| blob | 9b410a75fd446c713769992bce67975b1a47cc2c |
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, 2012
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
113 tbr_incomplete_type,
114 tbr_ambiguous_baseclass,
115 tbr_success
116 };
139 tree);
201 location_t);
211 /* Make the current scope suitable for access checking when we are
212 processing T. T can be FUNCTION_DECL for instantiated function
213 template, or VAR_DECL for static member variable (need by
214 instantiate_decl). */
216 static void
218 {
226 else
230 {
231 saved_access_scope = tree_cons
234 }
235 }
237 /* Restore the scope set up by push_access_scope. T is the node we
238 are processing. */
240 static void
242 {
244 {
247 }
251 else
253 }
255 /* Do any processing required when DECL (a member template
256 declaration) is finished. Returns the TEMPLATE_DECL corresponding
257 to DECL, unless it is a specialization, in which case the DECL
258 itself is returned. */
260 tree
262 {
269 {
270 tree type;
278 {
282 }
284 }
288 {
290 {
293 }
294 else
296 }
297 else
301 }
303 /* Create a template info node. */
305 tree
307 {
312 }
314 /* Return the template info node corresponding to T, whatever T is. */
316 tree
318 {
336 }
338 /* Returns the template nesting level of the indicated class TYPE.
340 For example, in:
341 template <class T>
342 struct A
343 {
344 template <class U>
345 struct B {};
346 };
348 A<T>::B<U> has depth two, while A<T> has depth one.
349 Both A<T>::B<int> and A<int>::B<U> have depth one, if
350 they are instantiations, not specializations.
352 This function is guaranteed to return 0 if passed NULL_TREE so
353 that, for example, `template_class_depth (current_class_type)' is
354 always safe. */
356 int
358 {
365 {
371 }
374 }
376 /* Subroutine of maybe_begin_member_template_processing.
377 Returns true if processing DECL needs us to push template parms. */
379 static bool
381 {
387 }
389 /* Subroutine of maybe_begin_member_template_processing.
390 Push the template parms in PARMS, starting from LEVELS steps into the
391 chain, and ending at the beginning, since template parms are listed
392 innermost first. */
394 static void
396 {
404 current_template_parms
410 NULL);
412 {
421 {
428 {
429 /* Make a CONST_DECL as is done in process_template_parm.
430 It is ugly that we recreate this here; the original
431 version built in process_template_parm is no longer
432 available. */
442 }
447 }
448 }
449 }
451 /* Restore the template parameter context for a member template or
452 a friend template defined in a class definition. */
454 void
456 {
457 tree parms;
461 {
466 {
469 }
472 }
474 /* Remember how many levels of template parameters we pushed so that
475 we can pop them later. */
477 }
479 /* Undo the effects of maybe_begin_member_template_processing. */
481 void
483 {
492 {
496 }
497 }
499 /* Return a new template argument vector which contains all of ARGS,
500 but has as its innermost set of arguments the EXTRA_ARGS. */
502 static tree
504 {
505 tree new_args;
523 }
525 /* Like add_to_template_args, but only the outermost ARGS are added to
526 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
527 (EXTRA_ARGS) levels are added. This function is used to combine
528 the template arguments from a partial instantiation with the
529 template arguments used to attain the full instantiation from the
530 partial instantiation. */
532 static tree
534 {
535 tree new_args;
537 /* If there are more levels of EXTRA_ARGS than there are ARGS,
538 something very fishy is going on. */
541 /* If *all* the new arguments will be the EXTRA_ARGS, just return
542 them. */
546 /* For the moment, we make ARGS look like it contains fewer levels. */
551 /* Now, we restore ARGS to its full dimensions. */
555 }
557 /* Return the N levels of innermost template arguments from the ARGS. */
559 tree
561 {
562 tree new_args;
568 /* If N is 1, just return the innermost set of template arguments. */
572 /* If we're not removing anything, just return the arguments we were
573 given. */
579 /* Make a new set of arguments, not containing the outer arguments. */
586 }
588 /* The inverse of get_innermost_template_args: Return all but the innermost
589 EXTRA_LEVELS levels of template arguments from the ARGS. */
591 static tree
593 {
594 tree new_args;
600 /* If N is 1, just return the outermost set of template arguments. */
604 /* If we're not removing anything, just return the arguments we were
605 given. */
610 /* Make a new set of arguments, not containing the inner arguments. */
617 }
619 /* We've got a template header coming up; push to a new level for storing
620 the parms. */
622 void
624 {
625 /* We use a non-tag-transparent scope here, which causes pushtag to
626 put tags in this scope, rather than in the enclosing class or
627 namespace scope. This is the right thing, since we want
628 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
629 global template class, push_template_decl handles putting the
630 TEMPLATE_DECL into top-level scope. For a nested template class,
631 e.g.:
633 template <class T> struct S1 {
634 template <class T> struct S2 {};
635 };
637 pushtag contains special code to call pushdecl_with_scope on the
638 TEMPLATE_DECL for S2. */
643 }
645 /* This routine is called when a specialization is declared. If it is
646 invalid to declare a specialization here, an error is reported and
647 false is returned, otherwise this routine will return true. */
649 static bool
651 {
654 /* [temp.expl.spec]
656 An explicit specialization shall be declared in the namespace of
657 which the template is a member, or, for member templates, in the
658 namespace of which the enclosing class or enclosing class
659 template is a member. An explicit specialization of a member
660 function, member class or static data member of a class template
661 shall be declared in the namespace of which the class template
662 is a member. */
664 {
667 }
669 /* [temp.expl.spec]
671 In an explicit specialization declaration for a member of a class
672 template or a member template that appears in namespace scope,
673 the member template and some of its enclosing class templates may
674 remain unspecialized, except that the declaration shall not
675 explicitly specialize a class member template if its enclosing
676 class templates are not explicitly specialized as well. */
678 {
681 }
684 }
686 /* We've just seen template <>. */
688 bool
690 {
694 }
696 /* Called at then end of processing a declaration preceded by
697 template<>. */
699 void
701 {
704 }
706 /* Any template <>'s that we have seen thus far are not referring to a
707 function specialization. */
709 void
711 {
714 }
716 /* We've just seen a template header. If SPECIALIZATION is nonzero,
717 it was of the form template <>. */
719 static void
721 {
723 template_header_count++;
724 }
726 /* We're beginning an explicit instantiation. */
728 void
730 {
733 }
736 void
738 {
741 }
743 /* An explicit specialization or partial specialization TMPL is being
744 declared. Check that the namespace in which the specialization is
745 occurring is permissible. Returns false iff it is invalid to
746 specialize TMPL in the current namespace. */
748 static bool
750 {
753 /* [tmpl.expl.spec]
755 An explicit specialization shall be declared in the namespace of
756 which the template is a member, or, for member templates, in the
757 namespace of which the enclosing class or enclosing class
758 template is a member. An explicit specialization of a member
759 function, member class or static data member of a class template
760 shall be declared in the namespace of which the class template is
761 a member. */
764 {
767 }
769 /* Same or super-using namespace. */
771 else
772 {
776 }
777 }
779 /* SPEC is an explicit instantiation. Check that it is valid to
780 perform this explicit instantiation in the current namespace. */
782 static void
784 {
785 tree ns;
787 /* DR 275: An explicit instantiation shall appear in an enclosing
788 namespace of its template. */
794 }
796 /* The TYPE is being declared. If it is a template type, that means it
797 is a partial specialization. Do appropriate error-checking. */
799 tree
801 {
802 tree context;
808 {
812 }
817 /* Consider non-class instantiations of alias templates as
818 well. */
823 {
824 /* This is for ordinary explicit specialization and partial
825 specialization of a template class such as:
827 template <> class C<int>;
829 or:
831 template <class T> class C<T*>;
833 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
838 {
842 {
846 }
847 }
853 {
857 }
858 }
864 {
865 /* This is for an explicit specialization of member class
866 template according to [temp.expl.spec/18]:
868 template <> template <class U> class C<int>::D;
870 The context `C<int>' must be an implicit instantiation.
871 Otherwise this is just a member class template declared
872 earlier like:
874 template <> class C<int> { template <class U> class D; };
875 template <> template <class U> class C<int>::D;
877 In the first case, `C<int>::D' is a specialization of `C<T>::D'
878 while in the second case, `C<int>::D' is a primary template
879 and `C<T>::D' may not exist. */
883 {
884 tree t;
889 {
892 }
894 /* Check for invalid specialization after instantiation:
896 template <> template <> class C<int>::D<int>;
897 template <> template <class U> class C<int>::D; */
901 {
904 {
905 /* We already have a full specialization of this partial
906 instantiation. Reassign it to the new member
907 specialization template. */
908 spec_entry elt;
925 }
927 /* But if we've had an implicit instantiation, that's a
928 problem ([temp.expl.spec]/6). */
931 }
933 /* Mark TYPE as a specialization. And as a result, we only
934 have one level of template argument for the innermost
935 class template. */
939 }
940 }
942 {
943 /* Someday C++0x may allow for enum template specialization. */
948 else
949 {
952 }
953 }
956 }
958 /* Returns nonzero if we can optimize the retrieval of specializations
959 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
960 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
964 {
967 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
968 parameter. */
970 /* The optimized lookup depends on the fact that the
971 template arguments for the member function template apply
972 purely to the containing class, which is not true if the
973 containing class is an explicit or partial
974 specialization. */
978 /* It is possible to have a template that is not a member
979 template and is not a member of a template class:
981 template <typename T>
982 struct S { friend A::f(); };
984 Here, the friend function is a template, but the context does
985 not have template information. The optimized lookup relies
986 on having ARGS be the template arguments for both the class
987 and the function template. */
989 }
991 /* Retrieve the specialization (in the sense of [temp.spec] - a
992 specialization is either an instantiation or an explicit
993 specialization) of TMPL for the given template ARGS. If there is
994 no such specialization, return NULL_TREE. The ARGS are a vector of
995 arguments, or a vector of vectors of arguments, in the case of
996 templates with more than one level of parameters.
998 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
999 then we search for a partial specialization matching ARGS. This
1000 parameter is ignored if TMPL is not a class template. */
1002 static tree
1004 {
1010 /* There should be as many levels of arguments as there are
1011 levels of parameters. */
1016 {
1017 tree class_template;
1018 tree class_specialization;
1020 tree fns;
1023 /* The template arguments actually apply to the containing
1024 class. Find the class specialization with those
1025 arguments. */
1027 class_specialization
1031 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1032 for the specialization. */
1036 /* Iterate through the methods with the indicated name, looking
1037 for the one that has an instance of TMPL. */
1040 {
1043 /* using-declarations can add base methods to the method vec,
1044 and we don't want those here. */
1047 }
1049 }
1050 else
1051 {
1053 spec_entry elt;
1054 htab_t specializations;
1062 else
1070 }
1073 }
1075 /* Like retrieve_specialization, but for local declarations. */
1077 static tree
1079 {
1087 }
1089 /* Returns nonzero iff DECL is a specialization of TMPL. */
1091 int
1093 {
1094 tree t;
1097 {
1103 }
1104 else
1105 {
1114 }
1117 }
1119 /* Returns nonzero iff DECL is a specialization of friend declaration
1120 FRIEND_DECL according to [temp.friend]. */
1122 bool
1124 {
1131 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1132 of a template class, we want to check if DECL is a specialization
1133 if this. */
1137 {
1138 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1141 }
1146 /* There is nothing to do if this is not a template friend. */
1153 /* [temp.friend/6]
1154 A member of a class template may be declared to be a friend of a
1155 non-template class. In this case, the corresponding member of
1156 every specialization of the class template is a friend of the
1157 class granting friendship.
1159 For example, given a template friend declaration
1161 template <class T> friend void A<T>::f();
1163 the member function below is considered a friend
1165 template <> struct A<int> {
1166 void f();
1167 };
1169 For this type of template friend, TEMPLATE_DEPTH below will be
1170 nonzero. To determine if DECL is a friend of FRIEND, we first
1171 check if the enclosing class is a specialization of another. */
1178 {
1179 /* Next, we check the members themselves. In order to handle
1180 a few tricky cases, such as when FRIEND_DECL's are
1182 template <class T> friend void A<T>::g(T t);
1183 template <class T> template <T t> friend void A<T>::h();
1185 and DECL's are
1187 void A<int>::g(int);
1188 template <int> void A<int>::h();
1190 we need to figure out ARGS, the template arguments from
1191 the context of DECL. This is required for template substitution
1192 of `T' in the function parameter of `g' and template parameter
1193 of `h' in the above examples. Here ARGS corresponds to `int'. */
1200 {
1202 {
1205 else
1207 current_depth++;
1208 }
1210 }
1213 {
1215 tree friend_type;
1216 tree decl_type;
1217 tree friend_args_type;
1218 tree decl_args_type;
1220 /* Make sure that both DECL and FRIEND_DECL are templates or
1221 non-templates. */
1227 {
1228 /* If both are templates, check template parameter list. */
1229 tree friend_parms
1234 friend_parms))
1238 }
1239 else
1247 /* Check if return types match. */
1251 /* Check if function parameter types match, ignoring the
1252 `this' parameter. */
1261 }
1262 else
1263 {
1264 /* DECL is a TYPE_DECL */
1268 /* Make sure that both DECL and FRIEND_DECL are templates or
1269 non-templates. */
1270 is_template
1277 {
1278 tree friend_parms;
1279 /* If both are templates, check the name of the two
1280 TEMPLATE_DECL's first because is_friend didn't. */
1285 /* Now check template parameter list. */
1286 friend_parms
1289 return comp_template_parms
1291 friend_parms);
1292 }
1293 else
1296 }
1297 }
1299 }
1301 /* Register the specialization SPEC as a specialization of TMPL with
1302 the indicated ARGS. IS_FRIEND indicates whether the specialization
1303 is actually just a friend declaration. Returns SPEC, or an
1304 equivalent prior declaration, if available. */
1306 static tree
1308 hashval_t hash)
1309 {
1310 tree fn;
1312 spec_entry elt;
1318 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1319 register it; we want the corresponding TEMPLATE_DECL instead.
1320 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1321 the more obvious `uses_template_parms (spec)' to avoid problems
1322 with default function arguments. In particular, given
1323 something like this:
1325 template <class T> void f(T t1, T t = T())
1327 the default argument expression is not substituted for in an
1328 instantiation unless and until it is actually needed. */
1332 /* We don't put these specializations in the hash table, but we might
1333 want to give an error about a mismatch. */
1335 else
1336 {
1344 slot =
1348 else
1350 }
1352 /* We can sometimes try to re-register a specialization that we've
1353 already got. In particular, regenerate_decl_from_template calls
1354 duplicate_decls which will update the specialization list. But,
1355 we'll still get called again here anyhow. It's more convenient
1356 to simply allow this than to try to prevent it. */
1360 {
1362 {
1365 {
1367 fn);
1369 }
1370 else
1371 {
1372 tree clone;
1373 /* This situation should occur only if the first
1374 specialization is an implicit instantiation, the
1375 second is an explicit specialization, and the
1376 implicit instantiation has not yet been used. That
1377 situation can occur if we have implicitly
1378 instantiated a member function and then specialized
1379 it later.
1381 We can also wind up here if a friend declaration that
1382 looked like an instantiation turns out to be a
1383 specialization:
1385 template <class T> void foo(T);
1386 class S { friend void foo<>(int) };
1387 template <> void foo(int);
1389 We transform the existing DECL in place so that any
1390 pointers to it become pointers to the updated
1391 declaration.
1393 If there was a definition for the template, but not
1394 for the specialization, we want this to look as if
1395 there were no definition, and vice versa. */
1398 /* The call to duplicate_decls will have applied
1399 [temp.expl.spec]:
1401 An explicit specialization of a function template
1402 is inline only if it is explicitly declared to be,
1403 and independently of whether its function template
1404 is.
1406 to the primary function; now copy the inline bits to
1407 the various clones. */
1409 {
1414 }
1418 }
1419 }
1421 {
1423 /* Dup decl failed, but this is a new definition. Set the
1424 line number so any errors match this new
1425 definition. */
1429 }
1430 }
1434 /* A specialization must be declared in the same namespace as the
1435 template it is specializing. */
1441 {
1449 /* TMPL is a forward declaration of a template function; keep a list
1450 of all specializations in case we need to reassign them to a friend
1451 template later in tsubst_friend_function. */
1454 }
1457 }
1459 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1460 TMPL and ARGS members, ignores SPEC. */
1462 static int
1464 {
1470 }
1472 /* Returns a hash for a template TMPL and template arguments ARGS. */
1474 static hashval_t
1476 {
1479 }
1481 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1482 ignoring SPEC. */
1484 static hashval_t
1486 {
1489 }
1491 /* Recursively calculate a hash value for a template argument ARG, for use
1492 in the hash tables of template specializations. */
1494 hashval_t
1496 {
1508 /* We can get one of these when re-hashing a previous entry in the middle
1509 of substituting into a pack expansion. Just look through it. */
1518 {
1526 {
1531 }
1553 {
1556 {
1559 }
1561 }
1565 {
1568 }
1579 val = iterative_hash_template_arg
1591 val);
1593 val);
1602 /* A lambda can't appear in a template arg, but don't crash on
1603 erroneous input. */
1615 /* Now hash operands as usual. */
1620 }
1623 {
1627 val);
1630 /* Otherwise just compare the types during lookup. */
1639 {
1644 }
1645 }
1648 }
1650 /* Unregister the specialization SPEC as a specialization of TMPL.
1651 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1652 if the SPEC was listed as a specialization of TMPL.
1654 Note that SPEC has been ggc_freed, so we can't look inside it. */
1656 bool
1658 {
1660 spec_entry elt;
1668 {
1673 }
1676 }
1678 /* Like register_specialization, but for local declarations. We are
1679 registering SPEC, an instantiation of TMPL. */
1681 static void
1683 {
1688 }
1690 /* TYPE is a class type. Returns true if TYPE is an explicitly
1691 specialized class. */
1693 bool
1695 {
1699 }
1701 /* Print the list of functions at FNS, going through all the overloads
1702 for each element of the list. Alternatively, FNS can not be a
1703 TREE_LIST, in which case it will be printed together with all the
1704 overloads.
1706 MORE and *STR should respectively be FALSE and NULL when the function
1707 is called from the outside. They are used internally on recursive
1708 calls. print_candidates manages the two parameters and leaves NULL
1709 in *STR when it ends. */
1711 static void
1713 {
1719 {
1723 }
1724 else
1725 {
1727 {
1728 /* Pick the prefix string. */
1730 {
1733 }
1737 }
1740 }
1743 {
1746 }
1747 }
1749 /* Print the list of candidate FNS in an error message. FNS can also
1750 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1752 void
1754 {
1758 }
1760 /* Returns the template (one of the functions given by TEMPLATE_ID)
1761 which can be specialized to match the indicated DECL with the
1762 explicit template args given in TEMPLATE_ID. The DECL may be
1763 NULL_TREE if none is available. In that case, the functions in
1764 TEMPLATE_ID are non-members.
1766 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1767 specialization of a member template.
1769 The TEMPLATE_COUNT is the number of references to qualifying
1770 template classes that appeared in the name of the function. See
1771 check_explicit_specialization for a more accurate description.
1773 TSK indicates what kind of template declaration (if any) is being
1774 declared. TSK_TEMPLATE indicates that the declaration given by
1775 DECL, though a FUNCTION_DECL, has template parameters, and is
1776 therefore a template function.
1778 The template args (those explicitly specified and those deduced)
1779 are output in a newly created vector *TARGS_OUT.
1781 If it is impossible to determine the result, an error message is
1782 issued. The error_mark_node is returned to indicate failure. */
1784 static tree
1786 tree decl,
1790 tmpl_spec_kind tsk)
1791 {
1792 tree fns;
1793 tree targs;
1794 tree explicit_targs;
1796 /* A TREE_LIST of templates of which DECL may be a specialization.
1797 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1798 corresponding TREE_PURPOSE is the set of template arguments that,
1799 when used to instantiate the template, would produce a function
1800 with the signature of DECL. */
1816 /* Check for baselinks. */
1821 {
1824 }
1826 /* Count the number of template headers specified for this
1827 specialization. */
1835 {
1839 {
1840 tree decl_arg_types;
1841 tree fn_arg_types;
1843 /* In case of explicit specialization, we need to check if
1844 the number of template headers appearing in the specialization
1845 is correct. This is usually done in check_explicit_specialization,
1846 but the check done there cannot be exhaustive when specializing
1847 member functions. Consider the following code:
1849 template <> void A<int>::f(int);
1850 template <> template <> void A<int>::f(int);
1852 Assuming that A<int> is not itself an explicit specialization
1853 already, the first line specializes "f" which is a non-template
1854 member function, whilst the second line specializes "f" which
1855 is a template member function. So both lines are syntactically
1856 correct, and check_explicit_specialization does not reject
1857 them.
1859 Here, we can do better, as we are matching the specialization
1860 against the declarations. We count the number of template
1861 headers, and we check if they match TEMPLATE_COUNT + 1
1862 (TEMPLATE_COUNT is the number of qualifying template classes,
1863 plus there must be another header for the member template
1864 itself).
1866 Notice that if header_count is zero, this is not a
1867 specialization but rather a template instantiation, so there
1868 is no check we can perform here. */
1872 /* Check that the number of template arguments at the
1873 innermost level for DECL is the same as for FN. */
1881 /* DECL might be a specialization of FN. */
1885 /* For a non-static member function, we need to make sure
1886 that the const qualification is the same. Since
1887 get_bindings does not try to merge the "this" parameter,
1888 we must do the comparison explicitly. */
1894 /* Skip the "this" parameter and, for constructors of
1895 classes with virtual bases, the VTT parameter. A
1896 full specialization of a constructor will have a VTT
1897 parameter, but a template never will. */
1898 decl_arg_types
1900 fn_arg_types
1903 /* Check that the number of function parameters matches.
1904 For example,
1905 template <class T> void f(int i = 0);
1906 template <> void f<int>();
1907 The specialization f<int> is invalid but is not caught
1908 by get_bindings below. */
1912 /* Function templates cannot be specializations; there are
1913 no partial specializations of functions. Therefore, if
1914 the type of DECL does not match FN, there is no
1915 match. */
1917 {
1921 }
1923 /* See whether this function might be a specialization of this
1924 template. */
1928 /* We cannot deduce template arguments that when used to
1929 specialize TMPL will produce DECL. */
1932 /* Save this template, and the arguments deduced. */
1934 }
1936 /* FN is an ordinary member function, and we need a
1937 specialization of a member template. */
1938 ;
1940 /* We can get IDENTIFIER_NODEs here in certain erroneous
1941 cases. */
1942 ;
1944 /* This is just an ordinary non-member function. Nothing can
1945 be a specialization of that. */
1946 ;
1948 /* Cannot specialize functions that are created implicitly. */
1949 ;
1950 else
1951 {
1952 tree decl_arg_types;
1954 /* This is an ordinary member function. However, since
1955 we're here, we can assume it's enclosing class is a
1956 template class. For example,
1958 template <typename T> struct S { void f(); };
1959 template <> void S<int>::f() {}
1961 Here, S<int>::f is a non-template, but S<int> is a
1962 template class. If FN has the same type as DECL, we
1963 might be in business. */
1966 /* Its enclosing class is an explicit specialization
1967 of a template class. This is not a candidate. */
1972 /* The return types differ. */
1975 /* Adjust the type of DECL in case FN is a static member. */
1982 decl_arg_types))
1983 /* They match! */
1985 }
1986 }
1989 {
1990 /* We have:
1992 [temp.expl.spec]
1994 It is possible for a specialization with a given function
1995 signature to be instantiated from more than one function
1996 template. In such cases, explicit specification of the
1997 template arguments must be used to uniquely identify the
1998 function template specialization being specialized.
2000 Note that here, there's no suggestion that we're supposed to
2001 determine which of the candidate templates is most
2002 specialized. However, we, also have:
2004 [temp.func.order]
2006 Partial ordering of overloaded function template
2007 declarations is used in the following contexts to select
2008 the function template to which a function template
2009 specialization refers:
2011 -- when an explicit specialization refers to a function
2012 template.
2014 So, we do use the partial ordering rules, at least for now.
2015 This extension can only serve to make invalid programs valid,
2016 so it's safe. And, there is strong anecdotal evidence that
2017 the committee intended the partial ordering rules to apply;
2018 the EDG front end has that behavior, and John Spicer claims
2019 that the committee simply forgot to delete the wording in
2020 [temp.expl.spec]. */
2023 {
2026 }
2027 }
2030 {
2038 }
2042 {
2048 }
2050 /* We have one, and exactly one, match. */
2052 {
2055 /* DECL is a re-declaration or partial instantiation of a template
2056 function. */
2059 /* It was a specialization of an ordinary member function in a
2060 template class. */
2062 }
2064 /* It was a specialization of a template. */
2067 {
2072 }
2073 else
2076 }
2078 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2079 but with the default argument values filled in from those in the
2080 TMPL_TYPES. */
2082 static tree
2084 tree tmpl_types)
2085 {
2086 tree new_spec_types;
2094 /* Substitute into the rest of the list. */
2095 new_spec_types =
2099 /* Add the default argument for this parameter. */
2102 new_spec_types);
2103 }
2105 /* DECL is an explicit specialization. Replicate default arguments
2106 from the template it specializes. (That way, code like:
2108 template <class T> void f(T = 3);
2109 template <> void f(double);
2110 void g () { f (); }
2112 works, as required.) An alternative approach would be to look up
2113 the correct default arguments at the call-site, but this approach
2114 is consistent with how implicit instantiations are handled. */
2116 static void
2118 {
2119 tree tmpl;
2120 tree spec_types;
2121 tree tmpl_types;
2122 tree new_spec_types;
2123 tree old_type;
2124 tree new_type;
2125 tree t;
2130 /* See if there's anything we need to do. */
2143 {
2144 /* Remove the this pointer, but remember the object's type for
2145 CV quals. */
2151 {
2152 /* DECL may contain more parameters than TMPL due to the extra
2153 in-charge parameter in constructors and destructors. */
2156 }
2158 {
2161 }
2162 }
2164 /* Compute the merged default arguments. */
2165 new_spec_types =
2168 /* Compute the new FUNCTION_TYPE. */
2170 {
2174 new_spec_types);
2177 /* Put the in-charge parameter back. */
2180 new_spec_types);
2184 new_spec_types);
2185 }
2186 else
2188 new_spec_types);
2194 }
2196 /* Check to see if the function just declared, as indicated in
2197 DECLARATOR, and in DECL, is a specialization of a function
2198 template. We may also discover that the declaration is an explicit
2199 instantiation at this point.
2201 Returns DECL, or an equivalent declaration that should be used
2202 instead if all goes well. Issues an error message if something is
2203 amiss. Returns error_mark_node if the error is not easily
2204 recoverable.
2206 FLAGS is a bitmask consisting of the following flags:
2208 2: The function has a definition.
2209 4: The function is a friend.
2211 The TEMPLATE_COUNT is the number of references to qualifying
2212 template classes that appeared in the name of the function. For
2213 example, in
2215 template <class T> struct S { void f(); };
2216 void S<int>::f();
2218 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2219 classes are not counted in the TEMPLATE_COUNT, so that in
2221 template <class T> struct S {};
2222 template <> struct S<int> { void f(); }
2223 template <> void S<int>::f();
2225 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2226 invalid; there should be no template <>.)
2228 If the function is a specialization, it is marked as such via
2229 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2230 is set up correctly, and it is added to the list of specializations
2231 for that template. */
2233 tree
2235 tree decl,
2238 {
2246 tmpl_spec_kind tsk;
2249 {
2252 else
2254 }
2255 else
2259 {
2262 {
2265 }
2267 {
2269 /* This could be something like:
2271 template <class T> void f(T);
2272 class S { friend void f<>(int); } */
2274 else
2275 {
2276 /* This case handles bogus declarations like template <>
2277 template <class T> void f<int>(); */
2280 declarator);
2282 }
2283 }
2287 /* The error has already been reported in
2288 check_specialization_scope. */
2294 /* Fall through. */
2307 decl);
2310 else
2314 /* Fall through. */
2319 else
2325 {
2326 /* This case handles bogus declarations like template <>
2327 template <class T> void f<int>(); */
2332 else
2334 declarator);
2336 }
2339 /* This is a specialization of a member template, without
2340 specialization the containing class. Something like:
2342 template <class T> struct S {
2343 template <class U> void f (U);
2344 };
2345 template <> template <class U> void S<int>::f(U) {}
2347 That's a specialization -- but of the entire template. */
2353 }
2356 {
2360 {
2364 }
2365 }
2368 {
2372 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2374 {
2375 tree fns;
2380 else
2381 {
2382 /* If there is no class context, the explicit instantiation
2383 must be at namespace scope. */
2386 /* Find the namespace binding, using the declaration
2387 context. */
2391 {
2394 }
2395 else
2396 {
2402 }
2403 }
2406 }
2412 {
2414 /* A specialization in class scope. This is invalid,
2415 but the error will already have been flagged by
2416 check_specialization_scope. */
2418 else
2419 {
2420 /* It's not valid to write an explicit instantiation in
2421 class scope, e.g.:
2423 class C { template void f(); }
2425 This case is caught by the parser. However, on
2426 something like:
2428 template class C { void f(); };
2430 (which is invalid) we can get here. The error will be
2431 issued later. */
2432 ;
2433 }
2436 }
2439 IDENTIFIER_NODE))
2440 {
2441 /* Find the list of functions in ctype that have the same
2442 name as the declared function. */
2448 {
2453 {
2454 /* From [temp.expl.spec]:
2456 If such an explicit specialization for the member
2457 of a class template names an implicitly-declared
2458 special member function (clause _special_), the
2459 program is ill-formed.
2461 Similar language is found in [temp.explicit]. */
2464 }
2467 }
2470 {
2474 }
2475 else
2476 {
2478 tree ovl;
2480 /* For a type-conversion operator, we cannot do a
2481 name-based lookup. We might be looking for `operator
2482 int' which will be a specialization of `operator T'.
2483 So, we find *all* the conversion operators, and then
2484 select from them. */
2492 {
2494 /* There are no more conversion functions. */
2497 /* Glue all these conversion functions together
2498 with those we already have. */
2501 }
2502 }
2505 {
2508 }
2509 else
2511 }
2513 /* Figure out what exactly is being specialized at this point.
