| blob | 21d0d3aa4e9cd78f90158c4001abea745030a8ae |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2014 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". */
50 /* The type of functions taking a tree, and some additional data, and
51 returning an int. */
54 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
55 instantiations have been deferred, either because their definitions
56 were not yet available, or because we were putting off doing the work. */
60 };
75 /* Live only within one (recursive) call to tsubst_expr. We use
76 this to pass the statement expression node from the STMT_EXPR
77 to the EXPR_STMT that is its result. */
80 /* True if we've recursed into fn_type_unification too many times. */
84 {
85 tree tmpl;
86 tree args;
87 tree spec;
88 };
91 {
94 };
100 /* Contains canonical template parameter types. The vector is indexed by
101 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
102 TREE_LIST, whose TREE_VALUEs contain the canonical template
103 parameters of various types and levels. */
106 #define UNIFY_ALLOW_NONE 0
107 #define UNIFY_ALLOW_MORE_CV_QUAL 1
108 #define UNIFY_ALLOW_LESS_CV_QUAL 2
109 #define UNIFY_ALLOW_DERIVED 4
110 #define UNIFY_ALLOW_INTEGER 8
111 #define UNIFY_ALLOW_OUTER_LEVEL 16
112 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
113 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
116 tbr_incomplete_type,
117 tbr_ambiguous_baseclass,
118 tbr_success
119 };
142 tree);
204 location_t);
212 /* Make the current scope suitable for access checking when we are
213 processing T. T can be FUNCTION_DECL for instantiated function
214 template, VAR_DECL for static member variable, or TYPE_DECL for
215 alias template (needed by instantiate_decl). */
217 static void
219 {
227 else
231 {
232 saved_access_scope = tree_cons
235 }
236 }
238 /* Restore the scope set up by push_access_scope. T is the node we
239 are processing. */
241 static void
243 {
245 {
248 }
252 else
254 }
256 /* Do any processing required when DECL (a member template
257 declaration) is finished. Returns the TEMPLATE_DECL corresponding
258 to DECL, unless it is a specialization, in which case the DECL
259 itself is returned. */
261 tree
263 {
270 {
271 tree type;
279 {
283 }
285 }
289 {
291 {
294 }
295 else
297 }
298 else
302 }
304 /* Create a template info node. */
306 tree
308 {
313 }
315 /* Return the template info node corresponding to T, whatever T is. */
317 tree
319 {
340 }
342 /* Returns the template nesting level of the indicated class TYPE.
344 For example, in:
345 template <class T>
346 struct A
347 {
348 template <class U>
349 struct B {};
350 };
352 A<T>::B<U> has depth two, while A<T> has depth one.
353 Both A<T>::B<int> and A<int>::B<U> have depth one, if
354 they are instantiations, not specializations.
356 This function is guaranteed to return 0 if passed NULL_TREE so
357 that, for example, `template_class_depth (current_class_type)' is
358 always safe. */
360 int
362 {
369 {
375 }
378 }
380 /* Subroutine of maybe_begin_member_template_processing.
381 Returns true if processing DECL needs us to push template parms. */
383 static bool
385 {
391 }
393 /* Subroutine of maybe_begin_member_template_processing.
394 Push the template parms in PARMS, starting from LEVELS steps into the
395 chain, and ending at the beginning, since template parms are listed
396 innermost first. */
398 static void
400 {
408 current_template_parms
414 NULL);
416 {
425 {
432 {
433 /* Make a CONST_DECL as is done in process_template_parm.
434 It is ugly that we recreate this here; the original
435 version built in process_template_parm is no longer
436 available. */
446 }
451 }
452 }
453 }
455 /* Restore the template parameter context for a member template, a
456 friend template defined in a class definition, or a non-template
457 member of template class. */
459 void
461 {
462 tree parms;
467 {
470 /* Disregard full specializations (c++/60999). */
473 }
476 {
481 {
484 }
487 }
489 /* Remember how many levels of template parameters we pushed so that
490 we can pop them later. */
492 }
494 /* Undo the effects of maybe_begin_member_template_processing. */
496 void
498 {
507 {
511 }
512 }
514 /* Return a new template argument vector which contains all of ARGS,
515 but has as its innermost set of arguments the EXTRA_ARGS. */
517 static tree
519 {
520 tree new_args;
538 }
540 /* Like add_to_template_args, but only the outermost ARGS are added to
541 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
542 (EXTRA_ARGS) levels are added. This function is used to combine
543 the template arguments from a partial instantiation with the
544 template arguments used to attain the full instantiation from the
545 partial instantiation. */
547 static tree
549 {
550 tree new_args;
552 /* If there are more levels of EXTRA_ARGS than there are ARGS,
553 something very fishy is going on. */
556 /* If *all* the new arguments will be the EXTRA_ARGS, just return
557 them. */
561 /* For the moment, we make ARGS look like it contains fewer levels. */
566 /* Now, we restore ARGS to its full dimensions. */
570 }
572 /* Return the N levels of innermost template arguments from the ARGS. */
574 tree
576 {
577 tree new_args;
583 /* If N is 1, just return the innermost set of template arguments. */
587 /* If we're not removing anything, just return the arguments we were
588 given. */
594 /* Make a new set of arguments, not containing the outer arguments. */
601 }
603 /* The inverse of get_innermost_template_args: Return all but the innermost
604 EXTRA_LEVELS levels of template arguments from the ARGS. */
606 static tree
608 {
609 tree new_args;
615 /* If N is 1, just return the outermost set of template arguments. */
619 /* If we're not removing anything, just return the arguments we were
620 given. */
625 /* Make a new set of arguments, not containing the inner arguments. */
632 }
634 /* We've got a template header coming up; push to a new level for storing
635 the parms. */
637 void
639 {
640 /* We use a non-tag-transparent scope here, which causes pushtag to
641 put tags in this scope, rather than in the enclosing class or
642 namespace scope. This is the right thing, since we want
643 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
644 global template class, push_template_decl handles putting the
645 TEMPLATE_DECL into top-level scope. For a nested template class,
646 e.g.:
648 template <class T> struct S1 {
649 template <class T> struct S2 {};
650 };
652 pushtag contains special code to call pushdecl_with_scope on the
653 TEMPLATE_DECL for S2. */
658 }
660 /* This routine is called when a specialization is declared. If it is
661 invalid to declare a specialization here, an error is reported and
662 false is returned, otherwise this routine will return true. */
664 static bool
666 {
669 /* [temp.expl.spec]
671 An explicit specialization shall be declared in the namespace of
672 which the template is a member, or, for member templates, in the
673 namespace of which the enclosing class or enclosing class
674 template is a member. An explicit specialization of a member
675 function, member class or static data member of a class template
676 shall be declared in the namespace of which the class template
677 is a member. */
679 {
682 }
684 /* [temp.expl.spec]
686 In an explicit specialization declaration for a member of a class
687 template or a member template that appears in namespace scope,
688 the member template and some of its enclosing class templates may
689 remain unspecialized, except that the declaration shall not
690 explicitly specialize a class member template if its enclosing
691 class templates are not explicitly specialized as well. */
693 {
696 }
699 }
701 /* We've just seen template <>. */
703 bool
705 {
709 }
711 /* Called at then end of processing a declaration preceded by
712 template<>. */
714 void
716 {
719 }
721 /* Any template <>'s that we have seen thus far are not referring to a
722 function specialization. */
724 void
726 {
729 }
731 /* We've just seen a template header. If SPECIALIZATION is nonzero,
732 it was of the form template <>. */
734 static void
736 {
738 template_header_count++;
739 }
741 /* We're beginning an explicit instantiation. */
743 void
745 {
748 }
751 void
753 {
756 }
758 /* An explicit specialization or partial specialization of TMPL is being
759 declared. Check that the namespace in which the specialization is
760 occurring is permissible. Returns false iff it is invalid to
761 specialize TMPL in the current namespace. */
763 static bool
765 {
768 /* [tmpl.expl.spec]
770 An explicit specialization shall be declared in the namespace of
771 which the template is a member, or, for member templates, in the
772 namespace of which the enclosing class or enclosing class
773 template is a member. An explicit specialization of a member
774 function, member class or static data member of a class template
775 shall be declared in the namespace of which the class template is
776 a member. */
779 {
782 }
784 /* Same or super-using namespace. */
786 else
787 {
791 }
792 }
794 /* SPEC is an explicit instantiation. Check that it is valid to
795 perform this explicit instantiation in the current namespace. */
797 static void
799 {
800 tree ns;
802 /* DR 275: An explicit instantiation shall appear in an enclosing
803 namespace of its template. */
809 }
811 /* The TYPE is being declared. If it is a template type, that means it
812 is a partial specialization. Do appropriate error-checking. */
814 tree
816 {
817 tree context;
822 /* A lambda that appears in specialization context is not itself a
823 specialization. */
828 {
832 }
837 {
842 else
845 }
847 {
848 /* This is for ordinary explicit specialization and partial
849 specialization of a template class such as:
851 template <> class C<int>;
853 or:
855 template <class T> class C<T*>;
857 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
861 {
868 {
872 }
873 }
879 /* Trying to define a specialization either without a template<> header
880 or in an inappropriate place. We've already given an error, so just
881 bail now so we don't actually define the specialization. */
883 }
889 {
890 /* This is for an explicit specialization of member class
891 template according to [temp.expl.spec/18]:
893 template <> template <class U> class C<int>::D;
895 The context `C<int>' must be an implicit instantiation.
896 Otherwise this is just a member class template declared
897 earlier like:
899 template <> class C<int> { template <class U> class D; };
900 template <> template <class U> class C<int>::D;
902 In the first case, `C<int>::D' is a specialization of `C<T>::D'
903 while in the second case, `C<int>::D' is a primary template
904 and `C<T>::D' may not exist. */
908 {
909 tree t;
914 {
917 }
919 /* Check for invalid specialization after instantiation:
921 template <> template <> class C<int>::D<int>;
922 template <> template <class U> class C<int>::D; */
926 {
930 {
931 /* We already have a full specialization of this partial
932 instantiation, or a full specialization has been
933 looked up but not instantiated. Reassign it to the
934 new member specialization template. */
935 spec_entry elt;
947 spec_entry **slot
952 }
953 else
954 /* But if we've had an implicit instantiation, that's a
955 problem ([temp.expl.spec]/6). */
958 }
960 /* Mark TYPE as a specialization. And as a result, we only
961 have one level of template argument for the innermost
962 class template. */
967 }
968 }
970 {
971 /* Someday C++0x may allow for enum template specialization. */
976 else
977 {
980 }
981 }
984 }
986 /* Returns nonzero if we can optimize the retrieval of specializations
987 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
988 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
992 {
995 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
996 parameter. */
998 /* The optimized lookup depends on the fact that the
999 template arguments for the member function template apply
1000 purely to the containing class, which is not true if the
1001 containing class is an explicit or partial
1002 specialization. */
1006 /* It is possible to have a template that is not a member
1007 template and is not a member of a template class:
1009 template <typename T>
1010 struct S { friend A::f(); };
1012 Here, the friend function is a template, but the context does
1013 not have template information. The optimized lookup relies
1014 on having ARGS be the template arguments for both the class
1015 and the function template. */
1017 }
1019 /* Retrieve the specialization (in the sense of [temp.spec] - a
1020 specialization is either an instantiation or an explicit
1021 specialization) of TMPL for the given template ARGS. If there is
1022 no such specialization, return NULL_TREE. The ARGS are a vector of
1023 arguments, or a vector of vectors of arguments, in the case of
1024 templates with more than one level of parameters.
1026 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1027 then we search for a partial specialization matching ARGS. This
1028 parameter is ignored if TMPL is not a class template.
1030 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1031 result is a NONTYPE_ARGUMENT_PACK. */
1033 static tree
1035 {
1045 /* There should be as many levels of arguments as there are
1046 levels of parameters. */
1053 {
1054 tree class_template;
1055 tree class_specialization;
1057 tree fns;
1060 /* The template arguments actually apply to the containing
1061 class. Find the class specialization with those
1062 arguments. */
1064 class_specialization
1068 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1069 for the specialization. */
1073 /* Iterate through the methods with the indicated name, looking
1074 for the one that has an instance of TMPL. */
1077 {
1080 /* using-declarations can add base methods to the method vec,
1081 and we don't want those here. */
1084 }
1086 }
1087 else
1088 {
1090 spec_entry elt;
1099 else
1107 }
1110 }
1112 /* Like retrieve_specialization, but for local declarations. */
1114 static tree
1116 {
1122 }
1124 /* Returns nonzero iff DECL is a specialization of TMPL. */
1126 int
1128 {
1129 tree t;
1132 {
1138 }
1139 else
1140 {
1149 }
1152 }
1154 /* Returns nonzero iff DECL is a specialization of friend declaration
1155 FRIEND_DECL according to [temp.friend]. */
1157 bool
1159 {
1166 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1167 of a template class, we want to check if DECL is a specialization
1168 if this. */
1172 {
1173 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1176 }
1181 /* There is nothing to do if this is not a template friend. */
1188 /* [temp.friend/6]
1189 A member of a class template may be declared to be a friend of a
1190 non-template class. In this case, the corresponding member of
1191 every specialization of the class template is a friend of the
1192 class granting friendship.
1194 For example, given a template friend declaration
1196 template <class T> friend void A<T>::f();
1198 the member function below is considered a friend
1200 template <> struct A<int> {
1201 void f();
1202 };
1204 For this type of template friend, TEMPLATE_DEPTH below will be
1205 nonzero. To determine if DECL is a friend of FRIEND, we first
1206 check if the enclosing class is a specialization of another. */
1213 {
1214 /* Next, we check the members themselves. In order to handle
1215 a few tricky cases, such as when FRIEND_DECL's are
1217 template <class T> friend void A<T>::g(T t);
1218 template <class T> template <T t> friend void A<T>::h();
1220 and DECL's are
1222 void A<int>::g(int);
1223 template <int> void A<int>::h();
1225 we need to figure out ARGS, the template arguments from
1226 the context of DECL. This is required for template substitution
1227 of `T' in the function parameter of `g' and template parameter
1228 of `h' in the above examples. Here ARGS corresponds to `int'. */
1235 {
1237 {
1240 else
1242 current_depth++;
1243 }
1245 }
1248 {
1250 tree friend_type;
1251 tree decl_type;
1252 tree friend_args_type;
1253 tree decl_args_type;
1255 /* Make sure that both DECL and FRIEND_DECL are templates or
1256 non-templates. */
1262 {
1263 /* If both are templates, check template parameter list. */
1264 tree friend_parms
1269 friend_parms))
1273 }
1274 else
1282 /* Check if return types match. */
1286 /* Check if function parameter types match, ignoring the
1287 `this' parameter. */
1296 }
1297 else
1298 {
1299 /* DECL is a TYPE_DECL */
1303 /* Make sure that both DECL and FRIEND_DECL are templates or
1304 non-templates. */
1305 is_template
1312 {
1313 tree friend_parms;
1314 /* If both are templates, check the name of the two
1315 TEMPLATE_DECL's first because is_friend didn't. */
1320 /* Now check template parameter list. */
1321 friend_parms
1324 return comp_template_parms
1326 friend_parms);
1327 }
1328 else
1331 }
1332 }
1334 }
1336 /* Register the specialization SPEC as a specialization of TMPL with
1337 the indicated ARGS. IS_FRIEND indicates whether the specialization
1338 is actually just a friend declaration. Returns SPEC, or an
1339 equivalent prior declaration, if available.
1341 We also store instantiations of field packs in the hash table, even
1342 though they are not themselves templates, to make lookup easier. */
1344 static tree
1346 hashval_t hash)
1347 {
1348 tree fn;
1350 spec_entry elt;
1358 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1359 register it; we want the corresponding TEMPLATE_DECL instead.
1360 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1361 the more obvious `uses_template_parms (spec)' to avoid problems
1362 with default function arguments. In particular, given
1363 something like this:
1365 template <class T> void f(T t1, T t = T())
1367 the default argument expression is not substituted for in an
1368 instantiation unless and until it is actually needed. */
1372 /* We don't put these specializations in the hash table, but we might
1373 want to give an error about a mismatch. */
1375 else
1376 {
1384 slot =
1388 else
1390 }
1392 /* We can sometimes try to re-register a specialization that we've
1393 already got. In particular, regenerate_decl_from_template calls
1394 duplicate_decls which will update the specialization list. But,
1395 we'll still get called again here anyhow. It's more convenient
1396 to simply allow this than to try to prevent it. */
1400 {
1402 {
1405 {
1407 fn);
1409 }
1410 else
1411 {
1412 tree clone;
1413 /* This situation should occur only if the first
1414 specialization is an implicit instantiation, the
1415 second is an explicit specialization, and the
1416 implicit instantiation has not yet been used. That
1417 situation can occur if we have implicitly
1418 instantiated a member function and then specialized
1419 it later.
1421 We can also wind up here if a friend declaration that
1422 looked like an instantiation turns out to be a
1423 specialization:
1425 template <class T> void foo(T);
1426 class S { friend void foo<>(int) };
1427 template <> void foo(int);
1429 We transform the existing DECL in place so that any
1430 pointers to it become pointers to the updated
1431 declaration.
1433 If there was a definition for the template, but not
1434 for the specialization, we want this to look as if
1435 there were no definition, and vice versa. */
1438 /* The call to duplicate_decls will have applied
1439 [temp.expl.spec]:
1441 An explicit specialization of a function template
1442 is inline only if it is explicitly declared to be,
1443 and independently of whether its function template
1444 is.
1446 to the primary function; now copy the inline bits to
1447 the various clones. */
1449 {
1456 }
1460 }
1461 }
1463 {
1465 /* Dup decl failed, but this is a new definition. Set the
1466 line number so any errors match this new
1467 definition. */
1471 }
1472 }
1476 /* A specialization must be declared in the same namespace as the
1477 template it is specializing. */
1483 {
1492 /* If TMPL is a forward declaration of a template function, keep a list
1493 of all specializations in case we need to reassign them to a friend
1494 template later in tsubst_friend_function.
1496 Also keep a list of all variable template instantiations so that
1497 process_partial_specialization can check whether a later partial
1498 specialization would have used it. */
1501 }
1504 }
1506 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1507 TMPL and ARGS members, ignores SPEC. */
1511 bool
1513 {
1522 }
1524 /* Returns a hash for a template TMPL and template arguments ARGS. */
1526 static hashval_t
1528 {
1531 }
1533 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1534 ignoring SPEC. */
1536 hashval_t
1538 {
1540 }
1542 /* Recursively calculate a hash value for a template argument ARG, for use
1543 in the hash tables of template specializations. */
1545 hashval_t
1547 {
1559 /* We can get one of these when re-hashing a previous entry in the middle
1560 of substituting into a pack expansion. Just look through it. */
1569 {
1577 {
1582 }
1604 {
1608 {
1611 }
1613 }
1617 {
1620 }
1631 val = iterative_hash_template_arg
1643 val);
1645 val);
1654 /* A lambda can't appear in a template arg, but don't crash on
1655 erroneous input. */
1667 /* Now hash operands as usual. */
1672 }
1675 {
1678 {
1679 // We want an alias specialization that survived strip_typedefs
1680 // to hash differently from its TYPE_CANONICAL, to avoid hash
1681 // collisions that compare as different in template_args_equal.
1682 // These could be dependent specializations that strip_typedefs
1683 // left alone, or untouched specializations because
1684 // coerce_template_parms returns the unconverted template
1685 // arguments if it sees incomplete argument packs.
1688 }
1691 val);
1694 /* Otherwise just compare the types during lookup. */
1703 {
1708 }
1709 }
1712 }
1714 /* Unregister the specialization SPEC as a specialization of TMPL.
1715 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1716 if the SPEC was listed as a specialization of TMPL.
1718 Note that SPEC has been ggc_freed, so we can't look inside it. */
1720 bool
1722 {
1724 spec_entry elt;
1732 {
1737 }
1740 }
1742 /* Like register_specialization, but for local declarations. We are
1743 registering SPEC, an instantiation of TMPL. */
1745 static void
1747 {
1749 }
1751 /* TYPE is a class type. Returns true if TYPE is an explicitly
1752 specialized class. */
1754 bool
1756 {
1760 }
1762 /* Print the list of functions at FNS, going through all the overloads
1763 for each element of the list. Alternatively, FNS can not be a
1764 TREE_LIST, in which case it will be printed together with all the
1765 overloads.
1767 MORE and *STR should respectively be FALSE and NULL when the function
1768 is called from the outside. They are used internally on recursive
1769 calls. print_candidates manages the two parameters and leaves NULL
1770 in *STR when it ends. */
1772 static void
1774 {
1780 {
1784 }
1785 else
1786 {
1789 {
1790 /* Pick the prefix string. */
1792 {
1796 }
1800 }
1803 }
1806 {
1809 }
1810 }
1812 /* Print the list of candidate FNS in an error message. FNS can also
1813 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1815 void
1817 {
1821 }
1823 /* Returns the template (one of the functions given by TEMPLATE_ID)
1824 which can be specialized to match the indicated DECL with the
1825 explicit template args given in TEMPLATE_ID. The DECL may be
1826 NULL_TREE if none is available. In that case, the functions in
1827 TEMPLATE_ID are non-members.
1829 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1830 specialization of a member template.
1832 The TEMPLATE_COUNT is the number of references to qualifying
1833 template classes that appeared in the name of the function. See
1834 check_explicit_specialization for a more accurate description.
1836 TSK indicates what kind of template declaration (if any) is being
1837 declared. TSK_TEMPLATE indicates that the declaration given by
1838 DECL, though a FUNCTION_DECL, has template parameters, and is
1839 therefore a template function.
1841 The template args (those explicitly specified and those deduced)
1842 are output in a newly created vector *TARGS_OUT.
1844 If it is impossible to determine the result, an error message is
1845 issued. The error_mark_node is returned to indicate failure. */
1847 static tree
1849 tree decl,
1853 tmpl_spec_kind tsk)
1854 {
1855 tree fns;
1856 tree targs;
1857 tree explicit_targs;
1859 /* A TREE_LIST of templates of which DECL may be a specialization.
1860 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1861 corresponding TREE_PURPOSE is the set of template arguments that,
1862 when used to instantiate the template, would produce a function
1863 with the signature of DECL. */
1873 /* We shouldn't be specializing a member template of an
1874 unspecialized class template; we already gave an error in
1875 check_specialization_scope, now avoid crashing. */
1878 {
1881 }
1889 /* Check for baselinks. */
1894 {
1897 }
1899 {
1902 }
1904 /* Count the number of template headers specified for this
1905 specialization. */
1915 {
1919 {
1920 tree decl_arg_types;
1921 tree fn_arg_types;
1922 tree insttype;
1924 /* In case of explicit specialization, we need to check if
1925 the number of template headers appearing in the specialization
1926 is correct. This is usually done in check_explicit_specialization,
1927 but the check done there cannot be exhaustive when specializing
1928 member functions. Consider the following code:
1930 template <> void A<int>::f(int);
1931 template <> template <> void A<int>::f(int);
1933 Assuming that A<int> is not itself an explicit specialization
1934 already, the first line specializes "f" which is a non-template
1935 member function, whilst the second line specializes "f" which
1936 is a template member function. So both lines are syntactically
1937 correct, and check_explicit_specialization does not reject
1938 them.
1940 Here, we can do better, as we are matching the specialization
1941 against the declarations. We count the number of template
1942 headers, and we check if they match TEMPLATE_COUNT + 1
1943 (TEMPLATE_COUNT is the number of qualifying template classes,
1944 plus there must be another header for the member template
1945 itself).
1947 Notice that if header_count is zero, this is not a
1948 specialization but rather a template instantiation, so there
1949 is no check we can perform here. */
1953 /* Check that the number of template arguments at the
1954 innermost level for DECL is the same as for FN. */
1962 /* DECL might be a specialization of FN. */
1966 /* For a non-static member function, we need to make sure
1967 that the const qualification is the same. Since
1968 get_bindings does not try to merge the "this" parameter,
1969 we must do the comparison explicitly. */
1975 /* Skip the "this" parameter and, for constructors of
1976 classes with virtual bases, the VTT parameter. A
1977 full specialization of a constructor will have a VTT
1978 parameter, but a template never will. */
1979 decl_arg_types
1981 fn_arg_types
1984 /* Function templates cannot be specializations; there are
1985 no partial specializations of functions. Therefore, if
1986 the type of DECL does not match FN, there is no
1987 match. */
1989 {
1993 }
1995 /* See whether this function might be a specialization of this
1996 template. Suppress access control because we might be trying
1997 to make this specialization a friend, and we have already done
1998 access control for the declaration of the specialization. */
2004 /* We cannot deduce template arguments that when used to
2005 specialize TMPL will produce DECL. */
2008 /* Make sure that the deduced arguments actually work. */
2012 fn_arg_types
2017 /* Save this template, and the arguments deduced. */
2019 }
2021 /* FN is an ordinary member function, and we need a
2022 specialization of a member template. */
2023 ;
2025 /* We can get IDENTIFIER_NODEs here in certain erroneous
2026 cases. */
2027 ;
2029 /* This is just an ordinary non-member function. Nothing can
2030 be a specialization of that. */
2031 ;
2033 /* Cannot specialize functions that are created implicitly. */
2034 ;
2035 else
2036 {
2037 tree decl_arg_types;
2039 /* This is an ordinary member function. However, since
2040 we're here, we can assume its enclosing class is a
2041 template class. For example,
2043 template <typename T> struct S { void f(); };
2044 template <> void S<int>::f() {}
2046 Here, S<int>::f is a non-template, but S<int> is a
2047 template class. If FN has the same type as DECL, we
2048 might be in business. */
2051 /* Its enclosing class is an explicit specialization
2052 of a template class. This is not a candidate. */
2057 /* The return types differ. */
2060 /* Adjust the type of DECL in case FN is a static member. */
2067 decl_arg_types))
2068 /* They match! */
2070 }
2071 }
2074 {
2075 /* We have:
2077 [temp.expl.spec]
2079 It is possible for a specialization with a given function
2080 signature to be instantiated from more than one function
2081 template. In such cases, explicit specification of the
2082 template arguments must be used to uniquely identify the
2083 function template specialization being specialized.
2085 Note that here, there's no suggestion that we're supposed to
2086 determine which of the candidate templates is most
2087 specialized. However, we, also have:
2089 [temp.func.order]
2091 Partial ordering of overloaded function template
2092 declarations is used in the following contexts to select
2093 the function template to which a function template
2094 specialization refers:
2096 -- when an explicit specialization refers to a function
2097 template.
2099 So, we do use the partial ordering rules, at least for now.
2100 This extension can only serve to make invalid programs valid,
2101 so it's safe. And, there is strong anecdotal evidence that
2102 the committee intended the partial ordering rules to apply;
2103 the EDG front end has that behavior, and John Spicer claims
2104 that the committee simply forgot to delete the wording in
2105 [temp.expl.spec]. */
2108 {
2111 }
2112 }
2115 {
2123 }
2127 {
2133 }
2135 /* We have one, and exactly one, match. */
2137 {
2140 /* DECL is a re-declaration or partial instantiation of a template
2141 function. */
2144 /* It was a specialization of an ordinary member function in a
2145 template class. */
2147 }
2149 /* It was a specialization of a template. */
2152 {
2157 }
2158 else
2161 }
2163 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2164 but with the default argument values filled in from those in the
2165 TMPL_TYPES. */
2167 static tree
2169 tree tmpl_types)
2170 {
2171 tree new_spec_types;
2179 /* Substitute into the rest of the list. */
2180 new_spec_types =
2184 /* Add the default argument for this parameter. */
2187 new_spec_types);
2188 }
2190 /* DECL is an explicit specialization. Replicate default arguments
2191 from the template it specializes. (That way, code like:
2193 template <class T> void f(T = 3);
2194 template <> void f(double);
2195 void g () { f (); }
2197 works, as required.) An alternative approach would be to look up
2198 the correct default arguments at the call-site, but this approach
2199 is consistent with how implicit instantiations are handled. */
2201 static void
2203 {
2204 tree tmpl;
2205 tree spec_types;
2206 tree tmpl_types;
2207 tree new_spec_types;
2208 tree old_type;
2209 tree new_type;
2210 tree t;
2215 /* See if there's anything we need to do. */
2228 {
2229 /* Remove the this pointer, but remember the object's type for
2230 CV quals. */
2236 {
2237 /* DECL may contain more parameters than TMPL due to the extra
2238 in-charge parameter in constructors and destructors. */
2241 }
2243 {
2246 }
2247 }
2249 /* Compute the merged default arguments. */
2250 new_spec_types =
2253 /* Compute the new FUNCTION_TYPE. */
2255 {
2259 new_spec_types);
2262 /* Put the in-charge parameter back. */
2265 new_spec_types);
2269 new_spec_types);
2270 }
2271 else
2273 new_spec_types);
2283 }
2285 /* Return the number of template headers we expect to see for a definition
2286 or specialization of CTYPE or one of its non-template members. */
2288 int
2290 {
2294 {
2295 /* You're supposed to have one `template <...>' for every
2296 template class, but you don't need one for a full
2297 specialization. For example:
2299 template <class T> struct S{};
2300 template <> struct S<int> { void f(); };
2301 void S<int>::f () {}
2303 is correct; there shouldn't be a `template <>' for the
2304 definition of `S<int>::f'. */
2306 /* If CTYPE does not have template information of any
2307 kind, then it is not a template, nor is it nested
2308 within a template. */
2316 }
2319 }
2321 /* Do a simple sanity check on the template headers that precede the
2322 variable declaration DECL. */
2324 void
2326 {
2331 {
2334 "variable templates only available with "
2337 // Namespace-scope variable templates should have a template header.
2339 }
2341 {
2348 "members of an explicitly specialized class are defined "
2350 }
2351 }
2353 /* Check to see if the function just declared, as indicated in
2354 DECLARATOR, and in DECL, is a specialization of a function
2355 template. We may also discover that the declaration is an explicit
2356 instantiation at this point.
2358 Returns DECL, or an equivalent declaration that should be used
2359 instead if all goes well. Issues an error message if something is
2360 amiss. Returns error_mark_node if the error is not easily
2361 recoverable.
2363 FLAGS is a bitmask consisting of the following flags:
2365 2: The function has a definition.
2366 4: The function is a friend.
2368 The TEMPLATE_COUNT is the number of references to qualifying
2369 template classes that appeared in the name of the function. For
2370 example, in
2372 template <class T> struct S { void f(); };
2373 void S<int>::f();
2375 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2376 classes are not counted in the TEMPLATE_COUNT, so that in
2378 template <class T> struct S {};
2379 template <> struct S<int> { void f(); }
2380 template <> void S<int>::f();
2382 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2383 invalid; there should be no template <>.)
2385 If the function is a specialization, it is marked as such via
2386 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2387 is set up correctly, and it is added to the list of specializations
2388 for that template. */
2390 tree
2392 tree decl,
2395 {
2403 tmpl_spec_kind tsk;
2406 {
2409 else
2411 }
2412 else
2416 {
2419 {
2422 }
2424 {
2426 /* This could be something like:
2428 template <class T> void f(T);
2429 class S { friend void f<>(int); } */
2431 else
2432 {
2433 /* This case handles bogus declarations like template <>
2434 template <class T> void f<int>(); */
2437 declarator);
2439 }
2440 }
2444 /* The error has already been reported in
2445 check_specialization_scope. */
2451 /* Fall through. */
2464 decl);
2467 else
2471 /* Fall through. */
2474 /* In cases like template<> constexpr bool v = true;
2475 We'll give an error in check_template_variable. */
2481 else
2487 {
2488 /* This case handles bogus declarations like template <>
2489 template <class T> void f<int>(); */
2493 declarator);
2495 {
2496 /* Partial specialization of variable template. */
2500 }
2504 else
2508 ok:;
2509 }
2512 /* This is a specialization of a member template, without
2513 specialization the containing class. Something like:
2515 template <class T> struct S {
2516 template <class U> void f (U);
2517 };
2518 template <> template <class U> void S<int>::f(U) {}
2520 That's a specialization -- but of the entire template. */
2526 }
2529 /* This doesn't apply to variable templates. */
2532 {
2536 {
2540 }
2541 }
2544 {
2549 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2551 {
2552 tree fns;
2557 else
2558 {
2559 /* If there is no class context, the explicit instantiation
2560 must be at namespace scope. */
2563 /* Find the namespace binding, using the declaration
2564 context. */
2568 {
2571 }
2572 else
2573 {
2579 }
2580 }
2583 }
2589 {
2591 /* A specialization in class scope. This is invalid,
2592 but the error will already have been flagged by
2593 check_specialization_scope. */
2595 else
2596 {
2597 /* It's not valid to write an explicit instantiation in
2598 class scope, e.g.:
2600 class C { template void f(); }
2602 This case is caught by the parser. However, on
2603 something like:
2605 template class C { void f(); };
2607 (which is invalid) we can get here. The error will be
2608 issued later. */
2609 ;
2610 }
2613 }
2616 {
2617 // We'll match variable templates in start_decl.
