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1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2015 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
52 /* The type of functions taking a tree, and some additional data, and
53 returning an int. */
56 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
57 instantiations have been deferred, either because their definitions
58 were not yet available, or because we were putting off doing the work. */
62 };
77 /* Live only within one (recursive) call to tsubst_expr. We use
78 this to pass the statement expression node from the STMT_EXPR
79 to the EXPR_STMT that is its result. */
82 /* True if we've recursed into fn_type_unification too many times. */
86 {
87 tree tmpl;
88 tree args;
89 tree spec;
90 };
93 {
96 };
102 /* Contains canonical template parameter types. The vector is indexed by
103 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
104 TREE_LIST, whose TREE_VALUEs contain the canonical template
105 parameters of various types and levels. */
108 #define UNIFY_ALLOW_NONE 0
109 #define UNIFY_ALLOW_MORE_CV_QUAL 1
110 #define UNIFY_ALLOW_LESS_CV_QUAL 2
111 #define UNIFY_ALLOW_DERIVED 4
112 #define UNIFY_ALLOW_INTEGER 8
113 #define UNIFY_ALLOW_OUTER_LEVEL 16
114 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
115 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
118 tbr_incomplete_type,
119 tbr_ambiguous_baseclass,
120 tbr_success
121 };
144 tree);
206 location_t);
215 /* Make the current scope suitable for access checking when we are
216 processing T. T can be FUNCTION_DECL for instantiated function
217 template, VAR_DECL for static member variable, or TYPE_DECL for
218 alias template (needed by instantiate_decl). */
220 static void
222 {
230 else
234 {
235 saved_access_scope = tree_cons
238 }
239 }
241 /* Restore the scope set up by push_access_scope. T is the node we
242 are processing. */
244 static void
246 {
248 {
251 }
255 else
257 }
259 /* Do any processing required when DECL (a member template
260 declaration) is finished. Returns the TEMPLATE_DECL corresponding
261 to DECL, unless it is a specialization, in which case the DECL
262 itself is returned. */
264 tree
266 {
273 {
274 tree type;
282 {
286 }
288 }
292 {
294 {
297 }
298 else
300 }
301 else
305 }
307 /* Create a template info node. */
309 tree
311 {
316 }
318 /* Return the template info node corresponding to T, whatever T is. */
320 tree
322 {
343 }
345 /* Returns the template nesting level of the indicated class TYPE.
347 For example, in:
348 template <class T>
349 struct A
350 {
351 template <class U>
352 struct B {};
353 };
355 A<T>::B<U> has depth two, while A<T> has depth one.
356 Both A<T>::B<int> and A<int>::B<U> have depth one, if
357 they are instantiations, not specializations.
359 This function is guaranteed to return 0 if passed NULL_TREE so
360 that, for example, `template_class_depth (current_class_type)' is
361 always safe. */
363 int
365 {
372 {
378 }
381 }
383 /* Subroutine of maybe_begin_member_template_processing.
384 Returns true if processing DECL needs us to push template parms. */
386 static bool
388 {
394 }
396 /* Subroutine of maybe_begin_member_template_processing.
397 Push the template parms in PARMS, starting from LEVELS steps into the
398 chain, and ending at the beginning, since template parms are listed
399 innermost first. */
401 static void
403 {
411 current_template_parms
417 NULL);
419 {
428 {
435 {
436 /* Make a CONST_DECL as is done in process_template_parm.
437 It is ugly that we recreate this here; the original
438 version built in process_template_parm is no longer
439 available. */
449 }
454 }
455 }
456 }
458 /* Restore the template parameter context for a member template, a
459 friend template defined in a class definition, or a non-template
460 member of template class. */
462 void
464 {
465 tree parms;
470 {
473 /* Disregard full specializations (c++/60999). */
476 }
479 {
484 {
487 }
490 }
492 /* Remember how many levels of template parameters we pushed so that
493 we can pop them later. */
495 }
497 /* Undo the effects of maybe_begin_member_template_processing. */
499 void
501 {
510 {
514 }
515 }
517 /* Return a new template argument vector which contains all of ARGS,
518 but has as its innermost set of arguments the EXTRA_ARGS. */
520 static tree
522 {
523 tree new_args;
541 }
543 /* Like add_to_template_args, but only the outermost ARGS are added to
544 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
545 (EXTRA_ARGS) levels are added. This function is used to combine
546 the template arguments from a partial instantiation with the
547 template arguments used to attain the full instantiation from the
548 partial instantiation. */
550 static tree
552 {
553 tree new_args;
555 /* If there are more levels of EXTRA_ARGS than there are ARGS,
556 something very fishy is going on. */
559 /* If *all* the new arguments will be the EXTRA_ARGS, just return
560 them. */
564 /* For the moment, we make ARGS look like it contains fewer levels. */
569 /* Now, we restore ARGS to its full dimensions. */
573 }
575 /* Return the N levels of innermost template arguments from the ARGS. */
577 tree
579 {
580 tree new_args;
586 /* If N is 1, just return the innermost set of template arguments. */
590 /* If we're not removing anything, just return the arguments we were
591 given. */
597 /* Make a new set of arguments, not containing the outer arguments. */
604 }
606 /* The inverse of get_innermost_template_args: Return all but the innermost
607 EXTRA_LEVELS levels of template arguments from the ARGS. */
609 static tree
611 {
612 tree new_args;
618 /* If N is 1, just return the outermost set of template arguments. */
622 /* If we're not removing anything, just return the arguments we were
623 given. */
628 /* Make a new set of arguments, not containing the inner arguments. */
635 }
637 /* We've got a template header coming up; push to a new level for storing
638 the parms. */
640 void
642 {
643 /* We use a non-tag-transparent scope here, which causes pushtag to
644 put tags in this scope, rather than in the enclosing class or
645 namespace scope. This is the right thing, since we want
646 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
647 global template class, push_template_decl handles putting the
648 TEMPLATE_DECL into top-level scope. For a nested template class,
649 e.g.:
651 template <class T> struct S1 {
652 template <class T> struct S2 {};
653 };
655 pushtag contains special code to call pushdecl_with_scope on the
656 TEMPLATE_DECL for S2. */
661 }
663 /* This routine is called when a specialization is declared. If it is
664 invalid to declare a specialization here, an error is reported and
665 false is returned, otherwise this routine will return true. */
667 static bool
669 {
672 /* [temp.expl.spec]
674 An explicit specialization shall be declared in the namespace of
675 which the template is a member, or, for member templates, in the
676 namespace of which the enclosing class or enclosing class
677 template is a member. An explicit specialization of a member
678 function, member class or static data member of a class template
679 shall be declared in the namespace of which the class template
680 is a member. */
682 {
685 }
687 /* [temp.expl.spec]
689 In an explicit specialization declaration for a member of a class
690 template or a member template that appears in namespace scope,
691 the member template and some of its enclosing class templates may
692 remain unspecialized, except that the declaration shall not
693 explicitly specialize a class member template if its enclosing
694 class templates are not explicitly specialized as well. */
696 {
699 }
702 }
704 /* We've just seen template <>. */
706 bool
708 {
712 }
714 /* Called at then end of processing a declaration preceded by
715 template<>. */
717 void
719 {
722 }
724 /* Any template <>'s that we have seen thus far are not referring to a
725 function specialization. */
727 void
729 {
732 }
734 /* We've just seen a template header. If SPECIALIZATION is nonzero,
735 it was of the form template <>. */
737 static void
739 {
741 template_header_count++;
742 }
744 /* We're beginning an explicit instantiation. */
746 void
748 {
751 }
754 void
756 {
759 }
761 /* An explicit specialization or partial specialization of TMPL is being
762 declared. Check that the namespace in which the specialization is
763 occurring is permissible. Returns false iff it is invalid to
764 specialize TMPL in the current namespace. */
766 static bool
768 {
771 /* [tmpl.expl.spec]
773 An explicit specialization shall be declared in the namespace of
774 which the template is a member, or, for member templates, in the
775 namespace of which the enclosing class or enclosing class
776 template is a member. An explicit specialization of a member
777 function, member class or static data member of a class template
778 shall be declared in the namespace of which the class template is
779 a member. */
782 {
785 }
787 /* Same or super-using namespace. */
789 else
790 {
794 }
795 }
797 /* SPEC is an explicit instantiation. Check that it is valid to
798 perform this explicit instantiation in the current namespace. */
800 static void
802 {
803 tree ns;
805 /* DR 275: An explicit instantiation shall appear in an enclosing
806 namespace of its template. */
812 }
814 /* The TYPE is being declared. If it is a template type, that means it
815 is a partial specialization. Do appropriate error-checking. */
817 tree
819 {
820 tree context;
825 /* A lambda that appears in specialization context is not itself a
826 specialization. */
831 {
835 }
840 {
845 else
848 }
850 {
851 /* This is for ordinary explicit specialization and partial
852 specialization of a template class such as:
854 template <> class C<int>;
856 or:
858 template <class T> class C<T*>;
860 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
864 {
871 {
875 }
876 }
882 /* Trying to define a specialization either without a template<> header
883 or in an inappropriate place. We've already given an error, so just
884 bail now so we don't actually define the specialization. */
886 }
892 {
893 /* This is for an explicit specialization of member class
894 template according to [temp.expl.spec/18]:
896 template <> template <class U> class C<int>::D;
898 The context `C<int>' must be an implicit instantiation.
899 Otherwise this is just a member class template declared
900 earlier like:
902 template <> class C<int> { template <class U> class D; };
903 template <> template <class U> class C<int>::D;
905 In the first case, `C<int>::D' is a specialization of `C<T>::D'
906 while in the second case, `C<int>::D' is a primary template
907 and `C<T>::D' may not exist. */
911 {
912 tree t;
917 {
920 }
922 /* Check for invalid specialization after instantiation:
924 template <> template <> class C<int>::D<int>;
925 template <> template <class U> class C<int>::D; */
929 {
933 {
934 /* We already have a full specialization of this partial
935 instantiation, or a full specialization has been
936 looked up but not instantiated. Reassign it to the
937 new member specialization template. */
938 spec_entry elt;
950 spec_entry **slot
955 }
956 else
957 /* But if we've had an implicit instantiation, that's a
958 problem ([temp.expl.spec]/6). */
961 }
963 /* Mark TYPE as a specialization. And as a result, we only
964 have one level of template argument for the innermost
965 class template. */
970 }
971 }
973 {
974 /* Someday C++0x may allow for enum template specialization. */
979 else
980 {
983 }
984 }
987 }
989 /* Returns nonzero if we can optimize the retrieval of specializations
990 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
991 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
995 {
998 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
999 parameter. */
1001 /* The optimized lookup depends on the fact that the
1002 template arguments for the member function template apply
1003 purely to the containing class, which is not true if the
1004 containing class is an explicit or partial
1005 specialization. */
1009 /* It is possible to have a template that is not a member
1010 template and is not a member of a template class:
1012 template <typename T>
1013 struct S { friend A::f(); };
1015 Here, the friend function is a template, but the context does
1016 not have template information. The optimized lookup relies
1017 on having ARGS be the template arguments for both the class
1018 and the function template. */
1020 }
1022 /* Retrieve the specialization (in the sense of [temp.spec] - a
1023 specialization is either an instantiation or an explicit
1024 specialization) of TMPL for the given template ARGS. If there is
1025 no such specialization, return NULL_TREE. The ARGS are a vector of
1026 arguments, or a vector of vectors of arguments, in the case of
1027 templates with more than one level of parameters.
1029 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1030 then we search for a partial specialization matching ARGS. This
1031 parameter is ignored if TMPL is not a class template.
1033 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1034 result is a NONTYPE_ARGUMENT_PACK. */
1036 static tree
1038 {
1048 /* There should be as many levels of arguments as there are
1049 levels of parameters. */
1055 #ifdef ENABLE_CHECKING
1056 /* We should have gone through coerce_template_parms by now. */
1061 #endif
1064 {
1065 tree class_template;
1066 tree class_specialization;
1068 tree fns;
1071 /* The template arguments actually apply to the containing
1072 class. Find the class specialization with those
1073 arguments. */
1075 class_specialization
1079 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1080 for the specialization. */
1084 /* Iterate through the methods with the indicated name, looking
1085 for the one that has an instance of TMPL. */
1088 {
1091 /* using-declarations can add base methods to the method vec,
1092 and we don't want those here. */
1095 }
1097 }
1098 else
1099 {
1101 spec_entry elt;
1110 else
1118 }
1121 }
1123 /* Like retrieve_specialization, but for local declarations. */
1125 static tree
1127 {
1133 }
1135 /* Returns nonzero iff DECL is a specialization of TMPL. */
1137 int
1139 {
1140 tree t;
1143 {
1149 }
1150 else
1151 {
1160 }
1163 }
1165 /* Returns nonzero iff DECL is a specialization of friend declaration
1166 FRIEND_DECL according to [temp.friend]. */
1168 bool
1170 {
1177 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1178 of a template class, we want to check if DECL is a specialization
1179 if this. */
1183 {
1184 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1187 }
1192 /* There is nothing to do if this is not a template friend. */
1199 /* [temp.friend/6]
1200 A member of a class template may be declared to be a friend of a
1201 non-template class. In this case, the corresponding member of
1202 every specialization of the class template is a friend of the
1203 class granting friendship.
1205 For example, given a template friend declaration
1207 template <class T> friend void A<T>::f();
1209 the member function below is considered a friend
1211 template <> struct A<int> {
1212 void f();
1213 };
1215 For this type of template friend, TEMPLATE_DEPTH below will be
1216 nonzero. To determine if DECL is a friend of FRIEND, we first
1217 check if the enclosing class is a specialization of another. */
1224 {
1225 /* Next, we check the members themselves. In order to handle
1226 a few tricky cases, such as when FRIEND_DECL's are
1228 template <class T> friend void A<T>::g(T t);
1229 template <class T> template <T t> friend void A<T>::h();
1231 and DECL's are
1233 void A<int>::g(int);
1234 template <int> void A<int>::h();
1236 we need to figure out ARGS, the template arguments from
1237 the context of DECL. This is required for template substitution
1238 of `T' in the function parameter of `g' and template parameter
1239 of `h' in the above examples. Here ARGS corresponds to `int'. */
1246 {
1248 {
1251 else
1253 current_depth++;
1254 }
1256 }
1259 {
1261 tree friend_type;
1262 tree decl_type;
1263 tree friend_args_type;
1264 tree decl_args_type;
1266 /* Make sure that both DECL and FRIEND_DECL are templates or
1267 non-templates. */
1273 {
1274 /* If both are templates, check template parameter list. */
1275 tree friend_parms
1280 friend_parms))
1284 }
1285 else
1293 /* Check if return types match. */
1297 /* Check if function parameter types match, ignoring the
1298 `this' parameter. */
1307 }
1308 else
1309 {
1310 /* DECL is a TYPE_DECL */
1314 /* Make sure that both DECL and FRIEND_DECL are templates or
1315 non-templates. */
1316 is_template
1323 {
1324 tree friend_parms;
1325 /* If both are templates, check the name of the two
1326 TEMPLATE_DECL's first because is_friend didn't. */
1331 /* Now check template parameter list. */
1332 friend_parms
1335 return comp_template_parms
1337 friend_parms);
1338 }
1339 else
1342 }
1343 }
1345 }
1347 /* Register the specialization SPEC as a specialization of TMPL with
1348 the indicated ARGS. IS_FRIEND indicates whether the specialization
1349 is actually just a friend declaration. Returns SPEC, or an
1350 equivalent prior declaration, if available.
1352 We also store instantiations of field packs in the hash table, even
1353 though they are not themselves templates, to make lookup easier. */
1355 static tree
1357 hashval_t hash)
1358 {
1359 tree fn;
1361 spec_entry elt;
1369 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1370 register it; we want the corresponding TEMPLATE_DECL instead.
1371 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1372 the more obvious `uses_template_parms (spec)' to avoid problems
1373 with default function arguments. In particular, given
1374 something like this:
1376 template <class T> void f(T t1, T t = T())
1378 the default argument expression is not substituted for in an
1379 instantiation unless and until it is actually needed. */
1383 /* We don't put these specializations in the hash table, but we might
1384 want to give an error about a mismatch. */
1386 else
1387 {
1395 slot =
1399 else
1401 }
1403 /* We can sometimes try to re-register a specialization that we've
1404 already got. In particular, regenerate_decl_from_template calls
1405 duplicate_decls which will update the specialization list. But,
1406 we'll still get called again here anyhow. It's more convenient
1407 to simply allow this than to try to prevent it. */
1411 {
1413 {
1416 {
1418 fn);
1420 }
1421 else
1422 {
1423 tree clone;
1424 /* This situation should occur only if the first
1425 specialization is an implicit instantiation, the
1426 second is an explicit specialization, and the
1427 implicit instantiation has not yet been used. That
1428 situation can occur if we have implicitly
1429 instantiated a member function and then specialized
1430 it later.
1432 We can also wind up here if a friend declaration that
1433 looked like an instantiation turns out to be a
1434 specialization:
1436 template <class T> void foo(T);
1437 class S { friend void foo<>(int) };
1438 template <> void foo(int);
1440 We transform the existing DECL in place so that any
1441 pointers to it become pointers to the updated
1442 declaration.
1444 If there was a definition for the template, but not
1445 for the specialization, we want this to look as if
1446 there were no definition, and vice versa. */
1449 /* The call to duplicate_decls will have applied
1450 [temp.expl.spec]:
1452 An explicit specialization of a function template
1453 is inline only if it is explicitly declared to be,
1454 and independently of whether its function template
1455 is.
1457 to the primary function; now copy the inline bits to
1458 the various clones. */
1460 {
1467 }
1471 }
1472 }
1474 {
1476 /* Dup decl failed, but this is a new definition. Set the
1477 line number so any errors match this new
1478 definition. */
1482 }
1483 }
1487 /* A specialization must be declared in the same namespace as the
1488 template it is specializing. */
1494 {
1503 /* If TMPL is a forward declaration of a template function, keep a list
1504 of all specializations in case we need to reassign them to a friend
1505 template later in tsubst_friend_function.
1507 Also keep a list of all variable template instantiations so that
1508 process_partial_specialization can check whether a later partial
1509 specialization would have used it. */
1512 }
1515 }
1517 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1518 TMPL and ARGS members, ignores SPEC. */
1522 bool
1524 {
1533 }
1535 /* Returns a hash for a template TMPL and template arguments ARGS. */
1537 static hashval_t
1539 {
1542 }
1544 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1545 ignoring SPEC. */
1547 hashval_t
1549 {
1551 }
1553 /* Recursively calculate a hash value for a template argument ARG, for use
1554 in the hash tables of template specializations. */
1556 hashval_t
1558 {
1570 /* We can get one of these when re-hashing a previous entry in the middle
1571 of substituting into a pack expansion. Just look through it. */
1580 {
1588 {
1593 }
1615 {
1619 {
1622 }
1624 }
1628 {
1631 }
1642 val = iterative_hash_template_arg
1654 val);
1656 val);
1665 /* A lambda can't appear in a template arg, but don't crash on
1666 erroneous input. */
1678 /* Now hash operands as usual. */
1683 }
1686 {
1689 {
1690 // We want an alias specialization that survived strip_typedefs
1691 // to hash differently from its TYPE_CANONICAL, to avoid hash
1692 // collisions that compare as different in template_args_equal.
1693 // These could be dependent specializations that strip_typedefs
1694 // left alone, or untouched specializations because
1695 // coerce_template_parms returns the unconverted template
1696 // arguments if it sees incomplete argument packs.
1699 }
1702 val);
1705 /* Otherwise just compare the types during lookup. */
1714 {
1719 }
1720 }
1723 }
1725 /* Unregister the specialization SPEC as a specialization of TMPL.
1726 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1727 if the SPEC was listed as a specialization of TMPL.
1729 Note that SPEC has been ggc_freed, so we can't look inside it. */
1731 bool
1733 {
1735 spec_entry elt;
1743 {
1748 }
1751 }
1753 /* Like register_specialization, but for local declarations. We are
1754 registering SPEC, an instantiation of TMPL. */
1756 static void
1758 {
1760 }
1762 /* TYPE is a class type. Returns true if TYPE is an explicitly
1763 specialized class. */
1765 bool
1767 {
1771 }
1773 /* Print the list of functions at FNS, going through all the overloads
1774 for each element of the list. Alternatively, FNS can not be a
1775 TREE_LIST, in which case it will be printed together with all the
1776 overloads.
1778 MORE and *STR should respectively be FALSE and NULL when the function
1779 is called from the outside. They are used internally on recursive
1780 calls. print_candidates manages the two parameters and leaves NULL
1781 in *STR when it ends. */
1783 static void
1785 {
1791 {
1795 }
1796 else
1797 {
1800 {
1801 /* Pick the prefix string. */
1803 {
1807 }
1811 }
1814 }
1817 {
1820 }
1821 }
1823 /* Print the list of candidate FNS in an error message. FNS can also
1824 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1826 void
1828 {
1832 }
1834 /* Returns the template (one of the functions given by TEMPLATE_ID)
1835 which can be specialized to match the indicated DECL with the
1836 explicit template args given in TEMPLATE_ID. The DECL may be
1837 NULL_TREE if none is available. In that case, the functions in
1838 TEMPLATE_ID are non-members.
1840 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1841 specialization of a member template.
1843 The TEMPLATE_COUNT is the number of references to qualifying
1844 template classes that appeared in the name of the function. See
1845 check_explicit_specialization for a more accurate description.
1847 TSK indicates what kind of template declaration (if any) is being
1848 declared. TSK_TEMPLATE indicates that the declaration given by
1849 DECL, though a FUNCTION_DECL, has template parameters, and is
1850 therefore a template function.
1852 The template args (those explicitly specified and those deduced)
1853 are output in a newly created vector *TARGS_OUT.
1855 If it is impossible to determine the result, an error message is
1856 issued. The error_mark_node is returned to indicate failure. */
1858 static tree
1860 tree decl,
1864 tmpl_spec_kind tsk)
1865 {
1866 tree fns;
1867 tree targs;
1868 tree explicit_targs;
1870 /* A TREE_LIST of templates of which DECL may be a specialization.
1871 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1872 corresponding TREE_PURPOSE is the set of template arguments that,
1873 when used to instantiate the template, would produce a function
1874 with the signature of DECL. */
1884 /* We shouldn't be specializing a member template of an
1885 unspecialized class template; we already gave an error in
1886 check_specialization_scope, now avoid crashing. */
1889 {
1892 }
1900 /* Check for baselinks. */
1905 {
1908 }
1910 {
1913 }
1915 /* Count the number of template headers specified for this
1916 specialization. */
1924 {
1927 tf_warning_or_error,
1930 }
1932 {
1936 {
1937 tree decl_arg_types;
1938 tree fn_arg_types;
1939 tree insttype;
1941 /* In case of explicit specialization, we need to check if
1942 the number of template headers appearing in the specialization
1943 is correct. This is usually done in check_explicit_specialization,
1944 but the check done there cannot be exhaustive when specializing
1945 member functions. Consider the following code:
1947 template <> void A<int>::f(int);
1948 template <> template <> void A<int>::f(int);
1950 Assuming that A<int> is not itself an explicit specialization
1951 already, the first line specializes "f" which is a non-template
1952 member function, whilst the second line specializes "f" which
1953 is a template member function. So both lines are syntactically
1954 correct, and check_explicit_specialization does not reject
1955 them.
1957 Here, we can do better, as we are matching the specialization
1958 against the declarations. We count the number of template
1959 headers, and we check if they match TEMPLATE_COUNT + 1
1960 (TEMPLATE_COUNT is the number of qualifying template classes,
1961 plus there must be another header for the member template
1962 itself).
1964 Notice that if header_count is zero, this is not a
1965 specialization but rather a template instantiation, so there
1966 is no check we can perform here. */
1970 /* Check that the number of template arguments at the
1971 innermost level for DECL is the same as for FN. */
1979 /* DECL might be a specialization of FN. */
1983 /* For a non-static member function, we need to make sure
1984 that the const qualification is the same. Since
1985 get_bindings does not try to merge the "this" parameter,
1986 we must do the comparison explicitly. */
1992 /* Skip the "this" parameter and, for constructors of
1993 classes with virtual bases, the VTT parameter. A
1994 full specialization of a constructor will have a VTT
1995 parameter, but a template never will. */
1996 decl_arg_types
1998 fn_arg_types
2001 /* Function templates cannot be specializations; there are
2002 no partial specializations of functions. Therefore, if
2003 the type of DECL does not match FN, there is no
2004 match. */
2006 {
2010 }
2012 /* See whether this function might be a specialization of this
2013 template. Suppress access control because we might be trying
2014 to make this specialization a friend, and we have already done
2015 access control for the declaration of the specialization. */
2021 /* We cannot deduce template arguments that when used to
2022 specialize TMPL will produce DECL. */
2025 /* Make sure that the deduced arguments actually work. */
2029 fn_arg_types
2034 /* Save this template, and the arguments deduced. */
2036 }
2038 /* FN is an ordinary member function, and we need a
2039 specialization of a member template. */
2040 ;
2042 /* We can get IDENTIFIER_NODEs here in certain erroneous
2043 cases. */
2044 ;
2046 /* This is just an ordinary non-member function. Nothing can
2047 be a specialization of that. */
2048 ;
2050 /* Cannot specialize functions that are created implicitly. */
2051 ;
2052 else
2053 {
2054 tree decl_arg_types;
2056 /* This is an ordinary member function. However, since
2057 we're here, we can assume its enclosing class is a
2058 template class. For example,
2060 template <typename T> struct S { void f(); };
2061 template <> void S<int>::f() {}
2063 Here, S<int>::f is a non-template, but S<int> is a
2064 template class. If FN has the same type as DECL, we
2065 might be in business. */
2068 /* Its enclosing class is an explicit specialization
2069 of a template class. This is not a candidate. */
2074 /* The return types differ. */
2077 /* Adjust the type of DECL in case FN is a static member. */
2084 decl_arg_types))
2085 /* They match! */
2087 }
2088 }
2091 {
2092 /* We have:
2094 [temp.expl.spec]
2096 It is possible for a specialization with a given function
2097 signature to be instantiated from more than one function
2098 template. In such cases, explicit specification of the
2099 template arguments must be used to uniquely identify the
2100 function template specialization being specialized.
2102 Note that here, there's no suggestion that we're supposed to
2103 determine which of the candidate templates is most
2104 specialized. However, we, also have:
2106 [temp.func.order]
2108 Partial ordering of overloaded function template
2109 declarations is used in the following contexts to select
2110 the function template to which a function template
2111 specialization refers:
2113 -- when an explicit specialization refers to a function
2114 template.
2116 So, we do use the partial ordering rules, at least for now.
2117 This extension can only serve to make invalid programs valid,
2118 so it's safe. And, there is strong anecdotal evidence that
2119 the committee intended the partial ordering rules to apply;
2120 the EDG front end has that behavior, and John Spicer claims
2121 that the committee simply forgot to delete the wording in
2122 [temp.expl.spec]. */
2125 {
2128 }
2129 }
2132 {
2140 }
2144 {
2150 }
2152 /* We have one, and exactly one, match. */
2154 {
2157 /* DECL is a re-declaration or partial instantiation of a template
2158 function. */
2161 /* It was a specialization of an ordinary member function in a
2162 template class. */
2164 }
2166 /* It was a specialization of a template. */
2169 {
2174 }
2175 else
2178 }
2180 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2181 but with the default argument values filled in from those in the
2182 TMPL_TYPES. */
2184 static tree
2186 tree tmpl_types)
2187 {
2188 tree new_spec_types;
2196 /* Substitute into the rest of the list. */
2197 new_spec_types =
2201 /* Add the default argument for this parameter. */
2204 new_spec_types);
2205 }
2207 /* DECL is an explicit specialization. Replicate default arguments
2208 from the template it specializes. (That way, code like:
2210 template <class T> void f(T = 3);
2211 template <> void f(double);
2212 void g () { f (); }
2214 works, as required.) An alternative approach would be to look up
2215 the correct default arguments at the call-site, but this approach
2216 is consistent with how implicit instantiations are handled. */
2218 static void
2220 {
2221 tree tmpl;
2222 tree spec_types;
2223 tree tmpl_types;
2224 tree new_spec_types;
2225 tree old_type;
2226 tree new_type;
2227 tree t;
2232 /* See if there's anything we need to do. */
2245 {
2246 /* Remove the this pointer, but remember the object's type for
2247 CV quals. */
2253 {
2254 /* DECL may contain more parameters than TMPL due to the extra
2255 in-charge parameter in constructors and destructors. */
2258 }
2260 {
2263 }
2264 }
2266 /* Compute the merged default arguments. */
2267 new_spec_types =
2270 /* Compute the new FUNCTION_TYPE. */
2272 {
2276 new_spec_types);
2279 /* Put the in-charge parameter back. */
2282 new_spec_types);
2286 new_spec_types);
2287 }
2288 else
2290 new_spec_types);
2300 }
2302 /* Return the number of template headers we expect to see for a definition
2303 or specialization of CTYPE or one of its non-template members. */
2305 int
2307 {
2311 {
2312 /* You're supposed to have one `template <...>' for every
2313 template class, but you don't need one for a full
2314 specialization. For example:
2316 template <class T> struct S{};
2317 template <> struct S<int> { void f(); };
2318 void S<int>::f () {}
2320 is correct; there shouldn't be a `template <>' for the
2321 definition of `S<int>::f'. */
2323 /* If CTYPE does not have template information of any
2324 kind, then it is not a template, nor is it nested
2325 within a template. */
2333 }
2336 }
2338 /* Do a simple sanity check on the template headers that precede the
2339 variable declaration DECL. */
2341 void
2343 {
2348 {
2351 "variable templates only available with "
2354 // Namespace-scope variable templates should have a template header.
2356 }
2358 {
2365 "members of an explicitly specialized class are defined "
2367 }
2368 }
2370 /* Check to see if the function just declared, as indicated in
2371 DECLARATOR, and in DECL, is a specialization of a function
2372 template. We may also discover that the declaration is an explicit
2373 instantiation at this point.
2375 Returns DECL, or an equivalent declaration that should be used
2376 instead if all goes well. Issues an error message if something is
2377 amiss. Returns error_mark_node if the error is not easily
2378 recoverable.
2380 FLAGS is a bitmask consisting of the following flags:
2382 2: The function has a definition.
2383 4: The function is a friend.
2385 The TEMPLATE_COUNT is the number of references to qualifying
2386 template classes that appeared in the name of the function. For
2387 example, in
2389 template <class T> struct S { void f(); };
2390 void S<int>::f();
2392 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2393 classes are not counted in the TEMPLATE_COUNT, so that in
2395 template <class T> struct S {};
2396 template <> struct S<int> { void f(); }
2397 template <> void S<int>::f();
2399 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2400 invalid; there should be no template <>.)
2402 If the function is a specialization, it is marked as such via
2403 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2404 is set up correctly, and it is added to the list of specializations
2405 for that template. */
2407 tree
2409 tree decl,
2412 {
2420 tmpl_spec_kind tsk;
2423 {
2426 else
2428 }
2429 else
2433 {
2436 {
2439 }
2441 {
2443 /* This could be something like:
2445 template <class T> void f(T);
2446 class S { friend void f<>(int); } */
2448 else
2449 {
2450 /* This case handles bogus declarations like template <>
2451 template <class T> void f<int>(); */
2454 declarator);
2456 }
2457 }
2461 /* The error has already been reported in
2462 check_specialization_scope. */
2468 /* Fall through. */
2481 decl);
2484 else
2488 /* Fall through. */
2491 /* In cases like template<> constexpr bool v = true;
2492 We'll give an error in check_template_variable. */
2498 else
2504 {
2505 /* This case handles bogus declarations like template <>
2506 template <class T> void f<int>(); */
2510 declarator);
2512 {
2513 /* Partial specialization of variable template. */
2517 }
2521 else
2525 ok:;
2526 }
2529 /* This is a specialization of a member template, without
2530 specialization the containing class. Something like:
2532 template <class T> struct S {
2533 template <class U> void f (U);
2534 };
2535 template <> template <class U> void S<int>::f(U) {}
2537 That's a specialization -- but of the entire template. */
2543 }
2546 /* This doesn't apply to variable templates. */
2549 {
2553 {
2557 }
2558 }
2561 {
2566 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2568 {
2569 tree fns;
2574 else
2575 {
2576 /* If there is no class context, the explicit instantiation
2577 must be at namespace scope. */
2580 /* Find the namespace binding, using the declaration
2581 context. */
2585 {
2588 }
2589 else
2590 {
2596 }
2597 }
2600 }
2606 {
2608 /* A specialization in class scope. This is invalid,
2609 but the error will already have been flagged by
2610 check_specialization_scope. */
2612 else
2613 {
2614 /* It's not valid to write an explicit instantiation in
2615 class scope, e.g.:
2617 class C { template void f(); }
2619 This case is caught by the parser. However, on
2620 something like:
2622 template class C { void f(); };
2624 (which is invalid) we can get here. The error will be
2625 issued later. */
2626 ;
2627 }
2630 }
2633 {
2634 // We'll match variable templates in start_decl.