2514 Note that for an explicit instantiation, even one for a
2515 member function, we cannot tell apriori whether the
2516 instantiation is for a member template, or just a member
2517 function of a template class. Even if a member template is
2518 being instantiated, the member template arguments may be
2519 elided if they can be deduced from the rest of the
2520 declaration. */
2523 member_specialization,
2524 template_count,
2525 tsk);
2528 /* We couldn't figure out what this declaration was
2529 specializing. */
2531 else
2532 {
2536 {
2537 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2538 is done by do_decl_instantiation later. */
2544 {
2545 /* If TMPL is not the most general template (for
2546 example, if TMPL is a friend template that is
2547 injected into namespace scope), then there will
2548 be too many levels of TARGS. Remove some of them
2549 here. */
2551 tree new_targs;
2558 }
2561 }
2563 /* If we thought that the DECL was a member function, but it
2564 turns out to be specializing a static member function,
2565 make DECL a static member function as well. */
2570 /* If this is a specialization of a member template of a
2571 template class, we want to return the TEMPLATE_DECL, not
2572 the specialization of it. */
2574 {
2579 {
2580 tree parm;
2584 /* We want to use the argument list specified in the
2585 definition, not in the original declaration. */
2590 }
2593 }
2595 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2598 /* Inherit default function arguments from the template
2599 DECL is specializing. */
2602 /* This specialization has the same protection as the
2603 template it specializes. */
2607 /* 7.1.1-1 [dcl.stc]
2609 A storage-class-specifier shall not be specified in an
2610 explicit specialization...
2612 The parser rejects these, so unless action is taken here,
2613 explicit function specializations will always appear with
2614 global linkage.
2616 The action recommended by the C++ CWG in response to C++
2617 defect report 605 is to make the storage class and linkage
2618 of the explicit specialization match the templated function:
2620 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2621 */
2623 {
2627 /* This specialization has the same linkage and visibility as
2628 the function template it specializes. */
2631 {
2634 }
2637 {
2640 }
2641 }
2643 /* If DECL is a friend declaration, declared using an
2644 unqualified name, the namespace associated with DECL may
2645 have been set incorrectly. For example, in:
2647 template <typename T> void f(T);
2648 namespace N {
2649 struct S { friend void f<int>(int); }
2650 }
2652 we will have set the DECL_CONTEXT for the friend
2653 declaration to N, rather than to the global namespace. */
2658 /* This is not really a declaration of a specialization.
2659 It's just the name of an instantiation. But, it's not
2660 a request for an instantiation, either. */
2663 /* This is indeed a specialization. In case of constructors
2664 and destructors, we need in-charge and not-in-charge
2665 versions in V3 ABI. */
2668 /* Register this specialization so that we can find it
2669 again. */
2671 }
2672 }
2675 }
2677 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2678 parameters. These are represented in the same format used for
2679 DECL_TEMPLATE_PARMS. */
2681 int
2683 {
2684 const_tree p1;
2685 const_tree p2;
2693 {
2705 {
2709 /* If either of the template parameters are invalid, assume
2710 they match for the sake of error recovery. */
2723 }
2724 }
2727 /* One set of parameters has more parameters lists than the
2728 other. */
2732 }
2734 /* Determine whether PARM is a parameter pack. */
2736 bool
2738 {
2739 /* Determine if we have a non-type template parameter pack. */
2746 /* If this is a list of template parameters, we could get a
2747 TYPE_DECL or a TEMPLATE_DECL. */
2751 /* Otherwise it must be a type template parameter. */
2755 }
2757 /* Determine if T is a function parameter pack. */
2759 bool
2761 {
2765 }
2767 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2768 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2770 tree
2772 {
2779 }
2781 /* Return true iff the function parameter PARAM_DECL was expanded
2782 from the function parameter pack PACK. */
2784 bool
2786 {
2791 /* The parameter pack and its pack arguments have the same
2792 DECL_PARM_INDEX. */
2794 }
2796 /* Determine whether ARGS describes a variadic template args list,
2797 i.e., one that is terminated by a template argument pack. */
2799 static bool
2801 {
2803 tree last_parm;
2817 }
2819 /* Generate a new name for the parameter pack name NAME (an
2820 IDENTIFIER_NODE) that incorporates its */
2822 static tree
2824 {
2825 /* Munge the name to include the parameter index. */
2826 #define NUMBUF_LEN 128
2838 }
2840 /* Return true if T is a primary function, class or alias template
2841 instantiation. */
2843 bool
2845 {
2862 }
2864 /* Return true if PARM is a template template parameter. */
2866 bool
2868 {
2870 }
2872 /* Return true iff PARM is a DECL representing a type template
2873 parameter. */
2875 bool
2877 {
2882 }
2884 /* Return the template parameters of T if T is a
2885 primary template instantiation, NULL otherwise. */
2887 tree
2889 {
2894 parms = INNERMOST_TEMPLATE_PARMS
2898 }
2900 /* Return the template parameters of the LEVELth level from the full list
2901 of template parameters PARMS. */
2903 tree
2905 {
2906 tree p;
2917 }
2919 /* Returns the template arguments of T if T is a template instantiation,
2920 NULL otherwise. */
2922 tree
2924 {
2932 }
2934 /* Return the argument pack elements of T if T is a template argument pack,
2935 NULL otherwise. */
2937 tree
2939 {
2945 }
2947 /* Structure used to track the progress of find_parameter_packs_r. */
2948 struct find_parameter_pack_data
2949 {
2950 /* TREE_LIST that will contain all of the parameter packs found by
2951 the traversal. */
2954 /* Set of AST nodes that have been visited by the traversal. */
2956 };
2958 /* Identifies all of the argument packs that occur in a template
2959 argument and appends them to the TREE_LIST inside DATA, which is a
2960 find_parameter_pack_data structure. This is a subroutine of
2961 make_pack_expansion and uses_parameter_packs. */
2962 static tree
2964 {
2970 /* Handle type aliases/typedefs. */
2975 {
2982 }
2984 /* Identify whether this is a parameter pack or not. */
2986 {
3001 {
3002 /* We don't want to walk into the type of a PARM_DECL,
3003 because we don't want to see the type parameter pack. */
3006 }
3013 /* Not a parameter pack. */
3015 }
3018 {
3019 /* Add this parameter pack to the list. */
3021 }
3027 /* This switch statement will return immediately if we don't find a
3028 parameter pack. */
3030 {
3035 /* Check the template itself. */
3038 /* Check the template arguments. */
3054 /* Fall through. */
3096 }
3099 }
3101 /* Determines if the expression or type T uses any parameter packs. */
3102 bool
3104 {
3112 }
3114 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3115 representation a base-class initializer into a parameter pack
3116 expansion. If all goes well, the resulting node will be an
3117 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3118 respectively. */
3119 tree
3121 {
3122 tree result;
3131 {
3132 /* The only time we will see a TREE_LIST here is for a base
3133 class initializer. In this case, the TREE_PURPOSE will be a
3134 _TYPE node (representing the base class expansion we're
3135 initializing) and the TREE_VALUE will be a TREE_LIST
3136 containing the initialization arguments.
3138 The resulting expansion looks somewhat different from most
3139 expansions. Rather than returning just one _EXPANSION, we
3140 return a TREE_LIST whose TREE_PURPOSE is a
3141 TYPE_PACK_EXPANSION containing the bases that will be
3142 initialized. The TREE_VALUE will be identical to the
3143 original TREE_VALUE, which is a list of arguments that will
3144 be passed to each base. We do not introduce any new pack
3145 expansion nodes into the TREE_VALUE (although it is possible
3146 that some already exist), because the TREE_PURPOSE and
3147 TREE_VALUE all need to be expanded together with the same
3148 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3149 resulting TREE_PURPOSE will mention the parameter packs in
3150 both the bases and the arguments to the bases. */
3151 tree purpose;
3152 tree value;
3155 /* Determine which parameter packs will be used by the base
3156 class expansion. */
3163 {
3167 }
3170 {
3171 /* Collect the sets of parameter packs used in each of the
3172 initialization arguments. */
3174 {
3175 /* Determine which parameter packs will be expanded in this
3176 argument. */
3179 }
3180 }
3184 /* Create the pack expansion type for the base type. */
3189 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3190 they will rarely be compared to anything. */
3194 }
3199 /* Build the PACK_EXPANSION_* node. */
3200 result = for_types
3205 {
3206 /* Propagate type and const-expression information. */
3209 }
3210 else
3211 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3212 they will rarely be compared to anything. */
3215 /* Determine which parameter packs will be expanded. */
3221 /* Make sure we found some parameter packs. */
3223 {
3226 else
3229 }
3235 }
3237 /* Checks T for any "bare" parameter packs, which have not yet been
3238 expanded, and issues an error if any are found. This operation can
3239 only be done on full expressions or types (e.g., an expression
3240 statement, "if" condition, etc.), because we could have expressions like:
3242 foo(f(g(h(args)))...)
3244 where "args" is a parameter pack. check_for_bare_parameter_packs
3245 should not be called for the subexpressions args, h(args),
3246 g(h(args)), or f(g(h(args))), because we would produce erroneous
3247 error messages.
3249 Returns TRUE and emits an error if there were bare parameter packs,
3250 returns FALSE otherwise. */
3251 bool
3253 {
3269 {
3272 {
3281 else
3286 else
3290 }
3293 }
3296 }
3298 /* Expand any parameter packs that occur in the template arguments in
3299 ARGS. */
3300 tree
3302 {
3308 /* First, determine if we need to expand anything, and the number of
3309 slots we'll need. */
3311 {
3316 {
3320 else
3322 }
3323 else
3324 {
3326 num_result_args++;
3327 }
3328 }
3330 /* If no expansion is necessary, we're done. */
3334 /* Expand arguments. */
3337 non_default_args_count =
3340 {
3343 {
3350 }
3351 else
3352 {
3355 }
3356 }
3360 }
3362 /* Checks if DECL shadows a template parameter.
3364 [temp.local]: A template-parameter shall not be redeclared within its
3365 scope (including nested scopes).
3367 Emits an error and returns TRUE if the DECL shadows a parameter,
3368 returns FALSE otherwise. */
3370 bool
3372 {
3373 tree olddecl;
3375 /* If we're not in a template, we can't possibly shadow a template
3376 parameter. */
3380 /* Figure out what we're shadowing. */
3385 /* If there's no previous binding for this name, we're not shadowing
3386 anything, let alone a template parameter. */
3390 /* If we're not shadowing a template parameter, we're done. Note
3391 that OLDDECL might be an OVERLOAD (or perhaps even an
3392 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3393 node. */
3397 /* We check for decl != olddecl to avoid bogus errors for using a
3398 name inside a class. We check TPFI to avoid duplicate errors for
3399 inline member templates. */
3407 }
3409 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3410 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3411 template parameters. */
3413 static tree
3418 tree decl,
3419 tree type)
3420 {
3432 }
3434 /* Find the canonical type parameter for the given template type
3435 parameter. Returns the canonical type parameter, which may be TYPE
3436 if no such parameter existed. */
3438 static tree
3440 {
3441 tree list;
3455 else
3456 {
3461 }
3462 }
3464 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3465 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3466 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3467 new one is created. */
3469 static tree
3471 tsubst_flags_t complain)
3472 {
3477 {
3497 /* Template template parameters need this. */
3502 }
3505 }
3507 /* Process information from new template parameter PARM and append it
3508 to the LIST being built. This new parameter is a non-type
3509 parameter iff IS_NON_TYPE is true. This new parameter is a
3510 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3511 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3512 parameter list PARM belongs to. This is used used to create a
3513 proper canonical type for the type of PARM that is to be created,
3514 iff PARM is a type. If the size is not known, this parameter shall
3515 be set to 0. */
3517 tree
3521 {
3523 tree defval;
3524 tree err_parm_list;
3531 {
3535 {
3539 else
3541 }
3544 }
3545 else
3549 {
3555 {
3559 }
3560 else
3561 {
3562 /* [temp.param]
3564 The top-level cv-qualifiers on the template-parameter are
3565 ignored when determining its type. */
3568 {
3572 }
3575 {
3576 /* This template parameter is not a parameter pack, but it
3577 should be. Complain about "bare" parameter packs. */
3580 /* Recover by calling this a parameter pack. */
3582 }
3583 }
3585 /* A template parameter is not modifiable. */
3594 processing_template_decl,
3595 num_template_parms,
3600 }
3601 else
3602 {
3603 tree t;
3607 {
3609 /* This is for distinguishing between real templates and template
3610 template parameters */
3614 }
3615 else
3616 {
3618 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3621 }
3628 processing_template_decl,
3629 num_template_parms,
3633 }
3639 }
3641 /* The end of a template parameter list has been reached. Process the
3642 tree list into a parameter vector, converting each parameter into a more
3643 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3644 as PARM_DECLs. */
3646 tree
3648 {
3653 current_template_parms
3658 {
3662 }
3667 }
3669 /* Create a new type almost identical to TYPE but which has the
3670 following differences:
3672 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3673 template sibling parameters of T.
3675 2/ T has a new canonical type that matches the new number
3676 of sibling parms.
3678 3/ From now on, T is going to be what lookups referring to the
3679 name of TYPE will return. No lookup should return TYPE anymore.
3681 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3683 This is a subroutine of fixup_template_parms. */
3685 static tree
3687 {
3689 tree t;
3690 /* This is the decl which name is inserted into the symbol table for
3691 the template parm type. So whenever we lookup the type name, this
3692 is the DECL we get. */
3693 tree decl;
3695 /* Do not fix up the type twice. */
3710 num_parms,
3721 /* Update the type associated to the type name stored in the symbol
3722 table. Now, whenever the type name is looked up, the resulting
3723 type is properly fixed up. */
3729 }
3731 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3732 identical to I, but that is fixed up as to:
3734 1/ carry the number of sibling parms (NUM_PARMS) of the template
3735 parm represented by I.
3737 2/ replace all references to template parm types declared before I
3738 (in the same template parm list as I) by references to template
3739 parm types contained in ARGS. ARGS should contain the list of
3740 template parms that have been fixed up so far, in a form suitable
3741 to be passed to tsubst.
3743 This is a subroutine of fixup_template_parms. */
3745 static tree
3747 {
3752 /* Do not fix up the index twice. */
3762 num_parms,
3774 }
3776 /*
3777 This is a subroutine of fixup_template_parms.
3779 It computes the canonical type of the type of the template
3780 parameter PARM_DESC and update all references to that type so that
3781 they use the newly computed canonical type. No access check is
3782 performed during the fixup. PARM_DESC is a TREE_LIST which
3783 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3784 default argument of the template parm if any. IDX is the index of
3785 the template parameter, starting at 0. NUM_PARMS is the number of
3786 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3787 TREE_VEC containing the full set of template parameters in a form
3788 suitable to be passed to substs functions as their ARGS
3789 argument. This is what current_template_args returns for a given
3790 template. The innermost vector of args in ARGLIST is the set of
3791 template parms that have been fixed up so far. This function adds
3792 the fixed up parameter into that vector. */
3794 static void
3798 tree arglist)
3799 {
3806 {
3807 /* PARM is a template type parameter. Fix up its type, add
3808 the fixed-up template parm to the vector of fixed-up
3809 template parms so far, and substitute the fixed-up
3810 template parms into the default argument of this
3811 parameter. */
3812 tree t =
3817 }
3819 {
3820 /* PARM is a template template parameter. This is going to
3821 be interesting. */
3825 /* First, fix up the parms of the template template parm
3826 because the parms are involved in defining the new canonical
3827 type of the template template parm. */
3829 /* So we need to substitute the template parm types that have
3830 been fixed up so far into the template parms of this template
3831 template parm. E.g, consider this:
3833 template<class T, template<T u> class TT> class S;
3835 In this case we want to substitute T into the
3836 template parameters of TT.
3838 So let's walk the template parms of PARM here, and
3839 tsubst ARGLIST into into each of the template
3840 parms. */
3842 /* For this substitution we need to build the full set of
3843 template parameters and use that as arguments for the
3844 tsubsting function. */
3847 /* This will contain the innermost parms of PARM into which
3848 we have substituted so far. */
3852 {
3853 tree parameter;
3857 /* INNERMOST_ARGS needs to have at least the same number
3858 of elements as the index PARAMETER, ortherwise
3859 tsubsting into PARAMETER will result in partially
3860 instantiating it, reducing its tempate parm
3861 level. Let's tactically fill INNERMOST_ARGS for that
3862 purpose. */
3868 targs);
3869 }
3871 /* Now fix up the type of the template template parm. */
3878 }
3880 {
3881 /* PARM is a non-type template parameter. We need to:
3883 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3884 proper number of sibling parameters.
3886 * Make lookups of the template parameter return a reference
3887 to the fixed-up index. No lookup should return references
3888 to the former index anymore.
3890 * Substitute the template parms that got fixed up so far
3892 * into the type of PARM. */
3896 /* PUSHED_DECL is the decl added to the symbol table with
3897 the name of the parameter. E,g:
3899 template<class T, T u> //#0
3900 auto my_function(T t) -> decltype(u); //#1
3902 Here, when looking up u at //#1, we get the decl of u
3903 resulting from the declaration in #0. This is what
3904 PUSHED_DECL is. We need to replace the reference to the
3905 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3906 fixed-up TEMPLATE_PARM_INDEX. */
3909 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3910 fixup the type of PUSHED_DECL as well and luckily
3911 fixup_template_parm_index does it for us too. */
3912 tree fixed_up_index =
3917 /* Add this fixed up PARM to the template parms we've fixed
3918 up so far and use that to substitute the fixed-up
3919 template parms into the type of PARM. */
3924 }
3931 }
3933 /* Walk the current template parms and properly compute the canonical
3934 types of the dependent types created during
3935 cp_parser_template_parameter_list. */
3937 void
3939 {
3940 tree arglist;
3941 tree parameter_vec;
3942 tree fixedup_args;
3951 /* This vector contains the current innermost template parms that
3952 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3953 to be passed to tsubst* functions as their ARGS argument. */
3956 /* This vector contains the full set of template parms in a form
3957 suitable to be passed to substs functions as their ARGS
3958 argument. */
3962 /* Let's do the proper fixup now. */
3966 }
3968 /* end_template_decl is called after a template declaration is seen. */
3970 void
3972 {
3978 /* This matches the pushlevel in begin_template_parm_list. */
3983 }
3985 /* Takes a TREE_LIST representing a template parameter and convert it
3986 into an argument suitable to be passed to the type substitution
3987 functions. Note that If the TREE_LIST contains an error_mark
3988 node, the returned argument is error_mark_node. */
3990 static tree
3992 {
4005 {
4009 {
4010 /* Turn this argument into a TYPE_ARGUMENT_PACK
4011 with a single element, which expands T. */
4013 #ifdef ENABLE_CHECKING
4014 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4016 #endif
4021 }
4022 }
4023 else
4024 {
4028 {
4029 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4030 with a single element, which expands T. */
4033 #ifdef ENABLE_CHECKING
4034 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4036 #endif
4042 }
4043 }
4045 }
4047 /* This function returns TRUE if PARM_PACK is a template parameter
4048 pack and if ARG_PACK is what template_parm_to_arg returned when
4049 passed PARM_PACK. */
4051 static bool
4053 {
4054 /* For clarity in the comments below let's use the representation
4055 argument_pack<elements>' to denote an argument pack and its
4056 elements.
4058 In the 'if' block below, we want to detect cases where
4059 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
4060 check if ARG_PACK is an argument pack which sole element is
4061 the expansion of PARM_PACK. That argument pack is typically
4062 created by template_parm_to_arg when passed a parameter
4063 pack. */
4068 {
4071 /* So we have an argument_pack<P...>. We want to test if P
4072 is actually PARM_PACK. We will not use cp_tree_equal to
4073 test P and PARM_PACK because during type fixup (by
4074 fixup_template_parm) P can be a pre-fixup version of a
4075 type and PARM_PACK be its post-fixup version.
4076 cp_tree_equal would consider them as different even
4077 though we would want to consider them compatible for our
4078 precise purpose here.
4080 Thus we are going to consider that P and PARM_PACK are
4081 compatible if they have the same DECL. */
4083 same DECL as parm_pack ... */
4087 /* ... or if PARM_PACK is a non-type parameter named by the
4088 same DECL as ARG_PACK. Note that PARM_PACK being a
4089 non-type parameter means it's either a PARM_DECL or a
4090 TEMPLATE_PARM_INDEX. */
4100 }
4102 }
4104 /* Within the declaration of a template, return all levels of template
4105 parameters that apply. The template parameters are represented as
4106 a TREE_VEC, in the form documented in cp-tree.h for template
4107 arguments. */
4109 static tree
4111 {
4112 tree header;
4117 /* If there is only one level of template parameters, we do not
4118 create a TREE_VEC of TREE_VECs. Instead, we return a single
4119 TREE_VEC containing the arguments. */
4124 {
4132 #ifdef ENABLE_CHECKING
4134 #endif
4138 else
4140 }
4143 /* This can happen for template parms of a template template
4144 parameter, e.g:
4146 template<template<class T, class U> class TT> struct S;
4148 Consider the level of the parms of TT; T and U both have
4149 level 2; TT has no template parm of level 1. So in this case
4150 the first element of full_template_args is NULL_TREE. If we
4151 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4152 of 2. This will make tsubst wrongly consider that T and U
4153 have level 1. Instead, let's create a dummy vector as the
4154 first element of full_template_args so that TMPL_ARG_DEPTH
4155 returns the correct depth for args. */
4158 }
4160 /* Update the declared TYPE by doing any lookups which were thought to be
4161 dependent, but are not now that we know the SCOPE of the declarator. */
4163 tree
4165 {
4176 /* Don't bother building up the args in this case. */
4178 {
4179 /* tsubst in the args corresponding to the template parameters,
4180 including auto if present. Most things will be unchanged, but
4181 make_typename_type and tsubst_qualified_id will resolve
4182 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4185 tree pushed;
4187 {
4191 }
4196 }
4202 {
4205 else
4207 }
4209 }
4211 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4212 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4213 a member template. Used by push_template_decl below. */
4215 static tree
4217 {
4225 }
4227 struct template_parm_data
4228 {
4229 /* The level of the template parameters we are currently
4230 processing. */
4233 /* The index of the specialization argument we are currently
4234 processing. */
4237 /* An array whose size is the number of template parameters. The
4238 elements are nonzero if the parameter has been used in any one
4239 of the arguments processed so far. */
4242 /* An array whose size is the number of template arguments. The
4243 elements are nonzero if the argument makes use of template
4244 parameters of this level. */
4246 };
4248 /* Subroutine of push_template_decl used to see if each template
4249 parameter in a partial specialization is used in the explicit
4250 argument list. If T is of the LEVEL given in DATA (which is
4251 treated as a template_parm_data*), then DATA->PARMS is marked
4252 appropriately. */
4254 static int
4256 {
4262 {
4265 }
4266 else
4267 {
4270 }
4273 {
4276 }
4278 /* Return zero so that for_each_template_parm will continue the
4279 traversal of the tree; we want to mark *every* template parm. */
4281 }
4283 /* Process the partial specialization DECL. */
4285 static tree
4287 {
4293 tree inner_parms;
4294 tree inst;
4307 /* We check that each of the template parameters given in the
4308 partial specialization is used in the argument list to the
4309 specialization. For example:
4311 template <class T> struct S;
4312 template <class T> struct S<T*>;
4314 The second declaration is OK because `T*' uses the template
4315 parameter T, whereas
4317 template <class T> struct S<int>;
4319 is no good. Even trickier is:
4321 template <class T>
4322 struct S1
4323 {
4324 template <class U>
4325 struct S2;
4326 template <class U>
4327 struct S2<T>;
4328 };
4330 The S2<T> declaration is actually invalid; it is a
4331 full-specialization. Of course,
4333 template <class U>
4334 struct S2<T (*)(U)>;
4336 or some such would have been OK. */
4344 {
4349 NULL,
4351 }
4354 {
4355 /* One of the template parms was not used in the
4356 specialization. */
4358 {
4361 }
4364 }
4369 /* [temp.class.spec]
4371 The argument list of the specialization shall not be identical to
4372 the implicit argument list of the primary template. */
4379 /* [temp.class.spec]
4381 A partially specialized non-type argument expression shall not
4382 involve template parameters of the partial specialization except
4383 when the argument expression is a simple identifier.
4385 The type of a template parameter corresponding to a specialized
4386 non-type argument shall not be dependent on a parameter of the
4387 specialization.
4389 Also, we verify that pack expansions only occur at the
4390 end of the argument list. */
4394 {
4401 {
4402 /* Extract the arguments from the argument pack. We'll be
4403 iterating over these in the following loop. */
4406 }
4409 {
4411 /* Get the Jth argument in the parameter pack. */
4415 {
4416 /* Pack expansions must come at the end of the
4417 argument list. */
4420 {
4424 else
4427 }
4428 }
4431 /* We only care about the pattern. */
4437 /* This next line is the `argument expression is not just a
4438 simple identifier' condition and also the `specialized
4439 non-type argument' bit. */
4441 {
4445 arg);
4446 else
4447 {
4448 /* Look at the corresponding template parameter,
4449 marking which template parameters its type depends
4450 upon. */
4454 {
4455 /* We haven't yet initialized TPD2. Do so now. */
4457 /* The number of parameters here is the number in the
4458 main template, which, as checked in the assertion
4459 above, is NARGS. */
4463 }
4465 /* Mark the template parameters. But this time, we're
4466 looking for the template parameters of the main
4467 template, not in the specialization. */
4474 NULL,
4478 {
4479 /* The type depended on some template parameters.
4480 If they are fully specialized in the
4481 specialization, that's OK. */
4490 "type %qT of template argument %qE depends "
4492 "type %qT of template argument %qE depends "
4494 type,
4495 arg);
4496 }
4497 }
4498 }
4499 }
4500 }
4502 /* We should only get here once. */
4512 {
4516 {
4520 "partial specialization of %qT after instantiation "
4522 }
4523 }
4526 }
4528 /* Check that a template declaration's use of default arguments and
4529 parameter packs is not invalid. Here, PARMS are the template
4530 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4531 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4532 specialization.
4535 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4536 declaration (but not a definition); 1 indicates a declaration, 2
4537 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4538 emitted for extraneous default arguments.
4540 Returns TRUE if there were no errors found, FALSE otherwise. */
4542 bool
4545 {
4548 tree parm_level;
4551 /* [temp.param]
4553 A default template-argument shall not be specified in a
4554 function template declaration or a function template definition, nor
4555 in the template-parameter-list of the definition of a member of a
4556 class template. */
4559 /* You can't have a function template declaration in a local
4560 scope, nor you can you define a member of a class template in a
4561 local scope. */
4568 /* If this is either a friend defined in the scope of the class
4569 or a member function. */
4575 /* And, if it was a member function, it really was defined in
4576 the scope of the class. */
4579 /* We already checked these parameters when the template was
4580 declared, so there's no need to do it again now. This function
4581 was defined in class scope, but we're processing it's body now
4582 that the class is complete. */
4585 /* Core issue 226 (C++0x only): the following only applies to class
4586 templates. */
4588 {
4589 /* [temp.param]
4591 If a template-parameter has a default template-argument, all
4592 subsequent template-parameters shall have a default
4593 template-argument supplied. */
4595 {
4602 {
4612 {
4614 /* For better subsequent error-recovery, we indicate that
4615 there should have been a default argument. */
4618 }
4620 && !is_partial
4621 && !is_friend_decl
4622 /* Don't complain about an enclosing partial
4623 specialization. */
4628 {
4629 /* A primary class template can only have one
4630 parameter pack, at the end of the template
4631 parameter list. */
4636 else
4644 }
4645 }
4646 }
4647 }
4650 || is_partial
4651 || !is_primary
4653 /* For an ordinary class template, default template arguments are
4654 allowed at the innermost level, e.g.:
4655 template <class T = int>
4656 struct S {};
4657 but, in a partial specialization, they're not allowed even
4658 there, as we have in [temp.class.spec]:
4660 The template parameter list of a specialization shall not
4661 contain default template argument values.
4663 So, for a partial specialization, or for a function template
4664 (in C++98/C++03), we look at all of them. */
4665 ;
4666 else
4667 /* But, for a primary class template that is not a partial
4668 specialization we look at all template parameters except the
4669 innermost ones. */
4672 /* Figure out what error message to issue. */
4685 else
4689 /* If we're inside a class definition, there's no need to
4690 examine the parameters to the class itself. On the one
4691 hand, they will be checked when the class is defined, and,
4692 on the other, default arguments are valid in things like:
4693 template <class T = double>
4694 struct S { template <class U> void f(U); };
4695 Here the default argument for `S' has no bearing on the
4696 declaration of `f'. */
4698 else
4699 /* Check everything. */
4705 {
4712 {
4717 {
4719 {
4726 }
4728 /* Clear out the default argument so that we are not
4729 confused later. */
4731 }
4732 }
4734 /* At this point, if we're still interested in issuing messages,
4735 they must apply to classes surrounding the object declared. */
4739 }
4742 }
4744 /* Worker for push_template_decl_real, called via
4745 for_each_template_parm. DATA is really an int, indicating the
4746 level of the parameters we are interested in. If T is a template
4747 parameter of that level, return nonzero. */
4749 static int
4751 {
4757 else
4760 }
4762 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4763 parameters given by current_template_args, or reuses a
4764 previously existing one, if appropriate. Returns the DECL, or an
4765 equivalent one, if it is replaced via a call to duplicate_decls.
4767 If IS_FRIEND is true, DECL is a friend declaration. */
4769 tree
4771 {
4772 tree tmpl;
4773 tree args;
4774 tree info;
4775 tree ctx;
4779 /* True if the template is a member template, in the sense of
4780 [temp.mem]. */
4786 /* See if this is a partial specialization. */
4795 /* For a friend, we want the context of the friend function, not
4796 the type of which it is a friend. */
4800 /* In the case of a virtual function, we want the class in which
4801 it is defined. */
4803 else
4804 /* Otherwise, if we're currently defining some class, the DECL
4805 is assumed to be a member of the class. */
4814 /* See if this is a primary template. */
4816 /* A friend template that specifies a class context, i.e.
