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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 {
1679 val);
1682 /* Otherwise just compare the types during lookup. */
1691 {
1696 }
1697 }
1700 }
1702 /* Unregister the specialization SPEC as a specialization of TMPL.
1703 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1704 if the SPEC was listed as a specialization of TMPL.
1706 Note that SPEC has been ggc_freed, so we can't look inside it. */
1708 bool
1710 {
1712 spec_entry elt;
1720 {
1725 }
1728 }
1730 /* Like register_specialization, but for local declarations. We are
1731 registering SPEC, an instantiation of TMPL. */
1733 static void
1735 {
1737 }
1739 /* TYPE is a class type. Returns true if TYPE is an explicitly
1740 specialized class. */
1742 bool
1744 {
1748 }
1750 /* Print the list of functions at FNS, going through all the overloads
1751 for each element of the list. Alternatively, FNS can not be a
1752 TREE_LIST, in which case it will be printed together with all the
1753 overloads.
1755 MORE and *STR should respectively be FALSE and NULL when the function
1756 is called from the outside. They are used internally on recursive
1757 calls. print_candidates manages the two parameters and leaves NULL
1758 in *STR when it ends. */
1760 static void
1762 {
1768 {
1772 }
1773 else
1774 {
1777 {
1778 /* Pick the prefix string. */
1780 {
1784 }
1788 }
1791 }
1794 {
1797 }
1798 }
1800 /* Print the list of candidate FNS in an error message. FNS can also
1801 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1803 void
1805 {
1809 }
1811 /* Returns the template (one of the functions given by TEMPLATE_ID)
1812 which can be specialized to match the indicated DECL with the
1813 explicit template args given in TEMPLATE_ID. The DECL may be
1814 NULL_TREE if none is available. In that case, the functions in
1815 TEMPLATE_ID are non-members.
1817 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1818 specialization of a member template.
1820 The TEMPLATE_COUNT is the number of references to qualifying
1821 template classes that appeared in the name of the function. See
1822 check_explicit_specialization for a more accurate description.
1824 TSK indicates what kind of template declaration (if any) is being
1825 declared. TSK_TEMPLATE indicates that the declaration given by
1826 DECL, though a FUNCTION_DECL, has template parameters, and is
1827 therefore a template function.
1829 The template args (those explicitly specified and those deduced)
1830 are output in a newly created vector *TARGS_OUT.
1832 If it is impossible to determine the result, an error message is
1833 issued. The error_mark_node is returned to indicate failure. */
1835 static tree
1837 tree decl,
1841 tmpl_spec_kind tsk)
1842 {
1843 tree fns;
1844 tree targs;
1845 tree explicit_targs;
1847 /* A TREE_LIST of templates of which DECL may be a specialization.
1848 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1849 corresponding TREE_PURPOSE is the set of template arguments that,
1850 when used to instantiate the template, would produce a function
1851 with the signature of DECL. */
1861 /* We shouldn't be specializing a member template of an
1862 unspecialized class template; we already gave an error in
1863 check_specialization_scope, now avoid crashing. */
1866 {
1869 }
1877 /* Check for baselinks. */
1882 {
1885 }
1887 {
1890 }
1892 /* Count the number of template headers specified for this
1893 specialization. */
1903 {
1907 {
1908 tree decl_arg_types;
1909 tree fn_arg_types;
1910 tree insttype;
1912 /* In case of explicit specialization, we need to check if
1913 the number of template headers appearing in the specialization
1914 is correct. This is usually done in check_explicit_specialization,
1915 but the check done there cannot be exhaustive when specializing
1916 member functions. Consider the following code:
1918 template <> void A<int>::f(int);
1919 template <> template <> void A<int>::f(int);
1921 Assuming that A<int> is not itself an explicit specialization
1922 already, the first line specializes "f" which is a non-template
1923 member function, whilst the second line specializes "f" which
1924 is a template member function. So both lines are syntactically
1925 correct, and check_explicit_specialization does not reject
1926 them.
1928 Here, we can do better, as we are matching the specialization
1929 against the declarations. We count the number of template
1930 headers, and we check if they match TEMPLATE_COUNT + 1
1931 (TEMPLATE_COUNT is the number of qualifying template classes,
1932 plus there must be another header for the member template
1933 itself).
1935 Notice that if header_count is zero, this is not a
1936 specialization but rather a template instantiation, so there
1937 is no check we can perform here. */
1941 /* Check that the number of template arguments at the
1942 innermost level for DECL is the same as for FN. */
1950 /* DECL might be a specialization of FN. */
1954 /* For a non-static member function, we need to make sure
1955 that the const qualification is the same. Since
1956 get_bindings does not try to merge the "this" parameter,
1957 we must do the comparison explicitly. */
1963 /* Skip the "this" parameter and, for constructors of
1964 classes with virtual bases, the VTT parameter. A
1965 full specialization of a constructor will have a VTT
1966 parameter, but a template never will. */
1967 decl_arg_types
1969 fn_arg_types
1972 /* Function templates cannot be specializations; there are
1973 no partial specializations of functions. Therefore, if
1974 the type of DECL does not match FN, there is no
1975 match. */
1977 {
1981 }
1983 /* See whether this function might be a specialization of this
1984 template. Suppress access control because we might be trying
1985 to make this specialization a friend, and we have already done
1986 access control for the declaration of the specialization. */
1992 /* We cannot deduce template arguments that when used to
1993 specialize TMPL will produce DECL. */
1996 /* Make sure that the deduced arguments actually work. */
2000 fn_arg_types
2005 /* Save this template, and the arguments deduced. */
2007 }
2009 /* FN is an ordinary member function, and we need a
2010 specialization of a member template. */
2011 ;
2013 /* We can get IDENTIFIER_NODEs here in certain erroneous
2014 cases. */
2015 ;
2017 /* This is just an ordinary non-member function. Nothing can
2018 be a specialization of that. */
2019 ;
2021 /* Cannot specialize functions that are created implicitly. */
2022 ;
2023 else
2024 {
2025 tree decl_arg_types;
2027 /* This is an ordinary member function. However, since
2028 we're here, we can assume its enclosing class is a
2029 template class. For example,
2031 template <typename T> struct S { void f(); };
2032 template <> void S<int>::f() {}
2034 Here, S<int>::f is a non-template, but S<int> is a
2035 template class. If FN has the same type as DECL, we
2036 might be in business. */
2039 /* Its enclosing class is an explicit specialization
2040 of a template class. This is not a candidate. */
2045 /* The return types differ. */
2048 /* Adjust the type of DECL in case FN is a static member. */
2055 decl_arg_types))
2056 /* They match! */
2058 }
2059 }
2062 {
2063 /* We have:
2065 [temp.expl.spec]
2067 It is possible for a specialization with a given function
2068 signature to be instantiated from more than one function
2069 template. In such cases, explicit specification of the
2070 template arguments must be used to uniquely identify the
2071 function template specialization being specialized.
2073 Note that here, there's no suggestion that we're supposed to
2074 determine which of the candidate templates is most
2075 specialized. However, we, also have:
2077 [temp.func.order]
2079 Partial ordering of overloaded function template
2080 declarations is used in the following contexts to select
2081 the function template to which a function template
2082 specialization refers:
2084 -- when an explicit specialization refers to a function
2085 template.
2087 So, we do use the partial ordering rules, at least for now.
2088 This extension can only serve to make invalid programs valid,
2089 so it's safe. And, there is strong anecdotal evidence that
2090 the committee intended the partial ordering rules to apply;
2091 the EDG front end has that behavior, and John Spicer claims
2092 that the committee simply forgot to delete the wording in
2093 [temp.expl.spec]. */
2096 {
2099 }
2100 }
2103 {
2111 }
2115 {
2121 }
2123 /* We have one, and exactly one, match. */
2125 {
2128 /* DECL is a re-declaration or partial instantiation of a template
2129 function. */
2132 /* It was a specialization of an ordinary member function in a
2133 template class. */
2135 }
2137 /* It was a specialization of a template. */
2140 {
2145 }
2146 else
2149 }
2151 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2152 but with the default argument values filled in from those in the
2153 TMPL_TYPES. */
2155 static tree
2157 tree tmpl_types)
2158 {
2159 tree new_spec_types;
2167 /* Substitute into the rest of the list. */
2168 new_spec_types =
2172 /* Add the default argument for this parameter. */
2175 new_spec_types);
2176 }
2178 /* DECL is an explicit specialization. Replicate default arguments
2179 from the template it specializes. (That way, code like:
2181 template <class T> void f(T = 3);
2182 template <> void f(double);
2183 void g () { f (); }
2185 works, as required.) An alternative approach would be to look up
2186 the correct default arguments at the call-site, but this approach
2187 is consistent with how implicit instantiations are handled. */
2189 static void
2191 {
2192 tree tmpl;
2193 tree spec_types;
2194 tree tmpl_types;
2195 tree new_spec_types;
2196 tree old_type;
2197 tree new_type;
2198 tree t;
2203 /* See if there's anything we need to do. */
2216 {
2217 /* Remove the this pointer, but remember the object's type for
2218 CV quals. */
2224 {
2225 /* DECL may contain more parameters than TMPL due to the extra
2226 in-charge parameter in constructors and destructors. */
2229 }
2231 {
2234 }
2235 }
2237 /* Compute the merged default arguments. */
2238 new_spec_types =
2241 /* Compute the new FUNCTION_TYPE. */
2243 {
2247 new_spec_types);
2250 /* Put the in-charge parameter back. */
2253 new_spec_types);
2257 new_spec_types);
2258 }
2259 else
2261 new_spec_types);
2271 }
2273 /* Return the number of template headers we expect to see for a definition
2274 or specialization of CTYPE or one of its non-template members. */
2276 int
2278 {
2282 {
2283 /* You're supposed to have one `template <...>' for every
2284 template class, but you don't need one for a full
2285 specialization. For example:
2287 template <class T> struct S{};
2288 template <> struct S<int> { void f(); };
2289 void S<int>::f () {}
2291 is correct; there shouldn't be a `template <>' for the
2292 definition of `S<int>::f'. */
2294 /* If CTYPE does not have template information of any
2295 kind, then it is not a template, nor is it nested
2296 within a template. */
2304 }
2307 }
2309 /* Do a simple sanity check on the template headers that precede the
2310 variable declaration DECL. */
2312 void
2314 {
2319 {
2322 "variable templates only available with "
2325 // Namespace-scope variable templates should have a template header.
2327 }
2329 {
2336 "members of an explicitly specialized class are defined "
2338 }
2339 }
2341 /* Check to see if the function just declared, as indicated in
2342 DECLARATOR, and in DECL, is a specialization of a function
2343 template. We may also discover that the declaration is an explicit
2344 instantiation at this point.
2346 Returns DECL, or an equivalent declaration that should be used
2347 instead if all goes well. Issues an error message if something is
2348 amiss. Returns error_mark_node if the error is not easily
2349 recoverable.
2351 FLAGS is a bitmask consisting of the following flags:
2353 2: The function has a definition.
2354 4: The function is a friend.
2356 The TEMPLATE_COUNT is the number of references to qualifying
2357 template classes that appeared in the name of the function. For
2358 example, in
2360 template <class T> struct S { void f(); };
2361 void S<int>::f();
2363 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2364 classes are not counted in the TEMPLATE_COUNT, so that in
2366 template <class T> struct S {};
2367 template <> struct S<int> { void f(); }
2368 template <> void S<int>::f();
2370 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2371 invalid; there should be no template <>.)
2373 If the function is a specialization, it is marked as such via
2374 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2375 is set up correctly, and it is added to the list of specializations
2376 for that template. */
2378 tree
2380 tree decl,
2383 {
2391 tmpl_spec_kind tsk;
2394 {
2397 else
2399 }
2400 else
2404 {
2407 {
2410 }
2412 {
2414 /* This could be something like:
2416 template <class T> void f(T);
2417 class S { friend void f<>(int); } */
2419 else
2420 {
2421 /* This case handles bogus declarations like template <>
2422 template <class T> void f<int>(); */
2425 declarator);
2427 }
2428 }
2432 /* The error has already been reported in
2433 check_specialization_scope. */
2439 /* Fall through. */
2452 decl);
2455 else
2459 /* Fall through. */
2462 /* In cases like template<> constexpr bool v = true;
2463 We'll give an error in check_template_variable. */
2469 else
2475 {
2476 /* This case handles bogus declarations like template <>
2477 template <class T> void f<int>(); */
2481 declarator);
2483 {
2484 /* Partial specialization of variable template. */
2488 }
2492 else
2496 ok:;
2497 }
2500 /* This is a specialization of a member template, without
2501 specialization the containing class. Something like:
2503 template <class T> struct S {
2504 template <class U> void f (U);
2505 };
2506 template <> template <class U> void S<int>::f(U) {}
2508 That's a specialization -- but of the entire template. */
2514 }
2517 /* This doesn't apply to variable templates. */
2520 {
2524 {
2528 }
2529 }
2532 {
2537 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2539 {
2540 tree fns;
2545 else
2546 {
2547 /* If there is no class context, the explicit instantiation
2548 must be at namespace scope. */
2551 /* Find the namespace binding, using the declaration
2552 context. */
2556 {
2559 }
2560 else
2561 {
2567 }
2568 }
2571 }
2577 {
2579 /* A specialization in class scope. This is invalid,
2580 but the error will already have been flagged by
2581 check_specialization_scope. */
2583 else
2584 {
2585 /* It's not valid to write an explicit instantiation in
2586 class scope, e.g.:
2588 class C { template void f(); }
2590 This case is caught by the parser. However, on
2591 something like:
2593 template class C { void f(); };
2595 (which is invalid) we can get here. The error will be
2596 issued later. */
2597 ;
2598 }
2601 }
2604 {
2605 // We'll match variable templates in start_decl.
2609 /* Find the list of functions in ctype that have the same
2610 name as the declared function. */
2616 {
2621 {
2622 /* From [temp.expl.spec]:
2624 If such an explicit specialization for the member
2625 of a class template names an implicitly-declared
2626 special member function (clause _special_), the
2627 program is ill-formed.
2629 Similar language is found in [temp.explicit]. */
2632 }
2635 }
2638 {
2642 }
2643 else
2644 {
2646 tree ovl;
2648 /* For a type-conversion operator, we cannot do a
2649 name-based lookup. We might be looking for `operator
2650 int' which will be a specialization of `operator T'.
2651 So, we find *all* the conversion operators, and then
2652 select from them. */
2660 {
2662 /* There are no more conversion functions. */
2665 /* Glue all these conversion functions together
2666 with those we already have. */
2669 }
2670 }
2673 {
2676 }
2677 else
2679 }
2681 /* Figure out what exactly is being specialized at this point.
2682 Note that for an explicit instantiation, even one for a
2683 member function, we cannot tell apriori whether the
2684 instantiation is for a member template, or just a member
2685 function of a template class. Even if a member template is
2686 being instantiated, the member template arguments may be
2687 elided if they can be deduced from the rest of the
2688 declaration. */
2691 member_specialization,
2692 template_count,
2693 tsk);
2696 /* We couldn't figure out what this declaration was
2697 specializing. */
2699 else
2700 {
2704 {
2705 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2706 is done by do_decl_instantiation later. */
2712 {
2713 /* If TMPL is not the most general template (for
2714 example, if TMPL is a friend template that is
2715 injected into namespace scope), then there will
2716 be too many levels of TARGS. Remove some of them
2717 here. */
2719 tree new_targs;
2726 }
2729 }
2731 /* If we thought that the DECL was a member function, but it
2732 turns out to be specializing a static member function,
2733 make DECL a static member function as well. */
2739 /* If this is a specialization of a member template of a
2740 template class, we want to return the TEMPLATE_DECL, not
2741 the specialization of it. */
2743 {
2748 {
2749 tree parm;
2753 /* We want to use the argument list specified in the
2754 definition, not in the original declaration. */
2759 }
2762 }
2764 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2770 /* Inherit default function arguments from the template
2771 DECL is specializing. */
2775 /* This specialization has the same protection as the
2776 template it specializes. */
2780 /* 7.1.1-1 [dcl.stc]
2782 A storage-class-specifier shall not be specified in an
2783 explicit specialization...
2785 The parser rejects these, so unless action is taken here,
2786 explicit function specializations will always appear with
2787 global linkage.
2789 The action recommended by the C++ CWG in response to C++
2790 defect report 605 is to make the storage class and linkage
2791 of the explicit specialization match the templated function:
2793 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2794 */
2796 {
2800 /* This specialization has the same linkage and visibility as
2801 the function template it specializes. */
2804 {
2807 }
2810 {
2813 }
2814 }
2816 /* If DECL is a friend declaration, declared using an
2817 unqualified name, the namespace associated with DECL may
2818 have been set incorrectly. For example, in:
2820 template <typename T> void f(T);
2821 namespace N {
2822 struct S { friend void f<int>(int); }
2823 }
2825 we will have set the DECL_CONTEXT for the friend
2826 declaration to N, rather than to the global namespace. */
2831 /* This is not really a declaration of a specialization.
2832 It's just the name of an instantiation. But, it's not
2833 a request for an instantiation, either. */
2836 /* A specialization is not necessarily COMDAT. */
2842 /* Register this specialization so that we can find it
2843 again. */
2846 /* A 'structor should already have clones. */
2852 }
2853 }
2856 }
2858 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2859 parameters. These are represented in the same format used for
2860 DECL_TEMPLATE_PARMS. */
2862 int
2864 {
2865 const_tree p1;
2866 const_tree p2;
2874 {
2886 {
2890 /* If either of the template parameters are invalid, assume
2891 they match for the sake of error recovery. */
2904 }
2905 }
2908 /* One set of parameters has more parameters lists than the
2909 other. */
2913 }
2915 /* Determine whether PARM is a parameter pack. */
2917 bool
2919 {
2920 /* Determine if we have a non-type template parameter pack. */
2927 /* If this is a list of template parameters, we could get a
2928 TYPE_DECL or a TEMPLATE_DECL. */
2932 /* Otherwise it must be a type template parameter. */
2936 }
2938 /* Determine if T is a function parameter pack. */
2940 bool
2942 {
2946 }
2948 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2949 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2951 tree
2953 {
2960 }
2962 /* Return true iff the function parameter PARAM_DECL was expanded
2963 from the function parameter pack PACK. */
2965 bool
2967 {
2972 /* The parameter pack and its pack arguments have the same
2973 DECL_PARM_INDEX. */
2975 }
2977 /* Determine whether ARGS describes a variadic template args list,
2978 i.e., one that is terminated by a template argument pack. */
2980 static bool
2982 {
2984 tree last_parm;
2998 }
3000 /* Generate a new name for the parameter pack name NAME (an
3001 IDENTIFIER_NODE) that incorporates its */
3003 static tree
3005 {
3006 /* Munge the name to include the parameter index. */
3007 #define NUMBUF_LEN 128
3021 }
3023 /* Return true if T is a primary function, class or alias template
3024 instantiation. */
3026 bool
3028 {
3042 }
3044 /* Return true if PARM is a template template parameter. */
3046 bool
3048 {
3050 }
3052 /* Return true iff PARM is a DECL representing a type template
3053 parameter. */
3055 bool
3057 {
3062 }
3064 /* Return the template parameters of T if T is a
3065 primary template instantiation, NULL otherwise. */
3067 tree
3069 {
3074 parms = INNERMOST_TEMPLATE_PARMS
3078 }
3080 /* Return the template parameters of the LEVELth level from the full list
3081 of template parameters PARMS. */
3083 tree
3085 {
3086 tree p;
3097 }
3099 /* Returns the template arguments of T if T is a template instantiation,
3100 NULL otherwise. */
3102 tree
3104 {
3112 }
3114 /* Return the argument pack elements of T if T is a template argument pack,
3115 NULL otherwise. */
3117 tree
3119 {
3125 }
3127 /* Structure used to track the progress of find_parameter_packs_r. */
3128 struct find_parameter_pack_data
3129 {
3130 /* TREE_LIST that will contain all of the parameter packs found by
3131 the traversal. */
3134 /* Set of AST nodes that have been visited by the traversal. */
3136 };
3138 /* Identifies all of the argument packs that occur in a template
3139 argument and appends them to the TREE_LIST inside DATA, which is a
3140 find_parameter_pack_data structure. This is a subroutine of
3141 make_pack_expansion and uses_parameter_packs. */
3142 static tree
3144 {
3150 /* Handle type aliases/typedefs. */
3152 {
3159 }
3161 /* Identify whether this is a parameter pack or not. */
3163 {
3179 {
3180 /* We don't want to walk into the type of a PARM_DECL,
3181 because we don't want to see the type parameter pack. */
3184 }
3187 /* Look through a lambda capture proxy to the field pack. */
3190 {
3196 }
3203 /* Not a parameter pack. */
3205 }
3208 {
3209 /* Add this parameter pack to the list. */
3211 }
3217 /* This switch statement will return immediately if we don't find a
3218 parameter pack. */
3220 {
3225 /* Check the template itself. */
3228 /* Check the template arguments. */
3244 /* Fall through. */
3286 }
3289 }
3291 /* Determines if the expression or type T uses any parameter packs. */
3292 bool
3294 {
3302 }
3304 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3305 representation a base-class initializer into a parameter pack
3306 expansion. If all goes well, the resulting node will be an
3307 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3308 respectively. */
3309 tree
3311 {
3312 tree result;
3321 {
3322 /* The only time we will see a TREE_LIST here is for a base
3323 class initializer. In this case, the TREE_PURPOSE will be a
3324 _TYPE node (representing the base class expansion we're
3325 initializing) and the TREE_VALUE will be a TREE_LIST
3326 containing the initialization arguments.
3328 The resulting expansion looks somewhat different from most
3329 expansions. Rather than returning just one _EXPANSION, we
3330 return a TREE_LIST whose TREE_PURPOSE is a
3331 TYPE_PACK_EXPANSION containing the bases that will be
3332 initialized. The TREE_VALUE will be identical to the
3333 original TREE_VALUE, which is a list of arguments that will
3334 be passed to each base. We do not introduce any new pack
3335 expansion nodes into the TREE_VALUE (although it is possible
3336 that some already exist), because the TREE_PURPOSE and
3337 TREE_VALUE all need to be expanded together with the same
3338 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3339 resulting TREE_PURPOSE will mention the parameter packs in
3340 both the bases and the arguments to the bases. */
3341 tree purpose;
3342 tree value;
3345 /* Determine which parameter packs will be used by the base
3346 class expansion. */
3353 {
3357 }
3360 {
3361 /* Collect the sets of parameter packs used in each of the
3362 initialization arguments. */
3364 {
3365 /* Determine which parameter packs will be expanded in this
3366 argument. */
3369 }
3370 }
3374 /* Create the pack expansion type for the base type. */
3379 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3380 they will rarely be compared to anything. */
3384 }
3389 /* Build the PACK_EXPANSION_* node. */
3390 result = for_types
3395 {
3396 /* Propagate type and const-expression information. */
3399 }
3400 else
3401 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3402 they will rarely be compared to anything. */
3405 /* Determine which parameter packs will be expanded. */
3411 /* Make sure we found some parameter packs. */
3413 {
3416 else
3419 }
3425 }
3427 /* Checks T for any "bare" parameter packs, which have not yet been
3428 expanded, and issues an error if any are found. This operation can
3429 only be done on full expressions or types (e.g., an expression
3430 statement, "if" condition, etc.), because we could have expressions like:
3432 foo(f(g(h(args)))...)
3434 where "args" is a parameter pack. check_for_bare_parameter_packs
3435 should not be called for the subexpressions args, h(args),
3436 g(h(args)), or f(g(h(args))), because we would produce erroneous
3437 error messages.
3439 Returns TRUE and emits an error if there were bare parameter packs,
3440 returns FALSE otherwise. */
3441 bool
3443 {
3459 {
3462 {
3471 else
3476 else
3480 }
3483 }
3486 }
3488 /* Expand any parameter packs that occur in the template arguments in
3489 ARGS. */
3490 tree
3492 {
3498 /* First, determine if we need to expand anything, and the number of
3499 slots we'll need. */
3501 {
3506 {
3510 else
3512 }
3513 else
3514 {
3516 num_result_args++;
3517 }
3518 }
3520 /* If no expansion is necessary, we're done. */
3524 /* Expand arguments. */
3527 non_default_args_count =
3530 {
3533 {
3540 }
3541 else
3542 {
3545 }
3546 }
3550 }
3552 /* Checks if DECL shadows a template parameter.
3554 [temp.local]: A template-parameter shall not be redeclared within its
3555 scope (including nested scopes).
3557 Emits an error and returns TRUE if the DECL shadows a parameter,
3558 returns FALSE otherwise. */
3560 bool
3562 {
3563 tree olddecl;
3565 /* If we're not in a template, we can't possibly shadow a template
3566 parameter. */
3570 /* Figure out what we're shadowing. */
3575 /* If there's no previous binding for this name, we're not shadowing
3576 anything, let alone a template parameter. */
3580 /* If we're not shadowing a template parameter, we're done. Note
3581 that OLDDECL might be an OVERLOAD (or perhaps even an
3582 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3583 node. */
3587 /* We check for decl != olddecl to avoid bogus errors for using a
3588 name inside a class. We check TPFI to avoid duplicate errors for
3589 inline member templates. */
3595 /* Don't complain about the injected class name, as we've already
3596 complained about the class itself. */
3603 }
3605 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3606 ORIG_LEVEL, DECL, and TYPE. */
3608 static tree
3612 tree decl,
3613 tree type)
3614 {
3625 }
3627 /* Find the canonical type parameter for the given template type
3628 parameter. Returns the canonical type parameter, which may be TYPE
3629 if no such parameter existed. */
3631 static tree
3633 {
3634 tree list;
3648 else
3649 {
3654 }
3655 }
3657 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3658 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3659 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3660 new one is created. */
3662 static tree
3664 tsubst_flags_t complain)
3665 {
3670 {
3689 /* Template template parameters need this. */
3694 }
3697 }
3699 /* Process information from new template parameter PARM and append it
3700 to the LIST being built. This new parameter is a non-type
3701 parameter iff IS_NON_TYPE is true. This new parameter is a
3702 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3703 is in PARM_LOC. */
3705 tree
3708 {
3710 tree defval;
3717 {
3721 {
3725 else
3727 }
3730 }
3733 {
3739 {
3740 /* [temp.param]
3742 The top-level cv-qualifiers on the template-parameter are
3743 ignored when determining its type. */
3748 && !is_parameter_pack
3749 /* If we're in a nested template parameter list, the template
3750 template parameter could be a parameter pack. */
3752 {
3753 /* This template parameter is not a parameter pack, but it
3754 should be. Complain about "bare" parameter packs. */
3757 /* Recover by calling this a parameter pack. */
3759 }
3760 }
3762 /* A template parameter is not modifiable. */
3771 processing_template_decl,
3776 }
3777 else
3778 {
3779 tree t;
3783 {
3785 /* This is for distinguishing between real templates and template
3786 template parameters */
3790 }
3791 else
3792 {
3794 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3797 }
3804 processing_template_decl,
3808 }
3814 }
3816 /* The end of a template parameter list has been reached. Process the
3817 tree list into a parameter vector, converting each parameter into a more
3818 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3819 as PARM_DECLs. */
3821 tree
3823 {
3828 current_template_parms
3833 {
3837 }
3842 }
3844 /* end_template_decl is called after a template declaration is seen. */
3846 void
3848 {
3854 /* This matches the pushlevel in begin_template_parm_list. */
3859 }
3861 /* Takes a TREE_LIST representing a template parameter and convert it
3862 into an argument suitable to be passed to the type substitution
3863 functions. Note that If the TREE_LIST contains an error_mark
3864 node, the returned argument is error_mark_node. */
3866 static tree
3868 {
3881 {
3885 {
3886 /* Turn this argument into a TYPE_ARGUMENT_PACK
3887 with a single element, which expands T. */
3889 #ifdef ENABLE_CHECKING
3890 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3892 #endif
3897 }
3898 }
3899 else
3900 {
3904 {
3905 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3906 with a single element, which expands T. */
3909 #ifdef ENABLE_CHECKING
3910 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3912 #endif
3919 }
3920 else
3922 }
3924 }
3926 /* Given a set of template parameters, return them as a set of template
3927 arguments. The template parameters are represented as a TREE_VEC, in
3928 the form documented in cp-tree.h for template arguments. */
3930 static tree
3932 {
3933 tree header;
3938 /* If there is only one level of template parameters, we do not
3939 create a TREE_VEC of TREE_VECs. Instead, we return a single
3940 TREE_VEC containing the arguments. */
3945 {
3953 #ifdef ENABLE_CHECKING
3955 #endif
3959 else
3961 }
3964 /* This can happen for template parms of a template template
3965 parameter, e.g:
3967 template<template<class T, class U> class TT> struct S;
3969 Consider the level of the parms of TT; T and U both have
3970 level 2; TT has no template parm of level 1. So in this case
3971 the first element of full_template_args is NULL_TREE. If we
3972 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3973 of 2. This will make tsubst wrongly consider that T and U
3974 have level 1. Instead, let's create a dummy vector as the
3975 first element of full_template_args so that TMPL_ARGS_DEPTH
3976 returns the correct depth for args. */
3979 }
3981 /* Within the declaration of a template, return the currently active
3982 template parameters as an argument TREE_VEC. */
3984 static tree
3986 {
3988 }
3990 /* Update the declared TYPE by doing any lookups which were thought to be
3991 dependent, but are not now that we know the SCOPE of the declarator. */
3993 tree
3995 {
4006 /* Don't bother building up the args in this case. */
4008 {
4009 /* tsubst in the args corresponding to the template parameters,
4010 including auto if present. Most things will be unchanged, but
4011 make_typename_type and tsubst_qualified_id will resolve
4012 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4015 tree pushed;
4017 {
4021 }
4026 }
4032 {
4035 else
4037 }
4039 }
4041 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4042 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4043 a member template. Used by push_template_decl below. */
4045 static tree
4047 {
4055 }
4057 struct template_parm_data
4058 {
4059 /* The level of the template parameters we are currently
4060 processing. */
4063 /* The index of the specialization argument we are currently
4064 processing. */
4067 /* An array whose size is the number of template parameters. The
4068 elements are nonzero if the parameter has been used in any one
4069 of the arguments processed so far. */
4072 /* An array whose size is the number of template arguments. The
4073 elements are nonzero if the argument makes use of template
4074 parameters of this level. */
4076 };
4078 /* Subroutine of push_template_decl used to see if each template
4079 parameter in a partial specialization is used in the explicit
4080 argument list. If T is of the LEVEL given in DATA (which is
4081 treated as a template_parm_data*), then DATA->PARMS is marked
4082 appropriately. */
4084 static int
4086 {
4094 {
4097 }
4099 /* Return zero so that for_each_template_parm will continue the
4100 traversal of the tree; we want to mark *every* template parm. */
4102 }
4104 /* Process the partial specialization DECL. */
4106 static tree
4108 {
4115 tree inner_parms;
4116 tree inst;
4129 /* We check that each of the template parameters given in the
4130 partial specialization is used in the argument list to the
4131 specialization. For example:
4133 template <class T> struct S;
4134 template <class T> struct S<T*>;
4136 The second declaration is OK because `T*' uses the template
4137 parameter T, whereas
4139 template <class T> struct S<int>;
4141 is no good. Even trickier is:
4143 template <class T>
4144 struct S1
4145 {
4146 template <class U>
4147 struct S2;
4148 template <class U>
4149 struct S2<T>;
4150 };
4152 The S2<T> declaration is actually invalid; it is a
4153 full-specialization. Of course,
4155 template <class U>
4156 struct S2<T (*)(U)>;
4158 or some such would have been OK. */
4166 {
4171 NULL,
4173 }
4176 {
4177 /* One of the template parms was not used in a deduced context in the
4178 specialization. */
4180 {
4184 }
4188 }
4193 /* [temp.class.spec]
4195 The argument list of the specialization shall not be identical to
4196 the implicit argument list of the primary template. */
4197 tree main_args
4203 /* A partial specialization that replaces multiple parameters of the
4204 primary template with a pack expansion is less specialized for those
4205 parameters. */
4207 {
4209 "primary template because it replaces multiple parameters "
4213 }
4215 /* [temp.class.spec]
4217 A partially specialized non-type argument expression shall not
4218 involve template parameters of the partial specialization except
4219 when the argument expression is a simple identifier.
