| blob | b95fdf728bd0c7ef27d02b64872ef26dd88472ee |
1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
49 /* The type of functions taking a tree, and some additional data, and
50 returning an int. */
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
59 };
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
81 local variables. */
85 {
86 tree tmpl;
87 tree args;
88 tree spec;
92 htab_t decl_specializations;
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
130 tree);
190 location_t);
195 /* Make the current scope suitable for access checking when we are
196 processing T. T can be FUNCTION_DECL for instantiated function
197 template, or VAR_DECL for static member variable (need by
198 instantiate_decl). */
200 static void
202 {
210 else
214 {
215 saved_access_scope = tree_cons
218 }
219 }
221 /* Restore the scope set up by push_access_scope. T is the node we
222 are processing. */
224 static void
226 {
228 {
231 }
235 else
237 }
239 /* Do any processing required when DECL (a member template
240 declaration) is finished. Returns the TEMPLATE_DECL corresponding
241 to DECL, unless it is a specialization, in which case the DECL
242 itself is returned. */
244 tree
246 {
253 {
254 tree type;
262 {
266 }
268 }
272 {
274 {
277 }
278 else
280 }
281 else
285 }
287 /* Create a template info node. */
289 tree
291 {
296 }
298 /* Return the template info node corresponding to T, whatever T is. */
300 tree
302 {
320 }
322 /* Returns the template nesting level of the indicated class TYPE.
324 For example, in:
325 template <class T>
326 struct A
327 {
328 template <class U>
329 struct B {};
330 };
332 A<T>::B<U> has depth two, while A<T> has depth one.
333 Both A<T>::B<int> and A<int>::B<U> have depth one, if
334 they are instantiations, not specializations.
336 This function is guaranteed to return 0 if passed NULL_TREE so
337 that, for example, `template_class_depth (current_class_type)' is
338 always safe. */
340 int
342 {
349 {
355 }
358 }
360 /* Subroutine of maybe_begin_member_template_processing.
361 Returns true if processing DECL needs us to push template parms. */
363 static bool
365 {
371 }
373 /* Subroutine of maybe_begin_member_template_processing.
374 Push the template parms in PARMS, starting from LEVELS steps into the
375 chain, and ending at the beginning, since template parms are listed
376 innermost first. */
378 static void
380 {
388 current_template_parms
394 NULL);
396 {
405 {
412 {
413 /* Make a CONST_DECL as is done in process_template_parm.
414 It is ugly that we recreate this here; the original
415 version built in process_template_parm is no longer
416 available. */
426 }
431 }
432 }
433 }
435 /* Restore the template parameter context for a member template or
436 a friend template defined in a class definition. */
438 void
440 {
441 tree parms;
445 {
450 {
453 }
456 }
458 /* Remember how many levels of template parameters we pushed so that
459 we can pop them later. */
461 }
463 /* Undo the effects of maybe_begin_member_template_processing. */
465 void
467 {
476 {
480 }
481 }
483 /* Return a new template argument vector which contains all of ARGS,
484 but has as its innermost set of arguments the EXTRA_ARGS. */
486 static tree
488 {
489 tree new_args;
507 }
509 /* Like add_to_template_args, but only the outermost ARGS are added to
510 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
511 (EXTRA_ARGS) levels are added. This function is used to combine
512 the template arguments from a partial instantiation with the
513 template arguments used to attain the full instantiation from the
514 partial instantiation. */
516 static tree
518 {
519 tree new_args;
521 /* If there are more levels of EXTRA_ARGS than there are ARGS,
522 something very fishy is going on. */
525 /* If *all* the new arguments will be the EXTRA_ARGS, just return
526 them. */
530 /* For the moment, we make ARGS look like it contains fewer levels. */
535 /* Now, we restore ARGS to its full dimensions. */
539 }
541 /* Return the N levels of innermost template arguments from the ARGS. */
543 tree
545 {
546 tree new_args;
552 /* If N is 1, just return the innermost set of template arguments. */
556 /* If we're not removing anything, just return the arguments we were
557 given. */
563 /* Make a new set of arguments, not containing the outer arguments. */
570 }
572 /* The inverse of get_innermost_template_args: Return all but the innermost
573 EXTRA_LEVELS levels of template arguments from the ARGS. */
575 static tree
577 {
578 tree new_args;
584 /* If N is 1, just return the outermost set of template arguments. */
588 /* If we're not removing anything, just return the arguments we were
589 given. */
594 /* Make a new set of arguments, not containing the inner arguments. */
601 }
603 /* We've got a template header coming up; push to a new level for storing
604 the parms. */
606 void
608 {
609 /* We use a non-tag-transparent scope here, which causes pushtag to
610 put tags in this scope, rather than in the enclosing class or
611 namespace scope. This is the right thing, since we want
612 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
613 global template class, push_template_decl handles putting the
614 TEMPLATE_DECL into top-level scope. For a nested template class,
615 e.g.:
617 template <class T> struct S1 {
618 template <class T> struct S2 {};
619 };
621 pushtag contains special code to call pushdecl_with_scope on the
622 TEMPLATE_DECL for S2. */
627 }
629 /* This routine is called when a specialization is declared. If it is
630 invalid to declare a specialization here, an error is reported and
631 false is returned, otherwise this routine will return true. */
633 static bool
635 {
638 /* [temp.expl.spec]
640 An explicit specialization shall be declared in the namespace of
641 which the template is a member, or, for member templates, in the
642 namespace of which the enclosing class or enclosing class
643 template is a member. An explicit specialization of a member
644 function, member class or static data member of a class template
645 shall be declared in the namespace of which the class template
646 is a member. */
648 {
651 }
653 /* [temp.expl.spec]
655 In an explicit specialization declaration for a member of a class
656 template or a member template that appears in namespace scope,
657 the member template and some of its enclosing class templates may
658 remain unspecialized, except that the declaration shall not
659 explicitly specialize a class member template if its enclosing
660 class templates are not explicitly specialized as well. */
662 {
665 }
668 }
670 /* We've just seen template <>. */
672 bool
674 {
678 }
680 /* Called at then end of processing a declaration preceded by
681 template<>. */
683 void
685 {
688 }
690 /* Any template <>'s that we have seen thus far are not referring to a
691 function specialization. */
693 void
695 {
698 }
700 /* We've just seen a template header. If SPECIALIZATION is nonzero,
701 it was of the form template <>. */
703 static void
705 {
707 template_header_count++;
708 }
710 /* We're beginning an explicit instantiation. */
712 void
714 {
717 }
720 void
722 {
725 }
727 /* An explicit specialization or partial specialization TMPL is being
728 declared. Check that the namespace in which the specialization is
729 occurring is permissible. Returns false iff it is invalid to
730 specialize TMPL in the current namespace. */
732 static bool
734 {
737 /* [tmpl.expl.spec]
739 An explicit specialization shall be declared in the namespace of
740 which the template is a member, or, for member templates, in the
741 namespace of which the enclosing class or enclosing class
742 template is a member. An explicit specialization of a member
743 function, member class or static data member of a class template
744 shall be declared in the namespace of which the class template is
745 a member. */
748 {
751 }
753 /* Same or super-using namespace. */
755 else
756 {
760 }
761 }
763 /* SPEC is an explicit instantiation. Check that it is valid to
764 perform this explicit instantiation in the current namespace. */
766 static void
768 {
769 tree ns;
771 /* DR 275: An explicit instantiation shall appear in an enclosing
772 namespace of its template. */
778 }
780 /* The TYPE is being declared. If it is a template type, that means it
781 is a partial specialization. Do appropriate error-checking. */
783 tree
785 {
786 tree context;
792 {
796 }
801 {
802 /* This is for ordinary explicit specialization and partial
803 specialization of a template class such as:
805 template <> class C<int>;
807 or:
809 template <class T> class C<T*>;
811 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
815 {
819 {
823 }
824 }
827 }
833 {
834 /* This is for an explicit specialization of member class
835 template according to [temp.expl.spec/18]:
837 template <> template <class U> class C<int>::D;
839 The context `C<int>' must be an implicit instantiation.
840 Otherwise this is just a member class template declared
841 earlier like:
843 template <> class C<int> { template <class U> class D; };
844 template <> template <class U> class C<int>::D;
846 In the first case, `C<int>::D' is a specialization of `C<T>::D'
847 while in the second case, `C<int>::D' is a primary template
848 and `C<T>::D' may not exist. */
852 {
853 tree t;
858 {
861 }
863 /* Check for invalid specialization after instantiation:
865 template <> template <> class C<int>::D<int>;
866 template <> template <class U> class C<int>::D; */
870 {
873 {
874 /* We already have a full specialization of this partial
875 instantiation. Reassign it to the new member
876 specialization template. */
877 spec_entry elt;
893 }
895 /* But if we've had an implicit instantiation, that's a
896 problem ([temp.expl.spec]/6). */
899 }
901 /* Mark TYPE as a specialization. And as a result, we only
902 have one level of template argument for the innermost
903 class template. */
907 }
908 }
910 {
913 }
916 }
918 /* Returns nonzero if we can optimize the retrieval of specializations
919 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
920 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
924 {
927 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
928 parameter. */
930 /* The optimized lookup depends on the fact that the
931 template arguments for the member function template apply
932 purely to the containing class, which is not true if the
933 containing class is an explicit or partial
934 specialization. */
938 /* It is possible to have a template that is not a member
939 template and is not a member of a template class:
941 template <typename T>
942 struct S { friend A::f(); };
944 Here, the friend function is a template, but the context does
945 not have template information. The optimized lookup relies
946 on having ARGS be the template arguments for both the class
947 and the function template. */
949 }
951 /* Retrieve the specialization (in the sense of [temp.spec] - a
952 specialization is either an instantiation or an explicit
953 specialization) of TMPL for the given template ARGS. If there is
954 no such specialization, return NULL_TREE. The ARGS are a vector of
955 arguments, or a vector of vectors of arguments, in the case of
956 templates with more than one level of parameters.
958 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
959 then we search for a partial specialization matching ARGS. This
960 parameter is ignored if TMPL is not a class template. */
962 static tree
964 {
970 /* There should be as many levels of arguments as there are
971 levels of parameters. */
976 {
977 tree class_template;
978 tree class_specialization;
980 tree fns;
983 /* The template arguments actually apply to the containing
984 class. Find the class specialization with those
985 arguments. */
987 class_specialization
991 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
992 for the specialization. */
996 /* Iterate through the methods with the indicated name, looking
997 for the one that has an instance of TMPL. */
1000 {
1003 /* using-declarations can add base methods to the method vec,
1004 and we don't want those here. */
1007 }
1009 }
1010 else
1011 {
1013 spec_entry elt;
1014 htab_t specializations;
1022 else
1030 }
1033 }
1035 /* Like retrieve_specialization, but for local declarations. */
1037 static tree
1039 {
1040 tree spec;
1048 }
1050 /* Returns nonzero iff DECL is a specialization of TMPL. */
1052 int
1054 {
1055 tree t;
1058 {
1064 }
1065 else
1066 {
1075 }
1078 }
1080 /* Returns nonzero iff DECL is a specialization of friend declaration
1081 FRIEND_DECL according to [temp.friend]. */
1083 bool
1085 {
1092 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1093 of a template class, we want to check if DECL is a specialization
1094 if this. */
1098 {
1099 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1102 }
1107 /* There is nothing to do if this is not a template friend. */
1114 /* [temp.friend/6]
1115 A member of a class template may be declared to be a friend of a
1116 non-template class. In this case, the corresponding member of
1117 every specialization of the class template is a friend of the
1118 class granting friendship.
1120 For example, given a template friend declaration
1122 template <class T> friend void A<T>::f();
1124 the member function below is considered a friend
1126 template <> struct A<int> {
1127 void f();
1128 };
1130 For this type of template friend, TEMPLATE_DEPTH below will be
1131 nonzero. To determine if DECL is a friend of FRIEND, we first
1132 check if the enclosing class is a specialization of another. */
1139 {
1140 /* Next, we check the members themselves. In order to handle
1141 a few tricky cases, such as when FRIEND_DECL's are
1143 template <class T> friend void A<T>::g(T t);
1144 template <class T> template <T t> friend void A<T>::h();
1146 and DECL's are
1148 void A<int>::g(int);
1149 template <int> void A<int>::h();
1151 we need to figure out ARGS, the template arguments from
1152 the context of DECL. This is required for template substitution
1153 of `T' in the function parameter of `g' and template parameter
1154 of `h' in the above examples. Here ARGS corresponds to `int'. */
1161 {
1163 {
1166 else
1168 current_depth++;
1169 }
1171 }
1174 {
1176 tree friend_type;
1177 tree decl_type;
1178 tree friend_args_type;
1179 tree decl_args_type;
1181 /* Make sure that both DECL and FRIEND_DECL are templates or
1182 non-templates. */
1188 {
1189 /* If both are templates, check template parameter list. */
1190 tree friend_parms
1195 friend_parms))
1199 }
1200 else
1208 /* Check if return types match. */
1212 /* Check if function parameter types match, ignoring the
1213 `this' parameter. */
1222 }
1223 else
1224 {
1225 /* DECL is a TYPE_DECL */
1229 /* Make sure that both DECL and FRIEND_DECL are templates or
1230 non-templates. */
1231 is_template
1238 {
1239 tree friend_parms;
1240 /* If both are templates, check the name of the two
1241 TEMPLATE_DECL's first because is_friend didn't. */
1246 /* Now check template parameter list. */
1247 friend_parms
1250 return comp_template_parms
1252 friend_parms);
1253 }
1254 else
1257 }
1258 }
1260 }
1262 /* Register the specialization SPEC as a specialization of TMPL with
1263 the indicated ARGS. IS_FRIEND indicates whether the specialization
1264 is actually just a friend declaration. Returns SPEC, or an
1265 equivalent prior declaration, if available. */
1267 static tree
1269 hashval_t hash)
1270 {
1271 tree fn;
1273 spec_entry elt;
1279 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1280 register it; we want the corresponding TEMPLATE_DECL instead.
1281 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1282 the more obvious `uses_template_parms (spec)' to avoid problems
1283 with default function arguments. In particular, given
1284 something like this:
1286 template <class T> void f(T t1, T t = T())
1288 the default argument expression is not substituted for in an
1289 instantiation unless and until it is actually needed. */
1293 /* We don't put these specializations in the hash table, but we might
1294 want to give an error about a mismatch. */
1296 else
1297 {
1309 else
1311 }
1313 /* We can sometimes try to re-register a specialization that we've
1314 already got. In particular, regenerate_decl_from_template calls
1315 duplicate_decls which will update the specialization list. But,
1316 we'll still get called again here anyhow. It's more convenient
1317 to simply allow this than to try to prevent it. */
1321 {
1323 {
1326 {
1328 fn);
1330 }
1331 else
1332 {
1333 tree clone;
1334 /* This situation should occur only if the first
1335 specialization is an implicit instantiation, the
1336 second is an explicit specialization, and the
1337 implicit instantiation has not yet been used. That
1338 situation can occur if we have implicitly
1339 instantiated a member function and then specialized
1340 it later.
1342 We can also wind up here if a friend declaration that
1343 looked like an instantiation turns out to be a
1344 specialization:
1346 template <class T> void foo(T);
1347 class S { friend void foo<>(int) };
1348 template <> void foo(int);
1350 We transform the existing DECL in place so that any
1351 pointers to it become pointers to the updated
1352 declaration.
1354 If there was a definition for the template, but not
1355 for the specialization, we want this to look as if
1356 there were no definition, and vice versa. */
1359 /* The call to duplicate_decls will have applied
1360 [temp.expl.spec]:
1362 An explicit specialization of a function template
1363 is inline only if it is explicitly declared to be,
1364 and independently of whether its function template
1365 is.
1367 to the primary function; now copy the inline bits to
1368 the various clones. */
1370 {
1375 }
1379 }
1380 }
1382 {
1384 /* Dup decl failed, but this is a new definition. Set the
1385 line number so any errors match this new
1386 definition. */
1390 }
1391 }
1395 /* A specialization must be declared in the same namespace as the
1396 template it is specializing. */
1402 {
1409 /* TMPL is a forward declaration of a template function; keep a list
1410 of all specializations in case we need to reassign them to a friend
1411 template later in tsubst_friend_function. */
1414 }
1417 }
1419 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1420 TMPL and ARGS members, ignores SPEC. */
1422 static int
1424 {
1430 }
1432 /* Returns a hash for a template TMPL and template arguments ARGS. */
1434 static hashval_t
1436 {
1439 }
1441 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1442 ignoring SPEC. */
1444 static hashval_t
1446 {
1449 }
1451 /* Recursively calculate a hash value for a template argument ARG, for use
1452 in the hash tables of template specializations. */
1454 static hashval_t
1456 {
1468 /* We can get one of these when re-hashing a previous entry in the middle
1469 of substituting into a pack expansion. Just look through it. */
1478 {
1486 {
1491 }
1512 {
1515 {
1518 }
1520 }
1535 val = iterative_hash_template_arg
1547 val);
1549 val);
1558 /* layout_type sets structural equality for arrays of
1559 incomplete type, so we can't rely on the canonical type
1560 for hashing. */
1565 /* A lambda can't appear in a template arg, but don't crash on
1566 erroneous input. */
1572 {
1576 val);
1579 /* Otherwise just compare the types during lookup. */
1588 {
1593 }
1594 }
1595 }
1598 }
1600 /* Unregister the specialization SPEC as a specialization of TMPL.
1601 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1602 if the SPEC was listed as a specialization of TMPL.
1604 Note that SPEC has been ggc_freed, so we can't look inside it. */
1606 bool
1608 {
1610 spec_entry elt;
1618 {
1623 }
1626 }
1628 /* Compare an entry in the local specializations hash table P1 (which
1629 is really a pointer to a TREE_LIST) with P2 (which is really a
1630 DECL). */
1632 static int
1634 {
1636 }
1638 /* Hash P1, an entry in the local specializations table. */
1640 static hashval_t
1642 {
1644 }
1646 /* Like register_specialization, but for local declarations. We are
1647 registering SPEC, an instantiation of TMPL. */
1649 static void
1651 {
1657 }
1659 /* TYPE is a class type. Returns true if TYPE is an explicitly
1660 specialized class. */
1662 bool
1664 {
1668 }
1670 /* Print the list of functions at FNS, going through all the overloads
1671 for each element of the list. Alternatively, FNS can not be a
1672 TREE_LIST, in which case it will be printed together with all the
1673 overloads.
1675 MORE and *STR should respectively be FALSE and NULL when the function
1676 is called from the outside. They are used internally on recursive
1677 calls. print_candidates manages the two parameters and leaves NULL
1678 in *STR when it ends. */
1680 static void
1682 {
1688 {
1693 }
1694 else
1695 {
1697 {
1698 /* Pick the prefix string. */
1700 {
1703 }
1707 }
1710 }
1713 {
1716 }
1717 }
1719 /* Print the list of candidate FNS in an error message. */
1721 void
1723 {
1727 }
1729 /* Returns the template (one of the functions given by TEMPLATE_ID)
1730 which can be specialized to match the indicated DECL with the
1731 explicit template args given in TEMPLATE_ID. The DECL may be
1732 NULL_TREE if none is available. In that case, the functions in
1733 TEMPLATE_ID are non-members.
1735 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1736 specialization of a member template.
1738 The TEMPLATE_COUNT is the number of references to qualifying
1739 template classes that appeared in the name of the function. See
1740 check_explicit_specialization for a more accurate description.
1742 TSK indicates what kind of template declaration (if any) is being
1743 declared. TSK_TEMPLATE indicates that the declaration given by
1744 DECL, though a FUNCTION_DECL, has template parameters, and is
1745 therefore a template function.
1747 The template args (those explicitly specified and those deduced)
1748 are output in a newly created vector *TARGS_OUT.
1750 If it is impossible to determine the result, an error message is
1751 issued. The error_mark_node is returned to indicate failure. */
1753 static tree
1755 tree decl,
1759 tmpl_spec_kind tsk)
1760 {
1761 tree fns;
1762 tree targs;
1763 tree explicit_targs;
1765 /* A TREE_LIST of templates of which DECL may be a specialization.
1766 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1767 corresponding TREE_PURPOSE is the set of template arguments that,
1768 when used to instantiate the template, would produce a function
1769 with the signature of DECL. */
1785 /* Check for baselinks. */
1790 {
1793 }
1795 /* Count the number of template headers specified for this
1796 specialization. */
1804 {
1808 {
1809 tree decl_arg_types;
1810 tree fn_arg_types;
1812 /* In case of explicit specialization, we need to check if
1813 the number of template headers appearing in the specialization
1814 is correct. This is usually done in check_explicit_specialization,
1815 but the check done there cannot be exhaustive when specializing
1816 member functions. Consider the following code:
1818 template <> void A<int>::f(int);
1819 template <> template <> void A<int>::f(int);
1821 Assuming that A<int> is not itself an explicit specialization
1822 already, the first line specializes "f" which is a non-template
1823 member function, whilst the second line specializes "f" which
1824 is a template member function. So both lines are syntactically
1825 correct, and check_explicit_specialization does not reject
1826 them.
1828 Here, we can do better, as we are matching the specialization
1829 against the declarations. We count the number of template
1830 headers, and we check if they match TEMPLATE_COUNT + 1
1831 (TEMPLATE_COUNT is the number of qualifying template classes,
1832 plus there must be another header for the member template
1833 itself).
1835 Notice that if header_count is zero, this is not a
1836 specialization but rather a template instantiation, so there
1837 is no check we can perform here. */
1841 /* Check that the number of template arguments at the
1842 innermost level for DECL is the same as for FN. */
1850 /* DECL might be a specialization of FN. */
1854 /* For a non-static member function, we need to make sure
1855 that the const qualification is the same. Since
1856 get_bindings does not try to merge the "this" parameter,
1857 we must do the comparison explicitly. */
1863 /* Skip the "this" parameter and, for constructors of
1864 classes with virtual bases, the VTT parameter. A
1865 full specialization of a constructor will have a VTT
1866 parameter, but a template never will. */
1867 decl_arg_types
1869 fn_arg_types
1872 /* Check that the number of function parameters matches.
1873 For example,
1874 template <class T> void f(int i = 0);
1875 template <> void f<int>();
1876 The specialization f<int> is invalid but is not caught
1877 by get_bindings below. */
1881 /* Function templates cannot be specializations; there are
1882 no partial specializations of functions. Therefore, if
1883 the type of DECL does not match FN, there is no
1884 match. */
1886 {
1890 }
1892 /* See whether this function might be a specialization of this
1893 template. */
1897 /* We cannot deduce template arguments that when used to
1898 specialize TMPL will produce DECL. */
1901 /* Save this template, and the arguments deduced. */
1903 }
1905 /* FN is an ordinary member function, and we need a
1906 specialization of a member template. */
1907 ;
1909 /* We can get IDENTIFIER_NODEs here in certain erroneous
1910 cases. */
1911 ;
1913 /* This is just an ordinary non-member function. Nothing can
1914 be a specialization of that. */
1915 ;
1917 /* Cannot specialize functions that are created implicitly. */
1918 ;
1919 else
1920 {
1921 tree decl_arg_types;
1923 /* This is an ordinary member function. However, since
1924 we're here, we can assume it's enclosing class is a
1925 template class. For example,
1927 template <typename T> struct S { void f(); };
1928 template <> void S<int>::f() {}
1930 Here, S<int>::f is a non-template, but S<int> is a
1931 template class. If FN has the same type as DECL, we
1932 might be in business. */
1935 /* Its enclosing class is an explicit specialization
1936 of a template class. This is not a candidate. */
1941 /* The return types differ. */
1944 /* Adjust the type of DECL in case FN is a static member. */
1951 decl_arg_types))
1952 /* They match! */
1954 }
1955 }
1958 {
1959 /* We have:
1961 [temp.expl.spec]
1963 It is possible for a specialization with a given function
1964 signature to be instantiated from more than one function
1965 template. In such cases, explicit specification of the
1966 template arguments must be used to uniquely identify the
1967 function template specialization being specialized.
1969 Note that here, there's no suggestion that we're supposed to
1970 determine which of the candidate templates is most
1971 specialized. However, we, also have:
1973 [temp.func.order]
1975 Partial ordering of overloaded function template
1976 declarations is used in the following contexts to select
1977 the function template to which a function template
1978 specialization refers:
1980 -- when an explicit specialization refers to a function
1981 template.
1983 So, we do use the partial ordering rules, at least for now.
1984 This extension can only serve to make invalid programs valid,
1985 so it's safe. And, there is strong anecdotal evidence that
1986 the committee intended the partial ordering rules to apply;
1987 the EDG front end has that behavior, and John Spicer claims
1988 that the committee simply forgot to delete the wording in
1989 [temp.expl.spec]. */
1992 {
1995 }
1996 }
1999 {
2007 }
2011 {
2017 }
2019 /* We have one, and exactly one, match. */
2021 {
2024 /* DECL is a re-declaration or partial instantiation of a template
2025 function. */
2028 /* It was a specialization of an ordinary member function in a
2029 template class. */
2031 }
2033 /* It was a specialization of a template. */
2036 {
2041 }
2042 else
2045 }
2047 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2048 but with the default argument values filled in from those in the
2049 TMPL_TYPES. */
2051 static tree
2053 tree tmpl_types)
2054 {
2055 tree new_spec_types;
2063 /* Substitute into the rest of the list. */
2064 new_spec_types =
2068 /* Add the default argument for this parameter. */
2071 new_spec_types);
2072 }
2074 /* DECL is an explicit specialization. Replicate default arguments
2075 from the template it specializes. (That way, code like:
2077 template <class T> void f(T = 3);
2078 template <> void f(double);
2079 void g () { f (); }
2081 works, as required.) An alternative approach would be to look up
2082 the correct default arguments at the call-site, but this approach
2083 is consistent with how implicit instantiations are handled. */
2085 static void
2087 {
2088 tree tmpl;
2089 tree spec_types;
2090 tree tmpl_types;
2091 tree new_spec_types;
2092 tree old_type;
2093 tree new_type;
2094 tree t;
2099 /* See if there's anything we need to do. */
2112 {
2113 /* Remove the this pointer, but remember the object's type for
2114 CV quals. */
2120 {
2121 /* DECL may contain more parameters than TMPL due to the extra
2122 in-charge parameter in constructors and destructors. */
2125 }
2127 {
2130 }
2131 }
2133 /* Compute the merged default arguments. */
2134 new_spec_types =
2137 /* Compute the new FUNCTION_TYPE. */
2139 {
2143 new_spec_types);
2146 /* Put the in-charge parameter back. */
2149 new_spec_types);
2153 new_spec_types);
2154 }
2155 else
2157 new_spec_types);
2163 }
2165 /* Check to see if the function just declared, as indicated in
2166 DECLARATOR, and in DECL, is a specialization of a function
2167 template. We may also discover that the declaration is an explicit
2168 instantiation at this point.
2170 Returns DECL, or an equivalent declaration that should be used
2171 instead if all goes well. Issues an error message if something is
2172 amiss. Returns error_mark_node if the error is not easily
2173 recoverable.
2175 FLAGS is a bitmask consisting of the following flags:
2177 2: The function has a definition.
2178 4: The function is a friend.
2180 The TEMPLATE_COUNT is the number of references to qualifying
2181 template classes that appeared in the name of the function. For
2182 example, in
2184 template <class T> struct S { void f(); };
2185 void S<int>::f();
2187 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2188 classes are not counted in the TEMPLATE_COUNT, so that in
2190 template <class T> struct S {};
2191 template <> struct S<int> { void f(); }
2192 template <> void S<int>::f();
2194 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2195 invalid; there should be no template <>.)