2621 /* Find the list of functions in ctype that have the same
2622 name as the declared function. */
2628 {
2633 {
2634 /* From [temp.expl.spec]:
2636 If such an explicit specialization for the member
2637 of a class template names an implicitly-declared
2638 special member function (clause _special_), the
2639 program is ill-formed.
2641 Similar language is found in [temp.explicit]. */
2644 }
2647 }
2650 {
2654 }
2655 else
2656 {
2658 tree ovl;
2660 /* For a type-conversion operator, we cannot do a
2661 name-based lookup. We might be looking for `operator
2662 int' which will be a specialization of `operator T'.
2663 So, we find *all* the conversion operators, and then
2664 select from them. */
2672 {
2674 /* There are no more conversion functions. */
2677 /* Glue all these conversion functions together
2678 with those we already have. */
2681 }
2682 }
2685 {
2688 }
2689 else
2691 }
2693 /* Figure out what exactly is being specialized at this point.
2694 Note that for an explicit instantiation, even one for a
2695 member function, we cannot tell apriori whether the
2696 instantiation is for a member template, or just a member
2697 function of a template class. Even if a member template is
2698 being instantiated, the member template arguments may be
2699 elided if they can be deduced from the rest of the
2700 declaration. */
2703 member_specialization,
2704 template_count,
2705 tsk);
2708 /* We couldn't figure out what this declaration was
2709 specializing. */
2711 else
2712 {
2716 {
2717 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2718 is done by do_decl_instantiation later. */
2724 {
2725 /* If TMPL is not the most general template (for
2726 example, if TMPL is a friend template that is
2727 injected into namespace scope), then there will
2728 be too many levels of TARGS. Remove some of them
2729 here. */
2731 tree new_targs;
2738 }
2741 }
2743 /* If we thought that the DECL was a member function, but it
2744 turns out to be specializing a static member function,
2745 make DECL a static member function as well. */
2751 /* If this is a specialization of a member template of a
2752 template class, we want to return the TEMPLATE_DECL, not
2753 the specialization of it. */
2755 {
2760 {
2761 tree parm;
2765 /* We want to use the argument list specified in the
2766 definition, not in the original declaration. */
2771 }
2774 }
2776 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2782 /* Inherit default function arguments from the template
2783 DECL is specializing. */
2787 /* This specialization has the same protection as the
2788 template it specializes. */
2792 /* 7.1.1-1 [dcl.stc]
2794 A storage-class-specifier shall not be specified in an
2795 explicit specialization...
2797 The parser rejects these, so unless action is taken here,
2798 explicit function specializations will always appear with
2799 global linkage.
2801 The action recommended by the C++ CWG in response to C++
2802 defect report 605 is to make the storage class and linkage
2803 of the explicit specialization match the templated function:
2805 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2806 */
2808 {
2812 /* This specialization has the same linkage and visibility as
2813 the function template it specializes. */
2816 {
2819 }
2822 {
2825 }
2826 }
2828 /* If DECL is a friend declaration, declared using an
2829 unqualified name, the namespace associated with DECL may
2830 have been set incorrectly. For example, in:
2832 template <typename T> void f(T);
2833 namespace N {
2834 struct S { friend void f<int>(int); }
2835 }
2837 we will have set the DECL_CONTEXT for the friend
2838 declaration to N, rather than to the global namespace. */
2843 /* This is not really a declaration of a specialization.
2844 It's just the name of an instantiation. But, it's not
2845 a request for an instantiation, either. */
2848 /* A specialization is not necessarily COMDAT. */
2854 /* Register this specialization so that we can find it
2855 again. */
2858 /* A 'structor should already have clones. */
2864 }
2865 }
2868 }
2870 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2871 parameters. These are represented in the same format used for
2872 DECL_TEMPLATE_PARMS. */
2874 int
2876 {
2877 const_tree p1;
2878 const_tree p2;
2886 {
2898 {
2902 /* If either of the template parameters are invalid, assume
2903 they match for the sake of error recovery. */
2916 }
2917 }
2920 /* One set of parameters has more parameters lists than the
2921 other. */
2925 }
2927 /* Determine whether PARM is a parameter pack. */
2929 bool
2931 {
2932 /* Determine if we have a non-type template parameter pack. */
2939 /* If this is a list of template parameters, we could get a
2940 TYPE_DECL or a TEMPLATE_DECL. */
2944 /* Otherwise it must be a type template parameter. */
2948 }
2950 /* Determine if T is a function parameter pack. */
2952 bool
2954 {
2958 }
2960 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2961 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2963 tree
2965 {
2972 }
2974 /* Return true iff the function parameter PARAM_DECL was expanded
2975 from the function parameter pack PACK. */
2977 bool
2979 {
2984 /* The parameter pack and its pack arguments have the same
2985 DECL_PARM_INDEX. */
2987 }
2989 /* Determine whether ARGS describes a variadic template args list,
2990 i.e., one that is terminated by a template argument pack. */
2992 static bool
2994 {
2996 tree last_parm;
3010 }
3012 /* Generate a new name for the parameter pack name NAME (an
3013 IDENTIFIER_NODE) that incorporates its */
3015 static tree
3017 {
3018 /* Munge the name to include the parameter index. */
3019 #define NUMBUF_LEN 128
3033 }
3035 /* Return true if T is a primary function, class or alias template
3036 instantiation. */
3038 bool
3040 {
3054 }
3056 /* Return true if PARM is a template template parameter. */
3058 bool
3060 {
3062 }
3064 /* Return true iff PARM is a DECL representing a type template
3065 parameter. */
3067 bool
3069 {
3074 }
3076 /* Return the template parameters of T if T is a
3077 primary template instantiation, NULL otherwise. */
3079 tree
3081 {
3086 parms = INNERMOST_TEMPLATE_PARMS
3090 }
3092 /* Return the template parameters of the LEVELth level from the full list
3093 of template parameters PARMS. */
3095 tree
3097 {
3098 tree p;
3109 }
3111 /* Returns the template arguments of T if T is a template instantiation,
3112 NULL otherwise. */
3114 tree
3116 {
3124 }
3126 /* Return the argument pack elements of T if T is a template argument pack,
3127 NULL otherwise. */
3129 tree
3131 {
3137 }
3139 /* Structure used to track the progress of find_parameter_packs_r. */
3140 struct find_parameter_pack_data
3141 {
3142 /* TREE_LIST that will contain all of the parameter packs found by
3143 the traversal. */
3146 /* Set of AST nodes that have been visited by the traversal. */
3148 };
3150 /* Identifies all of the argument packs that occur in a template
3151 argument and appends them to the TREE_LIST inside DATA, which is a
3152 find_parameter_pack_data structure. This is a subroutine of
3153 make_pack_expansion and uses_parameter_packs. */
3154 static tree
3156 {
3162 /* Handle type aliases/typedefs. */
3164 {
3171 }
3173 /* Identify whether this is a parameter pack or not. */
3175 {
3191 {
3192 /* We don't want to walk into the type of a PARM_DECL,
3193 because we don't want to see the type parameter pack. */
3196 }
3199 /* Look through a lambda capture proxy to the field pack. */
3202 {
3208 }
3215 /* Not a parameter pack. */
3217 }
3220 {
3221 /* Add this parameter pack to the list. */
3223 }
3229 /* This switch statement will return immediately if we don't find a
3230 parameter pack. */
3232 {
3237 /* Check the template itself. */
3240 /* Check the template arguments. */
3256 /* Fall through. */
3298 }
3301 }
3303 /* Determines if the expression or type T uses any parameter packs. */
3304 bool
3306 {
3314 }
3316 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3317 representation a base-class initializer into a parameter pack
3318 expansion. If all goes well, the resulting node will be an
3319 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3320 respectively. */
3321 tree
3323 {
3324 tree result;
3333 {
3334 /* The only time we will see a TREE_LIST here is for a base
3335 class initializer. In this case, the TREE_PURPOSE will be a
3336 _TYPE node (representing the base class expansion we're
3337 initializing) and the TREE_VALUE will be a TREE_LIST
3338 containing the initialization arguments.
3340 The resulting expansion looks somewhat different from most
3341 expansions. Rather than returning just one _EXPANSION, we
3342 return a TREE_LIST whose TREE_PURPOSE is a
3343 TYPE_PACK_EXPANSION containing the bases that will be
3344 initialized. The TREE_VALUE will be identical to the
3345 original TREE_VALUE, which is a list of arguments that will
3346 be passed to each base. We do not introduce any new pack
3347 expansion nodes into the TREE_VALUE (although it is possible
3348 that some already exist), because the TREE_PURPOSE and
3349 TREE_VALUE all need to be expanded together with the same
3350 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3351 resulting TREE_PURPOSE will mention the parameter packs in
3352 both the bases and the arguments to the bases. */
3353 tree purpose;
3354 tree value;
3357 /* Determine which parameter packs will be used by the base
3358 class expansion. */
3365 {
3369 }
3372 {
3373 /* Collect the sets of parameter packs used in each of the
3374 initialization arguments. */
3376 {
3377 /* Determine which parameter packs will be expanded in this
3378 argument. */
3381 }
3382 }
3386 /* Create the pack expansion type for the base type. */
3391 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3392 they will rarely be compared to anything. */
3396 }
3401 /* Build the PACK_EXPANSION_* node. */
3402 result = for_types
3407 {
3408 /* Propagate type and const-expression information. */
3411 }
3412 else
3413 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3414 they will rarely be compared to anything. */
3417 /* Determine which parameter packs will be expanded. */
3423 /* Make sure we found some parameter packs. */
3425 {
3428 else
3431 }
3437 }
3439 /* Checks T for any "bare" parameter packs, which have not yet been
3440 expanded, and issues an error if any are found. This operation can
3441 only be done on full expressions or types (e.g., an expression
3442 statement, "if" condition, etc.), because we could have expressions like:
3444 foo(f(g(h(args)))...)
3446 where "args" is a parameter pack. check_for_bare_parameter_packs
3447 should not be called for the subexpressions args, h(args),
3448 g(h(args)), or f(g(h(args))), because we would produce erroneous
3449 error messages.
3451 Returns TRUE and emits an error if there were bare parameter packs,
3452 returns FALSE otherwise. */
3453 bool
3455 {
3471 {
3474 {
3483 else
3488 else
3492 }
3495 }
3498 }
3500 /* Expand any parameter packs that occur in the template arguments in
3501 ARGS. */
3502 tree
3504 {
3510 /* First, determine if we need to expand anything, and the number of
3511 slots we'll need. */
3513 {
3518 {
3522 else
3524 }
3525 else
3526 {
3528 num_result_args++;
3529 }
3530 }
3532 /* If no expansion is necessary, we're done. */
3536 /* Expand arguments. */
3539 non_default_args_count =
3542 {
3545 {
3552 }
3553 else
3554 {
3557 }
3558 }
3562 }
3564 /* Checks if DECL shadows a template parameter.
3566 [temp.local]: A template-parameter shall not be redeclared within its
3567 scope (including nested scopes).
3569 Emits an error and returns TRUE if the DECL shadows a parameter,
3570 returns FALSE otherwise. */
3572 bool
3574 {
3575 tree olddecl;
3577 /* If we're not in a template, we can't possibly shadow a template
3578 parameter. */
3582 /* Figure out what we're shadowing. */
3587 /* If there's no previous binding for this name, we're not shadowing
3588 anything, let alone a template parameter. */
3592 /* If we're not shadowing a template parameter, we're done. Note
3593 that OLDDECL might be an OVERLOAD (or perhaps even an
3594 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3595 node. */
3599 /* We check for decl != olddecl to avoid bogus errors for using a
3600 name inside a class. We check TPFI to avoid duplicate errors for
3601 inline member templates. */
3607 /* Don't complain about the injected class name, as we've already
3608 complained about the class itself. */
3615 }
3617 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3618 ORIG_LEVEL, DECL, and TYPE. */
3620 static tree
3624 tree decl,
3625 tree type)
3626 {
3637 }
3639 /* Find the canonical type parameter for the given template type
3640 parameter. Returns the canonical type parameter, which may be TYPE
3641 if no such parameter existed. */
3643 static tree
3645 {
3646 tree list;
3660 else
3661 {
3666 }
3667 }
3669 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3670 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3671 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3672 new one is created. */
3674 static tree
3676 tsubst_flags_t complain)
3677 {
3682 {
3701 /* Template template parameters need this. */
3706 }
3709 }
3711 /* Process information from new template parameter PARM and append it
3712 to the LIST being built. This new parameter is a non-type
3713 parameter iff IS_NON_TYPE is true. This new parameter is a
3714 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3715 is in PARM_LOC. */
3717 tree
3720 {
3722 tree defval;
3729 {
3733 {
3737 else
3739 }
3742 }
3745 {
3751 {
3752 /* [temp.param]
3754 The top-level cv-qualifiers on the template-parameter are
3755 ignored when determining its type. */
3760 && !is_parameter_pack
3761 /* If we're in a nested template parameter list, the template
3762 template parameter could be a parameter pack. */
3764 {
3765 /* This template parameter is not a parameter pack, but it
3766 should be. Complain about "bare" parameter packs. */
3769 /* Recover by calling this a parameter pack. */
3771 }
3772 }
3774 /* A template parameter is not modifiable. */
3783 processing_template_decl,
3788 }
3789 else
3790 {
3791 tree t;
3795 {
3797 /* This is for distinguishing between real templates and template
3798 template parameters */
3802 }
3803 else
3804 {
3806 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3809 }
3816 processing_template_decl,
3820 }
3826 }
3828 /* The end of a template parameter list has been reached. Process the
3829 tree list into a parameter vector, converting each parameter into a more
3830 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3831 as PARM_DECLs. */
3833 tree
3835 {
3840 current_template_parms
3845 {
3849 }
3854 }
3856 /* end_template_decl is called after a template declaration is seen. */
3858 void
3860 {
3866 /* This matches the pushlevel in begin_template_parm_list. */
3871 }
3873 /* Takes a TREE_LIST representing a template parameter and convert it
3874 into an argument suitable to be passed to the type substitution
3875 functions. Note that If the TREE_LIST contains an error_mark
3876 node, the returned argument is error_mark_node. */
3878 static tree
3880 {
3893 {
3897 {
3898 /* Turn this argument into a TYPE_ARGUMENT_PACK
3899 with a single element, which expands T. */
3901 #ifdef ENABLE_CHECKING
3902 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3904 #endif
3909 }
3910 }
3911 else
3912 {
3916 {
3917 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3918 with a single element, which expands T. */
3921 #ifdef ENABLE_CHECKING
3922 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3924 #endif
3931 }
3932 else
3934 }
3936 }
3938 /* Given a set of template parameters, return them as a set of template
3939 arguments. The template parameters are represented as a TREE_VEC, in
3940 the form documented in cp-tree.h for template arguments. */
3942 static tree
3944 {
3945 tree header;
3950 /* If there is only one level of template parameters, we do not
3951 create a TREE_VEC of TREE_VECs. Instead, we return a single
3952 TREE_VEC containing the arguments. */
3957 {
3965 #ifdef ENABLE_CHECKING
3967 #endif
3971 else
3973 }
3976 /* This can happen for template parms of a template template
3977 parameter, e.g:
3979 template<template<class T, class U> class TT> struct S;
3981 Consider the level of the parms of TT; T and U both have
3982 level 2; TT has no template parm of level 1. So in this case
3983 the first element of full_template_args is NULL_TREE. If we
3984 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3985 of 2. This will make tsubst wrongly consider that T and U
3986 have level 1. Instead, let's create a dummy vector as the
3987 first element of full_template_args so that TMPL_ARGS_DEPTH
3988 returns the correct depth for args. */
3991 }
3993 /* Within the declaration of a template, return the currently active
3994 template parameters as an argument TREE_VEC. */
3996 static tree
3998 {
4000 }
4002 /* Update the declared TYPE by doing any lookups which were thought to be
4003 dependent, but are not now that we know the SCOPE of the declarator. */
4005 tree
4007 {
4018 /* Don't bother building up the args in this case. */
4020 {
4021 /* tsubst in the args corresponding to the template parameters,
4022 including auto if present. Most things will be unchanged, but
4023 make_typename_type and tsubst_qualified_id will resolve
4024 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4027 tree pushed;
4029 {
4033 }
4038 }
4044 {
4047 else
4049 }
4051 }
4053 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4054 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4055 a member template. Used by push_template_decl below. */
4057 static tree
4059 {
4067 }
4069 struct template_parm_data
4070 {
4071 /* The level of the template parameters we are currently
4072 processing. */
4075 /* The index of the specialization argument we are currently
4076 processing. */
4079 /* An array whose size is the number of template parameters. The
4080 elements are nonzero if the parameter has been used in any one
4081 of the arguments processed so far. */
4084 /* An array whose size is the number of template arguments. The
4085 elements are nonzero if the argument makes use of template
4086 parameters of this level. */
4088 };
4090 /* Subroutine of push_template_decl used to see if each template
4091 parameter in a partial specialization is used in the explicit
4092 argument list. If T is of the LEVEL given in DATA (which is
4093 treated as a template_parm_data*), then DATA->PARMS is marked
4094 appropriately. */
4096 static int
4098 {
4106 {
4109 }
4111 /* Return zero so that for_each_template_parm will continue the
4112 traversal of the tree; we want to mark *every* template parm. */
4114 }
4116 /* Process the partial specialization DECL. */
4118 static tree
4120 {
4127 tree inner_parms;
4128 tree inst;
4141 /* We check that each of the template parameters given in the
4142 partial specialization is used in the argument list to the
4143 specialization. For example:
4145 template <class T> struct S;
4146 template <class T> struct S<T*>;
4148 The second declaration is OK because `T*' uses the template
4149 parameter T, whereas
4151 template <class T> struct S<int>;
4153 is no good. Even trickier is:
4155 template <class T>
4156 struct S1
4157 {
4158 template <class U>
4159 struct S2;
4160 template <class U>
4161 struct S2<T>;
4162 };
4164 The S2<T> declaration is actually invalid; it is a
4165 full-specialization. Of course,
4167 template <class U>
4168 struct S2<T (*)(U)>;
4170 or some such would have been OK. */
4178 {
4183 NULL,
4185 }
4188 {
4189 /* One of the template parms was not used in a deduced context in the
4190 specialization. */
4192 {
4196 }
4200 }
4205 /* [temp.class.spec]
4207 The argument list of the specialization shall not be identical to
4208 the implicit argument list of the primary template. */
4209 tree main_args
4215 /* A partial specialization that replaces multiple parameters of the
4216 primary template with a pack expansion is less specialized for those
4217 parameters. */
4219 {
4221 "primary template because it replaces multiple parameters "
4225 }
4227 /* [temp.class.spec]
4229 A partially specialized non-type argument expression shall not
4230 involve template parameters of the partial specialization except
4231 when the argument expression is a simple identifier.
4233 The type of a template parameter corresponding to a specialized
4234 non-type argument shall not be dependent on a parameter of the
4235 specialization.
4237 Also, we verify that pack expansions only occur at the
4238 end of the argument list. */
4242 {
4249 {
4250 /* Extract the arguments from the argument pack. We'll be
4251 iterating over these in the following loop. */
4254 }
4257 {
4259 /* Get the Jth argument in the parameter pack. */
4263 {
4264 /* Pack expansions must come at the end of the
4265 argument list. */
4268 {
4272 else
4275 }
4276 }
4279 /* We only care about the pattern. */
4285 /* This next two lines are the `argument expression is not just a
4286 simple identifier' condition and also the `specialized
4287 non-type argument' bit. */
4291 {
4295 arg);
4296 else
4297 {
4298 /* Look at the corresponding template parameter,
4299 marking which template parameters its type depends
4300 upon. */
4304 {
4305 /* We haven't yet initialized TPD2. Do so now. */
4307 /* The number of parameters here is the number in the
4308 main template, which, as checked in the assertion
4309 above, is NARGS. */
4313 }
4315 /* Mark the template parameters. But this time, we're
4316 looking for the template parameters of the main
4317 template, not in the specialization. */
4324 NULL,
4328 {
4329 /* The type depended on some template parameters.
4330 If they are fully specialized in the
4331 specialization, that's OK. */
4340 "type %qT of template argument %qE depends "
4342 "type %qT of template argument %qE depends "
4344 type,
4345 arg);
4346 }
4347 }
4348 }
4349 }
4350 }
4352 /* We should only get here once. */
4371 {
4377 {
4380 {
4384 "partial specialization of %qD after instantiation "
4386 }
4387 }
4388 }
4391 }
4393 /* PARM is a template parameter of some form; return the corresponding
4394 TEMPLATE_PARM_INDEX. */
4396 static tree
4398 {
4410 }
4412 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4413 parameter packs used by the template parameter PARM. */
4415 static void
4417 {
4418 /* A type parm can't refer to another parm. */
4422 {
4426 }
4433 }
4435 /* PARM is a template parameter pack. Return any parameter packs used in
4436 its type or the type of any of its template parameters. If there are
4437 any such packs, it will be instantiated into a fixed template parameter
4438 list by partial instantiation rather than be fully deduced. */
4440 tree
4442 {
4443 /* This can only be true in a member template. */
4446 /* This can only be true for a parameter pack. */
4449 /* A type parm can't refer to another parm. */
4462 }
4464 /* Check that a template declaration's use of default arguments and
4465 parameter packs is not invalid. Here, PARMS are the template
4466 parameters. IS_PRIMARY is true if DECL is the thing declared by
4467 a primary template. IS_PARTIAL is true if DECL is a partial
4468 specialization.
4470 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4471 declaration (but not a definition); 1 indicates a declaration, 2
4472 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4473 emitted for extraneous default arguments.
4475 Returns TRUE if there were no errors found, FALSE otherwise. */
4477 bool
4480 {
4483 tree parm_level;
4486 /* [temp.param]
4488 A default template-argument shall not be specified in a
4489 function template declaration or a function template definition, nor
4490 in the template-parameter-list of the definition of a member of a
4491 class template. */
4495 /* You can't have a function template declaration in a local
4496 scope, nor you can you define a member of a class template in a
4497 local scope. */
4505 /* A lambda doesn't have an explicit declaration; don't complain
4506 about the parms of the enclosing class. */
4513 /* If this is either a friend defined in the scope of the class
4514 or a member function. */
4520 /* And, if it was a member function, it really was defined in
4521 the scope of the class. */
4524 /* We already checked these parameters when the template was
4525 declared, so there's no need to do it again now. This function
4526 was defined in class scope, but we're processing its body now
4527 that the class is complete. */
4530 /* Core issue 226 (C++0x only): the following only applies to class
4531 templates. */
4534 {
4535 /* [temp.param]
4537 If a template-parameter has a default template-argument, all
4538 subsequent template-parameters shall have a default
4539 template-argument supplied. */
4541 {
4548 {
4558 {
4560 /* For better subsequent error-recovery, we indicate that
4561 there should have been a default argument. */
4564 }
4566 && !is_friend_decl
4567 /* Don't complain about an enclosing partial
4568 specialization. */
4573 /* A fixed parameter pack will be partially
4574 instantiated into a fixed length list. */
4576 {
4577 /* A primary class template can only have one
4578 parameter pack, at the end of the template
4579 parameter list. */
4587 }
4588 }
4589 }
4590 }
4593 || is_partial
4594 || !is_primary
4596 /* For an ordinary class template, default template arguments are
4597 allowed at the innermost level, e.g.:
4598 template <class T = int>
4599 struct S {};
4600 but, in a partial specialization, they're not allowed even
4601 there, as we have in [temp.class.spec]:
4603 The template parameter list of a specialization shall not
4604 contain default template argument values.
4606 So, for a partial specialization, or for a function template
4607 (in C++98/C++03), we look at all of them. */
4608 ;
4609 else
4610 /* But, for a primary class template that is not a partial
4611 specialization we look at all template parameters except the
4612 innermost ones. */
4615 /* Figure out what error message to issue. */
4628 else
4632 /* If we're inside a class definition, there's no need to
4633 examine the parameters to the class itself. On the one
4634 hand, they will be checked when the class is defined, and,
4635 on the other, default arguments are valid in things like:
4636 template <class T = double>
4637 struct S { template <class U> void f(U); };
4638 Here the default argument for `S' has no bearing on the
4639 declaration of `f'. */
4641 else
4642 /* Check everything. */
4648 {
4655 {
4660 {
4662 {
4669 }
4671 /* Clear out the default argument so that we are not
4672 confused later. */
4674 }
4675 }
4677 /* At this point, if we're still interested in issuing messages,
4678 they must apply to classes surrounding the object declared. */
4682 }
4685 }
4687 /* Worker for push_template_decl_real, called via
4688 for_each_template_parm. DATA is really an int, indicating the
4689 level of the parameters we are interested in. If T is a template
4690 parameter of that level, return nonzero. */
4692 static int
4694 {
4700 else
4703 }
4705 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4706 parameters given by current_template_args, or reuses a
4707 previously existing one, if appropriate. Returns the DECL, or an
4708 equivalent one, if it is replaced via a call to duplicate_decls.
4710 If IS_FRIEND is true, DECL is a friend declaration. */
4712 tree
4714 {
4715 tree tmpl;
4716 tree args;
4717 tree info;
4718 tree ctx;
4722 /* True if the template is a member template, in the sense of
4723 [temp.mem]. */
4729 /* See if this is a partial specialization. */
4742 /* For a friend, we want the context of the friend function, not
4743 the type of which it is a friend. */
4747 /* In the case of a virtual function, we want the class in which
4748 it is defined. */
4750 else
4751 /* Otherwise, if we're currently defining some class, the DECL
4752 is assumed to be a member of the class. */
4761 /* See if this is a primary template. */
4764 /* A friend template that specifies a class context, i.e.
4765 template <typename T> friend void A<T>::f();
4766 is not primary. */
4771 else
4775 {
4780 {
4783 }
4785 {
4787 {
4790 }
4792 {
4793 /* [temp.mem]
4795 A destructor shall not be a member template. */
4798 }
4805 {
4806 /* [basic.stc.dynamic.allocation]
4808 An allocation function can be a function
4809 template. ... Template allocation functions shall
4810 have two or more parameters. */
4813 }
4814 }
4820 /* alias-declaration */
4824 else
4825 {
4828 }
4829 }
4831 /* Check to see that the rules regarding the use of default
4832 arguments are not being violated. */
4836 /* Ensure that there are no parameter packs in the type of this
4837 declaration that have not been expanded. */
4839 {
4840 /* Check each of the arguments individually to see if there are
4841 any bare parameter packs. */
4847 {
4850 {
4851 /* This is a PARM_DECL that contains unexpanded parameter
4852 packs. We have already complained about this in the
4853 check_for_bare_parameter_packs call, so just replace
4854 these types with ERROR_MARK_NODE. */
4857 }
4861 }
4863 /* Check for bare parameter packs in the return type and the
4864 exception specifiers. */
4866 /* Errors were already issued, set return type to int
4867 as the frontend doesn't expect error_mark_node as
4868 the return type. */
4872 }
4877 {
4880 }
4893 {
4898 /* If DECL is a TYPE_DECL for a class-template, then there won't
4899 be DECL_LANG_SPECIFIC. The information equivalent to
4900 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4904 {
4905 /* Since a template declaration already existed for this
4906 class-type, we must be redeclaring it here. Make sure
4907 that the redeclaration is valid. */
4909 current_template_parms);
4910 /* We don't need to create a new TEMPLATE_DECL; just use the
4911 one we already had. */
4913 }
4914 else
4915 {
4917 member_template_p);
4922 {
4923 /* A specialization of a member template of a template
4924 class. */
4928 }
4929 }
4930 }
4931 else
4932 {
4938 {
4941 }
4949 {
4950 tree new_tmpl;
4952 /* The declaration is a specialization of a member
4953 template, declared outside the class. Therefore, the
4954 innermost template arguments will be NULL, so we
4955 replace them with the arguments determined by the
4956 earlier call to check_explicit_specialization. */
4959 new_tmpl
4961 member_template_p);
4971 args,
4974 }
4976 /* Make sure the template headers we got make sense. */
4981 {
4986 }
4987 else
4989 {
4994 {
4998 else
5002 /* Avoid crash in import_export_decl. */
5005 }
5010 /* Can happen in erroneous input. */
5012 else
5014 }
5016 /* Check that the parms are used in the appropriate qualifying scopes
5017 in the declarator. */
5021 {
5027 /* Avoid crash in import_export_decl. */
5030 }
5031 }
5036 /* Push template declarations for global functions and types. Note
5037 that we do not try to push a global template friend declared in a
5038 template class; such a thing may well depend on the template
5039 parameters of the class. */
5042 {
5047 /* Hide template friend classes that haven't been declared yet. */
5049 {
5052 }
5053 }
5056 {
5062 {
5065 /* It is a conversion operator. See if the type converted to
5066 depends on innermost template operands. */
5069 depth))
5071 }
5073 /* Give template template parms a DECL_CONTEXT of the template
5074 for which they are a parameter. */
5077 {
5081 }
5082 }
5084 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5085 back to its most general template. If TMPL is a specialization,
5086 ARGS may only have the innermost set of arguments. Add the missing
5087 argument levels if necessary. */
5095 else
5096 {
5101 }
5104 && !is_friend
5107 /* Set DECL_COMDAT on template instantiations; if we force
5108 them to be emitted by explicit instantiation or -frepo,
5109 mark_needed will tell cgraph to do the right thing. */
5113 }
5115 tree
5117 {
5119 }
5121 /* FN is an inheriting constructor that inherits from the constructor
5122 template INHERITED; turn FN into a constructor template with a matching
5123 template header. */
5125 tree
5127 {
5128 tree inner_parms
5131 tree parms
5142 }
5144 /* Called when a class template TYPE is redeclared with the indicated
5145 template PARMS, e.g.:
5147 template <class T> struct S;
5148 template <class T> struct S {}; */
5150 bool
5152 {
5153 tree tmpl;
5154 tree tmpl_parms;
5158 {
5161 }
5165 /* The type is nested in some template class. Nothing to worry
5166 about here; there are no new template parameters for the nested
5167 type. */
5171 {
5173 tmpl);
5175 }
5181 {
5191 }
5194 {
5195 tree tmpl_parm;
5196 tree parm;
5197 tree tmpl_default;
5198 tree parm_default;
5212 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5213 TEMPLATE_DECL. */
5223 {
5227 }
5230 {
5231 /* We have in [temp.param]:
5233 A template-parameter may not be given default arguments
5234 by two different declarations in the same scope. */
5239 }
5242 /* Update the previous template parameters (which are the ones
5243 that will really count) with the new default value. */
5246 /* Update the new parameters, too; they'll be used as the
5247 parameters for any members. */
5249 }
5252 }
5254 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5255 to be used when the caller has already checked
5256 (processing_template_decl
5257 && !instantiation_dependent_expression_p (expr)
5258 && potential_constant_expression (expr))
5259 and cleared processing_template_decl. */
5261 tree
5263 {
5266 complain,
5270 }
5272 /* Simplify EXPR if it is a non-dependent expression. Returns the
5273 (possibly simplified) expression. */
5275 tree
5277 {
5281 /* If we're in a template, but EXPR isn't value dependent, simplify
5282 it. We're supposed to treat:
5284 template <typename T> void f(T[1 + 1]);
5285 template <typename T> void f(T[2]);
5287 as two declarations of the same function, for example. */
5291 {
5292 processing_template_decl_sentinel s;
5294 }
5296 }
5298 tree
5300 {
5302 }
5304 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5305 template declaration, or a TYPE_DECL for an alias declaration. */
5307 bool
5309 {
5317 }
5319 /* Return TRUE iff T is a specialization of an alias template. */
5321 bool
5323 {
5324 /* It's an alias template specialization if it's an alias and its
5325 TYPE_NAME is a specialization of a primary template. */
5327 {
5331 {
5334 }
5335 }
5337 }
5339 /* Return TRUE iff T is a specialization of an alias template with
5340 dependent template-arguments. */
5342 bool
5344 {
5346 && (any_dependent_template_arguments_p
5348 }
5350 /* Return the number of innermost template parameters in TMPL. */
5352 static int
5354 {
5357 }
5359 /* Return either TMPL or another template that it is equivalent to under DR
5360 1286: An alias that just changes the name of a template is equivalent to
5361 the other template. */
5363 static tree
5365 {
5368 {
5371 {
5376 {
5377 tree alias_args = INNERMOST_TEMPLATE_ARGS
5381 /* The alias type is equivalent to the pattern of the
5382 underlying template, so strip the alias. */
5385 }
5386 }
5388 }
5390 }
5392 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5393 must be a function or a pointer-to-function type, as specified
5394 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5395 and check that the resulting function has external linkage. */
5397 static tree
5399 tsubst_flags_t complain)
5400 {
5403 linkage_kind linkage;
5415 /* [temp.arg.nontype]/1
5417 A template-argument for a non-type, non-template template-parameter
5418 shall be one of:
5419 [...]