4817 template <typename T> friend void A<T>::f();
4818 is not primary. */
4820 else
4824 {
4829 {
4832 }
4834 {
4836 {
4837 /* [temp.mem]
4839 A destructor shall not be a member template. */
4842 }
4849 {
4850 /* [basic.stc.dynamic.allocation]
4852 An allocation function can be a function
4853 template. ... Template allocation functions shall
4854 have two or more parameters. */
4857 }
4858 }
4864 /* alias-declaration */
4866 else
4867 {
4870 }
4871 }
4873 /* Check to see that the rules regarding the use of default
4874 arguments are not being violated. */
4878 /* Ensure that there are no parameter packs in the type of this
4879 declaration that have not been expanded. */
4881 {
4882 /* Check each of the arguments individually to see if there are
4883 any bare parameter packs. */
4889 {
4892 {
4893 /* This is a PARM_DECL that contains unexpanded parameter
4894 packs. We have already complained about this in the
4895 check_for_bare_parameter_packs call, so just replace
4896 these types with ERROR_MARK_NODE. */
4899 }
4903 }
4905 /* Check for bare parameter packs in the return type and the
4906 exception specifiers. */
4908 /* Errors were already issued, set return type to int
4909 as the frontend doesn't expect error_mark_node as
4910 the return type. */
4914 }
4919 {
4922 }
4933 {
4938 /* If DECL is a TYPE_DECL for a class-template, then there won't
4939 be DECL_LANG_SPECIFIC. The information equivalent to
4940 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4944 {
4945 /* Since a template declaration already existed for this
4946 class-type, we must be redeclaring it here. Make sure
4947 that the redeclaration is valid. */
4949 current_template_parms);
4950 /* We don't need to create a new TEMPLATE_DECL; just use the
4951 one we already had. */
4953 }
4954 else
4955 {
4957 member_template_p);
4962 {
4963 /* A specialization of a member template of a template
4964 class. */
4968 }
4969 }
4970 }
4971 else
4972 {
4978 {
4981 }
4989 {
4990 tree new_tmpl;
4992 /* The declaration is a specialization of a member
4993 template, declared outside the class. Therefore, the
4994 innermost template arguments will be NULL, so we
4995 replace them with the arguments determined by the
4996 earlier call to check_explicit_specialization. */
4999 new_tmpl
5001 member_template_p);
5011 args,
5014 }
5016 /* Make sure the template headers we got make sense. */
5021 {
5024 }
5025 else
5027 {
5032 {
5036 else
5041 }
5046 /* Can happen in erroneous input. */
5048 else
5052 }
5054 /* Check that the parms are used in the appropriate qualifying scopes
5055 in the declarator. */
5059 {
5065 /* Avoid crash in import_export_decl. */
5068 }
5069 }
5074 /* Push template declarations for global functions and types. Note
5075 that we do not try to push a global template friend declared in a
5076 template class; such a thing may well depend on the template
5077 parameters of the class. */
5080 {
5085 /* Hide template friend classes that haven't been declared yet. */
5087 {
5090 }
5091 }
5094 {
5100 {
5103 /* It is a conversion operator. See if the type converted to
5104 depends on innermost template operands. */
5107 depth))
5109 }
5111 /* Give template template parms a DECL_CONTEXT of the template
5112 for which they are a parameter. */
5115 {
5119 }
5120 }
5122 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5123 back to its most general template. If TMPL is a specialization,
5124 ARGS may only have the innermost set of arguments. Add the missing
5125 argument levels if necessary. */
5133 else
5134 {
5139 }
5142 }
5144 tree
5146 {
5148 }
5150 /* Called when a class template TYPE is redeclared with the indicated
5151 template PARMS, e.g.:
5153 template <class T> struct S;
5154 template <class T> struct S {}; */
5156 bool
5158 {
5159 tree tmpl;
5160 tree tmpl_parms;
5164 {
5167 }
5171 /* The type is nested in some template class. Nothing to worry
5172 about here; there are no new template parameters for the nested
5173 type. */
5177 {
5179 tmpl);
5181 }
5187 {
5197 }
5200 {
5201 tree tmpl_parm;
5202 tree parm;
5203 tree tmpl_default;
5204 tree parm_default;
5218 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5219 TEMPLATE_DECL. */
5229 {
5233 }
5236 {
5237 /* We have in [temp.param]:
5239 A template-parameter may not be given default arguments
5240 by two different declarations in the same scope. */
5245 }
5248 /* Update the previous template parameters (which are the ones
5249 that will really count) with the new default value. */
5252 /* Update the new parameters, too; they'll be used as the
5253 parameters for any members. */
5255 }
5258 }
5260 /* Simplify EXPR if it is a non-dependent expression. Returns the
5261 (possibly simplified) expression. */
5263 static tree
5265 {
5269 /* If we're in a template, but EXPR isn't value dependent, simplify
5270 it. We're supposed to treat:
5272 template <typename T> void f(T[1 + 1]);
5273 template <typename T> void f(T[2]);
5275 as two declarations of the same function, for example. */
5280 {
5281 HOST_WIDE_INT saved_processing_template_decl;
5287 complain,
5292 }
5294 }
5296 tree
5298 {
5300 }
5302 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5303 template declaration, or a TYPE_DECL for an alias declaration. */
5305 bool
5307 {
5315 }
5317 /* Return TRUE iff is a specialization of an alias template. */
5319 bool
5321 {
5326 }
5328 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5329 must be a function or a pointer-to-function type, as specified
5330 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5331 and check that the resulting function has external linkage. */
5333 static tree
5335 {
5338 linkage_kind linkage;
5350 /* [temp.arg.nontype]/1
5352 A template-argument for a non-type, non-template template-parameter
5353 shall be one of:
5354 [...]
5355 -- the address of an object or function with external [C++11: or
5356 internal] linkage. */
5359 {
5364 else
5369 }
5372 }
5374 /* Subroutine of convert_nontype_argument.
5375 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5376 Emit an error otherwise. */
5378 static bool
5380 tsubst_flags_t complain)
5381 {
5388 {
5392 }
5394 }
5396 /* Returns TRUE iff the address of OP is value-dependent.
5398 14.6.2.4 [temp.dep.temp]:
5399 A non-integral non-type template-argument is dependent if its type is
5400 dependent or it has either of the following forms
5401 qualified-id
5402 & qualified-id
5403 and contains a nested-name-specifier which specifies a class-name that
5404 names a dependent type.
5406 We generalize this to just say that the address of a member of a
5407 dependent class is value-dependent; the above doesn't cover the
5408 address of a static data member named with an unqualified-id. */
5410 static bool
5412 {
5413 /* We could use get_inner_reference here, but there's no need;
5414 this is only relevant for template non-type arguments, which
5415 can only be expressed as &id-expression. */
5417 {
5421 }
5424 }
5426 /* The next set of functions are used for providing helpful explanatory
5427 diagnostics for failed overload resolution. Their messages should be
5428 indented by two spaces for consistency with the messages in
5429 call.c */
5431 static int
5433 {
5435 }
5437 static int
5439 {
5444 }
5446 static int
5448 {
5450 }
5452 static int
5454 {
5460 }
5462 static int
5464 {
5468 }
5470 static int
5472 {
5475 " template parameter %qD is not a parameter pack, but "
5479 }
5481 static int
5483 {
5486 " template argument %qE does not match "
5490 }
5492 static int
5494 {
5498 }
5500 static int
5502 {
5508 }
5510 static int
5512 {
5514 {
5519 else
5521 " deduced conflicting values for non-type parameter "
5523 }
5525 }
5527 static int
5529 {
5532 " variable-sized array type %qT is not "
5534 arg);
5536 }
5538 static int
5540 {
5544 arg);
5546 }
5548 static int
5550 {
5557 }
5559 static int
5561 {
5563 }
5565 static int
5567 {
5569 }
5571 static int
5574 {
5579 }
5581 static int
5584 {
5587 {
5595 }
5597 }
5599 static int
5601 {
5604 " template parameters of a template template argument are "
5607 }
5609 static int
5611 {
5617 }
5619 static int
5621 {
5626 }
5628 static int
5630 {
5634 arg);
5636 }
5638 /* Attempt to convert the non-type template parameter EXPR to the
5639 indicated TYPE. If the conversion is successful, return the
5640 converted value. If the conversion is unsuccessful, return
5641 NULL_TREE if we issued an error message, or error_mark_node if we
5642 did not. We issue error messages for out-and-out bad template
5643 parameters, but not simply because the conversion failed, since we
5644 might be just trying to do argument deduction. Both TYPE and EXPR
5645 must be non-dependent.
5647 The conversion follows the special rules described in
5648 [temp.arg.nontype], and it is much more strict than an implicit
5649 conversion.
5651 This function is called twice for each template argument (see
5652 lookup_template_class for a more accurate description of this
5653 problem). This means that we need to handle expressions which
5654 are not valid in a C++ source, but can be created from the
5655 first call (for instance, casts to perform conversions). These
5656 hacks can go away after we fix the double coercion problem. */
5658 static tree
5660 {
5661 tree expr_type;
5663 /* Detect immediately string literals as invalid non-type argument.
5664 This special-case is not needed for correctness (we would easily
5665 catch this later), but only to provide better diagnostic for this
5666 common user mistake. As suggested by DR 100, we do not mention
5667 linkage issues in the diagnostic as this is not the point. */
5668 /* FIXME we're making this OK. */
5670 {
5676 }
5678 /* Add the ADDR_EXPR now for the benefit of
5679 value_dependent_expression_p. */
5684 /* If we are in a template, EXPR may be non-dependent, but still
5685 have a syntactic, rather than semantic, form. For example, EXPR
5686 might be a SCOPE_REF, rather than the VAR_DECL to which the
5687 SCOPE_REF refers. Preserving the qualifying scope is necessary
5688 so that access checking can be performed when the template is
5689 instantiated -- but here we need the resolved form so that we can
5690 convert the argument. */
5701 else
5704 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5705 to a non-type argument of "nullptr". */
5710 /* In C++11, integral or enumeration non-type template arguments can be
5711 arbitrary constant expressions. Pointer and pointer to
5712 member arguments can be general constant expressions that evaluate
5713 to a null value, but otherwise still need to be of a specific form. */
5715 {
5717 /* A PTRMEM_CST is already constant, and a valid template
5718 argument for a parameter of pointer to member type, we just want
5719 to leave it in that form rather than lower it to a
5725 {
5730 }
5731 }
5733 /* HACK: Due to double coercion, we can get a
5734 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5735 which is the tree that we built on the first call (see
5736 below when coercing to reference to object or to reference to
5737 function). We just strip everything and get to the arg.
5738 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5739 for examples. */
5741 {
5747 {
5748 /* ??? Maybe we could use convert_from_reference here, but we
5749 would need to relax its constraints because the NOP_EXPR
5750 could actually change the type to something more cv-qualified,
5751 and this is not folded by convert_from_reference. */
5762 }
5763 }
5765 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5766 parameter is a pointer to object, through decay and
5767 qualification conversion. Let's strip everything. */
5769 {
5773 /* Skip the ADDR_EXPR only if it is part of the decay for
5774 an array. Otherwise, it is part of the original argument
5775 in the source code. */
5779 }
5781 /* [temp.arg.nontype]/5, bullet 1
5783 For a non-type template-parameter of integral or enumeration type,
5784 integral promotions (_conv.prom_) and integral conversions
5785 (_conv.integral_) are applied. */
5787 {
5796 /* Notice that there are constant expressions like '4 % 0' which
5797 do not fold into integer constants. */
5799 {
5801 {
5812 /* else cxx_constant_value complained but gave us
5813 a real constant, so go ahead. */
5815 }
5816 else
5818 }
5819 }
5820 /* [temp.arg.nontype]/5, bullet 2
5822 For a non-type template-parameter of type pointer to object,
5823 qualification conversions (_conv.qual_) and the array-to-pointer
5824 conversion (_conv.array_) are applied. */
5826 {
5827 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5829 A template-argument for a non-type, non-template template-parameter
5830 shall be one of: [...]
5832 -- the name of a non-type template-parameter;
5833 -- the address of an object or function with external linkage, [...]
5834 expressed as "& id-expression" where the & is optional if the name
5835 refers to a function or array, or if the corresponding
5836 template-parameter is a reference.
5838 Here, we do not care about functions, as they are invalid anyway
5839 for a parameter of type pointer-to-object. */
5842 /* Non-type template parameters are OK. */
5843 ;
5848 {
5850 {
5852 "because %qD is a variable, not the address of "
5856 }
5857 /* Other values, like integer constants, might be valid
5858 non-type arguments of some other type. */
5860 }
5861 else
5862 {
5863 tree decl;
5868 {
5873 }
5875 {
5880 }
5882 {
5887 }
5888 }
5897 }
5898 /* [temp.arg.nontype]/5, bullet 3
5900 For a non-type template-parameter of type reference to object, no
5901 conversions apply. The type referred to by the reference may be more
5902 cv-qualified than the (otherwise identical) type of the
5903 template-argument. The template-parameter is bound directly to the
5904 template-argument, which must be an lvalue. */
5906 {
5908 expr_type))
5912 {
5916 }
5919 {
5923 }
5925 /* [temp.arg.nontype]/1
5927 A template-argument for a non-type, non-template template-parameter
5928 shall be one of: [...]
5930 -- the address of an object or function with external linkage. */
5933 {
5936 {
5938 "because a reference variable does not have a constant "
5941 }
5942 }
5945 {
5950 }
5953 {
5958 }
5961 }
5962 /* [temp.arg.nontype]/5, bullet 4
5964 For a non-type template-parameter of type pointer to function, only
5965 the function-to-pointer conversion (_conv.func_) is applied. If the
5966 template-argument represents a set of overloaded functions (or a
5967 pointer to such), the matching function is selected from the set
5968 (_over.over_). */
5970 {
5971 /* If the argument is a template-id, we might not have enough
5972 context information to decay the pointer. */
5974 {
5978 }
5981 /* Null pointer values are OK in C++11. */
5989 {
5993 }
5994 }
5995 /* [temp.arg.nontype]/5, bullet 5
5997 For a non-type template-parameter of type reference to function, no
5998 conversions apply. If the template-argument represents a set of
5999 overloaded functions, the matching function is selected from the set
6000 (_over.over_). */
6002 {
6004 {
6009 }
6016 }
6017 /* [temp.arg.nontype]/5, bullet 6
6019 For a non-type template-parameter of type pointer to member function,
6020 no conversions apply. If the template-argument represents a set of
6021 overloaded member functions, the matching member function is selected
6022 from the set (_over.over_). */
6024 {
6029 /* [temp.arg.nontype] bullet 1 says the pointer to member
6030 expression must be a pointer-to-member constant. */
6034 /* There is no way to disable standard conversions in
6035 resolve_address_of_overloaded_function (called by
6036 instantiate_type). It is possible that the call succeeded by
6037 converting &B::I to &D::I (where B is a base of D), so we need
6038 to reject this conversion here.
6040 Actually, even if there was a way to disable standard conversions,
6041 it would still be better to reject them here so that we can
6042 provide a superior diagnostic. */
6044 {
6048 /* If we are just one standard conversion off, explain. */
6053 }
6054 }
6055 /* [temp.arg.nontype]/5, bullet 7
6057 For a non-type template-parameter of type pointer to data member,
6058 qualification conversions (_conv.qual_) are applied. */
6060 {
6061 /* [temp.arg.nontype] bullet 1 says the pointer to member
6062 expression must be a pointer-to-member constant. */
6069 }
6071 {
6073 {
6077 }
6079 }
6080 /* A template non-type parameter must be one of the above. */
6081 else
6084 /* Sanity check: did we actually convert the argument to the
6085 right type? */
6089 }
6091 /* Subroutine of coerce_template_template_parms, which returns 1 if
6092 PARM_PARM and ARG_PARM match using the rule for the template
6093 parameters of template template parameters. Both PARM and ARG are
6094 template parameters; the rest of the arguments are the same as for
6095 coerce_template_template_parms.
6096 */
6097 static int
6099 tree arg,
6100 tsubst_flags_t complain,
6101 tree in_decl,
6102 tree outer_args)
6103 {
6112 {
6114 /* We encounter instantiations of templates like
6115 template <template <template <class> class> class TT>
6116 class C; */
6117 {
6124 }
6125 /* Fall through. */
6130 /* Argument is a parameter pack but parameter is not. */
6135 /* The tsubst call is used to handle cases such as
6137 template <int> class C {};
6138 template <class T, template <T> class TT> class D {};
6139 D<int, C> d;
6141 i.e. the parameter list of TT depends on earlier parameters. */
6143 && !same_type_p
6150 /* Argument is a parameter pack but parameter is not. */
6157 }
6160 }
6163 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6164 template template parameters. Both PARM_PARMS and ARG_PARMS are
6165 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6166 or PARM_DECL.
6168 Consider the example:
6169 template <class T> class A;
6170 template<template <class U> class TT> class B;
6172 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6173 the parameters to A, and OUTER_ARGS contains A. */
6175 static int
6177 tree arg_parms,
6178 tsubst_flags_t complain,
6179 tree in_decl,
6180 tree outer_args)
6181 {
6192 /* Determine whether we have a parameter pack at the end of the
6193 template template parameter's template parameter list. */
6195 {
6202 {
6216 }
6217 }
6223 /* Check all of the template parameters except the parameter pack at
6224 the end (if any). */
6226 {
6235 outer_args))
6238 }
6241 {
6242 /* Check each of the template parameters in the template
6243 argument against the template parameter pack at the end of
6244 the template template parameter. */
6251 {
6258 outer_args))
6260 }
6261 }
6264 }
6266 /* Verifies that the deduced template arguments (in TARGS) for the
6267 template template parameters (in TPARMS) represent valid bindings,
6268 by comparing the template parameter list of each template argument
6269 to the template parameter list of its corresponding template
6270 template parameter, in accordance with DR150. This
6271 routine can only be called after all template arguments have been
6272 deduced. It will return TRUE if all of the template template
6273 parameter bindings are okay, FALSE otherwise. */
6274 bool
6276 {
6280 /* We're dealing with template parms in this process. */
6286 {
6291 {
6296 {
6297 /* Look inside the argument pack. */
6300 }
6303 {
6307 /* Extract the next argument from the argument
6308 pack. */
6312 /* Look at the pattern of the pack expansion. */
6315 /* Extract the template parameters from the template
6316 argument. */
6322 /* Verify that we can coerce the template template
6323 parameters from the template argument to the template
6324 parameter. This requires an exact match. */
6326 && !coerce_template_template_parms
6328 targ_parms,
6329 tf_none,
6330 tparm,
6331 targs))
6332 {
6335 }
6336 }
6337 }
6338 }
6340 out:
6344 }
6346 /* Since type attributes aren't mangled, we need to strip them from
6347 template type arguments. */
6349 static tree
6351 {
6352 tree mv;
6359 {
6364 }
6366 }
6368 /* Convert the indicated template ARG as necessary to match the
6369 indicated template PARM. Returns the converted ARG, or
6370 error_mark_node if the conversion was unsuccessful. Error and
6371 warning messages are issued under control of COMPLAIN. This
6372 conversion is for the Ith parameter in the parameter list. ARGS is
6373 the full set of template arguments deduced so far. */
6375 static tree
6377 tree arg,
6378 tree args,
6379 tsubst_flags_t complain,
6381 tree in_decl)
6382 {
6383 tree orig_arg;
6384 tree val;
6389 {
6390 /* The template argument was the name of some
6391 member function. That's usually
6392 invalid, but static members are OK. In any
6393 case, grab the underlying fields/functions
6394 and issue an error later if required. */
6397 }
6405 /* When determining whether an argument pack expansion is a template,
6406 look at the pattern. */
6410 /* Deal with an injected-class-name used as a template template arg. */
6412 {
6415 {
6425 }
6426 }
6428 is_tmpl_type =
6443 {
6445 {
6449 }
6452 "to refer to a type member of a template parameter, "
6457 typename_type,
6461 }
6463 {
6465 {
6467 {
6477 else
6479 }
6480 }
6482 }
6484 {
6486 {
6492 else
6494 }
6496 }
6499 {
6501 {
6503 /* The number of argument required is not known yet.
6504 Just accept it for now. */
6506 else
6507 {
6509 tree argparm;
6515 args))
6516 {
6519 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6520 TEMPLATE_DECL. */
6522 {
6527 }
6528 }
6529 else
6530 {
6532 {
6538 }
6541 }
6542 }
6543 }
6544 else
6546 /* We only form one instance of each template specialization.
6547 Therefore, if we use a non-canonical variant (i.e., a
6548 typedef), any future messages referring to the type will use
6549 the typedef, which is confusing if those future uses do not
6550 themselves also use the typedef. */
6553 }
6554 else
6555 {
6562 {
6565 else
6566 {
6567 /* Not sure if this is reachable, but it doesn't hurt
6568 to be robust. */
6571 }
6572 }
6574 /* We used to call digest_init here. However, digest_init
6575 will report errors, which we don't want when complain
6576 is zero. More importantly, digest_init will try too
6577 hard to convert things: for example, `0' should not be
6578 converted to pointer type at this point according to
6579 the standard. Accepting this is not merely an
6580 extension, since deciding whether or not these
6581 conversions can occur is part of determining which
6582 function template to call, or whether a given explicit
6583 argument specification is valid. */
6585 else
6594 {
6595 /* Strip typedefs from the SCOPE_REF. */
6598 complain);
6601 }
6602 }
6605 }
6607 /* Coerces the remaining template arguments in INNER_ARGS (from
6608 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6609 Returns the coerced argument pack. PARM_IDX is the position of this
6610 parameter in the template parameter list. ARGS is the original
6611 template argument list. */
6612 static tree
6615 tree args,
6616 tree inner_args,
6618 tree new_args,
6620 tree in_decl,
6621 tsubst_flags_t complain)
6622 {
6625 tree packed_args;
6626 tree argument_pack;
6636 {
6637 /* When the template parameter is a non-type template
6638 parameter pack whose type uses parameter packs, we need
6639 to look at each of the template arguments
6640 separately. Build a vector of the types for these
6641 non-type template parameters in PACKED_TYPES. */
6642 tree expansion
6650 /* Check that we have the right number of arguments. */
6654 {
6655 int needed_parms
6660 }
6662 /* If we aren't able to check the actual arguments now
6663 (because they haven't been expanded yet), we can at least
6664 verify that all of the types used for the non-type
6665 template parameter pack are, in fact, valid for non-type
6666 template parameters. */
6669 {
6672 {
6676 }
6677 }
6678 }
6680 /* Convert the remaining arguments, which will be a part of the
6681 parameter pack "parm". */
6683 {
6688 {
6689 /* When we have a vector of types (corresponding to the
6690 non-type template parameter pack that uses parameter
6691 packs in its type, as mention above), and the
6692 argument is not an expansion (which expands to a
6693 currently unknown number of arguments), clone the
6694 parm and give it the next type in PACKED_TYPES. */
6698 }
6703 in_decl);
6707 }
6712 else
6713 {
6718 }
6721 #ifdef ENABLE_CHECKING
6724 #endif
6726 }
6728 /* Convert all template arguments to their appropriate types, and
6729 return a vector containing the innermost resulting template
6730 arguments. If any error occurs, return error_mark_node. Error and
6731 warning messages are issued under control of COMPLAIN.
6733 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6734 for arguments not specified in ARGS. Otherwise, if
6735 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6736 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6737 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6738 ARGS. */
6740 static tree
6742 tree args,
6743 tree in_decl,
6744 tsubst_flags_t complain,
6747 {
6749 tree inner_args;
6750 tree new_args;
6751 tree new_inner_args;
6755 /* When used as a boolean value, indicates whether this is a
6756 variadic template parameter list. Since it's an int, we can also
6757 subtract it from nparms to get the number of non-variadic
6758 parameters. */
6767 /* Determine if there are any parameter packs. */
6769 {
6775 }
6778 /* If there are no parameters that follow a parameter pack, we need to
6779 expand any argument packs so that we can deduce a parameter pack from
6780 some non-packed args followed by an argument pack, as in variadic85.C.
6781 If there are such parameters, we need to leave argument packs intact
6782 so the arguments are assigned properly. This can happen when dealing
6783 with a nested class inside a partial specialization of a class
6784 template, as in variadic92.C, or when deducing a template parameter pack
6785 from a sub-declarator, as in variadic114.C. */
6792 && require_all_args
6793 && (!use_default_args
6796 {
6798 {
6800 {
6804 }
6805 else
6811 }
6814 }
6816 /* We need to evaluate the template arguments, even though this
6817 template-id may be nested within a "sizeof". */
6825 {
6826 tree arg;
6827 tree parm;
6829 /* Get the Ith template parameter. */
6833 {
6836 }
6838 /* Calculate the next argument. */
6841 else
6846 {
6847 /* All remaining arguments will be placed in the
6848 template parameter pack PARM. */
6854 /* Store this argument. */
6856 lost++;
6859 /* We are done with all of the arguments. */
6863 }
6865 {
6867 {
6868 /* We don't know how many args we have yet, just
6869 use the unconverted ones for now. */
6872 }
6873 }
6875 {
6876 /* There must be a default arg in this case. */
6879 /* The position of the first default template argument,
6880 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6881 Record that. */
6884 }
6885 else
6889 {
6892 }
6894 /* This only occurs if there was an error in the template
6895 parameter list itself (which we would already have
6896 reported) that we are trying to recover from, e.g., a class
6897 template with a parameter list such as
6898 template<typename..., typename>. */
6900 else
6906 lost++;
6908 }
6915 #ifdef ENABLE_CHECKING
6919 #endif
6922 }
6924 /* Returns 1 if template args OT and NT are equivalent. */
6926 static int
6928 {
6935 /* For member templates */
6944 {
6961 }
6963 {
6964 /* We get here probably because we are in the middle of substituting
6965 into the pattern of a pack expansion. In that case the
6966 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6967 interested in. So we want to use the initial pack argument for
6968 the comparison. */
6973 }
6978 else
6980 }
6982 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6983 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6984 NEWARG_PTR with the offending arguments if they are non-NULL. */
6986 static int
6989 {
7002 {
7007 {
7013 }
7014 }
7016 }
7018 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7019 of template arguments. Returns 0 otherwise. */
7021 int
7023 {
7025 }
7027 static void
7029 {
7039 /* We are called both from instantiate_decl, where we've already had a
7040 tinst_level pushed, and instantiate_template, where we haven't.
7041 Compensate. */
7052 else
7061 }
7064 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7065 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7066 documentation for TEMPLATE_ID_EXPR. */
7068 tree
7070 {
7071 tree type;
7079 {
7082 }
7085 {
7087 unknown_type_node,
7089 arglist);
7091 }
7098 }
7100 /* Within the scope of a template class S<T>, the name S gets bound
7101 (in build_self_reference) to a TYPE_DECL for the class, not a
7102 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7103 or one of its enclosing classes, and that type is a template,
7104 return the associated TEMPLATE_DECL. Otherwise, the original
7105 DECL is returned.
7107 Also handle the case when DECL is a TREE_LIST of ambiguous
7108 injected-class-names from different bases. */
7110 tree
7112 {
7116 /* DR 176: A lookup that finds an injected-class-name (10.2
7117 [class.member.lookup]) can result in an ambiguity in certain cases
7118 (for example, if it is found in more than one base class). If all of
7119 the injected-class-names that are found refer to specializations of
7120 the same class template, and if the name is followed by a
7121 template-argument-list, the reference refers to the class template
7122 itself and not a specialization thereof, and is not ambiguous. */
7124 {
7127 {
7133 }
7136 else
7138 }
7144 }
7146 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7147 parameters, find the desired type.
7149 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7151 IN_DECL, if non-NULL, is the template declaration we are trying to
7152 instantiate.
7154 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7155 the class we are looking up.
7157 Issue error and warning messages under control of COMPLAIN.
7159 If the template class is really a local class in a template
7160 function, then the FUNCTION_CONTEXT is the function in which it is
7161 being instantiated.
7163 ??? Note that this function is currently called *twice* for each
7164 template-id: the first time from the parser, while creating the
7165 incomplete type (finish_template_type), and the second type during the
7166 real instantiation (instantiate_template_class). This is surely something
7167 that we want to avoid. It also causes some problems with argument
7168 coercion (see convert_nontype_argument for more information on this). */
7170 static tree
7173 {
7175 tree t;
7178 spec_entry elt;
7179 hashval_t hash;
7182 {
7186 else
7187 {
7194 }
7197 }
7199 {
7202 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7203 an implicit typename for the second A. Deal with it. */
7208 {
7211 }
7212 }
7215 {
7218 }
7222 {
7226 }
7228 /* Issue an error message if we didn't find a template. */
7230 {
7234 }
7237 /* Make sure it's a user visible template, if it was named by
7238 the user. */
7241 {
7243 {
7247 }
7249 }
7254 {
7255 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7256 template arguments */
7258 tree parm;
7259 tree arglist2;
7260 tree outer;
7264 /* Consider an example where a template template parameter declared as
7266 template <class T, class U = std::allocator<T> > class TT
7268 The template parameter level of T and U are one level larger than
7269 of TT. To proper process the default argument of U, say when an
7270 instantiation `TT<int>' is seen, we need to build the full
7271 arguments containing {int} as the innermost level. Outer levels,
7272 available when not appearing as default template argument, can be
7273 obtained from the arguments of the enclosing template.
7275 Suppose that TT is later substituted with std::vector. The above
7276 instantiation is `TT<int, std::allocator<T> >' with TT at
7277 level 1, and T at level 2, while the template arguments at level 1
7278 becomes {std::vector} and the inner level 2 is {int}. */
7284 /* This is an argument of the current template, so we haven't set
7285 DECL_CONTEXT yet. */
7292 complain,
7302 }
7303 else
7304 {
7306 tree gen_tmpl;
7307 tree type_decl;
7315 /* An error occured while building the template TEMPL, and a
7316 diagnostic has most certainly been emitted for that
7317 already. Let's propagate that error. */
7326 {
7327 /* We've been given an incomplete set of template arguments.
7328 For example, given:
7330 template <class T> struct S1 {
7331 template <class U> struct S2 {};
7332 template <class U> struct S2<U*> {};
7333 };
7335 we will be called with an ARGLIST of `U*', but the
7336 TEMPLATE will be `template <class T> template
7337 <class U> struct S1<T>::S2'. We must fill in the missing
7338 arguments. */
7339 arglist
7341 arglist);
7343 }
7345 /* Now we should have enough arguments. */
7348 /* From here on, we're only interested in the most general
7349 template. */
7351 /* Calculate the BOUND_ARGS. These will be the args that are
7352 actually tsubst'd into the definition to create the
7353 instantiation. */
7355 {
7356 /* We have multiple levels of arguments to coerce, at once. */
7366 {
7367 tree a;
7371 complain,
7374 else
7375 /* Outer levels should have already been coerced. */
7378 /* Don't process further if one of the levels fails. */
7380 {
7381 /* Restore the ARGLIST to its full size. */
7384 }
7388 /* We temporarily reduce the length of the ARGLIST so
7389 that coerce_template_parms will see only the arguments
7390 corresponding to the template parameters it is
7391 examining. */
7393 }
7395 /* Restore the ARGLIST to its full size. */
7399 }
7400 else
7401 arglist
7404 gen_tmpl,
7405 complain,
7410 /* We were unable to bind the arguments. */
7413 /* In the scope of a template class, explicit references to the
7414 template class refer to the type of the template, not any
7415 instantiation of it. For example, in:
7417 template <class T> class C { void f(C<T>); }
7419 the `C<T>' is just the same as `C'. Outside of the
7420 class, however, such a reference is an instantiation. */
7424 /* comp_template_args is expensive, check it last. */
7426 arglist))
7429 /* If we already have this specialization, return it. */
7441 /* If the deduced arguments are invalid, then the binding
7442 failed. */
7446 complain))
7453 {
7458 }
7468 /* Create the type. */
7470 {
7472 {
7478 }
7479 else
7480 {
7481 /* We don't want to call start_enum for this type, since
7482 the values for the enumeration constants may involve
7483 template parameters. And, no one should be interested
7484 in the enumeration constants for such a type. */
7487 }
7491 }
7493 {
7494 /* The user referred to a specialization of an alias
7495 template represented by GEN_TMPL.
