| blob | 4980c19ae06993fe5868b4cbc6cf95c951a055ac |
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 the template parameters of T if T is a
2873 primary template instantiation, NULL otherwise. */
2875 tree
2877 {
2882 parms = INNERMOST_TEMPLATE_PARMS
2886 }
2888 /* Return the template parameters of the LEVELth level from the full list
2889 of template parameters PARMS. */
2891 tree
2893 {
2894 tree p;
2905 }
2907 /* Returns the template arguments of T if T is a template instantiation,
2908 NULL otherwise. */
2910 tree
2912 {
2920 }
2922 /* Return the argument pack elements of T if T is a template argument pack,
2923 NULL otherwise. */
2925 tree
2927 {
2933 }
2935 /* Structure used to track the progress of find_parameter_packs_r. */
2936 struct find_parameter_pack_data
2937 {
2938 /* TREE_LIST that will contain all of the parameter packs found by
2939 the traversal. */
2942 /* Set of AST nodes that have been visited by the traversal. */
2944 };
2946 /* Identifies all of the argument packs that occur in a template
2947 argument and appends them to the TREE_LIST inside DATA, which is a
2948 find_parameter_pack_data structure. This is a subroutine of
2949 make_pack_expansion and uses_parameter_packs. */
2950 static tree
2952 {
2958 /* Handle type aliases/typedefs. */
2963 {
2970 }
2972 /* Identify whether this is a parameter pack or not. */
2974 {
2989 {
2990 /* We don't want to walk into the type of a PARM_DECL,
2991 because we don't want to see the type parameter pack. */
2994 }
3001 /* Not a parameter pack. */
3003 }
3006 {
3007 /* Add this parameter pack to the list. */
3009 }
3015 /* This switch statement will return immediately if we don't find a
3016 parameter pack. */
3018 {
3023 /* Check the template itself. */
3026 /* Check the template arguments. */
3042 /* Fall through. */
3084 }
3087 }
3089 /* Determines if the expression or type T uses any parameter packs. */
3090 bool
3092 {
3100 }
3102 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3103 representation a base-class initializer into a parameter pack
3104 expansion. If all goes well, the resulting node will be an
3105 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3106 respectively. */
3107 tree
3109 {
3110 tree result;
3119 {
3120 /* The only time we will see a TREE_LIST here is for a base
3121 class initializer. In this case, the TREE_PURPOSE will be a
3122 _TYPE node (representing the base class expansion we're
3123 initializing) and the TREE_VALUE will be a TREE_LIST
3124 containing the initialization arguments.
3126 The resulting expansion looks somewhat different from most
3127 expansions. Rather than returning just one _EXPANSION, we
3128 return a TREE_LIST whose TREE_PURPOSE is a
3129 TYPE_PACK_EXPANSION containing the bases that will be
3130 initialized. The TREE_VALUE will be identical to the
3131 original TREE_VALUE, which is a list of arguments that will
3132 be passed to each base. We do not introduce any new pack
3133 expansion nodes into the TREE_VALUE (although it is possible
3134 that some already exist), because the TREE_PURPOSE and
3135 TREE_VALUE all need to be expanded together with the same
3136 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3137 resulting TREE_PURPOSE will mention the parameter packs in
3138 both the bases and the arguments to the bases. */
3139 tree purpose;
3140 tree value;
3143 /* Determine which parameter packs will be used by the base
3144 class expansion. */
3151 {
3155 }
3158 {
3159 /* Collect the sets of parameter packs used in each of the
3160 initialization arguments. */
3162 {
3163 /* Determine which parameter packs will be expanded in this
3164 argument. */
3167 }
3168 }
3172 /* Create the pack expansion type for the base type. */
3177 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3178 they will rarely be compared to anything. */
3182 }
3187 /* Build the PACK_EXPANSION_* node. */
3188 result = for_types
3193 {
3194 /* Propagate type and const-expression information. */
3197 }
3198 else
3199 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3200 they will rarely be compared to anything. */
3203 /* Determine which parameter packs will be expanded. */
3209 /* Make sure we found some parameter packs. */
3211 {
3214 else
3217 }
3223 }
3225 /* Checks T for any "bare" parameter packs, which have not yet been
3226 expanded, and issues an error if any are found. This operation can
3227 only be done on full expressions or types (e.g., an expression
3228 statement, "if" condition, etc.), because we could have expressions like:
3230 foo(f(g(h(args)))...)
3232 where "args" is a parameter pack. check_for_bare_parameter_packs
3233 should not be called for the subexpressions args, h(args),
3234 g(h(args)), or f(g(h(args))), because we would produce erroneous
3235 error messages.
3237 Returns TRUE and emits an error if there were bare parameter packs,
3238 returns FALSE otherwise. */
3239 bool
3241 {
3257 {
3260 {
3269 else
3274 else
3278 }
3281 }
3284 }
3286 /* Expand any parameter packs that occur in the template arguments in
3287 ARGS. */
3288 tree
3290 {
3296 /* First, determine if we need to expand anything, and the number of
3297 slots we'll need. */
3299 {
3304 {
3308 else
3310 }
3311 else
3312 {
3314 num_result_args++;
3315 }
3316 }
3318 /* If no expansion is necessary, we're done. */
3322 /* Expand arguments. */
3325 non_default_args_count =
3328 {
3331 {
3338 }
3339 else
3340 {
3343 }
3344 }
3348 }
3350 /* Checks if DECL shadows a template parameter.
3352 [temp.local]: A template-parameter shall not be redeclared within its
3353 scope (including nested scopes).
3355 Emits an error and returns TRUE if the DECL shadows a parameter,
3356 returns FALSE otherwise. */
3358 bool
3360 {
3361 tree olddecl;
3363 /* If we're not in a template, we can't possibly shadow a template
3364 parameter. */
3368 /* Figure out what we're shadowing. */
3373 /* If there's no previous binding for this name, we're not shadowing
3374 anything, let alone a template parameter. */
3378 /* If we're not shadowing a template parameter, we're done. Note
3379 that OLDDECL might be an OVERLOAD (or perhaps even an
3380 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3381 node. */
3385 /* We check for decl != olddecl to avoid bogus errors for using a
3386 name inside a class. We check TPFI to avoid duplicate errors for
3387 inline member templates. */
3395 }
3397 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3398 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3399 template parameters. */
3401 static tree
3406 tree decl,
3407 tree type)
3408 {
3420 }
3422 /* Find the canonical type parameter for the given template type
3423 parameter. Returns the canonical type parameter, which may be TYPE
3424 if no such parameter existed. */
3426 static tree
3428 {
3429 tree list;
3443 else
3444 {
3449 }
3450 }
3452 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3453 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3454 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3455 new one is created. */
3457 static tree
3459 tsubst_flags_t complain)
3460 {
3465 {
3485 /* Template template parameters need this. */
3490 }
3493 }
3495 /* Process information from new template parameter PARM and append it
3496 to the LIST being built. This new parameter is a non-type
3497 parameter iff IS_NON_TYPE is true. This new parameter is a
3498 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3499 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3500 parameter list PARM belongs to. This is used used to create a
3501 proper canonical type for the type of PARM that is to be created,
3502 iff PARM is a type. If the size is not known, this parameter shall
3503 be set to 0. */
3505 tree
3509 {
3511 tree defval;
3512 tree err_parm_list;
3519 {
3523 {
3527 else
3529 }
3532 }
3533 else
3537 {
3543 {
3547 }
3548 else
3549 {
3550 /* [temp.param]
3552 The top-level cv-qualifiers on the template-parameter are
3553 ignored when determining its type. */
3556 {
3560 }
3563 {
3564 /* This template parameter is not a parameter pack, but it
3565 should be. Complain about "bare" parameter packs. */
3568 /* Recover by calling this a parameter pack. */
3570 }
3571 }
3573 /* A template parameter is not modifiable. */
3582 processing_template_decl,
3583 num_template_parms,
3588 }
3589 else
3590 {
3591 tree t;
3595 {
3597 /* This is for distinguishing between real templates and template
3598 template parameters */
3602 }
3603 else
3604 {
3606 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3609 }
3616 processing_template_decl,
3617 num_template_parms,
3621 }
3627 }
3629 /* The end of a template parameter list has been reached. Process the
3630 tree list into a parameter vector, converting each parameter into a more
3631 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3632 as PARM_DECLs. */
3634 tree
3636 {
3641 current_template_parms
3646 {
3650 }
3655 }
3657 /* Create a new type almost identical to TYPE but which has the
3658 following differences:
3660 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3661 template sibling parameters of T.
3663 2/ T has a new canonical type that matches the new number
3664 of sibling parms.
3666 3/ From now on, T is going to be what lookups referring to the
3667 name of TYPE will return. No lookup should return TYPE anymore.
3669 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3671 This is a subroutine of fixup_template_parms. */
3673 static tree
3675 {
3677 tree t;
3678 /* This is the decl which name is inserted into the symbol table for
3679 the template parm type. So whenever we lookup the type name, this
3680 is the DECL we get. */
3681 tree decl;
3683 /* Do not fix up the type twice. */
3698 num_parms,
3709 /* Update the type associated to the type name stored in the symbol
3710 table. Now, whenever the type name is looked up, the resulting
3711 type is properly fixed up. */
3717 }
3719 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3720 identical to I, but that is fixed up as to:
3722 1/ carry the number of sibling parms (NUM_PARMS) of the template
3723 parm represented by I.
3725 2/ replace all references to template parm types declared before I
3726 (in the same template parm list as I) by references to template
3727 parm types contained in ARGS. ARGS should contain the list of
3728 template parms that have been fixed up so far, in a form suitable
3729 to be passed to tsubst.
3731 This is a subroutine of fixup_template_parms. */
3733 static tree
3735 {
3740 /* Do not fix up the index twice. */
3750 num_parms,
3762 }
3764 /*
3765 This is a subroutine of fixup_template_parms.
3767 It computes the canonical type of the type of the template
3768 parameter PARM_DESC and update all references to that type so that
3769 they use the newly computed canonical type. No access check is
3770 performed during the fixup. PARM_DESC is a TREE_LIST which
3771 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3772 default argument of the template parm if any. IDX is the index of
3773 the template parameter, starting at 0. NUM_PARMS is the number of
3774 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3775 TREE_VEC containing the full set of template parameters in a form
3776 suitable to be passed to substs functions as their ARGS
3777 argument. This is what current_template_args returns for a given
3778 template. The innermost vector of args in ARGLIST is the set of
3779 template parms that have been fixed up so far. This function adds
3780 the fixed up parameter into that vector. */
3782 static void
3786 tree arglist)
3787 {
3794 {
3795 /* PARM is a template type parameter. Fix up its type, add
3796 the fixed-up template parm to the vector of fixed-up
3797 template parms so far, and substitute the fixed-up
3798 template parms into the default argument of this
3799 parameter. */
3800 tree t =
3805 }
3807 {
3808 /* PARM is a template template parameter. This is going to
3809 be interesting. */
3813 /* First, fix up the parms of the template template parm
3814 because the parms are involved in defining the new canonical
3815 type of the template template parm. */
3817 /* So we need to substitute the template parm types that have
3818 been fixed up so far into the template parms of this template
3819 template parm. E.g, consider this:
3821 template<class T, template<T u> class TT> class S;
3823 In this case we want to substitute T into the
3824 template parameters of TT.
3826 So let's walk the template parms of PARM here, and
3827 tsubst ARGLIST into into each of the template
3828 parms. */
3830 /* For this substitution we need to build the full set of
3831 template parameters and use that as arguments for the
3832 tsubsting function. */
3835 /* This will contain the innermost parms of PARM into which
3836 we have substituted so far. */
3840 {
3841 tree parameter;
3845 /* INNERMOST_ARGS needs to have at least the same number
3846 of elements as the index PARAMETER, ortherwise
3847 tsubsting into PARAMETER will result in partially
3848 instantiating it, reducing its tempate parm
3849 level. Let's tactically fill INNERMOST_ARGS for that
3850 purpose. */
3856 targs);
3857 }
3859 /* Now fix up the type of the template template parm. */
3866 }
3868 {
3869 /* PARM is a non-type template parameter. We need to:
3871 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3872 proper number of sibling parameters.
3874 * Make lookups of the template parameter return a reference
3875 to the fixed-up index. No lookup should return references
3876 to the former index anymore.
3878 * Substitute the template parms that got fixed up so far
3880 * into the type of PARM. */
3884 /* PUSHED_DECL is the decl added to the symbol table with
3885 the name of the parameter. E,g:
3887 template<class T, T u> //#0
3888 auto my_function(T t) -> decltype(u); //#1
3890 Here, when looking up u at //#1, we get the decl of u
3891 resulting from the declaration in #0. This is what
3892 PUSHED_DECL is. We need to replace the reference to the
3893 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3894 fixed-up TEMPLATE_PARM_INDEX. */
3897 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3898 fixup the type of PUSHED_DECL as well and luckily
3899 fixup_template_parm_index does it for us too. */
3900 tree fixed_up_index =
3905 /* Add this fixed up PARM to the template parms we've fixed
3906 up so far and use that to substitute the fixed-up
3907 template parms into the type of PARM. */
3912 }
3919 }
3921 /* Walk the current template parms and properly compute the canonical
3922 types of the dependent types created during
3923 cp_parser_template_parameter_list. */
3925 void
3927 {
3928 tree arglist;
3929 tree parameter_vec;
3930 tree fixedup_args;
3939 /* This vector contains the current innermost template parms that
3940 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3941 to be passed to tsubst* functions as their ARGS argument. */
3944 /* This vector contains the full set of template parms in a form
3945 suitable to be passed to substs functions as their ARGS
3946 argument. */
3950 /* Let's do the proper fixup now. */
3954 }
3956 /* end_template_decl is called after a template declaration is seen. */
3958 void
3960 {
3966 /* This matches the pushlevel in begin_template_parm_list. */
3971 }
3973 /* Takes a TREE_LIST representing a template parameter and convert it
3974 into an argument suitable to be passed to the type substitution
3975 functions. Note that If the TREE_LIST contains an error_mark
3976 node, the returned argument is error_mark_node. */
3978 static tree
3980 {
3993 {
3997 {
3998 /* Turn this argument into a TYPE_ARGUMENT_PACK
3999 with a single element, which expands T. */
4001 #ifdef ENABLE_CHECKING
4002 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4004 #endif
4009 }
4010 }
4011 else
4012 {
4016 {
4017 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4018 with a single element, which expands T. */
4021 #ifdef ENABLE_CHECKING
4022 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4024 #endif
4030 }
4031 }
4033 }
4035 /* This function returns TRUE if PARM_PACK is a template parameter
4036 pack and if ARG_PACK is what template_parm_to_arg returned when
4037 passed PARM_PACK. */
4039 static bool
4041 {
4042 /* For clarity in the comments below let's use the representation
4043 argument_pack<elements>' to denote an argument pack and its
4044 elements.
4046 In the 'if' block below, we want to detect cases where
4047 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
4048 check if ARG_PACK is an argument pack which sole element is
4049 the expansion of PARM_PACK. That argument pack is typically
4050 created by template_parm_to_arg when passed a parameter
4051 pack. */
4056 {
4059 /* So we have an argument_pack<P...>. We want to test if P
4060 is actually PARM_PACK. We will not use cp_tree_equal to
4061 test P and PARM_PACK because during type fixup (by
4062 fixup_template_parm) P can be a pre-fixup version of a
4063 type and PARM_PACK be its post-fixup version.
4064 cp_tree_equal would consider them as different even
4065 though we would want to consider them compatible for our
4066 precise purpose here.
4068 Thus we are going to consider that P and PARM_PACK are
4069 compatible if they have the same DECL. */
4071 same DECL as parm_pack ... */
4075 /* ... or if PARM_PACK is a non-type parameter named by the
4076 same DECL as ARG_PACK. Note that PARM_PACK being a
4077 non-type parameter means it's either a PARM_DECL or a
4078 TEMPLATE_PARM_INDEX. */
4088 }
4090 }
4092 /* Within the declaration of a template, return all levels of template
4093 parameters that apply. The template parameters are represented as
4094 a TREE_VEC, in the form documented in cp-tree.h for template
4095 arguments. */
4097 static tree
4099 {
4100 tree header;
4105 /* If there is only one level of template parameters, we do not
4106 create a TREE_VEC of TREE_VECs. Instead, we return a single
4107 TREE_VEC containing the arguments. */
4112 {
4120 #ifdef ENABLE_CHECKING
4122 #endif
4126 else
4128 }
4131 /* This can happen for template parms of a template template
4132 parameter, e.g:
4134 template<template<class T, class U> class TT> struct S;
4136 Consider the level of the parms of TT; T and U both have
4137 level 2; TT has no template parm of level 1. So in this case
4138 the first element of full_template_args is NULL_TREE. If we
4139 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4140 of 2. This will make tsubst wrongly consider that T and U
4141 have level 1. Instead, let's create a dummy vector as the
4142 first element of full_template_args so that TMPL_ARG_DEPTH
4143 returns the correct depth for args. */
4146 }
4148 /* Update the declared TYPE by doing any lookups which were thought to be
4149 dependent, but are not now that we know the SCOPE of the declarator. */
4151 tree
4153 {
4164 /* Don't bother building up the args in this case. */
4166 {
4167 /* tsubst in the args corresponding to the template parameters,
4168 including auto if present. Most things will be unchanged, but
4169 make_typename_type and tsubst_qualified_id will resolve
4170 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4173 tree pushed;
4175 {
4179 }
4184 }
4190 {
4193 else
4195 }
4197 }
4199 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4200 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4201 a member template. Used by push_template_decl below. */
4203 static tree
4205 {
4213 }
4215 struct template_parm_data
4216 {
4217 /* The level of the template parameters we are currently
4218 processing. */
4221 /* The index of the specialization argument we are currently
4222 processing. */
4225 /* An array whose size is the number of template parameters. The
4226 elements are nonzero if the parameter has been used in any one
4227 of the arguments processed so far. */
4230 /* An array whose size is the number of template arguments. The
4231 elements are nonzero if the argument makes use of template
4232 parameters of this level. */
4234 };
4236 /* Subroutine of push_template_decl used to see if each template
4237 parameter in a partial specialization is used in the explicit
4238 argument list. If T is of the LEVEL given in DATA (which is
4239 treated as a template_parm_data*), then DATA->PARMS is marked
4240 appropriately. */
4242 static int
4244 {
4250 {
4253 }
4254 else
4255 {
4258 }
4261 {
4264 }
4266 /* Return zero so that for_each_template_parm will continue the
4267 traversal of the tree; we want to mark *every* template parm. */
4269 }
4271 /* Process the partial specialization DECL. */
4273 static tree
4275 {
4281 tree inner_parms;
4282 tree inst;
4295 /* We check that each of the template parameters given in the
4296 partial specialization is used in the argument list to the
4297 specialization. For example:
4299 template <class T> struct S;
4300 template <class T> struct S<T*>;
4302 The second declaration is OK because `T*' uses the template
4303 parameter T, whereas
4305 template <class T> struct S<int>;
4307 is no good. Even trickier is:
4309 template <class T>
4310 struct S1
4311 {
4312 template <class U>
4313 struct S2;
4314 template <class U>
4315 struct S2<T>;
4316 };
4318 The S2<T> declaration is actually invalid; it is a
4319 full-specialization. Of course,
4321 template <class U>
4322 struct S2<T (*)(U)>;
4324 or some such would have been OK. */
4332 {
4337 NULL,
4339 }
4342 {
4343 /* One of the template parms was not used in the
4344 specialization. */
4346 {
4349 }
4352 }
4357 /* [temp.class.spec]
4359 The argument list of the specialization shall not be identical to
4360 the implicit argument list of the primary template. */
4367 /* [temp.class.spec]
4369 A partially specialized non-type argument expression shall not
4370 involve template parameters of the partial specialization except
4371 when the argument expression is a simple identifier.
4373 The type of a template parameter corresponding to a specialized
4374 non-type argument shall not be dependent on a parameter of the
4375 specialization.
4377 Also, we verify that pack expansions only occur at the
4378 end of the argument list. */
4382 {
4389 {
4390 /* Extract the arguments from the argument pack. We'll be
4391 iterating over these in the following loop. */
4394 }
4397 {
4399 /* Get the Jth argument in the parameter pack. */
4403 {
4404 /* Pack expansions must come at the end of the
4405 argument list. */
4408 {
4412 else
4415 }
4416 }
4419 /* We only care about the pattern. */
4425 /* This next line is the `argument expression is not just a
4426 simple identifier' condition and also the `specialized
4427 non-type argument' bit. */
4429 {
4433 arg);
4434 else
4435 {
4436 /* Look at the corresponding template parameter,
4437 marking which template parameters its type depends
4438 upon. */
4442 {
4443 /* We haven't yet initialized TPD2. Do so now. */
4445 /* The number of parameters here is the number in the
4446 main template, which, as checked in the assertion
4447 above, is NARGS. */
4451 }
4453 /* Mark the template parameters. But this time, we're
4454 looking for the template parameters of the main
4455 template, not in the specialization. */
4462 NULL,
4466 {
4467 /* The type depended on some template parameters.
4468 If they are fully specialized in the
4469 specialization, that's OK. */
4478 "type %qT of template argument %qE depends "
4480 "type %qT of template argument %qE depends "
4482 type,
4483 arg);
4484 }
4485 }
4486 }
4487 }
4488 }
4490 /* We should only get here once. */
4500 {
4504 {
4508 "partial specialization of %qT after instantiation "
4510 }
4511 }
4514 }
4516 /* Check that a template declaration's use of default arguments and
4517 parameter packs is not invalid. Here, PARMS are the template
4518 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4519 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4520 specialization.
4523 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4524 declaration (but not a definition); 1 indicates a declaration, 2
4525 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4526 emitted for extraneous default arguments.
4528 Returns TRUE if there were no errors found, FALSE otherwise. */
4530 bool
4533 {
4536 tree parm_level;
4539 /* [temp.param]
4541 A default template-argument shall not be specified in a
4542 function template declaration or a function template definition, nor
4543 in the template-parameter-list of the definition of a member of a
4544 class template. */
4547 /* You can't have a function template declaration in a local
4548 scope, nor you can you define a member of a class template in a
4549 local scope. */
4556 /* If this is either a friend defined in the scope of the class
4557 or a member function. */
4563 /* And, if it was a member function, it really was defined in
4564 the scope of the class. */
4567 /* We already checked these parameters when the template was
4568 declared, so there's no need to do it again now. This function
4569 was defined in class scope, but we're processing it's body now
4570 that the class is complete. */
4573 /* Core issue 226 (C++0x only): the following only applies to class
4574 templates. */
4576 {
4577 /* [temp.param]
4579 If a template-parameter has a default template-argument, all
4580 subsequent template-parameters shall have a default
4581 template-argument supplied. */
4583 {
4590 {
4600 {
4602 /* For better subsequent error-recovery, we indicate that
4603 there should have been a default argument. */
4606 }
4608 && !is_partial
4609 && !is_friend_decl
4610 /* Don't complain about an enclosing partial
4611 specialization. */
4616 {
4617 /* A primary class template can only have one
4618 parameter pack, at the end of the template
4619 parameter list. */
4624 else
4632 }
4633 }
4634 }
4635 }
4638 || is_partial
4639 || !is_primary
4641 /* For an ordinary class template, default template arguments are
4642 allowed at the innermost level, e.g.:
4643 template <class T = int>
4644 struct S {};
4645 but, in a partial specialization, they're not allowed even
4646 there, as we have in [temp.class.spec]:
4648 The template parameter list of a specialization shall not
4649 contain default template argument values.
4651 So, for a partial specialization, or for a function template
4652 (in C++98/C++03), we look at all of them. */
4653 ;
4654 else
4655 /* But, for a primary class template that is not a partial
4656 specialization we look at all template parameters except the
4657 innermost ones. */
4660 /* Figure out what error message to issue. */
4673 else
4677 /* If we're inside a class definition, there's no need to
4678 examine the parameters to the class itself. On the one
4679 hand, they will be checked when the class is defined, and,
4680 on the other, default arguments are valid in things like:
4681 template <class T = double>
4682 struct S { template <class U> void f(U); };
4683 Here the default argument for `S' has no bearing on the
4684 declaration of `f'. */
4686 else
4687 /* Check everything. */
4693 {
4700 {
4705 {
4707 {
4714 }
4716 /* Clear out the default argument so that we are not
4717 confused later. */
4719 }
4720 }
4722 /* At this point, if we're still interested in issuing messages,
4723 they must apply to classes surrounding the object declared. */
4727 }
4730 }
4732 /* Worker for push_template_decl_real, called via
4733 for_each_template_parm. DATA is really an int, indicating the
4734 level of the parameters we are interested in. If T is a template
4735 parameter of that level, return nonzero. */
4737 static int
4739 {
4745 else
4748 }
4750 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4751 parameters given by current_template_args, or reuses a
4752 previously existing one, if appropriate. Returns the DECL, or an
4753 equivalent one, if it is replaced via a call to duplicate_decls.
4755 If IS_FRIEND is true, DECL is a friend declaration. */
4757 tree
4759 {
4760 tree tmpl;
4761 tree args;
4762 tree info;
4763 tree ctx;
4767 /* True if the template is a member template, in the sense of
4768 [temp.mem]. */
4774 /* See if this is a partial specialization. */
4783 /* For a friend, we want the context of the friend function, not
4784 the type of which it is a friend. */
4788 /* In the case of a virtual function, we want the class in which
4789 it is defined. */
4791 else
4792 /* Otherwise, if we're currently defining some class, the DECL
4793 is assumed to be a member of the class. */
4802 /* See if this is a primary template. */
4804 /* A friend template that specifies a class context, i.e.