2197 If the function is a specialization, it is marked as such via
2198 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2199 is set up correctly, and it is added to the list of specializations
2200 for that template. */
2202 tree
2204 tree decl,
2207 {
2215 tmpl_spec_kind tsk;
2218 {
2221 else
2223 }
2224 else
2228 {
2231 {
2234 }
2236 {
2238 /* This could be something like:
2240 template <class T> void f(T);
2241 class S { friend void f<>(int); } */
2243 else
2244 {
2245 /* This case handles bogus declarations like template <>
2246 template <class T> void f<int>(); */
2249 declarator);
2251 }
2252 }
2256 /* The error has already been reported in
2257 check_specialization_scope. */
2263 /* Fall through. */
2276 decl);
2279 else
2283 /* Fall through. */
2288 else
2294 {
2295 /* This case handles bogus declarations like template <>
2296 template <class T> void f<int>(); */
2301 else
2303 declarator);
2305 }
2308 /* This is a specialization of a member template, without
2309 specialization the containing class. Something like:
2311 template <class T> struct S {
2312 template <class U> void f (U);
2313 };
2314 template <> template <class U> void S<int>::f(U) {}
2316 That's a specialization -- but of the entire template. */
2322 }
2325 {
2329 {
2333 }
2334 }
2337 {
2341 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2343 {
2344 tree fns;
2349 else
2350 {
2351 /* If there is no class context, the explicit instantiation
2352 must be at namespace scope. */
2355 /* Find the namespace binding, using the declaration
2356 context. */
2360 {
2363 }
2364 else
2365 {
2371 }
2372 }
2375 }
2381 {
2383 /* A specialization in class scope. This is invalid,
2384 but the error will already have been flagged by
2385 check_specialization_scope. */
2387 else
2388 {
2389 /* It's not valid to write an explicit instantiation in
2390 class scope, e.g.:
2392 class C { template void f(); }
2394 This case is caught by the parser. However, on
2395 something like:
2397 template class C { void f(); };
2399 (which is invalid) we can get here. The error will be
2400 issued later. */
2401 ;
2402 }
2405 }
2408 IDENTIFIER_NODE))
2409 {
2410 /* Find the list of functions in ctype that have the same
2411 name as the declared function. */
2417 {
2422 {
2423 /* From [temp.expl.spec]:
2425 If such an explicit specialization for the member
2426 of a class template names an implicitly-declared
2427 special member function (clause _special_), the
2428 program is ill-formed.
2430 Similar language is found in [temp.explicit]. */
2433 }
2436 }
2439 {
2443 }
2444 else
2445 {
2447 tree ovl;
2449 /* For a type-conversion operator, we cannot do a
2450 name-based lookup. We might be looking for `operator
2451 int' which will be a specialization of `operator T'.
2452 So, we find *all* the conversion operators, and then
2453 select from them. */
2461 {
2463 /* There are no more conversion functions. */
2466 /* Glue all these conversion functions together
2467 with those we already have. */
2470 }
2471 }
2474 {
2477 }
2478 else
2480 }
2482 /* Figure out what exactly is being specialized at this point.
2483 Note that for an explicit instantiation, even one for a
2484 member function, we cannot tell apriori whether the
2485 instantiation is for a member template, or just a member
2486 function of a template class. Even if a member template is
2487 being instantiated, the member template arguments may be
2488 elided if they can be deduced from the rest of the
2489 declaration. */
2492 member_specialization,
2493 template_count,
2494 tsk);
2497 /* We couldn't figure out what this declaration was
2498 specializing. */
2500 else
2501 {
2505 {
2506 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2507 is done by do_decl_instantiation later. */
2513 {
2514 /* If TMPL is not the most general template (for
2515 example, if TMPL is a friend template that is
2516 injected into namespace scope), then there will
2517 be too many levels of TARGS. Remove some of them
2518 here. */
2520 tree new_targs;
2527 }
2530 }
2532 /* If we thought that the DECL was a member function, but it
2533 turns out to be specializing a static member function,
2534 make DECL a static member function as well. */
2539 /* If this is a specialization of a member template of a
2540 template class, we want to return the TEMPLATE_DECL, not
2541 the specialization of it. */
2543 {
2548 {
2549 tree parm;
2553 /* We want to use the argument list specified in the
2554 definition, not in the original declaration. */
2559 }
2562 }
2564 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2567 /* Inherit default function arguments from the template
2568 DECL is specializing. */
2571 /* This specialization has the same protection as the
2572 template it specializes. */
2576 /* 7.1.1-1 [dcl.stc]
2578 A storage-class-specifier shall not be specified in an
2579 explicit specialization...
2581 The parser rejects these, so unless action is taken here,
2582 explicit function specializations will always appear with
2583 global linkage.
2585 The action recommended by the C++ CWG in response to C++
2586 defect report 605 is to make the storage class and linkage
2587 of the explicit specialization match the templated function:
2589 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2590 */
2592 {
2596 /* This specialization has the same linkage and visibility as
2597 the function template it specializes. */
2600 {
2603 }
2606 {
2609 }
2610 }
2612 /* If DECL is a friend declaration, declared using an
2613 unqualified name, the namespace associated with DECL may
2614 have been set incorrectly. For example, in:
2616 template <typename T> void f(T);
2617 namespace N {
2618 struct S { friend void f<int>(int); }
2619 }
2621 we will have set the DECL_CONTEXT for the friend
2622 declaration to N, rather than to the global namespace. */
2627 /* This is not really a declaration of a specialization.
2628 It's just the name of an instantiation. But, it's not
2629 a request for an instantiation, either. */
2632 /* This is indeed a specialization. In case of constructors
2633 and destructors, we need in-charge and not-in-charge
2634 versions in V3 ABI. */
2637 /* Register this specialization so that we can find it
2638 again. */
2640 }
2641 }
2644 }
2646 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2647 parameters. These are represented in the same format used for
2648 DECL_TEMPLATE_PARMS. */
2650 int
2652 {
2653 const_tree p1;
2654 const_tree p2;
2662 {
2674 {
2678 /* If either of the template parameters are invalid, assume
2679 they match for the sake of error recovery. */
2692 }
2693 }
2696 /* One set of parameters has more parameters lists than the
2697 other. */
2701 }
2703 /* Determine whether PARM is a parameter pack. */
2705 bool
2707 {
2708 /* Determine if we have a non-type template parameter pack. */
2713 /* If this is a list of template parameters, we could get a
2714 TYPE_DECL or a TEMPLATE_DECL. */
2721 }
2723 /* Determine if T is a function parameter pack. */
2725 bool
2727 {
2731 }
2733 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2734 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2736 tree
2738 {
2745 }
2747 /* Return true iff the function parameter PARAM_DECL was expanded
2748 from the function parameter pack PACK. */
2750 bool
2752 {
2757 /* The parameter pack and its pack arguments have the same
2758 DECL_PARM_INDEX. */
2760 }
2762 /* Determine whether ARGS describes a variadic template args list,
2763 i.e., one that is terminated by a template argument pack. */
2765 static bool
2767 {
2769 tree last_parm;
2783 }
2785 /* Generate a new name for the parameter pack name NAME (an
2786 IDENTIFIER_NODE) that incorporates its */
2788 static tree
2790 {
2791 /* Munge the name to include the parameter index. */
2792 #define NUMBUF_LEN 128
2804 }
2806 /* Return true if T is a primary function
2807 or class template instantiation. */
2809 bool
2811 {
2823 }
2825 /* Return true if PARM is a template template parameter. */
2827 bool
2829 {
2831 }
2833 /* Return the template parameters of T if T is a
2834 primary template instantiation, NULL otherwise. */
2836 tree
2838 {
2843 parms = INNERMOST_TEMPLATE_PARMS
2847 }
2849 /* Return the template parameters of the LEVELth level from the full list
2850 of template parameters PARMS. */
2852 tree
2854 {
2855 tree p;
2866 }
2868 /* Returns the template arguments of T if T is a template instantiation,
2869 NULL otherwise. */
2871 tree
2873 {
2881 }
2883 /* Return the argument pack elements of T if T is a template argument pack,
2884 NULL otherwise. */
2886 tree
2888 {
2894 }
2896 /* Structure used to track the progress of find_parameter_packs_r. */
2897 struct find_parameter_pack_data
2898 {
2899 /* TREE_LIST that will contain all of the parameter packs found by
2900 the traversal. */
2903 /* Set of AST nodes that have been visited by the traversal. */
2905 };
2907 /* Identifies all of the argument packs that occur in a template
2908 argument and appends them to the TREE_LIST inside DATA, which is a
2909 find_parameter_pack_data structure. This is a subroutine of
2910 make_pack_expansion and uses_parameter_packs. */
2911 static tree
2913 {
2919 /* Identify whether this is a parameter pack or not. */
2921 {
2935 {
2936 /* We don't want to walk into the type of a PARM_DECL,
2937 because we don't want to see the type parameter pack. */
2940 }
2944 /* Not a parameter pack. */
2946 }
2949 {
2950 /* Add this parameter pack to the list. */
2952 }
2958 /* This switch statement will return immediately if we don't find a
2959 parameter pack. */
2961 {
2966 /* Check the template itself. */
2969 /* Check the template arguments. */
2985 /* Fall through. */
3026 }
3029 }
3031 /* Determines if the expression or type T uses any parameter packs. */
3032 bool
3034 {
3042 }
3044 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3045 representation a base-class initializer into a parameter pack
3046 expansion. If all goes well, the resulting node will be an
3047 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3048 respectively. */
3049 tree
3051 {
3052 tree result;
3061 {
3062 /* The only time we will see a TREE_LIST here is for a base
3063 class initializer. In this case, the TREE_PURPOSE will be a
3064 _TYPE node (representing the base class expansion we're
3065 initializing) and the TREE_VALUE will be a TREE_LIST
3066 containing the initialization arguments.
3068 The resulting expansion looks somewhat different from most
3069 expansions. Rather than returning just one _EXPANSION, we
3070 return a TREE_LIST whose TREE_PURPOSE is a
3071 TYPE_PACK_EXPANSION containing the bases that will be
3072 initialized. The TREE_VALUE will be identical to the
3073 original TREE_VALUE, which is a list of arguments that will
3074 be passed to each base. We do not introduce any new pack
3075 expansion nodes into the TREE_VALUE (although it is possible
3076 that some already exist), because the TREE_PURPOSE and
3077 TREE_VALUE all need to be expanded together with the same
3078 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3079 resulting TREE_PURPOSE will mention the parameter packs in
3080 both the bases and the arguments to the bases. */
3081 tree purpose;
3082 tree value;
3085 /* Determine which parameter packs will be used by the base
3086 class expansion. */
3093 {
3097 }
3100 {
3101 /* Collect the sets of parameter packs used in each of the
3102 initialization arguments. */
3104 {
3105 /* Determine which parameter packs will be expanded in this
3106 argument. */
3109 }
3110 }
3114 /* Create the pack expansion type for the base type. */
3119 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3120 they will rarely be compared to anything. */
3124 }
3129 /* Build the PACK_EXPANSION_* node. */
3130 result = for_types
3135 {
3136 /* Propagate type and const-expression information. */
3139 }
3140 else
3141 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3142 they will rarely be compared to anything. */
3145 /* Determine which parameter packs will be expanded. */
3151 /* Make sure we found some parameter packs. */
3153 {
3156 else
3159 }
3163 }
3165 /* Checks T for any "bare" parameter packs, which have not yet been
3166 expanded, and issues an error if any are found. This operation can
3167 only be done on full expressions or types (e.g., an expression
3168 statement, "if" condition, etc.), because we could have expressions like:
3170 foo(f(g(h(args)))...)
3172 where "args" is a parameter pack. check_for_bare_parameter_packs
3173 should not be called for the subexpressions args, h(args),
3174 g(h(args)), or f(g(h(args))), because we would produce erroneous
3175 error messages.
3177 Returns TRUE and emits an error if there were bare parameter packs,
3178 returns FALSE otherwise. */
3179 bool
3181 {
3197 {
3200 {
3209 else
3214 else
3218 }
3221 }
3224 }
3226 /* Expand any parameter packs that occur in the template arguments in
3227 ARGS. */
3228 tree
3230 {
3236 /* First, determine if we need to expand anything, and the number of
3237 slots we'll need. */
3239 {
3244 {
3248 else
3250 }
3251 else
3252 {
3254 num_result_args++;
3255 }
3256 }
3258 /* If no expansion is necessary, we're done. */
3262 /* Expand arguments. */
3265 non_default_args_count =
3268 {
3271 {
3278 }
3279 else
3280 {
3283 }
3284 }
3288 }
3290 /* Checks if DECL shadows a template parameter.
3292 [temp.local]: A template-parameter shall not be redeclared within its
3293 scope (including nested scopes).
3295 Emits an error and returns TRUE if the DECL shadows a parameter,
3296 returns FALSE otherwise. */
3298 bool
3300 {
3301 tree olddecl;
3303 /* If we're not in a template, we can't possibly shadow a template
3304 parameter. */
3308 /* Figure out what we're shadowing. */
3313 /* If there's no previous binding for this name, we're not shadowing
3314 anything, let alone a template parameter. */
3318 /* If we're not shadowing a template parameter, we're done. Note
3319 that OLDDECL might be an OVERLOAD (or perhaps even an
3320 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3321 node. */
3325 /* We check for decl != olddecl to avoid bogus errors for using a
3326 name inside a class. We check TPFI to avoid duplicate errors for
3327 inline member templates. */
3335 }
3337 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3338 ORIG_LEVEL, DECL, and TYPE. */
3340 static tree
3344 tree decl,
3345 tree type)
3346 {
3357 }
3359 /* Find the canonical type parameter for the given template type
3360 parameter. Returns the canonical type parameter, which may be TYPE
3361 if no such parameter existed. */
3362 static tree
3364 {
3365 tree list;
3379 else
3380 {
3385 }
3386 }
3388 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3389 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3390 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3391 new one is created. */
3393 static tree
3395 tsubst_flags_t complain)
3396 {
3401 {
3420 /* Template template parameters need this. */
3425 }
3428 }
3430 /* Process information from new template parameter PARM and append it to the
3431 LIST being built. This new parameter is a non-type parameter iff
3432 IS_NON_TYPE is true. This new parameter is a parameter
3433 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3434 PARM_LOC. */
3436 tree
3439 {
3441 tree defval;
3442 tree err_parm_list;
3449 {
3453 {
3457 else
3459 }
3462 }
3463 else
3467 {
3473 {
3477 }
3478 else
3479 {
3480 /* [temp.param]
3482 The top-level cv-qualifiers on the template-parameter are
3483 ignored when determining its type. */
3486 {
3490 }
3493 {
3494 /* This template parameter is not a parameter pack, but it
3495 should be. Complain about "bare" parameter packs. */
3498 /* Recover by calling this a parameter pack. */
3500 }
3501 }
3503 /* A template parameter is not modifiable. */
3512 processing_template_decl,
3517 }
3518 else
3519 {
3520 tree t;
3524 {
3526 /* This is for distinguishing between real templates and template
3527 template parameters */
3531 }
3532 else
3533 {
3535 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3538 }
3545 processing_template_decl,
3549 }
3555 }
3557 /* The end of a template parameter list has been reached. Process the
3558 tree list into a parameter vector, converting each parameter into a more
3559 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3560 as PARM_DECLs. */
3562 tree
3564 {
3569 current_template_parms
3574 {
3580 current_template_parms;
3581 }
3586 }
3588 /* end_template_decl is called after a template declaration is seen. */
3590 void
3592 {
3598 /* This matches the pushlevel in begin_template_parm_list. */
3603 }
3605 /* Within the declaration of a template, return all levels of template
3606 parameters that apply. The template parameters are represented as
3607 a TREE_VEC, in the form documented in cp-tree.h for template
3608 arguments. */
3610 static tree
3612 {
3613 tree header;
3618 /* If there is only one level of template parameters, we do not
3619 create a TREE_VEC of TREE_VECs. Instead, we return a single
3620 TREE_VEC containing the arguments. */
3625 {
3631 {
3634 /* T will be a list if we are called from within a
3635 begin/end_template_parm_list pair, but a vector directly
3636 if within a begin/end_member_template_processing pair. */
3638 {
3642 {
3645 {
3649 {
3650 /* Turn this argument into a TYPE_ARGUMENT_PACK
3651 with a single element, which expands T. */
3653 #ifdef ENABLE_CHECKING
3654 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3656 #endif
3661 }
3662 }
3663 else
3664 {
3668 {
3669 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3670 with a single element, which expands T. */
3673 #ifdef ENABLE_CHECKING
3674 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3676 #endif
3682 }
3683 }
3685 }
3686 }
3687 }
3689 #ifdef ENABLE_CHECKING
3691 #endif
3695 else
3697 }
3700 }
3702 /* Update the declared TYPE by doing any lookups which were thought to be
3703 dependent, but are not now that we know the SCOPE of the declarator. */
3705 tree
3707 {
3718 /* Don't bother building up the args in this case. */
3720 {
3721 /* tsubst in the args corresponding to the template parameters,
3722 including auto if present. Most things will be unchanged, but
3723 make_typename_type and tsubst_qualified_id will resolve
3724 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3727 tree pushed;
3729 {
3733 }
3738 }
3744 {
3747 else
3749 }
3751 }
3753 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3754 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3755 a member template. Used by push_template_decl below. */
3757 static tree
3759 {
3766 }
3768 struct template_parm_data
3769 {
3770 /* The level of the template parameters we are currently
3771 processing. */
3774 /* The index of the specialization argument we are currently
3775 processing. */
3778 /* An array whose size is the number of template parameters. The
3779 elements are nonzero if the parameter has been used in any one
3780 of the arguments processed so far. */
3783 /* An array whose size is the number of template arguments. The
3784 elements are nonzero if the argument makes use of template
3785 parameters of this level. */
3787 };
3789 /* Subroutine of push_template_decl used to see if each template
3790 parameter in a partial specialization is used in the explicit
3791 argument list. If T is of the LEVEL given in DATA (which is
3792 treated as a template_parm_data*), then DATA->PARMS is marked
3793 appropriately. */
3795 static int
3797 {
3803 {
3806 }
3807 else
3808 {
3811 }
3814 {
3817 }
3819 /* Return zero so that for_each_template_parm will continue the
3820 traversal of the tree; we want to mark *every* template parm. */
3822 }
3824 /* Process the partial specialization DECL. */
3826 static tree
3828 {
3834 tree inner_parms;
3847 /* We check that each of the template parameters given in the
3848 partial specialization is used in the argument list to the
3849 specialization. For example:
3851 template <class T> struct S;
3852 template <class T> struct S<T*>;
3854 The second declaration is OK because `T*' uses the template
3855 parameter T, whereas
3857 template <class T> struct S<int>;
3859 is no good. Even trickier is:
3861 template <class T>
3862 struct S1
3863 {
3864 template <class U>
3865 struct S2;
3866 template <class U>
3867 struct S2<T>;
3868 };
3870 The S2<T> declaration is actually invalid; it is a
3871 full-specialization. Of course,
3873 template <class U>
3874 struct S2<T (*)(U)>;
3876 or some such would have been OK. */
3884 {
3889 NULL,
3891 }
3894 {
3895 /* One of the template parms was not used in the
3896 specialization. */
3898 {
3901 }
3904 }
3909 /* [temp.class.spec]
3911 The argument list of the specialization shall not be identical to
3912 the implicit argument list of the primary template. */
3919 /* [temp.class.spec]
3921 A partially specialized non-type argument expression shall not
3922 involve template parameters of the partial specialization except
3923 when the argument expression is a simple identifier.
3925 The type of a template parameter corresponding to a specialized
3926 non-type argument shall not be dependent on a parameter of the
3927 specialization.
3929 Also, we verify that pack expansions only occur at the
3930 end of the argument list. */
3934 {
3941 {
3942 /* Extract the arguments from the argument pack. We'll be
3943 iterating over these in the following loop. */
3946 }
3949 {
3951 /* Get the Jth argument in the parameter pack. */
3955 {
3956 /* Pack expansions must come at the end of the
3957 argument list. */
3960 {
3964 else
3967 }
3968 }
3971 /* We only care about the pattern. */
3977 /* This next line is the `argument expression is not just a
3978 simple identifier' condition and also the `specialized
3979 non-type argument' bit. */
3981 {
3985 arg);
3986 else
3987 {
3988 /* Look at the corresponding template parameter,
3989 marking which template parameters its type depends
3990 upon. */
3994 {
3995 /* We haven't yet initialized TPD2. Do so now. */
3996 tpd2.arg_uses_template_parms
3998 /* The number of parameters here is the number in the
3999 main template, which, as checked in the assertion
4000 above, is NARGS. */
4004 }
4006 /* Mark the template parameters. But this time, we're
4007 looking for the template parameters of the main
4008 template, not in the specialization. */
4015 NULL,
4019 {
4020 /* The type depended on some template parameters.
4021 If they are fully specialized in the
4022 specialization, that's OK. */
4031 "type %qT of template argument %qE depends "
4033 "type %qT of template argument %qE depends "
4035 type,
4036 arg);
4037 }
4038 }
4039 }
4040 }
4041 }
4043 /* We should only get here once. */
4051 }
4053 /* Check that a template declaration's use of default arguments and
4054 parameter packs is not invalid. Here, PARMS are the template
4055 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4056 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4057 specialization.
4060 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4061 declaration (but not a definition); 1 indicates a declaration, 2
4062 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4063 emitted for extraneous default arguments.
4065 Returns TRUE if there were no errors found, FALSE otherwise. */
4067 bool
4070 {
4073 tree parm_level;
4076 /* [temp.param]
4078 A default template-argument shall not be specified in a
4079 function template declaration or a function template definition, nor
4080 in the template-parameter-list of the definition of a member of a
4081 class template. */
4084 /* You can't have a function template declaration in a local
4085 scope, nor you can you define a member of a class template in a
4086 local scope. */
4093 /* If this is either a friend defined in the scope of the class
4094 or a member function. */
4100 /* And, if it was a member function, it really was defined in
4101 the scope of the class. */
4104 /* We already checked these parameters when the template was
4105 declared, so there's no need to do it again now. This function
4106 was defined in class scope, but we're processing it's body now
4107 that the class is complete. */
4110 /* Core issue 226 (C++0x only): the following only applies to class
4111 templates. */
4113 {
4114 /* [temp.param]
4116 If a template-parameter has a default template-argument, all
4117 subsequent template-parameters shall have a default
4118 template-argument supplied. */
4120 {
4127 {
4137 {
4139 /* For better subsequent error-recovery, we indicate that
4140 there should have been a default argument. */
4143 }
4145 && !is_partial
4146 && !is_friend_decl
4147 /* Don't complain about an enclosing partial
4148 specialization. */
4153 {
4154 /* A primary class template can only have one
4155 parameter pack, at the end of the template
4156 parameter list. */
4161 else
4169 }
4170 }
4171 }
4172 }
4175 || is_partial
4176 || !is_primary
4178 /* For an ordinary class template, default template arguments are
4179 allowed at the innermost level, e.g.:
4180 template <class T = int>
4181 struct S {};
4182 but, in a partial specialization, they're not allowed even
4183 there, as we have in [temp.class.spec]:
4185 The template parameter list of a specialization shall not
4186 contain default template argument values.
4188 So, for a partial specialization, or for a function template
4189 (in C++98/C++03), we look at all of them. */
4190 ;
4191 else
4192 /* But, for a primary class template that is not a partial
4193 specialization we look at all template parameters except the
4194 innermost ones. */
4197 /* Figure out what error message to issue. */
4210 else
4214 /* If we're inside a class definition, there's no need to
4215 examine the parameters to the class itself. On the one
4216 hand, they will be checked when the class is defined, and,
4217 on the other, default arguments are valid in things like:
4218 template <class T = double>
4219 struct S { template <class U> void f(U); };
4220 Here the default argument for `S' has no bearing on the
4221 declaration of `f'. */
4223 else
4224 /* Check everything. */
4230 {
4237 {
4242 {
4244 {
4251 }
4253 /* Clear out the default argument so that we are not
4254 confused later. */
4256 }
4257 }
4259 /* At this point, if we're still interested in issuing messages,
4260 they must apply to classes surrounding the object declared. */
4264 }
4267 }
4269 /* Worker for push_template_decl_real, called via
4270 for_each_template_parm. DATA is really an int, indicating the
4271 level of the parameters we are interested in. If T is a template
4272 parameter of that level, return nonzero. */
4274 static int
4276 {
4282 else
4285 }
4287 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4288 parameters given by current_template_args, or reuses a
4289 previously existing one, if appropriate. Returns the DECL, or an
4290 equivalent one, if it is replaced via a call to duplicate_decls.
4292 If IS_FRIEND is true, DECL is a friend declaration. */
4294 tree
4296 {
4297 tree tmpl;
4298 tree args;
4299 tree info;
4300 tree ctx;
4304 /* True if the template is a member template, in the sense of
4305 [temp.mem]. */
4311 /* See if this is a partial specialization. */
4320 /* For a friend, we want the context of the friend function, not
4321 the type of which it is a friend. */
4325 /* In the case of a virtual function, we want the class in which
4326 it is defined. */
4328 else
4329 /* Otherwise, if we're currently defining some class, the DECL
4330 is assumed to be a member of the class. */
4339 /* See if this is a primary template. */
4341 /* A friend template that specifies a class context, i.e.
4342 template <typename T> friend void A<T>::f();
4343 is not primary. */
4345 else
4349 {
4354 {
4357 }
4359 {
4361 {
4362 /* [temp.mem]
4364 A destructor shall not be a member template. */
4367 }
4374 {
4375 /* [basic.stc.dynamic.allocation]
4377 An allocation function can be a function
4378 template. ... Template allocation functions shall
4379 have two or more parameters. */
4382 }
4383 }
4387 else
4388 {
4391 }
4392 }
4394 /* Check to see that the rules regarding the use of default
4395 arguments are not being violated. */
4399 /* Ensure that there are no parameter packs in the type of this
4400 declaration that have not been expanded. */
4402 {
4403 /* Check each of the arguments individually to see if there are
4404 any bare parameter packs. */
4410 {
4413 {
4414 /* This is a PARM_DECL that contains unexpanded parameter
4415 packs. We have already complained about this in the
4416 check_for_bare_parameter_packs call, so just replace
4417 these types with ERROR_MARK_NODE. */
4420 }
4424 }
4426 /* Check for bare parameter packs in the return type and the
4427 exception specifiers. */
4429 /* Errors were already issued, set return type to int
4430 as the frontend doesn't expect error_mark_node as
4431 the return type. */
4435 }
4437 {
4440 }
4451 {
4456 /* If DECL is a TYPE_DECL for a class-template, then there won't
4457 be DECL_LANG_SPECIFIC. The information equivalent to
4458 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4462 {
4463 /* Since a template declaration already existed for this
4464 class-type, we must be redeclaring it here. Make sure
4465 that the redeclaration is valid. */
4467 current_template_parms);
4468 /* We don't need to create a new TEMPLATE_DECL; just use the
4469 one we already had. */
4471 }
4472 else
4473 {
4475 member_template_p);
4480 {
4481 /* A specialization of a member template of a template
4482 class. */
4486 }
4487 }
4488 }
4489 else
4490 {
4496 {
4499 }
4507 {
4508 tree new_tmpl;
4510 /* The declaration is a specialization of a member
4511 template, declared outside the class. Therefore, the
4512 innermost template arguments will be NULL, so we
4513 replace them with the arguments determined by the
4514 earlier call to check_explicit_specialization. */
4517 new_tmpl
4519 member_template_p);
4529 args,
4532 }
4534 /* Make sure the template headers we got make sense. */
4539 {
4542 }
4543 else
4545 {
4550 {
4554 else
4559 }
4564 /* Can happen in erroneous input. */
4566 else
4570 }
4572 /* Check that the parms are used in the appropriate qualifying scopes
4573 in the declarator. */
4577 {
4583 /* Avoid crash in import_export_decl. */
4586 }
4587 }
4592 /* Push template declarations for global functions and types. Note
4593 that we do not try to push a global template friend declared in a
4594 template class; such a thing may well depend on the template
4595 parameters of the class. */
4598 {
4603 /* Hide template friend classes that haven't been declared yet. */
4605 {
4608 }
4609 }
4612 {
4618 {
4621 /* It is a conversion operator. See if the type converted to
4622 depends on innermost template operands. */
4625 depth))
4627 }
4629 /* Give template template parms a DECL_CONTEXT of the template
4630 for which they are a parameter. */
4633 {
4637 }
4638 }
4640 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4641 back to its most general template. If TMPL is a specialization,
4642 ARGS may only have the innermost set of arguments. Add the missing
4643 argument levels if necessary. */
4655 }
4657 tree
4659 {
4661 }
4663 /* Called when a class template TYPE is redeclared with the indicated
4664 template PARMS, e.g.:
4666 template <class T> struct S;
4667 template <class T> struct S {}; */
4669 bool
4671 {
4672 tree tmpl;
4673 tree tmpl_parms;
4677 {
4680 }
4684 /* The type is nested in some template class. Nothing to worry
4685 about here; there are no new template parameters for the nested
4686 type. */
4690 {
4692 tmpl);
4694 }
4700 {
4710 }
4713 {
4714 tree tmpl_parm;
4715 tree parm;
4716 tree tmpl_default;
4717 tree parm_default;
4731 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4732 TEMPLATE_DECL. */
4742 {
4746 }
4749 {
4750 /* We have in [temp.param]:
4752 A template-parameter may not be given default arguments
4753 by two different declarations in the same scope. */
4758 }
4761 /* Update the previous template parameters (which are the ones
4762 that will really count) with the new default value. */
4765 /* Update the new parameters, too; they'll be used as the
4766 parameters for any members. */
4768 }
4771 }
4773 /* Simplify EXPR if it is a non-dependent expression. Returns the
4774 (possibly simplified) expression. */
4776 tree
4778 {
4782 /* If we're in a template, but EXPR isn't value dependent, simplify
4783 it. We're supposed to treat:
4785 template <typename T> void f(T[1 + 1]);
4786 template <typename T> void f(T[2]);
4788 as two declarations of the same function, for example. */
4792 {
4793 HOST_WIDE_INT saved_processing_template_decl;
4799 tf_error,
4804 }
4806 }
4808 /* EXPR is an expression which is used in a constant-expression context.
