| blob | 77c95bc259ea591066b4c9edcc75a015ce5e88c2 |
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;
1842 tree insttype;
1844 /* In case of explicit specialization, we need to check if
1845 the number of template headers appearing in the specialization
1846 is correct. This is usually done in check_explicit_specialization,
1847 but the check done there cannot be exhaustive when specializing
1848 member functions. Consider the following code:
1850 template <> void A<int>::f(int);
1851 template <> template <> void A<int>::f(int);
1853 Assuming that A<int> is not itself an explicit specialization
1854 already, the first line specializes "f" which is a non-template
1855 member function, whilst the second line specializes "f" which
1856 is a template member function. So both lines are syntactically
1857 correct, and check_explicit_specialization does not reject
1858 them.
1860 Here, we can do better, as we are matching the specialization
1861 against the declarations. We count the number of template
1862 headers, and we check if they match TEMPLATE_COUNT + 1
1863 (TEMPLATE_COUNT is the number of qualifying template classes,
1864 plus there must be another header for the member template
1865 itself).
1867 Notice that if header_count is zero, this is not a
1868 specialization but rather a template instantiation, so there
1869 is no check we can perform here. */
1873 /* Check that the number of template arguments at the
1874 innermost level for DECL is the same as for FN. */
1882 /* DECL might be a specialization of FN. */
1886 /* For a non-static member function, we need to make sure
1887 that the const qualification is the same. Since
1888 get_bindings does not try to merge the "this" parameter,
1889 we must do the comparison explicitly. */
1895 /* Skip the "this" parameter and, for constructors of
1896 classes with virtual bases, the VTT parameter. A
1897 full specialization of a constructor will have a VTT
1898 parameter, but a template never will. */
1899 decl_arg_types
1901 fn_arg_types
1904 /* Function templates cannot be specializations; there are
1905 no partial specializations of functions. Therefore, if
1906 the type of DECL does not match FN, there is no
1907 match. */
1909 {
1913 }
1915 /* See whether this function might be a specialization of this
1916 template. */
1920 /* We cannot deduce template arguments that when used to
1921 specialize TMPL will produce DECL. */
1924 /* Make sure that the deduced arguments actually work. */
1928 fn_arg_types
1933 /* Save this template, and the arguments deduced. */
1935 }
1937 /* FN is an ordinary member function, and we need a
1938 specialization of a member template. */
1939 ;
1941 /* We can get IDENTIFIER_NODEs here in certain erroneous
1942 cases. */
1943 ;
1945 /* This is just an ordinary non-member function. Nothing can
1946 be a specialization of that. */
1947 ;
1949 /* Cannot specialize functions that are created implicitly. */
1950 ;
1951 else
1952 {
1953 tree decl_arg_types;
1955 /* This is an ordinary member function. However, since
1956 we're here, we can assume it's enclosing class is a
1957 template class. For example,
1959 template <typename T> struct S { void f(); };
1960 template <> void S<int>::f() {}
1962 Here, S<int>::f is a non-template, but S<int> is a
1963 template class. If FN has the same type as DECL, we
1964 might be in business. */
1967 /* Its enclosing class is an explicit specialization
1968 of a template class. This is not a candidate. */
1973 /* The return types differ. */
1976 /* Adjust the type of DECL in case FN is a static member. */
1983 decl_arg_types))
1984 /* They match! */
1986 }
1987 }
1990 {
1991 /* We have:
1993 [temp.expl.spec]
1995 It is possible for a specialization with a given function
1996 signature to be instantiated from more than one function
1997 template. In such cases, explicit specification of the
1998 template arguments must be used to uniquely identify the
1999 function template specialization being specialized.
2001 Note that here, there's no suggestion that we're supposed to
2002 determine which of the candidate templates is most
2003 specialized. However, we, also have:
2005 [temp.func.order]
2007 Partial ordering of overloaded function template
2008 declarations is used in the following contexts to select
2009 the function template to which a function template
2010 specialization refers:
2012 -- when an explicit specialization refers to a function
2013 template.
2015 So, we do use the partial ordering rules, at least for now.
2016 This extension can only serve to make invalid programs valid,
2017 so it's safe. And, there is strong anecdotal evidence that
2018 the committee intended the partial ordering rules to apply;
2019 the EDG front end has that behavior, and John Spicer claims
2020 that the committee simply forgot to delete the wording in
2021 [temp.expl.spec]. */
2024 {
2027 }
2028 }
2031 {
2039 }
2043 {
2049 }
2051 /* We have one, and exactly one, match. */
2053 {
2056 /* DECL is a re-declaration or partial instantiation of a template
2057 function. */
2060 /* It was a specialization of an ordinary member function in a
2061 template class. */
2063 }
2065 /* It was a specialization of a template. */
2068 {
2073 }
2074 else
2077 }
2079 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2080 but with the default argument values filled in from those in the
2081 TMPL_TYPES. */
2083 static tree
2085 tree tmpl_types)
2086 {
2087 tree new_spec_types;
2095 /* Substitute into the rest of the list. */
2096 new_spec_types =
2100 /* Add the default argument for this parameter. */
2103 new_spec_types);
2104 }
2106 /* DECL is an explicit specialization. Replicate default arguments
2107 from the template it specializes. (That way, code like:
2109 template <class T> void f(T = 3);
2110 template <> void f(double);
2111 void g () { f (); }
2113 works, as required.) An alternative approach would be to look up
2114 the correct default arguments at the call-site, but this approach
2115 is consistent with how implicit instantiations are handled. */
2117 static void
2119 {
2120 tree tmpl;
2121 tree spec_types;
2122 tree tmpl_types;
2123 tree new_spec_types;
2124 tree old_type;
2125 tree new_type;
2126 tree t;
2131 /* See if there's anything we need to do. */
2144 {
2145 /* Remove the this pointer, but remember the object's type for
2146 CV quals. */
2152 {
2153 /* DECL may contain more parameters than TMPL due to the extra
2154 in-charge parameter in constructors and destructors. */
2157 }
2159 {
2162 }
2163 }
2165 /* Compute the merged default arguments. */
2166 new_spec_types =
2169 /* Compute the new FUNCTION_TYPE. */
2171 {
2175 new_spec_types);
2178 /* Put the in-charge parameter back. */
2181 new_spec_types);
2185 new_spec_types);
2186 }
2187 else
2189 new_spec_types);
2195 }
2197 /* Check to see if the function just declared, as indicated in
2198 DECLARATOR, and in DECL, is a specialization of a function
2199 template. We may also discover that the declaration is an explicit
2200 instantiation at this point.
2202 Returns DECL, or an equivalent declaration that should be used
2203 instead if all goes well. Issues an error message if something is
2204 amiss. Returns error_mark_node if the error is not easily
2205 recoverable.
2207 FLAGS is a bitmask consisting of the following flags:
2209 2: The function has a definition.
2210 4: The function is a friend.
2212 The TEMPLATE_COUNT is the number of references to qualifying
2213 template classes that appeared in the name of the function. For
2214 example, in
2216 template <class T> struct S { void f(); };
2217 void S<int>::f();
2219 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2220 classes are not counted in the TEMPLATE_COUNT, so that in
2222 template <class T> struct S {};
2223 template <> struct S<int> { void f(); }
2224 template <> void S<int>::f();
2226 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2227 invalid; there should be no template <>.)
2229 If the function is a specialization, it is marked as such via
2230 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2231 is set up correctly, and it is added to the list of specializations
2232 for that template. */
2234 tree
2236 tree decl,
2239 {
2247 tmpl_spec_kind tsk;
2250 {
2253 else
2255 }
2256 else
2260 {
2263 {
2266 }
2268 {
2270 /* This could be something like:
2272 template <class T> void f(T);
2273 class S { friend void f<>(int); } */
2275 else
2276 {
2277 /* This case handles bogus declarations like template <>
2278 template <class T> void f<int>(); */
2281 declarator);
2283 }
2284 }
2288 /* The error has already been reported in
2289 check_specialization_scope. */
2295 /* Fall through. */
2308 decl);
2311 else
2315 /* Fall through. */
2320 else
2326 {
2327 /* This case handles bogus declarations like template <>
2328 template <class T> void f<int>(); */
2333 else
2335 declarator);
2337 }
2340 /* This is a specialization of a member template, without
2341 specialization the containing class. Something like:
2343 template <class T> struct S {
2344 template <class U> void f (U);
2345 };
2346 template <> template <class U> void S<int>::f(U) {}
2348 That's a specialization -- but of the entire template. */
2354 }
2357 {
2361 {
2365 }
2366 }
2369 {
2373 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2375 {
2376 tree fns;
2381 else
2382 {
2383 /* If there is no class context, the explicit instantiation
2384 must be at namespace scope. */
2387 /* Find the namespace binding, using the declaration
2388 context. */
2392 {
2395 }
2396 else
2397 {
2403 }
2404 }
2407 }
2413 {
2415 /* A specialization in class scope. This is invalid,
2416 but the error will already have been flagged by
2417 check_specialization_scope. */
2419 else
2420 {
2421 /* It's not valid to write an explicit instantiation in
2422 class scope, e.g.:
2424 class C { template void f(); }
2426 This case is caught by the parser. However, on
2427 something like:
2429 template class C { void f(); };
2431 (which is invalid) we can get here. The error will be
2432 issued later. */
2433 ;
2434 }
2437 }
2440 IDENTIFIER_NODE))
2441 {
2442 /* Find the list of functions in ctype that have the same
2443 name as the declared function. */
2449 {
2454 {
2455 /* From [temp.expl.spec]:
2457 If such an explicit specialization for the member
2458 of a class template names an implicitly-declared
2459 special member function (clause _special_), the
2460 program is ill-formed.
2462 Similar language is found in [temp.explicit]. */
2465 }
2468 }
2471 {
2475 }
2476 else
2477 {
2479 tree ovl;
2481 /* For a type-conversion operator, we cannot do a
2482 name-based lookup. We might be looking for `operator
2483 int' which will be a specialization of `operator T'.
2484 So, we find *all* the conversion operators, and then
2485 select from them. */
2493 {
2495 /* There are no more conversion functions. */
2498 /* Glue all these conversion functions together
2499 with those we already have. */
2502 }
2503 }
2506 {
2509 }
2510 else
2512 }
2514 /* Figure out what exactly is being specialized at this point.
2515 Note that for an explicit instantiation, even one for a
2516 member function, we cannot tell apriori whether the
2517 instantiation is for a member template, or just a member
2518 function of a template class. Even if a member template is
2519 being instantiated, the member template arguments may be
2520 elided if they can be deduced from the rest of the
2521 declaration. */
2524 member_specialization,
2525 template_count,
2526 tsk);
2529 /* We couldn't figure out what this declaration was
2530 specializing. */
2532 else
2533 {
2537 {
2538 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2539 is done by do_decl_instantiation later. */
2545 {
2546 /* If TMPL is not the most general template (for
2547 example, if TMPL is a friend template that is
2548 injected into namespace scope), then there will
2549 be too many levels of TARGS. Remove some of them
2550 here. */
2552 tree new_targs;
2559 }
2562 }
2564 /* If we thought that the DECL was a member function, but it
2565 turns out to be specializing a static member function,
2566 make DECL a static member function as well. */
2571 /* If this is a specialization of a member template of a
2572 template class, we want to return the TEMPLATE_DECL, not
2573 the specialization of it. */
2575 {
2580 {
2581 tree parm;
2585 /* We want to use the argument list specified in the
2586 definition, not in the original declaration. */
2591 }
2594 }
2596 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2599 /* Inherit default function arguments from the template
2600 DECL is specializing. */
2603 /* This specialization has the same protection as the
2604 template it specializes. */
2608 /* 7.1.1-1 [dcl.stc]
2610 A storage-class-specifier shall not be specified in an
2611 explicit specialization...
2613 The parser rejects these, so unless action is taken here,
2614 explicit function specializations will always appear with
2615 global linkage.
2617 The action recommended by the C++ CWG in response to C++
2618 defect report 605 is to make the storage class and linkage
2619 of the explicit specialization match the templated function:
2621 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2622 */
2624 {
2628 /* This specialization has the same linkage and visibility as
2629 the function template it specializes. */
2632 {
2635 }
2638 {
2641 }
2642 }
2644 /* If DECL is a friend declaration, declared using an
2645 unqualified name, the namespace associated with DECL may
2646 have been set incorrectly. For example, in:
2648 template <typename T> void f(T);
2649 namespace N {
2650 struct S { friend void f<int>(int); }
2651 }
2653 we will have set the DECL_CONTEXT for the friend
2654 declaration to N, rather than to the global namespace. */
2659 /* This is not really a declaration of a specialization.
2660 It's just the name of an instantiation. But, it's not
2661 a request for an instantiation, either. */
2664 /* This is indeed a specialization. In case of constructors
2665 and destructors, we need in-charge and not-in-charge
2666 versions in V3 ABI. */
2669 /* Register this specialization so that we can find it
2670 again. */
2672 }
2673 }
2676 }
2678 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2679 parameters. These are represented in the same format used for
2680 DECL_TEMPLATE_PARMS. */
2682 int
2684 {
2685 const_tree p1;
2686 const_tree p2;
2694 {
2706 {
2710 /* If either of the template parameters are invalid, assume
2711 they match for the sake of error recovery. */
2724 }
2725 }
2728 /* One set of parameters has more parameters lists than the
2729 other. */
2733 }
2735 /* Determine whether PARM is a parameter pack. */
2737 bool
2739 {
2740 /* Determine if we have a non-type template parameter pack. */
2747 /* If this is a list of template parameters, we could get a
2748 TYPE_DECL or a TEMPLATE_DECL. */
2752 /* Otherwise it must be a type template parameter. */
2756 }
2758 /* Determine if T is a function parameter pack. */
2760 bool
2762 {
2766 }
2768 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2769 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2771 tree
2773 {
2780 }
2782 /* Return true iff the function parameter PARAM_DECL was expanded
2783 from the function parameter pack PACK. */
2785 bool
2787 {
2792 /* The parameter pack and its pack arguments have the same
2793 DECL_PARM_INDEX. */
2795 }
2797 /* Determine whether ARGS describes a variadic template args list,
2798 i.e., one that is terminated by a template argument pack. */
2800 static bool
2802 {
2804 tree last_parm;
2818 }
2820 /* Generate a new name for the parameter pack name NAME (an
2821 IDENTIFIER_NODE) that incorporates its */
2823 static tree
2825 {
2826 /* Munge the name to include the parameter index. */
2827 #define NUMBUF_LEN 128
2839 }
2841 /* Return true if T is a primary function, class or alias template
2842 instantiation. */
2844 bool
2846 {
2863 }
2865 /* Return true if PARM is a template template parameter. */
2867 bool
2869 {
2871 }
2873 /* Return true iff PARM is a DECL representing a type template
2874 parameter. */
2876 bool
2878 {
2883 }
2885 /* Return the template parameters of T if T is a
2886 primary template instantiation, NULL otherwise. */
2888 tree
2890 {
2895 parms = INNERMOST_TEMPLATE_PARMS
2899 }
2901 /* Return the template parameters of the LEVELth level from the full list
2902 of template parameters PARMS. */
2904 tree
2906 {
2907 tree p;
2918 }
2920 /* Returns the template arguments of T if T is a template instantiation,
2921 NULL otherwise. */
2923 tree
2925 {
2933 }
2935 /* Return the argument pack elements of T if T is a template argument pack,
2936 NULL otherwise. */
2938 tree
2940 {
2946 }
2948 /* Structure used to track the progress of find_parameter_packs_r. */
2949 struct find_parameter_pack_data
2950 {
2951 /* TREE_LIST that will contain all of the parameter packs found by
2952 the traversal. */
2955 /* Set of AST nodes that have been visited by the traversal. */
2957 };
2959 /* Identifies all of the argument packs that occur in a template
2960 argument and appends them to the TREE_LIST inside DATA, which is a
2961 find_parameter_pack_data structure. This is a subroutine of
2962 make_pack_expansion and uses_parameter_packs. */
2963 static tree
2965 {
2971 /* Handle type aliases/typedefs. */
2976 {
2983 }
2985 /* Identify whether this is a parameter pack or not. */
2987 {
3002 {
3003 /* We don't want to walk into the type of a PARM_DECL,
3004 because we don't want to see the type parameter pack. */
3007 }
3014 /* Not a parameter pack. */
3016 }
3019 {
3020 /* Add this parameter pack to the list. */
3022 }
3028 /* This switch statement will return immediately if we don't find a
3029 parameter pack. */
3031 {
3036 /* Check the template itself. */
3039 /* Check the template arguments. */
3055 /* Fall through. */
3097 }
3100 }
3102 /* Determines if the expression or type T uses any parameter packs. */
3103 bool
3105 {
3113 }
3115 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3116 representation a base-class initializer into a parameter pack
3117 expansion. If all goes well, the resulting node will be an
3118 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3119 respectively. */
3120 tree
3122 {
3123 tree result;
3132 {
3133 /* The only time we will see a TREE_LIST here is for a base
3134 class initializer. In this case, the TREE_PURPOSE will be a
3135 _TYPE node (representing the base class expansion we're
3136 initializing) and the TREE_VALUE will be a TREE_LIST
3137 containing the initialization arguments.
3139 The resulting expansion looks somewhat different from most
3140 expansions. Rather than returning just one _EXPANSION, we
3141 return a TREE_LIST whose TREE_PURPOSE is a
3142 TYPE_PACK_EXPANSION containing the bases that will be
3143 initialized. The TREE_VALUE will be identical to the
3144 original TREE_VALUE, which is a list of arguments that will
3145 be passed to each base. We do not introduce any new pack
3146 expansion nodes into the TREE_VALUE (although it is possible
3147 that some already exist), because the TREE_PURPOSE and
3148 TREE_VALUE all need to be expanded together with the same
3149 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3150 resulting TREE_PURPOSE will mention the parameter packs in
3151 both the bases and the arguments to the bases. */
3152 tree purpose;
3153 tree value;
3156 /* Determine which parameter packs will be used by the base
3157 class expansion. */
3164 {
3168 }
3171 {
3172 /* Collect the sets of parameter packs used in each of the
3173 initialization arguments. */
3175 {
3176 /* Determine which parameter packs will be expanded in this
3177 argument. */
3180 }
3181 }
3185 /* Create the pack expansion type for the base type. */
3190 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3191 they will rarely be compared to anything. */
3195 }
3200 /* Build the PACK_EXPANSION_* node. */
3201 result = for_types
3206 {
3207 /* Propagate type and const-expression information. */
3210 }
3211 else
3212 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3213 they will rarely be compared to anything. */
3216 /* Determine which parameter packs will be expanded. */
3222 /* Make sure we found some parameter packs. */
3224 {
3227 else
3230 }
3236 }
3238 /* Checks T for any "bare" parameter packs, which have not yet been
3239 expanded, and issues an error if any are found. This operation can
3240 only be done on full expressions or types (e.g., an expression
3241 statement, "if" condition, etc.), because we could have expressions like:
3243 foo(f(g(h(args)))...)
3245 where "args" is a parameter pack. check_for_bare_parameter_packs
3246 should not be called for the subexpressions args, h(args),
3247 g(h(args)), or f(g(h(args))), because we would produce erroneous
3248 error messages.
3250 Returns TRUE and emits an error if there were bare parameter packs,
3251 returns FALSE otherwise. */
3252 bool
3254 {
3270 {
3273 {
3282 else
3287 else
3291 }
3294 }
3297 }
3299 /* Expand any parameter packs that occur in the template arguments in
3300 ARGS. */
3301 tree
3303 {
3309 /* First, determine if we need to expand anything, and the number of
3310 slots we'll need. */
3312 {
3317 {
3321 else
3323 }
3324 else
3325 {
3327 num_result_args++;
3328 }
3329 }
3331 /* If no expansion is necessary, we're done. */
3335 /* Expand arguments. */
3338 non_default_args_count =
3341 {
3344 {
3351 }
3352 else
3353 {
3356 }
3357 }
3361 }
3363 /* Checks if DECL shadows a template parameter.
3365 [temp.local]: A template-parameter shall not be redeclared within its
3366 scope (including nested scopes).
3368 Emits an error and returns TRUE if the DECL shadows a parameter,
3369 returns FALSE otherwise. */
3371 bool
3373 {
3374 tree olddecl;
3376 /* If we're not in a template, we can't possibly shadow a template
3377 parameter. */
3381 /* Figure out what we're shadowing. */
3386 /* If there's no previous binding for this name, we're not shadowing
3387 anything, let alone a template parameter. */
3391 /* If we're not shadowing a template parameter, we're done. Note
3392 that OLDDECL might be an OVERLOAD (or perhaps even an
3393 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3394 node. */
3398 /* We check for decl != olddecl to avoid bogus errors for using a
3399 name inside a class. We check TPFI to avoid duplicate errors for
3400 inline member templates. */
3408 }
3410 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3411 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3412 template parameters. */
3414 static tree
3419 tree decl,
3420 tree type)
3421 {
3433 }
3435 /* Find the canonical type parameter for the given template type
3436 parameter. Returns the canonical type parameter, which may be TYPE
3437 if no such parameter existed. */
3439 static tree
3441 {
3442 tree list;
3456 else
3457 {
3462 }
3463 }
3465 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3466 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3467 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3468 new one is created. */
3470 static tree
3472 tsubst_flags_t complain)
3473 {
3478 {
3498 /* Template template parameters need this. */
3503 }
3506 }
3508 /* Process information from new template parameter PARM and append it
3509 to the LIST being built. This new parameter is a non-type
3510 parameter iff IS_NON_TYPE is true. This new parameter is a
3511 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3512 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3513 parameter list PARM belongs to. This is used used to create a
3514 proper canonical type for the type of PARM that is to be created,
3515 iff PARM is a type. If the size is not known, this parameter shall
3516 be set to 0. */
3518 tree
3522 {
3524 tree defval;
3525 tree err_parm_list;
3532 {
3536 {
3540 else
3542 }
3545 }
3546 else
3550 {
3556 {
3560 }
3561 else
3562 {
3563 /* [temp.param]
3565 The top-level cv-qualifiers on the template-parameter are
3566 ignored when determining its type. */
3569 {
3573 }
3576 {
3577 /* This template parameter is not a parameter pack, but it
3578 should be. Complain about "bare" parameter packs. */
3581 /* Recover by calling this a parameter pack. */
3583 }
3584 }
3586 /* A template parameter is not modifiable. */
3595 processing_template_decl,
3596 num_template_parms,
3601 }
3602 else
3603 {
3604 tree t;
3608 {
3610 /* This is for distinguishing between real templates and template
3611 template parameters */
3615 }
3616 else
3617 {
3619 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3622 }
3629 processing_template_decl,
3630 num_template_parms,
3634 }
3640 }
3642 /* The end of a template parameter list has been reached. Process the
3643 tree list into a parameter vector, converting each parameter into a more
3644 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3645 as PARM_DECLs. */
3647 tree
3649 {
3654 current_template_parms
3659 {
3663 }
3668 }
3670 /* Create a new type almost identical to TYPE but which has the
3671 following differences:
3673 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3674 template sibling parameters of T.
3676 2/ T has a new canonical type that matches the new number
3677 of sibling parms.
3679 3/ From now on, T is going to be what lookups referring to the
3680 name of TYPE will return. No lookup should return TYPE anymore.
3682 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3684 This is a subroutine of fixup_template_parms. */
3686 static tree
3688 {
3690 tree t;
3691 /* This is the decl which name is inserted into the symbol table for
3692 the template parm type. So whenever we lookup the type name, this
3693 is the DECL we get. */
3694 tree decl;
3696 /* Do not fix up the type twice. */
3711 num_parms,
3722 /* Update the type associated to the type name stored in the symbol
3723 table. Now, whenever the type name is looked up, the resulting
3724 type is properly fixed up. */
3730 }
3732 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3733 identical to I, but that is fixed up as to:
3735 1/ carry the number of sibling parms (NUM_PARMS) of the template
3736 parm represented by I.
3738 2/ replace all references to template parm types declared before I
3739 (in the same template parm list as I) by references to template
3740 parm types contained in ARGS. ARGS should contain the list of
3741 template parms that have been fixed up so far, in a form suitable
3742 to be passed to tsubst.
3744 This is a subroutine of fixup_template_parms. */
3746 static tree
3748 {
3753 /* Do not fix up the index twice. */
3763 num_parms,
3775 }
3777 /*
3778 This is a subroutine of fixup_template_parms.
3780 It computes the canonical type of the type of the template
3781 parameter PARM_DESC and update all references to that type so that
3782 they use the newly computed canonical type. No access check is
3783 performed during the fixup. PARM_DESC is a TREE_LIST which
3784 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3785 default argument of the template parm if any. IDX is the index of
3786 the template parameter, starting at 0. NUM_PARMS is the number of
3787 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3788 TREE_VEC containing the full set of template parameters in a form
3789 suitable to be passed to substs functions as their ARGS
3790 argument. This is what current_template_args returns for a given
3791 template. The innermost vector of args in ARGLIST is the set of
3792 template parms that have been fixed up so far. This function adds
3793 the fixed up parameter into that vector. */
3795 static void
3799 tree arglist)
3800 {
3807 {
3808 /* PARM is a template type parameter. Fix up its type, add
3809 the fixed-up template parm to the vector of fixed-up
3810 template parms so far, and substitute the fixed-up
3811 template parms into the default argument of this
3812 parameter. */
3813 tree t =
3818 }
3820 {
3821 /* PARM is a template template parameter. This is going to
3822 be interesting. */
3826 /* First, fix up the parms of the template template parm
3827 because the parms are involved in defining the new canonical
3828 type of the template template parm. */
3830 /* So we need to substitute the template parm types that have
3831 been fixed up so far into the template parms of this template
3832 template parm. E.g, consider this:
3834 template<class T, template<T u> class TT> class S;
3836 In this case we want to substitute T into the
3837 template parameters of TT.
3839 So let's walk the template parms of PARM here, and
3840 tsubst ARGLIST into into each of the template
3841 parms. */
3843 /* For this substitution we need to build the full set of
3844 template parameters and use that as arguments for the
3845 tsubsting function. */
3848 /* This will contain the innermost parms of PARM into which
3849 we have substituted so far. */
3853 {
3854 tree parameter;
3858 /* INNERMOST_ARGS needs to have at least the same number
3859 of elements as the index PARAMETER, ortherwise
3860 tsubsting into PARAMETER will result in partially
3861 instantiating it, reducing its tempate parm
3862 level. Let's tactically fill INNERMOST_ARGS for that
3863 purpose. */
3869 targs);
3870 }
3872 /* Now fix up the type of the template template parm. */
3879 }
3881 {
3882 /* PARM is a non-type template parameter. We need to:
3884 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3885 proper number of sibling parameters.
3887 * Make lookups of the template parameter return a reference
3888 to the fixed-up index. No lookup should return references
3889 to the former index anymore.
3891 * Substitute the template parms that got fixed up so far
3893 * into the type of PARM. */
3897 /* PUSHED_DECL is the decl added to the symbol table with
3898 the name of the parameter. E,g:
3900 template<class T, T u> //#0
3901 auto my_function(T t) -> decltype(u); //#1
3903 Here, when looking up u at //#1, we get the decl of u
3904 resulting from the declaration in #0. This is what
3905 PUSHED_DECL is. We need to replace the reference to the
3906 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3907 fixed-up TEMPLATE_PARM_INDEX. */
3910 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3911 fixup the type of PUSHED_DECL as well and luckily
3912 fixup_template_parm_index does it for us too. */
3913 tree fixed_up_index =
3918 /* Add this fixed up PARM to the template parms we've fixed
3919 up so far and use that to substitute the fixed-up
3920 template parms into the type of PARM. */
3925 }
3932 }
3934 /* Walk the current template parms and properly compute the canonical
3935 types of the dependent types created during
3936 cp_parser_template_parameter_list. */
3938 void
3940 {
3941 tree arglist;
3942 tree parameter_vec;
3943 tree fixedup_args;
3952 /* This vector contains the current innermost template parms that
3953 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3954 to be passed to tsubst* functions as their ARGS argument. */
3957 /* This vector contains the full set of template parms in a form
3958 suitable to be passed to substs functions as their ARGS
3959 argument. */
3963 /* Let's do the proper fixup now. */
3967 }
3969 /* end_template_decl is called after a template declaration is seen. */
3971 void
3973 {
3979 /* This matches the pushlevel in begin_template_parm_list. */
3984 }
3986 /* Takes a TREE_LIST representing a template parameter and convert it
3987 into an argument suitable to be passed to the type substitution
3988 functions. Note that If the TREE_LIST contains an error_mark
3989 node, the returned argument is error_mark_node. */
3991 static tree
3993 {
4006 {
4010 {
4011 /* Turn this argument into a TYPE_ARGUMENT_PACK
4012 with a single element, which expands T. */
4014 #ifdef ENABLE_CHECKING
4015 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4017 #endif
4022 }
4023 }
4024 else
4025 {
4029 {
4030 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4031 with a single element, which expands T. */
4034 #ifdef ENABLE_CHECKING
4035 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4037 #endif
4043 }
4044 }
4046 }
4048 /* This function returns TRUE if PARM_PACK is a template parameter
4049 pack and if ARG_PACK is what template_parm_to_arg returned when
4050 passed PARM_PACK. */
4052 static bool
4054 {
4055 /* For clarity in the comments below let's use the representation
4056 argument_pack<elements>' to denote an argument pack and its
4057 elements.