4805 template <typename T> friend void A<T>::f();
4806 is not primary. */
4808 else
4812 {
4817 {
4820 }
4822 {
4824 {
4825 /* [temp.mem]
4827 A destructor shall not be a member template. */
4830 }
4837 {
4838 /* [basic.stc.dynamic.allocation]
4840 An allocation function can be a function
4841 template. ... Template allocation functions shall
4842 have two or more parameters. */
4845 }
4846 }
4852 /* alias-declaration */
4854 else
4855 {
4858 }
4859 }
4861 /* Check to see that the rules regarding the use of default
4862 arguments are not being violated. */
4866 /* Ensure that there are no parameter packs in the type of this
4867 declaration that have not been expanded. */
4869 {
4870 /* Check each of the arguments individually to see if there are
4871 any bare parameter packs. */
4877 {
4880 {
4881 /* This is a PARM_DECL that contains unexpanded parameter
4882 packs. We have already complained about this in the
4883 check_for_bare_parameter_packs call, so just replace
4884 these types with ERROR_MARK_NODE. */
4887 }
4891 }
4893 /* Check for bare parameter packs in the return type and the
4894 exception specifiers. */
4896 /* Errors were already issued, set return type to int
4897 as the frontend doesn't expect error_mark_node as
4898 the return type. */
4902 }
4907 {
4910 }
4921 {
4926 /* If DECL is a TYPE_DECL for a class-template, then there won't
4927 be DECL_LANG_SPECIFIC. The information equivalent to
4928 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4932 {
4933 /* Since a template declaration already existed for this
4934 class-type, we must be redeclaring it here. Make sure
4935 that the redeclaration is valid. */
4937 current_template_parms);
4938 /* We don't need to create a new TEMPLATE_DECL; just use the
4939 one we already had. */
4941 }
4942 else
4943 {
4945 member_template_p);
4950 {
4951 /* A specialization of a member template of a template
4952 class. */
4956 }
4957 }
4958 }
4959 else
4960 {
4966 {
4969 }
4977 {
4978 tree new_tmpl;
4980 /* The declaration is a specialization of a member
4981 template, declared outside the class. Therefore, the
4982 innermost template arguments will be NULL, so we
4983 replace them with the arguments determined by the
4984 earlier call to check_explicit_specialization. */
4987 new_tmpl
4989 member_template_p);
4999 args,
5002 }
5004 /* Make sure the template headers we got make sense. */
5009 {
5012 }
5013 else
5015 {
5020 {
5024 else
5029 }
5034 /* Can happen in erroneous input. */
5036 else
5040 }
5042 /* Check that the parms are used in the appropriate qualifying scopes
5043 in the declarator. */
5047 {
5053 /* Avoid crash in import_export_decl. */
5056 }
5057 }
5062 /* Push template declarations for global functions and types. Note
5063 that we do not try to push a global template friend declared in a
5064 template class; such a thing may well depend on the template
5065 parameters of the class. */
5068 {
5073 /* Hide template friend classes that haven't been declared yet. */
5075 {
5078 }
5079 }
5082 {
5088 {
5091 /* It is a conversion operator. See if the type converted to
5092 depends on innermost template operands. */
5095 depth))
5097 }
5099 /* Give template template parms a DECL_CONTEXT of the template
5100 for which they are a parameter. */
5103 {
5107 }
5108 }
5110 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5111 back to its most general template. If TMPL is a specialization,
5112 ARGS may only have the innermost set of arguments. Add the missing
5113 argument levels if necessary. */
5121 else
5122 {
5127 }
5130 }
5132 tree
5134 {
5136 }
5138 /* Called when a class template TYPE is redeclared with the indicated
5139 template PARMS, e.g.:
5141 template <class T> struct S;
5142 template <class T> struct S {}; */
5144 bool
5146 {
5147 tree tmpl;
5148 tree tmpl_parms;
5152 {
5155 }
5159 /* The type is nested in some template class. Nothing to worry
5160 about here; there are no new template parameters for the nested
5161 type. */
5165 {
5167 tmpl);
5169 }
5175 {
5185 }
5188 {
5189 tree tmpl_parm;
5190 tree parm;
5191 tree tmpl_default;
5192 tree parm_default;
5206 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5207 TEMPLATE_DECL. */
5217 {
5221 }
5224 {
5225 /* We have in [temp.param]:
5227 A template-parameter may not be given default arguments
5228 by two different declarations in the same scope. */
5233 }
5236 /* Update the previous template parameters (which are the ones
5237 that will really count) with the new default value. */
5240 /* Update the new parameters, too; they'll be used as the
5241 parameters for any members. */
5243 }
5246 }
5248 /* Simplify EXPR if it is a non-dependent expression. Returns the
5249 (possibly simplified) expression. */
5251 static tree
5253 {
5257 /* If we're in a template, but EXPR isn't value dependent, simplify
5258 it. We're supposed to treat:
5260 template <typename T> void f(T[1 + 1]);
5261 template <typename T> void f(T[2]);
5263 as two declarations of the same function, for example. */
5268 {
5269 HOST_WIDE_INT saved_processing_template_decl;
5275 complain,
5280 }
5282 }
5284 tree
5286 {
5288 }
5290 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5291 template declaration, or a TYPE_DECL for an alias declaration. */
5293 bool
5295 {
5303 }
5305 /* Return TRUE iff is a specialization of an alias template. */
5307 bool
5309 {
5314 }
5316 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5317 must be a function or a pointer-to-function type, as specified
5318 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5319 and check that the resulting function has external linkage. */
5321 static tree
5323 {
5326 linkage_kind linkage;
5338 /* [temp.arg.nontype]/1
5340 A template-argument for a non-type, non-template template-parameter
5341 shall be one of:
5342 [...]
5343 -- the address of an object or function with external [C++11: or
5344 internal] linkage. */
5347 {
5352 else
5357 }
5360 }
5362 /* Subroutine of convert_nontype_argument.
5363 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5364 Emit an error otherwise. */
5366 static bool
5368 tsubst_flags_t complain)
5369 {
5376 {
5380 }
5382 }
5384 /* Returns TRUE iff the address of OP is value-dependent.
5386 14.6.2.4 [temp.dep.temp]:
5387 A non-integral non-type template-argument is dependent if its type is
5388 dependent or it has either of the following forms
5389 qualified-id
5390 & qualified-id
5391 and contains a nested-name-specifier which specifies a class-name that
5392 names a dependent type.
5394 We generalize this to just say that the address of a member of a
5395 dependent class is value-dependent; the above doesn't cover the
5396 address of a static data member named with an unqualified-id. */
5398 static bool
5400 {
5401 /* We could use get_inner_reference here, but there's no need;
5402 this is only relevant for template non-type arguments, which
5403 can only be expressed as &id-expression. */
5405 {
5409 }
5412 }
5414 /* The next set of functions are used for providing helpful explanatory
5415 diagnostics for failed overload resolution. Their messages should be
5416 indented by two spaces for consistency with the messages in
5417 call.c */
5419 static int
5421 {
5423 }
5425 static int
5427 {
5432 }
5434 static int
5436 {
5438 }
5440 static int
5442 {
5448 }
5450 static int
5452 {
5456 }
5458 static int
5460 {
5463 " template parameter %qD is not a parameter pack, but "
5467 }
5469 static int
5471 {
5474 " template argument %qE does not match "
5478 }
5480 static int
5482 {
5486 }
5488 static int
5490 {
5496 }
5498 static int
5500 {
5502 {
5507 else
5509 " deduced conflicting values for non-type parameter "
5511 }
5513 }
5515 static int
5517 {
5520 " variable-sized array type %qT is not "
5522 arg);
5524 }
5526 static int
5528 {
5532 arg);
5534 }
5536 static int
5538 {
5545 }
5547 static int
5549 {
5551 }
5553 static int
5555 {
5557 }
5559 static int
5562 {
5567 }
5569 static int
5572 {
5575 {
5583 }
5585 }
5587 static int
5589 {
5592 " template parameters of a template template argument are "
5595 }
5597 static int
5599 {
5605 }
5607 static int
5609 {
5614 }
5616 static int
5618 {
5622 arg);
5624 }
5626 /* Attempt to convert the non-type template parameter EXPR to the
5627 indicated TYPE. If the conversion is successful, return the
5628 converted value. If the conversion is unsuccessful, return
5629 NULL_TREE if we issued an error message, or error_mark_node if we
5630 did not. We issue error messages for out-and-out bad template
5631 parameters, but not simply because the conversion failed, since we
5632 might be just trying to do argument deduction. Both TYPE and EXPR
5633 must be non-dependent.
5635 The conversion follows the special rules described in
5636 [temp.arg.nontype], and it is much more strict than an implicit
5637 conversion.
5639 This function is called twice for each template argument (see
5640 lookup_template_class for a more accurate description of this
5641 problem). This means that we need to handle expressions which
5642 are not valid in a C++ source, but can be created from the
5643 first call (for instance, casts to perform conversions). These
5644 hacks can go away after we fix the double coercion problem. */
5646 static tree
5648 {
5649 tree expr_type;
5651 /* Detect immediately string literals as invalid non-type argument.
5652 This special-case is not needed for correctness (we would easily
5653 catch this later), but only to provide better diagnostic for this
5654 common user mistake. As suggested by DR 100, we do not mention
5655 linkage issues in the diagnostic as this is not the point. */
5656 /* FIXME we're making this OK. */
5658 {
5664 }
5666 /* Add the ADDR_EXPR now for the benefit of
5667 value_dependent_expression_p. */
5672 /* If we are in a template, EXPR may be non-dependent, but still
5673 have a syntactic, rather than semantic, form. For example, EXPR
5674 might be a SCOPE_REF, rather than the VAR_DECL to which the
5675 SCOPE_REF refers. Preserving the qualifying scope is necessary
5676 so that access checking can be performed when the template is
5677 instantiated -- but here we need the resolved form so that we can
5678 convert the argument. */
5689 else
5692 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5693 to a non-type argument of "nullptr". */
5698 /* In C++11, integral or enumeration non-type template arguments can be
5699 arbitrary constant expressions. Pointer and pointer to
5700 member arguments can be general constant expressions that evaluate
5701 to a null value, but otherwise still need to be of a specific form. */
5703 {
5705 /* A PTRMEM_CST is already constant, and a valid template
5706 argument for a parameter of pointer to member type, we just want
5707 to leave it in that form rather than lower it to a
5713 {
5718 }
5719 }
5721 /* HACK: Due to double coercion, we can get a
5722 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5723 which is the tree that we built on the first call (see
5724 below when coercing to reference to object or to reference to
5725 function). We just strip everything and get to the arg.
5726 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5727 for examples. */
5729 {
5735 {
5736 /* ??? Maybe we could use convert_from_reference here, but we
5737 would need to relax its constraints because the NOP_EXPR
5738 could actually change the type to something more cv-qualified,
5739 and this is not folded by convert_from_reference. */
5750 }
5751 }
5753 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5754 parameter is a pointer to object, through decay and
5755 qualification conversion. Let's strip everything. */
5757 {
5761 /* Skip the ADDR_EXPR only if it is part of the decay for
5762 an array. Otherwise, it is part of the original argument
5763 in the source code. */
5767 }
5769 /* [temp.arg.nontype]/5, bullet 1
5771 For a non-type template-parameter of integral or enumeration type,
5772 integral promotions (_conv.prom_) and integral conversions
5773 (_conv.integral_) are applied. */
5775 {
5784 /* Notice that there are constant expressions like '4 % 0' which
5785 do not fold into integer constants. */
5787 {
5789 {
5800 /* else cxx_constant_value complained but gave us
5801 a real constant, so go ahead. */
5803 }
5804 else
5806 }
5807 }
5808 /* [temp.arg.nontype]/5, bullet 2
5810 For a non-type template-parameter of type pointer to object,
5811 qualification conversions (_conv.qual_) and the array-to-pointer
5812 conversion (_conv.array_) are applied. */
5814 {
5815 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5817 A template-argument for a non-type, non-template template-parameter
5818 shall be one of: [...]
5820 -- the name of a non-type template-parameter;
5821 -- the address of an object or function with external linkage, [...]
5822 expressed as "& id-expression" where the & is optional if the name
5823 refers to a function or array, or if the corresponding
5824 template-parameter is a reference.
5826 Here, we do not care about functions, as they are invalid anyway
5827 for a parameter of type pointer-to-object. */
5830 /* Non-type template parameters are OK. */
5831 ;
5836 {
5838 {
5840 "because %qD is a variable, not the address of "
5844 }
5845 /* Other values, like integer constants, might be valid
5846 non-type arguments of some other type. */
5848 }
5849 else
5850 {
5851 tree decl;
5856 {
5861 }
5863 {
5868 }
5870 {
5875 }
5876 }
5885 }
5886 /* [temp.arg.nontype]/5, bullet 3
5888 For a non-type template-parameter of type reference to object, no
5889 conversions apply. The type referred to by the reference may be more
5890 cv-qualified than the (otherwise identical) type of the
5891 template-argument. The template-parameter is bound directly to the
5892 template-argument, which must be an lvalue. */
5894 {
5896 expr_type))
5900 {
5904 }
5907 {
5911 }
5913 /* [temp.arg.nontype]/1
5915 A template-argument for a non-type, non-template template-parameter
5916 shall be one of: [...]
5918 -- the address of an object or function with external linkage. */
5921 {
5924 {
5926 "because a reference variable does not have a constant "
5929 }
5930 }
5933 {
5938 }
5941 {
5946 }
5949 }
5950 /* [temp.arg.nontype]/5, bullet 4
5952 For a non-type template-parameter of type pointer to function, only
5953 the function-to-pointer conversion (_conv.func_) is applied. If the
5954 template-argument represents a set of overloaded functions (or a
5955 pointer to such), the matching function is selected from the set
5956 (_over.over_). */
5958 {
5959 /* If the argument is a template-id, we might not have enough
5960 context information to decay the pointer. */
5962 {
5966 }
5969 /* Null pointer values are OK in C++11. */
5977 {
5981 }
5982 }
5983 /* [temp.arg.nontype]/5, bullet 5
5985 For a non-type template-parameter of type reference to function, no
5986 conversions apply. If the template-argument represents a set of
5987 overloaded functions, the matching function is selected from the set
5988 (_over.over_). */
5990 {
5992 {
5997 }
6004 }
6005 /* [temp.arg.nontype]/5, bullet 6
6007 For a non-type template-parameter of type pointer to member function,
6008 no conversions apply. If the template-argument represents a set of
6009 overloaded member functions, the matching member function is selected
6010 from the set (_over.over_). */
6012 {
6017 /* [temp.arg.nontype] bullet 1 says the pointer to member
6018 expression must be a pointer-to-member constant. */
6022 /* There is no way to disable standard conversions in
6023 resolve_address_of_overloaded_function (called by
6024 instantiate_type). It is possible that the call succeeded by
6025 converting &B::I to &D::I (where B is a base of D), so we need
6026 to reject this conversion here.
6028 Actually, even if there was a way to disable standard conversions,
6029 it would still be better to reject them here so that we can
6030 provide a superior diagnostic. */
6032 {
6036 /* If we are just one standard conversion off, explain. */
6041 }
6042 }
6043 /* [temp.arg.nontype]/5, bullet 7
6045 For a non-type template-parameter of type pointer to data member,
6046 qualification conversions (_conv.qual_) are applied. */
6048 {
6049 /* [temp.arg.nontype] bullet 1 says the pointer to member
6050 expression must be a pointer-to-member constant. */
6057 }
6059 {
6061 {
6065 }
6067 }
6068 /* A template non-type parameter must be one of the above. */
6069 else
6072 /* Sanity check: did we actually convert the argument to the
6073 right type? */
6077 }
6079 /* Subroutine of coerce_template_template_parms, which returns 1 if
6080 PARM_PARM and ARG_PARM match using the rule for the template
6081 parameters of template template parameters. Both PARM and ARG are
6082 template parameters; the rest of the arguments are the same as for
6083 coerce_template_template_parms.
6084 */
6085 static int
6087 tree arg,
6088 tsubst_flags_t complain,
6089 tree in_decl,
6090 tree outer_args)
6091 {
6100 {
6102 /* We encounter instantiations of templates like
6103 template <template <template <class> class> class TT>
6104 class C; */
6105 {
6112 }
6113 /* Fall through. */
6118 /* Argument is a parameter pack but parameter is not. */
6123 /* The tsubst call is used to handle cases such as
6125 template <int> class C {};
6126 template <class T, template <T> class TT> class D {};
6127 D<int, C> d;
6129 i.e. the parameter list of TT depends on earlier parameters. */
6131 && !same_type_p
6138 /* Argument is a parameter pack but parameter is not. */
6145 }
6148 }
6151 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6152 template template parameters. Both PARM_PARMS and ARG_PARMS are
6153 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6154 or PARM_DECL.
6156 Consider the example:
6157 template <class T> class A;
6158 template<template <class U> class TT> class B;
6160 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6161 the parameters to A, and OUTER_ARGS contains A. */
6163 static int
6165 tree arg_parms,
6166 tsubst_flags_t complain,
6167 tree in_decl,
6168 tree outer_args)
6169 {
6180 /* Determine whether we have a parameter pack at the end of the
6181 template template parameter's template parameter list. */
6183 {
6190 {
6204 }
6205 }
6211 /* Check all of the template parameters except the parameter pack at
6212 the end (if any). */
6214 {
6223 outer_args))
6226 }
6229 {
6230 /* Check each of the template parameters in the template
6231 argument against the template parameter pack at the end of
6232 the template template parameter. */
6239 {
6246 outer_args))
6248 }
6249 }
6252 }
6254 /* Verifies that the deduced template arguments (in TARGS) for the
6255 template template parameters (in TPARMS) represent valid bindings,
6256 by comparing the template parameter list of each template argument
6257 to the template parameter list of its corresponding template
6258 template parameter, in accordance with DR150. This
6259 routine can only be called after all template arguments have been
6260 deduced. It will return TRUE if all of the template template
6261 parameter bindings are okay, FALSE otherwise. */
6262 bool
6264 {
6268 /* We're dealing with template parms in this process. */
6274 {
6279 {
6284 {
6285 /* Look inside the argument pack. */
6288 }
6291 {
6295 /* Extract the next argument from the argument
6296 pack. */
6300 /* Look at the pattern of the pack expansion. */
6303 /* Extract the template parameters from the template
6304 argument. */
6310 /* Verify that we can coerce the template template
6311 parameters from the template argument to the template
6312 parameter. This requires an exact match. */
6314 && !coerce_template_template_parms
6316 targ_parms,
6317 tf_none,
6318 tparm,
6319 targs))
6320 {
6323 }
6324 }
6325 }
6326 }
6328 out:
6332 }
6334 /* Since type attributes aren't mangled, we need to strip them from
6335 template type arguments. */
6337 static tree
6339 {
6340 tree mv;
6347 {
6352 }
6354 }
6356 /* Convert the indicated template ARG as necessary to match the
6357 indicated template PARM. Returns the converted ARG, or
6358 error_mark_node if the conversion was unsuccessful. Error and
6359 warning messages are issued under control of COMPLAIN. This
6360 conversion is for the Ith parameter in the parameter list. ARGS is
6361 the full set of template arguments deduced so far. */
6363 static tree
6365 tree arg,
6366 tree args,
6367 tsubst_flags_t complain,
6369 tree in_decl)
6370 {
6371 tree orig_arg;
6372 tree val;
6377 {
6378 /* The template argument was the name of some
6379 member function. That's usually
6380 invalid, but static members are OK. In any
6381 case, grab the underlying fields/functions
6382 and issue an error later if required. */
6385 }
6393 /* When determining whether an argument pack expansion is a template,
6394 look at the pattern. */
6398 /* Deal with an injected-class-name used as a template template arg. */
6400 {
6403 {
6413 }
6414 }
6416 is_tmpl_type =
6431 {
6433 {
6437 }
6440 "to refer to a type member of a template parameter, "
6445 typename_type,
6449 }
6451 {
6453 {
6455 {
6465 else
6467 }
6468 }
6470 }
6472 {
6474 {
6480 else
6482 }
6484 }
6487 {
6489 {
6491 /* The number of argument required is not known yet.
6492 Just accept it for now. */
6494 else
6495 {
6497 tree argparm;
6503 args))
6504 {
6507 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6508 TEMPLATE_DECL. */
6510 {
6515 }
6516 }
6517 else
6518 {
6520 {
6526 }
6529 }
6530 }
6531 }
6532 else
6534 /* We only form one instance of each template specialization.
6535 Therefore, if we use a non-canonical variant (i.e., a
6536 typedef), any future messages referring to the type will use
6537 the typedef, which is confusing if those future uses do not
6538 themselves also use the typedef. */
6541 }
6542 else
6543 {
6550 {
6553 else
6554 {
6555 /* Not sure if this is reachable, but it doesn't hurt
6556 to be robust. */
6559 }
6560 }
6562 /* We used to call digest_init here. However, digest_init
6563 will report errors, which we don't want when complain
6564 is zero. More importantly, digest_init will try too
6565 hard to convert things: for example, `0' should not be
6566 converted to pointer type at this point according to
6567 the standard. Accepting this is not merely an
6568 extension, since deciding whether or not these
6569 conversions can occur is part of determining which
6570 function template to call, or whether a given explicit
6571 argument specification is valid. */
6573 else
6582 {
6583 /* Strip typedefs from the SCOPE_REF. */
6586 complain);
6589 }
6590 }
6593 }
6595 /* Coerces the remaining template arguments in INNER_ARGS (from
6596 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6597 Returns the coerced argument pack. PARM_IDX is the position of this
6598 parameter in the template parameter list. ARGS is the original
6599 template argument list. */
6600 static tree
6603 tree args,
6604 tree inner_args,
6606 tree new_args,
6608 tree in_decl,
6609 tsubst_flags_t complain)
6610 {
6613 tree packed_args;
6614 tree argument_pack;
6624 {
6625 /* When the template parameter is a non-type template
6626 parameter pack whose type uses parameter packs, we need
6627 to look at each of the template arguments
6628 separately. Build a vector of the types for these
6629 non-type template parameters in PACKED_TYPES. */
6630 tree expansion
6638 /* Check that we have the right number of arguments. */
6642 {
6643 int needed_parms
6648 }
6650 /* If we aren't able to check the actual arguments now
6651 (because they haven't been expanded yet), we can at least
6652 verify that all of the types used for the non-type
6653 template parameter pack are, in fact, valid for non-type
6654 template parameters. */
6657 {
6660 {
6664 }
6665 }
6666 }
6668 /* Convert the remaining arguments, which will be a part of the
6669 parameter pack "parm". */
6671 {
6676 {
6677 /* When we have a vector of types (corresponding to the
6678 non-type template parameter pack that uses parameter
6679 packs in its type, as mention above), and the
6680 argument is not an expansion (which expands to a
6681 currently unknown number of arguments), clone the
6682 parm and give it the next type in PACKED_TYPES. */
6686 }
6691 in_decl);
6695 }
6700 else
6701 {
6706 }
6709 #ifdef ENABLE_CHECKING
6712 #endif
6714 }
6716 /* Convert all template arguments to their appropriate types, and
6717 return a vector containing the innermost resulting template
6718 arguments. If any error occurs, return error_mark_node. Error and
6719 warning messages are issued under control of COMPLAIN.
6721 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6722 for arguments not specified in ARGS. Otherwise, if
6723 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6724 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6725 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6726 ARGS. */
6728 static tree
6730 tree args,
6731 tree in_decl,
6732 tsubst_flags_t complain,
6735 {
6737 tree inner_args;
6738 tree new_args;
6739 tree new_inner_args;
6743 /* When used as a boolean value, indicates whether this is a
6744 variadic template parameter list. Since it's an int, we can also
6745 subtract it from nparms to get the number of non-variadic
6746 parameters. */
6755 /* Determine if there are any parameter packs. */
6757 {
6763 }
6766 /* If there are no parameters that follow a parameter pack, we need to
6767 expand any argument packs so that we can deduce a parameter pack from
6768 some non-packed args followed by an argument pack, as in variadic85.C.
6769 If there are such parameters, we need to leave argument packs intact
6770 so the arguments are assigned properly. This can happen when dealing
6771 with a nested class inside a partial specialization of a class
6772 template, as in variadic92.C, or when deducing a template parameter pack
6773 from a sub-declarator, as in variadic114.C. */
6780 && require_all_args
6781 && (!use_default_args
6784 {
6786 {
6788 {
6792 }
6793 else
6799 }
6802 }
6804 /* We need to evaluate the template arguments, even though this
6805 template-id may be nested within a "sizeof". */
6813 {
6814 tree arg;
6815 tree parm;
6817 /* Get the Ith template parameter. */
6821 {
6824 }
6826 /* Calculate the next argument. */
6829 else
6834 {
6835 /* All remaining arguments will be placed in the
6836 template parameter pack PARM. */
6842 /* Store this argument. */
6844 lost++;
6847 /* We are done with all of the arguments. */
6851 }
6853 {
6855 {
6856 /* We don't know how many args we have yet, just
6857 use the unconverted ones for now. */
6860 }
6861 }
6863 {
6864 /* There must be a default arg in this case. */
6867 /* The position of the first default template argument,
6868 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6869 Record that. */
6872 }
6873 else
6877 {
6880 }
6882 /* This only occurs if there was an error in the template
6883 parameter list itself (which we would already have
6884 reported) that we are trying to recover from, e.g., a class
6885 template with a parameter list such as
6886 template<typename..., typename>. */
6888 else
6894 lost++;
6896 }
6903 #ifdef ENABLE_CHECKING
6907 #endif
6910 }
6912 /* Returns 1 if template args OT and NT are equivalent. */
6914 static int
6916 {
6923 /* For member templates */
6932 {
6949 }
6951 {
6952 /* We get here probably because we are in the middle of substituting
6953 into the pattern of a pack expansion. In that case the
6954 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6955 interested in. So we want to use the initial pack argument for
6956 the comparison. */
6961 }
6966 else
6968 }
6970 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6971 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6972 NEWARG_PTR with the offending arguments if they are non-NULL. */
6974 static int
6977 {
6990 {
6995 {
7001 }
7002 }
7004 }
7006 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7007 of template arguments. Returns 0 otherwise. */
7009 int
7011 {
7013 }
7015 static void
7017 {
7027 /* We are called both from instantiate_decl, where we've already had a
7028 tinst_level pushed, and instantiate_template, where we haven't.
7029 Compensate. */
7040 else
7049 }
7052 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7053 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7054 documentation for TEMPLATE_ID_EXPR. */
7056 tree
7058 {
7059 tree type;
7067 {
7070 }
7073 {
7075 unknown_type_node,
7077 arglist);
7079 }
7086 }
7088 /* Within the scope of a template class S<T>, the name S gets bound
7089 (in build_self_reference) to a TYPE_DECL for the class, not a
7090 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7091 or one of its enclosing classes, and that type is a template,
7092 return the associated TEMPLATE_DECL. Otherwise, the original
7093 DECL is returned.
7095 Also handle the case when DECL is a TREE_LIST of ambiguous
7096 injected-class-names from different bases. */
7098 tree
7100 {
7104 /* DR 176: A lookup that finds an injected-class-name (10.2
7105 [class.member.lookup]) can result in an ambiguity in certain cases
7106 (for example, if it is found in more than one base class). If all of
7107 the injected-class-names that are found refer to specializations of
7108 the same class template, and if the name is followed by a
7109 template-argument-list, the reference refers to the class template
7110 itself and not a specialization thereof, and is not ambiguous. */
7112 {
7115 {
7121 }
7124 else
7126 }
7132 }
7134 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7135 parameters, find the desired type.