5420 -- the address of an object or function with external [C++11: or
5421 internal] linkage. */
5424 {
5426 {
5432 else
5435 }
5437 }
5441 {
5443 {
5448 else
5452 }
5454 }
5457 }
5459 /* Subroutine of convert_nontype_argument.
5460 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5461 Emit an error otherwise. */
5463 static bool
5465 tsubst_flags_t complain)
5466 {
5477 {
5481 }
5483 }
5485 /* Returns TRUE iff the address of OP is value-dependent.
5487 14.6.2.4 [temp.dep.temp]:
5488 A non-integral non-type template-argument is dependent if its type is
5489 dependent or it has either of the following forms
5490 qualified-id
5491 & qualified-id
5492 and contains a nested-name-specifier which specifies a class-name that
5493 names a dependent type.
5495 We generalize this to just say that the address of a member of a
5496 dependent class is value-dependent; the above doesn't cover the
5497 address of a static data member named with an unqualified-id. */
5499 static bool
5501 {
5502 /* We could use get_inner_reference here, but there's no need;
5503 this is only relevant for template non-type arguments, which
5504 can only be expressed as &id-expression. */
5506 {
5510 }
5513 }
5515 /* The next set of functions are used for providing helpful explanatory
5516 diagnostics for failed overload resolution. Their messages should be
5517 indented by two spaces for consistency with the messages in
5518 call.c */
5520 static int
5522 {
5524 }
5526 static int
5528 {
5533 }
5535 static int
5537 {
5539 }
5541 static int
5543 {
5549 }
5551 static int
5553 {
5557 }
5559 static int
5561 {
5564 " template parameter %qD is not a parameter pack, but "
5568 }
5570 static int
5572 {
5575 " template argument %qE does not match "
5579 }
5581 static int
5583 {
5587 }
5589 static int
5591 {
5597 }
5599 static int
5601 {
5603 {
5608 else
5610 " deduced conflicting values for non-type parameter "
5612 }
5614 }
5616 static int
5618 {
5621 " variable-sized array type %qT is not "
5623 arg);
5625 }
5627 static int
5629 {
5633 arg);
5635 }
5637 static int
5639 {
5641 {
5647 else
5652 }
5654 }
5656 static int
5658 {
5660 }
5662 static int
5665 {
5667 }
5669 static int
5672 {
5678 }
5680 static int
5683 {
5686 {
5694 }
5696 }
5698 static int
5700 {
5703 " template parameters of a template template argument are "
5706 }
5708 static int
5710 {
5716 }
5718 static int
5720 {
5725 }
5727 static int
5729 {
5733 arg);
5735 }
5737 /* Attempt to convert the non-type template parameter EXPR to the
5738 indicated TYPE. If the conversion is successful, return the
5739 converted value. If the conversion is unsuccessful, return
5740 NULL_TREE if we issued an error message, or error_mark_node if we
5741 did not. We issue error messages for out-and-out bad template
5742 parameters, but not simply because the conversion failed, since we
5743 might be just trying to do argument deduction. Both TYPE and EXPR
5744 must be non-dependent.
5746 The conversion follows the special rules described in
5747 [temp.arg.nontype], and it is much more strict than an implicit
5748 conversion.
5750 This function is called twice for each template argument (see
5751 lookup_template_class for a more accurate description of this
5752 problem). This means that we need to handle expressions which
5753 are not valid in a C++ source, but can be created from the
5754 first call (for instance, casts to perform conversions). These
5755 hacks can go away after we fix the double coercion problem. */
5757 static tree
5759 {
5760 tree expr_type;
5762 /* Detect immediately string literals as invalid non-type argument.
5763 This special-case is not needed for correctness (we would easily
5764 catch this later), but only to provide better diagnostic for this
5765 common user mistake. As suggested by DR 100, we do not mention
5766 linkage issues in the diagnostic as this is not the point. */
5767 /* FIXME we're making this OK. */
5769 {
5775 }
5777 /* Add the ADDR_EXPR now for the benefit of
5778 value_dependent_expression_p. */
5781 {
5785 }
5787 /* If we are in a template, EXPR may be non-dependent, but still
5788 have a syntactic, rather than semantic, form. For example, EXPR
5789 might be a SCOPE_REF, rather than the VAR_DECL to which the
5790 SCOPE_REF refers. Preserving the qualifying scope is necessary
5791 so that access checking can be performed when the template is
5792 instantiated -- but here we need the resolved form so that we can
5793 convert the argument. */
5799 && processing_template_decl
5808 else
5811 /* If the argument is non-dependent, perform any conversions in
5812 non-dependent context as well. */
5817 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5818 to a non-type argument of "nullptr". */
5822 /* In C++11, integral or enumeration non-type template arguments can be
5823 arbitrary constant expressions. Pointer and pointer to
5824 member arguments can be general constant expressions that evaluate
5825 to a null value, but otherwise still need to be of a specific form. */
5827 {
5829 /* A PTRMEM_CST is already constant, and a valid template
5830 argument for a parameter of pointer to member type, we just want
5831 to leave it in that form rather than lower it to a
5836 {
5841 }
5842 }
5844 /* HACK: Due to double coercion, we can get a
5845 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5846 which is the tree that we built on the first call (see
5847 below when coercing to reference to object or to reference to
5848 function). We just strip everything and get to the arg.
5849 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5850 for examples. */
5852 {
5858 {
5859 /* ??? Maybe we could use convert_from_reference here, but we
5860 would need to relax its constraints because the NOP_EXPR
5861 could actually change the type to something more cv-qualified,
5862 and this is not folded by convert_from_reference. */
5867 && (same_type_ignoring_top_level_qualifiers_p
5870 {
5873 }
5874 }
5875 }
5877 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5878 parameter is a pointer to object, through decay and
5879 qualification conversion. Let's strip everything. */
5881 {
5886 {
5887 /* Skip the ADDR_EXPR only if it is part of the decay for
5888 an array. Otherwise, it is part of the original argument
5889 in the source code. */
5894 }
5895 }
5897 /* [temp.arg.nontype]/5, bullet 1
5899 For a non-type template-parameter of integral or enumeration type,
5900 integral promotions (_conv.prom_) and integral conversions
5901 (_conv.integral_) are applied. */
5903 {
5912 /* Notice that there are constant expressions like '4 % 0' which
5913 do not fold into integer constants. */
5915 {
5917 {
5928 /* else cxx_constant_value complained but gave us
5929 a real constant, so go ahead. */
5931 }
5932 else
5934 }
5936 /* Avoid typedef problems. */
5939 }
5940 /* [temp.arg.nontype]/5, bullet 2
5942 For a non-type template-parameter of type pointer to object,
5943 qualification conversions (_conv.qual_) and the array-to-pointer
5944 conversion (_conv.array_) are applied. */
5946 {
5947 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5949 A template-argument for a non-type, non-template template-parameter
5950 shall be one of: [...]
5952 -- the name of a non-type template-parameter;
5953 -- the address of an object or function with external linkage, [...]
5954 expressed as "& id-expression" where the & is optional if the name
5955 refers to a function or array, or if the corresponding
5956 template-parameter is a reference.
5958 Here, we do not care about functions, as they are invalid anyway
5959 for a parameter of type pointer-to-object. */
5962 /* Non-type template parameters are OK. */
5963 ;
5968 {
5970 {
5973 "because %qD is a variable, not the address of "
5976 }
5978 {
5984 }
5985 /* Other values, like integer constants, might be valid
5986 non-type arguments of some other type. */
5988 }
5989 else
5990 {
5991 tree decl;
5996 {
6001 }
6003 {
6009 }
6011 {
6016 }
6017 }
6026 }
6027 /* [temp.arg.nontype]/5, bullet 3
6029 For a non-type template-parameter of type reference to object, no
6030 conversions apply. The type referred to by the reference may be more
6031 cv-qualified than the (otherwise identical) type of the
6032 template-argument. The template-parameter is bound directly to the
6033 template-argument, which must be an lvalue. */
6035 {
6037 expr_type))
6041 {
6046 }
6049 {
6054 }
6056 /* [temp.arg.nontype]/1
6058 A template-argument for a non-type, non-template template-parameter
6059 shall be one of: [...]
6061 -- the address of an object or function with external linkage. */
6064 {
6067 {
6070 "because a reference variable does not have a constant "
6073 }
6074 }
6077 {
6083 }
6086 {
6092 }
6095 }
6096 /* [temp.arg.nontype]/5, bullet 4
6098 For a non-type template-parameter of type pointer to function, only
6099 the function-to-pointer conversion (_conv.func_) is applied. If the
6100 template-argument represents a set of overloaded functions (or a
6101 pointer to such), the matching function is selected from the set
6102 (_over.over_). */
6104 {
6105 /* If the argument is a template-id, we might not have enough
6106 context information to decay the pointer. */
6108 {
6112 }
6115 /* Null pointer values are OK in C++11. */
6121 }
6122 /* [temp.arg.nontype]/5, bullet 5
6124 For a non-type template-parameter of type reference to function, no
6125 conversions apply. If the template-argument represents a set of
6126 overloaded functions, the matching function is selected from the set
6127 (_over.over_). */
6129 {
6131 {
6133 {
6138 }
6140 }
6147 }
6148 /* [temp.arg.nontype]/5, bullet 6
6150 For a non-type template-parameter of type pointer to member function,
6151 no conversions apply. If the template-argument represents a set of
6152 overloaded member functions, the matching member function is selected
6153 from the set (_over.over_). */
6155 {
6160 /* [temp.arg.nontype] bullet 1 says the pointer to member
6161 expression must be a pointer-to-member constant. */
6165 /* There is no way to disable standard conversions in
6166 resolve_address_of_overloaded_function (called by
6167 instantiate_type). It is possible that the call succeeded by
6168 converting &B::I to &D::I (where B is a base of D), so we need
6169 to reject this conversion here.
6171 Actually, even if there was a way to disable standard conversions,
6172 it would still be better to reject them here so that we can
6173 provide a superior diagnostic. */
6175 {
6177 {
6181 /* If we are just one standard conversion off, explain. */
6185 }
6187 }
6188 }
6189 /* [temp.arg.nontype]/5, bullet 7
6191 For a non-type template-parameter of type pointer to data member,
6192 qualification conversions (_conv.qual_) are applied. */
6194 {
6195 /* [temp.arg.nontype] bullet 1 says the pointer to member
6196 expression must be a pointer-to-member constant. */
6203 }
6205 {
6207 {
6212 }
6214 }
6215 /* A template non-type parameter must be one of the above. */
6216 else
6219 /* Sanity check: did we actually convert the argument to the
6220 right type? */
6224 }
6226 /* Subroutine of coerce_template_template_parms, which returns 1 if
6227 PARM_PARM and ARG_PARM match using the rule for the template
6228 parameters of template template parameters. Both PARM and ARG are
6229 template parameters; the rest of the arguments are the same as for
6230 coerce_template_template_parms.
6231 */
6232 static int
6234 tree arg,
6235 tsubst_flags_t complain,
6236 tree in_decl,
6237 tree outer_args)
6238 {
6247 {
6249 /* We encounter instantiations of templates like
6250 template <template <template <class> class> class TT>
6251 class C; */
6252 {
6259 }
6260 /* Fall through. */
6265 /* Argument is a parameter pack but parameter is not. */
6270 /* The tsubst call is used to handle cases such as
6272 template <int> class C {};
6273 template <class T, template <T> class TT> class D {};
6274 D<int, C> d;
6276 i.e. the parameter list of TT depends on earlier parameters. */
6278 && !same_type_p
6285 /* Argument is a parameter pack but parameter is not. */
6292 }
6295 }
6298 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6299 template template parameters. Both PARM_PARMS and ARG_PARMS are
6300 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6301 or PARM_DECL.
6303 Consider the example:
6304 template <class T> class A;
6305 template<template <class U> class TT> class B;
6307 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6308 the parameters to A, and OUTER_ARGS contains A. */
6310 static int
6312 tree arg_parms,
6313 tsubst_flags_t complain,
6314 tree in_decl,
6315 tree outer_args)
6316 {
6327 /* Determine whether we have a parameter pack at the end of the
6328 template template parameter's template parameter list. */
6330 {
6337 {
6351 }
6352 }
6358 /* Check all of the template parameters except the parameter pack at
6359 the end (if any). */
6361 {
6370 outer_args))
6373 }
6376 {
6377 /* Check each of the template parameters in the template
6378 argument against the template parameter pack at the end of
6379 the template template parameter. */
6386 {
6393 outer_args))
6395 }
6396 }
6399 }
6401 /* Verifies that the deduced template arguments (in TARGS) for the
6402 template template parameters (in TPARMS) represent valid bindings,
6403 by comparing the template parameter list of each template argument
6404 to the template parameter list of its corresponding template
6405 template parameter, in accordance with DR150. This
6406 routine can only be called after all template arguments have been
6407 deduced. It will return TRUE if all of the template template
6408 parameter bindings are okay, FALSE otherwise. */
6409 bool
6411 {
6415 /* We're dealing with template parms in this process. */
6421 {
6426 {
6431 {
6432 /* Look inside the argument pack. */
6435 }
6438 {
6442 /* Extract the next argument from the argument
6443 pack. */
6447 /* Look at the pattern of the pack expansion. */
6450 /* Extract the template parameters from the template
6451 argument. */
6457 /* Verify that we can coerce the template template
6458 parameters from the template argument to the template
6459 parameter. This requires an exact match. */
6461 && !coerce_template_template_parms
6463 targ_parms,
6464 tf_none,
6465 tparm,
6466 targs))
6467 {
6470 }
6471 }
6472 }
6473 }
6475 out:
6479 }
6481 /* Since type attributes aren't mangled, we need to strip them from
6482 template type arguments. */
6484 static tree
6486 {
6487 tree mv;
6494 {
6499 }
6501 }
6503 /* Convert the indicated template ARG as necessary to match the
6504 indicated template PARM. Returns the converted ARG, or
6505 error_mark_node if the conversion was unsuccessful. Error and
6506 warning messages are issued under control of COMPLAIN. This
6507 conversion is for the Ith parameter in the parameter list. ARGS is
6508 the full set of template arguments deduced so far. */
6510 static tree
6512 tree arg,
6513 tree args,
6514 tsubst_flags_t complain,
6516 tree in_decl)
6517 {
6518 tree orig_arg;
6519 tree val;
6527 {
6528 /* The template argument was the name of some
6529 member function. That's usually
6530 invalid, but static members are OK. In any
6531 case, grab the underlying fields/functions
6532 and issue an error later if required. */
6535 }
6543 /* When determining whether an argument pack expansion is a template,
6544 look at the pattern. */
6548 /* Deal with an injected-class-name used as a template template arg. */
6550 {
6553 {
6563 }
6564 }
6566 is_tmpl_type =
6582 {
6584 {
6588 }
6591 "to refer to a type member of a template parameter, "
6596 typename_type,
6597 complain);
6600 }
6602 {
6604 {
6606 {
6618 else
6621 }
6622 }
6624 }
6626 {
6628 {
6635 else
6638 }
6640 }
6643 {
6645 {
6649 /* The number of argument required is not known yet.
6650 Just accept it for now. */
6652 else
6653 {
6655 tree argparm;
6657 /* Strip alias templates that are equivalent to another
6658 template. */
6664 args))
6665 {
6668 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6669 TEMPLATE_DECL. */
6671 {
6676 }
6677 }
6678 else
6679 {
6681 {
6688 }
6691 }
6692 }
6693 }
6694 else
6696 /* We only form one instance of each template specialization.
6697 Therefore, if we use a non-canonical variant (i.e., a
6698 typedef), any future messages referring to the type will use
6699 the typedef, which is confusing if those future uses do not
6700 themselves also use the typedef. */
6703 }
6704 else
6705 {
6712 {
6715 else
6716 {
6717 /* Not sure if this is reachable, but it doesn't hurt
6718 to be robust. */
6721 }
6722 }
6725 /* We used to call digest_init here. However, digest_init
6726 will report errors, which we don't want when complain
6727 is zero. More importantly, digest_init will try too
6728 hard to convert things: for example, `0' should not be
6729 converted to pointer type at this point according to
6730 the standard. Accepting this is not merely an
6731 extension, since deciding whether or not these
6732 conversions can occur is part of determining which
6733 function template to call, or whether a given explicit
6734 argument specification is valid. */
6736 else
6745 {
6746 /* Strip typedefs from the SCOPE_REF. */
6749 complain);
6752 }
6753 }
6756 }
6758 /* Coerces the remaining template arguments in INNER_ARGS (from
6759 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6760 Returns the coerced argument pack. PARM_IDX is the position of this
6761 parameter in the template parameter list. ARGS is the original
6762 template argument list. */
6763 static tree
6766 tree args,
6767 tree inner_args,
6769 tree new_args,
6771 tree in_decl,
6772 tsubst_flags_t complain)
6773 {
6776 tree packed_args;
6777 tree argument_pack;
6784 {
6785 /* When the template parameter is a non-type template parameter pack
6786 or template template parameter pack whose type or template
6787 parameters use parameter packs, we know exactly how many arguments
6788 we are looking for. Build a vector of the instantiated decls for
6789 these template parameters in PACKED_PARMS. */
6790 /* We can't use make_pack_expansion here because it would interpret a
6791 _DECL as a use rather than a declaration. */
6805 /* If we're doing a partial instantiation of a member template,
6806 verify that all of the types used for the non-type
6807 template parameter pack are, in fact, valid for non-type
6808 template parameters. */
6811 {
6814 {
6818 }
6819 }
6822 }
6823 else
6826 /* Convert the remaining arguments, which will be a part of the
6827 parameter pack "parm". */
6829 {
6835 {
6836 /* Once we've packed as many args as we have types, stop. */
6840 /* We don't know how many args we have yet, just
6841 use the unconverted ones for now. */
6843 else
6845 }
6848 {
6851 }
6852 else
6855 in_decl);
6859 }
6863 {
6868 }
6873 else
6874 {
6879 }
6882 #ifdef ENABLE_CHECKING
6885 #endif
6887 }
6889 /* Returns the number of pack expansions in the template argument vector
6890 ARGS. */
6892 static int
6894 {
6899 {
6903 }
6905 }
6907 /* Convert all template arguments to their appropriate types, and
6908 return a vector containing the innermost resulting template
6909 arguments. If any error occurs, return error_mark_node. Error and
6910 warning messages are issued under control of COMPLAIN.
6912 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6913 for arguments not specified in ARGS. Otherwise, if
6914 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6915 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6916 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6917 ARGS. */
6919 static tree
6921 tree args,
6922 tree in_decl,
6923 tsubst_flags_t complain,
6926 {
6928 tree orig_inner_args;
6929 tree inner_args;
6930 tree new_args;
6931 tree new_inner_args;
6935 /* When used as a boolean value, indicates whether this is a
6936 variadic template parameter list. Since it's an int, we can also
6937 subtract it from nparms to get the number of non-variadic
6938 parameters. */
6943 /* Likewise for parameters with default arguments. */
6951 /* Determine if there are any parameter packs or default arguments. */
6953 {
6961 }
6964 /* If there are no parameters that follow a parameter pack, we need to
6965 expand any argument packs so that we can deduce a parameter pack from
6966 some non-packed args followed by an argument pack, as in variadic85.C.
6967 If there are such parameters, we need to leave argument packs intact
6968 so the arguments are assigned properly. This can happen when dealing
6969 with a nested class inside a partial specialization of a class
6970 template, as in variadic92.C, or when deducing a template parameter pack
6971 from a sub-declarator, as in variadic114.C. */
6975 /* Count any pack expansion args. */
6981 && require_all_args
6982 && !variadic_args_p
6983 && (!use_default_args
6986 {
6988 {
6990 {
6994 }
6995 else
7001 }
7004 }
7005 /* We can't pass a pack expansion to a non-pack parameter of an alias
7006 template (DR 1430). */
7008 && variadic_args_p
7010 {
7012 {
7014 {
7020 {
7025 }
7026 }
7028 found:;
7029 }
7031 }
7033 /* We need to evaluate the template arguments, even though this
7034 template-id may be nested within a "sizeof". */
7043 {
7044 tree arg;
7045 tree parm;
7047 /* Get the Ith template parameter. */
7051 {
7054 }
7056 /* Calculate the next argument. */
7059 else
7064 {
7065 /* Some arguments will be placed in the
7066 template parameter pack PARM. */
7073 {
7074 /* We don't know how many args we have yet, just use the
7075 unconverted (and still packed) ones for now. */
7079 }
7083 /* Store this argument. */
7085 {
7086 lost++;
7087 /* We are done with all of the arguments. */
7089 }
7090 else
7091 {
7094 }
7097 }
7099 {
7101 {
7102 /* "If every valid specialization of a variadic template
7103 requires an empty template parameter pack, the template is
7104 ill-formed, no diagnostic required." So check that the
7105 pattern works with this parameter. */
7110 in_decl);
7112 {
7116 }
7118 /* Recover from missing typename. */
7122 /* We don't know how many args we have yet, just
7123 use the unconverted ones for now. */
7127 }
7128 }
7130 {
7131 /* There must be a default arg in this case. */
7134 /* The position of the first default template argument,
7135 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
7136 Record that. */
7140 }
7141 else
7145 {
7148 }
7150 /* This only occurs if there was an error in the template
7151 parameter list itself (which we would already have
7152 reported) that we are trying to recover from, e.g., a class
7153 template with a parameter list such as
7154 template<typename..., typename>. */
7156 else
7162 lost++;
7164 }
7169 {
7171 {
7176 }
7178 }
7183 #ifdef ENABLE_CHECKING
7187 #endif
7190 }
7192 /* Like coerce_template_parms. If PARMS represents all template
7193 parameters levels, this function returns a vector of vectors
7194 representing all the resulting argument levels. Note that in this
7195 case, only the innermost arguments are coerced because the
7196 outermost ones are supposed to have been coerced already.
7198 Otherwise, if PARMS represents only (the innermost) vector of
7199 parameters, this function returns a vector containing just the
7200 innermost resulting arguments. */
7202 static tree
7204 tree args,
7205 tree in_decl,
7206 tsubst_flags_t complain,
7209 {
7212 tree coerced_args;
7215 {
7217 tree level;
7223 {
7224 tree l;
7228 require_all_args,
7229 use_default_args);
7230 else
7237 }
7238 }
7239 else
7242 require_all_args,
7243 use_default_args);
7245 }
7247 /* Returns 1 if template args OT and NT are equivalent. */
7249 static int
7251 {
7258 /* For member templates */
7267 {
7284 }
7286 {
7287 /* We get here probably because we are in the middle of substituting
7288 into the pattern of a pack expansion. In that case the
7289 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7290 interested in. So we want to use the initial pack argument for
7291 the comparison. */
7296 }
7298 {
7301 /* Don't treat an alias template specialization with dependent
7302 arguments as equivalent to its underlying type when used as a
7303 template argument; we need them to be distinct so that we
7304 substitute into the specialization arguments at instantiation
7305 time. And aliases can't be equivalent without being ==, so
7306 we don't need to look any deeper. */
7309 else
7311 }
7314 else
7316 }
7318 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7319 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7320 NEWARG_PTR with the offending arguments if they are non-NULL. */
7322 static int
7325 {
7338 {
7343 {
7349 }
7350 }
7352 }
7354 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7355 of template arguments. Returns 0 otherwise. */
7357 int
7359 {
7361 }
7363 static void
7365 {
7375 /* We are called both from instantiate_decl, where we've already had a
7376 tinst_level pushed, and instantiate_template, where we haven't.
7377 Compensate. */
7388 else
7397 }
7400 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7401 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7402 documentation for TEMPLATE_ID_EXPR. */
7404 tree
7406 {
7407 tree type;
7415 {
7418 }
7421 {
7423 unknown_type_node,
7425 arglist);
7427 }
7434 }
7436 /* Within the scope of a template class S<T>, the name S gets bound
7437 (in build_self_reference) to a TYPE_DECL for the class, not a
7438 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7439 or one of its enclosing classes, and that type is a template,
7440 return the associated TEMPLATE_DECL. Otherwise, the original
7441 DECL is returned.
7443 Also handle the case when DECL is a TREE_LIST of ambiguous
7444 injected-class-names from different bases. */
7446 tree
7448 {
7452 /* DR 176: A lookup that finds an injected-class-name (10.2
7453 [class.member.lookup]) can result in an ambiguity in certain cases
7454 (for example, if it is found in more than one base class). If all of
7455 the injected-class-names that are found refer to specializations of
7456 the same class template, and if the name is followed by a
7457 template-argument-list, the reference refers to the class template
7458 itself and not a specialization thereof, and is not ambiguous. */
7460 {
7463 {
7469 }
7472 else
7474 }
7480 }
7482 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7483 parameters, find the desired type.
7485 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7487 IN_DECL, if non-NULL, is the template declaration we are trying to
7488 instantiate.
7490 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7491 the class we are looking up.
7493 Issue error and warning messages under control of COMPLAIN.
7495 If the template class is really a local class in a template
7496 function, then the FUNCTION_CONTEXT is the function in which it is
7497 being instantiated.
7499 ??? Note that this function is currently called *twice* for each
7500 template-id: the first time from the parser, while creating the
7501 incomplete type (finish_template_type), and the second type during the
7502 real instantiation (instantiate_template_class). This is surely something
7503 that we want to avoid. It also causes some problems with argument
7504 coercion (see convert_nontype_argument for more information on this). */
7506 static tree
7509 {
7511 tree t;
7514 spec_entry elt;
7515 hashval_t hash;
7518 {
7522 else
7523 {
7530 }
7533 }
7535 {
7538 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7539 an implicit typename for the second A. Deal with it. */
7544 {
7547 }
7548 }
7551 {
7554 }
7556 {
7560 }
7562 {
7565 }
7567 /* Issue an error message if we didn't find a template. */
7569 {
7573 }
7576 /* Make sure it's a user visible template, if it was named by
7577 the user. */
7580 {
7582 {
7586 }
7588 }
7592 /* An alias that just changes the name of a template is equivalent to the
7593 other template, so if any of the arguments are pack expansions, strip
7594 the alias to avoid problems with a pack expansion passed to a non-pack
7595 alias template parameter (DR 1430). */
7600 {
7601 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7602 template arguments */
7604 tree parm;
7605 tree arglist2;
7606 tree outer;
7610 /* Consider an example where a template template parameter declared as
7612 template <class T, class U = std::allocator<T> > class TT
7614 The template parameter level of T and U are one level larger than
7615 of TT. To proper process the default argument of U, say when an
7616 instantiation `TT<int>' is seen, we need to build the full
7617 arguments containing {int} as the innermost level. Outer levels,
7618 available when not appearing as default template argument, can be
7619 obtained from the arguments of the enclosing template.
7621 Suppose that TT is later substituted with std::vector. The above
7622 instantiation is `TT<int, std::allocator<T> >' with TT at
7623 level 1, and T at level 2, while the template arguments at level 1
7624 becomes {std::vector} and the inner level 2 is {int}. */
7630 /* This is an argument of the current template, so we haven't set
7631 DECL_CONTEXT yet. */
7638 complain,
7648 }
7649 else
7650 {
7652 tree gen_tmpl;
7653 tree type_decl;
7661 /* An error occurred while building the template TEMPL, and a
7662 diagnostic has most certainly been emitted for that
7663 already. Let's propagate that error. */
7672 {
7673 /* We've been given an incomplete set of template arguments.
7674 For example, given:
7676 template <class T> struct S1 {
7677 template <class U> struct S2 {};
7678 template <class U> struct S2<U*> {};
7679 };
7681 we will be called with an ARGLIST of `U*', but the
7682 TEMPLATE will be `template <class T> template
7683 <class U> struct S1<T>::S2'. We must fill in the missing
7684 arguments. */
7685 arglist
7687 arglist);
7689 }
7691 /* Now we should have enough arguments. */
7694 /* From here on, we're only interested in the most general
7695 template. */
7697 /* Calculate the BOUND_ARGS. These will be the args that are
7698 actually tsubst'd into the definition to create the
7699 instantiation. */
7701 {
7702 /* We have multiple levels of arguments to coerce, at once. */
7712 {
7713 tree a;
7717 complain,
7720 else
7721 /* Outer levels should have already been coerced. */
7724 /* Don't process further if one of the levels fails. */
7726 {
7727 /* Restore the ARGLIST to its full size. */
7730 }
7734 /* We temporarily reduce the length of the ARGLIST so
7735 that coerce_template_parms will see only the arguments
7736 corresponding to the template parameters it is
7737 examining. */
7739 }
7741 /* Restore the ARGLIST to its full size. */
7745 }
7746 else
7747 arglist
7750 gen_tmpl,
7751 complain,
7756 /* We were unable to bind the arguments. */
7759 /* In the scope of a template class, explicit references to the
7760 template class refer to the type of the template, not any
7761 instantiation of it. For example, in:
7763 template <class T> class C { void f(C<T>); }
7765 the `C<T>' is just the same as `C'. Outside of the
7766 class, however, such a reference is an instantiation. */
7770 /* comp_template_args is expensive, check it last. */
7772 arglist))
7775 /* If we already have this specialization, return it. */
7786 /* If the deduced arguments are invalid, then the binding
7787 failed. */
7791 complain))
7798 {
7803 }
7813 /* Create the type. */
7815 {
7816 /* The user referred to a specialization of an alias
7817 template represented by GEN_TMPL.
7819 [temp.alias]/2 says:
7821 When a template-id refers to the specialization of an
7822 alias template, it is equivalent to the associated
7823 type obtained by substitution of its
7824 template-arguments for the template-parameters in the
7825 type-id of the alias template. */
7828 /* Note that the call above (by indirectly calling
7829 register_specialization in tsubst_decl) registers the
7830 TYPE_DECL representing the specialization of the alias
7831 template. So next time someone substitutes ARGLIST for
7832 the template parms into the alias template (GEN_TMPL),
7833 she'll get that TYPE_DECL back. */
7837 }
7839 {
7841 {
7850 }
7851 else
7852 {
7853 /* We don't want to call start_enum for this type, since
7854 the values for the enumeration constants may involve
7855 template parameters. And, no one should be interested
7856 in the enumeration constants for such a type. */
7859 }
7863 }
7865 {
7872 /* A local class. Make sure the decl gets registered properly. */
7877 /* This instantiation is another name for the primary
7878 template type. Set the TYPE_CANONICAL field
7879 appropriately. */
7882 /* Some of the template arguments require structural
7883 equality testing, so this template class requires
7884 structural equality testing. */
7886 }
7887 else
7890 /* If we called start_enum or pushtag above, this information
7891 will already be set up. */
7893 {
7900 }
7901 else
7905 {
7911 {
7914 }
7915 }
7919 {
7922 {
7925 else
7929 }
7930 }
7932 /* Let's consider the explicit specialization of a member
7933 of a class template specialization that is implicitly instantiated,
7934 e.g.:
7935 template<class T>
7936 struct S
7937 {
7938 template<class U> struct M {}; //#0
7939 };
7941 template<>
7942 template<>
7943 struct S<int>::M<char> //#1
7944 {
7945 int i;
7946 };
7947 [temp.expl.spec]/4 says this is valid.
7949 In this case, when we write:
7950 S<int>::M<char> m;
7952 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7953 the one of #0.
7955 When we encounter #1, we want to store the partial instantiation
7956 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7958 For all cases other than this "explicit specialization of member of a
7959 class template", we just want to store the most general template into
7960 the CLASSTYPE_TI_TEMPLATE of M.
7962 This case of "explicit specialization of member of a class template"
7963 only happens when:
7964 1/ the enclosing class is an instantiation of, and therefore not
7965 the same as, the context of the most general template, and
7966 2/ we aren't looking at the partial instantiation itself, i.e.
7967 the innermost arguments are not the same as the innermost parms of
7968 the most general template.
7970 So it's only when 1/ and 2/ happens that we want to use the partial
7971 instantiation of the member template in lieu of its most general
7972 template. */
7976 /* the enclosing class must be an instantiation... */
7979 {
7980 tree partial_inst_args;
7983 partial_inst_args =
7989 use_partial_inst_tmpl =
7990 /*...and we must not be looking at the partial instantiation
7991 itself. */
7993 partial_inst_args);
7994 }
7997 /* This case is easy; there are no member templates involved. */
7999 else
8000 {
8001 /* This is a full instantiation of a member template. Find
8002 the partial instantiation of which this is an instance. */
8004 /* Temporarily reduce by one the number of levels in the ARGLIST
8005 so as to avoid comparing the last set of arguments. */
8009 /* FOUND is either a proper class type, or an alias
8010 template specialization. In the later case, it's a
8011 TYPE_DECL, resulting from the substituting of arguments
8012 for parameters in the TYPE_DECL of the alias template
8013 done earlier. So be careful while getting the template
8014 of FOUND. */
8018 }
8028 /* Note this use of the partial instantiation so we can check it
8029 later in maybe_process_partial_specialization. */
8036 /* Now that the type has been registered on the instantiations
8037 list, we set up the enumerators. Because the enumeration
8038 constants may involve the enumeration type itself, we make
8039 sure to register the type first, and then create the
8040 constants. That way, doing tsubst_expr for the enumeration
8041 constants won't result in recursive calls here; we'll find
8042 the instantiation and exit above. */
8046 /* If the type makes use of template parameters, the
8047 code that generates debugging information will crash. */
8050 /* Possibly limit visibility based on template args. */
8057 }
8058 }
8060 /* Wrapper for lookup_template_class_1. */
8062 tree
8065 {
8066 tree ret;
8072 }
8074 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST.
