been added to the field
8439 list by tsubst_enum in finish_member_declaration in the
8440 CLASSTYPE_NESTED_UTDS case above. */
8444 {
8447 }
8448 }
8449 }
8450 }
8451 else
8452 {
8454 {
8455 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8461 {
8462 /* template <class T> friend class C; */
8465 }
8467 {
8468 /* template <class T> friend class C::D; */
8474 }
8477 {
8478 /* This could be either
8480 friend class T::C;
8482 when dependent_type_p is false or
8484 template <class U> friend class T::C;
8486 otherwise. */
8489 /* Bump processing_template_decl for correct
8490 dependent_type_p calculation. */
8495 }
8498 {
8499 /* friend class C;
8501 where C hasn't been declared yet. Let's lookup name
8502 from namespace scope directly, bypassing any name that
8503 come from dependent base class. */
8506 /* The call to xref_tag_from_type does injection for friend
8507 classes. */
8509 friend_type =
8513 }
8515 /* friend class C<T>; */
8518 /* Otherwise it's
8520 friend class C;
8522 where C is already declared or
8524 friend class C<int>;
8526 We don't have to do anything in these cases. */
8529 /* Trick make_friend_class into realizing that the friend
8530 we're adding is a template, not an ordinary class. It's
8531 important that we use make_friend_class since it will
8532 perform some error-checking and output cross-reference
8533 information. */
8541 }
8542 else
8543 {
8544 /* Build new DECL_FRIENDLIST. */
8545 tree r;
8547 /* The file and line for this declaration, to
8548 assist in error message reporting. Since we
8549 called push_tinst_level above, we don't need to
8550 restore these. */
8554 {
8557 }
8562 {
8565 }
8566 }
8567 }
8568 }
8573 /* Set the file and line number information to whatever is given for
8574 the class itself. This puts error messages involving generated
8575 implicit functions at a predictable point, and the same point
8576 that would be used for non-template classes. */
8583 /* We don't instantiate default arguments for member functions. 14.7.1:
8585 The implicit instantiation of a class template specialization causes
8586 the implicit instantiation of the declarations, but not of the
8587 definitions or default arguments, of the class member functions,
8588 member classes, static data members and member templates.... */
8590 /* Some typedefs referenced from within the template code need to be access
8591 checked at template instantiation time, i.e now. These types were
8592 added to the template at parsing time. Let's get those and perform
8593 the access checks then. */
8602 /* The vtable for a template class can be emitted in any translation
8603 unit in which the class is instantiated. When there is no key
8604 method, however, finish_struct_1 will already have added TYPE to
8605 the keyed_classes list. */
8610 }
8612 /* Wrapper for instantiate_class_template_1. */
8614 tree
8616 {
8617 tree ret;
8622 }
8624 static tree
8626 {
8627 tree r;
8633 else
8634 {
8641 }
8643 }
8645 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8646 NONTYPE_ARGUMENT_PACK. */
8648 static tree
8650 {
8651 /* Collect all of the extra "packed" parameters into an
8652 argument pack. */
8653 tree parmvec;
8654 tree parmtypevec;
8659 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8663 {
8666 }
8668 /* Build the argument packs. */
8674 }
8676 /* Substitute ARGS into T, which is an pack expansion
8677 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8678 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8679 (if only a partial substitution could be performed) or
8680 ERROR_MARK_NODE if there was an error. */
8681 tree
8683 tree in_decl)
8684 {
8685 tree pattern;
8688 tree result;
8695 /* Determine the argument packs that will instantiate the parameter
8696 packs used in the expansion expression. While we're at it,
8697 compute the number of arguments to be expanded and make sure it
8698 is consistent. */
8701 {
8707 {
8710 else
8711 {
8712 /* We can't rely on local_specializations for a parameter
8713 name used later in a function declaration (such as in a
8714 late-specified return type). Even if it exists, it might
8715 have the wrong value for a recursive call. Just make a
8716 dummy decl, since it's only used for its type. */
8719 /* Partial instantiation of the parm_pack, we can't build
8720 up an argument pack yet. */
8722 else
8724 }
8725 }
8726 else
8727 {
8734 }
8741 /* This can only happen if we forget to expand an argument
8742 pack somewhere else. Just return an error, silently. */
8743 {
8747 }
8749 /* For clarity in the comments below let's use the
8750 representation 'argument_pack<elements>' to denote an
8751 argument pack and its elements.
8753 In the 'if' block below, we want to detect cases where
8754 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
8755 check if ARG_PACK is an argument pack which sole element is
8756 the expansion of PARM_PACK. That argument pack is typically
8757 created by template_parm_to_arg when passed a parameter
8758 pack. */
8762 {
8765 /* So we have an argument_pack<P...>. We want to test if P
8766 is actually PARM_PACK. We will not use cp_tree_equal to
8767 test P and PARM_PACK because during type fixup (by
8768 fixup_template_parm) P can be a pre-fixup version of a
8769 type and PARM_PACK be its post-fixup version.
8770 cp_tree_equal would consider them as different even
8771 though we would want to consider them compatible for our
8772 precise purpose here.
8774 Thus we are going to consider that P and PARM_PACK are
8775 compatible if they have the same DECL. */
8777 same DECL as parm_pack ... */
8781 /* ... or if ARG_PACK is a non-type parameter
8782 named by the same DECL as parm_pack ... */
8788 /* ... then the argument pack that the parameter maps to
8789 is just an expansion of the parameter itself, such as
8790 one would find in the implicit typedef of a class
8791 inside the class itself. Consider this parameter
8792 "unsubstituted", so that we will maintain the outer
8793 pack expansion. */
8795 }
8798 {
8802 /* It's all-or-nothing with incomplete argument packs. */
8812 {
8814 /* We got explicit args for some packs but not others;
8815 do nothing now and try again after deduction. */
8820 pattern);
8821 else
8824 pattern);
8826 }
8828 /* Keep track of the parameter packs and their corresponding
8829 argument packs. */
8832 }
8833 else
8834 /* We can't substitute for this parameter pack. */
8837 unsubstituted_packs);
8838 }
8840 /* We cannot expand this expansion expression, because we don't have
8841 all of the argument packs we need. Substitute into the pattern
8842 and return a PACK_EXPANSION_*. The caller will need to deal with
8843 that. */
8845 {
8846 tree new_pat;
8850 else
8853 }
8855 /* We could not find any argument packs that work. */
8860 {
8861 /* We're in a late-specified return type, so create our own local
8862 specializations table; the current table is either NULL or (in the
8863 case of recursive unification) might have bindings that we don't
8864 want to use or alter. */
8867 hash_local_specialization,
8868 eq_local_specializations,
8869 NULL);
8870 }
8872 /* For each argument in each argument pack, substitute into the
8873 pattern. */
8876 {
8877 /* For parameter pack, change the substitution of the parameter
8878 pack to the ith argument in its argument pack, then expand
8879 the pattern. */
8881 {
8885 {
8886 /* Select the Ith argument from the pack. */
8892 }
8893 else
8894 {
8900 {
8901 /* Select the Ith argument from the pack. */
8905 }
8907 /* Update the corresponding argument. */
8909 }
8910 }
8912 /* Substitute into the PATTERN with the altered arguments. */
8917 else
8921 /* When we have incomplete argument packs, the last "expanded"
8922 result is itself a pack expansion, which allows us
8923 to deduce more arguments. */
8928 {
8931 }
8932 }
8934 /* Update ARGS to restore the substitution from parameter packs to
8935 their argument packs. */
8937 {
8942 else
8943 {
8947 /* Update the corresponding argument. */
8951 else
8953 }
8954 }
8957 {
8960 }
8963 }
8965 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8966 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8967 parameter packs; all parms generated from a function parameter pack will
8968 have the same DECL_PARM_INDEX. */
8970 tree
8972 {
8974 tree patparm;
8977 {
8983 }
8984 else
8985 {
8990 }
8993 }
8995 /* Substitute ARGS into the vector or list of template arguments T. */
8997 static tree
8999 {
9011 {
9013 tree new_arg;
9018 {
9019 /* Substitute into an expansion expression. */
9023 /* Add to the expanded length adjustment the number of
9024 expanded arguments. We subtract one from this
9025 measurement, because the argument pack expression
9026 itself is already counted as 1 in
9027 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9028 the argument pack is empty. */
9030 }
9032 {
9033 /* Substitute into each of the arguments. */
9039 new_arg,
9053 }
9054 }
9055 else
9064 }
9069 /* Make space for the expanded arguments coming from template
9070 argument packs. */
9072 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9073 arguments for a member template.
9074 In that case each TREE_VEC in ORIG_T represents a level of template
9075 arguments, and ORIG_T won't carry any non defaulted argument count.
9076 It will rather be the nested TREE_VECs that will carry one.
9077 In other words, ORIG_T carries a non defaulted argument count only
9078 if it doesn't contain any nested TREE_VEC. */
9080 {
9084 }
9086 {
9090 {
9093 /* Now expand the template argument pack "in place". */
9096 }
9097 else
9098 {
9100 out++;
9101 }
9102 }
9105 }
9107 /* Return the result of substituting ARGS into the template parameters
9108 given by PARMS. If there are m levels of ARGS and m + n levels of
9109 PARMS, then the result will contain n levels of PARMS. For
9110 example, if PARMS is `template <class T> template <class U>
9111 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9112 result will be `template <int*, double, class V>'. */
9114 static tree
9116 {
9120 /* When substituting into a template, we must set
9121 PROCESSING_TEMPLATE_DECL as the template parameters may be
9122 dependent if they are based on one-another, and the dependency
9123 predicates are short-circuit outside of templates. */
9130 {
9131 tree new_vec =
9136 {
9137 tree tuple;
9149 }
9155 }
9160 }
9162 /* Return the result of substituting ARGS into one template parameter
9163 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9164 parameter and which TREE_PURPOSE is the default argument of the
9165 template parameter. */
9167 static tree
9169 {
9190 }
9192 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9193 type T. If T is not an aggregate or enumeration type, it is
9194 handled as if by tsubst. IN_DECL is as for tsubst. If
9195 ENTERING_SCOPE is nonzero, T is the context for a template which
9196 we are presently tsubst'ing. Return the substituted value. */
9198 static tree
9200 tree args,
9201 tsubst_flags_t complain,
9202 tree in_decl,
9204 {
9209 {
9214 /* Else fall through. */
9218 {
9219 tree argvec;
9220 tree context;
9221 tree r;
9225 /* In "sizeof(X<I>)" we need to evaluate "I". */
9231 /* First, determine the context for the type we are looking
9232 up. */
9235 {
9238 /* If context is a nested class inside a class template,
9239 it may still need to be instantiated (c++/33959). */
9242 }
9244 /* Then, figure out what arguments are appropriate for the
9245 type we are trying to find. For example, given:
9247 template <class T> struct S;
9248 template <class T, class U> void f(T, U) { S<U> su; }
9250 and supposing that we are instantiating f<int, double>,
9251 then our ARGS will be {int, double}, but, when looking up
9252 S we only want {double}. */
9257 else
9258 {
9262 }
9268 }
9269 else
9270 /* This is not a template type, so there's nothing to do. */
9275 }
9276 }
9278 /* Substitute into the default argument ARG (a default argument for
9279 FN), which has the indicated TYPE. */
9281 tree
9283 {
9287 /* This can happen in invalid code. */
9291 /* This default argument came from a template. Instantiate the
9292 default argument here, not in tsubst. In the case of
9293 something like:
9295 template <class T>
9296 struct S {
9297 static T t();
9298 void f(T = t());
9299 };
9301 we must be careful to do name lookup in the scope of S<T>,
9302 rather than in the current class. */
9304 /* The "this" pointer is not valid in a default argument. */
9306 {
9311 }
9314 /* The default argument expression may cause implicitly defined
9315 member functions to be synthesized, which will result in garbage
9316 collection. We must treat this situation as if we were within
9317 the body of function so as to avoid collecting live data on the
9318 stack. */
9326 /* Restore the "this" pointer. */
9328 {
9331 }
9333 /* Make sure the default argument is reasonable. */
9339 }
9341 /* Substitute into all the default arguments for FN. */
9343 static void
9345 {
9346 tree arg;
9347 tree tmpl_args;
9351 /* If this function is not yet instantiated, we certainly don't need
9352 its default arguments. */
9355 /* Don't do this again for clones. */
9360 arg;
9366 }
9368 /* Substitute the ARGS into the T, which is a _DECL. Return the
9369 result of the substitution. Issue error and warning messages under
9370 control of COMPLAIN. */
9372 static tree
9374 {
9375 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9376 location_t saved_loc;
9381 /* Set the filename and linenumber to improve error-reporting. */
9386 {
9388 {
9389 /* We can get here when processing a member function template,
9390 member class template, or template template parameter. */
9392 tree spec;
9393 tree tmpl_args;
9394 tree full_args;
9397 {
9398 /* Template template parameter is treated here. */
9411 complain);
9414 }
9416 /* We might already have an instance of this template.
9417 The ARGS are for the surrounding class type, so the
9418 full args contain the tsubst'd args for the context,
9419 plus the innermost args from the template decl. */
9423 /* Because this is a template, the arguments will still be
9424 dependent, even after substitution. If
9425 PROCESSING_TEMPLATE_DECL is not set, the dependency
9426 predicates will short-circuit. */
9434 /* If this is a default template template argument,
9435 tsubst might not have changed anything. */
9442 {
9445 }
9447 /* Make a new template decl. It will be similar to the
9448 original, but will record the current template arguments.
9449 We also create a new function declaration, which is just
9450 like the old one, but points to this new template, rather
9451 than the old one. */
9459 {
9460 tree new_type;
9472 }
9473 else
9474 {
9475 tree new_decl;
9487 }
9493 /* The template parameters for this new template are all the
9494 template parameters for the old template, except the
9495 outermost level of parameters. */
9498 complain);
9504 /* Record this non-type partial instantiation. */
9508 }
9512 {
9513 tree ctx;
9516 tree gen_tmpl;
9517 tree type;
9522 /* Nobody should be tsubst'ing into non-template functions. */
9526 {
9527 tree spec;
9530 /* If T is not dependent, just return it. We have to
9531 increment PROCESSING_TEMPLATE_DECL because
9532 value_dependent_expression_p assumes that nothing is
9533 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9540 /* Calculate the most general template of which R is a
9541 specialization, and the complete set of arguments used to
9542 specialize R. */
9545 (DECL_TEMPLATE_RESULT
9549 /* Check to see if we already have this specialization. */
9554 {
9557 }
9559 /* We can see more levels of arguments than parameters if
9560 there was a specialization of a member template, like
9561 this:
9563 template <class T> struct S { template <class U> void f(); }
9564 template <> template <class U> void S<int>::f(U);
9566 Here, we'll be substituting into the specialization,
9567 because that's where we can find the code we actually
9568 want to generate, but we'll have enough arguments for
9569 the most general template.
9571 We also deal with the peculiar case:
9573 template <class T> struct S {
9574 template <class U> friend void f();
9575 };
9576 template <class U> void f() {}
9577 template S<int>;
9578 template void f<double>();
9580 Here, the ARGS for the instantiation of will be {int,
9581 double}. But, we only need as many ARGS as there are
9582 levels of template parameters in CODE_PATTERN. We are
9583 careful not to get fooled into reducing the ARGS in
9584 situations like:
9586 template <class T> struct S { template <class U> void f(U); }
9587 template <class T> template <> void S<T>::f(int) {}
9589 which we can spot because the pattern will be a
9590 specialization in this case. */
9592 parms_depth =
9597 }
9598 else
9599 {
9600 /* This special case arises when we have something like this:
9602 template <class T> struct S {
9603 friend void f<int>(int, double);
9604 };
9606 Here, the DECL_TI_TEMPLATE for the friend declaration
9607 will be an IDENTIFIER_NODE. We are being called from
9608 tsubst_friend_function, and we want only to create a
9609 new decl (R) with appropriate types so that we can call
9610 determine_specialization. */
9612 }
9615 {
9618 else
9622 }
9623 else
9624 {
9627 }
9632 /* We do NOT check for matching decls pushed separately at this
9633 point, as they may not represent instantiations of this
9634 template, and in any case are considered separate under the
9635 discrete model. */
9639 /* Clear out the mangled name and RTL for the instantiation. */
9642 /* Leave DECL_INITIAL set on deleted instantiations. */
9648 /* Type-conversion operator. Reconstruct the name, in
9649 case it's the name of one of the template's parameters. */
9659 /* If this is an instantiation of a function with internal
9660 linkage, we already know what object file linkage will be
9661 assigned to the instantiation. */
9670 /* We'll re-clone as appropriate in instantiate_template. */
9673 /* If we aren't complaining now, return on error before we register
9674 the specialization so that we'll complain eventually. */
9680 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9681 this in the special friend case mentioned above where
9682 GEN_TMPL is NULL. */
9684 {
9690 /* We're not supposed to instantiate default arguments
9691 until they are called, for a template. But, for a
9692 declaration like:
9694 template <class T> void f ()
9695 { extern void g(int i = T()); }
9697 we should do the substitution when the template is
9698 instantiated. We handle the member function case in
9699 instantiate_class_template since the default arguments
9700 might refer to other members of the class. */
9705 }
9706 else
9709 /* Copy the list of befriending classes. */
9713 {
9717 in_decl);
9718 }
9721 {
9725 /* If this is an instantiation of a member template, clone it.