4809 For instance, it could be a VAR_DECL with a constant initializer.
4810 Extract the innermost constant expression.
4812 This is basically a more powerful version of
4813 integral_constant_value, which can be used also in templates where
4814 initializers can maintain a syntactic rather than semantic form
4815 (even if they are non-dependent, for access-checking purposes). */
4817 static tree
4819 {
4821 do
4822 {
4825 }
4829 }
4831 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4832 must be a function or a pointer-to-function type, as specified
4833 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4834 and check that the resulting function has external linkage. */
4836 static tree
4838 {
4852 /* [temp.arg.nontype]/1
4854 A template-argument for a non-type, non-template template-parameter
4855 shall be one of:
4856 [...]
4857 -- the address of an object or function with external linkage. */
4859 {
4864 }
4867 }
4869 /* Subroutine of convert_nontype_argument.
4870 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4871 Emit an error otherwise. */
4873 static bool
4875 {
4883 }
4885 /* Attempt to convert the non-type template parameter EXPR to the
4886 indicated TYPE. If the conversion is successful, return the
4887 converted value. If the conversion is unsuccessful, return
4888 NULL_TREE if we issued an error message, or error_mark_node if we
4889 did not. We issue error messages for out-and-out bad template
4890 parameters, but not simply because the conversion failed, since we
4891 might be just trying to do argument deduction. Both TYPE and EXPR
4892 must be non-dependent.
4894 The conversion follows the special rules described in
4895 [temp.arg.nontype], and it is much more strict than an implicit
4896 conversion.
4898 This function is called twice for each template argument (see
4899 lookup_template_class for a more accurate description of this
4900 problem). This means that we need to handle expressions which
4901 are not valid in a C++ source, but can be created from the
4902 first call (for instance, casts to perform conversions). These
4903 hacks can go away after we fix the double coercion problem. */
4905 static tree
4907 {
4908 tree expr_type;
4910 /* Detect immediately string literals as invalid non-type argument.
4911 This special-case is not needed for correctness (we would easily
4912 catch this later), but only to provide better diagnostic for this
4913 common user mistake. As suggested by DR 100, we do not mention
4914 linkage issues in the diagnostic as this is not the point. */
4916 {
4921 }
4923 /* If we are in a template, EXPR may be non-dependent, but still
4924 have a syntactic, rather than semantic, form. For example, EXPR
4925 might be a SCOPE_REF, rather than the VAR_DECL to which the
4926 SCOPE_REF refers. Preserving the qualifying scope is necessary
4927 so that access checking can be performed when the template is
4928 instantiated -- but here we need the resolved form so that we can
4929 convert the argument. */
4936 /* HACK: Due to double coercion, we can get a
4937 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4938 which is the tree that we built on the first call (see
4939 below when coercing to reference to object or to reference to
4940 function). We just strip everything and get to the arg.
4941 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4942 for examples. */
4944 {
4946 {
4947 /* ??? Maybe we could use convert_from_reference here, but we
4948 would need to relax its constraints because the NOP_EXPR
4949 could actually change the type to something more cv-qualified,
4950 and this is not folded by convert_from_reference. */
4961 }
4963 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4964 parameter is a pointer to object, through decay and
4965 qualification conversion. Let's strip everything. */
4967 {
4971 /* Skip the ADDR_EXPR only if it is part of the decay for
4972 an array. Otherwise, it is part of the original argument
4973 in the source code. */
4977 }
4978 }
4980 /* [temp.arg.nontype]/5, bullet 1
4982 For a non-type template-parameter of integral or enumeration type,
4983 integral promotions (_conv.prom_) and integral conversions
4984 (_conv.integral_) are applied. */
4986 {
4991 /* Notice that there are constant expressions like '4 % 0' which
4992 do not fold into integer constants. */
4994 {
4998 }
5000 /* At this point, an implicit conversion does what we want,
5001 because we already know that the expression is of integral
5002 type. */
5007 /* Conversion was allowed: fold it to a bare integer constant. */
5009 }
5010 /* [temp.arg.nontype]/5, bullet 2
5012 For a non-type template-parameter of type pointer to object,
5013 qualification conversions (_conv.qual_) and the array-to-pointer
5014 conversion (_conv.array_) are applied. */
5016 {
5017 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5019 A template-argument for a non-type, non-template template-parameter
5020 shall be one of: [...]
5022 -- the name of a non-type template-parameter;
5023 -- the address of an object or function with external linkage, [...]
5024 expressed as "& id-expression" where the & is optional if the name
5025 refers to a function or array, or if the corresponding
5026 template-parameter is a reference.
5028 Here, we do not care about functions, as they are invalid anyway
5029 for a parameter of type pointer-to-object. */
5032 /* Non-type template parameters are OK. */
5033 ;
5036 {
5038 {
5040 "because %qD is a variable, not the address of "
5044 }
5045 /* Other values, like integer constants, might be valid
5046 non-type arguments of some other type. */
5048 }
5049 else
5050 {
5051 tree decl;
5056 {
5061 }
5063 {
5068 }
5069 }
5078 }
5079 /* [temp.arg.nontype]/5, bullet 3
5081 For a non-type template-parameter of type reference to object, no
5082 conversions apply. The type referred to by the reference may be more
5083 cv-qualified than the (otherwise identical) type of the
5084 template-argument. The template-parameter is bound directly to the
5085 template-argument, which must be an lvalue. */
5087 {
5089 expr_type))
5093 {
5097 }
5100 {
5104 }
5106 /* [temp.arg.nontype]/1
5108 A template-argument for a non-type, non-template template-parameter
5109 shall be one of: [...]
5111 -- the address of an object or function with external linkage. */
5114 {
5117 {
5119 "because a reference variable does not have a constant "
5122 }
5123 }
5126 {
5131 }
5134 {
5139 }
5142 }
5143 /* [temp.arg.nontype]/5, bullet 4
5145 For a non-type template-parameter of type pointer to function, only
5146 the function-to-pointer conversion (_conv.func_) is applied. If the
5147 template-argument represents a set of overloaded functions (or a
5148 pointer to such), the matching function is selected from the set
5149 (_over.over_). */
5151 {
5152 /* If the argument is a template-id, we might not have enough
5153 context information to decay the pointer. */
5155 {
5159 }
5166 {
5170 }
5171 }
5172 /* [temp.arg.nontype]/5, bullet 5
5174 For a non-type template-parameter of type reference to function, no
5175 conversions apply. If the template-argument represents a set of
5176 overloaded functions, the matching function is selected from the set
5177 (_over.over_). */
5179 {
5181 {
5186 }
5193 }
5194 /* [temp.arg.nontype]/5, bullet 6
5196 For a non-type template-parameter of type pointer to member function,
5197 no conversions apply. If the template-argument represents a set of
5198 overloaded member functions, the matching member function is selected
5199 from the set (_over.over_). */
5201 {
5206 /* [temp.arg.nontype] bullet 1 says the pointer to member
5207 expression must be a pointer-to-member constant. */
5211 /* There is no way to disable standard conversions in
5212 resolve_address_of_overloaded_function (called by
5213 instantiate_type). It is possible that the call succeeded by
5214 converting &B::I to &D::I (where B is a base of D), so we need
5215 to reject this conversion here.
5217 Actually, even if there was a way to disable standard conversions,
5218 it would still be better to reject them here so that we can
5219 provide a superior diagnostic. */
5221 {
5225 /* If we are just one standard conversion off, explain. */
5230 }
5231 }
5232 /* [temp.arg.nontype]/5, bullet 7
5234 For a non-type template-parameter of type pointer to data member,
5235 qualification conversions (_conv.qual_) are applied. */
5237 {
5238 /* [temp.arg.nontype] bullet 1 says the pointer to member
5239 expression must be a pointer-to-member constant. */
5246 }
5247 /* A template non-type parameter must be one of the above. */
5248 else
5251 /* Sanity check: did we actually convert the argument to the
5252 right type? */
5255 }
5257 /* Subroutine of coerce_template_template_parms, which returns 1 if
5258 PARM_PARM and ARG_PARM match using the rule for the template
5259 parameters of template template parameters. Both PARM and ARG are
5260 template parameters; the rest of the arguments are the same as for
5261 coerce_template_template_parms.
5262 */
5263 static int
5265 tree arg,
5266 tsubst_flags_t complain,
5267 tree in_decl,
5268 tree outer_args)
5269 {
5278 {
5280 /* We encounter instantiations of templates like
5281 template <template <template <class> class> class TT>
5282 class C; */
5283 {
5290 }
5291 /* Fall through. */
5296 /* Argument is a parameter pack but parameter is not. */
5301 /* The tsubst call is used to handle cases such as
5303 template <int> class C {};
5304 template <class T, template <T> class TT> class D {};
5305 D<int, C> d;
5307 i.e. the parameter list of TT depends on earlier parameters. */
5309 && !same_type_p
5316 /* Argument is a parameter pack but parameter is not. */
5323 }
5326 }
5329 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5330 template template parameters. Both PARM_PARMS and ARG_PARMS are
5331 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5332 or PARM_DECL.
5334 Consider the example:
5335 template <class T> class A;
5336 template<template <class U> class TT> class B;
5338 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5339 the parameters to A, and OUTER_ARGS contains A. */
5341 static int
5343 tree arg_parms,
5344 tsubst_flags_t complain,
5345 tree in_decl,
5346 tree outer_args)
5347 {
5358 /* Determine whether we have a parameter pack at the end of the
5359 template template parameter's template parameter list. */
5361 {
5368 {
5382 }
5383 }
5389 /* Check all of the template parameters except the parameter pack at
5390 the end (if any). */
5392 {
5401 outer_args))
5404 }
5407 {
5408 /* Check each of the template parameters in the template
5409 argument against the template parameter pack at the end of
5410 the template template parameter. */
5417 {
5424 outer_args))
5426 }
5427 }
5430 }
5432 /* Verifies that the deduced template arguments (in TARGS) for the
5433 template template parameters (in TPARMS) represent valid bindings,
5434 by comparing the template parameter list of each template argument
5435 to the template parameter list of its corresponding template
5436 template parameter, in accordance with DR150. This
5437 routine can only be called after all template arguments have been
5438 deduced. It will return TRUE if all of the template template
5439 parameter bindings are okay, FALSE otherwise. */
5440 bool
5442 {
5446 /* We're dealing with template parms in this process. */
5452 {
5457 {
5462 {
5463 /* Look inside the argument pack. */
5466 }
5469 {
5473 /* Extract the next argument from the argument
5474 pack. */
5478 /* Look at the pattern of the pack expansion. */
5481 /* Extract the template parameters from the template
5482 argument. */
5488 /* Verify that we can coerce the template template
5489 parameters from the template argument to the template
5490 parameter. This requires an exact match. */
5492 && !coerce_template_template_parms
5494 targ_parms,
5495 tf_none,
5496 tparm,
5497 targs))
5498 {
5501 }
5502 }
5503 }
5504 }
5506 out:
5510 }
5512 /* Convert the indicated template ARG as necessary to match the
5513 indicated template PARM. Returns the converted ARG, or
5514 error_mark_node if the conversion was unsuccessful. Error and
5515 warning messages are issued under control of COMPLAIN. This
5516 conversion is for the Ith parameter in the parameter list. ARGS is
5517 the full set of template arguments deduced so far. */
5519 static tree
5521 tree arg,
5522 tree args,
5523 tsubst_flags_t complain,
5525 tree in_decl)
5526 {
5527 tree orig_arg;
5528 tree val;
5533 {
5534 /* The template argument was the name of some
5535 member function. That's usually
5536 invalid, but static members are OK. In any
5537 case, grab the underlying fields/functions
5538 and issue an error later if required. */
5541 }
5549 /* When determining whether an argument pack expansion is a template,
5550 look at the pattern. */
5554 /* Deal with an injected-class-name used as a template template arg. */
5556 {
5559 {
5567 }
5568 }
5570 is_tmpl_type =
5585 {
5591 typename_type,
5595 }
5597 {
5599 {
5601 {
5611 else
5613 }
5614 }
5616 }
5618 {
5620 {
5626 else
5628 }
5630 }
5633 {
5635 {
5637 /* The number of argument required is not known yet.
5638 Just accept it for now. */
5640 else
5641 {
5643 tree argparm;
5649 args))
5650 {
5653 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5654 TEMPLATE_DECL. */
5656 {
5661 }
5662 }
5663 else
5664 {
5666 {
5672 }
5675 }
5676 }
5677 }
5678 else
5680 /* We only form one instance of each template specialization.
5681 Therefore, if we use a non-canonical variant (i.e., a
5682 typedef), any future messages referring to the type will use
5683 the typedef, which is confusing if those future uses do not
5684 themselves also use the typedef. */
5687 }
5688 else
5689 {
5696 {
5699 else
5700 {
5701 /* Not sure if this is reachable, but it doesn't hurt
5702 to be robust. */
5705 }
5706 }
5708 /* We used to call digest_init here. However, digest_init
5709 will report errors, which we don't want when complain
5710 is zero. More importantly, digest_init will try too
5711 hard to convert things: for example, `0' should not be
5712 converted to pointer type at this point according to
5713 the standard. Accepting this is not merely an
5714 extension, since deciding whether or not these
5715 conversions can occur is part of determining which
5716 function template to call, or whether a given explicit
5717 argument specification is valid. */
5719 else
5728 {
5729 /* Strip typedefs from the SCOPE_REF. */
5734 }
5735 }
5738 }
5740 /* Coerces the remaining template arguments in INNER_ARGS (from
5741 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5742 Returns the coerced argument pack. PARM_IDX is the position of this
5743 parameter in the template parameter list. ARGS is the original
5744 template argument list. */
5745 static tree
5748 tree args,
5749 tree inner_args,
5751 tree new_args,
5753 tree in_decl,
5754 tsubst_flags_t complain)
5755 {
5758 tree packed_args;
5759 tree argument_pack;
5769 {
5770 /* When the template parameter is a non-type template
5771 parameter pack whose type uses parameter packs, we need
5772 to look at each of the template arguments
5773 separately. Build a vector of the types for these
5774 non-type template parameters in PACKED_TYPES. */
5775 tree expansion
5783 /* Check that we have the right number of arguments. */
5787 {
5788 int needed_parms
5793 }
5795 /* If we aren't able to check the actual arguments now
5796 (because they haven't been expanded yet), we can at least
5797 verify that all of the types used for the non-type
5798 template parameter pack are, in fact, valid for non-type
5799 template parameters. */
5802 {
5805 {
5809 }
5810 }
5811 }
5813 /* Convert the remaining arguments, which will be a part of the
5814 parameter pack "parm". */
5816 {
5821 {
5822 /* When we have a vector of types (corresponding to the
5823 non-type template parameter pack that uses parameter
5824 packs in its type, as mention above), and the
5825 argument is not an expansion (which expands to a
5826 currently unknown number of arguments), clone the
5827 parm and give it the next type in PACKED_TYPES. */
5831 }
5836 in_decl);
5840 }
5845 else
5846 {
5851 }
5854 #ifdef ENABLE_CHECKING
5857 #endif
5859 }
5861 /* Convert all template arguments to their appropriate types, and
5862 return a vector containing the innermost resulting template
5863 arguments. If any error occurs, return error_mark_node. Error and
5864 warning messages are issued under control of COMPLAIN.
5866 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5867 for arguments not specified in ARGS. Otherwise, if
5868 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5869 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5870 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5871 ARGS. */
5873 static tree
5875 tree args,
5876 tree in_decl,
5877 tsubst_flags_t complain,
5880 {
5882 tree inner_args;
5883 tree new_args;
5884 tree new_inner_args;
5888 /* When used as a boolean value, indicates whether this is a
5889 variadic template parameter list. Since it's an int, we can also
5890 subtract it from nparms to get the number of non-variadic
5891 parameters. */
5896 /* Determine if there are any parameter packs. */
5898 {
5902 }
5905 /* If there are 0 or 1 parameter packs, we need to expand any argument
5906 packs so that we can deduce a parameter pack from some non-packed args
5907 followed by an argument pack, as in variadic85.C. If there are more
5908 than that, we need to leave argument packs intact so the arguments are
5909 assigned to the right parameter packs. This should only happen when
5910 dealing with a nested class inside a partial specialization of a class
5911 template, as in variadic92.C. */
5918 && require_all_args
5919 && (!use_default_args
5922 {
5924 {
5927 {
5930 }
5937 }
5940 }
5942 /* We need to evaluate the template arguments, even though this
5943 template-id may be nested within a "sizeof". */
5951 {
5952 tree arg;
5953 tree parm;
5955 /* Get the Ith template parameter. */
5959 {
5962 }
5964 /* Calculate the next argument. */
5967 else
5972 {
5973 /* All remaining arguments will be placed in the
5974 template parameter pack PARM. */
5980 /* Store this argument. */
5982 lost++;
5985 /* We are done with all of the arguments. */
5989 }
5991 {
5993 {
5995 {
5996 /* FIXME this restriction was removed by N2555; see
5997 bug 35722. */
5998 /* If ARG is a pack expansion, but PARM is not a
5999 template parameter pack (if it were, we would have
6000 handled it above), we're trying to expand into a
6001 fixed-length argument list. */
6005 else
6008 }
6010 }
6011 }
6013 {
6014 /* There must be a default arg in this case. */
6017 /* The position of the first default template argument,
6018 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6019 Record that. */
6022 }
6023 else
6027 {
6030 }
6032 /* This only occurs if there was an error in the template
6033 parameter list itself (which we would already have
6034 reported) that we are trying to recover from, e.g., a class
6035 template with a parameter list such as
6036 template<typename..., typename>. */
6038 else
6044 lost++;
6046 }
6053 #ifdef ENABLE_CHECKING
6057 #endif
6060 }
6062 /* Returns 1 if template args OT and NT are equivalent. */
6064 static int
6066 {
6071 /* For member templates */
6078 {
6095 }
6097 {
6098 /* We get here probably because we are in the middle of substituting
6099 into the pattern of a pack expansion. In that case the
6100 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6101 interested in. So we want to use the initial pack argument for
6102 the comparison. */
6107 }
6112 else
6114 }
6116 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6117 of template arguments. Returns 0 otherwise. */
6119 int
6121 {
6128 {
6134 }
6136 }
6138 static void
6140 {
6150 /* We are called both from instantiate_decl, where we've already had a
6151 tinst_level pushed, and instantiate_template, where we haven't.
6152 Compensate. */
6163 else
6172 }
6175 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6176 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6177 documentation for TEMPLATE_ID_EXPR. */
6179 tree
6181 {
6182 tree type;
6192 {
6194 unknown_type_node,
6196 arglist);
6198 }
6205 }
6207 /* Within the scope of a template class S<T>, the name S gets bound
6208 (in build_self_reference) to a TYPE_DECL for the class, not a
6209 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6210 or one of its enclosing classes, and that type is a template,
6211 return the associated TEMPLATE_DECL. Otherwise, the original
6212 DECL is returned.
6214 Also handle the case when DECL is a TREE_LIST of ambiguous
6215 injected-class-names from different bases. */
6217 tree
6219 {
6223 /* DR 176: A lookup that finds an injected-class-name (10.2
6224 [class.member.lookup]) can result in an ambiguity in certain cases
6225 (for example, if it is found in more than one base class). If all of
6226 the injected-class-names that are found refer to specializations of
6227 the same class template, and if the name is followed by a
6228 template-argument-list, the reference refers to the class template
6229 itself and not a specialization thereof, and is not ambiguous. */
6231 {
6234 {
6240 }
6243 else
6245 }
6251 }
6253 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6254 parameters, find the desired type.
6256 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6258 IN_DECL, if non-NULL, is the template declaration we are trying to
6259 instantiate.
6261 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6262 the class we are looking up.
6264 Issue error and warning messages under control of COMPLAIN.
6266 If the template class is really a local class in a template
6267 function, then the FUNCTION_CONTEXT is the function in which it is
6268 being instantiated.
6270 ??? Note that this function is currently called *twice* for each
6271 template-id: the first time from the parser, while creating the
6272 incomplete type (finish_template_type), and the second type during the
6273 real instantiation (instantiate_template_class). This is surely something
6274 that we want to avoid. It also causes some problems with argument
6275 coercion (see convert_nontype_argument for more information on this). */
6277 tree
6279 tree arglist,
6280 tree in_decl,
6281 tree context,
6283 tsubst_flags_t complain)
6284 {
6286 tree t;
6289 spec_entry elt;
6290 hashval_t hash;
6295 {
6299 else
6300 {
6307 }
6310 }
6312 {
6315 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6316 an implicit typename for the second A. Deal with it. */
6321 {
6324 }
6325 }
6328 {
6331 }
6335 {
6339 }
6341 /* Issue an error message if we didn't find a template. */
6343 {
6347 }
6350 /* Make sure it's a user visible template, if it was named by
6351 the user. */
6354 {
6356 {
6360 }
6362 }
6367 {
6368 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6369 template arguments */
6371 tree parm;
6372 tree arglist2;
6373 tree outer;
6377 /* Consider an example where a template template parameter declared as
6379 template <class T, class U = std::allocator<T> > class TT
6381 The template parameter level of T and U are one level larger than
6382 of TT. To proper process the default argument of U, say when an
6383 instantiation `TT<int>' is seen, we need to build the full
6384 arguments containing {int} as the innermost level. Outer levels,
6385 available when not appearing as default template argument, can be
6386 obtained from the arguments of the enclosing template.
6388 Suppose that TT is later substituted with std::vector. The above
6389 instantiation is `TT<int, std::allocator<T> >' with TT at
6390 level 1, and T at level 2, while the template arguments at level 1
6391 becomes {std::vector} and the inner level 2 is {int}. */
6397 /* This is an argument of the current template, so we haven't set
6398 DECL_CONTEXT yet. */
6405 complain,
6415 }
6416 else
6417 {
6419 tree gen_tmpl;
6420 tree type_decl;
6433 {
6434 /* We've been given an incomplete set of template arguments.
6435 For example, given:
6437 template <class T> struct S1 {
6438 template <class U> struct S2 {};
6439 template <class U> struct S2<U*> {};
6440 };
6442 we will be called with an ARGLIST of `U*', but the
6443 TEMPLATE will be `template <class T> template
6444 <class U> struct S1<T>::S2'. We must fill in the missing
6445 arguments. */
6446 arglist
6448 arglist);
6450 }
6452 /* Now we should have enough arguments. */
6455 /* From here on, we're only interested in the most general
6456 template. */
6458 /* Calculate the BOUND_ARGS. These will be the args that are
6459 actually tsubst'd into the definition to create the
6460 instantiation. */
6462 {
6463 /* We have multiple levels of arguments to coerce, at once. */
6473 {
6476 complain,
6480 /* Don't process further if one of the levels fails. */
6482 {
6483 /* Restore the ARGLIST to its full size. */
6486 }
6490 /* We temporarily reduce the length of the ARGLIST so
6491 that coerce_template_parms will see only the arguments
6492 corresponding to the template parameters it is
6493 examining. */
6495 }
6497 /* Restore the ARGLIST to its full size. */
6501 }
6502 else
6503 arglist
6506 gen_tmpl,
6507 complain,
6512 /* We were unable to bind the arguments. */
6515 /* In the scope of a template class, explicit references to the
6516 template class refer to the type of the template, not any
6517 instantiation of it. For example, in:
6519 template <class T> class C { void f(C<T>); }
6521 the `C<T>' is just the same as `C'. Outside of the
6522 class, however, such a reference is an instantiation. */
6526 /* comp_template_args is expensive, check it last. */
6528 arglist))
6531 /* If we already have this specialization, return it. */
6543 /* If the deduced arguments are invalid, then the binding
6544 failed. */
6548 complain))
6555 {
6560 }
6567 /* Create the type. */
6569 {
6571 {
6577 }
6578 else
6579 {
6580 /* We don't want to call start_enum for this type, since
6581 the values for the enumeration constants may involve
6582 template parameters. And, no one should be interested
6583 in the enumeration constants for such a type. */
6586 }
6587 }
6588 else
6589 {
6596 /* A local class. Make sure the decl gets registered properly. */
6601 /* This instantiation is another name for the primary
6602 template type. Set the TYPE_CANONICAL field
6603 appropriately. */
6606 /* Some of the template arguments require structural
6607 equality testing, so this template class requires
6608 structural equality testing. */
6610 }
6612 /* If we called start_enum or pushtag above, this information
6613 will already be set up. */
6615 {
6622 }
6623 else
6631 {
6634 }
6636 /* Let's consider the explicit specialization of a member
6637 of a class template specialization that is implicitely instantiated,
6638 e.g.:
6639 template<class T>
6640 struct S
6641 {
6642 template<class U> struct M {}; //#0
6643 };
6645 template<>
6646 template<>
6647 struct S<int>::M<char> //#1
6648 {
6649 int i;
6650 };
6651 [temp.expl.spec]/4 says this is valid.
6653 In this case, when we write:
6654 S<int>::M<char> m;
6656 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
6657 the one of #0.
6659 When we encounter #1, we want to store the partial instantiation
6660 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
6662 For all cases other than this "explicit specialization of member of a
6663 class template", we just want to store the most general template into
6664 the CLASSTYPE_TI_TEMPLATE of M.
6666 This case of "explicit specialization of member of a class template"
6667 only happens when:
6668 1/ the enclosing class is an instantiation of, and therefore not
6669 the same as, the context of the most general template, and
6670 2/ we aren't looking at the partial instantiation itself, i.e.