7137 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7139 IN_DECL, if non-NULL, is the template declaration we are trying to
7140 instantiate.
7142 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7143 the class we are looking up.
7145 Issue error and warning messages under control of COMPLAIN.
7147 If the template class is really a local class in a template
7148 function, then the FUNCTION_CONTEXT is the function in which it is
7149 being instantiated.
7151 ??? Note that this function is currently called *twice* for each
7152 template-id: the first time from the parser, while creating the
7153 incomplete type (finish_template_type), and the second type during the
7154 real instantiation (instantiate_template_class). This is surely something
7155 that we want to avoid. It also causes some problems with argument
7156 coercion (see convert_nontype_argument for more information on this). */
7158 static tree
7161 {
7163 tree t;
7166 spec_entry elt;
7167 hashval_t hash;
7170 {
7174 else
7175 {
7182 }
7185 }
7187 {
7190 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7191 an implicit typename for the second A. Deal with it. */
7196 {
7199 }
7200 }
7203 {
7206 }
7210 {
7214 }
7216 /* Issue an error message if we didn't find a template. */
7218 {
7222 }
7225 /* Make sure it's a user visible template, if it was named by
7226 the user. */
7229 {
7231 {
7235 }
7237 }
7242 {
7243 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7244 template arguments */
7246 tree parm;
7247 tree arglist2;
7248 tree outer;
7252 /* Consider an example where a template template parameter declared as
7254 template <class T, class U = std::allocator<T> > class TT
7256 The template parameter level of T and U are one level larger than
7257 of TT. To proper process the default argument of U, say when an
7258 instantiation `TT<int>' is seen, we need to build the full
7259 arguments containing {int} as the innermost level. Outer levels,
7260 available when not appearing as default template argument, can be
7261 obtained from the arguments of the enclosing template.
7263 Suppose that TT is later substituted with std::vector. The above
7264 instantiation is `TT<int, std::allocator<T> >' with TT at
7265 level 1, and T at level 2, while the template arguments at level 1
7266 becomes {std::vector} and the inner level 2 is {int}. */
7272 /* This is an argument of the current template, so we haven't set
7273 DECL_CONTEXT yet. */
7280 complain,
7290 }
7291 else
7292 {
7294 tree gen_tmpl;
7295 tree type_decl;
7303 /* An error occured while building the template TEMPL, and a
7304 diagnostic has most certainly been emitted for that
7305 already. Let's propagate that error. */
7314 {
7315 /* We've been given an incomplete set of template arguments.
7316 For example, given:
7318 template <class T> struct S1 {
7319 template <class U> struct S2 {};
7320 template <class U> struct S2<U*> {};
7321 };
7323 we will be called with an ARGLIST of `U*', but the
7324 TEMPLATE will be `template <class T> template
7325 <class U> struct S1<T>::S2'. We must fill in the missing
7326 arguments. */
7327 arglist
7329 arglist);
7331 }
7333 /* Now we should have enough arguments. */
7336 /* From here on, we're only interested in the most general
7337 template. */
7339 /* Calculate the BOUND_ARGS. These will be the args that are
7340 actually tsubst'd into the definition to create the
7341 instantiation. */
7343 {
7344 /* We have multiple levels of arguments to coerce, at once. */
7354 {
7355 tree a;
7359 complain,
7362 else
7363 /* Outer levels should have already been coerced. */
7366 /* Don't process further if one of the levels fails. */
7368 {
7369 /* Restore the ARGLIST to its full size. */
7372 }
7376 /* We temporarily reduce the length of the ARGLIST so
7377 that coerce_template_parms will see only the arguments
7378 corresponding to the template parameters it is
7379 examining. */
7381 }
7383 /* Restore the ARGLIST to its full size. */
7387 }
7388 else
7389 arglist
7392 gen_tmpl,
7393 complain,
7398 /* We were unable to bind the arguments. */
7401 /* In the scope of a template class, explicit references to the
7402 template class refer to the type of the template, not any
7403 instantiation of it. For example, in:
7405 template <class T> class C { void f(C<T>); }
7407 the `C<T>' is just the same as `C'. Outside of the
7408 class, however, such a reference is an instantiation. */
7412 /* comp_template_args is expensive, check it last. */
7414 arglist))
7417 /* If we already have this specialization, return it. */
7429 /* If the deduced arguments are invalid, then the binding
7430 failed. */
7434 complain))
7441 {
7446 }
7456 /* Create the type. */
7458 {
7460 {
7466 }
7467 else
7468 {
7469 /* We don't want to call start_enum for this type, since
7470 the values for the enumeration constants may involve
7471 template parameters. And, no one should be interested
7472 in the enumeration constants for such a type. */
7475 }
7479 }
7481 {
7482 /* The user referred to a specialization of an alias
7483 template represented by GEN_TMPL.
7485 [temp.alias]/2 says:
7487 When a template-id refers to the specialization of an
7488 alias template, it is equivalent to the associated
7489 type obtained by substitution of its
7490 template-arguments for the template-parameters in the
7491 type-id of the alias template. */
7494 /* Note that the call above (by indirectly calling
7495 register_specialization in tsubst_decl) registers the
7496 TYPE_DECL representing the specialization of the alias
7497 template. So next time someone substitutes ARGLIST for
7498 the template parms into the alias template (GEN_TMPL),
7499 she'll get that TYPE_DECL back. */
7503 }
7505 {
7512 /* A local class. Make sure the decl gets registered properly. */
7517 /* This instantiation is another name for the primary
7518 template type. Set the TYPE_CANONICAL field
7519 appropriately. */
7522 /* Some of the template arguments require structural
7523 equality testing, so this template class requires
7524 structural equality testing. */
7526 }
7527 else
7530 /* If we called start_enum or pushtag above, this information
7531 will already be set up. */
7533 {
7540 }
7541 else
7545 {
7551 {
7554 }
7555 }
7557 /* Let's consider the explicit specialization of a member
7558 of a class template specialization that is implicitely instantiated,
7559 e.g.:
7560 template<class T>
7561 struct S
7562 {
7563 template<class U> struct M {}; //#0
7564 };
7566 template<>
7567 template<>
7568 struct S<int>::M<char> //#1
7569 {
7570 int i;
7571 };
7572 [temp.expl.spec]/4 says this is valid.
7574 In this case, when we write:
7575 S<int>::M<char> m;
7577 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7578 the one of #0.
7580 When we encounter #1, we want to store the partial instantiation
7581 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7583 For all cases other than this "explicit specialization of member of a
7584 class template", we just want to store the most general template into
7585 the CLASSTYPE_TI_TEMPLATE of M.
7587 This case of "explicit specialization of member of a class template"
7588 only happens when:
7589 1/ the enclosing class is an instantiation of, and therefore not
7590 the same as, the context of the most general template, and
7591 2/ we aren't looking at the partial instantiation itself, i.e.
7592 the innermost arguments are not the same as the innermost parms of
7593 the most general template.
7595 So it's only when 1/ and 2/ happens that we want to use the partial
7596 instantiation of the member template in lieu of its most general
7597 template. */
7601 /* the enclosing class must be an instantiation... */
7604 {
7605 tree partial_inst_args;
7608 partial_inst_args =
7614 use_partial_inst_tmpl =
7615 /*...and we must not be looking at the partial instantiation
7616 itself. */
7618 partial_inst_args);
7619 }
7622 /* This case is easy; there are no member templates involved. */
7624 else
7625 {
7626 /* This is a full instantiation of a member template. Find
7627 the partial instantiation of which this is an instance. */
7629 /* Temporarily reduce by one the number of levels in the ARGLIST
7630 so as to avoid comparing the last set of arguments. */
7634 /* FOUND is either a proper class type, or an alias
7635 template specialization. In the later case, it's a
7636 TYPE_DECL, resulting from the substituting of arguments
7637 for parameters in the TYPE_DECL of the alias template
7638 done earlier. So be careful while getting the template
7639 of FOUND. */
7643 }
7654 /* Note this use of the partial instantiation so we can check it
7655 later in maybe_process_partial_specialization. */
7661 /* Now that the type has been registered on the instantiations
7662 list, we set up the enumerators. Because the enumeration
7663 constants may involve the enumeration type itself, we make
7664 sure to register the type first, and then create the
7665 constants. That way, doing tsubst_expr for the enumeration
7666 constants won't result in recursive calls here; we'll find
7667 the instantiation and exit above. */
7671 /* If the type makes use of template parameters, the
7672 code that generates debugging information will crash. */
7675 /* Possibly limit visibility based on template args. */
7680 }
7681 }
7683 /* Wrapper for lookup_template_class_1. */
7685 tree
7688 {
7689 tree ret;
7695 }
7696 \f
7697 struct pair_fn_data
7698 {
7699 tree_fn_t fn;
7701 /* True when we should also visit template parameters that occur in
7702 non-deduced contexts. */
7705 };
7707 /* Called from for_each_template_parm via walk_tree. */
7709 static tree
7711 {
7724 {
7728 /* Fall through. */
7751 /* Since we're not going to walk subtrees, we have to do this
7752 explicitly here. */
7756 /* Fall through. */
7759 /* Check the return type. */
7764 /* Check the parameter types. Since default arguments are not
7765 instantiated until they are needed, the TYPE_ARG_TYPES may
7766 contain expressions that involve template parameters. But,
7767 no-one should be looking at them yet. And, once they're
7768 instantiated, they don't contain template parameters, so
7769 there's no point in looking at them then, either. */
7770 {
7771 tree parm;
7778 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7779 want walk_tree walking into them itself. */
7781 }
7799 /* Fall through. */
7815 /* Record template parameters such as `T' inside `TT<T>'. */
7819 /* Fall through. */
7831 /* A template template parameter is encountered. */
7837 /* Already substituted template template parameter */
7860 /* If there's no type, then this thing must be some expression
7861 involving template parameters. */
7883 }
7885 /* We didn't find any template parameters we liked. */
7887 }
7889 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7890 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7891 call FN with the parameter and the DATA.
7892 If FN returns nonzero, the iteration is terminated, and
7893 for_each_template_parm returns 1. Otherwise, the iteration
7894 continues. If FN never returns a nonzero value, the value
7895 returned by for_each_template_parm is 0. If FN is NULL, it is
7896 considered to be the function which always returns 1.
7898 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7899 parameters that occur in non-deduced contexts. When false, only
7900 visits those template parameters that can be deduced. */
7902 static int
7906 {
7910 /* Set up. */
7915 /* Walk the tree. (Conceptually, we would like to walk without
7916 duplicates, but for_each_template_parm_r recursively calls
7917 for_each_template_parm, so we would need to reorganize a fair
7918 bit to use walk_tree_without_duplicates, so we keep our own
7919 visited list.) */
7922 else
7925 for_each_template_parm_r,
7929 /* Clean up. */
7931 {
7934 }
7937 }
7939 /* Returns true if T depends on any template parameter. */
7941 int
7943 {
7970 else
7971 {
7974 }
7979 }
7981 /* Returns true if T depends on any template parameter with level LEVEL. */
7983 int
7985 {
7988 }
7990 /* Returns TRUE iff INST is an instantiation we don't need to do in an
7991 ill-formed translation unit, i.e. a variable or function that isn't
7992 usable in a constant expression. */
7996 {
8000 }
8002 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8003 neglectable and instantiated from within an erroneous instantiation. */
8005 static bool
8007 {
8018 }
8022 #ifdef GATHER_STATISTICS
8024 #endif
8027 /* We're starting to instantiate D; record the template instantiation context
8028 for diagnostics and to restore it later. */
8030 int
8032 {
8036 {
8042 else
8050 }
8052 /* If the current instantiation caused problems, don't let it instantiate
8053 anything else. Do allow deduction substitution and decls usable in
8054 constant expressions. */
8067 #ifdef GATHER_STATISTICS
8070 #endif
8073 }
8075 /* We're done instantiating this template; return to the instantiation
8076 context. */
8078 void
8080 {
8081 /* Restore the filename and line number stashed away when we started
8082 this instantiation. */
8086 }
8088 /* We're instantiating a deferred template; restore the template
8089 instantiation context in which the instantiation was requested, which
8090 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8092 static tree
8094 {
8106 }
8108 /* Returns the TINST_LEVEL which gives the original instantiation
8109 context. */
8113 {
8119 }
8121 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
8123 bool
8125 {
8126 tree parms;
8139 {
8148 }
8151 }
8153 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8154 vector of template arguments, as for tsubst.
8156 Returns an appropriate tsubst'd friend declaration. */
8158 static tree
8160 {
8161 tree new_friend;
8166 /* This was a friend declared with an explicit template
8167 argument list, e.g.:
8169 friend void f<>(T);
8171 to indicate that f was a template instantiation, not a new
8172 function declaration. Now, we have to figure out what
8173 instantiation of what template. */
8174 {
8176 tree new_args;
8177 tree tmpl;
8180 /* Friend functions are looked up in the containing namespace scope.
8181 We must enter that scope, to avoid finding member functions of the
8182 current class with same name. */
8197 tsk_none);
8199 }
8203 /* The NEW_FRIEND will look like an instantiation, to the
8204 compiler, but is not an instantiation from the point of view of
8205 the language. For example, we might have had:
8207 template <class T> struct S {
8208 template <class U> friend void f(T, U);
8209 };
8211 Then, in S<int>, template <class U> void f(int, U) is not an
8212 instantiation of anything. */
8218 {
8222 }
8224 /* The mangled name for the NEW_FRIEND is incorrect. The function
8225 is not a template instantiation and should not be mangled like
8226 one. Therefore, we forget the mangling here; we'll recompute it
8227 later if we need it. */
8229 {
8232 }
8235 {
8236 tree old_decl;
8237 tree new_friend_template_info;
8238 tree new_friend_result_template_info;
8239 tree ns;
8242 /* We must save some information from NEW_FRIEND before calling
8243 duplicate decls since that function will free NEW_FRIEND if
8244 possible. */
8246 new_friend_is_defn =
8251 {
8252 /* This declaration is a `primary' template. */
8255 new_friend_result_template_info
8257 }
8258 else
8261 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8265 /* Inside pushdecl_namespace_level, we will push into the
8266 current namespace. However, the friend function should go
8267 into the namespace of the template. */
8277 {
8278 /* This new friend declaration matched an existing
8279 declaration. For example, given:
8281 template <class T> void f(T);
8282 template <class U> class C {
8283 template <class T> friend void f(T) {}
8284 };
8286 the friend declaration actually provides the definition
8287 of `f', once C has been instantiated for some type. So,
8288 old_decl will be the out-of-class template declaration,
8289 while new_friend is the in-class definition.
8291 But, if `f' was called before this point, the
8292 instantiation of `f' will have DECL_TI_ARGS corresponding
8293 to `T' but not to `U', references to which might appear
8294 in the definition of `f'. Previously, the most general
8295 template for an instantiation of `f' was the out-of-class
8296 version; now it is the in-class version. Therefore, we
8297 run through all specialization of `f', adding to their
8298 DECL_TI_ARGS appropriately. In particular, they need a
8299 new set of outer arguments, corresponding to the
8300 arguments for this class instantiation.
8302 The same situation can arise with something like this:
8304 friend void f(int);
8305 template <class T> class C {
8306 friend void f(T) {}
8307 };
8309 when `C<int>' is instantiated. Now, `f(int)' is defined
8310 in the class. */
8313 /* On the other hand, if the in-class declaration does
8314 *not* provide a definition, then we don't want to alter
8315 existing definitions. We can just leave everything
8316 alone. */
8317 ;
8318 else
8319 {
8323 /* Overwrite whatever template info was there before, if
8324 any, with the new template information pertaining to
8325 the declaration. */
8329 {
8330 /* We should have called reregister_specialization in
8331 duplicate_decls. */
8336 /* Instantiate it if the global has already been used. */
8340 }
8341 else
8342 {
8343 tree t;
8345 /* Indicate that the old function template is a partial
8346 instantiation. */
8354 /* Reassign any specializations already in the hash table
8355 to the new more general template, and add the
8356 additional template args. */
8360 {
8362 spec_entry elt;
8374 register_specialization
8377 }
8379 }
8380 }
8382 /* The information from NEW_FRIEND has been merged into OLD_DECL
8383 by duplicate_decls. */
8385 }
8386 }
8387 else
8388 {
8392 /* In the code
8393 template <class T> class C {
8394 template <class U> friend void C1<U>::f (); // case 1
8395 friend void C2<T>::f (); // case 2
8396 };
8397 we only need to make sure CONTEXT is a complete type for
8398 case 2. To distinguish between the two cases, we note that
8399 CONTEXT of case 1 remains dependent type after tsubst while
8400 this isn't true for case 2. */
8410 {
8411 /* Check to see that the declaration is really present, and,
8412 possibly obtain an improved declaration. */
8418 }
8419 }
8422 }
8424 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8425 template arguments, as for tsubst.
8427 Returns an appropriate tsubst'd friend type or error_mark_node on
8428 failure. */
8430 static tree
8432 {
8433 tree friend_type;
8434 tree tmpl;
8435 tree context;
8440 {
8443 else
8445 }
8447 /* Look for a class template declaration. We look for hidden names
8448 because two friend declarations of the same template are the
8449 same. For example, in:
8451 struct A {
8452 template <typename> friend class F;
8453 };
8454 template <typename> struct B {
8455 template <typename> friend class F;
8456 };
8458 both F templates are the same. */
8463 /* But, if we don't find one, it might be because we're in a
8464 situation like this:
8466 template <class T>
8467 struct S {
8468 template <class U>
8469 friend struct S;
8470 };
8472 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8473 for `S<int>', not the TEMPLATE_DECL. */
8475 {
8478 }
8481 {
8482 /* The friend template has already been declared. Just
8483 check to see that the declarations match, and install any new
8484 default parameters. We must tsubst the default parameters,
8485 of course. We only need the innermost template parameters
8486 because that is all that redeclare_class_template will look
8487 at. */
8490 {
8491 tree parms;
8492 location_t saved_input_location;
8501 }
8504 }
8505 else
8506 {
8507 /* The friend template has not already been declared. In this
8508 case, the instantiation of the template class will cause the
8509 injection of this template into the global scope. */
8514 /* The new TMPL is not an instantiation of anything, so we
8515 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8516 the new type because that is supposed to be the corresponding
8517 template decl, i.e., TMPL. */
8524 /* Inject this template into the global scope. */
8526 }
8529 {
8532 else
8534 }
8537 }
8539 /* Returns zero if TYPE cannot be completed later due to circularity.
8540 Otherwise returns one. */
8542 static int
8544 {
8554 else
8556 }
8558 /* Apply any attributes which had to be deferred until instantiation
8559 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8560 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8562 static void
8565 {
8567 tree t;
8572 {
8576 }
8579 {
8583 }
8584 else
8588 {
8593 {
8596 {
8599 /* If the first attribute argument is an identifier, don't
8600 pass it through tsubst. Attributes like mode, format,
8601 cleanup and several target specific attributes expect it
8602 unmodified. */
8608 {
8609 tree chain
8611 in_decl,
8616 chain);
8617 }
8618 else
8624 }
8625 else
8627 }
8630 }
8631 }
8633 /* Perform (or defer) access check for typedefs that were referenced
8634 from within the template TMPL code.
8635 This is a subroutine of instantiate_template and instantiate_class_template.
8636 TMPL is the template to consider and TARGS is the list of arguments of
8637 that template. */
8639 static void
8641 {
8642 location_t saved_location;
8655 {
8667 /* Make access check error messages point to the location
8668 of the use of the typedef. */
8672 }
8674 }
8676 static tree
8678 {
8680 tree typedecl;
8681 tree pbinfo;
8682 tree base_list;
8692 /* Figure out which template is being instantiated. */
8696 /* Determine what specialization of the original template to
8697 instantiate. */
8700 {
8703 }
8705 {
8706 /* This TYPE is actually an instantiation of a partial
8707 specialization. We replace the innermost set of ARGS with
8708 the arguments appropriate for substitution. For example,
8709 given:
8711 template <class T> struct S {};
8712 template <class T> struct S<T*> {};
8714 and supposing that we are instantiating S<int*>, ARGS will
8715 presently be {int*} -- but we need {int}. */
8718 }
8719 else
8720 {
8723 }
8725 /* If the template we're instantiating is incomplete, then clearly
8726 there's nothing we can do. */
8730 /* If we've recursively instantiated too many templates, stop. */
8734 /* Now we're really doing the instantiation. Mark the type as in
8735 the process of being defined. */
8738 /* We may be in the middle of deferred access check. Disable
8739 it now. */
8743 /* Use #pragma pack from the template context. */
8749 /* Set the input location to the most specialized template definition.
8750 This is needed if tsubsting causes an error. */
8762 {
8765 /* Adjust visibility for template arguments. */
8767 }
8772 /* We should never instantiate a nested class before its enclosing
8773 class; we need to look up the nested class by name before we can
8774 instantiate it, and that lookup should instantiate the enclosing
8775 class. */
8781 {
8782 tree pbase_binfo;
8783 tree pushed_scope;
8786 /* We must enter the scope containing the type, as that is where
8787 the accessibility of types named in dependent bases are
8788 looked up from. */
8791 /* Substitute into each of the bases to determine the actual
8792 basetypes. */
8794 {
8795 tree base;
8801 {
8802 expanded_bases =
8809 }
8812 {
8814 /* Extract the already-expanded base class. */
8816 else
8817 /* Substitute to figure out the base class. */
8819 NULL_TREE);
8827 }
8828 }
8830 /* The list is now in reverse order; correct that. */
8835 }
8836 /* Now call xref_basetypes to set up all the base-class
8837 information. */
8845 /* Now that our base classes are set up, enter the scope of the
8846 class, so that name lookups into base classes, etc. will work
8847 correctly. This is precisely analogous to what we do in
8848 begin_class_definition when defining an ordinary non-template
8849 class, except we also need to push the enclosing classes. */
8852 /* Now members are processed in the order of declaration. */
8855 {
8859 {
8861 {
8862 /* Build new CLASSTYPE_NESTED_UTDS. */
8864 tree newtag;
8870 /* If the member is a class template, then -- even after
8871 substitution -- there may be dependent types in the
8872 template argument list for the class. We increment
8873 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8874 that function will assume that no types are dependent
8875 when outside of a template. */
8885 {
8889 /* Unfortunately, lookup_template_class sets
8890 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8891 instantiation (i.e., for the type of a member
8892 template class nested within a template class.)
8893 This behavior is required for
8894 maybe_process_partial_specialization to work
8895 correctly, but is not accurate in this case;
8896 the TAG is not an instantiation of anything.
8897 (The corresponding TEMPLATE_DECL is an
8898 instantiation, but the TYPE is not.) */
8901 /* Now, we call pushtag to put this NEWTAG into the scope of
8902 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8903 pushtag calling push_template_decl. We don't have to do
8904 this for enums because it will already have been done in
8905 tsubst_enum. */
8909 }
8910 }
8913 {
8914 /* Build new TYPE_METHODS. */
8915 tree r;
8924 /* Instantiate members marked with attribute used. */
8927 }
8928 else
8929 {
8930 /* Build new TYPE_FIELDS. */
8932 {
8933 tree condition =
8941 }
8943 {
8944 tree r;
8946 /* The file and line for this declaration, to
8947 assist in error message reporting. Since we
8948 called push_tinst_level above, we don't need to
8949 restore these. */
8958 {
8959 /* In [temp.inst]:
8961 [t]he initialization (and any associated
8962 side-effects) of a static data member does
8963 not occur unless the static data member is
8964 itself used in a way that requires the
8965 definition of the static data member to
8966 exist.