9726 If it isn't, that'll be handled by
9727 clone_constructors_and_destructors. */
9730 }
9741 /* Possibly limit visibility based on template args. */
9744 {
9748 }
9756 }
9760 {
9768 {
9769 /* If there is a local specialization that isn't a
9770 parameter pack, it means that we're doing a "simple"
9771 substitution from inside tsubst_pack_expansion. Just
9772 return the local specialization (which will be a single
9773 parm). */
9780 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9781 the parameters in this function parameter pack. */
9785 {
9788 /* Zero-length parameter packs are boring. Just substitute
9789 into the chain. */
9793 }
9794 else
9795 {
9796 /* All we did was update the type. Make a note of that. */
9799 }
9800 }
9802 /* Loop through all of the parameter's we'll build. When T is
9803 a function parameter pack, LEN is the number of expanded
9804 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9807 {
9814 /* We're on the Ith parameter of the function parameter
9815 pack. */
9816 {
9817 /* An argument of a function parameter pack is not a parameter
9818 pack. */
9821 /* Get the Ith type. */
9825 /* Rename the parameter to include the index. */
9828 }
9830 /* We're dealing with a normal parameter. */
9838 {
9841 else
9844 }
9854 /* Keep track of the first new parameter we
9855 generate. That's what will be returned to the
9856 caller. */
9860 /* Build a proper chain of parameters when substituting
9861 into a function parameter pack. */
9864 }
9870 /* FIRST_R contains the start of the chain we've built. */
9872 }
9876 {
9877 tree type;
9886 /* DECL_INITIAL gives the number of bits in a bit-field. */
9891 /* We don't have to set DECL_CONTEXT here; it is set by
9892 finish_member_declaration. */
9899 }
9903 /* We reach here only for member using decls. */
9905 {
9906 r = do_class_using_decl
9911 else
9912 {
9915 }
9916 }
9917 else
9918 {
9921 }
9926 {
9929 tree spec;
9931 tree ctx;
9937 {
9938 /* If this is the canonical decl, we don't have to
9939 mess with instantiations, and often we can't (for
9940 typename, template type parms and such). Note that
9941 TYPE_NAME is not correct for the above test if
9942 we've copied the type for a typedef. */
9948 }
9950 /* Check to see if we already have the specialization we
9951 need. */
9954 {
9955 /* T is a static data member or namespace-scope entity.
9956 We have to substitute into namespace-scope variables
9957 (even though such entities are never templates) because
9958 of cases like:
9960 template <class T> void f() { extern T t; }
9962 where the entity referenced is not known until
9963 instantiation time. */
9967 {
9969 complain,
9971 /* If CTX is unchanged, then T is in fact the
9972 specialization we want. That situation occurs when
9973 referencing a static data member within in its own
9974 class. We can use pointer equality, rather than
9975 same_type_p, because DECL_CONTEXT is always
9976 canonical. */
9979 }
9982 {
9988 }
9989 }
9990 else
9991 {
9992 /* A local variable. */
9994 /* Subsequent calls to pushdecl will fill this in. */
9997 }
9998 /* If we already have the specialization we need, there is
9999 nothing more to do. */
10001 {
10004 }
10006 /* Create a new node for the specialization we need. */
10009 {
10012 else
10017 }
10019 {
10020 /* Even if the original location is out of scope, the
10021 newly substituted one is not. */
10028 {
10029 /* It may seem that this case cannot occur, since:
10031 typedef void f();
10032 void g() { f x; }
10034 declares a function, not a variable. However:
10036 typedef void f();
10037 template <typename T> void g() { T t; }
10038 template void g<f>();
10040 is an attempt to declare a variable with function
10041 type. */
10043 /* R is not yet sufficiently initialized, so we
10044 just use its name. */
10047 }
10049 /* Wait until cp_finish_decl to set this again, to handle
10050 circular dependency (template/instantiate6.C). */
10055 {
10060 }
10061 }
10067 /* Clear out the mangled name and RTL for the instantiation. */
10071 /* The initializer must not be expanded until it is required;
10072 see [temp.inst]. */
10078 {
10079 /* Possibly limit visibility based on template args. */
10082 {
10086 }
10088 }
10091 {
10092 /* A static data member declaration is always marked
10093 external when it is declared in-class, even if an
10094 initializer is present. We mimic the non-template
10095 processing here. */
10101 }
10103 {
10104 /* We're substituting this var in a decltype outside of its
10105 scope, such as for a lambda return type. Don't add it to
10106 local_specializations, do perform auto deduction. */
10108 tree init
10113 {
10116 {
10119 }
10120 }
10121 }
10122 else
10131 /* Preserve a typedef that names a type. */
10133 {
10136 }
10139 }
10144 }
10145 #undef RETURN
10147 out:
10148 /* Restore the file and line information. */
10152 }
10154 /* Substitute into the ARG_TYPES of a function type. */
10156 static tree
10158 tree args,
10159 tsubst_flags_t complain,
10160 tree in_decl)
10161 {
10162 tree remaining_arg_types;
10166 tree default_arg;
10177 {
10178 /* For a pack expansion, perform substitution on the
10179 entire expression. Later on, we'll handle the arguments
10180 one-by-one. */
10185 /* So that we'll spin through the parameters, one by one. */
10187 else
10188 {
10189 /* We only partially substituted into the parameter
10190 pack. Our type is TYPE_PACK_EXPANSION. */
10193 }
10194 }
10207 {
10209 {
10213 }
10215 }
10217 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10218 top-level qualifiers as required. */
10221 /* We do not substitute into default arguments here. The standard
10222 mandates that they be instantiated only when needed, which is
10223 done in build_over_call. */
10227 {
10228 /* We've instantiated a template before its default arguments
10229 have been parsed. This can happen for a nested template
10230 class, and is not an error unless we require the default
10231 argument in a call of this function. */
10232 remaining_arg_types =
10235 remaining_arg_types);
10236 }
10237 else
10238 remaining_arg_types =
10240 }
10243 }
10245 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10246 *not* handle the exception-specification for FNTYPE, because the
10247 initial substitution of explicitly provided template parameters
10248 during argument deduction forbids substitution into the
10249 exception-specification:
10251 [temp.deduct]
10253 All references in the function type of the function template to the
10254 corresponding template parameters are replaced by the specified tem-
10255 plate argument values. If a substitution in a template parameter or
10256 in the function type of the function template results in an invalid
10257 type, type deduction fails. [Note: The equivalent substitution in
10258 exception specifications is done only when the function is instanti-
10259 ated, at which point a program is ill-formed if the substitution
10260 results in an invalid type.] */
10262 static tree
10264 tree args,
10265 tsubst_flags_t complain,
10266 tree in_decl)
10267 {
10268 tree return_type;
10269 tree arg_types;
10270 tree fntype;
10272 /* The TYPE_CONTEXT is not used for function/method types. */
10275 /* Substitute the return type. */
10279 /* The standard does not presently indicate that creation of a
10280 function type with an invalid return type is a deduction failure.
10281 However, that is clearly analogous to creating an array of "void"
10282 or a reference to a reference. This is core issue #486. */
10285 {
10287 {
10290 else
10292 }
10294 }
10296 /* Substitute the argument types. */
10302 /* Construct a new type node and return it. */
10304 {
10307 }
10308 else
10309 {
10312 {
10313 /* [temp.deduct]
10315 Type deduction may fail for any of the following
10316 reasons:
10318 -- Attempting to create "pointer to member of T" when T
10319 is not a class type. */
10322 r);
10324 }
10328 }
10332 }
10334 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10335 ARGS into that specification, and return the substituted
10336 specification. If there is no specification, return NULL_TREE. */
10338 static tree
10340 tree args,
10341 tsubst_flags_t complain,
10342 tree in_decl)
10343 {
10344 tree specs;
10345 tree new_specs;
10350 {
10351 /* A noexcept-specifier. */
10352 new_specs = tsubst_copy_and_build
10356 }
10358 {
10361 else
10363 {
10364 tree spec;
10369 {
10370 /* Expand the pack expansion type. */
10373 in_decl);
10379 else
10380 {
10381 /* We're substituting into a member template, so
10382 we got a TYPE_PACK_EXPANSION back. Add that
10383 expansion and move on. */
10387 expanded_specs,
10388 complain);
10391 }
10392 }
10395 {
10398 else
10403 complain);
10404 }
10407 }
10408 }
10410 }
10412 /* Take the tree structure T and replace template parameters used
10413 therein with the argument vector ARGS. IN_DECL is an associated
10414 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10415 Issue error and warning messages under control of COMPLAIN. Note
10416 that we must be relatively non-tolerant of extensions here, in
10417 order to preserve conformance; if we allow substitutions that
10418 should not be allowed, we may allow argument deductions that should
10419 not succeed, and therefore report ambiguous overload situations
10420 where there are none. In theory, we could allow the substitution,
10421 but indicate that it should have failed, and allow our caller to
10422 make sure that the right thing happens, but we don't try to do this
10423 yet.
10425 This function is used for dealing with types, decls and the like;
10426 for expressions, use tsubst_expr or tsubst_copy. */
10428 tree
10430 {
10453 else
10458 /* Reuse typedefs. We need to do this to handle dependent attributes,
10459 such as attribute aligned. */
10462 {
10468 {
10472 }
10477 else
10478 /* The typedef is from a non-template context. */
10482 {
10484 r = cp_build_qualified_type_real
10488 }
10489 /* Else we must be instantiating the typedef, so fall through. */
10490 }
10503 {
10529 {
10535 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10536 needed. */
10542 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10543 with TREE_SIDE_EFFECTS that indicates this is not an integral
10544 constant expression. */
10547 {
10550 }
10553 }
10559 {
10572 {
10576 /* See through ARGUMENT_PACK_SELECT arguments. */
10578 }
10583 {
10585 /* If ARG is an argument pack, we don't actually want to
10586 perform a substitution here, because substitutions
10587 for argument packs are only done
10588 element-by-element. We can get to this point when
10589 substituting the type of a non-type template
10590 parameter pack, when that type actually contains
10591 template parameter packs from an outer template, e.g.,
10593 template<typename... Types> struct A {
10594 template<Types... Values> struct B { };
10595 }; */
10599 {
10605 return cp_build_qualified_type_real
10607 }
10609 {
10610 /* We are processing a type constructed from a
10611 template template parameter. */
10617 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10618 are resolving nested-types in the signature of a
10619 member function templates. Otherwise ARG is a
10620 TEMPLATE_DECL and is the real template to be
10621 instantiated. */
10629 complain);
10630 return cp_build_qualified_type_real
10632 }
10633 else
10634 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10636 }
10639 /* This can happen during the attempted tsubst'ing in
10640 unify. This means that we don't yet have any information
10641 about the template parameter in question. */
10644 /* If we get here, we must have been looking at a parm for a
10645 more deeply nested template. Make a new version of this
10646 template parameter, but with a lower level. */
10648 {
10653 {
10655 r = cp_build_qualified_type_real
10659 }
10660 else
10661 {
10672 /* We have reduced the level of the template
10673 template parameter, but not the levels of its
10674 template parameters, so canonical_type_parameter
10675 will not be able to find the canonical template
10676 template parameter for this level. Thus, we
10677 require structural equality checking to compare
10678 TEMPLATE_TEMPLATE_PARMs. */
10682 else
10686 {
10694 }
10695 }
10704 }
10707 }
10710 {
10718 {
10722 }
10725 {
10729 }
10732 {
10736 }
10742 }
10745 /* We should never be tsubsting a binfo. */
10749 /* A vector of template arguments. */
10755 {
10759 /* [temp.deduct]
10761 Type deduction may fail for any of the following
10762 reasons:
10764 -- Attempting to create a pointer to reference type.
10765 -- Attempting to create a reference to a reference type or
10766 a reference to void.
10768 Core issue 106 says that creating a reference to a reference
10769 during instantiation is no longer a cause for failure. We
10770 only enforce this check in strict C++98 mode. */
10774 {
10777 /* We keep track of the last time we issued this error
10778 message to avoid spewing a ton of messages during a
10779 single bad template instantiation. */
10782 {
10787 else
10790 }
10793 }
10795 {
10799 }
10801 /* In C++0x, during template argument substitution, when there is an
10802 attempt to create a reference to a reference type, reference
10803 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10805 "If a template-argument for a template-parameter T names a type
10806 that is a reference to a type A, an attempt to create the type
10807 'lvalue reference to cv T' creates the type 'lvalue reference to
10808 A,' while an attempt to create the type type rvalue reference to
10809 cv T' creates the type T"
10810 */
10811 r = cp_build_reference_type
10814 else
10819 /* Will this ever be needed for TYPE_..._TO values? */
10823 }
10825 {
10828 {
10829 /* [temp.deduct]
10831 Type deduction may fail for any of the following
10832 reasons:
10834 -- Attempting to create "pointer to member of T" when T
10835 is not a class type. */
10839 }
10841 {
10845 }
10847 {
10851 }
10854 {
10855 /* The type of the implicit object parameter gets its
10856 cv-qualifiers from the FUNCTION_TYPE. */
10857 tree memptr;
10861 complain);
10862 }
10863 else
10866 complain);
10867 }
10870 {
10871 tree fntype;
10872 tree specs;
10877 /* Substitute the exception specification. */
10879 in_decl);
10885 }
10887 {
10892 /* As an optimization, we avoid regenerating the array type if
10893 it will obviously be the same as T. */
10897 /* These checks should match the ones in grokdeclarator.