6671 the innermost arguments are not the same as the innermost parms of
6672 the most general template.
6674 So it's only when 1/ and 2/ happens that we want to use the partial
6675 instantiation of the member template in lieu of its most general
6676 template. */
6680 /* the enclosing class must be an instantiation... */
6683 {
6684 tree partial_inst_args;
6687 partial_inst_args =
6693 use_partial_inst_tmpl =
6694 /*...and we must not be looking at the partial instantiation
6695 itself. */
6697 partial_inst_args);
6698 }
6701 /* This case is easy; there are no member templates involved. */
6703 else
6704 {
6705 /* This is a full instantiation of a member template. Find
6706 the partial instantiation of which this is an instance. */
6708 /* Temporarily reduce by one the number of levels in the ARGLIST
6709 so as to avoid comparing the last set of arguments. */
6714 }
6724 /* Note this use of the partial instantiation so we can check it
6725 later in maybe_process_partial_specialization. */
6731 /* Now that the type has been registered on the instantiations
6732 list, we set up the enumerators. Because the enumeration
6733 constants may involve the enumeration type itself, we make
6734 sure to register the type first, and then create the
6735 constants. That way, doing tsubst_expr for the enumeration
6736 constants won't result in recursive calls here; we'll find
6737 the instantiation and exit above. */
6741 /* If the type makes use of template parameters, the
6742 code that generates debugging information will crash. */
6745 /* Possibly limit visibility based on template args. */
6750 }
6752 }
6753 \f
6754 struct pair_fn_data
6755 {
6756 tree_fn_t fn;
6758 /* True when we should also visit template parameters that occur in
6759 non-deduced contexts. */
6762 };
6764 /* Called from for_each_template_parm via walk_tree. */
6766 static tree
6768 {
6781 {
6785 /* Fall through. */
6808 /* Since we're not going to walk subtrees, we have to do this
6809 explicitly here. */
6813 /* Fall through. */
6816 /* Check the return type. */
6821 /* Check the parameter types. Since default arguments are not
6822 instantiated until they are needed, the TYPE_ARG_TYPES may
6823 contain expressions that involve template parameters. But,
6824 no-one should be looking at them yet. And, once they're
6825 instantiated, they don't contain template parameters, so
6826 there's no point in looking at them then, either. */
6827 {
6828 tree parm;
6835 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6836 want walk_tree walking into them itself. */
6838 }
6855 /* Fall through. */
6871 /* Record template parameters such as `T' inside `TT<T>'. */
6875 /* Fall through. */
6887 /* A template template parameter is encountered. */
6893 /* Already substituted template template parameter */
6916 /* If there's no type, then this thing must be some expression
6917 involving template parameters. */
6938 }
6940 /* We didn't find any template parameters we liked. */
6942 }
6944 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6945 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6946 call FN with the parameter and the DATA.
6947 If FN returns nonzero, the iteration is terminated, and
6948 for_each_template_parm returns 1. Otherwise, the iteration
6949 continues. If FN never returns a nonzero value, the value
6950 returned by for_each_template_parm is 0. If FN is NULL, it is
6951 considered to be the function which always returns 1.
6953 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6954 parameters that occur in non-deduced contexts. When false, only
6955 visits those template parameters that can be deduced. */
6957 static int
6961 {
6965 /* Set up. */
6970 /* Walk the tree. (Conceptually, we would like to walk without
6971 duplicates, but for_each_template_parm_r recursively calls
6972 for_each_template_parm, so we would need to reorganize a fair
6973 bit to use walk_tree_without_duplicates, so we keep our own
6974 visited list.) */
6977 else
6980 for_each_template_parm_r,
6984 /* Clean up. */
6986 {
6989 }
6992 }
6994 /* Returns true if T depends on any template parameter. */
6996 int
6998 {
7025 else
7026 {
7029 }
7034 }
7036 /* Returns true if T depends on any template parameter with level LEVEL. */
7038 int
7040 {
7043 }
7047 #ifdef GATHER_STATISTICS
7049 #endif
7053 /* We're starting to instantiate D; record the template instantiation context
7054 for diagnostics and to restore it later. */
7056 int
7058 {
7062 {
7063 /* If the instantiation in question still has unbound template parms,
7064 we don't really care if we can't instantiate it, so just return.
7065 This happens with base instantiation for implicit `typename'. */
7077 }
7087 #ifdef GATHER_STATISTICS
7090 #endif
7094 }
7096 /* We're done instantiating this template; return to the instantiation
7097 context. */
7099 void
7101 {
7102 /* Restore the filename and line number stashed away when we started
7103 this instantiation. */
7108 }
7110 /* We're instantiating a deferred template; restore the template
7111 instantiation context in which the instantiation was requested, which
7112 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7114 static tree
7116 {
7126 }
7128 /* Returns the TINST_LEVEL which gives the original instantiation
7129 context. */
7133 {
7139 }
7141 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7143 bool
7145 {
7146 tree parms;
7163 }
7165 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7166 vector of template arguments, as for tsubst.
7168 Returns an appropriate tsubst'd friend declaration. */
7170 static tree
7172 {
7173 tree new_friend;
7178 /* This was a friend declared with an explicit template
7179 argument list, e.g.:
7181 friend void f<>(T);
7183 to indicate that f was a template instantiation, not a new
7184 function declaration. Now, we have to figure out what
7185 instantiation of what template. */
7186 {
7188 tree new_args;
7189 tree tmpl;
7192 /* Friend functions are looked up in the containing namespace scope.
7193 We must enter that scope, to avoid finding member functions of the
7194 current class with same name. */
7209 tsk_none);
7211 }
7215 /* The NEW_FRIEND will look like an instantiation, to the
7216 compiler, but is not an instantiation from the point of view of
7217 the language. For example, we might have had:
7219 template <class T> struct S {
7220 template <class U> friend void f(T, U);
7221 };
7223 Then, in S<int>, template <class U> void f(int, U) is not an
7224 instantiation of anything. */
7230 {
7234 }
7236 /* The mangled name for the NEW_FRIEND is incorrect. The function
7237 is not a template instantiation and should not be mangled like
7238 one. Therefore, we forget the mangling here; we'll recompute it
7239 later if we need it. */
7241 {
7244 }
7247 {
7248 tree old_decl;
7249 tree new_friend_template_info;
7250 tree new_friend_result_template_info;
7251 tree ns;
7254 /* We must save some information from NEW_FRIEND before calling
7255 duplicate decls since that function will free NEW_FRIEND if
7256 possible. */
7258 new_friend_is_defn =
7263 {
7264 /* This declaration is a `primary' template. */
7267 new_friend_result_template_info
7269 }
7270 else
7273 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7277 /* Inside pushdecl_namespace_level, we will push into the
7278 current namespace. However, the friend function should go
7279 into the namespace of the template. */
7289 {
7290 /* This new friend declaration matched an existing
7291 declaration. For example, given:
7293 template <class T> void f(T);
7294 template <class U> class C {
7295 template <class T> friend void f(T) {}
7296 };
7298 the friend declaration actually provides the definition
7299 of `f', once C has been instantiated for some type. So,
7300 old_decl will be the out-of-class template declaration,
7301 while new_friend is the in-class definition.
7303 But, if `f' was called before this point, the
7304 instantiation of `f' will have DECL_TI_ARGS corresponding
7305 to `T' but not to `U', references to which might appear
7306 in the definition of `f'. Previously, the most general
7307 template for an instantiation of `f' was the out-of-class
7308 version; now it is the in-class version. Therefore, we
7309 run through all specialization of `f', adding to their
7310 DECL_TI_ARGS appropriately. In particular, they need a
7311 new set of outer arguments, corresponding to the
7312 arguments for this class instantiation.
7314 The same situation can arise with something like this:
7316 friend void f(int);
7317 template <class T> class C {
7318 friend void f(T) {}
7319 };
7321 when `C<int>' is instantiated. Now, `f(int)' is defined
7322 in the class. */
7325 /* On the other hand, if the in-class declaration does
7326 *not* provide a definition, then we don't want to alter
7327 existing definitions. We can just leave everything
7328 alone. */
7329 ;
7330 else
7331 {
7335 /* Overwrite whatever template info was there before, if
7336 any, with the new template information pertaining to
7337 the declaration. */
7341 {
7342 /* We should have called reregister_specialization in
7343 duplicate_decls. */
7348 /* Instantiate it if the global has already been used. */
7352 }
7353 else
7354 {
7355 tree t;
7357 /* Indicate that the old function template is a partial
7358 instantiation. */
7366 /* Reassign any specializations already in the hash table
7367 to the new more general template, and add the
7368 additional template args. */
7372 {
7374 spec_entry elt;
7386 register_specialization
7389 }
7391 }
7392 }
7394 /* The information from NEW_FRIEND has been merged into OLD_DECL
7395 by duplicate_decls. */
7397 }
7398 }
7399 else
7400 {
7404 /* In the code
7405 template <class T> class C {
7406 template <class U> friend void C1<U>::f (); // case 1
7407 friend void C2<T>::f (); // case 2
7408 };
7409 we only need to make sure CONTEXT is a complete type for
7410 case 2. To distinguish between the two cases, we note that
7411 CONTEXT of case 1 remains dependent type after tsubst while
7412 this isn't true for case 2. */
7422 {
7423 /* Check to see that the declaration is really present, and,
7424 possibly obtain an improved declaration. */
7430 }
7431 }
7434 }
7436 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7437 template arguments, as for tsubst.
7439 Returns an appropriate tsubst'd friend type or error_mark_node on
7440 failure. */
7442 static tree
7444 {
7445 tree friend_type;
7446 tree tmpl;
7447 tree context;
7452 {
7455 else
7457 }
7459 /* Look for a class template declaration. We look for hidden names
7460 because two friend declarations of the same template are the
7461 same. For example, in:
7463 struct A {
7464 template <typename> friend class F;
7465 };
7466 template <typename> struct B {
7467 template <typename> friend class F;
7468 };
7470 both F templates are the same. */
7475 /* But, if we don't find one, it might be because we're in a
7476 situation like this:
7478 template <class T>
7479 struct S {
7480 template <class U>
7481 friend struct S;
7482 };
7484 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7485 for `S<int>', not the TEMPLATE_DECL. */
7487 {
7490 }
7493 {
7494 /* The friend template has already been declared. Just
7495 check to see that the declarations match, and install any new
7496 default parameters. We must tsubst the default parameters,
7497 of course. We only need the innermost template parameters
7498 because that is all that redeclare_class_template will look
7499 at. */
7502 {
7503 tree parms;
7504 location_t saved_input_location;
7513 }
7516 }
7517 else
7518 {
7519 /* The friend template has not already been declared. In this
7520 case, the instantiation of the template class will cause the
7521 injection of this template into the global scope. */
7526 /* The new TMPL is not an instantiation of anything, so we
7527 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7528 the new type because that is supposed to be the corresponding
7529 template decl, i.e., TMPL. */
7536 /* Inject this template into the global scope. */
7538 }
7541 {
7544 else
7546 }
7549 }
7551 /* Returns zero if TYPE cannot be completed later due to circularity.
7552 Otherwise returns one. */
7554 static int
7556 {
7566 else
7568 }
7570 /* Apply any attributes which had to be deferred until instantiation
7571 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7572 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7574 static void
7577 {
7579 tree t;
7584 {
7588 }
7591 {
7595 }
7596 else
7600 {
7605 {
7608 {
7611 /* If the first attribute argument is an identifier, don't
7612 pass it through tsubst. Attributes like mode, format,
7613 cleanup and several target specific attributes expect it
7614 unmodified. */
7620 {
7621 tree chain
7623 in_decl,
7628 chain);
7629 }
7630 else
7636 }
7637 else
7639 }
7642 }
7643 }
7645 /* Perform (or defer) access check for typedefs that were referenced
7646 from within the template TMPL code.
7647 This is a subroutine of instantiate_template and instantiate_class_template.
7648 TMPL is the template to consider and TARGS is the list of arguments of
7649 that template. */
7651 static void
7653 {
7654 location_t saved_location;
7669 {
7681 /* Make access check error messages point to the location
7682 of the use of the typedef. */
7686 }
7688 }
7690 tree
7692 {
7694 tree typedecl;
7695 tree pbinfo;
7696 tree base_list;
7707 /* Figure out which template is being instantiated. */
7711 /* Determine what specialization of the original template to
7712 instantiate. */
7715 {
7718 }
7720 {
7721 /* This TYPE is actually an instantiation of a partial
7722 specialization. We replace the innermost set of ARGS with
7723 the arguments appropriate for substitution. For example,
7724 given:
7726 template <class T> struct S {};
7727 template <class T> struct S<T*> {};
7729 and supposing that we are instantiating S<int*>, ARGS will
7730 presently be {int*} -- but we need {int}. */
7733 }
7734 else
7735 {
7738 }
7740 /* If the template we're instantiating is incomplete, then clearly
7741 there's nothing we can do. */
7745 /* If we've recursively instantiated too many templates, stop. */
7749 /* Now we're really doing the instantiation. Mark the type as in
7750 the process of being defined. */
7753 /* We may be in the middle of deferred access check. Disable
7754 it now. */
7758 /* Use #pragma pack from the template context. */
7764 /* Set the input location to the most specialized template definition.
7765 This is needed if tsubsting causes an error. */
7786 {
7789 }
7793 /* We should never instantiate a nested class before its enclosing
7794 class; we need to look up the nested class by name before we can
7795 instantiate it, and that lookup should instantiate the enclosing
7796 class. */
7803 {
7804 tree pbase_binfo;
7806 tree pushed_scope;
7809 /* We must enter the scope containing the type, as that is where
7810 the accessibility of types named in dependent bases are
7811 looked up from. */
7814 /* Substitute into each of the bases to determine the actual
7815 basetypes. */
7817 {
7818 tree base;
7824 {
7825 expanded_bases =
7832 }
7835 {
7837 /* Extract the already-expanded base class. */
7839 else
7840 /* Substitute to figure out the base class. */
7842 NULL_TREE);
7850 }
7851 }
7853 /* The list is now in reverse order; correct that. */
7858 }
7859 /* Now call xref_basetypes to set up all the base-class
7860 information. */
7867 /* Now that our base classes are set up, enter the scope of the
7868 class, so that name lookups into base classes, etc. will work
7869 correctly. This is precisely analogous to what we do in
7870 begin_class_definition when defining an ordinary non-template
7871 class, except we also need to push the enclosing classes. */
7874 /* Now members are processed in the order of declaration. */
7877 {
7881 {
7883 {
7884 /* Build new CLASSTYPE_NESTED_UTDS. */
7886 tree newtag;
7892 /* If the member is a class template, then -- even after
7893 substitution -- there may be dependent types in the
7894 template argument list for the class. We increment
7895 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7896 that function will assume that no types are dependent
7897 when outside of a template. */
7907 {
7911 /* Unfortunately, lookup_template_class sets
7912 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7913 instantiation (i.e., for the type of a member
7914 template class nested within a template class.)
7915 This behavior is required for
7916 maybe_process_partial_specialization to work
7917 correctly, but is not accurate in this case;
7918 the TAG is not an instantiation of anything.
7919 (The corresponding TEMPLATE_DECL is an
7920 instantiation, but the TYPE is not.) */
7923 /* Now, we call pushtag to put this NEWTAG into the scope of
7924 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7925 pushtag calling push_template_decl. We don't have to do
7926 this for enums because it will already have been done in
7927 tsubst_enum. */
7931 }
7932 }
7935 {
7936 /* Build new TYPE_METHODS. */
7937 tree r;
7946 }
7947 else
7948 {
7949 /* Build new TYPE_FIELDS. */
7951 {
7952 tree condition =
7960 }
7962 {
7963 tree r;
7965 /* The file and line for this declaration, to
7966 assist in error message reporting. Since we
7967 called push_tinst_level above, we don't need to
7968 restore these. */
7977 {
7978 /* In [temp.inst]:
7980 [t]he initialization (and any associated
7981 side-effects) of a static data member does
7982 not occur unless the static data member is
7983 itself used in a way that requires the
7984 definition of the static data member to
7985 exist.
7987 Therefore, we do not substitute into the
7988 initialized for the static data member here. */
7989 finish_static_data_member_decl
7997 }
7999 {
8000 /* Determine whether R has a valid type and can be
8001 completed later. If R is invalid, then it is
8002 replaced by error_mark_node so that it will not be
8003 added to TYPE_FIELDS. */
8009 {
8012 }
8013 }
8015 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8016 such a thing will already have been added to the field
8017 list by tsubst_enum in finish_member_declaration in the
8018 CLASSTYPE_NESTED_UTDS case above. */
8022 {
8025 }
8026 }
8027 }
8028 }
8029 else
8030 {
8032 {
8033 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8039 {
8040 /* template <class T> friend class C; */
8043 }
8045 {
8046 /* template <class T> friend class C::D; */
8052 }
8054 {
8055 /* This could be either
8057 friend class T::C;
8059 when dependent_type_p is false or
8061 template <class U> friend class T::C;
8063 otherwise. */
8066 /* Bump processing_template_decl for correct
8067 dependent_type_p calculation. */
8072 }
8075 {
8076 /* friend class C;
8078 where C hasn't been declared yet. Let's lookup name
8079 from namespace scope directly, bypassing any name that
8080 come from dependent base class. */
8083 /* The call to xref_tag_from_type does injection for friend
8084 classes. */
8086 friend_type =
8090 }
8092 /* friend class C<T>; */
8095 /* Otherwise it's
8097 friend class C;
8099 where C is already declared or
8101 friend class C<int>;
8103 We don't have to do anything in these cases. */
8106 /* Trick make_friend_class into realizing that the friend
8107 we're adding is a template, not an ordinary class. It's
8108 important that we use make_friend_class since it will
8109 perform some error-checking and output cross-reference
8110 information. */
8118 }
8119 else
8120 {
8121 /* Build new DECL_FRIENDLIST. */
8122 tree r;
8124 /* The file and line for this declaration, to
8125 assist in error message reporting. Since we
8126 called push_tinst_level above, we don't need to
8127 restore these. */
8131 {
8134 }
8139 {
8142 }
8143 }
8144 }
8145 }
8147 /* Set the file and line number information to whatever is given for
8148 the class itself. This puts error messages involving generated
8149 implicit functions at a predictable point, and the same point
8150 that would be used for non-template classes. */
8157 /* Now that the class is complete, instantiate default arguments for
8158 any member functions. We don't do this earlier because the
8159 default arguments may reference members of the class. */
8163 /* Implicitly generated member functions will not have template
8164 information; they are not instantiations, but instead are
8165 created "fresh" for each instantiation. */
8169 /* Some typedefs referenced from within the template code need to be access
8170 checked at template instantiation time, i.e now. These types were
8171 added to the template at parsing time. Let's get those and perform
8172 the access checks then. */
8181 /* The vtable for a template class can be emitted in any translation
8182 unit in which the class is instantiated. When there is no key
8183 method, however, finish_struct_1 will already have added TYPE to
8184 the keyed_classes list. */
8189 }
8191 static tree
8193 {
8194 tree r;
8200 else
8201 {
8205 }
8207 }
8209 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8210 NONTYPE_ARGUMENT_PACK. */
8212 static tree
8214 {
8215 /* Collect all of the extra "packed" parameters into an
8216 argument pack. */
8217 tree parmvec;
8218 tree parmtypevec;
8223 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8227 {
8230 }
8232 /* Build the argument packs. */
8238 }
8240 /* Substitute ARGS into T, which is an pack expansion
8241 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8242 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8243 (if only a partial substitution could be performed) or
8244 ERROR_MARK_NODE if there was an error. */
8245 tree
8247 tree in_decl)
8248 {
8249 tree pattern;
8252 tree result;
8259 /* Determine the argument packs that will instantiate the parameter
8260 packs used in the expansion expression. While we're at it,
8261 compute the number of arguments to be expanded and make sure it
8262 is consistent. */
8265 {
8271 {
8274 else
8275 {
8276 /* We can't rely on local_specializations for a parameter
8277 name used later in a function declaration (such as in a
8278 late-specified return type). Even if it exists, it might
8279 have the wrong value for a recursive call. Just make a
8280 dummy decl, since it's only used for its type. */
8283 }
8284 }
8285 else
8286 {
8293 }
8300 /* This can only happen if we forget to expand an argument
8301 pack somewhere else. Just return an error, silently. */
8302 {
8306 }
8311 {
8316 /* The argument pack that the parameter maps to is just an
8317 expansion of the parameter itself, such as one would
8318 find in the implicit typedef of a class inside the
8319 class itself. Consider this parameter "unsubstituted",
8320 so that we will maintain the outer pack expansion. */
8322 }
8325 {
8329 /* It's all-or-nothing with incomplete argument packs. */
8339 {
8341 /* We got explicit args for some packs but not others;
8342 do nothing now and try again after deduction. */
8347 pattern);
8348 else
8351 pattern);
8353 }
8355 /* Keep track of the parameter packs and their corresponding
8356 argument packs. */
8359 }
8360 else
8361 /* We can't substitute for this parameter pack. */
8364 unsubstituted_packs);
8365 }
8367 /* We cannot expand this expansion expression, because we don't have
8368 all of the argument packs we need. Substitute into the pattern
8369 and return a PACK_EXPANSION_*. The caller will need to deal with
8370 that. */
8372 {
8373 tree new_pat;
8377 else
8380 }
8382 /* We could not find any argument packs that work. */
8387 {
8388 /* We're in a late-specified return type, so create our own local
8389 specializations table; the current table is either NULL or (in the
8390 case of recursive unification) might have bindings that we don't
8391 want to use or alter. */
8394 hash_local_specialization,
8395 eq_local_specializations,
8396 NULL);
8397 }
8399 /* For each argument in each argument pack, substitute into the
8400 pattern. */
8403 {
8404 /* For parameter pack, change the substitution of the parameter
8405 pack to the ith argument in its argument pack, then expand
8406 the pattern. */
8408 {
8412 {
8413 /* Select the Ith argument from the pack. */
8419 }
8420 else
8421 {
8427 {
8428 /* Select the Ith argument from the pack. */
8432 }
8434 /* Update the corresponding argument. */
8436 }
8437 }
8439 /* Substitute into the PATTERN with the altered arguments. */
8444 else
8448 /* When we have incomplete argument packs, the last "expanded"
8449 result is itself a pack expansion, which allows us
8450 to deduce more arguments. */
8455 {
8458 }
8459 }
8461 /* Update ARGS to restore the substitution from parameter packs to
8462 their argument packs. */
8464 {
8469 else
8470 {
8474 /* Update the corresponding argument. */
8478 else
8480 }
8481 }
8484 {
8487 }
8490 }
8492 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8493 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8494 parameter packs; all parms generated from a function parameter pack will
8495 have the same DECL_PARM_INDEX. */
8497 tree
8499 {
8501 tree patparm;
8504 {
8510 }
8511 else
8512 {
8517 }
8520 }
8522 /* Substitute ARGS into the vector or list of template arguments T. */
8524 static tree
8526 {
8533 {
8535 tree new_arg;
8540 {
8541 /* Substitute into an expansion expression. */
8545 /* Add to the expanded length adjustment the number of
8546 expanded arguments. We subtract one from this
8547 measurement, because the argument pack expression
8548 itself is already counted as 1 in
8549 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8550 the argument pack is empty. */
8552 }
8554 {
8555 /* Substitute into each of the arguments. */
8561 new_arg,
8575 }
8576 }
8577 else
8586 }
8591 /* Make space for the expanded arguments coming from template
8592 argument packs. */
8594 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8595 arguments for a member template.
8596 In that case each TREE_VEC in ORIG_T represents a level of template
8597 arguments, and ORIG_T won't carry any non defaulted argument count.
8598 It will rather be the nested TREE_VECs that will carry one.
8599 In other words, ORIG_T carries a non defaulted argument count only
8600 if it doesn't contain any nested TREE_VEC. */
8602 {
8606 }
8608 {
8612 {
8615 /* Now expand the template argument pack "in place". */
8618 }
8619 else
8620 {
8622 out++;
8623 }
8624 }
8627 }
8629 /* Return the result of substituting ARGS into the template parameters
8630 given by PARMS. If there are m levels of ARGS and m + n levels of
8631 PARMS, then the result will contain n levels of PARMS. For
8632 example, if PARMS is `template <class T> template <class U>
8633 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8634 result will be `template <int*, double, class V>'. */
8636 static tree
8638 {
8642 /* When substituting into a template, we must set
8643 PROCESSING_TEMPLATE_DECL as the template parameters may be
8644 dependent if they are based on one-another, and the dependency
8645 predicates are short-circuit outside of templates. */
8652 {
8653 tree new_vec =
8658 {
8659 tree tuple;
8660 tree default_value;
8661 tree parm_decl;
8683 }
8689 }
8694 }
8696 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8697 type T. If T is not an aggregate or enumeration type, it is
8698 handled as if by tsubst. IN_DECL is as for tsubst. If
8699 ENTERING_SCOPE is nonzero, T is the context for a template which
8700 we are presently tsubst'ing. Return the substituted value. */
8702 static tree
8704 tree args,
8705 tsubst_flags_t complain,
8706 tree in_decl,
8708 {
8713 {
8718 /* Else fall through. */
8722 {
8723 tree argvec;
8724 tree context;
8725 tree r;
8729 /* In "sizeof(X<I>)" we need to evaluate "I". */
8735 /* First, determine the context for the type we are looking
8736 up. */
8739 {
8742 /* If context is a nested class inside a class template,
8743 it may still need to be instantiated (c++/33959). */
8746 }
8748 /* Then, figure out what arguments are appropriate for the
8749 type we are trying to find. For example, given:
8751 template <class T> struct S;
8752 template <class T, class U> void f(T, U) { S<U> su; }
8754 and supposing that we are instantiating f<int, double>,
8755 then our ARGS will be {int, double}, but, when looking up
8756 S we only want {double}. */
8761 else
8762 {
8766 }
8772 }
8773 else
8774 /* This is not a template type, so there's nothing to do. */
8779 }
8780 }
8782 /* Substitute into the default argument ARG (a default argument for
8783 FN), which has the indicated TYPE. */
8785 tree
8787 {
8791 /* This default argument came from a template. Instantiate the
8792 default argument here, not in tsubst. In the case of
8793 something like:
8795 template <class T>
8796 struct S {
8797 static T t();
8798 void f(T = t());
8799 };
8801 we must be careful to do name lookup in the scope of S<T>,
8802 rather than in the current class. */
8804 /* The "this" pointer is not valid in a default argument. */
8806 {
8811 }
8814 /* The default argument expression may cause implicitly defined
8815 member functions to be synthesized, which will result in garbage
8816 collection. We must treat this situation as if we were within
8817 the body of function so as to avoid collecting live data on the
8818 stack. */
8826 /* Restore the "this" pointer. */
8828 {
8831 }
8833 /* Make sure the default argument is reasonable. */
8839 }
8841 /* Substitute into all the default arguments for FN. */
8843 static void
8845 {
8846 tree arg;
8847 tree tmpl_args;
8851 /* If this function is not yet instantiated, we certainly don't need
8852 its default arguments. */
8857 arg;
8863 }
8865 /* Substitute the ARGS into the T, which is a _DECL. Return the
8866 result of the substitution. Issue error and warning messages under
8867 control of COMPLAIN. */
8869 static tree
8871 {
8872 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8873 location_t saved_loc;
8878 /* Set the filename and linenumber to improve error-reporting. */
8883 {
8885 {
8886 /* We can get here when processing a member function template,
8887 member class template, or template template parameter. */
8889 tree spec;
8890 tree tmpl_args;
8891 tree full_args;
8894 {
8895 /* Template template parameter is treated here. */
8908 complain);
8911 }
8913 /* We might already have an instance of this template.