7497 [temp.alias]/2 says:
7499 When a template-id refers to the specialization of an
7500 alias template, it is equivalent to the associated
7501 type obtained by substitution of its
7502 template-arguments for the template-parameters in the
7503 type-id of the alias template. */
7506 /* Note that the call above (by indirectly calling
7507 register_specialization in tsubst_decl) registers the
7508 TYPE_DECL representing the specialization of the alias
7509 template. So next time someone substitutes ARGLIST for
7510 the template parms into the alias template (GEN_TMPL),
7511 she'll get that TYPE_DECL back. */
7515 }
7517 {
7524 /* A local class. Make sure the decl gets registered properly. */
7529 /* This instantiation is another name for the primary
7530 template type. Set the TYPE_CANONICAL field
7531 appropriately. */
7534 /* Some of the template arguments require structural
7535 equality testing, so this template class requires
7536 structural equality testing. */
7538 }
7539 else
7542 /* If we called start_enum or pushtag above, this information
7543 will already be set up. */
7545 {
7552 }
7553 else
7557 {
7563 {
7566 }
7567 }
7569 /* Let's consider the explicit specialization of a member
7570 of a class template specialization that is implicitely instantiated,
7571 e.g.:
7572 template<class T>
7573 struct S
7574 {
7575 template<class U> struct M {}; //#0
7576 };
7578 template<>
7579 template<>
7580 struct S<int>::M<char> //#1
7581 {
7582 int i;
7583 };
7584 [temp.expl.spec]/4 says this is valid.
7586 In this case, when we write:
7587 S<int>::M<char> m;
7589 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7590 the one of #0.
7592 When we encounter #1, we want to store the partial instantiation
7593 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7595 For all cases other than this "explicit specialization of member of a
7596 class template", we just want to store the most general template into
7597 the CLASSTYPE_TI_TEMPLATE of M.
7599 This case of "explicit specialization of member of a class template"
7600 only happens when:
7601 1/ the enclosing class is an instantiation of, and therefore not
7602 the same as, the context of the most general template, and
7603 2/ we aren't looking at the partial instantiation itself, i.e.
7604 the innermost arguments are not the same as the innermost parms of
7605 the most general template.
7607 So it's only when 1/ and 2/ happens that we want to use the partial
7608 instantiation of the member template in lieu of its most general
7609 template. */
7613 /* the enclosing class must be an instantiation... */
7616 {
7617 tree partial_inst_args;
7620 partial_inst_args =
7626 use_partial_inst_tmpl =
7627 /*...and we must not be looking at the partial instantiation
7628 itself. */
7630 partial_inst_args);
7631 }
7634 /* This case is easy; there are no member templates involved. */
7636 else
7637 {
7638 /* This is a full instantiation of a member template. Find
7639 the partial instantiation of which this is an instance. */
7641 /* Temporarily reduce by one the number of levels in the ARGLIST
7642 so as to avoid comparing the last set of arguments. */
7646 /* FOUND is either a proper class type, or an alias
7647 template specialization. In the later case, it's a
7648 TYPE_DECL, resulting from the substituting of arguments
7649 for parameters in the TYPE_DECL of the alias template
7650 done earlier. So be careful while getting the template
7651 of FOUND. */
7655 }
7666 /* Note this use of the partial instantiation so we can check it
7667 later in maybe_process_partial_specialization. */
7673 /* Now that the type has been registered on the instantiations
7674 list, we set up the enumerators. Because the enumeration
7675 constants may involve the enumeration type itself, we make
7676 sure to register the type first, and then create the
7677 constants. That way, doing tsubst_expr for the enumeration
7678 constants won't result in recursive calls here; we'll find
7679 the instantiation and exit above. */
7683 /* If the type makes use of template parameters, the
7684 code that generates debugging information will crash. */
7687 /* Possibly limit visibility based on template args. */
7692 }
7693 }
7695 /* Wrapper for lookup_template_class_1. */
7697 tree
7700 {
7701 tree ret;
7707 }
7708 \f
7709 struct pair_fn_data
7710 {
7711 tree_fn_t fn;
7713 /* True when we should also visit template parameters that occur in
7714 non-deduced contexts. */
7717 };
7719 /* Called from for_each_template_parm via walk_tree. */
7721 static tree
7723 {
7736 {
7740 /* Fall through. */
7763 /* Since we're not going to walk subtrees, we have to do this
7764 explicitly here. */
7768 /* Fall through. */
7771 /* Check the return type. */
7776 /* Check the parameter types. Since default arguments are not
7777 instantiated until they are needed, the TYPE_ARG_TYPES may
7778 contain expressions that involve template parameters. But,
7779 no-one should be looking at them yet. And, once they're
7780 instantiated, they don't contain template parameters, so
7781 there's no point in looking at them then, either. */
7782 {
7783 tree parm;
7790 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7791 want walk_tree walking into them itself. */
7793 }
7811 /* Fall through. */
7827 /* Record template parameters such as `T' inside `TT<T>'. */
7831 /* Fall through. */
7843 /* A template template parameter is encountered. */
7849 /* Already substituted template template parameter */
7872 /* If there's no type, then this thing must be some expression
7873 involving template parameters. */
7895 }
7897 /* We didn't find any template parameters we liked. */
7899 }
7901 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7902 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7903 call FN with the parameter and the DATA.
7904 If FN returns nonzero, the iteration is terminated, and
7905 for_each_template_parm returns 1. Otherwise, the iteration
7906 continues. If FN never returns a nonzero value, the value
7907 returned by for_each_template_parm is 0. If FN is NULL, it is
7908 considered to be the function which always returns 1.
7910 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7911 parameters that occur in non-deduced contexts. When false, only
7912 visits those template parameters that can be deduced. */
7914 static int
7918 {
7922 /* Set up. */
7927 /* Walk the tree. (Conceptually, we would like to walk without
7928 duplicates, but for_each_template_parm_r recursively calls
7929 for_each_template_parm, so we would need to reorganize a fair
7930 bit to use walk_tree_without_duplicates, so we keep our own
7931 visited list.) */
7934 else
7937 for_each_template_parm_r,
7941 /* Clean up. */
7943 {
7946 }
7949 }
7951 /* Returns true if T depends on any template parameter. */
7953 int
7955 {
7982 else
7983 {
7986 }
7991 }
7993 /* Returns true if T depends on any template parameter with level LEVEL. */
7995 int
7997 {
8000 }
8002 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8003 ill-formed translation unit, i.e. a variable or function that isn't
8004 usable in a constant expression. */
8008 {
8012 }
8014 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8015 neglectable and instantiated from within an erroneous instantiation. */
8017 static bool
8019 {
8030 }
8034 #ifdef GATHER_STATISTICS
8036 #endif
8039 /* We're starting to instantiate D; record the template instantiation context
8040 for diagnostics and to restore it later. */
8042 int
8044 {
8048 {
8054 else
8062 }
8064 /* If the current instantiation caused problems, don't let it instantiate
8065 anything else. Do allow deduction substitution and decls usable in
8066 constant expressions. */
8079 #ifdef GATHER_STATISTICS
8082 #endif
8085 }
8087 /* We're done instantiating this template; return to the instantiation
8088 context. */
8090 void
8092 {
8093 /* Restore the filename and line number stashed away when we started
8094 this instantiation. */
8098 }
8100 /* We're instantiating a deferred template; restore the template
8101 instantiation context in which the instantiation was requested, which
8102 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8104 static tree
8106 {
8118 }
8120 /* Returns the TINST_LEVEL which gives the original instantiation
8121 context. */
8125 {
8131 }
8133 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8134 vector of template arguments, as for tsubst.
8136 Returns an appropriate tsubst'd friend declaration. */
8138 static tree
8140 {
8141 tree new_friend;
8146 /* This was a friend declared with an explicit template
8147 argument list, e.g.:
8149 friend void f<>(T);
8151 to indicate that f was a template instantiation, not a new
8152 function declaration. Now, we have to figure out what
8153 instantiation of what template. */
8154 {
8156 tree new_args;
8157 tree tmpl;
8160 /* Friend functions are looked up in the containing namespace scope.
8161 We must enter that scope, to avoid finding member functions of the
8162 current class with same name. */
8177 tsk_none);
8179 }
8183 /* The NEW_FRIEND will look like an instantiation, to the
8184 compiler, but is not an instantiation from the point of view of
8185 the language. For example, we might have had:
8187 template <class T> struct S {
8188 template <class U> friend void f(T, U);
8189 };
8191 Then, in S<int>, template <class U> void f(int, U) is not an
8192 instantiation of anything. */
8198 {
8202 }
8204 /* The mangled name for the NEW_FRIEND is incorrect. The function
8205 is not a template instantiation and should not be mangled like
8206 one. Therefore, we forget the mangling here; we'll recompute it
8207 later if we need it. */
8209 {
8212 }
8215 {
8216 tree old_decl;
8217 tree new_friend_template_info;
8218 tree new_friend_result_template_info;
8219 tree ns;
8222 /* We must save some information from NEW_FRIEND before calling
8223 duplicate decls since that function will free NEW_FRIEND if
8224 possible. */
8226 new_friend_is_defn =
8231 {
8232 /* This declaration is a `primary' template. */
8235 new_friend_result_template_info
8237 }
8238 else
8241 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8245 /* Inside pushdecl_namespace_level, we will push into the
8246 current namespace. However, the friend function should go
8247 into the namespace of the template. */
8257 {
8258 /* This new friend declaration matched an existing
8259 declaration. For example, given:
8261 template <class T> void f(T);
8262 template <class U> class C {
8263 template <class T> friend void f(T) {}
8264 };
8266 the friend declaration actually provides the definition
8267 of `f', once C has been instantiated for some type. So,
8268 old_decl will be the out-of-class template declaration,
8269 while new_friend is the in-class definition.
8271 But, if `f' was called before this point, the
8272 instantiation of `f' will have DECL_TI_ARGS corresponding
8273 to `T' but not to `U', references to which might appear
8274 in the definition of `f'. Previously, the most general
8275 template for an instantiation of `f' was the out-of-class
8276 version; now it is the in-class version. Therefore, we
8277 run through all specialization of `f', adding to their
8278 DECL_TI_ARGS appropriately. In particular, they need a
8279 new set of outer arguments, corresponding to the
8280 arguments for this class instantiation.
8282 The same situation can arise with something like this:
8284 friend void f(int);
8285 template <class T> class C {
8286 friend void f(T) {}
8287 };
8289 when `C<int>' is instantiated. Now, `f(int)' is defined
8290 in the class. */
8293 /* On the other hand, if the in-class declaration does
8294 *not* provide a definition, then we don't want to alter
8295 existing definitions. We can just leave everything
8296 alone. */
8297 ;
8298 else
8299 {
8303 /* Overwrite whatever template info was there before, if
8304 any, with the new template information pertaining to
8305 the declaration. */
8309 {
8310 /* We should have called reregister_specialization in
8311 duplicate_decls. */
8316 /* Instantiate it if the global has already been used. */
8320 }
8321 else
8322 {
8323 tree t;
8325 /* Indicate that the old function template is a partial
8326 instantiation. */
8334 /* Reassign any specializations already in the hash table
8335 to the new more general template, and add the
8336 additional template args. */
8340 {
8342 spec_entry elt;
8354 register_specialization
8357 }
8359 }
8360 }
8362 /* The information from NEW_FRIEND has been merged into OLD_DECL
8363 by duplicate_decls. */
8365 }
8366 }
8367 else
8368 {
8372 /* In the code
8373 template <class T> class C {
8374 template <class U> friend void C1<U>::f (); // case 1
8375 friend void C2<T>::f (); // case 2
8376 };
8377 we only need to make sure CONTEXT is a complete type for
8378 case 2. To distinguish between the two cases, we note that
8379 CONTEXT of case 1 remains dependent type after tsubst while
8380 this isn't true for case 2. */
8390 {
8391 /* Check to see that the declaration is really present, and,
8392 possibly obtain an improved declaration. */
8398 }
8399 }
8402 }
8404 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8405 template arguments, as for tsubst.
8407 Returns an appropriate tsubst'd friend type or error_mark_node on
8408 failure. */
8410 static tree
8412 {
8413 tree friend_type;
8414 tree tmpl;
8415 tree context;
8420 {
8423 else
8425 }
8427 /* Look for a class template declaration. We look for hidden names
8428 because two friend declarations of the same template are the
8429 same. For example, in:
8431 struct A {
8432 template <typename> friend class F;
8433 };
8434 template <typename> struct B {
8435 template <typename> friend class F;
8436 };
8438 both F templates are the same. */
8443 /* But, if we don't find one, it might be because we're in a
8444 situation like this:
8446 template <class T>
8447 struct S {
8448 template <class U>
8449 friend struct S;
8450 };
8452 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8453 for `S<int>', not the TEMPLATE_DECL. */
8455 {
8458 }
8461 {
8462 /* The friend template has already been declared. Just
8463 check to see that the declarations match, and install any new
8464 default parameters. We must tsubst the default parameters,
8465 of course. We only need the innermost template parameters
8466 because that is all that redeclare_class_template will look
8467 at. */
8470 {
8471 tree parms;
8472 location_t saved_input_location;
8481 }
8484 }
8485 else
8486 {
8487 /* The friend template has not already been declared. In this
8488 case, the instantiation of the template class will cause the
8489 injection of this template into the global scope. */
8494 /* The new TMPL is not an instantiation of anything, so we
8495 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8496 the new type because that is supposed to be the corresponding
8497 template decl, i.e., TMPL. */
8504 /* Inject this template into the global scope. */
8506 }
8509 {
8512 else
8514 }
8517 }
8519 /* Returns zero if TYPE cannot be completed later due to circularity.
8520 Otherwise returns one. */
8522 static int
8524 {
8534 else
8536 }
8538 /* Apply any attributes which had to be deferred until instantiation
8539 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8540 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8542 static void
8545 {
8547 tree t;
8552 {
8556 }
8559 {
8563 }
8564 else
8568 {
8573 {
8576 {
8579 /* If the first attribute argument is an identifier, don't
8580 pass it through tsubst. Attributes like mode, format,
8581 cleanup and several target specific attributes expect it
8582 unmodified. */
8588 {
8589 tree chain
8591 in_decl,
8596 chain);
8597 }
8598 else
8604 }
8605 else
8607 }
8610 }
8611 }
8613 /* Perform (or defer) access check for typedefs that were referenced
8614 from within the template TMPL code.
8615 This is a subroutine of instantiate_template and instantiate_class_template.
8616 TMPL is the template to consider and TARGS is the list of arguments of
8617 that template. */
8619 static void
8621 {
8622 location_t saved_location;
8635 {
8647 /* Make access check error messages point to the location
8648 of the use of the typedef. */
8652 }
8654 }
8656 static tree
8658 {
8660 tree typedecl;
8661 tree pbinfo;
8662 tree base_list;
8672 /* Figure out which template is being instantiated. */
8676 /* Determine what specialization of the original template to
8677 instantiate. */
8680 {
8683 }
8685 {
8686 /* This TYPE is actually an instantiation of a partial
8687 specialization. We replace the innermost set of ARGS with
8688 the arguments appropriate for substitution. For example,
8689 given:
8691 template <class T> struct S {};
8692 template <class T> struct S<T*> {};
8694 and supposing that we are instantiating S<int*>, ARGS will
8695 presently be {int*} -- but we need {int}. */
8698 }
8699 else
8700 {
8703 }
8705 /* If the template we're instantiating is incomplete, then clearly
8706 there's nothing we can do. */
8710 /* If we've recursively instantiated too many templates, stop. */
8714 /* Now we're really doing the instantiation. Mark the type as in
8715 the process of being defined. */
8718 /* We may be in the middle of deferred access check. Disable
8719 it now. */
8723 /* Use #pragma pack from the template context. */
8729 /* Set the input location to the most specialized template definition.
8730 This is needed if tsubsting causes an error. */
8742 {
8745 /* Adjust visibility for template arguments. */
8747 }
8752 /* We should never instantiate a nested class before its enclosing
8753 class; we need to look up the nested class by name before we can
8754 instantiate it, and that lookup should instantiate the enclosing
8755 class. */
8761 {
8762 tree pbase_binfo;
8763 tree pushed_scope;
8766 /* We must enter the scope containing the type, as that is where
8767 the accessibility of types named in dependent bases are
8768 looked up from. */
8771 /* Substitute into each of the bases to determine the actual
8772 basetypes. */
8774 {
8775 tree base;
8781 {
8782 expanded_bases =
8789 }
8792 {
8794 /* Extract the already-expanded base class. */
8796 else
8797 /* Substitute to figure out the base class. */
8799 NULL_TREE);
8807 }
8808 }
8810 /* The list is now in reverse order; correct that. */
8815 }
8816 /* Now call xref_basetypes to set up all the base-class
8817 information. */
8825 /* Now that our base classes are set up, enter the scope of the
8826 class, so that name lookups into base classes, etc. will work
8827 correctly. This is precisely analogous to what we do in
8828 begin_class_definition when defining an ordinary non-template
8829 class, except we also need to push the enclosing classes. */
8832 /* Now members are processed in the order of declaration. */
8835 {
8839 {
8841 {
8842 /* Build new CLASSTYPE_NESTED_UTDS. */
8844 tree newtag;
8850 /* If the member is a class template, then -- even after
8851 substitution -- there may be dependent types in the
8852 template argument list for the class. We increment
8853 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8854 that function will assume that no types are dependent
8855 when outside of a template. */
8865 {
8869 /* Unfortunately, lookup_template_class sets
8870 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8871 instantiation (i.e., for the type of a member
8872 template class nested within a template class.)
8873 This behavior is required for
8874 maybe_process_partial_specialization to work
8875 correctly, but is not accurate in this case;
8876 the TAG is not an instantiation of anything.
8877 (The corresponding TEMPLATE_DECL is an
8878 instantiation, but the TYPE is not.) */
8881 /* Now, we call pushtag to put this NEWTAG into the scope of
8882 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8883 pushtag calling push_template_decl. We don't have to do
8884 this for enums because it will already have been done in
8885 tsubst_enum. */
8889 }
8890 }
8893 {
8894 /* Build new TYPE_METHODS. */
8895 tree r;
8904 /* Instantiate members marked with attribute used. */
8907 }
8908 else
8909 {
8910 /* Build new TYPE_FIELDS. */
8912 {
8913 tree condition =
8921 }
8923 {
8924 tree r;
8926 /* The file and line for this declaration, to
8927 assist in error message reporting. Since we
8928 called push_tinst_level above, we don't need to
8929 restore these. */
8938 {
8939 /* In [temp.inst]:
8941 [t]he initialization (and any associated
8942 side-effects) of a static data member does
8943 not occur unless the static data member is
8944 itself used in a way that requires the
8945 definition of the static data member to
8946 exist.
8948 Therefore, we do not substitute into the
8949 initialized for the static data member here. */
8950 finish_static_data_member_decl
8956 /* Instantiate members marked with attribute used. */
8959 }
8961 {
8962 /* Determine whether R has a valid type and can be
8963 completed later. If R is invalid, then it is
8964 replaced by error_mark_node so that it will not be
8965 added to TYPE_FIELDS. */
8971 {
8974 }
8975 }
8977 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8978 such a thing will already have been added to the field
8979 list by tsubst_enum in finish_member_declaration in the
8980 CLASSTYPE_NESTED_UTDS case above. */
8984 {
8987 }
8988 }
8989 }
8990 }
8991 else
8992 {
8994 {
8995 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9001 {
9002 /* template <class T> friend class C; */
9005 }
9007 {
9008 /* template <class T> friend class C::D; */
9014 }
9017 {
9018 /* This could be either
9020 friend class T::C;
9022 when dependent_type_p is false or
9024 template <class U> friend class T::C;
9026 otherwise. */
9029 /* Bump processing_template_decl for correct
9030 dependent_type_p calculation. */
9035 }
9038 {
9039 /* friend class C;
9041 where C hasn't been declared yet. Let's lookup name
9042 from namespace scope directly, bypassing any name that
9043 come from dependent base class. */
9046 /* The call to xref_tag_from_type does injection for friend
9047 classes. */
9049 friend_type =
9053 }
9055 /* friend class C<T>; */
9058 /* Otherwise it's
9060 friend class C;
9062 where C is already declared or
9064 friend class C<int>;
9066 We don't have to do anything in these cases. */
9069 /* Trick make_friend_class into realizing that the friend
9070 we're adding is a template, not an ordinary class. It's
9071 important that we use make_friend_class since it will
9072 perform some error-checking and output cross-reference
9073 information. */
9081 }
9082 else
9083 {
9084 /* Build new DECL_FRIENDLIST. */
9085 tree r;
9087 /* The file and line for this declaration, to
9088 assist in error message reporting. Since we
9089 called push_tinst_level above, we don't need to
9090 restore these. */
9094 {
9097 }
9102 {
9105 }
9106 }
9107 }
9108 }
9111 {
9114 {
9117 }
9118 else
9120 }
9122 /* Set the file and line number information to whatever is given for
9123 the class itself. This puts error messages involving generated
9124 implicit functions at a predictable point, and the same point
9125 that would be used for non-template classes. */
9132 /* We don't instantiate default arguments for member functions. 14.7.1:
9134 The implicit instantiation of a class template specialization causes
9135 the implicit instantiation of the declarations, but not of the
9136 definitions or default arguments, of the class member functions,
9137 member classes, static data members and member templates.... */
9139 /* Some typedefs referenced from within the template code need to be access
9140 checked at template instantiation time, i.e now. These types were
9141 added to the template at parsing time. Let's get those and perform
9142 the access checks then. */
9151 /* The vtable for a template class can be emitted in any translation
9152 unit in which the class is instantiated. When there is no key
9153 method, however, finish_struct_1 will already have added TYPE to
9154 the keyed_classes list. */
9159 }
9161 /* Wrapper for instantiate_class_template_1. */
9163 tree
9165 {
9166 tree ret;
9171 }
9173 static tree
9175 {
9176 tree r;
9182 else
9183 {
9190 /* Preserve the raw-reference nature of T. */
9194 }
9196 }
9198 /* Given a function parameter pack TMPL_PARM and some function parameters
9199 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9200 and set *SPEC_P to point at the next point in the list. */
9202 static tree
9204 {
9205 /* Collect all of the extra "packed" parameters into an
9206 argument pack. */
9207 tree parmvec;
9208 tree parmtypevec;
9219 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9224 {
9227 }
9229 /* Build the argument packs. */
9236 }
9238 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9239 NONTYPE_ARGUMENT_PACK. */
9241 static tree
9243 {
9245 }
9247 /* Substitute ARGS into T, which is an pack expansion
9248 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9249 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9250 (if only a partial substitution could be performed) or
9251 ERROR_MARK_NODE if there was an error. */
9252 tree
9254 tree in_decl)
9255 {
9256 tree pattern;
9262 tree result;
9270 /* Add in any args remembered from an earlier partial instantiation. */
9275 /* Determine the argument packs that will instantiate the parameter
9276 packs used in the expansion expression. While we're at it,
9277 compute the number of arguments to be expanded and make sure it
9278 is consistent. */
9281 {
9288 {
9292 else
9295 }
9297 {
9300 else
9301 {
9302 /* We can't rely on local_specializations for a parameter
9303 name used later in a function declaration (such as in a
9304 late-specified return type). Even if it exists, it might
9305 have the wrong value for a recursive call. Just make a
9306 dummy decl, since it's only used for its type. */
9309 /* Partial instantiation of the parm_pack, we can't build
9310 up an argument pack yet. */
9312 else
9315 }
9316 }
9317 else
9318 {
9324 }
9331 /* This can only happen if we forget to expand an argument
9332 pack somewhere else. Just return an error, silently. */
9333 {
9337 }
9340 /* The argument pack that the parameter maps to is just an
9341 expansion of the parameter itself, such as one would find
9342 in the implicit typedef of a class inside the class itself.
9343 Consider this parameter "unsubstituted", so that we will
9344 maintain the outer pack expansion. */
9348 {
9352 /* Don't bother trying to do a partial substitution with
9353 incomplete packs; we'll try again after deduction. */
9360 {
9366 pattern);
9367 else
9370 pattern);
9372 }
9378 else
9381 /* Keep track of the parameter packs and their corresponding
9382 argument packs. */
9385 }
9386 else
9387 {
9388 /* We can't substitute for this parameter pack. We use a flag as
9389 well as the missing_level counter because function parameter
9390 packs don't have a level. */
9394 }
9395 }
9397 /* We cannot expand this expansion expression, because we don't have
9398 all of the argument packs we need. */
9400 {
9402 {
9403 /* We got some full packs, but we can't substitute them in until we
9404 have values for all the packs. So remember these until then. */
9405 tree save_args;
9409 /* The call to add_to_template_args above assumes no overlap
9410 between saved args and new args, so prune away any fake
9411 args, i.e. those that satisfied arg_from_parm_pack_p above. */
9413 {
9419 }
9420 else
9424 }
9425 else
9426 {
9427 /* There were no real arguments, we're just replacing a parameter
9428 pack with another version of itself. Substitute into the
9429 pattern and return a PACK_EXPANSION_*. The caller will need to
9430 deal with that. */
9434 else
9437 }
9439 }
9441 /* We could not find any argument packs that work. */
9446 {
9447 /* We're in a late-specified return type, so create our own local
9448 specializations map; the current map is either NULL or (in the
9449 case of recursive unification) might have bindings that we don't
9450 want to use or alter. */
9453 }
9455 /* For each argument in each argument pack, substitute into the
9456 pattern. */
9459 {
9460 /* For parameter pack, change the substitution of the parameter
9461 pack to the ith argument in its argument pack, then expand
9462 the pattern. */
9464 {
9466 tree arg;
9468 /* Select the Ith argument from the pack. */
9470 {
9472 {
9477 }
9478 else
9480 }
9481 else
9482 {
9487 {
9490 /* Update the corresponding argument. */
9492 }
9493 else
9494 /* Re-use the ARGUMENT_PACK_SELECT. */
9496 }
9498 }
9500 /* Substitute into the PATTERN with the altered arguments. */
9505 else
9509 {
9512 }
9513 }
9515 /* Update ARGS to restore the substitution from parameter packs to
9516 their argument packs. */
9518 {
9523 else
9524 {
9528 /* Update the corresponding argument. */
9532 else
9534 }
9535 }
9538 {
9541 }
9544 }
9546 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9547 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9548 parameter packs; all parms generated from a function parameter pack will
9549 have the same DECL_PARM_INDEX. */
9551 tree
9553 {
9555 tree patparm;
9558 {
9564 }
9565 else
9566 {
9571 }
9574 }
9576 /* Substitute ARGS into the vector or list of template arguments T. */
9578 static tree
9580 {
9592 {
9594 tree new_arg;
9599 {
9600 /* Substitute into an expansion expression. */
9604 /* Add to the expanded length adjustment the number of
9605 expanded arguments. We subtract one from this
9606 measurement, because the argument pack expression
9607 itself is already counted as 1 in
9608 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9609 the argument pack is empty. */
9611 }
9613 {
9614 /* Substitute into each of the arguments. */
9620 new_arg,
9634 }
9635 }
9636 else
9645 }
9650 /* Make space for the expanded arguments coming from template
9651 argument packs. */
9653 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9654 arguments for a member template.
9655 In that case each TREE_VEC in ORIG_T represents a level of template
9656 arguments, and ORIG_T won't carry any non defaulted argument count.
9657 It will rather be the nested TREE_VECs that will carry one.
9658 In other words, ORIG_T carries a non defaulted argument count only
9659 if it doesn't contain any nested TREE_VEC. */
9661 {
9665 }
9667 {
9671 {
9674 /* Now expand the template argument pack "in place". */
9677 }
9678 else
9679 {
9681 out++;
9682 }
9683 }
9686 }
9688 /* Return the result of substituting ARGS into the template parameters
9689 given by PARMS. If there are m levels of ARGS and m + n levels of
9690 PARMS, then the result will contain n levels of PARMS. For
9691 example, if PARMS is `template <class T> template <class U>
9692 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9693 result will be `template <int*, double, class V>'. */
9695 static tree
9697 {
9701 /* When substituting into a template, we must set
9702 PROCESSING_TEMPLATE_DECL as the template parameters may be
9703 dependent if they are based on one-another, and the dependency
9704 predicates are short-circuit outside of templates. */
9711 {
9712 tree new_vec =
9717 {
9718 tree tuple;
9730 }
9736 }
9741 }
9743 /* Return the result of substituting ARGS into one template parameter
9744 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9745 parameter and which TREE_PURPOSE is the default argument of the
9746 template parameter. */
9748 static tree
9750 {
9771 }
9773 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9774 type T. If T is not an aggregate or enumeration type, it is
9775 handled as if by tsubst. IN_DECL is as for tsubst. If
9776 ENTERING_SCOPE is nonzero, T is the context for a template which
9777 we are presently tsubst'ing. Return the substituted value. */
9779 static tree
9781 tree args,
9782 tsubst_flags_t complain,
9783 tree in_decl,
9785 {
9790 {
9795 /* Else fall through. */
9799 {
9800 tree argvec;
9801 tree context;
9802 tree r;
9806 /* In "sizeof(X<I>)" we need to evaluate "I". */
9812 /* First, determine the context for the type we are looking
9813 up. */
9816 {
9819 /* If context is a nested class inside a class template,
9820 it may still need to be instantiated (c++/33959). */
9822 }
9824 /* Then, figure out what arguments are appropriate for the
9825 type we are trying to find. For example, given:
9827 template <class T> struct S;
9828 template <class T, class U> void f(T, U) { S<U> su; }
9830 and supposing that we are instantiating f<int, double>,
9831 then our ARGS will be {int, double}, but, when looking up
9832 S we only want {double}. */
9837 else
9838 {
9842 }
9848 }
9849 else
9850 /* This is not a template type, so there's nothing to do. */
9855 }
9856 }
9858 /* Substitute into the default argument ARG (a default argument for
9859 FN), which has the indicated TYPE. */
9861 tree
9863 {
9867 /* This can happen in invalid code. */
9871 /* This default argument came from a template. Instantiate the
9872 default argument here, not in tsubst. In the case of
9873 something like:
9875 template <class T>
9876 struct S {
9877 static T t();
9878 void f(T = t());
9879 };
9881 we must be careful to do name lookup in the scope of S<T>,
9882 rather than in the current class. */
9884 /* The "this" pointer is not valid in a default argument. */
9886 {
9891 }
9894 /* The default argument expression may cause implicitly defined
9895 member functions to be synthesized, which will result in garbage
9896 collection. We must treat this situation as if we were within
9897 the body of function so as to avoid collecting live data on the
9898 stack. */
9906 /* Restore the "this" pointer. */
9908 {
9911 }
9913 /* Make sure the default argument is reasonable. */
9919 }
9921 /* Substitute into all the default arguments for FN. */
9923 static void
9925 {
9926 tree arg;
9927 tree tmpl_args;
9931 /* If this function is not yet instantiated, we certainly don't need
9932 its default arguments. */
9935 /* Don't do this again for clones. */
9940 arg;
9946 }
9948 /* Substitute the ARGS into the T, which is a _DECL. Return the
9949 result of the substitution. Issue error and warning messages under
9950 control of COMPLAIN. */
9952 static tree
9954 {
9955 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9956 location_t saved_loc;
9961 /* Set the filename and linenumber to improve error-reporting. */
9966 {
9968 {
9969 /* We can get here when processing a member function template,
9970 member class template, or template template parameter. */
9972 tree spec;
9973 tree tmpl_args;
9974 tree full_args;
9977 {
9978 /* Template template parameter is treated here. */
9991 complain);
9994 }
9996 /* We might already have an instance of this template.