8075 The type of the expression is the unknown_type_node since the
8076 template-id could refer to an explicit or partial specialization. */
8078 tree
8080 {
8087 }
8089 \f
8090 struct pair_fn_data
8091 {
8092 tree_fn_t fn;
8094 /* True when we should also visit template parameters that occur in
8095 non-deduced contexts. */
8098 };
8100 /* Called from for_each_template_parm via walk_tree. */
8102 static tree
8104 {
8117 {
8121 /* Fall through. */
8144 /* Since we're not going to walk subtrees, we have to do this
8145 explicitly here. */
8149 /* Fall through. */
8152 /* Check the return type. */
8157 /* Check the parameter types. Since default arguments are not
8158 instantiated until they are needed, the TYPE_ARG_TYPES may
8159 contain expressions that involve template parameters. But,
8160 no-one should be looking at them yet. And, once they're
8161 instantiated, they don't contain template parameters, so
8162 there's no point in looking at them then, either. */
8163 {
8164 tree parm;
8171 /* Since we've already handled the TYPE_ARG_TYPES, we don't
8172 want walk_tree walking into them itself. */
8174 }
8192 /* Fall through. */
8208 /* Record template parameters such as `T' inside `TT<T>'. */
8212 /* Fall through. */
8224 /* A template template parameter is encountered. */
8230 /* Already substituted template template parameter */
8253 /* If there's no type, then this thing must be some expression
8254 involving template parameters. */
8276 }
8278 /* We didn't find any template parameters we liked. */
8280 }
8282 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8283 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8284 call FN with the parameter and the DATA.
8285 If FN returns nonzero, the iteration is terminated, and
8286 for_each_template_parm returns 1. Otherwise, the iteration
8287 continues. If FN never returns a nonzero value, the value
8288 returned by for_each_template_parm is 0. If FN is NULL, it is
8289 considered to be the function which always returns 1.
8291 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8292 parameters that occur in non-deduced contexts. When false, only
8293 visits those template parameters that can be deduced. */
8295 static int
8299 {
8303 /* Set up. */
8308 /* Walk the tree. (Conceptually, we would like to walk without
8309 duplicates, but for_each_template_parm_r recursively calls
8310 for_each_template_parm, so we would need to reorganize a fair
8311 bit to use walk_tree_without_duplicates, so we keep our own
8312 visited list.) */
8315 else
8318 for_each_template_parm_r,
8322 /* Clean up. */
8324 {
8327 }
8330 }
8332 /* Returns true if T depends on any template parameter. */
8334 int
8336 {
8366 else
8367 {
8370 }
8375 }
8377 /* Returns true iff current_function_decl is an incompletely instantiated
8378 template. Useful instead of processing_template_decl because the latter
8379 is set to 0 during instantiate_non_dependent_expr. */
8381 bool
8383 {
8392 }
8394 /* Returns true if T depends on any template parameter with level LEVEL. */
8396 int
8398 {
8401 }
8403 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8404 ill-formed translation unit, i.e. a variable or function that isn't
8405 usable in a constant expression. */
8409 {
8413 }
8415 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8416 neglectable and instantiated from within an erroneous instantiation. */
8418 static bool
8420 {
8431 }
8439 /* We're starting to instantiate D; record the template instantiation context
8440 for diagnostics and to restore it later. */
8442 bool
8444 {
8446 }
8448 /* We're starting to instantiate D; record the template instantiation context
8449 at LOC for diagnostics and to restore it later. */
8451 bool
8453 {
8457 {
8460 max_tinst_depth);
8462 }
8464 /* If the current instantiation caused problems, don't let it instantiate
8465 anything else. Do allow deduction substitution and decls usable in
8466 constant expressions. */
8483 }
8485 /* We're done instantiating this template; return to the instantiation
8486 context. */
8488 void
8490 {
8491 /* Restore the filename and line number stashed away when we started
8492 this instantiation. */
8496 }
8498 /* We're instantiating a deferred template; restore the template
8499 instantiation context in which the instantiation was requested, which
8500 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8502 static tree
8504 {
8516 }
8518 /* Returns the TINST_LEVEL which gives the original instantiation
8519 context. */
8523 {
8529 }
8531 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8532 vector of template arguments, as for tsubst.
8534 Returns an appropriate tsubst'd friend declaration. */
8536 static tree
8538 {
8539 tree new_friend;
8544 /* This was a friend declared with an explicit template
8545 argument list, e.g.:
8547 friend void f<>(T);
8549 to indicate that f was a template instantiation, not a new
8550 function declaration. Now, we have to figure out what
8551 instantiation of what template. */
8552 {
8554 tree new_args;
8555 tree tmpl;
8558 /* Friend functions are looked up in the containing namespace scope.
8559 We must enter that scope, to avoid finding member functions of the
8560 current class with same name. */
8575 tsk_none);
8577 }
8581 /* The NEW_FRIEND will look like an instantiation, to the
8582 compiler, but is not an instantiation from the point of view of
8583 the language. For example, we might have had:
8585 template <class T> struct S {
8586 template <class U> friend void f(T, U);
8587 };
8589 Then, in S<int>, template <class U> void f(int, U) is not an
8590 instantiation of anything. */
8596 {
8600 }
8602 /* The mangled name for the NEW_FRIEND is incorrect. The function
8603 is not a template instantiation and should not be mangled like
8604 one. Therefore, we forget the mangling here; we'll recompute it
8605 later if we need it. */
8607 {
8610 }
8613 {
8614 tree old_decl;
8615 tree new_friend_template_info;
8616 tree new_friend_result_template_info;
8617 tree ns;
8620 /* We must save some information from NEW_FRIEND before calling
8621 duplicate decls since that function will free NEW_FRIEND if
8622 possible. */
8624 new_friend_is_defn =
8629 {
8630 /* This declaration is a `primary' template. */
8633 new_friend_result_template_info
8635 }
8636 else
8639 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8643 /* Inside pushdecl_namespace_level, we will push into the
8644 current namespace. However, the friend function should go
8645 into the namespace of the template. */
8655 {
8656 /* This new friend declaration matched an existing
8657 declaration. For example, given:
8659 template <class T> void f(T);
8660 template <class U> class C {
8661 template <class T> friend void f(T) {}
8662 };
8664 the friend declaration actually provides the definition
8665 of `f', once C has been instantiated for some type. So,
8666 old_decl will be the out-of-class template declaration,
8667 while new_friend is the in-class definition.
8669 But, if `f' was called before this point, the
8670 instantiation of `f' will have DECL_TI_ARGS corresponding
8671 to `T' but not to `U', references to which might appear
8672 in the definition of `f'. Previously, the most general
8673 template for an instantiation of `f' was the out-of-class
8674 version; now it is the in-class version. Therefore, we
8675 run through all specialization of `f', adding to their
8676 DECL_TI_ARGS appropriately. In particular, they need a
8677 new set of outer arguments, corresponding to the
8678 arguments for this class instantiation.
8680 The same situation can arise with something like this:
8682 friend void f(int);
8683 template <class T> class C {
8684 friend void f(T) {}
8685 };
8687 when `C<int>' is instantiated. Now, `f(int)' is defined
8688 in the class. */
8691 /* On the other hand, if the in-class declaration does
8692 *not* provide a definition, then we don't want to alter
8693 existing definitions. We can just leave everything
8694 alone. */
8695 ;
8696 else
8697 {
8701 /* Overwrite whatever template info was there before, if
8702 any, with the new template information pertaining to
8703 the declaration. */
8707 {
8708 /* We should have called reregister_specialization in
8709 duplicate_decls. */
8714 /* Instantiate it if the global has already been used. */
8718 }
8719 else
8720 {
8721 tree t;
8723 /* Indicate that the old function template is a partial
8724 instantiation. */
8732 /* Reassign any specializations already in the hash table
8733 to the new more general template, and add the
8734 additional template args. */
8738 {
8740 spec_entry elt;
8752 register_specialization
8755 }
8757 }
8758 }
8760 /* The information from NEW_FRIEND has been merged into OLD_DECL
8761 by duplicate_decls. */
8763 }
8764 }
8765 else
8766 {
8770 /* In the code
8771 template <class T> class C {
8772 template <class U> friend void C1<U>::f (); // case 1
8773 friend void C2<T>::f (); // case 2
8774 };
8775 we only need to make sure CONTEXT is a complete type for
8776 case 2. To distinguish between the two cases, we note that
8777 CONTEXT of case 1 remains dependent type after tsubst while
8778 this isn't true for case 2. */
8788 {
8790 /* do_friend adds the TEMPLATE_DECL for any member friend
8791 template even if it isn't a member template, i.e.
8792 template <class T> friend A<T>::f();
8793 Look through it in that case. */
8797 /* Check to see that the declaration is really present, and,
8798 possibly obtain an improved declaration. */
8803 }
8804 }
8807 }
8809 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8810 template arguments, as for tsubst.
8812 Returns an appropriate tsubst'd friend type or error_mark_node on
8813 failure. */
8815 static tree
8817 {
8818 tree friend_type;
8819 tree tmpl;
8820 tree context;
8823 {
8826 }
8831 {
8834 else
8836 }
8838 /* Look for a class template declaration. We look for hidden names
8839 because two friend declarations of the same template are the
8840 same. For example, in:
8842 struct A {
8843 template <typename> friend class F;
8844 };
8845 template <typename> struct B {
8846 template <typename> friend class F;
8847 };
8849 both F templates are the same. */
8853 /* But, if we don't find one, it might be because we're in a
8854 situation like this:
8856 template <class T>
8857 struct S {
8858 template <class U>
8859 friend struct S;
8860 };
8862 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8863 for `S<int>', not the TEMPLATE_DECL. */
8865 {
8868 }
8871 {
8872 /* The friend template has already been declared. Just
8873 check to see that the declarations match, and install any new
8874 default parameters. We must tsubst the default parameters,
8875 of course. We only need the innermost template parameters
8876 because that is all that redeclare_class_template will look
8877 at. */
8880 {
8881 tree parms;
8882 location_t saved_input_location;
8891 }
8894 }
8895 else
8896 {
8897 /* The friend template has not already been declared. In this
8898 case, the instantiation of the template class will cause the
8899 injection of this template into the global scope. */
8904 /* The new TMPL is not an instantiation of anything, so we
8905 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8906 the new type because that is supposed to be the corresponding
8907 template decl, i.e., TMPL. */
8914 /* Inject this template into the global scope. */
8916 }
8919 {
8922 else
8924 }
8927 }
8929 /* Returns zero if TYPE cannot be completed later due to circularity.
8930 Otherwise returns one. */
8932 static int
8934 {
8944 else
8946 }
8950 /* Apply any attributes which had to be deferred until instantiation
8951 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8952 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8954 static void
8957 {
8959 tree t;
8964 {
8968 }
8971 {
8975 }
8976 else
8980 {
8985 {
8988 {
8995 {
9002 clauses
9006 else
9008 }
9009 /* If the first attribute argument is an identifier, don't
9010 pass it through tsubst. Attributes like mode, format,
9011 cleanup and several target specific attributes expect it
9012 unmodified. */
9015 {
9016 tree chain
9018 in_decl,
9023 chain);
9024 }
9025 else
9031 }
9032 else
9034 }
9037 }
9038 }
9040 /* Perform (or defer) access check for typedefs that were referenced
9041 from within the template TMPL code.
9042 This is a subroutine of instantiate_decl and instantiate_class_template.
9043 TMPL is the template to consider and TARGS is the list of arguments of
9044 that template. */
9046 static void
9048 {
9049 location_t saved_location;
9060 {
9072 /* Make access check error messages point to the location
9073 of the use of the typedef. */
9077 tf_warning_or_error);
9078 }
9080 }
9082 static tree
9084 {
9086 tree typedecl;
9087 tree pbinfo;
9088 tree base_list;
9090 tree fn_context;
9099 /* Figure out which template is being instantiated. */
9103 /* Determine what specialization of the original template to
9104 instantiate. */
9107 {
9110 }
9112 {
9113 /* This TYPE is actually an instantiation of a partial
9114 specialization. We replace the innermost set of ARGS with
9115 the arguments appropriate for substitution. For example,
9116 given:
9118 template <class T> struct S {};
9119 template <class T> struct S<T*> {};
9121 and supposing that we are instantiating S<int*>, ARGS will
9122 presently be {int*} -- but we need {int}. */
9125 }
9126 else
9127 {
9130 }
9132 /* If the template we're instantiating is incomplete, then clearly
9133 there's nothing we can do. */
9137 /* If we've recursively instantiated too many templates, stop. */
9141 /* Now we're really doing the instantiation. Mark the type as in
9142 the process of being defined. */
9145 /* We may be in the middle of deferred access check. Disable
9146 it now. */
9150 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
9155 /* Use #pragma pack from the template context. */
9161 /* Set the input location to the most specialized template definition.
9162 This is needed if tsubsting causes an error. */
9174 {
9177 /* Adjust visibility for template arguments. */
9179 }
9185 /* We should never instantiate a nested class before its enclosing
9186 class; we need to look up the nested class by name before we can
9187 instantiate it, and that lookup should instantiate the enclosing
9188 class. */
9194 {
9195 tree pbase_binfo;
9196 tree pushed_scope;
9199 /* We must enter the scope containing the type, as that is where
9200 the accessibility of types named in dependent bases are
9201 looked up from. */
9204 /* Substitute into each of the bases to determine the actual
9205 basetypes. */
9207 {
9208 tree base;
9214 {
9215 expanded_bases =
9222 }
9225 {
9227 /* Extract the already-expanded base class. */
9229 else
9230 /* Substitute to figure out the base class. */
9232 NULL_TREE);
9240 }
9241 }
9243 /* The list is now in reverse order; correct that. */
9248 }
9249 /* Now call xref_basetypes to set up all the base-class
9250 information. */
9258 /* Now that our base classes are set up, enter the scope of the
9259 class, so that name lookups into base classes, etc. will work
9260 correctly. This is precisely analogous to what we do in
9261 begin_class_definition when defining an ordinary non-template
9262 class, except we also need to push the enclosing classes. */
9265 /* Now members are processed in the order of declaration. */
9268 {
9272 {
9274 {
9275 /* Build new CLASSTYPE_NESTED_UTDS. */
9277 tree newtag;
9283 /* If the member is a class template, then -- even after
9284 substitution -- there may be dependent types in the
9285 template argument list for the class. We increment
9286 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9287 that function will assume that no types are dependent
9288 when outside of a template. */
9298 {
9302 /* Unfortunately, lookup_template_class sets
9303 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9304 instantiation (i.e., for the type of a member
9305 template class nested within a template class.)
9306 This behavior is required for
9307 maybe_process_partial_specialization to work
9308 correctly, but is not accurate in this case;
9309 the TAG is not an instantiation of anything.
9310 (The corresponding TEMPLATE_DECL is an
9311 instantiation, but the TYPE is not.) */
9314 /* Now, we call pushtag to put this NEWTAG into the scope of
9315 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9316 pushtag calling push_template_decl. We don't have to do
9317 this for enums because it will already have been done in
9318 tsubst_enum. */
9322 }
9323 }
9325 {
9326 /* Build new TYPE_METHODS. */
9327 tree r;
9336 /* Instantiate members marked with attribute used. */
9342 }
9345 /* A closure type for a lambda in a default argument for a
9346 member template. Ignore it; it will be instantiated with
9348 else
9349 {
9350 /* Build new TYPE_FIELDS. */
9352 {
9353 tree condition;
9356 condition =
9366 }
9368 {
9369 tree r;
9373 /* The file and line for this declaration, to
9374 assist in error message reporting. Since we
9375 called push_tinst_level above, we don't need to
9376 restore these. */
9386 {
9387 /* A capture pack became multiple fields. */
9390 }
9393 {
9397 {
9398 /* In [temp.inst]:
9400 [t]he initialization (and any associated
9401 side-effects) of a static data member does
9402 not occur unless the static data member is
9403 itself used in a way that requires the
9404 definition of the static data member to
9405 exist.
9407 Therefore, we do not substitute into the
9408 initialized for the static data member here. */
9409 finish_static_data_member_decl
9415 /* Instantiate members marked with attribute used. */
9418 }
9420 {
9421 /* Determine whether R has a valid type and can be
9422 completed later. If R is invalid, then its type
9423 is replaced by error_mark_node. */
9429 {
9432 }
9433 }
9435 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9436 such a thing will already have been added to the field
9437 list by tsubst_enum in finish_member_declaration in the
9438 CLASSTYPE_NESTED_UTDS case above. */
9442 {
9445 }
9446 }
9447 }
9448 }
9449 }
9450 else
9451 {
9454 {
9455 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9461 {
9462 /* template <class T> friend class C; */
9465 }
9467 {
9468 /* template <class T> friend class C::D; */
9474 }
9477 {
9478 /* This could be either
9480 friend class T::C;
9482 when dependent_type_p is false or
9484 template <class U> friend class T::C;
9486 otherwise. */
9489 /* Bump processing_template_decl for correct
9490 dependent_type_p calculation. */
9495 }
9498 {
9499 /* friend class C;
9501 where C hasn't been declared yet. Let's lookup name
9502 from namespace scope directly, bypassing any name that
9503 come from dependent base class. */
9506 /* The call to xref_tag_from_type does injection for friend
9507 classes. */
9509 friend_type =
9513 }
9515 /* friend class C<T>; */
9518 /* Otherwise it's
9520 friend class C;
9522 where C is already declared or
9524 friend class C<int>;
9526 We don't have to do anything in these cases. */
9529 /* Trick make_friend_class into realizing that the friend
9530 we're adding is a template, not an ordinary class. It's
9531 important that we use make_friend_class since it will
9532 perform some error-checking and output cross-reference
9533 information. */
9541 }
9542 else
9543 {
9544 /* Build new DECL_FRIENDLIST. */
9545 tree r;
9547 /* The file and line for this declaration, to
9548 assist in error message reporting. Since we
9549 called push_tinst_level above, we don't need to
9550 restore these. */
9554 {
9557 }
9562 {
9565 }
9566 }
9567 }
9568 }
9571 {
9574 {
9579 /* We need to instantiate the capture list from the template
9580 after we've instantiated the closure members, but before we
9581 consider adding the conversion op. Also keep any captures
9582 that may have been added during instantiation of the op(). */
9584 tree tmpl_cap
9593 }
9594 else
9596 }
9598 /* Set the file and line number information to whatever is given for
9599 the class itself. This puts error messages involving generated
9600 implicit functions at a predictable point, and the same point
9601 that would be used for non-template classes. */
9608 /* We don't instantiate default arguments for member functions. 14.7.1:
9610 The implicit instantiation of a class template specialization causes
9611 the implicit instantiation of the declarations, but not of the
9612 definitions or default arguments, of the class member functions,
9613 member classes, static data members and member templates.... */
9615 /* Some typedefs referenced from within the template code need to be access
9616 checked at template instantiation time, i.e now. These types were
9617 added to the template at parsing time. Let's get those and perform
9618 the access checks then. */
9628 /* The vtable for a template class can be emitted in any translation
9629 unit in which the class is instantiated. When there is no key
9630 method, however, finish_struct_1 will already have added TYPE to
9631 the keyed_classes list. */
9636 }
9638 /* Wrapper for instantiate_class_template_1. */
9640 tree
9642 {
9643 tree ret;
9648 }
9650 static tree
9652 {
9653 tree r;
9659 else
9660 {
9667 }
9669 }
9671 /* Given a function parameter pack TMPL_PARM and some function parameters
9672 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9673 and set *SPEC_P to point at the next point in the list. */
9675 static tree
9677 {
9678 /* Collect all of the extra "packed" parameters into an
9679 argument pack. */
9680 tree parmvec;
9681 tree parmtypevec;
9692 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9697 {
9700 }
9702 /* Build the argument packs. */
9709 }
9711 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9712 NONTYPE_ARGUMENT_PACK. */
9714 static tree
9716 {
9718 }
9720 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9721 pack expansion. */
9723 static bool
9725 {
9730 }
9733 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9735 static tree
9737 {
9744 }
9746 /* This is a subroutine of tsubst_pack_expansion.
9748 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9749 mechanism to store the (non complete list of) arguments of the
9750 substitution and return a non substituted pack expansion, in order
9751 to wait for when we have enough arguments to really perform the
9752 substitution. */
9754 static bool
9758 {
9759 /* If one pack has an expansion and another pack has a normal
9760 argument or if one pack has an empty argument and an another
9761 one hasn't then tsubst_pack_expansion cannot perform the
9762 substitution and need to fall back on the
9763 PACK_EXPANSION_EXTRA mechanism. */
9771 {
9774 parm_pack;
9776 {
9781 else
9783 }
9787 }
9789 }
9791 /* [temp.variadic]/6 says that:
9793 The instantiation of a pack expansion [...]
9794 produces a list E1,E2, ..., En, where N is the number of elements
9795 in the pack expansion parameters.
9797 This subroutine of tsubst_pack_expansion produces one of these Ei.
9799 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9800 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9801 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9802 INDEX is the index 'i' of the element Ei to produce. ARGS,
9803 COMPLAIN, and IN_DECL are the same parameters as for the
9804 tsubst_pack_expansion function.
9806 The function returns the resulting Ei upon successful completion,
9807 or error_mark_node.
9809 Note that this function possibly modifies the ARGS parameter, so
9810 it's the responsibility of the caller to restore it. */
9812 static tree
9814 tree parm_packs,
9816 tree args /* This parm gets
9818 tsubst_flags_t complain,
9819 tree in_decl)
9820 {
9821 tree t;
9824 /* For each parameter pack, change the substitution of the parameter
9825 pack to the ith argument in its argument pack, then expand the
9826 pattern. */
9828 {
9833 ith_elem_is_expansion |=
9836 /* Select the Ith argument from the pack. */
9839 {
9841 {
9845 }
9846 else
9848 }
9849 else
9850 {
9855 {
9857 /* Update the corresponding argument. */
9859 }
9860 else
9861 /* Re-use the ARGUMENT_PACK_SELECT. */
9863 }
9865 }
9867 /* Substitute into the PATTERN with the (possibly altered)
9868 arguments. */
9870 /* Expanding a fixed parameter pack from
9871 coerce_template_parameter_pack. */
9876 else
9879 /* If the Ith argument pack element is a pack expansion, then
9880 the Ith element resulting from the substituting is going to
9881 be a pack expansion as well. */
9886 }
9888 /* Substitute ARGS into T, which is an pack expansion
9889 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9890 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9891 (if only a partial substitution could be performed) or
9892 ERROR_MARK_NODE if there was an error. */
9893 tree
9895 tree in_decl)
9896 {
9897 tree pattern;
9901 tree result;
9909 /* Add in any args remembered from an earlier partial instantiation. */
9914 /* Determine the argument packs that will instantiate the parameter
9915 packs used in the expansion expression. While we're at it,
9916 compute the number of arguments to be expanded and make sure it
9917 is consistent. */
9920 {
9927 {
9931 else
9934 }
9936 {
9939 else
9940 {
9941 /* We can't rely on local_specializations for a parameter
9942 name used later in a function declaration (such as in a
9943 late-specified return type). Even if it exists, it might
9944 have the wrong value for a recursive call. Just make a
9945 dummy decl, since it's only used for its type. */
9948 /* Partial instantiation of the parm_pack, we can't build
9949 up an argument pack yet. */
9951 else
9954 }
9955 }
9958 else
9959 {
9965 }
9972 /* This can only happen if we forget to expand an argument
9973 pack somewhere else. Just return an error, silently. */
9974 {
9978 }
9981 {
9985 /* Don't bother trying to do a partial substitution with
9986 incomplete packs; we'll try again after deduction. */
9993 {
9999 pattern);
10000 else
10003 pattern);
10005 }
10007 /* Keep track of the parameter packs and their corresponding
10008 argument packs. */
10011 }
10012 else
10013 {
10014 /* We can't substitute for this parameter pack. We use a flag as
10015 well as the missing_level counter because function parameter
10016 packs don't have a level. */
10018 }
10019 }
10021 /* If the expansion is just T..., return the matching argument pack. */
10024 {
10029 /* Otherwise use the normal path so we get convert_from_reference. */
10030 }
10032 /* We cannot expand this expansion expression, because we don't have
10033 all of the argument packs we need. */
10035 {
10036 /* We got some full packs, but we can't substitute them in until we
10037 have values for all the packs. So remember these until then. */
10042 }
10044 {
10045 /* There were no real arguments, we're just replacing a parameter
10046 pack with another version of itself. Substitute into the
10047 pattern and return a PACK_EXPANSION_*. The caller will need to
10048 deal with that. */
10052 else
10056 }
10061 {
10062 /* We're in a late-specified return type, so create our own local
10063 specializations map; the current map is either NULL or (in the
10064 case of recursive unification) might have bindings that we don't
10065 want to use or alter. */
10068 }
10070 /* For each argument in each argument pack, substitute into the
10071 pattern. */
10074 {
10076 i,
10078 in_decl);
10081 {
10084 }
10085 }
10087 /* Update ARGS to restore the substitution from parameter packs to
10088 their argument packs. */
10090 {
10096 else
10097 {
10105 /* Update the corresponding argument. */
10109 else
10111 }
10112 }
10115 {
10118 }
10121 }
10123 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
10124 TMPL. We do this using DECL_PARM_INDEX, which should work even with
10125 parameter packs; all parms generated from a function parameter pack will
10126 have the same DECL_PARM_INDEX. */
10128 tree
10130 {
10132 tree patparm;
10135 {
10141 }
10142 else
10143 {
10148 }
10151 }
10153 /* Substitute ARGS into the vector or list of template arguments T. */
10155 static tree
10157 {
10169 {
10171 tree new_arg;
10176 {
10177 /* Substitute into an expansion expression. */
10181 /* Add to the expanded length adjustment the number of
10182 expanded arguments. We subtract one from this
10183 measurement, because the argument pack expression
10184 itself is already counted as 1 in
10185 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
10186 the argument pack is empty. */
10188 }
10190 {
10191 /* Substitute into each of the arguments. */
10197 new_arg,
10211 }
10212 }
10213 else
10222 }
10227 /* Make space for the expanded arguments coming from template
10228 argument packs. */
10230 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10231 arguments for a member template.
10232 In that case each TREE_VEC in ORIG_T represents a level of template
10233 arguments, and ORIG_T won't carry any non defaulted argument count.
10234 It will rather be the nested TREE_VECs that will carry one.
10235 In other words, ORIG_T carries a non defaulted argument count only
10236 if it doesn't contain any nested TREE_VEC. */
10238 {
10242 }
10244 {
10248 {
10251 /* Now expand the template argument pack "in place". */
10254 }
10255 else
10256 {
10258 out++;
10259 }
10260 }
10263 }
10265 /* Return the result of substituting ARGS into the template parameters
10266 given by PARMS. If there are m levels of ARGS and m + n levels of
10267 PARMS, then the result will contain n levels of PARMS. For
10268 example, if PARMS is `template <class T> template <class U>
10269 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10270 result will be `template <int*, double, class V>'. */
10272 static tree
10274 {
10278 /* When substituting into a template, we must set
10279 PROCESSING_TEMPLATE_DECL as the template parameters may be
10280 dependent if they are based on one-another, and the dependency
10281 predicates are short-circuit outside of templates. */
10288 {
10289 tree new_vec =
10294 {
10295 tree tuple;
10307 }
10313 }
10318 }
10320 /* Return the result of substituting ARGS into one template parameter
10321 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10322 parameter and which TREE_PURPOSE is the default argument of the
10323 template parameter. */
10325 static tree
10327 {
10348 }
10350 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10351 type T. If T is not an aggregate or enumeration type, it is
10352 handled as if by tsubst. IN_DECL is as for tsubst. If
10353 ENTERING_SCOPE is nonzero, T is the context for a template which
10354 we are presently tsubst'ing. Return the substituted value. */
10356 static tree
10358 tree args,
10359 tsubst_flags_t complain,
10360 tree in_decl,
10362 {
10367 {
10372 /* Else fall through. */
10376 {
10377 tree argvec;
10378 tree context;
10379 tree r;
10383 /* In "sizeof(X<I>)" we need to evaluate "I". */
10389 /* First, determine the context for the type we are looking
10390 up. */
10393 {
10396 /* If context is a nested class inside a class template,
10397 it may still need to be instantiated (c++/33959). */
10399 }
10401 /* Then, figure out what arguments are appropriate for the
10402 type we are trying to find. For example, given:
10404 template <class T> struct S;
10405 template <class T, class U> void f(T, U) { S<U> su; }
10407 and supposing that we are instantiating f<int, double>,
10408 then our ARGS will be {int, double}, but, when looking up
10409 S we only want {double}. */
10414 else
10415 {
10419 }
10425 }
10426 else
10427 /* This is not a template type, so there's nothing to do. */
10432 }
10433 }
10435 /* Substitute into the default argument ARG (a default argument for
10436 FN), which has the indicated TYPE. */
10438 tree
10440 {
10445 /* This can happen in invalid code. */
10449 /* This default argument came from a template. Instantiate the
10450 default argument here, not in tsubst. In the case of
10451 something like:
10453 template <class T>
10454 struct S {
10455 static T t();
10456 void f(T = t());
10457 };
10459 we must be careful to do name lookup in the scope of S<T>,
10460 rather than in the current class. */
10462 /* The "this" pointer is not valid in a default argument. */
10464 {
10469 }
10472 /* The default argument expression may cause implicitly defined
10473 member functions to be synthesized, which will result in garbage
10474 collection. We must treat this situation as if we were within
10475 the body of function so as to avoid collecting live data on the
10476 stack. */
10484 /* Restore the "this" pointer. */
10486 {
10489 }
10496 /* Make sure the default argument is reasonable. */
10502 }
10504 /* Substitute into all the default arguments for FN. */
10506 static void
10508 {
10509 tree arg;
10510 tree tmpl_args;
10514 /* If this function is not yet instantiated, we certainly don't need
10515 its default arguments. */
10518 /* Don't do this again for clones. */
10523 arg;
10529 complain);
10530 }
10532 /* Substitute the ARGS into the T, which is a _DECL. Return the
10533 result of the substitution. Issue error and warning messages under
10534 control of COMPLAIN. */
10536 static tree
10538 {
10539 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10540 location_t saved_loc;
10545 /* Set the filename and linenumber to improve error-reporting. */
10550 {
10552 {
10553 /* We can get here when processing a member function template,
10554 member class template, or template template parameter. */
10556 tree spec;
10557 tree tmpl_args;
10558 tree full_args;
10561 {
10562 /* Template template parameter is treated here. */
10566 /* If we get a real template back, return it. This can happen in
10567 the context of most_specialized_partial_spec. */
10579 complain);
10582 }
10584 /* We might already have an instance of this template.
10585 The ARGS are for the surrounding class type, so the
10586 full args contain the tsubst'd args for the context,
10587 plus the innermost args from the template decl. */
10591 /* Because this is a template, the arguments will still be
10592 dependent, even after substitution. If
10593 PROCESSING_TEMPLATE_DECL is not set, the dependency
10594 predicates will short-circuit. */
10602 /* If this is a default template template argument,
10603 tsubst might not have changed anything. */
10610 {
10613 }
10615 /* Make a new template decl. It will be similar to the
10616 original, but will record the current template arguments.
10617 We also create a new function declaration, which is just
10618 like the old one, but points to this new template, rather
10619 than the old one. */
10628 {
10629 tree new_type;
10637 /* For a partial specialization, we need to keep pointing to
10638 the primary template. */
10644 }
10645 else
10646 {
10647 tree new_decl;
10659 }
10665 /* The template parameters for this new template are all the
10666 template parameters for the old template, except the
10667 outermost level of parameters. */
10670 complain);
10676 /* Record this non-type partial instantiation. */
10680 }
10684 {
10685 tree ctx;
10688 tree gen_tmpl;
10689 tree type;
10694 /* Nobody should be tsubst'ing into non-template functions. */
10698 {
10699 tree spec;
10702 /* If T is not dependent, just return it. We have to
10703 increment PROCESSING_TEMPLATE_DECL because
10704 value_dependent_expression_p assumes that nothing is
10705 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10712 /* Calculate the most general template of which R is a
10713 specialization, and the complete set of arguments used to
10714 specialize R. */
10717 (DECL_TEMPLATE_RESULT
10723 /* Check to see if we already have this specialization. */
10728 {
10731 }
10733 /* We can see more levels of arguments than parameters if
10734 there was a specialization of a member template, like
10735 this:
10737 template <class T> struct S { template <class U> void f(); }
10738 template <> template <class U> void S<int>::f(U);
10740 Here, we'll be substituting into the specialization,
10741 because that's where we can find the code we actually
10742 want to generate, but we'll have enough arguments for
10743 the most general template.