8914 The ARGS are for the surrounding class type, so the
8915 full args contain the tsubst'd args for the context,
8916 plus the innermost args from the template decl. */
8920 /* Because this is a template, the arguments will still be
8921 dependent, even after substitution. If
8922 PROCESSING_TEMPLATE_DECL is not set, the dependency
8923 predicates will short-circuit. */
8931 /* If this is a default template template argument,
8932 tsubst might not have changed anything. */
8939 {
8942 }
8944 /* Make a new template decl. It will be similar to the
8945 original, but will record the current template arguments.
8946 We also create a new function declaration, which is just
8947 like the old one, but points to this new template, rather
8948 than the old one. */
8956 {
8957 tree new_type;
8969 }
8970 else
8971 {
8972 tree new_decl;
8984 }
8990 /* The template parameters for this new template are all the
8991 template parameters for the old template, except the
8992 outermost level of parameters. */
8995 complain);
9001 /* Record this non-type partial instantiation. */
9005 }
9009 {
9010 tree ctx;
9013 tree gen_tmpl;
9014 tree type;
9019 /* Nobody should be tsubst'ing into non-template functions. */
9023 {
9024 tree spec;
9027 /* If T is not dependent, just return it. We have to
9028 increment PROCESSING_TEMPLATE_DECL because
9029 value_dependent_expression_p assumes that nothing is
9030 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9037 /* Calculate the most general template of which R is a
9038 specialization, and the complete set of arguments used to
9039 specialize R. */
9042 (DECL_TEMPLATE_RESULT
9046 /* Check to see if we already have this specialization. */
9051 {
9054 }
9056 /* We can see more levels of arguments than parameters if
9057 there was a specialization of a member template, like
9058 this:
9060 template <class T> struct S { template <class U> void f(); }
9061 template <> template <class U> void S<int>::f(U);
9063 Here, we'll be substituting into the specialization,
9064 because that's where we can find the code we actually
9065 want to generate, but we'll have enough arguments for
9066 the most general template.
9068 We also deal with the peculiar case:
9070 template <class T> struct S {
9071 template <class U> friend void f();
9072 };
9073 template <class U> void f() {}
9074 template S<int>;
9075 template void f<double>();
9077 Here, the ARGS for the instantiation of will be {int,
9078 double}. But, we only need as many ARGS as there are
9079 levels of template parameters in CODE_PATTERN. We are
9080 careful not to get fooled into reducing the ARGS in
9081 situations like:
9083 template <class T> struct S { template <class U> void f(U); }
9084 template <class T> template <> void S<T>::f(int) {}
9086 which we can spot because the pattern will be a
9087 specialization in this case. */
9089 parms_depth =
9094 }
9095 else
9096 {
9097 /* This special case arises when we have something like this:
9099 template <class T> struct S {
9100 friend void f<int>(int, double);
9101 };
9103 Here, the DECL_TI_TEMPLATE for the friend declaration
9104 will be an IDENTIFIER_NODE. We are being called from
9105 tsubst_friend_function, and we want only to create a
9106 new decl (R) with appropriate types so that we can call
9107 determine_specialization. */
9109 }
9112 {
9115 else
9119 }
9120 else
9121 {
9124 }
9129 /* We do NOT check for matching decls pushed separately at this
9130 point, as they may not represent instantiations of this
9131 template, and in any case are considered separate under the
9132 discrete model. */
9136 /* Clear out the mangled name and RTL for the instantiation. */
9139 /* Leave DECL_INITIAL set on deleted instantiations. */
9145 /* Type-conversion operator. Reconstruct the name, in
9146 case it's the name of one of the template's parameters. */
9156 /* If this is an instantiation of a function with internal
9157 linkage, we already know what object file linkage will be
9158 assigned to the instantiation. */
9167 /* We'll re-clone as appropriate in instantiate_template. */
9170 /* If we aren't complaining now, return on error before we register
9171 the specialization so that we'll complain eventually. */
9177 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9178 this in the special friend case mentioned above where
9179 GEN_TMPL is NULL. */
9181 {
9187 /* We're not supposed to instantiate default arguments
9188 until they are called, for a template. But, for a
9189 declaration like:
9191 template <class T> void f ()
9192 { extern void g(int i = T()); }
9194 we should do the substitution when the template is
9195 instantiated. We handle the member function case in
9196 instantiate_class_template since the default arguments
9197 might refer to other members of the class. */
9202 }
9203 else
9206 /* Copy the list of befriending classes. */
9210 {
9214 in_decl);
9215 }
9218 {
9222 /* If this is an instantiation of a member template, clone it.
9223 If it isn't, that'll be handled by
9224 clone_constructors_and_destructors. */
9227 }
9238 /* Possibly limit visibility based on template args. */
9241 {
9245 }
9253 }
9257 {
9265 {
9266 /* If there is a local specialization that isn't a
9267 parameter pack, it means that we're doing a "simple"
9268 substitution from inside tsubst_pack_expansion. Just
9269 return the local specialization (which will be a single
9270 parm). */
9277 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9278 the parameters in this function parameter pack. */
9282 {
9285 /* Zero-length parameter packs are boring. Just substitute
9286 into the chain. */
9290 }
9291 else
9292 {
9293 /* All we did was update the type. Make a note of that. */
9296 }
9297 }
9299 /* Loop through all of the parameter's we'll build. When T is
9300 a function parameter pack, LEN is the number of expanded
9301 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9304 {
9310 /* An argument of a function parameter pack is not a parameter
9311 pack. */
9315 /* We're on the Ith parameter of the function parameter
9316 pack. */
9317 {
9318 /* Get the Ith type. */
9322 /* Rename the parameter to include the index. */
9325 }
9327 /* We're dealing with a normal parameter. */
9335 {
9338 else
9341 }
9351 /* Keep track of the first new parameter we
9352 generate. That's what will be returned to the
9353 caller. */
9357 /* Build a proper chain of parameters when substituting
9358 into a function parameter pack. */
9361 }
9367 /* FIRST_R contains the start of the chain we've built. */
9369 }
9373 {
9374 tree type;
9383 /* DECL_INITIAL gives the number of bits in a bit-field. */
9388 /* We don't have to set DECL_CONTEXT here; it is set by
9389 finish_member_declaration. */
9396 }
9400 /* We reach here only for member using decls. */
9402 {
9403 r = do_class_using_decl
9408 else
9409 {
9412 }
9413 }
9414 else
9415 {
9418 }
9423 {
9426 tree spec;
9428 tree ctx;
9434 {
9435 /* If this is the canonical decl, we don't have to
9436 mess with instantiations, and often we can't (for
9437 typename, template type parms and such). Note that
9438 TYPE_NAME is not correct for the above test if
9439 we've copied the type for a typedef. */
9445 }
9447 /* Check to see if we already have the specialization we
9448 need. */
9451 {
9452 /* T is a static data member or namespace-scope entity.
9453 We have to substitute into namespace-scope variables
9454 (even though such entities are never templates) because
9455 of cases like:
9457 template <class T> void f() { extern T t; }
9459 where the entity referenced is not known until
9460 instantiation time. */
9464 {
9466 complain,
9468 /* If CTX is unchanged, then T is in fact the
9469 specialization we want. That situation occurs when
9470 referencing a static data member within in its own
9471 class. We can use pointer equality, rather than
9472 same_type_p, because DECL_CONTEXT is always
9473 canonical. */
9476 }
9479 {
9485 }
9486 }
9487 else
9488 {
9489 /* A local variable. */
9491 /* Subsequent calls to pushdecl will fill this in. */
9494 }
9495 /* If we already have the specialization we need, there is
9496 nothing more to do. */
9498 {
9501 }
9503 /* Create a new node for the specialization we need. */
9506 {
9509 else
9514 }
9516 {
9517 /* Even if the original location is out of scope, the
9518 newly substituted one is not. */
9525 {
9526 /* It may seem that this case cannot occur, since:
9528 typedef void f();
9529 void g() { f x; }
9531 declares a function, not a variable. However:
9533 typedef void f();
9534 template <typename T> void g() { T t; }
9535 template void g<f>();
9537 is an attempt to declare a variable with function
9538 type. */
9540 /* R is not yet sufficiently initialized, so we
9541 just use its name. */
9544 }
9551 {
9556 }
9557 }
9563 /* Clear out the mangled name and RTL for the instantiation. */
9567 /* The initializer must not be expanded until it is required;
9568 see [temp.inst]. */
9574 {
9575 /* Possibly limit visibility based on template args. */
9578 {
9582 }
9584 }
9587 {
9588 /* A static data member declaration is always marked
9589 external when it is declared in-class, even if an
9590 initializer is present. We mimic the non-template
9591 processing here. */
9597 }
9599 {
9600 /* We're substituting this var in a decltype outside of its
9601 scope, such as for a lambda return type. Don't add it to
9602 local_specializations, do perform auto deduction. */
9604 tree init
9609 {
9612 }
9613 }
9614 else
9623 /* Preserve a typedef that names a type. */
9625 {
9628 }
9631 }
9636 }
9637 #undef RETURN
9639 out:
9640 /* Restore the file and line information. */
9644 }
9646 /* Substitute into the ARG_TYPES of a function type. */
9648 static tree
9650 tree args,
9651 tsubst_flags_t complain,
9652 tree in_decl)
9653 {
9654 tree remaining_arg_types;
9658 tree default_arg;
9669 {
9670 /* For a pack expansion, perform substitution on the
9671 entire expression. Later on, we'll handle the arguments
9672 one-by-one. */
9677 /* So that we'll spin through the parameters, one by one. */
9679 else
9680 {
9681 /* We only partially substituted into the parameter
9682 pack. Our type is TYPE_PACK_EXPANSION. */
9685 }
9686 }
9699 {
9701 {
9705 }
9707 }
9709 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9710 top-level qualifiers as required. */
9713 /* We do not substitute into default arguments here. The standard
9714 mandates that they be instantiated only when needed, which is
9715 done in build_over_call. */
9719 {
9720 /* We've instantiated a template before its default arguments
9721 have been parsed. This can happen for a nested template
9722 class, and is not an error unless we require the default
9723 argument in a call of this function. */
9724 remaining_arg_types =
9727 remaining_arg_types);
9728 }
9729 else
9730 remaining_arg_types =
9732 }
9735 }
9737 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9738 *not* handle the exception-specification for FNTYPE, because the
9739 initial substitution of explicitly provided template parameters
9740 during argument deduction forbids substitution into the
9741 exception-specification:
9743 [temp.deduct]
9745 All references in the function type of the function template to the
9746 corresponding template parameters are replaced by the specified tem-
9747 plate argument values. If a substitution in a template parameter or
9748 in the function type of the function template results in an invalid
9749 type, type deduction fails. [Note: The equivalent substitution in
9750 exception specifications is done only when the function is instanti-
9751 ated, at which point a program is ill-formed if the substitution
9752 results in an invalid type.] */
9754 static tree
9756 tree args,
9757 tsubst_flags_t complain,
9758 tree in_decl)
9759 {
9760 tree return_type;
9761 tree arg_types;
9762 tree fntype;
9764 /* The TYPE_CONTEXT is not used for function/method types. */
9767 /* Substitute the return type. */
9771 /* The standard does not presently indicate that creation of a
9772 function type with an invalid return type is a deduction failure.
9773 However, that is clearly analogous to creating an array of "void"
9774 or a reference to a reference. This is core issue #486. */
9777 {
9779 {
9782 else
9784 }
9786 }
9788 /* Substitute the argument types. */
9794 /* Construct a new type node and return it. */
9796 {
9799 }
9800 else
9801 {
9804 {
9805 /* [temp.deduct]
9807 Type deduction may fail for any of the following
9808 reasons:
9810 -- Attempting to create "pointer to member of T" when T
9811 is not a class type. */
9814 r);
9816 }
9820 }
9824 }
9826 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9827 ARGS into that specification, and return the substituted
9828 specification. If there is no specification, return NULL_TREE. */
9830 static tree
9832 tree args,
9833 tsubst_flags_t complain,
9834 tree in_decl)
9835 {
9836 tree specs;
9837 tree new_specs;
9842 {
9843 /* A noexcept-specifier. */
9844 new_specs = tsubst_copy_and_build
9848 }
9850 {
9853 else
9855 {
9856 tree spec;
9861 {
9862 /* Expand the pack expansion type. */
9865 in_decl);
9871 else
9872 {
9873 /* We're substituting into a member template, so
9874 we got a TYPE_PACK_EXPANSION back. Add that
9875 expansion and move on. */
9879 expanded_specs,
9880 complain);
9883 }
9884 }
9887 {
9890 else
9895 complain);
9896 }
9899 }
9900 }
9902 }
9904 /* Take the tree structure T and replace template parameters used
9905 therein with the argument vector ARGS. IN_DECL is an associated
9906 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9907 Issue error and warning messages under control of COMPLAIN. Note
9908 that we must be relatively non-tolerant of extensions here, in
9909 order to preserve conformance; if we allow substitutions that
9910 should not be allowed, we may allow argument deductions that should
9911 not succeed, and therefore report ambiguous overload situations
9912 where there are none. In theory, we could allow the substitution,
9913 but indicate that it should have failed, and allow our caller to
9914 make sure that the right thing happens, but we don't try to do this
9915 yet.
9917 This function is used for dealing with types, decls and the like;
9918 for expressions, use tsubst_expr or tsubst_copy. */
9920 tree
9922 {
9941 else
9946 /* Reuse typedefs. We need to do this to handle dependent attributes,
9947 such as attribute aligned. */
9951 {
9957 {
9961 }
9966 else
9967 /* The typedef is from a non-template context. */
9971 {
9973 r = cp_build_qualified_type_real
9977 }
9978 /* Else we must be instantiating the typedef, so fall through. */
9979 }
9992 {
10019 {
10025 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10026 needed. */
10034 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10035 with TREE_SIDE_EFFECTS that indicates this is not an integral
10036 constant expression. */
10039 {
10042 }
10048 {
10052 }
10054 /* [temp.deduct]
10056 Type deduction may fail for any of the following
10057 reasons:
10059 Attempting to create an array with a size that is
10060 zero or negative. */
10062 /* We must fail if performing argument deduction (as
10063 indicated by the state of complain), so that
10064 another substitution can be found. */
10068 {
10073 }
10076 }
10082 {
10095 {
10099 /* See through ARGUMENT_PACK_SELECT arguments. */
10101 }
10106 {
10108 /* If ARG is an argument pack, we don't actually want to
10109 perform a substitution here, because substitutions
10110 for argument packs are only done
10111 element-by-element. We can get to this point when
10112 substituting the type of a non-type template
10113 parameter pack, when that type actually contains
10114 template parameter packs from an outer template, e.g.,
10116 template<typename... Types> struct A {
10117 template<Types... Values> struct B { };
10118 }; */
10122 {
10128 return cp_build_qualified_type_real
10130 }
10132 {
10133 /* We are processing a type constructed from a
10134 template template parameter. */
10140 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10141 are resolving nested-types in the signature of a
10142 member function templates. Otherwise ARG is a
10143 TEMPLATE_DECL and is the real template to be
10144 instantiated. */
10152 complain);
10153 return cp_build_qualified_type_real
10155 }
10156 else
10157 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10159 }
10162 /* This can happen during the attempted tsubst'ing in
10163 unify. This means that we don't yet have any information
10164 about the template parameter in question. */
10167 /* If we get here, we must have been looking at a parm for a
10168 more deeply nested template. Make a new version of this
10169 template parameter, but with a lower level. */
10171 {
10176 {
10178 r = cp_build_qualified_type_real
10182 }
10183 else
10184 {
10195 /* We have reduced the level of the template
10196 template parameter, but not the levels of its
10197 template parameters, so canonical_type_parameter
10198 will not be able to find the canonical template
10199 template parameter for this level. Thus, we
10200 require structural equality checking to compare
10201 TEMPLATE_TEMPLATE_PARMs. */
10205 else
10209 {
10217 }
10218 }
10227 }
10230 }
10233 {
10241 {
10245 }
10248 {
10252 }
10255 {
10259 }
10265 }
10268 /* We should never be tsubsting a binfo. */
10272 /* A vector of template arguments. */
10278 {
10287 /* [temp.deduct]
10289 Type deduction may fail for any of the following
10290 reasons:
10292 -- Attempting to create a pointer to reference type.
10293 -- Attempting to create a reference to a reference type or
10294 a reference to void.
10296 Core issue 106 says that creating a reference to a reference
10297 during instantiation is no longer a cause for failure. We
10298 only enforce this check in strict C++98 mode. */
10302 {
10305 /* We keep track of the last time we issued this error
10306 message to avoid spewing a ton of messages during a
10307 single bad template instantiation. */
10310 {
10315 else
10318 }
10321 }
10323 {
10327 }
10329 /* In C++0x, during template argument substitution, when there is an
10330 attempt to create a reference to a reference type, reference
10331 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10333 "If a template-argument for a template-parameter T names a type
10334 that is a reference to a type A, an attempt to create the type
10335 'lvalue reference to cv T' creates the type 'lvalue reference to
10336 A,' while an attempt to create the type type rvalue reference to
10337 cv T' creates the type T"
10338 */
10339 r = cp_build_reference_type
10342 else
10347 /* Will this ever be needed for TYPE_..._TO values? */
10351 }
10353 {
10356 {
10357 /* [temp.deduct]
10359 Type deduction may fail for any of the following
10360 reasons:
10362 -- Attempting to create "pointer to member of T" when T
10363 is not a class type. */
10367 }
10369 {
10373 }
10375 {
10379 }
10382 {
10383 /* The type of the implicit object parameter gets its
10384 cv-qualifiers from the FUNCTION_TYPE. */
10385 tree memptr;
10389 complain);
10390 }
10391 else
10394 complain);
10395 }
10398 {
10399 tree fntype;
10400 tree specs;
10405 /* Substitute the exception specification. */
10407 in_decl);
10413 }
10415 {
10420 /* As an optimization, we avoid regenerating the array type if
10421 it will obviously be the same as T. */
10425 /* These checks should match the ones in grokdeclarator.
10427 [temp.deduct]
10429 The deduction may fail for any of the following reasons:
10431 -- Attempting to create an array with an element type that
10432 is void, a function type, or a reference type, or [DR337]
10433 an abstract class type. */
10437 {
10441 }
10443 {
10446 type);
10448 }
10453 {
10456 }
10459 }
10463 {
10472 }
10476 {
10482 }
10485 {
10495 {
10499 }
10501 {
10502 /* Normally, make_typename_type does not require that the CTX
10503 have complete type in order to allow things like:
10505 template <class T> struct S { typename S<T>::X Y; };
10507 But, such constructs have already been resolved by this
10508 point, so here CTX really should have complete type, unless
10509 it's a partial instantiation. */
10513 {
10517 }
10518 }
10525 {
10528 }
10531 {
10538 }
10540 return cp_build_qualified_type_real
10542 }
10545 {
10557 }
10565 {
10573 }
10576 {
10584 }
10587 {
10588 tree type;
10604 complain);
10605 }
10608 {
10609 tree type;
10625 else
10626 type = finish_decltype_type
10631 complain);
10632 }
10636 {
10640 tree packed_out =
10642 args,
10643 complain,
10644 in_decl);
10647 /* For template nontype argument packs, also substitute into
10648 the type. */
10653 }
10660 }
10661 }
10663 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10664 type of the expression on the left-hand side of the "." or "->"
10665 operator. */
10667 static tree
10670 {
10671 tree name;
10672 tree qualifying_scope;
10673 tree fns;
10674 tree optype;
10678 /* A baselink indicates a function from a base class. Both the
10679 BASELINK_ACCESS_BINFO and the base class referenced may
10680 indicate bases of the template class, rather than the
10681 instantiated class. In addition, lookups that were not
10682 ambiguous before may be ambiguous now. Therefore, we perform
10683 the lookup again. */
10690 {
10697 }
10703 /* If lookup found a single function, mark it as used at this
10704 point. (If it lookup found multiple functions the one selected
10705 later by overload resolution will be marked as used at that
10706 point.) */
10712 /* Add back the template arguments, if present. */
10717 template_args);
10718 /* Update the conversion operator type. */
10724 qualifying_scope,
10725 object_type);
10726 }
10728 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10729 true if the qualified-id will be a postfix-expression in-and-of
10730 itself; false if more of the postfix-expression follows the
10731 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10732 of "&". */
10734 static tree
10738 {
10739 tree expr;
10740 tree scope;
10741 tree name;
10743 tree template_args;
10747 /* Figure out what name to look up. */
10750 {
10757 }
10758 else
10759 {
10762 }
10764 /* Substitute into the qualifying scope. When there are no ARGS, we
10765 are just trying to simplify a non-dependent expression. In that
10766 case the qualifying scope may be dependent, and, in any case,
10767 substituting will not help. */
10770 {
10773 }
10774 else
10782 {
10784 {
10785 /* A BIT_NOT_EXPR is used to represent a destructor. */
10787 {
10791 }
10792 else
10795 }
10796 else
10800 {
10802 {
10806 }
10808 }
10809 }
10812 {
10814 scope);
10815 /* Remember that there was a reference to this entity. */
10817 }
10820 {
10826 }
10835 {
10836 expr = (adjust_result_of_qualified_name_lookup
10838 expr = (finish_qualified_id_expr
10842 }
10844 /* Expressions do not generally have reference type. */
10846 /* However, if we're about to form a pointer-to-member, we just
10847 want the referenced member referenced. */
10852 }
10854 /* Like tsubst, but deals with expressions. This function just replaces
10855 template parms; to finish processing the resultant expression, use
10856 tsubst_expr. */
10858 static tree
10860 {
10862 tree r;
10870 {
10875 {
10876 tree c;
10877 /* This can happen for a parameter name used later in a function
10878 declaration (such as in a late-specified return type). Just
10879 make a dummy decl, since it's only used for its type. */
10881 /* We copy T because want to tsubst the PARM_DECL only,
10882 not the following PARM_DECLs that are chained to T. */
10885 /* Give it the template pattern as its context; its true context
10886 hasn't been instantiated yet and this is good enough for
10887 mangling. */
10889 }
10897 {
10898 tree enum_type;
10899 tree v;
10903 /* There is no need to substitute into namespace-scope
10904 enumerators. */
10907 /* If ARGS is NULL, then T is known to be non-dependent. */
10911 /* Unfortunately, we cannot just call lookup_name here.