4221 The type of a template parameter corresponding to a specialized
4222 non-type argument shall not be dependent on a parameter of the
4223 specialization.
4225 Also, we verify that pack expansions only occur at the
4226 end of the argument list. */
4230 {
4237 {
4238 /* Extract the arguments from the argument pack. We'll be
4239 iterating over these in the following loop. */
4242 }
4245 {
4247 /* Get the Jth argument in the parameter pack. */
4251 {
4252 /* Pack expansions must come at the end of the
4253 argument list. */
4256 {
4260 else
4263 }
4264 }
4267 /* We only care about the pattern. */
4273 /* This next two lines are the `argument expression is not just a
4274 simple identifier' condition and also the `specialized
4275 non-type argument' bit. */
4279 {
4283 arg);
4284 else
4285 {
4286 /* Look at the corresponding template parameter,
4287 marking which template parameters its type depends
4288 upon. */
4292 {
4293 /* We haven't yet initialized TPD2. Do so now. */
4295 /* The number of parameters here is the number in the
4296 main template, which, as checked in the assertion
4297 above, is NARGS. */
4301 }
4303 /* Mark the template parameters. But this time, we're
4304 looking for the template parameters of the main
4305 template, not in the specialization. */
4312 NULL,
4316 {
4317 /* The type depended on some template parameters.
4318 If they are fully specialized in the
4319 specialization, that's OK. */
4328 "type %qT of template argument %qE depends "
4330 "type %qT of template argument %qE depends "
4332 type,
4333 arg);
4334 }
4335 }
4336 }
4337 }
4338 }
4340 /* We should only get here once. */
4359 {
4365 {
4368 {
4372 "partial specialization of %qD after instantiation "
4374 }
4375 }
4376 }
4379 }
4381 /* PARM is a template parameter of some form; return the corresponding
4382 TEMPLATE_PARM_INDEX. */
4384 static tree
4386 {
4398 }
4400 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4401 parameter packs used by the template parameter PARM. */
4403 static void
4405 {
4406 /* A type parm can't refer to another parm. */
4410 {
4414 }
4421 }
4423 /* PARM is a template parameter pack. Return any parameter packs used in
4424 its type or the type of any of its template parameters. If there are
4425 any such packs, it will be instantiated into a fixed template parameter
4426 list by partial instantiation rather than be fully deduced. */
4428 tree
4430 {
4431 /* This can only be true in a member template. */
4434 /* This can only be true for a parameter pack. */
4437 /* A type parm can't refer to another parm. */
4450 }
4452 /* Check that a template declaration's use of default arguments and
4453 parameter packs is not invalid. Here, PARMS are the template
4454 parameters. IS_PRIMARY is true if DECL is the thing declared by
4455 a primary template. IS_PARTIAL is true if DECL is a partial
4456 specialization.
4458 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4459 declaration (but not a definition); 1 indicates a declaration, 2
4460 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4461 emitted for extraneous default arguments.
4463 Returns TRUE if there were no errors found, FALSE otherwise. */
4465 bool
4468 {
4471 tree parm_level;
4474 /* [temp.param]
4476 A default template-argument shall not be specified in a
4477 function template declaration or a function template definition, nor
4478 in the template-parameter-list of the definition of a member of a
4479 class template. */
4483 /* You can't have a function template declaration in a local
4484 scope, nor you can you define a member of a class template in a
4485 local scope. */
4493 /* A lambda doesn't have an explicit declaration; don't complain
4494 about the parms of the enclosing class. */
4501 /* If this is either a friend defined in the scope of the class
4502 or a member function. */
4508 /* And, if it was a member function, it really was defined in
4509 the scope of the class. */
4512 /* We already checked these parameters when the template was
4513 declared, so there's no need to do it again now. This function
4514 was defined in class scope, but we're processing its body now
4515 that the class is complete. */
4518 /* Core issue 226 (C++0x only): the following only applies to class
4519 templates. */
4522 {
4523 /* [temp.param]
4525 If a template-parameter has a default template-argument, all
4526 subsequent template-parameters shall have a default
4527 template-argument supplied. */
4529 {
4536 {
4546 {
4548 /* For better subsequent error-recovery, we indicate that
4549 there should have been a default argument. */
4552 }
4554 && !is_friend_decl
4555 /* Don't complain about an enclosing partial
4556 specialization. */
4561 /* A fixed parameter pack will be partially
4562 instantiated into a fixed length list. */
4564 {
4565 /* A primary class template can only have one
4566 parameter pack, at the end of the template
4567 parameter list. */
4572 else
4580 }
4581 }
4582 }
4583 }
4586 || is_partial
4587 || !is_primary
4589 /* For an ordinary class template, default template arguments are
4590 allowed at the innermost level, e.g.:
4591 template <class T = int>
4592 struct S {};
4593 but, in a partial specialization, they're not allowed even
4594 there, as we have in [temp.class.spec]:
4596 The template parameter list of a specialization shall not
4597 contain default template argument values.
4599 So, for a partial specialization, or for a function template
4600 (in C++98/C++03), we look at all of them. */
4601 ;
4602 else
4603 /* But, for a primary class template that is not a partial
4604 specialization we look at all template parameters except the
4605 innermost ones. */
4608 /* Figure out what error message to issue. */
4621 else
4625 /* If we're inside a class definition, there's no need to
4626 examine the parameters to the class itself. On the one
4627 hand, they will be checked when the class is defined, and,
4628 on the other, default arguments are valid in things like:
4629 template <class T = double>
4630 struct S { template <class U> void f(U); };
4631 Here the default argument for `S' has no bearing on the
4632 declaration of `f'. */
4634 else
4635 /* Check everything. */
4641 {
4648 {
4653 {
4655 {
4662 }
4664 /* Clear out the default argument so that we are not
4665 confused later. */
4667 }
4668 }
4670 /* At this point, if we're still interested in issuing messages,
4671 they must apply to classes surrounding the object declared. */
4675 }
4678 }
4680 /* Worker for push_template_decl_real, called via
4681 for_each_template_parm. DATA is really an int, indicating the
4682 level of the parameters we are interested in. If T is a template
4683 parameter of that level, return nonzero. */
4685 static int
4687 {
4693 else
4696 }
4698 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4699 parameters given by current_template_args, or reuses a
4700 previously existing one, if appropriate. Returns the DECL, or an
4701 equivalent one, if it is replaced via a call to duplicate_decls.
4703 If IS_FRIEND is true, DECL is a friend declaration. */
4705 tree
4707 {
4708 tree tmpl;
4709 tree args;
4710 tree info;
4711 tree ctx;
4715 /* True if the template is a member template, in the sense of
4716 [temp.mem]. */
4722 /* See if this is a partial specialization. */
4735 /* For a friend, we want the context of the friend function, not
4736 the type of which it is a friend. */
4740 /* In the case of a virtual function, we want the class in which
4741 it is defined. */
4743 else
4744 /* Otherwise, if we're currently defining some class, the DECL
4745 is assumed to be a member of the class. */
4754 /* See if this is a primary template. */
4757 /* A friend template that specifies a class context, i.e.
4758 template <typename T> friend void A<T>::f();
4759 is not primary. */
4764 else
4768 {
4773 {
4776 }
4778 {
4780 {
4783 }
4785 {
4786 /* [temp.mem]
4788 A destructor shall not be a member template. */
4791 }
4798 {
4799 /* [basic.stc.dynamic.allocation]
4801 An allocation function can be a function
4802 template. ... Template allocation functions shall
4803 have two or more parameters. */
4806 }
4807 }
4813 /* alias-declaration */
4817 else
4818 {
4821 }
4822 }
4824 /* Check to see that the rules regarding the use of default
4825 arguments are not being violated. */
4829 /* Ensure that there are no parameter packs in the type of this
4830 declaration that have not been expanded. */
4832 {
4833 /* Check each of the arguments individually to see if there are
4834 any bare parameter packs. */
4840 {
4843 {
4844 /* This is a PARM_DECL that contains unexpanded parameter
4845 packs. We have already complained about this in the
4846 check_for_bare_parameter_packs call, so just replace
4847 these types with ERROR_MARK_NODE. */
4850 }
4854 }
4856 /* Check for bare parameter packs in the return type and the
4857 exception specifiers. */
4859 /* Errors were already issued, set return type to int
4860 as the frontend doesn't expect error_mark_node as
4861 the return type. */
4865 }
4870 {
4873 }
4886 {
4891 /* If DECL is a TYPE_DECL for a class-template, then there won't
4892 be DECL_LANG_SPECIFIC. The information equivalent to
4893 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4897 {
4898 /* Since a template declaration already existed for this
4899 class-type, we must be redeclaring it here. Make sure
4900 that the redeclaration is valid. */
4902 current_template_parms);
4903 /* We don't need to create a new TEMPLATE_DECL; just use the
4904 one we already had. */
4906 }
4907 else
4908 {
4910 member_template_p);
4915 {
4916 /* A specialization of a member template of a template
4917 class. */
4921 }
4922 }
4923 }
4924 else
4925 {
4931 {
4934 }
4942 {
4943 tree new_tmpl;
4945 /* The declaration is a specialization of a member
4946 template, declared outside the class. Therefore, the
4947 innermost template arguments will be NULL, so we
4948 replace them with the arguments determined by the
4949 earlier call to check_explicit_specialization. */
4952 new_tmpl
4954 member_template_p);
4964 args,
4967 }
4969 /* Make sure the template headers we got make sense. */
4974 {
4979 }
4980 else
4982 {
4987 {
4991 else
4995 /* Avoid crash in import_export_decl. */
4998 }
5003 /* Can happen in erroneous input. */
5005 else
5007 }
5009 /* Check that the parms are used in the appropriate qualifying scopes
5010 in the declarator. */
5014 {
5020 /* Avoid crash in import_export_decl. */
5023 }
5024 }
5029 /* Push template declarations for global functions and types. Note
5030 that we do not try to push a global template friend declared in a
5031 template class; such a thing may well depend on the template
5032 parameters of the class. */
5035 {
5040 /* Hide template friend classes that haven't been declared yet. */
5042 {
5045 }
5046 }
5049 {
5055 {
5058 /* It is a conversion operator. See if the type converted to
5059 depends on innermost template operands. */
5062 depth))
5064 }
5066 /* Give template template parms a DECL_CONTEXT of the template
5067 for which they are a parameter. */
5070 {
5074 }
5075 }
5077 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5078 back to its most general template. If TMPL is a specialization,
5079 ARGS may only have the innermost set of arguments. Add the missing
5080 argument levels if necessary. */
5088 else
5089 {
5094 }
5097 && !is_friend
5100 /* Set DECL_COMDAT on template instantiations; if we force
5101 them to be emitted by explicit instantiation or -frepo,
5102 mark_needed will tell cgraph to do the right thing. */
5106 }
5108 tree
5110 {
5112 }
5114 /* FN is an inheriting constructor that inherits from the constructor
5115 template INHERITED; turn FN into a constructor template with a matching
5116 template header. */
5118 tree
5120 {
5121 tree inner_parms
5124 tree parms
5135 }
5137 /* Called when a class template TYPE is redeclared with the indicated
5138 template PARMS, e.g.:
5140 template <class T> struct S;
5141 template <class T> struct S {}; */
5143 bool
5145 {
5146 tree tmpl;
5147 tree tmpl_parms;
5151 {
5154 }
5158 /* The type is nested in some template class. Nothing to worry
5159 about here; there are no new template parameters for the nested
5160 type. */
5164 {
5166 tmpl);
5168 }
5174 {
5184 }
5187 {
5188 tree tmpl_parm;
5189 tree parm;
5190 tree tmpl_default;
5191 tree parm_default;
5205 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5206 TEMPLATE_DECL. */
5216 {
5220 }
5223 {
5224 /* We have in [temp.param]:
5226 A template-parameter may not be given default arguments
5227 by two different declarations in the same scope. */
5232 }
5235 /* Update the previous template parameters (which are the ones
5236 that will really count) with the new default value. */
5239 /* Update the new parameters, too; they'll be used as the
5240 parameters for any members. */
5242 }
5245 }
5247 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5248 to be used when the caller has already checked
5249 (processing_template_decl
5250 && !instantiation_dependent_expression_p (expr)
5251 && potential_constant_expression (expr))
5252 and cleared processing_template_decl. */
5254 tree
5256 {
5259 complain,
5263 }
5265 /* Simplify EXPR if it is a non-dependent expression. Returns the
5266 (possibly simplified) expression. */
5268 tree
5270 {
5274 /* If we're in a template, but EXPR isn't value dependent, simplify
5275 it. We're supposed to treat:
5277 template <typename T> void f(T[1 + 1]);
5278 template <typename T> void f(T[2]);
5280 as two declarations of the same function, for example. */
5284 {
5285 processing_template_decl_sentinel s;
5287 }
5289 }
5291 tree
5293 {
5295 }
5297 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5298 template declaration, or a TYPE_DECL for an alias declaration. */
5300 bool
5302 {
5310 }
5312 /* Return TRUE iff T is a specialization of an alias template. */
5314 bool
5316 {
5324 }
5326 /* Return TRUE iff T is a specialization of an alias template with
5327 dependent template-arguments. */
5329 bool
5331 {
5334 }
5336 /* Return the number of innermost template parameters in TMPL. */
5338 static int
5340 {
5343 }
5345 /* Return either TMPL or another template that it is equivalent to under DR
5346 1286: An alias that just changes the name of a template is equivalent to
5347 the other template. */
5349 static tree
5351 {
5354 {
5357 {
5362 {
5363 tree alias_args = INNERMOST_TEMPLATE_ARGS
5367 /* The alias type is equivalent to the pattern of the
5368 underlying template, so strip the alias. */
5371 }
5372 }
5374 }
5376 }
5378 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5379 must be a function or a pointer-to-function type, as specified
5380 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5381 and check that the resulting function has external linkage. */
5383 static tree
5385 tsubst_flags_t complain)
5386 {
5389 linkage_kind linkage;
5401 /* [temp.arg.nontype]/1
5403 A template-argument for a non-type, non-template template-parameter
5404 shall be one of:
5405 [...]
5406 -- the address of an object or function with external [C++11: or
5407 internal] linkage. */
5410 {
5412 {
5418 else
5421 }
5423 }
5427 {
5429 {
5434 else
5438 }
5440 }
5443 }
5445 /* Subroutine of convert_nontype_argument.
5446 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5447 Emit an error otherwise. */
5449 static bool
5451 tsubst_flags_t complain)
5452 {
5463 {
5467 }
5469 }
5471 /* Returns TRUE iff the address of OP is value-dependent.
5473 14.6.2.4 [temp.dep.temp]:
5474 A non-integral non-type template-argument is dependent if its type is
5475 dependent or it has either of the following forms
5476 qualified-id
5477 & qualified-id
5478 and contains a nested-name-specifier which specifies a class-name that
5479 names a dependent type.
5481 We generalize this to just say that the address of a member of a
5482 dependent class is value-dependent; the above doesn't cover the
5483 address of a static data member named with an unqualified-id. */
5485 static bool
5487 {
5488 /* We could use get_inner_reference here, but there's no need;
5489 this is only relevant for template non-type arguments, which
5490 can only be expressed as &id-expression. */
5492 {
5496 }
5499 }
5501 /* The next set of functions are used for providing helpful explanatory
5502 diagnostics for failed overload resolution. Their messages should be
5503 indented by two spaces for consistency with the messages in
5504 call.c */
5506 static int
5508 {
5510 }
5512 static int
5514 {
5519 }
5521 static int
5523 {
5525 }
5527 static int
5529 {
5535 }
5537 static int
5539 {
5543 }
5545 static int
5547 {
5550 " template parameter %qD is not a parameter pack, but "
5554 }
5556 static int
5558 {
5561 " template argument %qE does not match "
5565 }
5567 static int
5569 {
5573 }
5575 static int
5577 {
5583 }
5585 static int
5587 {
5589 {
5594 else
5596 " deduced conflicting values for non-type parameter "
5598 }
5600 }
5602 static int
5604 {
5607 " variable-sized array type %qT is not "
5609 arg);
5611 }
5613 static int
5615 {
5619 arg);
5621 }
5623 static int
5625 {
5627 {
5633 else
5638 }
5640 }
5642 static int
5644 {
5646 }
5648 static int
5651 {
5653 }
5655 static int
5658 {
5664 }
5666 static int
5669 {
5672 {
5680 }
5682 }
5684 static int
5686 {
5689 " template parameters of a template template argument are "
5692 }
5694 static int
5696 {
5702 }
5704 static int
5706 {
5711 }
5713 static int
5715 {
5719 arg);
5721 }
5723 /* Attempt to convert the non-type template parameter EXPR to the
5724 indicated TYPE. If the conversion is successful, return the
5725 converted value. If the conversion is unsuccessful, return
5726 NULL_TREE if we issued an error message, or error_mark_node if we
5727 did not. We issue error messages for out-and-out bad template
5728 parameters, but not simply because the conversion failed, since we
5729 might be just trying to do argument deduction. Both TYPE and EXPR
5730 must be non-dependent.
5732 The conversion follows the special rules described in
5733 [temp.arg.nontype], and it is much more strict than an implicit
5734 conversion.
5736 This function is called twice for each template argument (see
5737 lookup_template_class for a more accurate description of this
5738 problem). This means that we need to handle expressions which
5739 are not valid in a C++ source, but can be created from the
5740 first call (for instance, casts to perform conversions). These
5741 hacks can go away after we fix the double coercion problem. */
5743 static tree
5745 {
5746 tree expr_type;
5748 /* Detect immediately string literals as invalid non-type argument.
5749 This special-case is not needed for correctness (we would easily
5750 catch this later), but only to provide better diagnostic for this
5751 common user mistake. As suggested by DR 100, we do not mention
5752 linkage issues in the diagnostic as this is not the point. */
5753 /* FIXME we're making this OK. */
5755 {
5761 }
5763 /* Add the ADDR_EXPR now for the benefit of
5764 value_dependent_expression_p. */
5767 {
5771 }
5773 /* If we are in a template, EXPR may be non-dependent, but still
5774 have a syntactic, rather than semantic, form. For example, EXPR
5775 might be a SCOPE_REF, rather than the VAR_DECL to which the
5776 SCOPE_REF refers. Preserving the qualifying scope is necessary
5777 so that access checking can be performed when the template is
5778 instantiated -- but here we need the resolved form so that we can
5779 convert the argument. */
5785 && processing_template_decl
5794 else
5797 /* If the argument is non-dependent, perform any conversions in
5798 non-dependent context as well. */
5803 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5804 to a non-type argument of "nullptr". */
5808 /* In C++11, integral or enumeration non-type template arguments can be
5809 arbitrary constant expressions. Pointer and pointer to
5810 member arguments can be general constant expressions that evaluate
5811 to a null value, but otherwise still need to be of a specific form. */
5813 {
5815 /* A PTRMEM_CST is already constant, and a valid template
5816 argument for a parameter of pointer to member type, we just want
5817 to leave it in that form rather than lower it to a
5822 {
5827 }
5828 }
5830 /* HACK: Due to double coercion, we can get a
5831 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5832 which is the tree that we built on the first call (see
5833 below when coercing to reference to object or to reference to
5834 function). We just strip everything and get to the arg.
5835 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5836 for examples. */
5838 {
5844 {
5845 /* ??? Maybe we could use convert_from_reference here, but we
5846 would need to relax its constraints because the NOP_EXPR
5847 could actually change the type to something more cv-qualified,
5848 and this is not folded by convert_from_reference. */
5853 && (same_type_ignoring_top_level_qualifiers_p
5856 {
5859 }
5860 }
5861 }
5863 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5864 parameter is a pointer to object, through decay and
5865 qualification conversion. Let's strip everything. */
5867 {
5872 {
5873 /* Skip the ADDR_EXPR only if it is part of the decay for
5874 an array. Otherwise, it is part of the original argument
5875 in the source code. */
5880 }
5881 }
5883 /* [temp.arg.nontype]/5, bullet 1
5885 For a non-type template-parameter of integral or enumeration type,
5886 integral promotions (_conv.prom_) and integral conversions
5887 (_conv.integral_) are applied. */
5889 {
5898 /* Notice that there are constant expressions like '4 % 0' which
5899 do not fold into integer constants. */
5901 {
5903 {
5914 /* else cxx_constant_value complained but gave us
5915 a real constant, so go ahead. */
5917 }
5918 else
5920 }
5922 /* Avoid typedef problems. */
5925 }
5926 /* [temp.arg.nontype]/5, bullet 2
5928 For a non-type template-parameter of type pointer to object,
5929 qualification conversions (_conv.qual_) and the array-to-pointer
5930 conversion (_conv.array_) are applied. */
5932 {
5933 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5935 A template-argument for a non-type, non-template template-parameter
5936 shall be one of: [...]
5938 -- the name of a non-type template-parameter;
5939 -- the address of an object or function with external linkage, [...]
5940 expressed as "& id-expression" where the & is optional if the name
5941 refers to a function or array, or if the corresponding
5942 template-parameter is a reference.
5944 Here, we do not care about functions, as they are invalid anyway
5945 for a parameter of type pointer-to-object. */
5948 /* Non-type template parameters are OK. */
5949 ;
5954 {
5956 {
5959 "because %qD is a variable, not the address of "
5962 }
5964 {
5970 }
5971 /* Other values, like integer constants, might be valid
5972 non-type arguments of some other type. */
5974 }
5975 else
5976 {
5977 tree decl;
5982 {
5987 }
5989 {
5995 }
5997 {
6002 }
6003 }
6012 }
6013 /* [temp.arg.nontype]/5, bullet 3
6015 For a non-type template-parameter of type reference to object, no
6016 conversions apply. The type referred to by the reference may be more
6017 cv-qualified than the (otherwise identical) type of the
6018 template-argument. The template-parameter is bound directly to the
6019 template-argument, which must be an lvalue. */
6021 {
6023 expr_type))
6027 {
6032 }
6035 {
6040 }
6042 /* [temp.arg.nontype]/1
6044 A template-argument for a non-type, non-template template-parameter
6045 shall be one of: [...]
6047 -- the address of an object or function with external linkage. */
6050 {
6053 {
6056 "because a reference variable does not have a constant "
6059 }
6060 }
6063 {
6069 }
6072 {
6078 }
6081 }
6082 /* [temp.arg.nontype]/5, bullet 4
6084 For a non-type template-parameter of type pointer to function, only
6085 the function-to-pointer conversion (_conv.func_) is applied. If the
6086 template-argument represents a set of overloaded functions (or a
6087 pointer to such), the matching function is selected from the set
6088 (_over.over_). */
6090 {
6091 /* If the argument is a template-id, we might not have enough
6092 context information to decay the pointer. */
6094 {
6098 }
6101 /* Null pointer values are OK in C++11. */
6107 }
6108 /* [temp.arg.nontype]/5, bullet 5
6110 For a non-type template-parameter of type reference to function, no
6111 conversions apply. If the template-argument represents a set of
6112 overloaded functions, the matching function is selected from the set
6113 (_over.over_). */
6115 {
6117 {
6119 {
6124 }
6126 }
6133 }
6134 /* [temp.arg.nontype]/5, bullet 6
6136 For a non-type template-parameter of type pointer to member function,
6137 no conversions apply. If the template-argument represents a set of
6138 overloaded member functions, the matching member function is selected
6139 from the set (_over.over_). */
6141 {
6146 /* [temp.arg.nontype] bullet 1 says the pointer to member
6147 expression must be a pointer-to-member constant. */
6151 /* There is no way to disable standard conversions in
6152 resolve_address_of_overloaded_function (called by
6153 instantiate_type). It is possible that the call succeeded by
6154 converting &B::I to &D::I (where B is a base of D), so we need
6155 to reject this conversion here.
6157 Actually, even if there was a way to disable standard conversions,
6158 it would still be better to reject them here so that we can
6159 provide a superior diagnostic. */
6161 {
6163 {
6167 /* If we are just one standard conversion off, explain. */
6171 }
6173 }
6174 }
6175 /* [temp.arg.nontype]/5, bullet 7
6177 For a non-type template-parameter of type pointer to data member,
6178 qualification conversions (_conv.qual_) are applied. */
6180 {
6181 /* [temp.arg.nontype] bullet 1 says the pointer to member
6182 expression must be a pointer-to-member constant. */
6189 }
6191 {
6193 {
6198 }
6200 }
6201 /* A template non-type parameter must be one of the above. */
6202 else
6205 /* Sanity check: did we actually convert the argument to the
6206 right type? */
6210 }
6212 /* Subroutine of coerce_template_template_parms, which returns 1 if
6213 PARM_PARM and ARG_PARM match using the rule for the template
6214 parameters of template template parameters. Both PARM and ARG are
6215 template parameters; the rest of the arguments are the same as for
6216 coerce_template_template_parms.
6217 */
6218 static int
6220 tree arg,
6221 tsubst_flags_t complain,
6222 tree in_decl,
6223 tree outer_args)
6224 {
6233 {
6235 /* We encounter instantiations of templates like
6236 template <template <template <class> class> class TT>
6237 class C; */
6238 {
6245 }
6246 /* Fall through. */
6251 /* Argument is a parameter pack but parameter is not. */
6256 /* The tsubst call is used to handle cases such as
6258 template <int> class C {};
6259 template <class T, template <T> class TT> class D {};
6260 D<int, C> d;
6262 i.e. the parameter list of TT depends on earlier parameters. */
6264 && !same_type_p
6271 /* Argument is a parameter pack but parameter is not. */
6278 }
6281 }
6284 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6285 template template parameters. Both PARM_PARMS and ARG_PARMS are
6286 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6287 or PARM_DECL.
6289 Consider the example:
6290 template <class T> class A;
6291 template<template <class U> class TT> class B;
6293 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6294 the parameters to A, and OUTER_ARGS contains A. */
6296 static int
6298 tree arg_parms,
6299 tsubst_flags_t complain,
6300 tree in_decl,
6301 tree outer_args)
6302 {
6313 /* Determine whether we have a parameter pack at the end of the
6314 template template parameter's template parameter list. */
6316 {
6323 {
6337 }
6338 }
6344 /* Check all of the template parameters except the parameter pack at
6345 the end (if any). */
6347 {
6356 outer_args))
6359 }
6362 {
6363 /* Check each of the template parameters in the template
6364 argument against the template parameter pack at the end of
6365 the template template parameter. */
6372 {
6379 outer_args))
6381 }
6382 }
6385 }
6387 /* Verifies that the deduced template arguments (in TARGS) for the
6388 template template parameters (in TPARMS) represent valid bindings,
6389 by comparing the template parameter list of each template argument
6390 to the template parameter list of its corresponding template
6391 template parameter, in accordance with DR150. This
6392 routine can only be called after all template arguments have been
6393 deduced. It will return TRUE if all of the template template
6394 parameter bindings are okay, FALSE otherwise. */
6395 bool
6397 {
6401 /* We're dealing with template parms in this process. */
6407 {
6412 {
6417 {
6418 /* Look inside the argument pack. */
6421 }
6424 {
6428 /* Extract the next argument from the argument
6429 pack. */
6433 /* Look at the pattern of the pack expansion. */
6436 /* Extract the template parameters from the template
6437 argument. */
6443 /* Verify that we can coerce the template template
6444 parameters from the template argument to the template
6445 parameter. This requires an exact match. */
6447 && !coerce_template_template_parms
6449 targ_parms,
6450 tf_none,
6451 tparm,
6452 targs))
6453 {
6456 }
6457 }
6458 }
6459 }
6461 out:
6465 }
6467 /* Since type attributes aren't mangled, we need to strip them from
6468 template type arguments. */
6470 static tree
6472 {
6473 tree mv;
6480 {
6485 }
6487 }
6489 /* Convert the indicated template ARG as necessary to match the
6490 indicated template PARM. Returns the converted ARG, or
6491 error_mark_node if the conversion was unsuccessful. Error and
6492 warning messages are issued under control of COMPLAIN. This
6493 conversion is for the Ith parameter in the parameter list. ARGS is
6494 the full set of template arguments deduced so far. */
6496 static tree
6498 tree arg,
6499 tree args,
6500 tsubst_flags_t complain,
6502 tree in_decl)
6503 {
6504 tree orig_arg;
6505 tree val;
6510 {
6511 /* The template argument was the name of some
6512 member function. That's usually
6513 invalid, but static members are OK. In any
6514 case, grab the underlying fields/functions
6515 and issue an error later if required. */
6518 }
6526 /* When determining whether an argument pack expansion is a template,
6527 look at the pattern. */
6531 /* Deal with an injected-class-name used as a template template arg. */
6533 {
6536 {
6546 }
6547 }
6549 is_tmpl_type =
6565 {
6567 {
6571 }
6574 "to refer to a type member of a template parameter, "
6579 typename_type,
6580 complain);
6583 }
6585 {
6587 {
6589 {
6601 else
6604 }
6605 }
6607 }
6609 {
6611 {
6618 else
6621 }
6623 }
6626 {
6628 {
6632 /* The number of argument required is not known yet.