2638 /* Find the list of functions in ctype that have the same
2639 name as the declared function. */
2645 {
2650 {
2651 /* From [temp.expl.spec]:
2653 If such an explicit specialization for the member
2654 of a class template names an implicitly-declared
2655 special member function (clause _special_), the
2656 program is ill-formed.
2658 Similar language is found in [temp.explicit]. */
2661 }
2664 }
2667 {
2671 }
2672 else
2673 {
2675 tree ovl;
2677 /* For a type-conversion operator, we cannot do a
2678 name-based lookup. We might be looking for `operator
2679 int' which will be a specialization of `operator T'.
2680 So, we find *all* the conversion operators, and then
2681 select from them. */
2689 {
2691 /* There are no more conversion functions. */
2694 /* Glue all these conversion functions together
2695 with those we already have. */
2698 }
2699 }
2702 {
2705 }
2706 else
2708 }
2710 /* Figure out what exactly is being specialized at this point.
2711 Note that for an explicit instantiation, even one for a
2712 member function, we cannot tell apriori whether the
2713 instantiation is for a member template, or just a member
2714 function of a template class. Even if a member template is
2715 being instantiated, the member template arguments may be
2716 elided if they can be deduced from the rest of the
2717 declaration. */
2720 member_specialization,
2721 template_count,
2722 tsk);
2725 /* We couldn't figure out what this declaration was
2726 specializing. */
2728 else
2729 {
2733 {
2734 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2735 is done by do_decl_instantiation later. */
2741 {
2742 /* If TMPL is not the most general template (for
2743 example, if TMPL is a friend template that is
2744 injected into namespace scope), then there will
2745 be too many levels of TARGS. Remove some of them
2746 here. */
2748 tree new_targs;
2755 }
2758 }
2760 /* If we thought that the DECL was a member function, but it
2761 turns out to be specializing a static member function,
2762 make DECL a static member function as well. */
2768 /* If this is a specialization of a member template of a
2769 template class, we want to return the TEMPLATE_DECL, not
2770 the specialization of it. */
2772 {
2777 {
2778 tree parm;
2782 /* We want to use the argument list specified in the
2783 definition, not in the original declaration. */
2788 }
2791 }
2793 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2799 /* Inherit default function arguments from the template
2800 DECL is specializing. */
2804 /* This specialization has the same protection as the
2805 template it specializes. */
2809 /* 7.1.1-1 [dcl.stc]
2811 A storage-class-specifier shall not be specified in an
2812 explicit specialization...
2814 The parser rejects these, so unless action is taken here,
2815 explicit function specializations will always appear with
2816 global linkage.
2818 The action recommended by the C++ CWG in response to C++
2819 defect report 605 is to make the storage class and linkage
2820 of the explicit specialization match the templated function:
2822 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2823 */
2825 {
2829 /* This specialization has the same linkage and visibility as
2830 the function template it specializes. */
2833 {
2836 }
2839 {
2842 }
2843 }
2845 /* If DECL is a friend declaration, declared using an
2846 unqualified name, the namespace associated with DECL may
2847 have been set incorrectly. For example, in:
2849 template <typename T> void f(T);
2850 namespace N {
2851 struct S { friend void f<int>(int); }
2852 }
2854 we will have set the DECL_CONTEXT for the friend
2855 declaration to N, rather than to the global namespace. */
2860 /* This is not really a declaration of a specialization.
2861 It's just the name of an instantiation. But, it's not
2862 a request for an instantiation, either. */
2865 /* A specialization is not necessarily COMDAT. */
2871 /* Register this specialization so that we can find it
2872 again. */
2875 /* A 'structor should already have clones. */
2881 }
2882 }
2885 }
2887 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2888 parameters. These are represented in the same format used for
2889 DECL_TEMPLATE_PARMS. */
2891 int
2893 {
2894 const_tree p1;
2895 const_tree p2;
2903 {
2915 {
2919 /* If either of the template parameters are invalid, assume
2920 they match for the sake of error recovery. */
2933 }
2934 }
2937 /* One set of parameters has more parameters lists than the
2938 other. */
2942 }
2944 /* Determine whether PARM is a parameter pack. */
2946 bool
2948 {
2949 /* Determine if we have a non-type template parameter pack. */
2956 /* If this is a list of template parameters, we could get a
2957 TYPE_DECL or a TEMPLATE_DECL. */
2961 /* Otherwise it must be a type template parameter. */
2965 }
2967 /* Determine if T is a function parameter pack. */
2969 bool
2971 {
2975 }
2977 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2978 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2980 tree
2982 {
2989 }
2991 /* Return true iff the function parameter PARAM_DECL was expanded
2992 from the function parameter pack PACK. */
2994 bool
2996 {
3001 /* The parameter pack and its pack arguments have the same
3002 DECL_PARM_INDEX. */
3004 }
3006 /* Determine whether ARGS describes a variadic template args list,
3007 i.e., one that is terminated by a template argument pack. */
3009 static bool
3011 {
3013 tree last_parm;
3027 }
3029 /* Generate a new name for the parameter pack name NAME (an
3030 IDENTIFIER_NODE) that incorporates its */
3032 static tree
3034 {
3035 /* Munge the name to include the parameter index. */
3036 #define NUMBUF_LEN 128
3050 }
3052 /* Return true if T is a primary function, class or alias template
3053 instantiation. */
3055 bool
3057 {
3071 }
3073 /* Return true if PARM is a template template parameter. */
3075 bool
3077 {
3079 }
3081 /* Return true iff PARM is a DECL representing a type template
3082 parameter. */
3084 bool
3086 {
3091 }
3093 /* Return the template parameters of T if T is a
3094 primary template instantiation, NULL otherwise. */
3096 tree
3098 {
3103 parms = INNERMOST_TEMPLATE_PARMS
3107 }
3109 /* Return the template parameters of the LEVELth level from the full list
3110 of template parameters PARMS. */
3112 tree
3114 {
3115 tree p;
3126 }
3128 /* Returns the template arguments of T if T is a template instantiation,
3129 NULL otherwise. */
3131 tree
3133 {
3141 }
3143 /* Return the argument pack elements of T if T is a template argument pack,
3144 NULL otherwise. */
3146 tree
3148 {
3154 }
3156 /* Structure used to track the progress of find_parameter_packs_r. */
3157 struct find_parameter_pack_data
3158 {
3159 /* TREE_LIST that will contain all of the parameter packs found by
3160 the traversal. */
3163 /* Set of AST nodes that have been visited by the traversal. */
3165 };
3167 /* Identifies all of the argument packs that occur in a template
3168 argument and appends them to the TREE_LIST inside DATA, which is a
3169 find_parameter_pack_data structure. This is a subroutine of
3170 make_pack_expansion and uses_parameter_packs. */
3171 static tree
3173 {
3179 /* Handle type aliases/typedefs. */
3181 {
3188 }
3190 /* Identify whether this is a parameter pack or not. */
3192 {
3208 {
3209 /* We don't want to walk into the type of a PARM_DECL,
3210 because we don't want to see the type parameter pack. */
3213 }
3216 /* Look through a lambda capture proxy to the field pack. */
3219 {
3225 }
3232 /* Not a parameter pack. */
3234 }
3237 {
3238 /* Add this parameter pack to the list. */
3240 }
3246 /* This switch statement will return immediately if we don't find a
3247 parameter pack. */
3249 {
3254 /* Check the template itself. */
3257 /* Check the template arguments. */
3273 /* Fall through. */
3315 }
3318 }
3320 /* Determines if the expression or type T uses any parameter packs. */
3321 bool
3323 {
3331 }
3333 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3334 representation a base-class initializer into a parameter pack
3335 expansion. If all goes well, the resulting node will be an
3336 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3337 respectively. */
3338 tree
3340 {
3341 tree result;
3350 {
3351 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3352 class initializer. In this case, the TREE_PURPOSE will be a
3353 _TYPE node (representing the base class expansion we're
3354 initializing) and the TREE_VALUE will be a TREE_LIST
3355 containing the initialization arguments.
3357 The resulting expansion looks somewhat different from most
3358 expansions. Rather than returning just one _EXPANSION, we
3359 return a TREE_LIST whose TREE_PURPOSE is a
3360 TYPE_PACK_EXPANSION containing the bases that will be
3361 initialized. The TREE_VALUE will be identical to the
3362 original TREE_VALUE, which is a list of arguments that will
3363 be passed to each base. We do not introduce any new pack
3364 expansion nodes into the TREE_VALUE (although it is possible
3365 that some already exist), because the TREE_PURPOSE and
3366 TREE_VALUE all need to be expanded together with the same
3367 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3368 resulting TREE_PURPOSE will mention the parameter packs in
3369 both the bases and the arguments to the bases. */
3370 tree purpose;
3371 tree value;
3374 /* Determine which parameter packs will be used by the base
3375 class expansion. */
3382 {
3386 }
3389 {
3390 /* Collect the sets of parameter packs used in each of the
3391 initialization arguments. */
3393 {
3394 /* Determine which parameter packs will be expanded in this
3395 argument. */
3398 }
3399 }
3403 /* Create the pack expansion type for the base type. */
3408 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3409 they will rarely be compared to anything. */
3413 }
3418 /* Build the PACK_EXPANSION_* node. */
3419 result = for_types
3424 {
3425 /* Propagate type and const-expression information. */
3428 }
3429 else
3430 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3431 they will rarely be compared to anything. */
3434 /* Determine which parameter packs will be expanded. */
3440 /* Make sure we found some parameter packs. */
3442 {
3445 else
3448 }
3454 }
3456 /* Checks T for any "bare" parameter packs, which have not yet been
3457 expanded, and issues an error if any are found. This operation can
3458 only be done on full expressions or types (e.g., an expression
3459 statement, "if" condition, etc.), because we could have expressions like:
3461 foo(f(g(h(args)))...)
3463 where "args" is a parameter pack. check_for_bare_parameter_packs
3464 should not be called for the subexpressions args, h(args),
3465 g(h(args)), or f(g(h(args))), because we would produce erroneous
3466 error messages.
3468 Returns TRUE and emits an error if there were bare parameter packs,
3469 returns FALSE otherwise. */
3470 bool
3472 {
3488 {
3491 {
3500 else
3505 else
3509 }
3512 }
3515 }
3517 /* Expand any parameter packs that occur in the template arguments in
3518 ARGS. */
3519 tree
3521 {
3527 /* First, determine if we need to expand anything, and the number of
3528 slots we'll need. */
3530 {
3535 {
3539 else
3541 }
3542 else
3543 {
3545 num_result_args++;
3546 }
3547 }
3549 /* If no expansion is necessary, we're done. */
3553 /* Expand arguments. */
3556 non_default_args_count =
3559 {
3562 {
3569 }
3570 else
3571 {
3574 }
3575 }
3579 }
3581 /* Checks if DECL shadows a template parameter.
3583 [temp.local]: A template-parameter shall not be redeclared within its
3584 scope (including nested scopes).
3586 Emits an error and returns TRUE if the DECL shadows a parameter,
3587 returns FALSE otherwise. */
3589 bool
3591 {
3592 tree olddecl;
3594 /* If we're not in a template, we can't possibly shadow a template
3595 parameter. */
3599 /* Figure out what we're shadowing. */
3604 /* If there's no previous binding for this name, we're not shadowing
3605 anything, let alone a template parameter. */
3609 /* If we're not shadowing a template parameter, we're done. Note
3610 that OLDDECL might be an OVERLOAD (or perhaps even an
3611 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3612 node. */
3616 /* We check for decl != olddecl to avoid bogus errors for using a
3617 name inside a class. We check TPFI to avoid duplicate errors for
3618 inline member templates. */
3624 /* Don't complain about the injected class name, as we've already
3625 complained about the class itself. */
3632 }
3634 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3635 ORIG_LEVEL, DECL, and TYPE. */
3637 static tree
3641 tree decl,
3642 tree type)
3643 {
3654 }
3656 /* Find the canonical type parameter for the given template type
3657 parameter. Returns the canonical type parameter, which may be TYPE
3658 if no such parameter existed. */
3660 static tree
3662 {
3663 tree list;
3677 else
3678 {
3683 }
3684 }
3686 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3687 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3688 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3689 new one is created. */
3691 static tree
3693 tsubst_flags_t complain)
3694 {
3699 {
3718 /* Template template parameters need this. */
3723 }
3726 }
3728 /* Process information from new template parameter PARM and append it
3729 to the LIST being built. This new parameter is a non-type
3730 parameter iff IS_NON_TYPE is true. This new parameter is a
3731 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3732 is in PARM_LOC. */
3734 tree
3737 {
3739 tree defval;
3746 {
3750 {
3754 else
3756 }
3759 }
3762 {
3768 {
3769 /* [temp.param]
3771 The top-level cv-qualifiers on the template-parameter are
3772 ignored when determining its type. */
3777 && !is_parameter_pack
3778 /* If we're in a nested template parameter list, the template
3779 template parameter could be a parameter pack. */
3781 {
3782 /* This template parameter is not a parameter pack, but it
3783 should be. Complain about "bare" parameter packs. */
3786 /* Recover by calling this a parameter pack. */
3788 }
3789 }
3791 /* A template parameter is not modifiable. */
3800 processing_template_decl,
3805 }
3806 else
3807 {
3808 tree t;
3812 {
3814 /* This is for distinguishing between real templates and template
3815 template parameters */
3819 }
3820 else
3821 {
3823 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3826 }
3833 processing_template_decl,
3837 }
3843 }
3845 /* The end of a template parameter list has been reached. Process the
3846 tree list into a parameter vector, converting each parameter into a more
3847 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3848 as PARM_DECLs. */
3850 tree
3852 {
3857 current_template_parms
3862 {
3866 }
3871 }
3873 /* end_template_decl is called after a template declaration is seen. */
3875 void
3877 {
3883 /* This matches the pushlevel in begin_template_parm_list. */
3888 }
3890 /* Takes a TREE_LIST representing a template parameter and convert it
3891 into an argument suitable to be passed to the type substitution
3892 functions. Note that If the TREE_LIST contains an error_mark
3893 node, the returned argument is error_mark_node. */
3895 static tree
3897 {
3910 {
3914 {
3915 /* Turn this argument into a TYPE_ARGUMENT_PACK
3916 with a single element, which expands T. */
3918 #ifdef ENABLE_CHECKING
3919 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3921 #endif
3926 }
3927 }
3928 else
3929 {
3933 {
3934 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3935 with a single element, which expands T. */
3938 #ifdef ENABLE_CHECKING
3939 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3941 #endif
3948 }
3949 else
3951 }
3953 }
3955 /* Given a set of template parameters, return them as a set of template
3956 arguments. The template parameters are represented as a TREE_VEC, in
3957 the form documented in cp-tree.h for template arguments. */
3959 static tree
3961 {
3962 tree header;
3967 /* If there is only one level of template parameters, we do not
3968 create a TREE_VEC of TREE_VECs. Instead, we return a single
3969 TREE_VEC containing the arguments. */
3974 {
3982 #ifdef ENABLE_CHECKING
3984 #endif
3988 else
3990 }
3993 /* This can happen for template parms of a template template
3994 parameter, e.g:
3996 template<template<class T, class U> class TT> struct S;
3998 Consider the level of the parms of TT; T and U both have
3999 level 2; TT has no template parm of level 1. So in this case
4000 the first element of full_template_args is NULL_TREE. If we
4001 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
4002 of 2. This will make tsubst wrongly consider that T and U
4003 have level 1. Instead, let's create a dummy vector as the
4004 first element of full_template_args so that TMPL_ARGS_DEPTH
4005 returns the correct depth for args. */
4008 }
4010 /* Within the declaration of a template, return the currently active
4011 template parameters as an argument TREE_VEC. */
4013 static tree
4015 {
4017 }
4019 /* Update the declared TYPE by doing any lookups which were thought to be
4020 dependent, but are not now that we know the SCOPE of the declarator. */
4022 tree
4024 {
4035 /* Don't bother building up the args in this case. */
4037 {
4038 /* tsubst in the args corresponding to the template parameters,
4039 including auto if present. Most things will be unchanged, but
4040 make_typename_type and tsubst_qualified_id will resolve
4041 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4044 tree pushed;
4046 {
4050 }
4055 }
4061 {
4064 else
4066 }
4068 }
4070 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4071 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4072 a member template. Used by push_template_decl below. */
4074 static tree
4076 {
4084 }
4086 struct template_parm_data
4087 {
4088 /* The level of the template parameters we are currently
4089 processing. */
4092 /* The index of the specialization argument we are currently
4093 processing. */
4096 /* An array whose size is the number of template parameters. The
4097 elements are nonzero if the parameter has been used in any one
4098 of the arguments processed so far. */
4101 /* An array whose size is the number of template arguments. The
4102 elements are nonzero if the argument makes use of template
4103 parameters of this level. */
4105 };
4107 /* Subroutine of push_template_decl used to see if each template
4108 parameter in a partial specialization is used in the explicit
4109 argument list. If T is of the LEVEL given in DATA (which is
4110 treated as a template_parm_data*), then DATA->PARMS is marked
4111 appropriately. */
4113 static int
4115 {
4123 {
4126 }
4128 /* Return zero so that for_each_template_parm will continue the
4129 traversal of the tree; we want to mark *every* template parm. */
4131 }
4133 /* Process the partial specialization DECL. */
4135 static tree
4137 {
4144 tree inner_parms;
4145 tree inst;
4158 /* We check that each of the template parameters given in the
4159 partial specialization is used in the argument list to the
4160 specialization. For example:
4162 template <class T> struct S;
4163 template <class T> struct S<T*>;
4165 The second declaration is OK because `T*' uses the template
4166 parameter T, whereas
4168 template <class T> struct S<int>;
4170 is no good. Even trickier is:
4172 template <class T>
4173 struct S1
4174 {
4175 template <class U>
4176 struct S2;
4177 template <class U>
4178 struct S2<T>;
4179 };
4181 The S2<T> declaration is actually invalid; it is a
4182 full-specialization. Of course,
4184 template <class U>
4185 struct S2<T (*)(U)>;
4187 or some such would have been OK. */
4195 {
4200 NULL,
4202 }
4205 {
4206 /* One of the template parms was not used in a deduced context in the
4207 specialization. */
4209 {
4213 }
4217 }
4222 /* [temp.class.spec]
4224 The argument list of the specialization shall not be identical to
4225 the implicit argument list of the primary template. */
4226 tree main_args
4232 /* A partial specialization that replaces multiple parameters of the
4233 primary template with a pack expansion is less specialized for those
4234 parameters. */
4236 {
4238 "primary template because it replaces multiple parameters "
4242 }
4244 /* [temp.class.spec]
4246 A partially specialized non-type argument expression shall not
4247 involve template parameters of the partial specialization except
4248 when the argument expression is a simple identifier.
4250 The type of a template parameter corresponding to a specialized
4251 non-type argument shall not be dependent on a parameter of the
4252 specialization.
4254 Also, we verify that pack expansions only occur at the
4255 end of the argument list. */
4259 {
4266 {
4267 /* Extract the arguments from the argument pack. We'll be
4268 iterating over these in the following loop. */
4271 }
4274 {
4276 /* Get the Jth argument in the parameter pack. */
4280 {
4281 /* Pack expansions must come at the end of the
4282 argument list. */
4285 {
4289 else
4292 }
4293 }
4296 /* We only care about the pattern. */
4302 /* This next two lines are the `argument expression is not just a
4303 simple identifier' condition and also the `specialized
4304 non-type argument' bit. */
4308 {
4312 arg);
4313 else
4314 {
4315 /* Look at the corresponding template parameter,
4316 marking which template parameters its type depends
4317 upon. */
4321 {
4322 /* We haven't yet initialized TPD2. Do so now. */
4324 /* The number of parameters here is the number in the
4325 main template, which, as checked in the assertion
4326 above, is NARGS. */
4330 }
4332 /* Mark the template parameters. But this time, we're
4333 looking for the template parameters of the main
4334 template, not in the specialization. */
4341 NULL,
4345 {
4346 /* The type depended on some template parameters.
4347 If they are fully specialized in the
4348 specialization, that's OK. */
4357 "type %qT of template argument %qE depends "
4359 "type %qT of template argument %qE depends "
4361 type,
4362 arg);
4363 }
4364 }
4365 }
4366 }
4367 }
4369 /* We should only get here once. */
4388 {
4394 {
4397 {
4401 "partial specialization of %qD after instantiation "
4403 }
4404 }
4405 }
4408 }
4410 /* PARM is a template parameter of some form; return the corresponding
4411 TEMPLATE_PARM_INDEX. */
4413 static tree
4415 {
4428 }
4430 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4431 parameter packs used by the template parameter PARM. */
4433 static void
4435 {
4436 /* A type parm can't refer to another parm. */
4440 {
4444 }
4451 }
4453 /* PARM is a template parameter pack. Return any parameter packs used in
4454 its type or the type of any of its template parameters. If there are
4455 any such packs, it will be instantiated into a fixed template parameter
4456 list by partial instantiation rather than be fully deduced. */
4458 tree
4460 {
4461 /* This can only be true in a member template. */
4464 /* This can only be true for a parameter pack. */
4467 /* A type parm can't refer to another parm. */
4480 }
4482 /* Check that a template declaration's use of default arguments and
4483 parameter packs is not invalid. Here, PARMS are the template
4484 parameters. IS_PRIMARY is true if DECL is the thing declared by
4485 a primary template. IS_PARTIAL is true if DECL is a partial
4486 specialization.
4488 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4489 declaration (but not a definition); 1 indicates a declaration, 2
4490 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4491 emitted for extraneous default arguments.
4493 Returns TRUE if there were no errors found, FALSE otherwise. */
4495 bool
4498 {
4501 tree parm_level;
4504 /* [temp.param]
4506 A default template-argument shall not be specified in a
4507 function template declaration or a function template definition, nor
4508 in the template-parameter-list of the definition of a member of a
4509 class template. */
4513 /* You can't have a function template declaration in a local
4514 scope, nor you can you define a member of a class template in a
4515 local scope. */
4523 /* A lambda doesn't have an explicit declaration; don't complain
4524 about the parms of the enclosing class. */
4531 /* If this is either a friend defined in the scope of the class
4532 or a member function. */
4538 /* And, if it was a member function, it really was defined in
4539 the scope of the class. */
4542 /* We already checked these parameters when the template was
4543 declared, so there's no need to do it again now. This function
4544 was defined in class scope, but we're processing its body now
4545 that the class is complete. */
4548 /* Core issue 226 (C++0x only): the following only applies to class
4549 templates. */
4552 {
4553 /* [temp.param]
4555 If a template-parameter has a default template-argument, all
4556 subsequent template-parameters shall have a default
4557 template-argument supplied. */
4559 {
4566 {
4576 {
4578 /* For better subsequent error-recovery, we indicate that
4579 there should have been a default argument. */
4582 }
4584 && !is_friend_decl
4585 /* Don't complain about an enclosing partial
4586 specialization. */
4591 /* A fixed parameter pack will be partially
4592 instantiated into a fixed length list. */
4594 {
4595 /* A primary class template can only have one
4596 parameter pack, at the end of the template
4597 parameter list. */
4605 }
4606 }
4607 }
4608 }
4611 || is_partial
4612 || !is_primary
4614 /* For an ordinary class template, default template arguments are
4615 allowed at the innermost level, e.g.:
4616 template <class T = int>
4617 struct S {};
4618 but, in a partial specialization, they're not allowed even
4619 there, as we have in [temp.class.spec]:
4621 The template parameter list of a specialization shall not
4622 contain default template argument values.
4624 So, for a partial specialization, or for a function template
4625 (in C++98/C++03), we look at all of them. */
4626 ;
4627 else
4628 /* But, for a primary class template that is not a partial
4629 specialization we look at all template parameters except the
4630 innermost ones. */
4633 /* Figure out what error message to issue. */
4646 else
4650 /* If we're inside a class definition, there's no need to
4651 examine the parameters to the class itself. On the one
4652 hand, they will be checked when the class is defined, and,
4653 on the other, default arguments are valid in things like:
4654 template <class T = double>
4655 struct S { template <class U> void f(U); };
4656 Here the default argument for `S' has no bearing on the
4657 declaration of `f'. */
4659 else
4660 /* Check everything. */
4666 {
4673 {
4678 {
4680 {
4687 }
4689 /* Clear out the default argument so that we are not
4690 confused later. */
4692 }
4693 }
4695 /* At this point, if we're still interested in issuing messages,
4696 they must apply to classes surrounding the object declared. */
4700 }
4703 }
4705 /* Worker for push_template_decl_real, called via
4706 for_each_template_parm. DATA is really an int, indicating the
4707 level of the parameters we are interested in. If T is a template
4708 parameter of that level, return nonzero. */
4710 static int
4712 {
4718 else
4721 }
4723 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4724 parameters given by current_template_args, or reuses a
4725 previously existing one, if appropriate. Returns the DECL, or an
4726 equivalent one, if it is replaced via a call to duplicate_decls.
4728 If IS_FRIEND is true, DECL is a friend declaration. */
4730 tree
4732 {
4733 tree tmpl;
4734 tree args;
4735 tree info;
4736 tree ctx;
4740 /* True if the template is a member template, in the sense of
4741 [temp.mem]. */
4747 /* See if this is a partial specialization. */
4760 /* For a friend, we want the context of the friend function, not
4761 the type of which it is a friend. */
4765 /* In the case of a virtual function, we want the class in which
4766 it is defined. */
4768 else
4769 /* Otherwise, if we're currently defining some class, the DECL
4770 is assumed to be a member of the class. */
4779 /* See if this is a primary template. */
4782 /* A friend template that specifies a class context, i.e.
4783 template <typename T> friend void A<T>::f();
4784 is not primary. */
4789 else
4793 {
4798 {
4801 }
4803 {
4805 {
4808 }
4810 {
4811 /* [temp.mem]
4813 A destructor shall not be a member template. */
4816 }
4823 {
4824 /* [basic.stc.dynamic.allocation]
4826 An allocation function can be a function
4827 template. ... Template allocation functions shall
4828 have two or more parameters. */
4831 }
4832 }
4838 /* alias-declaration */
4842 else
4843 {
4846 }
4847 }
4849 /* Check to see that the rules regarding the use of default
4850 arguments are not being violated. */
4854 /* Ensure that there are no parameter packs in the type of this
4855 declaration that have not been expanded. */
4857 {
4858 /* Check each of the arguments individually to see if there are
4859 any bare parameter packs. */
4865 {
4868 {
4869 /* This is a PARM_DECL that contains unexpanded parameter
4870 packs. We have already complained about this in the
4871 check_for_bare_parameter_packs call, so just replace
4872 these types with ERROR_MARK_NODE. */
4875 }
4879 }
4881 /* Check for bare parameter packs in the return type and the
4882 exception specifiers. */
4884 /* Errors were already issued, set return type to int
4885 as the frontend doesn't expect error_mark_node as
4886 the return type. */
4890 }
4895 {
4898 }
4911 {
4916 /* If DECL is a TYPE_DECL for a class-template, then there won't
4917 be DECL_LANG_SPECIFIC. The information equivalent to
4918 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4922 {
4923 /* Since a template declaration already existed for this
4924 class-type, we must be redeclaring it here. Make sure
4925 that the redeclaration is valid. */
4927 current_template_parms);
4928 /* We don't need to create a new TEMPLATE_DECL; just use the
4929 one we already had. */
4931 }
4932 else
4933 {
4935 member_template_p);
4940 {
4941 /* A specialization of a member template of a template
4942 class. */
4946 }
4947 }
4948 }
4949 else
4950 {
4956 {
4959 }
4967 {
4968 tree new_tmpl;
4970 /* The declaration is a specialization of a member
4971 template, declared outside the class. Therefore, the
4972 innermost template arguments will be NULL, so we
4973 replace them with the arguments determined by the
4974 earlier call to check_explicit_specialization. */
4977 new_tmpl
4979 member_template_p);
4989 args,
4992 }
4994 /* Make sure the template headers we got make sense. */
4999 {
5004 }
5005 else
5007 {
5012 {
5016 else
5020 /* Avoid crash in import_export_decl. */
5023 }
5028 /* Can happen in erroneous input. */
5030 else
5032 }
5034 /* Check that the parms are used in the appropriate qualifying scopes
5035 in the declarator. */
5039 {
5045 /* Avoid crash in import_export_decl. */
5048 }
5049 }
5054 /* Push template declarations for global functions and types. Note
5055 that we do not try to push a global template friend declared in a
5056 template class; such a thing may well depend on the template
5057 parameters of the class. */
5060 {
5065 /* Hide template friend classes that haven't been declared yet. */
5067 {
5070 }
5071 }
5074 {
5080 {
5083 /* It is a conversion operator. See if the type converted to
5084 depends on innermost template operands. */
5087 depth))
5089 }
5091 /* Give template template parms a DECL_CONTEXT of the template
5092 for which they are a parameter. */
5095 {
5099 }
5105 }
5107 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5108 back to its most general template. If TMPL is a specialization,
5109 ARGS may only have the innermost set of arguments. Add the missing
5110 argument levels if necessary. */
5118 else
5119 {
5124 }
5127 && !is_friend
5130 /* Set DECL_COMDAT on template instantiations; if we force
5131 them to be emitted by explicit instantiation or -frepo,
5132 mark_needed will tell cgraph to do the right thing. */
5136 }
5138 tree
5140 {
5142 }
5144 /* FN is an inheriting constructor that inherits from the constructor
5145 template INHERITED; turn FN into a constructor template with a matching
5146 template header. */
5148 tree
5150 {
5151 tree inner_parms
5154 tree parms
5165 }
5167 /* Called when a class template TYPE is redeclared with the indicated
5168 template PARMS, e.g.:
5170 template <class T> struct S;
5171 template <class T> struct S {}; */
5173 bool
5175 {
5176 tree tmpl;
5177 tree tmpl_parms;
5181 {
5184 }
5188 /* The type is nested in some template class. Nothing to worry
5189 about here; there are no new template parameters for the nested
5190 type. */
5194 {
5196 tmpl);
5198 }
5204 {
5214 }
5217 {
5218 tree tmpl_parm;
5219 tree parm;
5220 tree tmpl_default;
5221 tree parm_default;
5235 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5236 TEMPLATE_DECL. */
5246 {
5250 }
5253 {
5254 /* We have in [temp.param]:
5256 A template-parameter may not be given default arguments
5257 by two different declarations in the same scope. */
5262 }
5265 /* Update the previous template parameters (which are the ones
5266 that will really count) with the new default value. */
5269 /* Update the new parameters, too; they'll be used as the
5270 parameters for any members. */
5272 }
5275 }
5277 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5278 to be used when the caller has already checked
5279 (processing_template_decl
5280 && !instantiation_dependent_expression_p (expr)
5281 && potential_constant_expression (expr))
5282 and cleared processing_template_decl. */
5284 tree
5286 {
5289 complain,
5293 }
5295 /* Simplify EXPR if it is a non-dependent expression. Returns the
5296 (possibly simplified) expression. */
5298 tree
5300 {
5304 /* If we're in a template, but EXPR isn't value dependent, simplify
5305 it. We're supposed to treat:
5307 template <typename T> void f(T[1 + 1]);
5308 template <typename T> void f(T[2]);
5310 as two declarations of the same function, for example. */
5314 {
5315 processing_template_decl_sentinel s;
5317 }
5319 }
5321 tree
5323 {
5325 }
5327 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5328 template declaration, or a TYPE_DECL for an alias declaration. */
5330 bool
5332 {
5340 }
5342 /* Return TRUE iff T is a specialization of an alias template. */
5344 bool
5346 {
5347 /* It's an alias template specialization if it's an alias and its
5348 TYPE_NAME is a specialization of a primary template. */
5350 {
5354 {
5357 }
5358 }
5360 }
5362 /* An alias template is complex from a SFINAE perspective if a template-id
5363 using that alias can be ill-formed when the expansion is not, as with
5364 the void_t template. We determine this by checking whether the
5365 expansion for the alias template uses all its template parameters. */
5367 struct uses_all_template_parms_data
5368 {
5371 };
5373 static int
5375 {
5383 }
5385 static bool
5387 {
5402 }
5404 /* Return TRUE iff T is a specialization of a complex alias template with
5405 dependent template-arguments. */
5407 bool
5409 {
5412 && (any_dependent_template_arguments_p
5414 }
5416 /* Return the number of innermost template parameters in TMPL. */
5418 static int
5420 {
5423 }
5425 /* Return either TMPL or another template that it is equivalent to under DR
5426 1286: An alias that just changes the name of a template is equivalent to
5427 the other template. */
5429 static tree
5431 {
5434 {
5437 {
5442 {
5443 tree alias_args = INNERMOST_TEMPLATE_ARGS
5447 /* The alias type is equivalent to the pattern of the
5448 underlying template, so strip the alias. */
5451 }
5452 }
5454 }
5456 }
5458 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5459 must be a function or a pointer-to-function type, as specified
5460 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5461 and check that the resulting function has external linkage. */
5463 static tree
5465 tsubst_flags_t complain)
5466 {
5469 linkage_kind linkage;
5481 /* [temp.arg.nontype]/1
5483 A template-argument for a non-type, non-template template-parameter
5484 shall be one of:
5485 [...]