4059 In the 'if' block below, we want to detect cases where
4060 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
4061 check if ARG_PACK is an argument pack which sole element is
4062 the expansion of PARM_PACK. That argument pack is typically
4063 created by template_parm_to_arg when passed a parameter
4064 pack. */
4069 {
4072 /* So we have an argument_pack<P...>. We want to test if P
4073 is actually PARM_PACK. We will not use cp_tree_equal to
4074 test P and PARM_PACK because during type fixup (by
4075 fixup_template_parm) P can be a pre-fixup version of a
4076 type and PARM_PACK be its post-fixup version.
4077 cp_tree_equal would consider them as different even
4078 though we would want to consider them compatible for our
4079 precise purpose here.
4081 Thus we are going to consider that P and PARM_PACK are
4082 compatible if they have the same DECL. */
4084 same DECL as parm_pack ... */
4088 /* ... or if PARM_PACK is a non-type parameter named by the
4089 same DECL as ARG_PACK. Note that PARM_PACK being a
4090 non-type parameter means it's either a PARM_DECL or a
4091 TEMPLATE_PARM_INDEX. */
4101 }
4103 }
4105 /* Within the declaration of a template, return all levels of template
4106 parameters that apply. The template parameters are represented as
4107 a TREE_VEC, in the form documented in cp-tree.h for template
4108 arguments. */
4110 static tree
4112 {
4113 tree header;
4118 /* If there is only one level of template parameters, we do not
4119 create a TREE_VEC of TREE_VECs. Instead, we return a single
4120 TREE_VEC containing the arguments. */
4125 {
4133 #ifdef ENABLE_CHECKING
4135 #endif
4139 else
4141 }
4144 /* This can happen for template parms of a template template
4145 parameter, e.g:
4147 template<template<class T, class U> class TT> struct S;
4149 Consider the level of the parms of TT; T and U both have
4150 level 2; TT has no template parm of level 1. So in this case
4151 the first element of full_template_args is NULL_TREE. If we
4152 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4153 of 2. This will make tsubst wrongly consider that T and U
4154 have level 1. Instead, let's create a dummy vector as the
4155 first element of full_template_args so that TMPL_ARG_DEPTH
4156 returns the correct depth for args. */
4159 }
4161 /* Update the declared TYPE by doing any lookups which were thought to be
4162 dependent, but are not now that we know the SCOPE of the declarator. */
4164 tree
4166 {
4177 /* Don't bother building up the args in this case. */
4179 {
4180 /* tsubst in the args corresponding to the template parameters,
4181 including auto if present. Most things will be unchanged, but
4182 make_typename_type and tsubst_qualified_id will resolve
4183 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4186 tree pushed;
4188 {
4192 }
4197 }
4203 {
4206 else
4208 }
4210 }
4212 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4213 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4214 a member template. Used by push_template_decl below. */
4216 static tree
4218 {
4226 }
4228 struct template_parm_data
4229 {
4230 /* The level of the template parameters we are currently
4231 processing. */
4234 /* The index of the specialization argument we are currently
4235 processing. */
4238 /* An array whose size is the number of template parameters. The
4239 elements are nonzero if the parameter has been used in any one
4240 of the arguments processed so far. */
4243 /* An array whose size is the number of template arguments. The
4244 elements are nonzero if the argument makes use of template
4245 parameters of this level. */
4247 };
4249 /* Subroutine of push_template_decl used to see if each template
4250 parameter in a partial specialization is used in the explicit
4251 argument list. If T is of the LEVEL given in DATA (which is
4252 treated as a template_parm_data*), then DATA->PARMS is marked
4253 appropriately. */
4255 static int
4257 {
4263 {
4266 }
4267 else
4268 {
4271 }
4274 {
4277 }
4279 /* Return zero so that for_each_template_parm will continue the
4280 traversal of the tree; we want to mark *every* template parm. */
4282 }
4284 /* Process the partial specialization DECL. */
4286 static tree
4288 {
4294 tree inner_parms;
4295 tree inst;
4308 /* We check that each of the template parameters given in the
4309 partial specialization is used in the argument list to the
4310 specialization. For example:
4312 template <class T> struct S;
4313 template <class T> struct S<T*>;
4315 The second declaration is OK because `T*' uses the template
4316 parameter T, whereas
4318 template <class T> struct S<int>;
4320 is no good. Even trickier is:
4322 template <class T>
4323 struct S1
4324 {
4325 template <class U>
4326 struct S2;
4327 template <class U>
4328 struct S2<T>;
4329 };
4331 The S2<T> declaration is actually invalid; it is a
4332 full-specialization. Of course,
4334 template <class U>
4335 struct S2<T (*)(U)>;
4337 or some such would have been OK. */
4345 {
4350 NULL,
4352 }
4355 {
4356 /* One of the template parms was not used in the
4357 specialization. */
4359 {
4362 }
4365 }
4370 /* [temp.class.spec]
4372 The argument list of the specialization shall not be identical to
4373 the implicit argument list of the primary template. */
4380 /* A partial specialization that replaces multiple parameters of the
4381 primary template with a pack expansion is less specialized for those
4382 parameters. */
4384 {
4386 "primary template because it replaces multiple parameters "
4390 }
4392 /* [temp.class.spec]
4394 A partially specialized non-type argument expression shall not
4395 involve template parameters of the partial specialization except
4396 when the argument expression is a simple identifier.
4398 The type of a template parameter corresponding to a specialized
4399 non-type argument shall not be dependent on a parameter of the
4400 specialization.
4402 Also, we verify that pack expansions only occur at the
4403 end of the argument list. */
4407 {
4414 {
4415 /* Extract the arguments from the argument pack. We'll be
4416 iterating over these in the following loop. */
4419 }
4422 {
4424 /* Get the Jth argument in the parameter pack. */
4428 {
4429 /* Pack expansions must come at the end of the
4430 argument list. */
4433 {
4437 else
4440 }
4441 }
4444 /* We only care about the pattern. */
4450 /* This next line is the `argument expression is not just a
4451 simple identifier' condition and also the `specialized
4452 non-type argument' bit. */
4454 {
4458 arg);
4459 else
4460 {
4461 /* Look at the corresponding template parameter,
4462 marking which template parameters its type depends
4463 upon. */
4467 {
4468 /* We haven't yet initialized TPD2. Do so now. */
4470 /* The number of parameters here is the number in the
4471 main template, which, as checked in the assertion
4472 above, is NARGS. */
4476 }
4478 /* Mark the template parameters. But this time, we're
4479 looking for the template parameters of the main
4480 template, not in the specialization. */
4487 NULL,
4491 {
4492 /* The type depended on some template parameters.
4493 If they are fully specialized in the
4494 specialization, that's OK. */
4503 "type %qT of template argument %qE depends "
4505 "type %qT of template argument %qE depends "
4507 type,
4508 arg);
4509 }
4510 }
4511 }
4512 }
4513 }
4515 /* We should only get here once. */
4525 {
4529 {
4533 "partial specialization of %qT after instantiation "
4535 }
4536 }
4539 }
4541 /* Check that a template declaration's use of default arguments and
4542 parameter packs is not invalid. Here, PARMS are the template
4543 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4544 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4545 specialization.
4548 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4549 declaration (but not a definition); 1 indicates a declaration, 2
4550 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4551 emitted for extraneous default arguments.
4553 Returns TRUE if there were no errors found, FALSE otherwise. */
4555 bool
4558 {
4561 tree parm_level;
4564 /* [temp.param]
4566 A default template-argument shall not be specified in a
4567 function template declaration or a function template definition, nor
4568 in the template-parameter-list of the definition of a member of a
4569 class template. */
4572 /* You can't have a function template declaration in a local
4573 scope, nor you can you define a member of a class template in a
4574 local scope. */
4581 /* If this is either a friend defined in the scope of the class
4582 or a member function. */
4588 /* And, if it was a member function, it really was defined in
4589 the scope of the class. */
4592 /* We already checked these parameters when the template was
4593 declared, so there's no need to do it again now. This function
4594 was defined in class scope, but we're processing it's body now
4595 that the class is complete. */
4598 /* Core issue 226 (C++0x only): the following only applies to class
4599 templates. */
4601 {
4602 /* [temp.param]
4604 If a template-parameter has a default template-argument, all
4605 subsequent template-parameters shall have a default
4606 template-argument supplied. */
4608 {
4615 {
4625 {
4627 /* For better subsequent error-recovery, we indicate that
4628 there should have been a default argument. */
4631 }
4633 && !is_partial
4634 && !is_friend_decl
4635 /* Don't complain about an enclosing partial
4636 specialization. */
4641 {
4642 /* A primary class template can only have one
4643 parameter pack, at the end of the template
4644 parameter list. */
4649 else
4657 }
4658 }
4659 }
4660 }
4663 || is_partial
4664 || !is_primary
4666 /* For an ordinary class template, default template arguments are
4667 allowed at the innermost level, e.g.:
4668 template <class T = int>
4669 struct S {};
4670 but, in a partial specialization, they're not allowed even
4671 there, as we have in [temp.class.spec]:
4673 The template parameter list of a specialization shall not
4674 contain default template argument values.
4676 So, for a partial specialization, or for a function template
4677 (in C++98/C++03), we look at all of them. */
4678 ;
4679 else
4680 /* But, for a primary class template that is not a partial
4681 specialization we look at all template parameters except the
4682 innermost ones. */
4685 /* Figure out what error message to issue. */
4698 else
4702 /* If we're inside a class definition, there's no need to
4703 examine the parameters to the class itself. On the one
4704 hand, they will be checked when the class is defined, and,
4705 on the other, default arguments are valid in things like:
4706 template <class T = double>
4707 struct S { template <class U> void f(U); };
4708 Here the default argument for `S' has no bearing on the
4709 declaration of `f'. */
4711 else
4712 /* Check everything. */
4718 {
4725 {
4730 {
4732 {
4739 }
4741 /* Clear out the default argument so that we are not
4742 confused later. */
4744 }
4745 }
4747 /* At this point, if we're still interested in issuing messages,
4748 they must apply to classes surrounding the object declared. */
4752 }
4755 }
4757 /* Worker for push_template_decl_real, called via
4758 for_each_template_parm. DATA is really an int, indicating the
4759 level of the parameters we are interested in. If T is a template
4760 parameter of that level, return nonzero. */
4762 static int
4764 {
4770 else
4773 }
4775 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4776 parameters given by current_template_args, or reuses a
4777 previously existing one, if appropriate. Returns the DECL, or an
4778 equivalent one, if it is replaced via a call to duplicate_decls.
4780 If IS_FRIEND is true, DECL is a friend declaration. */
4782 tree
4784 {
4785 tree tmpl;
4786 tree args;
4787 tree info;
4788 tree ctx;
4792 /* True if the template is a member template, in the sense of
4793 [temp.mem]. */
4799 /* See if this is a partial specialization. */
4808 /* For a friend, we want the context of the friend function, not
4809 the type of which it is a friend. */
4813 /* In the case of a virtual function, we want the class in which
4814 it is defined. */
4816 else
4817 /* Otherwise, if we're currently defining some class, the DECL
4818 is assumed to be a member of the class. */
4827 /* See if this is a primary template. */
4829 /* A friend template that specifies a class context, i.e.
4830 template <typename T> friend void A<T>::f();
4831 is not primary. */
4833 else
4837 {
4842 {
4845 }
4847 {
4849 {
4850 /* [temp.mem]
4852 A destructor shall not be a member template. */
4855 }
4862 {
4863 /* [basic.stc.dynamic.allocation]
4865 An allocation function can be a function
4866 template. ... Template allocation functions shall
4867 have two or more parameters. */
4870 }
4871 }
4877 /* alias-declaration */
4879 else
4880 {
4883 }
4884 }
4886 /* Check to see that the rules regarding the use of default
4887 arguments are not being violated. */
4891 /* Ensure that there are no parameter packs in the type of this
4892 declaration that have not been expanded. */
4894 {
4895 /* Check each of the arguments individually to see if there are
4896 any bare parameter packs. */
4902 {
4905 {
4906 /* This is a PARM_DECL that contains unexpanded parameter
4907 packs. We have already complained about this in the
4908 check_for_bare_parameter_packs call, so just replace
4909 these types with ERROR_MARK_NODE. */
4912 }
4916 }
4918 /* Check for bare parameter packs in the return type and the
4919 exception specifiers. */
4921 /* Errors were already issued, set return type to int
4922 as the frontend doesn't expect error_mark_node as
4923 the return type. */
4927 }
4932 {
4935 }
4946 {
4951 /* If DECL is a TYPE_DECL for a class-template, then there won't
4952 be DECL_LANG_SPECIFIC. The information equivalent to
4953 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4957 {
4958 /* Since a template declaration already existed for this
4959 class-type, we must be redeclaring it here. Make sure
4960 that the redeclaration is valid. */
4962 current_template_parms);
4963 /* We don't need to create a new TEMPLATE_DECL; just use the
4964 one we already had. */
4966 }
4967 else
4968 {
4970 member_template_p);
4975 {
4976 /* A specialization of a member template of a template
4977 class. */
4981 }
4982 }
4983 }
4984 else
4985 {
4991 {
4994 }
5002 {
5003 tree new_tmpl;
5005 /* The declaration is a specialization of a member
5006 template, declared outside the class. Therefore, the
5007 innermost template arguments will be NULL, so we
5008 replace them with the arguments determined by the
5009 earlier call to check_explicit_specialization. */
5012 new_tmpl
5014 member_template_p);
5024 args,
5027 }
5029 /* Make sure the template headers we got make sense. */
5034 {
5037 }
5038 else
5040 {
5045 {
5049 else
5054 }
5059 /* Can happen in erroneous input. */
5061 else
5065 }
5067 /* Check that the parms are used in the appropriate qualifying scopes
5068 in the declarator. */
5072 {
5078 /* Avoid crash in import_export_decl. */
5081 }
5082 }
5087 /* Push template declarations for global functions and types. Note
5088 that we do not try to push a global template friend declared in a
5089 template class; such a thing may well depend on the template
5090 parameters of the class. */
5093 {
5098 /* Hide template friend classes that haven't been declared yet. */
5100 {
5103 }
5104 }
5107 {
5113 {
5116 /* It is a conversion operator. See if the type converted to
5117 depends on innermost template operands. */
5120 depth))
5122 }
5124 /* Give template template parms a DECL_CONTEXT of the template
5125 for which they are a parameter. */
5128 {
5132 }
5133 }
5135 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5136 back to its most general template. If TMPL is a specialization,
5137 ARGS may only have the innermost set of arguments. Add the missing
5138 argument levels if necessary. */
5146 else
5147 {
5152 }
5155 }
5157 tree
5159 {
5161 }
5163 /* Called when a class template TYPE is redeclared with the indicated
5164 template PARMS, e.g.:
5166 template <class T> struct S;
5167 template <class T> struct S {}; */
5169 bool
5171 {
5172 tree tmpl;
5173 tree tmpl_parms;
5177 {
5180 }
5184 /* The type is nested in some template class. Nothing to worry
5185 about here; there are no new template parameters for the nested
5186 type. */
5190 {
5192 tmpl);
5194 }
5200 {
5210 }
5213 {
5214 tree tmpl_parm;
5215 tree parm;
5216 tree tmpl_default;
5217 tree parm_default;
5231 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5232 TEMPLATE_DECL. */
5242 {
5246 }
5249 {
5250 /* We have in [temp.param]:
5252 A template-parameter may not be given default arguments
5253 by two different declarations in the same scope. */
5258 }
5261 /* Update the previous template parameters (which are the ones
5262 that will really count) with the new default value. */
5265 /* Update the new parameters, too; they'll be used as the
5266 parameters for any members. */
5268 }
5271 }
5273 /* Simplify EXPR if it is a non-dependent expression. Returns the
5274 (possibly simplified) expression. */
5276 static tree
5278 {
5282 /* If we're in a template, but EXPR isn't value dependent, simplify
5283 it. We're supposed to treat:
5285 template <typename T> void f(T[1 + 1]);
5286 template <typename T> void f(T[2]);
5288 as two declarations of the same function, for example. */
5293 {
5294 HOST_WIDE_INT saved_processing_template_decl;
5300 complain,
5305 }
5307 }
5309 tree
5311 {
5313 }
5315 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5316 template declaration, or a TYPE_DECL for an alias declaration. */
5318 bool
5320 {
5328 }
5330 /* Return TRUE iff is a specialization of an alias template. */
5332 bool
5334 {
5339 }
5341 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5342 must be a function or a pointer-to-function type, as specified
5343 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5344 and check that the resulting function has external linkage. */
5346 static tree
5348 {
5351 linkage_kind linkage;
5363 /* [temp.arg.nontype]/1
5365 A template-argument for a non-type, non-template template-parameter
5366 shall be one of:
5367 [...]
5368 -- the address of an object or function with external [C++11: or
5369 internal] linkage. */
5372 {
5377 else
5382 }
5385 }
5387 /* Subroutine of convert_nontype_argument.
5388 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5389 Emit an error otherwise. */
5391 static bool
5393 tsubst_flags_t complain)
5394 {
5401 {
5405 }
5407 }
5409 /* Returns TRUE iff the address of OP is value-dependent.
5411 14.6.2.4 [temp.dep.temp]:
5412 A non-integral non-type template-argument is dependent if its type is
5413 dependent or it has either of the following forms
5414 qualified-id
5415 & qualified-id
5416 and contains a nested-name-specifier which specifies a class-name that
5417 names a dependent type.
5419 We generalize this to just say that the address of a member of a
5420 dependent class is value-dependent; the above doesn't cover the
5421 address of a static data member named with an unqualified-id. */
5423 static bool
5425 {
5426 /* We could use get_inner_reference here, but there's no need;
5427 this is only relevant for template non-type arguments, which
5428 can only be expressed as &id-expression. */
5430 {
5434 }
5437 }
5439 /* The next set of functions are used for providing helpful explanatory
5440 diagnostics for failed overload resolution. Their messages should be
5441 indented by two spaces for consistency with the messages in
5442 call.c */
5444 static int
5446 {
5448 }
5450 static int
5452 {
5457 }
5459 static int
5461 {
5463 }
5465 static int
5467 {
5473 }
5475 static int
5477 {
5481 }
5483 static int
5485 {
5488 " template parameter %qD is not a parameter pack, but "
5492 }
5494 static int
5496 {
5499 " template argument %qE does not match "
5503 }
5505 static int
5507 {
5511 }
5513 static int
5515 {
5521 }
5523 static int
5525 {
5527 {
5532 else
5534 " deduced conflicting values for non-type parameter "
5536 }
5538 }
5540 static int
5542 {
5545 " variable-sized array type %qT is not "
5547 arg);
5549 }
5551 static int
5553 {
5557 arg);
5559 }
5561 static int
5563 {
5570 }
5572 static int
5574 {
5576 }
5578 static int
5580 {
5582 }
5584 static int
5587 {
5592 }
5594 static int
5597 {
5600 {
5608 }
5610 }
5612 static int
5614 {
5617 " template parameters of a template template argument are "
5620 }
5622 static int
5624 {
5630 }
5632 static int
5634 {
5639 }
5641 static int
5643 {
5647 arg);
5649 }
5651 /* Attempt to convert the non-type template parameter EXPR to the
5652 indicated TYPE. If the conversion is successful, return the
5653 converted value. If the conversion is unsuccessful, return
5654 NULL_TREE if we issued an error message, or error_mark_node if we
5655 did not. We issue error messages for out-and-out bad template
5656 parameters, but not simply because the conversion failed, since we
5657 might be just trying to do argument deduction. Both TYPE and EXPR
5658 must be non-dependent.
5660 The conversion follows the special rules described in
5661 [temp.arg.nontype], and it is much more strict than an implicit
5662 conversion.
5664 This function is called twice for each template argument (see
5665 lookup_template_class for a more accurate description of this
5666 problem). This means that we need to handle expressions which
5667 are not valid in a C++ source, but can be created from the
5668 first call (for instance, casts to perform conversions). These
5669 hacks can go away after we fix the double coercion problem. */
5671 static tree
5673 {
5674 tree expr_type;
5676 /* Detect immediately string literals as invalid non-type argument.
5677 This special-case is not needed for correctness (we would easily
5678 catch this later), but only to provide better diagnostic for this
5679 common user mistake. As suggested by DR 100, we do not mention
5680 linkage issues in the diagnostic as this is not the point. */
5681 /* FIXME we're making this OK. */
5683 {
5689 }
5691 /* Add the ADDR_EXPR now for the benefit of
5692 value_dependent_expression_p. */
5695 {
5699 }
5701 /* If we are in a template, EXPR may be non-dependent, but still
5702 have a syntactic, rather than semantic, form. For example, EXPR
5703 might be a SCOPE_REF, rather than the VAR_DECL to which the
5704 SCOPE_REF refers. Preserving the qualifying scope is necessary
5705 so that access checking can be performed when the template is
5706 instantiated -- but here we need the resolved form so that we can
5707 convert the argument. */
5718 else
5721 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5722 to a non-type argument of "nullptr". */
5727 /* In C++11, integral or enumeration non-type template arguments can be
5728 arbitrary constant expressions. Pointer and pointer to
5729 member arguments can be general constant expressions that evaluate
5730 to a null value, but otherwise still need to be of a specific form. */
5732 {
5734 /* A PTRMEM_CST is already constant, and a valid template
5735 argument for a parameter of pointer to member type, we just want
5736 to leave it in that form rather than lower it to a
5742 {
5747 }
5748 }
5750 /* HACK: Due to double coercion, we can get a
5751 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5752 which is the tree that we built on the first call (see
5753 below when coercing to reference to object or to reference to
5754 function). We just strip everything and get to the arg.
5755 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5756 for examples. */
5758 {
5764 {
5765 /* ??? Maybe we could use convert_from_reference here, but we
5766 would need to relax its constraints because the NOP_EXPR
5767 could actually change the type to something more cv-qualified,
5768 and this is not folded by convert_from_reference. */
5779 }
5780 }
5782 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5783 parameter is a pointer to object, through decay and
5784 qualification conversion. Let's strip everything. */
5786 {
5790 /* Skip the ADDR_EXPR only if it is part of the decay for
5791 an array. Otherwise, it is part of the original argument
5792 in the source code. */
5796 }
5798 /* [temp.arg.nontype]/5, bullet 1
5800 For a non-type template-parameter of integral or enumeration type,
5801 integral promotions (_conv.prom_) and integral conversions
5802 (_conv.integral_) are applied. */
5804 {
5813 /* Notice that there are constant expressions like '4 % 0' which
5814 do not fold into integer constants. */
5816 {
5818 {
5829 /* else cxx_constant_value complained but gave us
5830 a real constant, so go ahead. */
5832 }
5833 else
5835 }
5836 }
5837 /* [temp.arg.nontype]/5, bullet 2
5839 For a non-type template-parameter of type pointer to object,
5840 qualification conversions (_conv.qual_) and the array-to-pointer
5841 conversion (_conv.array_) are applied. */
5843 {
5844 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5846 A template-argument for a non-type, non-template template-parameter
5847 shall be one of: [...]
5849 -- the name of a non-type template-parameter;
5850 -- the address of an object or function with external linkage, [...]
5851 expressed as "& id-expression" where the & is optional if the name
5852 refers to a function or array, or if the corresponding
5853 template-parameter is a reference.
5855 Here, we do not care about functions, as they are invalid anyway
5856 for a parameter of type pointer-to-object. */
5859 /* Non-type template parameters are OK. */
5860 ;
5865 {
5867 {
5869 "because %qD is a variable, not the address of "
5873 }
5874 /* Other values, like integer constants, might be valid
5875 non-type arguments of some other type. */
5877 }
5878 else
5879 {
5880 tree decl;
5885 {
5890 }
5892 {
5897 }
5899 {
5904 }
5905 }
5914 }
5915 /* [temp.arg.nontype]/5, bullet 3
5917 For a non-type template-parameter of type reference to object, no
5918 conversions apply. The type referred to by the reference may be more
5919 cv-qualified than the (otherwise identical) type of the
5920 template-argument. The template-parameter is bound directly to the
5921 template-argument, which must be an lvalue. */
5923 {
5925 expr_type))
5929 {
5933 }
5936 {
5940 }
5942 /* [temp.arg.nontype]/1
5944 A template-argument for a non-type, non-template template-parameter
5945 shall be one of: [...]
5947 -- the address of an object or function with external linkage. */
5950 {
5953 {
5955 "because a reference variable does not have a constant "
5958 }
5959 }
5962 {
5967 }
5970 {
5975 }
5978 }
5979 /* [temp.arg.nontype]/5, bullet 4
5981 For a non-type template-parameter of type pointer to function, only
5982 the function-to-pointer conversion (_conv.func_) is applied. If the
5983 template-argument represents a set of overloaded functions (or a
5984 pointer to such), the matching function is selected from the set
5985 (_over.over_). */
5987 {
5988 /* If the argument is a template-id, we might not have enough
5989 context information to decay the pointer. */
5991 {
5995 }
5998 /* Null pointer values are OK in C++11. */
6006 {
6010 }
6011 }
6012 /* [temp.arg.nontype]/5, bullet 5
6014 For a non-type template-parameter of type reference to function, no
6015 conversions apply. If the template-argument represents a set of
6016 overloaded functions, the matching function is selected from the set
6017 (_over.over_). */
6019 {
6021 {
6026 }
6033 }
6034 /* [temp.arg.nontype]/5, bullet 6
6036 For a non-type template-parameter of type pointer to member function,
6037 no conversions apply. If the template-argument represents a set of
6038 overloaded member functions, the matching member function is selected
6039 from the set (_over.over_). */
6041 {
6046 /* [temp.arg.nontype] bullet 1 says the pointer to member
6047 expression must be a pointer-to-member constant. */
6051 /* There is no way to disable standard conversions in
6052 resolve_address_of_overloaded_function (called by
6053 instantiate_type). It is possible that the call succeeded by
6054 converting &B::I to &D::I (where B is a base of D), so we need
6055 to reject this conversion here.
6057 Actually, even if there was a way to disable standard conversions,
6058 it would still be better to reject them here so that we can
6059 provide a superior diagnostic. */
6061 {
6065 /* If we are just one standard conversion off, explain. */
6070 }
6071 }
6072 /* [temp.arg.nontype]/5, bullet 7
6074 For a non-type template-parameter of type pointer to data member,
6075 qualification conversions (_conv.qual_) are applied. */
6077 {
6078 /* [temp.arg.nontype] bullet 1 says the pointer to member
6079 expression must be a pointer-to-member constant. */
6086 }
6088 {
6090 {
6094 }
6096 }
6097 /* A template non-type parameter must be one of the above. */
6098 else
6101 /* Sanity check: did we actually convert the argument to the
6102 right type? */
6106 }
6108 /* Subroutine of coerce_template_template_parms, which returns 1 if
6109 PARM_PARM and ARG_PARM match using the rule for the template
6110 parameters of template template parameters. Both PARM and ARG are
6111 template parameters; the rest of the arguments are the same as for
6112 coerce_template_template_parms.