8968 Therefore, we do not substitute into the
8969 initialized for the static data member here. */
8970 finish_static_data_member_decl
8976 /* Instantiate members marked with attribute used. */
8979 }
8981 {
8982 /* Determine whether R has a valid type and can be
8983 completed later. If R is invalid, then it is
8984 replaced by error_mark_node so that it will not be
8985 added to TYPE_FIELDS. */
8991 {
8994 }
8995 }
8997 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8998 such a thing will already have been added to the field
8999 list by tsubst_enum in finish_member_declaration in the
9000 CLASSTYPE_NESTED_UTDS case above. */
9004 {
9007 }
9008 }
9009 }
9010 }
9011 else
9012 {
9014 {
9015 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9021 {
9022 /* template <class T> friend class C; */
9025 }
9027 {
9028 /* template <class T> friend class C::D; */
9034 }
9037 {
9038 /* This could be either
9040 friend class T::C;
9042 when dependent_type_p is false or
9044 template <class U> friend class T::C;
9046 otherwise. */
9049 /* Bump processing_template_decl for correct
9050 dependent_type_p calculation. */
9055 }
9058 {
9059 /* friend class C;
9061 where C hasn't been declared yet. Let's lookup name
9062 from namespace scope directly, bypassing any name that
9063 come from dependent base class. */
9066 /* The call to xref_tag_from_type does injection for friend
9067 classes. */
9069 friend_type =
9073 }
9075 /* friend class C<T>; */
9078 /* Otherwise it's
9080 friend class C;
9082 where C is already declared or
9084 friend class C<int>;
9086 We don't have to do anything in these cases. */
9089 /* Trick make_friend_class into realizing that the friend
9090 we're adding is a template, not an ordinary class. It's
9091 important that we use make_friend_class since it will
9092 perform some error-checking and output cross-reference
9093 information. */
9101 }
9102 else
9103 {
9104 /* Build new DECL_FRIENDLIST. */
9105 tree r;
9107 /* The file and line for this declaration, to
9108 assist in error message reporting. Since we
9109 called push_tinst_level above, we don't need to
9110 restore these. */
9114 {
9117 }
9122 {
9125 }
9126 }
9127 }
9128 }
9131 {
9134 {
9137 {
9140 }
9143 }
9144 else
9146 }
9148 /* Set the file and line number information to whatever is given for
9149 the class itself. This puts error messages involving generated
9150 implicit functions at a predictable point, and the same point
9151 that would be used for non-template classes. */
9158 /* We don't instantiate default arguments for member functions. 14.7.1:
9160 The implicit instantiation of a class template specialization causes
9161 the implicit instantiation of the declarations, but not of the
9162 definitions or default arguments, of the class member functions,
9163 member classes, static data members and member templates.... */
9165 /* Some typedefs referenced from within the template code need to be access
9166 checked at template instantiation time, i.e now. These types were
9167 added to the template at parsing time. Let's get those and perform
9168 the access checks then. */
9177 /* The vtable for a template class can be emitted in any translation
9178 unit in which the class is instantiated. When there is no key
9179 method, however, finish_struct_1 will already have added TYPE to
9180 the keyed_classes list. */
9185 }
9187 /* Wrapper for instantiate_class_template_1. */
9189 tree
9191 {
9192 tree ret;
9197 }
9199 static tree
9201 {
9202 tree r;
9208 else
9209 {
9216 /* Preserve the raw-reference nature of T. */
9220 }
9222 }
9224 /* Given a function parameter pack TMPL_PARM and some function parameters
9225 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9226 and set *SPEC_P to point at the next point in the list. */
9228 static tree
9230 {
9231 /* Collect all of the extra "packed" parameters into an
9232 argument pack. */
9233 tree parmvec;
9234 tree parmtypevec;
9245 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9250 {
9253 }
9255 /* Build the argument packs. */
9262 }
9264 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9265 NONTYPE_ARGUMENT_PACK. */
9267 static tree
9269 {
9271 }
9273 /* Substitute ARGS into T, which is an pack expansion
9274 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9275 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9276 (if only a partial substitution could be performed) or
9277 ERROR_MARK_NODE if there was an error. */
9278 tree
9280 tree in_decl)
9281 {
9282 tree pattern;
9288 tree result;
9296 /* Add in any args remembered from an earlier partial instantiation. */
9301 /* Determine the argument packs that will instantiate the parameter
9302 packs used in the expansion expression. While we're at it,
9303 compute the number of arguments to be expanded and make sure it
9304 is consistent. */
9307 {
9314 {
9318 else
9321 }
9323 {
9326 else
9327 {
9328 /* We can't rely on local_specializations for a parameter
9329 name used later in a function declaration (such as in a
9330 late-specified return type). Even if it exists, it might
9331 have the wrong value for a recursive call. Just make a
9332 dummy decl, since it's only used for its type. */
9335 /* Partial instantiation of the parm_pack, we can't build
9336 up an argument pack yet. */
9338 else
9341 }
9342 }
9343 else
9344 {
9350 }
9357 /* This can only happen if we forget to expand an argument
9358 pack somewhere else. Just return an error, silently. */
9359 {
9363 }
9366 /* The argument pack that the parameter maps to is just an
9367 expansion of the parameter itself, such as one would find
9368 in the implicit typedef of a class inside the class itself.
9369 Consider this parameter "unsubstituted", so that we will
9370 maintain the outer pack expansion. */
9374 {
9378 /* Don't bother trying to do a partial substitution with
9379 incomplete packs; we'll try again after deduction. */
9386 {
9392 pattern);
9393 else
9396 pattern);
9398 }
9404 else
9407 /* Keep track of the parameter packs and their corresponding
9408 argument packs. */
9411 }
9412 else
9413 {
9414 /* We can't substitute for this parameter pack. We use a flag as
9415 well as the missing_level counter because function parameter
9416 packs don't have a level. */
9420 }
9421 }
9423 /* We cannot expand this expansion expression, because we don't have
9424 all of the argument packs we need. */
9426 {
9428 {
9429 /* We got some full packs, but we can't substitute them in until we
9430 have values for all the packs. So remember these until then. */
9431 tree save_args;
9435 /* The call to add_to_template_args above assumes no overlap
9436 between saved args and new args, so prune away any fake
9437 args, i.e. those that satisfied arg_from_parm_pack_p above. */
9439 {
9445 }
9446 else
9450 }
9451 else
9452 {
9453 /* There were no real arguments, we're just replacing a parameter
9454 pack with another version of itself. Substitute into the
9455 pattern and return a PACK_EXPANSION_*. The caller will need to
9456 deal with that. */
9460 else
9463 }
9465 }
9467 /* We could not find any argument packs that work. */
9472 {
9473 /* We're in a late-specified return type, so create our own local
9474 specializations map; the current map is either NULL or (in the
9475 case of recursive unification) might have bindings that we don't
9476 want to use or alter. */
9479 }
9481 /* For each argument in each argument pack, substitute into the
9482 pattern. */
9485 {
9486 /* For parameter pack, change the substitution of the parameter
9487 pack to the ith argument in its argument pack, then expand
9488 the pattern. */
9490 {
9492 tree arg;
9494 /* Select the Ith argument from the pack. */
9496 {
9498 {
9503 }
9504 else
9506 }
9507 else
9508 {
9513 {
9516 /* Update the corresponding argument. */
9518 }
9519 else
9520 /* Re-use the ARGUMENT_PACK_SELECT. */
9522 }
9524 }
9526 /* Substitute into the PATTERN with the altered arguments. */
9531 else
9535 {
9538 }
9539 }
9541 /* Update ARGS to restore the substitution from parameter packs to
9542 their argument packs. */
9544 {
9549 else
9550 {
9554 /* Update the corresponding argument. */
9558 else
9560 }
9561 }
9564 {
9567 }
9570 }
9572 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9573 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9574 parameter packs; all parms generated from a function parameter pack will
9575 have the same DECL_PARM_INDEX. */
9577 tree
9579 {
9581 tree patparm;
9584 {
9590 }
9591 else
9592 {
9597 }
9600 }
9602 /* Substitute ARGS into the vector or list of template arguments T. */
9604 static tree
9606 {
9618 {
9620 tree new_arg;
9625 {
9626 /* Substitute into an expansion expression. */
9630 /* Add to the expanded length adjustment the number of
9631 expanded arguments. We subtract one from this
9632 measurement, because the argument pack expression
9633 itself is already counted as 1 in
9634 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9635 the argument pack is empty. */
9637 }
9639 {
9640 /* Substitute into each of the arguments. */
9646 new_arg,
9660 }
9661 }
9662 else
9671 }
9676 /* Make space for the expanded arguments coming from template
9677 argument packs. */
9679 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9680 arguments for a member template.
9681 In that case each TREE_VEC in ORIG_T represents a level of template
9682 arguments, and ORIG_T won't carry any non defaulted argument count.
9683 It will rather be the nested TREE_VECs that will carry one.
9684 In other words, ORIG_T carries a non defaulted argument count only
9685 if it doesn't contain any nested TREE_VEC. */
9687 {
9691 }
9693 {
9697 {
9700 /* Now expand the template argument pack "in place". */
9703 }
9704 else
9705 {
9707 out++;
9708 }
9709 }
9712 }
9714 /* Return the result of substituting ARGS into the template parameters
9715 given by PARMS. If there are m levels of ARGS and m + n levels of
9716 PARMS, then the result will contain n levels of PARMS. For
9717 example, if PARMS is `template <class T> template <class U>
9718 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9719 result will be `template <int*, double, class V>'. */
9721 static tree
9723 {
9727 /* When substituting into a template, we must set
9728 PROCESSING_TEMPLATE_DECL as the template parameters may be
9729 dependent if they are based on one-another, and the dependency
9730 predicates are short-circuit outside of templates. */
9737 {
9738 tree new_vec =
9743 {
9744 tree tuple;
9756 }
9762 }
9767 }
9769 /* Return the result of substituting ARGS into one template parameter
9770 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9771 parameter and which TREE_PURPOSE is the default argument of the
9772 template parameter. */
9774 static tree
9776 {
9797 }
9799 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9800 type T. If T is not an aggregate or enumeration type, it is
9801 handled as if by tsubst. IN_DECL is as for tsubst. If
9802 ENTERING_SCOPE is nonzero, T is the context for a template which
9803 we are presently tsubst'ing. Return the substituted value. */
9805 static tree
9807 tree args,
9808 tsubst_flags_t complain,
9809 tree in_decl,
9811 {
9816 {
9821 /* Else fall through. */
9825 {
9826 tree argvec;
9827 tree context;
9828 tree r;
9832 /* In "sizeof(X<I>)" we need to evaluate "I". */
9838 /* First, determine the context for the type we are looking
9839 up. */
9842 {
9845 /* If context is a nested class inside a class template,
9846 it may still need to be instantiated (c++/33959). */
9848 }
9850 /* Then, figure out what arguments are appropriate for the
9851 type we are trying to find. For example, given:
9853 template <class T> struct S;
9854 template <class T, class U> void f(T, U) { S<U> su; }
9856 and supposing that we are instantiating f<int, double>,
9857 then our ARGS will be {int, double}, but, when looking up
9858 S we only want {double}. */
9863 else
9864 {
9868 }
9874 }
9875 else
9876 /* This is not a template type, so there's nothing to do. */
9881 }
9882 }
9884 /* Substitute into the default argument ARG (a default argument for
9885 FN), which has the indicated TYPE. */
9887 tree
9889 {
9893 /* This can happen in invalid code. */
9897 /* This default argument came from a template. Instantiate the
9898 default argument here, not in tsubst. In the case of
9899 something like:
9901 template <class T>
9902 struct S {
9903 static T t();
9904 void f(T = t());
9905 };
9907 we must be careful to do name lookup in the scope of S<T>,
9908 rather than in the current class. */
9910 /* The "this" pointer is not valid in a default argument. */
9912 {
9917 }
9920 /* The default argument expression may cause implicitly defined
9921 member functions to be synthesized, which will result in garbage
9922 collection. We must treat this situation as if we were within
9923 the body of function so as to avoid collecting live data on the
9924 stack. */
9932 /* Restore the "this" pointer. */
9934 {
9937 }
9939 /* Make sure the default argument is reasonable. */
9945 }
9947 /* Substitute into all the default arguments for FN. */
9949 static void
9951 {
9952 tree arg;
9953 tree tmpl_args;
9957 /* If this function is not yet instantiated, we certainly don't need
9958 its default arguments. */
9961 /* Don't do this again for clones. */
9966 arg;
9972 }
9974 /* Substitute the ARGS into the T, which is a _DECL. Return the
9975 result of the substitution. Issue error and warning messages under
9976 control of COMPLAIN. */
9978 static tree
9980 {
9981 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9982 location_t saved_loc;
9987 /* Set the filename and linenumber to improve error-reporting. */
9992 {
9994 {
9995 /* We can get here when processing a member function template,
9996 member class template, or template template parameter. */
9998 tree spec;
9999 tree tmpl_args;
10000 tree full_args;
10003 {
10004 /* Template template parameter is treated here. */
10017 complain);
10020 }
10022 /* We might already have an instance of this template.
10023 The ARGS are for the surrounding class type, so the
10024 full args contain the tsubst'd args for the context,
10025 plus the innermost args from the template decl. */
10029 /* Because this is a template, the arguments will still be
10030 dependent, even after substitution. If
10031 PROCESSING_TEMPLATE_DECL is not set, the dependency
10032 predicates will short-circuit. */
10040 /* If this is a default template template argument,
10041 tsubst might not have changed anything. */
10048 {
10051 }
10053 /* Make a new template decl. It will be similar to the
10054 original, but will record the current template arguments.
10055 We also create a new function declaration, which is just
10056 like the old one, but points to this new template, rather
10057 than the old one. */
10066 {
10067 tree new_type;
10079 }
10080 else
10081 {
10082 tree new_decl;
10094 }
10100 /* The template parameters for this new template are all the
10101 template parameters for the old template, except the
10102 outermost level of parameters. */
10105 complain);
10111 /* Record this non-type partial instantiation. */
10115 }
10119 {
10120 tree ctx;
10123 tree gen_tmpl;
10124 tree type;
10129 /* Nobody should be tsubst'ing into non-template functions. */
10133 {
10134 tree spec;
10137 /* If T is not dependent, just return it. We have to
10138 increment PROCESSING_TEMPLATE_DECL because
10139 value_dependent_expression_p assumes that nothing is
10140 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10147 /* Calculate the most general template of which R is a
10148 specialization, and the complete set of arguments used to
10149 specialize R. */
10152 (DECL_TEMPLATE_RESULT
10158 /* Check to see if we already have this specialization. */
10163 {
10166 }
10168 /* We can see more levels of arguments than parameters if
10169 there was a specialization of a member template, like
10170 this:
10172 template <class T> struct S { template <class U> void f(); }
10173 template <> template <class U> void S<int>::f(U);
10175 Here, we'll be substituting into the specialization,
10176 because that's where we can find the code we actually
10177 want to generate, but we'll have enough arguments for
10178 the most general template.
10180 We also deal with the peculiar case:
10182 template <class T> struct S {
10183 template <class U> friend void f();
10184 };
10185 template <class U> void f() {}
10186 template S<int>;
10187 template void f<double>();
10189 Here, the ARGS for the instantiation of will be {int,
10190 double}. But, we only need as many ARGS as there are
10191 levels of template parameters in CODE_PATTERN. We are
10192 careful not to get fooled into reducing the ARGS in
10193 situations like:
10195 template <class T> struct S { template <class U> void f(U); }
10196 template <class T> template <> void S<T>::f(int) {}
10198 which we can spot because the pattern will be a
10199 specialization in this case. */
10201 parms_depth =
10206 }
10207 else
10208 {
10209 /* This special case arises when we have something like this:
10211 template <class T> struct S {
10212 friend void f<int>(int, double);
10213 };
10215 Here, the DECL_TI_TEMPLATE for the friend declaration
10216 will be an IDENTIFIER_NODE. We are being called from
10217 tsubst_friend_function, and we want only to create a
10218 new decl (R) with appropriate types so that we can call
10219 determine_specialization. */
10221 }
10224 {
10227 else
10231 }
10232 else
10233 {
10236 }
10241 /* We do NOT check for matching decls pushed separately at this
10242 point, as they may not represent instantiations of this
10243 template, and in any case are considered separate under the
10244 discrete model. */
10248 /* Clear out the mangled name and RTL for the instantiation. */
10251 /* Leave DECL_INITIAL set on deleted instantiations. */
10257 /* Type-conversion operator. Reconstruct the name, in
10258 case it's the name of one of the template's parameters. */
10268 /* If this is an instantiation of a function with internal
10269 linkage, we already know what object file linkage will be
10270 assigned to the instantiation. */
10279 /* We'll re-clone as appropriate in instantiate_template. */
10282 /* If we aren't complaining now, return on error before we register
10283 the specialization so that we'll complain eventually. */
10289 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10290 this in the special friend case mentioned above where
10291 GEN_TMPL is NULL. */
10293 {
10299 /* We're not supposed to instantiate default arguments
10300 until they are called, for a template. But, for a
10301 declaration like:
10303 template <class T> void f ()
10304 { extern void g(int i = T()); }
10306 we should do the substitution when the template is
10307 instantiated. We handle the member function case in
10308 instantiate_class_template since the default arguments
10309 might refer to other members of the class. */
10314 }
10315 else
10318 /* Copy the list of befriending classes. */
10322 {
10326 in_decl);
10327 }
10330 {
10334 /* If this is an instantiation of a member template, clone it.
10335 If it isn't, that'll be handled by
10336 clone_constructors_and_destructors. */
10339 }
10350 /* Possibly limit visibility based on template args. */
10353 {
10357 }
10365 }
10369 {
10377 {
10378 /* If there is a local specialization that isn't a
10379 parameter pack, it means that we're doing a "simple"
10380 substitution from inside tsubst_pack_expansion. Just
10381 return the local specialization (which will be a single
10382 parm). */
10389 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10390 the parameters in this function parameter pack. */
10394 {
10397 /* Zero-length parameter packs are boring. Just substitute
10398 into the chain. */
10402 }
10403 else
10404 {
10405 /* All we did was update the type. Make a note of that. */
10408 }
10409 }
10411 /* Loop through all of the parameter's we'll build. When T is
10412 a function parameter pack, LEN is the number of expanded
10413 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10416 {
10423 /* We're on the Ith parameter of the function parameter
10424 pack. */
10425 {
10426 /* An argument of a function parameter pack is not a parameter
10427 pack. */
10430 /* Get the Ith type. */
10434 /* Rename the parameter to include the index. */
10437 }
10439 /* We're dealing with a normal parameter. */
10447 {
10450 else
10453 }
10463 /* Keep track of the first new parameter we
10464 generate. That's what will be returned to the
10465 caller. */
10469 /* Build a proper chain of parameters when substituting
10470 into a function parameter pack. */
10473 }
10479 /* FIRST_R contains the start of the chain we've built. */
10481 }
10485 {
10486 tree type;
10496 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10497 non-bit-fields DECL_INITIAL is a non-static data member
10498 initializer, which gets deferred instantiation. */
10504 {
10505 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10506 NSDMI in perform_member_init. Still set DECL_INITIAL
10507 so that we know there is one. */
10512 }
10513 /* We don't have to set DECL_CONTEXT here; it is set by
10514 finish_member_declaration. */
10521 }
10525 /* We reach here only for member using decls. */
10527 {
10528 r = do_class_using_decl
10533 else
10534 {
10537 }
10538 }
10539 else
10540 {
10543 }
10548 {
10551 tree spec;
10553 tree ctx;
10559 {
10560 /* If this is the canonical decl, we don't have to
10561 mess with instantiations, and often we can't (for
10562 typename, template type parms and such). Note that
10563 TYPE_NAME is not correct for the above test if
10564 we've copied the type for a typedef. */
10570 }
10572 /* Check to see if we already have the specialization we
10573 need. */
10576 {
10577 /* T is a static data member or namespace-scope entity.
10578 We have to substitute into namespace-scope variables
10579 (even though such entities are never templates) because
10580 of cases like:
10582 template <class T> void f() { extern T t; }
10584 where the entity referenced is not known until
10585 instantiation time. */
10589 {
10591 complain,
10593 /* If CTX is unchanged, then T is in fact the
10594 specialization we want. That situation occurs when
10595 referencing a static data member within in its own
10596 class. We can use pointer equality, rather than
10597 same_type_p, because DECL_CONTEXT is always
10598 canonical... */
10601 /* ... unless T is a member template; in which
10602 case our caller can be willing to create a
10603 specialization of that template represented
10604 by T. */
10608 }
10611 {
10617 }
10618 }
10619 else
10620 {
10621 /* A local variable. */
10623 /* Subsequent calls to pushdecl will fill this in. */
10626 }
10627 /* If we already have the specialization we need, there is
10628 nothing more to do. */
10630 {
10633 }
10635 /* Create a new node for the specialization we need. */
10638 {
10641 else
10648 }
10650 {
10651 /* Even if the original location is out of scope, the
10652 newly substituted one is not. */
10659 {
10660 /* It may seem that this case cannot occur, since:
10662 typedef void f();
10663 void g() { f x; }
10665 declares a function, not a variable. However:
10667 typedef void f();
10668 template <typename T> void g() { T t; }
10669 template void g<f>();
10671 is an attempt to declare a variable with function
10672 type. */
10674 /* R is not yet sufficiently initialized, so we
10675 just use its name. */
10678 }
10680 /* Wait until cp_finish_decl to set this again, to handle
10681 circular dependency (template/instantiate6.C). */
10686 {
10691 {
10694 }
10696 }
10697 }
10703 /* Clear out the mangled name and RTL for the instantiation. */
10707 /* The initializer must not be expanded until it is required;
10708 see [temp.inst]. */
10714 {
10715 /* Possibly limit visibility based on template args. */
10718 {
10722 }
10724 }
10727 {
10728 /* A static data member declaration is always marked
10729 external when it is declared in-class, even if an
10730 initializer is present. We mimic the non-template
10731 processing here. */
10737 }
10739 {
10740 /* We're substituting this var in a decltype outside of its
10741 scope, such as for a lambda return type. Don't add it to
10742 local_specializations, do perform auto deduction. */
10745 {
10746 tree init
10752 }
10753 }
10754 else
10763 /* Preserve a typedef that names a type. */
10765 {
10768 }
10771 }
10776 }
10777 #undef RETURN
10779 out:
10780 /* Restore the file and line information. */
10784 }
10786 /* Substitute into the ARG_TYPES of a function type. */
10788 static tree
10790 tree args,
10791 tsubst_flags_t complain,
10792 tree in_decl)
10793 {
10794 tree remaining_arg_types;
10798 tree default_arg;
10809 {
10810 /* For a pack expansion, perform substitution on the
10811 entire expression. Later on, we'll handle the arguments
10812 one-by-one. */
10817 /* So that we'll spin through the parameters, one by one. */
10819 else
10820 {
10821 /* We only partially substituted into the parameter
10822 pack. Our type is TYPE_PACK_EXPANSION. */
10825 }
10826 }
10839 {
10841 {
10845 }
10847 }
10849 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10850 top-level qualifiers as required. */
10853 /* We do not substitute into default arguments here. The standard
10854 mandates that they be instantiated only when needed, which is
10855 done in build_over_call. */
10859 {
10860 /* We've instantiated a template before its default arguments
10861 have been parsed. This can happen for a nested template
10862 class, and is not an error unless we require the default
10863 argument in a call of this function. */
10864 remaining_arg_types =
10867 remaining_arg_types);
10868 }
10869 else
10870 remaining_arg_types =
10872 }
10875 }
10877 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10878 *not* handle the exception-specification for FNTYPE, because the
10879 initial substitution of explicitly provided template parameters
10880 during argument deduction forbids substitution into the
10881 exception-specification:
10883 [temp.deduct]
10885 All references in the function type of the function template to the
10886 corresponding template parameters are replaced by the specified tem-
10887 plate argument values. If a substitution in a template parameter or
10888 in the function type of the function template results in an invalid
10889 type, type deduction fails. [Note: The equivalent substitution in
10890 exception specifications is done only when the function is instanti-
10891 ated, at which point a program is ill-formed if the substitution
10892 results in an invalid type.] */
10894 static tree
10896 tree args,
10897 tsubst_flags_t complain,
10898 tree in_decl)
10899 {
10900 tree return_type;
10901 tree arg_types;
10902 tree fntype;
10904 /* The TYPE_CONTEXT is not used for function/method types. */
10907 /* Substitute the return type. */
10911 /* The standard does not presently indicate that creation of a
10912 function type with an invalid return type is a deduction failure.
10913 However, that is clearly analogous to creating an array of "void"
10914 or a reference to a reference. This is core issue #486. */
10917 {
10919 {
10922 else
10924 }
10926 }
10928 /* Substitute the argument types. */
10934 /* Construct a new type node and return it. */
10936 {
10939 }
10940 else
10941 {
10944 {
10945 /* [temp.deduct]
10947 Type deduction may fail for any of the following
10948 reasons:
10950 -- Attempting to create "pointer to member of T" when T
10951 is not a class type. */
10954 r);
10956 }
10960 }
10964 }
10966 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10967 ARGS into that specification, and return the substituted
10968 specification. If there is no specification, return NULL_TREE. */
10970 static tree
10972 tree args,
10973 tsubst_flags_t complain,
10974 tree in_decl,
10976 {
10977 tree specs;
10978 tree new_specs;
10983 {
10984 /* A noexcept-specifier. */
10989 {
10990 /* Defer instantiation of noexcept-specifiers to avoid
10991 excessive instantiations (c++/49107). */
10994 {
10995 /* We already partially instantiated this member template,
10996 so combine the new args with the old. */
11001 }
11002 else
11003 {
11006 }
11007 }
11008 else
11009 new_specs = tsubst_copy_and_build
11013 }
11015 {
11018 else
11020 {
11021 tree spec;
11026 {
11027 /* Expand the pack expansion type. */
11030 in_decl);
11036 else
11037 {
11038 /* We're substituting into a member template, so
11039 we got a TYPE_PACK_EXPANSION back. Add that
11040 expansion and move on. */
11044 expanded_specs,
11045 complain);
11048 }
11049 }
11052 {
11055 else
11060 complain);
11061 }
11064 }
11065 }
11067 }
11069 /* Take the tree structure T and replace template parameters used
11070 therein with the argument vector ARGS. IN_DECL is an associated
11071 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11072 Issue error and warning messages under control of COMPLAIN. Note
11073 that we must be relatively non-tolerant of extensions here, in
11074 order to preserve conformance; if we allow substitutions that
11075 should not be allowed, we may allow argument deductions that should
11076 not succeed, and therefore report ambiguous overload situations
11077 where there are none. In theory, we could allow the substitution,
11078 but indicate that it should have failed, and allow our caller to
11079 make sure that the right thing happens, but we don't try to do this
11080 yet.