10912 Consider:
10914 template <int I> int f() {
10915 enum E { a = I };
10916 struct S { void g() { E e = a; } };
10917 };
10919 When we instantiate f<7>::S::g(), say, lookup_name is not
10920 clever enough to find f<7>::a. */
10921 enum_type
10931 /* We didn't find the name. That should never happen; if
10932 name-lookup found it during preliminary parsing, we
10933 should find it again here during instantiation. */
10935 }
10940 {
10941 tree ctx;
10946 {
10949 {
10953 }
10955 }
10956 }
10979 {
10980 /* Template template argument like the following example need
10981 special treatment:
10983 template <template <class> class TT> struct C {};
10984 template <class T> struct D {
10985 template <class U> struct E {};
10986 C<E> c; // #1
10987 };
10988 D<int> d; // #2
10990 We are processing the template argument `E' in #1 for
10991 the template instantiation #2. Originally, `E' is a
10992 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10993 have to substitute this with one having context `D<int>'. */
10997 }
10998 else
10999 /* Ordinary template template argument. */
11008 return build1
11014 {
11015 /* We only want to compute the number of arguments. */
11029 {
11036 else
11039 }
11040 else
11042 }
11043 /* Fall through */
11057 return build1
11062 {
11063 tree object;
11064 tree name;
11069 {
11073 }
11076 {
11086 }
11091 in_decl);
11092 else
11095 }
11133 return build_nt
11146 return build_nt
11153 {
11161 }
11166 {
11167 r = build_nt
11173 }
11176 {
11177 r = build_nt
11183 }
11186 {
11187 r = build_nt
11193 }
11196 {
11197 /* Substituted template arguments */
11206 }
11209 {
11229 }
11254 {
11257 }
11258 else
11262 /* This is handled by tsubst_copy_and_build. */
11267 in_decl),
11271 /* We shouldn't have built any of these during initial template
11272 generation. Instead, they should be built during instantiation
11273 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11290 }
11291 }
11293 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11295 static tree
11297 tree in_decl)
11298 {
11302 {
11308 {
11311 {
11317 }
11318 /* FALLTHRU */
11340 }
11341 }
11344 }
11346 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11348 static tree
11350 tree in_decl)
11351 {
11352 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11377 #undef RECUR
11378 }
11380 /* Substitute one OMP_FOR iterator. */
11382 static void
11387 {
11388 #define RECUR(NODE) \
11389 tsubst_expr ((NODE), args, complain, in_decl, \
11390 integral_constant_expression_p)
11399 {
11406 }
11410 {
11416 complain);
11417 else
11424 }
11427 {
11428 tree c;
11430 {
11441 }
11443 {
11448 {
11451 }
11452 }
11453 }
11459 else
11463 {
11474 {
11481 }
11482 else
11488 {
11494 }
11498 {
11505 }
11506 else
11512 }
11518 #undef RECUR
11519 }
11521 /* Like tsubst_copy for expressions, etc. but also does semantic
11522 processing. */
11524 static tree
11527 {
11528 #define RECUR(NODE) \
11529 tsubst_expr ((NODE), args, complain, in_decl, \
11530 integral_constant_expression_p)
11543 {
11545 {
11546 tree_stmt_iterator i;
11550 }
11565 else
11574 {
11575 tree decl;
11576 tree init;
11582 {
11585 tree decl;
11593 else
11595 }
11596 else
11597 {
11601 {
11602 /* By marking the declaration as instantiated, we avoid
11603 trying to instantiate it. Since instantiate_decl can't
11604 handle local variables, and since we've already done
11605 all that needs to be done, that's the right thing to
11606 do. */
11611 /* Anonymous aggregates are a special case. */
11613 else
11614 {
11618 {
11619 /* For __PRETTY_FUNCTION__ we have to adjust the
11620 initializer. */
11624 }
11625 else
11626 {
11630 /* If we had an initializer but it
11631 instantiated to nothing,
11632 value-initialize the object. This will
11633 only occur when the initializer was a
11634 pack expansion where the parameter packs
11635 used in that expansion were of length
11636 zero. */
11638 else
11640 }
11643 }
11644 }
11645 }
11647 /* A DECL_EXPR can also be used as an expression, in the condition
11648 clause of an if/for/while construct. */
11650 }
11688 {
11692 }
11700 else
11708 else
11735 {
11737 tree label;
11742 }
11748 /* Computed goto's must be tsubst'd into. On the other hand,
11749 non-computed gotos must not be; the identifier in question
11750 will have no binding. */
11752 else
11758 tmp = finish_asm_stmt
11765 {
11770 }
11775 {
11780 }
11781 else
11782 {
11787 else
11794 else
11800 else
11802 }
11806 {
11810 {
11812 /* Prevent instantiate_decl from trying to instantiate
11813 this variable. We've already done all that needs to be
11814 done. */
11817 }
11822 }
11830 {
11831 tree condition =
11833 args,
11840 }
11861 {
11876 integral_constant_expression_p);
11885 {
11889 }
11890 else
11891 {
11899 }
11913 }
11944 {
11949 }
11965 integral_constant_expression_p);
11966 }
11969 #undef RECUR
11970 }
11972 /* T is a postfix-expression that is not being used in a function
11973 call. Return the substituted version of T. */
11975 static tree
11977 tsubst_flags_t complain,
11978 tree in_decl)
11979 {
11983 else
11989 }
11991 /* Like tsubst but deals with expressions and performs semantic
11992 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11994 tree
11996 tree args,
11997 tsubst_flags_t complain,
11998 tree in_decl,
12001 {
12002 #define RECUR(NODE) \
12003 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12005 integral_constant_expression_p)
12007 tree op1;
12013 {
12016 /* Fall through. */
12018 {
12019 tree decl;
12020 cp_id_kind idk;
12025 {
12028 }
12030 /* Look up the name. */
12033 /* By convention, expressions use ERROR_MARK_NODE to indicate
12034 failure, not NULL_TREE. */
12040 integral_constant_expression_p,
12048 input_location);
12054 }
12057 {
12058 tree object;
12066 {
12069 }
12070 else
12077 else
12079 }
12082 {
12086 {
12087 /* A type conversion to reference type will be enclosed in
12088 such an indirect ref, but the substitution of the cast
12089 will have also added such an indirect ref. */
12092 }
12093 else
12096 }
12099 return build_nop
12108 {
12109 tree type;
12110 tree op;
12115 {
12120 }
12125 {
12138 }
12139 }
12157 complain);
12164 else
12166 in_decl);
12203 return build_x_binary_op
12207 ? ERROR_MARK
12211 ? ERROR_MARK
12214 complain);
12227 /* Fall through */
12232 {
12233 /* When there are no ARGS, we are trying to evaluate a
12234 non-dependent expression from the parser. Trying to do
12235 the substitutions may not work. */
12238 }
12239 else
12240 {
12248 }
12252 else
12268 {
12269 tree r = build_x_modify_expr
12273 complain);
12274 /* TREE_NO_WARNING must be set if either the expression was
12275 parenthesized or it uses an operator such as >>= rather
12276 than plain assignment. In the former case, it was already
12277 set and must be copied. In the latter case,
12278 build_x_modify_expr sets it and it must not be reset
12279 here. */
12283 }
12288 /* Remember that there was a reference to this entity. */
12294 {
12299 tree ret;
12303 else
12304 {
12308 }
12310 /* If there was an initializer in the original tree, but it
12311 instantiated to an empty list, then we should pass a
12312 non-NULL empty vector to tell build_new that it was an
12313 empty initializer() rather than no initializer. This can
12314 only happen when the initializer is a pack expansion whose
12315 parameter packs are of length zero. */
12318 else
12319 {
12323 else
12324 {
12327 }
12328 }
12335 complain);
12343 }
12346 return delete_sanity
12355 complain);
12358 {
12359 tree function;
12364 tree ret;
12367 /* When we parsed the expression, we determined whether or
12368 not Koenig lookup should be performed. */
12371 {
12376 }
12377 else
12378 {
12380 {
12386 }
12387 else
12391 in_decl,
12393 integral_constant_expression_p);
12397 }
12402 {
12408 else
12409 {
12410 /* Expand the pack expansion and push each entry onto
12411 CALL_ARGS. */
12414 {
12419 {
12424 }
12425 }
12426 else
12427 {
12428 /* A partial substitution. Add one entry. */
12430 }
12431 }
12432 }
12434 /* We do not perform argument-dependent lookup if normal
12435 lookup finds a non-function, in accordance with the
12436 expected resolution of DR 218. */
12439 /* If lookup found a member function, the Koenig lookup is
12440 not appropriate, even if an unqualified-name was used
12441 to denote the function. */
12444 /* Only do this when substitution turns a dependent call
12445 into a non-dependent call. */
12451 {
12455 }
12457 /* Remember that there was a reference to this entity. */
12464 {
12469 complain);
12470 else
12471 ret = (build_new_method_call
12477 complain));
12478 }
12479 else
12482 koenig_p,
12483 complain);
12488 }
12491 return build_x_conditional_expr
12495 complain);
12498 return finish_pseudo_destructor_expr
12504 {
12512 {
12513 /* We have pack expansions, so expand those and
12514 create a new list out of it. */
12517 tree chain;
12520 /* Expand the argument expressions. */
12528 /* Build the rest of the list. */
12533 /* Determine the number of arguments. */
12535 {
12538 }
12541 else
12542 {
12543 /* Since we only performed a partial substitution into
12544 the argument pack, we only return a single list
12545 node. */
12552 }
12554 /* Convert the argument vectors into a TREE_LIST */
12557 {
12558 /* Grab the Ith values. */
12559 i--;
12562 value
12566 /* Build the list (backwards). */
12568 }
12571 }
12587 }
12590 {
12591 tree object;
12592 tree object_type;
12593 tree member;
12597 /* Remember that there was a reference to this entity. */
12607 else
12613 {
12615 {
12620 {
12623 }
12625 {
12629 }
12630 }
12631 }
12634 {
12635 tree tmpl;
12636 tree args;
12638 /* Lookup the template functions now that we know what the
12639 scope is. */
12646 {
12649 args);
12650 member = (adjust_result_of_qualified_name_lookup
12652 object_type));
12653 }
12654 else
12655 {
12657 input_location);
12659 }
12660 }
12664 {
12666 {
12670 else
12673 }
12675 }
12681 complain);
12682 }
12685 return build_throw
12689 {
12697 tree r;
12702 /* digest_init will do the wrong thing if we let it. */
12706 /* We do not want to process the index of aggregate
12707 initializers as they are identifier nodes which will be
12708 looked up by digest_init. */
12714 {
12719 {
12720 /* Substitute into the pack expansion. */
12722 in_decl);
12725 ;
12727 /* Just move the argument into place. */
12729 else
12730 {
12731 /* Update the length of the final CONSTRUCTOR
12732 arguments vector, and note that we will need to
12733 copy.*/
12736 }
12737 }
12738 else
12740 }
12743 {
12748 idx++)
12749 {
12751 {
12756 }
12757 else
12759 }
12760 }
12769 }
12772 {
12777 }
12782 /* Fall through */
12785 {
12789 /* If the original type was a reference, we'll be wrapped in
12790 the appropriate INDIRECT_REF. */
12793 }
12798 in_decl));
12804 {
12813 }
12816 {
12822 integral_constant_expression_p);
12826 /* If the resulting list of expression statement is empty,
12827 fold it further into void_zero_node. */
12832 }
12836 /* As in finish_id_expression, we resolve enumeration constants
12837 to their underlying values. */
12839 {
12842 }
12846 {
12867 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12869 /* Now that we know visibility, instantiate the type so we have a
12870 declaration of the op() for later calls to lambda_function. */
12878 }
12881 /* Handle Objective-C++ constructs, if appropriate. */
12882 {
12883 tree subst
12888 }
12890 }
12892 #undef RECUR
12893 }
12895 /* Verify that the instantiated ARGS are valid. For type arguments,
12896 make sure that the type's linkage is ok. For non-type arguments,
12897 make sure they are constants if they are integral or enumerations.
12898 Emit an error under control of COMPLAIN, and return TRUE on error. */
12900 static bool
12902 {
12904 {
12914 }
12916 {
12917 /* [basic.link]: A name with no linkage (notably, the name
12918 of a class or enumeration declared in a local scope)
12919 shall not be used to declare an entity with linkage.
12920 This implies that names with no linkage cannot be used as
12921 template arguments
12923 DR 757 relaxes this restriction for C++0x. */
12928 {
12929 /* DR 488 makes use of a type with no linkage cause
12930 type deduction to fail. */
12932 {
12935 else
12938 }
12940 }
12941 /* In order to avoid all sorts of complications, we do not
12942 allow variably-modified types as template arguments. */
12944 {
12948 }
12949 }
12950 /* A non-type argument of integral or enumerated type must be a
12951 constant. */
12955 {
12959 }
12961 }
12963 static bool
12965 {
12970 {
12973 }
12977 }
12979 /* Instantiate the indicated variable or function template TMPL with
12980 the template arguments in TARG_PTR. */
12982 tree
12984 {
12986 tree fndecl;
12987 tree gen_tmpl;
12988 tree spec;
12989 HOST_WIDE_INT saved_processing_template_decl;
12996 /* If this function is a clone, handle it specially. */
12998 {
12999 tree spec;
13000 tree clone;
13002 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13003 DECL_CLONED_FUNCTION. */
13009 /* Look for the clone. */
13013 /* We should always have found the clone by now. */
13016 }
13018 /* Check to see if we already have this specialization. */
13021 /* The TMPL is a partial instantiation. To get a full set of
13022 arguments we must add the arguments used to perform the
13023 partial instantiation. */
13025 targ_ptr);
13027 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13028 but it doesn't seem to be on the hot path. */
13040 complain))
13043 /* We are building a FUNCTION_DECL, during which the access of its
13044 parameters and return types have to be checked. However this
13045 FUNCTION_DECL which is the desired context for access checking
13046 is not built yet. We solve this chicken-and-egg problem by
13047 deferring all checks until we have the FUNCTION_DECL. */
13050 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13051 (because, for example, we have encountered a non-dependent
13052 function call in the body of a template function and must now
13053 determine which of several overloaded functions will be called),
13054 within the instantiation itself we are not processing a
13055 template. */
13058 /* Substitute template parameters to obtain the specialization. */
13065 /* Now we know the specialization, compute access previously
13066 deferred. */
13069 /* Some typedefs referenced from within the template code need to be access
13070 checked at template instantiation time, i.e now. These types were
13071 added to the template at parsing time. Let's get those and perfom
13072 the acces checks then. */
13078 /* The DECL_TI_TEMPLATE should always be the immediate parent
13079 template, not the most general template. */
13082 /* If we've just instantiated the main entry point for a function,
13083 instantiate all the alternate entry points as well. We do this
13084 by cloning the instantiation of the main entry point, not by
13085 instantiating the template clones. */
13090 }
13092 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13093 NARGS elements of the arguments that are being used when calling
13094 it. TARGS is a vector into which the deduced template arguments
13095 are placed.
13097 Return zero for success, 2 for an incomplete match that doesn't resolve
13098 all the types, and 1 for complete failure. An error message will be
13099 printed only for an incomplete match.
13101 If FN is a conversion operator, or we are trying to produce a specific
13102 specialization, RETURN_TYPE is the return type desired.
13104 The EXPLICIT_TARGS are explicit template arguments provided via a
13105 template-id.
13107 The parameter STRICT is one of:
13109 DEDUCE_CALL:
13110 We are deducing arguments for a function call, as in
13111 [temp.deduct.call].
13113 DEDUCE_CONV:
13114 We are deducing arguments for a conversion function, as in
13115 [temp.deduct.conv].
13117 DEDUCE_EXACT:
13118 We are deducing arguments when doing an explicit instantiation
13119 as in [temp.explicit], when determining an explicit specialization
13120 as in [temp.expl.spec], or when taking the address of a function
13121 template, as in [temp.deduct.funcaddr]. */
13123 int
13125 tree explicit_targs,
13126 tree targs,
13129 tree return_type,
13130 unification_kind_t strict,
13132 {
13133 tree parms;
13134 tree fntype;
13142 {
13143 /* [temp.deduct]
13145 The specified template arguments must match the template
13146 parameters in kind (i.e., type, nontype, template), and there
13147 must not be more arguments than there are parameters;
13148 otherwise type deduction fails.
13150 Nontype arguments must match the types of the corresponding
13151 nontype template parameters, or must be convertible to the
13152 types of the corresponding nontype parameters as specified in
13153 _temp.arg.nontype_, otherwise type deduction fails.
13155 All references in the function type of the function template
13156 to the corresponding template parameters are replaced by the
13157 specified template argument values. If a substitution in a
13158 template parameter or in the function type of the function
13159 template results in an invalid type, type deduction fails. */
13162 tree converted_args;
13168 converted_args
13175 /* Substitute the explicit args into the function type. This is
13176 necessary so that, for instance, explicitly declared function
13177 arguments can match null pointed constants. If we were given
13178 an incomplete set of explicit args, we must not do semantic
13179 processing during substitution as we could create partial
13180 instantiations. */
13182 {
13186 /* Dig out the actual parm. */
13189 {
13192 }
13194 {
13197 }
13200 {
13202 tree targ;
13205 /* Mark the argument pack as "incomplete". We could
13206 still deduce more arguments during unification. */
13209 {
13213 }
13215 /* We have some incomplete argument packs. */
13217 }
13218 }
13221 /* Any substitution is guaranteed to be incomplete if there
13222 are incomplete argument packs, because we can still deduce
13223 more arguments. */
13225 else
13235 /* Place the explicitly specified arguments in TARGS. */
13238 }
13240 /* Never do unification on the 'this' parameter. */
13244 {
13253 }
13255 /* We allow incomplete unification without an error message here
13256 because the standard doesn't seem to explicitly prohibit it. Our
13257 callers must be ready to deal with unification failures in any
13258 event. */
13264 {
13267 /* Clear the "incomplete" flags on all argument packs. */
13269 {
13272 {
13275 }
13276 }
13277 }
13279 /* Now that we have bindings for all of the template arguments,
13280 ensure that the arguments deduced for the template template
13281 parameters have compatible template parameter lists. We cannot
13282 check this property before we have deduced all template
13283 arguments, because the template parameter types of a template
13284 template parameter might depend on prior template parameters
13285 deduced after the template template parameter. The following
13286 ill-formed example illustrates this issue:
13288 template<typename T, template<T> class C> void f(C<5>, T);
13290 template<int N> struct X {};
13292 void g() {
13293 f(X<5>(), 5l); // error: template argument deduction fails
13294 }
13296 The template parameter list of 'C' depends on the template type
13297 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13298 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13299 time that we deduce 'C'. */
13301 && !template_template_parm_bindings_ok_p
13306 /* All is well so far. Now, check:
13308 [temp.deduct]
13310 When all template arguments have been deduced, all uses of
13311 template parameters in nondeduced contexts are replaced with
13312 the corresponding deduced argument values. If the
13313 substitution results in an invalid type, as described above,
13314 type deduction fails. */
13315 {
13320 /* If we're looking for an exact match, check that what we got
13321 is indeed an exact match. It might not be if some template
13322 parameters are used in non-deduced contexts. */
13324 {
13327 tree sarg
13334 }
13335 }
13338 }
13340 /* Adjust types before performing type deduction, as described in
13341 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13342 sections are symmetric. PARM is the type of a function parameter
13343 or the return type of the conversion function. ARG is the type of
13344 the argument passed to the call, or the type of the value
13345 initialized with the result of the conversion function.
13346 ARG_EXPR is the original argument expression, which may be null. */
13348 static int
13352 tree arg_expr)
13353 {
13357 {
13362 {
13363 /* Swap PARM and ARG throughout the remainder of this
13364 function; the handling is precisely symmetric since PARM
13365 will initialize ARG rather than vice versa. */
13370 }
13373 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13374 too, but here handle it by stripping the reference from PARM
13375 rather than by adding it to ARG. */
13383 /* Nothing else to do in this case. */
13388 }
13391 {
13392 /* [temp.deduct.call]
13394 If P is not a reference type:
13396 --If A is an array type, the pointer type produced by the
13397 array-to-pointer standard conversion (_conv.array_) is
13398 used in place of A for type deduction; otherwise,
13400 --If A is a function type, the pointer type produced by
13401 the function-to-pointer standard conversion
13402 (_conv.func_) is used in place of A for type deduction;
13403 otherwise,
13405 --If A is a cv-qualified type, the top level
13406 cv-qualifiers of A's type are ignored for type
13407 deduction. */
13412 else
13414 }
13416 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13417 of the form T&&, where T is a template parameter, and the argument
13418 is an lvalue, T is deduced as A& */
13426 /* [temp.deduct.call]
13428 If P is a cv-qualified type, the top level cv-qualifiers
13429 of P's type are ignored for type deduction. If P is a
13430 reference type, the type referred to by P is used for
13431 type deduction. */
13434 {
13437 }
13439 /* DR 322. For conversion deduction, remove a reference type on parm
13440 too (which has been swapped into ARG). */
13445 }
13447 /* Most parms like fn_type_unification.
13449 If SUBR is 1, we're being called recursively (to unify the
13450 arguments of a function or method parameter of a function
13451 template). */
13453 static int
13455 tree targs,
13456 tree xparms,
13460 unification_kind_t strict,
13462 {
13468 tree parms;
13477 /* Reset the number of non-defaulted template arguments contained
13478 in in TARGS. */
13482 {
13498 }
13500 again:
13508 {
13521 /* We can't deduce anything from this, but we might get all the
13522 template args from other function args. */
13525 /* Conversions will be performed on a function argument that
13526 corresponds with a function parameter that contains only
13527 non-deducible template parameters and explicitly specified
13528 template parameters. */
13530 {
13531 tree type;
13535 else
13542 flags))
13546 }
13549 {
13552 {
13553 /* [temp.deduct.type]
13555 A template-argument can be deduced from a pointer to
13556 function or pointer to member function argument if
13557 the set of overloaded functions does not contain
13558 function templates and at most one of a set of
13559 overloaded functions provides a unique match. */
13565 }
13570 }
13572 {
13577 arg_expr);
13583 }
13584 }
13590 {
13591 /* Unify the remaining arguments with the pack expansion type. */
13592 tree argvec;
13595 /* Allocate a TREE_VEC and copy in all of the arguments */
13600 /* Copy the parameter into parmvec. */
13606 /* Advance to the end of the list of parameters. */
13608 }
13610 /* Fail if we've reached the end of the parm list, and more args
13611 are present, and the parm list isn't variadic. */
13614 /* Fail if parms are left and they don't have default values. */
13622 {
13623 tree tparm;
13630 /* If this is an undeduced nontype parameter that depends on
13631 a type parameter, try another pass; its type may have been
13632 deduced from a later argument than the one from which
13633 this parameter can be deduced. */
13639 /* Core issue #226 (C++0x) [temp.deduct]:
13641 If a template argument has not been deduced, its
13642 default template argument, if any, is used.
13644 When we are in C++98 mode, TREE_PURPOSE will either
13645 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13646 to explicitly check cxx_dialect here. */
13648 {
13656 else
13657 {
13659 /* The position of the first default template argument,
13660 is also the number of non-defaulted arguments in TARGS.
13661 Record that. */
13665 }
13666 }
13668 /* If the type parameter is a parameter pack, then it will
13669 be deduced to an empty parameter pack. */
13671 {
13672 tree arg;
13675 {
13679 }
13680 else
13687 }
13690 }
13691 #ifdef ENABLE_CHECKING
13694 #endif
13697 }
13699 /* Subroutine of type_unification_real. Args are like the variables
13700 at the call site. ARG is an overloaded function (or template-id);
13701 we try deducing template args from each of the overloads, and if
13702 only one succeeds, we go with that. Modifies TARGS and returns
13703 true on success. */
13705 static bool
13707 tree targs,
13708 tree parm,
13709 tree arg,
13710 unification_kind_t strict,
13712 {
13719 {
13722 }
13723 else
13727 /* Handle `&x' where `x' is some static or non-static member
13728 function name. */
13734 /* Strip baselink information. */
13739 {
13740 /* If we got some explicit template args, we need to plug them into
13741 the affected templates before we try to unify, in case the
13742 explicit args will completely resolve the templates in question. */
13748 {
13759 {
13764 {
13767 }
13768 }
13770 }
13771 }
13774 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13775 -- but the deduction does not succeed because the expression is
13776 not just the function on its own. */
13778 else
13784 {
13787 }
13789 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13790 to function or pointer to member function argument if the set of
13791 overloaded functions does not contain function templates and at most
13792 one of a set of overloaded functions provides a unique match.
13794 So if we found multiple possibilities, we return success but don't
13795 deduce anything. */
13798 {
13803 }
13808 }
13810 /* Core DR 115: In contexts where deduction is done and fails, or in
13811 contexts where deduction is not done, if a template argument list is
13812 specified and it, along with any default template arguments, identifies
13813 a single function template specialization, then the template-id is an
13814 lvalue for the function template specialization. */
13816 tree
13818 {
13831 {
13834 }
13836 {
13839 }
13841 {
13844 }
13847 {
13851 /* If we got some explicit template args, we need to plug them into
13852 the affected templates before we try to unify, in case the
13853 explicit args will completely resolve the templates in question. */
13861 {
13872 {
13875 {
13878 }
13880 {
13883 }
13884 }
13886 }
13888 {
13900 }
13902 /* There were no good options and at least one bad one, so let the
13903 user know what the problem is. */
13905 }
13907 }
13909 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13910 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13911 different overloads deduce different arguments for a given parm.
13912 ADDR_P is true if the expression for which deduction is being
13913 performed was of the form "& fn" rather than simply "fn".
13915 Returns 1 on success. */
13917 static int
13919 tree orig_targs,
13920 tree targs,
13921 tree parm,
13922 tree arg,
13923 unification_kind_t strict,
13926 {
13928 tree tempargs;
13931 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13932 to function or pointer to member function argument if the set of
13933 overloaded functions does not contain function templates and at most
13934 one of a set of overloaded functions provides a unique match.
13936 So if this is a template, just return success. */
13948 /* We don't copy orig_targs for this because if we have already deduced
13949 some template args from previous args, unify would complain when we
13950 try to deduce a template parameter for the same argument, even though
13951 there isn't really a conflict. */
13958 /* First make sure we didn't deduce anything that conflicts with
13959 explicitly specified args. */
13961 {
13968 /* Since we're unifying against ourselves, we will fill in
13969 template args used in the function parm list with our own
13970 template parms. Discard them. */
13974 }
13977 {
13982 }
13985 }
13987 /* PARM is a template class (perhaps with unbound template
13988 parameters). ARG is a fully instantiated type. If ARG can be
13989 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
13990 TARGS are as for unify. */
13992 static tree
13994 {
13995 tree copy_of_targs;
14002 /* We need to make a new template argument vector for the call to
14003 unify. If we used TARGS, we'd clutter it up with the result of
14004 the attempted unification, even if this class didn't work out.
14005 We also don't want to commit ourselves to all the unifications
14006 we've already done, since unification is supposed to be done on
14007 an argument-by-argument basis. In other words, consider the
14008 following pathological case:
14010 template <int I, int J, int K>
14011 struct S {};
14013 template <int I, int J>
14014 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14016 template <int I, int J, int K>
14017 void f(S<I, J, K>, S<I, I, I>);
14019 void g() {
14020 S<0, 0, 0> s0;
14021 S<0, 1, 2> s2;
14023 f(s0, s2);
14024 }
14026 Now, by the time we consider the unification involving `s2', we
14027 already know that we must have `f<0, 0, 0>'. But, even though
14028 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14029 because there are two ways to unify base classes of S<0, 1, 2>
14030 with S<I, I, I>. If we kept the already deduced knowledge, we
14031 would reject the possibility I=1. */
14034 /* If unification failed, we're done. */
14040 }
14042 /* Given a template type PARM and a class type ARG, find the unique
14043 base type in ARG that is an instance of PARM. We do not examine
14044 ARG itself; only its base-classes. If there is not exactly one
14045 appropriate base class, return NULL_TREE. PARM may be the type of
14046 a partial specialization, as well as a plain template type. Used
14047 by unify. */
14049 static tree
14051 {
14053 tree binfo;
14059 /* The type could not be completed. */
14062 /* Walk in inheritance graph order. The search order is not
14063 important, and this avoids multiple walks of virtual bases. */
14065 {
14069 {
14070 /* If there is more than one satisfactory baseclass, then:
14072 [temp.deduct.call]
14074 If they yield more than one possible deduced A, the type
14075 deduction fails.
14077 applies. */
14082 }
14083 }
14086 }
14088 /* Returns the level of DECL, which declares a template parameter. */
14090 static int
14092 {
14094 {
14104 }
14106 }
14108 /* Decide whether ARG can be unified with PARM, considering only the
14109 cv-qualifiers of each type, given STRICT as documented for unify.
14110 Returns nonzero iff the unification is OK on that basis. */
14112 static int
14114 {
14120 {
14121 /* Although a CVR qualifier is ignored when being applied to a
14122 substituted template parameter ([8.3.2]/1 for example), that
14123 does not allow us to unify "const T" with "int&" because both
14124 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14125 It is ok when we're allowing additional CV qualifiers
14126 at the outer level [14.8.2.1]/3,1st bullet. */
14136 }
14147 }
14149 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14150 void
14152 {
14156 {
14159 }
14160 else
14161 {
14164 }
14165 }
14167 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14168 expansion at the end of PACKED_PARMS. Returns 0 if the type
14169 deduction succeeds, 1 otherwise. STRICT is the same as in
14170 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14171 call argument list. We'll need to adjust the arguments to make them
14172 types. SUBR tells us if this is from a recursive call to
14173 type_unification_real. */
14174 int
14178 {
14179 tree parm
14186 /* Determine the parameter packs we will be deducing from the
14187 pattern, and record their current deductions. */
14190 {
14194 /* Determine the index and level of this parameter pack. */
14197 /* Keep track of the parameter packs and their corresponding
14198 argument packs. */
14201 }
14203 /* Loop through all of the arguments that have not yet been
14204 unified and unify each with the pattern. */
14206 {
14209 /* For each parameter pack, clear out the deduced value so that
14210 we can deduce it again. */
14212 {
14217 }
14219 /* Unify the pattern with the current argument. */
14220 {
14227 {
14230 /* This mirrors what we do in type_unification_real. */
14232 {
14234 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14235 | UNIFY_ALLOW_MORE_CV_QUAL
14249 }
14252 {
14255 {
14256 /* [temp.deduct.type] A template-argument can be
14257 deduced from a pointer to function or pointer
14258 to member function argument if the set of
14259 overloaded functions does not contain function
14260 templates and at most one of a set of
14261 overloaded functions provides a unique
14262 match. */
14267 sub_strict)
14271 }
14274 {
14279 }
14280 }
14285 arg_strict |=
14288 }
14291 {
14292 /* For deduction from an init-list we need the actual list. */
14297 }
14298 }
14300 /* For each parameter pack, collect the deduced value. */
14302 {
14308 }
14309 }
14311 /* Verify that the results of unification with the parameter packs
14312 produce results consistent with what we've seen before, and make
14313 the deduced argument packs available. */
14315 {
14322 /* By default keep the original deduced argument pack.
14323 If necessary, more specific code is going to update the
14324 resulting deduced argument later down in this function. */
14328 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14329 actually deduce anything. */
14337 {
14338 /* Prepend the explicit arguments onto NEW_ARGS. */
14344 /* Copy the explicit arguments. */
14349 /* Copy the deduced arguments. */
14353 }
14356 {
14357 tree result;
14358 /* Build the deduced *_ARGUMENT_PACK. */
14360 {
14365 }
14366 else
14371 /* Note the deduced argument packs for this parameter
14372 pack. */
14374 }
14378 {
14379 /* We only had the explicitly-provided arguments before, but
14380 now we have a complete set of arguments. */
14386 }
14388 new_args))
14389 /* Inconsistent unification of this parameter pack. */
14391 }
14394 }
14396 /* Deduce the value of template parameters. TPARMS is the (innermost)
14397 set of template parameters to a template. TARGS is the bindings
14398 for those template parameters, as determined thus far; TARGS may
14399 include template arguments for outer levels of template parameters
14400 as well. PARM is a parameter to a template function, or a
14401 subcomponent of that parameter; ARG is the corresponding argument.
14402 This function attempts to match PARM with ARG in a manner
14403 consistent with the existing assignments in TARGS. If more values
14404 are deduced, then TARGS is updated.
14406 Returns 0 if the type deduction succeeds, 1 otherwise. The
14407 parameter STRICT is a bitwise or of the following flags:
14409 UNIFY_ALLOW_NONE:
14410 Require an exact match between PARM and ARG.
14411 UNIFY_ALLOW_MORE_CV_QUAL:
14412 Allow the deduced ARG to be more cv-qualified (by qualification
14413 conversion) than ARG.
14414 UNIFY_ALLOW_LESS_CV_QUAL:
14415 Allow the deduced ARG to be less cv-qualified than ARG.
14416 UNIFY_ALLOW_DERIVED:
14417 Allow the deduced ARG to be a template base class of ARG,
14418 or a pointer to a template base class of the type pointed to by
14419 ARG.
14420 UNIFY_ALLOW_INTEGER:
14421 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14422 case for more information.