6113 */
6114 static int
6116 tree arg,
6117 tsubst_flags_t complain,
6118 tree in_decl,
6119 tree outer_args)
6120 {
6129 {
6131 /* We encounter instantiations of templates like
6132 template <template <template <class> class> class TT>
6133 class C; */
6134 {
6141 }
6142 /* Fall through. */
6147 /* Argument is a parameter pack but parameter is not. */
6152 /* The tsubst call is used to handle cases such as
6154 template <int> class C {};
6155 template <class T, template <T> class TT> class D {};
6156 D<int, C> d;
6158 i.e. the parameter list of TT depends on earlier parameters. */
6160 && !same_type_p
6167 /* Argument is a parameter pack but parameter is not. */
6174 }
6177 }
6180 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6181 template template parameters. Both PARM_PARMS and ARG_PARMS are
6182 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6183 or PARM_DECL.
6185 Consider the example:
6186 template <class T> class A;
6187 template<template <class U> class TT> class B;
6189 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6190 the parameters to A, and OUTER_ARGS contains A. */
6192 static int
6194 tree arg_parms,
6195 tsubst_flags_t complain,
6196 tree in_decl,
6197 tree outer_args)
6198 {
6209 /* Determine whether we have a parameter pack at the end of the
6210 template template parameter's template parameter list. */
6212 {
6219 {
6233 }
6234 }
6240 /* Check all of the template parameters except the parameter pack at
6241 the end (if any). */
6243 {
6252 outer_args))
6255 }
6258 {
6259 /* Check each of the template parameters in the template
6260 argument against the template parameter pack at the end of
6261 the template template parameter. */
6268 {
6275 outer_args))
6277 }
6278 }
6281 }
6283 /* Verifies that the deduced template arguments (in TARGS) for the
6284 template template parameters (in TPARMS) represent valid bindings,
6285 by comparing the template parameter list of each template argument
6286 to the template parameter list of its corresponding template
6287 template parameter, in accordance with DR150. This
6288 routine can only be called after all template arguments have been
6289 deduced. It will return TRUE if all of the template template
6290 parameter bindings are okay, FALSE otherwise. */
6291 bool
6293 {
6297 /* We're dealing with template parms in this process. */
6303 {
6308 {
6313 {
6314 /* Look inside the argument pack. */
6317 }
6320 {
6324 /* Extract the next argument from the argument
6325 pack. */
6329 /* Look at the pattern of the pack expansion. */
6332 /* Extract the template parameters from the template
6333 argument. */
6339 /* Verify that we can coerce the template template
6340 parameters from the template argument to the template
6341 parameter. This requires an exact match. */
6343 && !coerce_template_template_parms
6345 targ_parms,
6346 tf_none,
6347 tparm,
6348 targs))
6349 {
6352 }
6353 }
6354 }
6355 }
6357 out:
6361 }
6363 /* Since type attributes aren't mangled, we need to strip them from
6364 template type arguments. */
6366 static tree
6368 {
6369 tree mv;
6376 {
6381 }
6383 }
6385 /* Convert the indicated template ARG as necessary to match the
6386 indicated template PARM. Returns the converted ARG, or
6387 error_mark_node if the conversion was unsuccessful. Error and
6388 warning messages are issued under control of COMPLAIN. This
6389 conversion is for the Ith parameter in the parameter list. ARGS is
6390 the full set of template arguments deduced so far. */
6392 static tree
6394 tree arg,
6395 tree args,
6396 tsubst_flags_t complain,
6398 tree in_decl)
6399 {
6400 tree orig_arg;
6401 tree val;
6406 {
6407 /* The template argument was the name of some
6408 member function. That's usually
6409 invalid, but static members are OK. In any
6410 case, grab the underlying fields/functions
6411 and issue an error later if required. */
6414 }
6422 /* When determining whether an argument pack expansion is a template,
6423 look at the pattern. */
6427 /* Deal with an injected-class-name used as a template template arg. */
6429 {
6432 {
6442 }
6443 }
6445 is_tmpl_type =
6461 {
6463 {
6467 }
6470 "to refer to a type member of a template parameter, "
6475 typename_type,
6479 }
6481 {
6483 {
6485 {
6495 else
6497 }
6498 }
6500 }
6502 {
6504 {
6510 else
6512 }
6514 }
6517 {
6519 {
6523 /* The number of argument required is not known yet.
6524 Just accept it for now. */
6526 else
6527 {
6529 tree argparm;
6535 args))
6536 {
6539 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6540 TEMPLATE_DECL. */
6542 {
6547 }
6548 }
6549 else
6550 {
6552 {
6558 }
6561 }
6562 }
6563 }
6564 else
6566 /* We only form one instance of each template specialization.
6567 Therefore, if we use a non-canonical variant (i.e., a
6568 typedef), any future messages referring to the type will use
6569 the typedef, which is confusing if those future uses do not
6570 themselves also use the typedef. */
6573 }
6574 else
6575 {
6582 {
6585 else
6586 {
6587 /* Not sure if this is reachable, but it doesn't hurt
6588 to be robust. */
6591 }
6592 }
6594 /* We used to call digest_init here. However, digest_init
6595 will report errors, which we don't want when complain
6596 is zero. More importantly, digest_init will try too
6597 hard to convert things: for example, `0' should not be
6598 converted to pointer type at this point according to
6599 the standard. Accepting this is not merely an
6600 extension, since deciding whether or not these
6601 conversions can occur is part of determining which
6602 function template to call, or whether a given explicit
6603 argument specification is valid. */
6605 else
6614 {
6615 /* Strip typedefs from the SCOPE_REF. */
6618 complain);
6621 }
6622 }
6625 }
6627 /* Coerces the remaining template arguments in INNER_ARGS (from
6628 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6629 Returns the coerced argument pack. PARM_IDX is the position of this
6630 parameter in the template parameter list. ARGS is the original
6631 template argument list. */
6632 static tree
6635 tree args,
6636 tree inner_args,
6638 tree new_args,
6640 tree in_decl,
6641 tsubst_flags_t complain)
6642 {
6645 tree packed_args;
6646 tree argument_pack;
6656 {
6657 /* When the template parameter is a non-type template
6658 parameter pack whose type uses parameter packs, we need
6659 to look at each of the template arguments
6660 separately. Build a vector of the types for these
6661 non-type template parameters in PACKED_TYPES. */
6662 tree expansion
6670 /* Check that we have the right number of arguments. */
6674 {
6675 int needed_parms
6680 }
6682 /* If we aren't able to check the actual arguments now
6683 (because they haven't been expanded yet), we can at least
6684 verify that all of the types used for the non-type
6685 template parameter pack are, in fact, valid for non-type
6686 template parameters. */
6689 {
6692 {
6696 }
6697 }
6698 }
6700 /* Convert the remaining arguments, which will be a part of the
6701 parameter pack "parm". */
6703 {
6708 {
6709 /* When we have a vector of types (corresponding to the
6710 non-type template parameter pack that uses parameter
6711 packs in its type, as mention above), and the
6712 argument is not an expansion (which expands to a
6713 currently unknown number of arguments), clone the
6714 parm and give it the next type in PACKED_TYPES. */
6718 }
6721 {
6724 }
6725 else
6728 in_decl);
6732 }
6737 else
6738 {
6743 }
6746 #ifdef ENABLE_CHECKING
6749 #endif
6751 }
6753 /* Returns true if the template argument vector ARGS contains
6754 any pack expansions, false otherwise. */
6756 static bool
6758 {
6765 }
6767 /* Convert all template arguments to their appropriate types, and
6768 return a vector containing the innermost resulting template
6769 arguments. If any error occurs, return error_mark_node. Error and
6770 warning messages are issued under control of COMPLAIN.
6772 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6773 for arguments not specified in ARGS. Otherwise, if
6774 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6775 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6776 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6777 ARGS. */
6779 static tree
6781 tree args,
6782 tree in_decl,
6783 tsubst_flags_t complain,
6786 {
6788 tree inner_args;
6789 tree new_args;
6790 tree new_inner_args;
6794 /* When used as a boolean value, indicates whether this is a
6795 variadic template parameter list. Since it's an int, we can also
6796 subtract it from nparms to get the number of non-variadic
6797 parameters. */
6806 /* Determine if there are any parameter packs. */
6808 {
6814 }
6817 /* If there are no parameters that follow a parameter pack, we need to
6818 expand any argument packs so that we can deduce a parameter pack from
6819 some non-packed args followed by an argument pack, as in variadic85.C.
6820 If there are such parameters, we need to leave argument packs intact
6821 so the arguments are assigned properly. This can happen when dealing
6822 with a nested class inside a partial specialization of a class
6823 template, as in variadic92.C, or when deducing a template parameter pack
6824 from a sub-declarator, as in variadic114.C. */
6831 && require_all_args
6833 && (!use_default_args
6836 {
6838 {
6840 {
6844 }
6845 else
6851 }
6854 }
6856 /* We need to evaluate the template arguments, even though this
6857 template-id may be nested within a "sizeof". */
6865 {
6866 tree arg;
6867 tree parm;
6869 /* Get the Ith template parameter. */
6873 {
6876 }
6878 /* Calculate the next argument. */
6881 else
6886 {
6887 /* All remaining arguments will be placed in the
6888 template parameter pack PARM. */
6894 /* Store this argument. */
6896 lost++;
6899 /* We are done with all of the arguments. */
6903 }
6905 {
6907 {
6908 /* We don't know how many args we have yet, just
6909 use the unconverted ones for now. */
6912 }
6913 }
6915 {
6916 /* There must be a default arg in this case. */
6919 /* The position of the first default template argument,
6920 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6921 Record that. */
6924 }
6925 else
6929 {
6932 }
6934 /* This only occurs if there was an error in the template
6935 parameter list itself (which we would already have
6936 reported) that we are trying to recover from, e.g., a class
6937 template with a parameter list such as
6938 template<typename..., typename>. */
6940 else
6946 lost++;
6948 }
6955 #ifdef ENABLE_CHECKING
6959 #endif
6962 }
6964 /* Returns 1 if template args OT and NT are equivalent. */
6966 static int
6968 {
6975 /* For member templates */
6984 {
7001 }
7003 {
7004 /* We get here probably because we are in the middle of substituting
7005 into the pattern of a pack expansion. In that case the
7006 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7007 interested in. So we want to use the initial pack argument for
7008 the comparison. */
7013 }
7018 else
7020 }
7022 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7023 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7024 NEWARG_PTR with the offending arguments if they are non-NULL. */
7026 static int
7029 {
7042 {
7047 {
7053 }
7054 }
7056 }
7058 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7059 of template arguments. Returns 0 otherwise. */
7061 int
7063 {
7065 }
7067 static void
7069 {
7079 /* We are called both from instantiate_decl, where we've already had a
7080 tinst_level pushed, and instantiate_template, where we haven't.
7081 Compensate. */
7092 else
7101 }
7104 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7105 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7106 documentation for TEMPLATE_ID_EXPR. */
7108 tree
7110 {
7111 tree type;
7119 {
7122 }
7125 {
7127 unknown_type_node,
7129 arglist);
7131 }
7138 }
7140 /* Within the scope of a template class S<T>, the name S gets bound
7141 (in build_self_reference) to a TYPE_DECL for the class, not a
7142 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7143 or one of its enclosing classes, and that type is a template,
7144 return the associated TEMPLATE_DECL. Otherwise, the original
7145 DECL is returned.
7147 Also handle the case when DECL is a TREE_LIST of ambiguous
7148 injected-class-names from different bases. */
7150 tree
7152 {
7156 /* DR 176: A lookup that finds an injected-class-name (10.2
7157 [class.member.lookup]) can result in an ambiguity in certain cases
7158 (for example, if it is found in more than one base class). If all of
7159 the injected-class-names that are found refer to specializations of
7160 the same class template, and if the name is followed by a
7161 template-argument-list, the reference refers to the class template
7162 itself and not a specialization thereof, and is not ambiguous. */
7164 {
7167 {
7173 }
7176 else
7178 }
7184 }
7186 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7187 parameters, find the desired type.
7189 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7191 IN_DECL, if non-NULL, is the template declaration we are trying to
7192 instantiate.
7194 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7195 the class we are looking up.
7197 Issue error and warning messages under control of COMPLAIN.
7199 If the template class is really a local class in a template
7200 function, then the FUNCTION_CONTEXT is the function in which it is
7201 being instantiated.
7203 ??? Note that this function is currently called *twice* for each
7204 template-id: the first time from the parser, while creating the
7205 incomplete type (finish_template_type), and the second type during the
7206 real instantiation (instantiate_template_class). This is surely something
7207 that we want to avoid. It also causes some problems with argument
7208 coercion (see convert_nontype_argument for more information on this). */
7210 static tree
7213 {
7215 tree t;
7218 spec_entry elt;
7219 hashval_t hash;
7222 {
7226 else
7227 {
7234 }
7237 }
7239 {
7242 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7243 an implicit typename for the second A. Deal with it. */
7248 {
7251 }
7252 }
7255 {
7258 }
7262 {
7266 }
7268 /* Issue an error message if we didn't find a template. */
7270 {
7274 }
7277 /* Make sure it's a user visible template, if it was named by
7278 the user. */
7281 {
7283 {
7287 }
7289 }
7294 {
7295 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7296 template arguments */
7298 tree parm;
7299 tree arglist2;
7300 tree outer;
7304 /* Consider an example where a template template parameter declared as
7306 template <class T, class U = std::allocator<T> > class TT
7308 The template parameter level of T and U are one level larger than
7309 of TT. To proper process the default argument of U, say when an
7310 instantiation `TT<int>' is seen, we need to build the full
7311 arguments containing {int} as the innermost level. Outer levels,
7312 available when not appearing as default template argument, can be
7313 obtained from the arguments of the enclosing template.
7315 Suppose that TT is later substituted with std::vector. The above
7316 instantiation is `TT<int, std::allocator<T> >' with TT at
7317 level 1, and T at level 2, while the template arguments at level 1
7318 becomes {std::vector} and the inner level 2 is {int}. */
7324 /* This is an argument of the current template, so we haven't set
7325 DECL_CONTEXT yet. */
7332 complain,
7342 }
7343 else
7344 {
7346 tree gen_tmpl;
7347 tree type_decl;
7355 /* An error occured while building the template TEMPL, and a
7356 diagnostic has most certainly been emitted for that
7357 already. Let's propagate that error. */
7366 {
7367 /* We've been given an incomplete set of template arguments.
7368 For example, given:
7370 template <class T> struct S1 {
7371 template <class U> struct S2 {};
7372 template <class U> struct S2<U*> {};
7373 };
7375 we will be called with an ARGLIST of `U*', but the
7376 TEMPLATE will be `template <class T> template
7377 <class U> struct S1<T>::S2'. We must fill in the missing
7378 arguments. */
7379 arglist
7381 arglist);
7383 }
7385 /* Now we should have enough arguments. */
7388 /* From here on, we're only interested in the most general
7389 template. */
7391 /* Calculate the BOUND_ARGS. These will be the args that are
7392 actually tsubst'd into the definition to create the
7393 instantiation. */
7395 {
7396 /* We have multiple levels of arguments to coerce, at once. */
7406 {
7407 tree a;
7411 complain,
7414 else
7415 /* Outer levels should have already been coerced. */
7418 /* Don't process further if one of the levels fails. */
7420 {
7421 /* Restore the ARGLIST to its full size. */
7424 }
7428 /* We temporarily reduce the length of the ARGLIST so
7429 that coerce_template_parms will see only the arguments
7430 corresponding to the template parameters it is
7431 examining. */
7433 }
7435 /* Restore the ARGLIST to its full size. */
7439 }
7440 else
7441 arglist
7444 gen_tmpl,
7445 complain,
7450 /* We were unable to bind the arguments. */
7453 /* In the scope of a template class, explicit references to the
7454 template class refer to the type of the template, not any
7455 instantiation of it. For example, in:
7457 template <class T> class C { void f(C<T>); }
7459 the `C<T>' is just the same as `C'. Outside of the
7460 class, however, such a reference is an instantiation. */
7464 /* comp_template_args is expensive, check it last. */
7466 arglist))
7469 /* If we already have this specialization, return it. */
7481 /* If the deduced arguments are invalid, then the binding
7482 failed. */
7486 complain))
7493 {
7498 }
7508 /* Create the type. */
7510 {
7512 {
7518 }
7519 else
7520 {
7521 /* We don't want to call start_enum for this type, since
7522 the values for the enumeration constants may involve
7523 template parameters. And, no one should be interested
7524 in the enumeration constants for such a type. */
7527 }
7531 }
7533 {
7534 /* The user referred to a specialization of an alias
7535 template represented by GEN_TMPL.
7537 [temp.alias]/2 says:
7539 When a template-id refers to the specialization of an
7540 alias template, it is equivalent to the associated
7541 type obtained by substitution of its
7542 template-arguments for the template-parameters in the
7543 type-id of the alias template. */
7546 /* Note that the call above (by indirectly calling
7547 register_specialization in tsubst_decl) registers the
7548 TYPE_DECL representing the specialization of the alias
7549 template. So next time someone substitutes ARGLIST for
7550 the template parms into the alias template (GEN_TMPL),
7551 she'll get that TYPE_DECL back. */
7555 }
7557 {
7564 /* A local class. Make sure the decl gets registered properly. */
7569 /* This instantiation is another name for the primary
7570 template type. Set the TYPE_CANONICAL field
7571 appropriately. */
7574 /* Some of the template arguments require structural
7575 equality testing, so this template class requires
7576 structural equality testing. */
7578 }
7579 else
7582 /* If we called start_enum or pushtag above, this information
7583 will already be set up. */
7585 {
7592 }
7593 else
7597 {
7603 {
7606 }
7607 }
7609 /* Let's consider the explicit specialization of a member
7610 of a class template specialization that is implicitely instantiated,
7611 e.g.:
7612 template<class T>
7613 struct S
7614 {
7615 template<class U> struct M {}; //#0
7616 };
7618 template<>
7619 template<>
7620 struct S<int>::M<char> //#1
7621 {
7622 int i;
7623 };
7624 [temp.expl.spec]/4 says this is valid.
7626 In this case, when we write:
7627 S<int>::M<char> m;
7629 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7630 the one of #0.
7632 When we encounter #1, we want to store the partial instantiation
7633 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7635 For all cases other than this "explicit specialization of member of a
7636 class template", we just want to store the most general template into
7637 the CLASSTYPE_TI_TEMPLATE of M.
7639 This case of "explicit specialization of member of a class template"
7640 only happens when:
7641 1/ the enclosing class is an instantiation of, and therefore not
7642 the same as, the context of the most general template, and
7643 2/ we aren't looking at the partial instantiation itself, i.e.
7644 the innermost arguments are not the same as the innermost parms of
7645 the most general template.
7647 So it's only when 1/ and 2/ happens that we want to use the partial
7648 instantiation of the member template in lieu of its most general
7649 template. */
7653 /* the enclosing class must be an instantiation... */
7656 {
7657 tree partial_inst_args;
7660 partial_inst_args =
7666 use_partial_inst_tmpl =
7667 /*...and we must not be looking at the partial instantiation
7668 itself. */
7670 partial_inst_args);
7671 }
7674 /* This case is easy; there are no member templates involved. */
7676 else
7677 {
7678 /* This is a full instantiation of a member template. Find
7679 the partial instantiation of which this is an instance. */
7681 /* Temporarily reduce by one the number of levels in the ARGLIST
7682 so as to avoid comparing the last set of arguments. */
7686 /* FOUND is either a proper class type, or an alias
7687 template specialization. In the later case, it's a
7688 TYPE_DECL, resulting from the substituting of arguments
7689 for parameters in the TYPE_DECL of the alias template
7690 done earlier. So be careful while getting the template
7691 of FOUND. */
7695 }
7706 /* Note this use of the partial instantiation so we can check it
7707 later in maybe_process_partial_specialization. */
7713 /* Now that the type has been registered on the instantiations
7714 list, we set up the enumerators. Because the enumeration
7715 constants may involve the enumeration type itself, we make
7716 sure to register the type first, and then create the
7717 constants. That way, doing tsubst_expr for the enumeration
7718 constants won't result in recursive calls here; we'll find
7719 the instantiation and exit above. */
7723 /* If the type makes use of template parameters, the
7724 code that generates debugging information will crash. */
7727 /* Possibly limit visibility based on template args. */
7732 }
7733 }
7735 /* Wrapper for lookup_template_class_1. */
7737 tree
7740 {
7741 tree ret;
7747 }
7748 \f
7749 struct pair_fn_data
7750 {
7751 tree_fn_t fn;
7753 /* True when we should also visit template parameters that occur in
7754 non-deduced contexts. */
7757 };
7759 /* Called from for_each_template_parm via walk_tree. */
7761 static tree
7763 {
7776 {
7780 /* Fall through. */
7803 /* Since we're not going to walk subtrees, we have to do this
7804 explicitly here. */
7808 /* Fall through. */
7811 /* Check the return type. */
7816 /* Check the parameter types. Since default arguments are not
7817 instantiated until they are needed, the TYPE_ARG_TYPES may
7818 contain expressions that involve template parameters. But,
7819 no-one should be looking at them yet. And, once they're
7820 instantiated, they don't contain template parameters, so
7821 there's no point in looking at them then, either. */
7822 {
7823 tree parm;
7830 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7831 want walk_tree walking into them itself. */
7833 }
7851 /* Fall through. */
7867 /* Record template parameters such as `T' inside `TT<T>'. */
7871 /* Fall through. */
7883 /* A template template parameter is encountered. */
7889 /* Already substituted template template parameter */
7912 /* If there's no type, then this thing must be some expression
7913 involving template parameters. */
7935 }
7937 /* We didn't find any template parameters we liked. */
7939 }
7941 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7942 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7943 call FN with the parameter and the DATA.
7944 If FN returns nonzero, the iteration is terminated, and
7945 for_each_template_parm returns 1. Otherwise, the iteration
7946 continues. If FN never returns a nonzero value, the value
7947 returned by for_each_template_parm is 0. If FN is NULL, it is
7948 considered to be the function which always returns 1.
7950 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7951 parameters that occur in non-deduced contexts. When false, only
7952 visits those template parameters that can be deduced. */
7954 static int
7958 {
7962 /* Set up. */
7967 /* Walk the tree. (Conceptually, we would like to walk without
7968 duplicates, but for_each_template_parm_r recursively calls
7969 for_each_template_parm, so we would need to reorganize a fair
7970 bit to use walk_tree_without_duplicates, so we keep our own
7971 visited list.) */
7974 else
7977 for_each_template_parm_r,
7981 /* Clean up. */
7983 {
7986 }
7989 }
7991 /* Returns true if T depends on any template parameter. */
7993 int
7995 {
8022 else
8023 {
8026 }
8031 }
8033 /* Returns true if T depends on any template parameter with level LEVEL. */
8035 int
8037 {
8040 }
8042 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8043 ill-formed translation unit, i.e. a variable or function that isn't
8044 usable in a constant expression. */
8048 {
8052 }
8054 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8055 neglectable and instantiated from within an erroneous instantiation. */
8057 static bool
8059 {
8070 }
8074 #ifdef GATHER_STATISTICS
8076 #endif
8079 /* We're starting to instantiate D; record the template instantiation context
8080 for diagnostics and to restore it later. */
8082 int
8084 {
8088 {
8094 else
8102 }
8104 /* If the current instantiation caused problems, don't let it instantiate
8105 anything else. Do allow deduction substitution and decls usable in
8106 constant expressions. */
8119 #ifdef GATHER_STATISTICS
8122 #endif
8125 }
8127 /* We're done instantiating this template; return to the instantiation
8128 context. */
8130 void
8132 {
8133 /* Restore the filename and line number stashed away when we started
8134 this instantiation. */
8138 }
8140 /* We're instantiating a deferred template; restore the template
8141 instantiation context in which the instantiation was requested, which
8142 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8144 static tree
8146 {
8158 }
8160 /* Returns the TINST_LEVEL which gives the original instantiation
8161 context. */
8165 {
8171 }
8173 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8174 vector of template arguments, as for tsubst.
8176 Returns an appropriate tsubst'd friend declaration. */
8178 static tree
8180 {
8181 tree new_friend;
8186 /* This was a friend declared with an explicit template
8187 argument list, e.g.:
8189 friend void f<>(T);
8191 to indicate that f was a template instantiation, not a new
8192 function declaration. Now, we have to figure out what
8193 instantiation of what template. */
8194 {
8196 tree new_args;
8197 tree tmpl;
8200 /* Friend functions are looked up in the containing namespace scope.
8201 We must enter that scope, to avoid finding member functions of the
8202 current class with same name. */
8217 tsk_none);
8219 }
8223 /* The NEW_FRIEND will look like an instantiation, to the
8224 compiler, but is not an instantiation from the point of view of
8225 the language. For example, we might have had:
8227 template <class T> struct S {
8228 template <class U> friend void f(T, U);
8229 };
8231 Then, in S<int>, template <class U> void f(int, U) is not an
8232 instantiation of anything. */
8238 {
8242 }
8244 /* The mangled name for the NEW_FRIEND is incorrect. The function
8245 is not a template instantiation and should not be mangled like
8246 one. Therefore, we forget the mangling here; we'll recompute it
8247 later if we need it. */
8249 {
8252 }
8255 {
8256 tree old_decl;
8257 tree new_friend_template_info;
8258 tree new_friend_result_template_info;
8259 tree ns;
8262 /* We must save some information from NEW_FRIEND before calling
8263 duplicate decls since that function will free NEW_FRIEND if
8264 possible. */
8266 new_friend_is_defn =
8271 {
8272 /* This declaration is a `primary' template. */
8275 new_friend_result_template_info
8277 }
8278 else
8281 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8285 /* Inside pushdecl_namespace_level, we will push into the
8286 current namespace. However, the friend function should go
8287 into the namespace of the template. */
8297 {
8298 /* This new friend declaration matched an existing
8299 declaration. For example, given:
8301 template <class T> void f(T);
8302 template <class U> class C {
8303 template <class T> friend void f(T) {}
8304 };
8306 the friend declaration actually provides the definition
8307 of `f', once C has been instantiated for some type. So,
8308 old_decl will be the out-of-class template declaration,
8309 while new_friend is the in-class definition.
8311 But, if `f' was called before this point, the
8312 instantiation of `f' will have DECL_TI_ARGS corresponding
8313 to `T' but not to `U', references to which might appear
8314 in the definition of `f'. Previously, the most general
8315 template for an instantiation of `f' was the out-of-class
8316 version; now it is the in-class version. Therefore, we
8317 run through all specialization of `f', adding to their
8318 DECL_TI_ARGS appropriately. In particular, they need a
8319 new set of outer arguments, corresponding to the
8320 arguments for this class instantiation.
8322 The same situation can arise with something like this:
8324 friend void f(int);
8325 template <class T> class C {
8326 friend void f(T) {}
8327 };
8329 when `C<int>' is instantiated. Now, `f(int)' is defined
8330 in the class. */
8333 /* On the other hand, if the in-class declaration does
8334 *not* provide a definition, then we don't want to alter
8335 existing definitions. We can just leave everything
8336 alone. */
8337 ;
8338 else
8339 {
8343 /* Overwrite whatever template info was there before, if
8344 any, with the new template information pertaining to
8345 the declaration. */
8349 {
8350 /* We should have called reregister_specialization in
8351 duplicate_decls. */
8356 /* Instantiate it if the global has already been used. */
8360 }
8361 else
8362 {
8363 tree t;
8365 /* Indicate that the old function template is a partial
8366 instantiation. */
8374 /* Reassign any specializations already in the hash table
8375 to the new more general template, and add the
8376 additional template args. */
8380 {
8382 spec_entry elt;
8394 register_specialization
8397 }
8399 }
8400 }
8402 /* The information from NEW_FRIEND has been merged into OLD_DECL
8403 by duplicate_decls. */
8405 }
8406 }
8407 else
8408 {
8412 /* In the code
8413 template <class T> class C {
8414 template <class U> friend void C1<U>::f (); // case 1
8415 friend void C2<T>::f (); // case 2
8416 };
8417 we only need to make sure CONTEXT is a complete type for
8418 case 2. To distinguish between the two cases, we note that
8419 CONTEXT of case 1 remains dependent type after tsubst while
8420 this isn't true for case 2. */
8430 {
8431 /* Check to see that the declaration is really present, and,
8432 possibly obtain an improved declaration. */
8438 }
8439 }
8442 }
8444 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8445 template arguments, as for tsubst.