5486 -- the address of an object or function with external [C++11: or
5487 internal] linkage. */
5490 {
5492 {
5498 else
5501 }
5503 }
5507 {
5509 {
5514 else
5518 }
5520 }
5523 }
5525 /* Subroutine of convert_nontype_argument.
5526 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5527 Emit an error otherwise. */
5529 static bool
5531 tsubst_flags_t complain)
5532 {
5543 {
5547 }
5549 }
5551 /* Returns TRUE iff the address of OP is value-dependent.
5553 14.6.2.4 [temp.dep.temp]:
5554 A non-integral non-type template-argument is dependent if its type is
5555 dependent or it has either of the following forms
5556 qualified-id
5557 & qualified-id
5558 and contains a nested-name-specifier which specifies a class-name that
5559 names a dependent type.
5561 We generalize this to just say that the address of a member of a
5562 dependent class is value-dependent; the above doesn't cover the
5563 address of a static data member named with an unqualified-id. */
5565 static bool
5567 {
5568 /* We could use get_inner_reference here, but there's no need;
5569 this is only relevant for template non-type arguments, which
5570 can only be expressed as &id-expression. */
5572 {
5576 }
5579 }
5581 /* The next set of functions are used for providing helpful explanatory
5582 diagnostics for failed overload resolution. Their messages should be
5583 indented by two spaces for consistency with the messages in
5584 call.c */
5586 static int
5588 {
5590 }
5592 static int
5594 {
5599 }
5601 static int
5603 {
5605 }
5607 static int
5609 {
5615 }
5617 static int
5619 {
5623 }
5625 static int
5627 {
5630 " template parameter %qD is not a parameter pack, but "
5634 }
5636 static int
5638 {
5641 " template argument %qE does not match "
5645 }
5647 static int
5649 {
5653 }
5655 static int
5657 {
5663 }
5665 static int
5667 {
5669 {
5674 else
5676 " deduced conflicting values for non-type parameter "
5678 }
5680 }
5682 static int
5684 {
5687 " variable-sized array type %qT is not "
5689 arg);
5691 }
5693 static int
5695 {
5699 arg);
5701 }
5703 static int
5705 {
5707 {
5713 else
5718 }
5720 }
5722 static int
5724 {
5726 }
5728 static int
5731 {
5733 }
5735 static int
5738 {
5744 }
5746 static int
5749 {
5752 {
5760 }
5762 }
5764 static int
5766 {
5769 " template parameters of a template template argument are "
5772 }
5774 static int
5776 {
5782 }
5784 static int
5786 {
5791 }
5793 static int
5795 {
5799 arg);
5801 }
5803 /* Attempt to convert the non-type template parameter EXPR to the
5804 indicated TYPE. If the conversion is successful, return the
5805 converted value. If the conversion is unsuccessful, return
5806 NULL_TREE if we issued an error message, or error_mark_node if we
5807 did not. We issue error messages for out-and-out bad template
5808 parameters, but not simply because the conversion failed, since we
5809 might be just trying to do argument deduction. Both TYPE and EXPR
5810 must be non-dependent.
5812 The conversion follows the special rules described in
5813 [temp.arg.nontype], and it is much more strict than an implicit
5814 conversion.
5816 This function is called twice for each template argument (see
5817 lookup_template_class for a more accurate description of this
5818 problem). This means that we need to handle expressions which
5819 are not valid in a C++ source, but can be created from the
5820 first call (for instance, casts to perform conversions). These
5821 hacks can go away after we fix the double coercion problem. */
5823 static tree
5825 {
5826 tree expr_type;
5828 /* Detect immediately string literals as invalid non-type argument.
5829 This special-case is not needed for correctness (we would easily
5830 catch this later), but only to provide better diagnostic for this
5831 common user mistake. As suggested by DR 100, we do not mention
5832 linkage issues in the diagnostic as this is not the point. */
5833 /* FIXME we're making this OK. */
5835 {
5841 }
5843 /* Add the ADDR_EXPR now for the benefit of
5844 value_dependent_expression_p. */
5847 {
5851 }
5853 /* If we are in a template, EXPR may be non-dependent, but still
5854 have a syntactic, rather than semantic, form. For example, EXPR
5855 might be a SCOPE_REF, rather than the VAR_DECL to which the
5856 SCOPE_REF refers. Preserving the qualifying scope is necessary
5857 so that access checking can be performed when the template is
5858 instantiated -- but here we need the resolved form so that we can
5859 convert the argument. */
5865 && processing_template_decl
5874 else
5877 /* If the argument is non-dependent, perform any conversions in
5878 non-dependent context as well. */
5883 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5884 to a non-type argument of "nullptr". */
5888 /* In C++11, integral or enumeration non-type template arguments can be
5889 arbitrary constant expressions. Pointer and pointer to
5890 member arguments can be general constant expressions that evaluate
5891 to a null value, but otherwise still need to be of a specific form. */
5893 {
5895 /* A PTRMEM_CST is already constant, and a valid template
5896 argument for a parameter of pointer to member type, we just want
5897 to leave it in that form rather than lower it to a
5902 {
5907 }
5908 }
5910 /* HACK: Due to double coercion, we can get a
5911 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5912 which is the tree that we built on the first call (see
5913 below when coercing to reference to object or to reference to
5914 function). We just strip everything and get to the arg.
5915 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5916 for examples. */
5918 {
5924 {
5925 /* ??? Maybe we could use convert_from_reference here, but we
5926 would need to relax its constraints because the NOP_EXPR
5927 could actually change the type to something more cv-qualified,
5928 and this is not folded by convert_from_reference. */
5933 && (same_type_ignoring_top_level_qualifiers_p
5936 {
5939 }
5940 }
5941 }
5943 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5944 parameter is a pointer to object, through decay and
5945 qualification conversion. Let's strip everything. */
5947 {
5952 {
5953 /* Skip the ADDR_EXPR only if it is part of the decay for
5954 an array. Otherwise, it is part of the original argument
5955 in the source code. */
5960 }
5961 }
5963 /* [temp.arg.nontype]/5, bullet 1
5965 For a non-type template-parameter of integral or enumeration type,
5966 integral promotions (_conv.prom_) and integral conversions
5967 (_conv.integral_) are applied. */
5969 {
5978 /* Notice that there are constant expressions like '4 % 0' which
5979 do not fold into integer constants. */
5981 {
5983 {
5994 /* else cxx_constant_value complained but gave us
5995 a real constant, so go ahead. */
5997 }
5998 else
6000 }
6002 /* Avoid typedef problems. */
6005 }
6006 /* [temp.arg.nontype]/5, bullet 2
6008 For a non-type template-parameter of type pointer to object,
6009 qualification conversions (_conv.qual_) and the array-to-pointer
6010 conversion (_conv.array_) are applied. */
6012 {
6013 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6015 A template-argument for a non-type, non-template template-parameter
6016 shall be one of: [...]
6018 -- the name of a non-type template-parameter;
6019 -- the address of an object or function with external linkage, [...]
6020 expressed as "& id-expression" where the & is optional if the name
6021 refers to a function or array, or if the corresponding
6022 template-parameter is a reference.
6024 Here, we do not care about functions, as they are invalid anyway
6025 for a parameter of type pointer-to-object. */
6028 /* Non-type template parameters are OK. */
6029 ;
6034 {
6036 {
6039 "because %qD is a variable, not the address of "
6042 }
6044 {
6050 }
6051 /* Other values, like integer constants, might be valid
6052 non-type arguments of some other type. */
6054 }
6055 else
6056 {
6057 tree decl;
6062 {
6067 }
6069 {
6075 }
6077 {
6082 }
6083 }
6092 }
6093 /* [temp.arg.nontype]/5, bullet 3
6095 For a non-type template-parameter of type reference to object, no
6096 conversions apply. The type referred to by the reference may be more
6097 cv-qualified than the (otherwise identical) type of the
6098 template-argument. The template-parameter is bound directly to the
6099 template-argument, which must be an lvalue. */
6101 {
6103 expr_type))
6107 {
6112 }
6115 {
6120 }
6122 /* [temp.arg.nontype]/1
6124 A template-argument for a non-type, non-template template-parameter
6125 shall be one of: [...]
6127 -- the address of an object or function with external linkage. */
6130 {
6133 {
6136 "because a reference variable does not have a constant "
6139 }
6140 }
6143 {
6149 }
6152 {
6158 }
6161 }
6162 /* [temp.arg.nontype]/5, bullet 4
6164 For a non-type template-parameter of type pointer to function, only
6165 the function-to-pointer conversion (_conv.func_) is applied. If the
6166 template-argument represents a set of overloaded functions (or a
6167 pointer to such), the matching function is selected from the set
6168 (_over.over_). */
6170 {
6171 /* If the argument is a template-id, we might not have enough
6172 context information to decay the pointer. */
6174 {
6178 }
6181 /* Null pointer values are OK in C++11. */
6187 }
6188 /* [temp.arg.nontype]/5, bullet 5
6190 For a non-type template-parameter of type reference to function, no
6191 conversions apply. If the template-argument represents a set of
6192 overloaded functions, the matching function is selected from the set
6193 (_over.over_). */
6195 {
6197 {
6199 {
6204 }
6206 }
6213 }
6214 /* [temp.arg.nontype]/5, bullet 6
6216 For a non-type template-parameter of type pointer to member function,
6217 no conversions apply. If the template-argument represents a set of
6218 overloaded member functions, the matching member function is selected
6219 from the set (_over.over_). */
6221 {
6226 /* [temp.arg.nontype] bullet 1 says the pointer to member
6227 expression must be a pointer-to-member constant. */
6231 /* There is no way to disable standard conversions in
6232 resolve_address_of_overloaded_function (called by
6233 instantiate_type). It is possible that the call succeeded by
6234 converting &B::I to &D::I (where B is a base of D), so we need
6235 to reject this conversion here.
6237 Actually, even if there was a way to disable standard conversions,
6238 it would still be better to reject them here so that we can
6239 provide a superior diagnostic. */
6241 {
6243 {
6247 /* If we are just one standard conversion off, explain. */
6251 }
6253 }
6254 }
6255 /* [temp.arg.nontype]/5, bullet 7
6257 For a non-type template-parameter of type pointer to data member,
6258 qualification conversions (_conv.qual_) are applied. */
6260 {
6261 /* [temp.arg.nontype] bullet 1 says the pointer to member
6262 expression must be a pointer-to-member constant. */
6269 }
6271 {
6273 {
6278 }
6280 }
6281 /* A template non-type parameter must be one of the above. */
6282 else
6285 /* Sanity check: did we actually convert the argument to the
6286 right type? */
6290 }
6292 /* Subroutine of coerce_template_template_parms, which returns 1 if
6293 PARM_PARM and ARG_PARM match using the rule for the template
6294 parameters of template template parameters. Both PARM and ARG are
6295 template parameters; the rest of the arguments are the same as for
6296 coerce_template_template_parms.
6297 */
6298 static int
6300 tree arg,
6301 tsubst_flags_t complain,
6302 tree in_decl,
6303 tree outer_args)
6304 {
6313 {
6315 /* We encounter instantiations of templates like
6316 template <template <template <class> class> class TT>
6317 class C; */
6318 {
6325 }
6326 /* Fall through. */
6331 /* Argument is a parameter pack but parameter is not. */
6336 /* The tsubst call is used to handle cases such as
6338 template <int> class C {};
6339 template <class T, template <T> class TT> class D {};
6340 D<int, C> d;
6342 i.e. the parameter list of TT depends on earlier parameters. */
6344 && !same_type_p
6351 /* Argument is a parameter pack but parameter is not. */
6358 }
6361 }
6364 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6365 template template parameters. Both PARM_PARMS and ARG_PARMS are
6366 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6367 or PARM_DECL.
6369 Consider the example:
6370 template <class T> class A;
6371 template<template <class U> class TT> class B;
6373 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6374 the parameters to A, and OUTER_ARGS contains A. */
6376 static int
6378 tree arg_parms,
6379 tsubst_flags_t complain,
6380 tree in_decl,
6381 tree outer_args)
6382 {
6393 /* Determine whether we have a parameter pack at the end of the
6394 template template parameter's template parameter list. */
6396 {
6403 {
6417 }
6418 }
6424 /* Check all of the template parameters except the parameter pack at
6425 the end (if any). */
6427 {
6436 outer_args))
6439 }
6442 {
6443 /* Check each of the template parameters in the template
6444 argument against the template parameter pack at the end of
6445 the template template parameter. */
6452 {
6459 outer_args))
6461 }
6462 }
6465 }
6467 /* Verifies that the deduced template arguments (in TARGS) for the
6468 template template parameters (in TPARMS) represent valid bindings,
6469 by comparing the template parameter list of each template argument
6470 to the template parameter list of its corresponding template
6471 template parameter, in accordance with DR150. This
6472 routine can only be called after all template arguments have been
6473 deduced. It will return TRUE if all of the template template
6474 parameter bindings are okay, FALSE otherwise. */
6475 bool
6477 {
6481 /* We're dealing with template parms in this process. */
6487 {
6492 {
6497 {
6498 /* Look inside the argument pack. */
6501 }
6504 {
6508 /* Extract the next argument from the argument
6509 pack. */
6513 /* Look at the pattern of the pack expansion. */
6516 /* Extract the template parameters from the template
6517 argument. */
6523 /* Verify that we can coerce the template template
6524 parameters from the template argument to the template
6525 parameter. This requires an exact match. */
6527 && !coerce_template_template_parms
6529 targ_parms,
6530 tf_none,
6531 tparm,
6532 targs))
6533 {
6536 }
6537 }
6538 }
6539 }
6541 out:
6545 }
6547 /* Since type attributes aren't mangled, we need to strip them from
6548 template type arguments. */
6550 static tree
6552 {
6561 }
6563 /* Convert the indicated template ARG as necessary to match the
6564 indicated template PARM. Returns the converted ARG, or
6565 error_mark_node if the conversion was unsuccessful. Error and
6566 warning messages are issued under control of COMPLAIN. This
6567 conversion is for the Ith parameter in the parameter list. ARGS is
6568 the full set of template arguments deduced so far. */
6570 static tree
6572 tree arg,
6573 tree args,
6574 tsubst_flags_t complain,
6576 tree in_decl)
6577 {
6578 tree orig_arg;
6579 tree val;
6587 {
6588 /* The template argument was the name of some
6589 member function. That's usually
6590 invalid, but static members are OK. In any
6591 case, grab the underlying fields/functions
6592 and issue an error later if required. */
6595 }
6603 /* When determining whether an argument pack expansion is a template,
6604 look at the pattern. */
6608 /* Deal with an injected-class-name used as a template template arg. */
6610 {
6613 {
6623 }
6624 }
6626 is_tmpl_type =
6642 {
6644 {
6648 }
6651 "to refer to a type member of a template parameter, "
6656 typename_type,
6657 complain);
6660 }
6662 {
6664 {
6666 {
6678 else
6681 }
6682 }
6684 }
6686 {
6688 {
6695 else
6698 }
6700 }
6703 {
6705 {
6709 /* The number of argument required is not known yet.
6710 Just accept it for now. */
6712 else
6713 {
6715 tree argparm;
6717 /* Strip alias templates that are equivalent to another
6718 template. */
6724 args))
6725 {
6728 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6729 TEMPLATE_DECL. */
6731 {
6736 }
6737 }
6738 else
6739 {
6741 {
6748 }
6751 }
6752 }
6753 }
6754 else
6756 /* We only form one instance of each template specialization.
6757 Therefore, if we use a non-canonical variant (i.e., a
6758 typedef), any future messages referring to the type will use
6759 the typedef, which is confusing if those future uses do not
6760 themselves also use the typedef. */
6763 }
6764 else
6765 {
6772 {
6775 else
6776 {
6777 /* Not sure if this is reachable, but it doesn't hurt
6778 to be robust. */
6781 }
6782 }
6785 /* We used to call digest_init here. However, digest_init
6786 will report errors, which we don't want when complain
6787 is zero. More importantly, digest_init will try too
6788 hard to convert things: for example, `0' should not be
6789 converted to pointer type at this point according to
6790 the standard. Accepting this is not merely an
6791 extension, since deciding whether or not these
6792 conversions can occur is part of determining which
6793 function template to call, or whether a given explicit
6794 argument specification is valid. */
6796 else
6797 {
6800 }
6808 {
6809 /* Strip typedefs from the SCOPE_REF. */
6812 complain);
6815 }
6816 }
6819 }
6821 /* Coerces the remaining template arguments in INNER_ARGS (from
6822 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6823 Returns the coerced argument pack. PARM_IDX is the position of this
6824 parameter in the template parameter list. ARGS is the original
6825 template argument list. */
6826 static tree
6829 tree args,
6830 tree inner_args,
6832 tree new_args,
6834 tree in_decl,
6835 tsubst_flags_t complain)
6836 {
6839 tree packed_args;
6840 tree argument_pack;
6847 {
6848 /* When the template parameter is a non-type template parameter pack
6849 or template template parameter pack whose type or template
6850 parameters use parameter packs, we know exactly how many arguments
6851 we are looking for. Build a vector of the instantiated decls for
6852 these template parameters in PACKED_PARMS. */
6853 /* We can't use make_pack_expansion here because it would interpret a
6854 _DECL as a use rather than a declaration. */
6868 /* If we're doing a partial instantiation of a member template,
6869 verify that all of the types used for the non-type
6870 template parameter pack are, in fact, valid for non-type
6871 template parameters. */
6874 {
6877 {
6881 }
6882 /* We don't know how many args we have yet, just
6883 use the unconverted ones for now. */
6885 }
6888 }
6889 else
6892 /* Convert the remaining arguments, which will be a part of the
6893 parameter pack "parm". */
6895 {
6901 {
6902 /* Once we've packed as many args as we have types, stop. */
6906 /* We don't know how many args we have yet, just
6907 use the unconverted ones for now. */
6909 else
6911 }
6914 {
6917 }
6918 else
6921 in_decl);
6925 }
6929 {
6934 }
6939 else
6940 {
6945 }
6948 #ifdef ENABLE_CHECKING
6951 #endif
6953 }
6955 /* Returns the number of pack expansions in the template argument vector
6956 ARGS. */
6958 static int
6960 {
6965 {
6969 }
6971 }
6973 /* Convert all template arguments to their appropriate types, and
6974 return a vector containing the innermost resulting template
6975 arguments. If any error occurs, return error_mark_node. Error and
6976 warning messages are issued under control of COMPLAIN.
6978 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6979 for arguments not specified in ARGS. Otherwise, if
6980 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6981 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6982 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6983 ARGS. */
6985 static tree
6987 tree args,
6988 tree in_decl,
6989 tsubst_flags_t complain,
6992 {
6994 tree orig_inner_args;
6995 tree inner_args;
6996 tree new_args;
6997 tree new_inner_args;
7001 /* When used as a boolean value, indicates whether this is a
7002 variadic template parameter list. Since it's an int, we can also
7003 subtract it from nparms to get the number of non-variadic
7004 parameters. */
7009 /* Likewise for parameters with default arguments. */
7017 /* Determine if there are any parameter packs or default arguments. */
7019 {
7027 }
7030 /* If there are no parameters that follow a parameter pack, we need to
7031 expand any argument packs so that we can deduce a parameter pack from
7032 some non-packed args followed by an argument pack, as in variadic85.C.
7033 If there are such parameters, we need to leave argument packs intact
7034 so the arguments are assigned properly. This can happen when dealing
7035 with a nested class inside a partial specialization of a class
7036 template, as in variadic92.C, or when deducing a template parameter pack
7037 from a sub-declarator, as in variadic114.C. */
7041 /* Count any pack expansion args. */
7047 && require_all_args
7048 && !variadic_args_p
7049 && (!use_default_args
7052 {
7054 {
7056 {
7060 }
7061 else
7067 }
7070 }
7071 /* We can't pass a pack expansion to a non-pack parameter of an alias
7072 template (DR 1430). */
7074 && variadic_args_p
7076 {
7078 {
7080 {
7086 {
7091 }
7092 }
7094 found:;
7095 }
7097 }
7099 /* We need to evaluate the template arguments, even though this
7100 template-id may be nested within a "sizeof". */
7109 {
7110 tree arg;
7111 tree parm;
7113 /* Get the Ith template parameter. */
7117 {
7120 }
7122 /* Calculate the next argument. */
7125 else
7130 {
7131 /* Some arguments will be placed in the
7132 template parameter pack PARM. */
7139 {
7140 /* We don't know how many args we have yet, just use the
7141 unconverted (and still packed) ones for now. */
7145 }
7149 /* Store this argument. */
7151 {
7152 lost++;
7153 /* We are done with all of the arguments. */
7155 }
7156 else
7157 {
7160 }
7163 }
7165 {
7167 {
7168 /* "If every valid specialization of a variadic template
7169 requires an empty template parameter pack, the template is
7170 ill-formed, no diagnostic required." So check that the
7171 pattern works with this parameter. */
7176 in_decl);
7178 {
7182 }
7184 /* Recover from missing typename. */
7188 /* We don't know how many args we have yet, just
7189 use the unconverted ones for now. */
7193 }
7194 }
7196 {
7197 /* There must be a default arg in this case. */
7200 /* The position of the first default template argument,
7201 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
7202 Record that. */
7206 }
7207 else
7211 {
7214 }
7216 /* This only occurs if there was an error in the template
7217 parameter list itself (which we would already have
7218 reported) that we are trying to recover from, e.g., a class
7219 template with a parameter list such as
7220 template<typename..., typename>. */
7222 else
7228 lost++;
7230 }
7235 {
7237 {
7242 }
7244 }
7249 #ifdef ENABLE_CHECKING
7253 #endif
7256 }
7258 /* Like coerce_template_parms. If PARMS represents all template
7259 parameters levels, this function returns a vector of vectors
7260 representing all the resulting argument levels. Note that in this
7261 case, only the innermost arguments are coerced because the
7262 outermost ones are supposed to have been coerced already.
7264 Otherwise, if PARMS represents only (the innermost) vector of
7265 parameters, this function returns a vector containing just the
7266 innermost resulting arguments. */
7268 static tree
7270 tree args,
7271 tree in_decl,
7272 tsubst_flags_t complain,
7275 {
7278 tree coerced_args;
7281 {
7283 tree level;
7289 {
7290 tree l;
7294 require_all_args,
7295 use_default_args);
7296 else
7303 }
7304 }
7305 else
7308 require_all_args,
7309 use_default_args);
7311 }
7313 /* Returns 1 if template args OT and NT are equivalent. */
7315 static int
7317 {
7324 /* For member templates */
7333 {
7350 }
7352 {
7353 /* We get here probably because we are in the middle of substituting
7354 into the pattern of a pack expansion. In that case the
7355 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7356 interested in. So we want to use the initial pack argument for
7357 the comparison. */
7362 }
7364 {
7367 /* Don't treat an alias template specialization with dependent
7368 arguments as equivalent to its underlying type when used as a
7369 template argument; we need them to be distinct so that we
7370 substitute into the specialization arguments at instantiation
7371 time. And aliases can't be equivalent without being ==, so
7372 we don't need to look any deeper. */
7375 else
7377 }
7380 else
7381 {
7382 /* Try to treat a template non-type argument that has been converted
7383 to the parameter type as equivalent to one that hasn't yet. */
7396 }
7397 }
7399 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7400 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7401 NEWARG_PTR with the offending arguments if they are non-NULL. */
7403 static int
7406 {
7419 {
7424 {
7430 }
7431 }
7433 }
7435 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7436 of template arguments. Returns 0 otherwise. */
7438 int
7440 {
7442 }
7444 static void
7446 {
7456 /* We are called both from instantiate_decl, where we've already had a
7457 tinst_level pushed, and instantiate_template, where we haven't.
7458 Compensate. */
7469 else
7478 }
7481 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7482 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7483 documentation for TEMPLATE_ID_EXPR. */
7485 tree
7487 {
7488 tree type;
7496 {
7499 }
7502 {
7504 unknown_type_node,
7506 arglist);
7508 }
7515 }
7517 /* Within the scope of a template class S<T>, the name S gets bound
7518 (in build_self_reference) to a TYPE_DECL for the class, not a
7519 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7520 or one of its enclosing classes, and that type is a template,
7521 return the associated TEMPLATE_DECL. Otherwise, the original
7522 DECL is returned.
7524 Also handle the case when DECL is a TREE_LIST of ambiguous
7525 injected-class-names from different bases. */
7527 tree
7529 {
7533 /* DR 176: A lookup that finds an injected-class-name (10.2
7534 [class.member.lookup]) can result in an ambiguity in certain cases
7535 (for example, if it is found in more than one base class). If all of
7536 the injected-class-names that are found refer to specializations of
7537 the same class template, and if the name is followed by a
7538 template-argument-list, the reference refers to the class template
7539 itself and not a specialization thereof, and is not ambiguous. */
7541 {
7544 {
7550 }
7553 else
7555 }
7561 }
7563 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7564 parameters, find the desired type.
7566 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7568 IN_DECL, if non-NULL, is the template declaration we are trying to
7569 instantiate.
7571 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7572 the class we are looking up.
7574 Issue error and warning messages under control of COMPLAIN.
7576 If the template class is really a local class in a template
7577 function, then the FUNCTION_CONTEXT is the function in which it is
7578 being instantiated.
7580 ??? Note that this function is currently called *twice* for each
7581 template-id: the first time from the parser, while creating the
7582 incomplete type (finish_template_type), and the second type during the
7583 real instantiation (instantiate_template_class). This is surely something
7584 that we want to avoid. It also causes some problems with argument
7585 coercion (see convert_nontype_argument for more information on this). */
7587 static tree
7590 {
7592 tree t;
7595 spec_entry elt;
7596 hashval_t hash;
7599 {
7603 else
7604 {
7611 }
7614 }
7616 {
7619 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7620 an implicit typename for the second A. Deal with it. */
7625 {
7628 }
7629 }
7632 {
7635 }
7637 {
7641 }
7643 {
7646 }
7648 /* Issue an error message if we didn't find a template. */
7650 {
7654 }
7657 /* Make sure it's a user visible template, if it was named by
7658 the user. */
7661 {
7663 {
7667 }
7669 }
7673 /* An alias that just changes the name of a template is equivalent to the
7674 other template, so if any of the arguments are pack expansions, strip
7675 the alias to avoid problems with a pack expansion passed to a non-pack
7676 alias template parameter (DR 1430). */
7681 {
7682 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7683 template arguments */
7685 tree parm;
7686 tree arglist2;
7687 tree outer;
7691 /* Consider an example where a template template parameter declared as
7693 template <class T, class U = std::allocator<T> > class TT
7695 The template parameter level of T and U are one level larger than
7696 of TT. To proper process the default argument of U, say when an
7697 instantiation `TT<int>' is seen, we need to build the full
7698 arguments containing {int} as the innermost level. Outer levels,
7699 available when not appearing as default template argument, can be
7700 obtained from the arguments of the enclosing template.
7702 Suppose that TT is later substituted with std::vector. The above
7703 instantiation is `TT<int, std::allocator<T> >' with TT at
7704 level 1, and T at level 2, while the template arguments at level 1
7705 becomes {std::vector} and the inner level 2 is {int}. */
7711 /* This is an argument of the current template, so we haven't set
7712 DECL_CONTEXT yet. */
7719 complain,
7729 }
7730 else
7731 {
7733 tree gen_tmpl;
7734 tree type_decl;
7742 /* An error occurred while building the template TEMPL, and a
7743 diagnostic has most certainly been emitted for that
7744 already. Let's propagate that error. */
7753 {
7754 /* We've been given an incomplete set of template arguments.
7755 For example, given:
7757 template <class T> struct S1 {
7758 template <class U> struct S2 {};
7759 template <class U> struct S2<U*> {};
7760 };
7762 we will be called with an ARGLIST of `U*', but the
7763 TEMPLATE will be `template <class T> template
7764 <class U> struct S1<T>::S2'. We must fill in the missing
7765 arguments. */
7766 arglist
7768 arglist);
7770 }
7772 /* Now we should have enough arguments. */
7775 /* From here on, we're only interested in the most general
7776 template. */
7778 /* Calculate the BOUND_ARGS. These will be the args that are
7779 actually tsubst'd into the definition to create the
7780 instantiation. */
7782 complain,
7787 /* We were unable to bind the arguments. */
7790 /* In the scope of a template class, explicit references to the
7791 template class refer to the type of the template, not any
7792 instantiation of it. For example, in:
7794 template <class T> class C { void f(C<T>); }
7796 the `C<T>' is just the same as `C'. Outside of the
7797 class, however, such a reference is an instantiation. */
7801 /* comp_template_args is expensive, check it last. */
7803 arglist))
7806 /* If we already have this specialization, return it. */
7817 /* If the deduced arguments are invalid, then the binding
7818 failed. */
7822 complain))
7829 {
7834 }
7844 /* Create the type. */
7846 {
7847 /* The user referred to a specialization of an alias
7848 template represented by GEN_TMPL.
7850 [temp.alias]/2 says:
7852 When a template-id refers to the specialization of an
7853 alias template, it is equivalent to the associated
7854 type obtained by substitution of its
7855 template-arguments for the template-parameters in the
7856 type-id of the alias template. */
7859 /* Note that the call above (by indirectly calling
7860 register_specialization in tsubst_decl) registers the
7861 TYPE_DECL representing the specialization of the alias
7862 template. So next time someone substitutes ARGLIST for
7863 the template parms into the alias template (GEN_TMPL),
7864 she'll get that TYPE_DECL back. */
7868 }
7870 {
7872 {
7881 }
7882 else
7883 {
7884 /* We don't want to call start_enum for this type, since
7885 the values for the enumeration constants may involve
7886 template parameters. And, no one should be interested
7887 in the enumeration constants for such a type. */
7890 }
7894 }
7896 {
7903 /* A local class. Make sure the decl gets registered properly. */
7908 /* This instantiation is another name for the primary
7909 template type. Set the TYPE_CANONICAL field
7910 appropriately. */
7913 /* Some of the template arguments require structural
7914 equality testing, so this template class requires
7915 structural equality testing. */
7917 }
7918 else
7921 /* If we called start_enum or pushtag above, this information
7922 will already be set up. */
7924 {
7931 }
7932 else
7936 {
7942 {
7945 }
7946 }
7950 {
7954 {
7955 tree attributes
7959 ;
7962 else
7967 }
7968 }
7970 /* Let's consider the explicit specialization of a member
7971 of a class template specialization that is implicitly instantiated,
7972 e.g.:
7973 template<class T>
7974 struct S
7975 {
7976 template<class U> struct M {}; //#0
7977 };
7979 template<>
7980 template<>
7981 struct S<int>::M<char> //#1
7982 {
7983 int i;
7984 };
7985 [temp.expl.spec]/4 says this is valid.
7987 In this case, when we write:
7988 S<int>::M<char> m;
7990 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7991 the one of #0.
7993 When we encounter #1, we want to store the partial instantiation
7994 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7996 For all cases other than this "explicit specialization of member of a
7997 class template", we just want to store the most general template into
7998 the CLASSTYPE_TI_TEMPLATE of M.
8000 This case of "explicit specialization of member of a class template"
8001 only happens when:
8002 1/ the enclosing class is an instantiation of, and therefore not
8003 the same as, the context of the most general template, and
8004 2/ we aren't looking at the partial instantiation itself, i.e.
8005 the innermost arguments are not the same as the innermost parms of
8006 the most general template.
8008 So it's only when 1/ and 2/ happens that we want to use the partial
8009 instantiation of the member template in lieu of its most general
8010 template. */
8014 /* the enclosing class must be an instantiation... */
8017 {
8018 tree partial_inst_args;
8021 partial_inst_args =
8027 use_partial_inst_tmpl =
8028 /*...and we must not be looking at the partial instantiation
8029 itself. */
8031 partial_inst_args);
8032 }
8035 /* This case is easy; there are no member templates involved. */
8037 else
8038 {
8039 /* This is a full instantiation of a member template. Find
8040 the partial instantiation of which this is an instance. */
8042 /* Temporarily reduce by one the number of levels in the ARGLIST
8043 so as to avoid comparing the last set of arguments. */
8047 /* FOUND is either a proper class type, or an alias
8048 template specialization. In the later case, it's a
8049 TYPE_DECL, resulting from the substituting of arguments
8050 for parameters in the TYPE_DECL of the alias template
8051 done earlier. So be careful while getting the template
8052 of FOUND. */
8056 }
8066 /* Note this use of the partial instantiation so we can check it
8067 later in maybe_process_partial_specialization. */
8074 /* Now that the type has been registered on the instantiations
8075 list, we set up the enumerators. Because the enumeration
8076 constants may involve the enumeration type itself, we make
8077 sure to register the type first, and then create the
8078 constants. That way, doing tsubst_expr for the enumeration
8079 constants won't result in recursive calls here; we'll find
8080 the instantiation and exit above. */
8084 /* If the type makes use of template parameters, the
8085 code that generates debugging information will crash. */
8088 /* Possibly limit visibility based on template args. */
8095 }
8096 }
8098 /* Wrapper for lookup_template_class_1. */
8100 tree
8103 {
8104 tree ret;
8110 }
8112 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST.