11082 This function is used for dealing with types, decls and the like;
11083 for expressions, use tsubst_expr or tsubst_copy. */
11085 tree
11087 {
11110 else
11115 /* Reuse typedefs. We need to do this to handle dependent attributes,
11116 such as attribute aligned. */
11119 {
11126 {
11127 /* DECL represents an alias template and we want to
11128 instantiate it. Let's substitute our arguments for the
11129 template parameters into the declaration and get the
11130 resulting type. */
11132 }
11136 {
11140 }
11145 else
11146 /* The typedef is from a non-template context. */
11150 {
11152 r = cp_build_qualified_type_real
11156 }
11157 else
11158 /* We don't have an instantiation yet, so drop the typedef. */
11160 }
11173 {
11199 {
11205 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11206 needed. */
11212 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11213 with TREE_SIDE_EFFECTS that indicates this is not an integral
11214 constant expression. */
11217 {
11220 }
11223 }
11229 {
11242 {
11246 /* See through ARGUMENT_PACK_SELECT arguments. */
11248 }
11253 {
11255 /* If ARG is an argument pack, we don't actually want to
11256 perform a substitution here, because substitutions
11257 for argument packs are only done
11258 element-by-element. We can get to this point when
11259 substituting the type of a non-type template
11260 parameter pack, when that type actually contains
11261 template parameter packs from an outer template, e.g.,
11263 template<typename... Types> struct A {
11264 template<Types... Values> struct B { };
11265 }; */
11269 {
11275 return cp_build_qualified_type_real
11277 }
11279 {
11280 /* We are processing a type constructed from a
11281 template template parameter. */
11292 /* Consider this code:
11294 template <template <class> class Template>
11295 struct Internal {
11296 template <class Arg> using Bind = Template<Arg>;
11297 };
11299 template <template <class> class Template, class Arg>
11300 using Instantiate = Template<Arg>; //#0
11302 template <template <class> class Template,
11303 class Argument>
11304 using Bind =
11305 Instantiate<Internal<Template>::template Bind,
11306 Argument>; //#1
11308 When #1 is parsed, the
11309 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11310 parameter `Template' in #0 matches the
11311 UNBOUND_CLASS_TEMPLATE representing the argument
11312 `Internal<Template>::template Bind'; We then want
11313 to assemble the type `Bind<Argument>' that can't
11314 be fully created right now, because
11315 `Internal<Template>' not being complete, the Bind
11316 template cannot be looked up in that context. So
11317 we need to "store" `Bind<Argument>' for later
11318 when the context of Bind becomes complete. Let's
11319 store that in a TYPENAME_TYPE. */
11323 argvec),
11324 typename_type,
11325 complain);
11327 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11328 are resolving nested-types in the signature of a
11329 member function templates. Otherwise ARG is a
11330 TEMPLATE_DECL and is the real template to be
11331 instantiated. */
11339 complain);
11340 return cp_build_qualified_type_real
11342 }
11343 else
11344 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11346 }
11349 /* This can happen during the attempted tsubst'ing in
11350 unify. This means that we don't yet have any information
11351 about the template parameter in question. */
11354 /* If we get here, we must have been looking at a parm for a
11355 more deeply nested template. Make a new version of this
11356 template parameter, but with a lower level. */
11358 {
11363 {
11365 r = cp_build_qualified_type_real
11369 }
11370 else
11371 {
11382 /* We have reduced the level of the template
11383 template parameter, but not the levels of its
11384 template parameters, so canonical_type_parameter
11385 will not be able to find the canonical template
11386 template parameter for this level. Thus, we
11387 require structural equality checking to compare
11388 TEMPLATE_TEMPLATE_PARMs. */
11392 else
11396 {
11404 }
11405 }
11414 }
11417 }
11420 {
11428 {
11432 }
11435 {
11439 }
11442 {
11446 }
11452 }
11455 /* We should never be tsubsting a binfo. */
11459 /* A vector of template arguments. */
11465 {
11469 /* [temp.deduct]
11471 Type deduction may fail for any of the following
11472 reasons:
11474 -- Attempting to create a pointer to reference type.
11475 -- Attempting to create a reference to a reference type or
11476 a reference to void.
11478 Core issue 106 says that creating a reference to a reference
11479 during instantiation is no longer a cause for failure. We
11480 only enforce this check in strict C++98 mode. */
11484 {
11487 /* We keep track of the last time we issued this error
11488 message to avoid spewing a ton of messages during a
11489 single bad template instantiation. */
11492 {
11497 else
11500 }
11503 }
11505 {
11509 }
11511 /* In C++0x, during template argument substitution, when there is an
11512 attempt to create a reference to a reference type, reference
11513 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11515 "If a template-argument for a template-parameter T names a type
11516 that is a reference to a type A, an attempt to create the type
11517 'lvalue reference to cv T' creates the type 'lvalue reference to
11518 A,' while an attempt to create the type type rvalue reference to
11519 cv T' creates the type T"
11520 */
11521 r = cp_build_reference_type
11524 else
11529 /* Will this ever be needed for TYPE_..._TO values? */
11533 }
11535 {
11538 {
11539 /* [temp.deduct]
11541 Type deduction may fail for any of the following
11542 reasons:
11544 -- Attempting to create "pointer to member of T" when T
11545 is not a class type. */
11549 }
11551 {
11555 }
11557 {
11561 }
11564 {
11565 /* The type of the implicit object parameter gets its
11566 cv-qualifiers from the FUNCTION_TYPE. */
11567 tree memptr;
11571 complain);
11572 }
11573 else
11576 complain);
11577 }
11580 {
11581 tree fntype;
11582 tree specs;
11587 /* Substitute the exception specification. */
11595 }
11597 {
11602 /* As an optimization, we avoid regenerating the array type if
11603 it will obviously be the same as T. */
11607 /* These checks should match the ones in grokdeclarator.
11609 [temp.deduct]
11611 The deduction may fail for any of the following reasons:
11613 -- Attempting to create an array with an element type that
11614 is void, a function type, or a reference type, or [DR337]
11615 an abstract class type. */
11619 {
11623 }
11625 {
11628 type);
11630 }
11635 {
11638 }
11641 }
11644 {
11654 {
11658 }
11660 {
11661 /* Normally, make_typename_type does not require that the CTX
11662 have complete type in order to allow things like:
11664 template <class T> struct S { typename S<T>::X Y; };
11666 But, such constructs have already been resolved by this
11667 point, so here CTX really should have complete type, unless
11668 it's a partial instantiation. */
11671 {
11675 }
11676 }
11683 {
11686 }
11689 {
11691 {
11695 else
11697 }
11699 {
11703 else
11705 }
11706 }
11708 return cp_build_qualified_type_real
11710 }
11713 {
11725 }
11728 {
11729 tree type;
11745 complain);
11746 }
11749 {
11750 tree type;
11766 else
11767 type = finish_decltype_type
11772 complain);
11773 }
11776 {
11780 }
11784 {
11786 tree packed_out =
11788 args,
11789 complain,
11790 in_decl);
11793 /* For template nontype argument packs, also substitute into
11794 the type. */
11799 }
11814 /* We should use one of the expression tsubsts for these codes. */
11820 }
11821 }
11823 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11824 type of the expression on the left-hand side of the "." or "->"
11825 operator. */
11827 static tree
11830 {
11831 tree name;
11832 tree qualifying_scope;
11833 tree fns;
11834 tree optype;
11838 /* A baselink indicates a function from a base class. Both the
11839 BASELINK_ACCESS_BINFO and the base class referenced may
11840 indicate bases of the template class, rather than the
11841 instantiated class. In addition, lookups that were not
11842 ambiguous before may be ambiguous now. Therefore, we perform
11843 the lookup again. */
11850 {
11857 }
11865 /* If lookup found a single function, mark it as used at this
11866 point. (If it lookup found multiple functions the one selected
11867 later by overload resolution will be marked as used at that
11868 point.) */
11874 /* Add back the template arguments, if present. */
11879 template_args);
11880 /* Update the conversion operator type. */
11886 qualifying_scope,
11887 object_type);
11888 }
11890 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11891 true if the qualified-id will be a postfix-expression in-and-of
11892 itself; false if more of the postfix-expression follows the
11893 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11894 of "&". */
11896 static tree
11900 {
11901 tree expr;
11902 tree scope;
11903 tree name;
11905 tree template_args;
11909 /* Figure out what name to look up. */
11912 {
11919 }
11920 else
11921 {
11924 }
11926 /* Substitute into the qualifying scope. When there are no ARGS, we
11927 are just trying to simplify a non-dependent expression. In that
11928 case the qualifying scope may be dependent, and, in any case,
11929 substituting will not help. */
11932 {
11935 }
11936 else
11940 {
11945 }
11948 {
11950 {
11951 /* A BIT_NOT_EXPR is used to represent a destructor. */
11953 {
11957 }
11958 else
11961 }
11962 else
11966 {
11968 {
11972 }
11974 }
11975 }
11978 {
11980 scope);
11981 /* Remember that there was a reference to this entity. */
11983 }
11986 {
11992 }
12001 {
12002 expr = (adjust_result_of_qualified_name_lookup
12004 expr = (finish_qualified_id_expr
12008 }
12010 /* Expressions do not generally have reference type. */
12012 /* However, if we're about to form a pointer-to-member, we just
12013 want the referenced member referenced. */
12018 }
12020 /* Like tsubst, but deals with expressions. This function just replaces
12021 template parms; to finish processing the resultant expression, use
12022 tsubst_copy_and_build or tsubst_expr. */
12024 static tree
12026 {
12028 tree r;
12036 {
12041 {
12042 tree c;
12044 /* We get here for a use of 'this' in an NSDMI. */
12050 /* This can happen for a parameter name used later in a function
12051 declaration (such as in a late-specified return type). Just
12052 make a dummy decl, since it's only used for its type. */
12054 /* We copy T because want to tsubst the PARM_DECL only,
12055 not the following PARM_DECLs that are chained to T. */
12058 /* Give it the template pattern as its context; its true context
12059 hasn't been instantiated yet and this is good enough for
12060 mangling. */
12062 }
12070 {
12071 tree enum_type;
12072 tree v;
12076 /* There is no need to substitute into namespace-scope
12077 enumerators. */
12080 /* If ARGS is NULL, then T is known to be non-dependent. */
12084 /* Unfortunately, we cannot just call lookup_name here.
12085 Consider:
12087 template <int I> int f() {
12088 enum E { a = I };
12089 struct S { void g() { E e = a; } };
12090 };
12092 When we instantiate f<7>::S::g(), say, lookup_name is not
12093 clever enough to find f<7>::a. */
12094 enum_type
12104 /* We didn't find the name. That should never happen; if
12105 name-lookup found it during preliminary parsing, we
12106 should find it again here during instantiation. */
12108 }
12113 {
12114 tree ctx;
12119 {
12122 {
12126 }
12128 }
12129 }
12145 /* An OVERLOAD will always be a non-dependent overload set; an
12146 overload set from function scope will just be represented with an
12147 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12162 {
12163 /* Template template argument like the following example need
12164 special treatment:
12166 template <template <class> class TT> struct C {};
12167 template <class T> struct D {
12168 template <class U> struct E {};
12169 C<E> c; // #1
12170 };
12171 D<int> d; // #2
12173 We are processing the template argument `E' in #1 for
12174 the template instantiation #2. Originally, `E' is a
12175 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12176 have to substitute this with one having context `D<int>'. */
12180 }
12181 else
12182 /* Ordinary template template argument. */
12193 return build1
12199 {
12201 tree expanded;
12206 /* We only want to compute the number of arguments. */
12221 {
12228 else
12231 }
12232 else
12234 }
12235 /* Fall through */
12250 return build1
12255 {
12256 tree object;
12257 tree name;
12262 {
12266 }
12269 {
12279 }
12284 in_decl);
12285 else
12288 }
12326 return build_nt
12339 return build_nt
12346 {
12354 }
12359 {
12360 r = build_nt
12366 }
12369 {
12370 r = build_nt
12376 }
12379 {
12380 r = build_nt
12386 }
12389 {
12390 /* Substituted template arguments */
12399 }
12402 {
12422 }
12447 {
12450 }
12451 else
12455 /* This is handled by tsubst_copy_and_build. */
12460 in_decl),
12464 /* We shouldn't have built any of these during initial template
12465 generation. Instead, they should be built during instantiation
12466 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12470 r = build2
12490 {
12491 /* Instantiate any typedefs in the type. */
12496 }
12499 /* These can sometimes show up in a partial instantiation, but never
12500 involve template parms. */
12505 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12508 }
12509 }
12511 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12513 static tree
12515 tree in_decl)
12516 {
12520 {
12526 {
12529 {
12535 }
12536 /* FALLTHRU */
12560 }
12561 }
12564 }
12566 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12568 static tree
12570 tree in_decl)
12571 {
12572 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12592 {
12595 else
12596 {
12600 }
12601 }
12606 #undef RECUR
12607 }
12609 /* Substitute one OMP_FOR iterator. */
12611 static void
12616 {
12617 #define RECUR(NODE) \
12618 tsubst_expr ((NODE), args, complain, in_decl, \
12619 integral_constant_expression_p)
12628 {
12635 }
12639 {
12645 complain);
12646 else
12653 }
12656 {
12657 tree c;
12659 {
12670 }
12672 {
12677 {
12680 }
12681 }
12682 }
12688 else
12692 {
12703 {
12710 }
12711 else
12717 {
12723 }
12727 {
12734 }
12735 else
12741 }
12747 #undef RECUR
12748 }
12750 /* Like tsubst_copy for expressions, etc. but also does semantic
12751 processing. */
12753 static tree
12756 {
12757 #define RECUR(NODE) \
12758 tsubst_expr ((NODE), args, complain, in_decl, \
12759 integral_constant_expression_p)
12772 {
12774 {
12775 tree_stmt_iterator i;
12779 }
12794 else
12803 {
12805 tree init;
12811 {
12814 tree decl;
12822 else
12824 }
12825 else
12826 {
12830 {
12831 /* By marking the declaration as instantiated, we avoid
12832 trying to instantiate it. Since instantiate_decl can't
12833 handle local variables, and since we've already done
12834 all that needs to be done, that's the right thing to
12835 do. */
12840 /* Anonymous aggregates are a special case. */
12843 {
12846 }
12847 else
12848 {
12853 {
12854 /* For __PRETTY_FUNCTION__ we have to adjust the
12855 initializer. */
12859 }
12860 else
12861 {
12865 {
12866 /* If we had an initializer but it
12867 instantiated to nothing,
12868 value-initialize the object. This will
12869 only occur when the initializer was a
12870 pack expansion where the parameter packs
12871 used in that expansion were of length
12872 zero. */
12874 complain);
12877 }
12878 else
12880 }
12883 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12886 }
12887 }
12888 }
12890 /* A DECL_EXPR can also be used as an expression, in the condition
12891 clause of an if/for/while construct. */
12893 }
12908 {
12918 }
12945 {
12949 }
12957 else
12965 else
12992 {
12994 tree label;
12999 }
13005 /* Computed goto's must be tsubst'd into. On the other hand,
13006 non-computed gotos must not be; the identifier in question
13007 will have no binding. */
13009 else
13015 tmp = finish_asm_stmt
13022 {
13027 }
13032 {
13037 }
13038 else
13039 {
13044 else
13051 else
13057 else
13059 }
13063 {
13067 {
13069 /* Prevent instantiate_decl from trying to instantiate
13070 this variable. We've already done all that needs to be
13071 done. */
13074 }
13079 }
13087 {
13088 tree condition =
13090 args,
13097 }
13118 {
13133 integral_constant_expression_p);
13142 {
13146 }
13147 else
13148 {
13156 }
13170 }
13202 {
13207 {
13210 }
13215 }
13216 else
13217 {
13224 {
13227 }
13230 {
13235 {
13238 }
13242 }
13243 else
13244 {
13248 }
13250 }
13254 {
13260 {
13264 {
13269 }
13273 }
13274 else
13275 {
13280 }
13281 }
13301 integral_constant_expression_p);
13302 }
13305 #undef RECUR
13306 }
13308 /* T is a postfix-expression that is not being used in a function
13309 call. Return the substituted version of T. */
13311 static tree
13313 tsubst_flags_t complain,
13314 tree in_decl)
13315 {
13319 else
13325 }
13327 /* Like tsubst but deals with expressions and performs semantic
13328 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13330 tree
13332 tree args,
13333 tsubst_flags_t complain,
13334 tree in_decl,
13337 {
13338 #define RECUR(NODE) \
13339 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13341 integral_constant_expression_p)
13343 tree op1;
13349 {
13352 /* Fall through. */
13354 {
13355 tree decl;
13356 cp_id_kind idk;
13361 {
13364 }
13366 /* Look up the name. */
13369 /* By convention, expressions use ERROR_MARK_NODE to indicate
13370 failure, not NULL_TREE. */
13376 integral_constant_expression_p,
13384 input_location);
13388 {
13392 }
13394 }
13397 {
13398 tree object;
13406 {
13409 }
13410 else
13417 else
13419 }
13422 {
13426 {
13427 /* A type conversion to reference type will be enclosed in
13428 such an indirect ref, but the substitution of the cast
13429 will have also added such an indirect ref. */
13432 }
13433 else
13436 }
13439 return build_nop
13444 {
13451 flags);
13452 }
13455 return build1
13465 {
13466 tree type;
13467 tree op;
13472 {
13477 }
13482 {
13495 }
13496 }
13514 complain);
13528 else
13530 in_decl);
13564 {
13565 tree r = build_x_binary_op
13569 ? ERROR_MARK
13573 ? ERROR_MARK
13576 complain);
13580 }
13593 /* Fall through */
13598 {
13599 /* When there are no ARGS, we are trying to evaluate a
13600 non-dependent expression from the parser. Trying to do
13601 the substitutions may not work. */
13604 }
13605 else
13606 {
13614 }
13618 else
13623 {
13633 }
13647 {
13648 tree r = build_x_modify_expr
13652 complain);
13653 /* TREE_NO_WARNING must be set if either the expression was
13654 parenthesized or it uses an operator such as >>= rather
13655 than plain assignment. In the former case, it was already
13656 set and must be copied. In the latter case,
13657 build_x_modify_expr sets it and it must not be reset
13658 here. */
13662 }
13667 /* Remember that there was a reference to this entity. */
13673 {
13678 tree ret;
13682 else
13683 {
13687 }
13689 /* If there was an initializer in the original tree, but it
13690 instantiated to an empty list, then we should pass a
13691 non-NULL empty vector to tell build_new that it was an
13692 empty initializer() rather than no initializer. This can
13693 only happen when the initializer is a pack expansion whose
13694 parameter packs are of length zero. */
13697 else
13698 {
13702 else
13703 {
13706 }
13707 }
13714 complain);
13722 }
13725 return delete_sanity
13730 complain);
13735 complain);
13738 {
13739 tree function;
13744 tree ret;
13747 /* When we parsed the expression, we determined whether or
13748 not Koenig lookup should be performed. */
13751 {
13756 }
13758 {
13759 /* Do nothing; calling tsubst_copy_and_build on an identifier
13760 would incorrectly perform unqualified lookup again.
13762 Note that we can also have an IDENTIFIER_NODE if the earlier
13763 unqualified lookup found a member function; in that case
13764 koenig_p will be false and we do want to do the lookup
13765 again to find the instantiated member function.
13767 FIXME but doing that causes c++/15272, so we need to stop
13768 using IDENTIFIER_NODE in that situation. */
13770 }
13771 else
13772 {
13774 {
13780 }
13781 else
13785 in_decl,
13787 integral_constant_expression_p);
13791 }
13796 {
13802 else
13803 {
13804 /* Expand the pack expansion and push each entry onto
13805 CALL_ARGS. */
13808 {
13813 {
13818 }
13819 }
13820 else
13821 {
13822 /* A partial substitution. Add one entry. */
13824 }
13825 }
13826 }
13828 /* We do not perform argument-dependent lookup if normal
13829 lookup finds a non-function, in accordance with the
13830 expected resolution of DR 218. */
13833 /* If lookup found a member function, the Koenig lookup is
13834 not appropriate, even if an unqualified-name was used
13835 to denote the function. */
13838 /* Only do this when substitution turns a dependent call
13839 into a non-dependent call. */
13843 tf_none);
13847 {
13849 {
13850 /* For backwards compatibility and good diagnostics, try
13851 the unqualified lookup again if we aren't in SFINAE
13852 context. */
13853 tree unq = (tsubst_copy_and_build
13855 integral_constant_expression_p));
13860 {
13869 "%qD was not declared in this scope, "
13870 "and no declarations were found by "
13871 "argument-dependent lookup at the point "
13876 {
13878 "declarations in dependent base %qT are "
13884 else
13888 }
13889 else
13893 }
13894 }
13896 {
13900 }
13901 }
13903 /* Remember that there was a reference to this entity. */
13910 {
13925 complain);
13926 else
13927 ret = (build_new_method_call
13932 complain));
13933 }
13934 else
13937 koenig_p,
13938 complain);
13943 }
13946 return build_x_conditional_expr
13950 complain);
13953 return finish_pseudo_destructor_expr
13959 {
13967 {
13968 /* We have pack expansions, so expand those and
13969 create a new list out of it. */
13972 tree chain;
13975 /* Expand the argument expressions. */
13983 /* Build the rest of the list. */
13988 /* Determine the number of arguments. */
13990 {
13993 }
13996 else
13997 {
13998 /* Since we only performed a partial substitution into
13999 the argument pack, we only return a single list
14000 node. */
14007 }
14009 /* Convert the argument vectors into a TREE_LIST */
14012 {
14013 /* Grab the Ith values. */
14014 i--;
14017 value
14021 /* Build the list (backwards). */
14023 }
14026 }
14042 }
14045 {
14046 tree object;
14047 tree object_type;
14048 tree member;
14052 /* Remember that there was a reference to this entity. */
14062 else
14070 {
14072 {
14077 {
14080 }
14082 {
14086 }
14087 }
14088 }
14091 {
14092 /* Lookup the template functions now that we know what the
14093 scope is. */
14101 {
14104 args);
14105 member = (adjust_result_of_qualified_name_lookup
14107 object_type));
14108 }
14109 else
14110 {
14112 input_location);
14114 }
14115 }
14119 {
14121 {
14125 else
14128 }
14130 }
14136 complain);
14137 }
14140 return build_throw
14144 {
14152 tree r;
14157 /* digest_init will do the wrong thing if we let it. */
14161 /* We do not want to process the index of aggregate
14162 initializers as they are identifier nodes which will be
14163 looked up by digest_init. */
14169 {
14174 {
14175 /* Substitute into the pack expansion. */
14177 in_decl);
14181 ;
14183 /* Just move the argument into place. */
14185 else
14186 {
14187 /* Update the length of the final CONSTRUCTOR
14188 arguments vector, and note that we will need to
14189 copy.*/
14192 }
14193 }
14194 else
14196 }
14199 {
14204 {
14206 {
14211 }
14212 else
14214 }
14215 }
14225 }
14228 {
14231 {
14234 }
14235 else
14236 {
14239 }
14240 }
14245 /* Fall through */
14248 {
14252 /* If the original type was a reference, we'll be wrapped in
14253 the appropriate INDIRECT_REF. */
14256 }
14266 {
14275 }
14278 {
14284 integral_constant_expression_p);
14288 /* If the resulting list of expression statement is empty,
14289 fold it further into void_zero_node. */
14294 }
14298 /* As in finish_id_expression, we resolve enumeration constants
14299 to their underlying values. */
14301 {
14304 }
14308 {
14325 {
14328 }
14329 else
14336 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14338 /* Now that we know visibility, instantiate the type so we have a
14339 declaration of the op() for later calls to lambda_function. */
14342 /* The capture list refers to closure members, so this needs to
14343 wait until after we finish instantiating the type. */
14348 }
14351 /* We can get here for a constant initializer of non-dependent type.
14352 FIXME stop folding in cp_parser_initializer_clause. */
14354 {
14358 }
14362 integral_constant_expression_p);
14365 /* Handle Objective-C++ constructs, if appropriate. */
14366 {
14367 tree subst
14372 }
14374 }
14376 #undef RECUR
14377 }
14379 /* Verify that the instantiated ARGS are valid. For type arguments,
14380 make sure that the type's linkage is ok. For non-type arguments,
14381 make sure they are constants if they are integral or enumerations.
14382 Emit an error under control of COMPLAIN, and return TRUE on error. */
14384 static bool
14386 {
14388 {
14398 }
14400 {
14401 /* [basic.link]: A name with no linkage (notably, the name
14402 of a class or enumeration declared in a local scope)
14403 shall not be used to declare an entity with linkage.
14404 This implies that names with no linkage cannot be used as
14405 template arguments
14407 DR 757 relaxes this restriction for C++0x. */
14412 {
14413 /* DR 488 makes use of a type with no linkage cause
14414 type deduction to fail. */
14416 {
14419 else
14422 }
14424 }
14425 /* In order to avoid all sorts of complications, we do not
14426 allow variably-modified types as template arguments. */
14428 {
14432 }
14433 }
14434 /* A non-type argument of integral or enumerated type must be a
14435 constant. */
14439 {
14443 }
14445 }
14447 static bool
14449 {
14454 {
14457 }
14461 }
14463 /* In C++0x, it's possible to have a function template whose type depends
14464 on itself recursively. This is most obvious with decltype, but can also
14465 occur with enumeration scope (c++/48969). So we need to catch infinite
14466 recursion and reject the substitution at deduction time; this function
14467 will return error_mark_node for any repeated substitution.
14469 This also catches excessive recursion such as when f<N> depends on
14470 f<N-1> across all integers, and returns error_mark_node for all the
14471 substitutions back up to the initial one.
14473 This is, of course, not reentrant. */
14475 static tree
14477 {
14484 tree tinst;
14485 tree r;
14492 {
14496 }
14506 {
14509 /* Reset once we're all the way out. */
14511 }
14514 /* We can't free this if a pending_template entry or last_error_tinst_level
14515 is pointing at it. */
14520 }
14522 /* Instantiate the indicated variable or function template TMPL with
14523 the template arguments in TARG_PTR. */
14525 static tree
14527 {
14529 tree fndecl;
14530 tree gen_tmpl;
14531 tree spec;
14538 /* If this function is a clone, handle it specially. */
14540 {
14541 tree spec;
14542 tree clone;
14544 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14545 DECL_CLONED_FUNCTION. */
14551 /* Look for the clone. */
14555 /* We should always have found the clone by now. */
14558 }
14560 /* Check to see if we already have this specialization. */
14563 /* The TMPL is a partial instantiation. To get a full set of
14564 arguments we must add the arguments used to perform the
14565 partial instantiation. */
14567 targ_ptr);
14569 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14570 but it doesn't seem to be on the hot path. */
14582 complain))
14585 /* We are building a FUNCTION_DECL, during which the access of its
14586 parameters and return types have to be checked. However this
14587 FUNCTION_DECL which is the desired context for access checking
14588 is not built yet. We solve this chicken-and-egg problem by
14589 deferring all checks until we have the FUNCTION_DECL. */
14592 /* Instantiation of the function happens in the context of the function
14593 template, not the context of the overload resolution we're doing. */
14596 {
14600 }
14601 /* Substitute template parameters to obtain the specialization. */
14611 /* Now we know the specialization, compute access previously
14612 deferred. */
14615 /* Some typedefs referenced from within the template code need to be access
14616 checked at template instantiation time, i.e now. These types were
14617 added to the template at parsing time. Let's get those and perfom
14618 the acces checks then. */
14624 /* The DECL_TI_TEMPLATE should always be the immediate parent
14625 template, not the most general template. */
14628 /* If we've just instantiated the main entry point for a function,
14629 instantiate all the alternate entry points as well. We do this
14630 by cloning the instantiation of the main entry point, not by
14631 instantiating the template clones. */
14636 }
14638 /* Wrapper for instantiate_template_1. */
14640 tree
14642 {
14643 tree ret;
14648 }
14650 /* We're going to do deduction substitution on the type of TMPL, a function
14651 template. In C++11 mode, push into that access scope. In C++03 mode,
14652 disable access checking. */
14654 static void
14656 {
14658 {
14661 /* Preserve processing_template_decl across push_to_top_level. */
14664 }
14665 else
14667 }
14669 /* And pop back out. */
14671 static void
14673 {
14676 else
14678 }
14680 /* PARM is a template parameter pack for FN. Returns true iff
14681 PARM is used in a deducible way in the argument list of FN. */
14683 static bool
14685 {
14688 {
14690 tree packs;
14696 {
14697 /* The template parameter pack is used in a function parameter
14698 pack. If this is the end of the parameter list, the
14699 template parameter pack is deducible. */
14702 else
14703 /* Otherwise, not. Well, it could be deduced from
14704 a non-pack parameter, but doing so would end up with
14705 a deduction mismatch, so don't bother. */
14707 }
14708 }
14709 /* The template parameter pack isn't used in any function parameter
14710 packs, but it might be used deeper, e.g. tuple<Args...>. */
14712 }
14714 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14715 NARGS elements of the arguments that are being used when calling
14716 it. TARGS is a vector into which the deduced template arguments
14717 are placed.