8447 Returns an appropriate tsubst'd friend type or error_mark_node on
8448 failure. */
8450 static tree
8452 {
8453 tree friend_type;
8454 tree tmpl;
8455 tree context;
8460 {
8463 else
8465 }
8467 /* Look for a class template declaration. We look for hidden names
8468 because two friend declarations of the same template are the
8469 same. For example, in:
8471 struct A {
8472 template <typename> friend class F;
8473 };
8474 template <typename> struct B {
8475 template <typename> friend class F;
8476 };
8478 both F templates are the same. */
8483 /* But, if we don't find one, it might be because we're in a
8484 situation like this:
8486 template <class T>
8487 struct S {
8488 template <class U>
8489 friend struct S;
8490 };
8492 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8493 for `S<int>', not the TEMPLATE_DECL. */
8495 {
8498 }
8501 {
8502 /* The friend template has already been declared. Just
8503 check to see that the declarations match, and install any new
8504 default parameters. We must tsubst the default parameters,
8505 of course. We only need the innermost template parameters
8506 because that is all that redeclare_class_template will look
8507 at. */
8510 {
8511 tree parms;
8512 location_t saved_input_location;
8521 }
8524 }
8525 else
8526 {
8527 /* The friend template has not already been declared. In this
8528 case, the instantiation of the template class will cause the
8529 injection of this template into the global scope. */
8534 /* The new TMPL is not an instantiation of anything, so we
8535 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8536 the new type because that is supposed to be the corresponding
8537 template decl, i.e., TMPL. */
8544 /* Inject this template into the global scope. */
8546 }
8549 {
8552 else
8554 }
8557 }
8559 /* Returns zero if TYPE cannot be completed later due to circularity.
8560 Otherwise returns one. */
8562 static int
8564 {
8574 else
8576 }
8578 /* Apply any attributes which had to be deferred until instantiation
8579 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8580 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8582 static void
8585 {
8587 tree t;
8592 {
8596 }
8599 {
8603 }
8604 else
8608 {
8613 {
8616 {
8619 /* If the first attribute argument is an identifier, don't
8620 pass it through tsubst. Attributes like mode, format,
8621 cleanup and several target specific attributes expect it
8622 unmodified. */
8628 {
8629 tree chain
8631 in_decl,
8636 chain);
8637 }
8638 else
8644 }
8645 else
8647 }
8650 }
8651 }
8653 /* Perform (or defer) access check for typedefs that were referenced
8654 from within the template TMPL code.
8655 This is a subroutine of instantiate_template and instantiate_class_template.
8656 TMPL is the template to consider and TARGS is the list of arguments of
8657 that template. */
8659 static void
8661 {
8662 location_t saved_location;
8675 {
8687 /* Make access check error messages point to the location
8688 of the use of the typedef. */
8692 }
8694 }
8696 static tree
8698 {
8700 tree typedecl;
8701 tree pbinfo;
8702 tree base_list;
8712 /* Figure out which template is being instantiated. */
8716 /* Determine what specialization of the original template to
8717 instantiate. */
8720 {
8723 }
8725 {
8726 /* This TYPE is actually an instantiation of a partial
8727 specialization. We replace the innermost set of ARGS with
8728 the arguments appropriate for substitution. For example,
8729 given:
8731 template <class T> struct S {};
8732 template <class T> struct S<T*> {};
8734 and supposing that we are instantiating S<int*>, ARGS will
8735 presently be {int*} -- but we need {int}. */
8738 }
8739 else
8740 {
8743 }
8745 /* If the template we're instantiating is incomplete, then clearly
8746 there's nothing we can do. */
8750 /* If we've recursively instantiated too many templates, stop. */
8754 /* Now we're really doing the instantiation. Mark the type as in
8755 the process of being defined. */
8758 /* We may be in the middle of deferred access check. Disable
8759 it now. */
8763 /* Use #pragma pack from the template context. */
8769 /* Set the input location to the most specialized template definition.
8770 This is needed if tsubsting causes an error. */
8782 {
8785 /* Adjust visibility for template arguments. */
8787 }
8792 /* We should never instantiate a nested class before its enclosing
8793 class; we need to look up the nested class by name before we can
8794 instantiate it, and that lookup should instantiate the enclosing
8795 class. */
8801 {
8802 tree pbase_binfo;
8803 tree pushed_scope;
8806 /* We must enter the scope containing the type, as that is where
8807 the accessibility of types named in dependent bases are
8808 looked up from. */
8811 /* Substitute into each of the bases to determine the actual
8812 basetypes. */
8814 {
8815 tree base;
8821 {
8822 expanded_bases =
8829 }
8832 {
8834 /* Extract the already-expanded base class. */
8836 else
8837 /* Substitute to figure out the base class. */
8839 NULL_TREE);
8847 }
8848 }
8850 /* The list is now in reverse order; correct that. */
8855 }
8856 /* Now call xref_basetypes to set up all the base-class
8857 information. */
8865 /* Now that our base classes are set up, enter the scope of the
8866 class, so that name lookups into base classes, etc. will work
8867 correctly. This is precisely analogous to what we do in
8868 begin_class_definition when defining an ordinary non-template
8869 class, except we also need to push the enclosing classes. */
8872 /* Now members are processed in the order of declaration. */
8875 {
8879 {
8881 {
8882 /* Build new CLASSTYPE_NESTED_UTDS. */
8884 tree newtag;
8890 /* If the member is a class template, then -- even after
8891 substitution -- there may be dependent types in the
8892 template argument list for the class. We increment
8893 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8894 that function will assume that no types are dependent
8895 when outside of a template. */
8905 {
8909 /* Unfortunately, lookup_template_class sets
8910 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8911 instantiation (i.e., for the type of a member
8912 template class nested within a template class.)
8913 This behavior is required for
8914 maybe_process_partial_specialization to work
8915 correctly, but is not accurate in this case;
8916 the TAG is not an instantiation of anything.
8917 (The corresponding TEMPLATE_DECL is an
8918 instantiation, but the TYPE is not.) */
8921 /* Now, we call pushtag to put this NEWTAG into the scope of
8922 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8923 pushtag calling push_template_decl. We don't have to do
8924 this for enums because it will already have been done in
8925 tsubst_enum. */
8929 }
8930 }
8933 {
8934 /* Build new TYPE_METHODS. */
8935 tree r;
8944 /* Instantiate members marked with attribute used. */
8947 }
8948 else
8949 {
8950 /* Build new TYPE_FIELDS. */
8952 {
8953 tree condition;
8956 condition =
8966 }
8968 {
8969 tree r;
8971 /* The file and line for this declaration, to
8972 assist in error message reporting. Since we
8973 called push_tinst_level above, we don't need to
8974 restore these. */
8983 {
8984 /* In [temp.inst]:
8986 [t]he initialization (and any associated
8987 side-effects) of a static data member does
8988 not occur unless the static data member is
8989 itself used in a way that requires the
8990 definition of the static data member to
8991 exist.
8993 Therefore, we do not substitute into the
8994 initialized for the static data member here. */
8995 finish_static_data_member_decl
9001 /* Instantiate members marked with attribute used. */
9004 }
9006 {
9007 /* Determine whether R has a valid type and can be
9008 completed later. If R is invalid, then it is
9009 replaced by error_mark_node so that it will not be
9010 added to TYPE_FIELDS. */
9016 {
9019 }
9020 }
9022 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9023 such a thing will already have been added to the field
9024 list by tsubst_enum in finish_member_declaration in the
9025 CLASSTYPE_NESTED_UTDS case above. */
9029 {
9032 }
9033 }
9034 }
9035 }
9036 else
9037 {
9039 {
9040 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9046 {
9047 /* template <class T> friend class C; */
9050 }
9052 {
9053 /* template <class T> friend class C::D; */
9059 }
9062 {
9063 /* This could be either
9065 friend class T::C;
9067 when dependent_type_p is false or
9069 template <class U> friend class T::C;
9071 otherwise. */
9074 /* Bump processing_template_decl for correct
9075 dependent_type_p calculation. */
9080 }
9083 {
9084 /* friend class C;
9086 where C hasn't been declared yet. Let's lookup name
9087 from namespace scope directly, bypassing any name that
9088 come from dependent base class. */
9091 /* The call to xref_tag_from_type does injection for friend
9092 classes. */
9094 friend_type =
9098 }
9100 /* friend class C<T>; */
9103 /* Otherwise it's
9105 friend class C;
9107 where C is already declared or
9109 friend class C<int>;
9111 We don't have to do anything in these cases. */
9114 /* Trick make_friend_class into realizing that the friend
9115 we're adding is a template, not an ordinary class. It's
9116 important that we use make_friend_class since it will
9117 perform some error-checking and output cross-reference
9118 information. */
9126 }
9127 else
9128 {
9129 /* Build new DECL_FRIENDLIST. */
9130 tree r;
9132 /* The file and line for this declaration, to
9133 assist in error message reporting. Since we
9134 called push_tinst_level above, we don't need to
9135 restore these. */
9139 {
9142 }
9147 {
9150 }
9151 }
9152 }
9153 }
9156 {
9159 {
9162 }
9163 else
9165 }
9167 /* Set the file and line number information to whatever is given for
9168 the class itself. This puts error messages involving generated
9169 implicit functions at a predictable point, and the same point
9170 that would be used for non-template classes. */
9177 /* We don't instantiate default arguments for member functions. 14.7.1:
9179 The implicit instantiation of a class template specialization causes
9180 the implicit instantiation of the declarations, but not of the
9181 definitions or default arguments, of the class member functions,
9182 member classes, static data members and member templates.... */
9184 /* Some typedefs referenced from within the template code need to be access
9185 checked at template instantiation time, i.e now. These types were
9186 added to the template at parsing time. Let's get those and perform
9187 the access checks then. */
9196 /* The vtable for a template class can be emitted in any translation
9197 unit in which the class is instantiated. When there is no key
9198 method, however, finish_struct_1 will already have added TYPE to
9199 the keyed_classes list. */
9204 }
9206 /* Wrapper for instantiate_class_template_1. */
9208 tree
9210 {
9211 tree ret;
9216 }
9218 static tree
9220 {
9221 tree r;
9227 else
9228 {
9235 /* Preserve the raw-reference nature of T. */
9239 }
9241 }
9243 /* Given a function parameter pack TMPL_PARM and some function parameters
9244 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9245 and set *SPEC_P to point at the next point in the list. */
9247 static tree
9249 {
9250 /* Collect all of the extra "packed" parameters into an
9251 argument pack. */
9252 tree parmvec;
9253 tree parmtypevec;
9264 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9269 {
9272 }
9274 /* Build the argument packs. */
9281 }
9283 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9284 NONTYPE_ARGUMENT_PACK. */
9286 static tree
9288 {
9290 }
9292 /* Substitute ARGS into T, which is an pack expansion
9293 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9294 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9295 (if only a partial substitution could be performed) or
9296 ERROR_MARK_NODE if there was an error. */
9297 tree
9299 tree in_decl)
9300 {
9301 tree pattern;
9307 tree result;
9315 /* Add in any args remembered from an earlier partial instantiation. */
9320 /* Determine the argument packs that will instantiate the parameter
9321 packs used in the expansion expression. While we're at it,
9322 compute the number of arguments to be expanded and make sure it
9323 is consistent. */
9326 {
9333 {
9337 else
9340 }
9342 {
9345 else
9346 {
9347 /* We can't rely on local_specializations for a parameter
9348 name used later in a function declaration (such as in a
9349 late-specified return type). Even if it exists, it might
9350 have the wrong value for a recursive call. Just make a
9351 dummy decl, since it's only used for its type. */
9354 /* Partial instantiation of the parm_pack, we can't build
9355 up an argument pack yet. */
9357 else
9360 }
9361 }
9362 else
9363 {
9369 }
9376 /* This can only happen if we forget to expand an argument
9377 pack somewhere else. Just return an error, silently. */
9378 {
9382 }
9385 /* The argument pack that the parameter maps to is just an
9386 expansion of the parameter itself, such as one would find
9387 in the implicit typedef of a class inside the class itself.
9388 Consider this parameter "unsubstituted", so that we will
9389 maintain the outer pack expansion. */
9393 {
9397 /* Don't bother trying to do a partial substitution with
9398 incomplete packs; we'll try again after deduction. */
9405 {
9411 pattern);
9412 else
9415 pattern);
9417 }
9423 else
9426 /* Keep track of the parameter packs and their corresponding
9427 argument packs. */
9430 }
9431 else
9432 {
9433 /* We can't substitute for this parameter pack. We use a flag as
9434 well as the missing_level counter because function parameter
9435 packs don't have a level. */
9439 }
9440 }
9442 /* We cannot expand this expansion expression, because we don't have
9443 all of the argument packs we need. */
9445 {
9447 {
9448 /* We got some full packs, but we can't substitute them in until we
9449 have values for all the packs. So remember these until then. */
9450 tree save_args;
9454 /* The call to add_to_template_args above assumes no overlap
9455 between saved args and new args, so prune away any fake
9456 args, i.e. those that satisfied arg_from_parm_pack_p above. */
9458 {
9464 }
9465 else
9469 }
9470 else
9471 {
9472 /* There were no real arguments, we're just replacing a parameter
9473 pack with another version of itself. Substitute into the
9474 pattern and return a PACK_EXPANSION_*. The caller will need to
9475 deal with that. */
9479 else
9482 }
9484 }
9486 /* We could not find any argument packs that work. */
9491 {
9492 /* We're in a late-specified return type, so create our own local
9493 specializations map; the current map is either NULL or (in the
9494 case of recursive unification) might have bindings that we don't
9495 want to use or alter. */
9498 }
9500 /* For each argument in each argument pack, substitute into the
9501 pattern. */
9504 {
9505 /* For parameter pack, change the substitution of the parameter
9506 pack to the ith argument in its argument pack, then expand
9507 the pattern. */
9509 {
9511 tree arg;
9513 /* Select the Ith argument from the pack. */
9515 {
9517 {
9522 }
9523 else
9525 }
9526 else
9527 {
9532 {
9535 /* Update the corresponding argument. */
9537 }
9538 else
9539 /* Re-use the ARGUMENT_PACK_SELECT. */
9541 }
9543 }
9545 /* Substitute into the PATTERN with the altered arguments. */
9550 else
9554 {
9557 }
9558 }
9560 /* Update ARGS to restore the substitution from parameter packs to
9561 their argument packs. */
9563 {
9568 else
9569 {
9573 /* Update the corresponding argument. */
9577 else
9579 }
9580 }
9583 {
9586 }
9589 }
9591 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9592 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9593 parameter packs; all parms generated from a function parameter pack will
9594 have the same DECL_PARM_INDEX. */
9596 tree
9598 {
9600 tree patparm;
9603 {
9609 }
9610 else
9611 {
9616 }
9619 }
9621 /* Substitute ARGS into the vector or list of template arguments T. */
9623 static tree
9625 {
9637 {
9639 tree new_arg;
9644 {
9645 /* Substitute into an expansion expression. */
9649 /* Add to the expanded length adjustment the number of
9650 expanded arguments. We subtract one from this
9651 measurement, because the argument pack expression
9652 itself is already counted as 1 in
9653 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9654 the argument pack is empty. */
9656 }
9658 {
9659 /* Substitute into each of the arguments. */
9665 new_arg,
9679 }
9680 }
9681 else
9690 }
9695 /* Make space for the expanded arguments coming from template
9696 argument packs. */
9698 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9699 arguments for a member template.
9700 In that case each TREE_VEC in ORIG_T represents a level of template
9701 arguments, and ORIG_T won't carry any non defaulted argument count.
9702 It will rather be the nested TREE_VECs that will carry one.
9703 In other words, ORIG_T carries a non defaulted argument count only
9704 if it doesn't contain any nested TREE_VEC. */
9706 {
9710 }
9712 {
9716 {
9719 /* Now expand the template argument pack "in place". */
9722 }
9723 else
9724 {
9726 out++;
9727 }
9728 }
9731 }
9733 /* Return the result of substituting ARGS into the template parameters
9734 given by PARMS. If there are m levels of ARGS and m + n levels of
9735 PARMS, then the result will contain n levels of PARMS. For
9736 example, if PARMS is `template <class T> template <class U>
9737 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9738 result will be `template <int*, double, class V>'. */
9740 static tree
9742 {
9746 /* When substituting into a template, we must set
9747 PROCESSING_TEMPLATE_DECL as the template parameters may be
9748 dependent if they are based on one-another, and the dependency
9749 predicates are short-circuit outside of templates. */
9756 {
9757 tree new_vec =
9762 {
9763 tree tuple;
9775 }
9781 }
9786 }
9788 /* Return the result of substituting ARGS into one template parameter
9789 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9790 parameter and which TREE_PURPOSE is the default argument of the
9791 template parameter. */
9793 static tree
9795 {
9816 }
9818 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9819 type T. If T is not an aggregate or enumeration type, it is
9820 handled as if by tsubst. IN_DECL is as for tsubst. If
9821 ENTERING_SCOPE is nonzero, T is the context for a template which
9822 we are presently tsubst'ing. Return the substituted value. */
9824 static tree
9826 tree args,
9827 tsubst_flags_t complain,
9828 tree in_decl,
9830 {
9835 {
9840 /* Else fall through. */
9844 {
9845 tree argvec;
9846 tree context;
9847 tree r;
9851 /* In "sizeof(X<I>)" we need to evaluate "I". */
9857 /* First, determine the context for the type we are looking
9858 up. */
9861 {
9864 /* If context is a nested class inside a class template,
9865 it may still need to be instantiated (c++/33959). */
9867 }
9869 /* Then, figure out what arguments are appropriate for the
9870 type we are trying to find. For example, given:
9872 template <class T> struct S;
9873 template <class T, class U> void f(T, U) { S<U> su; }
9875 and supposing that we are instantiating f<int, double>,
9876 then our ARGS will be {int, double}, but, when looking up
9877 S we only want {double}. */
9882 else
9883 {
9887 }
9893 }
9894 else
9895 /* This is not a template type, so there's nothing to do. */
9900 }
9901 }
9903 /* Substitute into the default argument ARG (a default argument for
9904 FN), which has the indicated TYPE. */
9906 tree
9908 {
9912 /* This can happen in invalid code. */
9916 /* This default argument came from a template. Instantiate the
9917 default argument here, not in tsubst. In the case of
9918 something like:
9920 template <class T>
9921 struct S {
9922 static T t();
9923 void f(T = t());
9924 };
9926 we must be careful to do name lookup in the scope of S<T>,
9927 rather than in the current class. */
9929 /* The "this" pointer is not valid in a default argument. */
9931 {
9936 }
9939 /* The default argument expression may cause implicitly defined
9940 member functions to be synthesized, which will result in garbage
9941 collection. We must treat this situation as if we were within
9942 the body of function so as to avoid collecting live data on the
9943 stack. */
9951 /* Restore the "this" pointer. */
9953 {
9956 }
9958 /* Make sure the default argument is reasonable. */
9964 }
9966 /* Substitute into all the default arguments for FN. */
9968 static void
9970 {
9971 tree arg;
9972 tree tmpl_args;
9976 /* If this function is not yet instantiated, we certainly don't need
9977 its default arguments. */
9980 /* Don't do this again for clones. */
9985 arg;
9991 }
9993 /* Substitute the ARGS into the T, which is a _DECL. Return the
9994 result of the substitution. Issue error and warning messages under
9995 control of COMPLAIN. */
9997 static tree
9999 {
10000 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10001 location_t saved_loc;
10006 /* Set the filename and linenumber to improve error-reporting. */
10011 {
10013 {
10014 /* We can get here when processing a member function template,
10015 member class template, or template template parameter. */
10017 tree spec;
10018 tree tmpl_args;
10019 tree full_args;
10022 {
10023 /* Template template parameter is treated here. */
10036 complain);
10039 }
10041 /* We might already have an instance of this template.
10042 The ARGS are for the surrounding class type, so the
10043 full args contain the tsubst'd args for the context,
10044 plus the innermost args from the template decl. */
10048 /* Because this is a template, the arguments will still be
10049 dependent, even after substitution. If
10050 PROCESSING_TEMPLATE_DECL is not set, the dependency
10051 predicates will short-circuit. */
10059 /* If this is a default template template argument,
10060 tsubst might not have changed anything. */
10067 {
10070 }
10072 /* Make a new template decl. It will be similar to the
10073 original, but will record the current template arguments.
10074 We also create a new function declaration, which is just
10075 like the old one, but points to this new template, rather
10076 than the old one. */
10085 {
10086 tree new_type;
10098 }
10099 else
10100 {
10101 tree new_decl;
10113 }
10119 /* The template parameters for this new template are all the
10120 template parameters for the old template, except the
10121 outermost level of parameters. */
10124 complain);
10130 /* Record this non-type partial instantiation. */
10134 }
10138 {
10139 tree ctx;
10142 tree gen_tmpl;
10143 tree type;
10148 /* Nobody should be tsubst'ing into non-template functions. */
10152 {
10153 tree spec;
10156 /* If T is not dependent, just return it. We have to
10157 increment PROCESSING_TEMPLATE_DECL because
10158 value_dependent_expression_p assumes that nothing is
10159 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10166 /* Calculate the most general template of which R is a
10167 specialization, and the complete set of arguments used to
10168 specialize R. */
10171 (DECL_TEMPLATE_RESULT
10177 /* Check to see if we already have this specialization. */
10182 {
10185 }
10187 /* We can see more levels of arguments than parameters if
10188 there was a specialization of a member template, like
10189 this:
10191 template <class T> struct S { template <class U> void f(); }
10192 template <> template <class U> void S<int>::f(U);
10194 Here, we'll be substituting into the specialization,
10195 because that's where we can find the code we actually
10196 want to generate, but we'll have enough arguments for
10197 the most general template.
10199 We also deal with the peculiar case:
10201 template <class T> struct S {
10202 template <class U> friend void f();
10203 };
10204 template <class U> void f() {}
10205 template S<int>;
10206 template void f<double>();
10208 Here, the ARGS for the instantiation of will be {int,
10209 double}. But, we only need as many ARGS as there are
10210 levels of template parameters in CODE_PATTERN. We are
10211 careful not to get fooled into reducing the ARGS in
10212 situations like:
10214 template <class T> struct S { template <class U> void f(U); }
10215 template <class T> template <> void S<T>::f(int) {}
10217 which we can spot because the pattern will be a
10218 specialization in this case. */
10220 parms_depth =
10225 }
10226 else
10227 {
10228 /* This special case arises when we have something like this:
10230 template <class T> struct S {
10231 friend void f<int>(int, double);
10232 };
10234 Here, the DECL_TI_TEMPLATE for the friend declaration
10235 will be an IDENTIFIER_NODE. We are being called from
10236 tsubst_friend_function, and we want only to create a
10237 new decl (R) with appropriate types so that we can call
10238 determine_specialization. */
10240 }
10243 {
10246 else
10250 }
10251 else
10252 {
10255 }
10260 /* We do NOT check for matching decls pushed separately at this
10261 point, as they may not represent instantiations of this
10262 template, and in any case are considered separate under the
10263 discrete model. */
10267 /* Clear out the mangled name and RTL for the instantiation. */
10270 /* Leave DECL_INITIAL set on deleted instantiations. */
10276 /* Type-conversion operator. Reconstruct the name, in
10277 case it's the name of one of the template's parameters. */
10287 /* If this is an instantiation of a function with internal
10288 linkage, we already know what object file linkage will be
10289 assigned to the instantiation. */
10298 /* We'll re-clone as appropriate in instantiate_template. */
10301 /* If we aren't complaining now, return on error before we register
10302 the specialization so that we'll complain eventually. */
10308 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10309 this in the special friend case mentioned above where
10310 GEN_TMPL is NULL. */
10312 {
10318 /* We're not supposed to instantiate default arguments
10319 until they are called, for a template. But, for a
10320 declaration like:
10322 template <class T> void f ()
10323 { extern void g(int i = T()); }
10325 we should do the substitution when the template is
10326 instantiated. We handle the member function case in
10327 instantiate_class_template since the default arguments
10328 might refer to other members of the class. */
10333 }
10334 else
10337 /* Copy the list of befriending classes. */
10341 {
10345 in_decl);
10346 }
10349 {
10353 /* If this is an instantiation of a member template, clone it.
10354 If it isn't, that'll be handled by
10355 clone_constructors_and_destructors. */
10358 }
10369 /* Possibly limit visibility based on template args. */
10372 {
10376 }
10384 }
10388 {
10396 {
10397 /* If there is a local specialization that isn't a
10398 parameter pack, it means that we're doing a "simple"
10399 substitution from inside tsubst_pack_expansion. Just
10400 return the local specialization (which will be a single
10401 parm). */
10408 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10409 the parameters in this function parameter pack. */
10413 {
10416 /* Zero-length parameter packs are boring. Just substitute
10417 into the chain. */
10421 }
10422 else
10423 {
10424 /* All we did was update the type. Make a note of that. */
10427 }
10428 }
10430 /* Loop through all of the parameter's we'll build. When T is
10431 a function parameter pack, LEN is the number of expanded
10432 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10435 {
10442 /* We're on the Ith parameter of the function parameter
10443 pack. */
10444 {
10445 /* An argument of a function parameter pack is not a parameter
10446 pack. */
10449 /* Get the Ith type. */
10453 /* Rename the parameter to include the index. */
10456 }
10458 /* We're dealing with a normal parameter. */
10466 {
10469 else
10472 }
10482 /* Keep track of the first new parameter we
10483 generate. That's what will be returned to the
10484 caller. */
10488 /* Build a proper chain of parameters when substituting
10489 into a function parameter pack. */
10492 }
10498 /* FIRST_R contains the start of the chain we've built. */
10500 }
10504 {
10505 tree type;
10515 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10516 non-bit-fields DECL_INITIAL is a non-static data member
10517 initializer, which gets deferred instantiation. */
10523 {
10524 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10525 NSDMI in perform_member_init. Still set DECL_INITIAL
10526 so that we know there is one. */
10531 }
10532 /* We don't have to set DECL_CONTEXT here; it is set by
10533 finish_member_declaration. */
10540 }
10544 /* We reach here only for member using decls. */
10546 {
10547 r = do_class_using_decl
10552 else
10553 {
10556 }
10557 }
10558 else
10559 {
10562 }
10567 {
10570 tree spec;
10572 tree ctx;
10578 {
10579 /* If this is the canonical decl, we don't have to
10580 mess with instantiations, and often we can't (for
10581 typename, template type parms and such). Note that
10582 TYPE_NAME is not correct for the above test if
10583 we've copied the type for a typedef. */
10589 }
10591 /* Check to see if we already have the specialization we
10592 need. */
10595 {
10596 /* T is a static data member or namespace-scope entity.