8113 The type of the expression is the unknown_type_node since the
8114 template-id could refer to an explicit or partial specialization. */
8116 tree
8118 {
8121 }
8123 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
8125 tree
8127 {
8141 }
8142 \f
8143 struct pair_fn_data
8144 {
8145 tree_fn_t fn;
8147 /* True when we should also visit template parameters that occur in
8148 non-deduced contexts. */
8151 };
8153 /* Called from for_each_template_parm via walk_tree. */
8155 static tree
8157 {
8170 {
8174 /* Fall through. */
8197 /* Since we're not going to walk subtrees, we have to do this
8198 explicitly here. */
8202 /* Fall through. */
8205 /* Check the return type. */
8210 /* Check the parameter types. Since default arguments are not
8211 instantiated until they are needed, the TYPE_ARG_TYPES may
8212 contain expressions that involve template parameters. But,
8213 no-one should be looking at them yet. And, once they're
8214 instantiated, they don't contain template parameters, so
8215 there's no point in looking at them then, either. */
8216 {
8217 tree parm;
8224 /* Since we've already handled the TYPE_ARG_TYPES, we don't
8225 want walk_tree walking into them itself. */
8227 }
8245 /* Fall through. */
8261 /* Record template parameters such as `T' inside `TT<T>'. */
8265 /* Fall through. */
8277 /* A template template parameter is encountered. */
8283 /* Already substituted template template parameter */
8306 /* If there's no type, then this thing must be some expression
8307 involving template parameters. */
8329 }
8331 /* We didn't find any template parameters we liked. */
8333 }
8335 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8336 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8337 call FN with the parameter and the DATA.
8338 If FN returns nonzero, the iteration is terminated, and
8339 for_each_template_parm returns 1. Otherwise, the iteration
8340 continues. If FN never returns a nonzero value, the value
8341 returned by for_each_template_parm is 0. If FN is NULL, it is
8342 considered to be the function which always returns 1.
8344 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8345 parameters that occur in non-deduced contexts. When false, only
8346 visits those template parameters that can be deduced. */
8348 static int
8352 {
8356 /* Set up. */
8361 /* Walk the tree. (Conceptually, we would like to walk without
8362 duplicates, but for_each_template_parm_r recursively calls
8363 for_each_template_parm, so we would need to reorganize a fair
8364 bit to use walk_tree_without_duplicates, so we keep our own
8365 visited list.) */
8368 else
8371 for_each_template_parm_r,
8375 /* Clean up. */
8377 {
8380 }
8383 }
8385 /* Returns true if T depends on any template parameter. */
8387 int
8389 {
8419 else
8420 {
8423 }
8428 }
8430 /* Returns true iff current_function_decl is an incompletely instantiated
8431 template. Useful instead of processing_template_decl because the latter
8432 is set to 0 during instantiate_non_dependent_expr. */
8434 bool
8436 {
8445 }
8447 /* Returns true if T depends on any template parameter with level LEVEL. */
8449 int
8451 {
8454 }
8456 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8457 ill-formed translation unit, i.e. a variable or function that isn't
8458 usable in a constant expression. */
8462 {
8466 }
8468 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8469 neglectable and instantiated from within an erroneous instantiation. */
8471 static bool
8473 {
8484 }
8492 /* We're starting to instantiate D; record the template instantiation context
8493 for diagnostics and to restore it later. */
8495 bool
8497 {
8499 }
8501 /* We're starting to instantiate D; record the template instantiation context
8502 at LOC for diagnostics and to restore it later. */
8504 bool
8506 {
8510 {
8512 "template instantiation depth exceeds maximum of %d"
8514 max_tinst_depth);
8516 }
8518 /* If the current instantiation caused problems, don't let it instantiate
8519 anything else. Do allow deduction substitution and decls usable in
8520 constant expressions. */
8537 }
8539 /* We're done instantiating this template; return to the instantiation
8540 context. */
8542 void
8544 {
8545 /* Restore the filename and line number stashed away when we started
8546 this instantiation. */
8550 }
8552 /* We're instantiating a deferred template; restore the template
8553 instantiation context in which the instantiation was requested, which
8554 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8556 static tree
8558 {
8570 }
8572 /* Returns the TINST_LEVEL which gives the original instantiation
8573 context. */
8577 {
8583 }
8585 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8586 vector of template arguments, as for tsubst.
8588 Returns an appropriate tsubst'd friend declaration. */
8590 static tree
8592 {
8593 tree new_friend;
8598 /* This was a friend declared with an explicit template
8599 argument list, e.g.:
8601 friend void f<>(T);
8603 to indicate that f was a template instantiation, not a new
8604 function declaration. Now, we have to figure out what
8605 instantiation of what template. */
8606 {
8608 tree new_args;
8609 tree tmpl;
8612 /* Friend functions are looked up in the containing namespace scope.
8613 We must enter that scope, to avoid finding member functions of the
8614 current class with same name. */
8629 tsk_none);
8631 }
8635 /* The NEW_FRIEND will look like an instantiation, to the
8636 compiler, but is not an instantiation from the point of view of
8637 the language. For example, we might have had:
8639 template <class T> struct S {
8640 template <class U> friend void f(T, U);
8641 };
8643 Then, in S<int>, template <class U> void f(int, U) is not an
8644 instantiation of anything. */
8650 {
8654 }
8656 /* The mangled name for the NEW_FRIEND is incorrect. The function
8657 is not a template instantiation and should not be mangled like
8658 one. Therefore, we forget the mangling here; we'll recompute it
8659 later if we need it. */
8661 {
8664 }
8667 {
8668 tree old_decl;
8669 tree new_friend_template_info;
8670 tree new_friend_result_template_info;
8671 tree ns;
8674 /* We must save some information from NEW_FRIEND before calling
8675 duplicate decls since that function will free NEW_FRIEND if
8676 possible. */
8678 new_friend_is_defn =
8683 {
8684 /* This declaration is a `primary' template. */
8687 new_friend_result_template_info
8689 }
8690 else
8693 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8697 /* Inside pushdecl_namespace_level, we will push into the
8698 current namespace. However, the friend function should go
8699 into the namespace of the template. */
8709 {
8710 /* This new friend declaration matched an existing
8711 declaration. For example, given:
8713 template <class T> void f(T);
8714 template <class U> class C {
8715 template <class T> friend void f(T) {}
8716 };
8718 the friend declaration actually provides the definition
8719 of `f', once C has been instantiated for some type. So,
8720 old_decl will be the out-of-class template declaration,
8721 while new_friend is the in-class definition.
8723 But, if `f' was called before this point, the
8724 instantiation of `f' will have DECL_TI_ARGS corresponding
8725 to `T' but not to `U', references to which might appear
8726 in the definition of `f'. Previously, the most general
8727 template for an instantiation of `f' was the out-of-class
8728 version; now it is the in-class version. Therefore, we
8729 run through all specialization of `f', adding to their
8730 DECL_TI_ARGS appropriately. In particular, they need a
8731 new set of outer arguments, corresponding to the
8732 arguments for this class instantiation.
8734 The same situation can arise with something like this:
8736 friend void f(int);
8737 template <class T> class C {
8738 friend void f(T) {}
8739 };
8741 when `C<int>' is instantiated. Now, `f(int)' is defined
8742 in the class. */
8745 /* On the other hand, if the in-class declaration does
8746 *not* provide a definition, then we don't want to alter
8747 existing definitions. We can just leave everything
8748 alone. */
8749 ;
8750 else
8751 {
8755 /* Overwrite whatever template info was there before, if
8756 any, with the new template information pertaining to
8757 the declaration. */
8761 {
8762 /* We should have called reregister_specialization in
8763 duplicate_decls. */
8768 /* Instantiate it if the global has already been used. */
8772 }
8773 else
8774 {
8775 tree t;
8777 /* Indicate that the old function template is a partial
8778 instantiation. */
8786 /* Reassign any specializations already in the hash table
8787 to the new more general template, and add the
8788 additional template args. */
8792 {
8794 spec_entry elt;
8806 register_specialization
8809 }
8811 }
8812 }
8814 /* The information from NEW_FRIEND has been merged into OLD_DECL
8815 by duplicate_decls. */
8817 }
8818 }
8819 else
8820 {
8824 /* In the code
8825 template <class T> class C {
8826 template <class U> friend void C1<U>::f (); // case 1
8827 friend void C2<T>::f (); // case 2
8828 };
8829 we only need to make sure CONTEXT is a complete type for
8830 case 2. To distinguish between the two cases, we note that
8831 CONTEXT of case 1 remains dependent type after tsubst while
8832 this isn't true for case 2. */
8842 {
8844 /* do_friend adds the TEMPLATE_DECL for any member friend
8845 template even if it isn't a member template, i.e.
8846 template <class T> friend A<T>::f();
8847 Look through it in that case. */
8851 /* Check to see that the declaration is really present, and,
8852 possibly obtain an improved declaration. */
8857 }
8858 }
8861 }
8863 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8864 template arguments, as for tsubst.
8866 Returns an appropriate tsubst'd friend type or error_mark_node on
8867 failure. */
8869 static tree
8871 {
8872 tree friend_type;
8873 tree tmpl;
8874 tree context;
8877 {
8880 }
8885 {
8888 else
8890 }
8892 /* Look for a class template declaration. We look for hidden names
8893 because two friend declarations of the same template are the
8894 same. For example, in:
8896 struct A {
8897 template <typename> friend class F;
8898 };
8899 template <typename> struct B {
8900 template <typename> friend class F;
8901 };
8903 both F templates are the same. */
8907 /* But, if we don't find one, it might be because we're in a
8908 situation like this:
8910 template <class T>
8911 struct S {
8912 template <class U>
8913 friend struct S;
8914 };
8916 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8917 for `S<int>', not the TEMPLATE_DECL. */
8919 {
8922 }
8925 {
8926 /* The friend template has already been declared. Just
8927 check to see that the declarations match, and install any new
8928 default parameters. We must tsubst the default parameters,
8929 of course. We only need the innermost template parameters
8930 because that is all that redeclare_class_template will look
8931 at. */
8934 {
8935 tree parms;
8936 location_t saved_input_location;
8945 }
8948 }
8949 else
8950 {
8951 /* The friend template has not already been declared. In this
8952 case, the instantiation of the template class will cause the
8953 injection of this template into the global scope. */
8958 /* The new TMPL is not an instantiation of anything, so we
8959 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8960 the new type because that is supposed to be the corresponding
8961 template decl, i.e., TMPL. */
8968 /* Inject this template into the global scope. */
8970 }
8973 {
8976 else
8978 }
8981 }
8983 /* Returns zero if TYPE cannot be completed later due to circularity.
8984 Otherwise returns one. */
8986 static int
8988 {
8998 else
9000 }
9004 /* Apply any attributes which had to be deferred until instantiation
9005 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
9006 ARGS, COMPLAIN, IN_DECL are as tsubst. */
9008 static void
9011 {
9013 tree t;
9018 {
9022 }
9025 {
9029 }
9030 else
9034 {
9039 {
9042 {
9049 {
9056 clauses
9060 else
9062 }
9063 /* If the first attribute argument is an identifier, don't
9064 pass it through tsubst. Attributes like mode, format,
9065 cleanup and several target specific attributes expect it
9066 unmodified. */
9069 {
9070 tree chain
9072 in_decl,
9077 chain);
9078 }
9080 {
9081 /* An attribute pack expansion. */
9083 tree pack = (tsubst_pack_expansion
9087 {
9091 }
9093 }
9094 else
9100 }
9101 else
9103 }
9106 }
9107 }
9109 /* Perform (or defer) access check for typedefs that were referenced
9110 from within the template TMPL code.
9111 This is a subroutine of instantiate_decl and instantiate_class_template.
9112 TMPL is the template to consider and TARGS is the list of arguments of
9113 that template. */
9115 static void
9117 {
9118 location_t saved_location;
9129 {
9141 /* Make access check error messages point to the location
9142 of the use of the typedef. */
9146 tf_warning_or_error);
9147 }
9149 }
9151 static tree
9153 {
9155 tree typedecl;
9156 tree pbinfo;
9157 tree base_list;
9159 tree fn_context;
9168 /* Figure out which template is being instantiated. */
9172 /* Determine what specialization of the original template to
9173 instantiate. */
9176 {
9179 }
9181 {
9182 /* This TYPE is actually an instantiation of a partial
9183 specialization. We replace the innermost set of ARGS with
9184 the arguments appropriate for substitution. For example,
9185 given:
9187 template <class T> struct S {};
9188 template <class T> struct S<T*> {};
9190 and supposing that we are instantiating S<int*>, ARGS will
9191 presently be {int*} -- but we need {int}. */
9194 }
9195 else
9196 {
9199 }
9201 /* If the template we're instantiating is incomplete, then clearly
9202 there's nothing we can do. */
9206 /* If we've recursively instantiated too many templates, stop. */
9210 /* Now we're really doing the instantiation. Mark the type as in
9211 the process of being defined. */
9214 /* We may be in the middle of deferred access check. Disable
9215 it now. */
9222 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
9227 else
9228 {
9231 }
9232 /* Use #pragma pack from the template context. */
9238 /* Set the input location to the most specialized template definition.
9239 This is needed if tsubsting causes an error. */
9251 {
9254 /* Adjust visibility for template arguments. */
9256 }
9262 /* We should never instantiate a nested class before its enclosing
9263 class; we need to look up the nested class by name before we can
9264 instantiate it, and that lookup should instantiate the enclosing
9265 class. */
9271 {
9272 tree pbase_binfo;
9273 tree pushed_scope;
9276 /* We must enter the scope containing the type, as that is where
9277 the accessibility of types named in dependent bases are
9278 looked up from. */
9281 /* Substitute into each of the bases to determine the actual
9282 basetypes. */
9284 {
9285 tree base;
9291 {
9292 expanded_bases =
9299 }
9302 {
9304 /* Extract the already-expanded base class. */
9306 else
9307 /* Substitute to figure out the base class. */
9309 NULL_TREE);
9317 }
9318 }
9320 /* The list is now in reverse order; correct that. */
9325 }
9326 /* Now call xref_basetypes to set up all the base-class
9327 information. */
9335 /* Now that our base classes are set up, enter the scope of the
9336 class, so that name lookups into base classes, etc. will work
9337 correctly. This is precisely analogous to what we do in
9338 begin_class_definition when defining an ordinary non-template
9339 class, except we also need to push the enclosing classes. */
9342 /* Now members are processed in the order of declaration. */
9345 {
9349 {
9351 {
9352 /* Build new CLASSTYPE_NESTED_UTDS. */
9354 tree newtag;
9360 /* If the member is a class template, then -- even after
9361 substitution -- there may be dependent types in the
9362 template argument list for the class. We increment
9363 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9364 that function will assume that no types are dependent
9365 when outside of a template. */
9375 {
9379 /* Unfortunately, lookup_template_class sets
9380 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9381 instantiation (i.e., for the type of a member
9382 template class nested within a template class.)
9383 This behavior is required for
9384 maybe_process_partial_specialization to work
9385 correctly, but is not accurate in this case;
9386 the TAG is not an instantiation of anything.
9387 (The corresponding TEMPLATE_DECL is an
9388 instantiation, but the TYPE is not.) */
9391 /* Now, we call pushtag to put this NEWTAG into the scope of
9392 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9393 pushtag calling push_template_decl. We don't have to do
9394 this for enums because it will already have been done in
9395 tsubst_enum. */
9399 }
9400 }
9402 {
9403 /* Build new TYPE_METHODS. */
9404 tree r;
9413 /* Instantiate members marked with attribute used. */
9419 }
9422 /* A closure type for a lambda in a default argument for a
9423 member template. Ignore it; it will be instantiated with
9425 else
9426 {
9427 /* Build new TYPE_FIELDS. */
9429 {
9430 tree condition;
9433 condition =
9443 }
9445 {
9446 tree r;
9450 /* The file and line for this declaration, to
9451 assist in error message reporting. Since we
9452 called push_tinst_level above, we don't need to
9453 restore these. */
9463 {
9464 /* A capture pack became multiple fields. */
9467 }
9470 {
9474 {
9475 /* In [temp.inst]:
9477 [t]he initialization (and any associated
9478 side-effects) of a static data member does
9479 not occur unless the static data member is
9480 itself used in a way that requires the
9481 definition of the static data member to
9482 exist.
9484 Therefore, we do not substitute into the
9485 initialized for the static data member here. */
9486 finish_static_data_member_decl
9492 /* Instantiate members marked with attribute used. */
9495 }
9497 {
9498 /* Determine whether R has a valid type and can be
9499 completed later. If R is invalid, then its type
9500 is replaced by error_mark_node. */
9506 {
9509 }
9510 }
9512 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9513 such a thing will already have been added to the field
9514 list by tsubst_enum in finish_member_declaration in the
9515 CLASSTYPE_NESTED_UTDS case above. */
9519 {
9522 }
9523 }
9524 }
9525 }
9526 }
9527 else
9528 {
9531 {
9532 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9538 {
9539 /* template <class T> friend class C; */
9542 }
9544 {
9545 /* template <class T> friend class C::D; */
9551 }
9554 {
9555 /* This could be either
9557 friend class T::C;
9559 when dependent_type_p is false or
9561 template <class U> friend class T::C;
9563 otherwise. */
9566 /* Bump processing_template_decl for correct
9567 dependent_type_p calculation. */
9572 }
9575 {
9576 /* friend class C;
9578 where C hasn't been declared yet. Let's lookup name
9579 from namespace scope directly, bypassing any name that
9580 come from dependent base class. */
9583 /* The call to xref_tag_from_type does injection for friend
9584 classes. */
9586 friend_type =
9590 }
9592 /* friend class C<T>; */
9595 /* Otherwise it's
9597 friend class C;
9599 where C is already declared or
9601 friend class C<int>;
9603 We don't have to do anything in these cases. */
9606 /* Trick make_friend_class into realizing that the friend
9607 we're adding is a template, not an ordinary class. It's
9608 important that we use make_friend_class since it will
9609 perform some error-checking and output cross-reference
9610 information. */
9618 }
9619 else
9620 {
9621 /* Build new DECL_FRIENDLIST. */
9622 tree r;
9624 /* The file and line for this declaration, to
9625 assist in error message reporting. Since we
9626 called push_tinst_level above, we don't need to
9627 restore these. */
9631 {
9634 }
9639 {
9642 }
9643 }
9644 }
9645 }
9648 {
9649 /* Restore these before substituting into the lambda capture
9650 initializers. */
9653 }
9656 {
9659 {
9664 /* We need to instantiate the capture list from the template
9665 after we've instantiated the closure members, but before we
9666 consider adding the conversion op. Also keep any captures
9667 that may have been added during instantiation of the op(). */
9669 tree tmpl_cap
9678 }
9679 else
9681 }
9683 /* Set the file and line number information to whatever is given for
9684 the class itself. This puts error messages involving generated
9685 implicit functions at a predictable point, and the same point
9686 that would be used for non-template classes. */
9693 /* We don't instantiate default arguments for member functions. 14.7.1:
9695 The implicit instantiation of a class template specialization causes
9696 the implicit instantiation of the declarations, but not of the
9697 definitions or default arguments, of the class member functions,
9698 member classes, static data members and member templates.... */
9700 /* Some typedefs referenced from within the template code need to be access
9701 checked at template instantiation time, i.e now. These types were
9702 added to the template at parsing time. Let's get those and perform
9703 the access checks then. */
9713 /* The vtable for a template class can be emitted in any translation
9714 unit in which the class is instantiated. When there is no key
9715 method, however, finish_struct_1 will already have added TYPE to
9716 the keyed_classes list. */
9721 }
9723 /* Wrapper for instantiate_class_template_1. */
9725 tree
9727 {
9728 tree ret;
9733 }
9735 static tree
9737 {
9738 tree r;
9744 else
9745 {
9752 }
9754 }
9756 /* Given a function parameter pack TMPL_PARM and some function parameters
9757 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9758 and set *SPEC_P to point at the next point in the list. */
9760 static tree
9762 {
9763 /* Collect all of the extra "packed" parameters into an
9764 argument pack. */
9765 tree parmvec;
9766 tree parmtypevec;
9777 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9782 {
9785 }
9787 /* Build the argument packs. */
9794 }
9796 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9797 NONTYPE_ARGUMENT_PACK. */
9799 static tree
9801 {
9803 }
9805 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
9806 pack expansion with no extra args, 2 if it has extra args, or 0
9807 if it is not a pack expansion. */
9809 static int
9811 {
9821 }
9824 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9826 static tree
9828 {
9835 }
9837 /* This is a subroutine of tsubst_pack_expansion.
9839 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9840 mechanism to store the (non complete list of) arguments of the
9841 substitution and return a non substituted pack expansion, in order
9842 to wait for when we have enough arguments to really perform the
9843 substitution. */
9845 static bool
9849 {
9850 /* If one pack has an expansion and another pack has a normal
9851 argument or if one pack has an empty argument and an another
9852 one hasn't then tsubst_pack_expansion cannot perform the
9853 substitution and need to fall back on the
9854 PACK_EXPANSION_EXTRA mechanism. */
9862 {
9865 parm_pack;
9867 {
9872 /* We can't substitute a pack expansion with extra args into
9873 our pattern. */
9877 else
9879 }
9883 }
9885 }
9887 /* [temp.variadic]/6 says that:
9889 The instantiation of a pack expansion [...]
9890 produces a list E1,E2, ..., En, where N is the number of elements
9891 in the pack expansion parameters.
9893 This subroutine of tsubst_pack_expansion produces one of these Ei.
9895 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9896 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9897 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9898 INDEX is the index 'i' of the element Ei to produce. ARGS,
9899 COMPLAIN, and IN_DECL are the same parameters as for the
9900 tsubst_pack_expansion function.
9902 The function returns the resulting Ei upon successful completion,
9903 or error_mark_node.
9905 Note that this function possibly modifies the ARGS parameter, so
9906 it's the responsibility of the caller to restore it. */
9908 static tree
9910 tree parm_packs,
9912 tree args /* This parm gets
9914 tsubst_flags_t complain,
9915 tree in_decl)
9916 {
9917 tree t;
9920 /* For each parameter pack, change the substitution of the parameter
9921 pack to the ith argument in its argument pack, then expand the
9922 pattern. */
9924 {
9929 ith_elem_is_expansion |=
9932 /* Select the Ith argument from the pack. */
9935 {
9937 {
9942 }
9943 else
9945 }
9946 else
9947 {
9952 {
9954 /* Update the corresponding argument. */
9956 }
9957 else
9958 /* Re-use the ARGUMENT_PACK_SELECT. */
9960 }
9962 }
9964 /* Substitute into the PATTERN with the (possibly altered)
9965 arguments. */
9967 /* Expanding a fixed parameter pack from
9968 coerce_template_parameter_pack. */
9973 else
9976 /* If the Ith argument pack element is a pack expansion, then
9977 the Ith element resulting from the substituting is going to
9978 be a pack expansion as well. */
9983 }
9985 /* Substitute ARGS into T, which is an pack expansion
9986 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9987 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9988 (if only a partial substitution could be performed) or
9989 ERROR_MARK_NODE if there was an error. */
9990 tree
9992 tree in_decl)
9993 {
9994 tree pattern;
9998 tree result;
10006 /* Add in any args remembered from an earlier partial instantiation. */
10011 /* Determine the argument packs that will instantiate the parameter
10012 packs used in the expansion expression. While we're at it,
10013 compute the number of arguments to be expanded and make sure it
10014 is consistent. */
10017 {
10024 {
10028 else
10031 }
10033 {
10036 else
10037 {
10038 /* We can't rely on local_specializations for a parameter
10039 name used later in a function declaration (such as in a
10040 late-specified return type). Even if it exists, it might
10041 have the wrong value for a recursive call. Just make a
10042 dummy decl, since it's only used for its type. */
10045 /* Partial instantiation of the parm_pack, we can't build
10046 up an argument pack yet. */
10048 else
10051 }
10052 }
10055 else
10056 {
10062 }
10069 /* This can only happen if we forget to expand an argument
10070 pack somewhere else. Just return an error, silently. */
10071 {
10075 }
10078 {
10082 /* Don't bother trying to do a partial substitution with
10083 incomplete packs; we'll try again after deduction. */
10090 {
10096 pattern);
10097 else
10100 pattern);
10102 }
10104 /* Keep track of the parameter packs and their corresponding
10105 argument packs. */
10108 }
10109 else
10110 {
10111 /* We can't substitute for this parameter pack. We use a flag as
10112 well as the missing_level counter because function parameter
10113 packs don't have a level. */
10115 }
10116 }
10118 /* If the expansion is just T..., return the matching argument pack. */
10121 {
10126 /* Otherwise use the normal path so we get convert_from_reference. */
10127 }
10129 /* We cannot expand this expansion expression, because we don't have
10130 all of the argument packs we need. */
10132 {
10133 /* We got some full packs, but we can't substitute them in until we
10134 have values for all the packs. So remember these until then. */
10139 }
10141 {
10142 /* There were no real arguments, we're just replacing a parameter
10143 pack with another version of itself. Substitute into the
10144 pattern and return a PACK_EXPANSION_*. The caller will need to
10145 deal with that. */
10149 else
10153 }
10158 {
10159 /* We're in a late-specified return type, so create our own local
10160 specializations map; the current map is either NULL or (in the
10161 case of recursive unification) might have bindings that we don't
10162 want to use or alter. */
10165 }
10167 /* For each argument in each argument pack, substitute into the
10168 pattern. */
10171 {
10173 i,
10175 in_decl);
10178 {
10181 }
10182 }
10184 /* Update ARGS to restore the substitution from parameter packs to
10185 their argument packs. */
10187 {
10193 else
10194 {
10202 /* Update the corresponding argument. */
10206 else
10208 }
10209 }
10212 {
10215 }
10218 }
10220 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
10221 TMPL. We do this using DECL_PARM_INDEX, which should work even with
10222 parameter packs; all parms generated from a function parameter pack will
10223 have the same DECL_PARM_INDEX. */
10225 tree
10227 {
10229 tree patparm;
10232 {
10238 }
10239 else
10240 {
10245 }
10248 }
10250 /* Substitute ARGS into the vector or list of template arguments T. */
10252 static tree
10254 {
10266 {
10268 tree new_arg;
10273 {
10274 /* Substitute into an expansion expression. */
10278 /* Add to the expanded length adjustment the number of
10279 expanded arguments. We subtract one from this
10280 measurement, because the argument pack expression
10281 itself is already counted as 1 in
10282 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
10283 the argument pack is empty. */
10285 }
10287 {
10288 /* Substitute into each of the arguments. */
10294 new_arg,
10308 }
10309 }
10310 else
10319 }
10324 /* Make space for the expanded arguments coming from template
10325 argument packs. */
10327 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10328 arguments for a member template.
10329 In that case each TREE_VEC in ORIG_T represents a level of template
10330 arguments, and ORIG_T won't carry any non defaulted argument count.
10331 It will rather be the nested TREE_VECs that will carry one.
10332 In other words, ORIG_T carries a non defaulted argument count only
10333 if it doesn't contain any nested TREE_VEC. */
10335 {
10339 }
10341 {
10345 {
10348 /* Now expand the template argument pack "in place". */
10351 }
10352 else
10353 {
10355 out++;
10356 }
10357 }
10360 }
10362 /* Return the result of substituting ARGS into the template parameters
10363 given by PARMS. If there are m levels of ARGS and m + n levels of
10364 PARMS, then the result will contain n levels of PARMS. For
10365 example, if PARMS is `template <class T> template <class U>
10366 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10367 result will be `template <int*, double, class V>'. */
10369 static tree
10371 {
10375 /* When substituting into a template, we must set
10376 PROCESSING_TEMPLATE_DECL as the template parameters may be
10377 dependent if they are based on one-another, and the dependency
10378 predicates are short-circuit outside of templates. */
10385 {
10386 tree new_vec =
10391 {
10392 tree tuple;
10404 }
10410 }
10415 }
10417 /* Return the result of substituting ARGS into one template parameter
10418 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10419 parameter and which TREE_PURPOSE is the default argument of the
10420 template parameter. */
10422 static tree
10424 {
10445 }
10447 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10448 type T. If T is not an aggregate or enumeration type, it is
10449 handled as if by tsubst. IN_DECL is as for tsubst. If
10450 ENTERING_SCOPE is nonzero, T is the context for a template which
10451 we are presently tsubst'ing. Return the substituted value. */
10453 static tree
10455 tree args,
10456 tsubst_flags_t complain,
10457 tree in_decl,
10459 {
10464 {
10469 /* Else fall through. */
10473 {
10474 tree argvec;
10475 tree context;
10476 tree r;
10480 /* In "sizeof(X<I>)" we need to evaluate "I". */
10486 /* First, determine the context for the type we are looking
10487 up. */
10490 {
10493 /* If context is a nested class inside a class template,
10494 it may still need to be instantiated (c++/33959). */
10496 }
10498 /* Then, figure out what arguments are appropriate for the
10499 type we are trying to find. For example, given:
10501 template <class T> struct S;
10502 template <class T, class U> void f(T, U) { S<U> su; }
10504 and supposing that we are instantiating f<int, double>,
10505 then our ARGS will be {int, double}, but, when looking up
10506 S we only want {double}. */
10511 else
10512 {
10516 }
10522 }
10523 else
10524 /* This is not a template type, so there's nothing to do. */
10529 }
10530 }
10532 /* Substitute into the default argument ARG (a default argument for
10533 FN), which has the indicated TYPE. */
10535 tree
10537 {
10542 /* This can happen in invalid code. */
10546 /* This default argument came from a template. Instantiate the
10547 default argument here, not in tsubst. In the case of
10548 something like:
10550 template <class T>
10551 struct S {
10552 static T t();
10553 void f(T = t());
10554 };
10556 we must be careful to do name lookup in the scope of S<T>,
10557 rather than in the current class. */
10559 /* The "this" pointer is not valid in a default argument. */
10561 {
10566 }
10569 /* The default argument expression may cause implicitly defined
10570 member functions to be synthesized, which will result in garbage
10571 collection. We must treat this situation as if we were within
10572 the body of function so as to avoid collecting live data on the
10573 stack. */
10581 /* Restore the "this" pointer. */
10583 {
10586 }
10593 /* Make sure the default argument is reasonable. */
10599 }
10601 /* Substitute into all the default arguments for FN. */
10603 static void
10605 {
10606 tree arg;
10607 tree tmpl_args;
10611 /* If this function is not yet instantiated, we certainly don't need
10612 its default arguments. */
10615 /* Don't do this again for clones. */
10620 arg;
10626 complain);
10627 }
10629 /* Substitute the ARGS into the T, which is a _DECL. Return the
10630 result of the substitution. Issue error and warning messages under
10631 control of COMPLAIN. */
10633 static tree
10635 {
10636 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10637 location_t saved_loc;
10642 /* Set the filename and linenumber to improve error-reporting. */
10647 {
10649 {
10650 /* We can get here when processing a member function template,
10651 member class template, or template template parameter. */
10653 tree spec;
10654 tree tmpl_args;
10655 tree full_args;
10658 {
10659 /* Template template parameter is treated here. */
10663 /* If we get a real template back, return it. This can happen in
10664 the context of most_specialized_partial_spec. */
10676 complain);
10679 }
10681 /* We might already have an instance of this template.
10682 The ARGS are for the surrounding class type, so the
10683 full args contain the tsubst'd args for the context,
10684 plus the innermost args from the template decl. */
10688 /* Because this is a template, the arguments will still be
10689 dependent, even after substitution. If
10690 PROCESSING_TEMPLATE_DECL is not set, the dependency
10691 predicates will short-circuit. */
10699 /* If this is a default template template argument,
10700 tsubst might not have changed anything. */
10707 {
10710 }
10712 /* Make a new template decl. It will be similar to the
10713 original, but will record the current template arguments.
10714 We also create a new function declaration, which is just
10715 like the old one, but points to this new template, rather
10716 than the old one. */
10725 {
10726 tree new_type;
10734 /* For a partial specialization, we need to keep pointing to
10735 the primary template. */
10741 }
10742 else
10743 {
10744 tree new_decl;
10756 }
10762 /* The template parameters for this new template are all the
10763 template parameters for the old template, except the
10764 outermost level of parameters. */
10767 complain);
10773 /* Record this non-type partial instantiation. */
10777 }
10781 {
10782 tree ctx;
10785 tree gen_tmpl;
10786 tree type;
10791 /* Nobody should be tsubst'ing into non-template functions. */
10795 {
10796 tree spec;
10799 /* If T is not dependent, just return it. We have to
10800 increment PROCESSING_TEMPLATE_DECL because
10801 value_dependent_expression_p assumes that nothing is
10802 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10809 /* Calculate the most general template of which R is a
10810 specialization, and the complete set of arguments used to
10811 specialize R. */
10814 (DECL_TEMPLATE_RESULT
10820 /* Check to see if we already have this specialization. */
10825 {
10828 }
10830 /* We can see more levels of arguments than parameters if
10831 there was a specialization of a member template, like
10832 this:
10834 template <class T> struct S { template <class U> void f(); }
10835 template <> template <class U> void S<int>::f(U);
10837 Here, we'll be substituting into the specialization,
10838 because that's where we can find the code we actually
10839 want to generate, but we'll have enough arguments for
10840 the most general template.