9997 The ARGS are for the surrounding class type, so the
9998 full args contain the tsubst'd args for the context,
9999 plus the innermost args from the template decl. */
10003 /* Because this is a template, the arguments will still be
10004 dependent, even after substitution. If
10005 PROCESSING_TEMPLATE_DECL is not set, the dependency
10006 predicates will short-circuit. */
10014 /* If this is a default template template argument,
10015 tsubst might not have changed anything. */
10022 {
10025 }
10027 /* Make a new template decl. It will be similar to the
10028 original, but will record the current template arguments.
10029 We also create a new function declaration, which is just
10030 like the old one, but points to this new template, rather
10031 than the old one. */
10040 {
10041 tree new_type;
10053 }
10054 else
10055 {
10056 tree new_decl;
10068 }
10074 /* The template parameters for this new template are all the
10075 template parameters for the old template, except the
10076 outermost level of parameters. */
10079 complain);
10085 /* Record this non-type partial instantiation. */
10089 }
10093 {
10094 tree ctx;
10097 tree gen_tmpl;
10098 tree type;
10103 /* Nobody should be tsubst'ing into non-template functions. */
10107 {
10108 tree spec;
10111 /* If T is not dependent, just return it. We have to
10112 increment PROCESSING_TEMPLATE_DECL because
10113 value_dependent_expression_p assumes that nothing is
10114 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10121 /* Calculate the most general template of which R is a
10122 specialization, and the complete set of arguments used to
10123 specialize R. */
10126 (DECL_TEMPLATE_RESULT
10132 /* Check to see if we already have this specialization. */
10137 {
10140 }
10142 /* We can see more levels of arguments than parameters if
10143 there was a specialization of a member template, like
10144 this:
10146 template <class T> struct S { template <class U> void f(); }
10147 template <> template <class U> void S<int>::f(U);
10149 Here, we'll be substituting into the specialization,
10150 because that's where we can find the code we actually
10151 want to generate, but we'll have enough arguments for
10152 the most general template.
10154 We also deal with the peculiar case:
10156 template <class T> struct S {
10157 template <class U> friend void f();
10158 };
10159 template <class U> void f() {}
10160 template S<int>;
10161 template void f<double>();
10163 Here, the ARGS for the instantiation of will be {int,
10164 double}. But, we only need as many ARGS as there are
10165 levels of template parameters in CODE_PATTERN. We are
10166 careful not to get fooled into reducing the ARGS in
10167 situations like:
10169 template <class T> struct S { template <class U> void f(U); }
10170 template <class T> template <> void S<T>::f(int) {}
10172 which we can spot because the pattern will be a
10173 specialization in this case. */
10175 parms_depth =
10180 }
10181 else
10182 {
10183 /* This special case arises when we have something like this:
10185 template <class T> struct S {
10186 friend void f<int>(int, double);
10187 };
10189 Here, the DECL_TI_TEMPLATE for the friend declaration
10190 will be an IDENTIFIER_NODE. We are being called from
10191 tsubst_friend_function, and we want only to create a
10192 new decl (R) with appropriate types so that we can call
10193 determine_specialization. */
10195 }
10198 {
10201 else
10205 }
10206 else
10207 {
10210 }
10215 /* We do NOT check for matching decls pushed separately at this
10216 point, as they may not represent instantiations of this
10217 template, and in any case are considered separate under the
10218 discrete model. */
10222 /* Clear out the mangled name and RTL for the instantiation. */
10225 /* Leave DECL_INITIAL set on deleted instantiations. */
10231 /* Type-conversion operator. Reconstruct the name, in
10232 case it's the name of one of the template's parameters. */
10242 /* If this is an instantiation of a function with internal
10243 linkage, we already know what object file linkage will be
10244 assigned to the instantiation. */
10253 /* We'll re-clone as appropriate in instantiate_template. */
10256 /* If we aren't complaining now, return on error before we register
10257 the specialization so that we'll complain eventually. */
10263 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10264 this in the special friend case mentioned above where
10265 GEN_TMPL is NULL. */
10267 {
10273 /* We're not supposed to instantiate default arguments
10274 until they are called, for a template. But, for a
10275 declaration like:
10277 template <class T> void f ()
10278 { extern void g(int i = T()); }
10280 we should do the substitution when the template is
10281 instantiated. We handle the member function case in
10282 instantiate_class_template since the default arguments
10283 might refer to other members of the class. */
10288 }
10289 else
10292 /* Copy the list of befriending classes. */
10296 {
10300 in_decl);
10301 }
10304 {
10308 /* If this is an instantiation of a member template, clone it.
10309 If it isn't, that'll be handled by
10310 clone_constructors_and_destructors. */
10313 }
10324 /* Possibly limit visibility based on template args. */
10327 {
10331 }
10339 }
10343 {
10351 {
10352 /* If there is a local specialization that isn't a
10353 parameter pack, it means that we're doing a "simple"
10354 substitution from inside tsubst_pack_expansion. Just
10355 return the local specialization (which will be a single
10356 parm). */
10363 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10364 the parameters in this function parameter pack. */
10368 {
10371 /* Zero-length parameter packs are boring. Just substitute
10372 into the chain. */
10376 }
10377 else
10378 {
10379 /* All we did was update the type. Make a note of that. */
10382 }
10383 }
10385 /* Loop through all of the parameter's we'll build. When T is
10386 a function parameter pack, LEN is the number of expanded
10387 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10390 {
10397 /* We're on the Ith parameter of the function parameter
10398 pack. */
10399 {
10400 /* An argument of a function parameter pack is not a parameter
10401 pack. */
10404 /* Get the Ith type. */
10408 /* Rename the parameter to include the index. */
10411 }
10413 /* We're dealing with a normal parameter. */
10421 {
10424 else
10427 }
10437 /* Keep track of the first new parameter we
10438 generate. That's what will be returned to the
10439 caller. */
10443 /* Build a proper chain of parameters when substituting
10444 into a function parameter pack. */
10447 }
10453 /* FIRST_R contains the start of the chain we've built. */
10455 }
10459 {
10460 tree type;
10470 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10471 non-bit-fields DECL_INITIAL is a non-static data member
10472 initializer, which gets deferred instantiation. */
10478 {
10479 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10480 NSDMI in perform_member_init. Still set DECL_INITIAL
10481 so that we know there is one. */
10486 }
10487 /* We don't have to set DECL_CONTEXT here; it is set by
10488 finish_member_declaration. */
10495 }
10499 /* We reach here only for member using decls. */
10501 {
10502 r = do_class_using_decl
10507 else
10508 {
10511 }
10512 }
10513 else
10514 {
10517 }
10522 {
10525 tree spec;
10527 tree ctx;
10533 {
10534 /* If this is the canonical decl, we don't have to
10535 mess with instantiations, and often we can't (for
10536 typename, template type parms and such). Note that
10537 TYPE_NAME is not correct for the above test if
10538 we've copied the type for a typedef. */
10544 }
10546 /* Check to see if we already have the specialization we
10547 need. */
10550 {
10551 /* T is a static data member or namespace-scope entity.
10552 We have to substitute into namespace-scope variables
10553 (even though such entities are never templates) because
10554 of cases like:
10556 template <class T> void f() { extern T t; }
10558 where the entity referenced is not known until
10559 instantiation time. */
10563 {
10565 complain,
10567 /* If CTX is unchanged, then T is in fact the
10568 specialization we want. That situation occurs when
10569 referencing a static data member within in its own
10570 class. We can use pointer equality, rather than
10571 same_type_p, because DECL_CONTEXT is always
10572 canonical... */
10575 /* ... unless T is a member template; in which
10576 case our caller can be willing to create a
10577 specialization of that template represented
10578 by T. */
10582 }
10585 {
10591 }
10592 }
10593 else
10594 {
10595 /* A local variable. */
10597 /* Subsequent calls to pushdecl will fill this in. */
10600 }
10601 /* If we already have the specialization we need, there is
10602 nothing more to do. */
10604 {
10607 }
10609 /* Create a new node for the specialization we need. */
10612 {
10615 else
10622 }
10624 {
10625 /* Even if the original location is out of scope, the
10626 newly substituted one is not. */
10633 {
10634 /* It may seem that this case cannot occur, since:
10636 typedef void f();
10637 void g() { f x; }
10639 declares a function, not a variable. However:
10641 typedef void f();
10642 template <typename T> void g() { T t; }
10643 template void g<f>();
10645 is an attempt to declare a variable with function
10646 type. */
10648 /* R is not yet sufficiently initialized, so we
10649 just use its name. */
10652 }
10654 /* Wait until cp_finish_decl to set this again, to handle
10655 circular dependency (template/instantiate6.C). */
10660 {
10665 {
10668 }
10670 }
10671 }
10677 /* Clear out the mangled name and RTL for the instantiation. */
10681 /* The initializer must not be expanded until it is required;
10682 see [temp.inst]. */
10688 {
10689 /* Possibly limit visibility based on template args. */
10692 {
10696 }
10698 }
10701 {
10702 /* A static data member declaration is always marked
10703 external when it is declared in-class, even if an
10704 initializer is present. We mimic the non-template
10705 processing here. */
10711 }
10713 {
10714 /* We're substituting this var in a decltype outside of its
10715 scope, such as for a lambda return type. Don't add it to
10716 local_specializations, do perform auto deduction. */
10719 {
10720 tree init
10726 }
10727 }
10728 else
10737 /* Preserve a typedef that names a type. */
10739 {
10742 }
10745 }
10750 }
10751 #undef RETURN
10753 out:
10754 /* Restore the file and line information. */
10758 }
10760 /* Substitute into the ARG_TYPES of a function type. */
10762 static tree
10764 tree args,
10765 tsubst_flags_t complain,
10766 tree in_decl)
10767 {
10768 tree remaining_arg_types;
10772 tree default_arg;
10783 {
10784 /* For a pack expansion, perform substitution on the
10785 entire expression. Later on, we'll handle the arguments
10786 one-by-one. */
10791 /* So that we'll spin through the parameters, one by one. */
10793 else
10794 {
10795 /* We only partially substituted into the parameter
10796 pack. Our type is TYPE_PACK_EXPANSION. */
10799 }
10800 }
10813 {
10815 {
10819 }
10821 }
10823 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10824 top-level qualifiers as required. */
10827 /* We do not substitute into default arguments here. The standard
10828 mandates that they be instantiated only when needed, which is
10829 done in build_over_call. */
10833 {
10834 /* We've instantiated a template before its default arguments
10835 have been parsed. This can happen for a nested template
10836 class, and is not an error unless we require the default
10837 argument in a call of this function. */
10838 remaining_arg_types =
10841 remaining_arg_types);
10842 }
10843 else
10844 remaining_arg_types =
10846 }
10849 }
10851 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10852 *not* handle the exception-specification for FNTYPE, because the
10853 initial substitution of explicitly provided template parameters
10854 during argument deduction forbids substitution into the
10855 exception-specification:
10857 [temp.deduct]
10859 All references in the function type of the function template to the
10860 corresponding template parameters are replaced by the specified tem-
10861 plate argument values. If a substitution in a template parameter or
10862 in the function type of the function template results in an invalid
10863 type, type deduction fails. [Note: The equivalent substitution in
10864 exception specifications is done only when the function is instanti-
10865 ated, at which point a program is ill-formed if the substitution
10866 results in an invalid type.] */
10868 static tree
10870 tree args,
10871 tsubst_flags_t complain,
10872 tree in_decl)
10873 {
10874 tree return_type;
10875 tree arg_types;
10876 tree fntype;
10878 /* The TYPE_CONTEXT is not used for function/method types. */
10881 /* Substitute the return type. */
10885 /* The standard does not presently indicate that creation of a
10886 function type with an invalid return type is a deduction failure.
10887 However, that is clearly analogous to creating an array of "void"
10888 or a reference to a reference. This is core issue #486. */
10891 {
10893 {
10896 else
10898 }
10900 }
10902 /* Substitute the argument types. */
10908 /* Construct a new type node and return it. */
10910 {
10913 }
10914 else
10915 {
10918 {
10919 /* [temp.deduct]
10921 Type deduction may fail for any of the following
10922 reasons:
10924 -- Attempting to create "pointer to member of T" when T
10925 is not a class type. */
10928 r);
10930 }
10934 }
10938 }
10940 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10941 ARGS into that specification, and return the substituted
10942 specification. If there is no specification, return NULL_TREE. */
10944 static tree
10946 tree args,
10947 tsubst_flags_t complain,
10948 tree in_decl,
10950 {
10951 tree specs;
10952 tree new_specs;
10957 {
10958 /* A noexcept-specifier. */
10963 {
10964 /* Defer instantiation of noexcept-specifiers to avoid
10965 excessive instantiations (c++/49107). */
10968 {
10969 /* We already partially instantiated this member template,
10970 so combine the new args with the old. */
10975 }
10976 else
10977 {
10980 }
10981 }
10982 else
10983 new_specs = tsubst_copy_and_build
10987 }
10989 {
10992 else
10994 {
10995 tree spec;
11000 {
11001 /* Expand the pack expansion type. */
11004 in_decl);
11010 else
11011 {
11012 /* We're substituting into a member template, so
11013 we got a TYPE_PACK_EXPANSION back. Add that
11014 expansion and move on. */
11018 expanded_specs,
11019 complain);
11022 }
11023 }
11026 {
11029 else
11034 complain);
11035 }
11038 }
11039 }
11041 }
11043 /* Take the tree structure T and replace template parameters used
11044 therein with the argument vector ARGS. IN_DECL is an associated
11045 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11046 Issue error and warning messages under control of COMPLAIN. Note
11047 that we must be relatively non-tolerant of extensions here, in
11048 order to preserve conformance; if we allow substitutions that
11049 should not be allowed, we may allow argument deductions that should
11050 not succeed, and therefore report ambiguous overload situations
11051 where there are none. In theory, we could allow the substitution,
11052 but indicate that it should have failed, and allow our caller to
11053 make sure that the right thing happens, but we don't try to do this
11054 yet.
11056 This function is used for dealing with types, decls and the like;
11057 for expressions, use tsubst_expr or tsubst_copy. */
11059 tree
11061 {
11084 else
11089 /* Reuse typedefs. We need to do this to handle dependent attributes,
11090 such as attribute aligned. */
11093 {
11100 {
11101 /* DECL represents an alias template and we want to
11102 instantiate it. Let's substitute our arguments for the
11103 template parameters into the declaration and get the
11104 resulting type. */
11106 }
11110 {
11114 }
11119 else
11120 /* The typedef is from a non-template context. */
11124 {
11126 r = cp_build_qualified_type_real
11130 }
11131 else
11132 /* We don't have an instantiation yet, so drop the typedef. */
11134 }
11147 {
11173 {
11179 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11180 needed. */
11186 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11187 with TREE_SIDE_EFFECTS that indicates this is not an integral
11188 constant expression. */
11191 {
11194 }
11197 }
11203 {
11216 {
11220 /* See through ARGUMENT_PACK_SELECT arguments. */
11222 }
11227 {
11229 /* If ARG is an argument pack, we don't actually want to
11230 perform a substitution here, because substitutions
11231 for argument packs are only done
11232 element-by-element. We can get to this point when
11233 substituting the type of a non-type template
11234 parameter pack, when that type actually contains
11235 template parameter packs from an outer template, e.g.,
11237 template<typename... Types> struct A {
11238 template<Types... Values> struct B { };
11239 }; */
11243 {
11249 return cp_build_qualified_type_real
11251 }
11253 {
11254 /* We are processing a type constructed from a
11255 template template parameter. */
11266 /* Consider this code:
11268 template <template <class> class Template>
11269 struct Internal {
11270 template <class Arg> using Bind = Template<Arg>;
11271 };
11273 template <template <class> class Template, class Arg>
11274 using Instantiate = Template<Arg>; //#0
11276 template <template <class> class Template,
11277 class Argument>
11278 using Bind =
11279 Instantiate<Internal<Template>::template Bind,
11280 Argument>; //#1
11282 When #1 is parsed, the
11283 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11284 parameter `Template' in #0 matches the
11285 UNBOUND_CLASS_TEMPLATE representing the argument
11286 `Internal<Template>::template Bind'; We then want
11287 to assemble the type `Bind<Argument>' that can't
11288 be fully created right now, because
11289 `Internal<Template>' not being complete, the Bind
11290 template cannot be looked up in that context. So
11291 we need to "store" `Bind<Argument>' for later
11292 when the context of Bind becomes complete. Let's
11293 store that in a TYPENAME_TYPE. */
11297 argvec),
11298 typename_type,
11299 complain);
11301 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11302 are resolving nested-types in the signature of a
11303 member function templates. Otherwise ARG is a
11304 TEMPLATE_DECL and is the real template to be
11305 instantiated. */
11313 complain);
11314 return cp_build_qualified_type_real
11316 }
11317 else
11318 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11320 }
11323 /* This can happen during the attempted tsubst'ing in
11324 unify. This means that we don't yet have any information
11325 about the template parameter in question. */
11328 /* Early in template argument deduction substitution, we don't
11329 want to reduce the level of 'auto', or it will be confused
11330 with a normal template parm in subsequent deduction. */
11334 /* If we get here, we must have been looking at a parm for a
11335 more deeply nested template. Make a new version of this
11336 template parameter, but with a lower level. */
11338 {
11343 {
11345 r = cp_build_qualified_type_real
11349 }
11350 else
11351 {
11362 /* We have reduced the level of the template
11363 template parameter, but not the levels of its
11364 template parameters, so canonical_type_parameter
11365 will not be able to find the canonical template
11366 template parameter for this level. Thus, we
11367 require structural equality checking to compare
11368 TEMPLATE_TEMPLATE_PARMs. */
11372 else
11376 {
11384 }
11385 }
11394 }
11397 }
11400 {
11408 {
11412 }
11415 {
11419 }
11422 {
11426 }
11432 }
11435 /* We should never be tsubsting a binfo. */
11439 /* A vector of template arguments. */
11445 {
11449 /* [temp.deduct]
11451 Type deduction may fail for any of the following
11452 reasons:
11454 -- Attempting to create a pointer to reference type.
11455 -- Attempting to create a reference to a reference type or
11456 a reference to void.
11458 Core issue 106 says that creating a reference to a reference
11459 during instantiation is no longer a cause for failure. We
11460 only enforce this check in strict C++98 mode. */
11464 {
11467 /* We keep track of the last time we issued this error
11468 message to avoid spewing a ton of messages during a
11469 single bad template instantiation. */
11472 {
11477 else
11480 }
11483 }
11485 {
11489 }
11491 /* In C++0x, during template argument substitution, when there is an
11492 attempt to create a reference to a reference type, reference
11493 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11495 "If a template-argument for a template-parameter T names a type
11496 that is a reference to a type A, an attempt to create the type
11497 'lvalue reference to cv T' creates the type 'lvalue reference to
11498 A,' while an attempt to create the type type rvalue reference to
11499 cv T' creates the type T"
11500 */
11501 r = cp_build_reference_type
11504 else
11509 /* Will this ever be needed for TYPE_..._TO values? */
11513 }
11515 {
11518 {
11519 /* [temp.deduct]
11521 Type deduction may fail for any of the following
11522 reasons:
11524 -- Attempting to create "pointer to member of T" when T
11525 is not a class type. */
11529 }
11531 {
11535 }
11537 {
11541 }
11544 {
11545 /* The type of the implicit object parameter gets its
11546 cv-qualifiers from the FUNCTION_TYPE. */
11547 tree memptr;
11551 complain);
11552 }
11553 else
11556 complain);
11557 }
11560 {
11561 tree fntype;
11562 tree specs;
11567 /* Substitute the exception specification. */
11575 }
11577 {
11582 /* As an optimization, we avoid regenerating the array type if
11583 it will obviously be the same as T. */
11587 /* These checks should match the ones in grokdeclarator.
11589 [temp.deduct]
11591 The deduction may fail for any of the following reasons:
11593 -- Attempting to create an array with an element type that
11594 is void, a function type, or a reference type, or [DR337]
11595 an abstract class type. */
11599 {
11603 }
11605 {
11608 type);
11610 }
11615 {
11618 }
11621 }
11624 {
11634 {
11638 }
11640 {
11641 /* Normally, make_typename_type does not require that the CTX
11642 have complete type in order to allow things like:
11644 template <class T> struct S { typename S<T>::X Y; };
11646 But, such constructs have already been resolved by this
11647 point, so here CTX really should have complete type, unless
11648 it's a partial instantiation. */
11651 {
11655 }
11656 }
11663 {
11666 }
11669 {
11671 {
11675 else
11677 }
11679 {
11683 else
11685 }
11686 }
11688 return cp_build_qualified_type_real
11690 }
11693 {
11705 }
11708 {
11709 tree type;
11725 complain);
11726 }
11729 {
11730 tree type;
11746 else
11747 type = finish_decltype_type
11752 complain);
11753 }
11756 {
11760 }
11764 {
11766 tree packed_out =
11768 args,
11769 complain,
11770 in_decl);
11773 /* For template nontype argument packs, also substitute into
11774 the type. */
11779 }
11794 /* We should use one of the expression tsubsts for these codes. */
11800 }
11801 }
11803 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11804 type of the expression on the left-hand side of the "." or "->"
11805 operator. */
11807 static tree
11810 {
11811 tree name;
11812 tree qualifying_scope;
11813 tree fns;
11814 tree optype;
11819 /* A baselink indicates a function from a base class. Both the
11820 BASELINK_ACCESS_BINFO and the base class referenced may
11821 indicate bases of the template class, rather than the
11822 instantiated class. In addition, lookups that were not
11823 ambiguous before may be ambiguous now. Therefore, we perform
11824 the lookup again. */
11831 {
11838 }
11846 /* If lookup found a single function, mark it as used at this
11847 point. (If it lookup found multiple functions the one selected
11848 later by overload resolution will be marked as used at that
11849 point.) */
11855 /* Add back the template arguments, if present. */
11860 template_args);
11861 /* Update the conversion operator type. */
11869 qualifying_scope,
11870 object_type);
11872 }
11874 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11875 true if the qualified-id will be a postfix-expression in-and-of
11876 itself; false if more of the postfix-expression follows the
11877 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11878 of "&". */
11880 static tree
11884 {
11885 tree expr;
11886 tree scope;
11887 tree name;
11889 tree template_args;
11893 /* Figure out what name to look up. */
11896 {
11903 }
11904 else
11905 {
11908 }
11910 /* Substitute into the qualifying scope. When there are no ARGS, we
11911 are just trying to simplify a non-dependent expression. In that
11912 case the qualifying scope may be dependent, and, in any case,
11913 substituting will not help. */
11916 {
11919 }
11920 else
11924 {
11929 }
11932 {
11934 {
11935 /* A BIT_NOT_EXPR is used to represent a destructor. */
11937 {
11941 }
11942 else
11945 }
11946 else
11950 {
11952 {
11956 }
11958 }
11959 }
11962 {
11964 scope);
11965 /* Remember that there was a reference to this entity. */
11967 }
11970 {
11976 }
11985 {
11986 expr = (adjust_result_of_qualified_name_lookup
11988 expr = (finish_qualified_id_expr
11992 }
11994 /* Expressions do not generally have reference type. */
11996 /* However, if we're about to form a pointer-to-member, we just
11997 want the referenced member referenced. */
12002 }
12004 /* Like tsubst, but deals with expressions. This function just replaces
12005 template parms; to finish processing the resultant expression, use
12006 tsubst_copy_and_build or tsubst_expr. */
12008 static tree
12010 {
12012 tree r;
12020 {
12025 {
12026 tree c;
12028 /* We get here for a use of 'this' in an NSDMI. */
12034 /* This can happen for a parameter name used later in a function
12035 declaration (such as in a late-specified return type). Just
12036 make a dummy decl, since it's only used for its type. */
12038 /* We copy T because want to tsubst the PARM_DECL only,
12039 not the following PARM_DECLs that are chained to T. */
12042 /* Give it the template pattern as its context; its true context
12043 hasn't been instantiated yet and this is good enough for
12044 mangling. */
12046 }
12054 {
12055 tree enum_type;
12056 tree v;
12060 /* There is no need to substitute into namespace-scope
12061 enumerators. */
12064 /* If ARGS is NULL, then T is known to be non-dependent. */
12068 /* Unfortunately, we cannot just call lookup_name here.
12069 Consider:
12071 template <int I> int f() {
12072 enum E { a = I };
12073 struct S { void g() { E e = a; } };
12074 };
12076 When we instantiate f<7>::S::g(), say, lookup_name is not
12077 clever enough to find f<7>::a. */
12078 enum_type
12088 /* We didn't find the name. That should never happen; if
12089 name-lookup found it during preliminary parsing, we
12090 should find it again here during instantiation. */
12092 }
12097 {
12098 tree ctx;
12103 {
12106 {
12110 }
12112 }
12113 }
12129 /* An OVERLOAD will always be a non-dependent overload set; an
12130 overload set from function scope will just be represented with an
12131 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12146 {
12147 /* Template template argument like the following example need
12148 special treatment:
12150 template <template <class> class TT> struct C {};
12151 template <class T> struct D {
12152 template <class U> struct E {};
12153 C<E> c; // #1
12154 };
12155 D<int> d; // #2
12157 We are processing the template argument `E' in #1 for
12158 the template instantiation #2. Originally, `E' is a
12159 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12160 have to substitute this with one having context `D<int>'. */
12164 }
12165 else
12166 /* Ordinary template template argument. */
12177 return build1
12183 {
12185 tree expanded;
12190 /* We only want to compute the number of arguments. */
12205 {
12212 else
12215 }
12216 else
12218 }
12219 /* Fall through */
12234 return build1
12239 {
12240 tree object;
12241 tree name;
12246 {
12250 }
12253 {
12263 }
12268 in_decl);
12269 else
12272 }
12310 return build_nt
12323 return build_nt
12330 {
12338 }
12343 {
12344 r = build_nt
12350 }
12353 {
12354 r = build_nt
12360 }
12363 {
12364 r = build_nt
12370 }
12373 {
12374 /* Substituted template arguments */
12383 }
12386 {
12406 }
12431 {
12434 }
12435 else
12439 /* This is handled by tsubst_copy_and_build. */
12444 in_decl),
12448 /* We shouldn't have built any of these during initial template
12449 generation. Instead, they should be built during instantiation
12450 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12454 r = build2
12474 {
12475 /* Instantiate any typedefs in the type. */
12480 }
12483 /* These can sometimes show up in a partial instantiation, but never
12484 involve template parms. */
12489 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12492 }
12493 }
12495 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12497 static tree
12499 tree in_decl)
12500 {
12504 {
12510 {
12513 {
12519 }
12520 /* FALLTHRU */
12544 }
12545 }
12548 }
12550 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12552 static tree
12554 tree in_decl)
12555 {
12556 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12576 {
12579 else
12580 {
12584 }
12585 }
12590 #undef RECUR
12591 }
12593 /* Substitute one OMP_FOR iterator. */
12595 static void
12600 {
12601 #define RECUR(NODE) \
12602 tsubst_expr ((NODE), args, complain, in_decl, \
12603 integral_constant_expression_p)
12612 {
12619 }
12623 {
12629 complain);
12630 else
12637 }
12640 {
12641 tree c;
12643 {
12654 }
12656 {
12661 {
12664 }
12665 }
12666 }
12672 else
12676 {
12687 {
12694 }
12695 else
12701 {
12707 }
12711 {
12718 }
12719 else
12725 }
12731 #undef RECUR
12732 }
12734 /* Like tsubst_copy for expressions, etc. but also does semantic
12735 processing. */
12737 static tree
12740 {
12741 #define RECUR(NODE) \
12742 tsubst_expr ((NODE), args, complain, in_decl, \
12743 integral_constant_expression_p)
12756 {
12758 {
12759 tree_stmt_iterator i;
12763 }
12778 else
12787 {
12789 tree init;
12795 {
12798 tree decl;
12806 else
12808 }
12809 else
12810 {
12814 {
12815 /* By marking the declaration as instantiated, we avoid
12816 trying to instantiate it. Since instantiate_decl can't
12817 handle local variables, and since we've already done
12818 all that needs to be done, that's the right thing to
12819 do. */
12824 /* Anonymous aggregates are a special case. */
12827 {
12830 }
12831 else
12832 {
12837 {
12838 /* For __PRETTY_FUNCTION__ we have to adjust the
12839 initializer. */
12843 }
12844 else
12845 {
12849 {
12850 /* If we had an initializer but it
12851 instantiated to nothing,
12852 value-initialize the object. This will
12853 only occur when the initializer was a
12854 pack expansion where the parameter packs
12855 used in that expansion were of length
12856 zero. */
12858 complain);
12861 }
12862 else
12864 }
12867 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12870 }
12871 }
12872 }
12874 /* A DECL_EXPR can also be used as an expression, in the condition
12875 clause of an if/for/while construct. */
12877 }
12892 {
12902 }
12929 {
12933 }
12941 else
12949 else
12976 {
12978 tree label;
12983 }
12989 /* Computed goto's must be tsubst'd into. On the other hand,
12990 non-computed gotos must not be; the identifier in question
12991 will have no binding. */
12993 else
12999 tmp = finish_asm_stmt
13006 {
13011 }
13016 {
13021 }
13022 else
13023 {
13028 else
13035 else
13041 else
13043 }
13047 {
13051 {
13053 /* Prevent instantiate_decl from trying to instantiate
13054 this variable. We've already done all that needs to be
13055 done. */
13058 }
13063 }
13071 {
13072 tree condition =
13074 args,
13081 }
13102 {
13117 integral_constant_expression_p);
13126 {
13130 }
13131 else
13132 {
13140 }
13154 }
13186 {
13191 {
13194 }
13199 }
13200 else
13201 {
13208 {
13211 }
13214 {
13219 {
13222 }
13226 }
13227 else
13228 {
13232 }
13234 }
13238 {
13244 {
13248 {
13253 }
13257 }
13258 else
13259 {
13264 }
13265 }
13285 integral_constant_expression_p);
13286 }
13289 #undef RECUR
13290 }
13292 /* T is a postfix-expression that is not being used in a function
13293 call. Return the substituted version of T. */
13295 static tree
13297 tsubst_flags_t complain,
13298 tree in_decl)
13299 {
13303 else
13309 }
13311 /* Like tsubst but deals with expressions and performs semantic
13312 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13314 tree
13316 tree args,
13317 tsubst_flags_t complain,
13318 tree in_decl,
13321 {
13322 #define RECUR(NODE) \
13323 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13325 integral_constant_expression_p)
13327 tree op1;
13333 {
13336 /* Fall through. */
13338 {
13339 tree decl;
13340 cp_id_kind idk;
13345 {
13348 }
13350 /* Look up the name. */
13353 /* By convention, expressions use ERROR_MARK_NODE to indicate
13354 failure, not NULL_TREE. */
13360 integral_constant_expression_p,
13368 input_location);
13372 {
13376 }
13378 }
13381 {
13382 tree object;
13390 {
13393 }
13394 else
13401 else
13403 }
13406 {
13410 {
13411 /* A type conversion to reference type will be enclosed in
13412 such an indirect ref, but the substitution of the cast
13413 will have also added such an indirect ref. */
13416 }
13417 else
13420 }
13423 return build_nop
13428 {
13435 flags);
13436 }
13439 return build1
13449 {
13450 tree type;
13456 {
13461 }
13467 {
13485 }
13489 }
13507 complain);
13521 else
13523 in_decl);
13557 {
13558 tree r = build_x_binary_op
13562 ? ERROR_MARK
13566 ? ERROR_MARK
13569 complain);
13573 }
13586 /* Fall through */
13591 {
13592 /* When there are no ARGS, we are trying to evaluate a
13593 non-dependent expression from the parser. Trying to do
13594 the substitutions may not work. */
13597 }
13598 else
13599 {
13607 }
13611 else
13616 {
13626 }
13640 {
13641 tree r = build_x_modify_expr
13645 complain);
13646 /* TREE_NO_WARNING must be set if either the expression was
13647 parenthesized or it uses an operator such as >>= rather
13648 than plain assignment. In the former case, it was already
13649 set and must be copied. In the latter case,
13650 build_x_modify_expr sets it and it must not be reset
13651 here. */
13655 }
13660 /* Remember that there was a reference to this entity. */
13666 {
13671 tree ret;
13675 else
13676 {
13680 }
13682 /* If there was an initializer in the original tree, but it
13683 instantiated to an empty list, then we should pass a
13684 non-NULL empty vector to tell build_new that it was an
13685 empty initializer() rather than no initializer. This can
13686 only happen when the initializer is a pack expansion whose
13687 parameter packs are of length zero. */
13690 else
13691 {
13695 else
13696 {
13699 }
13700 }
13707 complain);
13715 }
13718 return delete_sanity
13723 complain);
13728 complain);
13731 {
13732 tree function;
13737 tree ret;
13740 /* When we parsed the expression, we determined whether or
13741 not Koenig lookup should be performed. */
13744 {
13749 }
13751 {
13752 /* Do nothing; calling tsubst_copy_and_build on an identifier
13753 would incorrectly perform unqualified lookup again.