14719 Return zero for success, 2 for an incomplete match that doesn't resolve
14720 all the types, and 1 for complete failure. An error message will be
14721 printed only for an incomplete match.
14723 If FN is a conversion operator, or we are trying to produce a specific
14724 specialization, RETURN_TYPE is the return type desired.
14726 The EXPLICIT_TARGS are explicit template arguments provided via a
14727 template-id.
14729 The parameter STRICT is one of:
14731 DEDUCE_CALL:
14732 We are deducing arguments for a function call, as in
14733 [temp.deduct.call].
14735 DEDUCE_CONV:
14736 We are deducing arguments for a conversion function, as in
14737 [temp.deduct.conv].
14739 DEDUCE_EXACT:
14740 We are deducing arguments when doing an explicit instantiation
14741 as in [temp.explicit], when determining an explicit specialization
14742 as in [temp.expl.spec], or when taking the address of a function
14743 template, as in [temp.deduct.funcaddr]. */
14745 int
14747 tree explicit_targs,
14748 tree targs,
14751 tree return_type,
14752 unification_kind_t strict,
14755 {
14756 tree parms;
14757 tree fntype;
14764 {
14765 /* [temp.deduct]
14767 The specified template arguments must match the template
14768 parameters in kind (i.e., type, nontype, template), and there
14769 must not be more arguments than there are parameters;
14770 otherwise type deduction fails.
14772 Nontype arguments must match the types of the corresponding
14773 nontype template parameters, or must be convertible to the
14774 types of the corresponding nontype parameters as specified in
14775 _temp.arg.nontype_, otherwise type deduction fails.
14777 All references in the function type of the function template
14778 to the corresponding template parameters are replaced by the
14779 specified template argument values. If a substitution in a
14780 template parameter or in the function type of the function
14781 template results in an invalid type, type deduction fails. */
14784 tree converted_args;
14790 converted_args
14792 (explain_p
14793 ? tf_warning_or_error
14800 /* Substitute the explicit args into the function type. This is
14801 necessary so that, for instance, explicitly declared function
14802 arguments can match null pointed constants. If we were given
14803 an incomplete set of explicit args, we must not do semantic
14804 processing during substitution as we could create partial
14805 instantiations. */
14807 {
14812 /* Dig out the actual parm. */
14815 {
14818 }
14820 {
14823 }
14826 /* No explicit argument for this template parameter. */
14830 {
14831 /* Mark the argument pack as "incomplete". We could
14832 still deduce more arguments during unification.
14833 We remove this mark in type_unification_real. */
14835 {
14839 }
14841 /* We have some incomplete argument packs. */
14843 }
14844 }
14848 (explain_p
14849 ? tf_warning_or_error
14856 /* Place the explicitly specified arguments in TARGS. */
14859 }
14861 /* Never do unification on the 'this' parameter. */
14865 {
14874 }
14876 /* We allow incomplete unification without an error message here
14877 because the standard doesn't seem to explicitly prohibit it. Our
14878 callers must be ready to deal with unification failures in any
14879 event. */
14884 /* Now that we have bindings for all of the template arguments,
14885 ensure that the arguments deduced for the template template
14886 parameters have compatible template parameter lists. We cannot
14887 check this property before we have deduced all template
14888 arguments, because the template parameter types of a template
14889 template parameter might depend on prior template parameters
14890 deduced after the template template parameter. The following
14891 ill-formed example illustrates this issue:
14893 template<typename T, template<T> class C> void f(C<5>, T);
14895 template<int N> struct X {};
14897 void g() {
14898 f(X<5>(), 5l); // error: template argument deduction fails
14899 }
14901 The template parameter list of 'C' depends on the template type
14902 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14903 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14904 time that we deduce 'C'. */
14906 && !template_template_parm_bindings_ok_p
14911 /* All is well so far. Now, check:
14913 [temp.deduct]
14915 When all template arguments have been deduced, all uses of
14916 template parameters in nondeduced contexts are replaced with
14917 the corresponding deduced argument values. If the
14918 substitution results in an invalid type, as described above,
14919 type deduction fails. */
14920 {
14922 (explain_p
14923 ? tf_warning_or_error
14928 /* If we're looking for an exact match, check that what we got
14929 is indeed an exact match. It might not be if some template
14930 parameters are used in non-deduced contexts. */
14932 {
14935 tree sarg
14943 }
14944 }
14947 }
14949 /* Adjust types before performing type deduction, as described in
14950 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14951 sections are symmetric. PARM is the type of a function parameter
14952 or the return type of the conversion function. ARG is the type of
14953 the argument passed to the call, or the type of the value
14954 initialized with the result of the conversion function.
14955 ARG_EXPR is the original argument expression, which may be null. */
14957 static int
14961 tree arg_expr)
14962 {
14966 {
14971 {
14972 /* Swap PARM and ARG throughout the remainder of this
14973 function; the handling is precisely symmetric since PARM
14974 will initialize ARG rather than vice versa. */
14979 }
14982 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14983 too, but here handle it by stripping the reference from PARM
14984 rather than by adding it to ARG. */
14992 /* Nothing else to do in this case. */
14997 }
15000 {
15001 /* [temp.deduct.call]
15003 If P is not a reference type:
15005 --If A is an array type, the pointer type produced by the
15006 array-to-pointer standard conversion (_conv.array_) is
15007 used in place of A for type deduction; otherwise,
15009 --If A is a function type, the pointer type produced by
15010 the function-to-pointer standard conversion
15011 (_conv.func_) is used in place of A for type deduction;
15012 otherwise,
15014 --If A is a cv-qualified type, the top level
15015 cv-qualifiers of A's type are ignored for type
15016 deduction. */
15021 else
15023 }
15025 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15026 of the form T&&, where T is a template parameter, and the argument
15027 is an lvalue, T is deduced as A& */
15033 /* try_one_overload doesn't provide an arg_expr, but
15034 functions are always lvalues. */
15038 /* [temp.deduct.call]
15040 If P is a cv-qualified type, the top level cv-qualifiers
15041 of P's type are ignored for type deduction. If P is a
15042 reference type, the type referred to by P is used for
15043 type deduction. */
15046 {
15049 }
15051 /* DR 322. For conversion deduction, remove a reference type on parm
15052 too (which has been swapped into ARG). */
15057 }
15059 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15060 template which does contain any deducible template parameters; check if
15061 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15062 unify_one_argument. */
15064 static int
15067 {
15068 tree type;
15072 else
15079 {
15082 }
15084 {
15087 flags))
15089 }
15093 else
15095 }
15097 /* Subroutine of type_unification_real and unify_pack_expansion to
15098 handle unification of a single P/A pair. Parameters are as
15099 for those functions. */
15101 static int
15105 {
15112 /* We can't deduce anything from this, but we might get all the
15113 template args from other function args. */
15116 /* FIXME uses_deducible_template_parms */
15119 explain_p);
15122 {
15124 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15125 | UNIFY_ALLOW_MORE_CV_QUAL
15139 }
15141 /* We only do these transformations if this is the top-level
15142 parameter_type_list in a call or declaration matching; in other
15143 situations (nested function declarators, template argument lists) we
15144 won't be comparing a type to an expression, and we don't do any type
15145 adjustments. */
15147 {
15149 {
15152 {
15153 /* [temp.deduct.type] A template-argument can be
15154 deduced from a pointer to function or pointer
15155 to member function argument if the set of
15156 overloaded functions does not contain function
15157 templates and at most one of a set of
15158 overloaded functions provides a unique
15159 match. */
15166 }
15172 }
15174 arg_strict |=
15176 }
15177 else
15181 /* For deduction from an init-list we need the actual list. */
15185 }
15187 /* Most parms like fn_type_unification.
15189 If SUBR is 1, we're being called recursively (to unify the
15190 arguments of a function or method parameter of a function
15191 template). */
15193 static int
15195 tree targs,
15196 tree xparms,
15200 unification_kind_t strict,
15203 {
15208 tree parms;
15217 /* Reset the number of non-defaulted template arguments contained
15218 in TARGS. */
15221 again:
15229 {
15234 /* For a function parameter pack that occurs at the end of the
15235 parameter-declaration-list, the type A of each remaining
15236 argument of the call is compared with the type P of the
15237 declarator-id of the function parameter pack. */
15243 /* For a function parameter pack that does not occur at the
15244 end of the parameter-declaration-list, the type of the
15245 parameter pack is a non-deduced context. */
15254 }
15259 {
15260 /* Unify the remaining arguments with the pack expansion type. */
15261 tree argvec;
15264 /* Allocate a TREE_VEC and copy in all of the arguments */
15269 /* Copy the parameter into parmvec. */
15275 /* Advance to the end of the list of parameters. */
15277 }
15279 /* Fail if we've reached the end of the parm list, and more args
15280 are present, and the parm list isn't variadic. */
15283 /* Fail if parms are left and they don't have default values. */
15286 {
15290 {
15291 count++;
15293 }
15295 }
15298 {
15299 tsubst_flags_t complain = (explain_p
15300 ? tf_warning_or_error
15303 /* Check to see if we need another pass before we start clearing
15304 ARGUMENT_PACK_INCOMPLETE_P. */
15306 {
15314 /* If this is an undeduced nontype parameter that depends on
15315 a type parameter, try another pass; its type may have been
15316 deduced from a later argument than the one from which
15317 this parameter can be deduced. */
15322 }
15325 {
15329 /* Clear the "incomplete" flags on all argument packs now so that
15330 substituting them into later default arguments works. */
15332 {
15335 }
15341 /* Core issue #226 (C++0x) [temp.deduct]:
15343 If a template argument has not been deduced, its
15344 default template argument, if any, is used.
15346 When we are in C++98 mode, TREE_PURPOSE will either
15347 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15348 to explicitly check cxx_dialect here. */
15350 {
15362 else
15363 {
15365 /* The position of the first default template argument,
15366 is also the number of non-defaulted arguments in TARGS.
15367 Record that. */
15371 }
15372 }
15374 /* If the type parameter is a parameter pack, then it will
15375 be deduced to an empty parameter pack. */
15377 {
15378 tree arg;
15381 {
15385 }
15386 else
15393 }
15396 }
15397 }
15398 #ifdef ENABLE_CHECKING
15401 #endif
15404 }
15406 /* Subroutine of type_unification_real. Args are like the variables
15407 at the call site. ARG is an overloaded function (or template-id);
15408 we try deducing template args from each of the overloads, and if
15409 only one succeeds, we go with that. Modifies TARGS and returns
15410 true on success. */
15412 static bool
15414 tree targs,
15415 tree parm,
15416 tree arg,
15417 unification_kind_t strict,
15420 {
15427 {
15430 }
15431 else
15435 /* Handle `&x' where `x' is some static or non-static member
15436 function name. */
15442 /* Strip baselink information. */
15447 {
15448 /* If we got some explicit template args, we need to plug them into
15449 the affected templates before we try to unify, in case the
15450 explicit args will completely resolve the templates in question. */
15457 {
15468 {
15473 {
15476 }
15477 }
15481 }
15482 /* If no templates (or more than one) are fully resolved by the
15483 explicit arguments, this template-id is a non-deduced context; it
15484 could still be OK if we deduce all template arguments for the
15485 enclosing call through other arguments. */
15488 }
15491 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15492 -- but the deduction does not succeed because the expression is
15493 not just the function on its own. */
15495 else
15501 {
15504 }
15506 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15507 to function or pointer to member function argument if the set of
15508 overloaded functions does not contain function templates and at most
15509 one of a set of overloaded functions provides a unique match.
15511 So if we found multiple possibilities, we return success but don't
15512 deduce anything. */
15515 {
15520 }
15525 }
15527 /* Core DR 115: In contexts where deduction is done and fails, or in
15528 contexts where deduction is not done, if a template argument list is
15529 specified and it, along with any default template arguments, identifies
15530 a single function template specialization, then the template-id is an
15531 lvalue for the function template specialization. */
15533 tree
15535 {
15548 {
15551 }
15553 {
15556 }
15558 {
15561 }
15564 {
15568 /* If we got some explicit template args, we need to plug them into
15569 the affected templates before we try to unify, in case the
15570 explicit args will completely resolve the templates in question. */
15578 {
15589 {
15592 {
15595 }
15597 {
15600 }
15601 }
15603 }
15605 {
15613 {
15614 tree base
15617 }
15621 }
15623 /* There were no good options and at least one bad one, so let the
15624 user know what the problem is. */
15626 }
15628 }
15630 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15631 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15632 different overloads deduce different arguments for a given parm.
15633 ADDR_P is true if the expression for which deduction is being
15634 performed was of the form "& fn" rather than simply "fn".
15636 Returns 1 on success. */
15638 static int
15640 tree orig_targs,
15641 tree targs,
15642 tree parm,
15643 tree arg,
15644 unification_kind_t strict,
15648 {
15650 tree tempargs;
15653 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15654 to function or pointer to member function argument if the set of
15655 overloaded functions does not contain function templates and at most
15656 one of a set of overloaded functions provides a unique match.
15658 So if this is a template, just return success. */
15670 /* We don't copy orig_targs for this because if we have already deduced
15671 some template args from previous args, unify would complain when we
15672 try to deduce a template parameter for the same argument, even though
15673 there isn't really a conflict. */
15680 /* First make sure we didn't deduce anything that conflicts with
15681 explicitly specified args. */
15683 {
15690 /* Since we're unifying against ourselves, we will fill in
15691 template args used in the function parm list with our own
15692 template parms. Discard them. */
15696 }
15699 {
15704 }
15707 }
15709 /* PARM is a template class (perhaps with unbound template
15710 parameters). ARG is a fully instantiated type. If ARG can be
15711 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15712 TARGS are as for unify. */
15714 static tree
15717 {
15718 tree copy_of_targs;
15725 /* We need to make a new template argument vector for the call to
15726 unify. If we used TARGS, we'd clutter it up with the result of
15727 the attempted unification, even if this class didn't work out.
15728 We also don't want to commit ourselves to all the unifications
15729 we've already done, since unification is supposed to be done on
15730 an argument-by-argument basis. In other words, consider the
15731 following pathological case:
15733 template <int I, int J, int K>
15734 struct S {};
15736 template <int I, int J>
15737 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15739 template <int I, int J, int K>
15740 void f(S<I, J, K>, S<I, I, I>);
15742 void g() {
15743 S<0, 0, 0> s0;
15744 S<0, 1, 2> s2;
15746 f(s0, s2);
15747 }
15749 Now, by the time we consider the unification involving `s2', we
15750 already know that we must have `f<0, 0, 0>'. But, even though
15751 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15752 because there are two ways to unify base classes of S<0, 1, 2>
15753 with S<I, I, I>. If we kept the already deduced knowledge, we
15754 would reject the possibility I=1. */
15757 /* If unification failed, we're done. */
15763 }
15765 /* Given a template type PARM and a class type ARG, find the unique
15766 base type in ARG that is an instance of PARM. We do not examine
15767 ARG itself; only its base-classes. If there is not exactly one
15768 appropriate base class, return NULL_TREE. PARM may be the type of
15769 a partial specialization, as well as a plain template type. Used
15770 by unify. */
15772 static enum template_base_result
15775 {
15777 tree binfo;
15783 {
15784 /* The type could not be completed. */
15787 }
15789 /* Walk in inheritance graph order. The search order is not
15790 important, and this avoids multiple walks of virtual bases. */
15792 {
15797 {
15798 /* If there is more than one satisfactory baseclass, then:
15800 [temp.deduct.call]
15802 If they yield more than one possible deduced A, the type
15803 deduction fails.
15805 applies. */
15807 {
15810 }
15813 }
15814 }
15818 }
15820 /* Returns the level of DECL, which declares a template parameter. */
15822 static int
15824 {
15826 {
15836 }
15838 }
15840 /* Decide whether ARG can be unified with PARM, considering only the
15841 cv-qualifiers of each type, given STRICT as documented for unify.
15842 Returns nonzero iff the unification is OK on that basis. */
15844 static int
15846 {
15852 {
15853 /* Although a CVR qualifier is ignored when being applied to a
15854 substituted template parameter ([8.3.2]/1 for example), that
15855 does not allow us to unify "const T" with "int&" because both
15856 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15857 It is ok when we're allowing additional CV qualifiers
15858 at the outer level [14.8.2.1]/3,1st bullet. */
15868 }
15879 }
15881 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15882 void
15884 {
15888 {
15891 }
15892 else
15893 {
15896 }
15897 }
15899 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15900 do { \
15901 if (unify (TP, TA, P, A, S, EP)) \
15902 return 1; \
15903 } while (0);
15905 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15906 expansion at the end of PACKED_PARMS. Returns 0 if the type
15907 deduction succeeds, 1 otherwise. STRICT is the same as in
15908 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15909 call argument list. We'll need to adjust the arguments to make them
15910 types. SUBR tells us if this is from a recursive call to
15911 type_unification_real, or for comparing two template argument
15912 lists. */
15914 static int
15918 {
15919 tree parm
15926 /* Determine the parameter packs we will be deducing from the
15927 pattern, and record their current deductions. */
15930 {
15934 /* Determine the index and level of this parameter pack. */
15937 /* Keep track of the parameter packs and their corresponding
15938 argument packs. */
15941 }
15943 /* Loop through all of the arguments that have not yet been
15944 unified and unify each with the pattern. */
15946 {
15947 tree parm;
15951 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
15952 or the element of its argument pack at the current index if
15953 this argument was explicitly specified. */
15955 {
15964 {
15967 }
15969 }
15971 /* If we had explicit template arguments, substitute them into the
15972 pattern before deduction. */
15974 {
15975 /* Some arguments might still be unspecified or dependent. */
15983 NULL_TREE);
15988 }
15989 else
15992 /* Unify the pattern with the current argument. */
15997 /* For each parameter pack, collect the deduced value. */
15999 {
16005 }
16006 }
16008 /* Verify that the results of unification with the parameter packs
16009 produce results consistent with what we've seen before, and make
16010 the deduced argument packs available. */
16012 {
16019 /* By default keep the original deduced argument pack.
16020 If necessary, more specific code is going to update the
16021 resulting deduced argument later down in this function. */
16025 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16026 actually deduce anything. */
16034 {
16035 /* If we had fewer function args than explicit template args,
16036 just use the explicits. */
16041 }
16044 {
16045 tree result;
16046 /* Build the deduced *_ARGUMENT_PACK. */
16048 {
16053 }
16054 else
16059 /* Note the deduced argument packs for this parameter
16060 pack. */
16062 }
16066 {
16067 /* We only had the explicitly-provided arguments before, but
16068 now we have a complete set of arguments. */
16074 }
16075 else
16076 {
16082 /* Inconsistent unification of this parameter pack. */
16084 bad_old_arg,
16085 bad_new_arg);
16086 }
16087 }
16090 }
16092 /* Deduce the value of template parameters. TPARMS is the (innermost)
16093 set of template parameters to a template. TARGS is the bindings
16094 for those template parameters, as determined thus far; TARGS may
16095 include template arguments for outer levels of template parameters
16096 as well. PARM is a parameter to a template function, or a
16097 subcomponent of that parameter; ARG is the corresponding argument.
16098 This function attempts to match PARM with ARG in a manner
16099 consistent with the existing assignments in TARGS. If more values
16100 are deduced, then TARGS is updated.
16102 Returns 0 if the type deduction succeeds, 1 otherwise. The
16103 parameter STRICT is a bitwise or of the following flags:
16105 UNIFY_ALLOW_NONE:
16106 Require an exact match between PARM and ARG.
16107 UNIFY_ALLOW_MORE_CV_QUAL:
16108 Allow the deduced ARG to be more cv-qualified (by qualification
16109 conversion) than ARG.
16110 UNIFY_ALLOW_LESS_CV_QUAL:
16111 Allow the deduced ARG to be less cv-qualified than ARG.
16112 UNIFY_ALLOW_DERIVED:
16113 Allow the deduced ARG to be a template base class of ARG,
16114 or a pointer to a template base class of the type pointed to by
16115 ARG.
16116 UNIFY_ALLOW_INTEGER:
16117 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16118 case for more information.
16119 UNIFY_ALLOW_OUTER_LEVEL:
16120 This is the outermost level of a deduction. Used to determine validity
16121 of qualification conversions. A valid qualification conversion must
16122 have const qualified pointers leading up to the inner type which
16123 requires additional CV quals, except at the outer level, where const
16124 is not required [conv.qual]. It would be normal to set this flag in
16125 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16126 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16127 This is the outermost level of a deduction, and PARM can be more CV
16128 qualified at this point.
16129 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16130 This is the outermost level of a deduction, and PARM can be less CV
16131 qualified at this point. */
16133 static int
16136 {
16138 tree targ;
16139 tree tparm;
16142 /* I don't think this will do the right thing with respect to types.
16143 But the only case I've seen it in so far has been array bounds, where
16144 signedness is the only information lost, and I think that will be
16145 okay. */
16153 /* We can't deduce anything from this, but we might get all the
16154 template args from other function args. */
16157 /* If PARM uses template parameters, then we can't bail out here,
16158 even if ARG == PARM, since we won't record unifications for the
16159 template parameters. We might need them if we're trying to
16160 figure out which of two things is more specialized. */
16164 /* Handle init lists early, so the rest of the function can assume
16165 we're dealing with a type. */
16167 {
16172 /* Replace T with std::initializer_list<T> for deduction. */
16178 /* We can only deduce from an initializer list argument if the
16179 parameter is std::initializer_list; otherwise this is a
16180 non-deduced context. */
16186 {
16193 {
16195 /* It should only be possible to get here for a call. */
16197 elt_strict |= maybe_adjust_types_for_deduction
16200 }
16203 explain_p);
16204 }
16206 /* If the std::initializer_list<T> deduction worked, replace the
16207 deduced A with std::initializer_list<A>. */
16209 {
16214 }
16216 }
16218 /* Immediately reject some pairs that won't unify because of
16219 cv-qualification mismatches. */
16222 /* It is the elements of the array which hold the cv quals of an array
16223 type, and the elements might be template type parms. We'll check
16224 when we recurse. */
16226 /* We check the cv-qualifiers when unifying with template type
16227 parameters below. We want to allow ARG `const T' to unify with
16228 PARM `T' for example, when computing which of two templates
16229 is more specialized, for example. */
16243 {
16247 /* In a type which contains a nested-name-specifier, template
16248 argument values cannot be deduced for template parameters used
16249 within the nested-name-specifier. */
16261 /* The PARM is not one we're trying to unify. Just check
16262 to see if it matches ARG. */
16263 {
16267 else
16269 }
16276 /* Check for mixed types and values. */
16284 {
16285 /* ARG must be constructed from a template class or a template
16286 template parameter. */
16291 {
16295 tree parm_parms
16296 = DECL_INNERMOST_TEMPLATE_PARMS
16301 /* The resolution to DR150 makes clear that default
16302 arguments for an N-argument may not be used to bind T
16303 to a template template parameter with fewer than N
16304 parameters. It is not safe to permit the binding of
16305 default arguments as an extension, as that may change
16306 the meaning of a conforming program. Consider:
16308 struct Dense { static const unsigned int dim = 1; };
16310 template <template <typename> class View,
16311 typename Block>
16312 void operator+(float, View<Block> const&);
16314 template <typename Block,
16315 unsigned int Dim = Block::dim>
16316 struct Lvalue_proxy { operator float() const; };
16318 void
16319 test_1d (void) {
16320 Lvalue_proxy<Dense> p;
16321 float b;
16322 b + p;
16323 }
16325 Here, if Lvalue_proxy is permitted to bind to View, then
16326 the global operator+ will be used; if they are not, the
16327 Lvalue_proxy will be converted to float. */
16329 full_argvec,
16331 (explain_p
16332 ? tf_warning_or_error
16339 /* Deduce arguments T, i from TT<T> or TT<i>.
16340 We check each element of PARMVEC and ARGVEC individually
16341 rather than the whole TREE_VEC since they can have
16342 different number of elements. */
16349 /* Check if the parameters end in a pack, making them
16350 variadic. */
16360 {
16365 }
16370 DEDUCE_EXACT,
16373 }
16376 /* Fall through to deduce template name. */
16377 }
16381 {
16382 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16384 /* Simple cases: Value already set, does match or doesn't. */
16389 }
16390 else
16391 {
16392 /* If PARM is `const T' and ARG is only `int', we don't have
16393 a match unless we are allowing additional qualification.
16394 If ARG is `const int' and PARM is just `T' that's OK;
16395 that binds `const int' to `T'. */
16400 /* Consider the case where ARG is `const volatile int' and
16401 PARM is `const T'. Then, T should be `volatile int'. */
16402 arg = cp_build_qualified_type_real
16407 /* Simple cases: Value already set, does match or doesn't. */
16413 /* Make sure that ARG is not a variable-sized array. (Note
16414 that were talking about variable-sized arrays (like
16415 `int[n]'), rather than arrays of unknown size (like
16416 `int[]').) We'll get very confused by such a type since
16417 the bound of the array is not constant, and therefore
16418 not mangleable. Besides, such types are not allowed in
16419 ISO C++, so we can do as we please here. We do allow
16420 them for 'auto' deduction, since that isn't ABI-exposed. */
16424 /* Strip typedefs as in convert_template_argument. */
16426 }
16428 /* If ARG is a parameter pack or an expansion, we cannot unify
16429 against it unless PARM is also a parameter pack. */
16434 /* If the argument deduction results is a METHOD_TYPE,
16435 then there is a problem.