10842 We also deal with the peculiar case:
10844 template <class T> struct S {
10845 template <class U> friend void f();
10846 };
10847 template <class U> void f() {}
10848 template S<int>;
10849 template void f<double>();
10851 Here, the ARGS for the instantiation of will be {int,
10852 double}. But, we only need as many ARGS as there are
10853 levels of template parameters in CODE_PATTERN. We are
10854 careful not to get fooled into reducing the ARGS in
10855 situations like:
10857 template <class T> struct S { template <class U> void f(U); }
10858 template <class T> template <> void S<T>::f(int) {}
10860 which we can spot because the pattern will be a
10861 specialization in this case. */
10863 parms_depth =
10868 }
10869 else
10870 {
10871 /* This special case arises when we have something like this:
10873 template <class T> struct S {
10874 friend void f<int>(int, double);
10875 };
10877 Here, the DECL_TI_TEMPLATE for the friend declaration
10878 will be an IDENTIFIER_NODE. We are being called from
10879 tsubst_friend_function, and we want only to create a
10880 new decl (R) with appropriate types so that we can call
10881 determine_specialization. */
10883 }
10886 {
10889 else
10893 }
10894 else
10895 {
10898 }
10903 /* If we hit excessive deduction depth, the type is bogus even if
10904 it isn't error_mark_node, so don't build a decl. */
10908 /* We do NOT check for matching decls pushed separately at this
10909 point, as they may not represent instantiations of this
10910 template, and in any case are considered separate under the
10911 discrete model. */
10915 /* Clear out the mangled name and RTL for the instantiation. */
10918 /* Leave DECL_INITIAL set on deleted instantiations. */
10923 /* OpenMP UDRs have the only argument a reference to the declared
10924 type. We want to diagnose if the declared type is a reference,
10925 which is invalid, but as references to references are usually
10926 quietly merged, diagnose it here. */
10928 {
10929 tree argtype
10934 "reference type %qT in "
10938 argtype);
10939 }
10942 /* Type-conversion operator. Reconstruct the name, in
10943 case it's the name of one of the template's parameters. */
10953 /* If this is an instantiation of a function with internal
10954 linkage, we already know what object file linkage will be
10955 assigned to the instantiation. */
10964 /* We'll re-clone as appropriate in instantiate_template. */
10967 /* If we aren't complaining now, return on error before we register
10968 the specialization so that we'll complain eventually. */
10974 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10975 this in the special friend case mentioned above where
10976 GEN_TMPL is NULL. */
10978 {
10983 tree new_r
10986 /* We instantiated this while substituting into
10987 the type earlier (template/friend54.C). */
10990 /* We're not supposed to instantiate default arguments
10991 until they are called, for a template. But, for a
10992 declaration like:
10994 template <class T> void f ()
10995 { extern void g(int i = T()); }
10997 we should do the substitution when the template is
10998 instantiated. We handle the member function case in
10999 instantiate_class_template since the default arguments
11000 might refer to other members of the class. */
11005 }
11006 else
11009 /* Copy the list of befriending classes. */
11013 {
11017 in_decl);
11018 }
11021 {
11027 /* If this is an instantiation of a member template, clone it.
11028 If it isn't, that'll be handled by
11029 clone_constructors_and_destructors. */
11032 }
11043 /* Possibly limit visibility based on template args. */
11046 {
11050 }
11058 }
11062 {
11070 {
11071 /* If there is a local specialization that isn't a
11072 parameter pack, it means that we're doing a "simple"
11073 substitution from inside tsubst_pack_expansion. Just
11074 return the local specialization (which will be a single
11075 parm). */
11082 /* Expand the TYPE_PACK_EXPANSION that provides the types for
11083 the parameters in this function parameter pack. */
11087 {
11090 /* Zero-length parameter packs are boring. Just substitute
11091 into the chain. */
11095 }
11096 else
11097 {
11098 /* All we did was update the type. Make a note of that. */
11101 }
11102 }
11104 /* Loop through all of the parameters we'll build. When T is
11105 a function parameter pack, LEN is the number of expanded
11106 types in EXPANDED_TYPES; otherwise, LEN is 1. */
11109 {
11116 /* We're on the Ith parameter of the function parameter
11117 pack. */
11118 {
11119 /* Get the Ith type. */
11122 /* Rename the parameter to include the index. */
11125 }
11127 /* We're dealing with a normal parameter. */
11135 {
11138 else
11141 }
11151 /* Keep track of the first new parameter we
11152 generate. That's what will be returned to the
11153 caller. */
11157 /* Build a proper chain of parameters when substituting
11158 into a function parameter pack. */
11161 }
11163 /* If cp_unevaluated_operand is set, we're just looking for a
11164 single dummy parameter, so don't keep going. */
11169 /* FIRST_R contains the start of the chain we've built. */
11171 }
11175 {
11182 {
11183 /* This field is a lambda capture pack. Return a TREE_VEC of
11184 the expanded fields to instantiate_class_template_1 and
11185 store them in the specializations hash table as a
11186 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
11190 {
11193 }
11194 else
11195 {
11196 /* All we did was update the type. Make a note of that. */
11199 }
11200 }
11203 {
11206 {
11210 }
11220 /* For bit-fields, DECL_INITIAL gives the number of bits. For
11221 non-bit-fields DECL_INITIAL is a non-static data member
11222 initializer, which gets deferred instantiation. */
11228 {
11229 /* Set up DECL_TEMPLATE_INFO so that we can get at the
11230 NSDMI in perform_member_init. Still set DECL_INITIAL
11231 so that we know there is one. */
11236 }
11237 /* We don't have to set DECL_CONTEXT here; it is set by
11238 finish_member_declaration. */
11246 }
11249 {
11257 }
11258 }
11262 /* We reach here only for member using decls. We also need to check
11263 uses_template_parms because DECL_DEPENDENT_P is not set for a
11264 using-declaration that designates a member of the current
11265 instantiation (c++/53549). */
11268 {
11275 else
11276 {
11279 }
11280 }
11281 else
11282 {
11285 }
11290 {
11293 tree spec;
11295 tree ctx;
11304 {
11305 /* If this is the canonical decl, we don't have to
11306 mess with instantiations, and often we can't (for
11307 typename, template type parms and such). Note that
11308 TYPE_NAME is not correct for the above test if
11309 we've copied the type for a typedef. */
11315 }
11317 /* Check to see if we already have the specialization we
11318 need. */
11321 {
11322 /* T is a static data member or namespace-scope entity.
11323 We have to substitute into namespace-scope variables
11324 (not just variable templates) because of cases like:
11326 template <class T> void f() { extern T t; }
11328 where the entity referenced is not known until
11329 instantiation time. */
11333 {
11335 complain,
11337 /* If CTX is unchanged, then T is in fact the
11338 specialization we want. That situation occurs when
11339 referencing a static data member within in its own
11340 class. We can use pointer equality, rather than
11341 same_type_p, because DECL_CONTEXT is always
11342 canonical... */
11344 /* ... unless T is a member template; in which
11345 case our caller can be willing to create a
11346 specialization of that template represented
11347 by T. */
11351 }
11354 {
11359 argvec = (coerce_innermost_template_parms
11367 }
11368 }
11369 else
11370 {
11371 /* A local variable. */
11373 /* Subsequent calls to pushdecl will fill this in. */
11376 }
11377 /* If we already have the specialization we need, there is
11378 nothing more to do. */
11380 {
11383 }
11385 /* Create a new node for the specialization we need. */
11388 {
11391 else
11398 }
11400 {
11401 /* Even if the original location is out of scope, the
11402 newly substituted one is not. */
11409 {
11410 /* It may seem that this case cannot occur, since:
11412 typedef void f();
11413 void g() { f x; }
11415 declares a function, not a variable. However:
11417 typedef void f();
11418 template <typename T> void g() { T t; }
11419 template void g<f>();
11421 is an attempt to declare a variable with function
11422 type. */
11424 /* R is not yet sufficiently initialized, so we
11425 just use its name. */
11428 }
11430 /* Wait until cp_finish_decl to set this again, to handle
11431 circular dependency (template/instantiate6.C). */
11436 {
11441 {
11444 }
11446 }
11449 }
11455 /* Clear out the mangled name and RTL for the instantiation. */
11459 /* The initializer must not be expanded until it is required;
11460 see [temp.inst]. */
11466 {
11467 /* Possibly limit visibility based on template args. */
11470 {
11474 }
11476 }
11479 {
11480 /* A static data member declaration is always marked
11481 external when it is declared in-class, even if an
11482 initializer is present. We mimic the non-template
11483 processing here. */
11491 }
11501 /* Preserve a typedef that names a type. */
11503 {
11506 }
11509 }
11514 }
11515 #undef RETURN
11517 out:
11518 /* Restore the file and line information. */
11522 }
11524 /* Substitute into the ARG_TYPES of a function type.
11525 If END is a TREE_CHAIN, leave it and any following types
11526 un-substituted. */
11528 static tree
11530 tree args,
11531 tree end,
11532 tsubst_flags_t complain,
11533 tree in_decl)
11534 {
11535 tree remaining_arg_types;
11539 tree default_arg;
11550 {
11551 /* For a pack expansion, perform substitution on the
11552 entire expression. Later on, we'll handle the arguments
11553 one-by-one. */
11558 /* So that we'll spin through the parameters, one by one. */
11560 else
11561 {
11562 /* We only partially substituted into the parameter
11563 pack. Our type is TYPE_PACK_EXPANSION. */
11566 }
11567 }
11580 {
11582 {
11586 }
11588 }
11589 /* DR 657. */
11593 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11594 top-level qualifiers as required. */
11597 /* We do not substitute into default arguments here. The standard
11598 mandates that they be instantiated only when needed, which is
11599 done in build_over_call. */
11603 {
11604 /* We've instantiated a template before its default arguments
11605 have been parsed. This can happen for a nested template
11606 class, and is not an error unless we require the default
11607 argument in a call of this function. */
11608 remaining_arg_types =
11611 }
11612 else
11613 remaining_arg_types =
11615 }
11618 }
11620 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11621 *not* handle the exception-specification for FNTYPE, because the
11622 initial substitution of explicitly provided template parameters
11623 during argument deduction forbids substitution into the
11624 exception-specification:
11626 [temp.deduct]
11628 All references in the function type of the function template to the
11629 corresponding template parameters are replaced by the specified tem-
11630 plate argument values. If a substitution in a template parameter or
11631 in the function type of the function template results in an invalid
11632 type, type deduction fails. [Note: The equivalent substitution in
11633 exception specifications is done only when the function is instanti-
11634 ated, at which point a program is ill-formed if the substitution
11635 results in an invalid type.] */
11637 static tree
11639 tree args,
11640 tsubst_flags_t complain,
11641 tree in_decl)
11642 {
11643 tree return_type;
11645 tree fntype;
11647 /* The TYPE_CONTEXT is not used for function/method types. */
11650 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
11651 failure. */
11655 {
11656 /* Substitute the argument types. */
11668 {
11669 /* DR 1207: 'this' is in scope in the trailing return type. */
11671 }
11673 /* Substitute the return type. */
11677 {
11680 }
11681 }
11682 else
11683 /* Substitute the return type. */
11688 /* DR 486 clarifies that creation of a function type with an
11689 invalid return type is a deduction failure. */
11692 {
11694 {
11697 else
11699 }
11701 }
11702 /* And DR 657. */
11707 {
11708 /* Substitute the argument types. */
11713 }
11715 /* Construct a new type node and return it. */
11717 {
11722 }
11723 else
11724 {
11726 /* Don't pick up extra function qualifiers from the basetype. */
11729 {
11730 /* [temp.deduct]
11732 Type deduction may fail for any of the following
11733 reasons:
11735 -- Attempting to create "pointer to member of T" when T
11736 is not a class type. */
11739 r);
11741 }
11746 }
11753 }
11755 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11756 ARGS into that specification, and return the substituted
11757 specification. If there is no specification, return NULL_TREE. */
11759 static tree
11761 tree args,
11762 tsubst_flags_t complain,
11763 tree in_decl,
11765 {
11766 tree specs;
11767 tree new_specs;
11772 {
11773 /* A noexcept-specifier. */
11778 {
11779 /* Defer instantiation of noexcept-specifiers to avoid
11780 excessive instantiations (c++/49107). */
11783 {
11784 /* We already partially instantiated this member template,
11785 so combine the new args with the old. */
11790 }
11791 else
11792 {
11795 }
11796 }
11797 else
11798 new_specs = tsubst_copy_and_build
11802 }
11804 {
11807 else
11809 {
11810 tree spec;
11815 {
11816 /* Expand the pack expansion type. */
11819 in_decl);
11825 else
11826 {
11827 /* We're substituting into a member template, so
11828 we got a TYPE_PACK_EXPANSION back. Add that
11829 expansion and move on. */
11833 expanded_specs,
11834 complain);
11837 }
11838 }
11841 {
11844 else
11849 complain);
11850 }
11853 }
11854 }
11856 }
11858 /* Take the tree structure T and replace template parameters used
11859 therein with the argument vector ARGS. IN_DECL is an associated
11860 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11861 Issue error and warning messages under control of COMPLAIN. Note
11862 that we must be relatively non-tolerant of extensions here, in
11863 order to preserve conformance; if we allow substitutions that
11864 should not be allowed, we may allow argument deductions that should
11865 not succeed, and therefore report ambiguous overload situations
11866 where there are none. In theory, we could allow the substitution,
11867 but indicate that it should have failed, and allow our caller to
11868 make sure that the right thing happens, but we don't try to do this
11869 yet.
11871 This function is used for dealing with types, decls and the like;
11872 for expressions, use tsubst_expr or tsubst_copy. */
11874 tree
11876 {
11899 else
11904 /* Reuse typedefs. We need to do this to handle dependent attributes,
11905 such as attribute aligned. */
11908 {
11912 {
11913 /* DECL represents an alias template and we want to
11914 instantiate it. */
11918 }
11922 {
11926 }
11931 else
11932 /* The typedef is from a non-template context. */
11936 {
11938 r = cp_build_qualified_type_real
11942 }
11943 else
11944 {
11945 /* We don't have an instantiation yet, so drop the typedef. */
11950 }
11951 }
11964 {
11990 {
11996 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11997 needed. */
12003 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
12004 with TREE_SIDE_EFFECTS that indicates this is not an integral
12005 constant expression. */
12008 {
12011 }
12014 }
12020 {
12033 {
12037 {
12038 /* See through ARGUMENT_PACK_SELECT arguments. */
12040 /* If the selected argument is an expansion E, that most
12041 likely means we were called from
12042 gen_elem_of_pack_expansion_instantiation during the
12043 substituting of pack an argument pack (which Ith
12044 element is a pack expansion, where I is
12045 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
12046 In this case, the Ith element resulting from this
12047 substituting is going to be a pack expansion, which
12048 pattern is the pattern of E. Let's return the
12049 pattern of E, and
12050 gen_elem_of_pack_expansion_instantiation will
12051 build the resulting pack expansion from it. */
12053 {
12054 /* Make sure we aren't throwing away arg info. */
12057 }
12058 }
12059 }
12064 {
12066 /* If ARG is an argument pack, we don't actually want to
12067 perform a substitution here, because substitutions
12068 for argument packs are only done
12069 element-by-element. We can get to this point when
12070 substituting the type of a non-type template
12071 parameter pack, when that type actually contains
12072 template parameter packs from an outer template, e.g.,
12074 template<typename... Types> struct A {
12075 template<Types... Values> struct B { };
12076 }; */
12080 {
12086 return cp_build_qualified_type_real
12088 }
12090 {
12091 /* We are processing a type constructed from a
12092 template template parameter. */
12103 /* Consider this code:
12105 template <template <class> class Template>
12106 struct Internal {
12107 template <class Arg> using Bind = Template<Arg>;
12108 };
12110 template <template <class> class Template, class Arg>
12111 using Instantiate = Template<Arg>; //#0
12113 template <template <class> class Template,
12114 class Argument>
12115 using Bind =
12116 Instantiate<Internal<Template>::template Bind,
12117 Argument>; //#1
12119 When #1 is parsed, the
12120 BOUND_TEMPLATE_TEMPLATE_PARM representing the
12121 parameter `Template' in #0 matches the
12122 UNBOUND_CLASS_TEMPLATE representing the argument
12123 `Internal<Template>::template Bind'; We then want
12124 to assemble the type `Bind<Argument>' that can't
12125 be fully created right now, because
12126 `Internal<Template>' not being complete, the Bind
12127 template cannot be looked up in that context. So
12128 we need to "store" `Bind<Argument>' for later
12129 when the context of Bind becomes complete. Let's
12130 store that in a TYPENAME_TYPE. */
12134 argvec),
12135 typename_type,
12136 complain);
12138 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
12139 are resolving nested-types in the signature of a
12140 member function templates. Otherwise ARG is a
12141 TEMPLATE_DECL and is the real template to be
12142 instantiated. */
12150 complain);
12151 return cp_build_qualified_type_real
12153 }
12154 else
12155 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
12157 }
12160 /* This can happen during the attempted tsubst'ing in
12161 unify. This means that we don't yet have any information
12162 about the template parameter in question. */
12165 /* Early in template argument deduction substitution, we don't
12166 want to reduce the level of 'auto', or it will be confused
12167 with a normal template parm in subsequent deduction. */
12171 /* If we get here, we must have been looking at a parm for a
12172 more deeply nested template. Make a new version of this
12173 template parameter, but with a lower level. */
12175 {
12180 {
12182 r = cp_build_qualified_type_real
12186 }
12187 else
12188 {
12199 /* We have reduced the level of the template
12200 template parameter, but not the levels of its
12201 template parameters, so canonical_type_parameter
12202 will not be able to find the canonical template
12203 template parameter for this level. Thus, we
12204 require structural equality checking to compare
12205 TEMPLATE_TEMPLATE_PARMs. */
12209 else
12213 {
12221 }
12222 }
12231 }
12234 }
12237 {
12245 {
12249 }
12252 {
12256 }
12259 {
12263 }
12269 }
12272 /* We should never be tsubsting a binfo. */
12276 /* A vector of template arguments. */
12282 {
12286 /* [temp.deduct]
12288 Type deduction may fail for any of the following
12289 reasons:
12291 -- Attempting to create a pointer to reference type.
12292 -- Attempting to create a reference to a reference type or
12293 a reference to void.
12295 Core issue 106 says that creating a reference to a reference
12296 during instantiation is no longer a cause for failure. We
12297 only enforce this check in strict C++98 mode. */
12301 {
12304 /* We keep track of the last time we issued this error
12305 message to avoid spewing a ton of messages during a
12306 single bad template instantiation. */
12309 {
12314 else
12317 }
12320 }
12324 {
12326 {
12329 type);
12330 else
12332 type);
12333 }
12335 }
12337 {
12341 }
12343 /* In C++0x, during template argument substitution, when there is an
12344 attempt to create a reference to a reference type, reference
12345 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
12347 "If a template-argument for a template-parameter T names a type
12348 that is a reference to a type A, an attempt to create the type
12349 'lvalue reference to cv T' creates the type 'lvalue reference to
12350 A,' while an attempt to create the type type rvalue reference to
12351 cv T' creates the type T"
12352 */
12353 r = cp_build_reference_type
12356 else
12361 /* Will this ever be needed for TYPE_..._TO values? */
12365 }
12367 {
12370 {
12371 /* [temp.deduct]
12373 Type deduction may fail for any of the following
12374 reasons:
12376 -- Attempting to create "pointer to member of T" when T
12377 is not a class type. */
12381 }
12383 {
12387 }
12389 {
12393 }
12396 {
12397 /* The type of the implicit object parameter gets its
12398 cv-qualifiers from the FUNCTION_TYPE. */
12399 tree memptr;
12400 tree method_type
12405 complain);
12406 }
12407 else
12410 complain);
12411 }
12414 {
12415 tree fntype;
12416 tree specs;
12421 /* Substitute the exception specification. */
12429 }
12431 {
12436 /* As an optimization, we avoid regenerating the array type if
12437 it will obviously be the same as T. */
12441 /* These checks should match the ones in create_array_type_for_decl.
12443 [temp.deduct]
12445 The deduction may fail for any of the following reasons:
12447 -- Attempting to create an array with an element type that
12448 is void, a function type, or a reference type, or [DR337]
12449 an abstract class type. */
12455 {
12459 }
12467 {
12470 }
12473 }
12476 {
12486 {
12490 }
12492 {
12493 /* Normally, make_typename_type does not require that the CTX
12494 have complete type in order to allow things like:
12496 template <class T> struct S { typename S<T>::X Y; };
12498 But, such constructs have already been resolved by this
12499 point, so here CTX really should have complete type, unless
12500 it's a partial instantiation. */
12503 {
12507 }
12508 }
12515 {
12518 }
12521 {
12523 {
12527 else
12529 }
12531 {
12535 else
12537 }
12538 }
12540 return cp_build_qualified_type_real
12542 }
12545 {
12557 }
12560 {
12561 tree type;
12577 complain);
12578 }
12581 {
12582 tree type;
12600 else
12601 {
12605 /* In a template ~id could be either a complement expression
12606 or an unqualified-id naming a destructor; if instantiating
12607 it produces an expression, it's not an id-expression or
12608 member access. */
12611 }
12616 }
12619 {
12623 }
12627 {
12629 tree packed_out =
12631 args,
12632 complain,
12633 in_decl);
12636 /* For template nontype argument packs, also substitute into
12637 the type. */
12642 }
12658 /* We should use one of the expression tsubsts for these codes. */
12664 }
12665 }
12667 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12668 type of the expression on the left-hand side of the "." or "->"
12669 operator. */
12671 static tree
12674 {
12675 tree name;
12676 tree qualifying_scope;
12677 tree fns;
12678 tree optype;
12683 /* A baselink indicates a function from a base class. Both the
12684 BASELINK_ACCESS_BINFO and the base class referenced may
12685 indicate bases of the template class, rather than the
12686 instantiated class. In addition, lookups that were not
12687 ambiguous before may be ambiguous now. Therefore, we perform
12688 the lookup again. */
12695 {
12702 }
12710 /* If lookup found a single function, mark it as used at this
12711 point. (If it lookup found multiple functions the one selected
12712 later by overload resolution will be marked as used at that
12713 point.) */
12720 /* Add back the template arguments, if present. */
12725 template_args);
12726 /* Update the conversion operator type. */
12734 qualifying_scope,
12735 object_type);
12737 }
12739 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12740 true if the qualified-id will be a postfix-expression in-and-of
12741 itself; false if more of the postfix-expression follows the
12742 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12743 of "&". */
12745 static tree
12749 {
12750 tree expr;
12751 tree scope;
12752 tree name;
12754 tree template_args;
12759 /* Figure out what name to look up. */
12762 {
12770 }
12771 else
12772 {
12775 }
12777 /* Substitute into the qualifying scope. When there are no ARGS, we
12778 are just trying to simplify a non-dependent expression. In that
12779 case the qualifying scope may be dependent, and, in any case,
12780 substituting will not help. */
12783 {
12786 }
12787 else
12791 {
12796 }
12799 {
12801 {
12802 /* A BIT_NOT_EXPR is used to represent a destructor. */
12804 {
12808 }
12809 else
12812 }
12813 else
12817 {
12819 {
12823 }
12825 }
12826 }
12829 {
12831 scope);
12832 /* Remember that there was a reference to this entity. */
12835 }
12838 {
12844 }
12853 {
12854 expr = (adjust_result_of_qualified_name_lookup
12856 expr = (finish_qualified_id_expr
12860 }
12862 /* Expressions do not generally have reference type. */
12864 /* However, if we're about to form a pointer-to-member, we just
12865 want the referenced member referenced. */
12870 }
12872 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
12873 initializer, DECL is the substituted VAR_DECL. Other arguments are as
12874 for tsubst. */
12876 static tree
12879 {
12886 {
12887 /* If we had an initializer but it
12888 instantiated to nothing,
12889 value-initialize the object. This will
12890 only occur when the initializer was a
12891 pack expansion where the parameter packs
12892 used in that expansion were of length
12893 zero. */
12895 complain);
12898 }
12901 }
12903 /* Like tsubst, but deals with expressions. This function just replaces
12904 template parms; to finish processing the resultant expression, use
12905 tsubst_copy_and_build or tsubst_expr. */
12907 static tree
12909 {
12911 tree r;
12919 {
12924 {
12925 /* We get here for a use of 'this' in an NSDMI. */
12927 && current_function_decl
12931 /* This can happen for a parameter name used later in a function
12932 declaration (such as in a late-specified return type). Just
12933 make a dummy decl, since it's only used for its type. */
12936 /* Give it the template pattern as its context; its true context
12937 hasn't been instantiated yet and this is good enough for
12938 mangling. */
12940 }
12949 {
12950 tree enum_type;
12951 tree v;
12955 /* There is no need to substitute into namespace-scope
12956 enumerators. */
12959 /* If ARGS is NULL, then T is known to be non-dependent. */
12963 /* Unfortunately, we cannot just call lookup_name here.
12964 Consider:
12966 template <int I> int f() {
12967 enum E { a = I };
12968 struct S { void g() { E e = a; } };
12969 };
12971 When we instantiate f<7>::S::g(), say, lookup_name is not
12972 clever enough to find f<7>::a. */
12973 enum_type
12983 /* We didn't find the name. That should never happen; if
12984 name-lookup found it during preliminary parsing, we
12985 should find it again here during instantiation. */
12987 }
12992 {
12993 /* Check for a local specialization set up by
12994 tsubst_pack_expansion. */
12996 {
13000 }
13002 /* When retrieving a capture pack from a generic lambda, remove the
13003 lambda call op's own template argument list from ARGS. Only the
13004 template arguments active for the closure type should be used to
13005 retrieve the pack specialization. */
13011 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
13012 tsubst_decl put in the hash table. */
13014 }
13017 {
13018 tree ctx;
13023 {
13026 {
13030 }
13032 }
13033 }
13042 {
13045 {
13046 /* First try name lookup to find the instantiation. */
13049 {
13050 /* Make sure that the one we found is the one we want. */
13055 }
13059 else
13060 {
13061 /* This can happen for a variable used in a
13062 late-specified return type of a local lambda, or for a
13063 local static or constant. Building a new VAR_DECL
13064 should be OK in all those cases. */
13067 {
13068 /* We can't call cp_finish_decl, so handle the
13069 initializer by hand. */
13080 }
13085 {
13088 at_eof);
13089 else
13091 }
13092 }
13093 /* Remember this for subsequent uses. */
13096 }
13097 }
13098 else
13108 /* An OVERLOAD will always be a non-dependent overload set; an
13109 overload set from function scope will just be represented with an
13110 IDENTIFIER_NODE, and from class scope with a BASELINK. */
13126 {
13127 /* Template template argument like the following example need
13128 special treatment:
13130 template <template <class> class TT> struct C {};
13131 template <class T> struct D {
13132 template <class U> struct E {};
13133 C<E> c; // #1
13134 };
13135 D<int> d; // #2
13137 We are processing the template argument `E' in #1 for
13138 the template instantiation #2. Originally, `E' is a
13139 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
13140 have to substitute this with one having context `D<int>'. */
13144 }
13145 else
13146 /* Ordinary template template argument. */
13157 {
13161 }
13165 {
13175 /* We only want to compute the number of arguments. */
13189 {
13196 else
13199 }
13200 else
13202 }
13204 {
13212 }
13213 /* Fall through */
13229 {
13233 }
13236 {
13237 tree object;
13238 tree name;
13243 {
13247 }
13250 {
13260 }
13265 in_decl);
13266 else
13269 }
13307 {
13311 }
13314 {
13319 }
13322 {
13326 }
13329 {
13337 }
13343 {
13350 }
13353 {
13360 }
13363 {
13370 }
13373 {
13374 /* Substituted template arguments */
13383 }
13386 {
13406 }
13431 /* Fall through. */
13434 {
13437 }
13438 else
13442 /* This is handled by tsubst_copy_and_build. */
13446 {
13450 }
13453 /* We shouldn't have built any of these during initial template
13454 generation. Instead, they should be built during instantiation
13455 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13459 {
13469 }
13487 {
13488 /* Instantiate any typedefs in the type. */
13493 }
13496 /* These can sometimes show up in a partial instantiation, but never
13497 involve template parms. */
13502 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13505 }
13506 }
13508 /* Helper function for tsubst_omp_clauses, used for instantiation of
13509 OMP_CLAUSE_DECL of clauses that handles also OpenMP array sections
13510 represented with TREE_LIST. */
13512 static tree
13514 tree in_decl)
13515 {
13517 {
13518 tree low_bound
13524 in_decl);
13530 }
13532 }
13534 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13536 static tree
13539 {
13543 {
13549 {
13552 {
13558 }
13559 /* FALLTHRU */
13575 in_decl);
13594 {
13597 {
13604 }
13605 else
13607 }
13634 }
13635 }
13641 }
13643 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13645 static tree
13647 tree in_decl)
13648 {
13649 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13669 {
13672 else
13673 {
13677 }
13678 }
13683 #undef RECUR
13684 }
13686 /* Substitute one OMP_FOR iterator. */
13688 static void
13693 {
13694 #define RECUR(NODE) \
13695 tsubst_expr ((NODE), args, complain, in_decl, \
13696 integral_constant_expression_p)
13705 {
13706 /* We need to jump through some hoops to handle declarations in the
13707 for-init-statement, since we might need to handle auto deduction,
13708 but we need to keep control of initialization. */
13712 }
13713 else
13725 {
13727 {
13728 /* Declare the variable, but don't let that initialize it. */
13733 }
13738 {
13743 }
13744 else
13751 }
13754 {
13755 /* Declare and initialize the variable. */
13758 }
13760 {
13761 tree c;
13763 {
13774 }
13776 {
13781 {
13784 }
13785 }
13786 }
13789 {
13793 }
13794 else
13798 {
13809 {
13817 }
13818 else
13824 {
13830 }
13834 {
13842 }
13843 else
13849 }
13855 #undef RECUR
13856 }
13858 /* Like tsubst_copy for expressions, etc. but also does semantic
13859 processing. */
13861 static tree
13864 {
13865 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13866 #define RECUR(NODE) \
13867 tsubst_expr ((NODE), args, complain, in_decl, \
13868 integral_constant_expression_p)
13871 tree r;
13872 location_t loc;
13884 {
13886 {
13887 tree_stmt_iterator i;
13891 }
13906 else
13915 {
13917 tree init;
13923 {
13926 tree decl;
13934 else
13936 }
13938 {
13939 /* Don't build up decls for a variadic capture proxy, we'll
13940 instantiate the elements directly as needed. */
13942 }
13943 else
13944 {
13948 {
13949 /* By marking the declaration as instantiated, we avoid
13950 trying to instantiate it. Since instantiate_decl can't
13951 handle local variables, and since we've already done
13952 all that needs to be done, that's the right thing to
13953 do. */
13958 /* Anonymous aggregates are a special case. */
13961 {
13964 {
13968 }
13970 }
13976 {
13981 }
13982 else
13983 {
13988 {
13989 /* For __PRETTY_FUNCTION__ we have to adjust the
13990 initializer. */
13994 }
13995 else
13999 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
14002 }
14003 }
14004 }
14007 }
14022 {
14032 }
14059 {
14063 }
14071 else
14079 else
14100 {
14104 }
14108 {
14110 tree label;
14115 }
14121 /* Computed goto's must be tsubst'd into. On the other hand,
14122 non-computed gotos must not be; the identifier in question
14123 will have no binding. */
14125 else
14131 {
14147 }
14152 {
14157 }
14158 else
14159 {
14164 else
14171 else
14177 else
14179 }
14183 {
14187 {
14189 /* Prevent instantiate_decl from trying to instantiate
14190 this variable. We've already done all that needs to be
14191 done. */
14194 }
14199 }
14205 {
14206 /* Local classes are not independent templates; they are
14207 instantiated along with their containing function. And this
14208 way we don't have to deal with pushing out of one local class
14209 to instantiate a member of another local class. */
14210 tree fn;
14211 /* Closures are handled by the LAMBDA_EXPR. */
14217 }
14221 {
14222 tree condition;
14225 condition =
14227 args,
14236 }
14261 {
14270 {
14275 }
14287 integral_constant_expression_p);
14296 else
14297 {
14305 }
14308 }
14367 {
14372 {
14375 }
14381 }
14382 else
14383 {
14390 {
14393 }
14396 {
14401 {
14404 }
14410 }
14411 else
14412 {
14416 }
14419 }
14423 {
14429 {
14433 {
14438 }
14442 }
14443 else
14444 {
14449 }
14450 }
14454 {
14458 }
14478 /* If the first operand was a statement, we're done with it. */
14482 complain));
14494 integral_constant_expression_p));
14495 }
14498 out:
14501 #undef RECUR
14502 #undef RETURN
14503 }
14505 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14506 function. For description of the body see comment above
14507 cp_parser_omp_declare_reduction_exprs. */
14509 static void
14511 {
14517 tree_stmt_iterator tsi;
14528 {
14547 }
14549 {
14569 }
14570 }
14572 /* T is a postfix-expression that is not being used in a function
14573 call. Return the substituted version of T. */
14575 static tree
14577 tsubst_flags_t complain,
14578 tree in_decl)
14579 {
14583 else
14589 }
14591 /* Like tsubst but deals with expressions and performs semantic
14592 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14594 tree
14596 tree args,
14597 tsubst_flags_t complain,
14598 tree in_decl,
14601 {
14602 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14603 #define RECUR(NODE) \
14604 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14606 integral_constant_expression_p)
14609 location_t loc;
14618 /* N3276 decltype magic only applies to calls at the top level or on the
14619 right side of a comma. */
14624 {
14627 /* Fall through. */
14629 {
14630 tree decl;
14631 cp_id_kind idk;
14636 {
14639 }
14641 /* Look up the name. */
14644 /* By convention, expressions use ERROR_MARK_NODE to indicate
14645 failure, not NULL_TREE. */
14651 integral_constant_expression_p,
14659 input_location);
14663 {
14667 }
14669 }
14672 {
14673 tree object;
14681 {
14684 }
14685 else
14692 else
14694 }
14697 {
14701 {
14702 /* A type conversion to reference type will be enclosed in
14703 such an indirect ref, but the substitution of the cast
14704 will have also added such an indirect ref. */
14707 }
14708 else
14712 }
14715 {
14719 }
14722 {
14729 flags));
14730 }
14733 {
14737 }
14744 {
14745 tree type;
14751 {
14756 }
14762 {
14780 }
14783 }
14817 else
14819 in_decl);
14854 {
14859 tree r = build_x_binary_op
14861 op0,
14863 ? ERROR_MARK
14865 op1,
14867 ? ERROR_MARK
14875 }
14878 {
14882 }
14895 {
14904 }
14908 /* Fall through */
14911 {
14912 tree r;
14918 {
14919 /* When there are no ARGS, we are trying to evaluate a
14920 non-dependent expression from the parser. Trying to do
14921 the substitutions may not work. */
14924 }
14925 else
14926 {
14931 else
14934 /*integral_constant_expression_p=*/
14938 }
14942 else
14946 {
14948 {
14950 {
14954 }
14955 else
14959 }
14961 }
14963 }
14966 {
14976 }
14992 {
14996 tree r = build_x_modify_expr
14999 /* TREE_NO_WARNING must be set if either the expression was
15000 parenthesized or it uses an operator such as >>= rather
15001 than plain assignment. In the former case, it was already
15002 set and must be copied. In the latter case,
15003 build_x_modify_expr sets it and it must not be reset
15004 here. */
15009 }
15014 /* Remember that there was a reference to this entity. */
15021 {
15026 tree ret;
15030 else
15031 {
15035 }
15037 /* If there was an initializer in the original tree, but it
15038 instantiated to an empty list, then we should pass a
15039 non-NULL empty vector to tell build_new that it was an
15040 empty initializer() rather than no initializer. This can
15041 only happen when the initializer is a pack expansion whose
15042 parameter packs are of length zero. */
15045 else
15046 {
15050 else
15051 {
15054 }
15055 }
15061 complain);
15069 }
15072 {
15078 complain));
15079 }
15082 {
15086 integral_constant_expression_p);
15088 op0,
15091 }
15094 {
15095 tree function;
15100 tree ret;
15103 /* When we parsed the expression, we determined whether or
15104 not Koenig lookup should be performed. */
15107 {
15112 }
15114 {
15115 /* Do nothing; calling tsubst_copy_and_build on an identifier
15116 would incorrectly perform unqualified lookup again.