10745 We also deal with the peculiar case:
10747 template <class T> struct S {
10748 template <class U> friend void f();
10749 };
10750 template <class U> void f() {}
10751 template S<int>;
10752 template void f<double>();
10754 Here, the ARGS for the instantiation of will be {int,
10755 double}. But, we only need as many ARGS as there are
10756 levels of template parameters in CODE_PATTERN. We are
10757 careful not to get fooled into reducing the ARGS in
10758 situations like:
10760 template <class T> struct S { template <class U> void f(U); }
10761 template <class T> template <> void S<T>::f(int) {}
10763 which we can spot because the pattern will be a
10764 specialization in this case. */
10766 parms_depth =
10771 }
10772 else
10773 {
10774 /* This special case arises when we have something like this:
10776 template <class T> struct S {
10777 friend void f<int>(int, double);
10778 };
10780 Here, the DECL_TI_TEMPLATE for the friend declaration
10781 will be an IDENTIFIER_NODE. We are being called from
10782 tsubst_friend_function, and we want only to create a
10783 new decl (R) with appropriate types so that we can call
10784 determine_specialization. */
10786 }
10789 {
10792 else
10796 }
10797 else
10798 {
10801 }
10806 /* If we hit excessive deduction depth, the type is bogus even if
10807 it isn't error_mark_node, so don't build a decl. */
10811 /* We do NOT check for matching decls pushed separately at this
10812 point, as they may not represent instantiations of this
10813 template, and in any case are considered separate under the
10814 discrete model. */
10818 /* Clear out the mangled name and RTL for the instantiation. */
10821 /* Leave DECL_INITIAL set on deleted instantiations. */
10826 /* OpenMP UDRs have the only argument a reference to the declared
10827 type. We want to diagnose if the declared type is a reference,
10828 which is invalid, but as references to references are usually
10829 quietly merged, diagnose it here. */
10831 {
10832 tree argtype
10837 "reference type %qT in "
10841 argtype);
10842 }
10845 /* Type-conversion operator. Reconstruct the name, in
10846 case it's the name of one of the template's parameters. */
10856 /* If this is an instantiation of a function with internal
10857 linkage, we already know what object file linkage will be
10858 assigned to the instantiation. */
10867 /* We'll re-clone as appropriate in instantiate_template. */
10870 /* If we aren't complaining now, return on error before we register
10871 the specialization so that we'll complain eventually. */
10877 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10878 this in the special friend case mentioned above where
10879 GEN_TMPL is NULL. */
10881 {
10886 tree new_r
10889 /* We instantiated this while substituting into
10890 the type earlier (template/friend54.C). */
10893 /* We're not supposed to instantiate default arguments
10894 until they are called, for a template. But, for a
10895 declaration like:
10897 template <class T> void f ()
10898 { extern void g(int i = T()); }
10900 we should do the substitution when the template is
10901 instantiated. We handle the member function case in
10902 instantiate_class_template since the default arguments
10903 might refer to other members of the class. */
10908 }
10909 else
10912 /* Copy the list of befriending classes. */
10916 {
10920 in_decl);
10921 }
10924 {
10930 /* If this is an instantiation of a member template, clone it.
10931 If it isn't, that'll be handled by
10932 clone_constructors_and_destructors. */
10935 }
10946 /* Possibly limit visibility based on template args. */
10949 {
10953 }
10961 }
10965 {
10973 {
10974 /* If there is a local specialization that isn't a
10975 parameter pack, it means that we're doing a "simple"
10976 substitution from inside tsubst_pack_expansion. Just
10977 return the local specialization (which will be a single
10978 parm). */
10985 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10986 the parameters in this function parameter pack. */
10990 {
10993 /* Zero-length parameter packs are boring. Just substitute
10994 into the chain. */
10998 }
10999 else
11000 {
11001 /* All we did was update the type. Make a note of that. */
11004 }
11005 }
11007 /* Loop through all of the parameters we'll build. When T is
11008 a function parameter pack, LEN is the number of expanded
11009 types in EXPANDED_TYPES; otherwise, LEN is 1. */
11012 {
11019 /* We're on the Ith parameter of the function parameter
11020 pack. */
11021 {
11022 /* Get the Ith type. */
11025 /* Rename the parameter to include the index. */
11028 }
11030 /* We're dealing with a normal parameter. */
11038 {
11041 else
11044 }
11054 /* Keep track of the first new parameter we
11055 generate. That's what will be returned to the
11056 caller. */
11060 /* Build a proper chain of parameters when substituting
11061 into a function parameter pack. */
11064 }
11066 /* If cp_unevaluated_operand is set, we're just looking for a
11067 single dummy parameter, so don't keep going. */
11072 /* FIRST_R contains the start of the chain we've built. */
11074 }
11078 {
11085 {
11086 /* This field is a lambda capture pack. Return a TREE_VEC of
11087 the expanded fields to instantiate_class_template_1 and
11088 store them in the specializations hash table as a
11089 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
11093 {
11096 }
11097 else
11098 {
11099 /* All we did was update the type. Make a note of that. */
11102 }
11103 }
11106 {
11109 {
11113 }
11123 /* For bit-fields, DECL_INITIAL gives the number of bits. For
11124 non-bit-fields DECL_INITIAL is a non-static data member
11125 initializer, which gets deferred instantiation. */
11131 {
11132 /* Set up DECL_TEMPLATE_INFO so that we can get at the
11133 NSDMI in perform_member_init. Still set DECL_INITIAL
11134 so that we know there is one. */
11139 }
11140 /* We don't have to set DECL_CONTEXT here; it is set by
11141 finish_member_declaration. */
11149 }
11152 {
11160 }
11161 }
11165 /* We reach here only for member using decls. We also need to check
11166 uses_template_parms because DECL_DEPENDENT_P is not set for a
11167 using-declaration that designates a member of the current
11168 instantiation (c++/53549). */
11171 {
11178 else
11179 {
11182 }
11183 }
11184 else
11185 {
11188 }
11193 {
11196 tree spec;
11198 tree ctx;
11207 {
11208 /* If this is the canonical decl, we don't have to
11209 mess with instantiations, and often we can't (for
11210 typename, template type parms and such). Note that
11211 TYPE_NAME is not correct for the above test if
11212 we've copied the type for a typedef. */
11218 }
11220 /* Check to see if we already have the specialization we
11221 need. */
11224 {
11225 /* T is a static data member or namespace-scope entity.
11226 We have to substitute into namespace-scope variables
11227 (even though such entities are never templates) because
11228 of cases like:
11230 template <class T> void f() { extern T t; }
11232 where the entity referenced is not known until
11233 instantiation time. */
11237 {
11239 complain,
11241 /* If CTX is unchanged, then T is in fact the
11242 specialization we want. That situation occurs when
11243 referencing a static data member within in its own
11244 class. We can use pointer equality, rather than
11245 same_type_p, because DECL_CONTEXT is always
11246 canonical... */
11248 /* ... unless T is a member template; in which
11249 case our caller can be willing to create a
11250 specialization of that template represented
11251 by T. */
11255 }
11258 {
11266 }
11267 }
11268 else
11269 {
11270 /* A local variable. */
11272 /* Subsequent calls to pushdecl will fill this in. */
11275 }
11276 /* If we already have the specialization we need, there is
11277 nothing more to do. */
11279 {
11282 }
11284 /* Create a new node for the specialization we need. */
11287 {
11290 else
11297 }
11299 {
11300 /* Even if the original location is out of scope, the
11301 newly substituted one is not. */
11308 {
11309 /* It may seem that this case cannot occur, since:
11311 typedef void f();
11312 void g() { f x; }
11314 declares a function, not a variable. However:
11316 typedef void f();
11317 template <typename T> void g() { T t; }
11318 template void g<f>();
11320 is an attempt to declare a variable with function
11321 type. */
11323 /* R is not yet sufficiently initialized, so we
11324 just use its name. */
11327 }
11329 /* Wait until cp_finish_decl to set this again, to handle
11330 circular dependency (template/instantiate6.C). */
11335 {
11340 {
11343 }
11345 }
11348 }
11354 /* Clear out the mangled name and RTL for the instantiation. */
11358 /* The initializer must not be expanded until it is required;
11359 see [temp.inst]. */
11365 {
11366 /* Possibly limit visibility based on template args. */
11369 {
11373 }
11375 }
11378 {
11379 /* A static data member declaration is always marked
11380 external when it is declared in-class, even if an
11381 initializer is present. We mimic the non-template
11382 processing here. */
11388 }
11398 /* Preserve a typedef that names a type. */
11400 {
11403 }
11406 }
11411 }
11412 #undef RETURN
11414 out:
11415 /* Restore the file and line information. */
11419 }
11421 /* Substitute into the ARG_TYPES of a function type.
11422 If END is a TREE_CHAIN, leave it and any following types
11423 un-substituted. */
11425 static tree
11427 tree args,
11428 tree end,
11429 tsubst_flags_t complain,
11430 tree in_decl)
11431 {
11432 tree remaining_arg_types;
11436 tree default_arg;
11447 {
11448 /* For a pack expansion, perform substitution on the
11449 entire expression. Later on, we'll handle the arguments
11450 one-by-one. */
11455 /* So that we'll spin through the parameters, one by one. */
11457 else
11458 {
11459 /* We only partially substituted into the parameter
11460 pack. Our type is TYPE_PACK_EXPANSION. */
11463 }
11464 }
11477 {
11479 {
11483 }
11485 }
11486 /* DR 657. */
11490 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11491 top-level qualifiers as required. */
11494 /* We do not substitute into default arguments here. The standard
11495 mandates that they be instantiated only when needed, which is
11496 done in build_over_call. */
11500 {
11501 /* We've instantiated a template before its default arguments
11502 have been parsed. This can happen for a nested template
11503 class, and is not an error unless we require the default
11504 argument in a call of this function. */
11505 remaining_arg_types =
11508 }
11509 else
11510 remaining_arg_types =
11512 }
11515 }
11517 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11518 *not* handle the exception-specification for FNTYPE, because the
11519 initial substitution of explicitly provided template parameters
11520 during argument deduction forbids substitution into the
11521 exception-specification:
11523 [temp.deduct]
11525 All references in the function type of the function template to the
11526 corresponding template parameters are replaced by the specified tem-
11527 plate argument values. If a substitution in a template parameter or
11528 in the function type of the function template results in an invalid
11529 type, type deduction fails. [Note: The equivalent substitution in
11530 exception specifications is done only when the function is instanti-
11531 ated, at which point a program is ill-formed if the substitution
11532 results in an invalid type.] */
11534 static tree
11536 tree args,
11537 tsubst_flags_t complain,
11538 tree in_decl)
11539 {
11540 tree return_type;
11542 tree fntype;
11544 /* The TYPE_CONTEXT is not used for function/method types. */
11547 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
11548 failure. */
11552 {
11553 /* Substitute the argument types. */
11565 {
11566 /* DR 1207: 'this' is in scope in the trailing return type. */
11568 }
11570 /* Substitute the return type. */
11574 {
11577 }
11578 }
11579 else
11580 /* Substitute the return type. */
11585 /* DR 486 clarifies that creation of a function type with an
11586 invalid return type is a deduction failure. */
11589 {
11591 {
11594 else
11596 }
11598 }
11599 /* And DR 657. */
11604 {
11605 /* Substitute the argument types. */
11610 }
11612 /* Construct a new type node and return it. */
11614 {
11619 }
11620 else
11621 {
11623 /* Don't pick up extra function qualifiers from the basetype. */
11626 {
11627 /* [temp.deduct]
11629 Type deduction may fail for any of the following
11630 reasons:
11632 -- Attempting to create "pointer to member of T" when T
11633 is not a class type. */
11636 r);
11638 }
11643 }
11650 }
11652 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11653 ARGS into that specification, and return the substituted
11654 specification. If there is no specification, return NULL_TREE. */
11656 static tree
11658 tree args,
11659 tsubst_flags_t complain,
11660 tree in_decl,
11662 {
11663 tree specs;
11664 tree new_specs;
11669 {
11670 /* A noexcept-specifier. */
11675 {
11676 /* Defer instantiation of noexcept-specifiers to avoid
11677 excessive instantiations (c++/49107). */
11680 {
11681 /* We already partially instantiated this member template,
11682 so combine the new args with the old. */
11687 }
11688 else
11689 {
11692 }
11693 }
11694 else
11695 new_specs = tsubst_copy_and_build
11699 }
11701 {
11704 else
11706 {
11707 tree spec;
11712 {
11713 /* Expand the pack expansion type. */
11716 in_decl);
11722 else
11723 {
11724 /* We're substituting into a member template, so
11725 we got a TYPE_PACK_EXPANSION back. Add that
11726 expansion and move on. */
11730 expanded_specs,
11731 complain);
11734 }
11735 }
11738 {
11741 else
11746 complain);
11747 }
11750 }
11751 }
11753 }
11755 /* Take the tree structure T and replace template parameters used
11756 therein with the argument vector ARGS. IN_DECL is an associated
11757 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11758 Issue error and warning messages under control of COMPLAIN. Note
11759 that we must be relatively non-tolerant of extensions here, in
11760 order to preserve conformance; if we allow substitutions that
11761 should not be allowed, we may allow argument deductions that should
11762 not succeed, and therefore report ambiguous overload situations
11763 where there are none. In theory, we could allow the substitution,
11764 but indicate that it should have failed, and allow our caller to
11765 make sure that the right thing happens, but we don't try to do this
11766 yet.
11768 This function is used for dealing with types, decls and the like;
11769 for expressions, use tsubst_expr or tsubst_copy. */
11771 tree
11773 {
11796 else
11801 /* Reuse typedefs. We need to do this to handle dependent attributes,
11802 such as attribute aligned. */
11805 {
11809 {
11810 /* DECL represents an alias template and we want to
11811 instantiate it. */
11815 }
11819 {
11823 }
11828 else
11829 /* The typedef is from a non-template context. */
11833 {
11835 r = cp_build_qualified_type_real
11839 }
11840 else
11841 {
11842 /* We don't have an instantiation yet, so drop the typedef. */
11847 }
11848 }
11861 {
11887 {
11893 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11894 needed. */
11900 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11901 with TREE_SIDE_EFFECTS that indicates this is not an integral
11902 constant expression. */
11905 {
11908 }
11911 }
11917 {
11930 {
11934 {
11935 /* See through ARGUMENT_PACK_SELECT arguments. */
11937 /* If the selected argument is an expansion E, that most
11938 likely means we were called from
11939 gen_elem_of_pack_expansion_instantiation during the
11940 substituting of pack an argument pack (which Ith
11941 element is a pack expansion, where I is
11942 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11943 In this case, the Ith element resulting from this
11944 substituting is going to be a pack expansion, which
11945 pattern is the pattern of E. Let's return the
11946 pattern of E, and
11947 gen_elem_of_pack_expansion_instantiation will
11948 build the resulting pack expansion from it. */
11950 {
11951 /* Make sure we aren't throwing away arg info. */
11954 }
11955 }
11956 }
11961 {
11963 /* If ARG is an argument pack, we don't actually want to
11964 perform a substitution here, because substitutions
11965 for argument packs are only done
11966 element-by-element. We can get to this point when
11967 substituting the type of a non-type template
11968 parameter pack, when that type actually contains
11969 template parameter packs from an outer template, e.g.,
11971 template<typename... Types> struct A {
11972 template<Types... Values> struct B { };
11973 }; */
11977 {
11983 return cp_build_qualified_type_real
11985 }
11987 {
11988 /* We are processing a type constructed from a
11989 template template parameter. */
12000 /* Consider this code:
12002 template <template <class> class Template>
12003 struct Internal {
12004 template <class Arg> using Bind = Template<Arg>;
12005 };
12007 template <template <class> class Template, class Arg>
12008 using Instantiate = Template<Arg>; //#0
12010 template <template <class> class Template,
12011 class Argument>
12012 using Bind =
12013 Instantiate<Internal<Template>::template Bind,
12014 Argument>; //#1
12016 When #1 is parsed, the
12017 BOUND_TEMPLATE_TEMPLATE_PARM representing the
12018 parameter `Template' in #0 matches the
12019 UNBOUND_CLASS_TEMPLATE representing the argument
12020 `Internal<Template>::template Bind'; We then want
12021 to assemble the type `Bind<Argument>' that can't
12022 be fully created right now, because
12023 `Internal<Template>' not being complete, the Bind
12024 template cannot be looked up in that context. So
12025 we need to "store" `Bind<Argument>' for later
12026 when the context of Bind becomes complete. Let's
12027 store that in a TYPENAME_TYPE. */
12031 argvec),
12032 typename_type,
12033 complain);
12035 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
12036 are resolving nested-types in the signature of a
12037 member function templates. Otherwise ARG is a
12038 TEMPLATE_DECL and is the real template to be
12039 instantiated. */
12047 complain);
12048 return cp_build_qualified_type_real
12050 }
12051 else
12052 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
12054 }
12057 /* This can happen during the attempted tsubst'ing in
12058 unify. This means that we don't yet have any information
12059 about the template parameter in question. */
12062 /* Early in template argument deduction substitution, we don't
12063 want to reduce the level of 'auto', or it will be confused
12064 with a normal template parm in subsequent deduction. */
12068 /* If we get here, we must have been looking at a parm for a
12069 more deeply nested template. Make a new version of this
12070 template parameter, but with a lower level. */
12072 {
12077 {
12079 r = cp_build_qualified_type_real
12083 }
12084 else
12085 {
12096 /* We have reduced the level of the template
12097 template parameter, but not the levels of its
12098 template parameters, so canonical_type_parameter
12099 will not be able to find the canonical template
12100 template parameter for this level. Thus, we
12101 require structural equality checking to compare
12102 TEMPLATE_TEMPLATE_PARMs. */
12106 else
12110 {
12118 }
12119 }
12128 }
12131 }
12134 {
12142 {
12146 }
12149 {
12153 }
12156 {
12160 }
12166 }
12169 /* We should never be tsubsting a binfo. */
12173 /* A vector of template arguments. */
12179 {
12183 /* [temp.deduct]
12185 Type deduction may fail for any of the following
12186 reasons:
12188 -- Attempting to create a pointer to reference type.
12189 -- Attempting to create a reference to a reference type or
12190 a reference to void.
12192 Core issue 106 says that creating a reference to a reference
12193 during instantiation is no longer a cause for failure. We
12194 only enforce this check in strict C++98 mode. */
12198 {
12201 /* We keep track of the last time we issued this error
12202 message to avoid spewing a ton of messages during a
12203 single bad template instantiation. */
12206 {
12211 else
12214 }
12217 }
12221 {
12223 {
12226 type);
12227 else
12229 type);
12230 }
12232 }
12234 {
12238 }
12240 /* In C++0x, during template argument substitution, when there is an
12241 attempt to create a reference to a reference type, reference
12242 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
12244 "If a template-argument for a template-parameter T names a type
12245 that is a reference to a type A, an attempt to create the type
12246 'lvalue reference to cv T' creates the type 'lvalue reference to
12247 A,' while an attempt to create the type type rvalue reference to
12248 cv T' creates the type T"
12249 */
12250 r = cp_build_reference_type
12253 else
12258 /* Will this ever be needed for TYPE_..._TO values? */
12262 }
12264 {
12267 {
12268 /* [temp.deduct]
12270 Type deduction may fail for any of the following
12271 reasons:
12273 -- Attempting to create "pointer to member of T" when T
12274 is not a class type. */
12278 }
12280 {
12284 }
12286 {
12290 }
12293 {
12294 /* The type of the implicit object parameter gets its
12295 cv-qualifiers from the FUNCTION_TYPE. */
12296 tree memptr;
12297 tree method_type
12302 complain);
12303 }
12304 else
12307 complain);
12308 }
12311 {
12312 tree fntype;
12313 tree specs;
12318 /* Substitute the exception specification. */
12326 }
12328 {
12333 /* As an optimization, we avoid regenerating the array type if
12334 it will obviously be the same as T. */
12338 /* These checks should match the ones in create_array_type_for_decl.
12340 [temp.deduct]
12342 The deduction may fail for any of the following reasons:
12344 -- Attempting to create an array with an element type that
12345 is void, a function type, or a reference type, or [DR337]
12346 an abstract class type. */
12352 {
12356 }
12364 {
12367 }
12370 }
12373 {
12383 {
12387 }
12389 {
12390 /* Normally, make_typename_type does not require that the CTX
12391 have complete type in order to allow things like:
12393 template <class T> struct S { typename S<T>::X Y; };
12395 But, such constructs have already been resolved by this
12396 point, so here CTX really should have complete type, unless
12397 it's a partial instantiation. */
12400 {
12404 }
12405 }
12412 {
12415 }
12418 {
12420 {
12424 else
12426 }
12428 {
12432 else
12434 }
12435 }
12437 return cp_build_qualified_type_real
12439 }
12442 {
12454 }
12457 {
12458 tree type;
12474 complain);
12475 }
12478 {
12479 tree type;
12497 else
12498 {
12502 /* In a template ~id could be either a complement expression
12503 or an unqualified-id naming a destructor; if instantiating
12504 it produces an expression, it's not an id-expression or
12505 member access. */
12508 }
12513 }
12516 {
12520 }
12524 {
12526 tree packed_out =
12528 args,
12529 complain,
12530 in_decl);
12533 /* For template nontype argument packs, also substitute into
12534 the type. */
12539 }
12555 /* We should use one of the expression tsubsts for these codes. */
12561 }
12562 }
12564 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12565 type of the expression on the left-hand side of the "." or "->"
12566 operator. */
12568 static tree
12571 {
12572 tree name;
12573 tree qualifying_scope;
12574 tree fns;
12575 tree optype;
12580 /* A baselink indicates a function from a base class. Both the
12581 BASELINK_ACCESS_BINFO and the base class referenced may
12582 indicate bases of the template class, rather than the
12583 instantiated class. In addition, lookups that were not
12584 ambiguous before may be ambiguous now. Therefore, we perform
12585 the lookup again. */
12592 {
12599 }
12607 /* If lookup found a single function, mark it as used at this
12608 point. (If it lookup found multiple functions the one selected
12609 later by overload resolution will be marked as used at that
12610 point.) */
12616 /* Add back the template arguments, if present. */
12621 template_args);
12622 /* Update the conversion operator type. */
12630 qualifying_scope,
12631 object_type);
12633 }
12635 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12636 true if the qualified-id will be a postfix-expression in-and-of
12637 itself; false if more of the postfix-expression follows the
12638 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12639 of "&". */
12641 static tree
12645 {
12646 tree expr;
12647 tree scope;
12648 tree name;
12650 tree template_args;
12655 /* Figure out what name to look up. */
12658 {
12666 }
12667 else
12668 {
12671 }
12673 /* Substitute into the qualifying scope. When there are no ARGS, we
12674 are just trying to simplify a non-dependent expression. In that
12675 case the qualifying scope may be dependent, and, in any case,
12676 substituting will not help. */
12679 {
12682 }
12683 else
12687 {
12692 }
12695 {
12697 {
12698 /* A BIT_NOT_EXPR is used to represent a destructor. */
12700 {
12704 }
12705 else
12708 }
12709 else
12713 {
12715 {
12719 }
12721 }
12722 }
12725 {
12727 scope);
12728 /* Remember that there was a reference to this entity. */
12730 }
12733 {
12739 }
12748 {
12749 expr = (adjust_result_of_qualified_name_lookup
12751 expr = (finish_qualified_id_expr
12755 }
12757 /* Expressions do not generally have reference type. */
12759 /* However, if we're about to form a pointer-to-member, we just
12760 want the referenced member referenced. */
12765 }
12767 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
12768 initializer, DECL is the substituted VAR_DECL. Other arguments are as
12769 for tsubst. */
12771 static tree
12774 {
12781 {
12782 /* If we had an initializer but it
12783 instantiated to nothing,
12784 value-initialize the object. This will
12785 only occur when the initializer was a
12786 pack expansion where the parameter packs
12787 used in that expansion were of length
12788 zero. */
12790 complain);
12793 }
12796 }
12798 /* Like tsubst, but deals with expressions. This function just replaces
12799 template parms; to finish processing the resultant expression, use
12800 tsubst_copy_and_build or tsubst_expr. */
12802 static tree
12804 {
12806 tree r;
12814 {
12819 {
12820 /* We get here for a use of 'this' in an NSDMI. */
12822 && current_function_decl
12826 /* This can happen for a parameter name used later in a function
12827 declaration (such as in a late-specified return type). Just
12828 make a dummy decl, since it's only used for its type. */
12831 /* Give it the template pattern as its context; its true context
12832 hasn't been instantiated yet and this is good enough for
12833 mangling. */
12835 }
12843 {
12844 tree enum_type;
12845 tree v;
12849 /* There is no need to substitute into namespace-scope
12850 enumerators. */
12853 /* If ARGS is NULL, then T is known to be non-dependent. */
12857 /* Unfortunately, we cannot just call lookup_name here.
12858 Consider:
12860 template <int I> int f() {
12861 enum E { a = I };
12862 struct S { void g() { E e = a; } };
12863 };
12865 When we instantiate f<7>::S::g(), say, lookup_name is not
12866 clever enough to find f<7>::a. */
12867 enum_type
12877 /* We didn't find the name. That should never happen; if
12878 name-lookup found it during preliminary parsing, we
12879 should find it again here during instantiation. */
12881 }
12886 {
12887 /* Check for a local specialization set up by
12888 tsubst_pack_expansion. */
12890 {
12894 }
12896 /* When retrieving a capture pack from a generic lambda, remove the
12897 lambda call op's own template argument list from ARGS. Only the
12898 template arguments active for the closure type should be used to
12899 retrieve the pack specialization. */
12905 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12906 tsubst_decl put in the hash table. */
12908 }
12911 {
12912 tree ctx;
12917 {
12920 {
12924 }
12926 }
12927 }
12936 {
12939 {
12940 /* First try name lookup to find the instantiation. */
12943 {
12944 /* Make sure that the one we found is the one we want. */
12949 }
12953 else
12954 {
12955 /* This can happen for a variable used in a
12956 late-specified return type of a local lambda, or for a
12957 local static or constant. Building a new VAR_DECL
12958 should be OK in all those cases. */
12961 {
12962 /* We can't call cp_finish_decl, so handle the
12963 initializer by hand. */
12974 }
12979 {
12982 at_eof);
12984 /* A use of a local constant decays to its value.
12985 FIXME update for core DR 696. */
12987 }
12988 }
12989 /* Remember this for subsequent uses. */
12992 }
12993 }
12994 else
13003 /* An OVERLOAD will always be a non-dependent overload set; an
13004 overload set from function scope will just be represented with an
13005 IDENTIFIER_NODE, and from class scope with a BASELINK. */
13021 {
13022 /* Template template argument like the following example need
13023 special treatment:
13025 template <template <class> class TT> struct C {};
13026 template <class T> struct D {
13027 template <class U> struct E {};
13028 C<E> c; // #1
13029 };
13030 D<int> d; // #2
13032 We are processing the template argument `E' in #1 for
13033 the template instantiation #2. Originally, `E' is a
13034 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
13035 have to substitute this with one having context `D<int>'. */
13039 }
13040 else
13041 /* Ordinary template template argument. */
13052 {
13056 }
13060 {
13070 /* We only want to compute the number of arguments. */
13084 {
13091 else
13094 }
13095 else
13097 }
13099 {
13107 }
13108 /* Fall through */
13124 {
13128 }
13131 {
13132 tree object;
13133 tree name;
13138 {
13142 }
13145 {
13155 }
13160 in_decl);
13161 else
13164 }
13202 {
13206 }
13209 {
13214 }
13217 {
13221 }
13224 {
13232 }
13238 {
13245 }
13248 {
13255 }
13258 {
13265 }
13268 {
13269 /* Substituted template arguments */
13278 }
13281 {
13301 }
13326 /* Fall through. */
13329 {
13332 }
13333 else
13337 /* This is handled by tsubst_copy_and_build. */
13341 {
13345 }
13348 /* We shouldn't have built any of these during initial template
13349 generation. Instead, they should be built during instantiation
13350 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13354 {
13362 }
13380 {
13381 /* Instantiate any typedefs in the type. */
13386 }
13389 /* These can sometimes show up in a partial instantiation, but never
13390 involve template parms. */
13395 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13398 }
13399 }
13401 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13403 static tree
13406 {
13410 {
13416 {
13419 {
13425 }
13426 /* FALLTHRU */
13454 {
13457 {
13464 }
13465 else
13467 }
13497 }
13498 }
13504 }
13506 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13508 static tree
13510 tree in_decl)
13511 {
13512 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13532 {
13535 else
13536 {
13540 }
13541 }
13546 #undef RECUR
13547 }
13549 /* Substitute one OMP_FOR iterator. */
13551 static void
13556 {
13557 #define RECUR(NODE) \
13558 tsubst_expr ((NODE), args, complain, in_decl, \
13559 integral_constant_expression_p)
13568 {
13569 /* We need to jump through some hoops to handle declarations in the
13570 for-init-statement, since we might need to handle auto deduction,
13571 but we need to keep control of initialization. */
13575 }
13576 else
13588 {
13590 {
13591 /* Declare the variable, but don't let that initialize it. */
13596 }
13601 {
13606 }
13607 else
13614 }
13617 {
13618 /* Declare and initialize the variable. */
13621 }
13623 {
13624 tree c;
13626 {
13637 }
13639 {
13644 {
13647 }
13648 }
13649 }
13652 {
13656 }
13657 else
13661 {
13672 {
13680 }
13681 else
13687 {
13693 }
13697 {
13705 }
13706 else
13712 }
13718 #undef RECUR
13719 }
13721 /* Like tsubst_copy for expressions, etc. but also does semantic
13722 processing. */
13724 static tree
13727 {
13728 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13729 #define RECUR(NODE) \
13730 tsubst_expr ((NODE), args, complain, in_decl, \
13731 integral_constant_expression_p)
13734 tree r;
13735 location_t loc;
13747 {
13749 {
13750 tree_stmt_iterator i;
13754 }
13769 else
13778 {
13780 tree init;
13786 {
13789 tree decl;
13797 else
13799 }
13801 {
13802 /* Don't build up decls for a variadic capture proxy, we'll
13803 instantiate the elements directly as needed. */
13805 }
13806 else
13807 {
13811 {
13812 /* By marking the declaration as instantiated, we avoid
13813 trying to instantiate it. Since instantiate_decl can't
13814 handle local variables, and since we've already done
13815 all that needs to be done, that's the right thing to
13816 do. */
13821 /* Anonymous aggregates are a special case. */
13824 {
13827 {
13831 }
13833 }
13839 {
13844 }
13845 else
13846 {
13851 {
13852 /* For __PRETTY_FUNCTION__ we have to adjust the
13853 initializer. */
13857 }
13858 else
13862 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13865 }
13866 }
13867 }
13870 }
13885 {
13895 }
13922 {
13926 }
13934 else
13942 else
13963 {
13967 }
13971 {
13973 tree label;
13978 }
13984 /* Computed goto's must be tsubst'd into. On the other hand,
13985 non-computed gotos must not be; the identifier in question
13986 will have no binding. */
13988 else
13994 {
14010 }
14015 {
14020 }
14021 else
14022 {
14027 else
14034 else
14040 else
14042 }
14046 {
14050 {
14052 /* Prevent instantiate_decl from trying to instantiate
14053 this variable. We've already done all that needs to be
14054 done. */
14057 }
14062 }
14068 {
14069 /* Local classes are not independent templates; they are
14070 instantiated along with their containing function. And this
14071 way we don't have to deal with pushing out of one local class
14072 to instantiate a member of another local class. */
14073 tree fn;
14074 /* Closures are handled by the LAMBDA_EXPR. */
14080 }
14084 {
14085 tree condition;
14088 condition =
14090 args,
14099 }
14124 {
14133 {
14138 }
14150 integral_constant_expression_p);
14159 else
14160 {
14168 }
14171 }
14230 {
14235 {
14238 }
14244 }
14245 else
14246 {
14253 {
14256 }
14259 {
14264 {
14267 }
14273 }
14274 else
14275 {
14279 }
14282 }
14286 {
14292 {
14296 {
14301 }
14305 }
14306 else
14307 {
14312 }
14313 }
14317 {
14321 }
14341 /* If the first operand was a statement, we're done with it. */
14345 complain));
14357 integral_constant_expression_p));
14358 }
14361 out:
14364 #undef RECUR
14365 #undef RETURN
14366 }
14368 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14369 function. For description of the body see comment above
14370 cp_parser_omp_declare_reduction_exprs. */
14372 static void
14374 {
14380 tree_stmt_iterator tsi;
14391 {
14410 }
14412 {
14432 }
14433 }
14435 /* T is a postfix-expression that is not being used in a function
14436 call. Return the substituted version of T. */
14438 static tree
14440 tsubst_flags_t complain,
14441 tree in_decl)
14442 {
14446 else
14452 }
14454 /* Like tsubst but deals with expressions and performs semantic
14455 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14457 tree
14459 tree args,
14460 tsubst_flags_t complain,
14461 tree in_decl,
14464 {
14465 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14466 #define RECUR(NODE) \
14467 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14469 integral_constant_expression_p)
14472 location_t loc;
14481 /* N3276 decltype magic only applies to calls at the top level or on the
14482 right side of a comma. */
14487 {
14490 /* Fall through. */
14492 {
14493 tree decl;
14494 cp_id_kind idk;
14499 {
14502 }
14504 /* Look up the name. */
14507 /* By convention, expressions use ERROR_MARK_NODE to indicate
14508 failure, not NULL_TREE. */
14514 integral_constant_expression_p,
14522 input_location);
14526 {
14530 }
14532 }
14535 {
14536 tree object;
14544 {
14547 }
14548 else
14555 else
14557 }
14560 {
14564 {
14565 /* A type conversion to reference type will be enclosed in
14566 such an indirect ref, but the substitution of the cast
14567 will have also added such an indirect ref. */
14570 }
14571 else
14575 }
14578 {
14582 }
14585 {
14592 flags));
14593 }
14596 {
14600 }
14607 {
14608 tree type;
14614 {
14619 }
14625 {
14643 }
14646 }
14680 else
14682 in_decl);
14717 {
14722 tree r = build_x_binary_op
14724 op0,
14726 ? ERROR_MARK
14728 op1,
14730 ? ERROR_MARK
14738 }
14741 {
14745 }
14758 {
14767 }
14771 /* Fall through */
14774 {
14775 tree r;
14781 {
14782 /* When there are no ARGS, we are trying to evaluate a
14783 non-dependent expression from the parser. Trying to do
14784 the substitutions may not work. */
14787 }
14788 else
14789 {
14794 else
14797 /*integral_constant_expression_p=*/
14801 }
14805 else
14809 {
14811 {
14813 {
14817 }
14818 else
14822 }
14824 }
14826 }
14829 {
14839 }
14855 {
14859 tree r = build_x_modify_expr
14862 /* TREE_NO_WARNING must be set if either the expression was
14863 parenthesized or it uses an operator such as >>= rather
14864 than plain assignment. In the former case, it was already
14865 set and must be copied. In the latter case,
14866 build_x_modify_expr sets it and it must not be reset
14867 here. */
14872 }
14877 /* Remember that there was a reference to this entity. */
14883 {
14888 tree ret;
14892 else
14893 {
14897 }
14899 /* If there was an initializer in the original tree, but it
14900 instantiated to an empty list, then we should pass a
14901 non-NULL empty vector to tell build_new that it was an
14902 empty initializer() rather than no initializer. This can
14903 only happen when the initializer is a pack expansion whose
14904 parameter packs are of length zero. */
14907 else
14908 {
14912 else
14913 {
14916 }
14917 }
14923 complain);
14931 }
14934 {
14940 complain));
14941 }
14944 {
14948 integral_constant_expression_p);
14950 op0,
14953 }
14956 {
14957 tree function;
14962 tree ret;
14965 /* When we parsed the expression, we determined whether or
14966 not Koenig lookup should be performed. */
14969 {
14974 }
14976 {
14977 /* Do nothing; calling tsubst_copy_and_build on an identifier
14978 would incorrectly perform unqualified lookup again.