6633 Just accept it for now. */
6635 else
6636 {
6638 tree argparm;
6640 /* Strip alias templates that are equivalent to another
6641 template. */
6647 args))
6648 {
6651 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6652 TEMPLATE_DECL. */
6654 {
6659 }
6660 }
6661 else
6662 {
6664 {
6671 }
6674 }
6675 }
6676 }
6677 else
6679 /* We only form one instance of each template specialization.
6680 Therefore, if we use a non-canonical variant (i.e., a
6681 typedef), any future messages referring to the type will use
6682 the typedef, which is confusing if those future uses do not
6683 themselves also use the typedef. */
6686 }
6687 else
6688 {
6695 {
6698 else
6699 {
6700 /* Not sure if this is reachable, but it doesn't hurt
6701 to be robust. */
6704 }
6705 }
6708 /* We used to call digest_init here. However, digest_init
6709 will report errors, which we don't want when complain
6710 is zero. More importantly, digest_init will try too
6711 hard to convert things: for example, `0' should not be
6712 converted to pointer type at this point according to
6713 the standard. Accepting this is not merely an
6714 extension, since deciding whether or not these
6715 conversions can occur is part of determining which
6716 function template to call, or whether a given explicit
6717 argument specification is valid. */
6719 else
6728 {
6729 /* Strip typedefs from the SCOPE_REF. */
6732 complain);
6735 }
6736 }
6739 }
6741 /* Coerces the remaining template arguments in INNER_ARGS (from
6742 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6743 Returns the coerced argument pack. PARM_IDX is the position of this
6744 parameter in the template parameter list. ARGS is the original
6745 template argument list. */
6746 static tree
6749 tree args,
6750 tree inner_args,
6752 tree new_args,
6754 tree in_decl,
6755 tsubst_flags_t complain)
6756 {
6759 tree packed_args;
6760 tree argument_pack;
6767 {
6768 /* When the template parameter is a non-type template parameter pack
6769 or template template parameter pack whose type or template
6770 parameters use parameter packs, we know exactly how many arguments
6771 we are looking for. Build a vector of the instantiated decls for
6772 these template parameters in PACKED_PARMS. */
6773 /* We can't use make_pack_expansion here because it would interpret a
6774 _DECL as a use rather than a declaration. */
6788 /* If we're doing a partial instantiation of a member template,
6789 verify that all of the types used for the non-type
6790 template parameter pack are, in fact, valid for non-type
6791 template parameters. */
6794 {
6797 {
6801 }
6802 }
6805 }
6806 else
6809 /* Convert the remaining arguments, which will be a part of the
6810 parameter pack "parm". */
6812 {
6818 {
6819 /* Once we've packed as many args as we have types, stop. */
6823 /* We don't know how many args we have yet, just
6824 use the unconverted ones for now. */
6826 else
6828 }
6831 {
6834 }
6835 else
6838 in_decl);
6842 }
6846 {
6851 }
6856 else
6857 {
6862 }
6865 #ifdef ENABLE_CHECKING
6868 #endif
6870 }
6872 /* Returns the number of pack expansions in the template argument vector
6873 ARGS. */
6875 static int
6877 {
6882 {
6886 }
6888 }
6890 /* Convert all template arguments to their appropriate types, and
6891 return a vector containing the innermost resulting template
6892 arguments. If any error occurs, return error_mark_node. Error and
6893 warning messages are issued under control of COMPLAIN.
6895 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6896 for arguments not specified in ARGS. Otherwise, if
6897 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6898 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6899 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6900 ARGS. */
6902 static tree
6904 tree args,
6905 tree in_decl,
6906 tsubst_flags_t complain,
6909 {
6911 tree orig_inner_args;
6912 tree inner_args;
6913 tree new_args;
6914 tree new_inner_args;
6918 /* When used as a boolean value, indicates whether this is a
6919 variadic template parameter list. Since it's an int, we can also
6920 subtract it from nparms to get the number of non-variadic
6921 parameters. */
6926 /* Likewise for parameters with default arguments. */
6934 /* Determine if there are any parameter packs or default arguments. */
6936 {
6944 }
6947 /* If there are no parameters that follow a parameter pack, we need to
6948 expand any argument packs so that we can deduce a parameter pack from
6949 some non-packed args followed by an argument pack, as in variadic85.C.
6950 If there are such parameters, we need to leave argument packs intact
6951 so the arguments are assigned properly. This can happen when dealing
6952 with a nested class inside a partial specialization of a class
6953 template, as in variadic92.C, or when deducing a template parameter pack
6954 from a sub-declarator, as in variadic114.C. */
6958 /* Count any pack expansion args. */
6964 && require_all_args
6965 && !variadic_args_p
6966 && (!use_default_args
6969 {
6971 {
6973 {
6977 }
6978 else
6984 }
6987 }
6988 /* We can't pass a pack expansion to a non-pack parameter of an alias
6989 template (DR 1430). */
6991 && variadic_args_p
6993 {
6995 {
6997 {
7003 {
7008 }
7009 }
7011 found:;
7012 }
7014 }
7016 /* We need to evaluate the template arguments, even though this
7017 template-id may be nested within a "sizeof". */
7026 {
7027 tree arg;
7028 tree parm;
7030 /* Get the Ith template parameter. */
7034 {
7037 }
7039 /* Calculate the next argument. */
7042 else
7047 {
7048 /* Some arguments will be placed in the
7049 template parameter pack PARM. */
7056 {
7057 /* We don't know how many args we have yet, just use the
7058 unconverted (and still packed) ones for now. */
7062 }
7066 /* Store this argument. */
7068 {
7069 lost++;
7070 /* We are done with all of the arguments. */
7072 }
7073 else
7074 {
7077 }
7080 }
7082 {
7084 {
7085 /* "If every valid specialization of a variadic template
7086 requires an empty template parameter pack, the template is
7087 ill-formed, no diagnostic required." So check that the
7088 pattern works with this parameter. */
7093 in_decl);
7095 {
7099 }
7101 /* Recover from missing typename. */
7105 /* We don't know how many args we have yet, just
7106 use the unconverted ones for now. */
7110 }
7111 }
7113 {
7114 /* There must be a default arg in this case. */
7117 /* The position of the first default template argument,
7118 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
7119 Record that. */
7123 }
7124 else
7128 {
7131 }
7133 /* This only occurs if there was an error in the template
7134 parameter list itself (which we would already have
7135 reported) that we are trying to recover from, e.g., a class
7136 template with a parameter list such as
7137 template<typename..., typename>. */
7139 else
7145 lost++;
7147 }
7152 {
7154 {
7159 }
7161 }
7166 #ifdef ENABLE_CHECKING
7170 #endif
7173 }
7175 /* Like coerce_template_parms. If PARMS represents all template
7176 parameters levels, this function returns a vector of vectors
7177 representing all the resulting argument levels. Note that in this
7178 case, only the innermost arguments are coerced because the
7179 outermost ones are supposed to have been coerced already.
7181 Otherwise, if PARMS represents only (the innermost) vector of
7182 parameters, this function returns a vector containing just the
7183 innermost resulting arguments. */
7185 static tree
7187 tree args,
7188 tree in_decl,
7189 tsubst_flags_t complain,
7192 {
7195 tree coerced_args;
7198 {
7200 tree level;
7206 {
7207 tree l;
7211 require_all_args,
7212 use_default_args);
7213 else
7220 }
7221 }
7222 else
7225 require_all_args,
7226 use_default_args);
7228 }
7230 /* Returns 1 if template args OT and NT are equivalent. */
7232 static int
7234 {
7241 /* For member templates */
7250 {
7267 }
7269 {
7270 /* We get here probably because we are in the middle of substituting
7271 into the pattern of a pack expansion. In that case the
7272 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7273 interested in. So we want to use the initial pack argument for
7274 the comparison. */
7279 }
7281 {
7284 /* Don't treat an alias template specialization with dependent
7285 arguments as equivalent to its underlying type when used as a
7286 template argument; we need them to hash differently. */
7296 else
7298 }
7301 else
7303 }
7305 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7306 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7307 NEWARG_PTR with the offending arguments if they are non-NULL. */
7309 static int
7312 {
7325 {
7330 {
7336 }
7337 }
7339 }
7341 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7342 of template arguments. Returns 0 otherwise. */
7344 int
7346 {
7348 }
7350 static void
7352 {
7362 /* We are called both from instantiate_decl, where we've already had a
7363 tinst_level pushed, and instantiate_template, where we haven't.
7364 Compensate. */
7375 else
7384 }
7387 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7388 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7389 documentation for TEMPLATE_ID_EXPR. */
7391 tree
7393 {
7394 tree type;
7402 {
7405 }
7408 {
7410 unknown_type_node,
7412 arglist);
7414 }
7421 }
7423 /* Within the scope of a template class S<T>, the name S gets bound
7424 (in build_self_reference) to a TYPE_DECL for the class, not a
7425 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7426 or one of its enclosing classes, and that type is a template,
7427 return the associated TEMPLATE_DECL. Otherwise, the original
7428 DECL is returned.
7430 Also handle the case when DECL is a TREE_LIST of ambiguous
7431 injected-class-names from different bases. */
7433 tree
7435 {
7439 /* DR 176: A lookup that finds an injected-class-name (10.2
7440 [class.member.lookup]) can result in an ambiguity in certain cases
7441 (for example, if it is found in more than one base class). If all of
7442 the injected-class-names that are found refer to specializations of
7443 the same class template, and if the name is followed by a
7444 template-argument-list, the reference refers to the class template
7445 itself and not a specialization thereof, and is not ambiguous. */
7447 {
7450 {
7456 }
7459 else
7461 }
7467 }
7469 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7470 parameters, find the desired type.
7472 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7474 IN_DECL, if non-NULL, is the template declaration we are trying to
7475 instantiate.
7477 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7478 the class we are looking up.
7480 Issue error and warning messages under control of COMPLAIN.
7482 If the template class is really a local class in a template
7483 function, then the FUNCTION_CONTEXT is the function in which it is
7484 being instantiated.
7486 ??? Note that this function is currently called *twice* for each
7487 template-id: the first time from the parser, while creating the
7488 incomplete type (finish_template_type), and the second type during the
7489 real instantiation (instantiate_template_class). This is surely something
7490 that we want to avoid. It also causes some problems with argument
7491 coercion (see convert_nontype_argument for more information on this). */
7493 static tree
7496 {
7498 tree t;
7501 spec_entry elt;
7502 hashval_t hash;
7505 {
7509 else
7510 {
7517 }
7520 }
7522 {
7525 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7526 an implicit typename for the second A. Deal with it. */
7531 {
7534 }
7535 }
7538 {
7541 }
7543 {
7547 }
7549 {
7552 }
7554 /* Issue an error message if we didn't find a template. */
7556 {
7560 }
7563 /* Make sure it's a user visible template, if it was named by
7564 the user. */
7567 {
7569 {
7573 }
7575 }
7579 /* An alias that just changes the name of a template is equivalent to the
7580 other template, so if any of the arguments are pack expansions, strip
7581 the alias to avoid problems with a pack expansion passed to a non-pack
7582 alias template parameter (DR 1430). */
7587 {
7588 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7589 template arguments */
7591 tree parm;
7592 tree arglist2;
7593 tree outer;
7597 /* Consider an example where a template template parameter declared as
7599 template <class T, class U = std::allocator<T> > class TT
7601 The template parameter level of T and U are one level larger than
7602 of TT. To proper process the default argument of U, say when an
7603 instantiation `TT<int>' is seen, we need to build the full
7604 arguments containing {int} as the innermost level. Outer levels,
7605 available when not appearing as default template argument, can be
7606 obtained from the arguments of the enclosing template.
7608 Suppose that TT is later substituted with std::vector. The above
7609 instantiation is `TT<int, std::allocator<T> >' with TT at
7610 level 1, and T at level 2, while the template arguments at level 1
7611 becomes {std::vector} and the inner level 2 is {int}. */
7617 /* This is an argument of the current template, so we haven't set
7618 DECL_CONTEXT yet. */
7625 complain,
7635 }
7636 else
7637 {
7639 tree gen_tmpl;
7640 tree type_decl;
7648 /* An error occurred while building the template TEMPL, and a
7649 diagnostic has most certainly been emitted for that
7650 already. Let's propagate that error. */
7659 {
7660 /* We've been given an incomplete set of template arguments.
7661 For example, given:
7663 template <class T> struct S1 {
7664 template <class U> struct S2 {};
7665 template <class U> struct S2<U*> {};
7666 };
7668 we will be called with an ARGLIST of `U*', but the
7669 TEMPLATE will be `template <class T> template
7670 <class U> struct S1<T>::S2'. We must fill in the missing
7671 arguments. */
7672 arglist
7674 arglist);
7676 }
7678 /* Now we should have enough arguments. */
7681 /* From here on, we're only interested in the most general
7682 template. */
7684 /* Calculate the BOUND_ARGS. These will be the args that are
7685 actually tsubst'd into the definition to create the
7686 instantiation. */
7688 {
7689 /* We have multiple levels of arguments to coerce, at once. */
7699 {
7700 tree a;
7704 complain,
7707 else
7708 /* Outer levels should have already been coerced. */
7711 /* Don't process further if one of the levels fails. */
7713 {
7714 /* Restore the ARGLIST to its full size. */
7717 }
7721 /* We temporarily reduce the length of the ARGLIST so
7722 that coerce_template_parms will see only the arguments
7723 corresponding to the template parameters it is
7724 examining. */
7726 }
7728 /* Restore the ARGLIST to its full size. */
7732 }
7733 else
7734 arglist
7737 gen_tmpl,
7738 complain,
7743 /* We were unable to bind the arguments. */
7746 /* In the scope of a template class, explicit references to the
7747 template class refer to the type of the template, not any
7748 instantiation of it. For example, in:
7750 template <class T> class C { void f(C<T>); }
7752 the `C<T>' is just the same as `C'. Outside of the
7753 class, however, such a reference is an instantiation. */
7757 /* comp_template_args is expensive, check it last. */
7759 arglist))
7762 /* If we already have this specialization, return it. */
7773 /* If the deduced arguments are invalid, then the binding
7774 failed. */
7778 complain))
7785 {
7790 }
7800 /* Create the type. */
7802 {
7803 /* The user referred to a specialization of an alias
7804 template represented by GEN_TMPL.
7806 [temp.alias]/2 says:
7808 When a template-id refers to the specialization of an
7809 alias template, it is equivalent to the associated
7810 type obtained by substitution of its
7811 template-arguments for the template-parameters in the
7812 type-id of the alias template. */
7815 /* Note that the call above (by indirectly calling
7816 register_specialization in tsubst_decl) registers the
7817 TYPE_DECL representing the specialization of the alias
7818 template. So next time someone substitutes ARGLIST for
7819 the template parms into the alias template (GEN_TMPL),
7820 she'll get that TYPE_DECL back. */
7824 }
7826 {
7828 {
7837 }
7838 else
7839 {
7840 /* We don't want to call start_enum for this type, since
7841 the values for the enumeration constants may involve
7842 template parameters. And, no one should be interested
7843 in the enumeration constants for such a type. */
7846 }
7850 }
7852 {
7859 /* A local class. Make sure the decl gets registered properly. */
7864 /* This instantiation is another name for the primary
7865 template type. Set the TYPE_CANONICAL field
7866 appropriately. */
7869 /* Some of the template arguments require structural
7870 equality testing, so this template class requires
7871 structural equality testing. */
7873 }
7874 else
7877 /* If we called start_enum or pushtag above, this information
7878 will already be set up. */
7880 {
7887 }
7888 else
7892 {
7898 {
7901 }
7902 }
7906 {
7909 {
7912 else
7916 }
7917 }
7919 /* Let's consider the explicit specialization of a member
7920 of a class template specialization that is implicitly instantiated,
7921 e.g.:
7922 template<class T>
7923 struct S
7924 {
7925 template<class U> struct M {}; //#0
7926 };
7928 template<>
7929 template<>
7930 struct S<int>::M<char> //#1
7931 {
7932 int i;
7933 };
7934 [temp.expl.spec]/4 says this is valid.
7936 In this case, when we write:
7937 S<int>::M<char> m;
7939 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7940 the one of #0.
7942 When we encounter #1, we want to store the partial instantiation
7943 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7945 For all cases other than this "explicit specialization of member of a
7946 class template", we just want to store the most general template into
7947 the CLASSTYPE_TI_TEMPLATE of M.
7949 This case of "explicit specialization of member of a class template"
7950 only happens when:
7951 1/ the enclosing class is an instantiation of, and therefore not
7952 the same as, the context of the most general template, and
7953 2/ we aren't looking at the partial instantiation itself, i.e.
7954 the innermost arguments are not the same as the innermost parms of
7955 the most general template.
7957 So it's only when 1/ and 2/ happens that we want to use the partial
7958 instantiation of the member template in lieu of its most general
7959 template. */
7963 /* the enclosing class must be an instantiation... */
7966 {
7967 tree partial_inst_args;
7970 partial_inst_args =
7976 use_partial_inst_tmpl =
7977 /*...and we must not be looking at the partial instantiation
7978 itself. */
7980 partial_inst_args);
7981 }
7984 /* This case is easy; there are no member templates involved. */
7986 else
7987 {
7988 /* This is a full instantiation of a member template. Find
7989 the partial instantiation of which this is an instance. */
7991 /* Temporarily reduce by one the number of levels in the ARGLIST
7992 so as to avoid comparing the last set of arguments. */
7996 /* FOUND is either a proper class type, or an alias
7997 template specialization. In the later case, it's a
7998 TYPE_DECL, resulting from the substituting of arguments
7999 for parameters in the TYPE_DECL of the alias template
8000 done earlier. So be careful while getting the template
8001 of FOUND. */
8005 }
8015 /* Note this use of the partial instantiation so we can check it
8016 later in maybe_process_partial_specialization. */
8023 /* Now that the type has been registered on the instantiations
8024 list, we set up the enumerators. Because the enumeration
8025 constants may involve the enumeration type itself, we make
8026 sure to register the type first, and then create the
8027 constants. That way, doing tsubst_expr for the enumeration
8028 constants won't result in recursive calls here; we'll find
8029 the instantiation and exit above. */
8033 /* If the type makes use of template parameters, the
8034 code that generates debugging information will crash. */
8037 /* Possibly limit visibility based on template args. */
8044 }
8045 }
8047 /* Wrapper for lookup_template_class_1. */
8049 tree
8052 {
8053 tree ret;
8059 }
8061 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST.
8062 The type of the expression is the unknown_type_node since the
8063 template-id could refer to an explicit or partial specialization. */
8065 tree
8067 {
8074 }
8076 \f
8077 struct pair_fn_data
8078 {
8079 tree_fn_t fn;
8081 /* True when we should also visit template parameters that occur in
8082 non-deduced contexts. */
8085 };
8087 /* Called from for_each_template_parm via walk_tree. */
8089 static tree
8091 {
8104 {
8108 /* Fall through. */
8131 /* Since we're not going to walk subtrees, we have to do this
8132 explicitly here. */
8136 /* Fall through. */
8139 /* Check the return type. */
8144 /* Check the parameter types. Since default arguments are not
8145 instantiated until they are needed, the TYPE_ARG_TYPES may
8146 contain expressions that involve template parameters. But,
8147 no-one should be looking at them yet. And, once they're
8148 instantiated, they don't contain template parameters, so
8149 there's no point in looking at them then, either. */
8150 {
8151 tree parm;
8158 /* Since we've already handled the TYPE_ARG_TYPES, we don't
8159 want walk_tree walking into them itself. */
8161 }
8179 /* Fall through. */
8195 /* Record template parameters such as `T' inside `TT<T>'. */
8199 /* Fall through. */
8211 /* A template template parameter is encountered. */
8217 /* Already substituted template template parameter */
8240 /* If there's no type, then this thing must be some expression
8241 involving template parameters. */
8263 }
8265 /* We didn't find any template parameters we liked. */
8267 }
8269 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8270 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8271 call FN with the parameter and the DATA.
8272 If FN returns nonzero, the iteration is terminated, and
8273 for_each_template_parm returns 1. Otherwise, the iteration
8274 continues. If FN never returns a nonzero value, the value
8275 returned by for_each_template_parm is 0. If FN is NULL, it is
8276 considered to be the function which always returns 1.
8278 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8279 parameters that occur in non-deduced contexts. When false, only
8280 visits those template parameters that can be deduced. */
8282 static int
8286 {
8290 /* Set up. */
8295 /* Walk the tree. (Conceptually, we would like to walk without
8296 duplicates, but for_each_template_parm_r recursively calls
8297 for_each_template_parm, so we would need to reorganize a fair
8298 bit to use walk_tree_without_duplicates, so we keep our own
8299 visited list.) */
8302 else
8305 for_each_template_parm_r,
8309 /* Clean up. */
8311 {
8314 }
8317 }
8319 /* Returns true if T depends on any template parameter. */
8321 int
8323 {
8353 else
8354 {
8357 }
8362 }
8364 /* Returns true iff current_function_decl is an incompletely instantiated
8365 template. Useful instead of processing_template_decl because the latter
8366 is set to 0 during instantiate_non_dependent_expr. */
8368 bool
8370 {
8379 }
8381 /* Returns true if T depends on any template parameter with level LEVEL. */
8383 int
8385 {
8388 }
8390 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8391 ill-formed translation unit, i.e. a variable or function that isn't
8392 usable in a constant expression. */
8396 {
8400 }
8402 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8403 neglectable and instantiated from within an erroneous instantiation. */
8405 static bool
8407 {
8418 }
8426 /* We're starting to instantiate D; record the template instantiation context
8427 for diagnostics and to restore it later. */
8429 bool
8431 {
8433 }
8435 /* We're starting to instantiate D; record the template instantiation context
8436 at LOC for diagnostics and to restore it later. */
8438 bool
8440 {
8444 {
8447 max_tinst_depth);
8449 }
8451 /* If the current instantiation caused problems, don't let it instantiate
8452 anything else. Do allow deduction substitution and decls usable in
8453 constant expressions. */
8470 }
8472 /* We're done instantiating this template; return to the instantiation
8473 context. */
8475 void
8477 {
8478 /* Restore the filename and line number stashed away when we started
8479 this instantiation. */
8483 }
8485 /* We're instantiating a deferred template; restore the template
8486 instantiation context in which the instantiation was requested, which
8487 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8489 static tree
8491 {
8503 }
8505 /* Returns the TINST_LEVEL which gives the original instantiation
8506 context. */
8510 {
8516 }
8518 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8519 vector of template arguments, as for tsubst.
8521 Returns an appropriate tsubst'd friend declaration. */
8523 static tree
8525 {
8526 tree new_friend;
8531 /* This was a friend declared with an explicit template
8532 argument list, e.g.:
8534 friend void f<>(T);
8536 to indicate that f was a template instantiation, not a new
8537 function declaration. Now, we have to figure out what
8538 instantiation of what template. */
8539 {
8541 tree new_args;
8542 tree tmpl;
8545 /* Friend functions are looked up in the containing namespace scope.
8546 We must enter that scope, to avoid finding member functions of the
8547 current class with same name. */
8562 tsk_none);
8564 }
8568 /* The NEW_FRIEND will look like an instantiation, to the
8569 compiler, but is not an instantiation from the point of view of
8570 the language. For example, we might have had:
8572 template <class T> struct S {
8573 template <class U> friend void f(T, U);
8574 };
8576 Then, in S<int>, template <class U> void f(int, U) is not an
8577 instantiation of anything. */
8583 {
8587 }
8589 /* The mangled name for the NEW_FRIEND is incorrect. The function
8590 is not a template instantiation and should not be mangled like
8591 one. Therefore, we forget the mangling here; we'll recompute it
8592 later if we need it. */
8594 {
8597 }
8600 {
8601 tree old_decl;
8602 tree new_friend_template_info;
8603 tree new_friend_result_template_info;
8604 tree ns;
8607 /* We must save some information from NEW_FRIEND before calling
8608 duplicate decls since that function will free NEW_FRIEND if
8609 possible. */
8611 new_friend_is_defn =
8616 {
8617 /* This declaration is a `primary' template. */
8620 new_friend_result_template_info
8622 }
8623 else
8626 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8630 /* Inside pushdecl_namespace_level, we will push into the
8631 current namespace. However, the friend function should go
8632 into the namespace of the template. */
8642 {
8643 /* This new friend declaration matched an existing
8644 declaration. For example, given:
8646 template <class T> void f(T);
8647 template <class U> class C {
8648 template <class T> friend void f(T) {}
8649 };
8651 the friend declaration actually provides the definition
8652 of `f', once C has been instantiated for some type. So,
8653 old_decl will be the out-of-class template declaration,
8654 while new_friend is the in-class definition.
8656 But, if `f' was called before this point, the
8657 instantiation of `f' will have DECL_TI_ARGS corresponding
8658 to `T' but not to `U', references to which might appear
8659 in the definition of `f'. Previously, the most general
8660 template for an instantiation of `f' was the out-of-class
8661 version; now it is the in-class version. Therefore, we
8662 run through all specialization of `f', adding to their
8663 DECL_TI_ARGS appropriately. In particular, they need a
8664 new set of outer arguments, corresponding to the
8665 arguments for this class instantiation.
8667 The same situation can arise with something like this:
8669 friend void f(int);
8670 template <class T> class C {
8671 friend void f(T) {}
8672 };
8674 when `C<int>' is instantiated. Now, `f(int)' is defined
8675 in the class. */
8678 /* On the other hand, if the in-class declaration does
8679 *not* provide a definition, then we don't want to alter
8680 existing definitions. We can just leave everything
8681 alone. */
8682 ;
8683 else
8684 {
8688 /* Overwrite whatever template info was there before, if
8689 any, with the new template information pertaining to
8690 the declaration. */
8694 {
8695 /* We should have called reregister_specialization in
8696 duplicate_decls. */
8701 /* Instantiate it if the global has already been used. */
8705 }
8706 else
8707 {
8708 tree t;
8710 /* Indicate that the old function template is a partial
8711 instantiation. */
8719 /* Reassign any specializations already in the hash table
8720 to the new more general template, and add the
8721 additional template args. */
8725 {
8727 spec_entry elt;
8739 register_specialization
8742 }
8744 }
8745 }
8747 /* The information from NEW_FRIEND has been merged into OLD_DECL
8748 by duplicate_decls. */
8750 }
8751 }
8752 else
8753 {
8757 /* In the code
8758 template <class T> class C {
8759 template <class U> friend void C1<U>::f (); // case 1
8760 friend void C2<T>::f (); // case 2
8761 };
8762 we only need to make sure CONTEXT is a complete type for
8763 case 2. To distinguish between the two cases, we note that
8764 CONTEXT of case 1 remains dependent type after tsubst while
8765 this isn't true for case 2. */
8775 {
8777 /* do_friend adds the TEMPLATE_DECL for any member friend
8778 template even if it isn't a member template, i.e.
8779 template <class T> friend A<T>::f();
8780 Look through it in that case. */
8784 /* Check to see that the declaration is really present, and,
8785 possibly obtain an improved declaration. */
8790 }
8791 }
8794 }
8796 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8797 template arguments, as for tsubst.
8799 Returns an appropriate tsubst'd friend type or error_mark_node on
8800 failure. */
8802 static tree
8804 {
8805 tree friend_type;
8806 tree tmpl;
8807 tree context;
8810 {
8813 }
8818 {
8821 else
8823 }
8825 /* Look for a class template declaration. We look for hidden names
8826 because two friend declarations of the same template are the
8827 same. For example, in:
8829 struct A {
8830 template <typename> friend class F;
8831 };
8832 template <typename> struct B {
8833 template <typename> friend class F;
8834 };
8836 both F templates are the same. */
8840 /* But, if we don't find one, it might be because we're in a
8841 situation like this:
8843 template <class T>
8844 struct S {
8845 template <class U>
8846 friend struct S;
8847 };
8849 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8850 for `S<int>', not the TEMPLATE_DECL. */
8852 {
8855 }
8858 {
8859 /* The friend template has already been declared. Just
8860 check to see that the declarations match, and install any new
8861 default parameters. We must tsubst the default parameters,
8862 of course. We only need the innermost template parameters
8863 because that is all that redeclare_class_template will look
8864 at. */
8867 {
8868 tree parms;
8869 location_t saved_input_location;
8878 }
8881 }
8882 else
8883 {
8884 /* The friend template has not already been declared. In this
8885 case, the instantiation of the template class will cause the
8886 injection of this template into the global scope. */
8891 /* The new TMPL is not an instantiation of anything, so we
8892 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8893 the new type because that is supposed to be the corresponding
8894 template decl, i.e., TMPL. */
8901 /* Inject this template into the global scope. */
8903 }
8906 {
8909 else
8911 }
8914 }
8916 /* Returns zero if TYPE cannot be completed later due to circularity.
8917 Otherwise returns one. */
8919 static int
8921 {
8931 else
8933 }
8937 /* Apply any attributes which had to be deferred until instantiation
8938 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8939 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8941 static void
8944 {
8946 tree t;
8951 {
8955 }
8958 {
8962 }
8963 else
8967 {
8972 {
8975 {
8982 {
8989 clauses
8993 else
8995 }
8996 /* If the first attribute argument is an identifier, don't
8997 pass it through tsubst. Attributes like mode, format,
8998 cleanup and several target specific attributes expect it
8999 unmodified. */
9002 {
9003 tree chain
9005 in_decl,
9010 chain);
9011 }
9012 else
9018 }
9019 else
9021 }
9024 }
9025 }
9027 /* Perform (or defer) access check for typedefs that were referenced
9028 from within the template TMPL code.