10899 [temp.deduct]
10901 The deduction may fail for any of the following reasons:
10903 -- Attempting to create an array with an element type that
10904 is void, a function type, or a reference type, or [DR337]
10905 an abstract class type. */
10909 {
10913 }
10915 {
10918 type);
10920 }
10925 {
10928 }
10931 }
10934 {
10944 {
10948 }
10950 {
10951 /* Normally, make_typename_type does not require that the CTX
10952 have complete type in order to allow things like:
10954 template <class T> struct S { typename S<T>::X Y; };
10956 But, such constructs have already been resolved by this
10957 point, so here CTX really should have complete type, unless
10958 it's a partial instantiation. */
10961 {
10965 }
10966 }
10973 {
10976 }
10979 {
10981 {
10985 else
10987 }
10989 {
10993 else
10995 }
10996 }
10998 return cp_build_qualified_type_real
11000 }
11003 {
11015 }
11018 {
11019 tree type;
11035 complain);
11036 }
11039 {
11040 tree type;
11056 else
11057 type = finish_decltype_type
11062 complain);
11063 }
11066 {
11070 }
11074 {
11076 tree packed_out =
11078 args,
11079 complain,
11080 in_decl);
11083 /* For template nontype argument packs, also substitute into
11084 the type. */
11089 }
11104 /* We should use one of the expression tsubsts for these codes. */
11110 }
11111 }
11113 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11114 type of the expression on the left-hand side of the "." or "->"
11115 operator. */
11117 static tree
11120 {
11121 tree name;
11122 tree qualifying_scope;
11123 tree fns;
11124 tree optype;
11128 /* A baselink indicates a function from a base class. Both the
11129 BASELINK_ACCESS_BINFO and the base class referenced may
11130 indicate bases of the template class, rather than the
11131 instantiated class. In addition, lookups that were not
11132 ambiguous before may be ambiguous now. Therefore, we perform
11133 the lookup again. */
11140 {
11147 }
11155 /* If lookup found a single function, mark it as used at this
11156 point. (If it lookup found multiple functions the one selected
11157 later by overload resolution will be marked as used at that
11158 point.) */
11164 /* Add back the template arguments, if present. */
11169 template_args);
11170 /* Update the conversion operator type. */
11176 qualifying_scope,
11177 object_type);
11178 }
11180 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11181 true if the qualified-id will be a postfix-expression in-and-of
11182 itself; false if more of the postfix-expression follows the
11183 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11184 of "&". */
11186 static tree
11190 {
11191 tree expr;
11192 tree scope;
11193 tree name;
11195 tree template_args;
11199 /* Figure out what name to look up. */
11202 {
11209 }
11210 else
11211 {
11214 }
11216 /* Substitute into the qualifying scope. When there are no ARGS, we
11217 are just trying to simplify a non-dependent expression. In that
11218 case the qualifying scope may be dependent, and, in any case,
11219 substituting will not help. */
11222 {
11225 }
11226 else
11234 {
11236 {
11237 /* A BIT_NOT_EXPR is used to represent a destructor. */
11239 {
11243 }
11244 else
11247 }
11248 else
11252 {
11254 {
11258 }
11260 }
11261 }
11264 {
11266 scope);
11267 /* Remember that there was a reference to this entity. */
11269 }
11272 {
11278 }
11287 {
11288 expr = (adjust_result_of_qualified_name_lookup
11290 expr = (finish_qualified_id_expr
11294 }
11296 /* Expressions do not generally have reference type. */
11298 /* However, if we're about to form a pointer-to-member, we just
11299 want the referenced member referenced. */
11304 }
11306 /* Like tsubst, but deals with expressions. This function just replaces
11307 template parms; to finish processing the resultant expression, use
11308 tsubst_expr. */
11310 static tree
11312 {
11314 tree r;
11322 {
11327 {
11328 tree c;
11329 /* This can happen for a parameter name used later in a function
11330 declaration (such as in a late-specified return type). Just
11331 make a dummy decl, since it's only used for its type. */
11333 /* We copy T because want to tsubst the PARM_DECL only,
11334 not the following PARM_DECLs that are chained to T. */
11337 /* Give it the template pattern as its context; its true context
11338 hasn't been instantiated yet and this is good enough for
11339 mangling. */
11341 }
11349 {
11350 tree enum_type;
11351 tree v;
11355 /* There is no need to substitute into namespace-scope
11356 enumerators. */
11359 /* If ARGS is NULL, then T is known to be non-dependent. */
11363 /* Unfortunately, we cannot just call lookup_name here.
11364 Consider:
11366 template <int I> int f() {
11367 enum E { a = I };
11368 struct S { void g() { E e = a; } };
11369 };
11371 When we instantiate f<7>::S::g(), say, lookup_name is not
11372 clever enough to find f<7>::a. */
11373 enum_type
11383 /* We didn't find the name. That should never happen; if
11384 name-lookup found it during preliminary parsing, we
11385 should find it again here during instantiation. */
11387 }
11392 {
11393 tree ctx;
11398 {
11401 {
11405 }
11407 }
11408 }
11421 /* An OVERLOAD will always be a non-dependent overload set; an
11422 overload set from function scope will just be represented with an
11423 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11438 {
11439 /* Template template argument like the following example need
11440 special treatment:
11442 template <template <class> class TT> struct C {};
11443 template <class T> struct D {
11444 template <class U> struct E {};
11445 C<E> c; // #1
11446 };
11447 D<int> d; // #2
11449 We are processing the template argument `E' in #1 for
11450 the template instantiation #2. Originally, `E' is a
11451 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11452 have to substitute this with one having context `D<int>'. */
11456 }
11457 else
11458 /* Ordinary template template argument. */
11467 return build1
11473 {
11475 tree expanded;
11480 /* We only want to compute the number of arguments. */
11495 {
11502 else
11505 }
11506 else
11508 }
11509 /* Fall through */
11524 return build1
11529 {
11530 tree object;
11531 tree name;
11536 {
11540 }
11543 {
11553 }
11558 in_decl);
11559 else
11562 }
11600 return build_nt
11613 return build_nt
11620 {
11628 }
11633 {
11634 r = build_nt
11640 }
11643 {
11644 r = build_nt
11650 }
11653 {
11654 r = build_nt
11660 }
11663 {
11664 /* Substituted template arguments */
11673 }
11676 {
11696 }
11721 {
11724 }
11725 else
11729 /* This is handled by tsubst_copy_and_build. */
11734 in_decl),
11738 /* We shouldn't have built any of these during initial template
11739 generation. Instead, they should be built during instantiation
11740 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11744 r = build2
11764 {
11765 /* Instantiate any typedefs in the type. */
11770 }
11773 /* These can sometimes show up in a partial instantiation, but never
11774 involve template parms. */
11779 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
11782 }
11783 }
11785 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11787 static tree
11789 tree in_decl)
11790 {
11794 {
11800 {
11803 {
11809 }
11810 /* FALLTHRU */
11832 }
11833 }
11836 }
11838 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11840 static tree
11842 tree in_decl)
11843 {
11844 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11869 #undef RECUR
11870 }
11872 /* Substitute one OMP_FOR iterator. */
11874 static void
11879 {
11880 #define RECUR(NODE) \
11881 tsubst_expr ((NODE), args, complain, in_decl, \
11882 integral_constant_expression_p)
11891 {
11898 }
11902 {
11908 complain);
11909 else
11916 }
11919 {
11920 tree c;
11922 {
11933 }
11935 {
11940 {
11943 }
11944 }
11945 }
11951 else
11955 {
11966 {
11973 }
11974 else
11980 {
11986 }
11990 {
11997 }
11998 else
12004 }
12010 #undef RECUR
12011 }
12013 /* Like tsubst_copy for expressions, etc. but also does semantic
12014 processing. */
12016 static tree
12019 {
12020 #define RECUR(NODE) \
12021 tsubst_expr ((NODE), args, complain, in_decl, \
12022 integral_constant_expression_p)
12035 {
12037 {
12038 tree_stmt_iterator i;
12042 }
12057 else
12066 {
12068 tree init;
12074 {
12077 tree decl;
12085 else
12087 }
12088 else
12089 {
12093 {
12094 /* By marking the declaration as instantiated, we avoid
12095 trying to instantiate it. Since instantiate_decl can't
12096 handle local variables, and since we've already done
12097 all that needs to be done, that's the right thing to
12098 do. */
12103 /* Anonymous aggregates are a special case. */
12105 else
12106 {
12111 {
12112 /* For __PRETTY_FUNCTION__ we have to adjust the
12113 initializer. */
12117 }
12118 else
12119 {
12123 {
12124 /* If we had an initializer but it
12125 instantiated to nothing,
12126 value-initialize the object. This will
12127 only occur when the initializer was a
12128 pack expansion where the parameter packs
12129 used in that expansion were of length
12130 zero. */
12132 complain);
12135 }
12136 else
12138 }
12141 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12144 }
12145 }
12146 }
12148 /* A DECL_EXPR can also be used as an expression, in the condition
12149 clause of an if/for/while construct. */
12151 }
12166 {
12176 }
12203 {
12207 }
12215 else
12223 else
12250 {
12252 tree label;
12257 }
12263 /* Computed goto's must be tsubst'd into. On the other hand,
12264 non-computed gotos must not be; the identifier in question
12265 will have no binding. */
12267 else
12273 tmp = finish_asm_stmt
12280 {
12285 }
12290 {
12295 }
12296 else
12297 {
12302 else
12309 else
12315 else
12317 }
12321 {
12325 {
12327 /* Prevent instantiate_decl from trying to instantiate
12328 this variable. We've already done all that needs to be
12329 done. */
12332 }
12337 }
12345 {
12346 tree condition =
12348 args,
12355 }
12376 {
12391 integral_constant_expression_p);
12400 {
12404 }
12405 else
12406 {
12414 }
12428 }
12459 {
12464 }
12480 integral_constant_expression_p);
12481 }
12484 #undef RECUR
12485 }
12487 /* T is a postfix-expression that is not being used in a function
12488 call. Return the substituted version of T. */
12490 static tree
12492 tsubst_flags_t complain,
12493 tree in_decl)
12494 {
12498 else
12504 }
12506 /* Like tsubst but deals with expressions and performs semantic
12507 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12509 tree
12511 tree args,
12512 tsubst_flags_t complain,
12513 tree in_decl,
12516 {
12517 #define RECUR(NODE) \
12518 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12520 integral_constant_expression_p)
12522 tree op1;
12528 {
12531 /* Fall through. */
12533 {
12534 tree decl;
12535 cp_id_kind idk;
12540 {
12543 }
12545 /* Look up the name. */
12548 /* By convention, expressions use ERROR_MARK_NODE to indicate
12549 failure, not NULL_TREE. */
12555 integral_constant_expression_p,
12563 input_location);
12569 }
12572 {
12573 tree object;
12581 {
12584 }
12585 else
12592 else
12594 }
12597 {
12601 {
12602 /* A type conversion to reference type will be enclosed in
12603 such an indirect ref, but the substitution of the cast
12604 will have also added such an indirect ref. */
12607 }
12608 else
12611 }
12614 return build_nop
12623 {
12624 tree type;
12625 tree op;
12630 {
12635 }
12640 {
12653 }
12654 }
12672 complain);
12682 else
12684 in_decl);
12718 return build_x_binary_op
12722 ? ERROR_MARK
12726 ? ERROR_MARK
12729 complain);
12742 /* Fall through */
12747 {
12748 /* When there are no ARGS, we are trying to evaluate a
12749 non-dependent expression from the parser. Trying to do
12750 the substitutions may not work. */
12753 }
12754 else
12755 {
12763 }
12767 else
12772 {
12782 }
12796 {
12797 tree r = build_x_modify_expr
12801 complain);
12802 /* TREE_NO_WARNING must be set if either the expression was
12803 parenthesized or it uses an operator such as >>= rather
12804 than plain assignment. In the former case, it was already
12805 set and must be copied. In the latter case,
12806 build_x_modify_expr sets it and it must not be reset
12807 here. */
12811 }
12816 /* Remember that there was a reference to this entity. */
12822 {
12827 tree ret;
12831 else
12832 {
12836 }
12838 /* If there was an initializer in the original tree, but it
12839 instantiated to an empty list, then we should pass a
12840 non-NULL empty vector to tell build_new that it was an
12841 empty initializer() rather than no initializer. This can
12842 only happen when the initializer is a pack expansion whose
12843 parameter packs are of length zero. */
12846 else
12847 {
12851 else
12852 {
12855 }
12856 }
12863 complain);
12871 }
12874 return delete_sanity
12879 complain);
12884 complain);
12887 {
12888 tree function;
12893 tree ret;
12896 /* When we parsed the expression, we determined whether or
12897 not Koenig lookup should be performed. */
12900 {
12905 }
12907 {
12908 /* Do nothing; calling tsubst_copy_and_build on an identifier
12909 would incorrectly perform unqualified lookup again.
12911 Note that we can also have an IDENTIFIER_NODE if the earlier
12912 unqualified lookup found a member function; in that case
12913 koenig_p will be false and we do want to do the lookup
12914 again to find the instantiated member function.
12916 FIXME but doing that causes c++/15272, so we need to stop
12917 using IDENTIFIER_NODE in that situation. */
12919 }
12920 else
12921 {
12923 {
12929 }
12930 else
12934 in_decl,
12936 integral_constant_expression_p);
12940 }
12945 {
12951 else
12952 {
12953 /* Expand the pack expansion and push each entry onto
12954 CALL_ARGS. */
12957 {
12962 {
12967 }
12968 }
12969 else
12970 {
12971 /* A partial substitution. Add one entry. */
12973 }
12974 }
12975 }
12977 /* We do not perform argument-dependent lookup if normal
12978 lookup finds a non-function, in accordance with the
12979 expected resolution of DR 218. */
12982 /* If lookup found a member function, the Koenig lookup is
12983 not appropriate, even if an unqualified-name was used
12984 to denote the function. */
12987 /* Only do this when substitution turns a dependent call
12988 into a non-dependent call. */
12992 tf_none);
12996 {
12998 {
12999 /* For backwards compatibility and good diagnostics, try
13000 the unqualified lookup again if we aren't in SFINAE
13001 context. */
13002 tree unq = (tsubst_copy_and_build
13004 integral_constant_expression_p));
13006 {
13013 "%qD was not declared in this scope, "
13014 "and no declarations were found by "
13015 "argument-dependent lookup at the point "
13018 {
13020 "declarations in dependent base %qT are "
13026 else
13030 }
13031 else
13035 }
13036 }
13038 {
13042 }
13043 }
13045 /* Remember that there was a reference to this entity. */
13052 {
13067 complain);
13068 else
13069 ret = (build_new_method_call
13074 complain));
13075 }
13076 else
13079 koenig_p,
13080 complain);
13085 }
13088 return build_x_conditional_expr
13092 complain);
13095 return finish_pseudo_destructor_expr
13101 {
13109 {
13110 /* We have pack expansions, so expand those and
13111 create a new list out of it. */
13114 tree chain;
13117 /* Expand the argument expressions. */
13125 /* Build the rest of the list. */
13130 /* Determine the number of arguments. */
13132 {
13135 }
13138 else
13139 {
13140 /* Since we only performed a partial substitution into
13141 the argument pack, we only return a single list
13142 node. */
13149 }
13151 /* Convert the argument vectors into a TREE_LIST */
13154 {
13155 /* Grab the Ith values. */
13156 i--;
13159 value
13163 /* Build the list (backwards). */
13165 }
13168 }
13184 }
13187 {
13188 tree object;
13189 tree object_type;
13190 tree member;
13194 /* Remember that there was a reference to this entity. */
13204 else
13210 {
13212 {
13217 {
13220 }
13222 {
13226 }
13227 }
13228 }
13231 {
13232 tree tmpl;
13233 tree args;
13235 /* Lookup the template functions now that we know what the
13236 scope is. */
13243 {
13246 args);
13247 member = (adjust_result_of_qualified_name_lookup
13249 object_type));
13250 }
13251 else
13252 {
13254 input_location);
13256 }
13257 }
13261 {
13263 {
13267 else
13270 }
13272 }
13278 complain);
13279 }
13282 return build_throw
13286 {
13294 tree r;
13299 /* digest_init will do the wrong thing if we let it. */
13303 /* We do not want to process the index of aggregate
13304 initializers as they are identifier nodes which will be
13305 looked up by digest_init. */
13311 {
13316 {
13317 /* Substitute into the pack expansion. */
13319 in_decl);
13323 ;
13325 /* Just move the argument into place. */
13327 else
13328 {
13329 /* Update the length of the final CONSTRUCTOR
13330 arguments vector, and note that we will need to
13331 copy.*/
13334 }
13335 }
13336 else
13338 }
13341 {
13346 {
13348 {
13353 }
13354 else
13356 }
13357 }
13367 }
13370 {
13373 {
13376 }
13377 else
13378 {
13381 }
13382 }
13387 /* Fall through */
13390 {
13394 /* If the original type was a reference, we'll be wrapped in
13395 the appropriate INDIRECT_REF. */
13398 }
13408 {
13417 }
13420 {
13426 integral_constant_expression_p);
13430 /* If the resulting list of expression statement is empty,
13431 fold it further into void_zero_node. */
13436 }
13440 /* As in finish_id_expression, we resolve enumeration constants
13441 to their underlying values. */
13443 {
13446 }
13450 {
13471 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
13473 /* Now that we know visibility, instantiate the type so we have a
13474 declaration of the op() for later calls to lambda_function. */
13482 }
13485 /* We can get here for a constant initializer of non-dependent type.
13486 FIXME stop folding in cp_parser_initializer_clause. */
13488 {
13492 }
13495 /* Handle Objective-C++ constructs, if appropriate. */
13496 {
13497 tree subst
13502 }
13504 }
13506 #undef RECUR
13507 }
13509 /* Verify that the instantiated ARGS are valid. For type arguments,
13510 make sure that the type's linkage is ok. For non-type arguments,
13511 make sure they are constants if they are integral or enumerations.
13512 Emit an error under control of COMPLAIN, and return TRUE on error. */
13514 static bool
13516 {
13518 {
13528 }
13530 {
13531 /* [basic.link]: A name with no linkage (notably, the name
13532 of a class or enumeration declared in a local scope)
13533 shall not be used to declare an entity with linkage.