14980 Note that we can also have an IDENTIFIER_NODE if the earlier
14981 unqualified lookup found a member function; in that case
14982 koenig_p will be false and we do want to do the lookup
14983 again to find the instantiated member function.
14985 FIXME but doing that causes c++/15272, so we need to stop
14986 using IDENTIFIER_NODE in that situation. */
14988 }
14989 else
14990 {
14992 {
14998 }
14999 else
15004 /* Avoid error about taking the address of a constructor. */
15008 in_decl,
15010 integral_constant_expression_p);
15014 }
15019 {
15024 else
15025 {
15026 /* Expand the pack expansion and push each entry onto
15027 CALL_ARGS. */
15030 {
15035 {
15040 }
15041 }
15042 else
15043 {
15044 /* A partial substitution. Add one entry. */
15046 }
15047 }
15048 }
15050 /* We do not perform argument-dependent lookup if normal
15051 lookup finds a non-function, in accordance with the
15052 expected resolution of DR 218. */
15055 /* If lookup found a member function, the Koenig lookup is
15056 not appropriate, even if an unqualified-name was used
15057 to denote the function. */
15060 /* Only do this when substitution turns a dependent call
15061 into a non-dependent call. */
15068 {
15070 {
15071 /* For backwards compatibility and good diagnostics, try
15072 the unqualified lookup again if we aren't in SFINAE
15073 context. */
15074 tree unq = (tsubst_copy_and_build
15076 integral_constant_expression_p));
15081 {
15090 "%qD was not declared in this scope, "
15091 "and no declarations were found by "
15092 "argument-dependent lookup at the point "
15094 {
15098 {
15100 input_location);
15102 "declarations in dependent base %qT are "
15108 else
15112 }
15113 else
15116 }
15118 }
15119 }
15121 {
15126 }
15127 }
15129 /* Remember that there was a reference to this entity. */
15133 /* Put back tf_decltype for the actual call. */
15138 complain);
15140 {
15155 complain);
15156 else
15157 ret = (build_new_method_call
15162 complain));
15163 }
15164 else
15167 koenig_p,
15168 complain);
15173 }
15176 {
15182 {
15184 {
15189 }
15190 else
15191 {
15196 }
15198 }
15199 else
15200 {
15203 }
15207 }
15210 {
15215 input_location));
15216 }
15219 {
15227 {
15228 /* We have pack expansions, so expand those and
15229 create a new list out of it. */
15232 tree chain;
15235 /* Expand the argument expressions. */
15243 /* Build the rest of the list. */
15248 /* Determine the number of arguments. */
15250 {
15253 }
15256 else
15257 {
15258 /* Since we only performed a partial substitution into
15259 the argument pack, we only RETURN (a single list
15260 node. */
15267 }
15269 /* Convert the argument vectors into a TREE_LIST */
15272 {
15273 /* Grab the Ith values. */
15274 i--;
15277 value
15281 /* Build the list (backwards). */
15283 }
15286 }
15302 }
15305 {
15306 tree object;
15307 tree object_type;
15308 tree member;
15309 tree r;
15313 /* Remember that there was a reference to this entity. */
15323 else
15331 {
15333 {
15338 {
15341 }
15343 {
15348 }
15349 }
15350 }
15353 {
15354 /* Lookup the template functions now that we know what the
15355 scope is. */
15363 {
15366 args);
15367 member = (adjust_result_of_qualified_name_lookup
15369 object_type));
15370 }
15371 else
15372 {
15374 input_location);
15376 }
15377 }
15381 {
15383 {
15387 else
15390 }
15392 }
15394 {
15399 }
15403 complain);
15407 }
15414 {
15422 tree r;
15427 /* digest_init will do the wrong thing if we let it. */
15431 /* We do not want to process the index of aggregate
15432 initializers as they are identifier nodes which will be
15433 looked up by digest_init. */
15439 {
15441 /* An identifier index is looked up in the type
15442 being initialized, not the current scope. */
15447 {
15448 /* Substitute into the pack expansion. */
15450 in_decl);
15454 ;
15456 /* Just move the argument into place. */
15458 else
15459 {
15460 /* Update the length of the final CONSTRUCTOR
15461 arguments vector, and note that we will need to
15462 copy.*/
15465 }
15466 }
15467 else
15469 }
15472 {
15477 {
15479 {
15484 }
15485 else
15487 }
15488 }
15498 }
15501 {
15504 {
15507 }
15508 else
15509 {
15512 }
15513 }
15519 {
15520 /* We don't build decls for an instantiation of a
15521 variadic capture proxy, we instantiate the elements
15522 when needed. */
15525 }
15526 /* Fall through */
15529 {
15531 /* ??? We're doing a subset of finish_id_expression here. */
15533 && !processing_template_decl
15534 && !cp_unevaluated_operand
15537 {
15539 /* Replace an evaluated use of the thread_local variable with
15540 a call to its wrapper. */
15542 }
15547 /* If the original type was a reference, we'll be wrapped in
15548 the appropriate INDIRECT_REF. */
15551 }
15554 {
15558 }
15565 {
15576 }
15579 {
15585 integral_constant_expression_p);
15589 /* If the resulting list of expression statement is empty,
15590 fold it further into void_node. */
15595 }
15598 {
15612 /* For a function scope, we want to use tsubst so that we don't
15613 complain about referring to an auto function before its return
15614 type has been deduced. Otherwise, we want to use tsubst_copy so
15615 that we look up the existing field/parameter/variable rather
15616 than build a new one. */
15621 {
15622 /* Look up the parameter we want directly, as tsubst_copy
15623 doesn't do what we need. */
15629 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15632 }
15633 else
15642 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15644 /* Now that we know visibility, instantiate the type so we have a
15645 declaration of the op() for later calls to lambda_function. */
15651 }
15654 /* We can get here for a constant initializer of non-dependent type.
15655 FIXME stop folding in cp_parser_initializer_clause. */
15656 {
15658 complain);
15660 }
15664 integral_constant_expression_p));
15670 {
15675 complain));
15676 }
15679 /* Handle Objective-C++ constructs, if appropriate. */
15680 {
15681 tree subst
15686 }
15688 }
15690 #undef RECUR
15691 #undef RETURN
15692 out:
15695 }
15697 /* Verify that the instantiated ARGS are valid. For type arguments,
15698 make sure that the type's linkage is ok. For non-type arguments,
15699 make sure they are constants if they are integral or enumerations.
15700 Emit an error under control of COMPLAIN, and return TRUE on error. */
15702 static bool
15704 {
15708 {
15718 }
15720 {
15721 /* [basic.link]: A name with no linkage (notably, the name
15722 of a class or enumeration declared in a local scope)
15723 shall not be used to declare an entity with linkage.
15724 This implies that names with no linkage cannot be used as
15725 template arguments
15727 DR 757 relaxes this restriction for C++0x. */
15732 {
15733 /* DR 488 makes use of a type with no linkage cause
15734 type deduction to fail. */
15736 {
15739 else
15742 }
15744 }
15745 /* In order to avoid all sorts of complications, we do not
15746 allow variably-modified types as template arguments. */
15748 {
15752 }
15753 }
15754 /* Class template and alias template arguments should be OK. */
15756 ;
15757 /* A non-type argument of integral or enumerated type must be a
15758 constant. */
15763 {
15767 }
15769 }
15771 static bool
15773 {
15778 {
15781 }
15785 }
15787 /* We're out of SFINAE context now, so generate diagnostics for the access
15788 errors we saw earlier when instantiating D from TMPL and ARGS. */
15790 static void
15792 {
15804 }
15806 /* Instantiate the indicated variable, function, or alias template TMPL with
15807 the template arguments in TARG_PTR. */
15809 static tree
15811 {
15813 tree fndecl;
15814 tree gen_tmpl;
15815 tree spec;
15823 /* If this function is a clone, handle it specially. */
15825 {
15826 tree spec;
15827 tree clone;
15829 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15830 DECL_CLONED_FUNCTION. */
15836 /* Look for the clone. */
15840 /* We should always have found the clone by now. */
15843 }
15848 /* Check to see if we already have this specialization. */
15851 /* The TMPL is a partial instantiation. To get a full set of
15852 arguments we must add the arguments used to perform the
15853 partial instantiation. */
15855 targ_ptr);
15857 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15858 but it doesn't seem to be on the hot path. */
15867 {
15869 {
15873 }
15875 }
15878 complain))
15881 /* We are building a FUNCTION_DECL, during which the access of its
15882 parameters and return types have to be checked. However this
15883 FUNCTION_DECL which is the desired context for access checking
15884 is not built yet. We solve this chicken-and-egg problem by
15885 deferring all checks until we have the FUNCTION_DECL. */
15888 /* Instantiation of the function happens in the context of the function
15889 template, not the context of the overload resolution we're doing. */
15891 /* If there are dependent arguments, e.g. because we're doing partial
15892 ordering, make sure processing_template_decl stays set. */
15896 {
15900 }
15905 {
15906 /* We need to determine if we're using a partial or explicit
15907 specialization now, because the type of the variable could be
15908 different. */
15914 {
15918 }
15919 }
15921 /* Substitute template parameters to obtain the specialization. */
15928 {
15931 }
15933 /* The DECL_TI_TEMPLATE should always be the immediate parent
15934 template, not the most general template. */
15937 /* Now we know the specialization, compute access previously
15938 deferred. */
15945 /* If we've just instantiated the main entry point for a function,
15946 instantiate all the alternate entry points as well. We do this
15947 by cloning the instantiation of the main entry point, not by
15948 instantiating the template clones. */
15953 {
15955 {
15956 /* Remember to reinstantiate when we're out of SFINAE so the user
15957 can see the errors. */
15959 }
15961 }
15963 }
15965 /* Wrapper for instantiate_template_1. */
15967 tree
15969 {
15970 tree ret;
15975 }
15977 /* Instantiate the alias template TMPL with ARGS. Also push a template
15978 instantiation level, which instantiate_template doesn't do because
15979 functions and variables have sufficient context established by the
15980 callers. */
15982 static tree
15984 {
15991 {
15994 }
15996 args =
16004 /* We can't free this if a pending_template entry or last_error_tinst_level
16005 is pointing at it. */
16011 }
16013 /* PARM is a template parameter pack for FN. Returns true iff
16014 PARM is used in a deducible way in the argument list of FN. */
16016 static bool
16018 {
16021 {
16023 tree packs;
16029 {
16030 /* The template parameter pack is used in a function parameter
16031 pack. If this is the end of the parameter list, the
16032 template parameter pack is deducible. */
16035 else
16036 /* Otherwise, not. Well, it could be deduced from
16037 a non-pack parameter, but doing so would end up with
16038 a deduction mismatch, so don't bother. */
16040 }
16041 }
16042 /* The template parameter pack isn't used in any function parameter
16043 packs, but it might be used deeper, e.g. tuple<Args...>. */
16045 }
16047 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
16048 NARGS elements of the arguments that are being used when calling
16049 it. TARGS is a vector into which the deduced template arguments
16050 are placed.
16052 Returns either a FUNCTION_DECL for the matching specialization of FN or
16053 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
16054 true, diagnostics will be printed to explain why it failed.
16056 If FN is a conversion operator, or we are trying to produce a specific
16057 specialization, RETURN_TYPE is the return type desired.
16059 The EXPLICIT_TARGS are explicit template arguments provided via a
16060 template-id.
16062 The parameter STRICT is one of:
16064 DEDUCE_CALL:
16065 We are deducing arguments for a function call, as in
16066 [temp.deduct.call].
16068 DEDUCE_CONV:
16069 We are deducing arguments for a conversion function, as in
16070 [temp.deduct.conv].
16072 DEDUCE_EXACT:
16073 We are deducing arguments when doing an explicit instantiation
16074 as in [temp.explicit], when determining an explicit specialization
16075 as in [temp.expl.spec], or when taking the address of a function
16076 template, as in [temp.deduct.funcaddr]. */
16078 tree
16080 tree explicit_targs,
16081 tree targs,
16084 tree return_type,
16085 unification_kind_t strict,
16089 {
16090 tree parms;
16091 tree fntype;
16099 tree tinst;
16105 /* In C++0x, it's possible to have a function template whose type depends
16106 on itself recursively. This is most obvious with decltype, but can also
16107 occur with enumeration scope (c++/48969). So we need to catch infinite
16108 recursion and reject the substitution at deduction time; this function
16109 will return error_mark_node for any repeated substitution.
16111 This also catches excessive recursion such as when f<N> depends on
16112 f<N-1> across all integers, and returns error_mark_node for all the
16113 substitutions back up to the initial one.
16115 This is, of course, not reentrant. */
16125 {
16126 /* [temp.deduct]
16128 The specified template arguments must match the template
16129 parameters in kind (i.e., type, nontype, template), and there
16130 must not be more arguments than there are parameters;
16131 otherwise type deduction fails.
16133 Nontype arguments must match the types of the corresponding
16134 nontype template parameters, or must be convertible to the
16135 types of the corresponding nontype parameters as specified in
16136 _temp.arg.nontype_, otherwise type deduction fails.
16138 All references in the function type of the function template
16139 to the corresponding template parameters are replaced by the
16140 specified template argument values. If a substitution in a
16141 template parameter or in the function type of the function
16142 template results in an invalid type, type deduction fails. */
16147 /* Adjust any explicit template arguments before entering the
16148 substitution context. */
16149 explicit_targs
16151 complain,
16157 /* Substitute the explicit args into the function type. This is
16158 necessary so that, for instance, explicitly declared function
16159 arguments can match null pointed constants. If we were given
16160 an incomplete set of explicit args, we must not do semantic
16161 processing during substitution as we could create partial
16162 instantiations. */
16164 {
16169 /* Dig out the actual parm. */
16172 {
16175 }
16177 {
16180 }
16183 /* No explicit argument for this template parameter. */
16187 {
16188 /* Mark the argument pack as "incomplete". We could
16189 still deduce more arguments during unification.
16190 We remove this mark in type_unification_real. */
16192 {
16196 }
16198 /* We have some incomplete argument packs. */
16200 }
16201 }
16205 {
16208 }
16211 /* Ignore any access checks; we'll see them again in
16212 instantiate_template and they might have the wrong
16213 access path at this point. */
16225 /* Place the explicitly specified arguments in TARGS. */
16228 }
16230 /* Never do unification on the 'this' parameter. */
16234 {
16243 }
16245 /* We allow incomplete unification without an error message here
16246 because the standard doesn't seem to explicitly prohibit it. Our
16247 callers must be ready to deal with unification failures in any
16248 event. */
16251 /* If we aren't explaining yet, push tinst context so we can see where
16252 any errors (e.g. from class instantiations triggered by instantiation
16253 of default template arguments) come from. If we are explaining, this
16254 context is redundant. */
16256 {
16259 }
16261 /* type_unification_real will pass back any access checks from default
16262 template argument substitution. */
16274 /* Now that we have bindings for all of the template arguments,
16275 ensure that the arguments deduced for the template template
16276 parameters have compatible template parameter lists. We cannot
16277 check this property before we have deduced all template
16278 arguments, because the template parameter types of a template
16279 template parameter might depend on prior template parameters
16280 deduced after the template template parameter. The following
16281 ill-formed example illustrates this issue:
16283 template<typename T, template<T> class C> void f(C<5>, T);
16285 template<int N> struct X {};
16287 void g() {
16288 f(X<5>(), 5l); // error: template argument deduction fails
16289 }
16291 The template parameter list of 'C' depends on the template type
16292 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
16293 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
16294 time that we deduce 'C'. */
16297 {
16300 }
16302 /* All is well so far. Now, check:
16304 [temp.deduct]
16306 When all template arguments have been deduced, all uses of
16307 template parameters in nondeduced contexts are replaced with
16308 the corresponding deduced argument values. If the
16309 substitution results in an invalid type, as described above,
16310 type deduction fails. */
16313 {
16316 }
16318 /* Also collect access checks from the instantiation. */
16331 /* Now perform any access checks encountered during substitution. */
16338 /* If we're looking for an exact match, check that what we got
16339 is indeed an exact match. It might not be if some template
16340 parameters are used in non-deduced contexts. But don't check
16341 for an exact match if we have dependent template arguments;
16342 in that case we're doing partial ordering, and we already know
16343 that we have two candidates that will provide the actual type. */
16345 {
16349 tree sarg
16355 {
16359 }
16360 }
16364 fail:
16367 {
16369 /* Reset once we're all the way out. */
16371 }
16373 /* We can't free this if a pending_template entry or last_error_tinst_level
16374 is pointing at it. */
16380 }
16382 /* Adjust types before performing type deduction, as described in
16383 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16384 sections are symmetric. PARM is the type of a function parameter
16385 or the return type of the conversion function. ARG is the type of
16386 the argument passed to the call, or the type of the value
16387 initialized with the result of the conversion function.
16388 ARG_EXPR is the original argument expression, which may be null. */
16390 static int
16394 tree arg_expr)
16395 {
16399 {
16404 {
16405 /* Swap PARM and ARG throughout the remainder of this
16406 function; the handling is precisely symmetric since PARM
16407 will initialize ARG rather than vice versa. */
16412 }
16415 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16416 too, but here handle it by stripping the reference from PARM
16417 rather than by adding it to ARG. */
16425 /* Nothing else to do in this case. */
16430 }
16433 {
16434 /* [temp.deduct.call]
16436 If P is not a reference type:
16438 --If A is an array type, the pointer type produced by the
16439 array-to-pointer standard conversion (_conv.array_) is
16440 used in place of A for type deduction; otherwise,
16442 --If A is a function type, the pointer type produced by
16443 the function-to-pointer standard conversion
16444 (_conv.func_) is used in place of A for type deduction;
16445 otherwise,
16447 --If A is a cv-qualified type, the top level
16448 cv-qualifiers of A's type are ignored for type
16449 deduction. */
16454 else
16456 }
16458 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16459 of the form T&&, where T is a template parameter, and the argument
16460 is an lvalue, T is deduced as A& */
16466 /* try_one_overload doesn't provide an arg_expr, but
16467 functions are always lvalues. */
16471 /* [temp.deduct.call]
16473 If P is a cv-qualified type, the top level cv-qualifiers
16474 of P's type are ignored for type deduction. If P is a
16475 reference type, the type referred to by P is used for
16476 type deduction. */
16479 {
16482 }
16484 /* DR 322. For conversion deduction, remove a reference type on parm
16485 too (which has been swapped into ARG). */
16490 }
16492 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16493 template which does contain any deducible template parameters; check if
16494 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16495 unify_one_argument. */
16497 static int
16500 {
16501 tree type;
16505 else
16512 {
16516 }
16518 {
16523 }
16527 else
16529 }
16533 /* Returns true iff the expression EXPR is one from which a template
16534 argument can be deduced. In other words, if it's an undecorated
16535 use of a template non-type parameter. */
16537 static bool
16539 {
16541 }
16543 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16544 deducible way; that is, if it has a max value of <PARM> - 1. */
16546 static bool
16548 {
16557 }
16559 /* Returns true iff the template arguments ARGS use a template parameter
16560 in a deducible way. */
16562 static bool
16564 {
16566 {
16571 else
16572 {
16579 else
16581 }
16584 }
16586 }
16588 /* Returns true iff TYPE contains any deducible references to template
16589 parameters, as per 14.8.2.5. */
16591 static bool
16593 {
16597 /* T
16598 cv-list T
16599 TT<T>
16600 TT<i>
16601 TT<> */
16606 /* T*
16607 T&
16608 T&& */
16612 /* T[integer-constant ]
16613 type [i] */
16618 /* T type ::*
16619 type T::*
16620 T T::*
16621 T (type ::*)()
16622 type (T::*)()
16623 type (type ::*)(T)
16624 type (T::*)(T)
16625 T (type ::*)(T)
16626 T (T::*)()
16627 T (T::*)(T) */
16630 || (uses_deducible_template_parms
16633 /* template-name <T> (where template-name refers to a class template)
16634 template-name <i> (where template-name refers to a class template) */
16641 /* type (T)
16642 T()
16643 T(T) */
16646 {
16655 }
16658 }
16660 /* Subroutine of type_unification_real and unify_pack_expansion to
16661 handle unification of a single P/A pair. Parameters are as
16662 for those functions. */
16664 static int
16668 {
16675 /* We can't deduce anything from this, but we might get all the
16676 template args from other function args. */
16679 /* Implicit conversions (Clause 4) will be performed on a function
16680 argument to convert it to the type of the corresponding function
16681 parameter if the parameter type contains no template-parameters that
16682 participate in template argument deduction. */
16684 /* For function parameters that contain no template-parameters at all,
16685 we have historically checked for convertibility in order to shortcut
16686 consideration of this candidate. */
16688 explain_p);
16691 /* For function parameters with only non-deducible template parameters,
16692 just return. */
16696 {
16698 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16699 | UNIFY_ALLOW_MORE_CV_QUAL
16713 }
16715 /* We only do these transformations if this is the top-level
16716 parameter_type_list in a call or declaration matching; in other
16717 situations (nested function declarators, template argument lists) we
16718 won't be comparing a type to an expression, and we don't do any type
16719 adjustments. */
16721 {
16723 {
16726 {
16727 /* [temp.deduct.type] A template-argument can be
16728 deduced from a pointer to function or pointer
16729 to member function argument if the set of
16730 overloaded functions does not contain function
16731 templates and at most one of a set of
16732 overloaded functions provides a unique
16733 match. */
16740 }
16746 }
16748 arg_strict |=
16750 }
16751 else
16756 /* For deduction from an init-list we need the actual list. */
16760 }
16762 /* Most parms like fn_type_unification.
16764 If SUBR is 1, we're being called recursively (to unify the
16765 arguments of a function or method parameter of a function
16766 template).
16768 CHECKS is a pointer to a vector of access checks encountered while
16769 substituting default template arguments. */
16771 static int
16773 tree targs,
16774 tree xparms,
16778 unification_kind_t strict,
16782 {
16787 tree parms;
16796 /* Reset the number of non-defaulted template arguments contained
16797 in TARGS. */
16800 again:
16808 {
16813 /* For a function parameter pack that occurs at the end of the
16814 parameter-declaration-list, the type A of each remaining
16815 argument of the call is compared with the type P of the
16816 declarator-id of the function parameter pack. */
16822 /* For a function parameter pack that does not occur at the
16823 end of the parameter-declaration-list, the type of the
16824 parameter pack is a non-deduced context. */
16833 }
16838 {
16839 /* Unify the remaining arguments with the pack expansion type. */
16840 tree argvec;
16843 /* Allocate a TREE_VEC and copy in all of the arguments */
16848 /* Copy the parameter into parmvec. */
16854 /* Advance to the end of the list of parameters. */
16856 }
16858 /* Fail if we've reached the end of the parm list, and more args
16859 are present, and the parm list isn't variadic. */
16862 /* Fail if parms are left and they don't have default values and
16863 they aren't all deduced as empty packs (c++/57397). This is
16864 consistent with sufficient_parms_p. */
16867 {
16871 do
16872 {
16875 count++;
16877 }
16881 type_pack_p);
16882 }
16885 {
16886 tsubst_flags_t complain = (explain_p
16887 ? tf_warning_or_error
16891 {
16895 /* Clear the "incomplete" flags on all argument packs now so that
16896 substituting them into later default arguments works. */
16898 {
16901 }
16907 /* If this is an undeduced nontype parameter that depends on
16908 a type parameter, try another pass; its type may have been
16909 deduced from a later argument than the one from which
16910 this parameter can be deduced. */
16916 /* Core issue #226 (C++0x) [temp.deduct]:
16918 If a template argument has not been deduced, its
16919 default template argument, if any, is used.
16921 When we are in C++98 mode, TREE_PURPOSE will either
16922 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16923 to explicitly check cxx_dialect here. */
16925 {
16940 else
16941 {
16943 /* The position of the first default template argument,
16944 is also the number of non-defaulted arguments in TARGS.
16945 Record that. */
16949 }
16950 }
16952 /* If the type parameter is a parameter pack, then it will
16953 be deduced to an empty parameter pack. */
16955 {
16956 tree arg;
16959 {
16963 }
16964 else
16971 }
16974 }
16975 }
16976 #ifdef ENABLE_CHECKING
16979 #endif
16982 }
16984 /* Subroutine of type_unification_real. Args are like the variables
16985 at the call site. ARG is an overloaded function (or template-id);
16986 we try deducing template args from each of the overloads, and if
16987 only one succeeds, we go with that. Modifies TARGS and returns
16988 true on success. */
16990 static bool
16992 tree targs,
16993 tree parm,
16994 tree arg,
16995 unification_kind_t strict,
16998 {
17005 {
17008 }
17009 else
17013 /* Handle `&x' where `x' is some static or non-static member
17014 function name. */
17020 /* Strip baselink information. */
17025 {
17026 /* If we got some explicit template args, we need to plug them into
17027 the affected templates before we try to unify, in case the
17028 explicit args will completely resolve the templates in question. */
17035 {
17048 {
17053 {
17056 }
17057 }
17060 }
17061 /* If no templates (or more than one) are fully resolved by the
17062 explicit arguments, this template-id is a non-deduced context; it
17063 could still be OK if we deduce all template arguments for the
17064 enclosing call through other arguments. */
17067 }
17070 /* If ARG is, for example, "(0, &f)" then its type will be unknown
17071 -- but the deduction does not succeed because the expression is
17072 not just the function on its own. */
17074 else
17080 {
17083 }
17085 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17086 to function or pointer to member function argument if the set of
17087 overloaded functions does not contain function templates and at most
17088 one of a set of overloaded functions provides a unique match.
17090 So if we found multiple possibilities, we return success but don't
17091 deduce anything. */
17094 {
17098 {
17103 /* Don't forget explicit template arguments in a pack. */
17107 }
17108 }
17113 }
17115 /* Core DR 115: In contexts where deduction is done and fails, or in
17116 contexts where deduction is not done, if a template argument list is
17117 specified and it, along with any default template arguments, identifies
17118 a single function template specialization, then the template-id is an
17119 lvalue for the function template specialization. */
17121 tree
17123 {
17136 {
17139 }
17141 {
17144 }
17146 {
17149 }
17152 {
17156 /* If we got some explicit template args, we need to plug them into
17157 the affected templates before we try to unify, in case the
17158 explicit args will completely resolve the templates in question. */
17166 {
17179 {
17182 {
17185 }
17187 {
17190 }
17191 }
17192 }
17194 {
17202 {
17203 tree base
17206 }
17210 }
17212 /* There were no good options and at least one bad one, so let the
17213 user know what the problem is. */
17215 }
17217 }
17219 /* Subroutine of resolve_overloaded_unification; does deduction for a single
17220 overload. Fills TARGS with any deduced arguments, or error_mark_node if
17221 different overloads deduce different arguments for a given parm.
17222 ADDR_P is true if the expression for which deduction is being
17223 performed was of the form "& fn" rather than simply "fn".
17225 Returns 1 on success. */
17227 static int
17229 tree orig_targs,
17230 tree targs,
17231 tree parm,
17232 tree arg,
17233 unification_kind_t strict,
17237 {
17239 tree tempargs;
17245 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17246 to function or pointer to member function argument if the set of
17247 overloaded functions does not contain function templates and at most
17248 one of a set of overloaded functions provides a unique match.
17250 So if this is a template, just return success. */
17262 /* We don't copy orig_targs for this because if we have already deduced
17263 some template args from previous args, unify would complain when we
17264 try to deduce a template parameter for the same argument, even though
17265 there isn't really a conflict. */
17272 /* First make sure we didn't deduce anything that conflicts with
17273 explicitly specified args. */
17275 {
17282 /* Since we're unifying against ourselves, we will fill in
17283 template args used in the function parm list with our own
17284 template parms. Discard them. */
17288 }
17291 {
17296 }
17299 }
17301 /* PARM is a template class (perhaps with unbound template
17302 parameters). ARG is a fully instantiated type. If ARG can be
17303 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
17304 TARGS are as for unify. */
17306 static tree
17309 {
17310 tree copy_of_targs;
17317 /* We need to make a new template argument vector for the call to
17318 unify. If we used TARGS, we'd clutter it up with the result of
17319 the attempted unification, even if this class didn't work out.
17320 We also don't want to commit ourselves to all the unifications
17321 we've already done, since unification is supposed to be done on
17322 an argument-by-argument basis. In other words, consider the
17323 following pathological case:
17325 template <int I, int J, int K>
17326 struct S {};
17328 template <int I, int J>
17329 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
17331 template <int I, int J, int K>
17332 void f(S<I, J, K>, S<I, I, I>);
17334 void g() {
17335 S<0, 0, 0> s0;
17336 S<0, 1, 2> s2;
17338 f(s0, s2);
17339 }
17341 Now, by the time we consider the unification involving `s2', we
17342 already know that we must have `f<0, 0, 0>'. But, even though
17343 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
17344 because there are two ways to unify base classes of S<0, 1, 2>
17345 with S<I, I, I>. If we kept the already deduced knowledge, we
17346 would reject the possibility I=1. */
17349 /* If unification failed, we're done. */
17355 }
17357 /* Given a template type PARM and a class type ARG, find the unique
17358 base type in ARG that is an instance of PARM. We do not examine
17359 ARG itself; only its base-classes. If there is not exactly one
17360 appropriate base class, return NULL_TREE. PARM may be the type of
17361 a partial specialization, as well as a plain template type. Used
17362 by unify. */
17364 static enum template_base_result
17367 {
17369 tree binfo;
17375 {
17376 /* The type could not be completed. */
17379 }
17381 /* Walk in inheritance graph order. The search order is not
17382 important, and this avoids multiple walks of virtual bases. */
17384 {
17389 {
17390 /* If there is more than one satisfactory baseclass, then:
17392 [temp.deduct.call]
17394 If they yield more than one possible deduced A, the type
17395 deduction fails.