16436 METHOD_TYPE doesn't map to any real C++ type the result of
16437 the deduction can not be of that type. */
16451 {
16452 /* The PARM is not one we're trying to unify. Just check
16453 to see if it matches ARG. */
16459 }
16465 {
16470 }
16472 /* [temp.deduct.type] If, in the declaration of a function template
16473 with a non-type template-parameter, the non-type
16474 template-parameter is used in an expression in the function
16475 parameter-list and, if the corresponding template-argument is
16476 deduced, the template-argument type shall match the type of the
16477 template-parameter exactly, except that a template-argument
16478 deduced from an array bound may be of any integral type.
16479 The non-type parameter might use already deduced type parameters. */
16482 /* Template-parameter dependent expression. Just accept it for now.
16483 It will later be processed in convert_template_argument. */
16484 ;
16490 /* Convert the ARG to the type of PARM; the deduced non-type
16491 template argument must exactly match the types of the
16492 corresponding parameter. */
16495 /* We haven't deduced the type of this parameter yet. Try again
16496 later. */
16498 else
16501 /* If ARG is a parameter pack or an expansion, we cannot unify
16502 against it unless PARM is also a parameter pack. */
16511 {
16512 /* A pointer-to-member constant can be unified only with
16513 another constant. */
16517 /* Just unify the class member. It would be useless (and possibly
16518 wrong, depending on the strict flags) to unify also
16519 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16520 arg refer to the same variable, even if through different
16521 classes. For instance:
16523 struct A { int x; };
16524 struct B : A { };
16526 Unification of &A::x and &B::x must succeed. */
16529 }
16532 {
16536 /* [temp.deduct.call]
16538 A can be another pointer or pointer to member type that can
16539 be converted to the deduced A via a qualification
16540 conversion (_conv.qual_).
16542 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16543 This will allow for additional cv-qualification of the
16544 pointed-to types if appropriate. */
16547 /* The derived-to-base conversion only persists through one
16548 level of pointers. */
16553 }
16568 {
16569 tree parm_max;
16570 tree arg_max;
16574 /* Our representation of array types uses "N - 1" as the
16575 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16576 not an integer constant. We cannot unify arbitrarily
16577 complex expressions, so we eliminate the MINUS_EXPRs
16578 here. */
16582 {
16585 }
16589 {
16590 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16591 trying to unify the type of a variable with the type
16592 of a template parameter. For example:
16594 template <unsigned int N>
16595 void f (char (&) [N]);
16596 int g();
16597 void h(int i) {
16598 char a[g(i)];
16599 f(a);
16600 }
16602 Here, the type of the ARG will be "int [g(i)]", and
16603 may be a SAVE_EXPR, etc. */
16607 }
16609 /* If only one of the bounds used a MINUS_EXPR, compensate
16610 by adding one to the other bound. */
16613 integer_type_node,
16614 parm_max,
16615 integer_one_node);
16618 integer_type_node,
16619 arg_max,
16620 integer_one_node);
16624 }
16639 /* We have already checked cv-qualification at the top of the
16640 function. */
16644 /* As far as unification is concerned, this wins. Later checks
16645 will invalidate it if necessary. */
16648 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16649 /* Type INTEGER_CST can come from ordinary constant template args. */
16661 {
16671 /* Check for pack expansions in the parameters. */
16673 {
16675 {
16677 /* We can unify against something with a trailing
16678 parameter pack. */
16680 else
16681 /* [temp.deduct.type]/9: If the template argument list of
16682 P contains a pack expansion that is not the last
16683 template argument, the entire template argument list
16684 is a non-deduced context. */
16686 }
16687 }
16689 /* If we don't have enough arguments to satisfy the parameters
16690 (not counting the pack expression at the end), or we have
16691 too many arguments for a parameter list that doesn't end in
16692 a pack expression, we can't unify. */
16698 /* Unify all of the parameters that precede the (optional)
16699 pack expression. */
16701 {
16706 }
16709 DEDUCE_EXACT,
16712 }
16720 {
16728 }
16731 {
16735 {
16736 /* First, we try to unify the PARM and ARG directly. */
16741 {
16742 /* Fallback to the special case allowed in
16743 [temp.deduct.call]:
16745 If P is a class, and P has the form
16746 template-id, then A can be a derived class of
16747 the deduced A. Likewise, if P is a pointer to
16748 a class of the form template-id, A can be a
16749 pointer to a derived class pointed to by the
16750 deduced A. */
16757 }
16758 }
16762 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16763 Then, we should unify `int' and `U'. */
16765 else
16766 /* There's no chance of unification succeeding. */
16771 }
16778 {
16781 tree a;
16787 /* CV qualifications for methods can never be deduced, they must
16788 match exactly. We need to check them explicitly here,
16789 because type_unification_real treats them as any other
16790 cv-qualified parameter. */
16792 && (!check_cv_quals_for_unify
16812 }
16815 /* Unify a pointer to member with a pointer to member function, which
16816 deduces the type of the member as a function type. */
16818 {
16819 tree method_type;
16820 tree fntype;
16822 /* Check top-level cv qualifiers */
16830 /* Determine the type of the function we are unifying against. */
16832 fntype =
16836 /* Extract the cv-qualifiers of the member function from the
16837 implicit object parameter and place them on the function
16838 type to be restored later. */
16841 }
16860 /* Matched cases are handled by the ARG == PARM test above. */
16864 /* A non-type template parameter that is a variable should be a
16865 an integral constant, in which case, it whould have been
16866 folded into its (constant) value. So we should not be getting
16867 a variable here. */
16878 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16879 or UNDERLYING_TYPE nodes. */
16883 /* Unification fails if we hit an error node. */
16887 /* An unresolved overload is a nondeduced context. */
16892 /* We must be looking at an expression. This can happen with
16893 something like:
16895 template <int I>
16896 void foo(S<I>, S<I + 2>);
16898 This is a "nondeduced context":
16900 [deduct.type]
16902 The nondeduced contexts are:
16904 --A type that is a template-id in which one or more of
16905 the template-arguments is an expression that references
16906 a template-parameter.
16908 In these cases, we assume deduction succeeded, but don't
16909 actually infer any unifications. */
16914 else
16916 }
16917 }
16918 #undef RECUR_AND_CHECK_FAILURE
16919 \f
16920 /* Note that DECL can be defined in this translation unit, if
16921 required. */
16923 static void
16925 {
16926 tree clone;
16930 }
16932 /* Called if RESULT is explicitly instantiated, or is a member of an
16933 explicitly instantiated class. */
16935 void
16937 {
16940 /* If this entity has already been written out, it's too late to
16941 make any modifications. */
16946 /* The TREE_PUBLIC flag for function declarations will have been
16947 set correctly by tsubst. */
16950 /* This might have been set by an earlier implicit instantiation. */
16955 else
16956 {
16958 /* Always make artificials weak. */
16961 /* For WIN32 we also want to put explicit instantiations in
16962 linkonce sections. */
16965 }
16967 /* If EXTERN_P, then this function will not be emitted -- unless
16968 followed by an explicit instantiation, at which point its linkage
16969 will be adjusted. If !EXTERN_P, then this function will be
16970 emitted here. In neither circumstance do we want
16971 import_export_decl to adjust the linkage. */
16973 }
16975 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16976 important template arguments. If any are missing, we check whether
16977 they're important by using error_mark_node for substituting into any
16978 args that were used for partial ordering (the ones between ARGS and END)
16979 and seeing if it bubbles up. */
16981 static bool
16983 {
16988 {
16991 }
16993 {
16995 {
16999 }
17000 }
17002 }
17004 /* Given two function templates PAT1 and PAT2, return:
17006 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17007 -1 if PAT2 is more specialized than PAT1.
17008 0 if neither is more specialized.
17010 LEN indicates the number of parameters we should consider
17011 (defaulted parameters should not be considered).
17013 The 1998 std underspecified function template partial ordering, and
17014 DR214 addresses the issue. We take pairs of arguments, one from
17015 each of the templates, and deduce them against each other. One of
17016 the templates will be more specialized if all the *other*
17017 template's arguments deduce against its arguments and at least one
17018 of its arguments *does* *not* deduce against the other template's
17019 corresponding argument. Deduction is done as for class templates.
17020 The arguments used in deduction have reference and top level cv
17021 qualifiers removed. Iff both arguments were originally reference
17022 types *and* deduction succeeds in both directions, the template
17023 with the more cv-qualified argument wins for that pairing (if
17024 neither is more cv-qualified, they both are equal). Unlike regular
17025 deduction, after all the arguments have been deduced in this way,
17026 we do *not* verify the deduced template argument values can be
17027 substituted into non-deduced contexts.
17029 The logic can be a bit confusing here, because we look at deduce1 and
17030 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17031 can find template arguments for pat1 to make arg1 look like arg2, that
17032 means that arg2 is at least as specialized as arg1. */
17034 int
17036 {
17049 /* Remove the this parameter from non-static member functions. If
17050 one is a non-static member function and the other is not a static
17051 member function, remove the first parameter from that function
17052 also. This situation occurs for operator functions where we
17053 locate both a member function (with this pointer) and non-member
17054 operator (with explicit first operand). */
17056 {
17061 }
17063 {
17066 {
17067 len--;
17069 }
17070 }
17072 /* If only one is a conversion operator, they are unordered. */
17076 /* Consider the return type for a conversion function */
17078 {
17081 len++;
17082 }
17084 processing_template_decl++;
17090 /* Stop when an ellipsis is seen. */
17092 {
17101 {
17102 /* When both arguments are pack expansions, we need only
17103 unify the patterns themselves. */
17107 /* This is the last comparison we need to do. */
17109 }
17112 {
17115 }
17118 {
17121 }
17124 {
17125 /* Only of the args is a reference, see if we should apply
17126 array/function pointer decay to it. This is not part of
17127 DR214, but is, IMHO, consistent with the deduction rules
17128 for the function call itself, and with our earlier
17129 implementation of the underspecified partial ordering
17130 rules. (nathan). */
17132 {
17134 {
17137 /* FALLTHROUGH. */
17144 }
17145 }
17146 else
17147 {
17149 {
17152 /* FALLTHROUGH. */
17159 }
17160 }
17161 }
17167 {
17173 /* Setup the parameter vector, which contains only ARG1. */
17176 /* Setup the argument vector, which contains the remaining
17177 arguments. */
17186 /* We cannot deduce in the other direction, because ARG1 is
17187 a pack expansion but ARG2 is not. */
17189 }
17191 {
17197 /* Setup the parameter vector, which contains only ARG1. */
17200 /* Setup the argument vector, which contains the remaining
17201 arguments. */
17210 /* We cannot deduce in the other direction, because ARG2 is
17211 a pack expansion but ARG1 is not.*/
17213 }
17215 else
17216 {
17217 /* The normal case, where neither argument is a pack
17218 expansion. */
17225 }
17227 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17228 arg2, then arg2 is not as specialized as arg1. */
17234 /* "If, for a given type, deduction succeeds in both directions
17235 (i.e., the types are identical after the transformations above)
17236 and if the type from the argument template is more cv-qualified
17237 than the type from the parameter template (as described above)
17238 that type is considered to be more specialized than the other. If
17239 neither type is more cv-qualified than the other then neither type
17240 is more specialized than the other." */
17244 {
17249 }
17252 /* We've failed to deduce something in either direction.
17253 These must be unordered. */
17258 /* We have already processed all of the arguments in our
17259 handing of the pack expansion type. */
17264 }
17266 /* "In most cases, all template parameters must have values in order for
17267 deduction to succeed, but for partial ordering purposes a template
17268 parameter may remain without a value provided it is not used in the
17269 types being used for partial ordering."
17271 Thus, if we are missing any of the targs1 we need to substitute into
17272 origs1, then pat2 is not as specialized as pat1. This can happen when
17273 there is a nondeduced context. */
17279 processing_template_decl--;
17281 /* All things being equal, if the next argument is a pack expansion
17282 for one function but not for the other, prefer the
17283 non-variadic function. FIXME this is bogus; see c++/41958. */
17287 {
17290 }
17296 else
17298 }
17300 /* Determine which of two partial specializations is more specialized.
17302 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17303 to the first partial specialization. The TREE_VALUE is the
17304 innermost set of template parameters for the partial
17305 specialization. PAT2 is similar, but for the second template.
17307 Return 1 if the first partial specialization is more specialized;
17308 -1 if the second is more specialized; 0 if neither is more
17309 specialized.
17311 See [temp.class.order] for information about determining which of
17312 two templates is more specialized. */
17314 static int
17316 {
17317 tree targs;
17325 /* Just like what happens for functions, if we are ordering between
17326 different class template specializations, we may encounter dependent
17327 types in the arguments, and we need our dependency check functions
17328 to behave correctly. */
17334 {
17337 }
17343 {
17346 }
17349 /* In the case of a tie where at least one of the class templates
17350 has a parameter pack at the end, the template with the most
17351 non-packed parameters wins. */
17353 && any_deductions
17356 {
17362 /* We don't count the pack expansion at the end. */
17372 }
17375 }
17377 /* Return the template arguments that will produce the function signature
17378 DECL from the function template FN, with the explicit template
17379 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17380 also match. Return NULL_TREE if no satisfactory arguments could be
17381 found. */
17383 static tree
17385 {
17388 tree decl_type;
17389 tree decl_arg_types;
17392 tree arg;
17394 /* Substitute the explicit template arguments into the type of DECL.
17395 The call to fn_type_unification will handle substitution into the
17396 FN. */
17399 {
17400 tree tmpl;
17401 tree converted_args;
17405 else
17406 /* We can get here for some invalid specializations. */
17409 converted_args
17412 tf_none,
17421 }
17423 /* Never do unification on the 'this' parameter. */
17442 }
17444 /* Return the innermost template arguments that, when applied to a
17445 template specialization whose innermost template parameters are
17446 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17447 ARGS.
17449 For example, suppose we have:
17451 template <class T, class U> struct S {};
17452 template <class T> struct S<T*, int> {};
17454 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17455 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17456 int}. The resulting vector will be {double}, indicating that `T'
17457 is bound to `double'. */
17459 static tree
17461 {
17463 tree deduced_args;
17464 tree innermost_deduced_args;
17468 {
17472 innermost_deduced_args);
17473 }
17474 else
17487 /* Verify that nondeduced template arguments agree with the type
17488 obtained from argument deduction.
17490 For example:
17492 struct A { typedef int X; };
17493 template <class T, class U> struct C {};
17494 template <class T> struct C<T, typename T::X> {};
17496 Then with the instantiation `C<A, int>', we can deduce that
17497 `T' is `A' but unify () does not check whether `typename T::X'
17498 is `int'. */
17501 /* We only need to check the innermost arguments; the other
17502 arguments will always agree. */
17507 /* Now that we have bindings for all of the template arguments,
17508 ensure that the arguments deduced for the template template
17509 parameters have compatible template parameter lists. See the use
17510 of template_template_parm_bindings_ok_p in fn_type_unification
17511 for more information. */
17516 }
17518 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17519 Return the TREE_LIST node with the most specialized template, if
17520 any. If there is no most specialized template, the error_mark_node
17521 is returned.
17523 Note that this function does not look at, or modify, the
17524 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17525 returned is one of the elements of INSTANTIATIONS, callers may
17526 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17527 and retrieve it from the value returned. */
17529 tree
17531 {
17538 {
17544 fate--;
17549 fate++;
17554 {
17555 /* Equally specialized, move to next function. If there
17556 is no next function, nothing's most specialized. */
17561 }
17562 }
17565 /* Now verify that champ is better than everything earlier in the
17566 instantiation list. */
17574 {
17577 }
17579 processing_template_decl--;
17585 }
17587 /* If DECL is a specialization of some template, return the most
17588 general such template. Otherwise, returns NULL_TREE.
17590 For example, given:
17592 template <class T> struct S { template <class U> void f(U); };
17594 if TMPL is `template <class U> void S<int>::f(U)' this will return
17595 the full template. This function will not trace past partial
17596 specializations, however. For example, given in addition:
17598 template <class T> struct S<T*> { template <class U> void f(U); };
17600 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17601 `template <class T> template <class U> S<T*>::f(U)'. */
17603 tree
17605 {
17606 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17607 an immediate specialization. */
17609 {
17613 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17614 template friend. */
17619 }
17621 /* Look for more and more general templates. */
17623 {
17624 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17625 (See cp-tree.h for details.) */
17633 /* Stop if we run into an explicitly specialized class template. */
17640 }
17643 }
17645 /* Return the most specialized of the class template partial
17646 specializations of TMPL which can produce TYPE, a specialization of
17647 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17648 a _TYPE node corresponding to the partial specialization, while the
17649 TREE_PURPOSE is the set of template arguments that must be
17650 substituted into the TREE_TYPE in order to generate TYPE.
17652 If the choice of partial specialization is ambiguous, a diagnostic
17653 is issued, and the error_mark_node is returned. If there are no
17654 partial specializations of TMPL matching TYPE, then NULL_TREE is
17655 returned. */
17657 static tree
17659 {
17661 tree t;
17662 tree champ;
17665 tree args;
17671 /* For determining which partial specialization to use, only the
17672 innermost args are interesting. */
17674 {
17677 }
17680 {
17681 tree partial_spec_args;
17682 tree spec_args;
17690 {
17693 /* Discard the outer levels of args, and then substitute in the
17694 template args from the enclosing class. */
17696 partial_spec_args = tsubst_template_args
17699 /* PARMS already refers to just the innermost parms, but the
17700 template parms in partial_spec_args had their levels lowered
17701 by tsubst, so we need to do the same for the parm list. We
17702 can't just tsubst the TREE_VEC itself, as tsubst wants to
17703 treat a TREE_VEC as an argument vector. */
17709 }
17711 partial_spec_args =
17714 partial_spec_args),
17725 partial_spec_args,
17726 args);
17728 {
17733 }
17734 }
17744 {
17747 ;
17748 else
17749 {
17751 {
17754 {
17757 }
17758 }
17760 }
17761 }
17765 {
17768 {
17771 }
17772 }
17775 {
17783 {
17786 }
17789 }
17792 }
17794 /* Explicitly instantiate DECL. */
17796 void
17798 {
17803 /* An error occurred, for which grokdeclarator has already issued
17804 an appropriate message. */
17807 {
17810 }
17812 {
17813 /* There is an asymmetry here in the way VAR_DECLs and
17814 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17815 the latter, the DECL we get back will be marked as a
17816 template instantiation, and the appropriate
17817 DECL_TEMPLATE_INFO will be set up. This does not happen for
17818 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17819 should handle VAR_DECLs as it currently handles
17820 FUNCTION_DECLs. */
17822 {
17825 }
17828 {
17831 }
17833 {
17838 }
17839 }
17841 {
17844 }
17845 else
17848 /* Check for various error cases. Note that if the explicit
17849 instantiation is valid the RESULT will currently be marked as an
17850 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17851 until we get here. */
17854 {
17855 /* DR 259 [temp.spec].
17857 Both an explicit instantiation and a declaration of an explicit
17858 specialization shall not appear in a program unless the explicit
17859 instantiation follows a declaration of the explicit specialization.
17861 For a given set of template parameters, if an explicit
17862 instantiation of a template appears after a declaration of an
17863 explicit specialization for that template, the explicit
17864 instantiation has no effect. */
17866 }
17868 {
17869 /* [temp.spec]
17871 No program shall explicitly instantiate any template more
17872 than once.
17874 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17875 the first instantiation was `extern' and the second is not,
17876 and EXTERN_P for the opposite case. */
17879 /* If an "extern" explicit instantiation follows an ordinary
17880 explicit instantiation, the template is instantiated. */
17883 }
17885 {
17888 }
17890 {
17893 }
17896 ;
17898 {
17901 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17904 }
17905 else
17913 }
17915 static void
17917 {
17923 {
17926 }
17927 }
17929 /* Called from do_type_instantiation through binding_table_foreach to
17930 do recursive instantiation for the type bound in ENTRY. */
17931 static void
17933 {
17939 }
17941 /* Called from do_type_instantiation to instantiate a member
17942 (a member function or a static member variable) of an
17943 explicitly instantiated class template. */
17944 static void
17946 {
17951 }
17953 /* Perform an explicit instantiation of template class T. STORAGE, if
17954 non-null, is the RID for extern, inline or static. COMPLAIN is
17955 nonzero if this is called from the parser, zero if called recursively,
17956 since the standard is unclear (as detailed below). */
17958 void
17960 {
17970 {
17971 tree tmpl =
17975 else
17978 }
17983 {
17986 t);
17988 }
17991 {
17993 {
17995 {
17998 "ISO C++ 1998 forbids the use of %<extern%> on "
18000 }
18001 else
18003 "ISO C++ forbids the use of %qE"
18005 }
18013 else
18014 {
18016 storage);
18018 }
18019 }
18022 {
18023 /* DR 259 [temp.spec].
18025 Both an explicit instantiation and a declaration of an explicit
18026 specialization shall not appear in a program unless the explicit
18027 instantiation follows a declaration of the explicit specialization.
18029 For a given set of template parameters, if an explicit
18030 instantiation of a template appears after a declaration of an
18031 explicit specialization for that template, the explicit
18032 instantiation has no effect. */
18034 }
18036 {
18037 /* [temp.spec]
18039 No program shall explicitly instantiate any template more
18040 than once.
18042 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18043 instantiation was `extern'. If EXTERN_P then the second is.
18044 These cases are OK. */
18051 /* If we've already instantiated the template, just return now. */
18054 }
18062 {
18063 tree tmp;
18065 /* In contrast to implicit instantiation, where only the
18066 declarations, and not the definitions, of members are
18067 instantiated, we have here:
18069 [temp.explicit]
18071 The explicit instantiation of a class template specialization
18072 implies the instantiation of all of its members not
18073 previously explicitly specialized in the translation unit
18074 containing the explicit instantiation.
18076 Of course, we can't instantiate member template classes, since
18077 we don't have any arguments for them. Note that the standard
18078 is unclear on whether the instantiation of the members are
18079 *explicit* instantiations or not. However, the most natural
18080 interpretation is that it should be an explicit instantiation. */
18095 }
18096 }
18098 /* Given a function DECL, which is a specialization of TMPL, modify
18099 DECL to be a re-instantiation of TMPL with the same template
18100 arguments. TMPL should be the template into which tsubst'ing
18101 should occur for DECL, not the most general template.
18103 One reason for doing this is a scenario like this:
18105 template <class T>
18106 void f(const T&, int i);
18108 void g() { f(3, 7); }
18110 template <class T>
18111 void f(const T& t, const int i) { }
18113 Note that when the template is first instantiated, with
18114 instantiate_template, the resulting DECL will have no name for the
18115 first parameter, and the wrong type for the second. So, when we go
18116 to instantiate the DECL, we regenerate it. */
18118 static void
18120 {
18121 /* The arguments used to instantiate DECL, from the most general
18122 template. */
18123 tree args;
18124 tree code_pattern;
18129 /* Make sure that we can see identifiers, and compute access
18130 correctly. */
18134 {
18135 tree decl_parm;
18136 tree pattern_parm;
18137 tree specs;
18151 specs);
18153 /* Merge parameter declarations. */
18156 pattern_parm
18160 {
18161 tree parm_type;
18162 tree attributes;
18167 NULL_TREE);
18173 {
18176 }
18179 }
18180 /* Merge any parameters that match with the function parameter
18181 pack. */
18183 {
18185 tree expanded_types;
18186 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18187 the parameters in this function parameter pack. */
18192 {
18193 tree parm_type;
18194 tree attributes;
18197 /* Rename the parameter to include the index. */
18206 {
18209 }
18211 }
18212 }
18213 /* Merge additional specifiers from the CODE_PATTERN. */
18217 }
18219 {
18227 }
18228 else
18232 }
18234 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18235 substituted to get DECL. */
18237 tree
18239 {
18242 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18243 for the instantiation. This is not always the most general
18244 template. Consider, for example:
18246 template <class T>
18247 struct S { template <class U> void f();
18248 template <> void f<int>(); };
18250 and an instantiation of S<double>::f<int>. We want TD to be the
18251 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18253 more general template. */
18255 /* We must also deal with friend templates. Given:
18257 template <class T> struct S {
18258 template <class U> friend void f() {};
18259 };
18261 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18262 so far as the language is concerned, but that's still
18263 where we get the pattern for the instantiation from. On
18264 other hand, if the definition comes outside the class, say:
18266 template <class T> struct S {
18267 template <class U> friend void f();
18268 };
18269 template <class U> friend void f() {}
18271 we don't need to look any further. That's what the check for
18272 DECL_INITIAL is for. */
18276 {
18277 /* The present template, TD, should not be a definition. If it
18278 were a definition, we should be using it! Note that we
18279 cannot restructure the loop to just keep going until we find
18280 a template with a definition, since that might go too far if
18281 a specialization was declared, but not defined. */
18285 /* Fetch the more general template. */
18287 }
18290 }
18292 /* Returns true if we need to instantiate this template instance even if we
18293 know we aren't going to emit it.. */
18295 bool
18297 {
18298 /* We always instantiate inline functions so that we can inline them. An
18299 explicit instantiation declaration prohibits implicit instantiation of
18300 non-inline functions. With high levels of optimization, we would
18301 normally inline non-inline functions -- but we're not allowed to do
18302 that for "extern template" functions. Therefore, we check
18303 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18306 /* And we need to instantiate static data members so that
18307 their initializers are available in integral constant
18308 expressions. */
18311 }
18313 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18314 instantiate it now, modifying TREE_TYPE (fn). */
18316 void
18318 {
18332 {
18334 {
18347 }
18348 else
18350 }
18351 else
18352 {
18353 /* This is an implicitly declared function, so NOEX is a list of
18354 other functions to evaluate and merge. */
18355 tree elt;
18358 {
18360 tree subspec;
18364 }
18365 }
18370 {
18373 else
18375 }
18376 }
18378 /* Produce the definition of D, a _DECL generated from a template. If
18379 DEFER_OK is nonzero, then we don't have to actually do the
18380 instantiation now; we just have to do it sometime. Normally it is
18381 an error if this is an explicit instantiation but D is undefined.