10597 We have to substitute into namespace-scope variables
10598 (even though such entities are never templates) because
10599 of cases like:
10601 template <class T> void f() { extern T t; }
10603 where the entity referenced is not known until
10604 instantiation time. */
10608 {
10610 complain,
10612 /* If CTX is unchanged, then T is in fact the
10613 specialization we want. That situation occurs when
10614 referencing a static data member within in its own
10615 class. We can use pointer equality, rather than
10616 same_type_p, because DECL_CONTEXT is always
10617 canonical... */
10620 /* ... unless T is a member template; in which
10621 case our caller can be willing to create a
10622 specialization of that template represented
10623 by T. */
10627 }
10630 {
10638 }
10639 }
10640 else
10641 {
10642 /* A local variable. */
10644 /* Subsequent calls to pushdecl will fill this in. */
10647 }
10648 /* If we already have the specialization we need, there is
10649 nothing more to do. */
10651 {
10654 }
10656 /* Create a new node for the specialization we need. */
10659 {
10662 else
10669 }
10671 {
10672 /* Even if the original location is out of scope, the
10673 newly substituted one is not. */
10680 {
10681 /* It may seem that this case cannot occur, since:
10683 typedef void f();
10684 void g() { f x; }
10686 declares a function, not a variable. However:
10688 typedef void f();
10689 template <typename T> void g() { T t; }
10690 template void g<f>();
10692 is an attempt to declare a variable with function
10693 type. */
10695 /* R is not yet sufficiently initialized, so we
10696 just use its name. */
10699 }
10701 /* Wait until cp_finish_decl to set this again, to handle
10702 circular dependency (template/instantiate6.C). */
10707 {
10712 {
10715 }
10717 }
10718 }
10724 /* Clear out the mangled name and RTL for the instantiation. */
10728 /* The initializer must not be expanded until it is required;
10729 see [temp.inst]. */
10735 {
10736 /* Possibly limit visibility based on template args. */
10739 {
10743 }
10745 }
10748 {
10749 /* A static data member declaration is always marked
10750 external when it is declared in-class, even if an
10751 initializer is present. We mimic the non-template
10752 processing here. */
10758 }
10760 {
10761 /* We're substituting this var in a decltype outside of its
10762 scope, such as for a lambda return type. Don't add it to
10763 local_specializations, do perform auto deduction. */
10766 {
10767 tree init
10773 }
10774 }
10775 else
10784 /* Preserve a typedef that names a type. */
10786 {
10789 }
10792 }
10797 }
10798 #undef RETURN
10800 out:
10801 /* Restore the file and line information. */
10805 }
10807 /* Substitute into the ARG_TYPES of a function type. */
10809 static tree
10811 tree args,
10812 tsubst_flags_t complain,
10813 tree in_decl)
10814 {
10815 tree remaining_arg_types;
10819 tree default_arg;
10830 {
10831 /* For a pack expansion, perform substitution on the
10832 entire expression. Later on, we'll handle the arguments
10833 one-by-one. */
10838 /* So that we'll spin through the parameters, one by one. */
10840 else
10841 {
10842 /* We only partially substituted into the parameter
10843 pack. Our type is TYPE_PACK_EXPANSION. */
10846 }
10847 }
10860 {
10862 {
10866 }
10868 }
10870 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10871 top-level qualifiers as required. */
10874 /* We do not substitute into default arguments here. The standard
10875 mandates that they be instantiated only when needed, which is
10876 done in build_over_call. */
10880 {
10881 /* We've instantiated a template before its default arguments
10882 have been parsed. This can happen for a nested template
10883 class, and is not an error unless we require the default
10884 argument in a call of this function. */
10885 remaining_arg_types =
10888 remaining_arg_types);
10889 }
10890 else
10891 remaining_arg_types =
10893 }
10896 }
10898 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10899 *not* handle the exception-specification for FNTYPE, because the
10900 initial substitution of explicitly provided template parameters
10901 during argument deduction forbids substitution into the
10902 exception-specification:
10904 [temp.deduct]
10906 All references in the function type of the function template to the
10907 corresponding template parameters are replaced by the specified tem-
10908 plate argument values. If a substitution in a template parameter or
10909 in the function type of the function template results in an invalid
10910 type, type deduction fails. [Note: The equivalent substitution in
10911 exception specifications is done only when the function is instanti-
10912 ated, at which point a program is ill-formed if the substitution
10913 results in an invalid type.] */
10915 static tree
10917 tree args,
10918 tsubst_flags_t complain,
10919 tree in_decl)
10920 {
10921 tree return_type;
10922 tree arg_types;
10923 tree fntype;
10925 /* The TYPE_CONTEXT is not used for function/method types. */
10928 /* Substitute the return type. */
10932 /* The standard does not presently indicate that creation of a
10933 function type with an invalid return type is a deduction failure.
10934 However, that is clearly analogous to creating an array of "void"
10935 or a reference to a reference. This is core issue #486. */
10938 {
10940 {
10943 else
10945 }
10947 }
10949 /* Substitute the argument types. */
10955 /* Construct a new type node and return it. */
10957 {
10960 }
10961 else
10962 {
10965 {
10966 /* [temp.deduct]
10968 Type deduction may fail for any of the following
10969 reasons:
10971 -- Attempting to create "pointer to member of T" when T
10972 is not a class type. */
10975 r);
10977 }
10981 }
10985 }
10987 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10988 ARGS into that specification, and return the substituted
10989 specification. If there is no specification, return NULL_TREE. */
10991 static tree
10993 tree args,
10994 tsubst_flags_t complain,
10995 tree in_decl,
10997 {
10998 tree specs;
10999 tree new_specs;
11004 {
11005 /* A noexcept-specifier. */
11010 {
11011 /* Defer instantiation of noexcept-specifiers to avoid
11012 excessive instantiations (c++/49107). */
11015 {
11016 /* We already partially instantiated this member template,
11017 so combine the new args with the old. */
11022 }
11023 else
11024 {
11027 }
11028 }
11029 else
11030 new_specs = tsubst_copy_and_build
11034 }
11036 {
11039 else
11041 {
11042 tree spec;
11047 {
11048 /* Expand the pack expansion type. */
11051 in_decl);
11057 else
11058 {
11059 /* We're substituting into a member template, so
11060 we got a TYPE_PACK_EXPANSION back. Add that
11061 expansion and move on. */
11065 expanded_specs,
11066 complain);
11069 }
11070 }
11073 {
11076 else
11081 complain);
11082 }
11085 }
11086 }
11088 }
11090 /* Take the tree structure T and replace template parameters used
11091 therein with the argument vector ARGS. IN_DECL is an associated
11092 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11093 Issue error and warning messages under control of COMPLAIN. Note
11094 that we must be relatively non-tolerant of extensions here, in
11095 order to preserve conformance; if we allow substitutions that
11096 should not be allowed, we may allow argument deductions that should
11097 not succeed, and therefore report ambiguous overload situations
11098 where there are none. In theory, we could allow the substitution,
11099 but indicate that it should have failed, and allow our caller to
11100 make sure that the right thing happens, but we don't try to do this
11101 yet.
11103 This function is used for dealing with types, decls and the like;
11104 for expressions, use tsubst_expr or tsubst_copy. */
11106 tree
11108 {
11131 else
11136 /* Reuse typedefs. We need to do this to handle dependent attributes,
11137 such as attribute aligned. */
11140 {
11147 {
11148 /* DECL represents an alias template and we want to
11149 instantiate it. Let's substitute our arguments for the
11150 template parameters into the declaration and get the
11151 resulting type. */
11153 }
11157 {
11161 }
11166 else
11167 /* The typedef is from a non-template context. */
11171 {
11173 r = cp_build_qualified_type_real
11177 }
11178 else
11179 /* We don't have an instantiation yet, so drop the typedef. */
11181 }
11194 {
11220 {
11226 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11227 needed. */
11233 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11234 with TREE_SIDE_EFFECTS that indicates this is not an integral
11235 constant expression. */
11238 {
11241 }
11244 }
11250 {
11263 {
11267 /* See through ARGUMENT_PACK_SELECT arguments. */
11269 }
11274 {
11276 /* If ARG is an argument pack, we don't actually want to
11277 perform a substitution here, because substitutions
11278 for argument packs are only done
11279 element-by-element. We can get to this point when
11280 substituting the type of a non-type template
11281 parameter pack, when that type actually contains
11282 template parameter packs from an outer template, e.g.,
11284 template<typename... Types> struct A {
11285 template<Types... Values> struct B { };
11286 }; */
11290 {
11296 return cp_build_qualified_type_real
11298 }
11300 {
11301 /* We are processing a type constructed from a
11302 template template parameter. */
11313 /* Consider this code:
11315 template <template <class> class Template>
11316 struct Internal {
11317 template <class Arg> using Bind = Template<Arg>;
11318 };
11320 template <template <class> class Template, class Arg>
11321 using Instantiate = Template<Arg>; //#0
11323 template <template <class> class Template,
11324 class Argument>
11325 using Bind =
11326 Instantiate<Internal<Template>::template Bind,
11327 Argument>; //#1
11329 When #1 is parsed, the
11330 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11331 parameter `Template' in #0 matches the
11332 UNBOUND_CLASS_TEMPLATE representing the argument
11333 `Internal<Template>::template Bind'; We then want
11334 to assemble the type `Bind<Argument>' that can't
11335 be fully created right now, because
11336 `Internal<Template>' not being complete, the Bind
11337 template cannot be looked up in that context. So
11338 we need to "store" `Bind<Argument>' for later
11339 when the context of Bind becomes complete. Let's
11340 store that in a TYPENAME_TYPE. */
11344 argvec),
11345 typename_type,
11346 complain);
11348 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11349 are resolving nested-types in the signature of a
11350 member function templates. Otherwise ARG is a
11351 TEMPLATE_DECL and is the real template to be
11352 instantiated. */
11360 complain);
11361 return cp_build_qualified_type_real
11363 }
11364 else
11365 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11367 }
11370 /* This can happen during the attempted tsubst'ing in
11371 unify. This means that we don't yet have any information
11372 about the template parameter in question. */
11375 /* Early in template argument deduction substitution, we don't
11376 want to reduce the level of 'auto', or it will be confused
11377 with a normal template parm in subsequent deduction. */
11381 /* If we get here, we must have been looking at a parm for a
11382 more deeply nested template. Make a new version of this
11383 template parameter, but with a lower level. */
11385 {
11390 {
11392 r = cp_build_qualified_type_real
11396 }
11397 else
11398 {
11409 /* We have reduced the level of the template
11410 template parameter, but not the levels of its
11411 template parameters, so canonical_type_parameter
11412 will not be able to find the canonical template
11413 template parameter for this level. Thus, we
11414 require structural equality checking to compare
11415 TEMPLATE_TEMPLATE_PARMs. */
11419 else
11423 {
11431 }
11432 }
11441 }
11444 }
11447 {
11455 {
11459 }
11462 {
11466 }
11469 {
11473 }
11479 }
11482 /* We should never be tsubsting a binfo. */
11486 /* A vector of template arguments. */
11492 {
11496 /* [temp.deduct]
11498 Type deduction may fail for any of the following
11499 reasons:
11501 -- Attempting to create a pointer to reference type.
11502 -- Attempting to create a reference to a reference type or
11503 a reference to void.
11505 Core issue 106 says that creating a reference to a reference
11506 during instantiation is no longer a cause for failure. We
11507 only enforce this check in strict C++98 mode. */
11511 {
11514 /* We keep track of the last time we issued this error
11515 message to avoid spewing a ton of messages during a
11516 single bad template instantiation. */
11519 {
11524 else
11527 }
11530 }
11532 {
11536 }
11538 /* In C++0x, during template argument substitution, when there is an
11539 attempt to create a reference to a reference type, reference
11540 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11542 "If a template-argument for a template-parameter T names a type
11543 that is a reference to a type A, an attempt to create the type
11544 'lvalue reference to cv T' creates the type 'lvalue reference to
11545 A,' while an attempt to create the type type rvalue reference to
11546 cv T' creates the type T"
11547 */
11548 r = cp_build_reference_type
11551 else
11556 /* Will this ever be needed for TYPE_..._TO values? */
11560 }
11562 {
11565 {
11566 /* [temp.deduct]
11568 Type deduction may fail for any of the following
11569 reasons:
11571 -- Attempting to create "pointer to member of T" when T
11572 is not a class type. */
11576 }
11578 {
11582 }
11584 {
11588 }
11591 {
11592 /* The type of the implicit object parameter gets its
11593 cv-qualifiers from the FUNCTION_TYPE. */
11594 tree memptr;
11598 complain);
11599 }
11600 else
11603 complain);
11604 }
11607 {
11608 tree fntype;
11609 tree specs;
11614 /* Substitute the exception specification. */
11622 }
11624 {
11629 /* As an optimization, we avoid regenerating the array type if
11630 it will obviously be the same as T. */
11634 /* These checks should match the ones in grokdeclarator.
11636 [temp.deduct]
11638 The deduction may fail for any of the following reasons:
11640 -- Attempting to create an array with an element type that
11641 is void, a function type, or a reference type, or [DR337]
11642 an abstract class type. */
11646 {
11650 }
11652 {
11655 type);
11657 }
11662 {
11665 }
11668 }
11671 {
11681 {
11685 }
11687 {
11688 /* Normally, make_typename_type does not require that the CTX
11689 have complete type in order to allow things like:
11691 template <class T> struct S { typename S<T>::X Y; };
11693 But, such constructs have already been resolved by this
11694 point, so here CTX really should have complete type, unless
11695 it's a partial instantiation. */
11698 {
11702 }
11703 }
11710 {
11713 }
11716 {
11718 {
11722 else
11724 }
11726 {
11730 else
11732 }
11733 }
11735 return cp_build_qualified_type_real
11737 }
11740 {
11752 }
11755 {
11756 tree type;
11772 complain);
11773 }
11776 {
11777 tree type;
11793 else
11794 type = finish_decltype_type
11799 complain);
11800 }
11803 {
11807 }
11811 {
11813 tree packed_out =
11815 args,
11816 complain,
11817 in_decl);
11820 /* For template nontype argument packs, also substitute into
11821 the type. */
11826 }
11841 /* We should use one of the expression tsubsts for these codes. */
11847 }
11848 }
11850 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11851 type of the expression on the left-hand side of the "." or "->"
11852 operator. */
11854 static tree
11857 {
11858 tree name;
11859 tree qualifying_scope;
11860 tree fns;
11861 tree optype;
11866 /* A baselink indicates a function from a base class. Both the
11867 BASELINK_ACCESS_BINFO and the base class referenced may
11868 indicate bases of the template class, rather than the
11869 instantiated class. In addition, lookups that were not
11870 ambiguous before may be ambiguous now. Therefore, we perform
11871 the lookup again. */
11878 {
11885 }
11893 /* If lookup found a single function, mark it as used at this
11894 point. (If it lookup found multiple functions the one selected
11895 later by overload resolution will be marked as used at that
11896 point.) */
11902 /* Add back the template arguments, if present. */
11907 template_args);
11908 /* Update the conversion operator type. */
11916 qualifying_scope,
11917 object_type);
11919 }
11921 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11922 true if the qualified-id will be a postfix-expression in-and-of
11923 itself; false if more of the postfix-expression follows the
11924 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11925 of "&". */
11927 static tree
11931 {
11932 tree expr;
11933 tree scope;
11934 tree name;
11936 tree template_args;
11940 /* Figure out what name to look up. */
11943 {
11950 }
11951 else
11952 {
11955 }
11957 /* Substitute into the qualifying scope. When there are no ARGS, we
11958 are just trying to simplify a non-dependent expression. In that
11959 case the qualifying scope may be dependent, and, in any case,
11960 substituting will not help. */
11963 {
11966 }
11967 else
11971 {
11976 }
11979 {
11981 {
11982 /* A BIT_NOT_EXPR is used to represent a destructor. */
11984 {
11988 }
11989 else
11992 }
11993 else
11997 {
11999 {
12003 }
12005 }
12006 }
12009 {
12011 scope);
12012 /* Remember that there was a reference to this entity. */
12014 }
12017 {
12023 }
12032 {
12033 expr = (adjust_result_of_qualified_name_lookup
12035 expr = (finish_qualified_id_expr
12039 }
12041 /* Expressions do not generally have reference type. */
12043 /* However, if we're about to form a pointer-to-member, we just
12044 want the referenced member referenced. */
12049 }
12051 /* Like tsubst, but deals with expressions. This function just replaces
12052 template parms; to finish processing the resultant expression, use
12053 tsubst_copy_and_build or tsubst_expr. */
12055 static tree
12057 {
12059 tree r;
12067 {
12072 {
12073 tree c;
12075 /* We get here for a use of 'this' in an NSDMI. */
12081 /* This can happen for a parameter name used later in a function
12082 declaration (such as in a late-specified return type). Just
12083 make a dummy decl, since it's only used for its type. */
12085 /* We copy T because want to tsubst the PARM_DECL only,
12086 not the following PARM_DECLs that are chained to T. */
12091 /* Give it the template pattern as its context; its true context
12092 hasn't been instantiated yet and this is good enough for
12093 mangling. */
12095 }
12103 {
12104 tree enum_type;
12105 tree v;
12109 /* There is no need to substitute into namespace-scope
12110 enumerators. */
12113 /* If ARGS is NULL, then T is known to be non-dependent. */
12117 /* Unfortunately, we cannot just call lookup_name here.
12118 Consider:
12120 template <int I> int f() {
12121 enum E { a = I };
12122 struct S { void g() { E e = a; } };
12123 };
12125 When we instantiate f<7>::S::g(), say, lookup_name is not
12126 clever enough to find f<7>::a. */
12127 enum_type
12137 /* We didn't find the name. That should never happen; if
12138 name-lookup found it during preliminary parsing, we
12139 should find it again here during instantiation. */
12141 }
12146 {
12147 tree ctx;
12152 {
12155 {
12159 }
12161 }
12162 }
12178 /* An OVERLOAD will always be a non-dependent overload set; an
12179 overload set from function scope will just be represented with an
12180 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12195 {
12196 /* Template template argument like the following example need
12197 special treatment:
12199 template <template <class> class TT> struct C {};
12200 template <class T> struct D {
12201 template <class U> struct E {};
12202 C<E> c; // #1
12203 };
12204 D<int> d; // #2
12206 We are processing the template argument `E' in #1 for
12207 the template instantiation #2. Originally, `E' is a
12208 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12209 have to substitute this with one having context `D<int>'. */
12213 }
12214 else
12215 /* Ordinary template template argument. */
12226 return build1
12232 {
12234 tree expanded;
12239 /* We only want to compute the number of arguments. */
12254 {
12261 else
12264 }
12265 else
12267 }
12268 /* Fall through */
12283 return build1
12288 {
12289 tree object;
12290 tree name;
12295 {
12299 }
12302 {
12312 }
12317 in_decl);
12318 else
12321 }
12359 return build_nt
12372 return build_nt
12379 {
12387 }
12392 {
12393 r = build_nt
12399 }
12402 {
12403 r = build_nt
12409 }
12412 {
12413 r = build_nt
12419 }
12422 {
12423 /* Substituted template arguments */
12432 }
12435 {
12455 }
12480 {
12483 }
12484 else
12488 /* This is handled by tsubst_copy_and_build. */
12494 in_decl),
12498 /* We shouldn't have built any of these during initial template
12499 generation. Instead, they should be built during instantiation
12500 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12504 r = build2
12524 {
12525 /* Instantiate any typedefs in the type. */
12530 }
12533 /* These can sometimes show up in a partial instantiation, but never
12534 involve template parms. */
12539 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12542 }
12543 }
12545 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12547 static tree
12549 tree in_decl)
12550 {
12554 {
12560 {
12563 {
12569 }
12570 /* FALLTHRU */
12594 }
12595 }
12598 }
12600 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12602 static tree
12604 tree in_decl)
12605 {
12606 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12626 {
12629 else
12630 {
12634 }
12635 }
12640 #undef RECUR
12641 }
12643 /* Substitute one OMP_FOR iterator. */
12645 static void
12650 {
12651 #define RECUR(NODE) \
12652 tsubst_expr ((NODE), args, complain, in_decl, \
12653 integral_constant_expression_p)
12662 {
12669 }
12673 {
12679 complain);
12680 else
12687 }
12690 {
12691 tree c;
12693 {
12704 }
12706 {
12711 {
12714 }
12715 }
12716 }
12722 else
12726 {
12737 {
12744 }
12745 else
12751 {
12757 }
12761 {
12768 }
12769 else
12775 }
12781 #undef RECUR
12782 }
12784 /* Like tsubst_copy for expressions, etc. but also does semantic
12785 processing. */
12787 static tree
12790 {
12791 #define RECUR(NODE) \
12792 tsubst_expr ((NODE), args, complain, in_decl, \
12793 integral_constant_expression_p)
12806 {
12808 {
12809 tree_stmt_iterator i;
12813 }
12828 else
12837 {
12839 tree init;
12845 {
12848 tree decl;
12856 else
12858 }
12859 else
12860 {
12864 {
12865 /* By marking the declaration as instantiated, we avoid
12866 trying to instantiate it. Since instantiate_decl can't
12867 handle local variables, and since we've already done
12868 all that needs to be done, that's the right thing to
12869 do. */
12874 /* Anonymous aggregates are a special case. */
12877 {
12880 }
12881 else
12882 {
12887 {
12888 /* For __PRETTY_FUNCTION__ we have to adjust the
12889 initializer. */
12893 }
12894 else
12895 {
12899 {
12900 /* If we had an initializer but it
12901 instantiated to nothing,
12902 value-initialize the object. This will
12903 only occur when the initializer was a
12904 pack expansion where the parameter packs
12905 used in that expansion were of length
12906 zero. */
12908 complain);
12911 }
12912 else
12914 }
12917 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12920 }
12921 }
12922 }
12924 /* A DECL_EXPR can also be used as an expression, in the condition
12925 clause of an if/for/while construct. */
12927 }
12942 {
12952 }
12979 {
12983 }
12991 else
12999 else
13026 {
13028 tree label;
13033 }
13039 /* Computed goto's must be tsubst'd into. On the other hand,
13040 non-computed gotos must not be; the identifier in question
13041 will have no binding. */
13043 else
13049 tmp = finish_asm_stmt
13056 {
13061 }
13066 {
13071 }
13072 else
13073 {
13078 else
13085 else
13091 else
13093 }
13097 {
13101 {
13103 /* Prevent instantiate_decl from trying to instantiate
13104 this variable. We've already done all that needs to be
13105 done. */
13108 }
13113 }
13121 {
13122 tree condition;
13125 condition =
13127 args,
13136 }
13157 {
13172 integral_constant_expression_p);
13181 {
13185 }
13186 else
13187 {
13195 }
13209 }
13241 {
13246 {
13249 }
13254 }
13255 else
13256 {
13263 {
13266 }
13269 {
13274 {
13277 }
13281 }
13282 else
13283 {
13287 }
13289 }
13293 {
13299 {
13303 {
13308 }
13312 }
13313 else
13314 {
13319 }
13320 }
13340 integral_constant_expression_p);
13341 }
13344 #undef RECUR
13345 }
13347 /* T is a postfix-expression that is not being used in a function
13348 call. Return the substituted version of T. */
13350 static tree
13352 tsubst_flags_t complain,
13353 tree in_decl)
13354 {
13358 else
13364 }
13366 /* Like tsubst but deals with expressions and performs semantic
13367 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13369 tree
13371 tree args,
13372 tsubst_flags_t complain,
13373 tree in_decl,
13376 {
13377 #define RECUR(NODE) \
13378 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13380 integral_constant_expression_p)
13382 tree op1;
13388 {
13391 /* Fall through. */
13393 {
13394 tree decl;
13395 cp_id_kind idk;
13400 {
13403 }
13405 /* Look up the name. */
13408 /* By convention, expressions use ERROR_MARK_NODE to indicate
13409 failure, not NULL_TREE. */
13415 integral_constant_expression_p,
13423 input_location);
13427 {
13431 }
13433 }
13436 {
13437 tree object;
13445 {
13448 }
13449 else
13456 else
13458 }
13461 {
13465 {
13466 /* A type conversion to reference type will be enclosed in
13467 such an indirect ref, but the substitution of the cast
13468 will have also added such an indirect ref. */
13471 }
13472 else
13475 }
13478 return build_nop
13483 {
13490 flags);
13491 }
13494 return build1
13504 {
13505 tree type;
13511 {
13516 }
13522 {
13540 }
13544 }
13576 else
13578 in_decl);
13612 {
13613 tree r = build_x_binary_op
13617 ? ERROR_MARK
13621 ? ERROR_MARK
13624 complain);
13628 }
13641 /* Fall through */
13646 {
13647 /* When there are no ARGS, we are trying to evaluate a
13648 non-dependent expression from the parser. Trying to do
13649 the substitutions may not work. */
13652 }
13653 else
13654 {
13662 }
13666 else
13671 {
13681 }
13695 {
13696 tree r = build_x_modify_expr
13700 complain);
13701 /* TREE_NO_WARNING must be set if either the expression was
13702 parenthesized or it uses an operator such as >>= rather
13703 than plain assignment. In the former case, it was already
13704 set and must be copied. In the latter case,
13705 build_x_modify_expr sets it and it must not be reset
13706 here. */
13710 }
13715 /* Remember that there was a reference to this entity. */
13721 {
13726 tree ret;
13730 else
13731 {
13735 }
13737 /* If there was an initializer in the original tree, but it
13738 instantiated to an empty list, then we should pass a
13739 non-NULL empty vector to tell build_new that it was an
13740 empty initializer() rather than no initializer. This can
13741 only happen when the initializer is a pack expansion whose
13742 parameter packs are of length zero. */
13745 else
13746 {
13750 else
13751 {
13754 }
13755 }
13762 complain);
13770 }
13773 return delete_sanity
13778 complain);
13783 complain);
13786 {
13787 tree function;
13792 tree ret;
13795 /* When we parsed the expression, we determined whether or
13796 not Koenig lookup should be performed. */
13799 {
13804 }
13806 {
13807 /* Do nothing; calling tsubst_copy_and_build on an identifier
13808 would incorrectly perform unqualified lookup again.
13810 Note that we can also have an IDENTIFIER_NODE if the earlier
13811 unqualified lookup found a member function; in that case
13812 koenig_p will be false and we do want to do the lookup
13813 again to find the instantiated member function.
13815 FIXME but doing that causes c++/15272, so we need to stop
13816 using IDENTIFIER_NODE in that situation. */
13818 }
13819 else
13820 {
13822 {
13828 }
13829 else
13833 in_decl,
13835 integral_constant_expression_p);
13839 }
13844 {
13850 else
13851 {
13852 /* Expand the pack expansion and push each entry onto
13853 CALL_ARGS. */
13856 {
13861 {
13866 }
13867 }
13868 else
13869 {
13870 /* A partial substitution. Add one entry. */
13872 }
13873 }
13874 }
13876 /* We do not perform argument-dependent lookup if normal
13877 lookup finds a non-function, in accordance with the
13878 expected resolution of DR 218. */
13881 /* If lookup found a member function, the Koenig lookup is
13882 not appropriate, even if an unqualified-name was used
13883 to denote the function. */
13886 /* Only do this when substitution turns a dependent call
13887 into a non-dependent call. */
13891 tf_none);
13895 {
13897 {
13898 /* For backwards compatibility and good diagnostics, try
13899 the unqualified lookup again if we aren't in SFINAE
13900 context. */
13901 tree unq = (tsubst_copy_and_build
13903 integral_constant_expression_p));
13908 {
13917 "%qD was not declared in this scope, "
13918 "and no declarations were found by "
13919 "argument-dependent lookup at the point "
13924 {
13926 "declarations in dependent base %qT are "
13932 else
13936 }
13937 else
13941 }
13942 }
13944 {
13948 }
13949 }
13951 /* Remember that there was a reference to this entity. */
13958 {
13973 complain);
13974 else
13975 ret = (build_new_method_call
13980 complain));
13981 }
13982 else
13985 koenig_p,
13986 complain);
13991 }
13994 {
13999 {
14001 {
14006 }
14007 else
14008 {
14013 }
14014 }
14015 else
14016 {
14019 }
14022 }
14025 return finish_pseudo_destructor_expr
14031 {
14039 {
14040 /* We have pack expansions, so expand those and
14041 create a new list out of it. */
14044 tree chain;
14047 /* Expand the argument expressions. */
14055 /* Build the rest of the list. */
14060 /* Determine the number of arguments. */
14062 {
14065 }
14068 else
14069 {
14070 /* Since we only performed a partial substitution into
14071 the argument pack, we only return a single list
14072 node. */
14079 }
14081 /* Convert the argument vectors into a TREE_LIST */
14084 {
14085 /* Grab the Ith values. */
14086 i--;
14089 value
14093 /* Build the list (backwards). */
14095 }
14098 }
14114 }
14117 {
14118 tree object;
14119 tree object_type;
14120 tree member;
14124 /* Remember that there was a reference to this entity. */
14134 else
14142 {
14144 {
14149 {
14152 }
14154 {
14158 }
14159 }
14160 }
14163 {
14164 /* Lookup the template functions now that we know what the
14165 scope is. */
14173 {
14176 args);
14177 member = (adjust_result_of_qualified_name_lookup
14179 object_type));
14180 }
14181 else
14182 {
14184 input_location);
14186 }
14187 }
14191 {
14193 {
14197 else
14200 }
14202 }
14208 complain);
14209 }
14212 return build_throw
14216 {
14224 tree r;
14229 /* digest_init will do the wrong thing if we let it. */
14233 /* We do not want to process the index of aggregate
14234 initializers as they are identifier nodes which will be
14235 looked up by digest_init. */
14241 {
14246 {
14247 /* Substitute into the pack expansion. */
14249 in_decl);
14253 ;
14255 /* Just move the argument into place. */
14257 else
14258 {
14259 /* Update the length of the final CONSTRUCTOR
14260 arguments vector, and note that we will need to
14261 copy.*/
14264 }
14265 }
14266 else
14268 }
14271 {
14276 {
14278 {
14283 }
14284 else
14286 }
14287 }
14297 }
14300 {
14303 {
14306 }
14307 else
14308 {
14311 }
14312 }
14317 /* Fall through */
14320 {
14324 /* If the original type was a reference, we'll be wrapped in
14325 the appropriate INDIRECT_REF. */
14328 }
14339 {
14348 }
14351 {
14357 integral_constant_expression_p);
14361 /* If the resulting list of expression statement is empty,
14362 fold it further into void_zero_node. */
14367 }
14371 /* As in finish_id_expression, we resolve enumeration constants
14372 to their underlying values. */
14374 {
14377 }
14381 {
14403 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14405 /* Now that we know visibility, instantiate the type so we have a
14406 declaration of the op() for later calls to lambda_function. */
14409 /* The capture list refers to closure members, so this needs to
14410 wait until after we finish instantiating the type. */
14415 }
14418 /* We can get here for a constant initializer of non-dependent type.