14423 UNIFY_ALLOW_OUTER_LEVEL:
14424 This is the outermost level of a deduction. Used to determine validity
14425 of qualification conversions. A valid qualification conversion must
14426 have const qualified pointers leading up to the inner type which
14427 requires additional CV quals, except at the outer level, where const
14428 is not required [conv.qual]. It would be normal to set this flag in
14429 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14430 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14431 This is the outermost level of a deduction, and PARM can be more CV
14432 qualified at this point.
14433 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14434 This is the outermost level of a deduction, and PARM can be less CV
14435 qualified at this point. */
14437 static int
14439 {
14441 tree targ;
14442 tree tparm;
14445 /* I don't think this will do the right thing with respect to types.
14446 But the only case I've seen it in so far has been array bounds, where
14447 signedness is the only information lost, and I think that will be
14448 okay. */
14456 /* We can't deduce anything from this, but we might get all the
14457 template args from other function args. */
14460 /* If PARM uses template parameters, then we can't bail out here,
14461 even if ARG == PARM, since we won't record unifications for the
14462 template parameters. We might need them if we're trying to
14463 figure out which of two things is more specialized. */
14467 /* Handle init lists early, so the rest of the function can assume
14468 we're dealing with a type. */
14470 {
14475 /* Replace T with std::initializer_list<T> for deduction. */
14481 /* We can only deduce from an initializer list argument if the
14482 parameter is std::initializer_list; otherwise this is a
14483 non-deduced context. */
14489 {
14496 {
14498 /* It should only be possible to get here for a call. */
14500 elt_strict |= maybe_adjust_types_for_deduction
14503 }
14507 }
14509 /* If the std::initializer_list<T> deduction worked, replace the
14510 deduced A with std::initializer_list<A>. */
14512 {
14517 }
14519 }
14521 /* Immediately reject some pairs that won't unify because of
14522 cv-qualification mismatches. */
14525 /* It is the elements of the array which hold the cv quals of an array
14526 type, and the elements might be template type parms. We'll check
14527 when we recurse. */
14529 /* We check the cv-qualifiers when unifying with template type
14530 parameters below. We want to allow ARG `const T' to unify with
14531 PARM `T' for example, when computing which of two templates
14532 is more specialized, for example. */
14546 {
14550 /* In a type which contains a nested-name-specifier, template
14551 argument values cannot be deduced for template parameters used
14552 within the nested-name-specifier. */
14564 /* The PARM is not one we're trying to unify. Just check
14565 to see if it matches ARG. */
14572 /* Check for mixed types and values. */
14580 {
14581 /* ARG must be constructed from a template class or a template
14582 template parameter. */
14587 {
14590 tree parm_parms
14591 = DECL_INNERMOST_TEMPLATE_PARMS
14596 /* The resolution to DR150 makes clear that default
14597 arguments for an N-argument may not be used to bind T
14598 to a template template parameter with fewer than N
14599 parameters. It is not safe to permit the binding of
14600 default arguments as an extension, as that may change
14601 the meaning of a conforming program. Consider:
14603 struct Dense { static const unsigned int dim = 1; };
14605 template <template <typename> class View,
14606 typename Block>
14607 void operator+(float, View<Block> const&);
14609 template <typename Block,
14610 unsigned int Dim = Block::dim>
14611 struct Lvalue_proxy { operator float() const; };
14613 void
14614 test_1d (void) {
14615 Lvalue_proxy<Dense> p;
14616 float b;
14617 b + p;
14618 }
14620 Here, if Lvalue_proxy is permitted to bind to View, then
14621 the global operator+ will be used; if they are not, the
14622 Lvalue_proxy will be converted to float. */
14624 argvec,
14626 tf_none,
14632 /* Deduce arguments T, i from TT<T> or TT<i>.
14633 We check each element of PARMVEC and ARGVEC individually
14634 rather than the whole TREE_VEC since they can have
14635 different number of elements. */
14642 /* Check if the parameters end in a pack, making them
14643 variadic. */
14652 {
14656 UNIFY_ALLOW_NONE))
14658 }
14663 UNIFY_ALLOW_NONE,
14667 }
14670 /* Fall through to deduce template name. */
14671 }
14675 {
14676 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14678 /* Simple cases: Value already set, does match or doesn't. */
14683 }
14684 else
14685 {
14686 /* If PARM is `const T' and ARG is only `int', we don't have
14687 a match unless we are allowing additional qualification.
14688 If ARG is `const int' and PARM is just `T' that's OK;
14689 that binds `const int' to `T'. */
14694 /* Consider the case where ARG is `const volatile int' and
14695 PARM is `const T'. Then, T should be `volatile int'. */
14696 arg = cp_build_qualified_type_real
14701 /* Simple cases: Value already set, does match or doesn't. */
14707 /* Make sure that ARG is not a variable-sized array. (Note
14708 that were talking about variable-sized arrays (like
14709 `int[n]'), rather than arrays of unknown size (like
14710 `int[]').) We'll get very confused by such a type since
14711 the bound of the array will not be computable in an
14712 instantiation. Besides, such types are not allowed in
14713 ISO C++, so we can do as we please here. */
14717 /* Strip typedefs as in convert_template_argument. */
14719 }
14721 /* If ARG is a parameter pack or an expansion, we cannot unify
14722 against it unless PARM is also a parameter pack. */
14727 /* If the argument deduction results is a METHOD_TYPE,
14728 then there is a problem.
14729 METHOD_TYPE doesn't map to any real C++ type the result of
14730 the deduction can not be of that type. */
14744 /* The PARM is not one we're trying to unify. Just check
14745 to see if it matches ARG. */
14755 /* [temp.deduct.type] If, in the declaration of a function template
14756 with a non-type template-parameter, the non-type
14757 template-parameter is used in an expression in the function
14758 parameter-list and, if the corresponding template-argument is
14759 deduced, the template-argument type shall match the type of the
14760 template-parameter exactly, except that a template-argument
14761 deduced from an array bound may be of any integral type.
14762 The non-type parameter might use already deduced type parameters. */
14765 /* Template-parameter dependent expression. Just accept it for now.
14766 It will later be processed in convert_template_argument. */
14767 ;
14773 /* Convert the ARG to the type of PARM; the deduced non-type
14774 template argument must exactly match the types of the
14775 corresponding parameter. */
14778 /* We haven't deduced the type of this parameter yet. Try again
14779 later. */
14781 else
14784 /* If ARG is a parameter pack or an expansion, we cannot unify
14785 against it unless PARM is also a parameter pack. */
14794 {
14795 /* A pointer-to-member constant can be unified only with
14796 another constant. */
14800 /* Just unify the class member. It would be useless (and possibly
14801 wrong, depending on the strict flags) to unify also
14802 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14803 arg refer to the same variable, even if through different
14804 classes. For instance:
14806 struct A { int x; };
14807 struct B : A { };
14809 Unification of &A::x and &B::x must succeed. */
14812 }
14815 {
14819 /* [temp.deduct.call]
14821 A can be another pointer or pointer to member type that can
14822 be converted to the deduced A via a qualification
14823 conversion (_conv.qual_).
14825 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14826 This will allow for additional cv-qualification of the
14827 pointed-to types if appropriate. */
14830 /* The derived-to-base conversion only persists through one
14831 level of pointers. */
14836 }
14851 {
14852 tree parm_max;
14853 tree arg_max;
14857 /* Our representation of array types uses "N - 1" as the
14858 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14859 not an integer constant. We cannot unify arbitrarily
14860 complex expressions, so we eliminate the MINUS_EXPRs
14861 here. */
14865 {
14868 }
14872 {
14873 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14874 trying to unify the type of a variable with the type
14875 of a template parameter. For example:
14877 template <unsigned int N>
14878 void f (char (&) [N]);
14879 int g();
14880 void h(int i) {
14881 char a[g(i)];
14882 f(a);
14883 }
14885 Here, the type of the ARG will be "int [g(i)]", and
14886 may be a SAVE_EXPR, etc. */
14890 }
14892 /* If only one of the bounds used a MINUS_EXPR, compensate
14893 by adding one to the other bound. */
14896 integer_type_node,
14897 parm_max,
14898 integer_one_node);
14901 integer_type_node,
14902 arg_max,
14903 integer_one_node);
14907 }
14921 /* We have already checked cv-qualification at the top of the
14922 function. */
14926 /* As far as unification is concerned, this wins. Later checks
14927 will invalidate it if necessary. */
14930 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14931 /* Type INTEGER_CST can come from ordinary constant template args. */
14941 {
14950 UNIFY_ALLOW_NONE))
14953 }
14961 {
14968 strict);
14969 }
14972 {
14976 {
14977 /* First, we try to unify the PARM and ARG directly. */
14982 {
14983 /* Fallback to the special case allowed in
14984 [temp.deduct.call]:
14986 If P is a class, and P has the form
14987 template-id, then A can be a derived class of
14988 the deduced A. Likewise, if P is a pointer to
14989 a class of the form template-id, A can be a
14990 pointer to a derived class pointed to by the
14991 deduced A. */
14996 }
14997 }
15001 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15002 Then, we should unify `int' and `U'. */
15004 else
15005 /* There's no chance of unification succeeding. */
15010 }
15017 {
15020 tree a;
15026 /* CV qualifications for methods can never be deduced, they must
15027 match exactly. We need to check them explicitly here,
15028 because type_unification_real treats them as any other
15029 cv-qualified parameter. */
15031 && (!check_cv_quals_for_unify
15051 LOOKUP_NORMAL);
15052 }
15055 /* Unify a pointer to member with a pointer to member function, which
15056 deduces the type of the member as a function type. */
15058 {
15059 tree method_type;
15060 tree fntype;
15062 /* Check top-level cv qualifiers */
15070 /* Determine the type of the function we are unifying against. */
15072 fntype =
15076 /* Extract the cv-qualifiers of the member function from the
15077 implicit object parameter and place them on the function
15078 type to be restored later. */
15081 }
15089 strict);
15100 /* Matched cases are handled by the ARG == PARM test above. */
15104 /* A non-type template parameter that is a variable should be a
15105 an integral constant, in which case, it whould have been
15106 folded into its (constant) value. So we should not be getting
15107 a variable here. */
15112 {
15120 {
15122 {
15124 /* We can unify against something with a trailing
15125 parameter pack. */
15127 else
15128 /* Since there is something following the pack
15129 expansion, we cannot unify this template argument
15130 list. */
15132 }
15133 }
15136 /* If we don't have enough arguments to satisfy the parameters
15137 (not counting the pack expression at the end), or we have
15138 too many arguments for a parameter list that doesn't end in
15139 a pack expression, we can't unify. */
15144 /* Unify all of the parameters that precede the (optional)
15145 pack expression. */
15147 {
15151 }
15159 }
15165 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15166 nodes. */
15170 /* Unification fails if we hit an error node. */
15176 /* We must be looking at an expression. This can happen with
15177 something like:
15179 template <int I>
15180 void foo(S<I>, S<I + 2>);
15182 This is a "nondeduced context":
15184 [deduct.type]
15186 The nondeduced contexts are:
15188 --A type that is a template-id in which one or more of
15189 the template-arguments is an expression that references
15190 a template-parameter.
15192 In these cases, we assume deduction succeeded, but don't
15193 actually infer any unifications. */
15198 else
15200 }
15201 }
15202 \f
15203 /* Note that DECL can be defined in this translation unit, if
15204 required. */
15206 static void
15208 {
15209 tree clone;
15213 }
15215 /* Called if RESULT is explicitly instantiated, or is a member of an
15216 explicitly instantiated class. */
15218 void
15220 {
15223 /* If this entity has already been written out, it's too late to
15224 make any modifications. */
15229 /* The TREE_PUBLIC flag for function declarations will have been
15230 set correctly by tsubst. */
15233 /* This might have been set by an earlier implicit instantiation. */
15238 else
15239 {
15241 /* Always make artificials weak. */
15244 /* For WIN32 we also want to put explicit instantiations in
15245 linkonce sections. */
15248 }
15250 /* If EXTERN_P, then this function will not be emitted -- unless
15251 followed by an explicit instantiation, at which point its linkage
15252 will be adjusted. If !EXTERN_P, then this function will be
15253 emitted here. In neither circumstance do we want
15254 import_export_decl to adjust the linkage. */
15256 }
15258 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15259 important template arguments. If any are missing, we check whether
15260 they're important by using error_mark_node for substituting into any
15261 args that were used for partial ordering (the ones between ARGS and END)
15262 and seeing if it bubbles up. */
15264 static bool
15266 {
15271 {
15274 }
15276 {
15278 {
15282 }
15283 }
15285 }
15287 /* Given two function templates PAT1 and PAT2, return:
15289 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15290 -1 if PAT2 is more specialized than PAT1.
15291 0 if neither is more specialized.
15293 LEN indicates the number of parameters we should consider
15294 (defaulted parameters should not be considered).
15296 The 1998 std underspecified function template partial ordering, and
15297 DR214 addresses the issue. We take pairs of arguments, one from
15298 each of the templates, and deduce them against each other. One of
15299 the templates will be more specialized if all the *other*
15300 template's arguments deduce against its arguments and at least one
15301 of its arguments *does* *not* deduce against the other template's
15302 corresponding argument. Deduction is done as for class templates.
15303 The arguments used in deduction have reference and top level cv
15304 qualifiers removed. Iff both arguments were originally reference
15305 types *and* deduction succeeds in both directions, the template
15306 with the more cv-qualified argument wins for that pairing (if
15307 neither is more cv-qualified, they both are equal). Unlike regular
15308 deduction, after all the arguments have been deduced in this way,
15309 we do *not* verify the deduced template argument values can be
15310 substituted into non-deduced contexts.
15312 The logic can be a bit confusing here, because we look at deduce1 and
15313 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15314 can find template arguments for pat1 to make arg1 look like arg2, that
15315 means that arg2 is at least as specialized as arg1. */
15317 int
15319 {
15332 /* Remove the this parameter from non-static member functions. If
15333 one is a non-static member function and the other is not a static
15334 member function, remove the first parameter from that function
15335 also. This situation occurs for operator functions where we
15336 locate both a member function (with this pointer) and non-member
15337 operator (with explicit first operand). */
15339 {
15344 }
15346 {
15349 {
15350 len--;
15352 }
15353 }
15355 /* If only one is a conversion operator, they are unordered. */
15359 /* Consider the return type for a conversion function */
15361 {
15364 len++;
15365 }
15367 processing_template_decl++;
15373 /* Stop when an ellipsis is seen. */
15375 {
15384 {
15385 /* When both arguments are pack expansions, we need only
15386 unify the patterns themselves. */
15390 /* This is the last comparison we need to do. */
15392 }
15395 {
15398 }
15401 {
15404 }
15407 {
15408 /* Only of the args is a reference, see if we should apply
15409 array/function pointer decay to it. This is not part of
15410 DR214, but is, IMHO, consistent with the deduction rules
15411 for the function call itself, and with our earlier
15412 implementation of the underspecified partial ordering
15413 rules. (nathan). */
15415 {
15417 {
15420 /* FALLTHROUGH. */
15427 }
15428 }
15429 else
15430 {
15432 {
15435 /* FALLTHROUGH. */
15442 }
15443 }
15444 }
15450 {
15456 /* Setup the parameter vector, which contains only ARG1. */
15459 /* Setup the argument vector, which contains the remaining
15460 arguments. */
15469 /* We cannot deduce in the other direction, because ARG1 is
15470 a pack expansion but ARG2 is not. */
15472 }
15474 {
15480 /* Setup the parameter vector, which contains only ARG1. */
15483 /* Setup the argument vector, which contains the remaining
15484 arguments. */
15493 /* We cannot deduce in the other direction, because ARG2 is
15494 a pack expansion but ARG1 is not.*/
15496 }
15498 else
15499 {
15500 /* The normal case, where neither argument is a pack
15501 expansion. */
15504 }
15506 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15507 arg2, then arg2 is not as specialized as arg1. */
15513 /* "If, for a given type, deduction succeeds in both directions
15514 (i.e., the types are identical after the transformations above)
15515 and if the type from the argument template is more cv-qualified
15516 than the type from the parameter template (as described above)
15517 that type is considered to be more specialized than the other. If
15518 neither type is more cv-qualified than the other then neither type
15519 is more specialized than the other." */
15523 {
15528 }
15531 /* We've failed to deduce something in either direction.
15532 These must be unordered. */
15537 /* We have already processed all of the arguments in our
15538 handing of the pack expansion type. */
15543 }
15545 /* "In most cases, all template parameters must have values in order for
15546 deduction to succeed, but for partial ordering purposes a template
15547 parameter may remain without a value provided it is not used in the
15548 types being used for partial ordering."
15550 Thus, if we are missing any of the targs1 we need to substitute into
15551 origs1, then pat2 is not as specialized as pat1. This can happen when
15552 there is a nondeduced context. */
15558 processing_template_decl--;
15560 /* All things being equal, if the next argument is a pack expansion
15561 for one function but not for the other, prefer the
15562 non-variadic function. FIXME this is bogus; see c++/41958. */
15566 {
15569 }
15575 else
15577 }
15579 /* Determine which of two partial specializations is more specialized.
15581 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15582 to the first partial specialization. The TREE_VALUE is the
15583 innermost set of template parameters for the partial
15584 specialization. PAT2 is similar, but for the second template.
15586 Return 1 if the first partial specialization is more specialized;
15587 -1 if the second is more specialized; 0 if neither is more
15588 specialized.
15590 See [temp.class.order] for information about determining which of
15591 two templates is more specialized. */
15593 static int
15595 {
15596 tree targs;
15604 /* Just like what happens for functions, if we are ordering between
15605 different class template specializations, we may encounter dependent
15606 types in the arguments, and we need our dependency check functions
15607 to behave correctly. */
15613 {
15616 }
15622 {
15625 }
15628 /* In the case of a tie where at least one of the class templates
15629 has a parameter pack at the end, the template with the most
15630 non-packed parameters wins. */
15632 && any_deductions
15635 {
15641 /* We don't count the pack expansion at the end. */
15651 }
15654 }
15656 /* Return the template arguments that will produce the function signature
15657 DECL from the function template FN, with the explicit template
15658 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15659 also match. Return NULL_TREE if no satisfactory arguments could be
15660 found. */
15662 static tree
15664 {
15667 tree decl_type;
15668 tree decl_arg_types;
15671 tree arg;
15673 /* Substitute the explicit template arguments into the type of DECL.
15674 The call to fn_type_unification will handle substitution into the
15675 FN. */
15678 {
15679 tree tmpl;
15680 tree converted_args;
15684 else
15685 /* We can get here for some invalid specializations. */
15688 converted_args
15691 tf_none,
15700 }
15702 /* Never do unification on the 'this' parameter. */
15721 }
15723 /* Return the innermost template arguments that, when applied to a
15724 template specialization whose innermost template parameters are
15725 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15726 ARGS.
15728 For example, suppose we have:
15730 template <class T, class U> struct S {};
15731 template <class T> struct S<T*, int> {};
15733 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15734 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15735 int}. The resulting vector will be {double}, indicating that `T'
15736 is bound to `double'. */
15738 static tree
15740 {
15742 tree deduced_args;
15743 tree innermost_deduced_args;
15747 {
15751 innermost_deduced_args);
15752 }
15753 else
15759 UNIFY_ALLOW_NONE))
15766 /* Verify that nondeduced template arguments agree with the type
15767 obtained from argument deduction.
15769 For example:
15771 struct A { typedef int X; };
15772 template <class T, class U> struct C {};
15773 template <class T> struct C<T, typename T::X> {};
15775 Then with the instantiation `C<A, int>', we can deduce that
15776 `T' is `A' but unify () does not check whether `typename T::X'
15777 is `int'. */
15780 /* We only need to check the innermost arguments; the other
15781 arguments will always agree. */
15786 /* Now that we have bindings for all of the template arguments,
15787 ensure that the arguments deduced for the template template
15788 parameters have compatible template parameter lists. See the use
15789 of template_template_parm_bindings_ok_p in fn_type_unification
15790 for more information. */
15795 }
15797 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15798 Return the TREE_LIST node with the most specialized template, if
15799 any. If there is no most specialized template, the error_mark_node
15800 is returned.
15802 Note that this function does not look at, or modify, the
15803 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15804 returned is one of the elements of INSTANTIATIONS, callers may
15805 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15806 and retrieve it from the value returned. */
15808 tree
15810 {
15817 {
15823 fate--;
15828 fate++;
15833 {
15834 /* Equally specialized, move to next function. If there
15835 is no next function, nothing's most specialized. */
15840 }
15841 }
15844 /* Now verify that champ is better than everything earlier in the
15845 instantiation list. */
15853 {
15856 }
15858 processing_template_decl--;
15864 }
15866 /* If DECL is a specialization of some template, return the most
15867 general such template. Otherwise, returns NULL_TREE.
15869 For example, given:
15871 template <class T> struct S { template <class U> void f(U); };
15873 if TMPL is `template <class U> void S<int>::f(U)' this will return
15874 the full template. This function will not trace past partial
15875 specializations, however. For example, given in addition:
15877 template <class T> struct S<T*> { template <class U> void f(U); };
15879 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15880 `template <class T> template <class U> S<T*>::f(U)'. */
15882 tree
15884 {
15885 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15886 an immediate specialization. */
15888 {
15892 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15893 template friend. */
15898 }
15900 /* Look for more and more general templates. */
15902 {
15903 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15904 (See cp-tree.h for details.) */
15912 /* Stop if we run into an explicitly specialized class template. */
15919 }
15922 }
15924 /* Return the most specialized of the class template partial
15925 specializations of TMPL which can produce TYPE, a specialization of
15926 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15927 a _TYPE node corresponding to the partial specialization, while the
15928 TREE_PURPOSE is the set of template arguments that must be
15929 substituted into the TREE_TYPE in order to generate TYPE.
15931 If the choice of partial specialization is ambiguous, a diagnostic
15932 is issued, and the error_mark_node is returned. If there are no
15933 partial specializations of TMPL matching TYPE, then NULL_TREE is
15934 returned. */
15936 static tree
15938 {
15940 tree t;
15941 tree champ;
15944 tree args;
15950 /* For determining which partial specialization to use, only the
15951 innermost args are interesting. */
15953 {
15956 }
15959 {
15960 tree partial_spec_args;
15961 tree spec_args;
15969 {
15972 /* Discard the outer levels of args, and then substitute in the
15973 template args from the enclosing class. */
15975 partial_spec_args = tsubst_template_args
15978 /* PARMS already refers to just the innermost parms, but the
15979 template parms in partial_spec_args had their levels lowered
15980 by tsubst, so we need to do the same for the parm list. We
15981 can't just tsubst the TREE_VEC itself, as tsubst wants to
15982 treat a TREE_VEC as an argument vector. */
15988 }
15990 partial_spec_args =
15993 partial_spec_args),
16004 partial_spec_args,
16005 args);
16007 {
16012 }
16013 }
16023 {
16026 ;
16027 else
16028 {
16030 {
16033 {
16036 }
16037 }
16039 }
16040 }
16044 {
16047 {
16050 }
16051 }
16054 {
16060 {
16063 }
16066 }
16069 }
16071 /* Explicitly instantiate DECL. */
16073 void
16075 {
16080 /* An error occurred, for which grokdeclarator has already issued
16081 an appropriate message. */
16084 {
16087 }
16089 {
16090 /* There is an asymmetry here in the way VAR_DECLs and
16091 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16092 the latter, the DECL we get back will be marked as a
16093 template instantiation, and the appropriate
16094 DECL_TEMPLATE_INFO will be set up. This does not happen for
16095 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16096 should handle VAR_DECLs as it currently handles
16097 FUNCTION_DECLs. */
16099 {
16102 }
16105 {
16108 }
16110 {
16115 }
16116 }
16118 {
16121 }
16122 else
16125 /* Check for various error cases. Note that if the explicit
16126 instantiation is valid the RESULT will currently be marked as an
16127 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16128 until we get here. */
16131 {
16132 /* DR 259 [temp.spec].
16134 Both an explicit instantiation and a declaration of an explicit
16135 specialization shall not appear in a program unless the explicit
16136 instantiation follows a declaration of the explicit specialization.
16138 For a given set of template parameters, if an explicit
16139 instantiation of a template appears after a declaration of an
16140 explicit specialization for that template, the explicit
16141 instantiation has no effect. */
16143 }
16145 {
16146 /* [temp.spec]
16148 No program shall explicitly instantiate any template more
16149 than once.
16151 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16152 the first instantiation was `extern' and the second is not,
16153 and EXTERN_P for the opposite case. */
16156 /* If an "extern" explicit instantiation follows an ordinary
16157 explicit instantiation, the template is instantiated. */
16160 }
16162 {
16165 }
16167 {
16170 }
16173 ;
16175 {
16178 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16181 }
16182 else
16190 }
16192 static void
16194 {
16200 {
16203 }
16204 }
16206 /* Called from do_type_instantiation through binding_table_foreach to
16207 do recursive instantiation for the type bound in ENTRY. */
16208 static void
16210 {
16216 }
16218 /* Called from do_type_instantiation to instantiate a member
16219 (a member function or a static member variable) of an
16220 explicitly instantiated class template. */
16221 static void
16223 {
16228 }
16230 /* Perform an explicit instantiation of template class T. STORAGE, if
16231 non-null, is the RID for extern, inline or static. COMPLAIN is
16232 nonzero if this is called from the parser, zero if called recursively,
16233 since the standard is unclear (as detailed below). */
16235 void
16237 {
16247 {
16250 }
16255 {
16258 t);
16260 }
16263 {
16265 {
16267 {
16270 "ISO C++ 1998 forbids the use of %<extern%> on "
16272 }
16273 else
16275 "ISO C++ forbids the use of %qE"
16277 }
16285 else
16286 {
16288 storage);
16290 }
16291 }
16294 {
16295 /* DR 259 [temp.spec].
16297 Both an explicit instantiation and a declaration of an explicit
16298 specialization shall not appear in a program unless the explicit
16299 instantiation follows a declaration of the explicit specialization.
16301 For a given set of template parameters, if an explicit
16302 instantiation of a template appears after a declaration of an
16303 explicit specialization for that template, the explicit
16304 instantiation has no effect. */
16306 }
16308 {
16309 /* [temp.spec]
16311 No program shall explicitly instantiate any template more
16312 than once.
16314 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16315 instantiation was `extern'. If EXTERN_P then the second is.
16316 These cases are OK. */
16323 /* If we've already instantiated the template, just return now. */
16326 }
16334 {
16335 tree tmp;
16337 /* In contrast to implicit instantiation, where only the
16338 declarations, and not the definitions, of members are
16339 instantiated, we have here:
16341 [temp.explicit]
16343 The explicit instantiation of a class template specialization
16344 implies the instantiation of all of its members not
16345 previously explicitly specialized in the translation unit
16346 containing the explicit instantiation.
16348 Of course, we can't instantiate member template classes, since
16349 we don't have any arguments for them. Note that the standard
16350 is unclear on whether the instantiation of the members are
16351 *explicit* instantiations or not. However, the most natural
16352 interpretation is that it should be an explicit instantiation. */
16367 }
16368 }
16370 /* Given a function DECL, which is a specialization of TMPL, modify
16371 DECL to be a re-instantiation of TMPL with the same template
16372 arguments. TMPL should be the template into which tsubst'ing
16373 should occur for DECL, not the most general template.