13534 This implies that names with no linkage cannot be used as
13535 template arguments
13537 DR 757 relaxes this restriction for C++0x. */
13542 {
13543 /* DR 488 makes use of a type with no linkage cause
13544 type deduction to fail. */
13546 {
13549 else
13552 }
13554 }
13555 /* In order to avoid all sorts of complications, we do not
13556 allow variably-modified types as template arguments. */
13558 {
13562 }
13563 }
13564 /* A non-type argument of integral or enumerated type must be a
13565 constant. */
13569 {
13573 }
13575 }
13577 static bool
13579 {
13584 {
13587 }
13591 }
13598 /* In C++0x, it's possible to have a function template whose type depends
13599 on itself recursively. This is most obvious with decltype, but can also
13600 occur with enumeration scope (c++/48969). So we need to catch infinite
13601 recursion and reject the substitution at deduction time.
13603 Use of a VEC here is O(n^2) in the depth of function template argument
13604 deduction substitution, but using a hash table creates a lot of constant
13605 overhead for the typical case of very low depth. So to make the typical
13606 case fast we start out with a VEC and switch to a hash table only if
13607 depth gets to be significant; in one metaprogramming testcase, even at
13608 depth 80 the overhead of the VEC relative to a hash table was only about
13609 0.5% of compile time. */
13611 static tree
13613 {
13617 spec_entry elt;
13618 tree r;
13619 hashval_t hash;
13623 /* We don't need to worry about this in C++98. */
13627 /* If we're seeing a lot of recursion, switch over to a hash table. The
13628 constant 40 is fairly arbitrary. */
13631 {
13635 {
13640 }
13642 }
13644 /* Now check everything in the vector, if any. */
13647 {
13650 }
13656 /* If we've created a hash table, look there. */
13658 {
13663 {
13664 /* We already have an entry for this. */
13667 }
13668 else
13669 {
13670 /* Create a new entry. */
13673 }
13674 }
13675 else
13676 {
13677 /* No hash table, so add it to the VEC. */
13680 }
13684 /* After doing the substitution, make sure we didn't hit it again. Note
13685 that we might have switched to a hash table during tsubst. */
13687 {
13692 NO_INSERT);
13696 }
13697 else
13698 {
13703 }
13705 }
13707 /* Instantiate the indicated variable or function template TMPL with
13708 the template arguments in TARG_PTR. */
13710 static tree
13712 {
13714 tree fndecl;
13715 tree gen_tmpl;
13716 tree spec;
13717 HOST_WIDE_INT saved_processing_template_decl;
13724 /* If this function is a clone, handle it specially. */
13726 {
13727 tree spec;
13728 tree clone;
13730 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13731 DECL_CLONED_FUNCTION. */
13737 /* Look for the clone. */
13741 /* We should always have found the clone by now. */
13744 }
13746 /* Check to see if we already have this specialization. */
13749 /* The TMPL is a partial instantiation. To get a full set of
13750 arguments we must add the arguments used to perform the
13751 partial instantiation. */
13753 targ_ptr);
13755 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13756 but it doesn't seem to be on the hot path. */
13768 complain))
13771 /* We are building a FUNCTION_DECL, during which the access of its
13772 parameters and return types have to be checked. However this
13773 FUNCTION_DECL which is the desired context for access checking
13774 is not built yet. We solve this chicken-and-egg problem by
13775 deferring all checks until we have the FUNCTION_DECL. */
13778 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13779 (because, for example, we have encountered a non-dependent
13780 function call in the body of a template function and must now
13781 determine which of several overloaded functions will be called),
13782 within the instantiation itself we are not processing a
13783 template. */
13786 /* Substitute template parameters to obtain the specialization. */
13793 /* Now we know the specialization, compute access previously
13794 deferred. */
13797 /* Some typedefs referenced from within the template code need to be access
13798 checked at template instantiation time, i.e now. These types were
13799 added to the template at parsing time. Let's get those and perfom
13800 the acces checks then. */
13806 /* The DECL_TI_TEMPLATE should always be the immediate parent
13807 template, not the most general template. */
13810 /* If we've just instantiated the main entry point for a function,
13811 instantiate all the alternate entry points as well. We do this
13812 by cloning the instantiation of the main entry point, not by
13813 instantiating the template clones. */
13818 }
13820 /* Wrapper for instantiate_template_1. */
13822 tree
13824 {
13825 tree ret;
13830 }
13832 /* We're going to do deduction substitution on the type of TMPL, a function
13833 template. In C++11 mode, push into that access scope. In C++03 mode,
13834 disable access checking. */
13836 static void
13838 {
13841 else
13843 }
13845 /* And pop back out. */
13847 static void
13849 {
13852 else
13854 }
13856 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13857 NARGS elements of the arguments that are being used when calling
13858 it. TARGS is a vector into which the deduced template arguments
13859 are placed.
13861 Return zero for success, 2 for an incomplete match that doesn't resolve
13862 all the types, and 1 for complete failure. An error message will be
13863 printed only for an incomplete match.
13865 If FN is a conversion operator, or we are trying to produce a specific
13866 specialization, RETURN_TYPE is the return type desired.
13868 The EXPLICIT_TARGS are explicit template arguments provided via a
13869 template-id.
13871 The parameter STRICT is one of:
13873 DEDUCE_CALL:
13874 We are deducing arguments for a function call, as in
13875 [temp.deduct.call].
13877 DEDUCE_CONV:
13878 We are deducing arguments for a conversion function, as in
13879 [temp.deduct.conv].
13881 DEDUCE_EXACT:
13882 We are deducing arguments when doing an explicit instantiation
13883 as in [temp.explicit], when determining an explicit specialization
13884 as in [temp.expl.spec], or when taking the address of a function
13885 template, as in [temp.deduct.funcaddr]. */
13887 int
13889 tree explicit_targs,
13890 tree targs,
13893 tree return_type,
13894 unification_kind_t strict,
13896 {
13897 tree parms;
13898 tree fntype;
13906 {
13907 /* [temp.deduct]
13909 The specified template arguments must match the template
13910 parameters in kind (i.e., type, nontype, template), and there
13911 must not be more arguments than there are parameters;
13912 otherwise type deduction fails.
13914 Nontype arguments must match the types of the corresponding
13915 nontype template parameters, or must be convertible to the
13916 types of the corresponding nontype parameters as specified in
13917 _temp.arg.nontype_, otherwise type deduction fails.
13919 All references in the function type of the function template
13920 to the corresponding template parameters are replaced by the
13921 specified template argument values. If a substitution in a
13922 template parameter or in the function type of the function
13923 template results in an invalid type, type deduction fails. */
13926 tree converted_args;
13932 converted_args
13939 /* Substitute the explicit args into the function type. This is
13940 necessary so that, for instance, explicitly declared function
13941 arguments can match null pointed constants. If we were given
13942 an incomplete set of explicit args, we must not do semantic
13943 processing during substitution as we could create partial
13944 instantiations. */
13946 {
13950 /* Dig out the actual parm. */
13953 {
13956 }
13958 {
13961 }
13964 {
13966 tree targ;
13969 /* Mark the argument pack as "incomplete". We could
13970 still deduce more arguments during unification.
13971 We remove this mark in type_unification_real. */
13974 {
13978 }
13980 /* We have some incomplete argument packs. */
13982 }
13983 }
13986 /* Any substitution is guaranteed to be incomplete if there
13987 are incomplete argument packs, because we can still deduce
13988 more arguments. */
13990 else
14002 /* Place the explicitly specified arguments in TARGS. */
14005 }
14007 /* Never do unification on the 'this' parameter. */
14011 {
14020 }
14022 /* We allow incomplete unification without an error message here
14023 because the standard doesn't seem to explicitly prohibit it. Our
14024 callers must be ready to deal with unification failures in any
14025 event. */
14030 /* Now that we have bindings for all of the template arguments,
14031 ensure that the arguments deduced for the template template
14032 parameters have compatible template parameter lists. We cannot
14033 check this property before we have deduced all template
14034 arguments, because the template parameter types of a template
14035 template parameter might depend on prior template parameters
14036 deduced after the template template parameter. The following
14037 ill-formed example illustrates this issue:
14039 template<typename T, template<T> class C> void f(C<5>, T);
14041 template<int N> struct X {};
14043 void g() {
14044 f(X<5>(), 5l); // error: template argument deduction fails
14045 }
14047 The template parameter list of 'C' depends on the template type
14048 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14049 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14050 time that we deduce 'C'. */
14052 && !template_template_parm_bindings_ok_p
14057 /* All is well so far. Now, check:
14059 [temp.deduct]
14061 When all template arguments have been deduced, all uses of
14062 template parameters in nondeduced contexts are replaced with
14063 the corresponding deduced argument values. If the
14064 substitution results in an invalid type, as described above,
14065 type deduction fails. */
14066 {
14067 tree substed;
14074 /* If we're looking for an exact match, check that what we got
14075 is indeed an exact match. It might not be if some template
14076 parameters are used in non-deduced contexts. */
14078 {
14081 tree sarg
14088 }
14089 }
14092 }
14094 /* Adjust types before performing type deduction, as described in
14095 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14096 sections are symmetric. PARM is the type of a function parameter
14097 or the return type of the conversion function. ARG is the type of
14098 the argument passed to the call, or the type of the value
14099 initialized with the result of the conversion function.
14100 ARG_EXPR is the original argument expression, which may be null. */
14102 static int
14106 tree arg_expr)
14107 {
14111 {
14116 {
14117 /* Swap PARM and ARG throughout the remainder of this
14118 function; the handling is precisely symmetric since PARM
14119 will initialize ARG rather than vice versa. */
14124 }
14127 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14128 too, but here handle it by stripping the reference from PARM
14129 rather than by adding it to ARG. */
14137 /* Nothing else to do in this case. */
14142 }
14145 {
14146 /* [temp.deduct.call]
14148 If P is not a reference type:
14150 --If A is an array type, the pointer type produced by the
14151 array-to-pointer standard conversion (_conv.array_) is
14152 used in place of A for type deduction; otherwise,
14154 --If A is a function type, the pointer type produced by
14155 the function-to-pointer standard conversion
14156 (_conv.func_) is used in place of A for type deduction;
14157 otherwise,
14159 --If A is a cv-qualified type, the top level
14160 cv-qualifiers of A's type are ignored for type
14161 deduction. */
14166 else
14168 }
14170 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
14171 of the form T&&, where T is a template parameter, and the argument
14172 is an lvalue, T is deduced as A& */
14178 /* try_one_overload doesn't provide an arg_expr, but
14179 functions are always lvalues. */
14183 /* [temp.deduct.call]
14185 If P is a cv-qualified type, the top level cv-qualifiers
14186 of P's type are ignored for type deduction. If P is a
14187 reference type, the type referred to by P is used for
14188 type deduction. */
14191 {
14194 }
14196 /* DR 322. For conversion deduction, remove a reference type on parm
14197 too (which has been swapped into ARG). */
14202 }
14204 /* Most parms like fn_type_unification.
14206 If SUBR is 1, we're being called recursively (to unify the
14207 arguments of a function or method parameter of a function
14208 template). */
14210 static int
14212 tree targs,
14213 tree xparms,
14217 unification_kind_t strict,
14219 {
14225 tree parms;
14234 /* Reset the number of non-defaulted template arguments contained
14235 in TARGS. */
14239 {
14255 }
14257 again:
14265 {
14270 /* For a function parameter pack that occurs at the end of the
14271 parameter-declaration-list, the type A of each remaining
14272 argument of the call is compared with the type P of the
14273 declarator-id of the function parameter pack. */
14279 /* For a function parameter pack that does not occur at the
14280 end of the parameter-declaration-list, the type of the
14281 parameter pack is a non-deduced context. */
14291 /* We can't deduce anything from this, but we might get all the
14292 template args from other function args. */
14295 /* Conversions will be performed on a function argument that
14296 corresponds with a function parameter that contains only
14297 non-deducible template parameters and explicitly specified
14298 template parameters. */
14300 {
14301 tree type;
14305 else
14312 flags))
14316 }
14319 {
14322 {
14323 /* [temp.deduct.type]
14325 A template-argument can be deduced from a pointer to
14326 function or pointer to member function argument if
14327 the set of overloaded functions does not contain
14328 function templates and at most one of a set of
14329 overloaded functions provides a unique match. */
14335 }
14340 }
14342 {
14347 arg_expr);
14353 }
14354 }
14360 {
14361 /* Unify the remaining arguments with the pack expansion type. */
14362 tree argvec;
14365 /* Allocate a TREE_VEC and copy in all of the arguments */
14370 /* Copy the parameter into parmvec. */
14376 /* Advance to the end of the list of parameters. */
14378 }
14380 /* Fail if we've reached the end of the parm list, and more args
14381 are present, and the parm list isn't variadic. */
14384 /* Fail if parms are left and they don't have default values. */
14390 {
14391 /* Check to see if we need another pass before we start clearing
14392 ARGUMENT_PACK_INCOMPLETE_P. */
14394 {
14402 /* If this is an undeduced nontype parameter that depends on
14403 a type parameter, try another pass; its type may have been
14404 deduced from a later argument than the one from which
14405 this parameter can be deduced. */
14410 }
14413 {
14417 /* Clear the "incomplete" flags on all argument packs now so that
14418 substituting them into later default arguments works. */
14420 {
14423 }
14429 /* Core issue #226 (C++0x) [temp.deduct]:
14431 If a template argument has not been deduced, its
14432 default template argument, if any, is used.
14434 When we are in C++98 mode, TREE_PURPOSE will either
14435 be NULL_TREE or ERROR_MARK_NODE, so we do not need
14436 to explicitly check cxx_dialect here. */
14438 {
14446 else
14447 {
14449 /* The position of the first default template argument,
14450 is also the number of non-defaulted arguments in TARGS.
14451 Record that. */
14455 }
14456 }
14458 /* If the type parameter is a parameter pack, then it will
14459 be deduced to an empty parameter pack. */
14461 {
14462 tree arg;
14465 {
14469 }
14470 else
14477 }
14480 }
14481 }
14482 #ifdef ENABLE_CHECKING
14485 #endif
14488 }
14490 /* Subroutine of type_unification_real. Args are like the variables
14491 at the call site. ARG is an overloaded function (or template-id);
14492 we try deducing template args from each of the overloads, and if
14493 only one succeeds, we go with that. Modifies TARGS and returns
14494 true on success. */
14496 static bool
14498 tree targs,
14499 tree parm,
14500 tree arg,
14501 unification_kind_t strict,
14503 {
14510 {
14513 }
14514 else
14518 /* Handle `&x' where `x' is some static or non-static member
14519 function name. */
14525 /* Strip baselink information. */
14530 {
14531 /* If we got some explicit template args, we need to plug them into
14532 the affected templates before we try to unify, in case the
14533 explicit args will completely resolve the templates in question. */
14539 {
14550 {
14555 {
14558 }
14559 }
14561 }
14562 }
14565 /* If ARG is, for example, "(0, &f)" then its type will be unknown
14566 -- but the deduction does not succeed because the expression is
14567 not just the function on its own. */
14569 else
14575 {
14578 }
14580 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14581 to function or pointer to member function argument if the set of
14582 overloaded functions does not contain function templates and at most
14583 one of a set of overloaded functions provides a unique match.
14585 So if we found multiple possibilities, we return success but don't
14586 deduce anything. */
14589 {
14594 }
14599 }
14601 /* Core DR 115: In contexts where deduction is done and fails, or in
14602 contexts where deduction is not done, if a template argument list is
14603 specified and it, along with any default template arguments, identifies
14604 a single function template specialization, then the template-id is an
14605 lvalue for the function template specialization. */
14607 tree
14609 {
14622 {
14625 }
14627 {
14630 }
14632 {
14635 }
14638 {
14642 /* If we got some explicit template args, we need to plug them into
14643 the affected templates before we try to unify, in case the
14644 explicit args will completely resolve the templates in question. */
14652 {
14663 {
14666 {
14669 }
14671 {
14674 }
14675 }
14677 }
14679 {
14686 {
14687 tree base
14690 }
14694 }
14696 /* There were no good options and at least one bad one, so let the
14697 user know what the problem is. */
14699 }
14701 }
14703 /* Subroutine of resolve_overloaded_unification; does deduction for a single
14704 overload. Fills TARGS with any deduced arguments, or error_mark_node if
14705 different overloads deduce different arguments for a given parm.
14706 ADDR_P is true if the expression for which deduction is being
14707 performed was of the form "& fn" rather than simply "fn".