14419 FIXME stop folding in cp_parser_initializer_clause. */
14421 {
14425 }
14429 integral_constant_expression_p);
14432 /* Handle Objective-C++ constructs, if appropriate. */
14433 {
14434 tree subst
14439 }
14441 }
14443 #undef RECUR
14444 }
14446 /* Verify that the instantiated ARGS are valid. For type arguments,
14447 make sure that the type's linkage is ok. For non-type arguments,
14448 make sure they are constants if they are integral or enumerations.
14449 Emit an error under control of COMPLAIN, and return TRUE on error. */
14451 static bool
14453 {
14455 {
14465 }
14467 {
14468 /* [basic.link]: A name with no linkage (notably, the name
14469 of a class or enumeration declared in a local scope)
14470 shall not be used to declare an entity with linkage.
14471 This implies that names with no linkage cannot be used as
14472 template arguments
14474 DR 757 relaxes this restriction for C++0x. */
14479 {
14480 /* DR 488 makes use of a type with no linkage cause
14481 type deduction to fail. */
14483 {
14486 else
14489 }
14491 }
14492 /* In order to avoid all sorts of complications, we do not
14493 allow variably-modified types as template arguments. */
14495 {
14499 }
14500 }
14501 /* A non-type argument of integral or enumerated type must be a
14502 constant. */
14506 {
14510 }
14512 }
14514 static bool
14516 {
14521 {
14524 }
14528 }
14530 /* In C++0x, it's possible to have a function template whose type depends
14531 on itself recursively. This is most obvious with decltype, but can also
14532 occur with enumeration scope (c++/48969). So we need to catch infinite
14533 recursion and reject the substitution at deduction time; this function
14534 will return error_mark_node for any repeated substitution.
14536 This also catches excessive recursion such as when f<N> depends on
14537 f<N-1> across all integers, and returns error_mark_node for all the
14538 substitutions back up to the initial one.
14540 This is, of course, not reentrant. */
14542 static tree
14544 {
14551 tree tinst;
14552 tree r;
14559 {
14563 }
14573 {
14576 /* Reset once we're all the way out. */
14578 }
14581 /* We can't free this if a pending_template entry or last_error_tinst_level
14582 is pointing at it. */
14587 }
14589 /* Instantiate the indicated variable or function template TMPL with
14590 the template arguments in TARG_PTR. */
14592 static tree
14594 {
14596 tree fndecl;
14597 tree gen_tmpl;
14598 tree spec;
14605 /* If this function is a clone, handle it specially. */
14607 {
14608 tree spec;
14609 tree clone;
14611 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14612 DECL_CLONED_FUNCTION. */
14618 /* Look for the clone. */
14622 /* We should always have found the clone by now. */
14625 }
14627 /* Check to see if we already have this specialization. */
14630 /* The TMPL is a partial instantiation. To get a full set of
14631 arguments we must add the arguments used to perform the
14632 partial instantiation. */
14634 targ_ptr);
14636 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14637 but it doesn't seem to be on the hot path. */
14649 complain))
14652 /* We are building a FUNCTION_DECL, during which the access of its
14653 parameters and return types have to be checked. However this
14654 FUNCTION_DECL which is the desired context for access checking
14655 is not built yet. We solve this chicken-and-egg problem by
14656 deferring all checks until we have the FUNCTION_DECL. */
14659 /* Instantiation of the function happens in the context of the function
14660 template, not the context of the overload resolution we're doing. */
14663 {
14667 }
14668 /* Substitute template parameters to obtain the specialization. */
14678 /* Now we know the specialization, compute access previously
14679 deferred. */
14682 /* Some typedefs referenced from within the template code need to be access
14683 checked at template instantiation time, i.e now. These types were
14684 added to the template at parsing time. Let's get those and perfom
14685 the acces checks then. */
14691 /* The DECL_TI_TEMPLATE should always be the immediate parent
14692 template, not the most general template. */
14695 /* If we've just instantiated the main entry point for a function,
14696 instantiate all the alternate entry points as well. We do this
14697 by cloning the instantiation of the main entry point, not by
14698 instantiating the template clones. */
14703 }
14705 /* Wrapper for instantiate_template_1. */
14707 tree
14709 {
14710 tree ret;
14715 }
14717 /* We're going to do deduction substitution on the type of TMPL, a function
14718 template. In C++11 mode, push into that access scope. In C++03 mode,
14719 disable access checking. */
14721 static void
14723 {
14725 {
14728 /* Preserve processing_template_decl across push_to_top_level. */
14731 }
14732 else
14734 }
14736 /* And pop back out. */
14738 static void
14740 {
14743 else
14745 }
14747 /* PARM is a template parameter pack for FN. Returns true iff
14748 PARM is used in a deducible way in the argument list of FN. */
14750 static bool
14752 {
14755 {
14757 tree packs;
14763 {
14764 /* The template parameter pack is used in a function parameter
14765 pack. If this is the end of the parameter list, the
14766 template parameter pack is deducible. */
14769 else
14770 /* Otherwise, not. Well, it could be deduced from
14771 a non-pack parameter, but doing so would end up with
14772 a deduction mismatch, so don't bother. */
14774 }
14775 }
14776 /* The template parameter pack isn't used in any function parameter
14777 packs, but it might be used deeper, e.g. tuple<Args...>. */
14779 }
14781 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14782 NARGS elements of the arguments that are being used when calling
14783 it. TARGS is a vector into which the deduced template arguments
14784 are placed.
14786 Return zero for success, 2 for an incomplete match that doesn't resolve
14787 all the types, and 1 for complete failure. An error message will be
14788 printed only for an incomplete match.
14790 If FN is a conversion operator, or we are trying to produce a specific
14791 specialization, RETURN_TYPE is the return type desired.
14793 The EXPLICIT_TARGS are explicit template arguments provided via a
14794 template-id.
14796 The parameter STRICT is one of:
14798 DEDUCE_CALL:
14799 We are deducing arguments for a function call, as in
14800 [temp.deduct.call].
14802 DEDUCE_CONV:
14803 We are deducing arguments for a conversion function, as in
14804 [temp.deduct.conv].
14806 DEDUCE_EXACT:
14807 We are deducing arguments when doing an explicit instantiation
14808 as in [temp.explicit], when determining an explicit specialization
14809 as in [temp.expl.spec], or when taking the address of a function
14810 template, as in [temp.deduct.funcaddr]. */
14812 int
14814 tree explicit_targs,
14815 tree targs,
14818 tree return_type,
14819 unification_kind_t strict,
14822 {
14823 tree parms;
14824 tree fntype;
14831 {
14832 /* [temp.deduct]
14834 The specified template arguments must match the template
14835 parameters in kind (i.e., type, nontype, template), and there
14836 must not be more arguments than there are parameters;
14837 otherwise type deduction fails.
14839 Nontype arguments must match the types of the corresponding
14840 nontype template parameters, or must be convertible to the
14841 types of the corresponding nontype parameters as specified in
14842 _temp.arg.nontype_, otherwise type deduction fails.
14844 All references in the function type of the function template
14845 to the corresponding template parameters are replaced by the
14846 specified template argument values. If a substitution in a
14847 template parameter or in the function type of the function
14848 template results in an invalid type, type deduction fails. */
14851 tree converted_args;
14857 converted_args
14859 (explain_p
14860 ? tf_warning_or_error
14867 /* Substitute the explicit args into the function type. This is
14868 necessary so that, for instance, explicitly declared function
14869 arguments can match null pointed constants. If we were given
14870 an incomplete set of explicit args, we must not do semantic
14871 processing during substitution as we could create partial
14872 instantiations. */
14874 {
14879 /* Dig out the actual parm. */
14882 {
14885 }
14887 {
14890 }
14893 /* No explicit argument for this template parameter. */
14897 {
14898 /* Mark the argument pack as "incomplete". We could
14899 still deduce more arguments during unification.
14900 We remove this mark in type_unification_real. */
14902 {
14906 }
14908 /* We have some incomplete argument packs. */
14910 }
14911 }
14915 (explain_p
14916 ? tf_warning_or_error
14923 /* Place the explicitly specified arguments in TARGS. */
14926 }
14928 /* Never do unification on the 'this' parameter. */
14932 {
14941 }
14943 /* We allow incomplete unification without an error message here
14944 because the standard doesn't seem to explicitly prohibit it. Our
14945 callers must be ready to deal with unification failures in any
14946 event. */
14951 /* Now that we have bindings for all of the template arguments,
14952 ensure that the arguments deduced for the template template
14953 parameters have compatible template parameter lists. We cannot
14954 check this property before we have deduced all template
14955 arguments, because the template parameter types of a template
14956 template parameter might depend on prior template parameters
14957 deduced after the template template parameter. The following
14958 ill-formed example illustrates this issue:
14960 template<typename T, template<T> class C> void f(C<5>, T);
14962 template<int N> struct X {};
14964 void g() {
14965 f(X<5>(), 5l); // error: template argument deduction fails
14966 }
14968 The template parameter list of 'C' depends on the template type
14969 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14970 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14971 time that we deduce 'C'. */
14973 && !template_template_parm_bindings_ok_p
14978 /* All is well so far. Now, check:
14980 [temp.deduct]
14982 When all template arguments have been deduced, all uses of
14983 template parameters in nondeduced contexts are replaced with
14984 the corresponding deduced argument values. If the
14985 substitution results in an invalid type, as described above,
14986 type deduction fails. */
14987 {
14989 (explain_p
14990 ? tf_warning_or_error
14995 /* If we're looking for an exact match, check that what we got
14996 is indeed an exact match. It might not be if some template
14997 parameters are used in non-deduced contexts. */
14999 {
15002 tree sarg
15010 }
15011 }
15014 }
15016 /* Adjust types before performing type deduction, as described in
15017 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15018 sections are symmetric. PARM is the type of a function parameter
15019 or the return type of the conversion function. ARG is the type of
15020 the argument passed to the call, or the type of the value
15021 initialized with the result of the conversion function.
15022 ARG_EXPR is the original argument expression, which may be null. */
15024 static int
15028 tree arg_expr)
15029 {
15033 {
15038 {
15039 /* Swap PARM and ARG throughout the remainder of this
15040 function; the handling is precisely symmetric since PARM
15041 will initialize ARG rather than vice versa. */
15046 }
15049 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15050 too, but here handle it by stripping the reference from PARM
15051 rather than by adding it to ARG. */
15059 /* Nothing else to do in this case. */
15064 }
15067 {
15068 /* [temp.deduct.call]
15070 If P is not a reference type:
15072 --If A is an array type, the pointer type produced by the
15073 array-to-pointer standard conversion (_conv.array_) is
15074 used in place of A for type deduction; otherwise,
15076 --If A is a function type, the pointer type produced by
15077 the function-to-pointer standard conversion
15078 (_conv.func_) is used in place of A for type deduction;
15079 otherwise,
15081 --If A is a cv-qualified type, the top level
15082 cv-qualifiers of A's type are ignored for type
15083 deduction. */
15088 else
15090 }
15092 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15093 of the form T&&, where T is a template parameter, and the argument
15094 is an lvalue, T is deduced as A& */
15100 /* try_one_overload doesn't provide an arg_expr, but
15101 functions are always lvalues. */
15105 /* [temp.deduct.call]
15107 If P is a cv-qualified type, the top level cv-qualifiers
15108 of P's type are ignored for type deduction. If P is a
15109 reference type, the type referred to by P is used for
15110 type deduction. */
15113 {
15116 }
15118 /* DR 322. For conversion deduction, remove a reference type on parm
15119 too (which has been swapped into ARG). */
15124 }
15126 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15127 template which does contain any deducible template parameters; check if
15128 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15129 unify_one_argument. */
15131 static int
15134 {
15135 tree type;
15139 else
15146 {
15150 }
15152 {
15157 }
15161 else
15163 }
15165 /* Subroutine of type_unification_real and unify_pack_expansion to
15166 handle unification of a single P/A pair. Parameters are as
15167 for those functions. */
15169 static int
15173 {
15180 /* We can't deduce anything from this, but we might get all the
15181 template args from other function args. */
15184 /* FIXME uses_deducible_template_parms */
15187 explain_p);
15190 {
15192 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15193 | UNIFY_ALLOW_MORE_CV_QUAL
15207 }
15209 /* We only do these transformations if this is the top-level
15210 parameter_type_list in a call or declaration matching; in other
15211 situations (nested function declarators, template argument lists) we
15212 won't be comparing a type to an expression, and we don't do any type
15213 adjustments. */
15215 {
15217 {
15220 {
15221 /* [temp.deduct.type] A template-argument can be
15222 deduced from a pointer to function or pointer
15223 to member function argument if the set of
15224 overloaded functions does not contain function
15225 templates and at most one of a set of
15226 overloaded functions provides a unique
15227 match. */
15234 }
15240 }
15242 arg_strict |=
15244 }
15245 else
15249 /* For deduction from an init-list we need the actual list. */
15253 }
15255 /* Most parms like fn_type_unification.
15257 If SUBR is 1, we're being called recursively (to unify the
15258 arguments of a function or method parameter of a function
15259 template). */
15261 static int
15263 tree targs,
15264 tree xparms,
15268 unification_kind_t strict,
15271 {
15276 tree parms;
15285 /* Reset the number of non-defaulted template arguments contained
15286 in TARGS. */
15289 again:
15297 {
15302 /* For a function parameter pack that occurs at the end of the
15303 parameter-declaration-list, the type A of each remaining
15304 argument of the call is compared with the type P of the
15305 declarator-id of the function parameter pack. */
15311 /* For a function parameter pack that does not occur at the
15312 end of the parameter-declaration-list, the type of the
15313 parameter pack is a non-deduced context. */
15322 }
15327 {
15328 /* Unify the remaining arguments with the pack expansion type. */
15329 tree argvec;
15332 /* Allocate a TREE_VEC and copy in all of the arguments */
15337 /* Copy the parameter into parmvec. */
15343 /* Advance to the end of the list of parameters. */
15345 }
15347 /* Fail if we've reached the end of the parm list, and more args
15348 are present, and the parm list isn't variadic. */
15351 /* Fail if parms are left and they don't have default values. */
15354 {
15358 {
15359 count++;
15361 }
15363 }
15366 {
15367 tsubst_flags_t complain = (explain_p
15368 ? tf_warning_or_error
15371 /* Check to see if we need another pass before we start clearing
15372 ARGUMENT_PACK_INCOMPLETE_P. */
15374 {
15382 /* If this is an undeduced nontype parameter that depends on
15383 a type parameter, try another pass; its type may have been
15384 deduced from a later argument than the one from which
15385 this parameter can be deduced. */
15390 }
15393 {
15397 /* Clear the "incomplete" flags on all argument packs now so that
15398 substituting them into later default arguments works. */
15400 {
15403 }
15409 /* Core issue #226 (C++0x) [temp.deduct]:
15411 If a template argument has not been deduced, its
15412 default template argument, if any, is used.
15414 When we are in C++98 mode, TREE_PURPOSE will either
15415 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15416 to explicitly check cxx_dialect here. */
15418 {
15430 else
15431 {
15433 /* The position of the first default template argument,
15434 is also the number of non-defaulted arguments in TARGS.
15435 Record that. */
15439 }
15440 }
15442 /* If the type parameter is a parameter pack, then it will
15443 be deduced to an empty parameter pack. */
15445 {
15446 tree arg;
15449 {
15453 }
15454 else
15461 }
15464 }
15465 }
15466 #ifdef ENABLE_CHECKING
15469 #endif
15472 }
15474 /* Subroutine of type_unification_real. Args are like the variables
15475 at the call site. ARG is an overloaded function (or template-id);
15476 we try deducing template args from each of the overloads, and if
15477 only one succeeds, we go with that. Modifies TARGS and returns
15478 true on success. */
15480 static bool
15482 tree targs,
15483 tree parm,
15484 tree arg,
15485 unification_kind_t strict,
15488 {
15495 {
15498 }
15499 else
15503 /* Handle `&x' where `x' is some static or non-static member
15504 function name. */
15510 /* Strip baselink information. */
15515 {
15516 /* If we got some explicit template args, we need to plug them into
15517 the affected templates before we try to unify, in case the
15518 explicit args will completely resolve the templates in question. */
15525 {
15536 {
15541 {
15544 }
15545 }
15549 }
15550 /* If no templates (or more than one) are fully resolved by the
15551 explicit arguments, this template-id is a non-deduced context; it
15552 could still be OK if we deduce all template arguments for the
15553 enclosing call through other arguments. */
15556 }
15559 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15560 -- but the deduction does not succeed because the expression is
15561 not just the function on its own. */
15563 else
15569 {
15572 }
15574 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15575 to function or pointer to member function argument if the set of
15576 overloaded functions does not contain function templates and at most
15577 one of a set of overloaded functions provides a unique match.
15579 So if we found multiple possibilities, we return success but don't
15580 deduce anything. */
15583 {
15588 }
15593 }
15595 /* Core DR 115: In contexts where deduction is done and fails, or in
15596 contexts where deduction is not done, if a template argument list is
15597 specified and it, along with any default template arguments, identifies
15598 a single function template specialization, then the template-id is an
15599 lvalue for the function template specialization. */
15601 tree
15603 {
15616 {
15619 }
15621 {
15624 }
15626 {
15629 }
15632 {
15636 /* If we got some explicit template args, we need to plug them into
15637 the affected templates before we try to unify, in case the
15638 explicit args will completely resolve the templates in question. */
15646 {
15657 {
15660 {
15663 }
15665 {
15668 }
15669 }
15671 }
15673 {
15681 {
15682 tree base
15685 }
15689 }
15691 /* There were no good options and at least one bad one, so let the
15692 user know what the problem is. */
15694 }
15696 }
15698 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15699 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15700 different overloads deduce different arguments for a given parm.
15701 ADDR_P is true if the expression for which deduction is being
15702 performed was of the form "& fn" rather than simply "fn".
15704 Returns 1 on success. */
15706 static int
15708 tree orig_targs,
15709 tree targs,
15710 tree parm,
15711 tree arg,
15712 unification_kind_t strict,
15716 {
15718 tree tempargs;
15721 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15722 to function or pointer to member function argument if the set of
15723 overloaded functions does not contain function templates and at most
15724 one of a set of overloaded functions provides a unique match.
15726 So if this is a template, just return success. */
15738 /* We don't copy orig_targs for this because if we have already deduced
15739 some template args from previous args, unify would complain when we
15740 try to deduce a template parameter for the same argument, even though
15741 there isn't really a conflict. */
15748 /* First make sure we didn't deduce anything that conflicts with
15749 explicitly specified args. */
15751 {
15758 /* Since we're unifying against ourselves, we will fill in
15759 template args used in the function parm list with our own
15760 template parms. Discard them. */
15764 }
15767 {
15772 }
15775 }
15777 /* PARM is a template class (perhaps with unbound template
15778 parameters). ARG is a fully instantiated type. If ARG can be
15779 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15780 TARGS are as for unify. */
15782 static tree
15785 {
15786 tree copy_of_targs;
15793 /* We need to make a new template argument vector for the call to
15794 unify. If we used TARGS, we'd clutter it up with the result of
15795 the attempted unification, even if this class didn't work out.
15796 We also don't want to commit ourselves to all the unifications
15797 we've already done, since unification is supposed to be done on
15798 an argument-by-argument basis. In other words, consider the
15799 following pathological case:
15801 template <int I, int J, int K>
15802 struct S {};
15804 template <int I, int J>
15805 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15807 template <int I, int J, int K>
15808 void f(S<I, J, K>, S<I, I, I>);
15810 void g() {
15811 S<0, 0, 0> s0;
15812 S<0, 1, 2> s2;
15814 f(s0, s2);
15815 }
15817 Now, by the time we consider the unification involving `s2', we
15818 already know that we must have `f<0, 0, 0>'. But, even though
15819 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15820 because there are two ways to unify base classes of S<0, 1, 2>
15821 with S<I, I, I>. If we kept the already deduced knowledge, we
15822 would reject the possibility I=1. */
15825 /* If unification failed, we're done. */
15831 }
15833 /* Given a template type PARM and a class type ARG, find the unique
15834 base type in ARG that is an instance of PARM. We do not examine
15835 ARG itself; only its base-classes. If there is not exactly one
15836 appropriate base class, return NULL_TREE. PARM may be the type of
15837 a partial specialization, as well as a plain template type. Used
15838 by unify. */
15840 static enum template_base_result
15843 {
15845 tree binfo;
15851 {
15852 /* The type could not be completed. */
15855 }
15857 /* Walk in inheritance graph order. The search order is not
15858 important, and this avoids multiple walks of virtual bases. */
15860 {
15865 {
15866 /* If there is more than one satisfactory baseclass, then:
15868 [temp.deduct.call]
15870 If they yield more than one possible deduced A, the type
15871 deduction fails.
15873 applies. */
15875 {
15878 }
15881 }
15882 }
15886 }
15888 /* Returns the level of DECL, which declares a template parameter. */
15890 static int
15892 {
15894 {
15904 }
15906 }
15908 /* Decide whether ARG can be unified with PARM, considering only the
15909 cv-qualifiers of each type, given STRICT as documented for unify.
15910 Returns nonzero iff the unification is OK on that basis. */
15912 static int
15914 {
15920 {
15921 /* Although a CVR qualifier is ignored when being applied to a
15922 substituted template parameter ([8.3.2]/1 for example), that
15923 does not allow us to unify "const T" with "int&" because both
15924 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15925 It is ok when we're allowing additional CV qualifiers
15926 at the outer level [14.8.2.1]/3,1st bullet. */
15936 }
15947 }
15949 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15950 void
15952 {
15956 {
15959 }
15960 else
15961 {
15964 }
15965 }
15967 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15968 do { \
15969 if (unify (TP, TA, P, A, S, EP)) \
15970 return 1; \
15971 } while (0);
15973 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15974 expansion at the end of PACKED_PARMS. Returns 0 if the type
15975 deduction succeeds, 1 otherwise. STRICT is the same as in
15976 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15977 call argument list. We'll need to adjust the arguments to make them
15978 types. SUBR tells us if this is from a recursive call to
15979 type_unification_real, or for comparing two template argument
15980 lists. */
15982 static int
15986 {
15987 tree parm
15994 /* Determine the parameter packs we will be deducing from the
15995 pattern, and record their current deductions. */
15998 {
16002 /* Determine the index and level of this parameter pack. */
16005 /* Keep track of the parameter packs and their corresponding
16006 argument packs. */
16009 }
16011 /* Loop through all of the arguments that have not yet been
16012 unified and unify each with the pattern. */
16014 {
16015 tree parm;
16019 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
16020 or the element of its argument pack at the current index if
16021 this argument was explicitly specified. */
16023 {
16032 {
16035 }
16037 }
16039 /* If we had explicit template arguments, substitute them into the
16040 pattern before deduction. */
16042 {
16043 /* Some arguments might still be unspecified or dependent. */
16051 NULL_TREE);
16056 }
16057 else
16060 /* Unify the pattern with the current argument. */
16065 /* For each parameter pack, collect the deduced value. */
16067 {
16073 }
16074 }
16076 /* Verify that the results of unification with the parameter packs
16077 produce results consistent with what we've seen before, and make
16078 the deduced argument packs available. */
16080 {
16087 /* By default keep the original deduced argument pack.
16088 If necessary, more specific code is going to update the
16089 resulting deduced argument later down in this function. */
16093 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16094 actually deduce anything. */
16102 {
16103 /* If we had fewer function args than explicit template args,
16104 just use the explicits. */
16109 }
16112 {
16113 tree result;
16114 /* Build the deduced *_ARGUMENT_PACK. */
16116 {
16121 }
16122 else
16127 /* Note the deduced argument packs for this parameter
16128 pack. */
16130 }
16134 {
16135 /* We only had the explicitly-provided arguments before, but
16136 now we have a complete set of arguments. */
16142 }
16143 else
16144 {
16150 /* Inconsistent unification of this parameter pack. */
16152 bad_old_arg,
16153 bad_new_arg);
16154 }
16155 }
16158 }
16160 /* Deduce the value of template parameters. TPARMS is the (innermost)
16161 set of template parameters to a template. TARGS is the bindings
16162 for those template parameters, as determined thus far; TARGS may
16163 include template arguments for outer levels of template parameters
16164 as well. PARM is a parameter to a template function, or a
16165 subcomponent of that parameter; ARG is the corresponding argument.
16166 This function attempts to match PARM with ARG in a manner
16167 consistent with the existing assignments in TARGS. If more values
16168 are deduced, then TARGS is updated.
16170 Returns 0 if the type deduction succeeds, 1 otherwise. The
16171 parameter STRICT is a bitwise or of the following flags:
16173 UNIFY_ALLOW_NONE:
16174 Require an exact match between PARM and ARG.
16175 UNIFY_ALLOW_MORE_CV_QUAL:
16176 Allow the deduced ARG to be more cv-qualified (by qualification
16177 conversion) than ARG.
16178 UNIFY_ALLOW_LESS_CV_QUAL:
16179 Allow the deduced ARG to be less cv-qualified than ARG.
16180 UNIFY_ALLOW_DERIVED:
16181 Allow the deduced ARG to be a template base class of ARG,
16182 or a pointer to a template base class of the type pointed to by
16183 ARG.
16184 UNIFY_ALLOW_INTEGER:
16185 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16186 case for more information.
16187 UNIFY_ALLOW_OUTER_LEVEL:
16188 This is the outermost level of a deduction. Used to determine validity
16189 of qualification conversions. A valid qualification conversion must
16190 have const qualified pointers leading up to the inner type which
16191 requires additional CV quals, except at the outer level, where const
16192 is not required [conv.qual]. It would be normal to set this flag in
16193 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16194 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16195 This is the outermost level of a deduction, and PARM can be more CV
16196 qualified at this point.
16197 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16198 This is the outermost level of a deduction, and PARM can be less CV
16199 qualified at this point. */
16201 static int
16204 {
16206 tree targ;
16207 tree tparm;
16210 /* I don't think this will do the right thing with respect to types.