13755 Note that we can also have an IDENTIFIER_NODE if the earlier
13756 unqualified lookup found a member function; in that case
13757 koenig_p will be false and we do want to do the lookup
13758 again to find the instantiated member function.
13760 FIXME but doing that causes c++/15272, so we need to stop
13761 using IDENTIFIER_NODE in that situation. */
13763 }
13764 else
13765 {
13767 {
13773 }
13774 else
13778 in_decl,
13780 integral_constant_expression_p);
13784 }
13789 {
13795 else
13796 {
13797 /* Expand the pack expansion and push each entry onto
13798 CALL_ARGS. */
13801 {
13806 {
13811 }
13812 }
13813 else
13814 {
13815 /* A partial substitution. Add one entry. */
13817 }
13818 }
13819 }
13821 /* We do not perform argument-dependent lookup if normal
13822 lookup finds a non-function, in accordance with the
13823 expected resolution of DR 218. */
13826 /* If lookup found a member function, the Koenig lookup is
13827 not appropriate, even if an unqualified-name was used
13828 to denote the function. */
13831 /* Only do this when substitution turns a dependent call
13832 into a non-dependent call. */
13836 tf_none);
13840 {
13842 {
13843 /* For backwards compatibility and good diagnostics, try
13844 the unqualified lookup again if we aren't in SFINAE
13845 context. */
13846 tree unq = (tsubst_copy_and_build
13848 integral_constant_expression_p));
13853 {
13862 "%qD was not declared in this scope, "
13863 "and no declarations were found by "
13864 "argument-dependent lookup at the point "
13869 {
13871 "declarations in dependent base %qT are "
13877 else
13881 }
13882 else
13886 }
13887 }
13889 {
13893 }
13894 }
13896 /* Remember that there was a reference to this entity. */
13903 {
13918 complain);
13919 else
13920 ret = (build_new_method_call
13925 complain));
13926 }
13927 else
13930 koenig_p,
13931 complain);
13936 }
13939 {
13944 {
13946 {
13951 }
13952 else
13953 {
13958 }
13959 }
13960 else
13961 {
13964 }
13967 }
13970 return finish_pseudo_destructor_expr
13976 {
13984 {
13985 /* We have pack expansions, so expand those and
13986 create a new list out of it. */
13989 tree chain;
13992 /* Expand the argument expressions. */
14000 /* Build the rest of the list. */
14005 /* Determine the number of arguments. */
14007 {
14010 }
14013 else
14014 {
14015 /* Since we only performed a partial substitution into
14016 the argument pack, we only return a single list
14017 node. */
14024 }
14026 /* Convert the argument vectors into a TREE_LIST */
14029 {
14030 /* Grab the Ith values. */
14031 i--;
14034 value
14038 /* Build the list (backwards). */
14040 }
14043 }
14059 }
14062 {
14063 tree object;
14064 tree object_type;
14065 tree member;
14069 /* Remember that there was a reference to this entity. */
14079 else
14087 {
14089 {
14094 {
14097 }
14099 {
14103 }
14104 }
14105 }
14108 {
14109 /* Lookup the template functions now that we know what the
14110 scope is. */
14118 {
14121 args);
14122 member = (adjust_result_of_qualified_name_lookup
14124 object_type));
14125 }
14126 else
14127 {
14129 input_location);
14131 }
14132 }
14136 {
14138 {
14142 else
14145 }
14147 }
14153 complain);
14154 }
14157 return build_throw
14161 {
14169 tree r;
14174 /* digest_init will do the wrong thing if we let it. */
14178 /* We do not want to process the index of aggregate
14179 initializers as they are identifier nodes which will be
14180 looked up by digest_init. */
14186 {
14191 {
14192 /* Substitute into the pack expansion. */
14194 in_decl);
14198 ;
14200 /* Just move the argument into place. */
14202 else
14203 {
14204 /* Update the length of the final CONSTRUCTOR
14205 arguments vector, and note that we will need to
14206 copy.*/
14209 }
14210 }
14211 else
14213 }
14216 {
14221 {
14223 {
14228 }
14229 else
14231 }
14232 }
14242 }
14245 {
14248 {
14251 }
14252 else
14253 {
14256 }
14257 }
14262 /* Fall through */
14265 {
14269 /* If the original type was a reference, we'll be wrapped in
14270 the appropriate INDIRECT_REF. */
14273 }
14283 {
14292 }
14295 {
14301 integral_constant_expression_p);
14305 /* If the resulting list of expression statement is empty,
14306 fold it further into void_zero_node. */
14311 }
14315 /* As in finish_id_expression, we resolve enumeration constants
14316 to their underlying values. */
14318 {
14321 }
14325 {
14347 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14349 /* Now that we know visibility, instantiate the type so we have a
14350 declaration of the op() for later calls to lambda_function. */
14353 /* The capture list refers to closure members, so this needs to
14354 wait until after we finish instantiating the type. */
14359 }
14362 /* We can get here for a constant initializer of non-dependent type.
14363 FIXME stop folding in cp_parser_initializer_clause. */
14365 {
14369 }
14373 integral_constant_expression_p);
14376 /* Handle Objective-C++ constructs, if appropriate. */
14377 {
14378 tree subst
14383 }
14385 }
14387 #undef RECUR
14388 }
14390 /* Verify that the instantiated ARGS are valid. For type arguments,
14391 make sure that the type's linkage is ok. For non-type arguments,
14392 make sure they are constants if they are integral or enumerations.
14393 Emit an error under control of COMPLAIN, and return TRUE on error. */
14395 static bool
14397 {
14399 {
14409 }
14411 {
14412 /* [basic.link]: A name with no linkage (notably, the name
14413 of a class or enumeration declared in a local scope)
14414 shall not be used to declare an entity with linkage.
14415 This implies that names with no linkage cannot be used as
14416 template arguments
14418 DR 757 relaxes this restriction for C++0x. */
14423 {
14424 /* DR 488 makes use of a type with no linkage cause
14425 type deduction to fail. */
14427 {
14430 else
14433 }
14435 }
14436 /* In order to avoid all sorts of complications, we do not
14437 allow variably-modified types as template arguments. */
14439 {
14443 }
14444 }
14445 /* A non-type argument of integral or enumerated type must be a
14446 constant. */
14450 {
14454 }
14456 }
14458 static bool
14460 {
14465 {
14468 }
14472 }
14474 /* In C++0x, it's possible to have a function template whose type depends
14475 on itself recursively. This is most obvious with decltype, but can also
14476 occur with enumeration scope (c++/48969). So we need to catch infinite
14477 recursion and reject the substitution at deduction time; this function
14478 will return error_mark_node for any repeated substitution.
14480 This also catches excessive recursion such as when f<N> depends on
14481 f<N-1> across all integers, and returns error_mark_node for all the
14482 substitutions back up to the initial one.
14484 This is, of course, not reentrant. */
14486 static tree
14488 {
14495 tree tinst;
14496 tree r;
14503 {
14507 }
14517 {
14520 /* Reset once we're all the way out. */
14522 }
14525 /* We can't free this if a pending_template entry or last_error_tinst_level
14526 is pointing at it. */
14531 }
14533 /* Instantiate the indicated variable or function template TMPL with
14534 the template arguments in TARG_PTR. */
14536 static tree
14538 {
14540 tree fndecl;
14541 tree gen_tmpl;
14542 tree spec;
14549 /* If this function is a clone, handle it specially. */
14551 {
14552 tree spec;
14553 tree clone;
14555 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14556 DECL_CLONED_FUNCTION. */
14562 /* Look for the clone. */
14566 /* We should always have found the clone by now. */
14569 }
14571 /* Check to see if we already have this specialization. */
14574 /* The TMPL is a partial instantiation. To get a full set of
14575 arguments we must add the arguments used to perform the
14576 partial instantiation. */
14578 targ_ptr);
14580 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14581 but it doesn't seem to be on the hot path. */
14593 complain))
14596 /* We are building a FUNCTION_DECL, during which the access of its
14597 parameters and return types have to be checked. However this
14598 FUNCTION_DECL which is the desired context for access checking
14599 is not built yet. We solve this chicken-and-egg problem by
14600 deferring all checks until we have the FUNCTION_DECL. */
14603 /* Instantiation of the function happens in the context of the function
14604 template, not the context of the overload resolution we're doing. */
14607 {
14611 }
14612 /* Substitute template parameters to obtain the specialization. */
14622 /* Now we know the specialization, compute access previously
14623 deferred. */
14626 /* Some typedefs referenced from within the template code need to be access
14627 checked at template instantiation time, i.e now. These types were
14628 added to the template at parsing time. Let's get those and perfom
14629 the acces checks then. */
14635 /* The DECL_TI_TEMPLATE should always be the immediate parent
14636 template, not the most general template. */
14639 /* If we've just instantiated the main entry point for a function,
14640 instantiate all the alternate entry points as well. We do this
14641 by cloning the instantiation of the main entry point, not by
14642 instantiating the template clones. */
14647 }
14649 /* Wrapper for instantiate_template_1. */
14651 tree
14653 {
14654 tree ret;
14659 }
14661 /* We're going to do deduction substitution on the type of TMPL, a function
14662 template. In C++11 mode, push into that access scope. In C++03 mode,
14663 disable access checking. */
14665 static void
14667 {
14669 {
14672 /* Preserve processing_template_decl across push_to_top_level. */
14675 }
14676 else
14678 }
14680 /* And pop back out. */
14682 static void
14684 {
14687 else
14689 }
14691 /* PARM is a template parameter pack for FN. Returns true iff
14692 PARM is used in a deducible way in the argument list of FN. */
14694 static bool
14696 {
14699 {
14701 tree packs;
14707 {
14708 /* The template parameter pack is used in a function parameter
14709 pack. If this is the end of the parameter list, the
14710 template parameter pack is deducible. */
14713 else
14714 /* Otherwise, not. Well, it could be deduced from
14715 a non-pack parameter, but doing so would end up with
14716 a deduction mismatch, so don't bother. */
14718 }
14719 }
14720 /* The template parameter pack isn't used in any function parameter
14721 packs, but it might be used deeper, e.g. tuple<Args...>. */
14723 }
14725 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14726 NARGS elements of the arguments that are being used when calling
14727 it. TARGS is a vector into which the deduced template arguments
14728 are placed.
14730 Return zero for success, 2 for an incomplete match that doesn't resolve
14731 all the types, and 1 for complete failure. An error message will be
14732 printed only for an incomplete match.
14734 If FN is a conversion operator, or we are trying to produce a specific
14735 specialization, RETURN_TYPE is the return type desired.
14737 The EXPLICIT_TARGS are explicit template arguments provided via a
14738 template-id.
14740 The parameter STRICT is one of:
14742 DEDUCE_CALL:
14743 We are deducing arguments for a function call, as in
14744 [temp.deduct.call].
14746 DEDUCE_CONV:
14747 We are deducing arguments for a conversion function, as in
14748 [temp.deduct.conv].
14750 DEDUCE_EXACT:
14751 We are deducing arguments when doing an explicit instantiation
14752 as in [temp.explicit], when determining an explicit specialization
14753 as in [temp.expl.spec], or when taking the address of a function
14754 template, as in [temp.deduct.funcaddr]. */
14756 int
14758 tree explicit_targs,
14759 tree targs,
14762 tree return_type,
14763 unification_kind_t strict,
14766 {
14767 tree parms;
14768 tree fntype;
14775 {
14776 /* [temp.deduct]
14778 The specified template arguments must match the template
14779 parameters in kind (i.e., type, nontype, template), and there
14780 must not be more arguments than there are parameters;
14781 otherwise type deduction fails.
14783 Nontype arguments must match the types of the corresponding
14784 nontype template parameters, or must be convertible to the
14785 types of the corresponding nontype parameters as specified in
14786 _temp.arg.nontype_, otherwise type deduction fails.
14788 All references in the function type of the function template
14789 to the corresponding template parameters are replaced by the
14790 specified template argument values. If a substitution in a
14791 template parameter or in the function type of the function
14792 template results in an invalid type, type deduction fails. */
14795 tree converted_args;
14801 converted_args
14803 (explain_p
14804 ? tf_warning_or_error
14811 /* Substitute the explicit args into the function type. This is
14812 necessary so that, for instance, explicitly declared function
14813 arguments can match null pointed constants. If we were given
14814 an incomplete set of explicit args, we must not do semantic
14815 processing during substitution as we could create partial
14816 instantiations. */
14818 {
14823 /* Dig out the actual parm. */
14826 {
14829 }
14831 {
14834 }
14837 /* No explicit argument for this template parameter. */
14841 {
14842 /* Mark the argument pack as "incomplete". We could
14843 still deduce more arguments during unification.
14844 We remove this mark in type_unification_real. */
14846 {
14850 }
14852 /* We have some incomplete argument packs. */
14854 }
14855 }
14859 (explain_p
14860 ? tf_warning_or_error
14867 /* Place the explicitly specified arguments in TARGS. */
14870 }
14872 /* Never do unification on the 'this' parameter. */
14876 {
14885 }
14887 /* We allow incomplete unification without an error message here
14888 because the standard doesn't seem to explicitly prohibit it. Our
14889 callers must be ready to deal with unification failures in any
14890 event. */
14895 /* Now that we have bindings for all of the template arguments,
14896 ensure that the arguments deduced for the template template
14897 parameters have compatible template parameter lists. We cannot
14898 check this property before we have deduced all template
14899 arguments, because the template parameter types of a template
14900 template parameter might depend on prior template parameters
14901 deduced after the template template parameter. The following
14902 ill-formed example illustrates this issue:
14904 template<typename T, template<T> class C> void f(C<5>, T);
14906 template<int N> struct X {};
14908 void g() {
14909 f(X<5>(), 5l); // error: template argument deduction fails
14910 }
14912 The template parameter list of 'C' depends on the template type
14913 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14914 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14915 time that we deduce 'C'. */
14917 && !template_template_parm_bindings_ok_p
14922 /* All is well so far. Now, check:
14924 [temp.deduct]
14926 When all template arguments have been deduced, all uses of
14927 template parameters in nondeduced contexts are replaced with
14928 the corresponding deduced argument values. If the
14929 substitution results in an invalid type, as described above,
14930 type deduction fails. */
14931 {
14933 (explain_p
14934 ? tf_warning_or_error
14939 /* If we're looking for an exact match, check that what we got
14940 is indeed an exact match. It might not be if some template
14941 parameters are used in non-deduced contexts. */
14943 {
14946 tree sarg
14954 }
14955 }
14958 }
14960 /* Adjust types before performing type deduction, as described in
14961 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14962 sections are symmetric. PARM is the type of a function parameter
14963 or the return type of the conversion function. ARG is the type of
14964 the argument passed to the call, or the type of the value
14965 initialized with the result of the conversion function.
14966 ARG_EXPR is the original argument expression, which may be null. */
14968 static int
14972 tree arg_expr)
14973 {
14977 {
14982 {
14983 /* Swap PARM and ARG throughout the remainder of this
14984 function; the handling is precisely symmetric since PARM
14985 will initialize ARG rather than vice versa. */
14990 }
14993 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14994 too, but here handle it by stripping the reference from PARM
14995 rather than by adding it to ARG. */
15003 /* Nothing else to do in this case. */
15008 }
15011 {
15012 /* [temp.deduct.call]
15014 If P is not a reference type:
15016 --If A is an array type, the pointer type produced by the
15017 array-to-pointer standard conversion (_conv.array_) is
15018 used in place of A for type deduction; otherwise,
15020 --If A is a function type, the pointer type produced by
15021 the function-to-pointer standard conversion
15022 (_conv.func_) is used in place of A for type deduction;
15023 otherwise,
15025 --If A is a cv-qualified type, the top level
15026 cv-qualifiers of A's type are ignored for type
15027 deduction. */
15032 else
15034 }
15036 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15037 of the form T&&, where T is a template parameter, and the argument
15038 is an lvalue, T is deduced as A& */
15044 /* try_one_overload doesn't provide an arg_expr, but
15045 functions are always lvalues. */
15049 /* [temp.deduct.call]
15051 If P is a cv-qualified type, the top level cv-qualifiers
15052 of P's type are ignored for type deduction. If P is a
15053 reference type, the type referred to by P is used for
15054 type deduction. */
15057 {
15060 }
15062 /* DR 322. For conversion deduction, remove a reference type on parm
15063 too (which has been swapped into ARG). */
15068 }
15070 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15071 template which does contain any deducible template parameters; check if
15072 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15073 unify_one_argument. */
15075 static int
15078 {
15079 tree type;
15083 else
15090 {
15093 }
15095 {
15098 flags))
15100 }
15104 else
15106 }
15108 /* Subroutine of type_unification_real and unify_pack_expansion to
15109 handle unification of a single P/A pair. Parameters are as
15110 for those functions. */
15112 static int
15116 {
15123 /* We can't deduce anything from this, but we might get all the
15124 template args from other function args. */
15127 /* FIXME uses_deducible_template_parms */
15130 explain_p);
15133 {
15135 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15136 | UNIFY_ALLOW_MORE_CV_QUAL
15150 }
15152 /* We only do these transformations if this is the top-level
15153 parameter_type_list in a call or declaration matching; in other
15154 situations (nested function declarators, template argument lists) we
15155 won't be comparing a type to an expression, and we don't do any type
15156 adjustments. */
15158 {
15160 {
15163 {
15164 /* [temp.deduct.type] A template-argument can be
15165 deduced from a pointer to function or pointer
15166 to member function argument if the set of
15167 overloaded functions does not contain function
15168 templates and at most one of a set of
15169 overloaded functions provides a unique
15170 match. */
15177 }
15183 }
15185 arg_strict |=
15187 }
15188 else
15192 /* For deduction from an init-list we need the actual list. */
15196 }
15198 /* Most parms like fn_type_unification.
15200 If SUBR is 1, we're being called recursively (to unify the
15201 arguments of a function or method parameter of a function
15202 template). */
15204 static int
15206 tree targs,
15207 tree xparms,
15211 unification_kind_t strict,
15214 {
15219 tree parms;
15228 /* Reset the number of non-defaulted template arguments contained
15229 in TARGS. */
15232 again:
15240 {
15245 /* For a function parameter pack that occurs at the end of the
15246 parameter-declaration-list, the type A of each remaining
15247 argument of the call is compared with the type P of the
15248 declarator-id of the function parameter pack. */
15254 /* For a function parameter pack that does not occur at the
15255 end of the parameter-declaration-list, the type of the
15256 parameter pack is a non-deduced context. */
15265 }
15270 {
15271 /* Unify the remaining arguments with the pack expansion type. */
15272 tree argvec;
15275 /* Allocate a TREE_VEC and copy in all of the arguments */
15280 /* Copy the parameter into parmvec. */
15286 /* Advance to the end of the list of parameters. */
15288 }
15290 /* Fail if we've reached the end of the parm list, and more args
15291 are present, and the parm list isn't variadic. */
15294 /* Fail if parms are left and they don't have default values. */
15297 {
15301 {
15302 count++;
15304 }
15306 }
15309 {
15310 tsubst_flags_t complain = (explain_p
15311 ? tf_warning_or_error
15314 /* Check to see if we need another pass before we start clearing
15315 ARGUMENT_PACK_INCOMPLETE_P. */
15317 {
15325 /* If this is an undeduced nontype parameter that depends on
15326 a type parameter, try another pass; its type may have been
15327 deduced from a later argument than the one from which
15328 this parameter can be deduced. */
15333 }
15336 {
15340 /* Clear the "incomplete" flags on all argument packs now so that
15341 substituting them into later default arguments works. */
15343 {
15346 }
15352 /* Core issue #226 (C++0x) [temp.deduct]:
15354 If a template argument has not been deduced, its
15355 default template argument, if any, is used.
15357 When we are in C++98 mode, TREE_PURPOSE will either
15358 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15359 to explicitly check cxx_dialect here. */
15361 {
15373 else
15374 {
15376 /* The position of the first default template argument,
15377 is also the number of non-defaulted arguments in TARGS.
15378 Record that. */
15382 }
15383 }
15385 /* If the type parameter is a parameter pack, then it will
15386 be deduced to an empty parameter pack. */
15388 {
15389 tree arg;
15392 {
15396 }
15397 else
15404 }
15407 }
15408 }
15409 #ifdef ENABLE_CHECKING
15412 #endif
15415 }
15417 /* Subroutine of type_unification_real. Args are like the variables
15418 at the call site. ARG is an overloaded function (or template-id);
15419 we try deducing template args from each of the overloads, and if
15420 only one succeeds, we go with that. Modifies TARGS and returns
15421 true on success. */
15423 static bool
15425 tree targs,
15426 tree parm,
15427 tree arg,
15428 unification_kind_t strict,
15431 {
15438 {
15441 }
15442 else
15446 /* Handle `&x' where `x' is some static or non-static member
15447 function name. */
15453 /* Strip baselink information. */
15458 {
15459 /* If we got some explicit template args, we need to plug them into
15460 the affected templates before we try to unify, in case the
15461 explicit args will completely resolve the templates in question. */
15468 {
15479 {
15484 {
15487 }
15488 }
15492 }
15493 /* If no templates (or more than one) are fully resolved by the
15494 explicit arguments, this template-id is a non-deduced context; it
15495 could still be OK if we deduce all template arguments for the
15496 enclosing call through other arguments. */
15499 }
15502 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15503 -- but the deduction does not succeed because the expression is
15504 not just the function on its own. */
15506 else
15512 {
15515 }
15517 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15518 to function or pointer to member function argument if the set of
15519 overloaded functions does not contain function templates and at most
15520 one of a set of overloaded functions provides a unique match.
15522 So if we found multiple possibilities, we return success but don't
15523 deduce anything. */
15526 {
15531 }
15536 }
15538 /* Core DR 115: In contexts where deduction is done and fails, or in
15539 contexts where deduction is not done, if a template argument list is
15540 specified and it, along with any default template arguments, identifies
15541 a single function template specialization, then the template-id is an
15542 lvalue for the function template specialization. */
15544 tree
15546 {
15559 {
15562 }
15564 {
15567 }
15569 {
15572 }
15575 {
15579 /* If we got some explicit template args, we need to plug them into
15580 the affected templates before we try to unify, in case the
15581 explicit args will completely resolve the templates in question. */
15589 {
15600 {
15603 {
15606 }
15608 {
15611 }
15612 }
15614 }
15616 {
15624 {
15625 tree base
15628 }
15632 }
15634 /* There were no good options and at least one bad one, so let the
15635 user know what the problem is. */
15637 }
15639 }
15641 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15642 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15643 different overloads deduce different arguments for a given parm.
15644 ADDR_P is true if the expression for which deduction is being
15645 performed was of the form "& fn" rather than simply "fn".
15647 Returns 1 on success. */
15649 static int
15651 tree orig_targs,
15652 tree targs,
15653 tree parm,
15654 tree arg,
15655 unification_kind_t strict,
15659 {
15661 tree tempargs;
15664 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15665 to function or pointer to member function argument if the set of
15666 overloaded functions does not contain function templates and at most
15667 one of a set of overloaded functions provides a unique match.
15669 So if this is a template, just return success. */
15681 /* We don't copy orig_targs for this because if we have already deduced
15682 some template args from previous args, unify would complain when we
15683 try to deduce a template parameter for the same argument, even though
15684 there isn't really a conflict. */
15691 /* First make sure we didn't deduce anything that conflicts with
15692 explicitly specified args. */
15694 {
15701 /* Since we're unifying against ourselves, we will fill in
15702 template args used in the function parm list with our own
15703 template parms. Discard them. */
15707 }
15710 {
15715 }
15718 }
15720 /* PARM is a template class (perhaps with unbound template
15721 parameters). ARG is a fully instantiated type. If ARG can be
15722 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15723 TARGS are as for unify. */
15725 static tree
15728 {
15729 tree copy_of_targs;
15736 /* We need to make a new template argument vector for the call to
15737 unify. If we used TARGS, we'd clutter it up with the result of
15738 the attempted unification, even if this class didn't work out.
15739 We also don't want to commit ourselves to all the unifications
15740 we've already done, since unification is supposed to be done on
15741 an argument-by-argument basis. In other words, consider the
15742 following pathological case:
15744 template <int I, int J, int K>
15745 struct S {};
15747 template <int I, int J>
15748 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15750 template <int I, int J, int K>
15751 void f(S<I, J, K>, S<I, I, I>);
15753 void g() {
15754 S<0, 0, 0> s0;
15755 S<0, 1, 2> s2;
15757 f(s0, s2);
15758 }
15760 Now, by the time we consider the unification involving `s2', we
15761 already know that we must have `f<0, 0, 0>'. But, even though
15762 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15763 because there are two ways to unify base classes of S<0, 1, 2>
15764 with S<I, I, I>. If we kept the already deduced knowledge, we
15765 would reject the possibility I=1. */
15768 /* If unification failed, we're done. */
15774 }
15776 /* Given a template type PARM and a class type ARG, find the unique
15777 base type in ARG that is an instance of PARM. We do not examine
15778 ARG itself; only its base-classes. If there is not exactly one
15779 appropriate base class, return NULL_TREE. PARM may be the type of
15780 a partial specialization, as well as a plain template type. Used
15781 by unify. */
15783 static enum template_base_result
15786 {
15788 tree binfo;
15794 {
15795 /* The type could not be completed. */
15798 }
15800 /* Walk in inheritance graph order. The search order is not
15801 important, and this avoids multiple walks of virtual bases. */
15803 {
15808 {
15809 /* If there is more than one satisfactory baseclass, then:
15811 [temp.deduct.call]
15813 If they yield more than one possible deduced A, the type
15814 deduction fails.
15816 applies. */
15818 {
15821 }
15824 }
15825 }
15829 }
15831 /* Returns the level of DECL, which declares a template parameter. */
15833 static int
15835 {
15837 {
15847 }
15849 }
15851 /* Decide whether ARG can be unified with PARM, considering only the
15852 cv-qualifiers of each type, given STRICT as documented for unify.