9029 This is a subroutine of instantiate_decl and instantiate_class_template.
9030 TMPL is the template to consider and TARGS is the list of arguments of
9031 that template. */
9033 static void
9035 {
9036 location_t saved_location;
9047 {
9059 /* Make access check error messages point to the location
9060 of the use of the typedef. */
9064 tf_warning_or_error);
9065 }
9067 }
9069 static tree
9071 {
9073 tree typedecl;
9074 tree pbinfo;
9075 tree base_list;
9077 tree fn_context;
9086 /* Figure out which template is being instantiated. */
9090 /* Determine what specialization of the original template to
9091 instantiate. */
9094 {
9097 }
9099 {
9100 /* This TYPE is actually an instantiation of a partial
9101 specialization. We replace the innermost set of ARGS with
9102 the arguments appropriate for substitution. For example,
9103 given:
9105 template <class T> struct S {};
9106 template <class T> struct S<T*> {};
9108 and supposing that we are instantiating S<int*>, ARGS will
9109 presently be {int*} -- but we need {int}. */
9112 }
9113 else
9114 {
9117 }
9119 /* If the template we're instantiating is incomplete, then clearly
9120 there's nothing we can do. */
9124 /* If we've recursively instantiated too many templates, stop. */
9128 /* Now we're really doing the instantiation. Mark the type as in
9129 the process of being defined. */
9132 /* We may be in the middle of deferred access check. Disable
9133 it now. */
9137 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
9142 /* Use #pragma pack from the template context. */
9148 /* Set the input location to the most specialized template definition.
9149 This is needed if tsubsting causes an error. */
9161 {
9164 /* Adjust visibility for template arguments. */
9166 }
9172 /* We should never instantiate a nested class before its enclosing
9173 class; we need to look up the nested class by name before we can
9174 instantiate it, and that lookup should instantiate the enclosing
9175 class. */
9181 {
9182 tree pbase_binfo;
9183 tree pushed_scope;
9186 /* We must enter the scope containing the type, as that is where
9187 the accessibility of types named in dependent bases are
9188 looked up from. */
9191 /* Substitute into each of the bases to determine the actual
9192 basetypes. */
9194 {
9195 tree base;
9201 {
9202 expanded_bases =
9209 }
9212 {
9214 /* Extract the already-expanded base class. */
9216 else
9217 /* Substitute to figure out the base class. */
9219 NULL_TREE);
9227 }
9228 }
9230 /* The list is now in reverse order; correct that. */
9235 }
9236 /* Now call xref_basetypes to set up all the base-class
9237 information. */
9245 /* Now that our base classes are set up, enter the scope of the
9246 class, so that name lookups into base classes, etc. will work
9247 correctly. This is precisely analogous to what we do in
9248 begin_class_definition when defining an ordinary non-template
9249 class, except we also need to push the enclosing classes. */
9252 /* Now members are processed in the order of declaration. */
9255 {
9259 {
9261 {
9262 /* Build new CLASSTYPE_NESTED_UTDS. */
9264 tree newtag;
9270 /* If the member is a class template, then -- even after
9271 substitution -- there may be dependent types in the
9272 template argument list for the class. We increment
9273 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9274 that function will assume that no types are dependent
9275 when outside of a template. */
9285 {
9289 /* Unfortunately, lookup_template_class sets
9290 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9291 instantiation (i.e., for the type of a member
9292 template class nested within a template class.)
9293 This behavior is required for
9294 maybe_process_partial_specialization to work
9295 correctly, but is not accurate in this case;
9296 the TAG is not an instantiation of anything.
9297 (The corresponding TEMPLATE_DECL is an
9298 instantiation, but the TYPE is not.) */
9301 /* Now, we call pushtag to put this NEWTAG into the scope of
9302 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9303 pushtag calling push_template_decl. We don't have to do
9304 this for enums because it will already have been done in
9305 tsubst_enum. */
9309 }
9310 }
9312 {
9313 /* Build new TYPE_METHODS. */
9314 tree r;
9323 /* Instantiate members marked with attribute used. */
9329 }
9332 /* A closure type for a lambda in a default argument for a
9333 member template. Ignore it; it will be instantiated with
9335 else
9336 {
9337 /* Build new TYPE_FIELDS. */
9339 {
9340 tree condition;
9343 condition =
9353 }
9355 {
9356 tree r;
9360 /* The file and line for this declaration, to
9361 assist in error message reporting. Since we
9362 called push_tinst_level above, we don't need to
9363 restore these. */
9373 {
9374 /* A capture pack became multiple fields. */
9377 }
9380 {
9384 {
9385 /* In [temp.inst]:
9387 [t]he initialization (and any associated
9388 side-effects) of a static data member does
9389 not occur unless the static data member is
9390 itself used in a way that requires the
9391 definition of the static data member to
9392 exist.
9394 Therefore, we do not substitute into the
9395 initialized for the static data member here. */
9396 finish_static_data_member_decl
9402 /* Instantiate members marked with attribute used. */
9405 }
9407 {
9408 /* Determine whether R has a valid type and can be
9409 completed later. If R is invalid, then its type
9410 is replaced by error_mark_node. */
9416 {
9419 }
9420 }
9422 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9423 such a thing will already have been added to the field
9424 list by tsubst_enum in finish_member_declaration in the
9425 CLASSTYPE_NESTED_UTDS case above. */
9429 {
9432 }
9433 }
9434 }
9435 }
9436 }
9437 else
9438 {
9441 {
9442 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9448 {
9449 /* template <class T> friend class C; */
9452 }
9454 {
9455 /* template <class T> friend class C::D; */
9461 }
9464 {
9465 /* This could be either
9467 friend class T::C;
9469 when dependent_type_p is false or
9471 template <class U> friend class T::C;
9473 otherwise. */
9476 /* Bump processing_template_decl for correct
9477 dependent_type_p calculation. */
9482 }
9485 {
9486 /* friend class C;
9488 where C hasn't been declared yet. Let's lookup name
9489 from namespace scope directly, bypassing any name that
9490 come from dependent base class. */
9493 /* The call to xref_tag_from_type does injection for friend
9494 classes. */
9496 friend_type =
9500 }
9502 /* friend class C<T>; */
9505 /* Otherwise it's
9507 friend class C;
9509 where C is already declared or
9511 friend class C<int>;
9513 We don't have to do anything in these cases. */
9516 /* Trick make_friend_class into realizing that the friend
9517 we're adding is a template, not an ordinary class. It's
9518 important that we use make_friend_class since it will
9519 perform some error-checking and output cross-reference
9520 information. */
9528 }
9529 else
9530 {
9531 /* Build new DECL_FRIENDLIST. */
9532 tree r;
9534 /* The file and line for this declaration, to
9535 assist in error message reporting. Since we
9536 called push_tinst_level above, we don't need to
9537 restore these. */
9541 {
9544 }
9549 {
9552 }
9553 }
9554 }
9555 }
9558 {
9561 {
9566 /* We need to instantiate the capture list from the template
9567 after we've instantiated the closure members, but before we
9568 consider adding the conversion op. Also keep any captures
9569 that may have been added during instantiation of the op(). */
9571 tree tmpl_cap
9580 }
9581 else
9583 }
9585 /* Set the file and line number information to whatever is given for
9586 the class itself. This puts error messages involving generated
9587 implicit functions at a predictable point, and the same point
9588 that would be used for non-template classes. */
9595 /* We don't instantiate default arguments for member functions. 14.7.1:
9597 The implicit instantiation of a class template specialization causes
9598 the implicit instantiation of the declarations, but not of the
9599 definitions or default arguments, of the class member functions,
9600 member classes, static data members and member templates.... */
9602 /* Some typedefs referenced from within the template code need to be access
9603 checked at template instantiation time, i.e now. These types were
9604 added to the template at parsing time. Let's get those and perform
9605 the access checks then. */
9615 /* The vtable for a template class can be emitted in any translation
9616 unit in which the class is instantiated. When there is no key
9617 method, however, finish_struct_1 will already have added TYPE to
9618 the keyed_classes list. */
9623 }
9625 /* Wrapper for instantiate_class_template_1. */
9627 tree
9629 {
9630 tree ret;
9635 }
9637 static tree
9639 {
9640 tree r;
9646 else
9647 {
9654 }
9656 }
9658 /* Given a function parameter pack TMPL_PARM and some function parameters
9659 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9660 and set *SPEC_P to point at the next point in the list. */
9662 static tree
9664 {
9665 /* Collect all of the extra "packed" parameters into an
9666 argument pack. */
9667 tree parmvec;
9668 tree parmtypevec;
9679 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9684 {
9687 }
9689 /* Build the argument packs. */
9696 }
9698 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9699 NONTYPE_ARGUMENT_PACK. */
9701 static tree
9703 {
9705 }
9707 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9708 pack expansion. */
9710 static bool
9712 {
9717 }
9720 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9722 static tree
9724 {
9731 }
9733 /* This is a subroutine of tsubst_pack_expansion.
9735 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9736 mechanism to store the (non complete list of) arguments of the
9737 substitution and return a non substituted pack expansion, in order
9738 to wait for when we have enough arguments to really perform the
9739 substitution. */
9741 static bool
9745 {
9746 /* If one pack has an expansion and another pack has a normal
9747 argument or if one pack has an empty argument and an another
9748 one hasn't then tsubst_pack_expansion cannot perform the
9749 substitution and need to fall back on the
9750 PACK_EXPANSION_EXTRA mechanism. */
9758 {
9761 parm_pack;
9763 {
9768 else
9770 }
9774 }
9776 }
9778 /* [temp.variadic]/6 says that:
9780 The instantiation of a pack expansion [...]
9781 produces a list E1,E2, ..., En, where N is the number of elements
9782 in the pack expansion parameters.
9784 This subroutine of tsubst_pack_expansion produces one of these Ei.
9786 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9787 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9788 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9789 INDEX is the index 'i' of the element Ei to produce. ARGS,
9790 COMPLAIN, and IN_DECL are the same parameters as for the
9791 tsubst_pack_expansion function.
9793 The function returns the resulting Ei upon successful completion,
9794 or error_mark_node.
9796 Note that this function possibly modifies the ARGS parameter, so
9797 it's the responsibility of the caller to restore it. */
9799 static tree
9801 tree parm_packs,
9803 tree args /* This parm gets
9805 tsubst_flags_t complain,
9806 tree in_decl)
9807 {
9808 tree t;
9811 /* For each parameter pack, change the substitution of the parameter
9812 pack to the ith argument in its argument pack, then expand the
9813 pattern. */
9815 {
9820 ith_elem_is_expansion |=
9823 /* Select the Ith argument from the pack. */
9826 {
9828 {
9832 }
9833 else
9835 }
9836 else
9837 {
9842 {
9844 /* Update the corresponding argument. */
9846 }
9847 else
9848 /* Re-use the ARGUMENT_PACK_SELECT. */
9850 }
9852 }
9854 /* Substitute into the PATTERN with the (possibly altered)
9855 arguments. */
9857 /* Expanding a fixed parameter pack from
9858 coerce_template_parameter_pack. */
9863 else
9866 /* If the Ith argument pack element is a pack expansion, then
9867 the Ith element resulting from the substituting is going to
9868 be a pack expansion as well. */
9873 }
9875 /* Substitute ARGS into T, which is an pack expansion
9876 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9877 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9878 (if only a partial substitution could be performed) or
9879 ERROR_MARK_NODE if there was an error. */
9880 tree
9882 tree in_decl)
9883 {
9884 tree pattern;
9888 tree result;
9896 /* Add in any args remembered from an earlier partial instantiation. */
9901 /* Determine the argument packs that will instantiate the parameter
9902 packs used in the expansion expression. While we're at it,
9903 compute the number of arguments to be expanded and make sure it
9904 is consistent. */
9907 {
9914 {
9918 else
9921 }
9923 {
9926 else
9927 {
9928 /* We can't rely on local_specializations for a parameter
9929 name used later in a function declaration (such as in a
9930 late-specified return type). Even if it exists, it might
9931 have the wrong value for a recursive call. Just make a
9932 dummy decl, since it's only used for its type. */
9935 /* Partial instantiation of the parm_pack, we can't build
9936 up an argument pack yet. */
9938 else
9941 }
9942 }
9945 else
9946 {
9952 }
9959 /* This can only happen if we forget to expand an argument
9960 pack somewhere else. Just return an error, silently. */
9961 {
9965 }
9968 {
9972 /* Don't bother trying to do a partial substitution with
9973 incomplete packs; we'll try again after deduction. */
9980 {
9986 pattern);
9987 else
9990 pattern);
9992 }
9994 /* Keep track of the parameter packs and their corresponding
9995 argument packs. */
9998 }
9999 else
10000 {
10001 /* We can't substitute for this parameter pack. We use a flag as
10002 well as the missing_level counter because function parameter
10003 packs don't have a level. */
10005 }
10006 }
10008 /* If the expansion is just T..., return the matching argument pack. */
10011 {
10016 /* Otherwise use the normal path so we get convert_from_reference. */
10017 }
10019 /* We cannot expand this expansion expression, because we don't have
10020 all of the argument packs we need. */
10022 {
10023 /* We got some full packs, but we can't substitute them in until we
10024 have values for all the packs. So remember these until then. */
10029 }
10031 {
10032 /* There were no real arguments, we're just replacing a parameter
10033 pack with another version of itself. Substitute into the
10034 pattern and return a PACK_EXPANSION_*. The caller will need to
10035 deal with that. */
10039 else
10043 }
10048 {
10049 /* We're in a late-specified return type, so create our own local
10050 specializations map; the current map is either NULL or (in the
10051 case of recursive unification) might have bindings that we don't
10052 want to use or alter. */
10055 }
10057 /* For each argument in each argument pack, substitute into the
10058 pattern. */
10061 {
10063 i,
10065 in_decl);
10068 {
10071 }
10072 }
10074 /* Update ARGS to restore the substitution from parameter packs to
10075 their argument packs. */
10077 {
10083 else
10084 {
10092 /* Update the corresponding argument. */
10096 else
10098 }
10099 }
10102 {
10105 }
10108 }
10110 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
10111 TMPL. We do this using DECL_PARM_INDEX, which should work even with
10112 parameter packs; all parms generated from a function parameter pack will
10113 have the same DECL_PARM_INDEX. */
10115 tree
10117 {
10119 tree patparm;
10122 {
10128 }
10129 else
10130 {
10135 }
10138 }
10140 /* Substitute ARGS into the vector or list of template arguments T. */
10142 static tree
10144 {
10156 {
10158 tree new_arg;
10163 {
10164 /* Substitute into an expansion expression. */
10168 /* Add to the expanded length adjustment the number of
10169 expanded arguments. We subtract one from this
10170 measurement, because the argument pack expression
10171 itself is already counted as 1 in
10172 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
10173 the argument pack is empty. */
10175 }
10177 {
10178 /* Substitute into each of the arguments. */
10184 new_arg,
10198 }
10199 }
10200 else
10209 }
10214 /* Make space for the expanded arguments coming from template
10215 argument packs. */
10217 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10218 arguments for a member template.
10219 In that case each TREE_VEC in ORIG_T represents a level of template
10220 arguments, and ORIG_T won't carry any non defaulted argument count.
10221 It will rather be the nested TREE_VECs that will carry one.
10222 In other words, ORIG_T carries a non defaulted argument count only
10223 if it doesn't contain any nested TREE_VEC. */
10225 {
10229 }
10231 {
10235 {
10238 /* Now expand the template argument pack "in place". */
10241 }
10242 else
10243 {
10245 out++;
10246 }
10247 }
10250 }
10252 /* Return the result of substituting ARGS into the template parameters
10253 given by PARMS. If there are m levels of ARGS and m + n levels of
10254 PARMS, then the result will contain n levels of PARMS. For
10255 example, if PARMS is `template <class T> template <class U>
10256 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10257 result will be `template <int*, double, class V>'. */
10259 static tree
10261 {
10265 /* When substituting into a template, we must set
10266 PROCESSING_TEMPLATE_DECL as the template parameters may be
10267 dependent if they are based on one-another, and the dependency
10268 predicates are short-circuit outside of templates. */
10275 {
10276 tree new_vec =
10281 {
10282 tree tuple;
10294 }
10300 }
10305 }
10307 /* Return the result of substituting ARGS into one template parameter
10308 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10309 parameter and which TREE_PURPOSE is the default argument of the
10310 template parameter. */
10312 static tree
10314 {
10335 }
10337 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10338 type T. If T is not an aggregate or enumeration type, it is
10339 handled as if by tsubst. IN_DECL is as for tsubst. If
10340 ENTERING_SCOPE is nonzero, T is the context for a template which
10341 we are presently tsubst'ing. Return the substituted value. */
10343 static tree
10345 tree args,
10346 tsubst_flags_t complain,
10347 tree in_decl,
10349 {
10354 {
10359 /* Else fall through. */
10363 {
10364 tree argvec;
10365 tree context;
10366 tree r;
10370 /* In "sizeof(X<I>)" we need to evaluate "I". */
10376 /* First, determine the context for the type we are looking
10377 up. */
10380 {
10383 /* If context is a nested class inside a class template,
10384 it may still need to be instantiated (c++/33959). */
10386 }
10388 /* Then, figure out what arguments are appropriate for the
10389 type we are trying to find. For example, given:
10391 template <class T> struct S;
10392 template <class T, class U> void f(T, U) { S<U> su; }
10394 and supposing that we are instantiating f<int, double>,
10395 then our ARGS will be {int, double}, but, when looking up
10396 S we only want {double}. */
10401 else
10402 {
10406 }
10412 }
10413 else
10414 /* This is not a template type, so there's nothing to do. */
10419 }
10420 }
10422 /* Substitute into the default argument ARG (a default argument for
10423 FN), which has the indicated TYPE. */
10425 tree
10427 {
10432 /* This can happen in invalid code. */
10436 /* This default argument came from a template. Instantiate the
10437 default argument here, not in tsubst. In the case of
10438 something like:
10440 template <class T>
10441 struct S {
10442 static T t();
10443 void f(T = t());
10444 };
10446 we must be careful to do name lookup in the scope of S<T>,
10447 rather than in the current class. */
10449 /* The "this" pointer is not valid in a default argument. */
10451 {
10456 }
10459 /* The default argument expression may cause implicitly defined
10460 member functions to be synthesized, which will result in garbage
10461 collection. We must treat this situation as if we were within
10462 the body of function so as to avoid collecting live data on the
10463 stack. */
10471 /* Restore the "this" pointer. */
10473 {
10476 }
10483 /* Make sure the default argument is reasonable. */
10489 }
10491 /* Substitute into all the default arguments for FN. */
10493 static void
10495 {
10496 tree arg;
10497 tree tmpl_args;
10501 /* If this function is not yet instantiated, we certainly don't need
10502 its default arguments. */
10505 /* Don't do this again for clones. */
10510 arg;
10516 complain);
10517 }
10519 /* Substitute the ARGS into the T, which is a _DECL. Return the
10520 result of the substitution. Issue error and warning messages under
10521 control of COMPLAIN. */
10523 static tree
10525 {
10526 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10527 location_t saved_loc;
10532 /* Set the filename and linenumber to improve error-reporting. */
10537 {
10539 {
10540 /* We can get here when processing a member function template,
10541 member class template, or template template parameter. */
10543 tree spec;
10544 tree tmpl_args;
10545 tree full_args;
10548 {
10549 /* Template template parameter is treated here. */
10553 /* If we get a real template back, return it. This can happen in
10554 the context of most_specialized_partial_spec. */
10566 complain);
10569 }
10571 /* We might already have an instance of this template.
10572 The ARGS are for the surrounding class type, so the
10573 full args contain the tsubst'd args for the context,
10574 plus the innermost args from the template decl. */
10578 /* Because this is a template, the arguments will still be
10579 dependent, even after substitution. If
10580 PROCESSING_TEMPLATE_DECL is not set, the dependency
10581 predicates will short-circuit. */
10589 /* If this is a default template template argument,
10590 tsubst might not have changed anything. */
10597 {
10600 }
10602 /* Make a new template decl. It will be similar to the
10603 original, but will record the current template arguments.
10604 We also create a new function declaration, which is just
10605 like the old one, but points to this new template, rather
10606 than the old one. */
10615 {
10616 tree new_type;
10624 /* For a partial specialization, we need to keep pointing to
10625 the primary template. */
10631 }
10632 else
10633 {
10634 tree new_decl;
10646 }
10652 /* The template parameters for this new template are all the
10653 template parameters for the old template, except the
10654 outermost level of parameters. */
10657 complain);
10663 /* Record this non-type partial instantiation. */
10667 }
10671 {
10672 tree ctx;
10675 tree gen_tmpl;
10676 tree type;
10681 /* Nobody should be tsubst'ing into non-template functions. */
10685 {
10686 tree spec;
10689 /* If T is not dependent, just return it. We have to
10690 increment PROCESSING_TEMPLATE_DECL because
10691 value_dependent_expression_p assumes that nothing is
10692 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10699 /* Calculate the most general template of which R is a
10700 specialization, and the complete set of arguments used to
10701 specialize R. */
10704 (DECL_TEMPLATE_RESULT
10710 /* Check to see if we already have this specialization. */
10715 {
10718 }
10720 /* We can see more levels of arguments than parameters if
10721 there was a specialization of a member template, like
10722 this:
10724 template <class T> struct S { template <class U> void f(); }
10725 template <> template <class U> void S<int>::f(U);
10727 Here, we'll be substituting into the specialization,
10728 because that's where we can find the code we actually
10729 want to generate, but we'll have enough arguments for
10730 the most general template.
10732 We also deal with the peculiar case:
10734 template <class T> struct S {
10735 template <class U> friend void f();
10736 };
10737 template <class U> void f() {}
10738 template S<int>;
10739 template void f<double>();
10741 Here, the ARGS for the instantiation of will be {int,
10742 double}. But, we only need as many ARGS as there are
10743 levels of template parameters in CODE_PATTERN. We are
10744 careful not to get fooled into reducing the ARGS in
10745 situations like:
10747 template <class T> struct S { template <class U> void f(U); }
10748 template <class T> template <> void S<T>::f(int) {}
10750 which we can spot because the pattern will be a
10751 specialization in this case. */
10753 parms_depth =
10758 }
10759 else
10760 {
10761 /* This special case arises when we have something like this:
10763 template <class T> struct S {
10764 friend void f<int>(int, double);
10765 };
10767 Here, the DECL_TI_TEMPLATE for the friend declaration
10768 will be an IDENTIFIER_NODE. We are being called from
10769 tsubst_friend_function, and we want only to create a
10770 new decl (R) with appropriate types so that we can call
10771 determine_specialization. */
10773 }
10776 {
10779 else
10783 }
10784 else
10785 {
10788 }
10793 /* If we hit excessive deduction depth, the type is bogus even if
10794 it isn't error_mark_node, so don't build a decl. */
10798 /* We do NOT check for matching decls pushed separately at this
10799 point, as they may not represent instantiations of this
10800 template, and in any case are considered separate under the
10801 discrete model. */
10805 /* Clear out the mangled name and RTL for the instantiation. */
10808 /* Leave DECL_INITIAL set on deleted instantiations. */
10813 /* OpenMP UDRs have the only argument a reference to the declared
10814 type. We want to diagnose if the declared type is a reference,
10815 which is invalid, but as references to references are usually
10816 quietly merged, diagnose it here. */
10818 {
10819 tree argtype
10824 "reference type %qT in "
10828 argtype);
10829 }
10832 /* Type-conversion operator. Reconstruct the name, in
10833 case it's the name of one of the template's parameters. */
10843 /* If this is an instantiation of a function with internal
10844 linkage, we already know what object file linkage will be
10845 assigned to the instantiation. */
10854 /* We'll re-clone as appropriate in instantiate_template. */
10857 /* If we aren't complaining now, return on error before we register
10858 the specialization so that we'll complain eventually. */
10864 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10865 this in the special friend case mentioned above where
10866 GEN_TMPL is NULL. */
10868 {
10873 tree new_r
10876 /* We instantiated this while substituting into
10877 the type earlier (template/friend54.C). */
10880 /* We're not supposed to instantiate default arguments
10881 until they are called, for a template. But, for a
10882 declaration like:
10884 template <class T> void f ()
10885 { extern void g(int i = T()); }
10887 we should do the substitution when the template is
10888 instantiated. We handle the member function case in
10889 instantiate_class_template since the default arguments
10890 might refer to other members of the class. */
10895 }
10896 else
10899 /* Copy the list of befriending classes. */
10903 {
10907 in_decl);
10908 }
10911 {
10917 /* If this is an instantiation of a member template, clone it.
10918 If it isn't, that'll be handled by
10919 clone_constructors_and_destructors. */
10922 }
10933 /* Possibly limit visibility based on template args. */
10936 {
10940 }
10948 }
10952 {
10960 {
10961 /* If there is a local specialization that isn't a
10962 parameter pack, it means that we're doing a "simple"
10963 substitution from inside tsubst_pack_expansion. Just
10964 return the local specialization (which will be a single
10965 parm). */
10972 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10973 the parameters in this function parameter pack. */
10977 {
10980 /* Zero-length parameter packs are boring. Just substitute
10981 into the chain. */
10985 }
10986 else
10987 {
10988 /* All we did was update the type. Make a note of that. */
10991 }
10992 }
10994 /* Loop through all of the parameters we'll build. When T is
10995 a function parameter pack, LEN is the number of expanded
10996 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10999 {
11006 /* We're on the Ith parameter of the function parameter
11007 pack. */
11008 {
11009 /* Get the Ith type. */
11012 /* Rename the parameter to include the index. */
11015 }
11017 /* We're dealing with a normal parameter. */
11025 {
11028 else
11031 }
11041 /* Keep track of the first new parameter we
11042 generate. That's what will be returned to the
11043 caller. */
11047 /* Build a proper chain of parameters when substituting
11048 into a function parameter pack. */
11051 }
11053 /* If cp_unevaluated_operand is set, we're just looking for a
11054 single dummy parameter, so don't keep going. */
11059 /* FIRST_R contains the start of the chain we've built. */
11061 }
11065 {
11072 {
11073 /* This field is a lambda capture pack. Return a TREE_VEC of
11074 the expanded fields to instantiate_class_template_1 and
11075 store them in the specializations hash table as a
11076 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
11080 {
11083 }
11084 else
11085 {
11086 /* All we did was update the type. Make a note of that. */
11089 }
11090 }
11093 {
11096 {
11100 }
11110 /* For bit-fields, DECL_INITIAL gives the number of bits. For
11111 non-bit-fields DECL_INITIAL is a non-static data member
11112 initializer, which gets deferred instantiation. */
11118 {
11119 /* Set up DECL_TEMPLATE_INFO so that we can get at the
11120 NSDMI in perform_member_init. Still set DECL_INITIAL
11121 so that we know there is one. */
11126 }
11127 /* We don't have to set DECL_CONTEXT here; it is set by
11128 finish_member_declaration. */
11136 }
11139 {
11147 }
11148 }
11152 /* We reach here only for member using decls. We also need to check
11153 uses_template_parms because DECL_DEPENDENT_P is not set for a
11154 using-declaration that designates a member of the current
11155 instantiation (c++/53549). */
11158 {
11165 else
11166 {
11169 }
11170 }
11171 else
11172 {
11175 }
11180 {
11183 tree spec;
11185 tree ctx;
11194 {
11195 /* If this is the canonical decl, we don't have to
11196 mess with instantiations, and often we can't (for
11197 typename, template type parms and such). Note that
11198 TYPE_NAME is not correct for the above test if
11199 we've copied the type for a typedef. */
11205 }
11207 /* Check to see if we already have the specialization we
11208 need. */
11211 {
11212 /* T is a static data member or namespace-scope entity.
11213 We have to substitute into namespace-scope variables
11214 (even though such entities are never templates) because
11215 of cases like:
11217 template <class T> void f() { extern T t; }
11219 where the entity referenced is not known until
11220 instantiation time. */
11224 {
11226 complain,
11228 /* If CTX is unchanged, then T is in fact the
11229 specialization we want. That situation occurs when
11230 referencing a static data member within in its own
11231 class. We can use pointer equality, rather than
11232 same_type_p, because DECL_CONTEXT is always
11233 canonical... */
11235 /* ... unless T is a member template; in which
11236 case our caller can be willing to create a
11237 specialization of that template represented
11238 by T. */
11242 }
11245 {
11253 }
11254 }
11255 else
11256 {
11257 /* A local variable. */
11259 /* Subsequent calls to pushdecl will fill this in. */
11262 }
11263 /* If we already have the specialization we need, there is
11264 nothing more to do. */
11266 {
11269 }
11271 /* Create a new node for the specialization we need. */
11274 {
11277 else
11284 }
11286 {
11287 /* Even if the original location is out of scope, the
11288 newly substituted one is not. */
11295 {
11296 /* It may seem that this case cannot occur, since:
11298 typedef void f();
11299 void g() { f x; }
11301 declares a function, not a variable. However:
11303 typedef void f();
11304 template <typename T> void g() { T t; }
11305 template void g<f>();
11307 is an attempt to declare a variable with function
11308 type. */
11310 /* R is not yet sufficiently initialized, so we
11311 just use its name. */
11314 }
11316 /* Wait until cp_finish_decl to set this again, to handle
11317 circular dependency (template/instantiate6.C). */
11322 {
11327 {
11330 }
11332 }
11335 }
11341 /* Clear out the mangled name and RTL for the instantiation. */
11345 /* The initializer must not be expanded until it is required;
11346 see [temp.inst]. */
11352 {
11353 /* Possibly limit visibility based on template args. */
11356 {
11360 }
11362 }
11365 {
11366 /* A static data member declaration is always marked
11367 external when it is declared in-class, even if an
11368 initializer is present. We mimic the non-template
11369 processing here. */
11375 }
11385 /* Preserve a typedef that names a type. */
11387 {
11390 }
11393 }
11398 }
11399 #undef RETURN
11401 out:
11402 /* Restore the file and line information. */
11406 }
11408 /* Substitute into the ARG_TYPES of a function type.