14709 Returns 1 on success. */
14711 static int
14713 tree orig_targs,
14714 tree targs,
14715 tree parm,
14716 tree arg,
14717 unification_kind_t strict,
14720 {
14722 tree tempargs;
14725 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14726 to function or pointer to member function argument if the set of
14727 overloaded functions does not contain function templates and at most
14728 one of a set of overloaded functions provides a unique match.
14730 So if this is a template, just return success. */
14742 /* We don't copy orig_targs for this because if we have already deduced
14743 some template args from previous args, unify would complain when we
14744 try to deduce a template parameter for the same argument, even though
14745 there isn't really a conflict. */
14752 /* First make sure we didn't deduce anything that conflicts with
14753 explicitly specified args. */
14755 {
14762 /* Since we're unifying against ourselves, we will fill in
14763 template args used in the function parm list with our own
14764 template parms. Discard them. */
14768 }
14771 {
14776 }
14779 }
14781 /* PARM is a template class (perhaps with unbound template
14782 parameters). ARG is a fully instantiated type. If ARG can be
14783 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14784 TARGS are as for unify. */
14786 static tree
14788 {
14789 tree copy_of_targs;
14796 /* We need to make a new template argument vector for the call to
14797 unify. If we used TARGS, we'd clutter it up with the result of
14798 the attempted unification, even if this class didn't work out.
14799 We also don't want to commit ourselves to all the unifications
14800 we've already done, since unification is supposed to be done on
14801 an argument-by-argument basis. In other words, consider the
14802 following pathological case:
14804 template <int I, int J, int K>
14805 struct S {};
14807 template <int I, int J>
14808 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14810 template <int I, int J, int K>
14811 void f(S<I, J, K>, S<I, I, I>);
14813 void g() {
14814 S<0, 0, 0> s0;
14815 S<0, 1, 2> s2;
14817 f(s0, s2);
14818 }
14820 Now, by the time we consider the unification involving `s2', we
14821 already know that we must have `f<0, 0, 0>'. But, even though
14822 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14823 because there are two ways to unify base classes of S<0, 1, 2>
14824 with S<I, I, I>. If we kept the already deduced knowledge, we
14825 would reject the possibility I=1. */
14828 /* If unification failed, we're done. */
14834 }
14836 /* Given a template type PARM and a class type ARG, find the unique
14837 base type in ARG that is an instance of PARM. We do not examine
14838 ARG itself; only its base-classes. If there is not exactly one
14839 appropriate base class, return NULL_TREE. PARM may be the type of
14840 a partial specialization, as well as a plain template type. Used
14841 by unify. */
14843 static tree
14845 {
14847 tree binfo;
14853 /* The type could not be completed. */
14856 /* Walk in inheritance graph order. The search order is not
14857 important, and this avoids multiple walks of virtual bases. */
14859 {
14863 {
14864 /* If there is more than one satisfactory baseclass, then:
14866 [temp.deduct.call]
14868 If they yield more than one possible deduced A, the type
14869 deduction fails.
14871 applies. */
14876 }
14877 }
14880 }
14882 /* Returns the level of DECL, which declares a template parameter. */
14884 static int
14886 {
14888 {
14898 }
14900 }
14902 /* Decide whether ARG can be unified with PARM, considering only the
14903 cv-qualifiers of each type, given STRICT as documented for unify.
14904 Returns nonzero iff the unification is OK on that basis. */
14906 static int
14908 {
14914 {
14915 /* Although a CVR qualifier is ignored when being applied to a
14916 substituted template parameter ([8.3.2]/1 for example), that
14917 does not allow us to unify "const T" with "int&" because both
14918 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14919 It is ok when we're allowing additional CV qualifiers
14920 at the outer level [14.8.2.1]/3,1st bullet. */
14930 }
14941 }
14943 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14944 void
14946 {
14950 {
14953 }
14954 else
14955 {
14958 }
14959 }
14961 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14962 expansion at the end of PACKED_PARMS. Returns 0 if the type
14963 deduction succeeds, 1 otherwise. STRICT is the same as in
14964 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14965 call argument list. We'll need to adjust the arguments to make them
14966 types. SUBR tells us if this is from a recursive call to
14967 type_unification_real. */
14968 int
14972 {
14973 tree parm
14980 /* Determine the parameter packs we will be deducing from the
14981 pattern, and record their current deductions. */
14984 {
14988 /* Determine the index and level of this parameter pack. */
14991 /* Keep track of the parameter packs and their corresponding
14992 argument packs. */
14995 }
14997 /* Loop through all of the arguments that have not yet been
14998 unified and unify each with the pattern. */
15000 {
15003 /* For each parameter pack, clear out the deduced value so that
15004 we can deduce it again. */
15006 {
15011 }
15013 /* Unify the pattern with the current argument. */
15014 {
15021 {
15024 /* This mirrors what we do in type_unification_real. */
15026 {
15028 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
15029 | UNIFY_ALLOW_MORE_CV_QUAL
15043 }
15046 {
15049 {
15050 /* [temp.deduct.type] A template-argument can be
15051 deduced from a pointer to function or pointer
15052 to member function argument if the set of
15053 overloaded functions does not contain function
15054 templates and at most one of a set of
15055 overloaded functions provides a unique
15056 match. */
15061 sub_strict)
15065 }
15068 {
15073 }
15074 }
15079 arg_strict |=
15082 }
15085 {
15086 /* For deduction from an init-list we need the actual list. */
15091 }
15092 }
15094 /* For each parameter pack, collect the deduced value. */
15096 {
15102 }
15103 }
15105 /* Verify that the results of unification with the parameter packs
15106 produce results consistent with what we've seen before, and make
15107 the deduced argument packs available. */
15109 {
15116 /* By default keep the original deduced argument pack.
15117 If necessary, more specific code is going to update the
15118 resulting deduced argument later down in this function. */
15122 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
15123 actually deduce anything. */
15131 {
15132 /* Prepend the explicit arguments onto NEW_ARGS. */
15138 /* Copy the explicit arguments. */
15143 /* Copy the deduced arguments. */
15147 }
15150 {
15151 tree result;
15152 /* Build the deduced *_ARGUMENT_PACK. */
15154 {
15159 }
15160 else
15165 /* Note the deduced argument packs for this parameter
15166 pack. */
15168 }
15172 {
15173 /* We only had the explicitly-provided arguments before, but
15174 now we have a complete set of arguments. */
15180 }
15182 new_args))
15183 /* Inconsistent unification of this parameter pack. */
15185 }
15188 }
15190 /* Deduce the value of template parameters. TPARMS is the (innermost)
15191 set of template parameters to a template. TARGS is the bindings
15192 for those template parameters, as determined thus far; TARGS may
15193 include template arguments for outer levels of template parameters
15194 as well. PARM is a parameter to a template function, or a
15195 subcomponent of that parameter; ARG is the corresponding argument.
15196 This function attempts to match PARM with ARG in a manner
15197 consistent with the existing assignments in TARGS. If more values
15198 are deduced, then TARGS is updated.
15200 Returns 0 if the type deduction succeeds, 1 otherwise. The
15201 parameter STRICT is a bitwise or of the following flags:
15203 UNIFY_ALLOW_NONE:
15204 Require an exact match between PARM and ARG.
15205 UNIFY_ALLOW_MORE_CV_QUAL:
15206 Allow the deduced ARG to be more cv-qualified (by qualification
15207 conversion) than ARG.
15208 UNIFY_ALLOW_LESS_CV_QUAL:
15209 Allow the deduced ARG to be less cv-qualified than ARG.
15210 UNIFY_ALLOW_DERIVED:
15211 Allow the deduced ARG to be a template base class of ARG,
15212 or a pointer to a template base class of the type pointed to by
15213 ARG.
15214 UNIFY_ALLOW_INTEGER:
15215 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
15216 case for more information.
15217 UNIFY_ALLOW_OUTER_LEVEL:
15218 This is the outermost level of a deduction. Used to determine validity
15219 of qualification conversions. A valid qualification conversion must
15220 have const qualified pointers leading up to the inner type which
15221 requires additional CV quals, except at the outer level, where const
15222 is not required [conv.qual]. It would be normal to set this flag in
15223 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
15224 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
15225 This is the outermost level of a deduction, and PARM can be more CV
15226 qualified at this point.
15227 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
15228 This is the outermost level of a deduction, and PARM can be less CV
15229 qualified at this point. */
15231 static int
15233 {
15235 tree targ;
15236 tree tparm;
15239 /* I don't think this will do the right thing with respect to types.
15240 But the only case I've seen it in so far has been array bounds, where
15241 signedness is the only information lost, and I think that will be
15242 okay. */
15250 /* We can't deduce anything from this, but we might get all the
15251 template args from other function args. */
15254 /* If PARM uses template parameters, then we can't bail out here,
15255 even if ARG == PARM, since we won't record unifications for the
15256 template parameters. We might need them if we're trying to
15257 figure out which of two things is more specialized. */
15261 /* Handle init lists early, so the rest of the function can assume
15262 we're dealing with a type. */
15264 {
15269 /* Replace T with std::initializer_list<T> for deduction. */
15275 /* We can only deduce from an initializer list argument if the
15276 parameter is std::initializer_list; otherwise this is a
15277 non-deduced context. */
15283 {
15290 {
15292 /* It should only be possible to get here for a call. */
15294 elt_strict |= maybe_adjust_types_for_deduction
15297 }
15301 }
15303 /* If the std::initializer_list<T> deduction worked, replace the
15304 deduced A with std::initializer_list<A>. */
15306 {
15311 }
15313 }
15315 /* Immediately reject some pairs that won't unify because of
15316 cv-qualification mismatches. */
15319 /* It is the elements of the array which hold the cv quals of an array
15320 type, and the elements might be template type parms. We'll check
15321 when we recurse. */
15323 /* We check the cv-qualifiers when unifying with template type
15324 parameters below. We want to allow ARG `const T' to unify with
15325 PARM `T' for example, when computing which of two templates
15326 is more specialized, for example. */
15340 {
15344 /* In a type which contains a nested-name-specifier, template
15345 argument values cannot be deduced for template parameters used
15346 within the nested-name-specifier. */
15358 /* The PARM is not one we're trying to unify. Just check
15359 to see if it matches ARG. */
15366 /* Check for mixed types and values. */
15374 {
15375 /* ARG must be constructed from a template class or a template
15376 template parameter. */
15381 {
15385 tree parm_parms
15386 = DECL_INNERMOST_TEMPLATE_PARMS
15391 /* The resolution to DR150 makes clear that default
15392 arguments for an N-argument may not be used to bind T
15393 to a template template parameter with fewer than N
15394 parameters. It is not safe to permit the binding of
15395 default arguments as an extension, as that may change
15396 the meaning of a conforming program. Consider:
15398 struct Dense { static const unsigned int dim = 1; };
15400 template <template <typename> class View,
15401 typename Block>
15402 void operator+(float, View<Block> const&);
15404 template <typename Block,
15405 unsigned int Dim = Block::dim>
15406 struct Lvalue_proxy { operator float() const; };
15408 void
15409 test_1d (void) {
15410 Lvalue_proxy<Dense> p;
15411 float b;
15412 b + p;
15413 }
15415 Here, if Lvalue_proxy is permitted to bind to View, then
15416 the global operator+ will be used; if they are not, the
15417 Lvalue_proxy will be converted to float. */
15419 full_argvec,
15421 tf_none,
15427 /* Deduce arguments T, i from TT<T> or TT<i>.
15428 We check each element of PARMVEC and ARGVEC individually
15429 rather than the whole TREE_VEC since they can have
15430 different number of elements. */
15437 /* Check if the parameters end in a pack, making them
15438 variadic. */
15447 {
15451 UNIFY_ALLOW_NONE))
15453 }
15458 UNIFY_ALLOW_NONE,
15462 }
15465 /* Fall through to deduce template name. */
15466 }
15470 {
15471 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
15473 /* Simple cases: Value already set, does match or doesn't. */
15478 }
15479 else
15480 {
15481 /* If PARM is `const T' and ARG is only `int', we don't have
15482 a match unless we are allowing additional qualification.
15483 If ARG is `const int' and PARM is just `T' that's OK;
15484 that binds `const int' to `T'. */
15489 /* Consider the case where ARG is `const volatile int' and
15490 PARM is `const T'. Then, T should be `volatile int'. */
15491 arg = cp_build_qualified_type_real
15496 /* Simple cases: Value already set, does match or doesn't. */
15502 /* Make sure that ARG is not a variable-sized array. (Note
15503 that were talking about variable-sized arrays (like
15504 `int[n]'), rather than arrays of unknown size (like
15505 `int[]').) We'll get very confused by such a type since
15506 the bound of the array will not be computable in an
15507 instantiation. Besides, such types are not allowed in
15508 ISO C++, so we can do as we please here. */
15512 /* Strip typedefs as in convert_template_argument. */
15514 }
15516 /* If ARG is a parameter pack or an expansion, we cannot unify
15517 against it unless PARM is also a parameter pack. */
15522 /* If the argument deduction results is a METHOD_TYPE,
15523 then there is a problem.
15524 METHOD_TYPE doesn't map to any real C++ type the result of
15525 the deduction can not be of that type. */
15539 /* The PARM is not one we're trying to unify. Just check
15540 to see if it matches ARG. */
15550 /* [temp.deduct.type] If, in the declaration of a function template
15551 with a non-type template-parameter, the non-type
15552 template-parameter is used in an expression in the function
15553 parameter-list and, if the corresponding template-argument is
15554 deduced, the template-argument type shall match the type of the
15555 template-parameter exactly, except that a template-argument
15556 deduced from an array bound may be of any integral type.
15557 The non-type parameter might use already deduced type parameters. */
15560 /* Template-parameter dependent expression. Just accept it for now.
15561 It will later be processed in convert_template_argument. */
15562 ;
15568 /* Convert the ARG to the type of PARM; the deduced non-type
15569 template argument must exactly match the types of the
15570 corresponding parameter. */
15573 /* We haven't deduced the type of this parameter yet. Try again
15574 later. */
15576 else
15579 /* If ARG is a parameter pack or an expansion, we cannot unify
15580 against it unless PARM is also a parameter pack. */
15589 {
15590 /* A pointer-to-member constant can be unified only with
15591 another constant. */
15595 /* Just unify the class member. It would be useless (and possibly
15596 wrong, depending on the strict flags) to unify also
15597 PTRMEM_CST_CLASS, because we want to be sure that both parm and
15598 arg refer to the same variable, even if through different
15599 classes. For instance:
15601 struct A { int x; };
15602 struct B : A { };
15604 Unification of &A::x and &B::x must succeed. */
15607 }
15610 {
15614 /* [temp.deduct.call]
15616 A can be another pointer or pointer to member type that can
15617 be converted to the deduced A via a qualification
15618 conversion (_conv.qual_).