18382 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18383 explicitly instantiated class template. */
18385 tree
18388 {
18390 tree gen_args;
18391 tree args;
18392 tree td;
18393 tree code_pattern;
18394 tree spec;
18395 tree gen_tmpl;
18401 /* This function should only be used to instantiate templates for
18402 functions and static member variables. */
18406 /* Variables are never deferred; if instantiation is required, they
18407 are instantiated right away. That allows for better code in the
18408 case that an expression refers to the value of the variable --
18409 if the variable has a constant value the referring expression can
18410 take advantage of that fact. */
18415 /* Don't instantiate cloned functions. Instead, instantiate the
18416 functions they cloned. */
18424 /* D has already been instantiated or explicitly specialized, so
18425 there's nothing for us to do here.
18427 It might seem reasonable to check whether or not D is an explicit
18428 instantiation, and, if so, stop here. But when an explicit
18429 instantiation is deferred until the end of the compilation,
18430 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18431 the instantiation. */
18434 /* Check to see whether we know that this template will be
18435 instantiated in some other file, as with "extern template"
18436 extension. */
18439 /* In general, we do not instantiate such templates. */
18447 /* We should already have the extra args. */
18450 /* And what's in the hash table should match D. */
18454 /* This needs to happen before any tsubsting. */
18460 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18461 for the instantiation. */
18465 /* We should never be trying to instantiate a member of a class
18466 template or partial specialization. */
18471 /* In the case of a friend template whose definition is provided
18472 outside the class, we may have too many arguments. Drop the
18473 ones we don't need. The same is true for specializations. */
18474 args = get_innermost_template_args
18476 else
18482 else
18485 /* We may be in the middle of deferred access check. Disable it now. */
18488 /* Unless an explicit instantiation directive has already determined
18489 the linkage of D, remember that a definition is available for
18490 this entity. */
18500 /* If D is a member of an explicitly instantiated class template,
18501 and no definition is available, treat it like an implicit
18502 instantiation. */
18505 {
18506 /* Leave linkage flags alone on instantiations with anonymous
18507 visibility. */
18509 {
18512 }
18514 }
18519 /* Recheck the substitutions to obtain any warning messages
18520 about ignoring cv qualifiers. Don't do this for artificial decls,
18521 as it breaks the context-sensitive substitution for lambda op(). */
18523 {
18527 /* Make sure that we can see identifiers, and compute access
18528 correctly. D is already the target FUNCTION_DECL with the
18529 right context. */
18533 {
18537 /* Don't simply tsubst the function type, as that will give
18538 duplicate warnings about poor parameter qualifications.
18539 The function arguments are the same as the decl_arguments
18540 without the top level cv qualifiers. */
18542 }
18546 }
18548 /* Defer all other templates, unless we have been explicitly
18549 forbidden from doing so. */
18551 template. */
18552 ! pattern_defined
18553 /* If it's OK to postpone instantiation, do so. */
18554 || defer_ok
18555 /* If this is a static data member that will be defined
18556 elsewhere, we don't want to instantiate the entire data
18557 member, but we do want to instantiate the initializer so that
18558 we can substitute that elsewhere. */
18560 {
18561 /* The definition of the static data member is now required so
18562 we must substitute the initializer. */
18566 {
18567 tree ns;
18568 tree init;
18575 args,
18578 /* Make sure the initializer is still constant, in case of
18579 circular dependency (template/instantiate6.C). */
18580 const_init
18584 LOOKUP_ONLYCONVERTING);
18587 }
18589 /* We restore the source position here because it's used by
18590 add_pending_template. */
18596 /* [temp.explicit]
18598 The definition of a non-exported function template, a
18599 non-exported member function template, or a non-exported
18600 member function or static data member of a class template
18601 shall be present in every translation unit in which it is
18602 explicitly instantiated. */
18606 /* If we're in unevaluated context, we just wanted to get the
18607 constant value; this isn't an odr use, so don't queue
18608 a full instantiation. */
18611 /* ??? Historically, we have instantiated inline functions, even
18612 when marked as "extern template". */
18616 }
18617 /* Tell the repository that D is available in this translation unit
18618 -- and see if it is supposed to be instantiated here. */
18620 {
18621 /* In a PCH file, despite the fact that the repository hasn't
18622 requested instantiation in the PCH it is still possible that
18623 an instantiation will be required in a file that includes the
18624 PCH. */
18627 /* Instantiate inline functions so that the inliner can do its
18628 job, even though we'll not be emitting a copy of this
18629 function. */
18632 }
18638 /* Mark D as instantiated so that recursive calls to
18639 instantiate_decl do not try to instantiate it again. */
18642 /* Regenerate the declaration in case the template has been modified
18643 by a subsequent redeclaration. */
18646 /* We already set the file and line above. Reset them now in case
18647 they changed as a result of calling regenerate_decl_from_template. */
18651 {
18652 tree init;
18655 /* Clear out DECL_RTL; whatever was there before may not be right
18656 since we've reset the type of the declaration. */
18660 /* The initializer is placed in DECL_INITIAL by
18661 regenerate_decl_from_template so we don't need to
18662 push/pop_access_scope again here. Pull it out so that
18663 cp_finish_decl can process it. */
18668 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18669 initializer. That function will defer actual emission until
18670 we have a chance to determine linkage. */
18673 /* Enter the scope of D so that access-checking works correctly. */
18678 }
18682 {
18684 tree subst_decl;
18685 tree tmpl_parm;
18686 tree spec_parm;
18688 /* Save away the current list, in case we are instantiating one
18689 template from within the body of another. */
18692 /* Set up the list of local specializations. */
18695 /* Set up context. */
18698 /* Create substitution entries for the parameters. */
18703 {
18707 }
18709 {
18711 {
18714 }
18715 else
18716 {
18717 /* Register the (value) argument pack as a specialization of
18718 TMPL_PARM, then move on. */
18721 }
18722 }
18725 /* Substitute into the body of the function. */
18730 /* Set the current input_location to the end of the function
18731 so that finish_function knows where we are. */
18734 /* We don't need the local specializations any more. */
18738 /* Finish the function. */
18741 }
18743 /* We're not deferring instantiation any more. */
18749 out:
18757 }
18759 /* Run through the list of templates that we wish we could
18760 instantiate, and instantiate any we can. RETRIES is the
18761 number of times we retry pending template instantiation. */
18763 void
18765 {
18769 /* Instantiating templates may trigger vtable generation. This in turn
18770 may require further template instantiations. We place a limit here
18771 to avoid infinite loop. */
18773 {
18777 " instantiating %q+D, possibly from virtual table generation"
18781 /* Pretend that we defined it. */
18784 }
18786 do
18787 {
18792 {
18797 {
18798 tree fn;
18801 {
18805 fn;
18813 }
18816 }
18817 else
18818 {
18821 {
18822 instantiation
18828 }
18832 }
18835 /* If INSTANTIATION has been instantiated, then we don't
18836 need to consider it again in the future. */
18838 else
18839 {
18842 }
18845 }
18847 }
18851 }
18853 /* Substitute ARGVEC into T, which is a list of initializers for
18854 either base class or a non-static data member. The TREE_PURPOSEs
18855 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18856 instantiate_decl. */
18858 static tree
18860 {
18864 {
18865 tree decl;
18866 tree init;
18872 {
18873 tree expr;
18874 tree arg;
18876 /* Expand the base class expansion type into separate base
18877 classes. */
18879 tf_warning_or_error,
18880 NULL_TREE);
18884 /* We'll be building separate TREE_LISTs of arguments for
18885 each base. */
18891 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18892 expand each argument in the TREE_VALUE of t. */
18899 /* VOID_TYPE_NODE is used to indicate
18900 value-initialization. */
18901 {
18904 }
18905 else
18906 {
18907 /* Substitute parameter packs into each argument in the
18908 TREE_LIST. */
18911 {
18912 tree expanded_exprs;
18914 /* Expand the argument. */
18916 expanded_exprs
18918 tf_warning_or_error,
18919 NULL_TREE);
18923 /* Prepend each of the expanded expressions to the
18924 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18926 {
18931 }
18932 }
18935 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18936 since we built them backwards. */
18938 {
18941 }
18942 }
18943 }
18946 {
18948 {
18952 }
18953 else
18954 {
18968 }
18971 {
18975 }
18976 }
18977 }
18979 }
18981 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
18983 static void
18985 {
18990 else
18992 }
18994 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
18995 is the instantiation (which should have been created with
18996 start_enum) and ARGS are the template arguments to use. */
18998 static void
19000 {
19001 tree e;
19007 {
19008 tree value;
19009 tree decl;
19012 /* Note that in a template enum, the TREE_VALUE is the
19013 CONST_DECL, not the corresponding INTEGER_CST. */
19018 /* Give this enumeration constant the correct access. */
19021 /* Actually build the enumerator itself. */
19022 build_enumerator
19024 }
19034 }
19036 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19037 its type -- but without substituting the innermost set of template
19038 arguments. So, innermost set of template parameters will appear in
19039 the type. */
19041 tree
19043 {
19044 tree fn_type;
19045 tree tmpl;
19046 tree targs;
19047 tree tparms;
19055 /* There should be as many levels of arguments as there are levels
19056 of parameters. */
19062 /* No substitution is necessary. */
19063 ;
19064 else
19065 {
19067 tree partial_args;
19069 /* Replace the innermost level of the TARGS with NULL_TREEs to
19070 let tsubst know not to substitute for those parameters. */
19079 /* Make sure that we can see identifiers, and compute access
19080 correctly. */
19084 /* Now, do the (partial) substitution to figure out the
19085 appropriate function type. */
19089 /* Substitute into the template parameters to obtain the real
19090 innermost set of parameters. This step is important if the
19091 innermost set of template parameters contains value
19092 parameters whose types depend on outer template parameters. */
19097 }
19100 }
19102 /* Return truthvalue if we're processing a template different from
19103 the last one involved in diagnostics. */
19104 int
19106 {
19108 }
19110 /* Remember current template involved in diagnostics. */
19111 void
19113 {
19115 }
19119 {
19121 }
19123 /* [temp.param] Check that template non-type parm TYPE is of an allowable
19124 type. Return zero for ok, nonzero for disallowed. Issue error and
19125 warning messages under control of COMPLAIN. */
19127 static int
19129 {
19146 {
19149 else
19151 type);
19152 }
19154 }
19156 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19157 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19159 static bool
19161 {
19162 tree scope;
19164 /* [temp.dep.type]
19166 A type is dependent if it is:
19168 -- a template parameter. Template template parameters are types
19169 for us (since TYPE_P holds true for them) so we handle
19170 them here. */
19174 /* -- a qualified-id with a nested-name-specifier which contains a
19175 class-name that names a dependent type or whose unqualified-id
19176 names a dependent type. */
19179 /* -- a cv-qualified type where the cv-unqualified type is
19180 dependent. */
19182 /* -- a compound type constructed from any dependent type. */
19192 {
19193 tree arg_type;
19198 arg_type;
19203 }
19204 /* -- an array type constructed from any dependent type or whose
19205 size is specified by a constant expression that is
19206 value-dependent.
19208 We checked for type- and value-dependence of the bounds in
19209 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19211 {
19216 }
19218 /* -- a template-id in which either the template name is a template
19219 parameter ... */
19222 /* ... or any of the template arguments is a dependent type or
19223 an expression that is type-dependent or value-dependent. */
19225 && (any_dependent_template_arguments_p
19229 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19230 dependent; if the argument of the `typeof' expression is not
19231 type-dependent, then it should already been have resolved. */
19237 /* A template argument pack is dependent if any of its packed
19238 arguments are. */
19240 {
19246 }
19248 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19249 be template parameters. */
19253 /* The standard does not specifically mention types that are local
19254 to template functions or local classes, but they should be
19255 considered dependent too. For example:
19257 template <int I> void f() {
19258 enum E { a = I };
19259 S<sizeof (E)> s;
19260 }
19262 The size of `E' cannot be known until the value of `I' has been
19263 determined. Therefore, `E' must be considered dependent. */
19267 /* Don't use type_dependent_expression_p here, as it can lead
19268 to infinite recursion trying to determine whether a lambda
19269 nested in a lambda is dependent (c++/47687). */
19273 && (any_dependent_template_arguments_p
19277 /* Other types are non-dependent. */
19279 }
19281 /* Returns TRUE if TYPE is dependent, in the sense of
19282 [temp.dep.type]. Note that a NULL type is considered dependent. */
19284 bool
19286 {
19287 /* If there are no template parameters in scope, then there can't be
19288 any dependent types. */
19290 {
19291 /* If we are not processing a template, then nobody should be
19292 providing us with a dependent type. */
19296 }
19298 /* If the type is NULL, we have not computed a type for the entity
19299 in question; in that case, the type is dependent. */
19303 /* Erroneous types can be considered non-dependent. */
19307 /* If we have not already computed the appropriate value for TYPE,
19308 do so now. */
19310 {
19313 }
19316 }
19318 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19319 lookup. In other words, a dependent type that is not the current
19320 instantiation. */
19322 bool
19324 {
19327 }
19329 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19330 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19331 expression. */
19333 /* Note that this predicate is not appropriate for general expressions;
19334 only constant expressions (that satisfy potential_constant_expression)
19335 can be tested for value dependence.
19337 We should really also have a predicate for "instantiation-dependent".
19339 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19340 (what about instantiation-dependent constant-expressions?)
19341 is_late_template_attribute: defer if instantiation-dependent.
19342 compute_array_index_type: proceed if constant and not t- or v-dependent
19343 if instantiation-dependent, need to remember full expression
19344 uses_template_parms: FIXME - need to audit callers
19345 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19346 dependent_type_p [array_type]: dependent if index type is dependent
19347 (or non-constant?)
19348 static_assert - instantiation-dependent */
19350 bool
19352 {
19356 /* A name declared with a dependent type. */
19361 {
19363 /* A name that has not been looked up -- must be dependent. */
19367 /* A non-type template parm. */
19371 /* A non-type template parm. */
19377 /* A constant with literal type and is initialized
19378 with an expression that is value-dependent. */
19390 /* These expressions are value-dependent if the type to which
19391 the cast occurs is dependent or the expression being casted
19392 is value-dependent. */
19393 {
19399 /* A functional cast has a list of operands. */
19402 {
19403 /* If there are no operands, it must be an expression such
19404 as "int()". This should not happen for aggregate types
19405 because it would form non-constant expressions. */
19410 }
19416 }
19421 /* A `sizeof' expression is value-dependent if the operand is
19422 type-dependent or is a pack expansion. */
19431 /* An 'encode' expression is value-dependent if the operand is
19432 type-dependent. */
19441 {
19444 }
19451 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19452 is value-dependent. */
19453 {
19462 }
19465 {
19469 }
19480 {
19484 }
19487 {
19494 {
19496 /* In a call to a constexpr member function, look through the
19497 implicit ADDR_EXPR on the object argument so that it doesn't
19498 cause the call to be considered value-dependent. We also
19499 look through it in potential_constant_expression. */
19506 }
19508 }
19511 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19512 type-dependent. */
19516 {
19518 tree val;
19523 }
19526 /* Treat a GNU statement expression as dependent to avoid crashing
19527 under fold_non_dependent_expr; it can't be constant. */
19531 /* A constant expression is value-dependent if any subexpression is
19532 value-dependent. */
19534 {
19541 {
19545 {
19548 /* In some cases, some of the operands may be missing.l
19549 (For example, in the case of PREDECREMENT_EXPR, the
19550 amount to increment by may be missing.) That doesn't
19551 make the expression dependent. */
19554 }
19555 }
19559 }
19561 }
19563 /* The expression is not value-dependent. */
19565 }
19567 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19568 [temp.dep.expr]. Note that an expression with no type is
19569 considered dependent. Other parts of the compiler arrange for an
19570 expression with type-dependent subexpressions to have no type, so
19571 this function doesn't have to be fully recursive. */
19573 bool
19575 {
19582 /* An unresolved name is always dependent. */
19587 /* Some expression forms are never type-dependent. */
19600 /* The types of these expressions depends only on the type to which
19601 the cast occurs. */
19610 /* The types of these expressions depends only on the type created
19611 by the expression. */
19614 {
19615 /* For NEW_EXPR tree nodes created inside a template, either
19616 the object type itself or a TREE_LIST may appear as the
19617 operand 1. */
19620 /* This is an array type. We need to check array dimensions
19621 as well. */
19623 || value_dependent_expression_p
19625 else
19627 }
19630 {
19634 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19635 contains an identifier associated by name lookup with one or more
19636 declarations declared with a dependent type, or...a
19637 nested-name-specifier or qualified-id that names a member of an
19638 unknown specialization. */
19641 }
19646 && (any_dependent_template_arguments_p
19658 {
19659 tree elt;
19663 {
19666 }
19668 }
19670 /* A static data member of the current instantiation with incomplete
19671 array type is type-dependent, as the definition and specializations
19672 can have different bounds. */
19680 {
19685 {
19691 }
19692 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19700 {
19705 }
19710 {
19714 }
19716 }
19721 }
19723 /* Like type_dependent_expression_p, but it also works while not processing
19724 a template definition, i.e. during substitution or mangling. */
19726 bool
19728 {
19734 }
19736 /* Returns TRUE if ARGS contains a type-dependent expression. */
19738 bool
19740 {
19742 tree arg;
19745 {
19748 }
19750 }
19752 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19753 expressions) contains any type-dependent expressions. */
19755 bool
19757 {
19763 }
19765 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19766 expressions) contains any value-dependent expressions. */
19768 bool
19770 {
19776 }
19778 /* Returns TRUE if the ARG (a template argument) is dependent. */
19780 bool
19782 {
19786 /* Assume a template argument that was wrongly written by the user
19787 is dependent. This is consistent with what
19788 any_dependent_template_arguments_p [that calls this function]
19789 does. */
19800 {
19804 {
19807 }
19810 }
19813 else
19816 }
19818 /* Returns true if ARGS (a collection of template arguments) contains
19819 any types that require structural equality testing. */
19821 bool
19823 {
19833 {
19836 {
19842 {
19843 /* Look inside the argument pack. */
19846 }
19849 {
19863 }
19864 }
19865 }
19868 }
19870 /* Returns true if ARGS (a collection of template arguments) contains
19871 any dependent arguments. */
19873 bool
19875 {
19885 {
19890 }
19893 }
19895 /* Returns TRUE if the template TMPL is dependent. */
19897 bool
19899 {
19901 {
19903 {
19907 }
19909 }
19911 /* Template template parameters are dependent. */
19915 /* So are names that have not been looked up. */
19919 /* So are member templates of dependent classes. */
19923 }
19925 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19927 bool
19929 {
19932 }
19934 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19935 is dependent. */
19937 bool
19939 {
19946 {
19967 {
19971 }
19975 {
19979 {
19984 }
19985 }
19986 }
19989 }
19991 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
19992 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
19993 no such TYPE can be found. Note that this function peers inside
19994 uninstantiated templates and therefore should be used only in
19995 extremely limited situations. ONLY_CURRENT_P restricts this
19996 peering to the currently open classes hierarchy (which is required
19997 when comparing types). */
19999 tree
20001 {
20002 tree scope;
20003 tree name;
20004 tree decl;
20006 tree pushed_scope;
20007 tree result;
20012 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
20013 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
20014 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
20015 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
20016 identifier of the TYPENAME_TYPE anymore.
20017 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
20018 TYPENAME_TYPE instead, we avoid messing up with a possible
20019 typedef variant case. */
20022 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
20023 it first before we can figure out what NAME refers to. */
20026 /* If we don't know what SCOPE refers to, then we cannot resolve the
20027 TYPENAME_TYPE. */
20030 /* If the SCOPE is a template type parameter, we have no way of
20031 resolving the name. */
20034 /* If the SCOPE is not the current instantiation, there's no reason
20035 to look inside it. */
20038 /* If this is a typedef, we don't want to look inside (c++/11987). */
20041 /* If SCOPE isn't the template itself, it will not have a valid
20042 TYPE_FIELDS list. */
20044 /* scope is either the template itself or a compatible instantiation
20045 like X<T>, so look up the name in the original template. */
20047 else
20048 /* scope is a partial instantiation, so we can't do the lookup or we
20049 will lose the template arguments. */
20051 /* Enter the SCOPE so that name lookup will be resolved as if we
20052 were in the class definition. In particular, SCOPE will no
20053 longer be considered a dependent type. */
20055 /* Look up the declaration. */
20057 tf_warning_or_error);
20061 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
20062 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
20067 {
20071 }
20074 {
20075 tree tmpl;
20076 tree args;
20077 /* Obtain the template and the arguments. */
20080 /* Instantiate the template. */
20086 }
20088 /* Leave the SCOPE. */
20092 /* If we failed to resolve it, return the original typename. */
20096 /* If lookup found a typename type, resolve that too. */
20098 {
20099 /* Ill-formed programs can cause infinite recursion here, so we
20100 must catch that. */
20104 }
20106 /* Qualify the resulting type. */
20112 }
20114 /* EXPR is an expression which is not type-dependent. Return a proxy
20115 for EXPR that can be used to compute the types of larger
20116 expressions containing EXPR. */
20118 tree
20120 {
20121 tree inner_expr;
20123 #ifdef ENABLE_CHECKING
20124 /* Try to get a constant value for all non-type-dependent expressions in
20125 order to expose bugs in *_dependent_expression_p and constexpr. */
20128 #endif
20130 /* Preserve OVERLOADs; the functions must be available to resolve
20131 types. */
20142 /* There is no need to return a proxy for a variable. */
20145 /* Preserve string constants; conversions from string constants to
20146 "char *" are allowed, even though normally a "const char *"
20147 cannot be used to initialize a "char *". */
20150 /* Preserve arithmetic constants, as an optimization -- there is no
20151 reason to create a new node. */
20154 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20155 There is at least one place where we want to know that a
20156 particular expression is a throw-expression: when checking a ?:
20157 expression, there are special rules if the second or third
20158 argument is a throw-expression. */
20162 /* Don't wrap an initializer list, we need to be able to look inside. */
20181 /* If the type is unknown, it can't really be non-dependent */
20184 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20186 }
20188 /* ARGS is a vector of expressions as arguments to a function call.
20189 Replace the arguments with equivalent non-dependent expressions.
20190 This modifies ARGS in place. */
20192 void
20194 {
20196 tree arg;
20199 {
20203 }
20204 }
20206 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20207 with a level one deeper than the actual template parms. */
20209 tree
20211 {
20224 }
20226 /* Given type ARG, return std::initializer_list<ARG>. */
20228 static tree
20230 {
20231 tree std_init_list = namespace_binding
20233 tree argvec;
20235 {
20239 }
20244 }
20246 /* Replace auto in TYPE with std::initializer_list<auto>. */
20248 static tree
20250 {
20257 }
20259 /* walk_tree helper for do_auto_deduction. */
20261 static tree
20264 {
20265 /* Is this a variable with the type we're looking for? */
20269 else
20271 }
20273 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20274 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20276 tree
20278 {
20281 tree decl;
20287 /* Not enough information to try this yet. */
20290 /* The name of the object being declared shall not appear in the
20291 initializer expression. */
20294 {
20298 }
20300 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20301 with either a new invented type template parameter U or, if the
20302 initializer is a braced-init-list (8.5.4), with
20303 std::initializer_list<U>. */
20319 {
20321 /* Try again at instantiation time. */
20324 /* If type is error_mark_node a diagnostic must have been
20325 emitted by now. Also, having a mention to '<type error>'
20326 in the diagnostic is not really useful to the user. */
20329 }
20331 /* If the list of declarators contains more than one declarator, the type
20332 of each declared variable is determined as described above. If the
20333 type deduced for the template parameter U is not the same in each
20334 deduction, the program is ill-formed. */
20337 {
20341 }
20347 }
20349 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20350 result. */
20352 tree
20354 {
20355 tree argvec;
20362 /* For a late-specified return type in a template type-parameter, we
20363 need to add a dummy argument level for its parmlist. */
20364 argvec = add_to_template_args
20369 }
20371 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20373 bool
20375 {
20379 else
20381 }
20383 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20384 appear as a type-specifier for the declaration in question, we don't
20385 have to look through the whole type. */
20387 tree
20389 {
20406 }
20408 /* For a given template T, return the vector of typedefs referenced
20409 in T for which access check is needed at T instantiation time.
20410 T is either a FUNCTION_DECL or a RECORD_TYPE.
20411 Those typedefs were added to T by the function
20412 append_type_to_template_for_access_check. */
20416 {
20417 tree ti;
20428 {
20433 }
20436 }
20438 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20439 tied to T. That list of typedefs will be access checked at
20440 T instantiation time.
20441 T is either a FUNCTION_DECL or a RECORD_TYPE.
20442 TYPE_DECL is a TYPE_DECL node representing a typedef.
20443 SCOPE is the scope through which TYPE_DECL is accessed.
20444 LOCATION is the location of the usage point of TYPE_DECL.
20446 This function is a subroutine of
20447 append_type_to_template_for_access_check. */
20449 static void
20451 tree type_decl,
20452 tree scope,
20453 location_t location)
20454 {
20455 qualified_typedef_usage_t typedef_usage;
20456 tree ti;
20463 && type_decl
20479 }
20481 /* Append TYPE_DECL to the template TEMPL.
20482 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20483 At TEMPL instanciation time, TYPE_DECL will be checked to see
20484 if it can be accessed through SCOPE.
20485 LOCATION is the location of the usage point of TYPE_DECL.
20487 e.g. consider the following code snippet:
20489 class C
20490 {
20491 typedef int myint;
20492 };
20494 template<class U> struct S
20495 {
20496 C::myint mi; // <-- usage point of the typedef C::myint
20497 };
20499 S<char> s;
20501 At S<char> instantiation time, we need to check the access of C::myint
20502 In other words, we need to check the access of the myint typedef through
20503 the C scope. For that purpose, this function will add the myint typedef
20504 and the scope C through which its being accessed to a list of typedefs
20505 tied to the template S. That list will be walked at template instantiation
20506 time and access check performed on each typedefs it contains.
20507 Note that this particular code snippet should yield an error because
20508 myint is private to C. */
20510 void
20512 tree type_decl,
20513 tree scope,
20514 location_t location)
20515 {
20521 /* Make sure we don't append the type to the template twice. */
20530 }
20532 /* Set up the hash tables for template instantiations. */
20534 void
20536 {
20538 hash_specialization,
20539 eq_specializations,
20540 ggc_free);
20542 hash_specialization,
20543 eq_specializations,
20544 ggc_free);
20545 }
20547 /* Print stats about the template hash tables for -fstats. */
20549 void
20551 {
20560 }