11409 If END is a TREE_CHAIN, leave it and any following types
11410 un-substituted. */
11412 static tree
11414 tree args,
11415 tree end,
11416 tsubst_flags_t complain,
11417 tree in_decl)
11418 {
11419 tree remaining_arg_types;
11423 tree default_arg;
11434 {
11435 /* For a pack expansion, perform substitution on the
11436 entire expression. Later on, we'll handle the arguments
11437 one-by-one. */
11442 /* So that we'll spin through the parameters, one by one. */
11444 else
11445 {
11446 /* We only partially substituted into the parameter
11447 pack. Our type is TYPE_PACK_EXPANSION. */
11450 }
11451 }
11464 {
11466 {
11470 }
11472 }
11473 /* DR 657. */
11477 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11478 top-level qualifiers as required. */
11481 /* We do not substitute into default arguments here. The standard
11482 mandates that they be instantiated only when needed, which is
11483 done in build_over_call. */
11487 {
11488 /* We've instantiated a template before its default arguments
11489 have been parsed. This can happen for a nested template
11490 class, and is not an error unless we require the default
11491 argument in a call of this function. */
11492 remaining_arg_types =
11495 }
11496 else
11497 remaining_arg_types =
11499 }
11502 }
11504 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11505 *not* handle the exception-specification for FNTYPE, because the
11506 initial substitution of explicitly provided template parameters
11507 during argument deduction forbids substitution into the
11508 exception-specification:
11510 [temp.deduct]
11512 All references in the function type of the function template to the
11513 corresponding template parameters are replaced by the specified tem-
11514 plate argument values. If a substitution in a template parameter or
11515 in the function type of the function template results in an invalid
11516 type, type deduction fails. [Note: The equivalent substitution in
11517 exception specifications is done only when the function is instanti-
11518 ated, at which point a program is ill-formed if the substitution
11519 results in an invalid type.] */
11521 static tree
11523 tree args,
11524 tsubst_flags_t complain,
11525 tree in_decl)
11526 {
11527 tree return_type;
11529 tree fntype;
11531 /* The TYPE_CONTEXT is not used for function/method types. */
11534 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
11535 failure. */
11539 {
11540 /* Substitute the argument types. */
11552 {
11553 /* DR 1207: 'this' is in scope in the trailing return type. */
11555 }
11557 /* Substitute the return type. */
11561 {
11564 }
11565 }
11566 else
11567 /* Substitute the return type. */
11572 /* DR 486 clarifies that creation of a function type with an
11573 invalid return type is a deduction failure. */
11576 {
11578 {
11581 else
11583 }
11585 }
11586 /* And DR 657. */
11591 {
11592 /* Substitute the argument types. */
11597 }
11599 /* Construct a new type node and return it. */
11601 {
11606 }
11607 else
11608 {
11610 /* Don't pick up extra function qualifiers from the basetype. */
11613 {
11614 /* [temp.deduct]
11616 Type deduction may fail for any of the following
11617 reasons:
11619 -- Attempting to create "pointer to member of T" when T
11620 is not a class type. */
11623 r);
11625 }
11630 }
11637 }
11639 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11640 ARGS into that specification, and return the substituted
11641 specification. If there is no specification, return NULL_TREE. */
11643 static tree
11645 tree args,
11646 tsubst_flags_t complain,
11647 tree in_decl,
11649 {
11650 tree specs;
11651 tree new_specs;
11656 {
11657 /* A noexcept-specifier. */
11662 {
11663 /* Defer instantiation of noexcept-specifiers to avoid
11664 excessive instantiations (c++/49107). */
11667 {
11668 /* We already partially instantiated this member template,
11669 so combine the new args with the old. */
11674 }
11675 else
11676 {
11679 }
11680 }
11681 else
11682 new_specs = tsubst_copy_and_build
11686 }
11688 {
11691 else
11693 {
11694 tree spec;
11699 {
11700 /* Expand the pack expansion type. */
11703 in_decl);
11709 else
11710 {
11711 /* We're substituting into a member template, so
11712 we got a TYPE_PACK_EXPANSION back. Add that
11713 expansion and move on. */
11717 expanded_specs,
11718 complain);
11721 }
11722 }
11725 {
11728 else
11733 complain);
11734 }
11737 }
11738 }
11740 }
11742 /* Take the tree structure T and replace template parameters used
11743 therein with the argument vector ARGS. IN_DECL is an associated
11744 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11745 Issue error and warning messages under control of COMPLAIN. Note
11746 that we must be relatively non-tolerant of extensions here, in
11747 order to preserve conformance; if we allow substitutions that
11748 should not be allowed, we may allow argument deductions that should
11749 not succeed, and therefore report ambiguous overload situations
11750 where there are none. In theory, we could allow the substitution,
11751 but indicate that it should have failed, and allow our caller to
11752 make sure that the right thing happens, but we don't try to do this
11753 yet.
11755 This function is used for dealing with types, decls and the like;
11756 for expressions, use tsubst_expr or tsubst_copy. */
11758 tree
11760 {
11783 else
11788 /* Reuse typedefs. We need to do this to handle dependent attributes,
11789 such as attribute aligned. */
11792 {
11796 {
11797 /* DECL represents an alias template and we want to
11798 instantiate it. */
11802 }
11806 {
11810 }
11815 else
11816 /* The typedef is from a non-template context. */
11820 {
11822 r = cp_build_qualified_type_real
11826 }
11827 else
11828 {
11829 /* We don't have an instantiation yet, so drop the typedef. */
11834 }
11835 }
11848 {
11874 {
11880 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11881 needed. */
11887 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11888 with TREE_SIDE_EFFECTS that indicates this is not an integral
11889 constant expression. */
11892 {
11895 }
11898 }
11904 {
11917 {
11921 {
11922 /* See through ARGUMENT_PACK_SELECT arguments. */
11924 /* If the selected argument is an expansion E, that most
11925 likely means we were called from
11926 gen_elem_of_pack_expansion_instantiation during the
11927 substituting of pack an argument pack (which Ith
11928 element is a pack expansion, where I is
11929 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11930 In this case, the Ith element resulting from this
11931 substituting is going to be a pack expansion, which
11932 pattern is the pattern of E. Let's return the
11933 pattern of E, and
11934 gen_elem_of_pack_expansion_instantiation will
11935 build the resulting pack expansion from it. */
11937 {
11938 /* Make sure we aren't throwing away arg info. */
11941 }
11942 }
11943 }
11948 {
11950 /* If ARG is an argument pack, we don't actually want to
11951 perform a substitution here, because substitutions
11952 for argument packs are only done
11953 element-by-element. We can get to this point when
11954 substituting the type of a non-type template
11955 parameter pack, when that type actually contains
11956 template parameter packs from an outer template, e.g.,
11958 template<typename... Types> struct A {
11959 template<Types... Values> struct B { };
11960 }; */
11964 {
11970 return cp_build_qualified_type_real
11972 }
11974 {
11975 /* We are processing a type constructed from a
11976 template template parameter. */
11987 /* Consider this code:
11989 template <template <class> class Template>
11990 struct Internal {
11991 template <class Arg> using Bind = Template<Arg>;
11992 };
11994 template <template <class> class Template, class Arg>
11995 using Instantiate = Template<Arg>; //#0
11997 template <template <class> class Template,
11998 class Argument>
11999 using Bind =
12000 Instantiate<Internal<Template>::template Bind,
12001 Argument>; //#1
12003 When #1 is parsed, the
12004 BOUND_TEMPLATE_TEMPLATE_PARM representing the
12005 parameter `Template' in #0 matches the
12006 UNBOUND_CLASS_TEMPLATE representing the argument
12007 `Internal<Template>::template Bind'; We then want
12008 to assemble the type `Bind<Argument>' that can't
12009 be fully created right now, because
12010 `Internal<Template>' not being complete, the Bind
12011 template cannot be looked up in that context. So
12012 we need to "store" `Bind<Argument>' for later
12013 when the context of Bind becomes complete. Let's
12014 store that in a TYPENAME_TYPE. */
12018 argvec),
12019 typename_type,
12020 complain);
12022 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
12023 are resolving nested-types in the signature of a
12024 member function templates. Otherwise ARG is a
12025 TEMPLATE_DECL and is the real template to be
12026 instantiated. */
12034 complain);
12035 return cp_build_qualified_type_real
12037 }
12038 else
12039 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
12041 }
12044 /* This can happen during the attempted tsubst'ing in
12045 unify. This means that we don't yet have any information
12046 about the template parameter in question. */
12049 /* Early in template argument deduction substitution, we don't
12050 want to reduce the level of 'auto', or it will be confused
12051 with a normal template parm in subsequent deduction. */
12055 /* If we get here, we must have been looking at a parm for a
12056 more deeply nested template. Make a new version of this
12057 template parameter, but with a lower level. */
12059 {
12064 {
12066 r = cp_build_qualified_type_real
12070 }
12071 else
12072 {
12083 /* We have reduced the level of the template
12084 template parameter, but not the levels of its
12085 template parameters, so canonical_type_parameter
12086 will not be able to find the canonical template
12087 template parameter for this level. Thus, we
12088 require structural equality checking to compare
12089 TEMPLATE_TEMPLATE_PARMs. */
12093 else
12097 {
12105 }
12106 }
12115 }
12118 }
12121 {
12129 {
12133 }
12136 {
12140 }
12143 {
12147 }
12153 }
12156 /* We should never be tsubsting a binfo. */
12160 /* A vector of template arguments. */
12166 {
12170 /* [temp.deduct]
12172 Type deduction may fail for any of the following
12173 reasons:
12175 -- Attempting to create a pointer to reference type.
12176 -- Attempting to create a reference to a reference type or
12177 a reference to void.
12179 Core issue 106 says that creating a reference to a reference
12180 during instantiation is no longer a cause for failure. We
12181 only enforce this check in strict C++98 mode. */
12185 {
12188 /* We keep track of the last time we issued this error
12189 message to avoid spewing a ton of messages during a
12190 single bad template instantiation. */
12193 {
12198 else
12201 }
12204 }
12208 {
12210 {
12213 type);
12214 else
12216 type);
12217 }
12219 }
12221 {
12225 }
12227 /* In C++0x, during template argument substitution, when there is an
12228 attempt to create a reference to a reference type, reference
12229 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
12231 "If a template-argument for a template-parameter T names a type
12232 that is a reference to a type A, an attempt to create the type
12233 'lvalue reference to cv T' creates the type 'lvalue reference to
12234 A,' while an attempt to create the type type rvalue reference to
12235 cv T' creates the type T"
12236 */
12237 r = cp_build_reference_type
12240 else
12245 /* Will this ever be needed for TYPE_..._TO values? */
12249 }
12251 {
12254 {
12255 /* [temp.deduct]
12257 Type deduction may fail for any of the following
12258 reasons:
12260 -- Attempting to create "pointer to member of T" when T
12261 is not a class type. */
12265 }
12267 {
12271 }
12273 {
12277 }
12280 {
12281 /* The type of the implicit object parameter gets its
12282 cv-qualifiers from the FUNCTION_TYPE. */
12283 tree memptr;
12284 tree method_type
12289 complain);
12290 }
12291 else
12294 complain);
12295 }
12298 {
12299 tree fntype;
12300 tree specs;
12305 /* Substitute the exception specification. */
12313 }
12315 {
12320 /* As an optimization, we avoid regenerating the array type if
12321 it will obviously be the same as T. */
12325 /* These checks should match the ones in create_array_type_for_decl.
12327 [temp.deduct]
12329 The deduction may fail for any of the following reasons:
12331 -- Attempting to create an array with an element type that
12332 is void, a function type, or a reference type, or [DR337]
12333 an abstract class type. */
12339 {
12343 }
12351 {
12354 }
12357 }
12360 {
12370 {
12374 }
12376 {
12377 /* Normally, make_typename_type does not require that the CTX
12378 have complete type in order to allow things like:
12380 template <class T> struct S { typename S<T>::X Y; };
12382 But, such constructs have already been resolved by this
12383 point, so here CTX really should have complete type, unless
12384 it's a partial instantiation. */
12387 {
12391 }
12392 }
12399 {
12402 }
12405 {
12407 {
12411 else
12413 }
12415 {
12419 else
12421 }
12422 }
12424 return cp_build_qualified_type_real
12426 }
12429 {
12441 }
12444 {
12445 tree type;
12461 complain);
12462 }
12465 {
12466 tree type;
12484 else
12485 {
12489 /* In a template ~id could be either a complement expression
12490 or an unqualified-id naming a destructor; if instantiating
12491 it produces an expression, it's not an id-expression or
12492 member access. */
12495 }
12500 }
12503 {
12507 }
12511 {
12513 tree packed_out =
12515 args,
12516 complain,
12517 in_decl);
12520 /* For template nontype argument packs, also substitute into
12521 the type. */
12526 }
12542 /* We should use one of the expression tsubsts for these codes. */
12548 }
12549 }
12551 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12552 type of the expression on the left-hand side of the "." or "->"
12553 operator. */
12555 static tree
12558 {
12559 tree name;
12560 tree qualifying_scope;
12561 tree fns;
12562 tree optype;
12567 /* A baselink indicates a function from a base class. Both the
12568 BASELINK_ACCESS_BINFO and the base class referenced may
12569 indicate bases of the template class, rather than the
12570 instantiated class. In addition, lookups that were not
12571 ambiguous before may be ambiguous now. Therefore, we perform
12572 the lookup again. */
12579 {
12586 }
12594 /* If lookup found a single function, mark it as used at this
12595 point. (If it lookup found multiple functions the one selected
12596 later by overload resolution will be marked as used at that
12597 point.) */
12603 /* Add back the template arguments, if present. */
12608 template_args);
12609 /* Update the conversion operator type. */
12617 qualifying_scope,
12618 object_type);
12620 }
12622 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12623 true if the qualified-id will be a postfix-expression in-and-of
12624 itself; false if more of the postfix-expression follows the
12625 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12626 of "&". */
12628 static tree
12632 {
12633 tree expr;
12634 tree scope;
12635 tree name;
12637 tree template_args;
12642 /* Figure out what name to look up. */
12645 {
12653 }
12654 else
12655 {
12658 }
12660 /* Substitute into the qualifying scope. When there are no ARGS, we
12661 are just trying to simplify a non-dependent expression. In that
12662 case the qualifying scope may be dependent, and, in any case,
12663 substituting will not help. */
12666 {
12669 }
12670 else
12674 {
12679 }
12682 {
12684 {
12685 /* A BIT_NOT_EXPR is used to represent a destructor. */
12687 {
12691 }
12692 else
12695 }
12696 else
12700 {
12702 {
12706 }
12708 }
12709 }
12712 {
12714 scope);
12715 /* Remember that there was a reference to this entity. */
12717 }
12720 {
12726 }
12735 {
12736 expr = (adjust_result_of_qualified_name_lookup
12738 expr = (finish_qualified_id_expr
12742 }
12744 /* Expressions do not generally have reference type. */
12746 /* However, if we're about to form a pointer-to-member, we just
12747 want the referenced member referenced. */
12752 }
12754 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
12755 initializer, DECL is the substituted VAR_DECL. Other arguments are as
12756 for tsubst. */
12758 static tree
12761 {
12768 {
12769 /* If we had an initializer but it
12770 instantiated to nothing,
12771 value-initialize the object. This will
12772 only occur when the initializer was a
12773 pack expansion where the parameter packs
12774 used in that expansion were of length
12775 zero. */
12777 complain);
12780 }
12783 }
12785 /* Like tsubst, but deals with expressions. This function just replaces
12786 template parms; to finish processing the resultant expression, use
12787 tsubst_copy_and_build or tsubst_expr. */
12789 static tree
12791 {
12793 tree r;
12801 {
12806 {
12807 /* We get here for a use of 'this' in an NSDMI. */
12809 && current_function_decl
12813 /* This can happen for a parameter name used later in a function
12814 declaration (such as in a late-specified return type). Just
12815 make a dummy decl, since it's only used for its type. */
12818 /* Give it the template pattern as its context; its true context
12819 hasn't been instantiated yet and this is good enough for
12820 mangling. */
12822 }
12830 {
12831 tree enum_type;
12832 tree v;
12836 /* There is no need to substitute into namespace-scope
12837 enumerators. */
12840 /* If ARGS is NULL, then T is known to be non-dependent. */
12844 /* Unfortunately, we cannot just call lookup_name here.
12845 Consider:
12847 template <int I> int f() {
12848 enum E { a = I };
12849 struct S { void g() { E e = a; } };
12850 };
12852 When we instantiate f<7>::S::g(), say, lookup_name is not
12853 clever enough to find f<7>::a. */
12854 enum_type
12864 /* We didn't find the name. That should never happen; if
12865 name-lookup found it during preliminary parsing, we
12866 should find it again here during instantiation. */
12868 }
12873 {
12874 /* Check for a local specialization set up by
12875 tsubst_pack_expansion. */
12877 {
12881 }
12883 /* When retrieving a capture pack from a generic lambda, remove the
12884 lambda call op's own template argument list from ARGS. Only the
12885 template arguments active for the closure type should be used to
12886 retrieve the pack specialization. */
12892 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12893 tsubst_decl put in the hash table. */
12895 }
12898 {
12899 tree ctx;
12904 {
12907 {
12911 }
12913 }
12914 }
12923 {
12926 {
12927 /* First try name lookup to find the instantiation. */
12930 {
12931 /* Make sure that the one we found is the one we want. */
12936 }
12940 else
12941 {
12942 /* This can happen for a variable used in a
12943 late-specified return type of a local lambda, or for a
12944 local static or constant. Building a new VAR_DECL
12945 should be OK in all those cases. */
12948 {
12949 /* We can't call cp_finish_decl, so handle the
12950 initializer by hand. */
12961 }
12966 {
12969 at_eof);
12971 /* A use of a local constant decays to its value.
12972 FIXME update for core DR 696. */
12974 }
12975 }
12976 /* Remember this for subsequent uses. */
12979 }
12980 }
12981 else
12990 /* An OVERLOAD will always be a non-dependent overload set; an
12991 overload set from function scope will just be represented with an
12992 IDENTIFIER_NODE, and from class scope with a BASELINK. */
13008 {
13009 /* Template template argument like the following example need
13010 special treatment:
13012 template <template <class> class TT> struct C {};
13013 template <class T> struct D {
13014 template <class U> struct E {};
13015 C<E> c; // #1
13016 };
13017 D<int> d; // #2
13019 We are processing the template argument `E' in #1 for
13020 the template instantiation #2. Originally, `E' is a
13021 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
13022 have to substitute this with one having context `D<int>'. */
13026 }
13027 else
13028 /* Ordinary template template argument. */
13039 {
13043 }
13047 {
13057 /* We only want to compute the number of arguments. */
13071 {
13078 else
13081 }
13082 else
13084 }
13086 {
13094 }
13095 /* Fall through */
13111 {
13115 }
13118 {
13119 tree object;
13120 tree name;
13125 {
13129 }
13132 {
13142 }
13147 in_decl);
13148 else
13151 }
13189 {
13193 }
13196 {
13201 }
13204 {
13208 }
13211 {
13219 }
13225 {
13232 }
13235 {
13242 }
13245 {
13252 }
13255 {
13256 /* Substituted template arguments */
13265 }
13268 {
13288 }
13313 /* Fall through. */
13316 {
13319 }
13320 else
13324 /* This is handled by tsubst_copy_and_build. */
13328 {
13332 }
13335 /* We shouldn't have built any of these during initial template
13336 generation. Instead, they should be built during instantiation
13337 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13341 {
13349 }
13367 {
13368 /* Instantiate any typedefs in the type. */
13373 }
13376 /* These can sometimes show up in a partial instantiation, but never
13377 involve template parms. */
13382 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13385 }
13386 }
13388 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13390 static tree
13393 {
13397 {
13403 {
13406 {
13412 }
13413 /* FALLTHRU */
13441 {
13444 {
13451 }
13452 else
13454 }
13484 }
13485 }
13491 }
13493 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13495 static tree
13497 tree in_decl)
13498 {
13499 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13519 {
13522 else
13523 {
13527 }
13528 }
13533 #undef RECUR
13534 }
13536 /* Substitute one OMP_FOR iterator. */
13538 static void
13543 {
13544 #define RECUR(NODE) \
13545 tsubst_expr ((NODE), args, complain, in_decl, \
13546 integral_constant_expression_p)
13555 {
13556 /* We need to jump through some hoops to handle declarations in the
13557 for-init-statement, since we might need to handle auto deduction,
13558 but we need to keep control of initialization. */
13562 }
13563 else
13575 {
13577 {
13578 /* Declare the variable, but don't let that initialize it. */
13583 }
13588 {
13593 }
13594 else
13601 }
13604 {
13605 /* Declare and initialize the variable. */
13608 }
13610 {
13611 tree c;
13613 {
13624 }
13626 {
13631 {
13634 }
13635 }
13636 }
13639 {
13643 }
13644 else
13648 {
13659 {
13667 }
13668 else
13674 {
13680 }
13684 {
13692 }
13693 else
13699 }
13705 #undef RECUR
13706 }
13708 /* Like tsubst_copy for expressions, etc. but also does semantic
13709 processing. */
13711 static tree
13714 {
13715 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13716 #define RECUR(NODE) \
13717 tsubst_expr ((NODE), args, complain, in_decl, \
13718 integral_constant_expression_p)
13721 tree r;
13722 location_t loc;
13734 {
13736 {
13737 tree_stmt_iterator i;
13741 }
13756 else
13765 {
13767 tree init;
13773 {
13776 tree decl;
13784 else
13786 }
13788 {
13789 /* Don't build up decls for a variadic capture proxy, we'll
13790 instantiate the elements directly as needed. */
13792 }
13793 else
13794 {
13798 {
13799 /* By marking the declaration as instantiated, we avoid
13800 trying to instantiate it. Since instantiate_decl can't
13801 handle local variables, and since we've already done
13802 all that needs to be done, that's the right thing to
13803 do. */
13808 /* Anonymous aggregates are a special case. */
13811 {
13814 {
13818 }
13820 }
13826 {
13831 }
13832 else
13833 {
13838 {
13839 /* For __PRETTY_FUNCTION__ we have to adjust the
13840 initializer. */
13844 }
13845 else
13849 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13852 }
13853 }
13854 }
13857 }
13872 {
13882 }
13909 {
13913 }
13921 else
13929 else
13950 {
13954 }
13958 {
13960 tree label;
13965 }
13971 /* Computed goto's must be tsubst'd into. On the other hand,
13972 non-computed gotos must not be; the identifier in question
13973 will have no binding. */
13975 else
13981 {
13997 }
14002 {
14007 }
14008 else
14009 {
14014 else
14021 else
14027 else
14029 }
14033 {
14037 {
14039 /* Prevent instantiate_decl from trying to instantiate
14040 this variable. We've already done all that needs to be
14041 done. */
14044 }
14049 }
14055 {
14056 /* Local classes are not independent templates; they are
14057 instantiated along with their containing function. And this
14058 way we don't have to deal with pushing out of one local class
14059 to instantiate a member of another local class. */
14060 tree fn;
14061 /* Closures are handled by the LAMBDA_EXPR. */
14067 }
14071 {
14072 tree condition;
14075 condition =
14077 args,
14086 }
14111 {
14120 {
14125 }
14137 integral_constant_expression_p);
14146 else
14147 {
14155 }
14158 }
14217 {
14222 {
14225 }
14231 }
14232 else
14233 {
14240 {
14243 }
14246 {
14251 {
14254 }
14260 }
14261 else
14262 {
14266 }
14269 }
14273 {
14279 {
14283 {
14288 }
14292 }
14293 else
14294 {
14299 }
14300 }
14304 {
14308 }
14328 /* If the first operand was a statement, we're done with it. */
14332 complain));
14344 integral_constant_expression_p));
14345 }
14348 out:
14351 #undef RECUR
14352 #undef RETURN
14353 }
14355 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14356 function. For description of the body see comment above
14357 cp_parser_omp_declare_reduction_exprs. */
14359 static void
14361 {
14367 tree_stmt_iterator tsi;
14378 {
14397 }
14399 {
14419 }
14420 }
14422 /* T is a postfix-expression that is not being used in a function
14423 call. Return the substituted version of T. */
14425 static tree
14427 tsubst_flags_t complain,
14428 tree in_decl)
14429 {
14433 else
14439 }
14441 /* Like tsubst but deals with expressions and performs semantic
14442 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14444 tree
14446 tree args,
14447 tsubst_flags_t complain,
14448 tree in_decl,
14451 {
14452 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14453 #define RECUR(NODE) \
14454 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14456 integral_constant_expression_p)
14459 location_t loc;
14468 /* N3276 decltype magic only applies to calls at the top level or on the
14469 right side of a comma. */
14474 {
14477 /* Fall through. */
14479 {
14480 tree decl;
14481 cp_id_kind idk;
14486 {
14489 }
14491 /* Look up the name. */
14494 /* By convention, expressions use ERROR_MARK_NODE to indicate
14495 failure, not NULL_TREE. */
14501 integral_constant_expression_p,
14509 input_location);
14513 {
14517 }
14519 }
14522 {
14523 tree object;
14531 {
14534 }
14535 else
14542 else
14544 }
14547 {
14551 {
14552 /* A type conversion to reference type will be enclosed in
14553 such an indirect ref, but the substitution of the cast
14554 will have also added such an indirect ref. */
14557 }
14558 else
14562 }
14565 {
14569 }
14572 {
14579 flags));
14580 }
14583 {
14587 }
14594 {
14595 tree type;
14601 {
14606 }
14612 {
14630 }
14633 }
14667 else
14669 in_decl);
14704 {
14709 tree r = build_x_binary_op
14711 op0,
14713 ? ERROR_MARK
14715 op1,
14717 ? ERROR_MARK
14725 }
14728 {
14732 }
14745 {
14754 }
14758 /* Fall through */
14761 {
14762 tree r;
14768 {
14769 /* When there are no ARGS, we are trying to evaluate a
14770 non-dependent expression from the parser. Trying to do
14771 the substitutions may not work. */
14774 }
14775 else
14776 {
14781 else
14784 /*integral_constant_expression_p=*/
14788 }
14792 else
14796 {
14798 {
14800 {
14804 }
14805 else
14809 }
14811 }
14813 }
14816 {
14826 }
14842 {
14846 tree r = build_x_modify_expr
14849 /* TREE_NO_WARNING must be set if either the expression was
14850 parenthesized or it uses an operator such as >>= rather
14851 than plain assignment. In the former case, it was already
14852 set and must be copied. In the latter case,
14853 build_x_modify_expr sets it and it must not be reset
14854 here. */
14859 }
14864 /* Remember that there was a reference to this entity. */
14870 {
14875 tree ret;
14879 else
14880 {
14884 }
14886 /* If there was an initializer in the original tree, but it
14887 instantiated to an empty list, then we should pass a
14888 non-NULL empty vector to tell build_new that it was an
14889 empty initializer() rather than no initializer. This can
14890 only happen when the initializer is a pack expansion whose
14891 parameter packs are of length zero. */
14894 else
14895 {
14899 else
14900 {
14903 }
14904 }
14910 complain);
14918 }
14921 {
14927 complain));
14928 }
14931 {
14935 integral_constant_expression_p);
14937 op0,
14940 }
14943 {
14944 tree function;
14949 tree ret;
14952 /* When we parsed the expression, we determined whether or
14953 not Koenig lookup should be performed. */
14956 {
14961 }
14963 {
14964 /* Do nothing; calling tsubst_copy_and_build on an identifier
14965 would incorrectly perform unqualified lookup again.
14967 Note that we can also have an IDENTIFIER_NODE if the earlier
14968 unqualified lookup found a member function; in that case
14969 koenig_p will be false and we do want to do the lookup
14970 again to find the instantiated member function.
14972 FIXME but doing that causes c++/15272, so we need to stop
14973 using IDENTIFIER_NODE in that situation. */
14975 }
14976 else
14977 {
14979 {
14985 }
14986 else
14991 /* Avoid error about taking the address of a constructor. */
14995 in_decl,
14997 integral_constant_expression_p);
15001 }
15006 {
15011 else
15012 {
15013 /* Expand the pack expansion and push each entry onto
15014 CALL_ARGS. */
15017 {
15022 {
15027 }
15028 }
15029 else
15030 {
15031 /* A partial substitution. Add one entry. */
15033 }
15034 }
15035 }
15037 /* We do not perform argument-dependent lookup if normal
15038 lookup finds a non-function, in accordance with the
15039 expected resolution of DR 218. */
15042 /* If lookup found a member function, the Koenig lookup is
15043 not appropriate, even if an unqualified-name was used
15044 to denote the function. */
15047 /* Only do this when substitution turns a dependent call
15048 into a non-dependent call. */
15055 {
15057 {
15058 /* For backwards compatibility and good diagnostics, try
15059 the unqualified lookup again if we aren't in SFINAE
15060 context. */
15061 tree unq = (tsubst_copy_and_build
15063 integral_constant_expression_p));
15068 {
15077 "%qD was not declared in this scope, "
15078 "and no declarations were found by "
15079 "argument-dependent lookup at the point "
15081 {
15085 {
15087 input_location);
15089 "declarations in dependent base %qT are "
15095 else
15099 }
15100 else
15103 }
15105 }
15106 }
15108 {
15113 }
15114 }
15116 /* Remember that there was a reference to this entity. */
15120 /* Put back tf_decltype for the actual call. */
15125 complain);
15127 {
15142 complain);
15143 else
15144 ret = (build_new_method_call
15149 complain));
15150 }
15151 else
15154 koenig_p,
15155 complain);
15160 }
15163 {
15169 {
15171 {
15176 }
15177 else
15178 {
15183 }
15185 }
15186 else
15187 {
15190 }
15194 }
15197 {
15202 input_location));
15203 }
15206 {
15214 {
15215 /* We have pack expansions, so expand those and
15216 create a new list out of it. */
15219 tree chain;
15222 /* Expand the argument expressions. */
15230 /* Build the rest of the list. */
15235 /* Determine the number of arguments. */
15237 {
15240 }
15243 else
15244 {
15245 /* Since we only performed a partial substitution into
15246 the argument pack, we only RETURN (a single list
15247 node. */
15254 }
15256 /* Convert the argument vectors into a TREE_LIST */
15259 {
15260 /* Grab the Ith values. */
15261 i--;
15264 value
15268 /* Build the list (backwards). */
15270 }
15273 }
15289 }
15292 {
15293 tree object;
15294 tree object_type;
15295 tree member;
15296 tree r;
15300 /* Remember that there was a reference to this entity. */
15310 else
15318 {
15320 {
15325 {
15328 }
15330 {
15335 }
15336 }
15337 }
15340 {
15341 /* Lookup the template functions now that we know what the
15342 scope is. */
15350 {
15353 args);
15354 member = (adjust_result_of_qualified_name_lookup
15356 object_type));
15357 }
15358 else
15359 {
15361 input_location);
15363 }
15364 }
15368 {
15370 {
15374 else
15377 }
15379 }
15381 {
15386 }
15390 complain);
15394 }
15401 {
15409 tree r;
15414 /* digest_init will do the wrong thing if we let it. */
15418 /* We do not want to process the index of aggregate
15419 initializers as they are identifier nodes which will be
15420 looked up by digest_init. */
15426 {
15428 /* An identifier index is looked up in the type
15429 being initialized, not the current scope. */
15434 {
15435 /* Substitute into the pack expansion. */
15437 in_decl);
15441 ;
15443 /* Just move the argument into place. */
15445 else
15446 {
15447 /* Update the length of the final CONSTRUCTOR
15448 arguments vector, and note that we will need to
15449 copy.*/
15452 }
15453 }
15454 else
15456 }
15459 {
15464 {
15466 {
15471 }
15472 else
15474 }
15475 }
15485 }
15488 {
15491 {
15494 }
15495 else
15496 {
15499 }
15500 }
15506 {
15507 /* We don't build decls for an instantiation of a
15508 variadic capture proxy, we instantiate the elements
15509 when needed. */
15512 }
15513 /* Fall through */
15516 {
15518 /* ??? We're doing a subset of finish_id_expression here. */
15520 && !processing_template_decl
15521 && !cp_unevaluated_operand
15524 {
15526 /* Replace an evaluated use of the thread_local variable with
15527 a call to its wrapper. */
15529 }
15534 /* If the original type was a reference, we'll be wrapped in
15535 the appropriate INDIRECT_REF. */
15538 }
15541 {
15545 }
15552 {
15563 }
15566 {
15572 integral_constant_expression_p);
15576 /* If the resulting list of expression statement is empty,
15577 fold it further into void_node. */
15582 }
15585 {
15599 /* For a function scope, we want to use tsubst so that we don't
15600 complain about referring to an auto function before its return
15601 type has been deduced. Otherwise, we want to use tsubst_copy so
15602 that we look up the existing field/parameter/variable rather
15603 than build a new one. */
15608 {
15609 /* Look up the parameter we want directly, as tsubst_copy
15610 doesn't do what we need. */
15616 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15619 }
15620 else
15629 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15631 /* Now that we know visibility, instantiate the type so we have a
15632 declaration of the op() for later calls to lambda_function. */
15638 }
15641 /* We can get here for a constant initializer of non-dependent type.