15853 Returns nonzero iff the unification is OK on that basis. */
15855 static int
15857 {
15863 {
15864 /* Although a CVR qualifier is ignored when being applied to a
15865 substituted template parameter ([8.3.2]/1 for example), that
15866 does not allow us to unify "const T" with "int&" because both
15867 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15868 It is ok when we're allowing additional CV qualifiers
15869 at the outer level [14.8.2.1]/3,1st bullet. */
15879 }
15890 }
15892 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15893 void
15895 {
15899 {
15902 }
15903 else
15904 {
15907 }
15908 }
15910 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15911 do { \
15912 if (unify (TP, TA, P, A, S, EP)) \
15913 return 1; \
15914 } while (0);
15916 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15917 expansion at the end of PACKED_PARMS. Returns 0 if the type
15918 deduction succeeds, 1 otherwise. STRICT is the same as in
15919 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15920 call argument list. We'll need to adjust the arguments to make them
15921 types. SUBR tells us if this is from a recursive call to
15922 type_unification_real, or for comparing two template argument
15923 lists. */
15925 static int
15929 {
15930 tree parm
15937 /* Determine the parameter packs we will be deducing from the
15938 pattern, and record their current deductions. */
15941 {
15945 /* Determine the index and level of this parameter pack. */
15948 /* Keep track of the parameter packs and their corresponding
15949 argument packs. */
15952 }
15954 /* Loop through all of the arguments that have not yet been
15955 unified and unify each with the pattern. */
15957 {
15958 tree parm;
15962 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
15963 or the element of its argument pack at the current index if
15964 this argument was explicitly specified. */
15966 {
15975 {
15978 }
15980 }
15982 /* If we had explicit template arguments, substitute them into the
15983 pattern before deduction. */
15985 {
15986 /* Some arguments might still be unspecified or dependent. */
15994 NULL_TREE);
15999 }
16000 else
16003 /* Unify the pattern with the current argument. */
16008 /* For each parameter pack, collect the deduced value. */
16010 {
16016 }
16017 }
16019 /* Verify that the results of unification with the parameter packs
16020 produce results consistent with what we've seen before, and make
16021 the deduced argument packs available. */
16023 {
16030 /* By default keep the original deduced argument pack.
16031 If necessary, more specific code is going to update the
16032 resulting deduced argument later down in this function. */
16036 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16037 actually deduce anything. */
16045 {
16046 /* If we had fewer function args than explicit template args,
16047 just use the explicits. */
16052 }
16055 {
16056 tree result;
16057 /* Build the deduced *_ARGUMENT_PACK. */
16059 {
16064 }
16065 else
16070 /* Note the deduced argument packs for this parameter
16071 pack. */
16073 }
16077 {
16078 /* We only had the explicitly-provided arguments before, but
16079 now we have a complete set of arguments. */
16085 }
16086 else
16087 {
16093 /* Inconsistent unification of this parameter pack. */
16095 bad_old_arg,
16096 bad_new_arg);
16097 }
16098 }
16101 }
16103 /* Deduce the value of template parameters. TPARMS is the (innermost)
16104 set of template parameters to a template. TARGS is the bindings
16105 for those template parameters, as determined thus far; TARGS may
16106 include template arguments for outer levels of template parameters
16107 as well. PARM is a parameter to a template function, or a
16108 subcomponent of that parameter; ARG is the corresponding argument.
16109 This function attempts to match PARM with ARG in a manner
16110 consistent with the existing assignments in TARGS. If more values
16111 are deduced, then TARGS is updated.
16113 Returns 0 if the type deduction succeeds, 1 otherwise. The
16114 parameter STRICT is a bitwise or of the following flags:
16116 UNIFY_ALLOW_NONE:
16117 Require an exact match between PARM and ARG.
16118 UNIFY_ALLOW_MORE_CV_QUAL:
16119 Allow the deduced ARG to be more cv-qualified (by qualification
16120 conversion) than ARG.
16121 UNIFY_ALLOW_LESS_CV_QUAL:
16122 Allow the deduced ARG to be less cv-qualified than ARG.
16123 UNIFY_ALLOW_DERIVED:
16124 Allow the deduced ARG to be a template base class of ARG,
16125 or a pointer to a template base class of the type pointed to by
16126 ARG.
16127 UNIFY_ALLOW_INTEGER:
16128 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16129 case for more information.
16130 UNIFY_ALLOW_OUTER_LEVEL:
16131 This is the outermost level of a deduction. Used to determine validity
16132 of qualification conversions. A valid qualification conversion must
16133 have const qualified pointers leading up to the inner type which
16134 requires additional CV quals, except at the outer level, where const
16135 is not required [conv.qual]. It would be normal to set this flag in
16136 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16137 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16138 This is the outermost level of a deduction, and PARM can be more CV
16139 qualified at this point.
16140 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16141 This is the outermost level of a deduction, and PARM can be less CV
16142 qualified at this point. */
16144 static int
16147 {
16149 tree targ;
16150 tree tparm;
16153 /* I don't think this will do the right thing with respect to types.
16154 But the only case I've seen it in so far has been array bounds, where
16155 signedness is the only information lost, and I think that will be
16156 okay. */
16164 /* We can't deduce anything from this, but we might get all the
16165 template args from other function args. */
16168 /* If PARM uses template parameters, then we can't bail out here,
16169 even if ARG == PARM, since we won't record unifications for the
16170 template parameters. We might need them if we're trying to
16171 figure out which of two things is more specialized. */
16175 /* Handle init lists early, so the rest of the function can assume
16176 we're dealing with a type. */
16178 {
16183 /* Replace T with std::initializer_list<T> for deduction. */
16189 /* We can only deduce from an initializer list argument if the
16190 parameter is std::initializer_list; otherwise this is a
16191 non-deduced context. */
16197 {
16204 {
16206 /* It should only be possible to get here for a call. */
16208 elt_strict |= maybe_adjust_types_for_deduction
16211 }
16214 explain_p);
16215 }
16217 /* If the std::initializer_list<T> deduction worked, replace the
16218 deduced A with std::initializer_list<A>. */
16220 {
16225 }
16227 }
16229 /* Immediately reject some pairs that won't unify because of
16230 cv-qualification mismatches. */
16233 /* It is the elements of the array which hold the cv quals of an array
16234 type, and the elements might be template type parms. We'll check
16235 when we recurse. */
16237 /* We check the cv-qualifiers when unifying with template type
16238 parameters below. We want to allow ARG `const T' to unify with
16239 PARM `T' for example, when computing which of two templates
16240 is more specialized, for example. */
16254 {
16258 /* In a type which contains a nested-name-specifier, template
16259 argument values cannot be deduced for template parameters used
16260 within the nested-name-specifier. */
16272 /* The PARM is not one we're trying to unify. Just check
16273 to see if it matches ARG. */
16274 {
16279 else
16281 }
16288 /* Check for mixed types and values. */
16296 {
16297 /* ARG must be constructed from a template class or a template
16298 template parameter. */
16303 {
16307 tree parm_parms
16308 = DECL_INNERMOST_TEMPLATE_PARMS
16313 /* The resolution to DR150 makes clear that default
16314 arguments for an N-argument may not be used to bind T
16315 to a template template parameter with fewer than N
16316 parameters. It is not safe to permit the binding of
16317 default arguments as an extension, as that may change
16318 the meaning of a conforming program. Consider:
16320 struct Dense { static const unsigned int dim = 1; };
16322 template <template <typename> class View,
16323 typename Block>
16324 void operator+(float, View<Block> const&);
16326 template <typename Block,
16327 unsigned int Dim = Block::dim>
16328 struct Lvalue_proxy { operator float() const; };
16330 void
16331 test_1d (void) {
16332 Lvalue_proxy<Dense> p;
16333 float b;
16334 b + p;
16335 }
16337 Here, if Lvalue_proxy is permitted to bind to View, then
16338 the global operator+ will be used; if they are not, the
16339 Lvalue_proxy will be converted to float. */
16341 full_argvec,
16343 (explain_p
16344 ? tf_warning_or_error
16351 /* Deduce arguments T, i from TT<T> or TT<i>.
16352 We check each element of PARMVEC and ARGVEC individually
16353 rather than the whole TREE_VEC since they can have
16354 different number of elements. */
16361 /* Check if the parameters end in a pack, making them
16362 variadic. */
16372 {
16377 }
16382 DEDUCE_EXACT,
16385 }
16388 /* Fall through to deduce template name. */
16389 }
16393 {
16394 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16396 /* Simple cases: Value already set, does match or doesn't. */
16401 }
16402 else
16403 {
16404 /* If PARM is `const T' and ARG is only `int', we don't have
16405 a match unless we are allowing additional qualification.
16406 If ARG is `const int' and PARM is just `T' that's OK;
16407 that binds `const int' to `T'. */
16412 /* Consider the case where ARG is `const volatile int' and
16413 PARM is `const T'. Then, T should be `volatile int'. */
16414 arg = cp_build_qualified_type_real
16419 /* Simple cases: Value already set, does match or doesn't. */
16425 /* Make sure that ARG is not a variable-sized array. (Note
16426 that were talking about variable-sized arrays (like
16427 `int[n]'), rather than arrays of unknown size (like
16428 `int[]').) We'll get very confused by such a type since
16429 the bound of the array is not constant, and therefore
16430 not mangleable. Besides, such types are not allowed in
16431 ISO C++, so we can do as we please here. We do allow
16432 them for 'auto' deduction, since that isn't ABI-exposed. */
16436 /* Strip typedefs as in convert_template_argument. */
16438 }
16440 /* If ARG is a parameter pack or an expansion, we cannot unify
16441 against it unless PARM is also a parameter pack. */
16446 /* If the argument deduction results is a METHOD_TYPE,
16447 then there is a problem.
16448 METHOD_TYPE doesn't map to any real C++ type the result of
16449 the deduction can not be of that type. */
16463 {
16464 /* The PARM is not one we're trying to unify. Just check
16465 to see if it matches ARG. */
16471 }
16477 {
16482 }
16484 /* [temp.deduct.type] If, in the declaration of a function template
16485 with a non-type template-parameter, the non-type
16486 template-parameter is used in an expression in the function
16487 parameter-list and, if the corresponding template-argument is
16488 deduced, the template-argument type shall match the type of the
16489 template-parameter exactly, except that a template-argument
16490 deduced from an array bound may be of any integral type.
16491 The non-type parameter might use already deduced type parameters. */
16494 /* Template-parameter dependent expression. Just accept it for now.
16495 It will later be processed in convert_template_argument. */
16496 ;
16502 /* Convert the ARG to the type of PARM; the deduced non-type
16503 template argument must exactly match the types of the
16504 corresponding parameter. */
16507 /* We haven't deduced the type of this parameter yet. Try again
16508 later. */
16510 else
16513 /* If ARG is a parameter pack or an expansion, we cannot unify
16514 against it unless PARM is also a parameter pack. */
16523 {
16524 /* A pointer-to-member constant can be unified only with
16525 another constant. */
16529 /* Just unify the class member. It would be useless (and possibly
16530 wrong, depending on the strict flags) to unify also
16531 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16532 arg refer to the same variable, even if through different
16533 classes. For instance:
16535 struct A { int x; };
16536 struct B : A { };
16538 Unification of &A::x and &B::x must succeed. */
16541 }
16544 {
16548 /* [temp.deduct.call]
16550 A can be another pointer or pointer to member type that can
16551 be converted to the deduced A via a qualification
16552 conversion (_conv.qual_).
16554 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16555 This will allow for additional cv-qualification of the
16556 pointed-to types if appropriate. */
16559 /* The derived-to-base conversion only persists through one
16560 level of pointers. */
16565 }
16580 {
16581 tree parm_max;
16582 tree arg_max;
16586 /* Our representation of array types uses "N - 1" as the
16587 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16588 not an integer constant. We cannot unify arbitrarily
16589 complex expressions, so we eliminate the MINUS_EXPRs
16590 here. */
16594 {
16597 }
16601 {
16602 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16603 trying to unify the type of a variable with the type
16604 of a template parameter. For example:
16606 template <unsigned int N>
16607 void f (char (&) [N]);
16608 int g();
16609 void h(int i) {
16610 char a[g(i)];
16611 f(a);
16612 }
16614 Here, the type of the ARG will be "int [g(i)]", and
16615 may be a SAVE_EXPR, etc. */
16619 }
16621 /* If only one of the bounds used a MINUS_EXPR, compensate
16622 by adding one to the other bound. */
16625 integer_type_node,
16626 parm_max,
16627 integer_one_node);
16630 integer_type_node,
16631 arg_max,
16632 integer_one_node);
16636 }
16651 /* We have already checked cv-qualification at the top of the
16652 function. */
16656 /* As far as unification is concerned, this wins. Later checks
16657 will invalidate it if necessary. */
16660 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16661 /* Type INTEGER_CST can come from ordinary constant template args. */
16673 {
16683 /* Check for pack expansions in the parameters. */
16685 {
16687 {
16689 /* We can unify against something with a trailing
16690 parameter pack. */
16692 else
16693 /* [temp.deduct.type]/9: If the template argument list of
16694 P contains a pack expansion that is not the last
16695 template argument, the entire template argument list
16696 is a non-deduced context. */
16698 }
16699 }
16701 /* If we don't have enough arguments to satisfy the parameters
16702 (not counting the pack expression at the end), or we have
16703 too many arguments for a parameter list that doesn't end in
16704 a pack expression, we can't unify. */
16710 /* Unify all of the parameters that precede the (optional)
16711 pack expression. */
16713 {
16718 }
16721 DEDUCE_EXACT,
16724 }
16732 {
16740 }
16743 {
16747 {
16748 /* First, we try to unify the PARM and ARG directly. */
16753 {
16754 /* Fallback to the special case allowed in
16755 [temp.deduct.call]:
16757 If P is a class, and P has the form
16758 template-id, then A can be a derived class of
16759 the deduced A. Likewise, if P is a pointer to
16760 a class of the form template-id, A can be a
16761 pointer to a derived class pointed to by the
16762 deduced A. */
16769 }
16770 }
16774 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16775 Then, we should unify `int' and `U'. */
16777 else
16778 /* There's no chance of unification succeeding. */
16783 }
16790 {
16793 tree a;
16799 /* CV qualifications for methods can never be deduced, they must
16800 match exactly. We need to check them explicitly here,
16801 because type_unification_real treats them as any other
16802 cv-qualified parameter. */
16804 && (!check_cv_quals_for_unify
16824 }
16827 /* Unify a pointer to member with a pointer to member function, which
16828 deduces the type of the member as a function type. */
16830 {
16831 tree method_type;
16832 tree fntype;
16834 /* Check top-level cv qualifiers */
16842 /* Determine the type of the function we are unifying against. */
16844 fntype =
16848 /* Extract the cv-qualifiers of the member function from the
16849 implicit object parameter and place them on the function
16850 type to be restored later. */
16853 }
16872 /* Matched cases are handled by the ARG == PARM test above. */
16876 /* A non-type template parameter that is a variable should be a
16877 an integral constant, in which case, it whould have been
16878 folded into its (constant) value. So we should not be getting
16879 a variable here. */
16890 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16891 or UNDERLYING_TYPE nodes. */
16895 /* Unification fails if we hit an error node. */
16899 /* An unresolved overload is a nondeduced context. */
16904 /* We must be looking at an expression. This can happen with
16905 something like:
16907 template <int I>
16908 void foo(S<I>, S<I + 2>);
16910 This is a "nondeduced context":
16912 [deduct.type]
16914 The nondeduced contexts are:
16916 --A type that is a template-id in which one or more of
16917 the template-arguments is an expression that references
16918 a template-parameter.
16920 In these cases, we assume deduction succeeded, but don't
16921 actually infer any unifications. */
16926 else
16928 }
16929 }
16930 #undef RECUR_AND_CHECK_FAILURE
16931 \f
16932 /* Note that DECL can be defined in this translation unit, if
16933 required. */
16935 static void
16937 {
16938 tree clone;
16942 }
16944 /* Called if RESULT is explicitly instantiated, or is a member of an
16945 explicitly instantiated class. */
16947 void
16949 {
16952 /* If this entity has already been written out, it's too late to
16953 make any modifications. */
16958 /* The TREE_PUBLIC flag for function declarations will have been
16959 set correctly by tsubst. */
16962 /* This might have been set by an earlier implicit instantiation. */
16967 else
16968 {
16970 /* Always make artificials weak. */
16973 /* For WIN32 we also want to put explicit instantiations in
16974 linkonce sections. */
16977 }
16979 /* If EXTERN_P, then this function will not be emitted -- unless
16980 followed by an explicit instantiation, at which point its linkage
16981 will be adjusted. If !EXTERN_P, then this function will be
16982 emitted here. In neither circumstance do we want
16983 import_export_decl to adjust the linkage. */
16985 }
16987 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16988 important template arguments. If any are missing, we check whether
16989 they're important by using error_mark_node for substituting into any
16990 args that were used for partial ordering (the ones between ARGS and END)
16991 and seeing if it bubbles up. */
16993 static bool
16995 {
17000 {
17003 }
17005 {
17007 {
17011 }
17012 }
17014 }
17016 /* Given two function templates PAT1 and PAT2, return:
17018 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17019 -1 if PAT2 is more specialized than PAT1.
17020 0 if neither is more specialized.
17022 LEN indicates the number of parameters we should consider
17023 (defaulted parameters should not be considered).
17025 The 1998 std underspecified function template partial ordering, and
17026 DR214 addresses the issue. We take pairs of arguments, one from
17027 each of the templates, and deduce them against each other. One of
17028 the templates will be more specialized if all the *other*
17029 template's arguments deduce against its arguments and at least one
17030 of its arguments *does* *not* deduce against the other template's
17031 corresponding argument. Deduction is done as for class templates.
17032 The arguments used in deduction have reference and top level cv
17033 qualifiers removed. Iff both arguments were originally reference
17034 types *and* deduction succeeds in both directions, the template
17035 with the more cv-qualified argument wins for that pairing (if
17036 neither is more cv-qualified, they both are equal). Unlike regular
17037 deduction, after all the arguments have been deduced in this way,
17038 we do *not* verify the deduced template argument values can be
17039 substituted into non-deduced contexts.
17041 The logic can be a bit confusing here, because we look at deduce1 and
17042 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17043 can find template arguments for pat1 to make arg1 look like arg2, that
17044 means that arg2 is at least as specialized as arg1. */
17046 int
17048 {
17061 /* Remove the this parameter from non-static member functions. If
17062 one is a non-static member function and the other is not a static
17063 member function, remove the first parameter from that function
17064 also. This situation occurs for operator functions where we
17065 locate both a member function (with this pointer) and non-member
17066 operator (with explicit first operand). */
17068 {
17073 }
17075 {
17078 {
17079 len--;
17081 }
17082 }
17084 /* If only one is a conversion operator, they are unordered. */
17088 /* Consider the return type for a conversion function */
17090 {
17093 len++;
17094 }
17096 processing_template_decl++;
17102 /* Stop when an ellipsis is seen. */
17104 {
17113 {
17114 /* When both arguments are pack expansions, we need only
17115 unify the patterns themselves. */
17119 /* This is the last comparison we need to do. */
17121 }
17124 {
17127 }
17130 {
17133 }
17136 {
17137 /* Only of the args is a reference, see if we should apply
17138 array/function pointer decay to it. This is not part of
17139 DR214, but is, IMHO, consistent with the deduction rules
17140 for the function call itself, and with our earlier
17141 implementation of the underspecified partial ordering
17142 rules. (nathan). */
17144 {
17146 {
17149 /* FALLTHROUGH. */
17156 }
17157 }
17158 else
17159 {
17161 {
17164 /* FALLTHROUGH. */
17171 }
17172 }
17173 }
17179 {
17185 /* Setup the parameter vector, which contains only ARG1. */
17188 /* Setup the argument vector, which contains the remaining
17189 arguments. */
17198 /* We cannot deduce in the other direction, because ARG1 is
17199 a pack expansion but ARG2 is not. */
17201 }
17203 {
17209 /* Setup the parameter vector, which contains only ARG1. */
17212 /* Setup the argument vector, which contains the remaining
17213 arguments. */
17222 /* We cannot deduce in the other direction, because ARG2 is
17223 a pack expansion but ARG1 is not.*/
17225 }
17227 else
17228 {
17229 /* The normal case, where neither argument is a pack
17230 expansion. */
17237 }
17239 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17240 arg2, then arg2 is not as specialized as arg1. */
17246 /* "If, for a given type, deduction succeeds in both directions
17247 (i.e., the types are identical after the transformations above)
17248 and if the type from the argument template is more cv-qualified
17249 than the type from the parameter template (as described above)
17250 that type is considered to be more specialized than the other. If
17251 neither type is more cv-qualified than the other then neither type
17252 is more specialized than the other." */
17256 {
17261 }
17264 /* We've failed to deduce something in either direction.
17265 These must be unordered. */
17270 /* We have already processed all of the arguments in our
17271 handing of the pack expansion type. */
17276 }
17278 /* "In most cases, all template parameters must have values in order for
17279 deduction to succeed, but for partial ordering purposes a template
17280 parameter may remain without a value provided it is not used in the
17281 types being used for partial ordering."
17283 Thus, if we are missing any of the targs1 we need to substitute into
17284 origs1, then pat2 is not as specialized as pat1. This can happen when
17285 there is a nondeduced context. */
17291 processing_template_decl--;
17293 /* All things being equal, if the next argument is a pack expansion
17294 for one function but not for the other, prefer the
17295 non-variadic function. FIXME this is bogus; see c++/41958. */
17299 {
17302 }
17308 else
17310 }
17312 /* Determine which of two partial specializations is more specialized.
17314 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17315 to the first partial specialization. The TREE_VALUE is the
17316 innermost set of template parameters for the partial
17317 specialization. PAT2 is similar, but for the second template.
17319 Return 1 if the first partial specialization is more specialized;
17320 -1 if the second is more specialized; 0 if neither is more
17321 specialized.
17323 See [temp.class.order] for information about determining which of
17324 two templates is more specialized. */
17326 static int
17328 {
17329 tree targs;
17337 /* Just like what happens for functions, if we are ordering between
17338 different class template specializations, we may encounter dependent
17339 types in the arguments, and we need our dependency check functions
17340 to behave correctly. */
17346 {
17349 }
17355 {
17358 }
17361 /* In the case of a tie where at least one of the class templates
17362 has a parameter pack at the end, the template with the most
17363 non-packed parameters wins. */
17365 && any_deductions
17368 {
17374 /* We don't count the pack expansion at the end. */
17384 }
17387 }
17389 /* Return the template arguments that will produce the function signature
17390 DECL from the function template FN, with the explicit template
17391 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17392 also match. Return NULL_TREE if no satisfactory arguments could be
17393 found. */
17395 static tree
17397 {
17400 tree decl_type;
17401 tree decl_arg_types;
17404 tree arg;
17406 /* Substitute the explicit template arguments into the type of DECL.
17407 The call to fn_type_unification will handle substitution into the
17408 FN. */
17411 {
17412 tree tmpl;
17413 tree converted_args;
17417 else
17418 /* We can get here for some invalid specializations. */
17421 converted_args
17424 tf_none,
17433 }
17435 /* Never do unification on the 'this' parameter. */
17454 }
17456 /* Return the innermost template arguments that, when applied to a
17457 template specialization whose innermost template parameters are
17458 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17459 ARGS.
17461 For example, suppose we have:
17463 template <class T, class U> struct S {};
17464 template <class T> struct S<T*, int> {};
17466 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17467 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17468 int}. The resulting vector will be {double}, indicating that `T'
17469 is bound to `double'. */
17471 static tree
17473 {
17475 tree deduced_args;
17476 tree innermost_deduced_args;
17480 {
17484 innermost_deduced_args);
17485 }
17486 else
17499 /* Verify that nondeduced template arguments agree with the type
17500 obtained from argument deduction.
17502 For example:
17504 struct A { typedef int X; };
17505 template <class T, class U> struct C {};
17506 template <class T> struct C<T, typename T::X> {};
17508 Then with the instantiation `C<A, int>', we can deduce that
17509 `T' is `A' but unify () does not check whether `typename T::X'
17510 is `int'. */
17513 /* We only need to check the innermost arguments; the other
17514 arguments will always agree. */
17519 /* Now that we have bindings for all of the template arguments,
17520 ensure that the arguments deduced for the template template
17521 parameters have compatible template parameter lists. See the use
17522 of template_template_parm_bindings_ok_p in fn_type_unification
17523 for more information. */
17528 }
17530 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17531 Return the TREE_LIST node with the most specialized template, if
17532 any. If there is no most specialized template, the error_mark_node
17533 is returned.
17535 Note that this function does not look at, or modify, the
17536 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17537 returned is one of the elements of INSTANTIATIONS, callers may
17538 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17539 and retrieve it from the value returned. */
17541 tree
17543 {
17550 {
17556 fate--;
17561 fate++;
17566 {
17567 /* Equally specialized, move to next function. If there
17568 is no next function, nothing's most specialized. */
17573 }
17574 }
17577 /* Now verify that champ is better than everything earlier in the
17578 instantiation list. */
17586 {
17589 }
17591 processing_template_decl--;
17597 }
17599 /* If DECL is a specialization of some template, return the most
17600 general such template. Otherwise, returns NULL_TREE.
17602 For example, given:
17604 template <class T> struct S { template <class U> void f(U); };
17606 if TMPL is `template <class U> void S<int>::f(U)' this will return
17607 the full template. This function will not trace past partial
17608 specializations, however. For example, given in addition:
17610 template <class T> struct S<T*> { template <class U> void f(U); };
17612 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17613 `template <class T> template <class U> S<T*>::f(U)'. */
17615 tree
17617 {
17618 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17619 an immediate specialization. */
17621 {
17625 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17626 template friend. */
17631 }
17633 /* Look for more and more general templates. */
17635 {
17636 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17637 (See cp-tree.h for details.) */
17645 /* Stop if we run into an explicitly specialized class template. */
17652 }
17655 }
17657 /* Return the most specialized of the class template partial
17658 specializations of TMPL which can produce TYPE, a specialization of
17659 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17660 a _TYPE node corresponding to the partial specialization, while the
17661 TREE_PURPOSE is the set of template arguments that must be
17662 substituted into the TREE_TYPE in order to generate TYPE.
17664 If the choice of partial specialization is ambiguous, a diagnostic
17665 is issued, and the error_mark_node is returned. If there are no
17666 partial specializations of TMPL matching TYPE, then NULL_TREE is
17667 returned. */
17669 static tree
17671 {
17673 tree t;
17674 tree champ;
17677 tree args;
17683 /* For determining which partial specialization to use, only the
17684 innermost args are interesting. */
17686 {
17689 }
17692 {
17693 tree partial_spec_args;
17694 tree spec_args;
17702 {
17705 /* Discard the outer levels of args, and then substitute in the
17706 template args from the enclosing class. */
17708 partial_spec_args = tsubst_template_args
17711 /* PARMS already refers to just the innermost parms, but the
17712 template parms in partial_spec_args had their levels lowered
17713 by tsubst, so we need to do the same for the parm list. We
17714 can't just tsubst the TREE_VEC itself, as tsubst wants to
17715 treat a TREE_VEC as an argument vector. */
17721 }
17723 partial_spec_args =
17726 partial_spec_args),
17737 partial_spec_args,
17738 args);
17740 {
17745 }
17746 }
17756 {
17759 ;
17760 else
17761 {
17763 {
17766 {
17769 }
17770 }
17772 }
17773 }
17777 {
17780 {
17783 }
17784 }
17787 {
17795 {
17798 }
17801 }
17804 }
17806 /* Explicitly instantiate DECL. */
17808 void
17810 {
17815 /* An error occurred, for which grokdeclarator has already issued
17816 an appropriate message. */
17819 {
17822 }
17824 {
17825 /* There is an asymmetry here in the way VAR_DECLs and
17826 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17827 the latter, the DECL we get back will be marked as a
17828 template instantiation, and the appropriate
17829 DECL_TEMPLATE_INFO will be set up. This does not happen for
17830 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17831 should handle VAR_DECLs as it currently handles
17832 FUNCTION_DECLs. */
17834 {
17837 }
17840 {
17843 }
17845 {
17850 }
17851 }
17853 {
17856 }
17857 else
17860 /* Check for various error cases. Note that if the explicit
17861 instantiation is valid the RESULT will currently be marked as an
17862 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17863 until we get here. */
17866 {
17867 /* DR 259 [temp.spec].
17869 Both an explicit instantiation and a declaration of an explicit
17870 specialization shall not appear in a program unless the explicit
17871 instantiation follows a declaration of the explicit specialization.
17873 For a given set of template parameters, if an explicit
17874 instantiation of a template appears after a declaration of an
17875 explicit specialization for that template, the explicit
17876 instantiation has no effect. */
17878 }
17880 {
17881 /* [temp.spec]
17883 No program shall explicitly instantiate any template more
17884 than once.
17886 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17887 the first instantiation was `extern' and the second is not,
17888 and EXTERN_P for the opposite case. */
17891 /* If an "extern" explicit instantiation follows an ordinary
17892 explicit instantiation, the template is instantiated. */
17895 }
17897 {
17900 }
17902 {
17905 }
17908 ;
17910 {
17913 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17916 }
17917 else
17925 }
17927 static void
17929 {
17935 {
17938 }
17939 }
17941 /* Called from do_type_instantiation through binding_table_foreach to
17942 do recursive instantiation for the type bound in ENTRY. */
17943 static void
17945 {
17951 }
17953 /* Called from do_type_instantiation to instantiate a member
17954 (a member function or a static member variable) of an
17955 explicitly instantiated class template. */
17956 static void
17958 {
17963 }
17965 /* Perform an explicit instantiation of template class T. STORAGE, if
17966 non-null, is the RID for extern, inline or static. COMPLAIN is
17967 nonzero if this is called from the parser, zero if called recursively,
17968 since the standard is unclear (as detailed below). */
17970 void
17972 {
17982 {
17983 tree tmpl =
17987 else
17990 }
17995 {
17998 t);
18000 }
18003 {
18005 {
18007 {
18010 "ISO C++ 1998 forbids the use of %<extern%> on "
18012 }
18013 else
18015 "ISO C++ forbids the use of %qE"
18017 }
18025 else
18026 {
18028 storage);
18030 }
18031 }
18034 {
18035 /* DR 259 [temp.spec].
18037 Both an explicit instantiation and a declaration of an explicit
18038 specialization shall not appear in a program unless the explicit
18039 instantiation follows a declaration of the explicit specialization.
18041 For a given set of template parameters, if an explicit
18042 instantiation of a template appears after a declaration of an
18043 explicit specialization for that template, the explicit
18044 instantiation has no effect. */
18046 }
18048 {
18049 /* [temp.spec]
18051 No program shall explicitly instantiate any template more
18052 than once.
18054 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18055 instantiation was `extern'. If EXTERN_P then the second is.
18056 These cases are OK. */
18063 /* If we've already instantiated the template, just return now. */
18066 }
18074 {
18075 tree tmp;
18077 /* In contrast to implicit instantiation, where only the
18078 declarations, and not the definitions, of members are
18079 instantiated, we have here:
18081 [temp.explicit]
18083 The explicit instantiation of a class template specialization
18084 implies the instantiation of all of its members not
18085 previously explicitly specialized in the translation unit
18086 containing the explicit instantiation.