17397 applies. */
17399 {
17402 }
17405 }
17406 }
17410 }
17412 /* Returns the level of DECL, which declares a template parameter. */
17414 static int
17416 {
17418 {
17428 }
17430 }
17432 /* Decide whether ARG can be unified with PARM, considering only the
17433 cv-qualifiers of each type, given STRICT as documented for unify.
17434 Returns nonzero iff the unification is OK on that basis. */
17436 static int
17438 {
17444 {
17445 /* Although a CVR qualifier is ignored when being applied to a
17446 substituted template parameter ([8.3.2]/1 for example), that
17447 does not allow us to unify "const T" with "int&" because both
17448 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17449 It is ok when we're allowing additional CV qualifiers
17450 at the outer level [14.8.2.1]/3,1st bullet. */
17460 }
17471 }
17473 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17474 void
17476 {
17480 {
17483 }
17484 else
17485 {
17488 }
17489 }
17491 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17492 do { \
17493 if (unify (TP, TA, P, A, S, EP)) \
17494 return 1; \
17495 } while (0);
17497 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17498 expansion at the end of PACKED_PARMS. Returns 0 if the type
17499 deduction succeeds, 1 otherwise. STRICT is the same as in
17500 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17501 call argument list. We'll need to adjust the arguments to make them
17502 types. SUBR tells us if this is from a recursive call to
17503 type_unification_real, or for comparing two template argument
17504 lists. */
17506 static int
17510 {
17511 tree parm
17521 /* Determine the parameter packs we will be deducing from the
17522 pattern, and record their current deductions. */
17525 {
17529 /* Determine the index and level of this parameter pack. */
17532 /* Keep track of the parameter packs and their corresponding
17533 argument packs. */
17536 }
17538 /* Loop through all of the arguments that have not yet been
17539 unified and unify each with the pattern. */
17541 {
17542 tree parm;
17546 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17547 or the element of its argument pack at the current index if
17548 this argument was explicitly specified. */
17550 {
17559 {
17562 }
17564 }
17566 /* If we had explicit template arguments, substitute them into the
17567 pattern before deduction. */
17569 {
17570 /* Some arguments might still be unspecified or dependent. */
17578 NULL_TREE);
17583 }
17584 else
17587 /* Unify the pattern with the current argument. */
17592 /* For each parameter pack, collect the deduced value. */
17594 {
17600 }
17601 }
17603 /* Verify that the results of unification with the parameter packs
17604 produce results consistent with what we've seen before, and make
17605 the deduced argument packs available. */
17607 {
17614 /* By default keep the original deduced argument pack.
17615 If necessary, more specific code is going to update the
17616 resulting deduced argument later down in this function. */
17620 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17621 actually deduce anything. */
17629 {
17630 /* If we had fewer function args than explicit template args,
17631 just use the explicits. */
17636 }
17639 {
17640 tree result;
17641 /* Build the deduced *_ARGUMENT_PACK. */
17643 {
17648 }
17649 else
17654 /* Note the deduced argument packs for this parameter
17655 pack. */
17657 }
17661 {
17662 /* We only had the explicitly-provided arguments before, but
17663 now we have a complete set of arguments. */
17669 }
17670 else
17671 {
17677 /* Inconsistent unification of this parameter pack. */
17679 bad_old_arg,
17680 bad_new_arg);
17681 }
17682 }
17685 }
17687 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17688 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17689 parameters and return value are as for unify. */
17691 static int
17695 {
17696 tree parm_max;
17697 tree arg_max;
17701 /* Our representation of array types uses "N - 1" as the
17702 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17703 not an integer constant. We cannot unify arbitrarily
17704 complex expressions, so we eliminate the MINUS_EXPRs
17705 here. */
17709 {
17712 }
17716 {
17717 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17718 trying to unify the type of a variable with the type
17719 of a template parameter. For example:
17721 template <unsigned int N>
17722 void f (char (&) [N]);
17723 int g();
17724 void h(int i) {
17725 char a[g(i)];
17726 f(a);
17727 }
17729 Here, the type of the ARG will be "int [g(i)]", and
17730 may be a SAVE_EXPR, etc. */
17734 }
17736 /* If only one of the bounds used a MINUS_EXPR, compensate
17737 by adding one to the other bound. */
17740 integer_type_node,
17741 parm_max,
17742 integer_one_node);
17745 integer_type_node,
17746 arg_max,
17747 integer_one_node);
17751 }
17753 /* Deduce the value of template parameters. TPARMS is the (innermost)
17754 set of template parameters to a template. TARGS is the bindings
17755 for those template parameters, as determined thus far; TARGS may
17756 include template arguments for outer levels of template parameters
17757 as well. PARM is a parameter to a template function, or a
17758 subcomponent of that parameter; ARG is the corresponding argument.
17759 This function attempts to match PARM with ARG in a manner
17760 consistent with the existing assignments in TARGS. If more values
17761 are deduced, then TARGS is updated.
17763 Returns 0 if the type deduction succeeds, 1 otherwise. The
17764 parameter STRICT is a bitwise or of the following flags:
17766 UNIFY_ALLOW_NONE:
17767 Require an exact match between PARM and ARG.
17768 UNIFY_ALLOW_MORE_CV_QUAL:
17769 Allow the deduced ARG to be more cv-qualified (by qualification
17770 conversion) than ARG.
17771 UNIFY_ALLOW_LESS_CV_QUAL:
17772 Allow the deduced ARG to be less cv-qualified than ARG.
17773 UNIFY_ALLOW_DERIVED:
17774 Allow the deduced ARG to be a template base class of ARG,
17775 or a pointer to a template base class of the type pointed to by
17776 ARG.
17777 UNIFY_ALLOW_INTEGER:
17778 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17779 case for more information.
17780 UNIFY_ALLOW_OUTER_LEVEL:
17781 This is the outermost level of a deduction. Used to determine validity
17782 of qualification conversions. A valid qualification conversion must
17783 have const qualified pointers leading up to the inner type which
17784 requires additional CV quals, except at the outer level, where const
17785 is not required [conv.qual]. It would be normal to set this flag in
17786 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17787 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17788 This is the outermost level of a deduction, and PARM can be more CV
17789 qualified at this point.
17790 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17791 This is the outermost level of a deduction, and PARM can be less CV
17792 qualified at this point. */
17794 static int
17797 {
17799 tree targ;
17800 tree tparm;
17803 /* I don't think this will do the right thing with respect to types.
17804 But the only case I've seen it in so far has been array bounds, where
17805 signedness is the only information lost, and I think that will be
17806 okay. */
17814 /* We can't deduce anything from this, but we might get all the
17815 template args from other function args. */
17818 /* If PARM uses template parameters, then we can't bail out here,
17819 even if ARG == PARM, since we won't record unifications for the
17820 template parameters. We might need them if we're trying to
17821 figure out which of two things is more specialized. */
17825 /* Handle init lists early, so the rest of the function can assume
17826 we're dealing with a type. */
17828 {
17833 /* Replace T with std::initializer_list<T> for deduction. */
17840 /* We can only deduce from an initializer list argument if the
17841 parameter is std::initializer_list or an array; otherwise this
17842 is a non-deduced context. */
17847 else
17851 {
17858 {
17860 /* It should only be possible to get here for a call. */
17862 elt_strict |= maybe_adjust_types_for_deduction
17865 }
17868 explain_p);
17869 }
17873 {
17874 /* Also deduce from the length of the initializer list. */
17881 }
17883 /* If the std::initializer_list<T> deduction worked, replace the
17884 deduced A with std::initializer_list<A>. */
17886 {
17891 }
17893 }
17895 /* Immediately reject some pairs that won't unify because of
17896 cv-qualification mismatches. */
17899 /* It is the elements of the array which hold the cv quals of an array
17900 type, and the elements might be template type parms. We'll check
17901 when we recurse. */
17903 /* We check the cv-qualifiers when unifying with template type
17904 parameters below. We want to allow ARG `const T' to unify with
17905 PARM `T' for example, when computing which of two templates
17906 is more specialized, for example. */
17920 {
17924 /* In a type which contains a nested-name-specifier, template
17925 argument values cannot be deduced for template parameters used
17926 within the nested-name-specifier. */
17938 /* The PARM is not one we're trying to unify. Just check
17939 to see if it matches ARG. */
17940 {
17945 else
17947 }
17954 /* Check for mixed types and values. */
17962 {
17963 /* ARG must be constructed from a template class or a template
17964 template parameter. */
17968 {
17970 /* An alias template name is never deduced. */
17975 tree parm_parms
17976 = DECL_INNERMOST_TEMPLATE_PARMS
17981 /* The resolution to DR150 makes clear that default
17982 arguments for an N-argument may not be used to bind T
17983 to a template template parameter with fewer than N
17984 parameters. It is not safe to permit the binding of
17985 default arguments as an extension, as that may change
17986 the meaning of a conforming program. Consider:
17988 struct Dense { static const unsigned int dim = 1; };
17990 template <template <typename> class View,
17991 typename Block>
17992 void operator+(float, View<Block> const&);
17994 template <typename Block,
17995 unsigned int Dim = Block::dim>
17996 struct Lvalue_proxy { operator float() const; };
17998 void
17999 test_1d (void) {
18000 Lvalue_proxy<Dense> p;
18001 float b;
18002 b + p;
18003 }
18005 Here, if Lvalue_proxy is permitted to bind to View, then
18006 the global operator+ will be used; if they are not, the
18007 Lvalue_proxy will be converted to float. */
18009 full_argvec,
18011 (explain_p
18012 ? tf_warning_or_error
18019 /* Deduce arguments T, i from TT<T> or TT<i>.
18020 We check each element of PARMVEC and ARGVEC individually
18021 rather than the whole TREE_VEC since they can have
18022 different number of elements. */
18029 /* Check if the parameters end in a pack, making them
18030 variadic. */
18036 /* If the template argument list of P contains a pack
18037 expansion that is not the last template argument, the
18038 entire template argument list is a non-deduced
18039 context. */
18048 {
18053 }
18058 DEDUCE_EXACT,
18061 }
18064 /* Fall through to deduce template name. */
18065 }
18069 {
18070 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
18072 /* Simple cases: Value already set, does match or doesn't. */
18077 }
18078 else
18079 {
18080 /* If PARM is `const T' and ARG is only `int', we don't have
18081 a match unless we are allowing additional qualification.
18082 If ARG is `const int' and PARM is just `T' that's OK;
18083 that binds `const int' to `T'. */
18088 /* Consider the case where ARG is `const volatile int' and
18089 PARM is `const T'. Then, T should be `volatile int'. */
18090 arg = cp_build_qualified_type_real
18095 /* Simple cases: Value already set, does match or doesn't. */
18101 /* Make sure that ARG is not a variable-sized array. (Note
18102 that were talking about variable-sized arrays (like
18103 `int[n]'), rather than arrays of unknown size (like
18104 `int[]').) We'll get very confused by such a type since
18105 the bound of the array is not constant, and therefore
18106 not mangleable. Besides, such types are not allowed in
18107 ISO C++, so we can do as we please here. We do allow
18108 them for 'auto' deduction, since that isn't ABI-exposed. */
18112 /* Strip typedefs as in convert_template_argument. */
18114 }
18116 /* If ARG is a parameter pack or an expansion, we cannot unify
18117 against it unless PARM is also a parameter pack. */
18122 /* If the argument deduction results is a METHOD_TYPE,
18123 then there is a problem.
18124 METHOD_TYPE doesn't map to any real C++ type the result of
18125 the deduction can not be of that type. */
18139 {
18140 /* The PARM is not one we're trying to unify. Just check
18141 to see if it matches ARG. */
18147 }
18153 {
18158 }
18160 /* [temp.deduct.type] If, in the declaration of a function template
18161 with a non-type template-parameter, the non-type
18162 template-parameter is used in an expression in the function
18163 parameter-list and, if the corresponding template-argument is
18164 deduced, the template-argument type shall match the type of the
18165 template-parameter exactly, except that a template-argument
18166 deduced from an array bound may be of any integral type.
18167 The non-type parameter might use already deduced type parameters. */
18170 /* Template-parameter dependent expression. Just accept it for now.
18171 It will later be processed in convert_template_argument. */
18172 ;
18177 /* Convert the ARG to the type of PARM; the deduced non-type
18178 template argument must exactly match the types of the
18179 corresponding parameter. */
18182 /* We haven't deduced the type of this parameter yet. Try again
18183 later. */
18185 else
18188 /* If ARG is a parameter pack or an expansion, we cannot unify
18189 against it unless PARM is also a parameter pack. */
18199 {
18200 /* A pointer-to-member constant can be unified only with
18201 another constant. */
18205 /* Just unify the class member. It would be useless (and possibly
18206 wrong, depending on the strict flags) to unify also
18207 PTRMEM_CST_CLASS, because we want to be sure that both parm and
18208 arg refer to the same variable, even if through different
18209 classes. For instance:
18211 struct A { int x; };
18212 struct B : A { };
18214 Unification of &A::x and &B::x must succeed. */
18217 }
18220 {
18224 /* [temp.deduct.call]
18226 A can be another pointer or pointer to member type that can
18227 be converted to the deduced A via a qualification
18228 conversion (_conv.qual_).
18230 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
18231 This will allow for additional cv-qualification of the
18232 pointed-to types if appropriate. */
18235 /* The derived-to-base conversion only persists through one
18236 level of pointers. */
18241 }
18273 /* We have already checked cv-qualification at the top of the
18274 function. */
18278 /* As far as unification is concerned, this wins. Later checks
18279 will invalidate it if necessary. */
18282 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
18283 /* Type INTEGER_CST can come from ordinary constant template args. */
18295 {
18305 /* Check for pack expansions in the parameters. */
18307 {
18309 {
18311 /* We can unify against something with a trailing
18312 parameter pack. */
18314 else
18315 /* [temp.deduct.type]/9: If the template argument list of
18316 P contains a pack expansion that is not the last
18317 template argument, the entire template argument list
18318 is a non-deduced context. */
18320 }
18321 }
18323 /* If we don't have enough arguments to satisfy the parameters
18324 (not counting the pack expression at the end), or we have
18325 too many arguments for a parameter list that doesn't end in
18326 a pack expression, we can't unify. */
18332 /* Unify all of the parameters that precede the (optional)
18333 pack expression. */
18335 {
18340 }
18343 DEDUCE_EXACT,
18346 }
18354 {
18362 }
18367 {
18371 {
18372 /* First, we try to unify the PARM and ARG directly. */
18377 {
18378 /* Fallback to the special case allowed in
18379 [temp.deduct.call]:
18381 If P is a class, and P has the form
18382 template-id, then A can be a derived class of
18383 the deduced A. Likewise, if P is a pointer to
18384 a class of the form template-id, A can be a
18385 pointer to a derived class pointed to by the
18386 deduced A. */
18393 }
18394 }
18398 /* Perhaps PARM is something like S<U> and ARG is S<int>.
18399 Then, we should unify `int' and `U'. */
18401 else
18402 /* There's no chance of unification succeeding. */
18407 }
18414 {
18417 tree a;
18423 /* CV qualifications for methods can never be deduced, they must
18424 match exactly. We need to check them explicitly here,
18425 because type_unification_real treats them as any other
18426 cv-qualified parameter. */
18428 && (!check_cv_quals_for_unify
18448 }
18451 /* Unify a pointer to member with a pointer to member function, which
18452 deduces the type of the member as a function type. */
18454 {
18455 /* Check top-level cv qualifiers */
18463 /* Determine the type of the function we are unifying against. */
18467 }
18486 /* Matched cases are handled by the ARG == PARM test above. */
18490 /* A non-type template parameter that is a variable should be a
18491 an integral constant, in which case, it whould have been
18492 folded into its (constant) value. So we should not be getting
18493 a variable here. */
18504 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18505 or UNDERLYING_TYPE nodes. */
18509 /* Unification fails if we hit an error node. */
18514 {
18519 }
18520 /* FALLTHRU */
18523 /* An unresolved overload is a nondeduced context. */
18528 /* We must be looking at an expression. This can happen with
18529 something like:
18531 template <int I>
18532 void foo(S<I>, S<I + 2>);
18534 This is a "nondeduced context":
18536 [deduct.type]
18538 The nondeduced contexts are:
18540 --A type that is a template-id in which one or more of
18541 the template-arguments is an expression that references
18542 a template-parameter.
18544 In these cases, we assume deduction succeeded, but don't
18545 actually infer any unifications. */
18550 else
18552 }
18553 }
18554 #undef RECUR_AND_CHECK_FAILURE
18555 \f
18556 /* Note that DECL can be defined in this translation unit, if
18557 required. */
18559 static void
18561 {
18562 tree clone;
18566 }
18568 /* Called if RESULT is explicitly instantiated, or is a member of an
18569 explicitly instantiated class. */
18571 void
18573 {
18576 /* If this entity has already been written out, it's too late to
18577 make any modifications. */
18581 /* For anonymous namespace we don't need to do anything. */
18583 {
18586 }
18589 /* The TREE_PUBLIC flag for function declarations will have been
18590 set correctly by tsubst. */
18593 /* This might have been set by an earlier implicit instantiation. */
18598 else
18599 {
18602 /* Always make artificials weak. */
18605 /* For WIN32 we also want to put explicit instantiations in
18606 linkonce sections. */
18609 }
18611 /* If EXTERN_P, then this function will not be emitted -- unless
18612 followed by an explicit instantiation, at which point its linkage
18613 will be adjusted. If !EXTERN_P, then this function will be
18614 emitted here. In neither circumstance do we want
18615 import_export_decl to adjust the linkage. */
18617 }
18619 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18620 important template arguments. If any are missing, we check whether
18621 they're important by using error_mark_node for substituting into any
18622 args that were used for partial ordering (the ones between ARGS and END)
18623 and seeing if it bubbles up. */
18625 static bool
18627 {
18632 {
18635 }
18637 {
18641 }
18643 }
18645 /* Given two function templates PAT1 and PAT2, return:
18647 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18648 -1 if PAT2 is more specialized than PAT1.
18649 0 if neither is more specialized.
18651 LEN indicates the number of parameters we should consider
18652 (defaulted parameters should not be considered).
18654 The 1998 std underspecified function template partial ordering, and
18655 DR214 addresses the issue. We take pairs of arguments, one from
18656 each of the templates, and deduce them against each other. One of
18657 the templates will be more specialized if all the *other*
18658 template's arguments deduce against its arguments and at least one
18659 of its arguments *does* *not* deduce against the other template's
18660 corresponding argument. Deduction is done as for class templates.
18661 The arguments used in deduction have reference and top level cv
18662 qualifiers removed. Iff both arguments were originally reference
18663 types *and* deduction succeeds in both directions, an lvalue reference
18664 wins against an rvalue reference and otherwise the template
18665 with the more cv-qualified argument wins for that pairing (if
18666 neither is more cv-qualified, they both are equal). Unlike regular
18667 deduction, after all the arguments have been deduced in this way,
18668 we do *not* verify the deduced template argument values can be
18669 substituted into non-deduced contexts.
18671 The logic can be a bit confusing here, because we look at deduce1 and
18672 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18673 can find template arguments for pat1 to make arg1 look like arg2, that
18674 means that arg2 is at least as specialized as arg1. */
18676 int
18678 {
18691 /* Remove the this parameter from non-static member functions. If
18692 one is a non-static member function and the other is not a static
18693 member function, remove the first parameter from that function
18694 also. This situation occurs for operator functions where we
18695 locate both a member function (with this pointer) and non-member
18696 operator (with explicit first operand). */
18698 {
18703 }
18705 {
18708 {
18709 len--;
18711 }
18712 }
18714 /* If only one is a conversion operator, they are unordered. */
18718 /* Consider the return type for a conversion function */
18720 {
18723 len++;
18724 }
18726 processing_template_decl++;
18732 /* Stop when an ellipsis is seen. */
18734 {
18745 {
18746 /* When both arguments are pack expansions, we need only
18747 unify the patterns themselves. */
18751 /* This is the last comparison we need to do. */
18753 }
18756 {
18760 }
18763 {
18767 }
18773 {
18779 /* Setup the parameter vector, which contains only ARG1. */
18782 /* Setup the argument vector, which contains the remaining
18783 arguments. */
18792 /* We cannot deduce in the other direction, because ARG1 is
18793 a pack expansion but ARG2 is not. */
18795 }
18797 {
18803 /* Setup the parameter vector, which contains only ARG1. */
18806 /* Setup the argument vector, which contains the remaining
18807 arguments. */
18816 /* We cannot deduce in the other direction, because ARG2 is
18817 a pack expansion but ARG1 is not.*/
18819 }
18821 else
18822 {
18823 /* The normal case, where neither argument is a pack
18824 expansion. */
18831 }
18833 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18834 arg2, then arg2 is not as specialized as arg1. */
18840 /* "If, for a given type, deduction succeeds in both directions
18841 (i.e., the types are identical after the transformations above)
18842 and both P and A were reference types (before being replaced with
18843 the type referred to above):
18844 - if the type from the argument template was an lvalue reference and
18845 the type from the parameter template was not, the argument type is
18846 considered to be more specialized than the other; otherwise,
18847 - if the type from the argument template is more cv-qualified
18848 than the type from the parameter template (as described above),
18849 the argument type is considered to be more specialized than the other;
18850 otherwise,
18851 - neither type is more specialized than the other." */
18854 {
18856 {
18859 else
18861 }
18863 {
18868 }
18869 }
18872 /* We've failed to deduce something in either direction.
18873 These must be unordered. */
18878 /* We have already processed all of the arguments in our
18879 handing of the pack expansion type. */
18884 }
18886 /* "In most cases, all template parameters must have values in order for
18887 deduction to succeed, but for partial ordering purposes a template
18888 parameter may remain without a value provided it is not used in the
18889 types being used for partial ordering."
18891 Thus, if we are missing any of the targs1 we need to substitute into
18892 origs1, then pat2 is not as specialized as pat1. This can happen when
18893 there is a nondeduced context. */
18899 processing_template_decl--;
18901 /* All things being equal, if the next argument is a pack expansion
18902 for one function but not for the other, prefer the
18903 non-variadic function. FIXME this is bogus; see c++/41958. */
18907 {
18910 }
18916 else
18918 }
18920 /* Determine which of two partial specializations of TMPL is more
18921 specialized.
18923 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
18924 to the first partial specialization. The TREE_PURPOSE is the
18925 innermost set of template parameters for the partial
18926 specialization. PAT2 is similar, but for the second template.
18928 Return 1 if the first partial specialization is more specialized;
18929 -1 if the second is more specialized; 0 if neither is more
18930 specialized.
18932 See [temp.class.order] for information about determining which of
18933 two templates is more specialized. */
18935 static int
18937 {
18938 tree targs;
18949 /* Just like what happens for functions, if we are ordering between
18950 different template specializations, we may encounter dependent
18951 types in the arguments, and we need our dependency check functions
18952 to behave correctly. */
18956 {
18959 }
18963 {
18966 }
18969 /* In the case of a tie where at least one of the templates
18970 has a parameter pack at the end, the template with the most
18971 non-packed parameters wins. */
18973 && any_deductions
18976 {
18982 /* We don't count the pack expansion at the end. */
18992 }
18995 }
18997 /* Return the template arguments that will produce the function signature
18998 DECL from the function template FN, with the explicit template
18999 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
19000 also match. Return NULL_TREE if no satisfactory arguments could be
19001 found. */
19003 static tree
19005 {
19009 tree decl_arg_types;
19012 tree arg;
19016 /* Never do unification on the 'this' parameter. */
19037 }
19039 /* Return the innermost template arguments that, when applied to a partial
19040 specialization of TMPL whose innermost template parameters are
19041 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
19042 ARGS.
19044 For example, suppose we have:
19046 template <class T, class U> struct S {};
19047 template <class T> struct S<T*, int> {};
19049 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
19050 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
19051 int}. The resulting vector will be {double}, indicating that `T'
19052 is bound to `double'. */
19054 static tree
19056 {
19058 tree deduced_args;
19059 tree innermost_deduced_args;
19063 {
19067 innermost_deduced_args);
19068 }
19069 else
19082 /* Verify that nondeduced template arguments agree with the type
19083 obtained from argument deduction.
19085 For example:
19087 struct A { typedef int X; };
19088 template <class T, class U> struct C {};
19089 template <class T> struct C<T, typename T::X> {};
19091 Then with the instantiation `C<A, int>', we can deduce that
19092 `T' is `A' but unify () does not check whether `typename T::X'
19093 is `int'. */
19099 /* We only need to check the innermost arguments; the other
19100 arguments will always agree. */
19105 /* Now that we have bindings for all of the template arguments,
19106 ensure that the arguments deduced for the template template
19107 parameters have compatible template parameter lists. See the use
19108 of template_template_parm_bindings_ok_p in fn_type_unification
19109 for more information. */
19114 }
19116 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
19117 Return the TREE_LIST node with the most specialized template, if
19118 any. If there is no most specialized template, the error_mark_node
19119 is returned.
19121 Note that this function does not look at, or modify, the
19122 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
19123 returned is one of the elements of INSTANTIATIONS, callers may
19124 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
19125 and retrieve it from the value returned. */
19127 tree
19129 {
19136 {
19142 fate--;
19147 fate++;
19152 {
19153 /* Equally specialized, move to next function. If there
19154 is no next function, nothing's most specialized. */
19159 }
19160 }
19163 /* Now verify that champ is better than everything earlier in the
19164 instantiation list. */
19172 {
19175 }
19177 processing_template_decl--;
19183 }
19185 /* If DECL is a specialization of some template, return the most
19186 general such template. Otherwise, returns NULL_TREE.
19188 For example, given:
19190 template <class T> struct S { template <class U> void f(U); };
19192 if TMPL is `template <class U> void S<int>::f(U)' this will return
19193 the full template. This function will not trace past partial
19194 specializations, however. For example, given in addition:
19196 template <class T> struct S<T*> { template <class U> void f(U); };
19198 if TMPL is `template <class U> void S<int*>::f(U)' this will return
19199 `template <class T> template <class U> S<T*>::f(U)'. */
19201 tree
19203 {
19205 {
19208 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
19209 template friend, or a FIELD_DECL for a capture pack. */
19212 }
19214 /* Look for more and more general templates. */
19216 {
19217 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
19218 (See cp-tree.h for details.) */
19227 /* Stop if we run into an explicitly specialized class template. */
19234 }
19237 }
19239 /* Return the most specialized of the template partial specializations
19240 which can produce TARGET, a specialization of some class or variable
19241 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
19242 a TEMPLATE_DECL node corresponding to the partial specialization, while
19243 the TREE_PURPOSE is the set of template arguments that must be
19244 substituted into the template pattern in order to generate TARGET.
19246 If the choice of partial specialization is ambiguous, a diagnostic
19247 is issued, and the error_mark_node is returned. If there are no
19248 partial specializations matching TARGET, then NULL_TREE is
19249 returned, indicating that the primary template should be used. */
19251 static tree
19253 {
19255 tree t;
19256 tree champ;
19263 {
19267 }
19269 {
19272 }
19274 {
19278 }
19279 else
19284 /* For determining which partial specialization to use, only the
19285 innermost args are interesting. */
19287 {
19290 }
19293 {
19294 tree partial_spec_args;
19295 tree spec_args;
19303 {
19304 /* Discard the outer levels of args, and then substitute in the
19305 template args from the enclosing class. */
19307 partial_spec_args = tsubst_template_args
19310 /* And the same for the partial specialization TEMPLATE_DECL. */
19312 }
19314 partial_spec_args =
19316 partial_spec_args,
19330 partial_spec_args,
19331 args);
19333 {
19338 }
19339 }
19349 {
19352 ;
19353 else
19354 {
19356 {
19359 {
19362 }
19363 }
19365 }
19366 }
19370 {
19373 {
19376 }
19377 }
19380 {
19387 else
19391 {
19396 }
19399 }
19402 }
19404 /* Explicitly instantiate DECL. */
19406 void
19408 {
19413 /* An error occurred, for which grokdeclarator has already issued
19414 an appropriate message. */
19417 {
19420 }
19426 {
19427 /* There is an asymmetry here in the way VAR_DECLs and
19428 FUNCTION_DECLs are handled by grokdeclarator. In the case of
19429 the latter, the DECL we get back will be marked as a
19430 template instantiation, and the appropriate
19431 DECL_TEMPLATE_INFO will be set up. This does not happen for
19432 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
19433 should handle VAR_DECLs as it currently handles
19434 FUNCTION_DECLs. */
19436 {
19439 }
19442 {
19445 }
19447 {
19452 }
19453 }
19455 {
19458 }
19459 else
19462 /* Check for various error cases. Note that if the explicit
19463 instantiation is valid the RESULT will currently be marked as an
19464 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19465 until we get here. */
19468 {
19469 /* DR 259 [temp.spec].
19471 Both an explicit instantiation and a declaration of an explicit
19472 specialization shall not appear in a program unless the explicit
19473 instantiation follows a declaration of the explicit specialization.
19475 For a given set of template parameters, if an explicit
19476 instantiation of a template appears after a declaration of an
19477 explicit specialization for that template, the explicit
19478 instantiation has no effect. */
19480 }
19482 {
19483 /* [temp.spec]
19485 No program shall explicitly instantiate any template more
19486 than once.
19488 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19489 the first instantiation was `extern' and the second is not,
19490 and EXTERN_P for the opposite case. */
19493 /* If an "extern" explicit instantiation follows an ordinary
19494 explicit instantiation, the template is instantiated. */
19497 }
19499 {
19502 }
19504 {
19507 }
19510 ;
19512 {
19515 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19518 }
19519 else
19527 }
19529 static void
19531 {
19537 {
19540 }
19541 }
19543 /* Called from do_type_instantiation through binding_table_foreach to
19544 do recursive instantiation for the type bound in ENTRY. */
19545 static void
19547 {
19553 }
19555 /* Called from do_type_instantiation to instantiate a member
19556 (a member function or a static member variable) of an
19557 explicitly instantiated class template. */
19558 static void
19560 {
19565 }
19567 /* Perform an explicit instantiation of template class T. STORAGE, if
19568 non-null, is the RID for extern, inline or static. COMPLAIN is
19569 nonzero if this is called from the parser, zero if called recursively,
19570 since the standard is unclear (as detailed below). */
19572 void
19574 {
19584 {
19585 tree tmpl =
19589 else
19592 }
19597 {
19600 t);
19602 }
19605 {
19607 {
19609 {
19612 "ISO C++ 1998 forbids the use of %<extern%> on "
19614 }
19615 else
19617 "ISO C++ forbids the use of %qE"
19619 }
19627 else
19628 {
19630 storage);
19632 }
19633 }
19636 {
19637 /* DR 259 [temp.spec].
19639 Both an explicit instantiation and a declaration of an explicit
19640 specialization shall not appear in a program unless the explicit
19641 instantiation follows a declaration of the explicit specialization.
19643 For a given set of template parameters, if an explicit
19644 instantiation of a template appears after a declaration of an
19645 explicit specialization for that template, the explicit
19646 instantiation has no effect. */
19648 }
19650 {
19651 /* [temp.spec]
19653 No program shall explicitly instantiate any template more
19654 than once.
19656 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19657 instantiation was `extern'. If EXTERN_P then the second is.
19658 These cases are OK. */
19665 /* If we've already instantiated the template, just return now. */
19668 }
19676 {
19677 tree tmp;
19679 /* In contrast to implicit instantiation, where only the
19680 declarations, and not the definitions, of members are
19681 instantiated, we have here:
19683 [temp.explicit]
19685 The explicit instantiation of a class template specialization
19686 implies the instantiation of all of its members not
19687 previously explicitly specialized in the translation unit
19688 containing the explicit instantiation.
19690 Of course, we can't instantiate member template classes, since
19691 we don't have any arguments for them. Note that the standard
19692 is unclear on whether the instantiation of the members are
19693 *explicit* instantiations or not. However, the most natural
19694 interpretation is that it should be an explicit instantiation. */
19709 }
19710 }
19712 /* Given a function DECL, which is a specialization of TMPL, modify
19713 DECL to be a re-instantiation of TMPL with the same template
19714 arguments. TMPL should be the template into which tsubst'ing
19715 should occur for DECL, not the most general template.