15642 FIXME stop folding in cp_parser_initializer_clause. */
15643 {
15645 complain);
15647 }
15651 integral_constant_expression_p));
15657 {
15662 complain));
15663 }
15666 /* Handle Objective-C++ constructs, if appropriate. */
15667 {
15668 tree subst
15673 }
15675 }
15677 #undef RECUR
15678 #undef RETURN
15679 out:
15682 }
15684 /* Verify that the instantiated ARGS are valid. For type arguments,
15685 make sure that the type's linkage is ok. For non-type arguments,
15686 make sure they are constants if they are integral or enumerations.
15687 Emit an error under control of COMPLAIN, and return TRUE on error. */
15689 static bool
15691 {
15695 {
15705 }
15707 {
15708 /* [basic.link]: A name with no linkage (notably, the name
15709 of a class or enumeration declared in a local scope)
15710 shall not be used to declare an entity with linkage.
15711 This implies that names with no linkage cannot be used as
15712 template arguments
15714 DR 757 relaxes this restriction for C++0x. */
15719 {
15720 /* DR 488 makes use of a type with no linkage cause
15721 type deduction to fail. */
15723 {
15726 else
15729 }
15731 }
15732 /* In order to avoid all sorts of complications, we do not
15733 allow variably-modified types as template arguments. */
15735 {
15739 }
15740 }
15741 /* Class template and alias template arguments should be OK. */
15743 ;
15744 /* A non-type argument of integral or enumerated type must be a
15745 constant. */
15750 {
15754 }
15756 }
15758 static bool
15760 {
15765 {
15768 }
15772 }
15774 /* We're out of SFINAE context now, so generate diagnostics for the access
15775 errors we saw earlier when instantiating D from TMPL and ARGS. */
15777 static void
15779 {
15791 }
15793 /* Instantiate the indicated variable, function, or alias template TMPL with
15794 the template arguments in TARG_PTR. */
15796 static tree
15798 {
15800 tree fndecl;
15801 tree gen_tmpl;
15802 tree spec;
15810 /* If this function is a clone, handle it specially. */
15812 {
15813 tree spec;
15814 tree clone;
15816 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15817 DECL_CLONED_FUNCTION. */
15823 /* Look for the clone. */
15827 /* We should always have found the clone by now. */
15830 }
15835 /* Check to see if we already have this specialization. */
15838 /* The TMPL is a partial instantiation. To get a full set of
15839 arguments we must add the arguments used to perform the
15840 partial instantiation. */
15842 targ_ptr);
15844 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15845 but it doesn't seem to be on the hot path. */
15854 {
15856 {
15860 }
15862 }
15865 complain))
15868 /* We are building a FUNCTION_DECL, during which the access of its
15869 parameters and return types have to be checked. However this
15870 FUNCTION_DECL which is the desired context for access checking
15871 is not built yet. We solve this chicken-and-egg problem by
15872 deferring all checks until we have the FUNCTION_DECL. */
15875 /* Instantiation of the function happens in the context of the function
15876 template, not the context of the overload resolution we're doing. */
15878 /* If there are dependent arguments, e.g. because we're doing partial
15879 ordering, make sure processing_template_decl stays set. */
15883 {
15887 }
15892 {
15893 /* We need to determine if we're using a partial or explicit
15894 specialization now, because the type of the variable could be
15895 different. */
15901 {
15905 }
15906 }
15908 /* Substitute template parameters to obtain the specialization. */
15915 {
15918 }
15920 /* The DECL_TI_TEMPLATE should always be the immediate parent
15921 template, not the most general template. */
15924 /* Now we know the specialization, compute access previously
15925 deferred. */
15932 /* If we've just instantiated the main entry point for a function,
15933 instantiate all the alternate entry points as well. We do this
15934 by cloning the instantiation of the main entry point, not by
15935 instantiating the template clones. */
15940 {
15942 {
15943 /* Remember to reinstantiate when we're out of SFINAE so the user
15944 can see the errors. */
15946 }
15948 }
15950 }
15952 /* Wrapper for instantiate_template_1. */
15954 tree
15956 {
15957 tree ret;
15962 }
15964 /* Instantiate the alias template TMPL with ARGS. Also push a template
15965 instantiation level, which instantiate_template doesn't do because
15966 functions and variables have sufficient context established by the
15967 callers. */
15969 static tree
15971 {
15978 {
15981 }
15983 args =
15991 /* We can't free this if a pending_template entry or last_error_tinst_level
15992 is pointing at it. */
15998 }
16000 /* PARM is a template parameter pack for FN. Returns true iff
16001 PARM is used in a deducible way in the argument list of FN. */
16003 static bool
16005 {
16008 {
16010 tree packs;
16016 {
16017 /* The template parameter pack is used in a function parameter
16018 pack. If this is the end of the parameter list, the
16019 template parameter pack is deducible. */
16022 else
16023 /* Otherwise, not. Well, it could be deduced from
16024 a non-pack parameter, but doing so would end up with
16025 a deduction mismatch, so don't bother. */
16027 }
16028 }
16029 /* The template parameter pack isn't used in any function parameter
16030 packs, but it might be used deeper, e.g. tuple<Args...>. */
16032 }
16034 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
16035 NARGS elements of the arguments that are being used when calling
16036 it. TARGS is a vector into which the deduced template arguments
16037 are placed.
16039 Returns either a FUNCTION_DECL for the matching specialization of FN or
16040 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
16041 true, diagnostics will be printed to explain why it failed.
16043 If FN is a conversion operator, or we are trying to produce a specific
16044 specialization, RETURN_TYPE is the return type desired.
16046 The EXPLICIT_TARGS are explicit template arguments provided via a
16047 template-id.
16049 The parameter STRICT is one of:
16051 DEDUCE_CALL:
16052 We are deducing arguments for a function call, as in
16053 [temp.deduct.call].
16055 DEDUCE_CONV:
16056 We are deducing arguments for a conversion function, as in
16057 [temp.deduct.conv].
16059 DEDUCE_EXACT:
16060 We are deducing arguments when doing an explicit instantiation
16061 as in [temp.explicit], when determining an explicit specialization
16062 as in [temp.expl.spec], or when taking the address of a function
16063 template, as in [temp.deduct.funcaddr]. */
16065 tree
16067 tree explicit_targs,
16068 tree targs,
16071 tree return_type,
16072 unification_kind_t strict,
16076 {
16077 tree parms;
16078 tree fntype;
16086 tree tinst;
16092 /* In C++0x, it's possible to have a function template whose type depends
16093 on itself recursively. This is most obvious with decltype, but can also
16094 occur with enumeration scope (c++/48969). So we need to catch infinite
16095 recursion and reject the substitution at deduction time; this function
16096 will return error_mark_node for any repeated substitution.
16098 This also catches excessive recursion such as when f<N> depends on
16099 f<N-1> across all integers, and returns error_mark_node for all the
16100 substitutions back up to the initial one.
16102 This is, of course, not reentrant. */
16112 {
16113 /* [temp.deduct]
16115 The specified template arguments must match the template
16116 parameters in kind (i.e., type, nontype, template), and there
16117 must not be more arguments than there are parameters;
16118 otherwise type deduction fails.
16120 Nontype arguments must match the types of the corresponding
16121 nontype template parameters, or must be convertible to the
16122 types of the corresponding nontype parameters as specified in
16123 _temp.arg.nontype_, otherwise type deduction fails.
16125 All references in the function type of the function template
16126 to the corresponding template parameters are replaced by the
16127 specified template argument values. If a substitution in a
16128 template parameter or in the function type of the function
16129 template results in an invalid type, type deduction fails. */
16134 /* Adjust any explicit template arguments before entering the
16135 substitution context. */
16136 explicit_targs
16138 complain,
16144 /* Substitute the explicit args into the function type. This is
16145 necessary so that, for instance, explicitly declared function
16146 arguments can match null pointed constants. If we were given
16147 an incomplete set of explicit args, we must not do semantic
16148 processing during substitution as we could create partial
16149 instantiations. */
16151 {
16156 /* Dig out the actual parm. */
16159 {
16162 }
16164 {
16167 }
16170 /* No explicit argument for this template parameter. */
16174 {
16175 /* Mark the argument pack as "incomplete". We could
16176 still deduce more arguments during unification.
16177 We remove this mark in type_unification_real. */
16179 {
16183 }
16185 /* We have some incomplete argument packs. */
16187 }
16188 }
16192 {
16195 }
16198 /* Ignore any access checks; we'll see them again in
16199 instantiate_template and they might have the wrong
16200 access path at this point. */
16212 /* Place the explicitly specified arguments in TARGS. */
16215 }
16217 /* Never do unification on the 'this' parameter. */
16221 {
16230 }
16232 /* We allow incomplete unification without an error message here
16233 because the standard doesn't seem to explicitly prohibit it. Our
16234 callers must be ready to deal with unification failures in any
16235 event. */
16238 /* If we aren't explaining yet, push tinst context so we can see where
16239 any errors (e.g. from class instantiations triggered by instantiation
16240 of default template arguments) come from. If we are explaining, this
16241 context is redundant. */
16243 {
16246 }
16248 /* type_unification_real will pass back any access checks from default
16249 template argument substitution. */
16261 /* Now that we have bindings for all of the template arguments,
16262 ensure that the arguments deduced for the template template
16263 parameters have compatible template parameter lists. We cannot
16264 check this property before we have deduced all template
16265 arguments, because the template parameter types of a template
16266 template parameter might depend on prior template parameters
16267 deduced after the template template parameter. The following
16268 ill-formed example illustrates this issue:
16270 template<typename T, template<T> class C> void f(C<5>, T);
16272 template<int N> struct X {};
16274 void g() {
16275 f(X<5>(), 5l); // error: template argument deduction fails
16276 }
16278 The template parameter list of 'C' depends on the template type
16279 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
16280 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
16281 time that we deduce 'C'. */
16284 {
16287 }
16289 /* All is well so far. Now, check:
16291 [temp.deduct]
16293 When all template arguments have been deduced, all uses of
16294 template parameters in nondeduced contexts are replaced with
16295 the corresponding deduced argument values. If the
16296 substitution results in an invalid type, as described above,
16297 type deduction fails. */
16300 {
16303 }
16305 /* Also collect access checks from the instantiation. */
16318 /* Now perform any access checks encountered during substitution. */
16325 /* If we're looking for an exact match, check that what we got
16326 is indeed an exact match. It might not be if some template
16327 parameters are used in non-deduced contexts. But don't check
16328 for an exact match if we have dependent template arguments;
16329 in that case we're doing partial ordering, and we already know
16330 that we have two candidates that will provide the actual type. */
16332 {
16336 tree sarg
16342 {
16346 }
16347 }
16351 fail:
16354 {
16356 /* Reset once we're all the way out. */
16358 }
16360 /* We can't free this if a pending_template entry or last_error_tinst_level
16361 is pointing at it. */
16367 }
16369 /* Adjust types before performing type deduction, as described in
16370 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16371 sections are symmetric. PARM is the type of a function parameter
16372 or the return type of the conversion function. ARG is the type of
16373 the argument passed to the call, or the type of the value
16374 initialized with the result of the conversion function.
16375 ARG_EXPR is the original argument expression, which may be null. */
16377 static int
16381 tree arg_expr)
16382 {
16386 {
16391 {
16392 /* Swap PARM and ARG throughout the remainder of this
16393 function; the handling is precisely symmetric since PARM
16394 will initialize ARG rather than vice versa. */
16399 }
16402 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16403 too, but here handle it by stripping the reference from PARM
16404 rather than by adding it to ARG. */
16412 /* Nothing else to do in this case. */
16417 }
16420 {
16421 /* [temp.deduct.call]
16423 If P is not a reference type:
16425 --If A is an array type, the pointer type produced by the
16426 array-to-pointer standard conversion (_conv.array_) is
16427 used in place of A for type deduction; otherwise,
16429 --If A is a function type, the pointer type produced by
16430 the function-to-pointer standard conversion
16431 (_conv.func_) is used in place of A for type deduction;
16432 otherwise,
16434 --If A is a cv-qualified type, the top level
16435 cv-qualifiers of A's type are ignored for type
16436 deduction. */
16441 else
16443 }
16445 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16446 of the form T&&, where T is a template parameter, and the argument
16447 is an lvalue, T is deduced as A& */
16453 /* try_one_overload doesn't provide an arg_expr, but
16454 functions are always lvalues. */
16458 /* [temp.deduct.call]
16460 If P is a cv-qualified type, the top level cv-qualifiers
16461 of P's type are ignored for type deduction. If P is a
16462 reference type, the type referred to by P is used for
16463 type deduction. */
16466 {
16469 }
16471 /* DR 322. For conversion deduction, remove a reference type on parm
16472 too (which has been swapped into ARG). */
16477 }
16479 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16480 template which does contain any deducible template parameters; check if
16481 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16482 unify_one_argument. */
16484 static int
16487 {
16488 tree type;
16492 else
16499 {
16503 }
16505 {
16510 }
16514 else
16516 }
16520 /* Returns true iff the expression EXPR is one from which a template
16521 argument can be deduced. In other words, if it's an undecorated
16522 use of a template non-type parameter. */
16524 static bool
16526 {
16528 }
16530 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16531 deducible way; that is, if it has a max value of <PARM> - 1. */
16533 static bool
16535 {
16544 }
16546 /* Returns true iff the template arguments ARGS use a template parameter
16547 in a deducible way. */
16549 static bool
16551 {
16553 {
16558 else
16559 {
16566 else
16568 }
16571 }
16573 }
16575 /* Returns true iff TYPE contains any deducible references to template
16576 parameters, as per 14.8.2.5. */
16578 static bool
16580 {
16584 /* T
16585 cv-list T
16586 TT<T>
16587 TT<i>
16588 TT<> */
16593 /* T*
16594 T&
16595 T&& */
16599 /* T[integer-constant ]
16600 type [i] */
16605 /* T type ::*
16606 type T::*
16607 T T::*
16608 T (type ::*)()
16609 type (T::*)()
16610 type (type ::*)(T)
16611 type (T::*)(T)
16612 T (type ::*)(T)
16613 T (T::*)()
16614 T (T::*)(T) */
16617 || (uses_deducible_template_parms
16620 /* template-name <T> (where template-name refers to a class template)
16621 template-name <i> (where template-name refers to a class template) */
16628 /* type (T)
16629 T()
16630 T(T) */
16633 {
16642 }
16645 }
16647 /* Subroutine of type_unification_real and unify_pack_expansion to
16648 handle unification of a single P/A pair. Parameters are as
16649 for those functions. */
16651 static int
16655 {
16662 /* We can't deduce anything from this, but we might get all the
16663 template args from other function args. */
16666 /* Implicit conversions (Clause 4) will be performed on a function
16667 argument to convert it to the type of the corresponding function
16668 parameter if the parameter type contains no template-parameters that
16669 participate in template argument deduction. */
16671 /* For function parameters that contain no template-parameters at all,
16672 we have historically checked for convertibility in order to shortcut
16673 consideration of this candidate. */
16675 explain_p);
16678 /* For function parameters with only non-deducible template parameters,
16679 just return. */
16683 {
16685 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16686 | UNIFY_ALLOW_MORE_CV_QUAL
16700 }
16702 /* We only do these transformations if this is the top-level
16703 parameter_type_list in a call or declaration matching; in other
16704 situations (nested function declarators, template argument lists) we
16705 won't be comparing a type to an expression, and we don't do any type
16706 adjustments. */
16708 {
16710 {
16713 {
16714 /* [temp.deduct.type] A template-argument can be
16715 deduced from a pointer to function or pointer
16716 to member function argument if the set of
16717 overloaded functions does not contain function
16718 templates and at most one of a set of
16719 overloaded functions provides a unique
16720 match. */
16727 }
16733 }
16735 arg_strict |=
16737 }
16738 else
16743 /* For deduction from an init-list we need the actual list. */
16747 }
16749 /* Most parms like fn_type_unification.
16751 If SUBR is 1, we're being called recursively (to unify the
16752 arguments of a function or method parameter of a function
16753 template).
16755 CHECKS is a pointer to a vector of access checks encountered while
16756 substituting default template arguments. */
16758 static int
16760 tree targs,
16761 tree xparms,
16765 unification_kind_t strict,
16769 {
16774 tree parms;
16783 /* Reset the number of non-defaulted template arguments contained
16784 in TARGS. */
16787 again:
16795 {
16800 /* For a function parameter pack that occurs at the end of the
16801 parameter-declaration-list, the type A of each remaining
16802 argument of the call is compared with the type P of the
16803 declarator-id of the function parameter pack. */
16809 /* For a function parameter pack that does not occur at the
16810 end of the parameter-declaration-list, the type of the
16811 parameter pack is a non-deduced context. */
16820 }
16825 {
16826 /* Unify the remaining arguments with the pack expansion type. */
16827 tree argvec;
16830 /* Allocate a TREE_VEC and copy in all of the arguments */
16835 /* Copy the parameter into parmvec. */
16841 /* Advance to the end of the list of parameters. */
16843 }
16845 /* Fail if we've reached the end of the parm list, and more args
16846 are present, and the parm list isn't variadic. */
16849 /* Fail if parms are left and they don't have default values and
16850 they aren't all deduced as empty packs (c++/57397). This is
16851 consistent with sufficient_parms_p. */
16854 {
16858 do
16859 {
16862 count++;
16864 }
16868 type_pack_p);
16869 }
16872 {
16873 tsubst_flags_t complain = (explain_p
16874 ? tf_warning_or_error
16878 {
16882 /* Clear the "incomplete" flags on all argument packs now so that
16883 substituting them into later default arguments works. */
16885 {
16888 }
16894 /* If this is an undeduced nontype parameter that depends on
16895 a type parameter, try another pass; its type may have been
16896 deduced from a later argument than the one from which
16897 this parameter can be deduced. */
16903 /* Core issue #226 (C++0x) [temp.deduct]:
16905 If a template argument has not been deduced, its
16906 default template argument, if any, is used.
16908 When we are in C++98 mode, TREE_PURPOSE will either
16909 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16910 to explicitly check cxx_dialect here. */
16912 {
16927 else
16928 {
16930 /* The position of the first default template argument,
16931 is also the number of non-defaulted arguments in TARGS.
16932 Record that. */
16936 }
16937 }
16939 /* If the type parameter is a parameter pack, then it will
16940 be deduced to an empty parameter pack. */
16942 {
16943 tree arg;
16946 {
16950 }
16951 else
16958 }
16961 }
16962 }
16963 #ifdef ENABLE_CHECKING
16966 #endif
16969 }
16971 /* Subroutine of type_unification_real. Args are like the variables
16972 at the call site. ARG is an overloaded function (or template-id);
16973 we try deducing template args from each of the overloads, and if
16974 only one succeeds, we go with that. Modifies TARGS and returns
16975 true on success. */
16977 static bool
16979 tree targs,
16980 tree parm,
16981 tree arg,
16982 unification_kind_t strict,
16985 {
16992 {
16995 }
16996 else
17000 /* Handle `&x' where `x' is some static or non-static member
17001 function name. */
17007 /* Strip baselink information. */
17012 {
17013 /* If we got some explicit template args, we need to plug them into
17014 the affected templates before we try to unify, in case the
17015 explicit args will completely resolve the templates in question. */
17022 {
17035 {
17040 {
17043 }
17044 }
17047 }
17048 /* If no templates (or more than one) are fully resolved by the
17049 explicit arguments, this template-id is a non-deduced context; it
17050 could still be OK if we deduce all template arguments for the
17051 enclosing call through other arguments. */
17054 }
17057 /* If ARG is, for example, "(0, &f)" then its type will be unknown
17058 -- but the deduction does not succeed because the expression is
17059 not just the function on its own. */
17061 else
17067 {
17070 }
17072 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17073 to function or pointer to member function argument if the set of
17074 overloaded functions does not contain function templates and at most
17075 one of a set of overloaded functions provides a unique match.
17077 So if we found multiple possibilities, we return success but don't
17078 deduce anything. */
17081 {
17085 {
17090 /* Don't forget explicit template arguments in a pack. */
17094 }
17095 }
17100 }
17102 /* Core DR 115: In contexts where deduction is done and fails, or in
17103 contexts where deduction is not done, if a template argument list is
17104 specified and it, along with any default template arguments, identifies
17105 a single function template specialization, then the template-id is an
17106 lvalue for the function template specialization. */
17108 tree
17110 {
17123 {
17126 }
17128 {
17131 }
17133 {
17136 }
17139 {
17143 /* If we got some explicit template args, we need to plug them into
17144 the affected templates before we try to unify, in case the
17145 explicit args will completely resolve the templates in question. */
17153 {
17166 {
17169 {
17172 }
17174 {
17177 }
17178 }
17179 }
17181 {
17189 {
17190 tree base
17193 }
17197 }
17199 /* There were no good options and at least one bad one, so let the
17200 user know what the problem is. */
17202 }
17204 }
17206 /* Subroutine of resolve_overloaded_unification; does deduction for a single
17207 overload. Fills TARGS with any deduced arguments, or error_mark_node if
17208 different overloads deduce different arguments for a given parm.
17209 ADDR_P is true if the expression for which deduction is being
17210 performed was of the form "& fn" rather than simply "fn".
17212 Returns 1 on success. */
17214 static int
17216 tree orig_targs,
17217 tree targs,
17218 tree parm,
17219 tree arg,
17220 unification_kind_t strict,
17224 {
17226 tree tempargs;
17232 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17233 to function or pointer to member function argument if the set of
17234 overloaded functions does not contain function templates and at most
17235 one of a set of overloaded functions provides a unique match.
17237 So if this is a template, just return success. */
17249 /* We don't copy orig_targs for this because if we have already deduced
17250 some template args from previous args, unify would complain when we
17251 try to deduce a template parameter for the same argument, even though
17252 there isn't really a conflict. */
17259 /* First make sure we didn't deduce anything that conflicts with
17260 explicitly specified args. */
17262 {
17269 /* Since we're unifying against ourselves, we will fill in
17270 template args used in the function parm list with our own
17271 template parms. Discard them. */
17275 }
17278 {
17283 }
17286 }
17288 /* PARM is a template class (perhaps with unbound template
17289 parameters). ARG is a fully instantiated type. If ARG can be
17290 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
17291 TARGS are as for unify. */
17293 static tree
17296 {
17297 tree copy_of_targs;
17304 /* We need to make a new template argument vector for the call to
17305 unify. If we used TARGS, we'd clutter it up with the result of
17306 the attempted unification, even if this class didn't work out.
17307 We also don't want to commit ourselves to all the unifications
17308 we've already done, since unification is supposed to be done on
17309 an argument-by-argument basis. In other words, consider the
17310 following pathological case:
17312 template <int I, int J, int K>
17313 struct S {};
17315 template <int I, int J>
17316 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
17318 template <int I, int J, int K>
17319 void f(S<I, J, K>, S<I, I, I>);
17321 void g() {
17322 S<0, 0, 0> s0;
17323 S<0, 1, 2> s2;
17325 f(s0, s2);
17326 }
17328 Now, by the time we consider the unification involving `s2', we
17329 already know that we must have `f<0, 0, 0>'. But, even though
17330 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
17331 because there are two ways to unify base classes of S<0, 1, 2>
17332 with S<I, I, I>. If we kept the already deduced knowledge, we
17333 would reject the possibility I=1. */
17336 /* If unification failed, we're done. */
17342 }
17344 /* Given a template type PARM and a class type ARG, find the unique
17345 base type in ARG that is an instance of PARM. We do not examine
17346 ARG itself; only its base-classes. If there is not exactly one
17347 appropriate base class, return NULL_TREE. PARM may be the type of
17348 a partial specialization, as well as a plain template type. Used
17349 by unify. */
17351 static enum template_base_result
17354 {
17356 tree binfo;
17362 {
17363 /* The type could not be completed. */
17366 }
17368 /* Walk in inheritance graph order. The search order is not
17369 important, and this avoids multiple walks of virtual bases. */
17371 {
17376 {
17377 /* If there is more than one satisfactory baseclass, then:
17379 [temp.deduct.call]
17381 If they yield more than one possible deduced A, the type
17382 deduction fails.
17384 applies. */
17386 {
17389 }
17392 }
17393 }
17397 }
17399 /* Returns the level of DECL, which declares a template parameter. */
17401 static int
17403 {
17405 {
17415 }
17417 }
17419 /* Decide whether ARG can be unified with PARM, considering only the
17420 cv-qualifiers of each type, given STRICT as documented for unify.
17421 Returns nonzero iff the unification is OK on that basis. */
17423 static int
17425 {
17431 {
17432 /* Although a CVR qualifier is ignored when being applied to a
17433 substituted template parameter ([8.3.2]/1 for example), that
17434 does not allow us to unify "const T" with "int&" because both
17435 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17436 It is ok when we're allowing additional CV qualifiers
17437 at the outer level [14.8.2.1]/3,1st bullet. */
17447 }
17458 }
17460 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17461 void
17463 {
17467 {
17470 }
17471 else
17472 {
17475 }
17476 }
17478 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17479 do { \
17480 if (unify (TP, TA, P, A, S, EP)) \
17481 return 1; \
17482 } while (0);
17484 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17485 expansion at the end of PACKED_PARMS. Returns 0 if the type
17486 deduction succeeds, 1 otherwise. STRICT is the same as in
17487 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17488 call argument list. We'll need to adjust the arguments to make them
17489 types. SUBR tells us if this is from a recursive call to
17490 type_unification_real, or for comparing two template argument
17491 lists. */
17493 static int
17497 {
17498 tree parm
17508 /* Determine the parameter packs we will be deducing from the
17509 pattern, and record their current deductions. */
17512 {
17516 /* Determine the index and level of this parameter pack. */
17519 /* Keep track of the parameter packs and their corresponding
17520 argument packs. */
17523 }
17525 /* Loop through all of the arguments that have not yet been
17526 unified and unify each with the pattern. */
17528 {
17529 tree parm;
17533 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17534 or the element of its argument pack at the current index if
17535 this argument was explicitly specified. */
17537 {
17546 {
17549 }
17551 }
17553 /* If we had explicit template arguments, substitute them into the
17554 pattern before deduction. */
17556 {
17557 /* Some arguments might still be unspecified or dependent. */
17565 NULL_TREE);
17570 }
17571 else
17574 /* Unify the pattern with the current argument. */
17579 /* For each parameter pack, collect the deduced value. */
17581 {
17587 }
17588 }
17590 /* Verify that the results of unification with the parameter packs
17591 produce results consistent with what we've seen before, and make
17592 the deduced argument packs available. */
17594 {
17601 /* By default keep the original deduced argument pack.
17602 If necessary, more specific code is going to update the
17603 resulting deduced argument later down in this function. */
17607 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17608 actually deduce anything. */
17616 {
17617 /* If we had fewer function args than explicit template args,
17618 just use the explicits. */
17623 }
17626 {
17627 tree result;
17628 /* Build the deduced *_ARGUMENT_PACK. */
17630 {
17635 }
17636 else
17641 /* Note the deduced argument packs for this parameter
17642 pack. */
17644 }
17648 {
17649 /* We only had the explicitly-provided arguments before, but
17650 now we have a complete set of arguments. */
17656 }
17657 else
17658 {
17664 /* Inconsistent unification of this parameter pack. */
17666 bad_old_arg,
17667 bad_new_arg);
17668 }
17669 }
17672 }
17674 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17675 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17676 parameters and return value are as for unify. */
17678 static int
17682 {
17683 tree parm_max;
17684 tree arg_max;
17688 /* Our representation of array types uses "N - 1" as the
17689 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17690 not an integer constant. We cannot unify arbitrarily
17691 complex expressions, so we eliminate the MINUS_EXPRs
17692 here. */
17696 {
17699 }
17703 {
17704 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17705 trying to unify the type of a variable with the type
17706 of a template parameter. For example:
17708 template <unsigned int N>
17709 void f (char (&) [N]);
17710 int g();
17711 void h(int i) {
17712 char a[g(i)];
17713 f(a);
17714 }
17716 Here, the type of the ARG will be "int [g(i)]", and
17717 may be a SAVE_EXPR, etc. */
17721 }
17723 /* If only one of the bounds used a MINUS_EXPR, compensate
17724 by adding one to the other bound. */
17727 integer_type_node,
17728 parm_max,
17729 integer_one_node);
17732 integer_type_node,
17733 arg_max,
17734 integer_one_node);
17738 }
17740 /* Deduce the value of template parameters. TPARMS is the (innermost)
17741 set of template parameters to a template. TARGS is the bindings
17742 for those template parameters, as determined thus far; TARGS may
17743 include template arguments for outer levels of template parameters
17744 as well. PARM is a parameter to a template function, or a
17745 subcomponent of that parameter; ARG is the corresponding argument.
17746 This function attempts to match PARM with ARG in a manner
17747 consistent with the existing assignments in TARGS. If more values
17748 are deduced, then TARGS is updated.