15620 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
15621 This will allow for additional cv-qualification of the
15622 pointed-to types if appropriate. */
15625 /* The derived-to-base conversion only persists through one
15626 level of pointers. */
15631 }
15646 {
15647 tree parm_max;
15648 tree arg_max;
15652 /* Our representation of array types uses "N - 1" as the
15653 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
15654 not an integer constant. We cannot unify arbitrarily
15655 complex expressions, so we eliminate the MINUS_EXPRs
15656 here. */
15660 {
15663 }
15667 {
15668 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
15669 trying to unify the type of a variable with the type
15670 of a template parameter. For example:
15672 template <unsigned int N>
15673 void f (char (&) [N]);
15674 int g();
15675 void h(int i) {
15676 char a[g(i)];
15677 f(a);
15678 }
15680 Here, the type of the ARG will be "int [g(i)]", and
15681 may be a SAVE_EXPR, etc. */
15685 }
15687 /* If only one of the bounds used a MINUS_EXPR, compensate
15688 by adding one to the other bound. */
15691 integer_type_node,
15692 parm_max,
15693 integer_one_node);
15696 integer_type_node,
15697 arg_max,
15698 integer_one_node);
15702 }
15716 /* We have already checked cv-qualification at the top of the
15717 function. */
15721 /* As far as unification is concerned, this wins. Later checks
15722 will invalidate it if necessary. */
15725 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
15726 /* Type INTEGER_CST can come from ordinary constant template args. */
15736 {
15745 UNIFY_ALLOW_NONE))
15748 }
15756 {
15763 strict);
15764 }
15767 {
15771 {
15772 /* First, we try to unify the PARM and ARG directly. */
15777 {
15778 /* Fallback to the special case allowed in
15779 [temp.deduct.call]:
15781 If P is a class, and P has the form
15782 template-id, then A can be a derived class of
15783 the deduced A. Likewise, if P is a pointer to
15784 a class of the form template-id, A can be a
15785 pointer to a derived class pointed to by the
15786 deduced A. */
15791 }
15792 }
15796 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15797 Then, we should unify `int' and `U'. */
15799 else
15800 /* There's no chance of unification succeeding. */
15805 }
15812 {
15815 tree a;
15821 /* CV qualifications for methods can never be deduced, they must
15822 match exactly. We need to check them explicitly here,
15823 because type_unification_real treats them as any other
15824 cv-qualified parameter. */
15826 && (!check_cv_quals_for_unify
15846 LOOKUP_NORMAL);
15847 }
15850 /* Unify a pointer to member with a pointer to member function, which
15851 deduces the type of the member as a function type. */
15853 {
15854 tree method_type;
15855 tree fntype;
15857 /* Check top-level cv qualifiers */
15865 /* Determine the type of the function we are unifying against. */
15867 fntype =
15871 /* Extract the cv-qualifiers of the member function from the
15872 implicit object parameter and place them on the function
15873 type to be restored later. */
15876 }
15884 strict);
15895 /* Matched cases are handled by the ARG == PARM test above. */
15899 /* A non-type template parameter that is a variable should be a
15900 an integral constant, in which case, it whould have been
15901 folded into its (constant) value. So we should not be getting
15902 a variable here. */
15907 {
15915 {
15917 {
15919 /* We can unify against something with a trailing
15920 parameter pack. */
15922 else
15923 /* Since there is something following the pack
15924 expansion, we cannot unify this template argument
15925 list. */
15927 }
15928 }
15931 /* If we don't have enough arguments to satisfy the parameters
15932 (not counting the pack expression at the end), or we have
15933 too many arguments for a parameter list that doesn't end in
15934 a pack expression, we can't unify. */
15939 /* Unify all of the parameters that precede the (optional)
15940 pack expression. */
15942 {
15946 }
15954 }
15961 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
15962 or UNDERLYING_TYPE nodes. */
15966 /* Unification fails if we hit an error node. */
15970 /* An unresolved overload is a nondeduced context. */
15975 /* We must be looking at an expression. This can happen with
15976 something like:
15978 template <int I>
15979 void foo(S<I>, S<I + 2>);
15981 This is a "nondeduced context":
15983 [deduct.type]
15985 The nondeduced contexts are:
15987 --A type that is a template-id in which one or more of
15988 the template-arguments is an expression that references
15989 a template-parameter.
15991 In these cases, we assume deduction succeeded, but don't
15992 actually infer any unifications. */
15997 else
15999 }
16000 }
16001 \f
16002 /* Note that DECL can be defined in this translation unit, if
16003 required. */
16005 static void
16007 {
16008 tree clone;
16012 }
16014 /* Called if RESULT is explicitly instantiated, or is a member of an
16015 explicitly instantiated class. */
16017 void
16019 {
16022 /* If this entity has already been written out, it's too late to
16023 make any modifications. */
16028 /* The TREE_PUBLIC flag for function declarations will have been
16029 set correctly by tsubst. */
16032 /* This might have been set by an earlier implicit instantiation. */
16037 else
16038 {
16040 /* Always make artificials weak. */
16043 /* For WIN32 we also want to put explicit instantiations in
16044 linkonce sections. */
16047 }
16049 /* If EXTERN_P, then this function will not be emitted -- unless
16050 followed by an explicit instantiation, at which point its linkage
16051 will be adjusted. If !EXTERN_P, then this function will be
16052 emitted here. In neither circumstance do we want
16053 import_export_decl to adjust the linkage. */
16055 }
16057 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16058 important template arguments. If any are missing, we check whether
16059 they're important by using error_mark_node for substituting into any
16060 args that were used for partial ordering (the ones between ARGS and END)
16061 and seeing if it bubbles up. */
16063 static bool
16065 {
16070 {
16073 }
16075 {
16077 {
16081 }
16082 }
16084 }
16086 /* Given two function templates PAT1 and PAT2, return:
16088 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
16089 -1 if PAT2 is more specialized than PAT1.
16090 0 if neither is more specialized.
16092 LEN indicates the number of parameters we should consider
16093 (defaulted parameters should not be considered).
16095 The 1998 std underspecified function template partial ordering, and
16096 DR214 addresses the issue. We take pairs of arguments, one from
16097 each of the templates, and deduce them against each other. One of
16098 the templates will be more specialized if all the *other*
16099 template's arguments deduce against its arguments and at least one
16100 of its arguments *does* *not* deduce against the other template's
16101 corresponding argument. Deduction is done as for class templates.
16102 The arguments used in deduction have reference and top level cv
16103 qualifiers removed. Iff both arguments were originally reference
16104 types *and* deduction succeeds in both directions, the template
16105 with the more cv-qualified argument wins for that pairing (if
16106 neither is more cv-qualified, they both are equal). Unlike regular
16107 deduction, after all the arguments have been deduced in this way,
16108 we do *not* verify the deduced template argument values can be
16109 substituted into non-deduced contexts.
16111 The logic can be a bit confusing here, because we look at deduce1 and
16112 targs1 to see if pat2 is at least as specialized, and vice versa; if we
16113 can find template arguments for pat1 to make arg1 look like arg2, that
16114 means that arg2 is at least as specialized as arg1. */
16116 int
16118 {
16131 /* Remove the this parameter from non-static member functions. If
16132 one is a non-static member function and the other is not a static
16133 member function, remove the first parameter from that function
16134 also. This situation occurs for operator functions where we
16135 locate both a member function (with this pointer) and non-member
16136 operator (with explicit first operand). */
16138 {
16143 }
16145 {
16148 {
16149 len--;
16151 }
16152 }
16154 /* If only one is a conversion operator, they are unordered. */
16158 /* Consider the return type for a conversion function */
16160 {
16163 len++;
16164 }
16166 processing_template_decl++;
16172 /* Stop when an ellipsis is seen. */
16174 {
16183 {
16184 /* When both arguments are pack expansions, we need only
16185 unify the patterns themselves. */
16189 /* This is the last comparison we need to do. */
16191 }
16194 {
16197 }
16200 {
16203 }
16206 {
16207 /* Only of the args is a reference, see if we should apply
16208 array/function pointer decay to it. This is not part of
16209 DR214, but is, IMHO, consistent with the deduction rules
16210 for the function call itself, and with our earlier
16211 implementation of the underspecified partial ordering
16212 rules. (nathan). */
16214 {
16216 {
16219 /* FALLTHROUGH. */
16226 }
16227 }
16228 else
16229 {
16231 {
16234 /* FALLTHROUGH. */
16241 }
16242 }
16243 }
16249 {
16255 /* Setup the parameter vector, which contains only ARG1. */
16258 /* Setup the argument vector, which contains the remaining
16259 arguments. */
16268 /* We cannot deduce in the other direction, because ARG1 is
16269 a pack expansion but ARG2 is not. */
16271 }
16273 {
16279 /* Setup the parameter vector, which contains only ARG1. */
16282 /* Setup the argument vector, which contains the remaining
16283 arguments. */
16292 /* We cannot deduce in the other direction, because ARG2 is
16293 a pack expansion but ARG1 is not.*/
16295 }
16297 else
16298 {
16299 /* The normal case, where neither argument is a pack
16300 expansion. */
16303 }
16305 /* If we couldn't deduce arguments for tparms1 to make arg1 match
16306 arg2, then arg2 is not as specialized as arg1. */
16312 /* "If, for a given type, deduction succeeds in both directions
16313 (i.e., the types are identical after the transformations above)
16314 and if the type from the argument template is more cv-qualified
16315 than the type from the parameter template (as described above)
16316 that type is considered to be more specialized than the other. If
16317 neither type is more cv-qualified than the other then neither type
16318 is more specialized than the other." */
16322 {
16327 }
16330 /* We've failed to deduce something in either direction.
16331 These must be unordered. */
16336 /* We have already processed all of the arguments in our
16337 handing of the pack expansion type. */
16342 }
16344 /* "In most cases, all template parameters must have values in order for
16345 deduction to succeed, but for partial ordering purposes a template
16346 parameter may remain without a value provided it is not used in the
16347 types being used for partial ordering."
16349 Thus, if we are missing any of the targs1 we need to substitute into
16350 origs1, then pat2 is not as specialized as pat1. This can happen when
16351 there is a nondeduced context. */
16357 processing_template_decl--;
16359 /* All things being equal, if the next argument is a pack expansion
16360 for one function but not for the other, prefer the
16361 non-variadic function. FIXME this is bogus; see c++/41958. */
16365 {
16368 }
16374 else
16376 }
16378 /* Determine which of two partial specializations is more specialized.
16380 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
16381 to the first partial specialization. The TREE_VALUE is the
16382 innermost set of template parameters for the partial
16383 specialization. PAT2 is similar, but for the second template.
16385 Return 1 if the first partial specialization is more specialized;
16386 -1 if the second is more specialized; 0 if neither is more
16387 specialized.
16389 See [temp.class.order] for information about determining which of
16390 two templates is more specialized. */
16392 static int
16394 {
16395 tree targs;
16403 /* Just like what happens for functions, if we are ordering between
16404 different class template specializations, we may encounter dependent
16405 types in the arguments, and we need our dependency check functions
16406 to behave correctly. */
16412 {
16415 }
16421 {
16424 }
16427 /* In the case of a tie where at least one of the class templates
16428 has a parameter pack at the end, the template with the most
16429 non-packed parameters wins. */
16431 && any_deductions
16434 {
16440 /* We don't count the pack expansion at the end. */
16450 }
16453 }
16455 /* Return the template arguments that will produce the function signature
16456 DECL from the function template FN, with the explicit template
16457 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
16458 also match. Return NULL_TREE if no satisfactory arguments could be
16459 found. */
16461 static tree
16463 {
16466 tree decl_type;
16467 tree decl_arg_types;
16470 tree arg;
16472 /* Substitute the explicit template arguments into the type of DECL.
16473 The call to fn_type_unification will handle substitution into the
16474 FN. */
16477 {
16478 tree tmpl;
16479 tree converted_args;
16483 else
16484 /* We can get here for some invalid specializations. */
16487 converted_args
16490 tf_none,
16499 }
16501 /* Never do unification on the 'this' parameter. */
16520 }
16522 /* Return the innermost template arguments that, when applied to a
16523 template specialization whose innermost template parameters are
16524 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
16525 ARGS.
16527 For example, suppose we have:
16529 template <class T, class U> struct S {};
16530 template <class T> struct S<T*, int> {};
16532 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
16533 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
16534 int}. The resulting vector will be {double}, indicating that `T'
16535 is bound to `double'. */
16537 static tree
16539 {
16541 tree deduced_args;
16542 tree innermost_deduced_args;
16546 {
16550 innermost_deduced_args);
16551 }
16552 else
16558 UNIFY_ALLOW_NONE))
16565 /* Verify that nondeduced template arguments agree with the type
16566 obtained from argument deduction.
16568 For example:
16570 struct A { typedef int X; };
16571 template <class T, class U> struct C {};
16572 template <class T> struct C<T, typename T::X> {};
16574 Then with the instantiation `C<A, int>', we can deduce that
16575 `T' is `A' but unify () does not check whether `typename T::X'
16576 is `int'. */
16579 /* We only need to check the innermost arguments; the other
16580 arguments will always agree. */
16585 /* Now that we have bindings for all of the template arguments,
16586 ensure that the arguments deduced for the template template
16587 parameters have compatible template parameter lists. See the use
16588 of template_template_parm_bindings_ok_p in fn_type_unification
16589 for more information. */
16594 }
16596 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
16597 Return the TREE_LIST node with the most specialized template, if
16598 any. If there is no most specialized template, the error_mark_node
16599 is returned.
16601 Note that this function does not look at, or modify, the
16602 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
16603 returned is one of the elements of INSTANTIATIONS, callers may
16604 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
16605 and retrieve it from the value returned. */
16607 tree
16609 {
16616 {
16622 fate--;
16627 fate++;
16632 {
16633 /* Equally specialized, move to next function. If there
16634 is no next function, nothing's most specialized. */
16639 }
16640 }
16643 /* Now verify that champ is better than everything earlier in the
16644 instantiation list. */
16652 {
16655 }
16657 processing_template_decl--;
16663 }
16665 /* If DECL is a specialization of some template, return the most
16666 general such template. Otherwise, returns NULL_TREE.
16668 For example, given:
16670 template <class T> struct S { template <class U> void f(U); };
16672 if TMPL is `template <class U> void S<int>::f(U)' this will return
16673 the full template. This function will not trace past partial
16674 specializations, however. For example, given in addition:
16676 template <class T> struct S<T*> { template <class U> void f(U); };
16678 if TMPL is `template <class U> void S<int*>::f(U)' this will return
16679 `template <class T> template <class U> S<T*>::f(U)'. */
16681 tree
16683 {
16684 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
16685 an immediate specialization. */
16687 {
16691 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
16692 template friend. */
16697 }
16699 /* Look for more and more general templates. */
16701 {
16702 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
16703 (See cp-tree.h for details.) */
16711 /* Stop if we run into an explicitly specialized class template. */
16718 }
16721 }
16723 /* Return the most specialized of the class template partial
16724 specializations of TMPL which can produce TYPE, a specialization of
16725 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
16726 a _TYPE node corresponding to the partial specialization, while the
16727 TREE_PURPOSE is the set of template arguments that must be
16728 substituted into the TREE_TYPE in order to generate TYPE.
16730 If the choice of partial specialization is ambiguous, a diagnostic
16731 is issued, and the error_mark_node is returned. If there are no
16732 partial specializations of TMPL matching TYPE, then NULL_TREE is
16733 returned. */
16735 static tree
16737 {
16739 tree t;
16740 tree champ;
16743 tree args;
16749 /* For determining which partial specialization to use, only the
16750 innermost args are interesting. */
16752 {
16755 }
16758 {
16759 tree partial_spec_args;
16760 tree spec_args;
16768 {
16771 /* Discard the outer levels of args, and then substitute in the
16772 template args from the enclosing class. */
16774 partial_spec_args = tsubst_template_args
16777 /* PARMS already refers to just the innermost parms, but the
16778 template parms in partial_spec_args had their levels lowered
16779 by tsubst, so we need to do the same for the parm list. We
16780 can't just tsubst the TREE_VEC itself, as tsubst wants to
16781 treat a TREE_VEC as an argument vector. */
16787 }
16789 partial_spec_args =
16792 partial_spec_args),
16803 partial_spec_args,
16804 args);
16806 {
16811 }
16812 }
16822 {
16825 ;
16826 else
16827 {
16829 {
16832 {
16835 }
16836 }
16838 }
16839 }
16843 {
16846 {
16849 }
16850 }
16853 {
16861 {
16864 }
16867 }
16870 }
16872 /* Explicitly instantiate DECL. */
16874 void
16876 {
16881 /* An error occurred, for which grokdeclarator has already issued
16882 an appropriate message. */
16885 {
16888 }
16890 {
16891 /* There is an asymmetry here in the way VAR_DECLs and
16892 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16893 the latter, the DECL we get back will be marked as a
16894 template instantiation, and the appropriate
16895 DECL_TEMPLATE_INFO will be set up. This does not happen for
16896 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16897 should handle VAR_DECLs as it currently handles
16898 FUNCTION_DECLs. */
16900 {
16903 }
16906 {
16909 }
16911 {
16916 }
16917 }
16919 {
16922 }
16923 else
16926 /* Check for various error cases. Note that if the explicit
16927 instantiation is valid the RESULT will currently be marked as an
16928 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16929 until we get here. */
16932 {
16933 /* DR 259 [temp.spec].
16935 Both an explicit instantiation and a declaration of an explicit
16936 specialization shall not appear in a program unless the explicit
16937 instantiation follows a declaration of the explicit specialization.
16939 For a given set of template parameters, if an explicit
16940 instantiation of a template appears after a declaration of an
16941 explicit specialization for that template, the explicit
16942 instantiation has no effect. */
16944 }
16946 {
16947 /* [temp.spec]
16949 No program shall explicitly instantiate any template more
16950 than once.