19717 One reason for doing this is a scenario like this:
19719 template <class T>
19720 void f(const T&, int i);
19722 void g() { f(3, 7); }
19724 template <class T>
19725 void f(const T& t, const int i) { }
19727 Note that when the template is first instantiated, with
19728 instantiate_template, the resulting DECL will have no name for the
19729 first parameter, and the wrong type for the second. So, when we go
19730 to instantiate the DECL, we regenerate it. */
19732 static void
19734 {
19735 /* The arguments used to instantiate DECL, from the most general
19736 template. */
19737 tree args;
19738 tree code_pattern;
19743 /* Make sure that we can see identifiers, and compute access
19744 correctly. */
19748 {
19749 tree decl_parm;
19750 tree pattern_parm;
19751 tree specs;
19765 specs);
19767 /* Merge parameter declarations. */
19770 pattern_parm
19774 {
19775 tree parm_type;
19776 tree attributes;
19781 NULL_TREE);
19787 {
19790 }
19793 }
19794 /* Merge any parameters that match with the function parameter
19795 pack. */
19797 {
19799 tree expanded_types;
19800 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19801 the parameters in this function parameter pack. */
19806 {
19807 tree parm_type;
19808 tree attributes;
19811 /* Rename the parameter to include the index. */
19820 {
19823 }
19825 }
19826 }
19827 /* Merge additional specifiers from the CODE_PATTERN. */
19831 }
19833 {
19841 }
19842 else
19846 }
19848 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19849 substituted to get DECL. */
19851 tree
19853 {
19856 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19857 for the instantiation. This is not always the most general
19858 template. Consider, for example:
19860 template <class T>
19861 struct S { template <class U> void f();
19862 template <> void f<int>(); };
19864 and an instantiation of S<double>::f<int>. We want TD to be the
19865 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19867 more general template. */
19869 /* We must also deal with friend templates. Given:
19871 template <class T> struct S {
19872 template <class U> friend void f() {};
19873 };
19875 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19876 so far as the language is concerned, but that's still
19877 where we get the pattern for the instantiation from. On
19878 other hand, if the definition comes outside the class, say:
19880 template <class T> struct S {
19881 template <class U> friend void f();
19882 };
19883 template <class U> friend void f() {}
19885 we don't need to look any further. That's what the check for
19886 DECL_INITIAL is for. */
19890 {
19891 /* The present template, TD, should not be a definition. If it
19892 were a definition, we should be using it! Note that we
19893 cannot restructure the loop to just keep going until we find
19894 a template with a definition, since that might go too far if
19895 a specialization was declared, but not defined. */
19897 /* Fetch the more general template. */
19899 }
19902 }
19904 /* Returns true if we need to instantiate this template instance even if we
19905 know we aren't going to emit it.. */
19907 bool
19909 {
19910 /* We always instantiate inline functions so that we can inline them. An
19911 explicit instantiation declaration prohibits implicit instantiation of
19912 non-inline functions. With high levels of optimization, we would
19913 normally inline non-inline functions -- but we're not allowed to do
19914 that for "extern template" functions. Therefore, we check
19915 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19919 /* And we need to instantiate static data members so that
19920 their initializers are available in integral constant
19921 expressions. */
19924 }
19926 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19927 instantiate it now, modifying TREE_TYPE (fn). */
19929 void
19931 {
19934 /* Don't instantiate a noexcept-specification from template context. */
19949 {
19953 {
19968 }
19969 else
19973 }
19976 {
19979 else
19981 }
19982 }
19984 /* Produce the definition of D, a _DECL generated from a template. If
19985 DEFER_OK is nonzero, then we don't have to actually do the
19986 instantiation now; we just have to do it sometime. Normally it is
19987 an error if this is an explicit instantiation but D is undefined.
19988 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19989 explicitly instantiated class template. */
19991 tree
19994 {
19996 tree gen_args;
19997 tree args;
19998 tree td;
19999 tree code_pattern;
20000 tree spec;
20001 tree gen_tmpl;
20008 tree fn_context;
20011 /* This function should only be used to instantiate templates for
20012 functions and static member variables. */
20015 /* Variables are never deferred; if instantiation is required, they
20016 are instantiated right away. That allows for better code in the
20017 case that an expression refers to the value of the variable --
20018 if the variable has a constant value the referring expression can
20019 take advantage of that fact. */
20024 /* Don't instantiate cloned functions. Instead, instantiate the
20025 functions they cloned. */
20033 /* D has already been instantiated or explicitly specialized, so
20034 there's nothing for us to do here.
20036 It might seem reasonable to check whether or not D is an explicit
20037 instantiation, and, if so, stop here. But when an explicit
20038 instantiation is deferred until the end of the compilation,
20039 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
20040 the instantiation. */
20043 /* Check to see whether we know that this template will be
20044 instantiated in some other file, as with "extern template"
20045 extension. */
20048 /* In general, we do not instantiate such templates. */
20056 /* We should already have the extra args. */
20059 /* And what's in the hash table should match D. */
20063 /* This needs to happen before any tsubsting. */
20069 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
20070 for the instantiation. */
20074 /* We should never be trying to instantiate a member of a class
20075 template or partial specialization. */
20080 /* In the case of a friend template whose definition is provided
20081 outside the class, we may have too many arguments. Drop the
20082 ones we don't need. The same is true for specializations. */
20083 args = get_innermost_template_args
20085 else
20089 {
20094 }
20095 else
20096 {
20099 }
20101 /* We may be in the middle of deferred access check. Disable it now. */
20104 /* Unless an explicit instantiation directive has already determined
20105 the linkage of D, remember that a definition is available for
20106 this entity. */
20116 /* If D is a member of an explicitly instantiated class template,
20117 and no definition is available, treat it like an implicit
20118 instantiation. */
20121 {
20122 /* Leave linkage flags alone on instantiations with anonymous
20123 visibility. */
20125 {
20128 }
20130 }
20132 /* Defer all other templates, unless we have been explicitly
20133 forbidden from doing so. */
20135 template. */
20136 ! pattern_defined
20137 /* If it's OK to postpone instantiation, do so. */
20138 || defer_ok
20139 /* If this is a static data member that will be defined
20140 elsewhere, we don't want to instantiate the entire data
20141 member, but we do want to instantiate the initializer so that
20142 we can substitute that elsewhere. */
20144 /* Handle here a deleted function too, avoid generating
20145 its body (c++/61080). */
20147 {
20148 /* The definition of the static data member is now required so
20149 we must substitute the initializer. */
20153 {
20154 tree ns;
20155 tree init;
20164 args,
20167 /* If instantiating the initializer involved instantiating this
20168 again, don't call cp_finish_decl twice. */
20170 {
20171 /* Make sure the initializer is still constant, in case of
20172 circular dependency (template/instantiate6.C). */
20173 const_init
20177 LOOKUP_ONLYCONVERTING);
20178 }
20182 }
20184 /* We restore the source position here because it's used by
20185 add_pending_template. */
20191 /* [temp.explicit]
20193 The definition of a non-exported function template, a
20194 non-exported member function template, or a non-exported
20195 member function or static data member of a class template
20196 shall be present in every translation unit in which it is
20197 explicitly instantiated. */
20201 /* If we're in unevaluated context, we just wanted to get the
20202 constant value; this isn't an odr use, so don't queue
20203 a full instantiation. */
20206 /* ??? Historically, we have instantiated inline functions, even
20207 when marked as "extern template". */
20211 }
20212 /* Tell the repository that D is available in this translation unit
20213 -- and see if it is supposed to be instantiated here. */
20215 {
20216 /* In a PCH file, despite the fact that the repository hasn't
20217 requested instantiation in the PCH it is still possible that
20218 an instantiation will be required in a file that includes the
20219 PCH. */
20222 /* Instantiate inline functions so that the inliner can do its
20223 job, even though we'll not be emitting a copy of this
20224 function. */
20227 }
20233 else
20234 {
20239 }
20241 /* Mark D as instantiated so that recursive calls to
20242 instantiate_decl do not try to instantiate it again. */
20245 /* Regenerate the declaration in case the template has been modified
20246 by a subsequent redeclaration. */
20249 /* We already set the file and line above. Reset them now in case
20250 they changed as a result of calling regenerate_decl_from_template. */
20254 {
20255 tree init;
20258 /* Clear out DECL_RTL; whatever was there before may not be right
20259 since we've reset the type of the declaration. */
20263 /* The initializer is placed in DECL_INITIAL by
20264 regenerate_decl_from_template so we don't need to
20265 push/pop_access_scope again here. Pull it out so that
20266 cp_finish_decl can process it. */
20271 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
20272 initializer. That function will defer actual emission until
20273 we have a chance to determine linkage. */
20276 /* Enter the scope of D so that access-checking works correctly. */
20289 }
20293 {
20295 tree subst_decl;
20296 tree tmpl_parm;
20297 tree spec_parm;
20300 /* Save away the current list, in case we are instantiating one
20301 template from within the body of another. */
20304 /* Set up the list of local specializations. */
20307 /* Set up context. */
20311 else
20314 /* Some typedefs referenced from within the template code need to be
20315 access checked at template instantiation time, i.e now. These
20316 types were added to the template at parsing time. Let's get those
20317 and perform the access checks then. */
20319 gen_args);
20321 /* Create substitution entries for the parameters. */
20326 {
20330 }
20332 {
20334 {
20337 }
20338 else
20339 {
20340 /* Register the (value) argument pack as a specialization of
20341 TMPL_PARM, then move on. */
20344 }
20345 }
20348 /* Substitute into the body of the function. */
20352 else
20353 {
20358 /* Set the current input_location to the end of the function
20359 so that finish_function knows where we are. */
20360 input_location
20363 /* Remember if we saw an infinite loop in the template. */
20364 current_function_infinite_loop
20366 }
20368 /* We don't need the local specializations any more. */
20372 /* Finish the function. */
20376 else
20377 {
20380 }
20384 }
20386 /* We're not deferring instantiation any more. */
20394 out:
20404 }
20406 /* Run through the list of templates that we wish we could
20407 instantiate, and instantiate any we can. RETRIES is the
20408 number of times we retry pending template instantiation. */
20410 void
20412 {
20416 /* Instantiating templates may trigger vtable generation. This in turn
20417 may require further template instantiations. We place a limit here
20418 to avoid infinite loop. */
20420 {
20424 " instantiating %q+D, possibly from virtual table generation"
20428 /* Pretend that we defined it. */
20431 }
20433 do
20434 {
20439 {
20444 {
20445 tree fn;
20448 {
20452 fn;
20460 }
20463 }
20464 else
20465 {
20468 {
20469 instantiation
20475 }
20479 }
20482 /* If INSTANTIATION has been instantiated, then we don't
20483 need to consider it again in the future. */
20485 else
20486 {
20489 }
20492 }
20494 }
20498 }
20500 /* Substitute ARGVEC into T, which is a list of initializers for
20501 either base class or a non-static data member. The TREE_PURPOSEs
20502 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20503 instantiate_decl. */
20505 static tree
20507 {
20511 {
20512 tree decl;
20513 tree init;
20519 {
20520 tree expr;
20521 tree arg;
20523 /* Expand the base class expansion type into separate base
20524 classes. */
20526 tf_warning_or_error,
20527 NULL_TREE);
20531 /* We'll be building separate TREE_LISTs of arguments for
20532 each base. */
20538 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20539 expand each argument in the TREE_VALUE of t. */
20546 /* VOID_TYPE_NODE is used to indicate
20547 value-initialization. */
20548 {
20551 }
20552 else
20553 {
20554 /* Substitute parameter packs into each argument in the
20555 TREE_LIST. */
20558 {
20559 tree expanded_exprs;
20561 /* Expand the argument. */
20563 expanded_exprs
20565 tf_warning_or_error,
20566 NULL_TREE);
20570 /* Prepend each of the expanded expressions to the
20571 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20573 {
20578 }
20579 }
20582 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20583 since we built them backwards. */
20585 {
20588 }
20589 }
20590 }
20593 {
20595 {
20599 }
20600 else
20601 {
20602 tree tmp;
20617 /* If we had an initializer but it instantiated to nothing,
20618 value-initialize the object. This will only occur when
20619 the initializer was a pack expansion where the parameter
20620 packs used in that expansion were of length zero. */
20623 }
20626 {
20630 }
20631 }
20632 }
20634 }
20636 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20638 static void
20640 {
20645 else
20647 }
20649 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20650 is the instantiation (which should have been created with
20651 start_enum) and ARGS are the template arguments to use. */
20653 static void
20655 {
20656 tree e;
20662 {
20663 tree value;
20664 tree decl;
20667 /* Note that in a template enum, the TREE_VALUE is the
20668 CONST_DECL, not the corresponding INTEGER_CST. */
20673 /* Give this enumeration constant the correct access. */
20676 /* Actually build the enumerator itself. */
20677 build_enumerator
20679 }
20689 }
20691 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20692 its type -- but without substituting the innermost set of template
20693 arguments. So, innermost set of template parameters will appear in
20694 the type. */
20696 tree
20698 {
20699 tree fn_type;
20700 tree tmpl;
20701 tree targs;
20702 tree tparms;
20710 /* There should be as many levels of arguments as there are levels
20711 of parameters. */
20717 /* No substitution is necessary. */
20718 ;
20719 else
20720 {
20722 tree partial_args;
20724 /* Replace the innermost level of the TARGS with NULL_TREEs to
20725 let tsubst know not to substitute for those parameters. */
20734 /* Make sure that we can see identifiers, and compute access
20735 correctly. */
20739 /* Now, do the (partial) substitution to figure out the
20740 appropriate function type. */
20744 /* Substitute into the template parameters to obtain the real
20745 innermost set of parameters. This step is important if the
20746 innermost set of template parameters contains value
20747 parameters whose types depend on outer template parameters. */
20752 }
20755 }
20757 /* Return truthvalue if we're processing a template different from
20758 the last one involved in diagnostics. */
20759 bool
20761 {
20763 }
20765 /* Remember current template involved in diagnostics. */
20766 void
20768 {
20770 }
20774 {
20776 }
20778 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20779 type. Return zero for ok, nonzero for disallowed. Issue error and
20780 warning messages under control of COMPLAIN. */
20782 static int
20784 {
20801 {
20804 else
20806 type);
20807 }
20809 }
20811 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20812 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20814 static bool
20816 {
20817 tree scope;
20819 /* [temp.dep.type]
20821 A type is dependent if it is:
20823 -- a template parameter. Template template parameters are types
20824 for us (since TYPE_P holds true for them) so we handle
20825 them here. */
20829 /* -- a qualified-id with a nested-name-specifier which contains a
20830 class-name that names a dependent type or whose unqualified-id
20831 names a dependent type. */
20834 /* -- a cv-qualified type where the cv-unqualified type is
20835 dependent.
20836 No code is necessary for this bullet; the code below handles
20837 cv-qualified types, and we don't want to strip aliases with
20838 TYPE_MAIN_VARIANT because of DR 1558. */
20839 /* -- a compound type constructed from any dependent type. */
20849 {
20850 tree arg_type;
20855 arg_type;
20860 }
20861 /* -- an array type constructed from any dependent type or whose
20862 size is specified by a constant expression that is
20863 value-dependent.
20865 We checked for type- and value-dependence of the bounds in
20866 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20868 {
20873 }
20875 /* -- a template-id in which either the template name is a template
20876 parameter ... */
20879 /* ... or any of the template arguments is a dependent type or
20880 an expression that is type-dependent or value-dependent. */
20882 && (any_dependent_template_arguments_p
20886 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20887 dependent; if the argument of the `typeof' expression is not
20888 type-dependent, then it should already been have resolved. */
20894 /* A template argument pack is dependent if any of its packed
20895 arguments are. */
20897 {
20903 }
20905 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20906 be template parameters. */
20910 /* The standard does not specifically mention types that are local
20911 to template functions or local classes, but they should be
20912 considered dependent too. For example:
20914 template <int I> void f() {
20915 enum E { a = I };
20916 S<sizeof (E)> s;
20917 }
20919 The size of `E' cannot be known until the value of `I' has been
20920 determined. Therefore, `E' must be considered dependent. */
20924 /* Don't use type_dependent_expression_p here, as it can lead
20925 to infinite recursion trying to determine whether a lambda
20926 nested in a lambda is dependent (c++/47687). */
20930 && (any_dependent_template_arguments_p
20934 /* Other types are non-dependent. */
20936 }
20938 /* Returns TRUE if TYPE is dependent, in the sense of
20939 [temp.dep.type]. Note that a NULL type is considered dependent. */
20941 bool
20943 {
20944 /* If there are no template parameters in scope, then there can't be
20945 any dependent types. */
20947 {
20948 /* If we are not processing a template, then nobody should be
20949 providing us with a dependent type. */
20953 }
20955 /* If the type is NULL, we have not computed a type for the entity
20956 in question; in that case, the type is dependent. */
20960 /* Erroneous types can be considered non-dependent. */
20964 /* If we have not already computed the appropriate value for TYPE,
20965 do so now. */
20967 {
20970 }
20973 }
20975 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20976 lookup. In other words, a dependent type that is not the current
20977 instantiation. */
20979 bool
20981 {
20984 }
20986 /* T is a SCOPE_REF; return whether we need to consider it
20987 instantiation-dependent so that we can check access at instantiation
20988 time even though we know which member it resolves to. */
20990 static bool
20992 {
20998 else
21000 }
21002 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
21003 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
21004 expression. */
21006 /* Note that this predicate is not appropriate for general expressions;
21007 only constant expressions (that satisfy potential_constant_expression)
21008 can be tested for value dependence. */
21010 bool
21012 {
21016 /* A name declared with a dependent type. */
21021 {
21023 /* A name that has not been looked up -- must be dependent. */
21027 /* A non-type template parm. */
21031 /* A non-type template parm. */
21037 /* A constant with literal type and is initialized
21038 with an expression that is value-dependent.
21040 Note that a non-dependent parenthesized initializer will have
21041 already been replaced with its constant value, so if we see
21042 a TREE_LIST it must be dependent. */
21046 /* cp_finish_decl doesn't fold reference initializers. */
21057 /* These expressions are value-dependent if the type to which
21058 the cast occurs is dependent or the expression being casted
21059 is value-dependent. */
21060 {
21066 /* A functional cast has a list of operands. */
21069 {
21070 /* If there are no operands, it must be an expression such
21071 as "int()". This should not happen for aggregate types
21072 because it would form non-constant expressions. */
21077 }
21083 }
21088 /* FALLTHRU */
21091 /* A `sizeof' expression is value-dependent if the operand is
21092 type-dependent or is a pack expansion. */
21101 /* An 'encode' expression is value-dependent if the operand is
21102 type-dependent. */
21111 /* All instantiation-dependent expressions should also be considered
21112 value-dependent. */
21120 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
21121 is value-dependent. */
21122 {
21131 }
21134 {
21138 }
21149 {
21153 }
21156 {
21163 {
21165 /* In a call to a constexpr member function, look through the
21166 implicit ADDR_EXPR on the object argument so that it doesn't
21167 cause the call to be considered value-dependent. We also
21168 look through it in potential_constant_expression. */
21175 }
21177 }
21180 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
21181 type-dependent. */
21185 {
21187 tree val;
21194 }
21197 /* Treat a GNU statement expression as dependent to avoid crashing
21198 under instantiate_non_dependent_expr; it can't be constant. */
21202 /* A constant expression is value-dependent if any subexpression is
21203 value-dependent. */
21205 {
21212 {
21216 {
21219 /* In some cases, some of the operands may be missing.l
21220 (For example, in the case of PREDECREMENT_EXPR, the
21221 amount to increment by may be missing.) That doesn't
21222 make the expression dependent. */
21225 }
21226 }
21230 }
21232 }
21234 /* The expression is not value-dependent. */
21236 }
21238 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
21239 [temp.dep.expr]. Note that an expression with no type is
21240 considered dependent. Other parts of the compiler arrange for an
21241 expression with type-dependent subexpressions to have no type, so
21242 this function doesn't have to be fully recursive. */
21244 bool
21246 {
21253 /* An unresolved name is always dependent. */
21257 /* Some expression forms are never type-dependent. */
21270 /* The types of these expressions depends only on the type to which
21271 the cast occurs. */
21280 /* The types of these expressions depends only on the type created
21281 by the expression. */
21284 {
21285 /* For NEW_EXPR tree nodes created inside a template, either
21286 the object type itself or a TREE_LIST may appear as the
21287 operand 1. */
21290 /* This is an array type. We need to check array dimensions
21291 as well. */
21293 || value_dependent_expression_p
21295 else
21297 }
21300 {
21304 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
21305 contains an identifier associated by name lookup with one or more
21306 declarations declared with a dependent type, or...a
21307 nested-name-specifier or qualified-id that names a member of an
21308 unknown specialization. */
21311 }
21316 && (any_dependent_template_arguments_p
21328 {
21329 tree elt;
21333 {
21336 }
21338 }
21340 /* A static data member of the current instantiation with incomplete
21341 array type is type-dependent, as the definition and specializations
21342 can have different bounds. */
21349 /* An array of unknown bound depending on a variadic parameter, eg:
21351 template<typename... Args>
21352 void foo (Args... args)
21353 {
21354 int arr[] = { args... };
21355 }
21357 template<int... vals>
21358 void bar ()
21359 {
21360 int arr[] = { vals... };
21361 }
21363 If the array has no length and has an initializer, it must be that
21364 we couldn't determine its length in cp_complete_array_type because
21365 it is dependent. */
21373 {
21378 {
21384 }
21385 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
21389 /* Always dependent, on the number of arguments if nothing else. */
21394 {
21399 }
21402 {
21407 }
21412 {
21416 }
21418 }
21423 }
21425 /* walk_tree callback function for instantiation_dependent_expression_p,
21426 below. Returns non-zero if a dependent subexpression is found. */
21428 static tree
21431 {
21433 {
21434 /* We don't have to worry about decltype currently because decltype
21435 of an instantiation-dependent expr is a dependent type. This
21436 might change depending on the resolution of DR 1172. */
21439 }
21442 {
21443 /* Don't treat an argument list as dependent just because it has no
21444 TREE_TYPE. */
21451 /* A constant with a dependent initializer is dependent. */
21459 /* Handle expressions with type operands. */
21464 {
21469 {
21472 else
21473 {
21476 }
21477 }
21479 }
21491 /* In a template, finish_class_member_access_expr creates a
21492 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21493 type-dependent, so that we can check access control at
21494 instantiation time (PR 42277). See also Core issue 1273. */
21501 else
21504 /* Treat statement-expressions as dependent. */
21510 }
21514 else
21516 }
21518 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21519 sense defined by the ABI:
21521 "An expression is instantiation-dependent if it is type-dependent
21522 or value-dependent, or it has a subexpression that is type-dependent
21523 or value-dependent." */
21525 bool
21527 {
21528 tree result;
21539 }
21541 /* Like type_dependent_expression_p, but it also works while not processing
21542 a template definition, i.e. during substitution or mangling. */
21544 bool
21546 {
21552 }
21554 /* Returns TRUE if ARGS contains a type-dependent expression. */
21556 bool
21558 {
21560 tree arg;
21563 {
21566 }
21568 }
21570 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21571 expressions) contains any type-dependent expressions. */
21573 bool
21575 {
21581 }
21583 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21584 expressions) contains any value-dependent expressions. */
21586 bool
21588 {
21594 }
21596 /* Returns TRUE if the ARG (a template argument) is dependent. */
21598 bool
21600 {
21604 /* Assume a template argument that was wrongly written by the user
21605 is dependent. This is consistent with what
21606 any_dependent_template_arguments_p [that calls this function]
21607 does. */
21618 {
21622 {
21625 }
21628 }
21631 else
21634 }
21636 /* Returns true if ARGS (a collection of template arguments) contains
21637 any types that require structural equality testing. */
21639 bool
21641 {
21651 {
21654 {
21660 {
21661 /* Look inside the argument pack. */
21664 }
21667 {
21680 }
21681 }
21682 }
21685 }
21687 /* Returns true if ARGS (a collection of template arguments) contains
21688 any dependent arguments. */
21690 bool
21692 {
21702 {
21707 }
21710 }
21712 /* Returns TRUE if the template TMPL is dependent. */
21714 bool
21716 {
21718 {
21720 {
21724 }
21726 }
21728 /* Template template parameters are dependent. */
21732 /* So are names that have not been looked up. */
21735 /* So are member templates of dependent classes. */
21739 }
21741 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21743 bool
21745 {
21748 }
21750 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21751 is dependent. */
21753 bool
21755 {
21762 {
21783 {
21787 }
21791 {
21795 {
21800 }
21801 }
21802 }
21805 }
21807 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21808 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21809 no such TYPE can be found. Note that this function peers inside
21810 uninstantiated templates and therefore should be used only in
21811 extremely limited situations. ONLY_CURRENT_P restricts this
21812 peering to the currently open classes hierarchy (which is required
21813 when comparing types). */
21815 tree
21817 {
21818 tree scope;
21819 tree name;
21820 tree decl;
21822 tree pushed_scope;
21823 tree result;
21828 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21829 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21830 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21831 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21832 identifier of the TYPENAME_TYPE anymore.
21833 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21834 TYPENAME_TYPE instead, we avoid messing up with a possible
21835 typedef variant case. */
21838 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21839 it first before we can figure out what NAME refers to. */
21841 {
21843 /* Given a class template A with a dependent base with nested type C,
21844 typedef typename A::C::C C will land us here, as trying to resolve
21845 the initial A::C leads to the local C typedef, which leads back to
21846 A::C::C. So we break the recursion now. */
21848 else
21850 }
21851 /* If we don't know what SCOPE refers to, then we cannot resolve the
21852 TYPENAME_TYPE. */
21855 /* If the SCOPE is a template type parameter, we have no way of
21856 resolving the name. */
21859 /* If the SCOPE is not the current instantiation, there's no reason
21860 to look inside it. */
21863 /* If this is a typedef, we don't want to look inside (c++/11987). */
21866 /* If SCOPE isn't the template itself, it will not have a valid
21867 TYPE_FIELDS list. */
21869 /* scope is either the template itself or a compatible instantiation
21870 like X<T>, so look up the name in the original template. */
21872 else
21873 /* scope is a partial instantiation, so we can't do the lookup or we
21874 will lose the template arguments. */
21876 /* Enter the SCOPE so that name lookup will be resolved as if we
21877 were in the class definition. In particular, SCOPE will no
21878 longer be considered a dependent type. */
21880 /* Look up the declaration. */
21882 tf_warning_or_error);
21886 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21887 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21892 {
21896 }
21899 {
21900 tree tmpl;
21901 tree args;
21902 /* Obtain the template and the arguments. */
21905 /* Instantiate the template. */
21911 }
21913 /* Leave the SCOPE. */
21917 /* If we failed to resolve it, return the original typename. */
21921 /* If lookup found a typename type, resolve that too. */
21923 {
21924 /* Ill-formed programs can cause infinite recursion here, so we
21925 must catch that. */
21929 }
21931 /* Qualify the resulting type. */
21937 }
21939 /* EXPR is an expression which is not type-dependent. Return a proxy
21940 for EXPR that can be used to compute the types of larger
21941 expressions containing EXPR. */
21943 tree
21945 {
21946 tree inner_expr;
21948 #ifdef ENABLE_CHECKING
21949 /* Try to get a constant value for all non-dependent expressions in
21950 order to expose bugs in *_dependent_expression_p and constexpr. */
21953 #endif
21955 /* Preserve OVERLOADs; the functions must be available to resolve
21956 types. */
21967 /* There is no need to return a proxy for a variable. */
21970 /* Preserve string constants; conversions from string constants to
21971 "char *" are allowed, even though normally a "const char *"
21972 cannot be used to initialize a "char *". */
21975 /* Preserve void and arithmetic constants, as an optimization -- there is no
21976 reason to create a new node. */
21981 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21982 There is at least one place where we want to know that a
21983 particular expression is a throw-expression: when checking a ?:
21984 expression, there are special rules if the second or third
21985 argument is a throw-expression. */
21989 /* Don't wrap an initializer list, we need to be able to look inside. */
21993 /* Don't wrap a dummy object, we need to be able to test for it. */
22012 /* If the type is unknown, it can't really be non-dependent */
22015 /* Otherwise, build a NON_DEPENDENT_EXPR. */
22017 }
22019 /* ARGS is a vector of expressions as arguments to a function call.
22020 Replace the arguments with equivalent non-dependent expressions.
22021 This modifies ARGS in place. */
22023 void
22025 {
22027 tree arg;
22030 {
22034 }
22035 }
22037 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
22038 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
22039 parms. */
22041 static tree
22043 {
22056 }
22058 tree
22060 {
22062 }
22064 tree
22066 {
22068 }
22070 /* Given type ARG, return std::initializer_list<ARG>. */
22072 static tree
22074 {
22075 tree std_init_list = namespace_binding
22077 tree argvec;
22079 {
22083 }
22088 }
22090 /* Replace auto in TYPE with std::initializer_list<auto>. */
22092 static tree
22094 {
22101 }
22103 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
22104 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
22106 tree
22108 {
22109 tree targs;
22115 /* Defining a subset of type-dependent expressions that we can deduce
22116 from ahead of time isn't worth the trouble. */
22119 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
22120 with either a new invented type template parameter U or, if the
22121 initializer is a braced-init-list (8.5.4), with
22122 std::initializer_list<U>. */
22124 {
22129 else
22130 {
22134 "for deduction to %<std::initializer_list%>, use copy-"
22137 }
22138 }
22144 {
22150 {
22153 }
22154 }
22155 else
22156 {
22167 {
22169 /* Try again at instantiation time. */
22172 /* If type is error_mark_node a diagnostic must have been
22173 emitted by now. Also, having a mention to '<type error>'
22174 in the diagnostic is not really useful to the user. */
22175 {
22179 else
22181 }
22183 }
22184 }
22186 /* If the list of declarators contains more than one declarator, the type
22187 of each declared variable is determined as described above. If the
22188 type deduced for the template parameter U is not the same in each
22189 deduction, the program is ill-formed. */
22192 {
22198 else
22202 }
22208 }
22210 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
22211 result. */
22213 tree
22215 {
22216 tree argvec;
22223 /* For a late-specified return type in a template type-parameter, we
22224 need to add a dummy argument level for its parmlist. */
22225 argvec = add_to_template_args
22230 }
22232 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
22233 'decltype(auto)'. */
22235 bool
22237 {
22242 else
22244 }
22246 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
22247 a use of `auto'. Returns NULL_TREE otherwise. */
22249 tree
22251 {
22253 }
22255 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
22256 'decltype(auto)' or a concept. */
22258 bool
22260 {
22262 }
22264 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
22265 a concept identifier) iff TYPE contains a use of a generic type. Returns
22266 NULL_TREE otherwise. */
22268 tree
22270 {
22272 }
22275 /* For a given template T, return the vector of typedefs referenced
22276 in T for which access check is needed at T instantiation time.
22277 T is either a FUNCTION_DECL or a RECORD_TYPE.
22278 Those typedefs were added to T by the function
22279 append_type_to_template_for_access_check. */
22283 {
22284 tree ti;
22295 {
22300 }
22303 }
22305 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
22306 tied to T. That list of typedefs will be access checked at
22307 T instantiation time.
22308 T is either a FUNCTION_DECL or a RECORD_TYPE.
22309 TYPE_DECL is a TYPE_DECL node representing a typedef.
22310 SCOPE is the scope through which TYPE_DECL is accessed.
22311 LOCATION is the location of the usage point of TYPE_DECL.
22313 This function is a subroutine of
22314 append_type_to_template_for_access_check. */
22316 static void
22318 tree type_decl,
22319 tree scope,
22320 location_t location)
22321 {
22322 qualified_typedef_usage_t typedef_usage;
22323 tree ti;
22330 && type_decl
22344 }
22346 /* Append TYPE_DECL to the template TEMPL.
22347 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
22348 At TEMPL instanciation time, TYPE_DECL will be checked to see
22349 if it can be accessed through SCOPE.
22350 LOCATION is the location of the usage point of TYPE_DECL.
22352 e.g. consider the following code snippet:
22354 class C
22355 {
22356 typedef int myint;
22357 };
22359 template<class U> struct S
22360 {
22361 C::myint mi; // <-- usage point of the typedef C::myint
22362 };
22364 S<char> s;
22366 At S<char> instantiation time, we need to check the access of C::myint
22367 In other words, we need to check the access of the myint typedef through
22368 the C scope. For that purpose, this function will add the myint typedef
22369 and the scope C through which its being accessed to a list of typedefs
22370 tied to the template S. That list will be walked at template instantiation
22371 time and access check performed on each typedefs it contains.
22372 Note that this particular code snippet should yield an error because
22373 myint is private to C. */
22375 void
22377 tree type_decl,
22378 tree scope,
22379 location_t location)
22380 {
22386 /* Make sure we don't append the type to the template twice. */
22393 }
22395 /* Convert the generic type parameters in PARM that match the types given in the
22396 range [START_IDX, END_IDX) from the current_template_parms into generic type
22397 packs. */
22399 tree
22401 {
22412 {
22413 /* Create a distinct parameter pack type from the current parm and add it
22414 to the replacement args to tsubst below into the generic function
22415 parameter. */
22430 }
22436 /* If there are more levels then build up the replacement with the outer
22437 template parms. */
22441 replacement);
22444 }
22447 /* Set up the hash tables for template instantiations. */
22449 void
22451 {
22454 }
22456 /* Print stats about the template hash tables for -fstats. */
22458 void
22460 {
22469 }