16211 But the only case I've seen it in so far has been array bounds, where
16212 signedness is the only information lost, and I think that will be
16213 okay. */
16221 /* We can't deduce anything from this, but we might get all the
16222 template args from other function args. */
16225 /* If PARM uses template parameters, then we can't bail out here,
16226 even if ARG == PARM, since we won't record unifications for the
16227 template parameters. We might need them if we're trying to
16228 figure out which of two things is more specialized. */
16232 /* Handle init lists early, so the rest of the function can assume
16233 we're dealing with a type. */
16235 {
16240 /* Replace T with std::initializer_list<T> for deduction. */
16246 /* We can only deduce from an initializer list argument if the
16247 parameter is std::initializer_list; otherwise this is a
16248 non-deduced context. */
16254 {
16261 {
16263 /* It should only be possible to get here for a call. */
16265 elt_strict |= maybe_adjust_types_for_deduction
16268 }
16271 explain_p);
16272 }
16274 /* If the std::initializer_list<T> deduction worked, replace the
16275 deduced A with std::initializer_list<A>. */
16277 {
16282 }
16284 }
16286 /* Immediately reject some pairs that won't unify because of
16287 cv-qualification mismatches. */
16290 /* It is the elements of the array which hold the cv quals of an array
16291 type, and the elements might be template type parms. We'll check
16292 when we recurse. */
16294 /* We check the cv-qualifiers when unifying with template type
16295 parameters below. We want to allow ARG `const T' to unify with
16296 PARM `T' for example, when computing which of two templates
16297 is more specialized, for example. */
16311 {
16315 /* In a type which contains a nested-name-specifier, template
16316 argument values cannot be deduced for template parameters used
16317 within the nested-name-specifier. */
16329 /* The PARM is not one we're trying to unify. Just check
16330 to see if it matches ARG. */
16331 {
16336 else
16338 }
16345 /* Check for mixed types and values. */
16353 {
16354 /* ARG must be constructed from a template class or a template
16355 template parameter. */
16360 {
16364 tree parm_parms
16365 = DECL_INNERMOST_TEMPLATE_PARMS
16370 /* The resolution to DR150 makes clear that default
16371 arguments for an N-argument may not be used to bind T
16372 to a template template parameter with fewer than N
16373 parameters. It is not safe to permit the binding of
16374 default arguments as an extension, as that may change
16375 the meaning of a conforming program. Consider:
16377 struct Dense { static const unsigned int dim = 1; };
16379 template <template <typename> class View,
16380 typename Block>
16381 void operator+(float, View<Block> const&);
16383 template <typename Block,
16384 unsigned int Dim = Block::dim>
16385 struct Lvalue_proxy { operator float() const; };
16387 void
16388 test_1d (void) {
16389 Lvalue_proxy<Dense> p;
16390 float b;
16391 b + p;
16392 }
16394 Here, if Lvalue_proxy is permitted to bind to View, then
16395 the global operator+ will be used; if they are not, the
16396 Lvalue_proxy will be converted to float. */
16398 full_argvec,
16400 (explain_p
16401 ? tf_warning_or_error
16408 /* Deduce arguments T, i from TT<T> or TT<i>.
16409 We check each element of PARMVEC and ARGVEC individually
16410 rather than the whole TREE_VEC since they can have
16411 different number of elements. */
16418 /* Check if the parameters end in a pack, making them
16419 variadic. */
16429 {
16434 }
16439 DEDUCE_EXACT,
16442 }
16445 /* Fall through to deduce template name. */
16446 }
16450 {
16451 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16453 /* Simple cases: Value already set, does match or doesn't. */
16458 }
16459 else
16460 {
16461 /* If PARM is `const T' and ARG is only `int', we don't have
16462 a match unless we are allowing additional qualification.
16463 If ARG is `const int' and PARM is just `T' that's OK;
16464 that binds `const int' to `T'. */
16469 /* Consider the case where ARG is `const volatile int' and
16470 PARM is `const T'. Then, T should be `volatile int'. */
16471 arg = cp_build_qualified_type_real
16476 /* Simple cases: Value already set, does match or doesn't. */
16482 /* Make sure that ARG is not a variable-sized array. (Note
16483 that were talking about variable-sized arrays (like
16484 `int[n]'), rather than arrays of unknown size (like
16485 `int[]').) We'll get very confused by such a type since
16486 the bound of the array is not constant, and therefore
16487 not mangleable. Besides, such types are not allowed in
16488 ISO C++, so we can do as we please here. We do allow
16489 them for 'auto' deduction, since that isn't ABI-exposed. */
16493 /* Strip typedefs as in convert_template_argument. */
16495 }
16497 /* If ARG is a parameter pack or an expansion, we cannot unify
16498 against it unless PARM is also a parameter pack. */
16503 /* If the argument deduction results is a METHOD_TYPE,
16504 then there is a problem.
16505 METHOD_TYPE doesn't map to any real C++ type the result of
16506 the deduction can not be of that type. */
16520 {
16521 /* The PARM is not one we're trying to unify. Just check
16522 to see if it matches ARG. */
16528 }
16534 {
16539 }
16541 /* [temp.deduct.type] If, in the declaration of a function template
16542 with a non-type template-parameter, the non-type
16543 template-parameter is used in an expression in the function
16544 parameter-list and, if the corresponding template-argument is
16545 deduced, the template-argument type shall match the type of the
16546 template-parameter exactly, except that a template-argument
16547 deduced from an array bound may be of any integral type.
16548 The non-type parameter might use already deduced type parameters. */
16551 /* Template-parameter dependent expression. Just accept it for now.
16552 It will later be processed in convert_template_argument. */
16553 ;
16559 /* Convert the ARG to the type of PARM; the deduced non-type
16560 template argument must exactly match the types of the
16561 corresponding parameter. */
16564 /* We haven't deduced the type of this parameter yet. Try again
16565 later. */
16567 else
16570 /* If ARG is a parameter pack or an expansion, we cannot unify
16571 against it unless PARM is also a parameter pack. */
16580 {
16581 /* A pointer-to-member constant can be unified only with
16582 another constant. */
16586 /* Just unify the class member. It would be useless (and possibly
16587 wrong, depending on the strict flags) to unify also
16588 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16589 arg refer to the same variable, even if through different
16590 classes. For instance:
16592 struct A { int x; };
16593 struct B : A { };
16595 Unification of &A::x and &B::x must succeed. */
16598 }
16601 {
16605 /* [temp.deduct.call]
16607 A can be another pointer or pointer to member type that can
16608 be converted to the deduced A via a qualification
16609 conversion (_conv.qual_).
16611 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16612 This will allow for additional cv-qualification of the
16613 pointed-to types if appropriate. */
16616 /* The derived-to-base conversion only persists through one
16617 level of pointers. */
16622 }
16637 {
16638 tree parm_max;
16639 tree arg_max;
16643 /* Our representation of array types uses "N - 1" as the
16644 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16645 not an integer constant. We cannot unify arbitrarily
16646 complex expressions, so we eliminate the MINUS_EXPRs
16647 here. */
16651 {
16654 }
16658 {
16659 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16660 trying to unify the type of a variable with the type
16661 of a template parameter. For example:
16663 template <unsigned int N>
16664 void f (char (&) [N]);
16665 int g();
16666 void h(int i) {
16667 char a[g(i)];
16668 f(a);
16669 }
16671 Here, the type of the ARG will be "int [g(i)]", and
16672 may be a SAVE_EXPR, etc. */
16676 }
16678 /* If only one of the bounds used a MINUS_EXPR, compensate
16679 by adding one to the other bound. */
16682 integer_type_node,
16683 parm_max,
16684 integer_one_node);
16687 integer_type_node,
16688 arg_max,
16689 integer_one_node);
16693 }
16708 /* We have already checked cv-qualification at the top of the
16709 function. */
16713 /* As far as unification is concerned, this wins. Later checks
16714 will invalidate it if necessary. */
16717 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16718 /* Type INTEGER_CST can come from ordinary constant template args. */
16730 {
16740 /* Check for pack expansions in the parameters. */
16742 {
16744 {
16746 /* We can unify against something with a trailing
16747 parameter pack. */
16749 else
16750 /* [temp.deduct.type]/9: If the template argument list of
16751 P contains a pack expansion that is not the last
16752 template argument, the entire template argument list
16753 is a non-deduced context. */
16755 }
16756 }
16758 /* If we don't have enough arguments to satisfy the parameters
16759 (not counting the pack expression at the end), or we have
16760 too many arguments for a parameter list that doesn't end in
16761 a pack expression, we can't unify. */
16767 /* Unify all of the parameters that precede the (optional)
16768 pack expression. */
16770 {
16775 }
16778 DEDUCE_EXACT,
16781 }
16789 {
16797 }
16800 {
16804 {
16805 /* First, we try to unify the PARM and ARG directly. */
16810 {
16811 /* Fallback to the special case allowed in
16812 [temp.deduct.call]:
16814 If P is a class, and P has the form
16815 template-id, then A can be a derived class of
16816 the deduced A. Likewise, if P is a pointer to
16817 a class of the form template-id, A can be a
16818 pointer to a derived class pointed to by the
16819 deduced A. */
16826 }
16827 }
16831 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16832 Then, we should unify `int' and `U'. */
16834 else
16835 /* There's no chance of unification succeeding. */
16840 }
16847 {
16850 tree a;
16856 /* CV qualifications for methods can never be deduced, they must
16857 match exactly. We need to check them explicitly here,
16858 because type_unification_real treats them as any other
16859 cv-qualified parameter. */
16861 && (!check_cv_quals_for_unify
16881 }
16884 /* Unify a pointer to member with a pointer to member function, which
16885 deduces the type of the member as a function type. */
16887 {
16888 tree method_type;
16889 tree fntype;
16891 /* Check top-level cv qualifiers */
16899 /* Determine the type of the function we are unifying against. */
16901 fntype =
16905 /* Extract the cv-qualifiers of the member function from the
16906 implicit object parameter and place them on the function
16907 type to be restored later. */
16910 }
16929 /* Matched cases are handled by the ARG == PARM test above. */
16933 /* A non-type template parameter that is a variable should be a
16934 an integral constant, in which case, it whould have been
16935 folded into its (constant) value. So we should not be getting
16936 a variable here. */
16947 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16948 or UNDERLYING_TYPE nodes. */
16952 /* Unification fails if we hit an error node. */
16956 /* An unresolved overload is a nondeduced context. */
16961 /* We must be looking at an expression. This can happen with
16962 something like:
16964 template <int I>
16965 void foo(S<I>, S<I + 2>);
16967 This is a "nondeduced context":
16969 [deduct.type]
16971 The nondeduced contexts are:
16973 --A type that is a template-id in which one or more of
16974 the template-arguments is an expression that references
16975 a template-parameter.
16977 In these cases, we assume deduction succeeded, but don't
16978 actually infer any unifications. */
16983 else
16985 }
16986 }
16987 #undef RECUR_AND_CHECK_FAILURE
16988 \f
16989 /* Note that DECL can be defined in this translation unit, if
16990 required. */
16992 static void
16994 {
16995 tree clone;
16999 }
17001 /* Called if RESULT is explicitly instantiated, or is a member of an
17002 explicitly instantiated class. */
17004 void
17006 {
17009 /* If this entity has already been written out, it's too late to
17010 make any modifications. */
17015 /* The TREE_PUBLIC flag for function declarations will have been
17016 set correctly by tsubst. */
17019 /* This might have been set by an earlier implicit instantiation. */
17024 else
17025 {
17027 /* Always make artificials weak. */
17030 /* For WIN32 we also want to put explicit instantiations in
17031 linkonce sections. */
17034 }
17036 /* If EXTERN_P, then this function will not be emitted -- unless
17037 followed by an explicit instantiation, at which point its linkage
17038 will be adjusted. If !EXTERN_P, then this function will be
17039 emitted here. In neither circumstance do we want
17040 import_export_decl to adjust the linkage. */
17042 }
17044 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17045 important template arguments. If any are missing, we check whether
17046 they're important by using error_mark_node for substituting into any
17047 args that were used for partial ordering (the ones between ARGS and END)
17048 and seeing if it bubbles up. */
17050 static bool
17052 {
17057 {
17060 }
17062 {
17064 {
17068 }
17069 }
17071 }
17073 /* Given two function templates PAT1 and PAT2, return:
17075 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17076 -1 if PAT2 is more specialized than PAT1.
17077 0 if neither is more specialized.
17079 LEN indicates the number of parameters we should consider
17080 (defaulted parameters should not be considered).
17082 The 1998 std underspecified function template partial ordering, and
17083 DR214 addresses the issue. We take pairs of arguments, one from
17084 each of the templates, and deduce them against each other. One of
17085 the templates will be more specialized if all the *other*
17086 template's arguments deduce against its arguments and at least one
17087 of its arguments *does* *not* deduce against the other template's
17088 corresponding argument. Deduction is done as for class templates.
17089 The arguments used in deduction have reference and top level cv
17090 qualifiers removed. Iff both arguments were originally reference
17091 types *and* deduction succeeds in both directions, the template
17092 with the more cv-qualified argument wins for that pairing (if
17093 neither is more cv-qualified, they both are equal). Unlike regular
17094 deduction, after all the arguments have been deduced in this way,
17095 we do *not* verify the deduced template argument values can be
17096 substituted into non-deduced contexts.
17098 The logic can be a bit confusing here, because we look at deduce1 and
17099 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17100 can find template arguments for pat1 to make arg1 look like arg2, that
17101 means that arg2 is at least as specialized as arg1. */
17103 int
17105 {
17118 /* Remove the this parameter from non-static member functions. If
17119 one is a non-static member function and the other is not a static
17120 member function, remove the first parameter from that function
17121 also. This situation occurs for operator functions where we
17122 locate both a member function (with this pointer) and non-member
17123 operator (with explicit first operand). */
17125 {
17130 }
17132 {
17135 {
17136 len--;
17138 }
17139 }
17141 /* If only one is a conversion operator, they are unordered. */
17145 /* Consider the return type for a conversion function */
17147 {
17150 len++;
17151 }
17153 processing_template_decl++;
17159 /* Stop when an ellipsis is seen. */
17161 {
17170 {
17171 /* When both arguments are pack expansions, we need only
17172 unify the patterns themselves. */
17176 /* This is the last comparison we need to do. */
17178 }
17181 {
17184 }
17187 {
17190 }
17196 {
17202 /* Setup the parameter vector, which contains only ARG1. */
17205 /* Setup the argument vector, which contains the remaining
17206 arguments. */
17215 /* We cannot deduce in the other direction, because ARG1 is
17216 a pack expansion but ARG2 is not. */
17218 }
17220 {
17226 /* Setup the parameter vector, which contains only ARG1. */
17229 /* Setup the argument vector, which contains the remaining
17230 arguments. */
17239 /* We cannot deduce in the other direction, because ARG2 is
17240 a pack expansion but ARG1 is not.*/
17242 }
17244 else
17245 {
17246 /* The normal case, where neither argument is a pack
17247 expansion. */
17254 }
17256 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17257 arg2, then arg2 is not as specialized as arg1. */
17263 /* "If, for a given type, deduction succeeds in both directions
17264 (i.e., the types are identical after the transformations above)
17265 and if the type from the argument template is more cv-qualified
17266 than the type from the parameter template (as described above)
17267 that type is considered to be more specialized than the other. If
17268 neither type is more cv-qualified than the other then neither type
17269 is more specialized than the other." */
17273 {
17278 }
17281 /* We've failed to deduce something in either direction.
17282 These must be unordered. */
17287 /* We have already processed all of the arguments in our
17288 handing of the pack expansion type. */
17293 }
17295 /* "In most cases, all template parameters must have values in order for
17296 deduction to succeed, but for partial ordering purposes a template
17297 parameter may remain without a value provided it is not used in the
17298 types being used for partial ordering."
17300 Thus, if we are missing any of the targs1 we need to substitute into
17301 origs1, then pat2 is not as specialized as pat1. This can happen when
17302 there is a nondeduced context. */
17308 processing_template_decl--;
17310 /* All things being equal, if the next argument is a pack expansion
17311 for one function but not for the other, prefer the
17312 non-variadic function. FIXME this is bogus; see c++/41958. */
17316 {
17319 }
17325 else
17327 }
17329 /* Determine which of two partial specializations is more specialized.
17331 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17332 to the first partial specialization. The TREE_VALUE is the
17333 innermost set of template parameters for the partial
17334 specialization. PAT2 is similar, but for the second template.
17336 Return 1 if the first partial specialization is more specialized;
17337 -1 if the second is more specialized; 0 if neither is more
17338 specialized.
17340 See [temp.class.order] for information about determining which of
17341 two templates is more specialized. */
17343 static int
17345 {
17346 tree targs;
17354 /* Just like what happens for functions, if we are ordering between
17355 different class template specializations, we may encounter dependent
17356 types in the arguments, and we need our dependency check functions
17357 to behave correctly. */
17363 {
17366 }
17372 {
17375 }
17378 /* In the case of a tie where at least one of the class templates
17379 has a parameter pack at the end, the template with the most
17380 non-packed parameters wins. */
17382 && any_deductions
17385 {
17391 /* We don't count the pack expansion at the end. */
17401 }
17404 }
17406 /* Return the template arguments that will produce the function signature
17407 DECL from the function template FN, with the explicit template
17408 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17409 also match. Return NULL_TREE if no satisfactory arguments could be
17410 found. */
17412 static tree
17414 {
17417 tree decl_type;
17418 tree decl_arg_types;
17421 tree arg;
17423 /* Substitute the explicit template arguments into the type of DECL.
17424 The call to fn_type_unification will handle substitution into the
17425 FN. */
17428 {
17429 tree tmpl;
17430 tree converted_args;
17434 else
17435 /* We can get here for some invalid specializations. */
17438 converted_args
17441 tf_none,
17450 }
17452 /* Never do unification on the 'this' parameter. */
17471 }
17473 /* Return the innermost template arguments that, when applied to a
17474 template specialization whose innermost template parameters are
17475 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17476 ARGS.
17478 For example, suppose we have:
17480 template <class T, class U> struct S {};
17481 template <class T> struct S<T*, int> {};
17483 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17484 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17485 int}. The resulting vector will be {double}, indicating that `T'
17486 is bound to `double'. */
17488 static tree
17490 {
17492 tree deduced_args;
17493 tree innermost_deduced_args;
17497 {
17501 innermost_deduced_args);
17502 }
17503 else
17516 /* Verify that nondeduced template arguments agree with the type
17517 obtained from argument deduction.
17519 For example:
17521 struct A { typedef int X; };
17522 template <class T, class U> struct C {};
17523 template <class T> struct C<T, typename T::X> {};
17525 Then with the instantiation `C<A, int>', we can deduce that
17526 `T' is `A' but unify () does not check whether `typename T::X'
17527 is `int'. */
17530 /* We only need to check the innermost arguments; the other
17531 arguments will always agree. */
17536 /* Now that we have bindings for all of the template arguments,
17537 ensure that the arguments deduced for the template template
17538 parameters have compatible template parameter lists. See the use
17539 of template_template_parm_bindings_ok_p in fn_type_unification
17540 for more information. */
17545 }
17547 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17548 Return the TREE_LIST node with the most specialized template, if
17549 any. If there is no most specialized template, the error_mark_node
17550 is returned.
17552 Note that this function does not look at, or modify, the
17553 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17554 returned is one of the elements of INSTANTIATIONS, callers may
17555 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17556 and retrieve it from the value returned. */
17558 tree
17560 {
17567 {
17573 fate--;
17578 fate++;
17583 {
17584 /* Equally specialized, move to next function. If there
17585 is no next function, nothing's most specialized. */
17590 }
17591 }
17594 /* Now verify that champ is better than everything earlier in the
17595 instantiation list. */
17603 {
17606 }
17608 processing_template_decl--;
17614 }
17616 /* If DECL is a specialization of some template, return the most
17617 general such template. Otherwise, returns NULL_TREE.
17619 For example, given:
17621 template <class T> struct S { template <class U> void f(U); };
17623 if TMPL is `template <class U> void S<int>::f(U)' this will return
17624 the full template. This function will not trace past partial
17625 specializations, however. For example, given in addition:
17627 template <class T> struct S<T*> { template <class U> void f(U); };
17629 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17630 `template <class T> template <class U> S<T*>::f(U)'. */
17632 tree
17634 {
17635 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17636 an immediate specialization. */
17638 {
17642 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17643 template friend. */
17648 }
17650 /* Look for more and more general templates. */
17652 {
17653 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17654 (See cp-tree.h for details.) */
17662 /* Stop if we run into an explicitly specialized class template. */
17669 }
17672 }
17674 /* Return the most specialized of the class template partial
17675 specializations of TMPL which can produce TYPE, a specialization of
17676 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17677 a _TYPE node corresponding to the partial specialization, while the
17678 TREE_PURPOSE is the set of template arguments that must be
17679 substituted into the TREE_TYPE in order to generate TYPE.
17681 If the choice of partial specialization is ambiguous, a diagnostic
17682 is issued, and the error_mark_node is returned. If there are no
17683 partial specializations of TMPL matching TYPE, then NULL_TREE is
17684 returned. */
17686 static tree
17688 {
17690 tree t;
17691 tree champ;
17694 tree args;
17700 /* For determining which partial specialization to use, only the
17701 innermost args are interesting. */
17703 {
17706 }
17709 {
17710 tree partial_spec_args;
17711 tree spec_args;
17719 {
17722 /* Discard the outer levels of args, and then substitute in the
17723 template args from the enclosing class. */
17725 partial_spec_args = tsubst_template_args
17728 /* PARMS already refers to just the innermost parms, but the
17729 template parms in partial_spec_args had their levels lowered
17730 by tsubst, so we need to do the same for the parm list. We
17731 can't just tsubst the TREE_VEC itself, as tsubst wants to
17732 treat a TREE_VEC as an argument vector. */
17738 }
17740 partial_spec_args =
17743 partial_spec_args),
17754 partial_spec_args,
17755 args);
17757 {
17762 }
17763 }
17773 {
17776 ;
17777 else
17778 {
17780 {
17783 {
17786 }
17787 }
17789 }
17790 }
17794 {
17797 {
17800 }
17801 }
17804 {
17812 {
17815 }
17818 }
17821 }
17823 /* Explicitly instantiate DECL. */
17825 void
17827 {
17832 /* An error occurred, for which grokdeclarator has already issued
17833 an appropriate message. */
17836 {
17839 }
17841 {
17842 /* There is an asymmetry here in the way VAR_DECLs and
17843 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17844 the latter, the DECL we get back will be marked as a
17845 template instantiation, and the appropriate
17846 DECL_TEMPLATE_INFO will be set up. This does not happen for
17847 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17848 should handle VAR_DECLs as it currently handles
17849 FUNCTION_DECLs. */
17851 {
17854 }
17857 {
17860 }
17862 {
17867 }
17868 }
17870 {
17873 }
17874 else
17877 /* Check for various error cases. Note that if the explicit
17878 instantiation is valid the RESULT will currently be marked as an
17879 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17880 until we get here. */
17883 {
17884 /* DR 259 [temp.spec].
17886 Both an explicit instantiation and a declaration of an explicit
17887 specialization shall not appear in a program unless the explicit
17888 instantiation follows a declaration of the explicit specialization.
17890 For a given set of template parameters, if an explicit
17891 instantiation of a template appears after a declaration of an
17892 explicit specialization for that template, the explicit
17893 instantiation has no effect. */
17895 }
17897 {
17898 /* [temp.spec]
17900 No program shall explicitly instantiate any template more
17901 than once.
17903 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17904 the first instantiation was `extern' and the second is not,
17905 and EXTERN_P for the opposite case. */
17908 /* If an "extern" explicit instantiation follows an ordinary
17909 explicit instantiation, the template is instantiated. */
17912 }
17914 {
17917 }
17919 {
17922 }
17925 ;
17927 {
17930 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17933 }
17934 else
17942 }
17944 static void
17946 {
17952 {
17955 }
17956 }
17958 /* Called from do_type_instantiation through binding_table_foreach to
17959 do recursive instantiation for the type bound in ENTRY. */
17960 static void
17962 {
17968 }
17970 /* Called from do_type_instantiation to instantiate a member
17971 (a member function or a static member variable) of an
17972 explicitly instantiated class template. */
17973 static void
17975 {
17980 }
17982 /* Perform an explicit instantiation of template class T. STORAGE, if
17983 non-null, is the RID for extern, inline or static. COMPLAIN is
17984 nonzero if this is called from the parser, zero if called recursively,
17985 since the standard is unclear (as detailed below). */
17987 void
17989 {
17999 {
18000 tree tmpl =
18004 else
18007 }
18012 {
18015 t);
18017 }
18020 {
18022 {
18024 {
18027 "ISO C++ 1998 forbids the use of %<extern%> on "
18029 }
18030 else
18032 "ISO C++ forbids the use of %qE"
18034 }
18042 else
18043 {
18045 storage);
18047 }
18048 }
18051 {
18052 /* DR 259 [temp.spec].
18054 Both an explicit instantiation and a declaration of an explicit
18055 specialization shall not appear in a program unless the explicit
18056 instantiation follows a declaration of the explicit specialization.
18058 For a given set of template parameters, if an explicit
18059 instantiation of a template appears after a declaration of an
18060 explicit specialization for that template, the explicit
18061 instantiation has no effect. */
18063 }
18065 {
18066 /* [temp.spec]
18068 No program shall explicitly instantiate any template more
18069 than once.
18071 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18072 instantiation was `extern'. If EXTERN_P then the second is.
18073 These cases are OK. */
18080 /* If we've already instantiated the template, just return now. */
18083 }
18091 {
18092 tree tmp;
18094 /* In contrast to implicit instantiation, where only the
18095 declarations, and not the definitions, of members are
18096 instantiated, we have here:
18098 [temp.explicit]
18100 The explicit instantiation of a class template specialization
18101 implies the instantiation of all of its members not
18102 previously explicitly specialized in the translation unit
18103 containing the explicit instantiation.
18105 Of course, we can't instantiate member template classes, since
18106 we don't have any arguments for them. Note that the standard
18107 is unclear on whether the instantiation of the members are
18108 *explicit* instantiations or not. However, the most natural
18109 interpretation is that it should be an explicit instantiation. */
18124 }
18125 }
18127 /* Given a function DECL, which is a specialization of TMPL, modify
18128 DECL to be a re-instantiation of TMPL with the same template
18129 arguments. TMPL should be the template into which tsubst'ing
18130 should occur for DECL, not the most general template.
18132 One reason for doing this is a scenario like this:
18134 template <class T>
18135 void f(const T&, int i);
18137 void g() { f(3, 7); }
18139 template <class T>
18140 void f(const T& t, const int i) { }
18142 Note that when the template is first instantiated, with
18143 instantiate_template, the resulting DECL will have no name for the
18144 first parameter, and the wrong type for the second. So, when we go
18145 to instantiate the DECL, we regenerate it. */
18147 static void
18149 {
18150 /* The arguments used to instantiate DECL, from the most general
18151 template. */
18152 tree args;
18153 tree code_pattern;
18158 /* Make sure that we can see identifiers, and compute access
18159 correctly. */
18163 {
18164 tree decl_parm;
18165 tree pattern_parm;
18166 tree specs;
18180 specs);
18182 /* Merge parameter declarations. */
18185 pattern_parm
18189 {
18190 tree parm_type;
18191 tree attributes;
18196 NULL_TREE);
18202 {
18205 }
18208 }
18209 /* Merge any parameters that match with the function parameter
18210 pack. */
18212 {
18214 tree expanded_types;
18215 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18216 the parameters in this function parameter pack. */
18221 {
18222 tree parm_type;
18223 tree attributes;
18226 /* Rename the parameter to include the index. */
18235 {
18238 }
18240 }
18241 }
18242 /* Merge additional specifiers from the CODE_PATTERN. */
18246 }
18248 {
18256 }
18257 else
18261 }
18263 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18264 substituted to get DECL. */
18266 tree
18268 {
18271 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18272 for the instantiation. This is not always the most general
18273 template. Consider, for example:
18275 template <class T>
18276 struct S { template <class U> void f();
18277 template <> void f<int>(); };
18279 and an instantiation of S<double>::f<int>. We want TD to be the
18280 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18282 more general template. */
18284 /* We must also deal with friend templates. Given:
18286 template <class T> struct S {
18287 template <class U> friend void f() {};
18288 };
18290 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18291 so far as the language is concerned, but that's still
18292 where we get the pattern for the instantiation from. On
18293 other hand, if the definition comes outside the class, say:
18295 template <class T> struct S {
18296 template <class U> friend void f();
18297 };
18298 template <class U> friend void f() {}
18300 we don't need to look any further. That's what the check for
18301 DECL_INITIAL is for. */
18305 {
18306 /* The present template, TD, should not be a definition. If it
18307 were a definition, we should be using it! Note that we
18308 cannot restructure the loop to just keep going until we find
18309 a template with a definition, since that might go too far if
18310 a specialization was declared, but not defined. */
18314 /* Fetch the more general template. */
18316 }
18319 }
18321 /* Returns true if we need to instantiate this template instance even if we
18322 know we aren't going to emit it.. */
18324 bool
18326 {
18327 /* We always instantiate inline functions so that we can inline them. An
18328 explicit instantiation declaration prohibits implicit instantiation of
18329 non-inline functions. With high levels of optimization, we would
18330 normally inline non-inline functions -- but we're not allowed to do
18331 that for "extern template" functions. Therefore, we check
18332 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18336 /* And we need to instantiate static data members so that
18337 their initializers are available in integral constant
18338 expressions. */
18341 }
18343 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18344 instantiate it now, modifying TREE_TYPE (fn). */
18346 void
18348 {
18362 {
18364 {
18377 }
18378 else
18380 }
18381 else
18382 {
18383 /* This is an implicitly declared function, so NOEX is a list of
18384 other functions to evaluate and merge. */
18385 tree elt;
18388 {
18390 tree subspec;
18394 }
18395 }
18400 {
18403 else
18405 }
18406 }
18408 /* Produce the definition of D, a _DECL generated from a template. If
18409 DEFER_OK is nonzero, then we don't have to actually do the
18410 instantiation now; we just have to do it sometime. Normally it is
18411 an error if this is an explicit instantiation but D is undefined.