18088 Of course, we can't instantiate member template classes, since
18089 we don't have any arguments for them. Note that the standard
18090 is unclear on whether the instantiation of the members are
18091 *explicit* instantiations or not. However, the most natural
18092 interpretation is that it should be an explicit instantiation. */
18107 }
18108 }
18110 /* Given a function DECL, which is a specialization of TMPL, modify
18111 DECL to be a re-instantiation of TMPL with the same template
18112 arguments. TMPL should be the template into which tsubst'ing
18113 should occur for DECL, not the most general template.
18115 One reason for doing this is a scenario like this:
18117 template <class T>
18118 void f(const T&, int i);
18120 void g() { f(3, 7); }
18122 template <class T>
18123 void f(const T& t, const int i) { }
18125 Note that when the template is first instantiated, with
18126 instantiate_template, the resulting DECL will have no name for the
18127 first parameter, and the wrong type for the second. So, when we go
18128 to instantiate the DECL, we regenerate it. */
18130 static void
18132 {
18133 /* The arguments used to instantiate DECL, from the most general
18134 template. */
18135 tree args;
18136 tree code_pattern;
18141 /* Make sure that we can see identifiers, and compute access
18142 correctly. */
18146 {
18147 tree decl_parm;
18148 tree pattern_parm;
18149 tree specs;
18163 specs);
18165 /* Merge parameter declarations. */
18168 pattern_parm
18172 {
18173 tree parm_type;
18174 tree attributes;
18179 NULL_TREE);
18185 {
18188 }
18191 }
18192 /* Merge any parameters that match with the function parameter
18193 pack. */
18195 {
18197 tree expanded_types;
18198 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18199 the parameters in this function parameter pack. */
18204 {
18205 tree parm_type;
18206 tree attributes;
18209 /* Rename the parameter to include the index. */
18218 {
18221 }
18223 }
18224 }
18225 /* Merge additional specifiers from the CODE_PATTERN. */
18229 }
18231 {
18239 }
18240 else
18244 }
18246 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18247 substituted to get DECL. */
18249 tree
18251 {
18254 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18255 for the instantiation. This is not always the most general
18256 template. Consider, for example:
18258 template <class T>
18259 struct S { template <class U> void f();
18260 template <> void f<int>(); };
18262 and an instantiation of S<double>::f<int>. We want TD to be the
18263 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18265 more general template. */
18267 /* We must also deal with friend templates. Given:
18269 template <class T> struct S {
18270 template <class U> friend void f() {};
18271 };
18273 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18274 so far as the language is concerned, but that's still
18275 where we get the pattern for the instantiation from. On
18276 other hand, if the definition comes outside the class, say:
18278 template <class T> struct S {
18279 template <class U> friend void f();
18280 };
18281 template <class U> friend void f() {}
18283 we don't need to look any further. That's what the check for
18284 DECL_INITIAL is for. */
18288 {
18289 /* The present template, TD, should not be a definition. If it
18290 were a definition, we should be using it! Note that we
18291 cannot restructure the loop to just keep going until we find
18292 a template with a definition, since that might go too far if
18293 a specialization was declared, but not defined. */
18297 /* Fetch the more general template. */
18299 }
18302 }
18304 /* Returns true if we need to instantiate this template instance even if we
18305 know we aren't going to emit it.. */
18307 bool
18309 {
18310 /* We always instantiate inline functions so that we can inline them. An
18311 explicit instantiation declaration prohibits implicit instantiation of
18312 non-inline functions. With high levels of optimization, we would
18313 normally inline non-inline functions -- but we're not allowed to do
18314 that for "extern template" functions. Therefore, we check
18315 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18319 /* And we need to instantiate static data members so that
18320 their initializers are available in integral constant
18321 expressions. */
18324 }
18326 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18327 instantiate it now, modifying TREE_TYPE (fn). */
18329 void
18331 {
18345 {
18347 {
18360 }
18361 else
18363 }
18364 else
18365 {
18366 /* This is an implicitly declared function, so NOEX is a list of
18367 other functions to evaluate and merge. */
18368 tree elt;
18371 {
18373 tree subspec;
18377 }
18378 }
18383 {
18386 else
18388 }
18389 }
18391 /* Produce the definition of D, a _DECL generated from a template. If
18392 DEFER_OK is nonzero, then we don't have to actually do the
18393 instantiation now; we just have to do it sometime. Normally it is
18394 an error if this is an explicit instantiation but D is undefined.
18395 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18396 explicitly instantiated class template. */
18398 tree
18401 {
18403 tree gen_args;
18404 tree args;
18405 tree td;
18406 tree code_pattern;
18407 tree spec;
18408 tree gen_tmpl;
18414 /* This function should only be used to instantiate templates for
18415 functions and static member variables. */
18419 /* Variables are never deferred; if instantiation is required, they
18420 are instantiated right away. That allows for better code in the
18421 case that an expression refers to the value of the variable --
18422 if the variable has a constant value the referring expression can
18423 take advantage of that fact. */
18428 /* Don't instantiate cloned functions. Instead, instantiate the
18429 functions they cloned. */
18437 /* D has already been instantiated or explicitly specialized, so
18438 there's nothing for us to do here.
18440 It might seem reasonable to check whether or not D is an explicit
18441 instantiation, and, if so, stop here. But when an explicit
18442 instantiation is deferred until the end of the compilation,
18443 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18444 the instantiation. */
18447 /* Check to see whether we know that this template will be
18448 instantiated in some other file, as with "extern template"
18449 extension. */
18452 /* In general, we do not instantiate such templates. */
18460 /* We should already have the extra args. */
18463 /* And what's in the hash table should match D. */
18467 /* This needs to happen before any tsubsting. */
18473 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18474 for the instantiation. */
18478 /* We should never be trying to instantiate a member of a class
18479 template or partial specialization. */
18484 /* In the case of a friend template whose definition is provided
18485 outside the class, we may have too many arguments. Drop the
18486 ones we don't need. The same is true for specializations. */
18487 args = get_innermost_template_args
18489 else
18495 else
18498 /* We may be in the middle of deferred access check. Disable it now. */
18501 /* Unless an explicit instantiation directive has already determined
18502 the linkage of D, remember that a definition is available for
18503 this entity. */
18513 /* If D is a member of an explicitly instantiated class template,
18514 and no definition is available, treat it like an implicit
18515 instantiation. */
18518 {
18519 /* Leave linkage flags alone on instantiations with anonymous
18520 visibility. */
18522 {
18525 }
18527 }
18532 /* Recheck the substitutions to obtain any warning messages
18533 about ignoring cv qualifiers. Don't do this for artificial decls,
18534 as it breaks the context-sensitive substitution for lambda op(). */
18536 {
18540 /* Make sure that we can see identifiers, and compute access
18541 correctly. D is already the target FUNCTION_DECL with the
18542 right context. */
18546 {
18550 /* Don't simply tsubst the function type, as that will give
18551 duplicate warnings about poor parameter qualifications.
18552 The function arguments are the same as the decl_arguments
18553 without the top level cv qualifiers. */
18555 }
18559 }
18561 /* Defer all other templates, unless we have been explicitly
18562 forbidden from doing so. */
18564 template. */
18565 ! pattern_defined
18566 /* If it's OK to postpone instantiation, do so. */
18567 || defer_ok
18568 /* If this is a static data member that will be defined
18569 elsewhere, we don't want to instantiate the entire data
18570 member, but we do want to instantiate the initializer so that
18571 we can substitute that elsewhere. */
18573 {
18574 /* The definition of the static data member is now required so
18575 we must substitute the initializer. */
18579 {
18580 tree ns;
18581 tree init;
18588 args,
18591 /* Make sure the initializer is still constant, in case of
18592 circular dependency (template/instantiate6.C). */
18593 const_init
18597 LOOKUP_ONLYCONVERTING);
18600 }
18602 /* We restore the source position here because it's used by
18603 add_pending_template. */
18609 /* [temp.explicit]
18611 The definition of a non-exported function template, a
18612 non-exported member function template, or a non-exported
18613 member function or static data member of a class template
18614 shall be present in every translation unit in which it is
18615 explicitly instantiated. */
18619 /* If we're in unevaluated context, we just wanted to get the
18620 constant value; this isn't an odr use, so don't queue
18621 a full instantiation. */
18624 /* ??? Historically, we have instantiated inline functions, even
18625 when marked as "extern template". */
18629 }
18630 /* Tell the repository that D is available in this translation unit
18631 -- and see if it is supposed to be instantiated here. */
18633 {
18634 /* In a PCH file, despite the fact that the repository hasn't
18635 requested instantiation in the PCH it is still possible that
18636 an instantiation will be required in a file that includes the
18637 PCH. */
18640 /* Instantiate inline functions so that the inliner can do its
18641 job, even though we'll not be emitting a copy of this
18642 function. */
18645 }
18651 /* Mark D as instantiated so that recursive calls to
18652 instantiate_decl do not try to instantiate it again. */
18655 /* Regenerate the declaration in case the template has been modified
18656 by a subsequent redeclaration. */
18659 /* We already set the file and line above. Reset them now in case
18660 they changed as a result of calling regenerate_decl_from_template. */
18664 {
18665 tree init;
18668 /* Clear out DECL_RTL; whatever was there before may not be right
18669 since we've reset the type of the declaration. */
18673 /* The initializer is placed in DECL_INITIAL by
18674 regenerate_decl_from_template so we don't need to
18675 push/pop_access_scope again here. Pull it out so that
18676 cp_finish_decl can process it. */
18681 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18682 initializer. That function will defer actual emission until
18683 we have a chance to determine linkage. */
18686 /* Enter the scope of D so that access-checking works correctly. */
18691 }
18695 {
18697 tree subst_decl;
18698 tree tmpl_parm;
18699 tree spec_parm;
18701 /* Save away the current list, in case we are instantiating one
18702 template from within the body of another. */
18705 /* Set up the list of local specializations. */
18708 /* Set up context. */
18711 /* Create substitution entries for the parameters. */
18716 {
18720 }
18722 {
18724 {
18727 }
18728 else
18729 {
18730 /* Register the (value) argument pack as a specialization of
18731 TMPL_PARM, then move on. */
18734 }
18735 }
18738 /* Substitute into the body of the function. */
18743 /* Set the current input_location to the end of the function
18744 so that finish_function knows where we are. */
18747 /* We don't need the local specializations any more. */
18751 /* Finish the function. */
18754 }
18756 /* We're not deferring instantiation any more. */
18762 out:
18770 }
18772 /* Run through the list of templates that we wish we could
18773 instantiate, and instantiate any we can. RETRIES is the
18774 number of times we retry pending template instantiation. */
18776 void
18778 {
18782 /* Instantiating templates may trigger vtable generation. This in turn
18783 may require further template instantiations. We place a limit here
18784 to avoid infinite loop. */
18786 {
18790 " instantiating %q+D, possibly from virtual table generation"
18794 /* Pretend that we defined it. */
18797 }
18799 do
18800 {
18805 {
18810 {
18811 tree fn;
18814 {
18818 fn;
18826 }
18829 }
18830 else
18831 {
18834 {
18835 instantiation
18841 }
18845 }
18848 /* If INSTANTIATION has been instantiated, then we don't
18849 need to consider it again in the future. */
18851 else
18852 {
18855 }
18858 }
18860 }
18864 }
18866 /* Substitute ARGVEC into T, which is a list of initializers for
18867 either base class or a non-static data member. The TREE_PURPOSEs
18868 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18869 instantiate_decl. */
18871 static tree
18873 {
18877 {
18878 tree decl;
18879 tree init;
18885 {
18886 tree expr;
18887 tree arg;
18889 /* Expand the base class expansion type into separate base
18890 classes. */
18892 tf_warning_or_error,
18893 NULL_TREE);
18897 /* We'll be building separate TREE_LISTs of arguments for
18898 each base. */
18904 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18905 expand each argument in the TREE_VALUE of t. */
18912 /* VOID_TYPE_NODE is used to indicate
18913 value-initialization. */
18914 {
18917 }
18918 else
18919 {
18920 /* Substitute parameter packs into each argument in the
18921 TREE_LIST. */
18924 {
18925 tree expanded_exprs;
18927 /* Expand the argument. */
18929 expanded_exprs
18931 tf_warning_or_error,
18932 NULL_TREE);
18936 /* Prepend each of the expanded expressions to the
18937 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18939 {
18944 }
18945 }
18948 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18949 since we built them backwards. */
18951 {
18954 }
18955 }
18956 }
18959 {
18961 {
18965 }
18966 else
18967 {
18981 }
18984 {
18988 }
18989 }
18990 }
18992 }
18994 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
18996 static void
18998 {
19003 else
19005 }
19007 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19008 is the instantiation (which should have been created with
19009 start_enum) and ARGS are the template arguments to use. */
19011 static void
19013 {
19014 tree e;
19020 {
19021 tree value;
19022 tree decl;
19025 /* Note that in a template enum, the TREE_VALUE is the
19026 CONST_DECL, not the corresponding INTEGER_CST. */
19031 /* Give this enumeration constant the correct access. */
19034 /* Actually build the enumerator itself. */
19035 build_enumerator
19037 }
19047 }
19049 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19050 its type -- but without substituting the innermost set of template
19051 arguments. So, innermost set of template parameters will appear in
19052 the type. */
19054 tree
19056 {
19057 tree fn_type;
19058 tree tmpl;
19059 tree targs;
19060 tree tparms;
19068 /* There should be as many levels of arguments as there are levels
19069 of parameters. */
19075 /* No substitution is necessary. */
19076 ;
19077 else
19078 {
19080 tree partial_args;
19082 /* Replace the innermost level of the TARGS with NULL_TREEs to
19083 let tsubst know not to substitute for those parameters. */
19092 /* Make sure that we can see identifiers, and compute access
19093 correctly. */
19097 /* Now, do the (partial) substitution to figure out the
19098 appropriate function type. */
19102 /* Substitute into the template parameters to obtain the real
19103 innermost set of parameters. This step is important if the
19104 innermost set of template parameters contains value
19105 parameters whose types depend on outer template parameters. */
19110 }
19113 }
19115 /* Return truthvalue if we're processing a template different from
19116 the last one involved in diagnostics. */
19117 int
19119 {
19121 }
19123 /* Remember current template involved in diagnostics. */
19124 void
19126 {
19128 }
19132 {
19134 }
19136 /* [temp.param] Check that template non-type parm TYPE is of an allowable
19137 type. Return zero for ok, nonzero for disallowed. Issue error and
19138 warning messages under control of COMPLAIN. */
19140 static int
19142 {
19159 {
19162 else
19164 type);
19165 }
19167 }
19169 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19170 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19172 static bool
19174 {
19175 tree scope;
19177 /* [temp.dep.type]
19179 A type is dependent if it is:
19181 -- a template parameter. Template template parameters are types
19182 for us (since TYPE_P holds true for them) so we handle
19183 them here. */
19187 /* -- a qualified-id with a nested-name-specifier which contains a
19188 class-name that names a dependent type or whose unqualified-id
19189 names a dependent type. */
19192 /* -- a cv-qualified type where the cv-unqualified type is
19193 dependent. */
19195 /* -- a compound type constructed from any dependent type. */
19205 {
19206 tree arg_type;
19211 arg_type;
19216 }
19217 /* -- an array type constructed from any dependent type or whose
19218 size is specified by a constant expression that is
19219 value-dependent.
19221 We checked for type- and value-dependence of the bounds in
19222 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19224 {
19229 }
19231 /* -- a template-id in which either the template name is a template
19232 parameter ... */
19235 /* ... or any of the template arguments is a dependent type or
19236 an expression that is type-dependent or value-dependent. */
19238 && (any_dependent_template_arguments_p
19242 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19243 dependent; if the argument of the `typeof' expression is not
19244 type-dependent, then it should already been have resolved. */
19250 /* A template argument pack is dependent if any of its packed
19251 arguments are. */
19253 {
19259 }
19261 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19262 be template parameters. */
19266 /* The standard does not specifically mention types that are local
19267 to template functions or local classes, but they should be
19268 considered dependent too. For example:
19270 template <int I> void f() {
19271 enum E { a = I };
19272 S<sizeof (E)> s;
19273 }
19275 The size of `E' cannot be known until the value of `I' has been
19276 determined. Therefore, `E' must be considered dependent. */
19280 /* Don't use type_dependent_expression_p here, as it can lead
19281 to infinite recursion trying to determine whether a lambda
19282 nested in a lambda is dependent (c++/47687). */
19286 && (any_dependent_template_arguments_p
19290 /* Other types are non-dependent. */
19292 }
19294 /* Returns TRUE if TYPE is dependent, in the sense of
19295 [temp.dep.type]. Note that a NULL type is considered dependent. */
19297 bool
19299 {
19300 /* If there are no template parameters in scope, then there can't be
19301 any dependent types. */
19303 {
19304 /* If we are not processing a template, then nobody should be
19305 providing us with a dependent type. */
19309 }
19311 /* If the type is NULL, we have not computed a type for the entity
19312 in question; in that case, the type is dependent. */
19316 /* Erroneous types can be considered non-dependent. */
19320 /* If we have not already computed the appropriate value for TYPE,
19321 do so now. */
19323 {
19326 }
19329 }
19331 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19332 lookup. In other words, a dependent type that is not the current
19333 instantiation. */
19335 bool
19337 {
19340 }
19342 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19343 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19344 expression. */
19346 /* Note that this predicate is not appropriate for general expressions;
19347 only constant expressions (that satisfy potential_constant_expression)
19348 can be tested for value dependence.
19350 We should really also have a predicate for "instantiation-dependent".
19352 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19353 (what about instantiation-dependent constant-expressions?)
19354 is_late_template_attribute: defer if instantiation-dependent.
19355 compute_array_index_type: proceed if constant and not t- or v-dependent
19356 if instantiation-dependent, need to remember full expression
19357 uses_template_parms: FIXME - need to audit callers
19358 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19359 dependent_type_p [array_type]: dependent if index type is dependent
19360 (or non-constant?)
19361 static_assert - instantiation-dependent */
19363 bool
19365 {
19369 /* A name declared with a dependent type. */
19374 {
19376 /* A name that has not been looked up -- must be dependent. */
19380 /* A non-type template parm. */
19384 /* A non-type template parm. */
19390 /* A constant with literal type and is initialized
19391 with an expression that is value-dependent. */
19403 /* These expressions are value-dependent if the type to which
19404 the cast occurs is dependent or the expression being casted
19405 is value-dependent. */
19406 {
19412 /* A functional cast has a list of operands. */
19415 {
19416 /* If there are no operands, it must be an expression such
19417 as "int()". This should not happen for aggregate types
19418 because it would form non-constant expressions. */
19423 }
19429 }
19434 /* A `sizeof' expression is value-dependent if the operand is
19435 type-dependent or is a pack expansion. */
19444 /* An 'encode' expression is value-dependent if the operand is
19445 type-dependent. */
19454 {
19457 }
19464 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19465 is value-dependent. */
19466 {
19475 }
19478 {
19482 }
19493 {
19497 }
19500 {
19507 {
19509 /* In a call to a constexpr member function, look through the
19510 implicit ADDR_EXPR on the object argument so that it doesn't
19511 cause the call to be considered value-dependent. We also
19512 look through it in potential_constant_expression. */
19519 }
19521 }
19524 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19525 type-dependent. */
19529 {
19531 tree val;
19536 }
19539 /* Treat a GNU statement expression as dependent to avoid crashing
19540 under fold_non_dependent_expr; it can't be constant. */
19544 /* A constant expression is value-dependent if any subexpression is
19545 value-dependent. */
19547 {
19554 {
19558 {
19561 /* In some cases, some of the operands may be missing.l
19562 (For example, in the case of PREDECREMENT_EXPR, the
19563 amount to increment by may be missing.) That doesn't
19564 make the expression dependent. */
19567 }
19568 }
19572 }
19574 }
19576 /* The expression is not value-dependent. */
19578 }
19580 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19581 [temp.dep.expr]. Note that an expression with no type is
19582 considered dependent. Other parts of the compiler arrange for an
19583 expression with type-dependent subexpressions to have no type, so
19584 this function doesn't have to be fully recursive. */
19586 bool
19588 {
19595 /* An unresolved name is always dependent. */
19600 /* Some expression forms are never type-dependent. */
19613 /* The types of these expressions depends only on the type to which
19614 the cast occurs. */
19623 /* The types of these expressions depends only on the type created
19624 by the expression. */
19627 {
19628 /* For NEW_EXPR tree nodes created inside a template, either
19629 the object type itself or a TREE_LIST may appear as the
19630 operand 1. */
19633 /* This is an array type. We need to check array dimensions
19634 as well. */
19636 || value_dependent_expression_p
19638 else
19640 }
19643 {
19647 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19648 contains an identifier associated by name lookup with one or more
19649 declarations declared with a dependent type, or...a
19650 nested-name-specifier or qualified-id that names a member of an
19651 unknown specialization. */
19654 }
19659 && (any_dependent_template_arguments_p
19671 {
19672 tree elt;
19676 {
19679 }
19681 }
19683 /* A static data member of the current instantiation with incomplete
19684 array type is type-dependent, as the definition and specializations
19685 can have different bounds. */
19693 {
19698 {
19704 }
19705 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19713 {
19718 }
19723 {
19727 }
19729 }
19734 }
19736 /* Like type_dependent_expression_p, but it also works while not processing
19737 a template definition, i.e. during substitution or mangling. */
19739 bool
19741 {
19747 }
19749 /* Returns TRUE if ARGS contains a type-dependent expression. */
19751 bool
19753 {
19755 tree arg;
19758 {
19761 }
19763 }
19765 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19766 expressions) contains any type-dependent expressions. */
19768 bool
19770 {
19776 }
19778 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19779 expressions) contains any value-dependent expressions. */
19781 bool
19783 {
19789 }
19791 /* Returns TRUE if the ARG (a template argument) is dependent. */
19793 bool
19795 {
19799 /* Assume a template argument that was wrongly written by the user
19800 is dependent. This is consistent with what
19801 any_dependent_template_arguments_p [that calls this function]
19802 does. */
19813 {
19817 {
19820 }
19823 }
19826 else
19829 }
19831 /* Returns true if ARGS (a collection of template arguments) contains
19832 any types that require structural equality testing. */
19834 bool
19836 {
19846 {
19849 {
19855 {
19856 /* Look inside the argument pack. */
19859 }
19862 {
19876 }
19877 }
19878 }
19881 }
19883 /* Returns true if ARGS (a collection of template arguments) contains
19884 any dependent arguments. */
19886 bool
19888 {
19898 {
19903 }
19906 }
19908 /* Returns TRUE if the template TMPL is dependent. */
19910 bool
19912 {
19914 {
19916 {
19920 }
19922 }
19924 /* Template template parameters are dependent. */
19928 /* So are names that have not been looked up. */
19932 /* So are member templates of dependent classes. */
19936 }
19938 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19940 bool
19942 {
19945 }
19947 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19948 is dependent. */
19950 bool
19952 {
19959 {
19980 {
19984 }
19988 {
19992 {
19997 }
19998 }
19999 }
20002 }
20004 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
20005 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
20006 no such TYPE can be found. Note that this function peers inside
20007 uninstantiated templates and therefore should be used only in
20008 extremely limited situations. ONLY_CURRENT_P restricts this
20009 peering to the currently open classes hierarchy (which is required
20010 when comparing types). */
20012 tree
20014 {
20015 tree scope;
20016 tree name;
20017 tree decl;
20019 tree pushed_scope;
20020 tree result;
20025 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
20026 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
20027 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
20028 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
20029 identifier of the TYPENAME_TYPE anymore.
20030 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
20031 TYPENAME_TYPE instead, we avoid messing up with a possible
20032 typedef variant case. */
20035 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
20036 it first before we can figure out what NAME refers to. */
20039 /* If we don't know what SCOPE refers to, then we cannot resolve the
20040 TYPENAME_TYPE. */
20043 /* If the SCOPE is a template type parameter, we have no way of
20044 resolving the name. */
20047 /* If the SCOPE is not the current instantiation, there's no reason
20048 to look inside it. */
20051 /* If this is a typedef, we don't want to look inside (c++/11987). */
20054 /* If SCOPE isn't the template itself, it will not have a valid
20055 TYPE_FIELDS list. */
20057 /* scope is either the template itself or a compatible instantiation
20058 like X<T>, so look up the name in the original template. */
20060 else
20061 /* scope is a partial instantiation, so we can't do the lookup or we
20062 will lose the template arguments. */
20064 /* Enter the SCOPE so that name lookup will be resolved as if we
20065 were in the class definition. In particular, SCOPE will no
20066 longer be considered a dependent type. */
20068 /* Look up the declaration. */
20070 tf_warning_or_error);
20074 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
20075 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
20080 {
20084 }
20087 {
20088 tree tmpl;
20089 tree args;
20090 /* Obtain the template and the arguments. */
20093 /* Instantiate the template. */
20099 }
20101 /* Leave the SCOPE. */
20105 /* If we failed to resolve it, return the original typename. */
20109 /* If lookup found a typename type, resolve that too. */
20111 {
20112 /* Ill-formed programs can cause infinite recursion here, so we
20113 must catch that. */
20117 }
20119 /* Qualify the resulting type. */
20125 }
20127 /* EXPR is an expression which is not type-dependent. Return a proxy
20128 for EXPR that can be used to compute the types of larger
20129 expressions containing EXPR. */
20131 tree
20133 {
20134 tree inner_expr;
20136 #ifdef ENABLE_CHECKING
20137 /* Try to get a constant value for all non-type-dependent expressions in
20138 order to expose bugs in *_dependent_expression_p and constexpr. */
20141 #endif
20143 /* Preserve OVERLOADs; the functions must be available to resolve
20144 types. */
20155 /* There is no need to return a proxy for a variable. */
20158 /* Preserve string constants; conversions from string constants to
20159 "char *" are allowed, even though normally a "const char *"
20160 cannot be used to initialize a "char *". */
20163 /* Preserve arithmetic constants, as an optimization -- there is no
20164 reason to create a new node. */
20167 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20168 There is at least one place where we want to know that a
20169 particular expression is a throw-expression: when checking a ?:
20170 expression, there are special rules if the second or third
20171 argument is a throw-expression. */
20175 /* Don't wrap an initializer list, we need to be able to look inside. */
20194 /* If the type is unknown, it can't really be non-dependent */
20197 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20199 }
20201 /* ARGS is a vector of expressions as arguments to a function call.
20202 Replace the arguments with equivalent non-dependent expressions.
20203 This modifies ARGS in place. */
20205 void
20207 {
20209 tree arg;
20212 {
20216 }
20217 }
20219 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20220 with a level one deeper than the actual template parms. */
20222 tree
20224 {
20237 }
20239 /* Given type ARG, return std::initializer_list<ARG>. */
20241 static tree
20243 {
20244 tree std_init_list = namespace_binding
20246 tree argvec;
20248 {
20252 }
20257 }
20259 /* Replace auto in TYPE with std::initializer_list<auto>. */
20261 static tree
20263 {
20270 }
20272 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20273 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20275 tree
20277 {
20288 /* Not enough information to try this yet. */
20291 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20292 with either a new invented type template parameter U or, if the
20293 initializer is a braced-init-list (8.5.4), with
20294 std::initializer_list<U>. */
20310 {
20312 /* Try again at instantiation time. */
20315 /* If type is error_mark_node a diagnostic must have been
20316 emitted by now. Also, having a mention to '<type error>'
20317 in the diagnostic is not really useful to the user. */
20318 {
20322 else
20324 }
20326 }
20328 /* If the list of declarators contains more than one declarator, the type
20329 of each declared variable is determined as described above. If the
20330 type deduced for the template parameter U is not the same in each
20331 deduction, the program is ill-formed. */
20334 {
20340 else
20344 }
20350 }
20352 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20353 result. */
20355 tree
20357 {
20358 tree argvec;
20365 /* For a late-specified return type in a template type-parameter, we
20366 need to add a dummy argument level for its parmlist. */
20367 argvec = add_to_template_args
20372 }
20374 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20376 bool
20378 {
20382 else
20384 }
20386 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20387 appear as a type-specifier for the declaration in question, we don't
20388 have to look through the whole type. */
20390 tree
20392 {
20409 }
20411 /* For a given template T, return the vector of typedefs referenced
20412 in T for which access check is needed at T instantiation time.
20413 T is either a FUNCTION_DECL or a RECORD_TYPE.
20414 Those typedefs were added to T by the function
20415 append_type_to_template_for_access_check. */
20419 {
20420 tree ti;
20431 {
20436 }
20439 }
20441 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20442 tied to T. That list of typedefs will be access checked at
20443 T instantiation time.
20444 T is either a FUNCTION_DECL or a RECORD_TYPE.
20445 TYPE_DECL is a TYPE_DECL node representing a typedef.
20446 SCOPE is the scope through which TYPE_DECL is accessed.
20447 LOCATION is the location of the usage point of TYPE_DECL.
20449 This function is a subroutine of
20450 append_type_to_template_for_access_check. */
20452 static void
20454 tree type_decl,
20455 tree scope,
20456 location_t location)
20457 {
20458 qualified_typedef_usage_t typedef_usage;
20459 tree ti;
20466 && type_decl
20482 }
20484 /* Append TYPE_DECL to the template TEMPL.
20485 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20486 At TEMPL instanciation time, TYPE_DECL will be checked to see
20487 if it can be accessed through SCOPE.
20488 LOCATION is the location of the usage point of TYPE_DECL.
20490 e.g. consider the following code snippet:
20492 class C
20493 {
20494 typedef int myint;
20495 };
20497 template<class U> struct S
20498 {
20499 C::myint mi; // <-- usage point of the typedef C::myint
20500 };
20502 S<char> s;
20504 At S<char> instantiation time, we need to check the access of C::myint
20505 In other words, we need to check the access of the myint typedef through
20506 the C scope. For that purpose, this function will add the myint typedef
20507 and the scope C through which its being accessed to a list of typedefs
20508 tied to the template S. That list will be walked at template instantiation
20509 time and access check performed on each typedefs it contains.
20510 Note that this particular code snippet should yield an error because
20511 myint is private to C. */
20513 void
20515 tree type_decl,
20516 tree scope,
20517 location_t location)
20518 {
20524 /* Make sure we don't append the type to the template twice. */
20533 }
20535 /* Set up the hash tables for template instantiations. */
20537 void
20539 {
20541 hash_specialization,
20542 eq_specializations,
20543 ggc_free);
20545 hash_specialization,
20546 eq_specializations,
20547 ggc_free);
20548 }
20550 /* Print stats about the template hash tables for -fstats. */
20552 void
20554 {
20563 }