15118 Note that we can also have an IDENTIFIER_NODE if the earlier
15119 unqualified lookup found a member function; in that case
15120 koenig_p will be false and we do want to do the lookup
15121 again to find the instantiated member function.
15123 FIXME but doing that causes c++/15272, so we need to stop
15124 using IDENTIFIER_NODE in that situation. */
15126 }
15127 else
15128 {
15130 {
15136 }
15137 else
15142 /* Avoid error about taking the address of a constructor. */
15146 in_decl,
15148 integral_constant_expression_p);
15152 }
15157 {
15162 else
15163 {
15164 /* Expand the pack expansion and push each entry onto
15165 CALL_ARGS. */
15168 {
15173 {
15178 }
15179 }
15180 else
15181 {
15182 /* A partial substitution. Add one entry. */
15184 }
15185 }
15186 }
15188 /* We do not perform argument-dependent lookup if normal
15189 lookup finds a non-function, in accordance with the
15190 expected resolution of DR 218. */
15193 /* If lookup found a member function, the Koenig lookup is
15194 not appropriate, even if an unqualified-name was used
15195 to denote the function. */
15198 /* Only do this when substitution turns a dependent call
15199 into a non-dependent call. */
15206 {
15208 {
15209 /* For backwards compatibility and good diagnostics, try
15210 the unqualified lookup again if we aren't in SFINAE
15211 context. */
15212 tree unq = (tsubst_copy_and_build
15214 integral_constant_expression_p));
15219 {
15228 "%qD was not declared in this scope, "
15229 "and no declarations were found by "
15230 "argument-dependent lookup at the point "
15232 {
15236 {
15238 input_location);
15240 "declarations in dependent base %qT are "
15246 else
15250 }
15251 else
15254 }
15256 }
15257 }
15259 {
15264 }
15265 }
15267 /* Remember that there was a reference to this entity. */
15272 /* Put back tf_decltype for the actual call. */
15277 complain);
15279 {
15294 complain);
15295 else
15296 ret = (build_new_method_call
15301 complain));
15302 }
15303 else
15306 koenig_p,
15307 complain);
15312 }
15315 {
15321 {
15323 {
15328 }
15329 else
15330 {
15335 }
15337 }
15338 else
15339 {
15342 }
15346 }
15349 {
15354 input_location));
15355 }
15358 {
15366 {
15367 /* We have pack expansions, so expand those and
15368 create a new list out of it. */
15371 tree chain;
15374 /* Expand the argument expressions. */
15382 /* Build the rest of the list. */
15387 /* Determine the number of arguments. */
15389 {
15392 }
15395 else
15396 {
15397 /* Since we only performed a partial substitution into
15398 the argument pack, we only RETURN (a single list
15399 node. */
15406 }
15408 /* Convert the argument vectors into a TREE_LIST */
15411 {
15412 /* Grab the Ith values. */
15413 i--;
15416 value
15420 /* Build the list (backwards). */
15422 }
15425 }
15441 }
15444 {
15445 tree object;
15446 tree object_type;
15447 tree member;
15448 tree r;
15452 /* Remember that there was a reference to this entity. */
15463 else
15471 {
15473 {
15478 {
15481 }
15483 {
15488 }
15489 }
15490 }
15493 {
15494 /* Lookup the template functions now that we know what the
15495 scope is. */
15503 {
15506 args);
15507 member = (adjust_result_of_qualified_name_lookup
15509 object_type));
15510 }
15511 else
15512 {
15514 input_location);
15516 }
15517 }
15521 {
15523 {
15527 else
15530 }
15532 }
15534 {
15539 }
15543 complain);
15547 }
15554 {
15562 tree r;
15567 /* digest_init will do the wrong thing if we let it. */
15571 /* We do not want to process the index of aggregate
15572 initializers as they are identifier nodes which will be
15573 looked up by digest_init. */
15579 {
15581 /* An identifier index is looked up in the type
15582 being initialized, not the current scope. */
15587 {
15588 /* Substitute into the pack expansion. */
15590 in_decl);
15594 ;
15596 /* Just move the argument into place. */
15598 else
15599 {
15600 /* Update the length of the final CONSTRUCTOR
15601 arguments vector, and note that we will need to
15602 copy.*/
15605 }
15606 }
15607 else
15609 }
15612 {
15617 {
15619 {
15624 }
15625 else
15627 }
15628 }
15638 }
15641 {
15644 {
15647 }
15648 else
15649 {
15652 }
15653 }
15659 {
15660 /* We don't build decls for an instantiation of a
15661 variadic capture proxy, we instantiate the elements
15662 when needed. */
15665 }
15666 /* Fall through */
15669 {
15671 /* ??? We're doing a subset of finish_id_expression here. */
15673 && !processing_template_decl
15674 && !cp_unevaluated_operand
15677 {
15679 /* Replace an evaluated use of the thread_local variable with
15680 a call to its wrapper. */
15682 }
15684 {
15688 }
15691 /* If the original type was a reference, we'll be wrapped in
15692 the appropriate INDIRECT_REF. */
15695 }
15698 {
15702 }
15709 {
15720 }
15723 {
15729 integral_constant_expression_p);
15733 /* If the resulting list of expression statement is empty,
15734 fold it further into void_node. */
15739 }
15742 {
15756 /* For a function scope, we want to use tsubst so that we don't
15757 complain about referring to an auto function before its return
15758 type has been deduced. Otherwise, we want to use tsubst_copy so
15759 that we look up the existing field/parameter/variable rather
15760 than build a new one. */
15765 {
15766 /* Look up the parameter we want directly, as tsubst_copy
15767 doesn't do what we need. */
15773 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15776 }
15777 else
15786 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15788 /* Now that we know visibility, instantiate the type so we have a
15789 declaration of the op() for later calls to lambda_function. */
15795 }
15798 /* We can get here for a constant initializer of non-dependent type.
15799 FIXME stop folding in cp_parser_initializer_clause. */
15800 {
15802 complain);
15804 }
15808 integral_constant_expression_p));
15814 {
15819 complain));
15820 }
15823 /* Handle Objective-C++ constructs, if appropriate. */
15824 {
15825 tree subst
15830 }
15832 }
15834 #undef RECUR
15835 #undef RETURN
15836 out:
15839 }
15841 /* Verify that the instantiated ARGS are valid. For type arguments,
15842 make sure that the type's linkage is ok. For non-type arguments,
15843 make sure they are constants if they are integral or enumerations.
15844 Emit an error under control of COMPLAIN, and return TRUE on error. */
15846 static bool
15848 {
15852 {
15862 }
15864 {
15865 /* [basic.link]: A name with no linkage (notably, the name
15866 of a class or enumeration declared in a local scope)
15867 shall not be used to declare an entity with linkage.
15868 This implies that names with no linkage cannot be used as
15869 template arguments
15871 DR 757 relaxes this restriction for C++0x. */
15876 {
15877 /* DR 488 makes use of a type with no linkage cause
15878 type deduction to fail. */
15880 {
15883 else
15886 }
15888 }
15889 /* In order to avoid all sorts of complications, we do not
15890 allow variably-modified types as template arguments. */
15892 {
15896 }
15897 }
15898 /* Class template and alias template arguments should be OK. */
15900 ;
15901 /* A non-type argument of integral or enumerated type must be a
15902 constant. */
15907 {
15911 }
15913 }
15915 static bool
15917 {
15922 {
15925 }
15929 }
15931 /* We're out of SFINAE context now, so generate diagnostics for the access
15932 errors we saw earlier when instantiating D from TMPL and ARGS. */
15934 static void
15936 {
15948 }
15950 /* Instantiate the indicated variable, function, or alias template TMPL with
15951 the template arguments in TARG_PTR. */
15953 static tree
15955 {
15957 tree fndecl;
15958 tree gen_tmpl;
15959 tree spec;
15967 /* If this function is a clone, handle it specially. */
15969 {
15970 tree spec;
15971 tree clone;
15973 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15974 DECL_CLONED_FUNCTION. */
15980 /* Look for the clone. */
15984 /* We should always have found the clone by now. */
15987 }
15992 /* Check to see if we already have this specialization. */
15995 /* The TMPL is a partial instantiation. To get a full set of
15996 arguments we must add the arguments used to perform the
15997 partial instantiation. */
15999 targ_ptr);
16001 /* It would be nice to avoid hashing here and then again in tsubst_decl,
16002 but it doesn't seem to be on the hot path. */
16011 {
16013 {
16017 }
16019 }
16022 complain))
16025 /* We are building a FUNCTION_DECL, during which the access of its
16026 parameters and return types have to be checked. However this
16027 FUNCTION_DECL which is the desired context for access checking
16028 is not built yet. We solve this chicken-and-egg problem by
16029 deferring all checks until we have the FUNCTION_DECL. */
16032 /* Instantiation of the function happens in the context of the function
16033 template, not the context of the overload resolution we're doing. */
16035 /* If there are dependent arguments, e.g. because we're doing partial
16036 ordering, make sure processing_template_decl stays set. */
16040 {
16044 }
16049 {
16050 /* We need to determine if we're using a partial or explicit
16051 specialization now, because the type of the variable could be
16052 different. */
16058 {
16062 }
16063 }
16065 /* Substitute template parameters to obtain the specialization. */
16072 {
16075 }
16077 /* The DECL_TI_TEMPLATE should always be the immediate parent
16078 template, not the most general template. */
16081 /* Now we know the specialization, compute access previously
16082 deferred. */
16089 /* If we've just instantiated the main entry point for a function,
16090 instantiate all the alternate entry points as well. We do this
16091 by cloning the instantiation of the main entry point, not by
16092 instantiating the template clones. */
16097 {
16099 {
16100 /* Remember to reinstantiate when we're out of SFINAE so the user
16101 can see the errors. */
16103 }
16105 }
16107 }
16109 /* Wrapper for instantiate_template_1. */
16111 tree
16113 {
16114 tree ret;
16119 }
16121 /* Instantiate the alias template TMPL with ARGS. Also push a template
16122 instantiation level, which instantiate_template doesn't do because
16123 functions and variables have sufficient context established by the
16124 callers. */
16126 static tree
16128 {
16135 {
16138 }
16140 args =
16148 /* We can't free this if a pending_template entry or last_error_tinst_level
16149 is pointing at it. */
16155 }
16157 /* PARM is a template parameter pack for FN. Returns true iff
16158 PARM is used in a deducible way in the argument list of FN. */
16160 static bool
16162 {
16165 {
16167 tree packs;
16173 {
16174 /* The template parameter pack is used in a function parameter
16175 pack. If this is the end of the parameter list, the
16176 template parameter pack is deducible. */
16179 else
16180 /* Otherwise, not. Well, it could be deduced from
16181 a non-pack parameter, but doing so would end up with
16182 a deduction mismatch, so don't bother. */
16184 }
16185 }
16186 /* The template parameter pack isn't used in any function parameter
16187 packs, but it might be used deeper, e.g. tuple<Args...>. */
16189 }
16191 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
16192 NARGS elements of the arguments that are being used when calling
16193 it. TARGS is a vector into which the deduced template arguments
16194 are placed.
16196 Returns either a FUNCTION_DECL for the matching specialization of FN or
16197 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
16198 true, diagnostics will be printed to explain why it failed.
16200 If FN is a conversion operator, or we are trying to produce a specific
16201 specialization, RETURN_TYPE is the return type desired.
16203 The EXPLICIT_TARGS are explicit template arguments provided via a
16204 template-id.
16206 The parameter STRICT is one of:
16208 DEDUCE_CALL:
16209 We are deducing arguments for a function call, as in
16210 [temp.deduct.call].
16212 DEDUCE_CONV:
16213 We are deducing arguments for a conversion function, as in
16214 [temp.deduct.conv].
16216 DEDUCE_EXACT:
16217 We are deducing arguments when doing an explicit instantiation
16218 as in [temp.explicit], when determining an explicit specialization
16219 as in [temp.expl.spec], or when taking the address of a function
16220 template, as in [temp.deduct.funcaddr]. */
16222 tree
16224 tree explicit_targs,
16225 tree targs,
16228 tree return_type,
16229 unification_kind_t strict,
16233 {
16234 tree parms;
16235 tree fntype;
16243 tree tinst;
16249 /* In C++0x, it's possible to have a function template whose type depends
16250 on itself recursively. This is most obvious with decltype, but can also
16251 occur with enumeration scope (c++/48969). So we need to catch infinite
16252 recursion and reject the substitution at deduction time; this function
16253 will return error_mark_node for any repeated substitution.
16255 This also catches excessive recursion such as when f<N> depends on
16256 f<N-1> across all integers, and returns error_mark_node for all the
16257 substitutions back up to the initial one.
16259 This is, of course, not reentrant. */
16269 {
16270 /* [temp.deduct]
16272 The specified template arguments must match the template
16273 parameters in kind (i.e., type, nontype, template), and there
16274 must not be more arguments than there are parameters;
16275 otherwise type deduction fails.
16277 Nontype arguments must match the types of the corresponding
16278 nontype template parameters, or must be convertible to the
16279 types of the corresponding nontype parameters as specified in
16280 _temp.arg.nontype_, otherwise type deduction fails.
16282 All references in the function type of the function template
16283 to the corresponding template parameters are replaced by the
16284 specified template argument values. If a substitution in a
16285 template parameter or in the function type of the function
16286 template results in an invalid type, type deduction fails. */
16291 /* Adjust any explicit template arguments before entering the
16292 substitution context. */
16293 explicit_targs
16295 complain,
16301 /* Substitute the explicit args into the function type. This is
16302 necessary so that, for instance, explicitly declared function
16303 arguments can match null pointed constants. If we were given
16304 an incomplete set of explicit args, we must not do semantic
16305 processing during substitution as we could create partial
16306 instantiations. */
16308 {
16313 /* Dig out the actual parm. */
16316 {
16319 }
16321 {
16324 }
16327 /* No explicit argument for this template parameter. */
16331 {
16332 /* Mark the argument pack as "incomplete". We could
16333 still deduce more arguments during unification.
16334 We remove this mark in type_unification_real. */
16336 {
16340 }
16342 /* We have some incomplete argument packs. */
16344 }
16345 }
16349 {
16352 }
16355 /* Ignore any access checks; we'll see them again in
16356 instantiate_template and they might have the wrong
16357 access path at this point. */
16369 /* Place the explicitly specified arguments in TARGS. */
16372 }
16374 /* Never do unification on the 'this' parameter. */
16378 {
16387 }
16389 /* We allow incomplete unification without an error message here
16390 because the standard doesn't seem to explicitly prohibit it. Our
16391 callers must be ready to deal with unification failures in any
16392 event. */
16395 /* If we aren't explaining yet, push tinst context so we can see where
16396 any errors (e.g. from class instantiations triggered by instantiation
16397 of default template arguments) come from. If we are explaining, this
16398 context is redundant. */
16400 {
16403 }
16405 /* type_unification_real will pass back any access checks from default
16406 template argument substitution. */
16418 /* Now that we have bindings for all of the template arguments,
16419 ensure that the arguments deduced for the template template
16420 parameters have compatible template parameter lists. We cannot
16421 check this property before we have deduced all template
16422 arguments, because the template parameter types of a template
16423 template parameter might depend on prior template parameters
16424 deduced after the template template parameter. The following
16425 ill-formed example illustrates this issue:
16427 template<typename T, template<T> class C> void f(C<5>, T);
16429 template<int N> struct X {};
16431 void g() {
16432 f(X<5>(), 5l); // error: template argument deduction fails
16433 }
16435 The template parameter list of 'C' depends on the template type
16436 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
16437 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
16438 time that we deduce 'C'. */
16441 {
16444 }
16446 /* All is well so far. Now, check:
16448 [temp.deduct]
16450 When all template arguments have been deduced, all uses of
16451 template parameters in nondeduced contexts are replaced with
16452 the corresponding deduced argument values. If the
16453 substitution results in an invalid type, as described above,
16454 type deduction fails. */
16457 {
16460 }
16462 /* Also collect access checks from the instantiation. */
16475 /* Now perform any access checks encountered during substitution. */
16482 /* If we're looking for an exact match, check that what we got
16483 is indeed an exact match. It might not be if some template
16484 parameters are used in non-deduced contexts. But don't check
16485 for an exact match if we have dependent template arguments;
16486 in that case we're doing partial ordering, and we already know
16487 that we have two candidates that will provide the actual type. */
16489 {
16493 tree sarg
16499 {
16503 }
16504 }
16508 fail:
16511 {
16513 /* Reset once we're all the way out. */
16515 }
16517 /* We can't free this if a pending_template entry or last_error_tinst_level
16518 is pointing at it. */
16524 }
16526 /* Adjust types before performing type deduction, as described in
16527 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16528 sections are symmetric. PARM is the type of a function parameter
16529 or the return type of the conversion function. ARG is the type of
16530 the argument passed to the call, or the type of the value
16531 initialized with the result of the conversion function.
16532 ARG_EXPR is the original argument expression, which may be null. */
16534 static int
16538 tree arg_expr)
16539 {
16543 {
16548 /* Swap PARM and ARG throughout the remainder of this
16549 function; the handling is precisely symmetric since PARM
16550 will initialize ARG rather than vice versa. */
16555 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16556 too, but here handle it by stripping the reference from PARM
16557 rather than by adding it to ARG. */
16565 /* Nothing else to do in this case. */
16570 }
16573 {
16574 /* [temp.deduct.call]
16576 If P is not a reference type:
16578 --If A is an array type, the pointer type produced by the
16579 array-to-pointer standard conversion (_conv.array_) is
16580 used in place of A for type deduction; otherwise,
16582 --If A is a function type, the pointer type produced by
16583 the function-to-pointer standard conversion
16584 (_conv.func_) is used in place of A for type deduction;
16585 otherwise,
16587 --If A is a cv-qualified type, the top level
16588 cv-qualifiers of A's type are ignored for type
16589 deduction. */
16594 else
16596 }
16598 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16599 of the form T&&, where T is a template parameter, and the argument
16600 is an lvalue, T is deduced as A& */
16606 /* try_one_overload doesn't provide an arg_expr, but
16607 functions are always lvalues. */
16611 /* [temp.deduct.call]
16613 If P is a cv-qualified type, the top level cv-qualifiers
16614 of P's type are ignored for type deduction. If P is a
16615 reference type, the type referred to by P is used for
16616 type deduction. */
16619 {
16622 }
16624 /* DR 322. For conversion deduction, remove a reference type on parm
16625 too (which has been swapped into ARG). */
16630 }
16632 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16633 template which does contain any deducible template parameters; check if
16634 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16635 unify_one_argument. */
16637 static int
16640 {
16641 tree type;
16645 else
16652 {
16656 }
16658 {
16663 }
16667 else
16669 }
16673 /* Returns true iff the expression EXPR is one from which a template
16674 argument can be deduced. In other words, if it's an undecorated
16675 use of a template non-type parameter. */
16677 static bool
16679 {
16681 }
16683 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16684 deducible way; that is, if it has a max value of <PARM> - 1. */
16686 static bool
16688 {
16697 }
16699 /* Returns true iff the template arguments ARGS use a template parameter
16700 in a deducible way. */
16702 static bool
16704 {
16706 {
16711 else
16712 {
16719 else
16721 }
16724 }
16726 }
16728 /* Returns true iff TYPE contains any deducible references to template
16729 parameters, as per 14.8.2.5. */
16731 static bool
16733 {
16737 /* T
16738 cv-list T
16739 TT<T>
16740 TT<i>
16741 TT<> */
16746 /* T*
16747 T&
16748 T&& */
16752 /* T[integer-constant ]
16753 type [i] */
16758 /* T type ::*
16759 type T::*
16760 T T::*
16761 T (type ::*)()
16762 type (T::*)()
16763 type (type ::*)(T)
16764 type (T::*)(T)
16765 T (type ::*)(T)
16766 T (T::*)()
16767 T (T::*)(T) */
16770 || (uses_deducible_template_parms
16773 /* template-name <T> (where template-name refers to a class template)
16774 template-name <i> (where template-name refers to a class template) */
16781 /* type (T)
16782 T()
16783 T(T) */
16786 {
16795 }
16798 }
16800 /* Subroutine of type_unification_real and unify_pack_expansion to
16801 handle unification of a single P/A pair. Parameters are as
16802 for those functions. */
16804 static int
16808 {
16815 /* We can't deduce anything from this, but we might get all the
16816 template args from other function args. */
16819 /* Implicit conversions (Clause 4) will be performed on a function
16820 argument to convert it to the type of the corresponding function
16821 parameter if the parameter type contains no template-parameters that
16822 participate in template argument deduction. */
16825 /* For function parameters with no deducible template parameters,
16826 just return. We'll check non-dependent conversions later. */
16830 {
16832 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16833 | UNIFY_ALLOW_MORE_CV_QUAL
16847 }
16849 /* We only do these transformations if this is the top-level
16850 parameter_type_list in a call or declaration matching; in other
16851 situations (nested function declarators, template argument lists) we
16852 won't be comparing a type to an expression, and we don't do any type
16853 adjustments. */
16855 {
16857 {
16860 {
16861 /* [temp.deduct.type] A template-argument can be
16862 deduced from a pointer to function or pointer
16863 to member function argument if the set of
16864 overloaded functions does not contain function
16865 templates and at most one of a set of
16866 overloaded functions provides a unique
16867 match. */
16874 }
16880 }
16882 arg_strict |=
16884 }
16885 else
16890 /* For deduction from an init-list we need the actual list. */
16894 }
16896 /* Most parms like fn_type_unification.
16898 If SUBR is 1, we're being called recursively (to unify the
16899 arguments of a function or method parameter of a function
16900 template).
16902 CHECKS is a pointer to a vector of access checks encountered while
16903 substituting default template arguments. */
16905 static int
16907 tree targs,
16908 tree xparms,
16912 unification_kind_t strict,
16916 {
16921 tree parms;
16930 /* Reset the number of non-defaulted template arguments contained
16931 in TARGS. */
16934 again:
16942 {
16947 /* For a function parameter pack that occurs at the end of the
16948 parameter-declaration-list, the type A of each remaining
16949 argument of the call is compared with the type P of the
16950 declarator-id of the function parameter pack. */
16956 /* For a function parameter pack that does not occur at the
16957 end of the parameter-declaration-list, the type of the
16958 parameter pack is a non-deduced context. */
16965 explain_p))
16967 }
16972 {
16973 /* Unify the remaining arguments with the pack expansion type. */
16974 tree argvec;
16977 /* Allocate a TREE_VEC and copy in all of the arguments */
16982 /* Copy the parameter into parmvec. */
16988 /* Advance to the end of the list of parameters. */
16990 }
16992 /* Fail if we've reached the end of the parm list, and more args
16993 are present, and the parm list isn't variadic. */
16996 /* Fail if parms are left and they don't have default values and
16997 they aren't all deduced as empty packs (c++/57397). This is
16998 consistent with sufficient_parms_p. */
17001 {
17005 do
17006 {
17009 count++;
17011 }
17015 type_pack_p);
17016 }
17019 {
17020 tsubst_flags_t complain = (explain_p
17021 ? tf_warning_or_error
17025 {
17029 /* Clear the "incomplete" flags on all argument packs now so that
17030 substituting them into later default arguments works. */
17032 {
17035 }
17041 /* If this is an undeduced nontype parameter that depends on
17042 a type parameter, try another pass; its type may have been
17043 deduced from a later argument than the one from which
17044 this parameter can be deduced. */
17048 {
17051 }
17053 /* Core issue #226 (C++0x) [temp.deduct]:
17055 If a template argument has not been deduced, its
17056 default template argument, if any, is used.
17058 When we are in C++98 mode, TREE_PURPOSE will either
17059 be NULL_TREE or ERROR_MARK_NODE, so we do not need
17060 to explicitly check cxx_dialect here. */
17062 /* OK, there is a default argument. Wait until after the
17063 conversion check to do substitution. */
17066 /* If the type parameter is a parameter pack, then it will
17067 be deduced to an empty parameter pack. */
17069 {
17070 tree arg;
17073 {
17077 }
17078 else
17085 }
17088 }
17090 /* DR 1391: All parameters have args, now check non-dependent parms for
17091 convertibility. */
17095 {
17101 /* For a function parameter pack that occurs at the end of the
17102 parameter-declaration-list, the type A of each remaining
17103 argument of the call is compared with the type P of the
17104 declarator-id of the function parameter pack. */
17110 /* For a function parameter pack that does not occur at the
17111 end of the parameter-declaration-list, the type of the
17112 parameter pack is a non-deduced context. */
17121 explain_p))
17123 }
17125 /* Now substitute into the default template arguments. */
17127 {
17153 else
17154 {
17156 /* The position of the first default template argument,
17157 is also the number of non-defaulted arguments in TARGS.
17158 Record that. */
17162 }
17163 }
17167 }
17168 #ifdef ENABLE_CHECKING
17171 #endif
17174 }
17176 /* Subroutine of type_unification_real. Args are like the variables
17177 at the call site. ARG is an overloaded function (or template-id);
17178 we try deducing template args from each of the overloads, and if
17179 only one succeeds, we go with that. Modifies TARGS and returns
17180 true on success. */
17182 static bool
17184 tree targs,
17185 tree parm,
17186 tree arg,
17187 unification_kind_t strict,
17190 {
17197 {
17200 }
17201 else
17205 /* Handle `&x' where `x' is some static or non-static member
17206 function name. */
17212 /* Strip baselink information. */
17217 {
17218 /* If we got some explicit template args, we need to plug them into
17219 the affected templates before we try to unify, in case the
17220 explicit args will completely resolve the templates in question. */
17227 {
17240 {
17245 {
17248 }
17249 }
17252 }
17253 /* If no templates (or more than one) are fully resolved by the
17254 explicit arguments, this template-id is a non-deduced context; it
17255 could still be OK if we deduce all template arguments for the
17256 enclosing call through other arguments. */
17259 }
17262 /* If ARG is, for example, "(0, &f)" then its type will be unknown
17263 -- but the deduction does not succeed because the expression is
17264 not just the function on its own. */
17266 else
17272 {
17275 }
17277 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17278 to function or pointer to member function argument if the set of
17279 overloaded functions does not contain function templates and at most
17280 one of a set of overloaded functions provides a unique match.
17282 So if we found multiple possibilities, we return success but don't
17283 deduce anything. */
17286 {
17290 {
17295 /* Don't forget explicit template arguments in a pack. */
17299 }
17300 }
17305 }
17307 /* Core DR 115: In contexts where deduction is done and fails, or in
17308 contexts where deduction is not done, if a template argument list is
17309 specified and it, along with any default template arguments, identifies
17310 a single function template specialization, then the template-id is an
17311 lvalue for the function template specialization. */
17313 tree
17315 {
17328 {
17331 }
17333 {
17336 }
17338 {
17341 }
17344 {
17348 /* If we got some explicit template args, we need to plug them into
17349 the affected templates before we try to unify, in case the
17350 explicit args will completely resolve the templates in question. */
17358 {
17371 {
17374 {
17377 }
17379 {
17382 }
17383 }
17384 }
17386 {
17394 {
17395 tree base
17398 }
17402 }
17404 /* There were no good options and at least one bad one, so let the
17405 user know what the problem is. */
17407 }
17409 }
17411 /* Subroutine of resolve_overloaded_unification; does deduction for a single
17412 overload. Fills TARGS with any deduced arguments, or error_mark_node if
17413 different overloads deduce different arguments for a given parm.
17414 ADDR_P is true if the expression for which deduction is being
17415 performed was of the form "& fn" rather than simply "fn".
17417 Returns 1 on success. */
17419 static int
17421 tree orig_targs,
17422 tree targs,
17423 tree parm,
17424 tree arg,
17425 unification_kind_t strict,
17429 {
17431 tree tempargs;
17437 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17438 to function or pointer to member function argument if the set of
17439 overloaded functions does not contain function templates and at most
17440 one of a set of overloaded functions provides a unique match.
17442 So if this is a template, just return success. */
17454 /* We don't copy orig_targs for this because if we have already deduced
17455 some template args from previous args, unify would complain when we
17456 try to deduce a template parameter for the same argument, even though
17457 there isn't really a conflict. */
17464 /* First make sure we didn't deduce anything that conflicts with
17465 explicitly specified args. */
17467 {
17474 /* Since we're unifying against ourselves, we will fill in
17475 template args used in the function parm list with our own
17476 template parms. Discard them. */
17480 }
17483 {
17488 }
17491 }
17493 /* PARM is a template class (perhaps with unbound template
17494 parameters). ARG is a fully instantiated type. If ARG can be
17495 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
17496 TARGS are as for unify. */
17498 static tree
17501 {
17502 tree copy_of_targs;
17509 /* We need to make a new template argument vector for the call to
17510 unify. If we used TARGS, we'd clutter it up with the result of
17511 the attempted unification, even if this class didn't work out.
17512 We also don't want to commit ourselves to all the unifications
17513 we've already done, since unification is supposed to be done on
17514 an argument-by-argument basis. In other words, consider the
17515 following pathological case:
17517 template <int I, int J, int K>
17518 struct S {};
17520 template <int I, int J>
17521 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
17523 template <int I, int J, int K>
17524 void f(S<I, J, K>, S<I, I, I>);
17526 void g() {
17527 S<0, 0, 0> s0;
17528 S<0, 1, 2> s2;
17530 f(s0, s2);
17531 }
17533 Now, by the time we consider the unification involving `s2', we
17534 already know that we must have `f<0, 0, 0>'. But, even though
17535 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
17536 because there are two ways to unify base classes of S<0, 1, 2>
17537 with S<I, I, I>. If we kept the already deduced knowledge, we
17538 would reject the possibility I=1. */
17541 /* If unification failed, we're done. */
17547 }
17549 /* Given a template type PARM and a class type ARG, find the unique
17550 base type in ARG that is an instance of PARM. We do not examine
17551 ARG itself; only its base-classes. If there is not exactly one
17552 appropriate base class, return NULL_TREE. PARM may be the type of
17553 a partial specialization, as well as a plain template type. Used
17554 by unify. */
17556 static enum template_base_result
17559 {
17561 tree binfo;
17567 {
17568 /* The type could not be completed. */
17571 }
17573 /* Walk in inheritance graph order. The search order is not
17574 important, and this avoids multiple walks of virtual bases. */
17576 {
17581 {
17582 /* If there is more than one satisfactory baseclass, then:
17584 [temp.deduct.call]
17586 If they yield more than one possible deduced A, the type
17587 deduction fails.