16375 One reason for doing this is a scenario like this:
16377 template <class T>
16378 void f(const T&, int i);
16380 void g() { f(3, 7); }
16382 template <class T>
16383 void f(const T& t, const int i) { }
16385 Note that when the template is first instantiated, with
16386 instantiate_template, the resulting DECL will have no name for the
16387 first parameter, and the wrong type for the second. So, when we go
16388 to instantiate the DECL, we regenerate it. */
16390 static void
16392 {
16393 /* The arguments used to instantiate DECL, from the most general
16394 template. */
16395 tree args;
16396 tree code_pattern;
16401 /* Make sure that we can see identifiers, and compute access
16402 correctly. */
16406 {
16407 tree decl_parm;
16408 tree pattern_parm;
16409 tree specs;
16422 specs);
16424 /* Merge parameter declarations. */
16427 pattern_parm
16431 {
16432 tree parm_type;
16433 tree attributes;
16438 NULL_TREE);
16444 {
16447 }
16450 }
16451 /* Merge any parameters that match with the function parameter
16452 pack. */
16454 {
16456 tree expanded_types;
16457 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16458 the parameters in this function parameter pack. */
16463 {
16464 tree parm_type;
16465 tree attributes;
16468 /* Rename the parameter to include the index. */
16477 {
16480 }
16482 }
16483 }
16484 /* Merge additional specifiers from the CODE_PATTERN. */
16488 }
16490 {
16498 }
16499 else
16503 }
16505 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16506 substituted to get DECL. */
16508 tree
16510 {
16513 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16514 for the instantiation. This is not always the most general
16515 template. Consider, for example:
16517 template <class T>
16518 struct S { template <class U> void f();
16519 template <> void f<int>(); };
16521 and an instantiation of S<double>::f<int>. We want TD to be the
16522 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16524 more general template. */
16526 /* We must also deal with friend templates. Given:
16528 template <class T> struct S {
16529 template <class U> friend void f() {};
16530 };
16532 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16533 so far as the language is concerned, but that's still
16534 where we get the pattern for the instantiation from. On
16535 other hand, if the definition comes outside the class, say:
16537 template <class T> struct S {
16538 template <class U> friend void f();
16539 };
16540 template <class U> friend void f() {}
16542 we don't need to look any further. That's what the check for
16543 DECL_INITIAL is for. */
16547 {
16548 /* The present template, TD, should not be a definition. If it
16549 were a definition, we should be using it! Note that we
16550 cannot restructure the loop to just keep going until we find
16551 a template with a definition, since that might go too far if
16552 a specialization was declared, but not defined. */
16556 /* Fetch the more general template. */
16558 }
16561 }
16563 /* Returns true if we need to instantiate this template instance even if we
16564 know we aren't going to emit it.. */
16566 bool
16568 {
16569 /* We always instantiate inline functions so that we can inline them. An
16570 explicit instantiation declaration prohibits implicit instantiation of
16571 non-inline functions. With high levels of optimization, we would
16572 normally inline non-inline functions -- but we're not allowed to do
16573 that for "extern template" functions. Therefore, we check
16574 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16577 /* And we need to instantiate static data members so that
16578 their initializers are available in integral constant
16579 expressions. */
16582 }
16584 /* Produce the definition of D, a _DECL generated from a template. If
16585 DEFER_OK is nonzero, then we don't have to actually do the
16586 instantiation now; we just have to do it sometime. Normally it is
16587 an error if this is an explicit instantiation but D is undefined.
16588 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16589 explicitly instantiated class template. */
16591 tree
16594 {
16596 tree gen_args;
16597 tree args;
16598 tree td;
16599 tree code_pattern;
16600 tree spec;
16601 tree gen_tmpl;
16607 /* This function should only be used to instantiate templates for
16608 functions and static member variables. */
16612 /* Variables are never deferred; if instantiation is required, they
16613 are instantiated right away. That allows for better code in the
16614 case that an expression refers to the value of the variable --
16615 if the variable has a constant value the referring expression can
16616 take advantage of that fact. */
16620 /* Don't instantiate cloned functions. Instead, instantiate the
16621 functions they cloned. */
16627 /* D has already been instantiated or explicitly specialized, so
16628 there's nothing for us to do here.
16630 It might seem reasonable to check whether or not D is an explicit
16631 instantiation, and, if so, stop here. But when an explicit
16632 instantiation is deferred until the end of the compilation,
16633 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16634 the instantiation. */
16637 /* Check to see whether we know that this template will be
16638 instantiated in some other file, as with "extern template"
16639 extension. */
16642 /* In general, we do not instantiate such templates. */
16650 /* We should already have the extra args. */
16653 /* And what's in the hash table should match D. */
16657 /* This needs to happen before any tsubsting. */
16663 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16664 for the instantiation. */
16668 /* We should never be trying to instantiate a member of a class
16669 template or partial specialization. */
16674 /* In the case of a friend template whose definition is provided
16675 outside the class, we may have too many arguments. Drop the
16676 ones we don't need. The same is true for specializations. */
16677 args = get_innermost_template_args
16679 else
16684 else
16687 /* We may be in the middle of deferred access check. Disable it now. */
16690 /* Unless an explicit instantiation directive has already determined
16691 the linkage of D, remember that a definition is available for
16692 this entity. */
16700 /* If D is a member of an explicitly instantiated class template,
16701 and no definition is available, treat it like an implicit
16702 instantiation. */
16705 {
16709 }
16711 /* Recheck the substitutions to obtain any warning messages
16712 about ignoring cv qualifiers. Don't do this for artificial decls,
16713 as it breaks the context-sensitive substitution for lambda op(). */
16715 {
16719 /* Make sure that we can see identifiers, and compute access
16720 correctly. D is already the target FUNCTION_DECL with the
16721 right context. */
16725 {
16728 d);
16729 /* Don't simply tsubst the function type, as that will give
16730 duplicate warnings about poor parameter qualifications.
16731 The function arguments are the same as the decl_arguments
16732 without the top level cv qualifiers. */
16734 }
16738 }
16740 /* Defer all other templates, unless we have been explicitly
16741 forbidden from doing so. */
16743 template. */
16744 ! pattern_defined
16745 /* If it's OK to postpone instantiation, do so. */
16746 || defer_ok
16747 /* If this is a static data member that will be defined
16748 elsewhere, we don't want to instantiate the entire data
16749 member, but we do want to instantiate the initializer so that
16750 we can substitute that elsewhere. */
16752 {
16753 /* The definition of the static data member is now required so
16754 we must substitute the initializer. */
16758 {
16759 tree ns;
16760 tree init;
16766 args,
16771 LOOKUP_ONLYCONVERTING);
16774 }
16776 /* We restore the source position here because it's used by
16777 add_pending_template. */
16783 /* [temp.explicit]
16785 The definition of a non-exported function template, a
16786 non-exported member function template, or a non-exported
16787 member function or static data member of a class template
16788 shall be present in every translation unit in which it is
16789 explicitly instantiated. */
16793 /* ??? Historically, we have instantiated inline functions, even
16794 when marked as "extern template". */
16798 }
16799 /* Tell the repository that D is available in this translation unit
16800 -- and see if it is supposed to be instantiated here. */
16802 {
16803 /* In a PCH file, despite the fact that the repository hasn't
16804 requested instantiation in the PCH it is still possible that
16805 an instantiation will be required in a file that includes the
16806 PCH. */
16809 /* Instantiate inline functions so that the inliner can do its
16810 job, even though we'll not be emitting a copy of this
16811 function. */
16814 }
16820 /* Mark D as instantiated so that recursive calls to
16821 instantiate_decl do not try to instantiate it again. */
16824 /* Regenerate the declaration in case the template has been modified
16825 by a subsequent redeclaration. */
16828 /* We already set the file and line above. Reset them now in case
16829 they changed as a result of calling regenerate_decl_from_template. */
16833 {
16834 tree init;
16836 /* Clear out DECL_RTL; whatever was there before may not be right
16837 since we've reset the type of the declaration. */
16841 /* The initializer is placed in DECL_INITIAL by
16842 regenerate_decl_from_template. Pull it out so that
16843 cp_finish_decl can process it. */
16848 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16849 initializer. That function will defer actual emission until
16850 we have a chance to determine linkage. */
16853 /* Enter the scope of D so that access-checking works correctly. */
16857 }
16859 {
16860 htab_t saved_local_specializations;
16861 tree subst_decl;
16862 tree tmpl_parm;
16863 tree spec_parm;
16865 /* Save away the current list, in case we are instantiating one
16866 template from within the body of another. */
16869 /* Set up the list of local specializations. */
16871 hash_local_specialization,
16872 eq_local_specializations,
16873 NULL);
16875 /* Set up context. */
16878 /* Create substitution entries for the parameters. */
16883 {
16887 }
16889 {
16893 }
16895 {
16896 /* Register the (value) argument pack as a specialization of
16897 TMPL_PARM, then move on. */
16902 }
16905 /* Substitute into the body of the function. */
16910 /* Set the current input_location to the end of the function
16911 so that finish_function knows where we are. */
16914 /* We don't need the local specializations any more. */
16918 /* Finish the function. */
16921 }
16923 /* We're not deferring instantiation any more. */
16929 out:
16937 }
16939 /* Run through the list of templates that we wish we could
16940 instantiate, and instantiate any we can. RETRIES is the
16941 number of times we retry pending template instantiation. */
16943 void
16945 {
16949 /* Instantiating templates may trigger vtable generation. This in turn
16950 may require further template instantiations. We place a limit here
16951 to avoid infinite loop. */
16953 {
16957 " instantiating %q+D, possibly from virtual table generation"
16961 /* Pretend that we defined it. */
16964 }
16966 do
16967 {
16972 {
16977 {
16978 tree fn;
16981 {
16985 fn;
16993 }
16996 }
16997 else
16998 {
17001 {
17002 instantiation
17008 }
17012 }
17015 /* If INSTANTIATION has been instantiated, then we don't
17016 need to consider it again in the future. */
17018 else
17019 {
17022 }
17025 }
17027 }
17031 }
17033 /* Substitute ARGVEC into T, which is a list of initializers for
17034 either base class or a non-static data member. The TREE_PURPOSEs
17035 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17036 instantiate_decl. */
17038 static tree
17040 {
17044 {
17045 tree decl;
17046 tree init;
17052 {
17053 tree expr;
17054 tree arg;
17056 /* Expand the base class expansion type into separate base
17057 classes. */
17059 tf_warning_or_error,
17060 NULL_TREE);
17064 /* We'll be building separate TREE_LISTs of arguments for
17065 each base. */
17071 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17072 expand each argument in the TREE_VALUE of t. */
17078 /* VOID_TYPE_NODE is used to indicate
17079 value-initialization. */
17080 {
17083 }
17084 else
17085 {
17086 /* Substitute parameter packs into each argument in the
17087 TREE_LIST. */
17090 {
17091 tree expanded_exprs;
17093 /* Expand the argument. */
17095 expanded_exprs
17097 tf_warning_or_error,
17098 NULL_TREE);
17102 /* Prepend each of the expanded expressions to the
17103 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17105 {
17110 }
17111 }
17114 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17115 since we built them backwards. */
17117 {
17120 }
17121 }
17122 }
17125 {
17127 {
17131 }
17132 else
17133 {
17145 }
17148 {
17152 }
17153 }
17154 }
17156 }
17158 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17160 static void
17162 {
17167 else
17169 }
17171 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17172 is the instantiation (which should have been created with
17173 start_enum) and ARGS are the template arguments to use. */
17175 static void
17177 {
17178 tree e;
17181 {
17182 tree value;
17183 tree decl;
17186 /* Note that in a template enum, the TREE_VALUE is the
17187 CONST_DECL, not the corresponding INTEGER_CST. */
17192 /* Give this enumeration constant the correct access. */
17195 /* Actually build the enumerator itself. */
17197 }
17202 }
17204 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17205 its type -- but without substituting the innermost set of template
17206 arguments. So, innermost set of template parameters will appear in
17207 the type. */
17209 tree
17211 {
17212 tree fn_type;
17213 tree tmpl;
17214 tree targs;
17215 tree tparms;
17223 /* There should be as many levels of arguments as there are levels
17224 of parameters. */
17230 /* No substitution is necessary. */
17231 ;
17232 else
17233 {
17235 tree partial_args;
17237 /* Replace the innermost level of the TARGS with NULL_TREEs to
17238 let tsubst know not to substitute for those parameters. */
17247 /* Disable access control as this function is used only during
17248 name-mangling. */
17253 /* Now, do the (partial) substitution to figure out the
17254 appropriate function type. */
17258 /* Substitute into the template parameters to obtain the real
17259 innermost set of parameters. This step is important if the
17260 innermost set of template parameters contains value
17261 parameters whose types depend on outer template parameters. */
17266 }
17269 }
17271 /* Return truthvalue if we're processing a template different from
17272 the last one involved in diagnostics. */
17273 int
17275 {
17277 }
17279 /* Remember current template involved in diagnostics. */
17280 void
17282 {
17284 }
17288 {
17290 }
17292 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17293 type. Return zero for ok, nonzero for disallowed. Issue error and
17294 warning messages under control of COMPLAIN. */
17296 static int
17298 {
17313 }
17315 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17316 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17318 static bool
17320 {
17321 tree scope;
17323 /* [temp.dep.type]
17325 A type is dependent if it is:
17327 -- a template parameter. Template template parameters are types
17328 for us (since TYPE_P holds true for them) so we handle
17329 them here. */
17333 /* -- a qualified-id with a nested-name-specifier which contains a
17334 class-name that names a dependent type or whose unqualified-id
17335 names a dependent type. */
17338 /* -- a cv-qualified type where the cv-unqualified type is
17339 dependent. */
17341 /* -- a compound type constructed from any dependent type. */
17351 {
17352 tree arg_type;
17357 arg_type;
17362 }
17363 /* -- an array type constructed from any dependent type or whose
17364 size is specified by a constant expression that is
17365 value-dependent. */
17367 {
17372 }
17375 {
17376 /* If this is the TYPE_DOMAIN of an array type, consider it
17377 dependent. We already checked for value-dependence in
17378 compute_array_index_type. */
17380 }
17382 /* -- a template-id in which either the template name is a template
17383 parameter ... */
17386 /* ... or any of the template arguments is a dependent type or
17387 an expression that is type-dependent or value-dependent. */
17389 && (any_dependent_template_arguments_p
17393 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17394 argument of the `typeof' expression is not type-dependent, then
17395 it should already been have resolved. */
17400 /* A template argument pack is dependent if any of its packed
17401 arguments are. */
17403 {
17409 }
17411 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17412 be template parameters. */
17416 /* The standard does not specifically mention types that are local
17417 to template functions or local classes, but they should be
17418 considered dependent too. For example:
17420 template <int I> void f() {
17421 enum E { a = I };
17422 S<sizeof (E)> s;
17423 }
17425 The size of `E' cannot be known until the value of `I' has been
17426 determined. Therefore, `E' must be considered dependent. */
17433 /* Other types are non-dependent. */
17435 }
17437 /* Returns TRUE if TYPE is dependent, in the sense of
17438 [temp.dep.type]. */
17440 bool
17442 {
17443 /* If there are no template parameters in scope, then there can't be
17444 any dependent types. */
17446 {
17447 /* If we are not processing a template, then nobody should be
17448 providing us with a dependent type. */
17452 }
17454 /* If the type is NULL, we have not computed a type for the entity
17455 in question; in that case, the type is dependent. */
17459 /* Erroneous types can be considered non-dependent. */
17463 /* If we have not already computed the appropriate value for TYPE,
17464 do so now. */
17466 {
17469 }
17472 }
17474 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17475 lookup. In other words, a dependent type that is not the current
17476 instantiation. */
17478 bool
17480 {
17483 }
17485 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
17487 static bool
17489 {
17490 tree scope;
17491 tree name;
17501 /* [temp.dep.expr]
17503 An id-expression is type-dependent if it contains a
17504 nested-name-specifier that contains a class-name that names a
17505 dependent type. */
17506 /* The suggested resolution to Core Issue 224 implies that if the
17507 qualifying type is the current class, then we must peek
17508 inside it. */
17517 }
17519 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17520 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17521 expression. */
17523 bool
17525 {
17529 /* A name declared with a dependent type. */
17534 {
17536 /* A name that has not been looked up -- must be dependent. */
17540 /* A non-type template parm. */
17544 /* A non-type template parm. */
17550 /* A constant with integral or enumeration type and is initialized
17551 with an expression that is value-dependent. */
17563 /* These expressions are value-dependent if the type to which
17564 the cast occurs is dependent or the expression being casted
17565 is value-dependent. */
17566 {
17572 /* A functional cast has a list of operands. */
17575 {
17576 /* If there are no operands, it must be an expression such
17577 as "int()". This should not happen for aggregate types
17578 because it would form non-constant expressions. */
17582 }
17588 }
17592 /* A `sizeof' expression is value-dependent if the operand is
17593 type-dependent or is a pack expansion. */
17603 /* FIXME why check value-dependency? */
17615 /* A CALL_EXPR may appear in a constant expression if it is a
17616 call to a builtin function, e.g., __builtin_constant_p. All
17617 such calls are value-dependent. */
17621 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17622 is value-dependent. */
17623 {
17632 }
17635 {
17639 }
17646 /* A constant expression is value-dependent if any subexpression is
17647 value-dependent. */
17649 {
17659 || (value_dependent_expression_p
17664 {
17667 /* In some cases, some of the operands may be missing.
17668 (For example, in the case of PREDECREMENT_EXPR, the
17669 amount to increment by may be missing.) That doesn't
17670 make the expression dependent. */
17672 && (value_dependent_expression_p
17676 }
17680 }
17681 }
17683 /* The expression is not value-dependent. */
17685 }
17687 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17688 [temp.dep.expr]. */
17690 bool
17692 {
17699 /* An unresolved name is always dependent. */
17704 /* Some expression forms are never type-dependent. */
17716 /* The types of these expressions depends only on the type to which
17717 the cast occurs. */
17725 /* The types of these expressions depends only on the type created
17726 by the expression. */
17729 {
17730 /* For NEW_EXPR tree nodes created inside a template, either
17731 the object type itself or a TREE_LIST may appear as the
17732 operand 1. */
17735 /* This is an array type. We need to check array dimensions
17736 as well. */
17738 || value_dependent_expression_p
17740 else
17742 }
17746 type_dependent_expression_p))
17752 && (any_dependent_template_arguments_p
17764 {
17765 tree elt;
17769 {
17772 }
17774 }
17776 /* A static data member of the current instantiation with incomplete
17777 array type is type-dependent, as the definition and specializations
17778 can have different bounds. */
17786 {
17791 {
17797 }
17798 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17806 {
17811 }
17816 {
17820 }
17822 }
17827 }
17829 /* Like type_dependent_expression_p, but it also works while not processing
17830 a template definition, i.e. during substitution or mangling. */
17832 bool
17834 {
17840 }
17842 /* Returns TRUE if ARGS contains a type-dependent expression. */
17844 bool
17846 {
17848 tree arg;
17851 {
17854 }
17856 }
17858 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17859 expressions) contains any value-dependent expressions. */
17861 bool
17863 {
17869 }
17871 /* Returns TRUE if the ARG (a template argument) is dependent. */
17873 bool
17875 {
17883 {
17887 {
17890 }
17893 }
17896 else
17899 }
17901 /* Returns true if ARGS (a collection of template arguments) contains
17902 any types that require structural equality testing. */
17904 bool
17906 {
17916 {
17919 {
17925 {
17926 /* Look inside the argument pack. */
17929 }
17932 {
17946 }
17947 }
17948 }
17951 }
17953 /* Returns true if ARGS (a collection of template arguments) contains
17954 any dependent arguments. */
17956 bool
17958 {
17968 {
17973 }
17976 }
17978 /* Returns TRUE if the template TMPL is dependent. */
17980 bool
17982 {
17984 {
17986 {
17990 }
17992 }
17994 /* Template template parameters are dependent. */
17998 /* So are names that have not been looked up. */
18002 /* So are member templates of dependent classes. */
18006 }
18008 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18010 bool
18012 {
18015 }
18017 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18018 is dependent. */
18020 bool
18022 {
18029 {
18050 {
18054 }
18058 {
18062 {
18067 }
18068 }
18069 }
18072 }
18074 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18075 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18076 no such TYPE can be found. Note that this function peers inside
18077 uninstantiated templates and therefore should be used only in
18078 extremely limited situations. ONLY_CURRENT_P restricts this
18079 peering to the currently open classes hierarchy (which is required
18080 when comparing types). */
18082 tree
18084 {
18085 tree scope;
18086 tree name;
18087 tree decl;
18089 tree pushed_scope;
18090 tree result;
18095 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18096 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18097 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18098 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18099 identifier of the TYPENAME_TYPE anymore.
18100 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18101 TYPENAME_TYPE instead, we avoid messing up with a possible
18102 typedef variant case. */
18105 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18106 it first before we can figure out what NAME refers to. */
18109 /* If we don't know what SCOPE refers to, then we cannot resolve the
18110 TYPENAME_TYPE. */
18113 /* If the SCOPE is a template type parameter, we have no way of
18114 resolving the name. */
18117 /* If the SCOPE is not the current instantiation, there's no reason
18118 to look inside it. */
18121 /* If this is a typedef, we don't want to look inside (c++/11987). */
18124 /* If SCOPE isn't the template itself, it will not have a valid
18125 TYPE_FIELDS list. */
18127 /* scope is either the template itself or a compatible instantiation
18128 like X<T>, so look up the name in the original template. */
18130 else
18131 /* scope is a partial instantiation, so we can't do the lookup or we
18132 will lose the template arguments. */
18134 /* Enter the SCOPE so that name lookup will be resolved as if we
18135 were in the class definition. In particular, SCOPE will no
18136 longer be considered a dependent type. */
18138 /* Look up the declaration. */
18143 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18144 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18149 {
18153 }
18156 {
18157 tree tmpl;
18158 tree args;
18159 /* Obtain the template and the arguments. */
18162 /* Instantiate the template. */
18168 }
18170 /* Leave the SCOPE. */
18174 /* If we failed to resolve it, return the original typename. */
18178 /* If lookup found a typename type, resolve that too. */
18180 {
18181 /* Ill-formed programs can cause infinite recursion here, so we
18182 must catch that. */
18186 }
18188 /* Qualify the resulting type. */
18194 }
18196 /* EXPR is an expression which is not type-dependent. Return a proxy
18197 for EXPR that can be used to compute the types of larger
18198 expressions containing EXPR. */
18200 tree
18202 {
18203 tree inner_expr;
18205 /* Preserve null pointer constants so that the type of things like
18206 "p == 0" where "p" is a pointer can be determined. */
18209 /* Preserve OVERLOADs; the functions must be available to resolve
18210 types. */
18221 /* There is no need to return a proxy for a variable. */
18224 /* Preserve string constants; conversions from string constants to
18225 "char *" are allowed, even though normally a "const char *"
18226 cannot be used to initialize a "char *". */
18229 /* Preserve arithmetic constants, as an optimization -- there is no
18230 reason to create a new node. */
18233 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18234 There is at least one place where we want to know that a
18235 particular expression is a throw-expression: when checking a ?:
18236 expression, there are special rules if the second or third
18237 argument is a throw-expression. */
18256 /* If the type is unknown, it can't really be non-dependent */
18259 /* Otherwise, build a NON_DEPENDENT_EXPR.
18261 REFERENCE_TYPEs are not stripped for expressions in templates
18262 because doing so would play havoc with mangling. Consider, for
18263 example:
18265 template <typename T> void f<T& g>() { g(); }
18267 In the body of "f", the expression for "g" will have
18268 REFERENCE_TYPE, even though the standard says that it should
18269 not. The reason is that we must preserve the syntactic form of
18270 the expression so that mangling (say) "f<g>" inside the body of
18271 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18272 stripped here. */
18274 }
18276 /* ARGS is a vector of expressions as arguments to a function call.
18277 Replace the arguments with equivalent non-dependent expressions.
18278 This modifies ARGS in place. */
18280 void
18282 {
18284 tree arg;
18287 {
18291 }
18292 }
18294 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18295 with a level one deeper than the actual template parms. */
18297 tree
18299 {
18312 }
18314 /* Given type ARG, return std::initializer_list<ARG>. */
18316 static tree
18318 {
18319 tree std_init_list = namespace_binding
18321 tree argvec;
18323 {
18327 }
18332 }
18334 /* Replace auto in TYPE with std::initializer_list<auto>. */
18336 static tree
18338 {
18345 }
18347 /* walk_tree helper for do_auto_deduction. */
18349 static tree
18352 {
18353 /* Is this a variable with the type we're looking for? */
18357 else
18359 }
18361 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18362 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18364 tree
18366 {
18369 tree decl;
18372 /* The name of the object being declared shall not appear in the
18373 initializer expression. */
18376 {
18380 }
18382 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18383 with either a new invented type template parameter U or, if the
18384 initializer is a braced-init-list (8.5.4), with
18385 std::initializer_list<U>. */
18398 {
18401 }
18403 /* If the list of declarators contains more than one declarator, the type
18404 of each declared variable is determined as described above. If the
18405 type deduced for the template parameter U is not the same in each
18406 deduction, the program is ill-formed. */
18409 {
18413 }
18419 }
18421 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18422 result. */
18424 tree
18426 {
18427 tree argvec;
18436 }
18438 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18440 bool
18442 {
18446 else
18448 }
18450 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18451 appear as a type-specifier for the declaration in question, we don't
18452 have to look through the whole type. */
18454 tree
18456 {
18473 }
18475 /* For a given template T, return the vector of typedefs referenced
18476 in T for which access check is needed at T instantiation time.
18477 T is either a FUNCTION_DECL or a RECORD_TYPE.
18478 Those typedefs were added to T by the function
18479 append_type_to_template_for_access_check. */
18483 {
18484 tree ti;
18495 {
18500 }
18503 }
18505 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18506 tied to T. That list of typedefs will be access checked at
18507 T instantiation time.
18508 T is either a FUNCTION_DECL or a RECORD_TYPE.
18509 TYPE_DECL is a TYPE_DECL node representing a typedef.
18510 SCOPE is the scope through which TYPE_DECL is accessed.
18511 LOCATION is the location of the usage point of TYPE_DECL.
18513 This function is a subroutine of
18514 append_type_to_template_for_access_check. */
18516 static void
18518 tree type_decl,
18519 tree scope,
18520 location_t location)
18521 {
18522 qualified_typedef_usage_t typedef_usage;
18523 tree ti;
18530 && type_decl
18546 }
18548 /* Append TYPE_DECL to the template TEMPL.
18549 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18550 At TEMPL instanciation time, TYPE_DECL will be checked to see
18551 if it can be accessed through SCOPE.
18552 LOCATION is the location of the usage point of TYPE_DECL.
18554 e.g. consider the following code snippet:
18556 class C
18557 {
18558 typedef int myint;
18559 };
18561 template<class U> struct S
18562 {
18563 C::myint mi; // <-- usage point of the typedef C::myint
18564 };
18566 S<char> s;
18568 At S<char> instantiation time, we need to check the access of C::myint
18569 In other words, we need to check the access of the myint typedef through
18570 the C scope. For that purpose, this function will add the myint typedef
18571 and the scope C through which its being accessed to a list of typedefs
18572 tied to the template S. That list will be walked at template instantiation
18573 time and access check performed on each typedefs it contains.
18574 Note that this particular code snippet should yield an error because
18575 myint is private to C. */
18577 void
18579 tree type_decl,
18580 tree scope,
18581 location_t location)
18582 {
18588 /* Make sure we don't append the type to the template twice. */
18599 }
18601 /* Set up the hash tables for template instantiations. */
18603 void
18605 {
18607 hash_specialization,
18608 eq_specializations,
18609 ggc_free);
18611 hash_specialization,
18612 eq_specializations,
18613 ggc_free);
18614 }
18616 /* Print stats about the template hash tables for -fstats. */
18618 void
18620 {
18629 }