17750 Returns 0 if the type deduction succeeds, 1 otherwise. The
17751 parameter STRICT is a bitwise or of the following flags:
17753 UNIFY_ALLOW_NONE:
17754 Require an exact match between PARM and ARG.
17755 UNIFY_ALLOW_MORE_CV_QUAL:
17756 Allow the deduced ARG to be more cv-qualified (by qualification
17757 conversion) than ARG.
17758 UNIFY_ALLOW_LESS_CV_QUAL:
17759 Allow the deduced ARG to be less cv-qualified than ARG.
17760 UNIFY_ALLOW_DERIVED:
17761 Allow the deduced ARG to be a template base class of ARG,
17762 or a pointer to a template base class of the type pointed to by
17763 ARG.
17764 UNIFY_ALLOW_INTEGER:
17765 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17766 case for more information.
17767 UNIFY_ALLOW_OUTER_LEVEL:
17768 This is the outermost level of a deduction. Used to determine validity
17769 of qualification conversions. A valid qualification conversion must
17770 have const qualified pointers leading up to the inner type which
17771 requires additional CV quals, except at the outer level, where const
17772 is not required [conv.qual]. It would be normal to set this flag in
17773 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17774 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17775 This is the outermost level of a deduction, and PARM can be more CV
17776 qualified at this point.
17777 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17778 This is the outermost level of a deduction, and PARM can be less CV
17779 qualified at this point. */
17781 static int
17784 {
17786 tree targ;
17787 tree tparm;
17790 /* I don't think this will do the right thing with respect to types.
17791 But the only case I've seen it in so far has been array bounds, where
17792 signedness is the only information lost, and I think that will be
17793 okay. */
17801 /* We can't deduce anything from this, but we might get all the
17802 template args from other function args. */
17805 /* If PARM uses template parameters, then we can't bail out here,
17806 even if ARG == PARM, since we won't record unifications for the
17807 template parameters. We might need them if we're trying to
17808 figure out which of two things is more specialized. */
17812 /* Handle init lists early, so the rest of the function can assume
17813 we're dealing with a type. */
17815 {
17820 /* Replace T with std::initializer_list<T> for deduction. */
17827 /* We can only deduce from an initializer list argument if the
17828 parameter is std::initializer_list or an array; otherwise this
17829 is a non-deduced context. */
17834 else
17838 {
17845 {
17847 /* It should only be possible to get here for a call. */
17849 elt_strict |= maybe_adjust_types_for_deduction
17852 }
17855 explain_p);
17856 }
17860 {
17861 /* Also deduce from the length of the initializer list. */
17868 }
17870 /* If the std::initializer_list<T> deduction worked, replace the
17871 deduced A with std::initializer_list<A>. */
17873 {
17878 }
17880 }
17882 /* Immediately reject some pairs that won't unify because of
17883 cv-qualification mismatches. */
17886 /* It is the elements of the array which hold the cv quals of an array
17887 type, and the elements might be template type parms. We'll check
17888 when we recurse. */
17890 /* We check the cv-qualifiers when unifying with template type
17891 parameters below. We want to allow ARG `const T' to unify with
17892 PARM `T' for example, when computing which of two templates
17893 is more specialized, for example. */
17907 {
17911 /* In a type which contains a nested-name-specifier, template
17912 argument values cannot be deduced for template parameters used
17913 within the nested-name-specifier. */
17925 /* The PARM is not one we're trying to unify. Just check
17926 to see if it matches ARG. */
17927 {
17932 else
17934 }
17941 /* Check for mixed types and values. */
17949 {
17950 /* ARG must be constructed from a template class or a template
17951 template parameter. */
17955 {
17957 /* An alias template name is never deduced. */
17962 tree parm_parms
17963 = DECL_INNERMOST_TEMPLATE_PARMS
17968 /* The resolution to DR150 makes clear that default
17969 arguments for an N-argument may not be used to bind T
17970 to a template template parameter with fewer than N
17971 parameters. It is not safe to permit the binding of
17972 default arguments as an extension, as that may change
17973 the meaning of a conforming program. Consider:
17975 struct Dense { static const unsigned int dim = 1; };
17977 template <template <typename> class View,
17978 typename Block>
17979 void operator+(float, View<Block> const&);
17981 template <typename Block,
17982 unsigned int Dim = Block::dim>
17983 struct Lvalue_proxy { operator float() const; };
17985 void
17986 test_1d (void) {
17987 Lvalue_proxy<Dense> p;
17988 float b;
17989 b + p;
17990 }
17992 Here, if Lvalue_proxy is permitted to bind to View, then
17993 the global operator+ will be used; if they are not, the
17994 Lvalue_proxy will be converted to float. */
17996 full_argvec,
17998 (explain_p
17999 ? tf_warning_or_error
18006 /* Deduce arguments T, i from TT<T> or TT<i>.
18007 We check each element of PARMVEC and ARGVEC individually
18008 rather than the whole TREE_VEC since they can have
18009 different number of elements. */
18016 /* Check if the parameters end in a pack, making them
18017 variadic. */
18023 /* If the template argument list of P contains a pack
18024 expansion that is not the last template argument, the
18025 entire template argument list is a non-deduced
18026 context. */
18035 {
18040 }
18045 DEDUCE_EXACT,
18048 }
18051 /* Fall through to deduce template name. */
18052 }
18056 {
18057 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
18059 /* Simple cases: Value already set, does match or doesn't. */
18064 }
18065 else
18066 {
18067 /* If PARM is `const T' and ARG is only `int', we don't have
18068 a match unless we are allowing additional qualification.
18069 If ARG is `const int' and PARM is just `T' that's OK;
18070 that binds `const int' to `T'. */
18075 /* Consider the case where ARG is `const volatile int' and
18076 PARM is `const T'. Then, T should be `volatile int'. */
18077 arg = cp_build_qualified_type_real
18082 /* Simple cases: Value already set, does match or doesn't. */
18088 /* Make sure that ARG is not a variable-sized array. (Note
18089 that were talking about variable-sized arrays (like
18090 `int[n]'), rather than arrays of unknown size (like
18091 `int[]').) We'll get very confused by such a type since
18092 the bound of the array is not constant, and therefore
18093 not mangleable. Besides, such types are not allowed in
18094 ISO C++, so we can do as we please here. We do allow
18095 them for 'auto' deduction, since that isn't ABI-exposed. */
18099 /* Strip typedefs as in convert_template_argument. */
18101 }
18103 /* If ARG is a parameter pack or an expansion, we cannot unify
18104 against it unless PARM is also a parameter pack. */
18109 /* If the argument deduction results is a METHOD_TYPE,
18110 then there is a problem.
18111 METHOD_TYPE doesn't map to any real C++ type the result of
18112 the deduction can not be of that type. */
18126 {
18127 /* The PARM is not one we're trying to unify. Just check
18128 to see if it matches ARG. */
18134 }
18140 {
18145 }
18147 /* [temp.deduct.type] If, in the declaration of a function template
18148 with a non-type template-parameter, the non-type
18149 template-parameter is used in an expression in the function
18150 parameter-list and, if the corresponding template-argument is
18151 deduced, the template-argument type shall match the type of the
18152 template-parameter exactly, except that a template-argument
18153 deduced from an array bound may be of any integral type.
18154 The non-type parameter might use already deduced type parameters. */
18157 /* Template-parameter dependent expression. Just accept it for now.
18158 It will later be processed in convert_template_argument. */
18159 ;
18164 /* Convert the ARG to the type of PARM; the deduced non-type
18165 template argument must exactly match the types of the
18166 corresponding parameter. */
18169 /* We haven't deduced the type of this parameter yet. Try again
18170 later. */
18172 else
18175 /* If ARG is a parameter pack or an expansion, we cannot unify
18176 against it unless PARM is also a parameter pack. */
18186 {
18187 /* A pointer-to-member constant can be unified only with
18188 another constant. */
18192 /* Just unify the class member. It would be useless (and possibly
18193 wrong, depending on the strict flags) to unify also
18194 PTRMEM_CST_CLASS, because we want to be sure that both parm and
18195 arg refer to the same variable, even if through different
18196 classes. For instance:
18198 struct A { int x; };
18199 struct B : A { };
18201 Unification of &A::x and &B::x must succeed. */
18204 }
18207 {
18211 /* [temp.deduct.call]
18213 A can be another pointer or pointer to member type that can
18214 be converted to the deduced A via a qualification
18215 conversion (_conv.qual_).
18217 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
18218 This will allow for additional cv-qualification of the
18219 pointed-to types if appropriate. */
18222 /* The derived-to-base conversion only persists through one
18223 level of pointers. */
18228 }
18260 /* We have already checked cv-qualification at the top of the
18261 function. */
18265 /* As far as unification is concerned, this wins. Later checks
18266 will invalidate it if necessary. */
18269 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
18270 /* Type INTEGER_CST can come from ordinary constant template args. */
18282 {
18292 /* Check for pack expansions in the parameters. */
18294 {
18296 {
18298 /* We can unify against something with a trailing
18299 parameter pack. */
18301 else
18302 /* [temp.deduct.type]/9: If the template argument list of
18303 P contains a pack expansion that is not the last
18304 template argument, the entire template argument list
18305 is a non-deduced context. */
18307 }
18308 }
18310 /* If we don't have enough arguments to satisfy the parameters
18311 (not counting the pack expression at the end), or we have
18312 too many arguments for a parameter list that doesn't end in
18313 a pack expression, we can't unify. */
18319 /* Unify all of the parameters that precede the (optional)
18320 pack expression. */
18322 {
18327 }
18330 DEDUCE_EXACT,
18333 }
18341 {
18349 }
18354 {
18358 {
18359 /* First, we try to unify the PARM and ARG directly. */
18364 {
18365 /* Fallback to the special case allowed in
18366 [temp.deduct.call]:
18368 If P is a class, and P has the form
18369 template-id, then A can be a derived class of
18370 the deduced A. Likewise, if P is a pointer to
18371 a class of the form template-id, A can be a
18372 pointer to a derived class pointed to by the
18373 deduced A. */
18380 }
18381 }
18385 /* Perhaps PARM is something like S<U> and ARG is S<int>.
18386 Then, we should unify `int' and `U'. */
18388 else
18389 /* There's no chance of unification succeeding. */
18394 }
18401 {
18404 tree a;
18410 /* CV qualifications for methods can never be deduced, they must
18411 match exactly. We need to check them explicitly here,
18412 because type_unification_real treats them as any other
18413 cv-qualified parameter. */
18415 && (!check_cv_quals_for_unify
18435 }
18438 /* Unify a pointer to member with a pointer to member function, which
18439 deduces the type of the member as a function type. */
18441 {
18442 /* Check top-level cv qualifiers */
18450 /* Determine the type of the function we are unifying against. */
18454 }
18473 /* Matched cases are handled by the ARG == PARM test above. */
18477 /* A non-type template parameter that is a variable should be a
18478 an integral constant, in which case, it whould have been
18479 folded into its (constant) value. So we should not be getting
18480 a variable here. */
18491 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18492 or UNDERLYING_TYPE nodes. */
18496 /* Unification fails if we hit an error node. */
18501 {
18506 }
18507 /* FALLTHRU */
18510 /* An unresolved overload is a nondeduced context. */
18515 /* We must be looking at an expression. This can happen with
18516 something like:
18518 template <int I>
18519 void foo(S<I>, S<I + 2>);
18521 This is a "nondeduced context":
18523 [deduct.type]
18525 The nondeduced contexts are:
18527 --A type that is a template-id in which one or more of
18528 the template-arguments is an expression that references
18529 a template-parameter.
18531 In these cases, we assume deduction succeeded, but don't
18532 actually infer any unifications. */
18537 else
18539 }
18540 }
18541 #undef RECUR_AND_CHECK_FAILURE
18542 \f
18543 /* Note that DECL can be defined in this translation unit, if
18544 required. */
18546 static void
18548 {
18549 tree clone;
18553 }
18555 /* Called if RESULT is explicitly instantiated, or is a member of an
18556 explicitly instantiated class. */
18558 void
18560 {
18563 /* If this entity has already been written out, it's too late to
18564 make any modifications. */
18568 /* For anonymous namespace we don't need to do anything. */
18570 {
18573 }
18576 /* The TREE_PUBLIC flag for function declarations will have been
18577 set correctly by tsubst. */
18580 /* This might have been set by an earlier implicit instantiation. */
18585 else
18586 {
18589 /* Always make artificials weak. */
18592 /* For WIN32 we also want to put explicit instantiations in
18593 linkonce sections. */
18596 }
18598 /* If EXTERN_P, then this function will not be emitted -- unless
18599 followed by an explicit instantiation, at which point its linkage
18600 will be adjusted. If !EXTERN_P, then this function will be
18601 emitted here. In neither circumstance do we want
18602 import_export_decl to adjust the linkage. */
18604 }
18606 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18607 important template arguments. If any are missing, we check whether
18608 they're important by using error_mark_node for substituting into any
18609 args that were used for partial ordering (the ones between ARGS and END)
18610 and seeing if it bubbles up. */
18612 static bool
18614 {
18619 {
18622 }
18624 {
18628 }
18630 }
18632 /* Given two function templates PAT1 and PAT2, return:
18634 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18635 -1 if PAT2 is more specialized than PAT1.
18636 0 if neither is more specialized.
18638 LEN indicates the number of parameters we should consider
18639 (defaulted parameters should not be considered).
18641 The 1998 std underspecified function template partial ordering, and
18642 DR214 addresses the issue. We take pairs of arguments, one from
18643 each of the templates, and deduce them against each other. One of
18644 the templates will be more specialized if all the *other*
18645 template's arguments deduce against its arguments and at least one
18646 of its arguments *does* *not* deduce against the other template's
18647 corresponding argument. Deduction is done as for class templates.
18648 The arguments used in deduction have reference and top level cv
18649 qualifiers removed. Iff both arguments were originally reference
18650 types *and* deduction succeeds in both directions, an lvalue reference
18651 wins against an rvalue reference and otherwise the template
18652 with the more cv-qualified argument wins for that pairing (if
18653 neither is more cv-qualified, they both are equal). Unlike regular
18654 deduction, after all the arguments have been deduced in this way,
18655 we do *not* verify the deduced template argument values can be
18656 substituted into non-deduced contexts.
18658 The logic can be a bit confusing here, because we look at deduce1 and
18659 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18660 can find template arguments for pat1 to make arg1 look like arg2, that
18661 means that arg2 is at least as specialized as arg1. */
18663 int
18665 {
18678 /* Remove the this parameter from non-static member functions. If
18679 one is a non-static member function and the other is not a static
18680 member function, remove the first parameter from that function
18681 also. This situation occurs for operator functions where we
18682 locate both a member function (with this pointer) and non-member
18683 operator (with explicit first operand). */
18685 {
18690 }
18692 {
18695 {
18696 len--;
18698 }
18699 }
18701 /* If only one is a conversion operator, they are unordered. */
18705 /* Consider the return type for a conversion function */
18707 {
18710 len++;
18711 }
18713 processing_template_decl++;
18719 /* Stop when an ellipsis is seen. */
18721 {
18732 {
18733 /* When both arguments are pack expansions, we need only
18734 unify the patterns themselves. */
18738 /* This is the last comparison we need to do. */
18740 }
18743 {
18747 }
18750 {
18754 }
18760 {
18766 /* Setup the parameter vector, which contains only ARG1. */
18769 /* Setup the argument vector, which contains the remaining
18770 arguments. */
18779 /* We cannot deduce in the other direction, because ARG1 is
18780 a pack expansion but ARG2 is not. */
18782 }
18784 {
18790 /* Setup the parameter vector, which contains only ARG1. */
18793 /* Setup the argument vector, which contains the remaining
18794 arguments. */
18803 /* We cannot deduce in the other direction, because ARG2 is
18804 a pack expansion but ARG1 is not.*/
18806 }
18808 else
18809 {
18810 /* The normal case, where neither argument is a pack
18811 expansion. */
18818 }
18820 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18821 arg2, then arg2 is not as specialized as arg1. */
18827 /* "If, for a given type, deduction succeeds in both directions
18828 (i.e., the types are identical after the transformations above)
18829 and both P and A were reference types (before being replaced with
18830 the type referred to above):
18831 - if the type from the argument template was an lvalue reference and
18832 the type from the parameter template was not, the argument type is
18833 considered to be more specialized than the other; otherwise,
18834 - if the type from the argument template is more cv-qualified
18835 than the type from the parameter template (as described above),
18836 the argument type is considered to be more specialized than the other;
18837 otherwise,
18838 - neither type is more specialized than the other." */
18841 {
18843 {
18846 else
18848 }
18850 {
18855 }
18856 }
18859 /* We've failed to deduce something in either direction.
18860 These must be unordered. */
18865 /* We have already processed all of the arguments in our
18866 handing of the pack expansion type. */
18871 }
18873 /* "In most cases, all template parameters must have values in order for
18874 deduction to succeed, but for partial ordering purposes a template
18875 parameter may remain without a value provided it is not used in the
18876 types being used for partial ordering."
18878 Thus, if we are missing any of the targs1 we need to substitute into
18879 origs1, then pat2 is not as specialized as pat1. This can happen when
18880 there is a nondeduced context. */
18886 processing_template_decl--;
18888 /* All things being equal, if the next argument is a pack expansion
18889 for one function but not for the other, prefer the
18890 non-variadic function. FIXME this is bogus; see c++/41958. */
18894 {
18897 }
18903 else
18905 }
18907 /* Determine which of two partial specializations of TMPL is more
18908 specialized.
18910 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
18911 to the first partial specialization. The TREE_PURPOSE is the
18912 innermost set of template parameters for the partial
18913 specialization. PAT2 is similar, but for the second template.
18915 Return 1 if the first partial specialization is more specialized;
18916 -1 if the second is more specialized; 0 if neither is more
18917 specialized.
18919 See [temp.class.order] for information about determining which of
18920 two templates is more specialized. */
18922 static int
18924 {
18925 tree targs;
18936 /* Just like what happens for functions, if we are ordering between
18937 different template specializations, we may encounter dependent
18938 types in the arguments, and we need our dependency check functions
18939 to behave correctly. */
18943 {
18946 }
18950 {
18953 }
18956 /* In the case of a tie where at least one of the templates
18957 has a parameter pack at the end, the template with the most
18958 non-packed parameters wins. */
18960 && any_deductions
18963 {
18969 /* We don't count the pack expansion at the end. */
18979 }
18982 }
18984 /* Return the template arguments that will produce the function signature
18985 DECL from the function template FN, with the explicit template
18986 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18987 also match. Return NULL_TREE if no satisfactory arguments could be
18988 found. */
18990 static tree
18992 {
18996 tree decl_arg_types;
18999 tree arg;
19003 /* Never do unification on the 'this' parameter. */
19024 }
19026 /* Return the innermost template arguments that, when applied to a partial
19027 specialization of TMPL whose innermost template parameters are
19028 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
19029 ARGS.
19031 For example, suppose we have:
19033 template <class T, class U> struct S {};
19034 template <class T> struct S<T*, int> {};
19036 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
19037 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
19038 int}. The resulting vector will be {double}, indicating that `T'
19039 is bound to `double'. */
19041 static tree
19043 {
19045 tree deduced_args;
19046 tree innermost_deduced_args;
19050 {
19054 innermost_deduced_args);
19055 }
19056 else
19069 /* Verify that nondeduced template arguments agree with the type
19070 obtained from argument deduction.
19072 For example:
19074 struct A { typedef int X; };
19075 template <class T, class U> struct C {};
19076 template <class T> struct C<T, typename T::X> {};
19078 Then with the instantiation `C<A, int>', we can deduce that
19079 `T' is `A' but unify () does not check whether `typename T::X'
19080 is `int'. */
19086 /* We only need to check the innermost arguments; the other
19087 arguments will always agree. */
19092 /* Now that we have bindings for all of the template arguments,
19093 ensure that the arguments deduced for the template template
19094 parameters have compatible template parameter lists. See the use
19095 of template_template_parm_bindings_ok_p in fn_type_unification
19096 for more information. */
19101 }
19103 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
19104 Return the TREE_LIST node with the most specialized template, if
19105 any. If there is no most specialized template, the error_mark_node
19106 is returned.
19108 Note that this function does not look at, or modify, the
19109 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
19110 returned is one of the elements of INSTANTIATIONS, callers may
19111 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
19112 and retrieve it from the value returned. */
19114 tree
19116 {
19123 {
19129 fate--;
19134 fate++;
19139 {
19140 /* Equally specialized, move to next function. If there
19141 is no next function, nothing's most specialized. */
19146 }
19147 }
19150 /* Now verify that champ is better than everything earlier in the
19151 instantiation list. */
19159 {
19162 }
19164 processing_template_decl--;
19170 }
19172 /* If DECL is a specialization of some template, return the most
19173 general such template. Otherwise, returns NULL_TREE.
19175 For example, given:
19177 template <class T> struct S { template <class U> void f(U); };
19179 if TMPL is `template <class U> void S<int>::f(U)' this will return
19180 the full template. This function will not trace past partial
19181 specializations, however. For example, given in addition:
19183 template <class T> struct S<T*> { template <class U> void f(U); };
19185 if TMPL is `template <class U> void S<int*>::f(U)' this will return
19186 `template <class T> template <class U> S<T*>::f(U)'. */
19188 tree
19190 {
19192 {
19195 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
19196 template friend, or a FIELD_DECL for a capture pack. */
19199 }
19201 /* Look for more and more general templates. */
19203 {
19204 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
19205 (See cp-tree.h for details.) */
19213 /* Stop if we run into an explicitly specialized class template. */
19220 }
19223 }
19225 /* Return the most specialized of the template partial specializations
19226 which can produce TARGET, a specialization of some class or variable
19227 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
19228 a TEMPLATE_DECL node corresponding to the partial specialization, while
19229 the TREE_PURPOSE is the set of template arguments that must be
19230 substituted into the template pattern in order to generate TARGET.
19232 If the choice of partial specialization is ambiguous, a diagnostic
19233 is issued, and the error_mark_node is returned. If there are no
19234 partial specializations matching TARGET, then NULL_TREE is
19235 returned, indicating that the primary template should be used. */
19237 static tree
19239 {
19241 tree t;
19242 tree champ;
19249 {
19253 }
19255 {
19258 }
19260 {
19264 }
19265 else
19270 /* For determining which partial specialization to use, only the
19271 innermost args are interesting. */
19273 {
19276 }
19279 {
19280 tree partial_spec_args;
19281 tree spec_args;
19289 {
19290 /* Discard the outer levels of args, and then substitute in the
19291 template args from the enclosing class. */
19293 partial_spec_args = tsubst_template_args
19296 /* And the same for the partial specialization TEMPLATE_DECL. */
19298 }
19300 partial_spec_args =
19302 partial_spec_args,
19316 partial_spec_args,
19317 args);
19319 {
19324 }
19325 }
19335 {
19338 ;
19339 else
19340 {
19342 {
19345 {
19348 }
19349 }
19351 }
19352 }
19356 {
19359 {
19362 }
19363 }
19366 {
19373 else
19377 {
19382 }
19385 }
19388 }
19390 /* Explicitly instantiate DECL. */
19392 void
19394 {
19399 /* An error occurred, for which grokdeclarator has already issued
19400 an appropriate message. */
19403 {
19406 }
19412 {
19413 /* There is an asymmetry here in the way VAR_DECLs and
19414 FUNCTION_DECLs are handled by grokdeclarator. In the case of
19415 the latter, the DECL we get back will be marked as a
19416 template instantiation, and the appropriate
19417 DECL_TEMPLATE_INFO will be set up. This does not happen for
19418 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
19419 should handle VAR_DECLs as it currently handles
19420 FUNCTION_DECLs. */
19422 {
19425 }
19428 {
19431 }
19433 {
19438 }
19439 }
19441 {
19444 }
19445 else
19448 /* Check for various error cases. Note that if the explicit
19449 instantiation is valid the RESULT will currently be marked as an
19450 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19451 until we get here. */
19454 {
19455 /* DR 259 [temp.spec].
19457 Both an explicit instantiation and a declaration of an explicit
19458 specialization shall not appear in a program unless the explicit
19459 instantiation follows a declaration of the explicit specialization.
19461 For a given set of template parameters, if an explicit
19462 instantiation of a template appears after a declaration of an
19463 explicit specialization for that template, the explicit
19464 instantiation has no effect. */
19466 }
19468 {
19469 /* [temp.spec]
19471 No program shall explicitly instantiate any template more
19472 than once.
19474 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19475 the first instantiation was `extern' and the second is not,
19476 and EXTERN_P for the opposite case. */
19479 /* If an "extern" explicit instantiation follows an ordinary
19480 explicit instantiation, the template is instantiated. */
19483 }
19485 {
19488 }
19490 {
19493 }
19496 ;
19498 {
19501 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19504 }
19505 else
19513 }
19515 static void
19517 {
19523 {
19526 }
19527 }
19529 /* Called from do_type_instantiation through binding_table_foreach to
19530 do recursive instantiation for the type bound in ENTRY. */
19531 static void
19533 {
19539 }
19541 /* Called from do_type_instantiation to instantiate a member
19542 (a member function or a static member variable) of an
19543 explicitly instantiated class template. */
19544 static void
19546 {
19551 }
19553 /* Perform an explicit instantiation of template class T. STORAGE, if
19554 non-null, is the RID for extern, inline or static. COMPLAIN is
19555 nonzero if this is called from the parser, zero if called recursively,
19556 since the standard is unclear (as detailed below). */
19558 void
19560 {
19570 {
19571 tree tmpl =
19575 else
19578 }
19583 {
19586 t);
19588 }
19591 {
19593 {
19595 {
19598 "ISO C++ 1998 forbids the use of %<extern%> on "
19600 }
19601 else
19603 "ISO C++ forbids the use of %qE"
19605 }
19613 else
19614 {
19616 storage);
19618 }
19619 }
19622 {
19623 /* DR 259 [temp.spec].
19625 Both an explicit instantiation and a declaration of an explicit
19626 specialization shall not appear in a program unless the explicit
19627 instantiation follows a declaration of the explicit specialization.
19629 For a given set of template parameters, if an explicit
19630 instantiation of a template appears after a declaration of an
19631 explicit specialization for that template, the explicit
19632 instantiation has no effect. */
19634 }
19636 {
19637 /* [temp.spec]
19639 No program shall explicitly instantiate any template more
19640 than once.
19642 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19643 instantiation was `extern'. If EXTERN_P then the second is.
19644 These cases are OK. */
19651 /* If we've already instantiated the template, just return now. */
19654 }
19662 {
19663 tree tmp;
19665 /* In contrast to implicit instantiation, where only the
19666 declarations, and not the definitions, of members are
19667 instantiated, we have here:
19669 [temp.explicit]
19671 The explicit instantiation of a class template specialization
19672 implies the instantiation of all of its members not
19673 previously explicitly specialized in the translation unit
19674 containing the explicit instantiation.
19676 Of course, we can't instantiate member template classes, since
19677 we don't have any arguments for them. Note that the standard
19678 is unclear on whether the instantiation of the members are
19679 *explicit* instantiations or not. However, the most natural
19680 interpretation is that it should be an explicit instantiation. */
19695 }
19696 }
19698 /* Given a function DECL, which is a specialization of TMPL, modify
19699 DECL to be a re-instantiation of TMPL with the same template
19700 arguments. TMPL should be the template into which tsubst'ing
19701 should occur for DECL, not the most general template.
19703 One reason for doing this is a scenario like this:
19705 template <class T>
19706 void f(const T&, int i);
19708 void g() { f(3, 7); }
19710 template <class T>
19711 void f(const T& t, const int i) { }
19713 Note that when the template is first instantiated, with
19714 instantiate_template, the resulting DECL will have no name for the
19715 first parameter, and the wrong type for the second. So, when we go
19716 to instantiate the DECL, we regenerate it. */
19718 static void
19720 {
19721 /* The arguments used to instantiate DECL, from the most general
19722 template. */
19723 tree args;
19724 tree code_pattern;
19729 /* Make sure that we can see identifiers, and compute access
19730 correctly. */
19734 {
19735 tree decl_parm;
19736 tree pattern_parm;
19737 tree specs;
19751 specs);
19753 /* Merge parameter declarations. */
19756 pattern_parm
19760 {
19761 tree parm_type;
19762 tree attributes;
19767 NULL_TREE);
19773 {
19776 }
19779 }
19780 /* Merge any parameters that match with the function parameter
19781 pack. */
19783 {
19785 tree expanded_types;
19786 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19787 the parameters in this function parameter pack. */
19792 {
19793 tree parm_type;
19794 tree attributes;
19797 /* Rename the parameter to include the index. */
19806 {
19809 }
19811 }
19812 }
19813 /* Merge additional specifiers from the CODE_PATTERN. */
19817 }
19819 {
19827 }
19828 else
19832 }
19834 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19835 substituted to get DECL. */
19837 tree
19839 {
19842 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19843 for the instantiation. This is not always the most general
19844 template. Consider, for example:
19846 template <class T>
19847 struct S { template <class U> void f();
19848 template <> void f<int>(); };
19850 and an instantiation of S<double>::f<int>. We want TD to be the
19851 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19853 more general template. */
19855 /* We must also deal with friend templates. Given:
19857 template <class T> struct S {
19858 template <class U> friend void f() {};
19859 };
19861 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19862 so far as the language is concerned, but that's still
19863 where we get the pattern for the instantiation from. On
19864 other hand, if the definition comes outside the class, say:
19866 template <class T> struct S {
19867 template <class U> friend void f();
19868 };
19869 template <class U> friend void f() {}
19871 we don't need to look any further. That's what the check for
19872 DECL_INITIAL is for. */
19876 {
19877 /* The present template, TD, should not be a definition. If it
19878 were a definition, we should be using it! Note that we
19879 cannot restructure the loop to just keep going until we find
19880 a template with a definition, since that might go too far if
19881 a specialization was declared, but not defined. */
19883 /* Fetch the more general template. */
19885 }
19888 }
19890 /* Returns true if we need to instantiate this template instance even if we
19891 know we aren't going to emit it.. */
19893 bool
19895 {
19896 /* We always instantiate inline functions so that we can inline them. An
19897 explicit instantiation declaration prohibits implicit instantiation of
19898 non-inline functions. With high levels of optimization, we would
19899 normally inline non-inline functions -- but we're not allowed to do
19900 that for "extern template" functions. Therefore, we check
19901 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19905 /* And we need to instantiate static data members so that
19906 their initializers are available in integral constant
19907 expressions. */
19910 }
19912 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19913 instantiate it now, modifying TREE_TYPE (fn). */
19915 void
19917 {
19920 /* Don't instantiate a noexcept-specification from template context. */
19935 {
19939 {
19954 }
19955 else
19959 }
19962 {
19965 else
19967 }
19968 }
19970 /* Produce the definition of D, a _DECL generated from a template. If
19971 DEFER_OK is nonzero, then we don't have to actually do the
19972 instantiation now; we just have to do it sometime. Normally it is
19973 an error if this is an explicit instantiation but D is undefined.