18412 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18413 explicitly instantiated class template. */
18415 tree
18418 {
18420 tree gen_args;
18421 tree args;
18422 tree td;
18423 tree code_pattern;
18424 tree spec;
18425 tree gen_tmpl;
18431 /* This function should only be used to instantiate templates for
18432 functions and static member variables. */
18436 /* Variables are never deferred; if instantiation is required, they
18437 are instantiated right away. That allows for better code in the
18438 case that an expression refers to the value of the variable --
18439 if the variable has a constant value the referring expression can
18440 take advantage of that fact. */
18445 /* Don't instantiate cloned functions. Instead, instantiate the
18446 functions they cloned. */
18454 /* D has already been instantiated or explicitly specialized, so
18455 there's nothing for us to do here.
18457 It might seem reasonable to check whether or not D is an explicit
18458 instantiation, and, if so, stop here. But when an explicit
18459 instantiation is deferred until the end of the compilation,
18460 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18461 the instantiation. */
18464 /* Check to see whether we know that this template will be
18465 instantiated in some other file, as with "extern template"
18466 extension. */
18469 /* In general, we do not instantiate such templates. */
18477 /* We should already have the extra args. */
18480 /* And what's in the hash table should match D. */
18484 /* This needs to happen before any tsubsting. */
18490 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18491 for the instantiation. */
18495 /* We should never be trying to instantiate a member of a class
18496 template or partial specialization. */
18501 /* In the case of a friend template whose definition is provided
18502 outside the class, we may have too many arguments. Drop the
18503 ones we don't need. The same is true for specializations. */
18504 args = get_innermost_template_args
18506 else
18512 else
18515 /* We may be in the middle of deferred access check. Disable it now. */
18518 /* Unless an explicit instantiation directive has already determined
18519 the linkage of D, remember that a definition is available for
18520 this entity. */
18530 /* If D is a member of an explicitly instantiated class template,
18531 and no definition is available, treat it like an implicit
18532 instantiation. */
18535 {
18536 /* Leave linkage flags alone on instantiations with anonymous
18537 visibility. */
18539 {
18542 }
18544 }
18549 /* Recheck the substitutions to obtain any warning messages
18550 about ignoring cv qualifiers. Don't do this for artificial decls,
18551 as it breaks the context-sensitive substitution for lambda op(). */
18553 {
18557 /* Make sure that we can see identifiers, and compute access
18558 correctly. D is already the target FUNCTION_DECL with the
18559 right context. */
18563 {
18567 /* Don't simply tsubst the function type, as that will give
18568 duplicate warnings about poor parameter qualifications.
18569 The function arguments are the same as the decl_arguments
18570 without the top level cv qualifiers. */
18572 }
18576 }
18578 /* Defer all other templates, unless we have been explicitly
18579 forbidden from doing so. */
18581 template. */
18582 ! pattern_defined
18583 /* If it's OK to postpone instantiation, do so. */
18584 || defer_ok
18585 /* If this is a static data member that will be defined
18586 elsewhere, we don't want to instantiate the entire data
18587 member, but we do want to instantiate the initializer so that
18588 we can substitute that elsewhere. */
18590 {
18591 /* The definition of the static data member is now required so
18592 we must substitute the initializer. */
18596 {
18597 tree ns;
18598 tree init;
18605 args,
18608 /* Make sure the initializer is still constant, in case of
18609 circular dependency (template/instantiate6.C). */
18610 const_init
18614 LOOKUP_ONLYCONVERTING);
18617 }
18619 /* We restore the source position here because it's used by
18620 add_pending_template. */
18626 /* [temp.explicit]
18628 The definition of a non-exported function template, a
18629 non-exported member function template, or a non-exported
18630 member function or static data member of a class template
18631 shall be present in every translation unit in which it is
18632 explicitly instantiated. */
18636 /* If we're in unevaluated context, we just wanted to get the
18637 constant value; this isn't an odr use, so don't queue
18638 a full instantiation. */
18641 /* ??? Historically, we have instantiated inline functions, even
18642 when marked as "extern template". */
18646 }
18647 /* Tell the repository that D is available in this translation unit
18648 -- and see if it is supposed to be instantiated here. */
18650 {
18651 /* In a PCH file, despite the fact that the repository hasn't
18652 requested instantiation in the PCH it is still possible that
18653 an instantiation will be required in a file that includes the
18654 PCH. */
18657 /* Instantiate inline functions so that the inliner can do its
18658 job, even though we'll not be emitting a copy of this
18659 function. */
18662 }
18668 /* Mark D as instantiated so that recursive calls to
18669 instantiate_decl do not try to instantiate it again. */
18672 /* Regenerate the declaration in case the template has been modified
18673 by a subsequent redeclaration. */
18676 /* We already set the file and line above. Reset them now in case
18677 they changed as a result of calling regenerate_decl_from_template. */
18681 {
18682 tree init;
18685 /* Clear out DECL_RTL; whatever was there before may not be right
18686 since we've reset the type of the declaration. */
18690 /* The initializer is placed in DECL_INITIAL by
18691 regenerate_decl_from_template so we don't need to
18692 push/pop_access_scope again here. Pull it out so that
18693 cp_finish_decl can process it. */
18698 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18699 initializer. That function will defer actual emission until
18700 we have a chance to determine linkage. */
18703 /* Enter the scope of D so that access-checking works correctly. */
18708 }
18712 {
18714 tree subst_decl;
18715 tree tmpl_parm;
18716 tree spec_parm;
18718 /* Save away the current list, in case we are instantiating one
18719 template from within the body of another. */
18722 /* Set up the list of local specializations. */
18725 /* Set up context. */
18728 /* Create substitution entries for the parameters. */
18733 {
18737 }
18739 {
18741 {
18744 }
18745 else
18746 {
18747 /* Register the (value) argument pack as a specialization of
18748 TMPL_PARM, then move on. */
18751 }
18752 }
18755 /* Substitute into the body of the function. */
18760 /* Set the current input_location to the end of the function
18761 so that finish_function knows where we are. */
18764 /* We don't need the local specializations any more. */
18768 /* Finish the function. */
18771 }
18773 /* We're not deferring instantiation any more. */
18779 out:
18787 }
18789 /* Run through the list of templates that we wish we could
18790 instantiate, and instantiate any we can. RETRIES is the
18791 number of times we retry pending template instantiation. */
18793 void
18795 {
18799 /* Instantiating templates may trigger vtable generation. This in turn
18800 may require further template instantiations. We place a limit here
18801 to avoid infinite loop. */
18803 {
18807 " instantiating %q+D, possibly from virtual table generation"
18811 /* Pretend that we defined it. */
18814 }
18816 do
18817 {
18822 {
18827 {
18828 tree fn;
18831 {
18835 fn;
18843 }
18846 }
18847 else
18848 {
18851 {
18852 instantiation
18858 }
18862 }
18865 /* If INSTANTIATION has been instantiated, then we don't
18866 need to consider it again in the future. */
18868 else
18869 {
18872 }
18875 }
18877 }
18881 }
18883 /* Substitute ARGVEC into T, which is a list of initializers for
18884 either base class or a non-static data member. The TREE_PURPOSEs
18885 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18886 instantiate_decl. */
18888 static tree
18890 {
18894 {
18895 tree decl;
18896 tree init;
18902 {
18903 tree expr;
18904 tree arg;
18906 /* Expand the base class expansion type into separate base
18907 classes. */
18909 tf_warning_or_error,
18910 NULL_TREE);
18914 /* We'll be building separate TREE_LISTs of arguments for
18915 each base. */
18921 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18922 expand each argument in the TREE_VALUE of t. */
18929 /* VOID_TYPE_NODE is used to indicate
18930 value-initialization. */
18931 {
18934 }
18935 else
18936 {
18937 /* Substitute parameter packs into each argument in the
18938 TREE_LIST. */
18941 {
18942 tree expanded_exprs;
18944 /* Expand the argument. */
18946 expanded_exprs
18948 tf_warning_or_error,
18949 NULL_TREE);
18953 /* Prepend each of the expanded expressions to the
18954 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18956 {
18961 }
18962 }
18965 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18966 since we built them backwards. */
18968 {
18971 }
18972 }
18973 }
18976 {
18978 {
18982 }
18983 else
18984 {
18985 tree tmp;
19000 /* If we had an initializer but it instantiated to nothing,
19001 value-initialize the object. This will only occur when
19002 the initializer was a pack expansion where the parameter
19003 packs used in that expansion were of length zero. */
19006 }
19009 {
19013 }
19014 }
19015 }
19017 }
19019 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19021 static void
19023 {
19028 else
19030 }
19032 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19033 is the instantiation (which should have been created with
19034 start_enum) and ARGS are the template arguments to use. */
19036 static void
19038 {
19039 tree e;
19045 {
19046 tree value;
19047 tree decl;
19050 /* Note that in a template enum, the TREE_VALUE is the
19051 CONST_DECL, not the corresponding INTEGER_CST. */
19056 /* Give this enumeration constant the correct access. */
19059 /* Actually build the enumerator itself. */
19060 build_enumerator
19062 }
19072 }
19074 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19075 its type -- but without substituting the innermost set of template
19076 arguments. So, innermost set of template parameters will appear in
19077 the type. */
19079 tree
19081 {
19082 tree fn_type;
19083 tree tmpl;
19084 tree targs;
19085 tree tparms;
19093 /* There should be as many levels of arguments as there are levels
19094 of parameters. */
19100 /* No substitution is necessary. */
19101 ;
19102 else
19103 {
19105 tree partial_args;
19107 /* Replace the innermost level of the TARGS with NULL_TREEs to
19108 let tsubst know not to substitute for those parameters. */
19117 /* Make sure that we can see identifiers, and compute access
19118 correctly. */
19122 /* Now, do the (partial) substitution to figure out the
19123 appropriate function type. */
19127 /* Substitute into the template parameters to obtain the real
19128 innermost set of parameters. This step is important if the
19129 innermost set of template parameters contains value
19130 parameters whose types depend on outer template parameters. */
19135 }
19138 }
19140 /* Return truthvalue if we're processing a template different from
19141 the last one involved in diagnostics. */
19142 int
19144 {
19146 }
19148 /* Remember current template involved in diagnostics. */
19149 void
19151 {
19153 }
19157 {
19159 }
19161 /* [temp.param] Check that template non-type parm TYPE is of an allowable
19162 type. Return zero for ok, nonzero for disallowed. Issue error and
19163 warning messages under control of COMPLAIN. */
19165 static int
19167 {
19184 {
19187 else
19189 type);
19190 }
19192 }
19194 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19195 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19197 static bool
19199 {
19200 tree scope;
19202 /* [temp.dep.type]
19204 A type is dependent if it is:
19206 -- a template parameter. Template template parameters are types
19207 for us (since TYPE_P holds true for them) so we handle
19208 them here. */
19212 /* -- a qualified-id with a nested-name-specifier which contains a
19213 class-name that names a dependent type or whose unqualified-id
19214 names a dependent type. */
19217 /* -- a cv-qualified type where the cv-unqualified type is
19218 dependent. */
19220 /* -- a compound type constructed from any dependent type. */
19230 {
19231 tree arg_type;
19236 arg_type;
19241 }
19242 /* -- an array type constructed from any dependent type or whose
19243 size is specified by a constant expression that is
19244 value-dependent.
19246 We checked for type- and value-dependence of the bounds in
19247 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19249 {
19254 }
19256 /* -- a template-id in which either the template name is a template
19257 parameter ... */
19260 /* ... or any of the template arguments is a dependent type or
19261 an expression that is type-dependent or value-dependent. */
19263 && (any_dependent_template_arguments_p
19267 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19268 dependent; if the argument of the `typeof' expression is not
19269 type-dependent, then it should already been have resolved. */
19275 /* A template argument pack is dependent if any of its packed
19276 arguments are. */
19278 {
19284 }
19286 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19287 be template parameters. */
19291 /* The standard does not specifically mention types that are local
19292 to template functions or local classes, but they should be
19293 considered dependent too. For example:
19295 template <int I> void f() {
19296 enum E { a = I };
19297 S<sizeof (E)> s;
19298 }
19300 The size of `E' cannot be known until the value of `I' has been
19301 determined. Therefore, `E' must be considered dependent. */
19305 /* Don't use type_dependent_expression_p here, as it can lead
19306 to infinite recursion trying to determine whether a lambda
19307 nested in a lambda is dependent (c++/47687). */
19311 && (any_dependent_template_arguments_p
19315 /* Other types are non-dependent. */
19317 }
19319 /* Returns TRUE if TYPE is dependent, in the sense of
19320 [temp.dep.type]. Note that a NULL type is considered dependent. */
19322 bool
19324 {
19325 /* If there are no template parameters in scope, then there can't be
19326 any dependent types. */
19328 {
19329 /* If we are not processing a template, then nobody should be
19330 providing us with a dependent type. */
19334 }
19336 /* If the type is NULL, we have not computed a type for the entity
19337 in question; in that case, the type is dependent. */
19341 /* Erroneous types can be considered non-dependent. */
19345 /* If we have not already computed the appropriate value for TYPE,
19346 do so now. */
19348 {
19351 }
19354 }
19356 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19357 lookup. In other words, a dependent type that is not the current
19358 instantiation. */
19360 bool
19362 {
19365 }
19367 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19368 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19369 expression. */
19371 /* Note that this predicate is not appropriate for general expressions;
19372 only constant expressions (that satisfy potential_constant_expression)
19373 can be tested for value dependence.
19375 We should really also have a predicate for "instantiation-dependent".
19377 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19378 (what about instantiation-dependent constant-expressions?)
19379 is_late_template_attribute: defer if instantiation-dependent.
19380 compute_array_index_type: proceed if constant and not t- or v-dependent
19381 if instantiation-dependent, need to remember full expression
19382 uses_template_parms: FIXME - need to audit callers
19383 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19384 dependent_type_p [array_type]: dependent if index type is dependent
19385 (or non-constant?)
19386 static_assert - instantiation-dependent */
19388 bool
19390 {
19394 /* A name declared with a dependent type. */
19399 {
19401 /* A name that has not been looked up -- must be dependent. */
19405 /* A non-type template parm. */
19409 /* A non-type template parm. */
19415 /* A constant with literal type and is initialized
19416 with an expression that is value-dependent. */
19428 /* These expressions are value-dependent if the type to which
19429 the cast occurs is dependent or the expression being casted
19430 is value-dependent. */
19431 {
19437 /* A functional cast has a list of operands. */
19440 {
19441 /* If there are no operands, it must be an expression such
19442 as "int()". This should not happen for aggregate types
19443 because it would form non-constant expressions. */
19448 }
19454 }
19459 /* A `sizeof' expression is value-dependent if the operand is
19460 type-dependent or is a pack expansion. */
19469 /* An 'encode' expression is value-dependent if the operand is
19470 type-dependent. */
19479 {
19482 }
19489 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19490 is value-dependent. */
19491 {
19500 }
19503 {
19507 }
19518 {
19522 }
19525 {
19532 {
19534 /* In a call to a constexpr member function, look through the
19535 implicit ADDR_EXPR on the object argument so that it doesn't
19536 cause the call to be considered value-dependent. We also
19537 look through it in potential_constant_expression. */
19544 }
19546 }
19549 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19550 type-dependent. */
19554 {
19556 tree val;
19561 }
19564 /* Treat a GNU statement expression as dependent to avoid crashing
19565 under fold_non_dependent_expr; it can't be constant. */
19569 /* A constant expression is value-dependent if any subexpression is
19570 value-dependent. */
19572 {
19579 {
19583 {
19586 /* In some cases, some of the operands may be missing.l
19587 (For example, in the case of PREDECREMENT_EXPR, the
19588 amount to increment by may be missing.) That doesn't
19589 make the expression dependent. */
19592 }
19593 }
19597 }
19599 }
19601 /* The expression is not value-dependent. */
19603 }
19605 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19606 [temp.dep.expr]. Note that an expression with no type is
19607 considered dependent. Other parts of the compiler arrange for an
19608 expression with type-dependent subexpressions to have no type, so
19609 this function doesn't have to be fully recursive. */
19611 bool
19613 {
19620 /* An unresolved name is always dependent. */
19625 /* Some expression forms are never type-dependent. */
19638 /* The types of these expressions depends only on the type to which
19639 the cast occurs. */
19648 /* The types of these expressions depends only on the type created
19649 by the expression. */
19652 {
19653 /* For NEW_EXPR tree nodes created inside a template, either
19654 the object type itself or a TREE_LIST may appear as the
19655 operand 1. */
19658 /* This is an array type. We need to check array dimensions
19659 as well. */
19661 || value_dependent_expression_p
19663 else
19665 }
19668 {
19672 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19673 contains an identifier associated by name lookup with one or more
19674 declarations declared with a dependent type, or...a
19675 nested-name-specifier or qualified-id that names a member of an
19676 unknown specialization. */
19679 }
19684 && (any_dependent_template_arguments_p
19696 {
19697 tree elt;
19701 {
19704 }
19706 }
19708 /* A static data member of the current instantiation with incomplete
19709 array type is type-dependent, as the definition and specializations
19710 can have different bounds. */
19718 {
19723 {
19729 }
19730 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19738 {
19743 }
19748 {
19752 }
19754 }
19759 }
19761 /* Like type_dependent_expression_p, but it also works while not processing
19762 a template definition, i.e. during substitution or mangling. */
19764 bool
19766 {
19772 }
19774 /* Returns TRUE if ARGS contains a type-dependent expression. */
19776 bool
19778 {
19780 tree arg;
19783 {
19786 }
19788 }
19790 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19791 expressions) contains any type-dependent expressions. */
19793 bool
19795 {
19801 }
19803 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19804 expressions) contains any value-dependent expressions. */
19806 bool
19808 {
19814 }
19816 /* Returns TRUE if the ARG (a template argument) is dependent. */
19818 bool
19820 {
19824 /* Assume a template argument that was wrongly written by the user
19825 is dependent. This is consistent with what
19826 any_dependent_template_arguments_p [that calls this function]
19827 does. */
19838 {
19842 {
19845 }
19848 }
19851 else
19854 }
19856 /* Returns true if ARGS (a collection of template arguments) contains
19857 any types that require structural equality testing. */
19859 bool
19861 {
19871 {
19874 {
19880 {
19881 /* Look inside the argument pack. */
19884 }
19887 {
19901 }
19902 }
19903 }
19906 }
19908 /* Returns true if ARGS (a collection of template arguments) contains
19909 any dependent arguments. */
19911 bool
19913 {
19923 {
19928 }
19931 }
19933 /* Returns TRUE if the template TMPL is dependent. */
19935 bool
19937 {
19939 {
19941 {
19945 }
19947 }
19949 /* Template template parameters are dependent. */
19953 /* So are names that have not been looked up. */
19957 /* So are member templates of dependent classes. */
19961 }
19963 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19965 bool
19967 {
19970 }
19972 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19973 is dependent. */
19975 bool
19977 {
19984 {
20005 {
20009 }
20013 {
20017 {
20022 }
20023 }
20024 }
20027 }
20029 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
20030 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
20031 no such TYPE can be found. Note that this function peers inside
20032 uninstantiated templates and therefore should be used only in
20033 extremely limited situations. ONLY_CURRENT_P restricts this
20034 peering to the currently open classes hierarchy (which is required
20035 when comparing types). */
20037 tree
20039 {
20040 tree scope;
20041 tree name;
20042 tree decl;
20044 tree pushed_scope;
20045 tree result;
20050 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
20051 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
20052 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
20053 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
20054 identifier of the TYPENAME_TYPE anymore.
20055 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
20056 TYPENAME_TYPE instead, we avoid messing up with a possible
20057 typedef variant case. */
20060 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
20061 it first before we can figure out what NAME refers to. */
20064 /* If we don't know what SCOPE refers to, then we cannot resolve the
20065 TYPENAME_TYPE. */
20068 /* If the SCOPE is a template type parameter, we have no way of
20069 resolving the name. */
20072 /* If the SCOPE is not the current instantiation, there's no reason
20073 to look inside it. */
20076 /* If this is a typedef, we don't want to look inside (c++/11987). */
20079 /* If SCOPE isn't the template itself, it will not have a valid
20080 TYPE_FIELDS list. */
20082 /* scope is either the template itself or a compatible instantiation
20083 like X<T>, so look up the name in the original template. */
20085 else
20086 /* scope is a partial instantiation, so we can't do the lookup or we
20087 will lose the template arguments. */
20089 /* Enter the SCOPE so that name lookup will be resolved as if we
20090 were in the class definition. In particular, SCOPE will no
20091 longer be considered a dependent type. */
20093 /* Look up the declaration. */
20095 tf_warning_or_error);
20099 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
20100 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
20105 {
20109 }
20112 {
20113 tree tmpl;
20114 tree args;
20115 /* Obtain the template and the arguments. */
20118 /* Instantiate the template. */
20124 }
20126 /* Leave the SCOPE. */
20130 /* If we failed to resolve it, return the original typename. */
20134 /* If lookup found a typename type, resolve that too. */
20136 {
20137 /* Ill-formed programs can cause infinite recursion here, so we
20138 must catch that. */
20142 }
20144 /* Qualify the resulting type. */
20150 }
20152 /* EXPR is an expression which is not type-dependent. Return a proxy
20153 for EXPR that can be used to compute the types of larger
20154 expressions containing EXPR. */
20156 tree
20158 {
20159 tree inner_expr;
20161 #ifdef ENABLE_CHECKING
20162 /* Try to get a constant value for all non-type-dependent expressions in
20163 order to expose bugs in *_dependent_expression_p and constexpr. */
20166 #endif
20168 /* Preserve OVERLOADs; the functions must be available to resolve
20169 types. */
20180 /* There is no need to return a proxy for a variable. */
20183 /* Preserve string constants; conversions from string constants to
20184 "char *" are allowed, even though normally a "const char *"
20185 cannot be used to initialize a "char *". */
20188 /* Preserve arithmetic constants, as an optimization -- there is no
20189 reason to create a new node. */
20192 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20193 There is at least one place where we want to know that a
20194 particular expression is a throw-expression: when checking a ?:
20195 expression, there are special rules if the second or third
20196 argument is a throw-expression. */
20200 /* Don't wrap an initializer list, we need to be able to look inside. */
20219 /* If the type is unknown, it can't really be non-dependent */
20222 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20224 }
20226 /* ARGS is a vector of expressions as arguments to a function call.
20227 Replace the arguments with equivalent non-dependent expressions.
20228 This modifies ARGS in place. */
20230 void
20232 {
20234 tree arg;
20237 {
20241 }
20242 }
20244 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20245 with a level one deeper than the actual template parms. */
20247 tree
20249 {
20262 }
20264 /* Given type ARG, return std::initializer_list<ARG>. */
20266 static tree
20268 {
20269 tree std_init_list = namespace_binding
20271 tree argvec;
20273 {
20277 }
20282 }
20284 /* Replace auto in TYPE with std::initializer_list<auto>. */
20286 static tree
20288 {
20295 }
20297 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20298 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20300 tree
20302 {
20313 /* Not enough information to try this yet. */
20316 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20317 with either a new invented type template parameter U or, if the
20318 initializer is a braced-init-list (8.5.4), with
20319 std::initializer_list<U>. */
20335 {
20337 /* Try again at instantiation time. */
20340 /* If type is error_mark_node a diagnostic must have been
20341 emitted by now. Also, having a mention to '<type error>'
20342 in the diagnostic is not really useful to the user. */
20343 {
20347 else
20349 }
20351 }
20353 /* If the list of declarators contains more than one declarator, the type
20354 of each declared variable is determined as described above. If the
20355 type deduced for the template parameter U is not the same in each
20356 deduction, the program is ill-formed. */
20359 {
20365 else
20369 }
20375 }
20377 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20378 result. */
20380 tree
20382 {
20383 tree argvec;
20390 /* For a late-specified return type in a template type-parameter, we
20391 need to add a dummy argument level for its parmlist. */
20392 argvec = add_to_template_args
20397 }
20399 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20401 bool
20403 {
20407 else
20409 }
20411 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20412 appear as a type-specifier for the declaration in question, we don't
20413 have to look through the whole type. */
20415 tree
20417 {
20434 }
20436 /* For a given template T, return the vector of typedefs referenced
20437 in T for which access check is needed at T instantiation time.
20438 T is either a FUNCTION_DECL or a RECORD_TYPE.
20439 Those typedefs were added to T by the function
20440 append_type_to_template_for_access_check. */
20444 {
20445 tree ti;
20456 {
20461 }
20464 }
20466 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20467 tied to T. That list of typedefs will be access checked at
20468 T instantiation time.
20469 T is either a FUNCTION_DECL or a RECORD_TYPE.
20470 TYPE_DECL is a TYPE_DECL node representing a typedef.
20471 SCOPE is the scope through which TYPE_DECL is accessed.
20472 LOCATION is the location of the usage point of TYPE_DECL.
20474 This function is a subroutine of
20475 append_type_to_template_for_access_check. */
20477 static void
20479 tree type_decl,
20480 tree scope,
20481 location_t location)
20482 {
20483 qualified_typedef_usage_t typedef_usage;
20484 tree ti;
20491 && type_decl
20507 }
20509 /* Append TYPE_DECL to the template TEMPL.
20510 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20511 At TEMPL instanciation time, TYPE_DECL will be checked to see
20512 if it can be accessed through SCOPE.
20513 LOCATION is the location of the usage point of TYPE_DECL.
20515 e.g. consider the following code snippet:
20517 class C
20518 {
20519 typedef int myint;
20520 };
20522 template<class U> struct S
20523 {
20524 C::myint mi; // <-- usage point of the typedef C::myint
20525 };
20527 S<char> s;
20529 At S<char> instantiation time, we need to check the access of C::myint
20530 In other words, we need to check the access of the myint typedef through
20531 the C scope. For that purpose, this function will add the myint typedef
20532 and the scope C through which its being accessed to a list of typedefs
20533 tied to the template S. That list will be walked at template instantiation
20534 time and access check performed on each typedefs it contains.
20535 Note that this particular code snippet should yield an error because
20536 myint is private to C. */
20538 void
20540 tree type_decl,
20541 tree scope,
20542 location_t location)
20543 {
20549 /* Make sure we don't append the type to the template twice. */
20558 }
20560 /* Set up the hash tables for template instantiations. */
20562 void
20564 {
20566 hash_specialization,
20567 eq_specializations,
20568 ggc_free);
20570 hash_specialization,
20571 eq_specializations,
20572 ggc_free);
20573 }
20575 /* Print stats about the template hash tables for -fstats. */
20577 void
20579 {
20588 }