17589 applies. */
17591 {
17594 }
17597 }
17598 }
17602 }
17604 /* Returns the level of DECL, which declares a template parameter. */
17606 static int
17608 {
17610 {
17620 }
17622 }
17624 /* Decide whether ARG can be unified with PARM, considering only the
17625 cv-qualifiers of each type, given STRICT as documented for unify.
17626 Returns nonzero iff the unification is OK on that basis. */
17628 static int
17630 {
17636 {
17637 /* Although a CVR qualifier is ignored when being applied to a
17638 substituted template parameter ([8.3.2]/1 for example), that
17639 does not allow us to unify "const T" with "int&" because both
17640 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17641 It is ok when we're allowing additional CV qualifiers
17642 at the outer level [14.8.2.1]/3,1st bullet. */
17652 }
17663 }
17665 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17666 void
17668 {
17672 {
17675 }
17676 else
17677 {
17680 }
17681 }
17683 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17684 do { \
17685 if (unify (TP, TA, P, A, S, EP)) \
17686 return 1; \
17687 } while (0);
17689 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17690 expansion at the end of PACKED_PARMS. Returns 0 if the type
17691 deduction succeeds, 1 otherwise. STRICT is the same as in
17692 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17693 call argument list. We'll need to adjust the arguments to make them
17694 types. SUBR tells us if this is from a recursive call to
17695 type_unification_real, or for comparing two template argument
17696 lists. */
17698 static int
17702 {
17703 tree parm
17713 /* Determine the parameter packs we will be deducing from the
17714 pattern, and record their current deductions. */
17717 {
17721 /* Determine the index and level of this parameter pack. */
17724 /* Keep track of the parameter packs and their corresponding
17725 argument packs. */
17728 }
17730 /* Loop through all of the arguments that have not yet been
17731 unified and unify each with the pattern. */
17733 {
17734 tree parm;
17738 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17739 or the element of its argument pack at the current index if
17740 this argument was explicitly specified. */
17742 {
17751 {
17754 }
17756 }
17758 /* If we had explicit template arguments, substitute them into the
17759 pattern before deduction. */
17761 {
17762 /* Some arguments might still be unspecified or dependent. */
17770 NULL_TREE);
17775 }
17776 else
17779 /* Unify the pattern with the current argument. */
17781 explain_p))
17784 /* For each parameter pack, collect the deduced value. */
17786 {
17792 }
17793 }
17795 /* Verify that the results of unification with the parameter packs
17796 produce results consistent with what we've seen before, and make
17797 the deduced argument packs available. */
17799 {
17806 /* By default keep the original deduced argument pack.
17807 If necessary, more specific code is going to update the
17808 resulting deduced argument later down in this function. */
17812 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17813 actually deduce anything. */
17821 {
17822 /* If we had fewer function args than explicit template args,
17823 just use the explicits. */
17828 }
17831 {
17832 tree result;
17833 /* Build the deduced *_ARGUMENT_PACK. */
17835 {
17840 }
17841 else
17846 /* Note the deduced argument packs for this parameter
17847 pack. */
17849 }
17853 {
17854 /* We only had the explicitly-provided arguments before, but
17855 now we have a complete set of arguments. */
17861 }
17862 else
17863 {
17869 /* Inconsistent unification of this parameter pack. */
17871 bad_old_arg,
17872 bad_new_arg);
17873 }
17874 }
17877 }
17879 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17880 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17881 parameters and return value are as for unify. */
17883 static int
17887 {
17888 tree parm_max;
17889 tree arg_max;
17893 /* Our representation of array types uses "N - 1" as the
17894 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17895 not an integer constant. We cannot unify arbitrarily
17896 complex expressions, so we eliminate the MINUS_EXPRs
17897 here. */
17901 {
17904 }
17908 {
17909 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17910 trying to unify the type of a variable with the type
17911 of a template parameter. For example:
17913 template <unsigned int N>
17914 void f (char (&) [N]);
17915 int g();
17916 void h(int i) {
17917 char a[g(i)];
17918 f(a);
17919 }
17921 Here, the type of the ARG will be "int [g(i)]", and
17922 may be a SAVE_EXPR, etc. */
17926 }
17928 /* If only one of the bounds used a MINUS_EXPR, compensate
17929 by adding one to the other bound. */
17932 integer_type_node,
17933 parm_max,
17934 integer_one_node);
17937 integer_type_node,
17938 arg_max,
17939 integer_one_node);
17943 }
17945 /* Deduce the value of template parameters. TPARMS is the (innermost)
17946 set of template parameters to a template. TARGS is the bindings
17947 for those template parameters, as determined thus far; TARGS may
17948 include template arguments for outer levels of template parameters
17949 as well. PARM is a parameter to a template function, or a
17950 subcomponent of that parameter; ARG is the corresponding argument.
17951 This function attempts to match PARM with ARG in a manner
17952 consistent with the existing assignments in TARGS. If more values
17953 are deduced, then TARGS is updated.
17955 Returns 0 if the type deduction succeeds, 1 otherwise. The
17956 parameter STRICT is a bitwise or of the following flags:
17958 UNIFY_ALLOW_NONE:
17959 Require an exact match between PARM and ARG.
17960 UNIFY_ALLOW_MORE_CV_QUAL:
17961 Allow the deduced ARG to be more cv-qualified (by qualification
17962 conversion) than ARG.
17963 UNIFY_ALLOW_LESS_CV_QUAL:
17964 Allow the deduced ARG to be less cv-qualified than ARG.
17965 UNIFY_ALLOW_DERIVED:
17966 Allow the deduced ARG to be a template base class of ARG,
17967 or a pointer to a template base class of the type pointed to by
17968 ARG.
17969 UNIFY_ALLOW_INTEGER:
17970 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17971 case for more information.
17972 UNIFY_ALLOW_OUTER_LEVEL:
17973 This is the outermost level of a deduction. Used to determine validity
17974 of qualification conversions. A valid qualification conversion must
17975 have const qualified pointers leading up to the inner type which
17976 requires additional CV quals, except at the outer level, where const
17977 is not required [conv.qual]. It would be normal to set this flag in
17978 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17979 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17980 This is the outermost level of a deduction, and PARM can be more CV
17981 qualified at this point.
17982 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17983 This is the outermost level of a deduction, and PARM can be less CV
17984 qualified at this point. */
17986 static int
17989 {
17991 tree targ;
17992 tree tparm;
17995 /* I don't think this will do the right thing with respect to types.
17996 But the only case I've seen it in so far has been array bounds, where
17997 signedness is the only information lost, and I think that will be
17998 okay. */
18006 /* We can't deduce anything from this, but we might get all the
18007 template args from other function args. */
18010 /* If PARM uses template parameters, then we can't bail out here,
18011 even if ARG == PARM, since we won't record unifications for the
18012 template parameters. We might need them if we're trying to
18013 figure out which of two things is more specialized. */
18017 /* Handle init lists early, so the rest of the function can assume
18018 we're dealing with a type. */
18020 {
18025 /* Replace T with std::initializer_list<T> for deduction. */
18032 /* We can only deduce from an initializer list argument if the
18033 parameter is std::initializer_list or an array; otherwise this
18034 is a non-deduced context. */
18039 else
18040 {
18042 /* Deduction is defined in terms of a single type, so just punt
18043 on the (bizarre) std::initializer_list<T...>. */
18046 }
18049 {
18056 {
18060 /* It should only be possible to get here for a call. */
18062 elt_strict |= maybe_adjust_types_for_deduction
18065 }
18068 explain_p);
18069 }
18073 {
18074 /* Also deduce from the length of the initializer list. */
18081 }
18083 /* If the std::initializer_list<T> deduction worked, replace the
18084 deduced A with std::initializer_list<A>. */
18086 {
18091 }
18093 }
18095 /* Immediately reject some pairs that won't unify because of
18096 cv-qualification mismatches. */
18099 /* It is the elements of the array which hold the cv quals of an array
18100 type, and the elements might be template type parms. We'll check
18101 when we recurse. */
18103 /* We check the cv-qualifiers when unifying with template type
18104 parameters below. We want to allow ARG `const T' to unify with
18105 PARM `T' for example, when computing which of two templates
18106 is more specialized, for example. */
18120 {
18124 /* In a type which contains a nested-name-specifier, template
18125 argument values cannot be deduced for template parameters used
18126 within the nested-name-specifier. */
18138 /* The PARM is not one we're trying to unify. Just check
18139 to see if it matches ARG. */
18140 {
18145 else
18147 }
18154 /* Check for mixed types and values. */
18162 {
18163 /* ARG must be constructed from a template class or a template
18164 template parameter. */
18168 {
18170 /* An alias template name is never deduced. */
18175 tree parm_parms
18176 = DECL_INNERMOST_TEMPLATE_PARMS
18181 /* The resolution to DR150 makes clear that default
18182 arguments for an N-argument may not be used to bind T
18183 to a template template parameter with fewer than N
18184 parameters. It is not safe to permit the binding of
18185 default arguments as an extension, as that may change
18186 the meaning of a conforming program. Consider:
18188 struct Dense { static const unsigned int dim = 1; };
18190 template <template <typename> class View,
18191 typename Block>
18192 void operator+(float, View<Block> const&);
18194 template <typename Block,
18195 unsigned int Dim = Block::dim>
18196 struct Lvalue_proxy { operator float() const; };
18198 void
18199 test_1d (void) {
18200 Lvalue_proxy<Dense> p;
18201 float b;
18202 b + p;
18203 }
18205 Here, if Lvalue_proxy is permitted to bind to View, then
18206 the global operator+ will be used; if they are not, the
18207 Lvalue_proxy will be converted to float. */
18209 full_argvec,
18211 (explain_p
18212 ? tf_warning_or_error
18219 /* Deduce arguments T, i from TT<T> or TT<i>.
18220 We check each element of PARMVEC and ARGVEC individually
18221 rather than the whole TREE_VEC since they can have
18222 different number of elements. */
18229 /* Check if the parameters end in a pack, making them
18230 variadic. */
18236 /* If the template argument list of P contains a pack
18237 expansion that is not the last template argument, the
18238 entire template argument list is a non-deduced
18239 context. */
18248 {
18253 }
18258 DEDUCE_EXACT,
18261 }
18264 /* Fall through to deduce template name. */
18265 }
18269 {
18270 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
18272 /* Simple cases: Value already set, does match or doesn't. */
18277 }
18278 else
18279 {
18280 /* If PARM is `const T' and ARG is only `int', we don't have
18281 a match unless we are allowing additional qualification.
18282 If ARG is `const int' and PARM is just `T' that's OK;
18283 that binds `const int' to `T'. */
18288 /* Consider the case where ARG is `const volatile int' and
18289 PARM is `const T'. Then, T should be `volatile int'. */
18290 arg = cp_build_qualified_type_real
18295 /* Simple cases: Value already set, does match or doesn't. */
18301 /* Make sure that ARG is not a variable-sized array. (Note
18302 that were talking about variable-sized arrays (like
18303 `int[n]'), rather than arrays of unknown size (like
18304 `int[]').) We'll get very confused by such a type since
18305 the bound of the array is not constant, and therefore
18306 not mangleable. Besides, such types are not allowed in
18307 ISO C++, so we can do as we please here. We do allow
18308 them for 'auto' deduction, since that isn't ABI-exposed. */
18312 /* Strip typedefs as in convert_template_argument. */
18314 }
18316 /* If ARG is a parameter pack or an expansion, we cannot unify
18317 against it unless PARM is also a parameter pack. */
18322 /* If the argument deduction results is a METHOD_TYPE,
18323 then there is a problem.
18324 METHOD_TYPE doesn't map to any real C++ type the result of
18325 the deduction can not be of that type. */
18339 {
18340 /* The PARM is not one we're trying to unify. Just check
18341 to see if it matches ARG. */
18347 }
18353 {
18358 }
18360 /* [temp.deduct.type] If, in the declaration of a function template
18361 with a non-type template-parameter, the non-type
18362 template-parameter is used in an expression in the function
18363 parameter-list and, if the corresponding template-argument is
18364 deduced, the template-argument type shall match the type of the
18365 template-parameter exactly, except that a template-argument
18366 deduced from an array bound may be of any integral type.
18367 The non-type parameter might use already deduced type parameters. */
18370 /* Template-parameter dependent expression. Just accept it for now.
18371 It will later be processed in convert_template_argument. */
18372 ;
18377 /* Convert the ARG to the type of PARM; the deduced non-type
18378 template argument must exactly match the types of the
18379 corresponding parameter. */
18382 /* We haven't deduced the type of this parameter yet. Try again
18383 later. */
18385 else
18388 /* If ARG is a parameter pack or an expansion, we cannot unify
18389 against it unless PARM is also a parameter pack. */
18394 {
18397 }
18402 {
18403 /* A pointer-to-member constant can be unified only with
18404 another constant. */
18408 /* Just unify the class member. It would be useless (and possibly
18409 wrong, depending on the strict flags) to unify also
18410 PTRMEM_CST_CLASS, because we want to be sure that both parm and
18411 arg refer to the same variable, even if through different
18412 classes. For instance:
18414 struct A { int x; };
18415 struct B : A { };
18417 Unification of &A::x and &B::x must succeed. */
18420 }
18423 {
18427 /* [temp.deduct.call]
18429 A can be another pointer or pointer to member type that can
18430 be converted to the deduced A via a qualification
18431 conversion (_conv.qual_).
18433 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
18434 This will allow for additional cv-qualification of the
18435 pointed-to types if appropriate. */
18438 /* The derived-to-base conversion only persists through one
18439 level of pointers. */
18444 }
18476 /* We have already checked cv-qualification at the top of the
18477 function. */
18481 /* As far as unification is concerned, this wins. Later checks
18482 will invalidate it if necessary. */
18485 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
18486 /* Type INTEGER_CST can come from ordinary constant template args. */
18498 {
18508 /* Check for pack expansions in the parameters. */
18510 {
18512 {
18514 /* We can unify against something with a trailing
18515 parameter pack. */
18517 else
18518 /* [temp.deduct.type]/9: If the template argument list of
18519 P contains a pack expansion that is not the last
18520 template argument, the entire template argument list
18521 is a non-deduced context. */
18523 }
18524 }
18526 /* If we don't have enough arguments to satisfy the parameters
18527 (not counting the pack expression at the end), or we have
18528 too many arguments for a parameter list that doesn't end in
18529 a pack expression, we can't unify. */
18535 /* Unify all of the parameters that precede the (optional)
18536 pack expression. */
18538 {
18543 }
18546 DEDUCE_EXACT,
18549 }
18557 {
18565 }
18570 {
18574 {
18575 /* First, we try to unify the PARM and ARG directly. */
18580 {
18581 /* Fallback to the special case allowed in
18582 [temp.deduct.call]:
18584 If P is a class, and P has the form
18585 template-id, then A can be a derived class of
18586 the deduced A. Likewise, if P is a pointer to
18587 a class of the form template-id, A can be a
18588 pointer to a derived class pointed to by the
18589 deduced A. */
18596 }
18597 }
18601 /* Perhaps PARM is something like S<U> and ARG is S<int>.
18602 Then, we should unify `int' and `U'. */
18604 else
18605 /* There's no chance of unification succeeding. */
18610 }
18617 {
18620 tree a;
18626 /* CV qualifications for methods can never be deduced, they must
18627 match exactly. We need to check them explicitly here,
18628 because type_unification_real treats them as any other
18629 cv-qualified parameter. */
18631 && (!check_cv_quals_for_unify
18651 }
18654 /* Unify a pointer to member with a pointer to member function, which
18655 deduces the type of the member as a function type. */
18657 {
18658 /* Check top-level cv qualifiers */
18666 /* Determine the type of the function we are unifying against. */
18670 }
18689 /* Matched cases are handled by the ARG == PARM test above. */
18693 /* A non-type template parameter that is a variable should be a
18694 an integral constant, in which case, it whould have been
18695 folded into its (constant) value. So we should not be getting
18696 a variable here. */
18707 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18708 or UNDERLYING_TYPE nodes. */
18712 /* Unification fails if we hit an error node. */
18717 {
18722 }
18723 /* FALLTHRU */
18726 /* An unresolved overload is a nondeduced context. */
18731 /* We must be looking at an expression. This can happen with
18732 something like:
18734 template <int I>
18735 void foo(S<I>, S<I + 2>);
18737 This is a "nondeduced context":
18739 [deduct.type]
18741 The nondeduced contexts are:
18743 --A type that is a template-id in which one or more of
18744 the template-arguments is an expression that references
18745 a template-parameter.
18747 In these cases, we assume deduction succeeded, but don't
18748 actually infer any unifications. */
18753 else
18755 }
18756 }
18757 #undef RECUR_AND_CHECK_FAILURE
18758 \f
18759 /* Note that DECL can be defined in this translation unit, if
18760 required. */
18762 static void
18764 {
18765 tree clone;
18769 }
18771 /* Called if RESULT is explicitly instantiated, or is a member of an
18772 explicitly instantiated class. */
18774 void
18776 {
18779 /* If this entity has already been written out, it's too late to
18780 make any modifications. */
18784 /* For anonymous namespace we don't need to do anything. */
18786 {
18789 }
18792 /* The TREE_PUBLIC flag for function declarations will have been
18793 set correctly by tsubst. */
18796 /* This might have been set by an earlier implicit instantiation. */
18801 else
18802 {
18805 /* Always make artificials weak. */
18808 /* For WIN32 we also want to put explicit instantiations in
18809 linkonce sections. */
18812 }
18814 /* If EXTERN_P, then this function will not be emitted -- unless
18815 followed by an explicit instantiation, at which point its linkage
18816 will be adjusted. If !EXTERN_P, then this function will be
18817 emitted here. In neither circumstance do we want
18818 import_export_decl to adjust the linkage. */
18820 }
18822 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18823 important template arguments. If any are missing, we check whether
18824 they're important by using error_mark_node for substituting into any
18825 args that were used for partial ordering (the ones between ARGS and END)
18826 and seeing if it bubbles up. */
18828 static bool
18830 {
18835 {
18838 }
18840 {
18844 }
18846 }
18848 /* Given two function templates PAT1 and PAT2, return:
18850 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18851 -1 if PAT2 is more specialized than PAT1.
18852 0 if neither is more specialized.
18854 LEN indicates the number of parameters we should consider
18855 (defaulted parameters should not be considered).
18857 The 1998 std underspecified function template partial ordering, and
18858 DR214 addresses the issue. We take pairs of arguments, one from
18859 each of the templates, and deduce them against each other. One of
18860 the templates will be more specialized if all the *other*
18861 template's arguments deduce against its arguments and at least one
18862 of its arguments *does* *not* deduce against the other template's
18863 corresponding argument. Deduction is done as for class templates.
18864 The arguments used in deduction have reference and top level cv
18865 qualifiers removed. Iff both arguments were originally reference
18866 types *and* deduction succeeds in both directions, an lvalue reference
18867 wins against an rvalue reference and otherwise the template
18868 with the more cv-qualified argument wins for that pairing (if
18869 neither is more cv-qualified, they both are equal). Unlike regular
18870 deduction, after all the arguments have been deduced in this way,
18871 we do *not* verify the deduced template argument values can be
18872 substituted into non-deduced contexts.
18874 The logic can be a bit confusing here, because we look at deduce1 and
18875 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18876 can find template arguments for pat1 to make arg1 look like arg2, that
18877 means that arg2 is at least as specialized as arg1. */
18879 int
18881 {
18894 /* Remove the this parameter from non-static member functions. If
18895 one is a non-static member function and the other is not a static
18896 member function, remove the first parameter from that function
18897 also. This situation occurs for operator functions where we
18898 locate both a member function (with this pointer) and non-member
18899 operator (with explicit first operand). */
18901 {
18906 }
18908 {
18911 {
18912 len--;
18914 }
18915 }
18917 /* If only one is a conversion operator, they are unordered. */
18921 /* Consider the return type for a conversion function */
18923 {
18926 len++;
18927 }
18929 processing_template_decl++;
18935 /* Stop when an ellipsis is seen. */
18937 {
18948 {
18949 /* When both arguments are pack expansions, we need only
18950 unify the patterns themselves. */
18954 /* This is the last comparison we need to do. */
18956 }
18959 {
18963 }
18966 {
18970 }
18976 {
18982 /* Setup the parameter vector, which contains only ARG1. */
18985 /* Setup the argument vector, which contains the remaining
18986 arguments. */
18995 /* We cannot deduce in the other direction, because ARG1 is
18996 a pack expansion but ARG2 is not. */
18998 }
19000 {
19006 /* Setup the parameter vector, which contains only ARG1. */
19009 /* Setup the argument vector, which contains the remaining
19010 arguments. */
19019 /* We cannot deduce in the other direction, because ARG2 is
19020 a pack expansion but ARG1 is not.*/
19022 }
19024 else
19025 {
19026 /* The normal case, where neither argument is a pack
19027 expansion. */
19034 }
19036 /* If we couldn't deduce arguments for tparms1 to make arg1 match
19037 arg2, then arg2 is not as specialized as arg1. */
19043 /* "If, for a given type, deduction succeeds in both directions
19044 (i.e., the types are identical after the transformations above)
19045 and both P and A were reference types (before being replaced with
19046 the type referred to above):
19047 - if the type from the argument template was an lvalue reference and
19048 the type from the parameter template was not, the argument type is
19049 considered to be more specialized than the other; otherwise,
19050 - if the type from the argument template is more cv-qualified
19051 than the type from the parameter template (as described above),
19052 the argument type is considered to be more specialized than the other;
19053 otherwise,
19054 - neither type is more specialized than the other." */
19057 {
19059 {
19062 else
19064 }
19066 {
19071 }
19072 }
19075 /* We've failed to deduce something in either direction.
19076 These must be unordered. */
19081 /* We have already processed all of the arguments in our
19082 handing of the pack expansion type. */
19087 }
19089 /* "In most cases, all template parameters must have values in order for
19090 deduction to succeed, but for partial ordering purposes a template
19091 parameter may remain without a value provided it is not used in the
19092 types being used for partial ordering."
19094 Thus, if we are missing any of the targs1 we need to substitute into
19095 origs1, then pat2 is not as specialized as pat1. This can happen when
19096 there is a nondeduced context. */
19102 processing_template_decl--;
19104 /* All things being equal, if the next argument is a pack expansion
19105 for one function but not for the other, prefer the
19106 non-variadic function. FIXME this is bogus; see c++/41958. */
19110 {
19113 }
19119 else
19121 }
19123 /* Determine which of two partial specializations of TMPL is more
19124 specialized.
19126 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
19127 to the first partial specialization. The TREE_PURPOSE is the
19128 innermost set of template parameters for the partial
19129 specialization. PAT2 is similar, but for the second template.
19131 Return 1 if the first partial specialization is more specialized;
19132 -1 if the second is more specialized; 0 if neither is more
19133 specialized.
19135 See [temp.class.order] for information about determining which of
19136 two templates is more specialized. */
19138 static int
19140 {
19141 tree targs;
19152 /* Just like what happens for functions, if we are ordering between
19153 different template specializations, we may encounter dependent
19154 types in the arguments, and we need our dependency check functions
19155 to behave correctly. */
19159 {
19162 }
19166 {
19169 }
19172 /* In the case of a tie where at least one of the templates
19173 has a parameter pack at the end, the template with the most
19174 non-packed parameters wins. */
19176 && any_deductions
19179 {
19185 /* We don't count the pack expansion at the end. */
19195 }
19198 }
19200 /* Return the template arguments that will produce the function signature
19201 DECL from the function template FN, with the explicit template
19202 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
19203 also match. Return NULL_TREE if no satisfactory arguments could be
19204 found. */
19206 static tree
19208 {
19212 tree decl_arg_types;
19215 tree arg;
19219 /* Never do unification on the 'this' parameter. */
19240 }
19242 /* Return the innermost template arguments that, when applied to a partial
19243 specialization of TMPL whose innermost template parameters are
19244 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
19245 ARGS.
19247 For example, suppose we have:
19249 template <class T, class U> struct S {};
19250 template <class T> struct S<T*, int> {};
19252 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
19253 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
19254 int}. The resulting vector will be {double}, indicating that `T'
19255 is bound to `double'. */
19257 static tree
19259 {
19261 tree deduced_args;
19262 tree innermost_deduced_args;
19266 {
19270 innermost_deduced_args);
19271 }
19272 else
19285 /* Verify that nondeduced template arguments agree with the type
19286 obtained from argument deduction.
19288 For example:
19290 struct A { typedef int X; };
19291 template <class T, class U> struct C {};
19292 template <class T> struct C<T, typename T::X> {};
19294 Then with the instantiation `C<A, int>', we can deduce that
19295 `T' is `A' but unify () does not check whether `typename T::X'
19296 is `int'. */
19302 /* We only need to check the innermost arguments; the other
19303 arguments will always agree. */
19308 /* Now that we have bindings for all of the template arguments,
19309 ensure that the arguments deduced for the template template
19310 parameters have compatible template parameter lists. See the use
19311 of template_template_parm_bindings_ok_p in fn_type_unification
19312 for more information. */
19317 }
19319 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
19320 Return the TREE_LIST node with the most specialized template, if
19321 any. If there is no most specialized template, the error_mark_node
19322 is returned.
19324 Note that this function does not look at, or modify, the
19325 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
19326 returned is one of the elements of INSTANTIATIONS, callers may
19327 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
19328 and retrieve it from the value returned. */
19330 tree
19332 {
19339 {
19345 fate--;
19350 fate++;
19355 {
19356 /* Equally specialized, move to next function. If there
19357 is no next function, nothing's most specialized. */
19362 }
19363 }
19366 /* Now verify that champ is better than everything earlier in the
19367 instantiation list. */
19375 {
19378 }
19380 processing_template_decl--;
19386 }
19388 /* If DECL is a specialization of some template, return the most
19389 general such template. Otherwise, returns NULL_TREE.
19391 For example, given:
19393 template <class T> struct S { template <class U> void f(U); };
19395 if TMPL is `template <class U> void S<int>::f(U)' this will return
19396 the full template. This function will not trace past partial
19397 specializations, however. For example, given in addition:
19399 template <class T> struct S<T*> { template <class U> void f(U); };
19401 if TMPL is `template <class U> void S<int*>::f(U)' this will return
19402 `template <class T> template <class U> S<T*>::f(U)'. */
19404 tree
19406 {
19408 {
19411 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
19412 template friend, or a FIELD_DECL for a capture pack. */
19415 }
19417 /* Look for more and more general templates. */
19419 {
19420 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
19421 (See cp-tree.h for details.) */
19430 /* Stop if we run into an explicitly specialized class template. */
19437 }
19440 }
19442 /* Return the most specialized of the template partial specializations
19443 which can produce TARGET, a specialization of some class or variable
19444 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
19445 a TEMPLATE_DECL node corresponding to the partial specialization, while
19446 the TREE_PURPOSE is the set of template arguments that must be
19447 substituted into the template pattern in order to generate TARGET.
19449 If the choice of partial specialization is ambiguous, a diagnostic
19450 is issued, and the error_mark_node is returned. If there are no
19451 partial specializations matching TARGET, then NULL_TREE is
19452 returned, indicating that the primary template should be used. */
19454 static tree
19456 {
19458 tree t;
19459 tree champ;
19466 {
19470 }
19472 {
19475 }
19477 {
19481 }
19482 else
19487 /* For determining which partial specialization to use, only the
19488 innermost args are interesting. */
19490 {
19493 }
19496 {
19497 tree partial_spec_args;
19498 tree spec_args;
19506 {
19507 /* Discard the outer levels of args, and then substitute in the
19508 template args from the enclosing class. */
19510 partial_spec_args = tsubst_template_args
19513 /* And the same for the partial specialization TEMPLATE_DECL. */
19515 }
19517 partial_spec_args =
19519 partial_spec_args,
19533 partial_spec_args,
19534 args);
19536 {
19541 }
19542 }
19552 {
19555 ;
19556 else
19557 {
19559 {
19562 {
19565 }
19566 }
19568 }
19569 }
19573 {
19576 {
19579 }
19580 }
19583 {
19590 else
19594 {
19599 }
19602 }
19605 }
19607 /* Explicitly instantiate DECL. */
19609 void
19611 {
19616 /* An error occurred, for which grokdeclarator has already issued
19617 an appropriate message. */
19620 {
19623 }
19629 {
19630 /* There is an asymmetry here in the way VAR_DECLs and
19631 FUNCTION_DECLs are handled by grokdeclarator. In the case of
19632 the latter, the DECL we get back will be marked as a
19633 template instantiation, and the appropriate
19634 DECL_TEMPLATE_INFO will be set up. This does not happen for
19635 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
19636 should handle VAR_DECLs as it currently handles
19637 FUNCTION_DECLs. */
19639 {
19642 }
19645 {
19648 }
19650 {
19655 }
19656 }
19658 {
19661 }
19662 else
19665 /* Check for various error cases. Note that if the explicit
19666 instantiation is valid the RESULT will currently be marked as an
19667 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19668 until we get here. */
19671 {
19672 /* DR 259 [temp.spec].
19674 Both an explicit instantiation and a declaration of an explicit
19675 specialization shall not appear in a program unless the explicit
19676 instantiation follows a declaration of the explicit specialization.
19678 For a given set of template parameters, if an explicit
19679 instantiation of a template appears after a declaration of an
19680 explicit specialization for that template, the explicit
19681 instantiation has no effect. */
19683 }
19685 {
19686 /* [temp.spec]
19688 No program shall explicitly instantiate any template more
19689 than once.
19691 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19692 the first instantiation was `extern' and the second is not,
19693 and EXTERN_P for the opposite case. */
19696 /* If an "extern" explicit instantiation follows an ordinary
19697 explicit instantiation, the template is instantiated. */
19700 }
19702 {
19705 }
19707 {
19710 }
19713 ;
19715 {
19718 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19721 }
19722 else
19730 }
19732 static void
19734 {
19740 {
19743 }
19744 }
19746 /* Called from do_type_instantiation through binding_table_foreach to
19747 do recursive instantiation for the type bound in ENTRY. */
19748 static void
19750 {
19756 }
19758 /* Called from do_type_instantiation to instantiate a member
19759 (a member function or a static member variable) of an
19760 explicitly instantiated class template. */
19761 static void
19763 {
19768 }
19770 /* Perform an explicit instantiation of template class T. STORAGE, if
19771 non-null, is the RID for extern, inline or static. COMPLAIN is
19772 nonzero if this is called from the parser, zero if called recursively,
19773 since the standard is unclear (as detailed below). */
19775 void
19777 {
19787 {
19788 tree tmpl =
19792 else
19795 }
19800 {
19803 t);
19805 }
19808 {
19810 {
19812 {
19815 "ISO C++ 1998 forbids the use of %<extern%> on "
19817 }
19818 else
19820 "ISO C++ forbids the use of %qE"
19822 }
19830 else
19831 {
19833 storage);
19835 }
19836 }
19839 {
19840 /* DR 259 [temp.spec].
19842 Both an explicit instantiation and a declaration of an explicit
19843 specialization shall not appear in a program unless the explicit
19844 instantiation follows a declaration of the explicit specialization.
19846 For a given set of template parameters, if an explicit
19847 instantiation of a template appears after a declaration of an
19848 explicit specialization for that template, the explicit
19849 instantiation has no effect. */
19851 }
19853 {
19854 /* [temp.spec]
19856 No program shall explicitly instantiate any template more
19857 than once.
19859 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19860 instantiation was `extern'. If EXTERN_P then the second is.
19861 These cases are OK. */
19868 /* If we've already instantiated the template, just return now. */
19871 }
19879 {
19880 tree tmp;
19882 /* In contrast to implicit instantiation, where only the
19883 declarations, and not the definitions, of members are
19884 instantiated, we have here:
19886 [temp.explicit]
19888 The explicit instantiation of a class template specialization
19889 implies the instantiation of all of its members not
19890 previously explicitly specialized in the translation unit
19891 containing the explicit instantiation.
19893 Of course, we can't instantiate member template classes, since
19894 we don't have any arguments for them. Note that the standard
19895 is unclear on whether the instantiation of the members are
19896 *explicit* instantiations or not. However, the most natural
19897 interpretation is that it should be an explicit instantiation. */
19912 }
19913 }
19915 /* Given a function DECL, which is a specialization of TMPL, modify
19916 DECL to be a re-instantiation of TMPL with the same template
19917 arguments. TMPL should be the template into which tsubst'ing
19918 should occur for DECL, not the most general template.