19974 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19975 explicitly instantiated class template. */
19977 tree
19980 {
19982 tree gen_args;
19983 tree args;
19984 tree td;
19985 tree code_pattern;
19986 tree spec;
19987 tree gen_tmpl;
19994 tree fn_context;
19997 /* This function should only be used to instantiate templates for
19998 functions and static member variables. */
20001 /* Variables are never deferred; if instantiation is required, they
20002 are instantiated right away. That allows for better code in the
20003 case that an expression refers to the value of the variable --
20004 if the variable has a constant value the referring expression can
20005 take advantage of that fact. */
20010 /* Don't instantiate cloned functions. Instead, instantiate the
20011 functions they cloned. */
20019 /* D has already been instantiated or explicitly specialized, so
20020 there's nothing for us to do here.
20022 It might seem reasonable to check whether or not D is an explicit
20023 instantiation, and, if so, stop here. But when an explicit
20024 instantiation is deferred until the end of the compilation,
20025 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
20026 the instantiation. */
20029 /* Check to see whether we know that this template will be
20030 instantiated in some other file, as with "extern template"
20031 extension. */
20034 /* In general, we do not instantiate such templates. */
20042 /* We should already have the extra args. */
20045 /* And what's in the hash table should match D. */
20049 /* This needs to happen before any tsubsting. */
20055 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
20056 for the instantiation. */
20060 /* We should never be trying to instantiate a member of a class
20061 template or partial specialization. */
20066 /* In the case of a friend template whose definition is provided
20067 outside the class, we may have too many arguments. Drop the
20068 ones we don't need. The same is true for specializations. */
20069 args = get_innermost_template_args
20071 else
20075 {
20080 }
20081 else
20082 {
20085 }
20087 /* We may be in the middle of deferred access check. Disable it now. */
20090 /* Unless an explicit instantiation directive has already determined
20091 the linkage of D, remember that a definition is available for
20092 this entity. */
20102 /* If D is a member of an explicitly instantiated class template,
20103 and no definition is available, treat it like an implicit
20104 instantiation. */
20107 {
20108 /* Leave linkage flags alone on instantiations with anonymous
20109 visibility. */
20111 {
20114 }
20116 }
20118 /* Defer all other templates, unless we have been explicitly
20119 forbidden from doing so. */
20121 template. */
20122 ! pattern_defined
20123 /* If it's OK to postpone instantiation, do so. */
20124 || defer_ok
20125 /* If this is a static data member that will be defined
20126 elsewhere, we don't want to instantiate the entire data
20127 member, but we do want to instantiate the initializer so that
20128 we can substitute that elsewhere. */
20130 /* Handle here a deleted function too, avoid generating
20131 its body (c++/61080). */
20133 {
20134 /* The definition of the static data member is now required so
20135 we must substitute the initializer. */
20139 {
20140 tree ns;
20141 tree init;
20150 args,
20153 /* If instantiating the initializer involved instantiating this
20154 again, don't call cp_finish_decl twice. */
20156 {
20157 /* Make sure the initializer is still constant, in case of
20158 circular dependency (template/instantiate6.C). */
20159 const_init
20163 LOOKUP_ONLYCONVERTING);
20164 }
20168 }
20170 /* We restore the source position here because it's used by
20171 add_pending_template. */
20177 /* [temp.explicit]
20179 The definition of a non-exported function template, a
20180 non-exported member function template, or a non-exported
20181 member function or static data member of a class template
20182 shall be present in every translation unit in which it is
20183 explicitly instantiated. */
20187 /* If we're in unevaluated context, we just wanted to get the
20188 constant value; this isn't an odr use, so don't queue
20189 a full instantiation. */
20192 /* ??? Historically, we have instantiated inline functions, even
20193 when marked as "extern template". */
20197 }
20198 /* Tell the repository that D is available in this translation unit
20199 -- and see if it is supposed to be instantiated here. */
20201 {
20202 /* In a PCH file, despite the fact that the repository hasn't
20203 requested instantiation in the PCH it is still possible that
20204 an instantiation will be required in a file that includes the
20205 PCH. */
20208 /* Instantiate inline functions so that the inliner can do its
20209 job, even though we'll not be emitting a copy of this
20210 function. */
20213 }
20219 else
20220 {
20225 }
20227 /* Mark D as instantiated so that recursive calls to
20228 instantiate_decl do not try to instantiate it again. */
20231 /* Regenerate the declaration in case the template has been modified
20232 by a subsequent redeclaration. */
20235 /* We already set the file and line above. Reset them now in case
20236 they changed as a result of calling regenerate_decl_from_template. */
20240 {
20241 tree init;
20244 /* Clear out DECL_RTL; whatever was there before may not be right
20245 since we've reset the type of the declaration. */
20249 /* The initializer is placed in DECL_INITIAL by
20250 regenerate_decl_from_template so we don't need to
20251 push/pop_access_scope again here. Pull it out so that
20252 cp_finish_decl can process it. */
20257 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
20258 initializer. That function will defer actual emission until
20259 we have a chance to determine linkage. */
20262 /* Enter the scope of D so that access-checking works correctly. */
20275 }
20279 {
20281 tree subst_decl;
20282 tree tmpl_parm;
20283 tree spec_parm;
20286 /* Save away the current list, in case we are instantiating one
20287 template from within the body of another. */
20290 /* Set up the list of local specializations. */
20293 /* Set up context. */
20297 else
20300 /* Some typedefs referenced from within the template code need to be
20301 access checked at template instantiation time, i.e now. These
20302 types were added to the template at parsing time. Let's get those
20303 and perform the access checks then. */
20305 gen_args);
20307 /* Create substitution entries for the parameters. */
20312 {
20316 }
20318 {
20320 {
20323 }
20324 else
20325 {
20326 /* Register the (value) argument pack as a specialization of
20327 TMPL_PARM, then move on. */
20330 }
20331 }
20334 /* Substitute into the body of the function. */
20338 else
20339 {
20344 /* Set the current input_location to the end of the function
20345 so that finish_function knows where we are. */
20346 input_location
20349 /* Remember if we saw an infinite loop in the template. */
20350 current_function_infinite_loop
20352 }
20354 /* We don't need the local specializations any more. */
20358 /* Finish the function. */
20362 else
20363 {
20366 }
20370 }
20372 /* We're not deferring instantiation any more. */
20380 out:
20390 }
20392 /* Run through the list of templates that we wish we could
20393 instantiate, and instantiate any we can. RETRIES is the
20394 number of times we retry pending template instantiation. */
20396 void
20398 {
20402 /* Instantiating templates may trigger vtable generation. This in turn
20403 may require further template instantiations. We place a limit here
20404 to avoid infinite loop. */
20406 {
20410 " instantiating %q+D, possibly from virtual table generation"
20414 /* Pretend that we defined it. */
20417 }
20419 do
20420 {
20425 {
20430 {
20431 tree fn;
20434 {
20438 fn;
20446 }
20449 }
20450 else
20451 {
20454 {
20455 instantiation
20461 }
20465 }
20468 /* If INSTANTIATION has been instantiated, then we don't
20469 need to consider it again in the future. */
20471 else
20472 {
20475 }
20478 }
20480 }
20484 }
20486 /* Substitute ARGVEC into T, which is a list of initializers for
20487 either base class or a non-static data member. The TREE_PURPOSEs
20488 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20489 instantiate_decl. */
20491 static tree
20493 {
20497 {
20498 tree decl;
20499 tree init;
20505 {
20506 tree expr;
20507 tree arg;
20509 /* Expand the base class expansion type into separate base
20510 classes. */
20512 tf_warning_or_error,
20513 NULL_TREE);
20517 /* We'll be building separate TREE_LISTs of arguments for
20518 each base. */
20524 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20525 expand each argument in the TREE_VALUE of t. */
20532 /* VOID_TYPE_NODE is used to indicate
20533 value-initialization. */
20534 {
20537 }
20538 else
20539 {
20540 /* Substitute parameter packs into each argument in the
20541 TREE_LIST. */
20544 {
20545 tree expanded_exprs;
20547 /* Expand the argument. */
20549 expanded_exprs
20551 tf_warning_or_error,
20552 NULL_TREE);
20556 /* Prepend each of the expanded expressions to the
20557 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20559 {
20564 }
20565 }
20568 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20569 since we built them backwards. */
20571 {
20574 }
20575 }
20576 }
20579 {
20581 {
20585 }
20586 else
20587 {
20588 tree tmp;
20603 /* If we had an initializer but it instantiated to nothing,
20604 value-initialize the object. This will only occur when
20605 the initializer was a pack expansion where the parameter
20606 packs used in that expansion were of length zero. */
20609 }
20612 {
20616 }
20617 }
20618 }
20620 }
20622 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20624 static void
20626 {
20631 else
20633 }
20635 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20636 is the instantiation (which should have been created with
20637 start_enum) and ARGS are the template arguments to use. */
20639 static void
20641 {
20642 tree e;
20648 {
20649 tree value;
20650 tree decl;
20653 /* Note that in a template enum, the TREE_VALUE is the
20654 CONST_DECL, not the corresponding INTEGER_CST. */
20659 /* Give this enumeration constant the correct access. */
20662 /* Actually build the enumerator itself. */
20663 build_enumerator
20665 }
20675 }
20677 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20678 its type -- but without substituting the innermost set of template
20679 arguments. So, innermost set of template parameters will appear in
20680 the type. */
20682 tree
20684 {
20685 tree fn_type;
20686 tree tmpl;
20687 tree targs;
20688 tree tparms;
20696 /* There should be as many levels of arguments as there are levels
20697 of parameters. */
20703 /* No substitution is necessary. */
20704 ;
20705 else
20706 {
20708 tree partial_args;
20710 /* Replace the innermost level of the TARGS with NULL_TREEs to
20711 let tsubst know not to substitute for those parameters. */
20720 /* Make sure that we can see identifiers, and compute access
20721 correctly. */
20725 /* Now, do the (partial) substitution to figure out the
20726 appropriate function type. */
20730 /* Substitute into the template parameters to obtain the real
20731 innermost set of parameters. This step is important if the
20732 innermost set of template parameters contains value
20733 parameters whose types depend on outer template parameters. */
20738 }
20741 }
20743 /* Return truthvalue if we're processing a template different from
20744 the last one involved in diagnostics. */
20745 bool
20747 {
20749 }
20751 /* Remember current template involved in diagnostics. */
20752 void
20754 {
20756 }
20760 {
20762 }
20764 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20765 type. Return zero for ok, nonzero for disallowed. Issue error and
20766 warning messages under control of COMPLAIN. */
20768 static int
20770 {
20787 {
20790 else
20792 type);
20793 }
20795 }
20797 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20798 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20800 static bool
20802 {
20803 tree scope;
20805 /* [temp.dep.type]
20807 A type is dependent if it is:
20809 -- a template parameter. Template template parameters are types
20810 for us (since TYPE_P holds true for them) so we handle
20811 them here. */
20815 /* -- a qualified-id with a nested-name-specifier which contains a
20816 class-name that names a dependent type or whose unqualified-id
20817 names a dependent type. */
20820 /* -- a cv-qualified type where the cv-unqualified type is
20821 dependent.
20822 No code is necessary for this bullet; the code below handles
20823 cv-qualified types, and we don't want to strip aliases with
20824 TYPE_MAIN_VARIANT because of DR 1558. */
20825 /* -- a compound type constructed from any dependent type. */
20835 {
20836 tree arg_type;
20841 arg_type;
20846 }
20847 /* -- an array type constructed from any dependent type or whose
20848 size is specified by a constant expression that is
20849 value-dependent.
20851 We checked for type- and value-dependence of the bounds in
20852 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20854 {
20859 }
20861 /* -- a template-id in which either the template name is a template
20862 parameter ... */
20865 /* ... or any of the template arguments is a dependent type or
20866 an expression that is type-dependent or value-dependent. */
20868 && (any_dependent_template_arguments_p
20872 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20873 dependent; if the argument of the `typeof' expression is not
20874 type-dependent, then it should already been have resolved. */
20880 /* A template argument pack is dependent if any of its packed
20881 arguments are. */
20883 {
20889 }
20891 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20892 be template parameters. */
20896 /* The standard does not specifically mention types that are local
20897 to template functions or local classes, but they should be
20898 considered dependent too. For example:
20900 template <int I> void f() {
20901 enum E { a = I };
20902 S<sizeof (E)> s;
20903 }
20905 The size of `E' cannot be known until the value of `I' has been
20906 determined. Therefore, `E' must be considered dependent. */
20910 /* Don't use type_dependent_expression_p here, as it can lead
20911 to infinite recursion trying to determine whether a lambda
20912 nested in a lambda is dependent (c++/47687). */
20916 && (any_dependent_template_arguments_p
20920 /* Other types are non-dependent. */
20922 }
20924 /* Returns TRUE if TYPE is dependent, in the sense of
20925 [temp.dep.type]. Note that a NULL type is considered dependent. */
20927 bool
20929 {
20930 /* If there are no template parameters in scope, then there can't be
20931 any dependent types. */
20933 {
20934 /* If we are not processing a template, then nobody should be
20935 providing us with a dependent type. */
20939 }
20941 /* If the type is NULL, we have not computed a type for the entity
20942 in question; in that case, the type is dependent. */
20946 /* Erroneous types can be considered non-dependent. */
20950 /* If we have not already computed the appropriate value for TYPE,
20951 do so now. */
20953 {
20956 }
20959 }
20961 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20962 lookup. In other words, a dependent type that is not the current
20963 instantiation. */
20965 bool
20967 {
20970 }
20972 /* T is a SCOPE_REF; return whether we need to consider it
20973 instantiation-dependent so that we can check access at instantiation
20974 time even though we know which member it resolves to. */
20976 static bool
20978 {
20984 else
20986 }
20988 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20989 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20990 expression. */
20992 /* Note that this predicate is not appropriate for general expressions;
20993 only constant expressions (that satisfy potential_constant_expression)
20994 can be tested for value dependence. */
20996 bool
20998 {
21002 /* A name declared with a dependent type. */
21007 {
21009 /* A name that has not been looked up -- must be dependent. */
21013 /* A non-type template parm. */
21017 /* A non-type template parm. */
21023 /* A constant with literal type and is initialized
21024 with an expression that is value-dependent.
21026 Note that a non-dependent parenthesized initializer will have
21027 already been replaced with its constant value, so if we see
21028 a TREE_LIST it must be dependent. */
21032 /* cp_finish_decl doesn't fold reference initializers. */
21043 /* These expressions are value-dependent if the type to which
21044 the cast occurs is dependent or the expression being casted
21045 is value-dependent. */
21046 {
21052 /* A functional cast has a list of operands. */
21055 {
21056 /* If there are no operands, it must be an expression such
21057 as "int()". This should not happen for aggregate types
21058 because it would form non-constant expressions. */
21063 }
21069 }
21074 /* FALLTHRU */
21077 /* A `sizeof' expression is value-dependent if the operand is
21078 type-dependent or is a pack expansion. */
21087 /* An 'encode' expression is value-dependent if the operand is
21088 type-dependent. */
21097 /* All instantiation-dependent expressions should also be considered
21098 value-dependent. */
21106 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
21107 is value-dependent. */
21108 {
21117 }
21120 {
21124 }
21135 {
21139 }
21142 {
21149 {
21151 /* In a call to a constexpr member function, look through the
21152 implicit ADDR_EXPR on the object argument so that it doesn't
21153 cause the call to be considered value-dependent. We also
21154 look through it in potential_constant_expression. */
21161 }
21163 }
21166 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
21167 type-dependent. */
21171 {
21173 tree val;
21180 }
21183 /* Treat a GNU statement expression as dependent to avoid crashing
21184 under instantiate_non_dependent_expr; it can't be constant. */
21188 /* A constant expression is value-dependent if any subexpression is
21189 value-dependent. */
21191 {
21198 {
21202 {
21205 /* In some cases, some of the operands may be missing.l
21206 (For example, in the case of PREDECREMENT_EXPR, the
21207 amount to increment by may be missing.) That doesn't
21208 make the expression dependent. */
21211 }
21212 }
21216 }
21218 }
21220 /* The expression is not value-dependent. */
21222 }
21224 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
21225 [temp.dep.expr]. Note that an expression with no type is
21226 considered dependent. Other parts of the compiler arrange for an
21227 expression with type-dependent subexpressions to have no type, so
21228 this function doesn't have to be fully recursive. */
21230 bool
21232 {
21239 /* An unresolved name is always dependent. */
21243 /* Some expression forms are never type-dependent. */
21256 /* The types of these expressions depends only on the type to which
21257 the cast occurs. */
21266 /* The types of these expressions depends only on the type created
21267 by the expression. */
21270 {
21271 /* For NEW_EXPR tree nodes created inside a template, either
21272 the object type itself or a TREE_LIST may appear as the
21273 operand 1. */
21276 /* This is an array type. We need to check array dimensions
21277 as well. */
21279 || value_dependent_expression_p
21281 else
21283 }
21286 {
21290 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
21291 contains an identifier associated by name lookup with one or more
21292 declarations declared with a dependent type, or...a
21293 nested-name-specifier or qualified-id that names a member of an
21294 unknown specialization. */
21297 }
21302 && (any_dependent_template_arguments_p
21314 {
21315 tree elt;
21319 {
21322 }
21324 }
21326 /* A static data member of the current instantiation with incomplete
21327 array type is type-dependent, as the definition and specializations
21328 can have different bounds. */
21335 /* An array of unknown bound depending on a variadic parameter, eg:
21337 template<typename... Args>
21338 void foo (Args... args)
21339 {
21340 int arr[] = { args... };
21341 }
21343 template<int... vals>
21344 void bar ()
21345 {
21346 int arr[] = { vals... };
21347 }
21349 If the array has no length and has an initializer, it must be that
21350 we couldn't determine its length in cp_complete_array_type because
21351 it is dependent. */
21359 {
21364 {
21370 }
21371 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
21375 /* Always dependent, on the number of arguments if nothing else. */
21380 {
21385 }
21388 {
21393 }
21398 {
21402 }
21404 }
21409 }
21411 /* walk_tree callback function for instantiation_dependent_expression_p,
21412 below. Returns non-zero if a dependent subexpression is found. */
21414 static tree
21417 {
21419 {
21420 /* We don't have to worry about decltype currently because decltype
21421 of an instantiation-dependent expr is a dependent type. This
21422 might change depending on the resolution of DR 1172. */
21425 }
21428 {
21429 /* Don't treat an argument list as dependent just because it has no
21430 TREE_TYPE. */
21437 /* A constant with a dependent initializer is dependent. */
21445 /* Handle expressions with type operands. */
21450 {
21455 {
21458 else
21459 {
21462 }
21463 }
21465 }
21477 /* In a template, finish_class_member_access_expr creates a
21478 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21479 type-dependent, so that we can check access control at
21480 instantiation time (PR 42277). See also Core issue 1273. */
21487 else
21490 /* Treat statement-expressions as dependent. */
21496 }
21500 else
21502 }
21504 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21505 sense defined by the ABI:
21507 "An expression is instantiation-dependent if it is type-dependent
21508 or value-dependent, or it has a subexpression that is type-dependent
21509 or value-dependent." */
21511 bool
21513 {
21514 tree result;
21525 }
21527 /* Like type_dependent_expression_p, but it also works while not processing
21528 a template definition, i.e. during substitution or mangling. */
21530 bool
21532 {
21538 }
21540 /* Returns TRUE if ARGS contains a type-dependent expression. */
21542 bool
21544 {
21546 tree arg;
21549 {
21552 }
21554 }
21556 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21557 expressions) contains any type-dependent expressions. */
21559 bool
21561 {
21567 }
21569 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21570 expressions) contains any value-dependent expressions. */
21572 bool
21574 {
21580 }
21582 /* Returns TRUE if the ARG (a template argument) is dependent. */
21584 bool
21586 {
21590 /* Assume a template argument that was wrongly written by the user
21591 is dependent. This is consistent with what
21592 any_dependent_template_arguments_p [that calls this function]
21593 does. */
21604 {
21608 {
21611 }
21614 }
21617 else
21620 }
21622 /* Returns true if ARGS (a collection of template arguments) contains
21623 any types that require structural equality testing. */
21625 bool
21627 {
21637 {
21640 {
21646 {
21647 /* Look inside the argument pack. */
21650 }
21653 {
21666 }
21667 }
21668 }
21671 }
21673 /* Returns true if ARGS (a collection of template arguments) contains
21674 any dependent arguments. */
21676 bool
21678 {
21688 {
21693 }
21696 }
21698 /* Returns TRUE if the template TMPL is dependent. */
21700 bool
21702 {
21704 {
21706 {
21710 }
21712 }
21714 /* Template template parameters are dependent. */
21718 /* So are names that have not been looked up. */
21721 /* So are member templates of dependent classes. */
21725 }
21727 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21729 bool
21731 {
21734 }
21736 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21737 is dependent. */
21739 bool
21741 {
21748 {
21769 {
21773 }
21777 {
21781 {
21786 }
21787 }
21788 }
21791 }
21793 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21794 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21795 no such TYPE can be found. Note that this function peers inside
21796 uninstantiated templates and therefore should be used only in
21797 extremely limited situations. ONLY_CURRENT_P restricts this
21798 peering to the currently open classes hierarchy (which is required
21799 when comparing types). */
21801 tree
21803 {
21804 tree scope;
21805 tree name;
21806 tree decl;
21808 tree pushed_scope;
21809 tree result;
21814 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21815 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21816 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21817 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21818 identifier of the TYPENAME_TYPE anymore.
21819 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21820 TYPENAME_TYPE instead, we avoid messing up with a possible
21821 typedef variant case. */
21824 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21825 it first before we can figure out what NAME refers to. */
21827 {
21829 /* Given a class template A with a dependent base with nested type C,
21830 typedef typename A::C::C C will land us here, as trying to resolve
21831 the initial A::C leads to the local C typedef, which leads back to
21832 A::C::C. So we break the recursion now. */
21834 else
21836 }
21837 /* If we don't know what SCOPE refers to, then we cannot resolve the
21838 TYPENAME_TYPE. */
21841 /* If the SCOPE is a template type parameter, we have no way of
21842 resolving the name. */
21845 /* If the SCOPE is not the current instantiation, there's no reason
21846 to look inside it. */
21849 /* If this is a typedef, we don't want to look inside (c++/11987). */
21852 /* If SCOPE isn't the template itself, it will not have a valid
21853 TYPE_FIELDS list. */
21855 /* scope is either the template itself or a compatible instantiation
21856 like X<T>, so look up the name in the original template. */
21858 else
21859 /* scope is a partial instantiation, so we can't do the lookup or we
21860 will lose the template arguments. */
21862 /* Enter the SCOPE so that name lookup will be resolved as if we
21863 were in the class definition. In particular, SCOPE will no
21864 longer be considered a dependent type. */
21866 /* Look up the declaration. */
21868 tf_warning_or_error);
21872 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21873 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21878 {
21882 }
21885 {
21886 tree tmpl;
21887 tree args;
21888 /* Obtain the template and the arguments. */
21891 /* Instantiate the template. */
21897 }
21899 /* Leave the SCOPE. */
21903 /* If we failed to resolve it, return the original typename. */
21907 /* If lookup found a typename type, resolve that too. */
21909 {
21910 /* Ill-formed programs can cause infinite recursion here, so we
21911 must catch that. */
21915 }
21917 /* Qualify the resulting type. */
21923 }
21925 /* EXPR is an expression which is not type-dependent. Return a proxy
21926 for EXPR that can be used to compute the types of larger
21927 expressions containing EXPR. */
21929 tree
21931 {
21932 tree inner_expr;
21934 #ifdef ENABLE_CHECKING
21935 /* Try to get a constant value for all non-dependent expressions in
21936 order to expose bugs in *_dependent_expression_p and constexpr. */
21939 #endif
21941 /* Preserve OVERLOADs; the functions must be available to resolve
21942 types. */
21953 /* There is no need to return a proxy for a variable. */
21956 /* Preserve string constants; conversions from string constants to
21957 "char *" are allowed, even though normally a "const char *"
21958 cannot be used to initialize a "char *". */
21961 /* Preserve void and arithmetic constants, as an optimization -- there is no
21962 reason to create a new node. */
21967 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21968 There is at least one place where we want to know that a
21969 particular expression is a throw-expression: when checking a ?:
21970 expression, there are special rules if the second or third
21971 argument is a throw-expression. */
21975 /* Don't wrap an initializer list, we need to be able to look inside. */
21979 /* Don't wrap a dummy object, we need to be able to test for it. */
21998 /* If the type is unknown, it can't really be non-dependent */
22001 /* Otherwise, build a NON_DEPENDENT_EXPR. */
22003 }
22005 /* ARGS is a vector of expressions as arguments to a function call.
22006 Replace the arguments with equivalent non-dependent expressions.
22007 This modifies ARGS in place. */
22009 void
22011 {
22013 tree arg;
22016 {
22020 }
22021 }
22023 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
22024 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
22025 parms. */
22027 static tree
22029 {
22042 }
22044 tree
22046 {
22048 }
22050 tree
22052 {
22054 }
22056 /* Given type ARG, return std::initializer_list<ARG>. */
22058 static tree
22060 {
22061 tree std_init_list = namespace_binding
22063 tree argvec;
22065 {
22069 }
22074 }
22076 /* Replace auto in TYPE with std::initializer_list<auto>. */
22078 static tree
22080 {
22087 }
22089 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
22090 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
22092 tree
22094 {
22095 tree targs;
22101 /* Defining a subset of type-dependent expressions that we can deduce
22102 from ahead of time isn't worth the trouble. */
22105 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
22106 with either a new invented type template parameter U or, if the
22107 initializer is a braced-init-list (8.5.4), with
22108 std::initializer_list<U>. */
22110 {
22115 else
22116 {
22120 "for deduction to %<std::initializer_list%>, use copy-"
22123 }
22124 }
22130 {
22136 {
22139 }
22140 }
22141 else
22142 {
22153 {
22155 /* Try again at instantiation time. */
22158 /* If type is error_mark_node a diagnostic must have been
22159 emitted by now. Also, having a mention to '<type error>'
22160 in the diagnostic is not really useful to the user. */
22161 {
22165 else
22167 }
22169 }
22170 }
22172 /* If the list of declarators contains more than one declarator, the type
22173 of each declared variable is determined as described above. If the
22174 type deduced for the template parameter U is not the same in each
22175 deduction, the program is ill-formed. */
22178 {
22184 else
22188 }
22194 }
22196 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
22197 result. */
22199 tree
22201 {
22202 tree argvec;
22209 /* For a late-specified return type in a template type-parameter, we
22210 need to add a dummy argument level for its parmlist. */
22211 argvec = add_to_template_args
22216 }
22218 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
22219 'decltype(auto)'. */
22221 bool
22223 {
22228 else
22230 }
22232 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
22233 a use of `auto'. Returns NULL_TREE otherwise. */
22235 tree
22237 {
22239 }
22241 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
22242 'decltype(auto)' or a concept. */
22244 bool
22246 {
22248 }
22250 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
22251 a concept identifier) iff TYPE contains a use of a generic type. Returns
22252 NULL_TREE otherwise. */
22254 tree
22256 {
22258 }
22261 /* For a given template T, return the vector of typedefs referenced
22262 in T for which access check is needed at T instantiation time.
22263 T is either a FUNCTION_DECL or a RECORD_TYPE.
22264 Those typedefs were added to T by the function
22265 append_type_to_template_for_access_check. */
22269 {
22270 tree ti;
22281 {
22286 }
22289 }
22291 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
22292 tied to T. That list of typedefs will be access checked at
22293 T instantiation time.
22294 T is either a FUNCTION_DECL or a RECORD_TYPE.
22295 TYPE_DECL is a TYPE_DECL node representing a typedef.
22296 SCOPE is the scope through which TYPE_DECL is accessed.
22297 LOCATION is the location of the usage point of TYPE_DECL.
22299 This function is a subroutine of
22300 append_type_to_template_for_access_check. */
22302 static void
22304 tree type_decl,
22305 tree scope,
22306 location_t location)
22307 {
22308 qualified_typedef_usage_t typedef_usage;
22309 tree ti;
22316 && type_decl
22330 }
22332 /* Append TYPE_DECL to the template TEMPL.
22333 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
22334 At TEMPL instanciation time, TYPE_DECL will be checked to see
22335 if it can be accessed through SCOPE.
22336 LOCATION is the location of the usage point of TYPE_DECL.
22338 e.g. consider the following code snippet:
22340 class C
22341 {
22342 typedef int myint;
22343 };
22345 template<class U> struct S
22346 {
22347 C::myint mi; // <-- usage point of the typedef C::myint
22348 };
22350 S<char> s;
22352 At S<char> instantiation time, we need to check the access of C::myint
22353 In other words, we need to check the access of the myint typedef through
22354 the C scope. For that purpose, this function will add the myint typedef
22355 and the scope C through which its being accessed to a list of typedefs
22356 tied to the template S. That list will be walked at template instantiation
22357 time and access check performed on each typedefs it contains.
22358 Note that this particular code snippet should yield an error because
22359 myint is private to C. */
22361 void
22363 tree type_decl,
22364 tree scope,
22365 location_t location)
22366 {
22372 /* Make sure we don't append the type to the template twice. */
22379 }
22381 /* Convert the generic type parameters in PARM that match the types given in the
22382 range [START_IDX, END_IDX) from the current_template_parms into generic type
22383 packs. */
22385 tree
22387 {
22398 {
22399 /* Create a distinct parameter pack type from the current parm and add it
22400 to the replacement args to tsubst below into the generic function
22401 parameter. */
22416 }
22422 /* If there are more levels then build up the replacement with the outer
22423 template parms. */
22427 replacement);
22430 }
22433 /* Set up the hash tables for template instantiations. */
22435 void
22437 {
22440 }
22442 /* Print stats about the template hash tables for -fstats. */
22444 void
22446 {
22455 }