16952 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16953 the first instantiation was `extern' and the second is not,
16954 and EXTERN_P for the opposite case. */
16957 /* If an "extern" explicit instantiation follows an ordinary
16958 explicit instantiation, the template is instantiated. */
16961 }
16963 {
16966 }
16968 {
16971 }
16974 ;
16976 {
16979 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16982 }
16983 else
16991 }
16993 static void
16995 {
17001 {
17004 }
17005 }
17007 /* Called from do_type_instantiation through binding_table_foreach to
17008 do recursive instantiation for the type bound in ENTRY. */
17009 static void
17011 {
17017 }
17019 /* Called from do_type_instantiation to instantiate a member
17020 (a member function or a static member variable) of an
17021 explicitly instantiated class template. */
17022 static void
17024 {
17029 }
17031 /* Perform an explicit instantiation of template class T. STORAGE, if
17032 non-null, is the RID for extern, inline or static. COMPLAIN is
17033 nonzero if this is called from the parser, zero if called recursively,
17034 since the standard is unclear (as detailed below). */
17036 void
17038 {
17048 {
17051 }
17056 {
17059 t);
17061 }
17064 {
17066 {
17068 {
17071 "ISO C++ 1998 forbids the use of %<extern%> on "
17073 }
17074 else
17076 "ISO C++ forbids the use of %qE"
17078 }
17086 else
17087 {
17089 storage);
17091 }
17092 }
17095 {
17096 /* DR 259 [temp.spec].
17098 Both an explicit instantiation and a declaration of an explicit
17099 specialization shall not appear in a program unless the explicit
17100 instantiation follows a declaration of the explicit specialization.
17102 For a given set of template parameters, if an explicit
17103 instantiation of a template appears after a declaration of an
17104 explicit specialization for that template, the explicit
17105 instantiation has no effect. */
17107 }
17109 {
17110 /* [temp.spec]
17112 No program shall explicitly instantiate any template more
17113 than once.
17115 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
17116 instantiation was `extern'. If EXTERN_P then the second is.
17117 These cases are OK. */
17124 /* If we've already instantiated the template, just return now. */
17127 }
17135 {
17136 tree tmp;
17138 /* In contrast to implicit instantiation, where only the
17139 declarations, and not the definitions, of members are
17140 instantiated, we have here:
17142 [temp.explicit]
17144 The explicit instantiation of a class template specialization
17145 implies the instantiation of all of its members not
17146 previously explicitly specialized in the translation unit
17147 containing the explicit instantiation.
17149 Of course, we can't instantiate member template classes, since
17150 we don't have any arguments for them. Note that the standard
17151 is unclear on whether the instantiation of the members are
17152 *explicit* instantiations or not. However, the most natural
17153 interpretation is that it should be an explicit instantiation. */
17168 }
17169 }
17171 /* Given a function DECL, which is a specialization of TMPL, modify
17172 DECL to be a re-instantiation of TMPL with the same template
17173 arguments. TMPL should be the template into which tsubst'ing
17174 should occur for DECL, not the most general template.
17176 One reason for doing this is a scenario like this:
17178 template <class T>
17179 void f(const T&, int i);
17181 void g() { f(3, 7); }
17183 template <class T>
17184 void f(const T& t, const int i) { }
17186 Note that when the template is first instantiated, with
17187 instantiate_template, the resulting DECL will have no name for the
17188 first parameter, and the wrong type for the second. So, when we go
17189 to instantiate the DECL, we regenerate it. */
17191 static void
17193 {
17194 /* The arguments used to instantiate DECL, from the most general
17195 template. */
17196 tree args;
17197 tree code_pattern;
17202 /* Make sure that we can see identifiers, and compute access
17203 correctly. */
17207 {
17208 tree decl_parm;
17209 tree pattern_parm;
17210 tree specs;
17223 specs);
17225 /* Merge parameter declarations. */
17228 pattern_parm
17232 {
17233 tree parm_type;
17234 tree attributes;
17239 NULL_TREE);
17245 {
17248 }
17251 }
17252 /* Merge any parameters that match with the function parameter
17253 pack. */
17255 {
17257 tree expanded_types;
17258 /* Expand the TYPE_PACK_EXPANSION that provides the types for
17259 the parameters in this function parameter pack. */
17264 {
17265 tree parm_type;
17266 tree attributes;
17269 /* Rename the parameter to include the index. */
17278 {
17281 }
17283 }
17284 }
17285 /* Merge additional specifiers from the CODE_PATTERN. */
17289 }
17291 {
17299 }
17300 else
17304 }
17306 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
17307 substituted to get DECL. */
17309 tree
17311 {
17314 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
17315 for the instantiation. This is not always the most general
17316 template. Consider, for example:
17318 template <class T>
17319 struct S { template <class U> void f();
17320 template <> void f<int>(); };
17322 and an instantiation of S<double>::f<int>. We want TD to be the
17323 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
17325 more general template. */
17327 /* We must also deal with friend templates. Given:
17329 template <class T> struct S {
17330 template <class U> friend void f() {};
17331 };
17333 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
17334 so far as the language is concerned, but that's still
17335 where we get the pattern for the instantiation from. On
17336 other hand, if the definition comes outside the class, say:
17338 template <class T> struct S {
17339 template <class U> friend void f();
17340 };
17341 template <class U> friend void f() {}
17343 we don't need to look any further. That's what the check for
17344 DECL_INITIAL is for. */
17348 {
17349 /* The present template, TD, should not be a definition. If it
17350 were a definition, we should be using it! Note that we
17351 cannot restructure the loop to just keep going until we find
17352 a template with a definition, since that might go too far if
17353 a specialization was declared, but not defined. */
17357 /* Fetch the more general template. */
17359 }
17362 }
17364 /* Returns true if we need to instantiate this template instance even if we
17365 know we aren't going to emit it.. */
17367 bool
17369 {
17370 /* We always instantiate inline functions so that we can inline them. An
17371 explicit instantiation declaration prohibits implicit instantiation of
17372 non-inline functions. With high levels of optimization, we would
17373 normally inline non-inline functions -- but we're not allowed to do
17374 that for "extern template" functions. Therefore, we check
17375 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
17378 /* And we need to instantiate static data members so that
17379 their initializers are available in integral constant
17380 expressions. */
17383 }
17385 /* Produce the definition of D, a _DECL generated from a template. If
17386 DEFER_OK is nonzero, then we don't have to actually do the
17387 instantiation now; we just have to do it sometime. Normally it is
17388 an error if this is an explicit instantiation but D is undefined.
17389 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
17390 explicitly instantiated class template. */
17392 tree
17395 {
17397 tree gen_args;
17398 tree args;
17399 tree td;
17400 tree code_pattern;
17401 tree spec;
17402 tree gen_tmpl;
17408 /* This function should only be used to instantiate templates for
17409 functions and static member variables. */
17413 /* Variables are never deferred; if instantiation is required, they
17414 are instantiated right away. That allows for better code in the
17415 case that an expression refers to the value of the variable --
17416 if the variable has a constant value the referring expression can
17417 take advantage of that fact. */
17422 /* Don't instantiate cloned functions. Instead, instantiate the
17423 functions they cloned. */
17429 /* D has already been instantiated or explicitly specialized, so
17430 there's nothing for us to do here.
17432 It might seem reasonable to check whether or not D is an explicit
17433 instantiation, and, if so, stop here. But when an explicit
17434 instantiation is deferred until the end of the compilation,
17435 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
17436 the instantiation. */
17439 /* Check to see whether we know that this template will be
17440 instantiated in some other file, as with "extern template"
17441 extension. */
17444 /* In general, we do not instantiate such templates. */
17452 /* We should already have the extra args. */
17455 /* And what's in the hash table should match D. */
17459 /* This needs to happen before any tsubsting. */
17465 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
17466 for the instantiation. */
17470 /* We should never be trying to instantiate a member of a class
17471 template or partial specialization. */
17476 /* In the case of a friend template whose definition is provided
17477 outside the class, we may have too many arguments. Drop the
17478 ones we don't need. The same is true for specializations. */
17479 args = get_innermost_template_args
17481 else
17487 else
17490 /* We may be in the middle of deferred access check. Disable it now. */
17493 /* Unless an explicit instantiation directive has already determined
17494 the linkage of D, remember that a definition is available for
17495 this entity. */
17505 /* If D is a member of an explicitly instantiated class template,
17506 and no definition is available, treat it like an implicit
17507 instantiation. */
17510 {
17511 /* Leave linkage flags alone on instantiations with anonymous
17512 visibility. */
17514 {
17517 }
17519 }
17521 /* Recheck the substitutions to obtain any warning messages
17522 about ignoring cv qualifiers. Don't do this for artificial decls,
17523 as it breaks the context-sensitive substitution for lambda op(). */
17525 {
17529 /* Make sure that we can see identifiers, and compute access
17530 correctly. D is already the target FUNCTION_DECL with the
17531 right context. */
17535 {
17538 d);
17539 /* Don't simply tsubst the function type, as that will give
17540 duplicate warnings about poor parameter qualifications.
17541 The function arguments are the same as the decl_arguments
17542 without the top level cv qualifiers. */
17544 }
17548 }
17550 /* Defer all other templates, unless we have been explicitly
17551 forbidden from doing so. */
17553 template. */
17554 ! pattern_defined
17555 /* If it's OK to postpone instantiation, do so. */
17556 || defer_ok
17557 /* If this is a static data member that will be defined
17558 elsewhere, we don't want to instantiate the entire data
17559 member, but we do want to instantiate the initializer so that
17560 we can substitute that elsewhere. */
17562 {
17563 /* The definition of the static data member is now required so
17564 we must substitute the initializer. */
17568 {
17569 tree ns;
17570 tree init;
17577 args,
17580 /* Make sure the initializer is still constant, in case of
17581 circular dependency (template/instantiate6.C). */
17582 const_init
17586 LOOKUP_ONLYCONVERTING);
17589 }
17591 /* We restore the source position here because it's used by
17592 add_pending_template. */
17598 /* [temp.explicit]
17600 The definition of a non-exported function template, a
17601 non-exported member function template, or a non-exported
17602 member function or static data member of a class template
17603 shall be present in every translation unit in which it is
17604 explicitly instantiated. */
17608 /* If we're in unevaluated context, we just wanted to get the
17609 constant value; this isn't an odr use, so don't queue
17610 a full instantiation. */
17613 /* ??? Historically, we have instantiated inline functions, even
17614 when marked as "extern template". */
17618 }
17619 /* Tell the repository that D is available in this translation unit
17620 -- and see if it is supposed to be instantiated here. */
17622 {
17623 /* In a PCH file, despite the fact that the repository hasn't
17624 requested instantiation in the PCH it is still possible that
17625 an instantiation will be required in a file that includes the
17626 PCH. */
17629 /* Instantiate inline functions so that the inliner can do its
17630 job, even though we'll not be emitting a copy of this
17631 function. */
17634 }
17640 /* Mark D as instantiated so that recursive calls to
17641 instantiate_decl do not try to instantiate it again. */
17644 /* Regenerate the declaration in case the template has been modified
17645 by a subsequent redeclaration. */
17648 /* We already set the file and line above. Reset them now in case
17649 they changed as a result of calling regenerate_decl_from_template. */
17653 {
17654 tree init;
17657 /* Clear out DECL_RTL; whatever was there before may not be right
17658 since we've reset the type of the declaration. */
17662 /* The initializer is placed in DECL_INITIAL by
17663 regenerate_decl_from_template so we don't need to
17664 push/pop_access_scope again here. Pull it out so that
17665 cp_finish_decl can process it. */
17670 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
17671 initializer. That function will defer actual emission until
17672 we have a chance to determine linkage. */
17675 /* Enter the scope of D so that access-checking works correctly. */
17680 }
17684 {
17685 htab_t saved_local_specializations;
17686 tree subst_decl;
17687 tree tmpl_parm;
17688 tree spec_parm;
17690 /* Save away the current list, in case we are instantiating one
17691 template from within the body of another. */
17694 /* Set up the list of local specializations. */
17696 hash_local_specialization,
17697 eq_local_specializations,
17698 NULL);
17700 /* Set up context. */
17703 /* Create substitution entries for the parameters. */
17708 {
17712 }
17714 {
17718 }
17720 {
17721 /* Register the (value) argument pack as a specialization of
17722 TMPL_PARM, then move on. */
17727 }
17730 /* Substitute into the body of the function. */
17735 /* Set the current input_location to the end of the function
17736 so that finish_function knows where we are. */
17739 /* We don't need the local specializations any more. */
17743 /* Finish the function. */
17746 }
17748 /* We're not deferring instantiation any more. */
17754 out:
17762 }
17764 /* Run through the list of templates that we wish we could
17765 instantiate, and instantiate any we can. RETRIES is the
17766 number of times we retry pending template instantiation. */
17768 void
17770 {
17774 /* Instantiating templates may trigger vtable generation. This in turn
17775 may require further template instantiations. We place a limit here
17776 to avoid infinite loop. */
17778 {
17782 " instantiating %q+D, possibly from virtual table generation"
17786 /* Pretend that we defined it. */
17789 }
17791 do
17792 {
17797 {
17802 {
17803 tree fn;
17806 {
17810 fn;
17818 }
17821 }
17822 else
17823 {
17826 {
17827 instantiation
17833 }
17837 }
17840 /* If INSTANTIATION has been instantiated, then we don't
17841 need to consider it again in the future. */
17843 else
17844 {
17847 }
17850 }
17852 }
17856 }
17858 /* Substitute ARGVEC into T, which is a list of initializers for
17859 either base class or a non-static data member. The TREE_PURPOSEs
17860 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17861 instantiate_decl. */
17863 static tree
17865 {
17869 {
17870 tree decl;
17871 tree init;
17877 {
17878 tree expr;
17879 tree arg;
17881 /* Expand the base class expansion type into separate base
17882 classes. */
17884 tf_warning_or_error,
17885 NULL_TREE);
17889 /* We'll be building separate TREE_LISTs of arguments for
17890 each base. */
17896 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17897 expand each argument in the TREE_VALUE of t. */
17903 /* VOID_TYPE_NODE is used to indicate
17904 value-initialization. */
17905 {
17908 }
17909 else
17910 {
17911 /* Substitute parameter packs into each argument in the
17912 TREE_LIST. */
17915 {
17916 tree expanded_exprs;
17918 /* Expand the argument. */
17920 expanded_exprs
17922 tf_warning_or_error,
17923 NULL_TREE);
17927 /* Prepend each of the expanded expressions to the
17928 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17930 {
17935 }
17936 }
17939 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17940 since we built them backwards. */
17942 {
17945 }
17946 }
17947 }
17950 {
17952 {
17956 }
17957 else
17958 {
17972 }
17975 {
17979 }
17980 }
17981 }
17983 }
17985 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17987 static void
17989 {
17994 else
17996 }
17998 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17999 is the instantiation (which should have been created with
18000 start_enum) and ARGS are the template arguments to use. */
18002 static void
18004 {
18005 tree e;
18011 {
18012 tree value;
18013 tree decl;
18016 /* Note that in a template enum, the TREE_VALUE is the
18017 CONST_DECL, not the corresponding INTEGER_CST. */
18022 /* Give this enumeration constant the correct access. */
18025 /* Actually build the enumerator itself. */
18026 build_enumerator
18028 }
18038 }
18040 /* DECL is a FUNCTION_DECL that is a template specialization. Return
18041 its type -- but without substituting the innermost set of template
18042 arguments. So, innermost set of template parameters will appear in
18043 the type. */
18045 tree
18047 {
18048 tree fn_type;
18049 tree tmpl;
18050 tree targs;
18051 tree tparms;
18059 /* There should be as many levels of arguments as there are levels
18060 of parameters. */
18066 /* No substitution is necessary. */
18067 ;
18068 else
18069 {
18071 tree partial_args;
18073 /* Replace the innermost level of the TARGS with NULL_TREEs to
18074 let tsubst know not to substitute for those parameters. */
18083 /* Disable access control as this function is used only during
18084 name-mangling. */
18088 /* Now, do the (partial) substitution to figure out the
18089 appropriate function type. */
18093 /* Substitute into the template parameters to obtain the real
18094 innermost set of parameters. This step is important if the
18095 innermost set of template parameters contains value
18096 parameters whose types depend on outer template parameters. */
18101 }
18104 }
18106 /* Return truthvalue if we're processing a template different from
18107 the last one involved in diagnostics. */
18108 int
18110 {
18112 }
18114 /* Remember current template involved in diagnostics. */
18115 void
18117 {
18119 }
18123 {
18125 }
18127 /* [temp.param] Check that template non-type parm TYPE is of an allowable
18128 type. Return zero for ok, nonzero for disallowed. Issue error and
18129 warning messages under control of COMPLAIN. */
18131 static int
18133 {
18150 }
18152 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
18153 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
18155 static bool
18157 {
18158 tree scope;
18160 /* [temp.dep.type]
18162 A type is dependent if it is:
18164 -- a template parameter. Template template parameters are types
18165 for us (since TYPE_P holds true for them) so we handle
18166 them here. */
18170 /* -- a qualified-id with a nested-name-specifier which contains a
18171 class-name that names a dependent type or whose unqualified-id
18172 names a dependent type. */
18175 /* -- a cv-qualified type where the cv-unqualified type is
18176 dependent. */
18178 /* -- a compound type constructed from any dependent type. */
18188 {
18189 tree arg_type;
18194 arg_type;
18199 }
18200 /* -- an array type constructed from any dependent type or whose
18201 size is specified by a constant expression that is
18202 value-dependent.