19920 One reason for doing this is a scenario like this:
19922 template <class T>
19923 void f(const T&, int i);
19925 void g() { f(3, 7); }
19927 template <class T>
19928 void f(const T& t, const int i) { }
19930 Note that when the template is first instantiated, with
19931 instantiate_template, the resulting DECL will have no name for the
19932 first parameter, and the wrong type for the second. So, when we go
19933 to instantiate the DECL, we regenerate it. */
19935 static void
19937 {
19938 /* The arguments used to instantiate DECL, from the most general
19939 template. */
19940 tree args;
19941 tree code_pattern;
19946 /* Make sure that we can see identifiers, and compute access
19947 correctly. */
19951 {
19952 tree decl_parm;
19953 tree pattern_parm;
19954 tree specs;
19968 specs);
19970 /* Merge parameter declarations. */
19973 pattern_parm
19977 {
19978 tree parm_type;
19979 tree attributes;
19984 NULL_TREE);
19990 {
19993 }
19996 }
19997 /* Merge any parameters that match with the function parameter
19998 pack. */
20000 {
20002 tree expanded_types;
20003 /* Expand the TYPE_PACK_EXPANSION that provides the types for
20004 the parameters in this function parameter pack. */
20009 {
20010 tree parm_type;
20011 tree attributes;
20014 /* Rename the parameter to include the index. */
20023 {
20026 }
20028 }
20029 }
20030 /* Merge additional specifiers from the CODE_PATTERN. */
20034 }
20036 {
20044 }
20045 else
20049 }
20051 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
20052 substituted to get DECL. */
20054 tree
20056 {
20059 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
20060 for the instantiation. This is not always the most general
20061 template. Consider, for example:
20063 template <class T>
20064 struct S { template <class U> void f();
20065 template <> void f<int>(); };
20067 and an instantiation of S<double>::f<int>. We want TD to be the
20068 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
20070 more general template. */
20072 /* We must also deal with friend templates. Given:
20074 template <class T> struct S {
20075 template <class U> friend void f() {};
20076 };
20078 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
20079 so far as the language is concerned, but that's still
20080 where we get the pattern for the instantiation from. On
20081 other hand, if the definition comes outside the class, say:
20083 template <class T> struct S {
20084 template <class U> friend void f();
20085 };
20086 template <class U> friend void f() {}
20088 we don't need to look any further. That's what the check for
20089 DECL_INITIAL is for. */
20093 {
20094 /* The present template, TD, should not be a definition. If it
20095 were a definition, we should be using it! Note that we
20096 cannot restructure the loop to just keep going until we find
20097 a template with a definition, since that might go too far if
20098 a specialization was declared, but not defined. */
20100 /* Fetch the more general template. */
20102 }
20105 }
20107 /* Returns true if we need to instantiate this template instance even if we
20108 know we aren't going to emit it.. */
20110 bool
20112 {
20113 /* We always instantiate inline functions so that we can inline them. An
20114 explicit instantiation declaration prohibits implicit instantiation of
20115 non-inline functions. With high levels of optimization, we would
20116 normally inline non-inline functions -- but we're not allowed to do
20117 that for "extern template" functions. Therefore, we check
20118 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
20122 /* And we need to instantiate static data members so that
20123 their initializers are available in integral constant
20124 expressions. */
20127 }
20129 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
20130 instantiate it now, modifying TREE_TYPE (fn). */
20132 void
20134 {
20137 /* Don't instantiate a noexcept-specification from template context. */
20152 {
20156 {
20171 }
20172 else
20176 }
20179 {
20182 else
20184 }
20185 }
20187 /* Produce the definition of D, a _DECL generated from a template. If
20188 DEFER_OK is nonzero, then we don't have to actually do the
20189 instantiation now; we just have to do it sometime. Normally it is
20190 an error if this is an explicit instantiation but D is undefined.
20191 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
20192 explicitly instantiated class template. */
20194 tree
20197 {
20199 tree gen_args;
20200 tree args;
20201 tree td;
20202 tree code_pattern;
20203 tree spec;
20204 tree gen_tmpl;
20211 tree fn_context;
20214 /* This function should only be used to instantiate templates for
20215 functions and static member variables. */
20218 /* Variables are never deferred; if instantiation is required, they
20219 are instantiated right away. That allows for better code in the
20220 case that an expression refers to the value of the variable --
20221 if the variable has a constant value the referring expression can
20222 take advantage of that fact. */
20227 /* Don't instantiate cloned functions. Instead, instantiate the
20228 functions they cloned. */
20236 /* D has already been instantiated or explicitly specialized, so
20237 there's nothing for us to do here.
20239 It might seem reasonable to check whether or not D is an explicit
20240 instantiation, and, if so, stop here. But when an explicit
20241 instantiation is deferred until the end of the compilation,
20242 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
20243 the instantiation. */
20246 /* Check to see whether we know that this template will be
20247 instantiated in some other file, as with "extern template"
20248 extension. */
20251 /* In general, we do not instantiate such templates. */
20259 /* We should already have the extra args. */
20262 /* And what's in the hash table should match D. */
20266 /* This needs to happen before any tsubsting. */
20272 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
20273 for the instantiation. */
20277 /* We should never be trying to instantiate a member of a class
20278 template or partial specialization. */
20283 /* In the case of a friend template whose definition is provided
20284 outside the class, we may have too many arguments. Drop the
20285 ones we don't need. The same is true for specializations. */
20286 args = get_innermost_template_args
20288 else
20292 {
20297 }
20298 else
20299 {
20302 }
20304 /* We may be in the middle of deferred access check. Disable it now. */
20307 /* Unless an explicit instantiation directive has already determined
20308 the linkage of D, remember that a definition is available for
20309 this entity. */
20319 /* If D is a member of an explicitly instantiated class template,
20320 and no definition is available, treat it like an implicit
20321 instantiation. */
20324 {
20325 /* Leave linkage flags alone on instantiations with anonymous
20326 visibility. */
20328 {
20331 }
20333 }
20335 /* Defer all other templates, unless we have been explicitly
20336 forbidden from doing so. */
20338 template. */
20339 ! pattern_defined
20340 /* If it's OK to postpone instantiation, do so. */
20341 || defer_ok
20342 /* If this is a static data member that will be defined
20343 elsewhere, we don't want to instantiate the entire data
20344 member, but we do want to instantiate the initializer so that
20345 we can substitute that elsewhere. */
20347 /* Handle here a deleted function too, avoid generating
20348 its body (c++/61080). */
20350 {
20351 /* The definition of the static data member is now required so
20352 we must substitute the initializer. */
20356 {
20357 tree ns;
20358 tree init;
20367 args,
20370 /* If instantiating the initializer involved instantiating this
20371 again, don't call cp_finish_decl twice. */
20373 {
20374 /* Make sure the initializer is still constant, in case of
20375 circular dependency (template/instantiate6.C). */
20376 const_init
20380 LOOKUP_ONLYCONVERTING);
20381 }
20385 }
20387 /* We restore the source position here because it's used by
20388 add_pending_template. */
20394 /* [temp.explicit]
20396 The definition of a non-exported function template, a
20397 non-exported member function template, or a non-exported
20398 member function or static data member of a class template
20399 shall be present in every translation unit in which it is
20400 explicitly instantiated. */
20404 /* If we're in unevaluated context, we just wanted to get the
20405 constant value; this isn't an odr use, so don't queue
20406 a full instantiation. */
20409 /* ??? Historically, we have instantiated inline functions, even
20410 when marked as "extern template". */
20414 }
20415 /* Tell the repository that D is available in this translation unit
20416 -- and see if it is supposed to be instantiated here. */
20418 {
20419 /* In a PCH file, despite the fact that the repository hasn't
20420 requested instantiation in the PCH it is still possible that
20421 an instantiation will be required in a file that includes the
20422 PCH. */
20425 /* Instantiate inline functions so that the inliner can do its
20426 job, even though we'll not be emitting a copy of this
20427 function. */
20430 }
20436 else
20437 {
20442 }
20444 /* Mark D as instantiated so that recursive calls to
20445 instantiate_decl do not try to instantiate it again. */
20448 /* Regenerate the declaration in case the template has been modified
20449 by a subsequent redeclaration. */
20452 /* We already set the file and line above. Reset them now in case
20453 they changed as a result of calling regenerate_decl_from_template. */
20457 {
20458 tree init;
20461 /* Clear out DECL_RTL; whatever was there before may not be right
20462 since we've reset the type of the declaration. */
20466 /* The initializer is placed in DECL_INITIAL by
20467 regenerate_decl_from_template so we don't need to
20468 push/pop_access_scope again here. Pull it out so that
20469 cp_finish_decl can process it. */
20474 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
20475 initializer. That function will defer actual emission until
20476 we have a chance to determine linkage. */
20479 /* Enter the scope of D so that access-checking works correctly. */
20492 }
20496 {
20498 tree subst_decl;
20499 tree tmpl_parm;
20500 tree spec_parm;
20503 /* Save away the current list, in case we are instantiating one
20504 template from within the body of another. */
20507 /* Set up the list of local specializations. */
20510 /* Set up context. */
20514 else
20517 /* Some typedefs referenced from within the template code need to be
20518 access checked at template instantiation time, i.e now. These
20519 types were added to the template at parsing time. Let's get those
20520 and perform the access checks then. */
20522 gen_args);
20524 /* Create substitution entries for the parameters. */
20529 {
20533 }
20535 {
20537 {
20540 }
20541 else
20542 {
20543 /* Register the (value) argument pack as a specialization of
20544 TMPL_PARM, then move on. */
20547 }
20548 }
20551 /* Substitute into the body of the function. */
20555 else
20556 {
20561 /* Set the current input_location to the end of the function
20562 so that finish_function knows where we are. */
20563 input_location
20566 /* Remember if we saw an infinite loop in the template. */
20567 current_function_infinite_loop
20569 }
20571 /* We don't need the local specializations any more. */
20575 /* Finish the function. */
20579 else
20580 {
20583 }
20587 }
20589 /* We're not deferring instantiation any more. */
20597 out:
20607 }
20609 /* Run through the list of templates that we wish we could
20610 instantiate, and instantiate any we can. RETRIES is the
20611 number of times we retry pending template instantiation. */
20613 void
20615 {
20619 /* Instantiating templates may trigger vtable generation. This in turn
20620 may require further template instantiations. We place a limit here
20621 to avoid infinite loop. */
20623 {
20627 "template instantiation depth exceeds maximum of %d"
20628 " instantiating %q+D, possibly from virtual table generation"
20632 /* Pretend that we defined it. */
20635 }
20637 do
20638 {
20643 {
20648 {
20649 tree fn;
20652 {
20656 fn;
20664 }
20667 }
20668 else
20669 {
20672 {
20673 instantiation
20679 }
20683 }
20686 /* If INSTANTIATION has been instantiated, then we don't
20687 need to consider it again in the future. */
20689 else
20690 {
20693 }
20696 }
20698 }
20702 }
20704 /* Substitute ARGVEC into T, which is a list of initializers for
20705 either base class or a non-static data member. The TREE_PURPOSEs
20706 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20707 instantiate_decl. */
20709 static tree
20711 {
20715 {
20716 tree decl;
20717 tree init;
20723 {
20724 tree expr;
20725 tree arg;
20727 /* Expand the base class expansion type into separate base
20728 classes. */
20730 tf_warning_or_error,
20731 NULL_TREE);
20735 /* We'll be building separate TREE_LISTs of arguments for
20736 each base. */
20742 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20743 expand each argument in the TREE_VALUE of t. */
20750 /* VOID_TYPE_NODE is used to indicate
20751 value-initialization. */
20752 {
20755 }
20756 else
20757 {
20758 /* Substitute parameter packs into each argument in the
20759 TREE_LIST. */
20762 {
20763 tree expanded_exprs;
20765 /* Expand the argument. */
20767 expanded_exprs
20769 tf_warning_or_error,
20770 NULL_TREE);
20774 /* Prepend each of the expanded expressions to the
20775 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20777 {
20782 }
20783 }
20786 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20787 since we built them backwards. */
20789 {
20792 }
20793 }
20794 }
20797 {
20799 {
20803 }
20804 else
20805 {
20806 tree tmp;
20821 /* If we had an initializer but it instantiated to nothing,
20822 value-initialize the object. This will only occur when
20823 the initializer was a pack expansion where the parameter
20824 packs used in that expansion were of length zero. */
20827 }
20830 {
20834 }
20835 }
20836 }
20838 }
20840 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20842 static void
20844 {
20849 else
20851 }
20853 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20854 is the instantiation (which should have been created with
20855 start_enum) and ARGS are the template arguments to use. */
20857 static void
20859 {
20860 tree e;
20866 {
20867 tree value;
20868 tree decl;
20871 /* Note that in a template enum, the TREE_VALUE is the
20872 CONST_DECL, not the corresponding INTEGER_CST. */
20877 /* Give this enumeration constant the correct access. */
20880 /* Actually build the enumerator itself. Here we're assuming that
20881 enumerators can't have dependent attributes. */
20884 }
20894 }
20896 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20897 its type -- but without substituting the innermost set of template
20898 arguments. So, innermost set of template parameters will appear in
20899 the type. */
20901 tree
20903 {
20904 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
20906 }
20908 /* Return truthvalue if we're processing a template different from
20909 the last one involved in diagnostics. */
20910 bool
20912 {
20914 }
20916 /* Remember current template involved in diagnostics. */
20917 void
20919 {
20921 }
20925 {
20927 }
20929 /* Return TRUE if current_function_decl is being instantiated, false
20930 otherwise. */
20932 bool
20934 {
20937 }
20939 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20940 type. Return zero for ok, nonzero for disallowed. Issue error and
20941 warning messages under control of COMPLAIN. */
20943 static int
20945 {
20962 {
20965 else
20967 type);
20968 }
20970 }
20972 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20973 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20975 static bool
20977 {
20978 tree scope;
20980 /* [temp.dep.type]
20982 A type is dependent if it is:
20984 -- a template parameter. Template template parameters are types
20985 for us (since TYPE_P holds true for them) so we handle
20986 them here. */
20990 /* -- a qualified-id with a nested-name-specifier which contains a
20991 class-name that names a dependent type or whose unqualified-id
20992 names a dependent type. */
20995 /* -- a cv-qualified type where the cv-unqualified type is
20996 dependent.
20997 No code is necessary for this bullet; the code below handles
20998 cv-qualified types, and we don't want to strip aliases with
20999 TYPE_MAIN_VARIANT because of DR 1558. */
21000 /* -- a compound type constructed from any dependent type. */
21010 {
21011 tree arg_type;
21016 arg_type;
21021 }
21022 /* -- an array type constructed from any dependent type or whose
21023 size is specified by a constant expression that is
21024 value-dependent.
21026 We checked for type- and value-dependence of the bounds in
21027 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
21029 {
21034 }
21036 /* -- a template-id in which either the template name is a template
21037 parameter ... */
21040 /* ... or any of the template arguments is a dependent type or
21041 an expression that is type-dependent or value-dependent. */
21043 && (any_dependent_template_arguments_p
21046 /* For an alias template specialization, check the arguments both to the
21047 class template and the alias template. */
21051 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
21052 dependent; if the argument of the `typeof' expression is not
21053 type-dependent, then it should already been have resolved. */
21059 /* A template argument pack is dependent if any of its packed
21060 arguments are. */
21062 {
21068 }
21070 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
21071 be template parameters. */
21075 /* The standard does not specifically mention types that are local
21076 to template functions or local classes, but they should be
21077 considered dependent too. For example:
21079 template <int I> void f() {
21080 enum E { a = I };
21081 S<sizeof (E)> s;
21082 }
21084 The size of `E' cannot be known until the value of `I' has been
21085 determined. Therefore, `E' must be considered dependent. */
21089 /* Don't use type_dependent_expression_p here, as it can lead
21090 to infinite recursion trying to determine whether a lambda
21091 nested in a lambda is dependent (c++/47687). */
21095 && (any_dependent_template_arguments_p
21099 /* Other types are non-dependent. */
21101 }
21103 /* Returns TRUE if TYPE is dependent, in the sense of
21104 [temp.dep.type]. Note that a NULL type is considered dependent. */
21106 bool
21108 {
21109 /* If there are no template parameters in scope, then there can't be
21110 any dependent types. */
21112 {
21113 /* If we are not processing a template, then nobody should be
21114 providing us with a dependent type. */
21118 }
21120 /* If the type is NULL, we have not computed a type for the entity
21121 in question; in that case, the type is dependent. */
21125 /* Erroneous types can be considered non-dependent. */
21129 /* If we have not already computed the appropriate value for TYPE,
21130 do so now. */
21132 {
21135 }
21138 }
21140 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
21141 lookup. In other words, a dependent type that is not the current
21142 instantiation. */
21144 bool
21146 {
21149 }
21151 /* T is a SCOPE_REF; return whether we need to consider it
21152 instantiation-dependent so that we can check access at instantiation
21153 time even though we know which member it resolves to. */
21155 static bool
21157 {
21163 else
21165 }
21167 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
21168 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
21169 expression. */
21171 /* Note that this predicate is not appropriate for general expressions;
21172 only constant expressions (that satisfy potential_constant_expression)
21173 can be tested for value dependence. */
21175 bool
21177 {
21181 /* A name declared with a dependent type. */
21186 {
21188 /* A name that has not been looked up -- must be dependent. */
21192 /* A non-type template parm. */
21196 /* A non-type template parm. */
21202 /* A constant with literal type and is initialized
21203 with an expression that is value-dependent.
21205 Note that a non-dependent parenthesized initializer will have
21206 already been replaced with its constant value, so if we see
21207 a TREE_LIST it must be dependent. */
21211 /* cp_finish_decl doesn't fold reference initializers. */
21222 /* These expressions are value-dependent if the type to which
21223 the cast occurs is dependent or the expression being casted
21224 is value-dependent. */
21225 {
21231 /* A functional cast has a list of operands. */
21234 {
21235 /* If there are no operands, it must be an expression such
21236 as "int()". This should not happen for aggregate types
21237 because it would form non-constant expressions. */
21242 }
21248 }
21253 /* FALLTHRU */
21256 /* A `sizeof' expression is value-dependent if the operand is
21257 type-dependent or is a pack expansion. */
21266 /* An 'encode' expression is value-dependent if the operand is
21267 type-dependent. */
21276 /* All instantiation-dependent expressions should also be considered
21277 value-dependent. */
21285 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
21286 is value-dependent. */
21287 {
21296 }
21299 {
21303 }
21314 {
21318 }
21321 {
21328 {
21330 /* In a call to a constexpr member function, look through the
21331 implicit ADDR_EXPR on the object argument so that it doesn't
21332 cause the call to be considered value-dependent. We also
21333 look through it in potential_constant_expression. */
21340 }
21342 }
21345 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
21346 type-dependent. */
21350 {
21352 tree val;
21359 }
21362 /* Treat a GNU statement expression as dependent to avoid crashing
21363 under instantiate_non_dependent_expr; it can't be constant. */
21367 /* A constant expression is value-dependent if any subexpression is
21368 value-dependent. */
21370 {
21377 {
21381 {
21384 /* In some cases, some of the operands may be missing.l
21385 (For example, in the case of PREDECREMENT_EXPR, the
21386 amount to increment by may be missing.) That doesn't
21387 make the expression dependent. */
21390 }
21391 }
21395 }
21397 }
21399 /* The expression is not value-dependent. */
21401 }
21403 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
21404 [temp.dep.expr]. Note that an expression with no type is
21405 considered dependent. Other parts of the compiler arrange for an
21406 expression with type-dependent subexpressions to have no type, so
21407 this function doesn't have to be fully recursive. */
21409 bool
21411 {
21418 /* An unresolved name is always dependent. */
21422 /* Some expression forms are never type-dependent. */
21435 /* The types of these expressions depends only on the type to which
21436 the cast occurs. */
21445 /* The types of these expressions depends only on the type created
21446 by the expression. */
21449 {
21450 /* For NEW_EXPR tree nodes created inside a template, either
21451 the object type itself or a TREE_LIST may appear as the
21452 operand 1. */
21455 /* This is an array type. We need to check array dimensions
21456 as well. */
21458 || value_dependent_expression_p
21460 else
21462 }
21465 {
21469 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
21470 contains an identifier associated by name lookup with one or more
21471 declarations declared with a dependent type, or...a
21472 nested-name-specifier or qualified-id that names a member of an
21473 unknown specialization. */
21476 }
21481 && (any_dependent_template_arguments_p
21493 {
21494 tree elt;
21498 {
21501 }
21503 }
21505 /* A static data member of the current instantiation with incomplete
21506 array type is type-dependent, as the definition and specializations
21507 can have different bounds. */
21514 /* An array of unknown bound depending on a variadic parameter, eg:
21516 template<typename... Args>
21517 void foo (Args... args)
21518 {
21519 int arr[] = { args... };
21520 }
21522 template<int... vals>
21523 void bar ()
21524 {
21525 int arr[] = { vals... };
21526 }
21528 If the array has no length and has an initializer, it must be that
21529 we couldn't determine its length in cp_complete_array_type because
21530 it is dependent. */
21537 /* A variable template specialization is type-dependent if it has any
21538 dependent template arguments. */
21545 /* Always dependent, on the number of arguments if nothing else. */
21550 {
21555 {
21561 }
21562 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
21567 {
21572 }
21575 {
21580 }
21585 {
21589 }
21591 }
21596 }
21598 /* walk_tree callback function for instantiation_dependent_expression_p,
21599 below. Returns non-zero if a dependent subexpression is found. */
21601 static tree
21604 {
21606 {
21607 /* We don't have to worry about decltype currently because decltype
21608 of an instantiation-dependent expr is a dependent type. This
21609 might change depending on the resolution of DR 1172. */
21612 }
21615 {
21616 /* Don't treat an argument list as dependent just because it has no
21617 TREE_TYPE. */
21624 /* A constant with a dependent initializer is dependent. */
21632 /* Handle expressions with type operands. */
21637 {
21642 {
21645 else
21646 {
21649 }
21650 }
21652 }
21664 /* In a template, finish_class_member_access_expr creates a
21665 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21666 type-dependent, so that we can check access control at
21667 instantiation time (PR 42277). See also Core issue 1273. */
21674 else
21677 /* Treat statement-expressions as dependent. */
21683 }
21687 else
21689 }
21691 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21692 sense defined by the ABI:
21694 "An expression is instantiation-dependent if it is type-dependent
21695 or value-dependent, or it has a subexpression that is type-dependent
21696 or value-dependent." */
21698 bool
21700 {
21701 tree result;
21712 }
21714 /* Like type_dependent_expression_p, but it also works while not processing
21715 a template definition, i.e. during substitution or mangling. */
21717 bool
21719 {
21725 }
21727 /* Returns TRUE if ARGS contains a type-dependent expression. */
21729 bool
21731 {
21733 tree arg;
21736 {
21739 }
21741 }
21743 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21744 expressions) contains any type-dependent expressions. */
21746 bool
21748 {
21754 }
21756 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21757 expressions) contains any value-dependent expressions. */
21759 bool
21761 {
21767 }
21769 /* Returns TRUE if the ARG (a template argument) is dependent. */
21771 bool
21773 {
21777 /* Assume a template argument that was wrongly written by the user
21778 is dependent. This is consistent with what
21779 any_dependent_template_arguments_p [that calls this function]
21780 does. */
21791 {
21795 {
21798 }
21801 }
21804 else
21807 }
21809 /* Returns true if ARGS (a collection of template arguments) contains
21810 any types that require structural equality testing. */
21812 bool
21814 {
21824 {
21827 {
21833 {
21834 /* Look inside the argument pack. */
21837 }
21840 {
21853 }
21854 }
21855 }
21858 }
21860 /* Returns true if ARGS (a collection of template arguments) contains
21861 any dependent arguments. */
21863 bool
21865 {
21875 {
21880 }
21883 }
21885 /* Returns TRUE if the template TMPL is dependent. */
21887 bool
21889 {
21891 {
21893 {
21897 }
21899 }
21901 /* Template template parameters are dependent. */
21905 /* So are names that have not been looked up. */
21908 /* So are member templates of dependent classes. */
21912 }
21914 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21916 bool
21918 {
21921 }
21923 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21924 is dependent. */
21926 bool
21928 {
21935 {
21956 {
21960 }
21964 {
21968 {
21973 }
21974 }
21975 }
21978 }
21980 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21981 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21982 no such TYPE can be found. Note that this function peers inside
21983 uninstantiated templates and therefore should be used only in
21984 extremely limited situations. ONLY_CURRENT_P restricts this
21985 peering to the currently open classes hierarchy (which is required
21986 when comparing types). */
21988 tree
21990 {
21991 tree scope;
21992 tree name;
21993 tree decl;
21995 tree pushed_scope;
21996 tree result;
22001 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
22002 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
22003 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
22004 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
22005 identifier of the TYPENAME_TYPE anymore.
22006 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
22007 TYPENAME_TYPE instead, we avoid messing up with a possible
22008 typedef variant case. */
22011 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
22012 it first before we can figure out what NAME refers to. */
22014 {
22016 /* Given a class template A with a dependent base with nested type C,
22017 typedef typename A::C::C C will land us here, as trying to resolve
22018 the initial A::C leads to the local C typedef, which leads back to
22019 A::C::C. So we break the recursion now. */
22021 else
22023 }
22024 /* If we don't know what SCOPE refers to, then we cannot resolve the
22025 TYPENAME_TYPE. */
22028 /* If the SCOPE is a template type parameter, we have no way of
22029 resolving the name. */
22032 /* If the SCOPE is not the current instantiation, there's no reason
22033 to look inside it. */
22036 /* If this is a typedef, we don't want to look inside (c++/11987). */
22039 /* If SCOPE isn't the template itself, it will not have a valid
22040 TYPE_FIELDS list. */
22042 /* scope is either the template itself or a compatible instantiation
22043 like X<T>, so look up the name in the original template. */
22045 else
22046 /* scope is a partial instantiation, so we can't do the lookup or we
22047 will lose the template arguments. */
22049 /* Enter the SCOPE so that name lookup will be resolved as if we
22050 were in the class definition. In particular, SCOPE will no
22051 longer be considered a dependent type. */
22053 /* Look up the declaration. */
22055 tf_warning_or_error);
22059 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
22060 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
22065 {
22069 }
22072 {
22073 tree tmpl;
22074 tree args;
22075 /* Obtain the template and the arguments. */
22078 /* Instantiate the template. */
22084 }
22086 /* Leave the SCOPE. */
22090 /* If we failed to resolve it, return the original typename. */
22094 /* If lookup found a typename type, resolve that too. */
22096 {
22097 /* Ill-formed programs can cause infinite recursion here, so we
22098 must catch that. */
22102 }
22104 /* Qualify the resulting type. */
22110 }
22112 /* EXPR is an expression which is not type-dependent. Return a proxy
22113 for EXPR that can be used to compute the types of larger
22114 expressions containing EXPR. */
22116 tree
22118 {
22119 tree inner_expr;
22121 #ifdef ENABLE_CHECKING
22122 /* Try to get a constant value for all non-dependent expressions in
22123 order to expose bugs in *_dependent_expression_p and constexpr. */
22126 #endif
22128 /* Preserve OVERLOADs; the functions must be available to resolve
22129 types. */
22140 /* There is no need to return a proxy for a variable. */
22143 /* Preserve string constants; conversions from string constants to
22144 "char *" are allowed, even though normally a "const char *"
22145 cannot be used to initialize a "char *". */
22148 /* Preserve void and arithmetic constants, as an optimization -- there is no
22149 reason to create a new node. */
22154 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
22155 There is at least one place where we want to know that a
22156 particular expression is a throw-expression: when checking a ?:
22157 expression, there are special rules if the second or third
22158 argument is a throw-expression. */
22162 /* Don't wrap an initializer list, we need to be able to look inside. */
22166 /* Don't wrap a dummy object, we need to be able to test for it. */
22185 /* If the type is unknown, it can't really be non-dependent */
22188 /* Otherwise, build a NON_DEPENDENT_EXPR. */
22190 }
22192 /* ARGS is a vector of expressions as arguments to a function call.
22193 Replace the arguments with equivalent non-dependent expressions.
22194 This modifies ARGS in place. */
22196 void
22198 {
22200 tree arg;
22203 {
22207 }
22208 }
22210 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
22211 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
22212 parms. */
22214 static tree
22216 {
22229 }
22231 tree
22233 {
22235 }
22237 tree
22239 {
22241 }
22243 /* Given type ARG, return std::initializer_list<ARG>. */
22245 static tree
22247 {
22248 tree std_init_list = namespace_binding
22250 tree argvec;
22252 {
22256 }
22261 }
22263 /* Replace auto in TYPE with std::initializer_list<auto>. */
22265 static tree
22267 {
22274 }
22276 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
22277 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
22279 tree
22281 {
22282 tree targs;
22288 /* Defining a subset of type-dependent expressions that we can deduce
22289 from ahead of time isn't worth the trouble. */
22292 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
22293 with either a new invented type template parameter U or, if the
22294 initializer is a braced-init-list (8.5.4), with
22295 std::initializer_list<U>. */
22297 {
22302 else
22303 {
22307 "for deduction to %<std::initializer_list%>, use copy-"
22310 }
22311 }
22317 {
22323 {
22326 }
22327 }
22328 else
22329 {
22340 {
22342 /* Try again at instantiation time. */
22345 /* If type is error_mark_node a diagnostic must have been
22346 emitted by now. Also, having a mention to '<type error>'
22347 in the diagnostic is not really useful to the user. */
22348 {
22352 else
22354 }
22356 }
22357 }
22359 /* If the list of declarators contains more than one declarator, the type
22360 of each declared variable is determined as described above. If the
22361 type deduced for the template parameter U is not the same in each
22362 deduction, the program is ill-formed. */
22365 {
22371 else
22375 }
22381 }
22383 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
22384 result. */
22386 tree
22388 {
22389 tree argvec;
22396 /* For a late-specified return type in a template type-parameter, we
22397 need to add a dummy argument level for its parmlist. */
22398 argvec = add_to_template_args
22403 }
22405 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
22406 'decltype(auto)'. */
22408 bool
22410 {
22415 else
22417 }
22419 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
22420 a use of `auto'. Returns NULL_TREE otherwise. */
22422 tree
22424 {
22426 }
22428 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
22429 'decltype(auto)' or a concept. */
22431 bool
22433 {
22435 }
22437 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
22438 a concept identifier) iff TYPE contains a use of a generic type. Returns
22439 NULL_TREE otherwise. */
22441 tree
22443 {
22445 }
22448 /* For a given template T, return the vector of typedefs referenced
22449 in T for which access check is needed at T instantiation time.
22450 T is either a FUNCTION_DECL or a RECORD_TYPE.
22451 Those typedefs were added to T by the function
22452 append_type_to_template_for_access_check. */
22456 {
22457 tree ti;
22468 {
22473 }
22476 }
22478 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
22479 tied to T. That list of typedefs will be access checked at
22480 T instantiation time.
22481 T is either a FUNCTION_DECL or a RECORD_TYPE.
22482 TYPE_DECL is a TYPE_DECL node representing a typedef.
22483 SCOPE is the scope through which TYPE_DECL is accessed.
22484 LOCATION is the location of the usage point of TYPE_DECL.
22486 This function is a subroutine of
22487 append_type_to_template_for_access_check. */
22489 static void
22491 tree type_decl,
22492 tree scope,
22493 location_t location)
22494 {
22495 qualified_typedef_usage_t typedef_usage;
22496 tree ti;
22503 && type_decl
22517 }
22519 /* Append TYPE_DECL to the template TEMPL.
22520 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
22521 At TEMPL instanciation time, TYPE_DECL will be checked to see
22522 if it can be accessed through SCOPE.
22523 LOCATION is the location of the usage point of TYPE_DECL.
22525 e.g. consider the following code snippet:
22527 class C
22528 {
22529 typedef int myint;
22530 };
22532 template<class U> struct S
22533 {
22534 C::myint mi; // <-- usage point of the typedef C::myint
22535 };
22537 S<char> s;
22539 At S<char> instantiation time, we need to check the access of C::myint
22540 In other words, we need to check the access of the myint typedef through
22541 the C scope. For that purpose, this function will add the myint typedef
22542 and the scope C through which its being accessed to a list of typedefs
22543 tied to the template S. That list will be walked at template instantiation
22544 time and access check performed on each typedefs it contains.
22545 Note that this particular code snippet should yield an error because
22546 myint is private to C. */
22548 void
22550 tree type_decl,
22551 tree scope,
22552 location_t location)
22553 {
22559 /* Make sure we don't append the type to the template twice. */
22566 }
22568 /* Convert the generic type parameters in PARM that match the types given in the
22569 range [START_IDX, END_IDX) from the current_template_parms into generic type
22570 packs. */
22572 tree
22574 {
22585 {
22586 /* Create a distinct parameter pack type from the current parm and add it
22587 to the replacement args to tsubst below into the generic function
22588 parameter. */
22603 }
22609 /* If there are more levels then build up the replacement with the outer
22610 template parms. */
22614 replacement);
22617 }
22620 /* Set up the hash tables for template instantiations. */
22622 void
22624 {
22627 }
22629 /* Print stats about the template hash tables for -fstats. */
22631 void
22633 {
22642 }