18204 We checked for type- and value-dependence of the bounds in
18205 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
18207 {
18212 }
18214 /* -- a template-id in which either the template name is a template
18215 parameter ... */
18218 /* ... or any of the template arguments is a dependent type or
18219 an expression that is type-dependent or value-dependent. */
18221 && (any_dependent_template_arguments_p
18225 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
18226 dependent; if the argument of the `typeof' expression is not
18227 type-dependent, then it should already been have resolved. */
18233 /* A template argument pack is dependent if any of its packed
18234 arguments are. */
18236 {
18242 }
18244 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
18245 be template parameters. */
18249 /* The standard does not specifically mention types that are local
18250 to template functions or local classes, but they should be
18251 considered dependent too. For example:
18253 template <int I> void f() {
18254 enum E { a = I };
18255 S<sizeof (E)> s;
18256 }
18258 The size of `E' cannot be known until the value of `I' has been
18259 determined. Therefore, `E' must be considered dependent. */
18266 /* Other types are non-dependent. */
18268 }
18270 /* Returns TRUE if TYPE is dependent, in the sense of
18271 [temp.dep.type]. Note that a NULL type is considered dependent. */
18273 bool
18275 {
18276 /* If there are no template parameters in scope, then there can't be
18277 any dependent types. */
18279 {
18280 /* If we are not processing a template, then nobody should be
18281 providing us with a dependent type. */
18285 }
18287 /* If the type is NULL, we have not computed a type for the entity
18288 in question; in that case, the type is dependent. */
18292 /* Erroneous types can be considered non-dependent. */
18296 /* If we have not already computed the appropriate value for TYPE,
18297 do so now. */
18299 {
18302 }
18305 }
18307 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
18308 lookup. In other words, a dependent type that is not the current
18309 instantiation. */
18311 bool
18313 {
18316 }
18318 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
18319 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
18320 expression. */
18322 /* Note that this predicate is not appropriate for general expressions;
18323 only constant expressions (that satisfy potential_constant_expression)
18324 can be tested for value dependence.
18326 We should really also have a predicate for "instantiation-dependent".
18328 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
18329 (what about instantiation-dependent constant-expressions?)
18330 is_late_template_attribute: defer if instantiation-dependent.
18331 compute_array_index_type: proceed if constant and not t- or v-dependent
18332 if instantiation-dependent, need to remember full expression
18333 uses_template_parms: FIXME - need to audit callers
18334 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
18335 dependent_type_p [array_type]: dependent if index type is dependent
18336 (or non-constant?)
18337 static_assert - instantiation-dependent */
18339 bool
18341 {
18345 /* A name declared with a dependent type. */
18350 {
18352 /* A name that has not been looked up -- must be dependent. */
18356 /* A non-type template parm. */
18360 /* A non-type template parm. */
18366 /* A constant with literal type and is initialized
18367 with an expression that is value-dependent. */
18379 /* These expressions are value-dependent if the type to which
18380 the cast occurs is dependent or the expression being casted
18381 is value-dependent. */
18382 {
18388 /* A functional cast has a list of operands. */
18391 {
18392 /* If there are no operands, it must be an expression such
18393 as "int()". This should not happen for aggregate types
18394 because it would form non-constant expressions. */
18399 }
18405 }
18410 /* A `sizeof' expression is value-dependent if the operand is
18411 type-dependent or is a pack expansion. */
18420 /* An 'encode' expression is value-dependent if the operand is
18421 type-dependent. */
18430 {
18433 }
18440 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
18441 is value-dependent. */
18442 {
18451 }
18454 {
18458 }
18469 {
18473 }
18476 {
18483 {
18485 /* In a call to a constexpr member function, look through the
18486 implicit ADDR_EXPR on the object argument so that it doesn't
18487 cause the call to be considered value-dependent. We also
18488 look through it in potential_constant_expression. */
18495 }
18497 }
18500 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
18501 type-dependent. */
18505 {
18507 tree val;
18512 }
18515 /* A constant expression is value-dependent if any subexpression is
18516 value-dependent. */
18518 {
18525 {
18529 {
18532 /* In some cases, some of the operands may be missing.l
18533 (For example, in the case of PREDECREMENT_EXPR, the
18534 amount to increment by may be missing.) That doesn't
18535 make the expression dependent. */
18538 }
18539 }
18543 }
18545 }
18547 /* The expression is not value-dependent. */
18549 }
18551 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
18552 [temp.dep.expr]. Note that an expression with no type is
18553 considered dependent. Other parts of the compiler arrange for an
18554 expression with type-dependent subexpressions to have no type, so
18555 this function doesn't have to be fully recursive. */
18557 bool
18559 {
18566 /* An unresolved name is always dependent. */
18571 /* Some expression forms are never type-dependent. */
18584 /* The types of these expressions depends only on the type to which
18585 the cast occurs. */
18593 /* The types of these expressions depends only on the type created
18594 by the expression. */
18597 {
18598 /* For NEW_EXPR tree nodes created inside a template, either
18599 the object type itself or a TREE_LIST may appear as the
18600 operand 1. */
18603 /* This is an array type. We need to check array dimensions
18604 as well. */
18606 || value_dependent_expression_p
18608 else
18610 }
18613 {
18617 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
18618 contains an identifier associated by name lookup with one or more
18619 declarations declared with a dependent type, or...a
18620 nested-name-specifier or qualified-id that names a member of an
18621 unknown specialization. */
18624 }
18629 && (any_dependent_template_arguments_p
18641 {
18642 tree elt;
18646 {
18649 }
18651 }
18653 /* A static data member of the current instantiation with incomplete
18654 array type is type-dependent, as the definition and specializations
18655 can have different bounds. */
18663 {
18668 {
18674 }
18675 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
18683 {
18688 }
18693 {
18697 }
18699 }
18704 }
18706 /* Like type_dependent_expression_p, but it also works while not processing
18707 a template definition, i.e. during substitution or mangling. */
18709 bool
18711 {
18717 }
18719 /* Returns TRUE if ARGS contains a type-dependent expression. */
18721 bool
18723 {
18725 tree arg;
18728 {
18731 }
18733 }
18735 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
18736 expressions) contains any type-dependent expressions. */
18738 bool
18740 {
18746 }
18748 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
18749 expressions) contains any value-dependent expressions. */
18751 bool
18753 {
18759 }
18761 /* Returns TRUE if the ARG (a template argument) is dependent. */
18763 bool
18765 {
18769 /* Assume a template argument that was wrongly written by the user
18770 is dependent. This is consistent with what
18771 any_dependent_template_arguments_p [that calls this function]
18772 does. */
18783 {
18787 {
18790 }
18793 }
18796 else
18799 }
18801 /* Returns true if ARGS (a collection of template arguments) contains
18802 any types that require structural equality testing. */
18804 bool
18806 {
18816 {
18819 {
18825 {
18826 /* Look inside the argument pack. */
18829 }
18832 {
18846 }
18847 }
18848 }
18851 }
18853 /* Returns true if ARGS (a collection of template arguments) contains
18854 any dependent arguments. */
18856 bool
18858 {
18868 {
18873 }
18876 }
18878 /* Returns TRUE if the template TMPL is dependent. */
18880 bool
18882 {
18884 {
18886 {
18890 }
18892 }
18894 /* Template template parameters are dependent. */
18898 /* So are names that have not been looked up. */
18902 /* So are member templates of dependent classes. */
18906 }
18908 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18910 bool
18912 {
18915 }
18917 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18918 is dependent. */
18920 bool
18922 {
18929 {
18950 {
18954 }
18958 {
18962 {
18967 }
18968 }
18969 }
18972 }
18974 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18975 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18976 no such TYPE can be found. Note that this function peers inside
18977 uninstantiated templates and therefore should be used only in
18978 extremely limited situations. ONLY_CURRENT_P restricts this
18979 peering to the currently open classes hierarchy (which is required
18980 when comparing types). */
18982 tree
18984 {
18985 tree scope;
18986 tree name;
18987 tree decl;
18989 tree pushed_scope;
18990 tree result;
18995 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18996 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18997 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18998 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18999 identifier of the TYPENAME_TYPE anymore.
19000 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
19001 TYPENAME_TYPE instead, we avoid messing up with a possible
19002 typedef variant case. */
19005 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
19006 it first before we can figure out what NAME refers to. */
19009 /* If we don't know what SCOPE refers to, then we cannot resolve the
19010 TYPENAME_TYPE. */
19013 /* If the SCOPE is a template type parameter, we have no way of
19014 resolving the name. */
19017 /* If the SCOPE is not the current instantiation, there's no reason
19018 to look inside it. */
19021 /* If this is a typedef, we don't want to look inside (c++/11987). */
19024 /* If SCOPE isn't the template itself, it will not have a valid
19025 TYPE_FIELDS list. */
19027 /* scope is either the template itself or a compatible instantiation
19028 like X<T>, so look up the name in the original template. */
19030 else
19031 /* scope is a partial instantiation, so we can't do the lookup or we
19032 will lose the template arguments. */
19034 /* Enter the SCOPE so that name lookup will be resolved as if we
19035 were in the class definition. In particular, SCOPE will no
19036 longer be considered a dependent type. */
19038 /* Look up the declaration. */
19043 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
19044 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
19049 {
19053 }
19056 {
19057 tree tmpl;
19058 tree args;
19059 /* Obtain the template and the arguments. */
19062 /* Instantiate the template. */
19068 }
19070 /* Leave the SCOPE. */
19074 /* If we failed to resolve it, return the original typename. */
19078 /* If lookup found a typename type, resolve that too. */
19080 {
19081 /* Ill-formed programs can cause infinite recursion here, so we
19082 must catch that. */
19086 }
19088 /* Qualify the resulting type. */
19094 }
19096 /* EXPR is an expression which is not type-dependent. Return a proxy
19097 for EXPR that can be used to compute the types of larger
19098 expressions containing EXPR. */
19100 tree
19102 {
19103 tree inner_expr;
19105 #ifdef ENABLE_CHECKING
19106 /* Try to get a constant value for all non-type-dependent expressions in
19107 order to expose bugs in *_dependent_expression_p and constexpr. */
19110 #endif
19112 /* Preserve OVERLOADs; the functions must be available to resolve
19113 types. */
19124 /* There is no need to return a proxy for a variable. */
19127 /* Preserve string constants; conversions from string constants to
19128 "char *" are allowed, even though normally a "const char *"
19129 cannot be used to initialize a "char *". */
19132 /* Preserve arithmetic constants, as an optimization -- there is no
19133 reason to create a new node. */
19136 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
19137 There is at least one place where we want to know that a
19138 particular expression is a throw-expression: when checking a ?:
19139 expression, there are special rules if the second or third
19140 argument is a throw-expression. */
19159 /* Keep dereferences outside the NON_DEPENDENT_EXPR so lvalue_kind
19160 doesn't need to look inside. */
19165 /* If the type is unknown, it can't really be non-dependent */
19168 /* Otherwise, build a NON_DEPENDENT_EXPR. */
19170 }
19172 /* ARGS is a vector of expressions as arguments to a function call.
19173 Replace the arguments with equivalent non-dependent expressions.
19174 This modifies ARGS in place. */
19176 void
19178 {
19180 tree arg;
19183 {
19187 }
19188 }
19190 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
19191 with a level one deeper than the actual template parms. */
19193 tree
19195 {
19208 }
19210 /* Given type ARG, return std::initializer_list<ARG>. */
19212 static tree
19214 {
19215 tree std_init_list = namespace_binding
19217 tree argvec;
19219 {
19223 }
19228 }
19230 /* Replace auto in TYPE with std::initializer_list<auto>. */
19232 static tree
19234 {
19241 }
19243 /* walk_tree helper for do_auto_deduction. */
19245 static tree
19248 {
19249 /* Is this a variable with the type we're looking for? */
19253 else
19255 }
19257 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
19258 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
19260 tree
19262 {
19265 tree decl;
19268 /* The name of the object being declared shall not appear in the
19269 initializer expression. */
19272 {
19276 }
19278 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
19279 with either a new invented type template parameter U or, if the
19280 initializer is a braced-init-list (8.5.4), with
19281 std::initializer_list<U>. */
19296 {
19298 /* If type is error_mark_node a diagnostic must have been
19299 emitted by now. Also, having a mention to '<type error>'
19300 in the diagnostic is not really useful to the user. */
19303 }
19305 /* If the list of declarators contains more than one declarator, the type
19306 of each declared variable is determined as described above. If the
19307 type deduced for the template parameter U is not the same in each
19308 deduction, the program is ill-formed. */
19311 {
19315 }
19321 }
19323 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
19324 result. */
19326 tree
19328 {
19329 tree argvec;
19336 /* For a late-specified return type in a template type-parameter, we
19337 need to add a dummy argument level for its parmlist. */
19338 argvec = add_to_template_args
19343 }
19345 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
19347 bool
19349 {
19353 else
19355 }
19357 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
19358 appear as a type-specifier for the declaration in question, we don't
19359 have to look through the whole type. */
19361 tree
19363 {
19380 }
19382 /* For a given template T, return the vector of typedefs referenced
19383 in T for which access check is needed at T instantiation time.
19384 T is either a FUNCTION_DECL or a RECORD_TYPE.
19385 Those typedefs were added to T by the function
19386 append_type_to_template_for_access_check. */
19390 {
19391 tree ti;
19402 {
19407 }
19410 }
19412 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
19413 tied to T. That list of typedefs will be access checked at
19414 T instantiation time.
19415 T is either a FUNCTION_DECL or a RECORD_TYPE.
19416 TYPE_DECL is a TYPE_DECL node representing a typedef.
19417 SCOPE is the scope through which TYPE_DECL is accessed.
19418 LOCATION is the location of the usage point of TYPE_DECL.
19420 This function is a subroutine of
19421 append_type_to_template_for_access_check. */
19423 static void
19425 tree type_decl,
19426 tree scope,
19427 location_t location)
19428 {
19429 qualified_typedef_usage_t typedef_usage;
19430 tree ti;
19437 && type_decl
19453 }
19455 /* Append TYPE_DECL to the template TEMPL.
19456 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
19457 At TEMPL instanciation time, TYPE_DECL will be checked to see
19458 if it can be accessed through SCOPE.
19459 LOCATION is the location of the usage point of TYPE_DECL.
19461 e.g. consider the following code snippet:
19463 class C
19464 {
19465 typedef int myint;
19466 };
19468 template<class U> struct S
19469 {
19470 C::myint mi; // <-- usage point of the typedef C::myint
19471 };
19473 S<char> s;
19475 At S<char> instantiation time, we need to check the access of C::myint
19476 In other words, we need to check the access of the myint typedef through
19477 the C scope. For that purpose, this function will add the myint typedef
19478 and the scope C through which its being accessed to a list of typedefs
19479 tied to the template S. That list will be walked at template instantiation
19480 time and access check performed on each typedefs it contains.
19481 Note that this particular code snippet should yield an error because
19482 myint is private to C. */
19484 void
19486 tree type_decl,
19487 tree scope,
19488 location_t location)
19489 {
19495 /* Make sure we don't append the type to the template twice. */
19504 }
19506 /* Set up the hash tables for template instantiations. */
19508 void
19510 {
19512 hash_specialization,
19513 eq_specializations,
19514 ggc_free);
19516 hash_specialization,
19517 eq_specializations,
19518 ggc_free);
19519 }
19521 /* Print stats about the template hash tables for -fstats. */
19523 void
19525 {
19539 }